U.S. patent application number 17/703137 was filed with the patent office on 2022-09-29 for cobalt extraction and recycling from permanent magnets.
The applicant listed for this patent is Pioneer Astronautics. Invention is credited to Diana Aksenova, Mark Berggren, Steven Fatur, Alex Roman, Robert Zubrin.
Application Number | 20220307148 17/703137 |
Document ID | / |
Family ID | 1000006283827 |
Filed Date | 2022-09-29 |
United States Patent
Application |
20220307148 |
Kind Code |
A1 |
Fatur; Steven ; et
al. |
September 29, 2022 |
COBALT EXTRACTION AND RECYCLING FROM PERMANENT MAGNETS
Abstract
Systems and methods for recovering cobalt and other valuable
metals from cobalt permanent magnets of various compositions, such
as samarium cobalt magnets, are presented herein. In one
embodiment, a method includes converting the permanent magnet
material to a higher surface area form, such as a powder. The
method also includes treating the converted permanent magnet
material with an aqueous solution of ammonium carbonate to form a
mixture (e.g., a slurry) that includes dissolved cobalt. In some
embodiments, the method includes exposing the mixture to an oxidant
to oxidize metallic constituents and form soluble species. The
method also includes filtering the mixture to yield a filtrate and
electroplating the cobalt onto a cathode from the filtrate.
Inventors: |
Fatur; Steven; (Boulder,
CO) ; Roman; Alex; (Golden, CO) ; Aksenova;
Diana; (Lakewood, CO) ; Berggren; Mark;
(Lakewood, CO) ; Zubrin; Robert; (Lakewood,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Pioneer Astronautics |
Lakewood |
CO |
US |
|
|
Family ID: |
1000006283827 |
Appl. No.: |
17/703137 |
Filed: |
March 24, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63165467 |
Mar 24, 2021 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25C 1/12 20130101; C25C
1/08 20130101; C25C 7/00 20130101 |
International
Class: |
C25C 1/08 20060101
C25C001/08; C25C 1/12 20060101 C25C001/12; C25C 7/00 20060101
C25C007/00 |
Goverment Interests
GOVERNMENT SUPPORT STATEMENT
[0002] This invention was made with government support under U.S.
Department of Energy contract no. DE-SC0020853. The government has
certain rights in this invention.
Claims
1. A method of recovering cobalt from a permanent magnet material
having variable composition, the method comprising: converting the
permanent magnet material to a higher surface area form; treating
the converted permanent magnet material with an aqueous solution of
ammonium carbonate to form a mixture that includes dissolved
cobalt; filtering the mixture to yield a filtrate; and
electroplating the cobalt onto a cathode from the filtrate.
2. The method of claim 1, wherein: the permanent magnet material
comprises samarium cobalt magnets.
3. The method of claim 1, wherein converting the permanent magnet
material to a higher surface area form comprises: at least one of
grinding or milling the permanent magnet material.
4. The method of claim 1, further comprising: heating the mixture
in at least one of air, oxygen, an inert atmosphere, or hydrogen to
temperatures up to 1500.degree. C.
5. The method of claim 1, further comprising: demagnetizing the
mixture using an externally applied magnetic field or a mechanical
shock treatment.
6. The method of claim 1, further comprising: adjusting an
oxidation state of the mixture prior to extraction with a chemical
oxidant, a reductant, or an electrochemical method that employs an
electric current to transfer electrons between materials.
7. The method of claim 1, wherein: the aqueous solution of ammonium
carbonate comprises ammonium carbonate and ammonia.
8. The method of claim 1, further comprising: recycling the aqueous
solution of ammonium carbonate after use.
9. The method of claim 8, wherein recycling the aqueous solution of
ammonium carbonate after use comprises: thermally treating the
aqueous solution of ammonium carbonate after use to convert the
used ammonium carbonate solution into ammonia and carbon
dioxide.
10. The method of claim 1, wherein treating the converted permanent
magnet material with an aqueous solution of ammonium carbonate
comprises: adding at least one of oxygen gas, air, hydrogen
peroxide, a chemical oxidant, hydrogen gas, or a chemical
reductant.
11. The method of claim 1, further comprising: applying an
electrical potential to a slurry containing alkaline carbonates and
the permanent magnet material to increase a dissolution rate.
