U.S. patent application number 16/230082 was filed with the patent office on 2019-07-18 for methods for forming metal-containing particles in barton reactors and for retrofitting barton reactors.
This patent application is currently assigned to Hammond Group, Inc.. The applicant listed for this patent is Hammond Group, Inc.. Invention is credited to Philip Michael Kowalski, Terrence Hyde Murphy, William Peter Wilke, IV.
Application Number | 20190217391 16/230082 |
Document ID | / |
Family ID | 67212587 |
Filed Date | 2019-07-18 |
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United States Patent
Application |
20190217391 |
Kind Code |
A1 |
Murphy; Terrence Hyde ; et
al. |
July 18, 2019 |
METHODS FOR FORMING METAL-CONTAINING PARTICLES IN BARTON REACTORS
AND FOR RETROFITTING BARTON REACTORS
Abstract
According to one or more embodiments presently described,
metal-containing particles may be formed by a method including
forming a molten material from a solid supply material, introducing
the molten material into a reaction zone of a Barton reactor, and
contacting the molten material with a processing gas in the
reaction zone to form solid metal-containing particles comprising
solid metallic particles and solid metal oxide particles. The
Barton reactor may include a reaction vessel which may include a
top cover and sidewalls defining the reaction zone, an agitator, a
processing gas inlet, and a product outlet. The molten material may
be introduced to the reaction zone in a laminar flow or as atomized
molten particles. Less than 99% of the particles may include metal
oxide.
Inventors: |
Murphy; Terrence Hyde;
(Chicago, IL) ; Wilke, IV; William Peter; (Saint
John, IN) ; Kowalski; Philip Michael; (Wanatah,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hammond Group, Inc. |
Hammond |
IN |
US |
|
|
Assignee: |
Hammond Group, Inc.
Hammond
IN
|
Family ID: |
67212587 |
Appl. No.: |
16/230082 |
Filed: |
December 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62616593 |
Jan 12, 2018 |
|
|
|
62743698 |
Oct 10, 2018 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 4/364 20130101;
B22F 2999/00 20130101; C22C 1/1042 20130101; B22F 2302/25 20130101;
C01P 2004/61 20130101; C22C 1/053 20130101; B22F 2009/0848
20130101; C01P 2006/12 20130101; C01G 21/06 20130101; B22F 2301/30
20130101; C01P 2002/30 20130101; C22C 1/053 20130101; B22F 2201/03
20130101; C01P 2004/51 20130101; H01M 10/06 20130101; H01M 4/57
20130101; B22F 9/082 20130101; C01P 2006/60 20130101; B22F
2009/0876 20130101; B22F 2999/00 20130101; H01M 4/56 20130101; B22F
9/26 20130101; B22F 2009/0824 20130101 |
International
Class: |
B22F 9/08 20060101
B22F009/08; B22F 9/26 20060101 B22F009/26 |
Claims
1. A method for forming metal-containing particles, the method
comprising: forming a molten material from a solid supply material;
introducing the molten material into a reaction zone of a Barton
reactor, the Barton reactor comprising a reaction vessel comprising
a top cover and sidewalls defining the reaction zone, an agitator,
a processing gas inlet, and a product outlet, wherein the molten
material is introduced to the reaction zone in a laminar flow or as
atomized molten particles; and contacting the molten material with
a processing gas in the reaction zone to form solid
metal-containing particles comprising solid metallic particles and
solid metal oxide particles, wherein less than 99% of the particles
comprise metal oxide.
2. The method of claim 1, wherein the formed metal-containing
particles include lead oxide particles and lead metal particles,
and wherein the weight ratio of formed lead oxide particles to lead
metal particles is less than 99:1
3. The method of claim 2, wherein the weight ratio of formed solid
lead oxide particles to solid lead metal particles is from 50:50 to
90:10.
4. The method of claim 2, wherein the reaction zone has a
temperature of from 621.degree. F. to 880.degree. F.
5. The method of claim 2, wherein the majority by weight of solid
lead oxide particles comprise alpha lead oxide having a tetragonal
crystal structure, and wherein the particles are suitable for lead
acid battery manufacturing.
6. The method of claim 1, wherein the weight ratio of formed solid
lead oxide particles to solid lead metal particles is from 50:50 to
90:10, and wherein the majority by weight of solid lead oxide
particles comprise alpha lead oxide having a tetragonal crystal
structure.
7. The method of claim 1, wherein at least 99% of the particles are
non-oxidized metals, metalloids, or alloys.
8. The method of claim 1, wherein the molten metal lead material is
introduced into the reaction zone in a hollow conical laminar
spray.
9. The method of claim 1, wherein the molten metal lead material is
introduced into the reaction zone in an atomized form.
10. The method of claim 1, wherein the molten metal lead material
is introduced into the reaction zone through a nozzle.
11. The method of claim 1, wherein the processing gas is an
oxidizing agent such as oxygen, air, or combinations thereof.
12. The method of claim 1, wherein the formed metal-containing
particles include lead oxide particles and lead metal particles,
and wherein the weight ratio of formed lead oxide particles to lead
metal particles is from 50:50 to 90:10, and wherein at least 90 wt.
% of solid lead oxide particles comprise alpha lead oxide having a
tetragonal crystal structure.
13. A method for retrofitting a Barton reactor, the method
comprising: replacing a conventional molten material inlet of a
Barton reactor with an injector operable to receive molten material
and inject the molten material into a reaction zone of the Barton
reactor; wherein the injector is operable to pass molten
metal-containing material into the reaction zone with a laminar
flow or in an atomized form.
14. The method of claim 13, wherein the conventional molten
material inlet comprises a pipe.
15. The method of claim 13, wherein the conventional molten
material inlet comprises a trough, dam, lip, or like device.
16. The method of claim 13, wherein the injector comprises a
nozzle.
17. the method of claim 13, wherein the injector is operable to
pass the molten metal-containing material into the reaction zone
with a laminar flow.
18. The method of claim 13, wherein the injector is operable to
pass the molten metal-containing material into the reaction zone in
an atomized form.
19. The method of claim 13, further comprising operating the
retrofitted Barton reactor to form lead metal particles, lead oxide
particles, or a mixture thereof.
20. The method of claim 19, wherein the operation of the
retrofitted Barton reactor forms a mixture of lead metal particles
and lead oxide particles suitable for use in a lead acid battery,
and wherein the retrofitted Barton reactor is operated at a
temperature of from 621.degree. F. to 880.degree. F.
Description
CROSS-REFERENCE TO RELATED CASES
[0001] The present application claims priority to U.S. Provisional
Application No. 62/616,593, filed Jan. 12, 2018, entitled "METHODS
AND SYSTEMS FOR PRODUCING METAL-CONTAINING PARTICLES", and claims
priority to U.S. Provisional Patent Application Ser. No.
62/743,698, filed Oct. 10, 2018, entitled "METHODS AND SYSTEMS FOR
PRODUCING METAL-CONTAINING PARTICLES", each of which are
incorporated by reference in their entirety herein.
BACKGROUND
Field
[0002] The present disclosure relates to methods and systems for
producing metal-containing particles and, more particularly, to
methods and systems for converting source metal-containing
materials into metal-containing solid particles.
Technical Background
[0003] Powdered pure metals and/or metal oxides are utilized in a
wide variety of manufacturing and material formation. For example,
mixtures of lead oxide and pure lead may be utilized in the
manufacture of lead acid batteries. Other metal powders may be
utilized in the formation of bulk metals and tools, such as through
sintering or other alloy formation techniques. Additionally, pure
or alloy metal particles may be utilized as additives in paints,
coatings, lubricants, or X-Ray shielding.
BRIEF SUMMARY
[0004] Accordingly, there is a need for improved methods and
systems for making such particles. One or more of the presently
disclosed embodiments relate to systems and/or methods for
processing metal-containing materials into particle-sized,
metal-containing materials (e.g., powders) having either the same
or a different chemical composition as the source metal-containing
material. For example, molten feed metals may be processed into
solid particulates of pure metals, alloys, or metal oxides. In one
or more embodiments, metals such as lead may be chemically
processed by changing the composition (such as into lead oxide) or
may be physically changed by changing the shape, size, or crystal
structure. For example, lead metal may be processed to form
powdered lead oxides having one or more crystal morphologies
through mechanical and chemical means. The formation of non-lead
metals and metal oxides is also contemplated by the presently
disclosed methods and systems.
[0005] According to one or more embodiments, metal-containing
particles may be formed by a method comprising forming a molten
material from a solid supply material, introducing the molten
material into a reaction zone of a Barton reactor, and contacting
the molten material with a processing gas in the reaction zone to
form solid metal-containing particles comprising solid metallic
particles and solid metal oxide particles. The Barton reactor may
comprise a reaction vessel which may comprising a top cover and
sidewalls defining the reaction zone, an agitator, a processing gas
inlet, and a product outlet. The molten material may be introduced
to the reaction zone in a laminar flow or as atomized molten
particles. Less than 99% of the particles may comprise metal
oxide.
[0006] According to one or more additional embodiments, a Barton
reactor may be retrofitted by a method comprising replacing a
conventional molten material inlet of a Barton reactor with an
injector operable to receive molten material and inject the molten
material into a reaction zone of the Barton reactor. The injector
may be operable to pass molten metal-containing material into the
reaction zone with a laminar flow or in an atomized form.
[0007] Additional features and advantages of the technology
described in this disclosure will be set forth in the detailed
description which follows, and in part will be readily apparent to
those skilled in the art from the description or recognized by
practicing the technology as described in this disclosure,
including the detailed description which follows, the claims, as
well as the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following detailed description of specific embodiments
of the present disclosure can be best understood when read in
conjunction with the following drawings, where like structure is
indicated with like reference numerals and in which:
[0009] FIG. 1 schematically depicts a side view of a Barton-style
system used for forming metal-containing particles, according to
one or more embodiments described herein;
[0010] FIG. 2 schematically depicts a top view of the system of
FIG. 1, according to one or more embodiments described herein;
[0011] FIG. 3 schematically depicts a perspective side view of
another system used for forming metal-containing particles,
according to one or more embodiments described herein;
[0012] FIG. 4 schematically depicts a perspective top down view of
the system for forming metal-containing particles of FIG. 3,
according to one or more embodiments described herein;
[0013] FIG. 5 schematically depicts a side view of a molten
material reservoir and injector, according to one or more
embodiments described herein;
[0014] FIG. 6 schematically depicts a side view of a molten
material injector, according to one or more embodiments described
herein;
[0015] FIG. 7A schematically depicts a cross-sectional side view of
a single-conduit injector, according to one or more embodiments
described herein;
[0016] FIG. 7B schematically depicts a cross-sectional side view of
a single-conduit injector, according to one or more embodiments
described herein;
[0017] FIG. 8 schematically depicts a top-down view of the
atomization nozzle of FIG. 6 or 7A, according to one or more
embodiments described herein;
[0018] FIG. 9 schematically depicts a bottom-up view of the gas
manifold shown in FIG. 6, according to one or more embodiments
described herein;
[0019] FIG. 10 schematically depicts a side view of a system used
for forming metal-containing particles that includes a molten
material reservoir, according to one or more embodiments described
herein;
[0020] FIG. 11 schematically depicts a side view of a multi-conduit
reactor, according to one or more embodiments described in this
disclosure;
[0021] FIG. 12 schematically depicts a top view of the
multi-conduit reactor of FIG. 11, according to one or more
embodiments described in this disclosure;
[0022] FIG. 13 schematically depicts a reactor system that includes
a multi-conduit reactor, according to one or more embodiments
described in this disclosure;
[0023] FIG. 14 depicts a mathematical model relevant to producing
metal-containing particles in a multi-conduit injector, according
to one or more embodiments described in this disclosure;
[0024] FIG. 15 depicts another mathematical model relevant to
producing metal-containing particles in a multi-conduit injector,
according to one or more embodiments described in this disclosure;
and
[0025] FIG. 16 depicts another mathematical model relevant to
producing metal-containing particles in a multi-conduit injector,
according to one or more embodiments described in this
disclosure.
[0026] It should further be noted that in some figures, such as
FIG. 13, arrows in the drawings may refer to process streams.
However, the arrows may equivalently refer to transfer lines which
may serve to transfer process steams between two or more system
components. Additionally, arrows that connect to system components
define inlets or outlets in each given system component. The arrow
direction corresponds generally with the major direction of
movement of the materials of the stream contained within the
physical transfer line signified by the arrow. Furthermore, arrows
which do not connect two or more system components signify a system
product stream which exits the depicted system or a system inlet
stream which enters the depicted system. System product streams may
be further processed in accompanying chemical processing systems or
may be commercialized as end products. System inlet streams may be
streams transferred from accompanying chemical processing systems
or may be non-processed feedstock materials.
[0027] Additionally, arrows in the drawings may schematically
depict process steps of transporting a stream from one system
component to another system component. For example, an arrow from
one system component pointing to another system component may
represent "passing" a system component effluent to another system
component, which may include the contents of a process stream
"exiting" or being "removed" from one system component and
"introducing" the contents of that product stream to another system
component.
[0028] For the purpose of describing the simplified schematic
illustrations and descriptions of FIGS. 1-13, the numerous valves,
temperature sensors, electronic controllers and the like that may
be employed and well known to those of ordinary skill in the art of
certain chemical processing operations are not included. Further,
accompanying components that are often included in conventional
chemical processing operations are not depicted. It should be
understood that these components are within the spirit and scope of
the present embodiments disclosed. However, operational components,
such as those described in the present disclosure, may be added to
the embodiments described in this disclosure.
