U.S. patent application number 10/452194 was filed with the patent office on 2004-12-09 for metal scrap packages and methods and apparatus capable of being used therewith.
This patent application is currently assigned to PECHINEY ROLLED PRODUCTS. Invention is credited to Austin, L. Keith.
Application Number | 20040244535 10/452194 |
Document ID | / |
Family ID | 33489429 |
Filed Date | 2004-12-09 |
United States Patent
Application |
20040244535 |
Kind Code |
A1 |
Austin, L. Keith |
December 9, 2004 |
Metal scrap packages and methods and apparatus capable of being
used therewith
Abstract
The present invention relates to a material package comprising a
housing, at least one piece of scrap material contained in the
housing, wherein the weight of the housing is from 1 to 5% of the
weight of said scrap material, and the housing and the scrap
material have melting points that are greater than about
300.degree. F. The present invention further relates to associated
methods and products employed with material packages as well as
meltable housings, per se.
Inventors: |
Austin, L. Keith;
(Mansfield, TX) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ LLP
SUITE 800
1990 M STREET NW
WASHINGTON
DC
20036-3425
US
|
Assignee: |
PECHINEY ROLLED PRODUCTS
Ravenswood
WV
26164
|
Family ID: |
33489429 |
Appl. No.: |
10/452194 |
Filed: |
June 3, 2003 |
Current U.S.
Class: |
75/687 |
Current CPC
Class: |
Y02P 10/214 20151101;
C22B 1/005 20130101; C22B 21/0069 20130101; Y02P 10/20 20151101;
Y02P 10/218 20151101; C22B 21/0092 20130101 |
Class at
Publication: |
075/687 |
International
Class: |
C22B 021/00 |
Claims
What is claimed is:
1. A material package comprising: a housing, at least one piece of
scrap material contained in said housing, wherein the weight of
said housing is from 1 to 5% of the weight of said scrap material,
and said housing and said scrap material have melting points that
are greater than 300.degree. F.
2. A material package according to claim 1, wherein said housing
comprises a mesh basket.
3. A material package according to claim 2, wherein said mesh
basket comprises aluminum.
4. A material package according to claim 2, wherein said scrap
material comprises aluminum.
5. A material package according to claim 2, wherein both said scrap
material and said mesh basket comprise aluminum.
6. A material package according to claim 5, wherein said scrap
material comprises Al--Li.
7. A method for recycling scrap material comprising loading said
scrap material in a housing, optionally drying said scrap material
and said housing to remove residual contaminates and/or moisture,
optionally loading virgin material having a composition that is
substantially the same as said scrap material into said housing,
and subjecting said scrap material and said housing to a treatment
sufficient to melt said scrap material and said housing.
8. A method according to claim 7, wherein said housing comprises a
mesh basket.
9. A method according to claim 8, wherein said mesh basket
comprises aluminum.
10. A method according to claim 8, wherein said scrap material
comprises aluminum.
11. A method according to claim 8, wherein both said scrap material
and said mesh basket comprise aluminum.
12. A method according to claim 11, wherein said scrap material
comprises Al--Li.
13. An aluminum alloy wherein at least 5% thereof was prepared from
a material package according to claim 1.
14. An aluminum alloy comprising recycled material, wherein said
aluminum alloy was prepared according to a method of claim 7.
15. A housing capable of recycling metal comprising two sheets,
optionally formed of mesh, said sheets being transposed with
respect to each other to form a basket structure, wherein edges of
said sheets are interwoven at an angle ranging from 80 to 110
degrees.
16. A material package comprising a housing according to claim 15
and scrap material therein.
17. A housing according to claim 15 comprising aluminum alloy AA
3003 mesh material.
18. A material package according to claim 16, wherein said scrap
material comprises aluminum.
19. A material package according to claim 18, wherein said scrap
material comprises aluminum lithium.
20. A material package according to claim 1, wherein the gauge of
said housing is about 0.11.