12. The method of claim 1, further comprising: heating the aqueous
solution of ammonium carbonate to a temperature between 0.degree.
C. and 100.degree. C. at a pressure above 1 bar.
13. The method of claim 1, wherein: one or more of said converting,
treating the converted permanent magnet material, filtering, and
treating the filtrate are performed in a container constructed of
at least one of stainless steel, glass, polytetrafluoroethylene,
fiberglass-reinforced plastic, corrosion resistant alloy, or a
corrosion barrier.
14. The method of claim 1, further comprising: electroplating at
least one of copper or nickel onto the cathode.
15. The method of claim 1, further comprising: adding reagents to
the mixture to slow hydrogen evolution at the cathode or to
increase a rate of oxygen evolution at an anode.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of U.S.
Provisional Patent Application No. 63/165,467 (entitled "Cobalt
Extraction and Recycling from Permanent Magnets" and filed on Mar.
24, 2021), the contents of which are hereby incorporated by
reference.
BACKGROUND
[0003] Cobalt is commonly used to produce samarium cobalt permanent
magnets, lithium-ion battery cathodes, catalysts, and high-grade
metal alloys. These important strategic uses for cobalt combined
with its limited domestic production have led the U.S. Department
of the Interior to list it as a critical material. Furthermore,
approximately 70% of the world's supply of mined cobalt comes from
the Democratic Republic of the Congo where concerns over
environmental degradation and child labor have led some large
cobalt consumers to selectively purchase cobalt from suppliers who
meet certain standards, providing an economic incentive to develop
alternate cobalt sources. Recycling has already been shown to be a
viable cobalt source with an estimated 29% of cobalt consumption in
the United States coming from recycled scrap. One source for
recycled cobalt is from samarium cobalt (SmCo) magnets, which are
commonly used as high-strength permanent magnets in applications
where thermal stability and corrosion resistance is required. These
magnets have been produced with two nominal formulas: SmCo.sub.5
and Sm.sub.2Co.sub.17 with the second generation Sm.sub.2Co.sub.17
formulation being more common and representing the bulk of the
market. In practice, Sm.sub.2Co.sub.17 magnets contain additional
transition metals including iron, copper, and zirconium which makes
their recovery and reuse challenging and expensive. However, as
these magnets typically contain about 50% cobalt by weight, they
are a desirable secondary source for cobalt.
[0004] Several processes have been developed for the recovery of
cobalt from secondary sources. One such process was developed by
the U.S. Bureau of Mines using a double-membrane electrolytic cell
to electro-refine alloy scrap into high-purity cobalt. This process
uses an electrolytic dissolution step, multiple purification steps
including cementation and multiple solvent extraction steps to
produce a purified cobalt solution prior to electrodeposition of
the cobalt. This process can produce high purity cobalt but
requires many processing steps that increase the overall cost if
additional valuable metals are not also purified and recovered,
e.g., nickel in this approach.
[0005] Direct recycling of samarium cobalt magnets is possible
through a process termed hydrogen disproportionation desorption
recombination (HDDR). First, magnet scrap is converted into a
powder through reaction with hydrogen at high pressure or
temperature causing dissociation of the material to elemental forms
or hydrides. Next, the hydrogen is desorbed by heating in vacuum
leading to recombination of the material, which can then be
sintered or plastic bonded to form a new magnet. However, this
process requires high-pressure or high-temperature conditions to
fully dissociate the material and, as magnet manufacturing is not
the major use of cobalt, is limited to the production of additional
samarium cobalt magnets.
[0006] Alternate approaches include acidic digestion and solvent
extraction using various surfactants and complexing ligands.
However, these approaches all suffer from various drawbacks. Acidic
digestion solutions are not recyclable and require significant
consumption of base to neutralize the acid, generating a
significant amount of waste in the process. Solvent extraction
often requires many stages to achieve sufficient purity resulting
in complex and costly systems.
SUMMARY
[0007] Systems and methods herein provide for recovering cobalt
(and/or other metals) from a permanent magnet material having
variable composition, such as samarium cobalt magnets. In one
embodiment, a method includes converting the permanent magnet
material to a higher surface area form, such as a powder. The
method also includes treating the converted permanent magnet
material with an aqueous solution of ammonium carbonate to form a
mixture (e.g., a slurry) that includes dissolved cobalt. In some
embodiments, the method includes exposing the mixture to an oxidant
to oxidize metallic constituents and form soluble species. The
method also includes filtering the mixture to yield a filtrate, and
electroplating the cobalt and/or other metals, such as copper or
nickel, onto a cathode from the filtrate.