[0029] Reference will now be made in greater detail to various
embodiments, some embodiments of which are illustrated in the
accompanying drawings. Whenever possible, the same reference
numerals will be used throughout the drawings to refer to the same
or similar parts.
DETAILED DESCRIPTION
[0030] The present application, according to one or more
embodiments, is directed to methods and/or systems utilized in the
formation of metal-containing particles. It has been discovered
that the introduction of a molten metal-containing material in an
atomized form (i.e., comprising liquid particles), or with a
laminar flow, may have several advantages for producing
metal-containing particles as compared with conventional methods
which generally utilize the introduction of a bulk liquid stream of
molten metal-containing material into a reactor such as a Barton.
For example, conventional processes may utilize the introduction of
molten material into a reactor from the end of a pipe in a
non-laminar, turbulent flow. For example, according to one or more
embodiments disclosed herein, the introduction of the molten
metal-containing material in an atomized or laminar form may
provide more reactive surface area, and therefore enhance the
oxidation rate of reaction, and correspondingly enhance the
production rate of metal oxides, such as lead oxide. The
incorporation of a controlled, atomized or laminar molten feed
stream into the reactor may enhance control of the physical
characteristics (e.g., particle size), chemical characteristics
(e.g., average oxidation state, crystal morphology) and/or the
product manufacturing rates of the metal-containing particles. For
example, it is contemplated that atomization of a molten
metal-containing material may be performed by injection of the
molten metal-containing material from an atomizing injector which
may directly atomize the molten metal-containing material when it
is passed out of a nozzle (for example, a misting nozzle), or may
pass a laminar flow of molten metal-containing material out of a
nozzle which is subsequently atomized by impingement with a flow of
relatively high velocity gas. In other embodiments, a laminar flow
of molten metal-containing material may improve process output as
compared with a similar process that introduces the molten
metal-containing material through a conventional pipe source.
Additionally, the molten metal-containing material may be passed
from a nozzle in a laminar flow pattern which increases the surface
area to volume ratio of the molten metal-containing material,
allowing for increased contact with surrounding gasses. For
example, a hollow cone laminar flow pattern may be utilized which
increases the surface to volume ratio of the molten
metal-containing material as it is expelled from the injector and
enters the reactor. In additional embodiments the laminar flow
pattern may sufficiently increase the surface area to volume ratio
of the molten metal-containing material (as compared with
introduction by a pipe or simple trough overflow scheme) such that
when the laminar molten metal-containing material is contacted by
an agitator it atomizes. These and other aspects of the presently
disclosed technology are described herein in the context of systems
and methods which may be utilized to form metal-containing
particles.
[0031] According to one or more embodiments, by any of the methods
or systems presently disclosed, a mixture of lead metal particles
(sometimes called "free lead") and lead oxide particles may be
formed. In some embodiments presently disclosed, the weight ratio
of formed solid lead oxide particles to solid lead metal particles
may be less than 99:1. For example, the particles formed by the
presently disclosed methods may have a weight ratio of formed solid
lead oxide particles to solid lead metal particles of from 50:50 to
99:1 (such as from 50:50 to 60:40, from 60:40 to 70:30, from 70:30
to 80:20, from 80:20 to 90:10, or from 90:10 to 99:1, or
combinations thereof) or any combination thereof). In additional
embodiments, the weight ratio of formed solid lead oxide particles
to solid lead metal particles may be from 50:50 to 90:10, such as
form 50:50 to 85:15. Such ratios may be well suited for lead acid
batteries. However, it is contemplated that other ratios may be
utilized for lead acid batteries as well. In additional
embodiments, a majority by weight of the product is metallic lead
(e.g., the product comprises at least 75 wt. %, at least 90 wt. %,
at least 95 wt. %, or even at least 99 wt. % of metallic lead
particles (non-oxidized).
[0032] In one or more embodiments, the lead oxide formed may be
majority by weight alpha lead oxide having a tetragonal crystal
structure. For example, at least 50 wt. %, at least 60 wt. %, at
least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 99
wt. %, or even at least 99.9 wt. % of the formed lead oxide may be
alpha lead oxide. In such embodiments, a minority of the formed
lead oxide may be beta lead oxide having an orthorhombic crystal
structure. For example, less than 50 wt. %, 40 wt. %, 30 wt. %, 20
wt. %, 10 wt. %, or even 1 wt. % of the formed lead oxide may be
beta lead oxide. However, in additional embodiments, a majority by
weight of beta lead oxide is contemplated. It should be understood
that mixtures of free lead and lead oxide, where the majority by
weight of the lead oxide is alpha lead oxide, may be suitable for
lead acid batteries. For example, in one or more embodiments, the
weight ratio of formed solid lead oxide particles to solid lead
metal particles of from 50:50 to 99:1 and the majority by weight of
the lead oxide may be alpha lead oxide. In additional embodiments,
the weight ratio of formed solid lead oxide particles to solid lead
metal particles of from 50:50 to 90:10 and at least 90 wt. %, or
even 99 wt. % of the lead oxide may be alpha lead oxide.
[0033] In one or more embodiments, the reaction to form lead oxide
may take place at from 621.degree. F. (about the melting point of
lead) to 850.degree. F. or even to 880.degree. F. (e.g., from
621.degree. F. to 700.degree. F., from 700.degree. F. to
800.degree. F., from 800.degree. F. to 850.degree. F., from
850.degree. F. to 880.degree. F., or combinations thereof). Such
temperatures may be suitable for forming majority by weight alpha
lead oxide and/or allowing for at least 1 wt. % of the product to
remain as metallic lead (i.e., not converted to lead oxide).
Without being bound by theory, it is believed the higher processing
temperatures may lead to almost total conversion of lead to lead
oxide (e.g., greater than 99 wt. % lead oxide as product) and/or
the formation of majority by weight beta lead oxide. Such
temperatures (from 621.degree. F. to 880.degree. F.) may be
suitable for forming lead oxide which can be utilized in lead oxide
batteries.
[0034] According to additional embodiments, a majority of the
produced lead oxide is beta lead oxide. For example, at least 50
wt. %, at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at
least 90 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of
the formed lead oxide may be beta lead oxide. In such embodiments,
free lead may be present in the product in amounts of at least 1
wt. %, at least 2 wt. %, at least 5 wt. %, at least 10 wt. %, at
least 20 wt. %, or even at least 50 wt. %. It is contemplated that
reactor temperatures of greater than 880.degree. F. may be utilized
in some embodiments, such as when beta lead is a desired
product.
[0035] It should be understood that one or more embodiments of the
present disclosure are directed to molten material injectors
(sometimes referred to herein as injector devices) that may be
compatible for use with a Barton reactor. For example, according to
some embodiments, a conventional Barton reactor that utilizes a
non-atomized or non-laminar flow of molten metal-containing
material into the conventional Barton pot (e.g., by passing the
molten metal-containing material into the Barton pot through a
stand pipe or the like) may be enhanced by retrofitting the
conventional Barton reactor with the molten material injectors
presently described herein. The use of the presently described
molten material injectors may improve product output, among other
desirable results. However, it is contemplated that the disclosed
injectors may be incorporated into a wide variety of reactor types,
of which several non-limiting examples are provided herein.
[0036] As described herein, "metal-containing" materials include
any materials which comprise a metal or metalloid element. For
example, metal-containing materials include metal oxides, metal
alloys, or substantially pure metallic materials. Pure or near pure
metals (e.g., those comprising at least 99 wt. %, 99.5 wt. %, 99.9
wt. %, or even 99.99 wt. % of a single element) may be referred to
as "metallic," such as "metallic lead" or "metallic aluminum",
etc., or simply as "metal," such as "lead metal" or "aluminum
metal." Furthermore, as described herein, "pure metals" and
"alloys" are non-oxidized (i.e., contain less than 1% of molecules
oxidized). While the formation of particles comprising any
metal-containing materials are presently contemplated in this
disclosure, the conversion of lead to lead oxide is described with
reference to several of the herein disclosed embodiments. As such,
some embodiments disclosed herein may be described with respect to
the production of lead oxide from metallic lead. However, it should
be appreciated that similar methods and systems for the production
of non-lead materials may be utilized within the scope of the
present disclosure. By way of example, metals processed by the
methods and systems disclosed herein may include lead, bismuth,
aluminum, zinc, nickel, antimony, alloys thereof, and oxides
thereof.
[0037] Additionally, as described herein, "particles" or
"particulate form" may refer to solid or liquid matter in discrete
bodies with diameters of 1000 microns or less (such as 500 microns
or less, 400 microns or less, 300 microns or less, 200 microns or
less, 100 microns or less, 50 microns, 25 microns or less, or even
smaller). For example, the vast number of formed solid particles by
the presently disclosed processes may fit through a No. 50 mesh US
standard sieve and have a diameter of 300 microns or less. However,
some particles may be much smaller than those having a diameter of
300 microns or less. For example, the d.sub.50 of the particles
formed by the presently disclosed processes may be from 1 to 5
microns, from 5 microns to 10 microns, from 10 microns to 25
microns, from 25 microns to 50 microns, from 50 microns to 100
microns, from 100 microns to 150 microns, from 150 microns to 200
microns, from 200 microns to 250 microns, from 250 microns to 300
microns, or any combination thereof. In one or more embodiments, a
lead oxide particles may be formed where 95 wt. % of the lead oxide
particles has a diameter of 100 microns or less. In one or more
embodiments, a metallic lead particles may be formed where 95 wt. %
of the lead particles have a diameter of 1000 microns or less.
Molten materials in particle form may be referred to as "atomized,"
or being in an "atomized form." Also contemplated herein are
embodiments where only a portion of the molten feed is atomized. It
should be understood that "atomized" molten materials may refer to
molten materials that are in particulate liquid or droplet form.
For example, according to some embodiments, at least 50 vol.%, at
least 60 vol.%, at least 70 vol.%, at least 90 vol.%, or even at
least 95 vol.% of the molten material injected into the reactor may
have be in discrete bodies having a diameter of 1000 micron or
less.
[0038] As used herein, a "chemical change" refers to a change which
affects the chemical composition of a material. For example
oxidation of a metal or alloy in the feed stream to form a metal
oxide is considered a chemical change. Additionally, as used
herein, a "physical change" refers to a change affecting the form
of a chemical substance, but not its chemical composition. Examples
of physical changes include changes in size, shape, phase, etc. It
should be understood that, in some embodiments, a chemical and
physical change may take place. However, in other embodiments, a
chemical change may not take place. For example, the contents of
the feed stream may be powderized, but maintain their chemical
composition. Without being bound by theory, it is believed that the
contents of the fluid stream may at least partially determine
whether a chemical change takes place. For example, a fluid stream
comprising oxygen may allow for combustion, forming metal oxides,
but an inert fluid stream such as nitrogen may not alter the
composition of the metal or alloy in the feed stream, as will be
discussed in detail herein. Additionally, without being bound by
theory, it is believed that particular characteristics of the fluid
stream, such as its momentum flux relative to that of the feed
stream may atomize the metal or alloy present in the feed stream,
resulting in the formation of powderized metals, alloys, and/or
oxides thereof in the product stream.
[0039] As used herein, "atomizing" a material refers to converting
a bulk material into fine particles or droplets. For example, a
metal or alloy included in the feed stream may be atomized into
fine particles when contacted by the fluid stream.
[0040] As compared with one or more embodiments of the presently
disclosed systems, a conventional Barton reactor may be an
inefficient atomizer (e.g., by means of its agitator blade as
described subsequently herein), producing particles with a larger
than desired particle size distribution. As described herein, a
"conventional Barton" reactor refers to one which introduces molten
metal by pipe, overflow or a trough, or similar means (i.e., not by
the injectors presently disclosed). A "modified Barton" may be
referred to herein and includes some means for introducing the
molten metal in an atomized or laminar flow form. However, it
should be understood that a "modified Barton" may refer to a
Barton-style reactor which was not previously fitted with a pipe
style injector and then retrofitted. For example, the present
description is intended to include Barton reactors which were
originally fitted with the injectors presently disclosed.
[0041] In one or more embodiments of conventional Barton operation,
the agitator atomizes a portion of the lead feed in an atmosphere
which allows the oxidation of lead particles. Some of the lead
oxide remains in the bath until its particle size is small enough
to allow it to be conveyed out of the reactor. When the
conventional Barton reactor is operating in a steady state there is
a mixing of lead and lead oxide which is also conducive to
oxidation. Atomization may be needed to get rapid oxidation. Molten
lead on the surface of the melt kettle oxidizes slowly over hours
of operation. Molten lead from the injector does not appear to
oxidize until the lead film breaks into small particles. As such,
in one or more embodiments, the Barton agitator does atomize a
significant portion of the lead feed but it is not an efficient
atomizer and it produces a wider variation in particle size
distribution by the nature of the lead feed and the lead feed's
point of impact on the agitator. The presently disclosed
embodiments may directly introduce the molten metal as a
particulate or in laminar flow, which may generate greater contact
and reaction between the molten materials and process fluids such
as air.
[0042] Referring now to FIG. 1, a modified Barton reactor system
utilized to form metal-containing particles is depicted. According
to one or more embodiments, the reactor system 100 may include a
reactor 101, a molten material injector device 300, and a molten
metal-containing material source 162. According to one or more
embodiments, molten metal-containing material may be fed from the
molten metal-containing material source 162 to the molten material
injector device 300. The molten material injector device 300 may
inject the molten metal-containing material into the reactor 101,
where it is processed into solid metal-containing particles, such
as lead particles, lead oxide particles, or both.