21. A method for forming an alloy comprising placing at least two
different materials in a meltable housing and subjecting the
housing containing said materials to a temperature sufficient to
melt said housing and said materials.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field of the Invention
[0002] The present invention relates generally to metal scrap and
associated methods, and in particular, to methods suitable for use
with Al--Li scrap as well as associated apparatus and products
produced thereby.
[0003] 2.. Description of Related Art
[0004] With the large volume of products made of metal worldwide,
there is inevitably an issue about what to do with the huge
quantities of scrap metal that is left over after many
manufacturing and machining operations. The scrap metal produced
from these operations varies in size from small machined chips or
swarf to various sized solid remnant. Moreover, since many metal
alloys are constantly being reengineered and developed, large
quantities of alloy scrap are often generated for every pound of
usable metal produced. For example, a typical aircraft part
machined from plate may have a "start-to-finish" ratio (the ratio
of the starting raw stock weight to the finished part weight) of
between 10 to 120 lbs of starting raw material weight for every
pound of finished weight. This is particularly the case with
respect to aluminum lithium metal alloys that are very lightweight
and are still in many cases, in the experimental stage. Furthermore
prior attempts recovering scrap Al--Li have been limited to large
scrap that is produced during the manufacturing process at the
mill, i.e., ingot heads and ingot butts. Solid Al--Li scrap
material must be placed in the induction furnace quickly and
carefully to avoid damaging the furnace linings. Thus, Al--Li of
small sizes cannot be successfully recycled at all due to these
problems, and hence, often goes to waste.
[0005] With respect to aluminum lithium and other alloys, it has
been proposed in the past according, for example, to U.S. Pat. Nos.
4,882,017 and 4,973,390 to employ an electrolytic cell to extract
lithium from the scrap, apparently in an effort to separate the
alloying elements and reuse them individually. Further, with
respect to other metals and alloys, other recycling methodologies
have been suggested such as in U.S. Pat. Nos. 5,032,171, 6,074,455,
6,273,932 and 5,167,700. In these and related processes, various
mechanisms for remelting and/or reincorporating scrap metal alloys
are described. However, none of the methods proposed heretofore has
provided a reliable and simple mechanism that can be used in any
shop or facility that enables storage and separation of particular
metal alloys.
SUMMARY OF THE INVENTION
[0006] It was therefore an object of the present invention to
provide a method for recycling and/or incorporating metal alloys
such as aluminum lithium alloys of virtually any size. Since most
of the scrap material from machine shops is small, i.e., various
shapes ranging from 1 pound to 200 pounds each, a method has been
proposed capable of packaging scrap such that it could be loaded as
a large quantity as quickly as possible.
[0007] In accordance with these and other objects, there is
provided a meltable housing capable of receivingly accepting at
least one metal alloy therein. The meltable housing preferably has
a melting point lower than the casting temperature of the metal
alloy sought to be contained therein. That is, the meltable housing
preferably has a melting point that is high enough to maintain
sufficient structural integrity to hold the weight of metal alloy
scrap during elevated temperature drying operations and during
insertion into the casting furnace.
[0008] In one embodiment, the meltable housing forms a mesh
"basket" with at least one entryway provided therein such that
metal to be recycled can be placed therein. The mesh basket for
melting aluminum lithium alloys can be made, for example, of 3003
or any suitable material that may be desired for a particular type
of alloy.
[0009] The present invention is further directed to methods of
recycling metal as well as to metal packages and products formed
thereby.
[0010] Additional objects, features and advantages of the invention
will be set forth in the description which follows, and in part,
will be obvious from the description, or may be learned by practice
of the invention. The objects, features and advantages of the
invention may be realized and obtained by means of the
instrumentalities and combination particularly pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a layout of a mesh basket prior to assembly
according to one embodiment of the present invention.
[0012] FIG. 2 is a side view of a mesh basket manufactured
according to one embodiment of the present invention.