[0008] For example, in some embodiments, filtering the slurry may
remove precipitated compounds and form a filtrate. From there, the
filtrate may be placed in an electrochemical reactor which
selectively reduces elements by applying a potential across two
electrodes to plate other metal contaminants or coproducts (e.g.
copper). Then, the electrode and plated metal (e.g., on the
cathode) from solution can be removed. This process may be repeated
at increasing electric potential to sequentially plate additional
metals, to remove the plated cobalt metal from the electrode, and
to rinse the cobalt metal product. The extraction solution,
depleted of cobalt and any coproducts, can be directly reused to
extract more cobalt or coproducts from additional cobalt-containing
material.
[0009] The ammonium carbonate process is a recyclable solution that
eliminates waste generated from neutralizing acids, and avoids the
complexity and cost of the many stages used in traditional solvent
extraction methods. For example, reagents such as ammonium
carbonate, oxygen, and water can be recycled in a process that uses
moderate temperatures, pressures, and environmentally benign
chemicals.
[0010] In some embodiments, the permanent magnet material comprises
samarium cobalt magnets (e.g., either partially or completely
oxidized samarium cobalt magnets). In some embodiments, the method
includes deriving the permanent magnet material from magnet
manufacturing wastes.
[0011] In some embodiments, electroplating the cobalt includes
recovering at least one of copper or nickel from the electroplating
as a co-product. In some embodiments, converting the permanent
magnet material to a higher surface area form includes at least one
of grinding or milling the permanent magnet material.
[0012] In some embodiments, the method also includes heating the
mixture in at least one of air, an inert atmosphere, or hydrogen to
temperatures up to 1500.degree. C. The method may also include
demagnetizing the mixture using an externally applied magnetic
field or a mechanical shock treatment. The method may also include
adjusting an oxidation state of the mixture prior to extraction
with a chemical oxidant, a reductant, or an electrochemical method
that employs an electric current to transfer electrons between
materials.
[0013] In some embodiments, the aqueous solution of ammonium
carbonate comprises ammonium carbonate and ammonia, and the method
also includes recycling the aqueous solution of ammonium carbonate
after use. For example, the aqueous solution of ammonium carbonate
may be thermally treated after use to convert the used ammonium
carbonate solution into ammonia and carbon dioxide.
[0014] In some embodiments, treating the converted permanent magnet
material with an aqueous solution of ammonium carbonate includes
adding at least one of oxygen gas, air, hydrogen peroxide, a
chemical oxidant, hydrogen gas, or a chemical reductant. In some
embodiments, the method also includes applying an electrical
potential to a slurry containing alkaline carbonates and the
permanent magnet material to increase a dissolution rate. In some
embodiments, the method also includes heating the aqueous solution
of ammonium carbonate to a temperature between 0.degree. C. and
100.degree. C. at a pressure above 1 bar.
[0015] In some embodiments, one or more of said converting,
treating the converted permanent magnet material, filtering, and
treating the filtrate are performed in a container constructed of
at least one of stainless steel, glass, polytetrafluoroethylene,
fiberglass-reinforced plastic, corrosion resistant alloy, or a
corrosion barrier. In some embodiments, the method also includes
adding reagents to the mixture to slow hydrogen evolution at the
cathode or to increase a rate of oxygen evolution at an anode.
[0016] In some embodiments, additives may improve the quality of
the electroplating. An electroplating reactor may include at least
one of a single chamber or multiple chambers separated by an
ionically conductive membrane. Two or more electrodes may be used
in the electroplating (e.g., for reduction, oxidation, and/or
reference). And, solids obtained by filtration may be recovered as
a byproduct for additional processing or recycled use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a block diagram of an exemplary system for
recovering cobalt and/or other metals from permanent samarium
cobalt magnets.
[0018] FIG. 2 is a flowchart of an exemplary process of the system
of FIG. 1.
[0019] FIG. 3 is a block diagram of an exemplary computing system
in which a computer readable medium provides instructions for
performing methods herein.