[0043] The molten metal-containing material source 162 may comprise
piping which is fluidly connected to a melt kettle (not depicted in
FIG. 1) or other apparatus which may melt solid metal-containing
supply materials. For example, the melt kettle may melt solid
metallic lead into molten lead. A valve may control the flow of the
molten metal-containing material. In some embodiments, the molten
material may be conveyed with a pump (such as a pump submerged in a
melt kettle). In additional embodiments, the molten material may be
conveyed by gravity alone, or at least in part. According to one or
more embodiments, metal, such as lead, may be melted in the melt
kettle to a temperature at or exceeding the metal's melting point,
such as about 621.degree. F. for lead, and less than that of the
metals boiling point, such as about 3,180.degree. F. for lead.
Without limitation, in one embodiment, the molten material may be
pumped from the melt kettle through a pipe directly to the molten
material injector device 300.
[0044] Moreover, and as described herein, conventional Barton
processes provide a stream of molten lead through a pipe, trough,
or other like introduction device from a melting kettle leading to
a Barton Reactor. A trough design may be similarly referred to as a
"dam" or "lip" where molten metal spills over a raised wall and
into the Barton or other reactor. In one or more embodiments
presently described, such trough, dam, lip, or like device is not
utilized. The molten lead flow in conventional Barton processes is
typically controlled with a manual valve that is submerged in the
melting kettle or a lead pump. Such a pump may be submerged below
the surface of the molten metal adjacent to the area where bars of
lead are fed into the melting kettle. The mass flow rate of molten
lead feeding into the Barton reactor can be modified by controlling
the pump's rpms. As the melt kettle is depleted of molten lead, it
is replenished with solid bars of lead that subsequently melt and
increase the level of molten lead. As the stream of molten lead is
introduced into the Barton reactor, the distance between the end of
the pipe and the Barton agitator may be relatively small and
insufficient to allow the major portion of the fluid stream to
break up and form molten lead droplets or atomize. Additionally,
the relative velocity of the air surrounding the molten stream of
lead is generally inadequate to promote atomization. Likewise, the
mass flowrate of the molten lead stream is irregular and does not
promote the formation of liquid droplets. Additionally, the process
of repeatedly adding solid bars of lead into the melting kettle
introduces both temperature and mass flow rate variation to the
molten stream of lead. When a solid bar of lead is introduced into
the melting kettle, the temperature of the molten lead drops as the
solid lead component absorbs thermal energy. Once the solid lead
has completely been melted, the temperature rises to a prescribed
temperature. As the level of molten lead rises and falls, the head
pressure at the lead pipe inlet changes and therefore continuously
changes the mass flow rate of molten lead delivered to the Barton
reactor. Such deficiencies may be overcome by the embodiments
described herein.
[0045] Some embodiments, as depicted in FIG. 1, may utilize a
molten material pump 165 to provide sufficiently pressurized molten
metal-containing material to the molten material injector device.
It should be appreciated that the system of FIG. 1 may operate with
any of the molten material injector devices 300 described herein,
and that the molten material pump 165 may be sufficient in one or
more embodiments to maintain a relatively constant pressure of
molten metal-containing material to the molten material injector
device 300 such that the flow of molten metal-containing material
into the reactor 101 is relatively constant and at a pressure
sufficient to atomize and/or form a laminar flow pattern on the
molten metal-containing material.
[0046] In some embodiments, the molten material injector device 300
may comprise a gas manifold, as described in additional detail
hereinbelow. The air manifold may be directly connected to a gas
supply 132. It should be understood that the molten material
injector device 300 of the system of FIG. 1 may be utilized with a
reservoir 161 (as is depicted in FIG. 10 and subsequently described
herein) or with a pump such as in the embodiment of FIG. 1.
[0047] According to one or more embodiments, the reactor 101 may
include a bottom bowl 103, a top cover 106, and sidewalls 104
defining a reaction zone 108. As depicted in the embodiments of
FIGS. 1 and 2, the reactor 101 may be cylindrically shaped,
although other shapes are contemplated such as, for example, a dome
shape. The reactor 101 may additionally include a gas inlet 122 and
a water inlet 124. An oxidizing gas such as air, may enter the
reactor 101 via the gas inlet 122, an inert gas such as nitrogen,
may enter the reactor 101 via the gas inlet 122. The product
material (i.e., solid metal-containing particles) may exit the
reactor 101 through a solid metal-containing material outlet 126.
The metal-containing material outlet may comprise, for example a
duct, chute, or other passage. The gas may pass into the reaction
zone 108 via gas inlet 122 and may pass out of the reaction zone
108 (along with the solid particle products) via solid
metal-containing material outlet 126. The gas exiting through the
solid metal-containing material outlet 126 gas may at least
partially aid in transporting the solid particles out of the
reactor 101. The reactor 101 may additionally include a water inlet
124. Water may be injected into the reaction zone 108 to control
the temperature in the reaction zone 108. It should be understood
that while FIGS. 1 and 2 depict one embodiment of a reactor
suitable for the presently described processes, other reactor
configurations are contemplated, such as reactor configurations
with varying geometric shapes and positions for the one or more
inlets and outlets of the reactor. For example, the molten material
injector device 300 may be positioned on a sidewall 104 of the
reactor 101.
[0048] The reactor 101 includes a reaction zone 108 where a
reaction or physical change to the molten material takes place. As
described herein, the "reaction" may include any chemical or
physical change of the injected molten metal-containing material.
For example, the molten metal-containing material may be oxidized
in the reaction zone 108. However, in other embodiments, the molten
metal-containing material may not undergo a chemical reaction, and
may instead be converted to solid particles of a similar or smaller
size than the molten metal-containing material entering the reactor
101. For example, an oxidation reaction may take place when an
oxidizing gas, such air, is injected into the reactor 101. However,
nitrogen or other non-reactive gasses may be utilized when
oxidation is not desired. It should further be appreciated that the
use of an oxidizing gas may yield both oxidized and metallic
product in a mixture. It is contemplated that in any embodiment
described herein which generates a metal oxide by exposure to
oxygen, air, pure oxygen, or any combination or mixture thereof may
be utilized. For example, molar ratios of air to oxygen of about
10:0, 7.5:2.5, 5:5, 2.5:7.5 and 0:10 are contemplated.
[0049] The reactor 101 may include, in some embodiments, an
agitator 114, such as a blade The blade may rotate to mix and
agitate molten metal-containing materials passed into the reactor
101. The agitator 114 may be driven by the rotation of a rotor 112,
where one or more appendages spin to agitate the molten material in
the reactor 101.
[0050] FIG. 1 depicts a Barton reactor (sometimes referred to as a
Barton pot), such as disclosed in in U.S. Pat. No. 633,533. In one
or more embodiments presently disclosed, a Barton reactor may be
modified by the addition of a molten material injector device 300.
In a conventional process utilizing a Barton reactor, a large
heated pot may be fed with a stream of molten lead (non-atomized)
which is maintained at a shallow depth in the bottom of the pot. A
rapidly rotating blade in the bottom of the pot may continuously
agitate the molten lead, which is oxidized in the presence of a
stream of air and water or steam. A portion of the oxidized lead
particles and/or atomized lead droplets may be drawn from the pot
by the air stream while the heavier lead droplets fall by gravity
to the bottom of the pot for further agitation and oxidation. The
process may be controlled by adjusting the rate of feed of the
molten lead, the air flow through the pot, and/or the speed of the
blade. In one or more embodiments, a Barton process may operate at
relatively high temperatures, substantially above the melting point
of lead which is 327.degree. C. (621.degree. F.) when oxidized lead
is desired.
[0051] Conventional Barton reactors and processes (without the
modifications described herein) may have several inherent
disadvantages to the processes described herein utilizing an
atomized or laminar flow introduction of molten metal. For example,
when used for producing high free lead litharge for battery
manufacturing, the lead oxides produced are often too coarse for
use in the formulation of battery active material paste and must,
therefore, be subjected to hammer mill processing subsequent to
their initial production in a Barton pot. In addition, the
conventional Barton process may be difficult to control when used
to produce low free lead litharge and may not be capable of
consistently producing lead oxide with a free lead content of less
than 1 wt. % (or even with a free lead content of less than 2 wt.
%, 3 wt. %, 4 wt. %, 5 wt. %, 10 wt. %, 15 wt. %, 20 wt. %, 25 wt.
%, 30 wt. %, 35 wt. % or even 40 wt. %). Additionally, the
operation of a conventional Barton pot may result in a build-up of
lead on the blade and walls, requiring periodic shut down and
manual cleaning of the component surfaces.
[0052] According to some of the embodiments presently disclosed, a
Barton or Barton-type reactor is not utilized for the formation of
the particles. As would be appreciated by one skilled in the art,
Barton reactors may be utilized to form lead oxides. However, it
has been discovered, as is described herein, that other reactor
configurations may be utilized to form metal-containing particles.
In one or more embodiments, these presently described reactors may
form particles through contact with an injected stream of molten
metal with a process gas in a reactor prior to the molten metal
contacting the bottom of the reactor.
[0053] Referring now to FIG. 3, a side perspective view of a
reactor system 200 utilized to form metal-containing particles is
depicted. According to one or more embodiments, the reactor system
200 may include a reactor 201 defining a reaction zone 220. The
reactor system 200 may include a separation zone 202 generally
downstream of the reactor 201. A molten material may be supplied to
the reactor 201 via a molten metal material supply system 260, and
subsequently through a molten material injector device 300. A gas
may be supplied to the reactor 201 by a gas supply system 270. The
molten material injector device 300 may generally positioned on an
upper portion of the reaction zone 202 and pass the molten material
downwardly. The process gas may enter the reaction zone through one
or more inlets that are tangential to the perimeter of the reaction
zone, allowing for the process gas to swirl around the perimeter of
the reaction zone tangential to the sidewalls. For example, a
cyclonic processing gas pattern may be formed around the perimeter
of the reaction zone. The injector 300 may be positioned near the
center of the upper portion of the reaction zone 202 such that the
process gas swirls around the perimeter of the reaction zone 202
and contacts the molten material as it passes through the reaction
zone 202.
[0054] According to one or more embodiments, as is described
herein, the molten metal is injected into the reactor 201 and is
contacted by a process gas, which forms a solid, metal-containing
particle. The solid particles are collected in the separation zone
202 where the various reaction gases are separated from the
particles. The reactor zone may operate at temperatures of at least
621.degree. F., such as temperatures contemplated in other reactor
embodiments and described herein. The separation zone may have a
lower temperature, such as below the melting point of material of
the formed particles, such as 621.degree. F. for lead.
[0055] According to one or more embodiments, the molten metal
material supply system 260 may include a molten metal material
source 262, a molten metal material pump 265, and a molten metal
material supply line 263. The molten metal material supply line 263
may be in fluid communication with the molten material injector
device 300. The molten metal material source 262 may be in fluid
communication with a source of molten metal, such as a kettle. In
other embodiments, the molten metal material may be supplied to the
molten material injector device 300 at an appropriate and
consistent pressure using other means such as a gravity pressurized
reservoir. The molten material injector device 300, which is
explained in detail below, injects the molten metal into the
reactor 201.
[0056] The molten metal material source 262 may comprise piping
which is fluidly connected to a melt kettle (not depicted in FIG.
3) or other apparatus which may melt solid metal-containing supply
materials. For example, the melt kettle may melt solid metallic
lead into molten lead. In additional embodiments, the molten
material may be conveyed by gravity alone, or at least in part.
According to one or more embodiments, metal, such as lead, may be
melted in the melt kettle to a temperature at or exceeding the
metal's melting point, such as 621.degree. F. for lead, and less
than that of the metals boiling point, such as 3,180.degree. F. for
lead. Without limitation, in one embodiment, the molten material
may be pumped from the melt kettle through a pipe into the
reservoir (not shown) or directly to the molten material injector
device 300.
[0057] The reactor 201 may define a reaction zone 220, and may
include an upper section 223 having a circular cross section, such
as a cylindrical shape, with a defined height and diameter, and a
lower frustum section 205 with a defined height and lower opening
diameter. Gas may be supplied to the upper cylindrical section 223
using a gas supply system 270. According to some embodiments, the
gas supply system 270 may include a blower 271, a gas inlet 272,
and a gas injection line 273. According to some embodiments, the
gas supply system 270 may be configured to supply an oxidizing gas,
such as air, for the production of metal oxide particles. According
to other embodiments, the gas supply system may provide inert gas
such as nitrogen, for the production of solid metal particles.
Other components not depicted may be used to provide a suitable
ratio of oxidizing to inert gas in the gas supply system 270, these
components may be pressure swing absorbers, electrolyzers,
cryogenic nitrogen tanks, cryogenic oxygen tanks, compressed
nitrogen tanks, compressed oxygen tanks, chillers, compressors, or
any other related air handling equipment. According to some
embodiments, the gas supply system 270 may supply gas at an ambient
environmental temperature, such as about 25.degree. C. (e.g.,
20-35.degree. C.). In additional embodiments, the gas supply may be
heated, such as to a temperature of from 25.degree. C. to
5000.degree. C., such as from 25.degree. C. to 50.degree. C.,
50.degree. C. to 75.degree. C., 75.degree. C. to 100.degree. C.,
100.degree. C. to 125.degree. C., 125.degree. C. to 150.degree. C.,
150.degree. C. to 200.degree. C., 200.degree. C. to 250.degree. C.,
250.degree. C. to 300.degree. C., 300.degree. C. to 350.degree. C.,
350.degree. C. to 400.degree. C., 400.degree. C. to 450.degree. C.,
450.degree. C. to 500.degree. C., 500.degree. C. to 550.degree. C.,
550.degree. C. to 600.degree. C., 600.degree. C. to 650.degree. C.,
650.degree. C. to 700.degree. C., 700.degree. C. to 750.degree. C.,
750.degree. C. to 800.degree. C., 800.degree. C. to 850.degree. C.,
850.degree. C. to 900.degree. C., 900.degree. C. to 950.degree. C.,
950.degree. C. to 1000.degree. C., 1000.degree. C. to 1100.degree.
