Processing of cobaltous sulfate / cobaltous dithionate solutions derived from cobalt sources.

Abstract

To provide a method for processing cobaltous sulphate / dithionate liquors derived from cobalt resource.SOLUTION: There is provided a process for water removal and / or recycling of sodium sulphate and / or sodium dithionate containing liquors derived from processing a cobalt resource derived from components of lithium ion batteries comprising the steps of: deriving a solution containing cobalt sulphate and cobalt dithionate from the cobalt resource; precipitating cobalt as cobaltous carbonate or cobaltous hydroxide followed by removal thereof from the liquor; crystallizing sodium sulphate and sodium dithionate and removing resulting crystals followed by heating the crystals to anhydrous sodium sulphate, sulfur dioxide and water; and then separating the anhydrous sodium sulphate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application is a continuation-in-part of co-pending application Ser. No. 15 / 806,183, and claims priority to Provisional Application No. 62 / 421,139, filed Nov. 11, 2016. This invention relates to the recovery of water and sulfate from sulfate- and dithionate-containing solutions, such as those derived from the hydrometallurgical processing of cobalt-containing source materials, such as cathode materials from lithium-ion batteries. The cathode materials from lithium-ion batteries may be wholly or partially bound to metallic aluminum and / or mixed with carbon and / or graphite derived from co-processing with the anode. and / or mixed with fluorinated compounds derived from co-processing with lithium ion battery electrolytes. [Background technology]

[0002] It is generally known that cobalt can be leached from source materials containing higher valent cobalt, such as cobalt(III) oxide, using a reducing agent such as sulfur dioxide in combination with sulfuric acid to yield cobaltous sulfate and cobaltous dithionate, as illustrated by the following reaction: Co2O3+SO2+H2SO4=2CoSO4+H2O

[0003] Co2O3+2SO2+H2SO4=2CoS2O6+H2O

[0004] Cobalt present in the cathode material of rechargeable lithium-ion batteries is in the trivalent state and is expected to be leached with sulfur dioxide and sulfuric acid. Lithium cobalt oxides such as LiCoO2, a common cathode material for high-energy lithium-ion batteries typically used in personal electronic devices, are expected to leach according to the following reaction:

[0005] 2LiCoO2+SO2+2H2SO4=Li2SO4+2CoSO4+2H2O

[0006] 2LiCoO2+3SO2+2H2SO4=Li2SO4+2CoS2O6+2H2O

[0007] 2LiCoO2+4SO2+2H2SO4=Li2S2O6+2CoS2O6+2H2O

[0008] Experimental studies carried out on the leaching of lithium cobalt oxide with sulfur dioxide and sulfuric acid confirmed that up to 100% extraction of lithium and cobalt was achieved and dithionite was detected in all leaching tests carried out.

[0003]

[0009] LiNi 0.33 Mn 0.33 Co 0.33 Lithium nickel manganese cobalt oxide, such as O2, is an emerging cathode material that has both high energy and high power output suitable for use in electric vehicles and is expected to be leached according to the following reaction:

[0010] 2LiNi 0.33 Mn 0.33 Co 0.33 O2+SO2+2H2SO4= Li2SO4+2(Ni,Co,Mn)SO4+2H2O

[0011] 2LiNi 0.33 Mn 0.33 Co 0.33 O2+3SO2+2H2SO4 =Li2SO4+ 2(Ni,Co,Mn)CoS2O6+2H2O

[0012] 2LiNi 0.33 Mn 0.33 Co 0.33 O2+4SO2+2H2SO4 =Li2S2O6 + 2(Ni,Co,Mn)S2O6 + 2H2O

[0013] (Ni,Co,Mn)SO4 and (Ni,Co,Mn)S2O6 are represents mixed metal sulfates and mixed metal dithionates.

[0004]

[0014] Leaching of lithium nickel manganese cobalt oxide with sulfur dioxide and sulfuric acid Experimental studies carried out on the material confirmed that up to 100% extraction of lithium, nickel, manganese and cobalt was achieved and dithionite was detected in all leaching tests carried out.

[0005]

[0015] LiNi 0.8 Co 0.15 Al 0.05 Lithium nickel oxide like O2 Iron aluminum oxide is another emerging cathode material that has both high energy and high power output suitable for use in electric vehicles and is expected to leach according to the following reaction:

[0016] 2LiNi 0.8 Co 0.15 Al 0.05 O2+SO2+2H2SO4=L i2SO4+2(Ni,Co,Al)SO4+2H2O

[0017] 2LiNi 0.8 Co 0.15 Al 0.05 O2+3SO2+2H2SO4= Li2SO4+2(Ni,Co,Al)CoS2O6+2H2O

[0018] 2LiNi 0.8 Co 0.15 Al 0.05 O2+4SO2+2H2SO4= Li2S2O6+2(Ni,Co,Al)S2O6+2H2O

[0019] (Ni,Co,Al)SO4 and (Ni,Co,Al)S2O6 are represents mixed metal sulfates and mixed metal dithionates.

[0006]

[0020] Leaching of lithium nickel manganese cobalt oxide with sulfur dioxide and sulfuric acid Experimental studies carried out on the material confirmed that extraction of up to 100% of lithium, nickel, cobalt and aluminium was achieved and dithionite was detected in all leaching tests carried out.

[0007]

[0021] Dithionite compatible, recovers water in an energy-efficient manner, and reduces CO2 There are no known prior art methods for recovering valuable metals from cobalt-containing spent lithium-ion battery cathode materials using reductive leaching with sulfur. U.S. Patent Publication No. 8,460,631 describes the treatment of a solution containing manganese sulfate and manganese dithionate, which also contains sodium sulfate and sodium dithionate. However, the invention does not disclose how to treat sodium sulfate and sodium dithionate together with cobaltous sulfate and cobaltous dithionate in the presence or absence of lithium sulfate and lithium dithionate. Furthermore, it has been discovered that a process that accommodates dithionate, recovers water, and recycles the treatment solution back to the leach solution in a locked cycle, when present, significantly improves lithium recovery. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent Publication No. 8,460,631 Summary of the Invention

[0009]

[0022] Thus, the present invention provides a method for producing sodium sulfate derived from the processing of a cobalt source. and a method for removing and / or recycling water from a sodium dithionite-containing solution, the method comprising the steps of: treating material derived from components of a lithium-ion battery to derive a cobalt source; mixing sulfur dioxide and sulfuric acid with the cobalt source to derive a solution containing cobalt sulfate and cobalt dithionate; precipitating the cobalt, in whole or in part, as cobaltous carbonate or cobaltous hydroxide, which is then removed, in whole or in part, from the solution by filtration; crystallizing the sodium sulfate and sodium dithionite to separate most of the sodium sulfate and sodium dithionite from the solution; heating the sodium sulfate and sodium dithionite crystals to form anhydrous sodium sulfate, sulfur dioxide, and water; and separating the anhydrous sodium sulfate from the sulfur dioxide and water. [Brief explanation of the drawings]

[0010]

[0023] 1 to 3 illustrate process flow sheets relating to the first embodiment of the present invention. "S" indicates the solid phase and "L" indicates the liquid phase. [Figure 1]

[0024] FIG. 1 illustrates a process flowsheet for a first embodiment for treating spent lithium cobalt oxide. [Figure 2]

[0025] FIG. 2 illustrates a process flowsheet for a first embodiment for treating spent lithium nickel manganese cobalt oxide. [Figure 3]

[0026] FIG. 3 illustrates a process flow sheet for a first embodiment for treating spent lithium nickel cobalt aluminum oxide. [Figure 4]

[0027] FIG. 4 illustrates a process flowsheet for a second embodiment for treating spent lithium cobalt oxide. [Figure 5]

[0028] FIG. 5 illustrates a process flowsheet for a second embodiment for treating spent lithium nickel manganese cobalt oxide. [Figure 6]

[0029] FIG. 6 illustrates a process flow sheet for a second embodiment for treating spent lithium nickel cobalt aluminum oxide. [Figure 7]

[0030] FIG. 7 illustrates a process flowsheet for a third embodiment for treating spent lithium cobalt oxide. [Figure 8]

[0031] FIG. 8 illustrates a process flowsheet for a third embodiment for treating spent lithium nickel manganese cobalt oxide. [Figure 9]

[0032] FIG. 9 illustrates a process flow sheet for a third embodiment for treating spent lithium nickel cobalt aluminum oxide. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0033] In accordance with the present invention, a lithium ion battery cathode material such as that recovered from the cathode material of the lithium ion battery is obtained. The present invention provides a hydrometallurgical treatment process for cobaltous sulfate and cobaltous dithionate-containing liquors derived from the sulfurous and sulfuric acid leaching of such cobalt(III) oxide-containing source materials.

[0012]

[0034] Regarding embodiment 1, reference is made to FIGS.

[0035] Cobaltous sulfate and cobaltous dithionate-containing solutions were treated with sodium carbonate. The mixture is then reacted to form cobaltous carbonate solids and a liquid containing sodium sulfate and sodium dithionite.

[0013]

[0036] Lithium sulfate and lithium dithionate, when present, are cobaltous carbonates. Along with the solids, lithium carbonate partially precipitates as a solid.

[0037] The cobaltous carbonate-containing solids and, if present, the lithium carbonate solids are filtered or The carbonate treatment solution is removed by centrifugation or by other suitable means.

[0014]

[0038] Washing the cobaltous carbonate-containing solid and, if present, the lithium carbonate solid, , removing soluble impurities and producing clean material for reuse, such as cathode material for lithium-ion batteries.

[0015]

[0039] Sodium sulfate and sodium dithionite, if present, with the remaining sulfuric acid The filtrate or centrate containing lithium and lithium dithionate together is treated in a crystallizer to crystallize the majority of the sodium sulfate and sodium dithionate crystals.

[0016]

[0040] Crystallization was carried out by precipitating sodium sulfate decahydrate and sodium dithionite dihydrate. This can be accomplished by cooling to precipitate (crystallize) or by multi-effect crystallization to precipitate (crystallize) anhydrous sodium sulfate and sodium dithionite.

[0017]

[0041] Sodium sulfate and sodium dithionite crystals were mixed with sodium dithionite crystals. The crystals are heated to a temperature sufficient to convert them to sodium sulfate and water for recyclable sulfur dioxide and cobalt source material leaching. The temperature at which sodium dithionite is converted to sodium sulfate and sulfur dioxide is described in Chow et al., "New Developments in the Recovery of Manganese from Lower-Grade Resources," Minerals & Metallurgical Processing, Vol. 29, No. 1, February 2012, pp. 70-71.

[0018]

[0042] Most of the sodium sulfate and sodium dithionite have been removed, If lithium was present in the source material, the crystallizer liquor, which contains lithium sulfate and lithium dithionate, is recycled to the leaching circuit to recover further previously unrecovered lithium and cobalt and to recycle water in an energy efficient manner.