DETAILED DESCRIPTION
[0020] The figures and the following description illustrate
specific exemplary embodiments of the invention. It will thus be
appreciated that those skilled in the art will be able to devise
various arrangements that, although not explicitly described or
shown herein, embody the principles of the invention and are
included within the scope of the invention. Furthermore, any
examples described herein are intended to aid in understanding the
principles of the invention and are to be construed as being
without limitation to such specifically recited examples and
conditions. As a result, the invention is not limited to the
specific embodiments or examples described below.
[0021] Exemplary Cobalt Extraction and Recycling from Permanent
Magnets (CERPM) processes are disclosed herein and are operable to
recover cobalt and other valuable metal elements from samarium
cobalt magnets.
[0022] FIG. 1 is a block diagram of an exemplary system 10 for
recovering cobalt and/or other metals from permanent samarium
cobalt magnets. In this embodiment, the system 10 includes a
milling/grinding module 12 that is operable to convert a samarium
cobalt magnet feed into a higher surface area form, such as powder.
Generally, the samarium cobalt magnet feed is obtained from
recycling samarium cobalt magnets and/or from waste associated with
manufacturing samarium cobalt magnets. After milling/grinding the
samarium cobalt magnet feed, the samarium cobalt magnet powder is
transferred to a leaching vessel 14.
[0023] The leaching vessel 14 is generally a sealed container in
which (NH.sub.4).sub.2CO.sub.3 and air (and/or O.sub.2) is combined
with the samarium cobalt magnet powder to selectively dissolve the
materials of the samarium cobalt magnet powder. For example, the
samarium cobalt magnet may comprise materials other than samarium
cobalt, including iron, copper, nickel, etc. The leaching vessel 14
dissolves these materials with the (NH.sub.4).sub.2CO.sub.3 and
air/O.sub.2 and transfers the solution to a filter 16. Iron and/or
samarium are removed from the solution and come out as solids. The
filtrate from filter 16 is transferred to an electrowinning cell 18
comprising a cathode and an anode (not shown).
[0024] The electrowinning cell 18 performs an electrowinning (also
called an electroextraction) on the filtrate from the filter 16,
which results in the electrodeposition of metals, such as cobalt,
copper, nickel, and the like, from the filtrate on the cathode. In
some embodiments, this electrodeposition may be a
selective/repetitive process. For example, the anode may initiate
with a relatively low voltage such that copper from the filtrate
may be deposited on the cathode. Then, the anode and the cathode
may be removed such that the copper may be recovered. The anode and
the cathode may then operate on the filtrate by applying a higher
voltage on the anode to extract cobalt from the filtrate on the
cathode. This process may repeat until all of the desired metals
had been recovered from the filtrate.
[0025] FIG. 2 is a flowchart of an exemplary process 50 of the
system 10 of FIG. 1. In this embodiment, a permanent magnet
material is converted to a higher surface area form, such as a
powder, in the process element 52. For example, the
milling/grinding module 12 may grind a samarium cobalt magnet feed
into a powder. Then, the feed may be treated with an aqueous
solution of ammonium carbonate to form a mixture that includes the
dissolved cobalt, in the process element 54. For example,
(NH.sub.4).sub.2CO.sub.3 and air/O.sub.2 may be added to a sealed
leaching vessel 14 to selectively dissolve the metals within the
powder. Then, the filter 16 may filter the mixture to yield a
filtrate, in the process element 56. In this regard, iron may be
filtered out of the mixture and output from the system 10 as iron
solids. The remaining portion of the mixture may then be
transferred to the electrowinning cell 18 such that the cobalt in
the filtrate may be electroplated onto a cathode, in the process
element 58. Again, other metals may be selectively recovered in
this electroplating step via the adjustment of voltage and/or
amperage in the electroplating process.
[0026] Based on the foregoing, the system 10 is any device, system,
software, or combination thereof operable to convert a samarium
cobalt permanent magnet into a higher surface area form such that
cobalt and/or other metals may be extracted for reuse. Other
exemplary embodiments are shown and described below.
[0027] While this embodiment illustrates one exemplary process for
extracting cobalt from a permanent magnet material feed, the
embodiments may also be operable to extract other metals, such as
iron, copper, nickel, etc. from the permanent magnet material feed.
In some embodiments, the system 10 may be operable to extract
cobalt from various forms of ore materials that have been mined
and/or are a result of manufacturing waste. Additionally, the
processing and extraction of the materials described herein are not
intended to be limited to materials mined or manufactured on earth.