C., 1100.degree. C. to 1200.degree. C., 1200.degree. C. to
1300.degree. C., 1300.degree. C. to 1400.degree. C., 1400.degree.
C. to 1500.degree. C., 1500.degree. C. to 1600.degree. C.,
1600.degree. C. to 1700.degree. C., 1700.degree. C. to 1800.degree.
C., 1800.degree. C. to 1900.degree. C., 1900.degree. C. to
2000.degree. C., 2000.degree. C. to 2250.degree. C., 2250.degree.
C. to 2500.degree. C., 2500.degree. C. to 2750.degree. C.,
2750.degree. C. to 3000.degree. C., 3000.degree. C. to 3275.degree.
C., 3275.degree. C. to 3500.degree. C., 3500.degree. C. to
3750.degree. C., 3750.degree. C. to 4000.degree. C., 4000.degree.
C. to 4275.degree. C., 4275.degree. C. to 4500.degree. C.,
4500.degree. C. to 4750.degree. C., 4750.degree. C. to 5000.degree.
C., or any combination thereof. Other components not depicted may
be used to provide process heat to the gas supply system 270, these
components may include resistive heaters, heat exchangers, natural
gas heaters, boilers, direct combustion heaters, arc heaters,
induction heaters, microwave heaters, or any other related process
heat systems.
[0058] The reaction zone 220 may generally be where the reaction or
physical change to the molten material takes place. As described
herein, the "reaction" may include any chemical or physical change
of the injected molten metal-containing material. For example, the
molten metal-containing material may be oxidized in the reaction
zone 220. However, in other embodiments, the molten
metal-containing material may not undergo a chemical reaction, and
may instead be converted to solid particles of a similar or smaller
size than the molten metal-containing material entering the
reaction zone 220. For example, an oxidation reaction may take
place when an oxidizing gas, such air, is injected into the
reaction zone 220. However, nitrogen or other non-reactive gasses
may be utilized when oxidation is not desired.
[0059] The process may operate at relatively high temperatures,
substantially above the melting point of lead which is (621.degree.
F.) when oxidized lead is desired or substantially below the
melting point of lead which is 327.degree. C. (620.degree. F.) when
powdered lead metal is desired.
[0060] Downstream of the reaction vessel may be a separation zone
202. The separation zone 202 may include a one or more exhaust
ports 215 and one or more solid particle exits, such as the
depicted solid particle removal pathway 216.
[0061] The separation zone may include an upper exhaust region 212
and a lower frustum 211. The metal containing particles 219 may
accumulate in the separation zone 202 and be directed to the solid
particle removal pathway 216. The solid particle removal pathway
216 may comprise a one or more of bins, hoppers, chutes, feeders,
pneumatic conveyors, belt conveyors, hydraulic conveyors, or any
other solid particle transfer equipment. Between the reaction zone
220 and / or the separation zone 202, it may be necessary to cool
the metal containing particles 219. According to some embodiments,
a cooling gas or liquid may introduced to the falling metal
containing particles using a cooling air supply 285. The cooling
air supply may include a blower 281, an air intake 283, and an air
injector 282.
[0062] The metal-containing material outlet may comprise, for
example a duct, chute, or other passage. The gas may pass into the
reaction zone 220 via reaction gas injector 274 and may pass out of
the reaction zone (along with the solid particle products) via an
opening at the bottom of the reaction zone 220. The gas exiting
through the bottom of the reaction zone frustum may at least
partially aid in transporting the solid particles out of the
reaction zone 220.
[0063] The reactor system 200 may additionally include a water
inlet (not shown). Water may be injected into the reaction zone 220
to control the temperature in the reaction zone.
[0064] FIG. 4 is a top down perspective view of the reactor system
200, showing the upper cylindrical section 223 positioned within
the upper exhaust region 212. The housing also contains the one or
more exhaust ports 215. According to some embodiments the gas
outlets may be round, according to other embodiments they may be
square, constitute an annulus surrounding the upper cylindrical
section 223, or be any other shape found desirable. According to
some embodiments the reaction gas injector 274 may tangential to
the upper cylindrical section 223, such as to cause the molten
material and gas to swirl within the reactor, creating turbulent
conditions.
[0065] It should be understood that while FIGS. 3 and 4 depict one
embodiment of a reactor suitable for the presently described
processes, other reactor configurations are contemplated, such as
reactor configurations with varying geometric shapes and positions
for the one or more inlets and outlets of the reactor. For example,
the molten material injector device 300 may be positioned on the
upper cylindrical section 223 of the reactor system 200.
[0066] It should be appreciated that a wide variety of injector
devices 300 may be utilized in the disclosed systems and methods,
these injector devices varying in size, interior shape, etc.
According to one or more embodiments, the molten material injector
device 300 may comprise a single-conduit injector 140. For example,
embodiments of single-conduit injectors are depicted in FIGS. 6, 7A
and 7B. As described herein, the single-conduit injector 140 may
function as an atomizer, or at least inject molten metal-containing
material with a laminar flow. In additional embodiments, such as
that depicted in FIG. 6, the single-conduit injector 140 may
include a gas annulus 135 which may function to impinge the flow of
the molten metal.
[0067] Referring now to FIG. 5, a cross-sectional view of an
embodiment of a molten material injector device 300 is depicted.
The molten material injector device 300 may be comprised of two or
more components including a single-conduit injector 140, depicted
in greater detail in at least FIGS. 6, 7A and 7B, and a gas
manifold 130, depicted in greater detail in FIGS. 6 and 9. It
should be understood that the single-conduit injector 140, under
certain conditions, may be capable of sufficiently atomizing the
molten metal-containing material without the gas manifold 130.
[0068] According to one or more embodiments disclosed herein, the
molten material injector device 300 may comprise a single-conduit
injector 140, such as depicted in FIG. 5. The single-conduit
injector 140 may comprise a cylindrical conduit tube 143 with
defined length and inside diameter, with multiple or single inlets
142 located at the molten material feed end 144, and a nozzle 148,
with defined geometry and ejection opening located at the outlet
end 146. Molten materials at variable pressures may be introduced
into the feed end 144 of single-conduit injector 140 and may exit
the outlet end 146 in the physical form of a laminar sheet or
atomized droplets. A single-conduit injector may improve control of
molten material atomization, resulting in some embodiments in
improved control of the product particle size distribution,
improved control of residual free lead, and/or increased lead oxide
production rates (in processes where lead is oxidized).
[0069] As described herein, the molten material injector device 300
may function as an atomizer, or at least inject molten
metal-containing material with a laminar flow. In additional
embodiments, such as that depicted in FIG. 4, the molten material
injector device 300 may include a gas annulus 135 which may
function to impinge the flow of the molten metal.
[0070] Various physical parameters characteristic to molten
materials (e.g., molten lead) such as, but not limited to, density
viscosity and surface tension may affect the fluid properties of
the molten feed stream exiting the single-conduit injector 140.
Various design parameters, such as, but not limited to injector
inlet geometry, injector inlet area, injector inlet perpendicular
to tangential orientation, injector inside cylindrical length,
injector inside cylindrical diameter, nozzle converging section
design, nozzle throat diameter, and inside surface finish may
affect the interaction between the molten feed stream and the
Single-Conduit Injector, wherein the control of each of these
characteristics are contemplated herein.'
[0071] While the reactor systems 100, 200 of FIGS. 1 and 3 depict a
single molten material injector device 300 positioned at the cover
top 106, 206 of the reactor 101, 201, it is contemplated that more
than one molten material injector devices 300 may be utilized on a
single reactor 101, 201 which may be positioned at other areas of
the reactor 101, 201. For example, molten material injector devices
300 may be positioned on other portions of the top cover 106, 206
or on the sidewalls 104, 204 of the reactor 101, 201.
[0072] As depicted in FIG. 6, in some embodiments the
single-conduit injector 140 may be positioned to release molten
metal-containing material within a gas annulus 135 discharged
through gas manifold 130. The gas annulus 135 may be supplied by a
gas manifold 130 and through a gas discharge 133. The gas manifold
130 may be in direct contact with the exterior of the
single-conduit injector 140. Each of the single-conduit injector
140 and the gas manifold 130 may each be assembled from more than
one body. For example, in one embodiment, the single-conduit
injector device may have a lower nozzle piece and an upper cap
piece, the two pieces threading into one another. Other methods of
connecting the two pieces are contemplated as well including press
fit, adhesives, epoxies, welding, brazing, bolts, external clamps
or fittings, and the like.
[0073] As depicted in FIG. 6, in one or more embodiments, the
molten metal-containing material may be dispensed in a hollow
conical pattern, which may be contacted by the gas annulus flowing
down at a different angle, such as normal with respect to the top
cover 106, 206 of the reactor 101, 201. According to additional
embodiments, the molten metal-containing material may be atomized
by the single-conduit injector 140, such as when the single-conduit
injector 140 acts as a sprayer. Without being bound by theory, it
is believed that when a stream of high viscosity molten
metal-containing material, such as lead, flows through an
single-conduit injector 140 at relatively high mass flow rates, the
difference in velocity between the stream of molten
metal-containing material and surrounding air, or an inert gas,
promote droplet atomization. The atomized droplets may then be
introduced into, for example, the reaction zone 120, 220 of the
reactors of FIG. 1 or 3, which may enhance chemical reaction rates
and manufacturing output.
[0074] According to one or more embodiments, the single-conduit
injector 140 may produce a laminar flow of molten metal-containing
material entering the reactor 101, 201 and subsequently the laminar
flow may be impinged upon with a high velocity gas annulus 135, as
depicted in FIG. 6. Without being bound by theory, it is believed
that when streams of high viscosity molten metal-containing
materials, such as lead, flow through an injector, such as the
single-conduit injector 140, at relatively low mass flow rates and
are impinged with high velocity gas, atomized molten droplets may
form. The high velocity gas flow may enhance molten lead
atomization as the laminar flow of molten lead comes in contact
with gas annulus high velocity gas, along with the turbulent gas
environment of the reactor 101, 201.
[0075] According to one or more additional embodiments disclosed
herein, the molten material injector device 300 may comprise air
sprayers, inert gas sprayers, oxidizing gas sprayers, pressure
sprayers, electrostatic sprayers, or ultrasonic sprayers. The
selection of an appropriate molten material injector device may
affect various properties of the output product material. For
example, and without limitation, the injection of the molten
metal-containing material may be selected to influence one or more
of particle size distribution (lead oxide or free lead), particle
shape, lead oxide surface area, lead oxide acid absorption, and/or
manufacturing rate. A desired molten material injector device may
also be determined by process specification such as head pressure,
etc.
[0076] Referring now to FIG. 5, a cross-sectional view of an
embodiment of a molten material injector device 300 is depicted.
The molten material injector device may be comprised of two or more
components including a molten material injector device 300,
depicted in greater detail in FIG. 6, and a gas manifold 130,
depicted in greater detail in FIG. 7A. It should be understood that
the molten material injector device 300, under certain conditions,
may be capable of sufficiently atomizing the molten
metal-containing material without the gas manifold 130. As depicted
in FIG. 6, in some embodiments the molten material injector device
300 may be positioned to release molten metal-containing material
within a gas annulus 135 discharged through gas manifold 130. The
gas annulus 135 may be supplied by a gas manifold 130 and through a
gas discharge 133. The gas manifold 130 may be in direct contact
with the exterior of the molten material injector device 300. Both
the molten material injector device 300 and the gas manifold 130
may each be assembled from more than one body. For example, in one
embodiment, the single-conduit injector device may have a lower
nozzle piece and an upper cap piece, the two pieces threading into
one another. Other methods of connecting the two pieces are
contemplated as well including press fit, adhesives, epoxies,
welding, brazing, bolts, external clamps or fittings, and the
like.
[0077] Now referring to FIG. 7A, a single-conduit injector 140 is
depicted. The single-conduit injector 140 may comprise an outer
surface 145; a cylindrical conduit tube 143 with defined length and
inside diameter; multiple or single inlets 142 located at the
molten material feed end 144; a converging section 141 with defined
length; and a nozzle 149 with defined length, geometry, and orifice
area located at the outlet end 146. In some embodiments, such as
that as depicted in FIG. 8 the multiple or single inlets 142 may be
positioned tangentially to the circumference of the cylindrical
conduit tube 143, and normal to the height of the conduit tube. The
top 144 of the single-conduit injector 140 may be circular and cap
the device.
[0078] According the some embodiments, the angle between converging
section 141 and the cylindrical conduit tube 143 may be from
90.degree. to 180.degree., such as from 90.degree. to 115.degree.,
from 115.degree. to 130.degree., from 130.degree. to 145.degree.,
from 145.degree. to 160.degree., from 160.degree. to 175.degree.,
from 175.degree. to 180.degree., or any combination thereof.
[0079] It should be appreciated that one or more embodiments of the
disclosed single-conduit injector 140 may not include a converging
section 141 (e.g. ,the cylindrical conduit tube 143 has a diameter
about the same as the nozzle 149. This can be considered analogous
to the angle between the converging section 141 and the cylindrical
conduit tube 143 equal to about 180.degree. (i.e., on the same
plane).
[0080] As depicted in FIG. 6, molten metal-containing material may
enter the single-conduit injector at the one or more inlets 142,
travel through the converging section 141 towards the nozzle 149.