[0019]

[0043] Alternatively, most of the sodium sulfate and sodium dithionite may be removed. In this case, a portion of the crystallizer liquor containing lithium sulfate and lithium dithionate, if lithium was present in the source material, is passed through a nanofiltration membrane to produce a water-rich, sulfate- and dithionate-free liquor output for recycle and a sodium sulfate and dithionate-free liquor output for recycle. Sodium sulfate and sodium dithionate concentrates and lithium sulfate and lithium dithionate can be produced for recycle to the sodium phosphate crystallizer.

[0020]

[0044] The precipitated cobalt and lithium-containing compounds are used to form cathodes for lithium-ion batteries. This is generally done by combining cobalt and lithium containing compounds in the desired ratios and subjecting the mixture to a heat treatment procedure. Jones et al. ("Li x CoO2(0 <x≦1): A New Cathode "Material for Batteries of High Energy Density", Solid State Ionics, 3 / 4, 1981, pp. 171-174) describe a method for producing lithium cobalt oxide cathode material by processing lithium and cobalt compounds. Lu et al. ("U.S. Patent Publication No. 8,685,565", April 2014) describe a method for producing lithium nickel manganese cobalt oxide by processing lithium, nickel, manganese, and cobalt compounds. Kim et al. ("Synthesis of High-Density Nickel Cobalt Aluminum Hydroxide by Continuous Coprecipitation Method", ACS Applied Materials & Interfaces, 4, 2012, pp. 586-589) describe a method for producing lithium nickel cobalt aluminum oxide by processing lithium, nickel, cobalt, and aluminum compounds. Commercial battery manufacturers typically develop and use their own proprietary processing methods to produce cathode materials for lithium-ion batteries.

[0021]

[0045] Cobaltous sulfate and cobaltous dithionate to give sodium sulfate and dithionite Conversion to sodium dithionite provides a novel method for treating dithionite, improving lithium recovery and recycling water in an energy-efficient manner.

[0022]

[0046] Regarding the second embodiment, reference is made to FIGS.

[0047] Cobaltous sulfate and cobaltous dithionate containing solutions were treated with sodium hydroxide. treating to form cobaltous hydroxide solids and a sodium sulfate and sodium dithionite containing liquid;

[0048] The cobaltous hydroxide-containing solid is filtered or centrifuged to obtain a hydroxide-treated solution. Remove from;

[0049] The cobaltous hydroxide-containing solid is washed to remove soluble impurities and to remove lithium ions. producing clean materials for reuse, such as cathode materials for lithium-ion batteries;

[0050] Sodium carbonate is added to the remaining solution, converting some of the lithium, if any, to carbonate. Precipitates as lithium;

[0051] The lithium carbonate solids are removed from the carbonate treatment solution by filtration or centrifugation. ;

[0052] Lithium carbonate solids are washed to remove soluble impurities and used for lithium-ion batteries. producing clean materials for reuse, such as cathode materials;

[0053] Sodium sulfate and sodium dithionite, if present, with the remaining sulfuric acid treating the filtrate or centrate containing lithium and lithium dithionate together in a crystallizer to crystallize most of the sodium sulfate and sodium dithionate crystals;

[0054] Crystallization was carried out by precipitating sodium sulfate decahydrate and sodium dithionite dihydrate. This can be done by cooling to precipitate (crystallize) or by multiple effect crystallization to precipitate (crystallize) anhydrous sodium sulfate and sodium dithionite;

[0055] Sodium sulfate and sodium dithionite crystals were mixed with sodium dithionite crystals. heating the crystals to a temperature sufficient to convert them to sodium sulfate and water for leaching a recyclable sulfur dioxide and cobalt source material;

[0056] Most of the sodium sulfate and sodium dithionite have been removed, If lithium was present in the source material, the crystallizer liquor, which contains lithium sulfate and lithium dithionate, is recycled to the leaching circuit to recover further previously unrecovered lithium and cobalt and to recycle water in an energy efficient manner.

[0023]

[0057] Alternatively, most of the sodium sulfate and sodium dithionite may be removed. In this case, a portion of the crystallizer liquor containing lithium sulfate and lithium dithionate if lithium was present in the source material can be passed through a nanofiltration membrane to produce a water-rich, sulfate- and dithionate-free liquor product for recycle, and a sodium sulfate and sodium dithionate concentrate for recycle to the sodium sulfate and sodium dithionate crystallizer and lithium sulfate and lithium dithionate if lithium was present in the source material.

[0024]

[0058] Regarding the third embodiment, reference is made to FIGS.

[0059] Treatment of cobaltous sulfate and cobaltous dithionate containing solutions with lithium hydroxide treating the cobaltous hydroxide to form a cobaltous hydroxide solid and a lithium sulfate and lithium dithionate containing liquid;

[0060] Lithium hydroxide is recovered from the previous operation in the flowsheet. Wietelmann et al. ("Lithium and Lithium Compounds", Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co, 2013, p. 24) describe a method for producing lithium hydroxide by reacting lithium carbonate with calcium hydroxide;

[0061] The cobaltous hydroxide-containing solid is filtered or centrifuged to obtain a hydroxide-treated solution. Remove from;

[0062] The cobaltous hydroxide-containing solid is washed to remove soluble impurities and to remove lithium ions. producing clean materials for reuse, such as cathode materials for lithium-ion batteries;

[0063] Sodium carbonate is added to the remaining solution, converting some of the lithium, if any, to carbonate. Precipitates as lithium;

[0064] The lithium carbonate solids are removed from the carbonate treatment solution by filtration or centrifugation. ;

[0065] Lithium carbonate solids are washed to remove soluble impurities and used for lithium-ion batteries. producing clean materials for reuse, such as cathode materials;

[0066] Sodium sulfate and sodium dithionite, if present, with the remaining sulfuric acid treating the filtrate or centrate containing lithium and lithium dithionate together in a crystallizer to crystallize most of the sodium sulfate and sodium dithionate crystals;

[0067] Crystallization was carried out by precipitating sodium sulfate decahydrate and sodium dithionite dihydrate. This can be done by cooling to precipitate (crystallize) or by multiple effect crystallization to precipitate (crystallize) anhydrous sodium sulfate and sodium dithionite;

[0068] Sodium sulfate and sodium dithionite crystals were mixed with sodium dithionite crystals. heating the crystals to a temperature sufficient to convert them to sodium sulfate and water for leaching a recyclable sulfur dioxide and cobalt source material;

[0069] Most of the sodium sulfate and sodium dithionite have been removed, If lithium was present in the source material, the crystallizer liquor, which contains lithium sulfate and lithium dithionate, is recycled to the leaching circuit to recover further previously unrecovered lithium and cobalt and to recycle water in an energy efficient manner.

[0025]

[0070] Alternatively, most of the sodium sulfate and sodium dithionite may be removed. In this case, a portion of the crystallizer liquor containing lithium sulfate and lithium dithionate can be passed through a nanofiltration membrane to produce a water-rich, sulfate- and dithionate-free liquor product for recycle, and sodium sulfate and sodium dithionate concentrates and lithium sulfate and lithium dithionate for recycle to the sodium sulfate and sodium dithionate crystallizer.

[0026]

[0071] The precipitated cobalt and lithium-containing compounds are used to form cathodes for lithium-ion batteries. It can be used to manufacture metal materials.

[0072] Regarding the first aspect of the lithium cobalt oxide treatment shown in FIG. The route is written as follows:

[0073] In the leaching reactor (12), spent lithium having the chemical formula LiCoO2 is The ion battery cathode material is combined and mixed with a solution containing SO2 and H2SO4 reagents, water, and optionally lithium and / or cobalt not recovered prior to the final step in the flowsheet. The lithium and cobalt dissolve in solution to produce a leach solution containing cobalt sulfate, cobalt dithionate, lithium sulfate, and lithium dithionate.

[0027]

[0074] The leach solution is transferred to a precipitation reactor (20) where sodium carbonate solution is added. and mixing to precipitate the cobalt and some of the dissolved lithium as cobalt carbonate and lithium carbonate solids, forming a solution containing primarily lithium sulfate, lithium dithionite, sodium sulfate, and sodium dithionite.

[0028]

[0075] The precipitation reaction occurs as follows:

[0076] CoSO4 + Na2CO3 = CoCO3 + Na2SO4 Almost complete conversion

[0077] CoS2O6 + Na2CO3 = CoCO3 + Na2S2O6 Almost complete conversion transformation

[0078] Li2SO4 + Na2CO3 = Li2CO3 + Na2SO4 partial conversion

[0079] Li2S2O6 + Na2CO3 = Li2CO3 + Na2S2O6 partially transformation

[0080] The slurry containing the mixture of solids and liquid is filtered (14) to obtain lithium carbonate. and cobalt carbonate is separated and rinsed to produce collected product (16).

[0029]

[0081] The filtrate is transferred to a crystallizer (18) where sodium sulfate and dithiocarbamate are added. A portion of the sodium is crystallized as solid crystals by multiple effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionite crystals are separated by centrifuge or filter ( The sodium sulfate and sodium dithionite crystals are collected from the solution using a crystallizer (22). The sodium sulfate and sodium dithionite crystals are heated to approximately 120°C (24) to decompose the sodium dithionite into sodium sulfate by-product and SO2, and the SO2 can be recycled to the leaching. The mother solution contains the remaining lithium sulfate, lithium dithionite, sodium sulfate, sodium dithionite, and water and is recycled back to the leaching (26) to minimize water consumption and maximize lithium recovery throughout the flowsheet. Alternatively, a portion of the mother solution can be treated by nanofiltration (28) to produce clean water (30) for rinsing the product, and the spent rinse water (32) can be reused back in the leaching. The concentrate from the nanofiltration (34) is recycled back to the crystallizer to maximize sodium sulfate recovery. The mixed collected lithium carbonate and cobalt carbonate product (16) is thermally treated (36) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium carbonate and / or cobalt carbonate may be added to the collected product to achieve the desired ratio of lithium to cobalt prior to heat treatment.

[0030]

[0082] Embodiment 1 of the Treatment of Lithium Nickel Manganese Cobalt Oxide as Shown in FIG. The flow sheet is as follows:

[0083] In the leaching reactor (40), a nitrate of formula LiNi- 0.33 Mn 0.33 Co 0.33 The spent lithium nickel manganese cobalt oxide cathode material with O2 is combined and mixed with a solution containing SO2 and H2SO4 reagents, water, and optionally lithium and / or nickel and / or manganese and / or cobalt not recovered prior to the final step in the flowsheet. The lithium, nickel, manganese, and cobalt dissolve in solution to produce a leach solution containing nickel manganese cobalt sulfate, nickel manganese cobalt dithionate, lithium sulfate, and lithium dithionate.