Rather, the materials described herein may be extracted from ore
material mined from various planets, moons, asteroids, and the
like.
[0028] Experimental
[0029] Although the following exemplary experimental procedures are
described in detail, they are illustrative and non-limiting. Two
different starting magnet materials were used for the research.
Samarium cobalt disc magnets (3/8'' diameter.times.1/8'' thick,
SMCO-D5) were used and crushed in a hydraulic press prior to use.
This resulted in a collection of magnetic particles which were used
without further preparation. Alternate preparation methods and
demagnetization were investigated and will be described where
appropriate. Samarium cobalt cutting swarf submerged in an impure
aqueous fluid was received as a smooth powder/paste from a
manufacturer. 110.0 g of the wet swarf was filtered, washed with
distilled water (400 mL), and allowed to dry in a Buchner funnel
under vacuum filtration. The mass of solid remaining was 82.6 g or
75.1%. This partially dried sample was then placed in a ceramic
dish and heated to 120.degree. C. in a furnace for 2 hours. After
cooling to room temperature, the final mass was 70.8 g. This
material was used in leaching experiments without further
processing. In some experiments, oxidized magnet material was used
instead of the alloys. In this case, the material was heated to
850.degree. C. in a muffle furnace for 8 hours (ramp rate:
10.degree. C./min) prior to use. The sintered material was then
lightly ground using a glass mortar and pestle to further break up
any agglomerated particles. X-ray fluorescence (XRF) analysis was
performed at Pioneer Astronautics using a Rigaku NEX-DE
Energy-Dispersive XRF spectrometer with a silicon photodetector and
a 60 kV sealed-tube source. A fundamental parameters measurement
method was used for all samples. As this measurement is sensitive
to elements from Na--U, all XRF results are given as mass % of a
specific element out of the total mass of all detectable elements.
So, even if the metals were most likely present as oxides, the
analytical results will give relative amounts of one metal to
another. Powder samples were placed in polypropylene sample cups or
microsample cups and tamped by hand to create a packed powder.
Liquid samples were analyzed by adding 4 g to a sample cup and
running a manufacturer-installed method.
Experiment 1: General
[0030] 1 gram (2.5 g/L) of crushed magnets was added to a 500 mL
round-bottom flask along with a magnetic stir bar and 400 mL of 1.6
molar (NH.sub.4).sub.2CO.sub.3. Some of the magnet powder was
attracted to the stir bar, but while stirring vigorously, the
liquid became cloudy and it was clear that a suspension was
obtained. The suspension was stirred for 3 days at room temperature
and left open to ambient air during which it turned a dark purple
hue. Upon filtering the suspension, a purple solution and a brown
solid fraction were obtained with the solid fraction composed
primarily of iron and samarium. The purple solution was heated at
120.degree. C. to evaporate water and decompose ammonium carbonate
into ammonia, carbon dioxide, and water which then were evolved as
gasses. The remaining solids were composed of 83% cobalt and
yielded a mass of cobalt equivalent to 100% of the initial cobalt
in the magnets.
Experiment 2: Recycled Leach Solution
[0031] 1 gram of crushed magnets was leached as outlined in
Experiment 1, but the process was performed in a nitrogen
atmosphere instead of being open to air. The solids collected at
the end of the experiment were composed of 87% cobalt and yielded a
mass of cobalt equivalent to 18% of the initial cobalt in the
magnets.
Experiment 3:
[0032] 40 mL of the filtrate obtained from Experiment 1 were added
to a 50 mL beaker and a nickel plate anode and a carbon plate
cathode were placed in the solution and separated by a distance of
one inch. A controlled potential of 2.5 V was applied across the
electrodes while the solution was magnetically stirred for two
hours. Afterward, the cathode was removed and found to have plated
a copper-colored solid with a mass of 23 mg and was found to be
composed of 80% copper, 18.4% cobalt, and 0.6% iron via XRF
analysis. A new, identical cathode was placed in the solution,
electrically connected as before, and a controlled current of 300
mA was passed while the voltage was allowed to float. After 40
minutes, the cathode was removed, rinsed with distilled water, and
allowed to dry. The cathode was found to have a dark coating with a
mass of 82 mg and was found to be composed of 93.3% cobalt, 4.3%
nickel, 1.1% iron, and 0.8% copper. The remaining solution was
found to have a pH of 9.4, largely unchanged from the starting
value of 9.2.