As the molten metal-containing material travels across the
converging section the available cross sectional area decreases and
the speed of the material increases. The parameters which control
the eventual mass and velocity of the molten metal-containing
material as it exits the outlet end 146 are the inlet pressure,
inlet 142 diameter and position, the cylindrical conduit tube 143
length and diameter, the converging section 141 length and angle,
and the nozzle 149 length and diameter. In some embodiments the
configuration of the single-conduit injector will cause the molten
metal-containing material to spray out in a hollow cone, in other
embodiments the molten metal-containing material may spray out in
other patterns such as a swirl or a stream.
[0081] As depicted in FIG. 8, in one or more embodiments, as the
molten metal-containing material enters the single-conduit injector
140 through the one or more inlets 142, it swirls within the
cylindrical conduit tube 143. This further affects the flow profile
of the molten metal-containing material as it exits through the
nozzle 149.
[0082] As depicted in FIG. 6, the single-conduit injector 140 may
be positioned in the center of a gas annulus 135 with defined
diameter and gap width. Molten metal-containing materials at
variable pressures may be introduced into the feed end 144 of
single-conduit injector 140 and may exit the outlet end 146 in the
physical form of a laminar sheet or atomized droplets. A high
velocity flow of gas 135 (in an annulus) impinges upon the laminar
flow of molten lead such that atomization of molten
metal-containing material is enhanced, resulting in some
embodiments in improved control of the product particle size
distribution, improved control of residual free lead, and/or
increased lead oxide production rates (in processes where lead is
oxidized.
[0083] Referring now to FIG. 9, a bottom up view of a gas manifold
130 is depicted. In some embodiments, one or more gas supplies 132
enter from the side of a spherical manifold. According to other
embodiments the exterior of the manifold may be square,
rectangular, octagonal, or any other geometric shape. In
embodiments which utilize the gas manifold, the single-conduit
injector 140 passes molten metal-containing material through a
molten metal material injector opening 134. The single-conduit
injector may be disposed within a molten metal material injector
opening 134 or it may be disposed above the opening and release
molten metal-containing material through the opening. In some
embodiments, gas enters through the one or more gas supplies 132
and exits through the gas discharge 133, preferably, substantially
all of the gas exits perpendicular to the diameter of the
cylindrical conduit tube 143. This gas exiting the gas discharge
133 forms the gas annulus 135 in embodiments which utilize a gas
annulus. A molten metal material injector opening 134 may comprise
an inner diameter and an outer diameter. The inner diameter of the
gas discharge may be from 3 to 10 in, or from 5 to 9 in, or from 6
to 8 in. The outer diameter of the gas discharge may be from 0.0001
in to 2 in, or from 0.0005 in to 1 in, or from 0.001 in to 0.1 in,
or from 0.001 in to 0.01 in, larger than the inner diameter of the
gas discharge.
[0084] According to one or more embodiments, the molten material
injector device 300 may atomize the molten metal-containing
material to a d.sub.50 size of from 1 to 5 microns, from 5 microns
to 10 microns, from 10 microns to 25 microns, from 25 microns to 50
microns, from 50 microns to 100 microns, from 100 microns to 150
microns, from 150 microns to 200 microns, from 200 microns to 250
microns, from 250 microns to 300 microns, or any combination
thereof. The atomized introduction of molten metal to the reactor
101 may result in solid product particles having a d.sub.50 of from
0.5 microns to 300 microns (such as from 0.5 microns to 5 microns,
from 5 microns to 10 microns, from 10 microns to 25 microns, from
25 microns to 50 microns, from 50 microns to 100 microns, from 100
microns to 200 microns, from 200 microns to 300 microns, or any
combination thereof. The product particles may have a relatively
uniform size.
[0085] According to one or more embodiments, the molten material
injector device 300 may produce a laminar flow of molten
metal-containing material entering the reactor 101, 201. Without
being bound by theory, it is believed that when streams of high
viscosity molten metal-containing materials, such as lead, flow
through an molten material injector device 300 at relatively low
mass flow rates, absent of any external gas turbulence, molten
droplets may form and align in parallel streams resulting in a
laminar flow. The laminar flow may be a parabolic stream in
appearance and may enhance molten lead atomization as the laminar
flow enters the turbulent environment of the reactor 101, 201.
[0086] According to one or more embodiments, the velocity,
temperature, viscosity, density, and/or surface tension of the
molten metal-containing material feed stream may influence the
atomization properties, such as droplet size. In some embodiments,
the molten stream velocity entering the reactor 101, 201 may be
increased by controlling the molten metal-containing material
stream head pressure, such that the mass flow rate exceeds the mass
flow rate feed typical of a standard Barton Reactor. The relatively
high pressure may also result in reduced molten particle size
(i.e., increased atomization).
[0087] In one or more embodiments, the reactor system 100, 200
fitted with a molten material injector device 300 may be capable
atomizing a molten stream of lead into solid particles that are
significantly smaller than droplet sizes achieved by a traditional
Barton Reactor (i.e., one in which molten metal-containing material
enters in a non-atomized form). Therefore, the presently described
reactor systems may be capable of higher production rates when
compared to conventional Barton technology.
[0088] While the reactor systems 100, 200 of FIGS. 1 and 3 depict a
single molten material injector device 300 positioned at the cover
top 106, 206 of reactor 101, 201 it is contemplated that more than
one molten material injector devices 300 may be utilized on a
reactor 101, 201, which may be positioned at other areas of the
reactor 101, 201. For example, molten material injector devices 300
may be positioned on other portions of the vessel top 106, 206 or
on the sidewalls 104, 204 of the reactor 101, 201.
[0089] Various physical parameters characteristic to molten
metal-containing materials (e.g., molten lead) such as, but not
limited to, density viscosity and surface tension may affect the
fluid properties of the molten feed stream exiting the
single-conduit injector 140. Various design parameters, such as,
but not limited to injector inlet geometry, injector inlet area,
injector inlet perpendicular to tangential orientation, injector
inside cylindrical length, injector inside cylindrical diameter,
nozzle converging section design, nozzle throat diameter, and
inside surface finish may affect the interaction between the molten
feed stream and the Single-Conduit Injector, wherein the control of
each of these characteristics are contemplated herein.
[0090] In additional embodiments, various operating parameters
relative to the molten metal-containing material (such as metallic
lead) such as, but not limited to, temperature, mass flow rate,
head pressure, and/or superficial velocity, may affect the
interaction between the molten feed stream and the single-conduit
injector 140, such that the molten lead exiting the nozzle 149 of
the single-conduit injector 140 efficiently and/or controllably
forms a laminar sheet, a stream of atomized droplets, or a uniform
diameter flow.
[0091] According to one or more embodiments, the temperature of a
molten metal-containing material feed stream entering the
single-conduit injector 140 may be controlled to attain a desired
molten metal-containing material density, viscosity, and/or lead
surface tension, such that the desired atomization and droplet size
are achieved. For example, molten lead may be at a temperature
greater than lead's melting point, 327.5.degree. C., and less than
lead's boiling point, 1,740.degree. C., such that the molten lead
density is conducive to achieve the desired laminar flow,
atomization and/or droplet size.
[0092] According to one or more embodiments, the superficial
velocity, head pressure, of a molten metal-containing material feed
stream within the single-conduit injector 140 may be controlled to
attain a desired laminar flow or atomized droplet size. For
example, the laminar velocity may be from 1 m/s to 100 m/s. The
head pressure may be from 1 psi to 250 psi. In one or more
embodiments, superficial velocity, mass flow rate, head pressure,
and/or the free material's reactivity with oxygen may be functions
of the temperature of the molten metal-containing material feed
stream entering and exiting the single-conduit injector 140. For
example, if lead is processed, the temperature of the molten lead
may be from 327.5.degree. C. to 1740.degree. C. According to one or
more embodiments, the mass flow rate of the molten lead into the
reactor 101, 201 may determine the process production rate of
product solid particles. In one or more embodiments, mass flow
rates are attainable from 500 lb/hr to 20,000 lb/hr.
[0093] Referring again to FIG. 7A, according to some embodiments,
the inlet 142 diameter could be from 0.01 in to 1 in, or from 0.03
in to 0.16 in, or from 0.03 in to 0.125 in, or from 0.089 in to
0.125 in. The discharge 146 diameter could be from 0.1 in to 1 in,
or from 0.25 in to 1.6 in, or from 0.35 in to 0.55 in. The outlet
end 146 length could be from 0.1 in to 2 in, or from 0.1 in to 1 in
or from 0.25 in to 0.5 in. The length of the converging section
could be 0 in, or from 0.1 in to 1 in, or from 0.25 in to 1 in, or
from 0.25 in to 0.5 in. The conduit tube 143 diameter could be from
0.1 in to 8 in, or from 0.2 in to 6 in, or from 0.25 in to 2 in, or
from 0.5 in to 1.5 in. The cylindrical conduit tube 143 length
could be from 0.1 in to 8 in, or from 0.25 in to 6 in, or from 0.5
in to 4 in, or from 2 in to 4 in. The single-conduit injector 140
may be constructed of metal and may be polished to a 300 grit
finish in its interior.
[0094] Referring now to FIG. 7B, according to some embodiments, the
inlet 142 diameter may be substantially aligned with the
cylindrical conduit tube 143. The converging section 141 may be
substantially perpendicular to the cylindrical conduit tube 143.
Single-conduit injector 140 may be configured with a variety of
attachment mechanisms including threads, glue, welding, epoxy,
brazing, or press fittings. According to one embodiment, outer
surface 145 includes threads. Inlet 142 diameter may be from 0.1 in
to 1 in, such as, from 0.1 in to 0.2 in, or from 0.2 in to 0.3 in,
or 0.3 in to 0.4 in, or from 0.4 in to 0.5 in, or from 0.5 in to
0.6 in, or from 0.6 in to 0.7 in, or from 0.7 in to 0.8 in, or from
0.8 in to 0.9 in, or from 0.9 in to 1 in, or any combination
thereof. The discharge 146 diameter may be from 0.05 in to 0.3 in,
such as from 0.05 in to 0.06 in, or from 0.06 in to 0.07 in, or
from 0.07 in to 0.08 in, or from 0.08 in to 0.09 in, or from 0.09
in to 0.1 in, or from 0.1 in to 0.11 in, or from 0.11 in to 0.12
in, or from 0.12 in to 0.13 in, or from 0.13 in to 0.14 in, or from
0.14 in to 0.15 in, or from 0.15 in to 0.16 in, or from 0.16 in to
0.17 in, or from 0.17 in to 0.18 in, or from 0.18 in to 0.19 in, or
from 0.19 in to 0.20 in, or from 0.20 in to 0.21 in, or from 0.21
in to 0.22 in, or from 0.22 in to 0.23 in, or from 0.23 in to 0.24
in, or from 0.24 in to 0.25 in, or from 0.25 in to 0.26 in, or from
0.26 in to 0.27 in, or from 0.27 in to 0.28 in, or from 0.28 in to
0.29 in, or from 0.29 in to 0.30 in, or any combination thereof.
According to some embodiments, the single-conduit injector 140 may
be comprised of steel, or stainless steel, or iron, or nickel, or
titanium, or copper, or brass, or ceramic, or glass, or a
combination thereof.
[0095] Referring again to FIG. 7A, according to some embodiments,
the inlet 142 diameter could be from 0.01 in to 1 in, or from 0.03
in to 0.16 in, or from 0.03 in to 0.125 in, or from 0.089 in to
0.125 in. The discharge 146 diameter could be from 0.1 in to 1 in,
or from 0.25 in to 1.6 in, or from 0.35 in to 0.55 in. The oulet
end 146 length could be from 0.1 in to 2 in, or from 0.1 in to 1 in
or from 0.25 in to 0.5 in. The length of the converging section
could be 0 in, or from 0.1 in to 1 in, or from 0.25 in to 1 in, or
from 0.25 in to 0.5 in. The conduit tube 143 diameter could be from
0.1 in to 8 in, or from 0.2 in to 6 in, or from 0.25 in to 2 in, or
from 0.5 in to 1.5 in. The cylindrical conduit tube 143 length
could be from 0.1 in to 8 in, or from 0.25 in to 6 in, or from 0.5
in to 4 in, or from 2 in to 4 in. The single-conduit injector 140
may be constructed of metal and may be polished to a 300 grit
finish in its interior.
[0096] According to one or more embodiments described herein, lead
may be melted and fed to the reactor, where at least a portion of
the lead is oxidized by an oxidizing gas, into lead oxide. The
oxidation reaction may be exothermic and produce different lead
oxide morphologies depending upon reaction conditions. For example,
alpha (tetragonal) lead oxide may be formed, which may be brown or
red in color, and beta (orthorhombic) lead oxide may be formed,
which may be green to yellow in color. Some lead may not be
oxidized, referred to as free lead. The physical properties of the
products may be customized based on process inputs.
[0097] In one or more embodiments, the product material of the
presently described processes may comprise from 0 wt. % to 100 wt.
% of orthorhombic lead monoxide. For example, the product material
may comprise orthorhombic lead monoxide in an amount of from 0 wt.
% to 10 wt. %, from 10 wt. % to 20 wt. %, from 20 wt. % to 30 wt.
%, from 30 wt. % to 40 wt. %, from 40 wt. % to 50 wt. %, from 50
wt. % to 60 wt. %, from 60 wt. % to 70 wt. %, from 70 wt. % to 80
wt. %, from 80 wt. % to 90 wt. %, from 90 wt. % to 100 wt. %, or
any combination thereof.
[0098] In additional embodiments, the product material of the
presently described processes may comprise from 0 wt. % to 100 wt.