[0031]

[0084] The leach solution is transferred to the precipitation reactor (48), where sodium carbonate is added and mixed. Combined, the nickel, manganese, and cobalt and some of the dissolved lithium precipitate as nickel, manganese, cobalt, and lithium carbonate solids to form a solution containing primarily lithium sulfate, lithium dithionite, sodium sulfate, and sodium dithionite.

[0032]

[0085] The precipitation reaction occurs as follows:

[0086] (Ni,Mn,Co)SO4 + Na2CO3 = (Ni,Mn,Co)CO3 + Na2SO4 Almost complete conversion

[0087] (Ni,Mn,Co)S2O6+Na2CO3=(Ni,Mn,Co)CO3 +Na2S2O6 almost completely converted

[0088] Li2SO4 + Na2CO3 = Li2CO3 + Na2SO4 partial conversion

[0089] Li2S2O6 + Na2CO3 = Li2CO3 + Na2S2O6 partially transformation

[0090] The slurry containing the mixture of solids and liquid is filtered (42) to remove the lithium carbonate. and nickel manganese cobalt carbonate, which is then rinsed to form a collected product (44).

[0033]

[0091] The filtrate is transferred to a crystallizer (46) where sodium sulfate and dithiocarbamate are added. A portion of the sodium is crystallized as solid crystals by multi-effect crystallization or cooling crystallization. Solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (50). The sodium sulfate and sodium dithionate crystals are heated to approximately 120°C (52) to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to leaching. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to leaching (54) to minimize water consumption and maximize lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (56) to produce clean water for rinsing the product (58), and the spent rinse water (60) can be recycled back to leaching. The concentrate (62) from nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The mixed collected product (44) of lithium carbonate and nickel manganese cobalt carbonate is heat treated (64) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium, nickel, manganese and / or cobalt compounds may be added to the collected product to achieve the desired ratio of lithium, nickel, manganese and cobalt prior to heat treatment.

[0034]

[0092] The treatment state of lithium nickel cobalt aluminum oxide shown in FIG. For Scheme 1, the flowsheet is as follows:

[0093] In the leaching reactor (70), a leachate of, for example, the formula LiNi 0.8 Co 0.15 Al 0.05 The spent lithium nickel cobalt aluminum oxide cathode material with O is combined and mixed with a solution containing SO and HSO reagents, water, and optionally lithium and / or nickel and / or cobalt and / or aluminum not recovered prior to the final step in the flowsheet. The lithium, nickel, cobalt, and aluminum dissolve in the solution to produce a leach solution containing nickel cobalt aluminum sulfate, nickel cobalt aluminum dithionate, lithium sulfate, and lithium dithionate.

[0035]

[0094] The leach solution is transferred to a precipitation reactor (78) where sodium carbonate is added and mixed. Combined, the nickel, cobalt, and aluminum and some of the dissolved lithium precipitate as nickel, cobalt, aluminum, and lithium carbonate solids to form a solution containing primarily lithium sulfate, lithium dithionite, sodium sulfate, and sodium dithionite.

[0036]

[0095] The precipitation reaction occurs as follows:

[0096] (Ni,Co,Al)SO4+Na2CO3=(Ni,Co,Al)CO3+ Na2SO4 almost completely converted

[0097] (Ni,Co,Al)S2O6+Na2CO3=(Ni,Co,Al)CO3 +Na2S2O6 almost completely converted

[0098] Li2SO4 + Na2CO3 = Li2CO3 + Na2SO4 partial conversion

[0099] Li2S2O6 + Na2CO3 = Li2CO3 + Na2S2O6 partially transformation [000100] The slurry containing the mixture of solids and liquids is filtered (72) to separate the lithium carbonate and nickel cobalt aluminum carbonate, which is rinsed to produce collected product (74).

[0037] [000101] The filtrate is transferred to a crystallizer (76), where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (80). The sodium sulfate and sodium dithionate crystals are heated to approximately 120°C (82) to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to the leaching. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to the leaching (84), minimizing water consumption and maximizing lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (86) to produce clean water (88) for rinsing the product, and the used rinse water (90) can be recycled back to the leaching. The concentrate (92) from the nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The mixed collected product (74) of lithium carbonate and nickel cobalt aluminum carbonate is heat treated (94) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium, nickel, cobalt, and / or aluminum compounds may be added to the collected product to achieve the desired ratio of lithium, nickel, cobalt, and aluminum prior to heat treatment.

[0038] [000102] Regarding embodiment 2 for the processing of lithium cobalt oxide shown in Figure 4, the flowsheet is described as follows: [000103] In leaching reactor (100), spent lithium ion battery cathode material having the formula LiCoO2 is combined and mixed with SO2 and H2SO4 reagents, and a solution containing water and, optionally, lithium and / or cobalt not recovered prior to the final step in the flowsheet. The lithium and cobalt dissolve in solution to produce a leach solution containing cobalt sulfate, cobalt dithionate, lithium sulfate, and lithium dithionate.

[0039] [000104] The leach solution is transferred to a precipitation reactor (108) where sodium hydroxide is added and mixed to selectively precipitate cobalt as cobalt hydroxide, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0040] [000105] The precipitation reaction occurs as follows: [000106] CoSO4 + 2NaOH = Co(OH)2 + Na2SO4 almost completely converted [000107] CoS2O6 + 2NaOH = Co(OH)2 + Na2S2O6 almost completely converted [000108] The slurry containing the mixture of solids and liquids is filtered (102) to separate the cobalt hydroxide, which is rinsed to produce a collected product (104).

[0041] [000109] The filtered solution is transferred to a second precipitation reactor (106) where sodium carbonate is added and mixed to precipitate a portion of the dissolved lithium as lithium carbonate solid, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0042] [000110] The slurry containing the mixture of solids and liquids is filtered (118) to separate the lithium carbonate, which is rinsed to produce a collected product (120). [000111] The filtrate is transferred to a crystallizer (114), where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (116). The sodium sulfate and sodium dithionate crystals are heated (110) to approximately 120°C to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to the leaching. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to the leaching (112), minimizing water consumption and maximizing lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (122) to produce clean water (124) for rinsing the product, and the spent rinse water (126, 128) can be recycled back to the leaching. The concentrate (130) from the nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The collected product of lithium carbonate (120) and cobalt hydroxide (104) is mixed with the desired ratio of lithium and cobalt and heat treated (132) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium and / or cobalt compounds may be added to the collected product to achieve the desired ratio of lithium and cobalt prior to heat treatment.

[0043] [000112] Regarding embodiment 2 for the processing of lithium nickel manganese cobalt oxide shown in Figure 5, the flow sheet is described as follows: [000113] In the leaching reactor (140), a leachate of, for example, the formula LiNi- 0.33 Mn 0.3 3Co 0.33The spent lithium nickel manganese cobalt oxide cathode material with O2 is combined and mixed with a solution containing SO2 and H2SO4 reagents, water, and optionally lithium and / or nickel and / or manganese and / or cobalt not recovered prior to the final step in the flowsheet. The lithium, nickel, manganese, and cobalt dissolve in solution to produce a leach solution containing nickel manganese cobalt sulfate, nickel manganese cobalt dithionate, lithium sulfate, and lithium dithionate.

[0044] [000114] The leach solution is transferred to a precipitation reactor (148) where sodium hydroxide is added and mixed to selectively precipitate nickel, manganese, and cobalt as nickel manganese cobalt hydroxides, forming a solution containing primarily lithium sulfate, lithium dithionite, sodium sulfate, and sodium dithionite.

[0045] [000115] The precipitation reaction occurs as follows: [000116] (Ni,Mn,Co)SO4 + 2NaOH = (Ni,Mn,Co)(OH)2 + Na2SO4 almost completely converted [000117] (Ni,Mn,Co)S2O6 + 2NaOH = (Ni,Mn,Co)(OH)2 + Na2S2O6 almost completely converted [000118] The slurry containing the mixture of solids and liquids is filtered (142) to separate the nickel manganese cobalt hydroxide, which is rinsed to produce a collected product (144).

[0046] [000119] The filtered solution is transferred to a second precipitation reactor (146) where sodium carbonate is added and mixed to precipitate a portion of the dissolved lithium as lithium carbonate solid, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0047] [000120] The slurry containing the mixture of solids and liquids is filtered (158) to separate the lithium carbonate, which is rinsed to produce a collected product (160). [000121] The filtrate is transferred to a crystallizer (154), where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (156). The sodium sulfate and sodium dithionate crystals are heated (150) to approximately 120°C to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to the leaching. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to the leaching (152), minimizing water consumption and maximizing lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (162) to produce clean water (164) for rinsing the product, and the used rinse water (166, 168) can be recycled back to the leaching. The concentrate (170) from the nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The collected product of lithium carbonate (160) and nickel manganese cobalt hydroxide (144) is mixed with desired ratios of lithium, nickel, manganese, and cobalt and heat treated (172) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium, nickel, manganese, and / or cobalt compounds may be added to the collected product to achieve the desired ratio of lithium, nickel, manganese, and cobalt prior to heat treatment.

[0048] [000122] Regarding embodiment 2 for the processing of lithium nickel cobalt aluminum oxide shown in Figure 6, the flow sheet is described as follows: [000123] In the leaching reactor (180), for example, 0.8 Co 0.15 Al 0.05The spent lithium nickel cobalt aluminum oxide cathode material with O is combined and mixed with a solution containing SO and HSO reagents, water, and optionally lithium and / or nickel and / or cobalt and / or aluminum not recovered prior to the final step in the flowsheet. The lithium, nickel, cobalt, and aluminum dissolve in the solution to produce a leach solution containing nickel cobalt aluminum sulfate, nickel cobalt aluminum dithionate, lithium sulfate, and lithium dithionate.

[0049] [000124] The leach solution is transferred to a precipitation reactor (188) where sodium hydroxide is added and mixed to selectively precipitate nickel, cobalt, and aluminum as nickel cobalt aluminum hydroxide, forming a solution containing primarily lithium sulfate, lithium dithionite, sodium sulfate, and sodium dithionite.

[0050] [000125] The precipitation reaction occurs as follows: [000126] (Ni,Co,Al)SO4 + 2NaOH = (Ni,Co,Al)(OH)2 + Na2SO4 almost completely converted [000127] (Ni,Co,Al)S2O6 + 2NaOH = (Ni,Co,Al)(OH)2 + Na2S2O6 almost completely converted [000128] The slurry containing the mixture of solids and liquids is filtered (182) to separate the nickel cobalt aluminum hydroxide, which is rinsed to produce a collected product (184).