Experiment 4:
[0033] 2 g (5 g/L) of samarium cobalt magnet swarf was added to a
500 mL round-bottom flask along with a magnetic stir bar and 400 mL
of 1.6 molar (NH.sub.4).sub.2CO.sub.3. Some of the magnet powder
was attracted to the stir bar, but while stirring vigorously, the
liquid became cloudy, and it was clear that a suspension was
obtained. The suspension was stirred for 48 hours at room
temperature and left open to ambient air during which it turned a
dark purple hue. Upon filtering the suspension, a purple solution
and a brown solid fraction were obtained. The solids were found to
be composed of 48.0% iron, 41.1% samarium, 8.8% cobalt, and 1.4%
zirconium, likely as either oxides or carbonates. The purple
solution was analyzed and found to contain dissolved metals as 85%
cobalt, 8% copper, 3% zirconium, 2% iron, and 2% samarium.
Experiment 5:
[0034] A hydrothermal experiment was conducted in a 50 mL autoclave
reactor with a PTFE liner and a pressure limit of 870 psia. 15 mL
of distilled water, 10 mL of 34% hydrogen peroxide solution, and 5
g of ammonium carbonate were added to the autoclave reactor along
with 1 g of crushed samarium cobalt magnets. The sealed reactor was
then placed into a muffle furnace and heated to 130.degree. C. at a
rate of 10.degree. C./min and held at that temperature for 16
hours, resulting in an estimated pressure inside the vessel of
greater than 300 psia. The reactor was then allowed to cool to room
temperature prior to opening the reactor. Upon opening, the reactor
contents were filtered, and the filtrate was completely evaporated
at 120.degree. C. to isolate the dissolved solids as a residue.
This residue was calcined at 850.degree. C. for eight hours and
washed with distilled water to remove soluble salts prior to
analysis using Scanning Electron Microscopy/Energy Dispersive X-Ray
Spectroscopy (SEM/EDS) by a commercial analytical lab. 13 percent
of the initial cobalt was recovered in the final product which was
81% cobalt. The concentration of dissolved solids was estimated as
13 g/L, far in excess of what was obtained in the alternate
approaches described above.
[0035] Any of the above embodiments herein may be rearranged and/or
combined with other embodiments. Accordingly, the concepts herein
are not to be limited to any particular embodiment disclosed
herein. Additionally, the embodiments can take the form of entirely
hardware or comprising both hardware and software elements.
Portions of the embodiments may be implemented in software, which
includes but is not limited to firmware, resident software,
microcode, etc. For example, software may be used to control
various reactions, processes, and hardware (e.g., pumps, reactors,
condensers, etc.) presented herein. FIG. 3 illustrates one
exemplary computing system 500 in which a computer readable medium
506 may provide instructions for performing any of the methods
disclosed herein.
[0036] Furthermore, the embodiments can take the form of a computer
program product accessible from the computer readable medium 506
providing program code for use by or in connection with a computer
or any instruction execution system. For the purposes of this
description, the computer readable medium 506 can be any apparatus
that can tangibly store the program for use by or in connection
with the instruction execution system, apparatus, or device,
including the computer system 500.
[0037] The medium 506 can be any tangible electronic, magnetic,
optical, electromagnetic, infrared, or semiconductor system (or
apparatus or device). Examples of a computer readable medium 506
include a semiconductor or solid state memory, magnetic tape, a
removable computer diskette, a random access memory (RAM), NAND
flash memory, a read-only memory (ROM), a rigid magnetic disk and
an optical disk. Some examples of optical disks include compact
disk--read only memory (CD-ROM), compact disk--read/write (CD-R/W)
and digital versatile disc (DVD).
[0038] The computing system 500, suitable for storing and/or
executing program code, can include one or more processors 502
coupled directly or indirectly to memory 508 through a system bus
510. The memory 508 can include local memory employed during actual
execution of the program code, bulk storage, and cache memories
which provide temporary storage of at least some program code in
order to reduce the number of times code is retrieved from bulk
storage during execution. Input/output or I/O devices 504
(including but not limited to keyboards, displays, pointing
devices, etc.) can be coupled to the system either directly or
through intervening I/O controllers. Network adapters may also be
coupled to the system to enable the computing system 500 to become
coupled to other data processing systems, such as through host
systems interfaces 512, or remote printers or storage devices
through intervening private or public networks. Modems, cable modem
and Ethernet cards are just a few of the currently available types
of network adapters.