[0013] FIG. 3 is a top view of a basket of FIG. 2.
[0014] FIG. 4 is a close up view of a portion of FIG. 2 showing how
mesh could be designed according to one embodiment of the present
invention.
[0015] FIG. 5 is an assembled view of a mesh basket showing metal
scrap loaded therein.
[0016] FIG. 6 is a graph representing percent savings capable being
achieved compared with virgin material according to one embodiment
of the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0017] Since most scrap material from machine shops is small, i.e.,
various shapes ranging from 1 pound to 200 pounds each, a method
was needed to package the scrap such that it could be loaded as a
large quantity (i.e. quantities ranging from 1000 to 4000 pounds,
preferably from 2500 to 3500 pounds) as quickly and easily as
possible. In connection with the present invention, there is
provided a meltable basket, preferably formed of metal such as
aluminum alloy AA 3003 mesh material. However, the composition of
the housing does not necessarily have to comprise aluminum, but
actually can be fabricated in any desired composition or shape
depending on the material sought to be packaged therein. In one
embodiment, the metal basket is formed into a rectangular basket.
See FIGS. 1-5. The meltable housing can be formed of any
commercially available product and preferably has a melting point
lower than the casting temperature of the metal alloy contained
therein that is sought to be recycled. For example, a meltable
housing made of AA 3003 would have a solidus temperature of
approximately 1190.degree. F. and a liquidus temperature of
approximately 1210.degree. F. The meltable housing in such an
embodiment would melt at a temperature below the casting
temperature for aluminum lithium alloys. 3003 also has sufficient
strength at temperatures between room temperature and the melting
temperature of Al--Li to hold the weight of the metal alloy
contained in the housing when subjected to elevated temperature
drying operations and during insertion into the casting
furnace.
[0018] In one embodiment as shown in FIG. 1, two pieces of mesh
metal 10 that melts at a temperature below the casting temperature
of the metal alloy contained therein, for example between 1190 and
1210.degree. F. with respect to Al--Li, is formed into rectangular
shape of any desired size A.times.B.times.C, whereby A is the
width, B is the height, and C is the length. In one embodiment, the
rectangular shape is 30".times.60".times.30" corresponding to a
volume consistent with the furnace capabilities and loading
methods. FIG. 1 shows the forming locations 70 where the mesh metal
is bent to form the rectangular shape. The formed parts are placed
90.degree. with respect to each other as shown in FIG. 2 and FIG. 3
to form a rectangular basket 20 that has a double thick bottom 80
and top with dimensions of A.times.C" and sides of B.times.C". The
sides are interlocked together (see FIG. 4) and can be wired
together by any desired means, such as with aluminum wire 40, 50.
The mesh in the basket is preferably of a size having openings
ranging from 0.04" to 2", and more preferably has diamond shaped
mesh opening sizes ranging from 0.7" to 1.5". By having mesh that
is relatively small as described above, a machine shop is then able
to load the baskets with small sized scrap metal 30. As shown for
example in FIG. 4, an exploded close up view of an advantageous
design of mesh is shown. The sheets are secured using any desired
mechanism. In a preferred embodiment, the edges of the sheets 10
are bent in a particular fashion as shown, for example in FIG. 4.
The edges of the sheets 10 alternates in a "bend up" 40 "bend down"
50 orientation at angles 60 preferably ranging from 45.degree. to
170.degree., more preferably from 80.degree. to 110.degree.. The
edges shown in FIG. 4 are shown prior to bending to interlock the
edges together. Note that it is also possible to form a housing
that is not mesh but designed to fully contain a quantity of metal
sought to be recycled. The overlapping edges of the sheets 40, 50
are shown in FIG. 4 is advantageous because the sheets 10 are able
to be intermeshed to form a strong joint without necessarily
requiring wires or other fasteners. In addition, the interlocking
is preferably oriented in the depicted "bend up" "bend down"
configuration because it minimizes the use of other alloy additions
such as aluminum wire to the melt.