[0051] [000129] The filtered solution is transferred to a second precipitation reactor (186) where sodium carbonate is added and mixed to precipitate a portion of the dissolved lithium as lithium carbonate solid, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0052] [000130] The slurry containing the mixture of solids and liquids is filtered (198) to separate the lithium carbonate, which is rinsed to produce a collected product (200). [000131] The filtrate is transferred to a crystallizer (194), where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (196). The sodium sulfate and sodium dithionate crystals are heated (190) to approximately 120°C to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to the leaching. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to the leaching (192), minimizing water consumption and maximizing lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (202) to produce clean water (204) for rinsing the product, and the used rinse water (206, 208) can be recycled back to the leaching. The concentrate (210) from the nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The collected product of lithium carbonate (200) and nickel cobalt aluminum hydroxide (184) is mixed with the desired ratios of lithium, nickel, cobalt, and aluminum and heat treated (212) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium, nickel, cobalt, and / or aluminum compounds are added to the collected product to achieve the desired ratios of lithium, nickel, cobalt, and aluminum prior to heat treatment. A good ratio may be achieved.

[0053] [000132] With respect to embodiment 3 for the processing of lithium cobalt oxide shown in Figure 7, the flowsheet is set out as follows: [000133] In leaching reactor (220), spent lithium-ion battery cathode material having the formula LiCoO2 is combined and mixed with SO2 and H2SO4 reagents, and a solution containing water and, optionally, lithium and / or cobalt not recovered prior to the final step in the flowsheet. The lithium and cobalt dissolve in solution to produce a leach solution containing cobalt sulfate, cobalt dithionate, lithium sulfate, and lithium dithionate.

[0054] [000134] The leach solution is transferred to a precipitation reactor (228) where lithium hydroxide is added and mixed to selectively precipitate cobalt as cobalt hydroxide, forming a solution containing primarily lithium sulfate and lithium dithionate.

[0055] [000135] The precipitation reaction occurs as follows: [000136] CoSO4 + 2LiOH = Co(OH)2 + Li2SO4 almost completely converted [000137] CoS2O6 + 2LiOH = Co(OH)2 + Li2S2O6 almost completely converted [000138] The slurry containing the mixture of solids and liquids is filtered (222) to separate the cobalt hydroxide, which is rinsed to produce a collected product (224).

[0056] [000139] The filtered solution is transferred to a second precipitation reactor (226) where sodium carbonate is added and mixed to precipitate a portion of the dissolved lithium as lithium carbonate solid, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0057] [000140] The slurry containing the mixture of solids and liquids is filtered (238) to separate the lithium carbonate, which is then rinsed (240). A portion of the lithium carbonate is collected as product (242). The remaining portion of the lithium carbonate is further mixed (244) with calcium hydroxide to produce a slurry containing dissolved lithium hydroxide and solid calcium carbonate. The slurry is filtered (246) to separate the calcium carbonate solids from the lithium hydroxide solution, which is reused to precipitate cobalt compounds (228).

[0058] [000141] The filtrate from the second filter (238) is transferred to a crystallizer (234) where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (236). The sodium sulfate and sodium dithionate crystals are heated (230) to approximately 120°C to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to the leach. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to the leach (232), minimizing water consumption and maximizing lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (248) to produce clean water (250) for rinsing the product, with the spent rinse water (252, 254) recycled back into the leaching. The concentrate (256) from the nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The collected product of lithium carbonate (242) and cobalt hydroxide (224) is mixed with the desired ratio of lithium and cobalt and heat treated (258) to produce new cathode compounds for use in lithium-ion batteries. If necessary, additional lithium and / or cobalt compounds can be added to the collected product to increase the lithium and cobalt content prior to heat treatment. The desired ratio of copper and cobalt may be achieved.

[0059] [000142] Regarding embodiment 3 for the processing of lithium nickel manganese cobalt oxide shown in Figure 8, the flow sheet is described as follows: [000143] In the leaching reactor (270), a nitrate solution containing, for example, a compound of the formula LiNi- 0.33 Mn 0.3 3Co 0.33 The spent lithium nickel manganese cobalt oxide cathode material with O2 is combined and mixed with SO2 and H2SO4 reagents, and a solution containing water and, optionally, lithium and / or nickel and / or manganese and / or cobalt not recovered prior to the final step in the flowsheet. The lithium, nickel, manganese, and cobalt dissolve in solution to produce a leach solution containing nickel manganese cobalt sulfate, nickel manganese cobalt dithionate, lithium sulfate, and lithium dithionate.

[0060] [000144] The leach solution is transferred to a precipitation reactor (278) where lithium hydroxide is added and mixed to selectively precipitate nickel, manganese, and cobalt as nickel manganese cobalt hydroxides, forming a solution containing primarily lithium sulfate and lithium dithionate.

[0061] [000145] The precipitation reaction occurs as follows: [000146] (Ni,Mn,Co)SO4 + 2LiOH = (Ni,Mn,Co)(OH)2 + Li2SO4 almost completely converted [000147] (Ni,Mn,Co)S2O6 + 2LiOH = (Ni,Mn,Co)(OH)2 + Li2S2O6 almost completely converted [000148] The slurry containing the mixture of solids and liquids is filtered (272) to separate the nickel manganese cobalt hydroxide, which is rinsed to produce collected product (274).

[0062] [000149] The filtered solution is transferred to a second precipitation reactor (276) where sodium carbonate is added and mixed to precipitate a portion of the dissolved lithium as lithium carbonate solid, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0063] [000150] The slurry containing the mixture of solids and liquids is filtered (288) to separate the lithium carbonate, which is then rinsed (290). A portion of the lithium carbonate is collected as product (292). The remaining portion of the lithium carbonate is further mixed (294) with calcium hydroxide to produce a slurry containing dissolved lithium hydroxide and solid calcium carbonate. The slurry is filtered (296) to separate the calcium carbonate solids from the lithium hydroxide solution, which is reused to precipitate cobalt compounds (278).

[0064] [000151] The filtrate from the second filter (288) is transferred to a crystallizer (284) where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (286). The sodium sulfate and sodium dithionate crystals are heated (280) to approximately 120°C to decompose the sodium dithionate into sodium sulfate by-product and SO2, which can be recycled to the leach. The mother liquor contains the remaining lithium sulfate, lithium dithionate, sodium sulfate, sodium dithionate, and water and is recycled back to the leach (282), minimizing water consumption and maximizing lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (298) to produce clean water (300) for rinsing the product, and the spent rinse water (302, 304) can be reused back in the leaching. The concentrate (306) from the nanofiltration can be recycled back to the crystallizer to produce sodium sulfate. The collected product of lithium carbonate (292) and nickel manganese cobalt hydroxide (274) is mixed with desired ratios of lithium, nickel, manganese, and cobalt and heat treated (308) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium, nickel, manganese, and / or cobalt compounds may be added to the collected product to achieve the desired ratios of lithium, nickel, manganese, and cobalt prior to heat treatment.

[0065] [000152] With respect to embodiment 3 for the processing of lithium nickel cobalt aluminum oxide shown in Figure 9, the flow sheet is described as follows: [000153] In the leaching reactor (320), for example, 0.8 Co 0.15 Al 0.05 The spent lithium nickel cobalt aluminum oxide cathode material with O is combined and mixed with a solution containing SO and HSO reagents, water, and optionally lithium and / or nickel and / or cobalt and / or aluminum not recovered prior to the final step in the flowsheet. The lithium, nickel, cobalt, and aluminum dissolve in the solution to produce a leach solution containing nickel cobalt aluminum sulfate, nickel cobalt aluminum dithionate, lithium sulfate, and lithium dithionate.

[0066] [000154] The leach solution is transferred to a precipitation reactor (328) where lithium hydroxide is added and mixed to selectively precipitate nickel, cobalt, and aluminum as nickel cobalt aluminum hydroxide, forming a solution containing primarily lithium sulfate and lithium dithionate.

[0067] [000155] The precipitation reaction occurs as follows: [000156] (Ni,Co,Al)SO4 + 2LiOH = (Ni,Co,Al)(OH)2 + Li2SO4 almost completely converted [000157] (Ni,Co,Al)S2O6 + 2LiOH = (Ni,Co,Al)(OH)2 + Li2S2O6 almost completely converted [000158] The slurry containing the mixture of solids and liquids is filtered (322) to separate the nickel cobalt aluminum hydroxide, which is rinsed to produce a collected product (324).

[0068] [000159] The filtered solution is transferred to a second precipitation reactor (326) where sodium carbonate is added and mixed to precipitate a portion of the dissolved lithium as lithium carbonate solid, forming a solution containing primarily lithium sulfate, lithium dithionate, sodium sulfate, and sodium dithionate.

[0069] [000160] The slurry containing the mixture of solids and liquids is filtered (338) to separate the lithium carbonate, which is then rinsed (340). A portion of the lithium carbonate is collected as product (342). The remaining portion of the lithium carbonate is further mixed (344) with calcium hydroxide to produce a slurry containing dissolved lithium hydroxide and solid calcium carbonate. The slurry is filtered (346) to separate the calcium carbonate solids from the lithium hydroxide solution, which is reused to precipitate nickel, cobalt, and aluminum compounds (328).

[0070] [000161] The filtrate from the second filter (338) is transferred to a crystallizer (334) where a portion of the sodium sulfate and sodium dithionate are crystallized as solid crystals by multiple-effect crystallization or cooling crystallization. The solid sodium sulfate and sodium dithionate crystals are collected from the solution using a centrifuge or filter (336). The sodium sulfate and sodium dithionate crystals are heated (330) to about 120°C to form a crystallizer containing sodium dithionate. The lithium is decomposed into sodium sulfate by-product and SO2, and the SO2 can be recycled to the leaching. The mother liquor contains the remaining lithium sulfate, lithium dithionite, sodium sulfate, sodium dithionite, and water and is recycled back to the leaching (332) to minimize water consumption and maximize lithium recovery throughout the flowsheet. Alternatively, a portion of the mother liquor can be treated by nanofiltration (348) to produce clean water (350) for rinsing the product, and the spent rinse water (352, 354) can be reused back to the leaching. The concentrate (356) from the nanofiltration is recycled back to the crystallizer to maximize sodium sulfate recovery. The collected product of lithium carbonate (342) and nickel cobalt aluminum hydroxide (324) is mixed in the desired ratio of lithium, nickel, cobalt, and aluminum and heat-treated (358) to produce a new cathode compound for use in lithium-ion batteries. If necessary, additional lithium, nickel, cobalt and / or aluminum compounds may be added to the collected product to achieve the desired ratios of lithium, nickel, cobalt and aluminum prior to heat treatment. [Example]

[0071] [000162] Examples illustrating the present invention: 1. Lithium Cobalt Oxide Leached with Sulfur Dioxide and Sulfuric Acid (Test #LT4) Lithium cobalt oxide (Alfa Aesar), with the chemical formula LiCoO2, was used in this study. Leaching was performed by mixing 25 grams of LiCoO2 with 250 mL of 2 molar sulfuric acid. Sulfur dioxide gas was continuously sparged into the leaching solution to maintain an oxidation-reduction potential (ORP) of ≤400 mV. The leaching vessel consisted of a three-necked round-bottom flask, and stirring was achieved with a magnetic stir bar. One neck of the flask was used for ORP monitoring, another neck was fitted with a condenser to condense vapors back into the vessel, and the remaining neck was used for temperature measurement. The experiment was conducted without temperature control. The leaching was determined to be exothermic because the temperature rose to 71°C after 5 minutes of leaching and then fell to 21°C after a further 120 minutes of experimentation. Inductively coupled plasma spectroscopy (ICP) analysis of the solution indicated that 100% of the lithium and cobalt were extracted after 5 minutes of leaching.