VARIOUS EMBODIMENTS
[0039] In one embodiment, a Cobalt Extraction and Recycling from
Permanent Magnets (CERPM) process recovers cobalt and other
valuable metal elements from samarium cobalt magnets.
[0040] In one embodiment, the CERPM process recovers cobalt and
other valuable metal elements from partially or fully oxidized
samarium cobalt magnets.
[0041] In one embodiment, the CERPM process recovers copper as a
co-product.
[0042] In one embodiment, the CERPM process recovers nickel as a
co-product.
[0043] In one embodiment the CERPM process recovers cobalt, copper,
or nickel from manufacturing wastes such as cutting swarf in which
oxidation of the alloy may have occurred.
[0044] In one embodiment the CERPM process recovers cobalt and
other valuable metal elements as high-quality feed stock to support
manufacture of new high-performance magnets. The product metals may
be combined with fresh material in any proportion to alter or
enhance the magnetic properties.
[0045] In one embodiment, the cobalt metal product may be used as a
high-quality feed stock for battery production.
[0046] In one embodiment, the cobalt metal product may be sold as a
commodity to manufacturers or end-users.
[0047] In one embodiment of the process, a mechanical crushing
pre-treatment is used to increase the surface area and partially
demagnetize the starting material.
[0048] In one embodiment of the process, a hydraulic press is used
to crush the starting material.
[0049] In another embodiment, pretreatment may include further
grinding or milling of the brittle magnet material to open
additional surface area.
[0050] In other embodiments, additional pretreatment may be applied
to adjust the oxidation state prior to extraction using chemical,
electrical, or other oxidation or reduction methods.
[0051] In one embodiment of the process, pretreatment of magnet
powders by exposure to air at temperatures up to 1500.degree. C. to
oxidize magnet powder prior to extraction.
[0052] In one embodiment of the process, pretreatment of magnet
powders heating in an oxygen-free atmosphere above the Curie
temperature to demagnetize magnet powder prior to extraction. This
may be up to 1500.degree. C. for typical applications, or higher
for specific feeds.
[0053] In one embodiment of the process, pretreatment of magnet
powders by exposure to hydrogen at temperatures up to 1500.degree.
C. to reduce cobalt and other oxides to metal prior to
extraction.
[0054] In one embodiment of the process, pretreatment of magnets by
exposure to hydrogen at high temperature or pressure to decompose
the phases to elemental or hydride forms.
[0055] In one embodiment of the process, pretreatment may include
demagnetization of the magnetic starting material using an
externally applied magnetic field or a shock treatment.
[0056] In one embodiment, a recoverable aqueous ammonium carbonate
leach solution is used to decompose permanent magnet alloy
compositions at low temperature and pressure into insoluble
precipitates and soluble metal complexes.
[0057] In one embodiment, the leach solution is composed of 1.6
molar ammonium carbonate.
[0058] In other embodiments, the leach solution is composed of
ammonia and ammonium carbonate in any proportion from 0.1 molar to
saturated.
[0059] In one embodiment, after selective recovery of constituents
from the mixture, the extraction solution is directly recycled.
[0060] In another embodiment, the extraction solution is heated to
release ammonia and carbon dioxide, which are recovered and then
recycled to the process.
[0061] In one embodiment, oxygen gas is used as an oxidant in the
leaching step.
[0062] In one embodiment, air is used as an oxidant in the leaching
step.
[0063] In one embodiment, a chemical oxidant such as hydrogen
peroxide is used as an oxidant in the leaching step.
[0064] In one embodiment, an inert atmosphere is used in the
leaching step.
[0065] In one embodiment, hydrogen gas or another chemical
reductant is used in the leaching step.
[0066] In one embodiment, the extraction process is typically
carried out at ambient temperature.
[0067] In one embodiment, the extraction process is typically
carried out at temperatures between ambient and 60.degree. C.
[0068] In one embodiment, the extraction process is typically
carried out at temperatures above 60.degree. C. and at pressure
greater than 1 atmosphere.
[0069] In one embodiment, the extraction process is typically
carried out at temperatures above 100.degree. C. and at pressure
greater than 1 atmosphere.