% of tetragonal lead monoxide. For example, the product material
may comprise tetragonal lead monoxide in an amount of from 0 wt. %
to 10 wt. %, from 10 wt. % to 20 wt. %, from 20 wt. % to 30 wt. %,
from 30 wt. % to 40 wt. %, from 40 wt. % to 50 wt. %, from 50 wt. %
to 60 wt. %, from 60 wt. % to 70 wt. %, from 70 wt. % to 80 wt. %,
from 80 wt. % to 90 wt. %, from 90 wt. % to 100 wt. %, or any
combination thereof.
[0099] According to additional embodiments, the product material of
the presently described processes may comprise from 0 wt. % to 100
wt. % of metallic lead (sometimes referred to as powdered lead or
free lead when lead oxide is produced). For example, the product
material may comprise metallic lead in an amount of from 0 wt. % to
10 wt. %, from 10 wt. % to 20 wt. %, from 20 wt. % to 30 wt. %,
from 30 wt. % to 40 wt. %, from 40 wt. % to 50 wt. %, from 50 wt. %
to 60 wt. %, from 60 wt. % to 70 wt. %, from 70 wt. % to 80 wt. %,
from 80 wt. % to 90 wt. %, from 90 wt. % to 100 wt. %, or any
combination thereof. The metallic lead may comprise at least 99 wt.
%, 99.5 wt. %, 99.9 wt. %, or even 99.99 wt. % of a lead.
[0100] According to additional embodiments, the product material of
the presently described processes may comprise a mixture of
tetragonal lead monoxide, orthorhombic lead monoxide and metallic
lead (otherwise referred to as free lead), in all proportions from
0 wt. % to 100 wt. for any single component. Typical requirements
for lead acid battery active material specify a mixture of
tetragonal lead monoxide as a major component, metallic lead as a
minor component and orthorhombic lead monoxide permissible in small
amounts. For example, the product may comprise of a mixture of
tetragonal lead monoxide, orthorhombic lead monoxide and metallic
lead in the wt. % proportions of: 90:0:10, 85:0:15, 80:0:20,
75:0:25, 70:0:30, 65:0:35, 90:5:5, 85:5:10, 80:5:15, 75:5:20,
70:5:25, 65:5:30, 60:5:35, 80:15:5, 75:15:10, 70:15:15, 65:15:20,
60:15:25, 55:15:30, 50:15:35, or in any other 3-component
combination thereof. However, some lead acid battery technologies
may require a mixture with a greater portion of orthorhombic lead
monoxide. For example, the product may comprise of a mixture of
tetragonal lead monoxide, orthorhombic lead monoxide and metallic
lead, where the orthorhombic portion may comprise in an amount from
15 wt. % to 20 wt. %, 20 wt. % to 25 wt. %, 25 wt. % to 30 wt. %,
30 wt. % to 35 wt. %, 35 wt. % to 40 wt. %, 40 wt. % to 45 wt. %,
45 wt. % to 50 wt. %, or any combination thereof.
[0101] According to additional embodiments, the product material of
the presently described processes may comprise from 0 wt. % to 100
wt. % of lead monoxide. For example, the product material may
comprise lead oxide in an amount of from 0 wt. % to 10 wt. %, from
10 wt. % to 20 wt. %, from 20 wt. % to 30 wt. %, from 30 wt. % to
40 wt. %, from 40 wt. % to 50 wt. %, from 50 wt. % to 60 wt. %,
from 60 wt. % to 70 wt. %, from 70 wt. % to 80 wt. %, from 80 wt. %
to 90 wt. %, from 90 wt. % to 100 wt. %, or any combination
thereof.
[0102] According to additional embodiments, the product material of
the presently described processes may comprise BET surface area of
from 0.1 m.sup.2/g to 3.0 m.sup.2/g.
[0103] According to additional embodiments, the product material of
the presently described processes may have acid absorption of from
100 mg H.sub.2SO.sub.4/g PbO to 300 H.sub.2SO.sub.4/g PbO, such as
140 H.sub.2SO.sub.4/g PbO to 260 H.sub.2SO.sub.4/g PbO.
[0104] It has been discovered that the introduction of a molten
metal-containing material into a molten material injector device
300 using a molten material pump 165 may induce variation in mass
flow rate and head pressure, leading to variation in the size and
quality of metal or metal oxide particles produced in a reactor. As
such, in one or more embodiments, as depicted in FIGS. 5 and 10,
molten material reservoir is utilized to control the head pressure
of the molten metal-containing material. The molten
metal-containing material may pass through a reservoir 161 before
entering the molten material injector device 300. The reservoir 161
may comprise a pipe or other vessel. For example, the reservoir 161
may comprise a pipe having an internal size of 6.00 to 12 inches in
diameter and a length of from 1 to 600 inches. The top of the
reservoir 161 may be open to the atmosphere, while the bottom may
be capped with a base 174. The center of the base 174 may be
drilled and threaded to a diameter and thread size appropriate to
receive the threaded single-conduit injector 140, as shown in FIG.
5. The single-conduit injector may be threaded into the base 174 of
the reservoir 161 such that the inlets 142 of the single-conduit
injector 140 are centered and, for example, 0.05 to 1.0 inches from
the base 174.
[0105] The reservoir 161 may be heated to prevent the molten
metal-containing material from freezing. The reservoir pipe may be
enclosed with an insulated (e.g., 12-inch) duct with a hot gas
inlet 180 located at the base and hot gas outlet 182 located at the
top of the duct, opposite of the hot gas inlet 180. A molten
material supply pipe 184 may extend through the lower portion of
the duct opposite of the hot gas inlet 180 and supply molten
metal-containing material to the reservoir 161. The molten material
supply pipe 184 may be in fluid communication with the molten
metal-containing material source 162, 262 or may be the same
apparatus as the molten metal-containing material source 162, 262
of FIGS. 1 and 3.
[0106] The reservoir 161 may comprise a head pressure gauge 190,
which may be utilized to measure the pressure of the molten
metal-containing material at the inlet 142 of the molten material
injector device 300. Additionally, a molten material volume monitor
150 (such as a molten material height or level monitor) is also
utilized in the reservoir 161 to measure the height of the molten
metal-containing material in the reservoir. The reservoir may be
utilized to keep head pressure relatively constant by maintaining a
relatively constant amount of molten metal-containing material in
the reservoir (i.e., a relatively constant height of molten
metal-containing material). For example, the rate or introduction
of molten metal-containing material into the reaction zone 108 may
not vary by more than 20%, more than 10%, more than 5%, or even by
more than 1%.
[0107] The molten material volume monitor 150 may comprise any
device operable to monitor the height of the molten
metal-containing material in the reservoir 161. For example, and
without limitation, pressure gauges and/or visual monitors may be
utilized to monitor the height. The amount of molten
metal-containing material in the reservoir 161 is then manipulated
by adding additional molten metal into the reservoir 161 via molten
material supply pipe 184. Suitable pressure gauges may include,
without limitation, manometers, analog, or digital pressure gauges,
LASER implemented monitoring devices, cameras, sonic or sonar
devices, or piezo-electric devices.
[0108] According to one or more embodiments, a method for
processing molten metal-containing materials into particles may
include monitoring or setting a target head pressure for the molten
material injector 140 by utilizing the head pressure gauge 190. For
example, if a known head pressure is desired, the head pressure
gauge 190 can be utilized to determine the approximate height of
molten metal in the reservoir 161 that will produce such a head
pressure. Thereafter, the target head pressure may be held by
utilizing the molten material volume monitor 150 (such as a
manometer) to control when and how much additional molten
metal-containing material is passed into the reservoir 161. Thus,
the height of material in the reservoir may be relatively constant,
causing the head pressure to be relatively constant.
[0109] For example, according to at least one embodiment, the
molten material volume monitor 150 in conjunction with the valve
164 controlling flow rate of molten metal-containing material, may
maintain the molten flow into the reactor 101, 201 within 1% or
even within 0.1%. A Reliable Pressure Drop Device such as a valve,
orifice, atomizer, injector, nozzle or any other suitable device
may be used to generate a repeatable pressure difference.
[0110] According to one or more embodiments, the molten material
volume monitor 150 may comprise a manometer 152, such as shown in
FIG. 5. The precise level of molten material can be maintained in
the reservoir 161 by utilizing the difference in densities of the
molten material, such as lead, and water. A manometer 152
calibrated in 1/10's of an inch of water column is inserted in the
reservoir 161. A bleed valve 154 may be inserted in the tube 156
between the reservoir 161 and the water 158 in the manometer 152.
The bleed valve 154 is initially left open to atmosphere. When the
desired level of molten material has been reached in the reservoir
161, as measured on the head pressure gauge 190, the bleed valve
154 is closed. After the bleed valve 154 is closed, variations in
the level in the reservoir 161 register a change in the height of
the water 158 in the manometer. An electronic controller may
monitor the manometer 152 and send a signal to open or close the
valve 164 (increasing or decreasing mass flow rate of molten
material through the molten material supply pipe 184).
[0111] For example, the density of lead is about 11 times that of
water. Therefore, a 0.01 inch change in lead level results in 0.11
inch change on a gauge measuring in inches of water. The density
effect magnifies small changes in lead levels into larger changes
in water levels. The more sensitive manometer 152 is used to
control the lead level in the reservoir 161 by sending a signal to
the valve 164 attached to the melt kettle to maintain proper molten
lead level in the reservoir.
[0112] According to one or more embodiments, the velocity,
temperature, viscosity, density, and/or surface tension of the
molten material feed stream may influence the atomization
properties, such as droplet size. In some embodiments, the molten
stream velocity entering the reactor 101, 201 may be increased by
controlling the molten material stream head pressure, such that the
mass flow rate exceeds the mass flow rate feed typical of a
standard Barton Reactor. The relatively high pressure may also
result in reduced molten particle size (i.e., increased
atomization).
[0113] In one or more embodiments, a Barton reactor fitted with a
single-conduit injector 140 may be capable atomizing a molten
stream of lead into solid particles that are significantly smaller
than droplet sizes achieved by a traditional Barton Reactor (i.e.,
one in which molten material enters in a non-atomized form).
Therefore, a Barton reactor fitted with a single-conduit injector
140 may be capable of higher production rates when compared to
conventional Barton technology.
[0114] Now referring to FIG. 11, another system suitable for the
formation of metallic or metal oxide powders is disclosed.
According to one or more embodiments, a feed stream may be passed
through a first conduit of the multi-conduit reactor, and a fluid
stream may be passed through a second conduit of the multi-conduit
reactor, where the feed stream and the fluid stream contact one
another in a mixing zone and form a product stream which exits the
multi-conduit reactor. Optionally, a quench stream may further
enter the mixing zone through a third conduit. Various process
parameters such as, but not limited to, stream compositions, stream
temperatures, stream flow rates, and stream superficial velocities
may affect the interaction between the feed stream and the fluid
stream.
[0115] Referring to FIG. 11, a multi-conduit reactor 800 is
schematically depicted. The multi-conduit reactor 800 may comprise
at least a first conduit 810 and a second conduit 830 which lead to
a mixing zone 870. The first conduit 810 may include an inlet 812
and an outlet 814, and the second conduit 830 may include an inlet
832 and an outlet 834. The first conduit 810 and the second conduit
830 may be divided from one another by a first tubular wall 816. As
depicted in FIG. 11, the first conduit 810 and the second conduit
830 may form a coaxial geometry, such that the first conduit 810 is
axially surrounded by the second conduit 830. The second conduit
830 may be defined by the first tubular wall 816 on its inner
perimeter and by a second tubular wall 836 on its outer perimeter.
According to some embodiments, the multi-conduit reactor 800 may
additionally comprise a third conduit 850 defined by the second
tubular wall 836 and a third tubular wall 856. The first conduit
810, the second conduit 830, and the third conduit 850 may form a
multi-axial geometry where the second conduit 830 axially surrounds
the first conduit 810 and the third conduit 850 axially surrounds
the second conduit 830.
[0116] According to some embodiments, at least a portion of the
first tubular wall 816 may be circular in cross-section, such as
the embodiment schematically depicted in FIG. 12. In such an
embodiment, at least a portion of the first conduit may have a
circular cross-section defined by the first tubular wall 816 as its
outer perimeter. In some embodiments, the second tubular wall 836
may be circular in cross-section. In such an embodiment, at least a
portion of the second conduit 830 may have a circular inner cross
section and a circular outer cross section (i.e., ring shaped). At
least a portion of the third conduit 850 may likewise have a
circular inner cross-section and a circular outer cross-section, as
depicted in FIG. 12.
[0117] According to some embodiments, the entirety of the first
conduit may be tubular in shape, where a substantially straight
pathway connects the first conduit inlet 812 and the first conduit
outlet 814. The second conduit 830 may have an annular
cross-section surrounding a portion of the first conduit, and may
have an inlet 832 which emanates from a side of the multi-conduit
reactor 800. In some embodiments, the third conduit 850 may also
have an annular cross-section and have an inlet 852 which emanates
from a side of the first reactor 800. FIG. 12 schematically depicts
a top view of the axially aligned first conduit 810, second conduit
830, and third conduit 850, where the second conduit 830 has its
inlet 832 emanating from a side of the multi-conduit reactor 800,
and where the third conduit 850 has its inlet 852 emanating from a
side of the multi-conduit reactor 800.
[0118] In one or more embodiments, the first conduit 810 may taper
outward at or near its outlet 814, such that its cross-sectional
area is greater at or near the outlet 814 than at or near the inlet
812 or area of the first conduit 810 between the inlet 812 and the
outlet 814. The second conduit 830 and third conduit 850 may each
taper inwards at or near their respective outlets 834, 854.