[0072] 2. Lithium Cobalt Oxide Leached with Metabisulfite and Sulfuric Acid (Test #LT6) Leaching was carried out by mixing 12.5 grams of LiCoO2 with 250 mL of 2 molar sulfuric acid and 0.67 molar sodium metabisulfite. The leaching vessel consisted of a three-necked round-bottom flask, and stirring was provided by a magnetic stir bar. One neck of the flask was used for ORP monitoring, another neck was fitted with a condenser to condense vapors back into the vessel, and the remaining neck was used for temperature measurement. The experiment was carried out without temperature control. The leaching was determined to be exothermic, as the temperature rose to 60°C after 5 minutes of leaching and then fell to 25°C after a further 120 minutes of experimentation. ICP analysis of the solution indicated that 100% of the lithium and cobalt were extracted after 5 minutes of leaching.

[0073] 3. Precipitation of Cobalt and Lithium as Cobaltous Carbonate and Lithium Carbonate (Test #PTCL1) A 200 mL solution containing 5.59 g / L lithium and 50.01 g / L cobalt and having a pH of 1.59 was prepared by leaching lithium cobalt oxide with sulfur dioxide in combination with sulfuric acid. A precipitation test was performed by adding 31.83 grams of anhydrous sodium carbonate (calculated to be 1.2 times the stoichiometric amount of sodium carbonate required to precipitate all the lithium and cobalt as carbonates). The pH was then raised to 11.14 by adding 10 moles of sodium hydroxide. The test was performed in a 1000 mL beaker with an overhead stirrer. The slurry was filtered; 35.33 grams of residue and 118 mL of filtrate were collected. Evaporation was observed. The residue was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue indicated that 100% of the cobalt and 82.11% of the lithium had precipitated as mixed cobalt and lithium carbonates.

[0074] 4. Precipitation of Cobalt as Cobaltous Hydroxide (Test #PTC3-2) A 450 mL solution containing 5.59 g / L lithium and 50.01 g / L cobalt and a pH of 1.59 was prepared by leaching lithium cobalt oxide with sulfur dioxide in combination with sulfuric acid. A precipitation test was performed by gradually adding 10 molar sodium hydroxide to raise the pH to 10.61 to precipitate the cobalt. The test was performed in a 1000 mL beaker with an overhead stirrer. The slurry was filtered; 46.48 grams of residue and 390 mL of filtrate were collected. The residue was washed with deionized water, filtered again, and dried. Analysis of the residue indicated that 100% of the cobalt had been selectively precipitated as cobalt hydroxide from the lithium- and cobalt-containing solution. The final residue contained trace amounts of lithium (approximately 0.0292%). It is likely that it could be further purified with additional rinsing.

[0075] 5. Precipitation of Lithium as Lithium Carbonate (Test #PTL3-2) This test used 385 mL of the remaining solution from the filtrate after Test #PTC3-2 above. A precipitation test was performed by adding 25 grams of sodium carbonate monohydrate (calculated to be 1.2 times the stoichiometric amount required to precipitate all of the lithium into solution as lithium carbonate). The test was performed in a 1000 mL beaker using an overhead mixer. The slurry was filtered; 7.82 grams of residue and 318 mL of filtrate were collected. The residue was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue indicated that 53.9% of the lithium had precipitated as lithium carbonate.

[0076] 6. Formation of dithionite from leached lithium cobalt oxide leached with sulfur dioxide and sulfuric acid Lithium cobalt oxide (Alfa Aesar), with the chemical formula LiCoO2, was used in this study. Several leaching experiments were performed by mixing 36–50 grams of LiCoO2 with 250 mL of sulfuric acid at concentrations ranging from 0.8 molar to 1.5 molar. Sulfur dioxide gas was continuously sparged into the leaching solution. The final oxidation-reduction potential (ORP) range tested was 102 mV to 401 mV. The leaching vessel consisted of a three-necked round-bottom flask, and stirring was achieved with a magnetic stir bar. One neck of the flask was used for ORP monitoring, another neck was fitted with a condenser to condense vapors back into the vessel, and the remaining neck was used for temperature measurement. The experiments were performed without temperature control. After 120 minutes of leaching, samples were removed for dithionate analysis by ion chromatography. The results are summarized in Table 1.

[0077] [Table 1]

[0078] 7. Rock cycle test on lithium cobalt oxide treatment Lithium cobalt oxide (Alfa Aesar), with the chemical formula LiCoO, was used in this test study. The lithium cobalt oxide was processed in a rock cycle manner to simulate the major unit operations in the flowsheet described in Embodiment 2. The rock cycle test demonstrates the removal of sulfate and dithionate from the circuit, allowing unrecovered lithium and water at the end of the flowsheet from the previous cycle to be recycled and recovered at the front end of the flowsheet of the next cycle.

[0079] Leaching conditions consisted of pH control to approximately 1.5; 1.2M H2SO4 at the leaching head; 8% pulp consistency; and SO2 sparing with a target ORP of 350 mV. For each leaching step in the cull, after 2 hours of SO2 reduction leaching, all head solids had visually disappeared.

[0080] The leachate from the previous leaching step was adjusted to pH 11 with 10 M NaOH to precipitate the dissolved cobalt as Co(OH)2. This was followed by two repulp washing steps and filtration. The wet solid was dried at 60°C.

[0081] The filtrate from the previous step was then mixed with 1.2 times the stoichiometric amount of Na2CO3 relative to the lithium concentration measured by ICP. The mixed solution was then heated to 95°C for 30 minutes, after which the Li2CO3 precipitate was removed by filtration. The precipitate was washed with saturated Li2CO3 at 95°C. Except for Lock Cycle #1, all saturated Li2CO3 wash solutions were prepared with Li2CO3 solids from the previous cycle. In the Lock Cycle, lithium is expected to accumulate in solution, resulting in increased Li recovery. The results from ICP and calculations supported this conclusion. The calculated lithium recovery for each cycle of the flowsheet is shown in Table 2.

[0082] [Table 2]

[0083] The filtrate from the previous step, containing a mixture of sodium sulfate, sodium dithionite, and unrecovered lithium ion solution, was cooled to 5°C for 2 hours with gentle mixing in an overhead mixer to crystallize sodium sulfate decahydrate and sodium dithionite dihydrate. The crystals were collected by filtration and dried at 60°C to collect the anhydrous crystals. The weights of the dried crystals from cycles 1 through 4 are shown in Table 3.

[0084] [Table 3]

[0085] An example of a nanofiltration step is described in Example 20. 8. Lithium Nickel Manganese Cobalt Oxide Leached with Sulfur Dioxide and Sulfuric Acid (Test #NMC3-5) Chemical formula LiNi 0.33 Mn 0.33 Co 0.33 Lithium nickel manganese cobalt oxide (Sigma Aldrich) consisting of 0 was used in this test study. 30 grams of LiNi 0.33 Mn 0.33 Co 0.33 Leaching was carried out by mixing O2 with 255 mL of 1.2 M sulfuric acid. Sulfur dioxide gas was continuously sparged into the leaching solution to maintain an oxidation-reduction potential (ORP) of 550 mV. The leaching vessel consisted of a three-necked round-bottom flask, and stirring was achieved with a magnetic stir bar. One neck of the flask was used for ORP monitoring, another neck was equipped with a condenser to condense vapors back into the vessel, and the remaining neck was used for temperature measurement. The experiment was conducted without temperature control. The leaching was determined to be exothermic because the temperature rose to 66°C after 30 minutes of leaching and then fell to 28°C after 120 minutes of the experiment. Inductively coupled plasma spectroscopy (ICP) analysis of the solution indicated that 100% of the lithium, nickel, manganese, and cobalt had been extracted after 120 minutes of leaching. Ion chromatography analysis indicated that the final leach solution contained 24.1 g / L of dithionite.

[0086] 9. Precipitation of Nickel, Manganese, and Cobalt with NaOH as (Ni,Mn,Co)(OH)2 (Test #NMC-2-PTC11) A 200 mL solution containing 7.71 g / L lithium, 19.83 g / L nickel, 18.09 g / L manganese, and 19.38 g / L cobalt and having a pH of 0.8 was prepared by leaching lithium nickel manganese cobalt oxide with sulfur dioxide in combination with sulfuric acid. A precipitation test was performed by gradually adding 10 M sodium hydroxide to raise the pH to 10.70, precipitating the nickel, manganese, and cobalt. The test was performed in a 500 mL beaker using a magnetic stirrer. The slurry was filtered. 18.70 grams of dry residue and 140 mL of filtrate were collected. The residue was washed with deionized water, filtered again, and dried. Analysis of the residue showed that 100% of the nickel, 100% of the manganese, and 100% of the cobalt had precipitated as metal hydroxides from the solution containing lithium, nickel, manganese, and cobalt. The final residue contained a small amount of lithium (approximately 0.155%), which could be further purified with additional rinsing.

[0087] 10. Precipitation of nickel, manganese, and cobalt hydroxides with NaOH followed by precipitation of lithium as lithium carbonate (Test #NMC-2-PTL11) This test used the residue from the filtrate after test #NMC-2-PTC-11. A precipitation test was performed by adding 14.12 grams of sodium carbonate (calculated to be 1.2 times the stoichiometric amount required to precipitate all of the lithium into solution as lithium carbonate). The test was performed in a 500 mL beaker with a magnetic stirrer at 95°C for 15 minutes. The slurry was filtered; 2.39 grams of dry residue and 130 mL of filtrate were collected. The residue was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue indicated that 34.6% of the lithium had precipitated as lithium carbonate.