[0019] In one embodiment the gauge of the material forming the
basket or housing is advantageously from 0.10" to 0.31" and when
formed into a basket, can house about 3500 lbs of scrap. In one
embodiment, the gauge is about 0.11." However, the gauge can be
adjusted higher or lower depending on the requirements of the
particular product being recycled and remelted.
[0020] A metal package housed as described above, is advantageous
in that it can easily be lifted and moved with a common forklift
and hoisted into a truck or other trailer or railway car for
removal and transport to be remelted.
[0021] With respect to aluminum lithium alloys, the mesh design is
particularly advantageous because the scrap material can be cleaned
and/or dried after it is packaged. Once the housing or basket is
full, the metal to be remelted can be dried at any suitable
temperature, such as at a temperature from about 100.degree. to
350.degree. F. to remove water, oils and contaminates. The housing
or basket can also be immersed or sprayed with a cleaning solution
or suitable solvent to remove oils and contaminates prior to drying
at elevated temperatures. The drying temperature should
advantageously be lower than the melting temperature housing or the
metal contained therein. The weight of the housing is preferably
from 1% to 5% , more preferably from 2% to 3% of the weight of the
material to be contained therein. These weight ratios are desirable
because they minimize any undesirable alloy additions that may be
present in the commercial metal basket materials. With respect to
housing made of 3003, such an alloy has a higher iron level than
many aluminum lithium alloys. The low weight ratio of the housing
alloy to the weight of the aluminum lithium dilutes the iron levels
close to the level of the aluminum lithium. The total material
package generally has a weight that is preferably less than 3500
lbs. in order to ensure transportability thereof.
[0022] Once the housing 20 is loaded with a desired amount of scrap
or other material to be housed, a "material package" is formed. In
one embodiment, for example as shown in FIG. 5, the material
package 20 comprises a mesh basket comprising at least one piece of
metal 30 therein. When the material package 20 is sought to be
melted, one or more material packages are delivered into a furnace
(not shown) such as an Al--Li furnace to preferably provide for at
least a 25% charge. In terms of Al--Li materials and other alloys
where one or more of the alloying elements is relatively expensive,
employing at least a 50% charge may reduce the need for Li and
other expensive alloying elements and reduces the cost of the metal
by up to 200% in some cases. The reduction in cost is possible
without sacrificing any properties of the underlying material since
the scrap being recycled is preferably of the identical composition
as the materials being generated and formed into ingots.
[0023] Aluminum-Lithium solid remnant or compressed swarf/chips are
particularly difficult to recycle from end-users such as machine
shops because the remnant sizes are small (from 1 to 200 pounds)
and difficult to load quickly and safely into the induction
furnace. Methods to join the scrap together such as steel banding,
welding, or other methods are not easily accomplished or introduce
undesirable alloying elements into the furnace. The instant method
and material package provides an affordable way for machine shops
and other end-users to package the solid remnant or compressed
swarf/chips into a container that is preferably capable of being
melted along with the remnant material. This method is suitable for
virtually any conventional aluminum alloys including Al--Li alloys
as well as any other metal or product that needs to be recovered
and returned to use with virgin material. Other materials capable
of employing the instant material package and method include steel
remnants, magnesium metals, copper alloys, titanium alloys, nickel
alloys, thermoplastic materials, and polymers. The housing 10 to be
used with materials other than aluminum will be formed of a
material having a melting point that is similar to the melting
point of the material(s) sought to be recycled. As such, the
melting point of housings for materials other than aluminum alloys
may not have melting points from 1190.degree. to 1210.degree. F. as
described above with respect to aluminum materials, but rather,
will be chosen to optimize the melting and remelting of the
material package being treated.