[0119] The first conduit 810, the second conduit 830, and the
optional third conduit 850 may lead into a mixing zone 870, which
may be substantially cylindrical in shape (i.e., having a circular
cross-section.) The mixing zone 870 may be defined by a mixing zone
wall 872. Product streams may flow out of the mixing zone 870, and
the multi-conduit reactor 800, through the outlet 874.
[0120] According to various embodiments, the cross-sectional area
of the first conduit 810 at the outlet 814 may be from 0.049 square
inches to 0.45 square inches. For example, the cross-sectional area
of the first conduit 810 at the outlet 814 may be from 0.049 square
inches to 0.1 square inches, from 0.1 square inches to 0.2 square
inches, from 0.2 square inches to 0.3 square inches, or from 0.3
square inches to 0.4 square inches. The first conduit 810 may be
tapered such that the cross-sectional area of the first conduit 810
at the outlet 814 is greater than the cross-sectional area of the
first conduit 810 at or near the inlet 812. For example, the
cross-sectional area of the first conduit 810 at or near the inlet
812 may be from 0.049 square inches to 0.2 square inches, such as
from 0.049 square inches to 0.1 square inches, from 0.1 square
inches to 0.15 square inches, or from 0.15 square inches to 0.2
square inches.
[0121] The cross-sectional area of the second conduit 830 at the
outlet 834 may be from 0.49 square inches to 7.1 square inches. For
example, the cross-sectional area of the second conduit 830 at the
outlet 834 may be from 0.49 square inches to 2 square inches, from
2 square inches to 4 square inches, from 4 square inches to 7.1
square inches, or from 0.5 square inches to 1.5 square inches. The
second conduit 830 may be tapered such that the cross-sectional
area of the second conduit 830 at the outlet 834 is less than the
cross-sectional area of the second conduit 830 at or near the inlet
832. For example, the cross-sectional area of the second conduit
830 at or near the inlet 832 may be from 0.78 square inches to 7.1
square inches, such as from 0.78 square inches to 2 square inches,
2 square inches to 4 square inches, from 4 square inches to 7.1
square inches, or from 2.5 square inches to 3 square inches.
[0122] The cross-sectional area of the third conduit 850 at the
outlet 854 may be from 0.5 square inches to 20 square inches. For
example, the cross-sectional area of the first conduit 850 at the
outlet 854 may be from 0.5 square inches to 5 square inches, from 5
square inches to 10 square inches, from 10 square inches to 15
square inches, from 15 square inches to 20 square inches, or from
0.5 square inches to 1.5 square inches. The third conduit 850 may
be tapered such that the cross-sectional area of the third conduit
850 at the outlet 854 is less than the cross-sectional area of the
third conduit 850 at or near the inlet 852. For example, the
cross-sectional area of the third conduit 850 at or near the inlet
852 may be from 3 square inches to 20 square inches, such as from 8
square inches to 9.5 square inches, from 3 square inches to 7
square inches, from 7 square inches to 14 square inches, or from 14
square inches to 20 square inches.
[0123] According to one or more embodiments, the ratio of the
cross-sectional area of the third conduit 850 at the outlet 854 to
the cross-sectional area of the second conduit 830 at the outlet
834 is from 0 to 3, such as from 0 to 1, from 1 to 2, from 2 to 3,
or from 0.7 to 1.1.
[0124] The various portions of the multi-conduit reactor 800 may be
constructed from a wide variety of materials which are suitable for
the thermal loads required by the methods described herein. For
example, one or more portions of the multi-conduit reactor may be
made of Inconel alloy (such as Iconel 601) or Haynes 230 alloy,
which may be capable of withstanding temperatures of up to
2100.degree. F.
[0125] It should be understood that the various streams may be
characterized by their momentum flux, their superficial velocity,
mass flowrate, etc. These properties, unless stated otherwise, are
described with relation to the given stream as it enters the mixing
zone 870 (i.e., at the feed stream outlet 814, the fluid stream
outlet 834, and the quench stream outlet 854, respectively).
[0126] It should be appreciated that the design of the
multi-conduit reactor 800 may be varied according to embodiments of
the presently disclosed methods for processing metals and alloys
disclosed herein. For example, the cross-sectional shape and/or
relative size of one or more of the first conduit 810, the second
conduit 830, and/or the third conduit 870 may be different from
that depicted in FIG. 11 and described herein. For example, the
conduits 810, 830, 850 may not share common walls with one another,
and may have different shapes. Additionally, it should be
appreciated that in some embodiments a third conduit 850 may not be
included in the multi-conduit reactor 800. In additional
embodiments, the conduit outlets 814, 834, 854 may be positioned on
other portions of the mixing zone 870, and may not be adjacent to
one another.
[0127] Now referring to FIG. 13, a reactor system 900 is depicted
which includes, in addition to the multi-conduit reactor 800 of
FIG. 11, additional stream pre-processing units such as a feed
stream pre-processing unit 910, a fluid stream pre-processing unit
920, and a quench stream pre-processing unit 930. The
pre-processing units 910, 920, 930 may change the temperature,
pressure, or other characteristics of a given stream such a mass
flow rate or superficial velocity. A feed stream pre-processing
unit 910 may treat the feed stream 912 prior to the feed stream 912
entering the multi-conduit reactor 800. In one embodiment, the
pre-processing unit 910 may heat the feed stream 912 to a
temperature which liquefies the metals and/or alloys of the feed
stream. In such embodiments, the feed stream pre-processing unit
910 may comprise a heater or heat exchanger. The fluid stream
pre-processing unit 920 may treat the fluid stream 922 prior to the
fluid stream 922 entering the multi-conduit reactor 800. In one
embodiment, the fluid stream pre-processing unit 920 may heat the
fluid stream 922 as well as pressurize the fluid stream 922. In
such embodiments, the fluid stream pre-processing unit 920 may
comprise a compressor, pump, or other pressure altering means, and
a heater or heat exchanger. The quench stream pre-processing unit
930 may treat the quench stream 932 prior to the quench stream 932
entering the multi-conduit reactor 800. In one embodiment, the
quench stream pre-processing unit 920 may cool the quench stream
932. For example, the quench stream pre-processing unit 930 may
include a refrigeration means or heat exchanger.
[0128] Referring again to FIG. 11, in operation of the
multi-conduit reactor 800, a feed stream may be passed through the
first conduit 810 and a fluid stream may be passed through the
second conduit 830. The feed stream may be contacted by the fluid
stream in the mixing zone 870. Contact of the feed stream with the
fluid stream may cause a chemical change and/or physical change in
the feed stream, producing a product which exits the multi-conduit
reactor 800 through the mixing zone outlet 874 in a product stream.
A quench stream may also enter the mixing zone 870 via the third
conduit 850 and mix with one or more of the feed stream, the fluid
stream, or some product formed by the contact between the feed
stream and the conduit stream.
[0129] In one or more embodiments, the feed stream may comprise one
or more metal compounds, or alloys thereof. Throughout this
disclosure, it should be understood that the term metal may include
an alloy. According to one embodiment, the feed stream may comprise
one or more metals in an amount of at least 50 wt. % of the total
mass of the feed stream. In additional embodiments, the feed stream
comprises one or more metals in an amount of at least 60 wt. %, at
least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 95
wt. %, at least 98 wt. %, or even at least 99 wt. % of the total
mass of the feed stream. In some embodiments, the metal in the feed
stream may consist essentially of, or consists of, a single metal
or alloy species. For example, the metal or alloy in the feed
stream may consist essentially of lead.
[0130] The feed stream may additionally include a carrier gas. The
carrier gas may serve to move the feed stream in a direction
generally towards the multi-conduit reactor 800 and into the mixing
zone 870. In some embodiments, the carrier gas may be an inert gas,
such as nitrogen. In additional embodiments, the carrier gas may be
air or another gas that includes oxygen or other reactive
species.
[0131] The feed stream may be heated to an elevated temperature,
such that the metals or alloys of the feed stream are molten. For
example, the feed stream may have a temperature greater than or
equal to the melting point of the material of the feed stream. If
more than one material is contained in the feed stream, the melting
point of the feed stream may be considered to be the melting point
of the lowest melting point material in the feed stream or the
melting point of the feed stream may be considered as the eutectic
melting point which is a temperature that is lower than the melting
point for any single mixture constituent. In additional
embodiments, the feed stream may be at a temperature greater than
or equal to the melting point of the highest melting point material
in the feed stream or greater than the eutectic melting point for
mixtures comprising multiple molten metals. For example, if lead is
processed in the multi-conduit reactor 800, the feed stream may
have a temperature of at least about 621.5.degree. F., which is the
melting point of lead.
[0132] According to various embodiments, the feed stream may have a
temperature of at least 50.degree. F., at least 100.degree. F., at
least 150.degree. F., at least 200.degree. F., at least 250.degree.
F., at least 300.degree. F., at least 350.degree. F., at least
400.degree. F., at least 450.degree. F., at least 500.degree. F.,
at least 550.degree. F., at least 600.degree. F., at least
650.degree. F., at least 700.degree. F., at least 750.degree. F.,
at least 800.degree. F., at least 850.degree. F., at least
900.degree. F., at least 950.degree. F., at least 1000.degree. F.,
at least 1050.degree. F., at least 1100.degree. F., at least
1150.degree. F., at least 1200.degree. F., at least 1250.degree.
F., at least 1300.degree. F., at least 1350.degree. F., at least
1400.degree. F., at least 1450.degree. F., or even at least
1500.degree. F. For example, the feed stream may have a temperature
of from 400.degree. F. to 1200.degree. F., such as from 500.degree.
F. to 1000.degree. F., from 600.degree. F. to 800.degree. F., or
from 650.degree. F. to 750.degree. F. In additional embodiments,
the feed stream may have a temperature of at least the melting
point of any of the metals or alloys identified herein or the feed
stream may have a eutectic melting point temperature of any metal
or metalloid mixtures or metal alloys.
[0133] The feed stream may have a superficial velocity of from 0.1
ft/s to 100 ft/s. For example, the superficial velocity of the feed
stream may be at least 0.1 ft/s, at least 0.5 ft/s, at least 1
ft/s, at least 5 ft/s, at least 10 ft/s, or at least 30 ft/s, such
as from 0.1 ft/s to 1 ft/s, from 1 ft/s to 10 ft/s, from 10 ft/s to
50 ft/s, or from 50 ft/s to 100 ft/s.
[0134] The feed stream may have a mass flowrate of from 0.2 lbs/s
to 10 lbs/s. For example, the mass flowrate of the feed stream may
be at least 0.2 lbs/s, at least 0.5 lbs/s, at least 1 lbs/s, at
least 3 lbs/s, or at least 5 lbs/s, such as from 0.2 lbs/s to 1
lbs/s, from 1 lbs/s to 3 lbs/s, from 3 lbs/s to 5 lbs/s, from 5
lbs/s to 7 lbs/s, or from 7 lbs/s to 10 lbs/s.
[0135] The fluid stream may comprise one or more chemical species
in a gas phase. According to some embodiments, the fluid stream may
comprise a combustible gas, such as oxygen. For example, the fluid
stream may comprise, consist essentially of, or consist of air. In
one or more embodiments, the fluid stream may comprise oxygen in an
amount of at least 5 wt. % of the total mass of the fluid stream.
In additional embodiments, the fluid stream may comprise oxygen in
an amount of at least 10 wt. %, at least 15 wt. %, at least 20 wt.
%, at least 25 wt. %, at least 30 wt. %, at least 40 wt. %, at
least 50 wt. %, at least 60 wt. %, at least 70 wt. %, at least 80
wt. %, at least 90 wt. %, or even at least 95 wt of the total mass
of the fluid stream.
[0136] In other embodiments, the fluid stream contains little or no
combustible gas species. The fluid stream may not be chemically
reactive with the feed stream. For example, the feeds stream may
comprise, consist essentially of, or consist of inert gases such as
nitrogen. In one or more embodiments, the fluid stream may comprise
inert gas, such as nitrogen, in an amount of at least 5 wt. % of
the total mass of the fluid stream. In additional embodiments, the
fluid stream may comprise oxygen in an amount of at least 10 wt. %,
at least 15 wt. %, at least 20 wt. %, at least 25 wt. %, at least
30 wt. %, at least 40 wt. %, at least 50 wt. %, at least 60 wt. %,
at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, or even at
least 95 wt of the total mass of the fluid stream. In additional
embodiments, the fluid stream may comprise oxygen in an amount of
less than or equal to 10 wt. % of the total mass of the fluid
stream. For example, the fluid stream may comprise oxygen in an
amount of less than or equal to 7.5 wt. %, less than or equal to 5
wt. %, less than or equal to 4 wt. %, less than or equal to 3 wt.
%, less than or equal to 2 wt. %, or even less than or equal to 1
wt. % of the total mass of the fluid stream.
[0137] The fluid stream may be at an ambient temperature, or may be
heated to an elevated temperature. According to various
embodiments, the fluid stream may be heated and have a temperature
of at least 100.degree. F., at least 150.degree. F., at least
200.degree. F., at least 250.degree. F., at least 300.degree. F.,
at least 350.degree. F., at least 400.degree. F., at least
450.degree. F., at least 500.degree. F., at least 550.degree. F.,
at least 600.degree. F., at least 650.degree. F., at least
700.degree. F., at least 750.degree. F., at least 800.degree. F.,
at least 850.degree. F., at least 900.degree. F., at least
950.degree. F., at least 1000.degree. F., at least 1050.degree. F.,
at least 1100.degree. F., at least 1150.degree. F., at least
1200.degree. F., at least 1250.degree. F., at least 1300.degree.