[0070] In one embodiment, the extraction process is typically
carried out in vessels constructed of stainless-steel without any
lining.
[0071] In one embodiment, the extraction process is typically
carried out in vessels composed of or lined with glass.
[0072] In one embodiment, the extraction process is typically
carried out in vessels composed of or lined with
polytetrafluoroethylene (PTFE).
[0073] In other embodiments, the extraction process is typically
carried out in vessels composed of or lined with a corrosion
barrier that does not react with the mixture.
[0074] In one embodiment of the process, CO.sub.2 is added to the
filtrate to precipitate some of the dissolved compounds prior to
further processing.
[0075] In one embodiment of the process, addition of a base to the
filtrate causes precipitation of dissolved cobalt.
[0076] In one embodiment of the process, addition of an acid to the
filtrate causes precipitation of dissolved cobalt.
[0077] In one embodiment of the process, addition of either an acid
or a base to the filtrate causes precipitation of dissolved iron or
another base metal.
[0078] In one embodiment of the process, CO.sub.2, air, oxygen,
hydrogen peroxide, etc. is used to change the Eh of the filtrate
and cause precipitation of the cobalt or dissolved iron.
[0079] In one embodiment of the process, heat, steam, or
evaporation is employed to cause precipitation of dissolved
compounds from the filtrate.
[0080] In one embodiment of the process, a reagent such as a sulfur
compound is added to the filtrate to form an insoluble cobalt
species.
[0081] In one embodiment, the electrochemical reactor consists of
two electrodes in a single chamber.
[0082] In another embodiment, the electrochemical reactor consists
of two electrodes in two separate chambers.
[0083] In another embodiment, the electrochemical reactor consists
of two electrodes separated by a membrane which allows some but not
all components to pass through.
[0084] In another embodiment, a third or fourth electrode is used
as a reference electrode.
[0085] In one embodiment, the potential is held constant throughout
the electrowinning step.
[0086] In another embodiment, the current passed is held constant
throughout the electrowinning step.
[0087] In another embodiment, the potential or current are varied
or swept following a programmed pattern throughout the
electrowinning step.
[0088] In one embodiment, the anode is composed of nickel and the
cathode is composed of carbon.
[0089] In other embodiments, the anode or cathode may be composed
of any conductive material.
[0090] In another embodiment, the anode or cathode may be prepared
or structured to increase the surface area, increase the rate of
the desired reaction, or limit the rate of undesired reactions.
[0091] In another embodiment, additional chemicals may be added to
the solution to improve the quality of the plating.
[0092] In another embodiment, additional chemicals may be added to
improve the reaction kinetics of oxygen evolution at the anode.
[0093] In another embodiment, additional chemicals are added to
slow the hydrogen evolution reaction at the cathode.
[0094] In one embodiment, copper metal or another coproduct is
plated prior to plating cobalt.
[0095] In another embodiment, copper, cobalt, and/or other
dissolved metal compounds are co-plated on an electrode.
[0096] In one embodiment of the process, direct recycle of ammonium
carbonate and/or ammonia is done after precipitation of solids.
[0097] In one embodiment of the process, multiple extraction stages
are employed to further separate cobalt from iron or other
contaminants.
[0098] In one embodiment of the process, additives for leaching or
precipitation are recovered and reused.
[0099] In one embodiment, the solution is heated after
electrowinning cobalt to evolve ammonia and carbon dioxide for
capture and reuse.
[0100] In one embodiment of the process, the process feed is
obtained from an asteroid, the moon, Mars, or other
extraterrestrial resources.
[0101] In situ resource utilization (ISRU) may be generally defined
as the collection, processing, storing and use of materials
encountered in the course of human or robotic terrestrial or space
exploration that replace materials that would otherwise be brought
from a remote location such as another geographic location or
another planet or location in space.
[0102] In some embodiments, the process employs ISRU leveraging
resources found or manufactured on other astronomical objects (the
Moon, Mars, asteroids, etc.) to fulfill or enhance the requirements
and capabilities of a space or terrestrial mission.
[0103] In other embodiments, the process is useful in recovering
cobalt, rare-earth, and/or precious metals from an asteroid and
other extra-terrestrial site such as planet Mars or the moon.
[0104] In one embodiment, the process is used in asteroid mining to
recover valuable cobalt, rare-earth metals, and precious
metals.
* * * * *