[0088] 11. Precipitation of Nickel, Manganese, and Cobalt with LiOH as (Ni,Mn,Co)(OH)2 (Test #NMC-2-CT-PTC3) A 200 mL solution containing 7.30 g / L lithium, 18.27 g / L nickel, 17.05 g / L manganese, and 18.24 g / L cobalt and having a pH of 0.66 was prepared by leaching lithium nickel manganese cobalt oxide with sulfur dioxide in combination with sulfuric acid. A precipitation test was performed by gradually adding 3.34 moles of lithium hydroxide to raise the pH to 11.07, precipitating the nickel, manganese, and cobalt. The test was performed in a 500 mL beaker using a magnetic stirrer. The slurry was filtered; 18.24 grams of residue and 206 mL of filtrate were collected. The residue was washed with deionized water, filtered again, and dried. Analysis of the residue showed that 100% of the nickel, 100% of the manganese, and 100% of the cobalt had precipitated as metal hydroxides from the solution containing lithium, nickel, manganese, and cobalt. The final residue contained a small amount of lithium (approximately 0.787%), which could be further purified with additional rinsing.

[0089] 12. Precipitation of nickel, manganese, and cobalt hydroxides with LiOH followed by precipitation of lithium as lithium carbonate (Test #NMC-2-CT-PTL3) This test used the residue from the filtrate after test #NMC-2-CT-PT3. A precipitation test was performed by adding 27.74 grams of sodium carbonate (calculated to be 1.2 times the stoichiometric amount required to precipitate all of the lithium into solution as the carbonate salt). The test was performed in a 500 mL beaker at 95°C for 15 minutes using a magnetic stirrer. The slurry was filtered; 12.12 grams of dry residue and 184 mL of filtrate were collected. The residue was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue indicated that 49.8% of the lithium had precipitated as lithium carbonate.

[0090] 13. Rock cycle test on lithium nickel manganese cobalt oxide treatment Chemical formula LiNi 0.33 Mn 0.33 Co 0.33 Lithium nickel manganese cobalt oxide (Sigma Aldrich), composed of O, was used in this pilot study. The lithium nickel manganese cobalt oxide was processed in a rock cycle mode to simulate the major unit operations in the flowsheet described in Example 3. The rock cycle test demonstrated the removal of sulfate and dithionite from the circuit, allowing unrecovered lithium and water at the end of the flowsheet from the previous cycle to be recycled and recovered at the front end of the flowsheet of the next cycle.

[0091] The leaching conditions consisted of processing 100 g of sample with pH controlled at approximately 1.5; 1.5 M H2SO4 in the leaching head; 10% pulp consistency; and SO2 sparging at a target ORP of 550 mV. For each leaching step within the four cycles, the head solids were visually eliminated after 2 hours of SO2 reduction leaching.

[0092] The leachate from the previous leaching step was adjusted to pH 11 with saturated LiOH to precipitate the dissolved nickel, manganese, and cobalt as (Ni,Mn,Co)(OH). This was followed by two repulp washing steps and filtration. The wet solid was dried at 60°C.

[0093] The filtrate from the previous step was then mixed with 1.0x stoichiometric Na2CO3 based on the lithium concentration measured by ICP. The mixed solution was then heated to 95°C for 30 minutes, after which the Li2CO3 precipitate was removed by filtration. The precipitate was washed with saturated Li2CO3 at 95°C. Except for lock cycle #1, all saturated Li2CO3 wash solutions were prepared with Li2CO3 solids from the previous cycle. In the lock cycle, lithium is expected to accumulate in solution, resulting in increased Li recovery. The results from ICP and calculations supported this conclusion. The calculated lithium recovery for each cycle of the flowsheet is shown in Table 4.

[0094] [Table 4]

[0095] The filtrate from the previous step, containing a mixture of sodium sulfate, sodium dithionite, and unrecovered lithium ion solution, was cooled to 5°C for 2 hours with gentle mixing using an overhead mixer to crystallize sodium sulfate decahydrate and sodium dithionite dihydrate. The crystals were collected by filtration and dried at 60°C to collect the anhydrous crystals. The weights of the dried crystals from cycles 1 through 4 are shown in Table 5.

[0096] [Table 5]

[0097] An example of a nanofiltration step is described in Example 20. 14. Lithium Nickel Cobalt Aluminum Oxide Leached with Sulfur Dioxide and Sulfuric Acid (Test #NCA-LT8) Chemical formula LiNi 0.08 Co 0.15 Al 0.05 Lithium nickel cobalt aluminum oxide (MTI Corp) consisting of 0 was used in this test study. 30 grams of LiNi 0.8 Co 0.15 Al 0.05 Leaching was carried out by mixing O2 with 245 mL of 1.2 M sulfuric acid. Sulfur dioxide gas was continuously sparged into the leaching solution to maintain an oxidation-reduction potential (ORP) of 550 mV. The leaching vessel consisted of a four-neck glass reactor, with stirring provided by an overhead mixer. One neck of the flask was used for ORP monitoring, another neck was used to add a condenser to condense vapors back into the vessel, another neck was used to measure temperature, and the final neck was used for the overhead mixer. The experiment was conducted without temperature control. The leaching was determined to be exothermic because the temperature rose to 88°C after 30 minutes of leaching and then fell to 50°C after 120 minutes of experimentation. Inductively coupled plasma spectroscopy (ICP) analysis of the solution indicated that 100% of the lithium, nickel, cobalt, and aluminum had been extracted after 120 minutes of leaching. Ion chromatography analysis indicated that the final leaching solution contained 11.3 g / L of dithionite.

[0098] 15. Precipitation of Nickel, Cobalt, and Aluminum with NaOH as (Ni,Co,Al)(OH)2 (Test #NCA-PTC1) A 200 mL solution containing 8.63 g / L lithium, 57.82 g / L nickel, 10.54 g / L cobalt, and 1.17 g / L aluminum and having a pH of 1.06 was prepared by leaching lithium nickel cobalt aluminum oxide with sulfur dioxide in combination with sulfuric acid. A precipitation test was performed by gradually adding 10 M sodium hydroxide to raise the pH to 11.09, precipitating the nickel, cobalt, and aluminum. The test was performed in a 500 mL beaker using a magnetic stirrer. The slurry was filtered. 27.15 grams of dry residue and 135 mL of filtrate were collected. The residue was washed with deionized water, filtered again, and dried. Analysis of the residue showed that 100% of the nickel, 100% of the manganese, and 100% of the cobalt had precipitated as metal hydroxides from the solution containing lithium, nickel, manganese, and cobalt. The final residue contained a small amount of lithium (approximately 0.078%), which could be further purified with additional rinsing.

[0099] 16. Precipitation of nickel, cobalt, and aluminum hydroxides with NaOH followed by precipitation of lithium as lithium carbonate (Test #NCA-PTL1) This test used the residue from the filtrate after test #NCA-PTL1. A precipitation test was performed by adding 15.82 grams of sodium carbonate (calculated to be 1.2 times the stoichiometric amount required to precipitate all of the lithium into solution as the carbonate salt). The test was performed in a 500 mL beaker at 95°C for 15 minutes with a magnetic stirrer. The slurry was filtered; 2.88 grams of dry residue and 125 mL of filtrate were collected. The residue was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue showed that 31.5% of the lithium had precipitated as lithium carbonate.

[0100] 17. Precipitation of Nickel, Cobalt, and Aluminum with LiOH as (Ni,Co,Al)(OH)2 (Test #NCA-CT-PTC2) A 200 mL solution containing 6.64 g / L lithium, 46.84 g / L nickel, 8.45 g / L cobalt, and 0.89 g / L aluminum and having a pH of 0.35 was prepared by leaching lithium nickel cobalt aluminum oxide with sulfur dioxide in combination with sulfuric acid. A precipitation test was performed by gradually adding 4.44 moles of lithium hydroxide to raise the pH to 11.03, precipitating nickel, cobalt, and aluminum. The test was performed in a 500 mL beaker using a magnetic stirrer. The slurry was filtered; 18.55 grams of residue and 202 mL of filtrate were collected. The residue was washed with deionized water, filtered again, and dried. Analysis of the residue showed that 100% of the nickel, 100% of the cobalt, and 100% of the aluminum had precipitated as metal hydroxides from the solution containing lithium, nickel, cobalt, and aluminum. The final residue contained a small amount of lithium (approximately 0.648%), which could be further purified with additional rinses.

[0101] 18. Precipitation of nickel, cobalt, and aluminum hydroxides with LiOH followed by precipitation of lithium as lithium carbonate (Test #NCA-CT-PTL2) This test used the residue from the filtrate after test #NCA-CT-PTC2. A precipitation test was performed by adding 27.31 grams of sodium carbonate (calculated to be 1.0 times the stoichiometric amount required to precipitate all of the lithium into solution as the carbonate salt). The test was performed in a 500 mL beaker at 95°C for 15 minutes with a magnetic stirrer. The slurry was filtered; 14.04 grams of dry residue and 185 mL of filtrate were collected. The residue was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue indicated that 55.97% of the lithium had precipitated as lithium carbonate.

[0102] 19. Rock cycle test on lithium nickel cobalt aluminum oxide treatment Chemical formula LiNi 0.8 Co 0.15 Al 0.05 Lithium nickel cobalt aluminum oxide (MTI Corp.), consisting of O2, was used in this test study. The lithium nickel cobalt aluminum oxide was processed in a rock cycle mode to simulate the major unit operations in the flowsheet described in Embodiment 3. The rock cycle test demonstrated the removal of sulfate and dithionite from the circuit, allowing unrecovered lithium and water at the end of the flowsheet from the previous cycle to be recycled and recovered at the front end of the flowsheet of the next cycle.

[0103] The leaching was carried out by treating 400 g of sample with a controlled pH of approximately 1.5; The leaching consisted of H2SO4; 10% pulp consistency; and SO2 sparge at a target ORP of 550 mV. For each leaching step within 7 cycles, the head solids were visually eliminated after 2 hours of SO2 reduction leaching.

[0104] The leachate from the previous leaching step was adjusted to pH 10.5 with saturated LiOH to precipitate the dissolved nickel, cobalt, and aluminum as (Ni,Co,Al)(OH)2. This was followed by two repulp washing steps and filtration. The wet solid was dried at 60°C.

[0105] The filtrate from the previous step was then mixed with 1.2 times the stoichiometric amount of Na2CO3 relative to the lithium concentration measured by ICP. The mixed solution was then heated to 95°C for 30 minutes, after which the Li2CO3 precipitate was removed by filtration. The precipitate was washed with saturated Li2CO3 at 95°C. Except for lock cycle #1, all saturated Li2CO3 wash solutions were prepared with Li2CO3 solids from the previous cycle. In the lock cycle, lithium was expected to accumulate in solution, resulting in increased Li recovery. The results from ICP and calculations supported this conclusion. The calculated lithium recovery for each cycle of the flowsheet is shown in Table 6.