F., at least 1350.degree. F., at least 1400.degree. F., at least
1450.degree. F., or even at least 1500.degree. F. For example, the
fluid stream may have a temperature of from 400.degree. F. to
900.degree. F., such as from 500.degree. F. to 800.degree. F., from
600.degree. F. to 700.degree. F., or from 500.degree. F. to
650.degree. F. In other embodiments, the fluid stream may have a
temperature of from about 0.degree. F. to 100.degree. F., such as
from 50.degree. F. to 90.degree. F., or from 60.degree. F. to
80.degree. F.
[0138] The fluid stream may have a superficial velocity of from 100
ft/s to 2500 ft/s. For example, the superficial velocity of the
fluid stream may be at least 200 ft/s, at least 500 ft/s, at least
1000 ft/s, at least 1500 ft/s, or at least 2000 ft/s, such as from
100 ft/s to 300 ft/s, from 300 ft/s to 500 ft/s, from 500 ft/s to
1000 ft/s, from 1000 ft/s to 2000 ft/s, or from 2000 ft/s to 2500
ft/s.
[0139] As described herein, the feed stream is passed through the
first conduit 810 of the multi-conduit reactor 800 and the fluid
stream is passed through the second conduit 830 of the
multi-conduit reactor 800, where the feed stream and the fluid
stream contact one another in the mixing zone 870. In one or more
embodiments, the contacting of the fluid stream with the feed
stream may atomize some or all materials of the feed stream.
[0140] In one or more embodiments, the characteristics of the
atomization of the materials in the feed stream may be a function
of the momentum flux ratio. For example, the particle size may be
correlated to the momentum flux ratio. As used herein, the momentum
flux ratio is the ratio of the momentum flux of the fluid stream to
the momentum flux of the feed stream. The momentum flux ratio can
be represented by Equation 1, where M represents the momentum flux
ratio, .rho..sub.fluid is the density of the feed stream,
U.sub.Fluid is the superficial velocity of the feed stream, PFeed
is the density of the feed stream, and U.sub.Feed is the
superficial velocity of the feed stream.
M = .rho. Fluid U Fluid 2 .rho. Feed U Feed 2 Equation 1
##EQU00001##
[0141] Without being bound by any particular theory, the momentum
flux ratio may be correlated to the characteristics of the
atomization by the Weiss & Worsham model (available in the
publication by Malcom Weiss and Charles Worsham, entitled
Atomization in High Velocity Airstreams, Esso Research and
Engineering Co., Linden N.J., 1959), allowing for a desired
atomization to be achieved by selection of the superficial velocity
of the feed stream and the superficial velocity of the fluid
stream. However, it should be understood that other models may be
suitable for various reactor geometries and designs, where the
Reynolds Number and/or Weber Number of one or more of the streams
varies. According to one or more embodiments, the momentum flux
ratio may be from 0.3 to 48. In additional embodiments, the
momentum flux ratio may be from 0.1 to 100, such as from 0.1 to 1,
from 1 to 5, from 5 to 25, from 25 to 50, from 50 to 75, or from 75
to 100.
[0142] According to one or more embodiments, the feed stream may be
atomized into droplets having a Sauter Mean Diameter of less than
or equal to 1 mm. For example, the Sauter Mean Diameter of the
atomized droplets may be less than or equal to 750 microns, less
than or equal to 500 microns, less than or equal to 250 microns, or
even less than or equal to 100 microns, such as from 1 micron to 25
microns, from 25 microns to 100 microns, from 100 microns to 500
microns, from 500 microns to 1000 microns, or from 10 micron to 15
microns.
[0143] The contacting of the feed stream with the fluid stream may
also cause a combustion reaction, particularly in embodiments where
the fluid stream comprises oxygen. The combustion reaction may form
metal oxides from the one or more metals or alloys of the feed
stream. The oxidation of these metals or alloys may be exothermic,
and may release heat sufficient to maintain a flame temperature in
the mixing zone 870 of the multi-conduit reactor 800 which allows
for the perpetual continuation of the combustion reaction. The
flame temperature may be greater than the melting point of the
metal or alloy in the feed stream (or even much greater than (e.g.,
at least 100.degree. F. greater than) the melting point of the
metal or alloy in the feed stream, but within the operating
temperatures permitted by the materials of the multi-conduit
reactor 800. Additionally, in the flame temperature may be below a
temperature which would form oxides of nitrogen.
[0144] According to some embodiments, the flame temperature in the
mixing zone 870 may be a function of the ratio of gas from the
fluid stream to metal or metal alloy from the feed stream. Since
the flame temperature may be controlled by adjusting the ratio of
gas from the fluid stream to metal or metal alloy from the feed
stream, the ratio of gas from the fluid stream to metal or metal
alloy from the feed stream may be selected such that the flame
temperature meets the operation parameters discussed herein, such
as being greater than the melting point of the metal but less than
a temperature not suitable for the materials of the reactor and a
temperature which oxidizes nitrogen. For example, if lead is
contained in the feed stream, the ratio of gas from the fluid
stream to lead in the feed stream may be from 0.3 to 4.5, such as
from 0.4 to 0.65, such that the flame temperature is from
1700.degree. F. to 3000.degree. F. FIG. 14 depicts an example
relationship between the flame temperature and the ratio of gas to
metal. According to one or more additional embodiments, the ratio
of gas from the fluid stream to metal or metal alloy from the feed
stream may be from 0.25 to 10, such as from 0.25 to 1, from 1 to 2,
from 2 to 4, from 4 to 6, from 6 to 8, or from 8-10. As described
herein, the ratio of gas from the fluid stream to metal or metal
alloy from the feed stream is a weight basis measurement.
[0145] In addition to the ratio of oxygen to metal, in some
embodiments, the temperature of the feed stream and/or the
temperature of the fluid stream may affect the flame temperature.
In general, the flame temperature may rise with increasing feed
stream temperatures and/or increasing fluid stream temperatures.
FIG. 15 depicts an example relationship between the flame
temperature and the feed stream temperature. Moreover, FIG. 16
depicts the momentum ratio when plotted against pressure, where
each line represents a liquid molten metal velocity. The lead
velocity has a significant impact on momentum ratio base on the
data of FIG. 16. As such, in some embodiments, about 5 ft/s molten
metal velocity may be desirable so that momentum ratio is maximized
while the flowrate of molten metal is still reasonable high.
[0146] In one or more embodiments, the ratio of the mass flowrate
of the feed stream to the mass flowrate of the fluid stream may be
from 0.05 to 0.5, such as from 0.2 to 0.3, from 0.3 to 0.4, or from
0.4 to 0.5.
[0147] In some embodiments, the multi-conduit reactor 800 may
comprise a supplemental heating source in the mixing zone. The
supplemental heating source may be utilized to ignite the
combustion reaction. Once the combustion reaction begins, the flame
temperature may be held without supplemental heating as long as
adequate fuel (i.e., the metal or alloy from the feed stream) and
oxygen is supplied. The supplemental heating source may comprise
one or more of an ignition system, a burner, or any other apparatus
suitable for supplying heat or a flame.
[0148] According to additional embodiments, a quench stream may
enter the mixing zone 870 via the third conduit 850 and react with
the components of the feed stream. Without being bound by theory,
the quench stream may change one or more characteristics of the
metal or metal oxide in the product stream, and may aid in cooling
the product stream to a temperature below the melting point of the
metal or alloy in the product stream, forming solids. The quench
stream may alter the crystal structure of the components of the
product stream. Without being bound by theory, it is believed that
the rate of cooling of the product stream may affect the crystal
structure of the metal, alloy, or metal oxide. The crystal
structure may determine the color of the metal in the feed stream,
so color of the product stream may be a controllable property in
some embodiments.
[0149] In some embodiments, the quench stream may change the
oxidation state the metals in the product stream from what they
would have been had the quench stream not been present. For
example, a quench stream that comprises oxygen may raise the
oxidation state of a metal in the product stream.
[0150] The quench stream may comprise one or more chemical species
in a gas phase. According to some embodiments, the quench stream
may comprise a combustible gas, such as oxygen. For example, the
quench stream may comprise, consist essentially of, or consist of
air. In one or more embodiments, the quench stream may comprise
oxygen in an amount of at least 5 wt. % of the total mass of the
quench stream. In additional embodiments, the quench stream may
comprise oxygen in an amount of at least 10 wt. %, at least 15 wt.
%, at least 20 wt. %, at least 25 wt. %, at least 30 wt. %, at
least 40 wt. %, at least 50 wt. %, at least 60 wt. %, at least 70
wt. %, at least 80 wt. %, at least 90 wt. %, or even at least 95
wt. % of the total mass of the quench stream.
[0151] In other embodiments, the quench stream contains little or
no combustible gas species. The quench stream may not be chemically
reactive with the feed stream. For example, the feeds stream may
comprise, consist essentially of, or consist of inert gases such as
nitrogen. In one or more embodiments, the quench stream may
comprise inert gas, such as nitrogen, in an amount of at least 5
wt. % of the total mass of the quench stream. In additional
embodiments, the quench stream may comprise oxygen in an amount of
at least 10 wt. %, at least 15 wt. %, at least 20 wt. %, at least
25 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %,
at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least
90 wt. %, or even at least 95 wt of the total mass of the quench
stream. In additional embodiments, the quench stream may comprise
oxygen in an amount of less than or equal to 10 wt. % of the total
mass of the quench stream. For example, the quench stream may
comprise oxygen in an amount of less than or equal to 7.5 wt. %,
less than or equal to 5 wt. %, less than or equal to 4 wt. %, less
than or equal to 3 wt. %, less than or equal to 2 wt. %, or even
less than or equal to 1 wt. % of the total mass of the quench
stream.
[0152] The quench stream may be at an ambient temperature, or may
be heated to an elevated temperature. In some embodiments, the
quench stream may have a temperature of from about 0.degree. F. to
100.degree. F., such as from 50.degree. F. to 90.degree. F., or
from 60.degree. F. to 80.degree. F. In some embodiments, the quench
stream may be ambient air or cooled air.
[0153] In other embodiments, the quench stream may be heated and
have a temperature of at least 100.degree. F., at least 150.degree.
F., at least 200.degree. F., at least 250.degree. F., at least
300.degree. F., at least 350.degree. F., at least 400.degree. F.,
at least 450.degree. F., at least 500.degree. F., at least
550.degree. F., at least 600.degree. F., at least 650.degree. F.,
at least 700.degree. F., at least 750.degree. F., at least
800.degree. F., at least 850.degree. F., at least 900.degree. F.,
at least 950.degree. F., at least 1000.degree. F., at least
1050.degree. F., at least 1100.degree. F., at least 1150.degree.
F., at least 1200.degree. F., at least 1250.degree. F., at least
1300.degree. F., at least 1350.degree. F., at least 1400.degree.
F., at least 1450.degree. F., or even at least 1500.degree. F. In
additional embodiments, the quench stream may have a temperature of
from -20.degree. F. to 150.degree. F.
[0154] In one or more embodiments, the quench stream may have a
pressure of at least 15 psia. For example, the quench stream may
have a pressure of at least 20 psia, at least 30 psia, at least 40
psia, or even at least 50 psia, such as from 15 psia to 100 psia,
from 30 psia to 100 psia, or from 50 psia to 100 psia.
[0155] The quench stream may have a superficial velocity of from
100 ft/s to 2500 ft/s. For example, the superficial velocity of the
quench stream may be at least 100 ft/s, at least 500 ft/s, at least
1000 ft/s, at least 1500 ft/s, or at least 2000 ft/s, such as from
100 ft/s to 500 ft/s, from 500 ft/s to 1000 ft/s, from 1000 ft/s to
1500 ft/s, from 1500 ft/s to 2000 ft/s, or from 2000 ft/s to 2500
ft/s.
[0156] The quench stream may have a mass flowrate of from 0.05
lbs/s to 50 lbs/s. For example, the mass flowrate of the quench
stream may be at least 0.05 lbs/s, at least 0.5 lbs/s, at least 1
lbs/s, at least 5 lbs/s, or at least 10 lbs/s, such as from 0.05
lbs/s to 0.5 lbs/s, from 0.5 lbs/s to 1 lbs/s, from 1 lbs/s to 10
lbs/s, from 10 lbs/s to 30 lbs/s, or from 30 lbs/s to 50 lbs/s. For
example, the quench stream may have a mass flowrate of from 0.2
lbs/s to 0.5 lbs/s
[0157] The resulting components following the contacting of the
feed stream and the fluid stream form a product stream, which exits
the multi-conduit reactor. The product stream may comprise one or
more powdered metals or alloys, or oxides thereof. According to one
embodiment, if one or more of the fluid stream or the quench stream
comprises oxygen, a metal oxide may be present in the product
stream. Without being bound by theory, as disclosed above, it is
believed that the size of the particles of the powder of the
product stream may be a function of the momentum flux ratio, as
explained previously in this disclosure. The metal, alloy, or oxide
particles present in the product stream may have the same or
similar size as the liquefied, atomized droplets of the feed stream
when it is contacted by the fluid stream.
[0158] Having described the subject matter of the present
disclosure in detail and by reference to specific embodiments, it
is noted that the various details described in this disclosure
should not be taken to imply that these details relate to elements
that are essential components of the various embodiments described
in this disclosure, even in cases where a particular element is
illustrated in each of the drawings that accompany the present
description. Rather, the claims appended hereto should be taken as
the sole representation of the breadth of the present disclosure
and the corresponding scope of the various embodiments described in
this disclosure. Further, it will be apparent that modifications
and variations are possible without departing from the scope of the
appended claims.
* * * * *