[0024] It is anticipated that end-users would be able to use the
baskets as a normal part of their manufacturing process, thus
reducing their overall scrap handling issues and providing an easy
method of segregating solid scrap by alloy. In addition, in
accordance with another embodiment of the present invention, such a
meltable housing can be used to create new alloys by introducing
two or more different materials therein and subjecting the filled
housing to a temperature sufficient to melt the housing and the
contents so as to form a final product. In some embodiments, the
housing and the materials sought to be melted therein will have
melting temperatures greater than 300.degree. F.
[0025] Other types of baskets or packages could alternatively be
employed such as wrapping the scrap in remeltable sheet or mesh
containers. Automated processes or machines that would package the
scrap in such a manner could also be utilized if desired for any
reason.
EXAMPLES
Example 1
[0026] Container and Method Description:
[0027] An aluminum 3003 expanded mesh sheet was formed into a
rectangular basket and wired together using 6063 aluminum wire. For
an Al--Li furnace, a basket having dimensions of
30".times.30".times.60" was produced and filled with 3000 lbs. of
remnant Al--Li material having size dimensions ranging from 1 to
2000 cubic inches. The package was secured using 6063 aluminum
wire, and shipped to the cast house. The basket contained
approximately 3000 lbs of solid remnant with a wire basket weight
of about 46 lbs. In this example, the weight ratio between the 3003
basket and remnant material was 1.5% and this ratio allowed for
dilution of any undesirable alloy elements such as Fe in the 3003
basket material. The filled basket was heated to a temperature of
250.degree. F. that was suitable to off-gas any moisture or other
contaminates prior to lowering into the induction furnace. A
typical range for such heating could be between 100.degree. F. and
500.degree. F. After heating to remove contaminates, the scrap
basket was lowered into a remelt furnace as typically done with
large scrap pieces.
Example 2
[0028] According to Example 2, the following materials were
prepared as set forth below:
[0029] 100% virgin aluminum standard ingot (no baskets)
[0030] 60% virgin aluminum ingot+40% scrap (Two 2500 lb
baskets)
[0031] 20% virgin aluminum ingot+80% scrap (Four 2500 lb
baskets)
[0032] The material employed was aluminum mesh--2 pieces 0.125"
thick.times.30".times.210" to produce a form. The form was broken
at the locations 70 as shown in FIG. 2 and sheets 10 were combined
together using the center section 80 as a "double bottom" to
provide additional strength. The basket was filled with solid scrap
and compressed chips, segregated by alloy. The top of the basket 20
was closed and the edges were interwoven with the sides of the
basket as shown in FIG. 4. The basket was shipped to a casting
facility with the basket labeled with the name of the alloy. The
basket was heated in an air furnace to above 250.degree. F. to
remove water and oils that may have been on the surface of scrap
and this temperature was held for a time commensurate with the
level of contamination to ensure removal of contaminates based on
condition of scrap. The induction furnace was loaded with the scrap
containing baskets and the remaining void was filled with virgin
metal. The load was melted and cast according to known techniques.
The baskets melted along with scrap and virgin material.
[0033] FIG. 6 illustrates certain cost reductions possible through
the utilization of one or more scrap baskets in a casting operation
according to one embodiment of the present invention as exemplified
in Example 2. FIG. 6 compares the use of 100% virgin metals,
alloying elements, and hardeners (A), 40% scrap/60% virgin metals
(B), and 80% scrap/20% virgin metals (C) according to the results
reported in Example 2. The use of one (B) or two (C) scrap
containers has been demonstrated to reduce the metal cost
associated with casting operations from 22 to 44% over the use of
100% virgin materials (A). The left hand side of FIG. 6 shows the
potential cost savings versus 100% virgin metal.
[0034] Additional advantages, features and modifications will
readily occur to those skilled in the art. Therefore, the invention
in its broader aspects is not limited to the specific details, and
representative devices, shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
[0035] All documents referred to herein are specifically
incorporated herein by reference in their entireties.
[0036] As used herein and in the following claims, articles such as
"the", "a" and "an" can connote the singular or plural.
* * * * *