[0106] [Table 6]

[0107] The filtrate from the previous step, containing sodium sulfate, sodium dithionite, and unrecovered lithium ion solution, was cooled to 5°C for 2 hours with gentle mixing in an overhead mixer to crystallize sodium sulfate decahydrate and sodium dithionite dihydrate. The crystals were collected by filtration and dried at 60°C to collect the anhydrous crystals. The weights of the dried crystals from cycles 1 through 4 are shown in Table 7.

[0108] [Table 7]

[0109] An example of a nanofiltration step is described in Example 20. 20. Nanofiltration Nanofiltration tests were conducted by pumping a feed solution containing 32.23 g / L of sulfate and 24.0 g / L of dithionate through a Dow Filmtec NF270-400 nanofiltration membrane. The feed flow rate was set at 5.65 L / min. The pressure at the membrane inlet was measured at 29.1 Bar. The pressure at the concentrate outlet was measured at 28.5 Bar. The permeate flow rate through the membrane was measured at 0.65 L / min. A permeate sample was collected and measured by ion chromatography to contain 2.30 g / L of sulfate and 2.84 g / L of dithionate. The concentrate flow rate was calculated to be 5.0 L / min. The concentrate was calculated to contain 36.13 g / L of sulfate and 26.80 g / L of dithionate. The sulfate rejection was calculated to be 92.2%, and the dithionate rejection was calculated to be 85.5%.

[0110] 21. Processing of lithium-ion battery cathode scrap One hundred grams of lithium-ion battery cathode scrap consisting of cobalt source material containing lithium nickel manganese cobalt oxide coated on metallic aluminum foil and exhibiting a content of 85.7 g / kg Al metal, 59.3 g / kg Li, 237.9 g / kg Ni, 135.7 g / kg Mn, and 120.2 g / kg Co was mixed into 1900 g (1857 mL) of a solution containing 0.5 M HSO at 30° C.

[0111] After 40 minutes with gentle mixing, the cobalt source material was visually separated from the metallic aluminum foil, and the resulting solution contained 8.68% Al, 64.97% Li, 40.41% Ni, 39.27% Mn, and 43.99% Co.

[0112] The separated aluminum foil was sieved from the slurry using a No. 13 / 18 sieve. The slurry containing the residual acidic solution, extracted metals, and residual cobalt source material was sparged with SO to cumulatively extract 94.55% Li, 95.03% Ni, 95.22% Mn, and 94.67% Co. The solution was then filtered to remove insoluble materials, such as residual separator material, adhering to the active cathode material.

[0113] The pH of the filtrate was then increased to pH 5 by adding 50% NaOH aqueous solution to remove Al. 100% was precipitated and extracted as Al(OH). The Al(OH) was filtered, and the Ni, Mn, and Co in the filtrate solution were precipitated as metal hydroxides by raising the pH to 11 with 50% NaOH solution. The overall recovery of base metals from the original cobalt source material was 97.23% Ni, 97.61% Mn, and 97.50% Co. The precipitated base metal hydroxides were then filtered in a Buchner funnel. Solid NaCO was added to the filtrate at 90 degrees Celsius to precipitate Li as LiCO. 68% of the Li precipitated as LiCO. After filtration of LiCO, the filtrate containing soluble Li can be recycled back to the initial Al separation step to maximize Li recovery.

[0114] 22. Processing of cobalt source materials containing fluorinated compounds. The cobalt source material was supplied by a European battery recycler that prepared the material by separating individual battery cells from electric vehicle battery packs, roasting the battery cells at high temperatures, mechanically crushing the roasted battery cells, and sieving and mechanically processing the crushed material to separate the majority of the copper, aluminum, and iron from the cobalt source material concentrate. The fluorinated compounds present with the cobalt source material are compounds derived from the high-temperature roasting of the electrolyte contained in the battery cells.

[0115] One hundred grams of cobalt source material containing fluorinated compounds analyzed as follows: 40.3 g / kg Al, 40.3 g / kg Li, 106.1 g / kg Ni, 114.3 g / kg Mn, 95.5 g / kg Co, 30.5 g / kg Cu, and 32.5 g / kg F was leached in 900 mL of deionized water at 60°C. The test was conducted for 30 minutes in a 2000 mL beaker using a magnetic stirrer. The slurry was filtered. The residue was repulped three times with deionized water, filtered again, and dried. Analysis of the solution indicated that only lithium, fluoride, and aluminum had been extracted. The extraction yields were 75% Li, 16% Al, and 90% F.

[0116] The combined filtrate and wash solution after water leaching were analyzed and contained 134 mg / L Li, 7 mg / L Al, and 263 mg / L F. A precipitation test was performed by adding 0.54 grams of 50% calcium hydroxide slurry (calculated to be 2.0 times the stoichiometric amount required to precipitate all fluoride into solution as calcium fluoride). The test was conducted at room temperature with a magnetic stirrer using 250 mL of the combined solution in a 500 mL beaker for 120 minutes. The slurry was filtered; 0.172 grams of dried precipitate and 223 mL of filtrate were collected. The precipitate was washed with deionized water, filtered again, and dried. Analysis of the precipitate indicated that 98.7% of the fluoride had precipitated as calcium fluoride.

[0117] The residue from the water leach, consisting of the cobalt source material with most of the fluoride removed, was used for SO2 leaching. Leaching was carried out by mixing 64 grams of the residue with 703 mL of 1.0 M sulfuric acid at 80°C and controlling the pH at approximately 1.0. 40.8 g of sulfur dioxide gas was continuously sparged into the leach solution to maintain a stable oxidation-reduction potential (ORP). The leaching vessel had four necks, and stirring was provided by an overhead mixer. One neck of the flask was used for ORP and pH monitoring, another neck was added with a condenser to condense vapors back into the vessel, and the other neck was used for temperature measurement. The experiment was carried out with a heating mantle to control the temperature. Inductively coupled plasma spectroscopy (ICP) analysis of the solution indicated that 100% of the Li, Ni, Mn, and Co and 90% of the Al were extracted after 120 minutes of leaching.

[0118] An 800 mL solution containing 5.30 g / L Li, 9.1 g / L Ni, 10.4 g / L Mn, 8.4 g / L Co, and 0.13 g / L Al with a pH of 0.56 was used for the precipitation test. The precipitation test was performed by gradually adding 4.18 M NaOH to raise the pH to 5.2, thereby precipitating the Al. The test was performed using an overhead mixer for 1 minute. The reaction was carried out in a 000 mL beaker. The slurry was filtered; 7.05 grams of residue and 850 mL of filtrate were collected. The residue was washed with deionized water, filtered again, and dried. Analysis of the residue showed that 99% of the Al had precipitated as Al(OH)3.

[0119] A portion of the filtrate after Al precipitation was used in this test. The precipitation test was performed by gradually adding 4.18 moles of NaOH to raise the pH to 11.02 to precipitate Ni, Mn, and Co. The test was performed in a 1000 mL beaker using an overhead mixer. The slurry was filtered; 40.91 grams of precipitate and 764 mL of filtrate were collected. The precipitate was washed with deionized water, filtered again, and dried. Analysis of the precipitate showed that 100% of the Ni, Mn, and Co precipitated from solution as base metal hydroxides.

[0120] A portion of the filtrate after base metal hydroxide precipitation was used in this test. The precipitation test was performed by adding 68.31 grams of Na2CO3 (calculated to be 1.2 times the stoichiometric amount required to precipitate all of the Li into solution as carbonate). The test was performed in a 1000 mL beaker with a magnetic stirrer at 95°C for 15 minutes. The slurry was filtered; 29.9 grams of dry precipitate and 605 mL of filtrate were collected. The precipitate was washed with saturated lithium carbonate solution, filtered again, and dried. Analysis of the residue indicated that 63.86% of the Li had precipitated as Li2CO3.

[0121] 23. Processing of carbon-containing cobalt source material derived from the processing of spent lithium-ion batteries. The cobalt source material was supplied by a European battery recycler. This material was prepared by separating individual battery cells from an electric vehicle battery pack, roasting the cells at high temperatures, mechanically crushing the roasted battery cells, and sieving and mechanically processing the crushed material to separate most of the copper, aluminum, and iron from the cobalt source material. The cathode-derived cobalt source material contained a mixture of graphite-coated anode-derived carbon and roasted plastic material from spent lithium-ion batteries.

[0122] A flotation step was used to separate the carbon and graphite from the cobalt source material in the mixed fine residue, which contains all fine components, e.g., the cobalt source material, such as the active lithium-ion-metal oxide cathode material, fine metallic copper and aluminum, the graphite anode material, and carbon and salts derived from the pyrolysis of the organic binder and organic film.

[0123] In the examples given, samples of this type of material were obtained containing about 40% total carbon by weight. In addition to carbon, the samples contained 13% each of nickel and manganese, 11% cobalt, about 4% each of aluminum and lithium, and 2% copper. The samples also contained smaller but significant amounts of iron, phosphorus, and fluoride.

[0124] To achieve this separation, the dried sample is mixed with water in a flotation cell (Denver sub-A) in this example, although other types are also suitable. The initial solids concentration is 10%, but any similar concentration (e.g., 5-30%) can be used. After the slurry is first stirred at 1250 rpm for 5 minutes, the suspended slurry can be sieved and passed through a gravity separator to remove the coarser metallic copper and aluminum. The remaining pulp is returned to the flotation cell, and 2000 g / t kerosene is added to the pulp and conditioned for an additional 5 minutes at 1250 rpm. Any fuel oil (e.g., diesel) can be added instead of kerosene.

[0125] After conditioning, a foaming agent is added to the pulp to create a stable foam. Commercially available foaming agent F131 was used, but other foaming agents, such as MIBC or glycol-based foaming agents, may be substituted. Initial foaming agent addition is in the range of 100 grams per ton. Subsequent air application results in a foam of air bubbles that retains the carbon and leaves other materials in the slurry. The coarser foam concentrate is collected and sent to another flotation step for washing. The tails slurry remaining in the residual flotation pulp is rich in base metals and can be further processed to recover cobalt source material. The concentrate is purified by dilution in a small flotation cell with additional foaming agent. A total of three purification steps were performed in this example, and in each case, the concentrate from the previous step was used as the feed, along with additional make-up water and foaming agent as needed (50-80 g / t per step). In the final step, an additional 400 g / t of kerosene was added in the initial conditioning step to maintain carbon recovery. A 10 minute flotation time was used for the coarser coarse flotation and the first two cleaner steps, and a 4 minute conditioning step followed by a 5 minute flotation was used for the final cleaning step.

[0126] In this example, the procedure described results in 93.2% of the carbon in the feed material being reported in the final concentrate. The tailings consist of cobalt source material with most of the carbon removed. This cobalt source material can be treated as in the previous example for the treatment of the cobaltous sulfate / cobaltous dithionate solution.

[0127] [000163] While preferred embodiments of the present invention have been disclosed for purposes of illustration, it should be understood that the embodiments may incorporate various changes, modifications, and substitutions without departing from the spirit of the invention as defined by the following claims. The present invention includes the following aspects. [1] 1. A method for removing and / or recycling water from a sodium sulfate and sodium dithionite containing liquor derived from the processing of a cobalt source, comprising: a. processing a material derived from a component of a lithium-ion battery to derive a cobalt source; b. mixing sulfur dioxide and sulfuric acid with a cobalt source to derive a solution containing cobalt sulfate and cobalt dithionate; c. Precipitating the cobalt, in whole or in part, as cobaltous carbonate or cobaltous hydroxide, which is then removed in whole or in part from the liquor by filtration; d. crystallizing the sodium sulfate and sodium dithionate to separate most of the sodium sulfate and sodium dithionate from the liquor; e. heating sodium sulfate and sodium dithionite crystals to form anhydrous sodium sulfate, sulfur dioxide, and water; and f. separating the anhydrous sodium sulfate from the sulfur dioxide and water; The method comprising: [2] The material derived from components of a lithium ion battery is a cathode material comprising a cobalt-containing compound bound to a metallic aluminum foil, the cobalt source being: a. immersing the cathode material in a sulfuric acid solution to separate the metallic aluminum foil from the cobalt-containing compound; b. Sifting the metallic aluminum foil present as fragments to separate it from the cobalt source present as particles mixed in the sulfuric acid solution; The method according to [1], which is derived by [3] The materials derived from the components of the lithium ion battery consist of a cobalt compound derived from the cathode material and a carbon and / or graphite material derived from the anode material and / or heat-treated plastic, and the cobalt source is a. treating the material by froth flotation to separate the majority of the carbon and / or graphite from the cobalt source; The method according to [1], which is derived by [4] The material derived from the components of the lithium ion battery comprises a cobalt compound derived from the cathode material and a fluorinated compound derived from the electrolyte, and the cobalt source is a. Extracting most of the fluorinated compounds from the material by immersion in water; b. separating the cobalt source from the water containing the extracted fluorinated compounds by filtration; c. treating the water containing the extracted fluorinated compounds with lime to precipitate the fluorinated compounds as calcium fluoride; d. separating the calcium fluoride from the treated water by filtration; The method according to [1], which is derived by [5] 1. The method according to claim 1, wherein cobaltous carbonate is precipitated by adding sodium carbonate to a solution containing cobalt sulfate and cobalt dithionate. [6] 1. The method according to claim 1, wherein cobaltous hydroxide is precipitated by adding sodium hydroxide to a solution containing cobalt sulfate and cobalt dithionate. [7] The method according to [1], wherein the sulfates and dithionates are derived from sulfur dioxide, sulfites, metasulfites, bisulfates with or without sulfuric acid. [8] The method according to [1], wherein water is separated from sodium dithionite and sodium sulfate by nanofiltration of the liquid. [9] The method according to [1], which includes a recycle step of sodium dithionite and sodium sulfate.

[10] The method of [1], including the presence of manganese in a cobalt source to co-derive a solution containing manganese sulfate, manganese dithionate, cobalt sulfate, and cobalt dithionate.

[11]

[10] The method of

[10] , wherein the manganese is recovered by combining with cobaltous carbonate to co-precipitate as manganese carbonate, which is then wholly or partially removed from the liquor by filtration.

[12]

[10] The method of

[10] , wherein the manganese is recovered by combining it with cobaltous carbonate and lithium carbonate to co-precipitate as manganese carbonate, which is then removed in whole or in part from the liquor by filtration.

[13]

[10] The method of

[10] , wherein the manganese is recovered by combining with cobaltous hydroxide to co-precipitate as manganese hydroxide, which is then wholly or partially removed from the liquor by filtration.

[14] The method of [1], including the presence of nickel in a cobalt source to co-derive a solution containing nickel sulfate, nickel dithionate, cobalt sulfate and cobalt dithionate.

[15]

[14] The method of

[14] , wherein the nickel is recovered by combining with cobaltous carbonate to co-precipitate as nickel carbonate, which is then wholly or partially removed from the liquor by filtration.

[16]

[14] The method of

[14] , wherein the nickel is recovered by combining it with cobaltous carbonate and lithium carbonate to co-precipitate as nickel carbonate, which is then removed in whole or in part from the liquor by filtration.

[17]

[14] The method of

[14] , wherein the nickel is recovered by combining with cobaltous hydroxide to co-precipitate as nickel hydroxide, which is then wholly or partially removed from the liquor by filtration.

[18] 1. The method of claim 1, including the presence of lithium in a cobalt source to co-derive a solution containing lithium sulfate, lithium dithionate, cobalt sulfate and cobalt dithionate, wherein cobalt precipitates as cobalt hydroxide and lithium, still in the solution in step c, is subsequently precipitated from the solution as lithium carbonate by the addition of sodium carbonate. [Explanation of symbols]

[0128] (12) Leaching reactor (14) Filtration (16) Collected Products (18) Crystallizer (20) Precipitation reactor (22) Centrifuge or filter (24) Heating (26) Recirculation (28) Nanofiltration (30) Clean water for rinsing (32) Used rinse water (34) Concentrate (36) Heat treatment (40) Leaching reactor (42) Filtration (44) Collected Products (46) Crystallizer (48) Precipitation reactor (50) Centrifuge or filter (52) Heating (54) Recirculation (56) Nanofiltration (58) Clean water for rinsing (60) Used rinse water (62) Concentrate (64) Heat Treatment (70) Leaching reactor (72) Filtration (74) Collected Products (76) Crystallizer (78) Precipitation reactor (80) Centrifuge or filter (82) Heating (84) Recirculation (86) Nanofiltration (88) Clean water for rinsing (90) Used rinse water (92) Concentrate (94) Heat Treatment (100) Leaching reactor (102) Filtration (104) Collected Products (106) Second Precipitation Reactor (108) Precipitation reactor (110) Heating (112) Recirculation (114) Crystallizer (116) Centrifuge or filter (118) Filtration (120) Collected Products (122) Nanofiltration (124) Clean water for rinsing (126) Used rinse water (128) Used rinse water (130) Concentrate (132) Heat Treatment (140) Leaching reactor (142) Filtration (144) Collected Products (146) Second Precipitation Reactor (148) Precipitation reactor (150) Heating (152) Recirculation (154) Crystallizer (156) Centrifuge or filter (158) Filtration (160) Collected Products (162) Nanofiltration (164) Clean water for rinsing (166) Used rinse water (168) Used rinse water (170) Concentrate (172) Heat Treatment (180) Leaching reactor (182) Filtration (184) Collected Products (186) Second Precipitation Reactor (188) Precipitation reactor (190) Heating (192) Recirculation (194) Crystallizer (196) Centrifuge or filter (198) Filtration (200) Collected Products (202) Nanofiltration (204) Clean water for rinsing (206) Used rinse water (208) Used rinse water (210) Concentrate (212) Heat Treatment (220) Leaching reactor (222) Filtration (224) Collected Products (226) Second Precipitation Reactor (228) Precipitation Reactor (230) Heating (232) Recirculation (234) Crystallizer (236) Centrifuge or filter (238) Second Filter (240) Lithium Carbonate (242) Product (244) Mixed (246) Filtration (248) Nanofiltration (250) Clean water for rinsing (252) Used rinse water (254) Used rinse water (256) Concentrate (258) Heat Treatment (270) Leaching reactor (272) Filtration (274) Collected Products (276) Second Precipitation Reactor (278) Precipitation Reactor (280) Heating (282) Recirculation (284) Crystallizer (286) Centrifuge or filter (288) Second Filter (290) Lithium Carbonate (292) Product (294) Mixed (296) Filtration (298) Nanofiltration (300) Clean water for rinsing (302) Used rinse water (304) Used rinse water (306) Concentrate (308) Heat Treatment (320) Leaching reactor (322) Filtration (324) Collected Products (326) Second Precipitation Reactor (328) Precipitation Reactor (330) Heating (332) Recirculation (334) Crystallizer (336) Centrifuge or filter (338) Second Filter (340) Lithium Carbonate (342) Product (344) Mixed (346) Filtration (348) Nanofiltration (350) Clean water for rinsing (352) Used rinse water (354) Used rinse water (356) Concentrate (358) Heat Treatment

Claims

1. 1. A method for removing and / or recycling water from a sodium sulfate and sodium dithionite containing liquor derived from the processing of a cobalt source, comprising: a. treating a material derived from a lithium ion battery component to derive a cobalt source, wherein the material derived from a lithium ion battery component comprises a cobalt compound derived from a cathode material and a fluorinated compound derived from an electrolyte, and the cobalt source is extracting most of the fluorinated compounds from the material by immersion in water; separating the cobalt source from the water containing the extracted fluorinated compounds by filtration; treating the water containing the extracted fluorinated compounds with lime to precipitate the fluorinated compounds as calcium fluoride; separating the calcium fluoride from the treated water by filtration; Induced by; b. mixing sulfur dioxide and sulfuric acid with a cobalt source to derive a solution containing cobalt sulfate and cobalt dithionate; c) precipitating the cobalt, in whole or in part, as cobaltous carbonate or cobaltous hydroxide, which is then removed in whole or in part from the liquor by filtration; d. crystallizing the sodium sulfate and sodium dithionate to separate most of the sodium sulfate and sodium dithionate from the liquor; e. heating sodium sulfate and sodium dithionite crystals to form anhydrous sodium sulfate, sulfur dioxide, and water; and f. Separating the anhydrous sodium sulfate from the sulfur dioxide and water; The method comprising:

2. The materials derived from the components of the lithium ion battery consist of a cobalt compound derived from the cathode material and a carbon and / or graphite material derived from the anode material and / or heat-treated plastic, and the cobalt source is a. treating the material with froth flotation to separate the majority of the carbon and / or graphite from the cobalt source; The method of claim 1 , wherein the method is induced by

3. 2. The method of claim 1, wherein the cobaltous carbonate is precipitated by adding sodium carbonate to a solution containing cobalt sulfate and cobalt dithionate.

4. 2. The method of claim 1, wherein the cobaltous hydroxide is precipitated by adding sodium hydroxide to a solution containing cobalt sulfate and cobalt dithionate.

5. 10. The method of claim 1, wherein the sulfates and dithionates are derived from sulfur dioxide, sulfites, metasulfites, bisulfates, with or without sulfuric acid.

6. 10. The method of claim 1, wherein the water is separated from the sodium dithionite and sodium sulfate by nanofiltration of the liquid.

7. 10. The method of claim 1 including a step of recycling sodium dithionite and sodium sulfate.

8. 10. The method of claim 1 including the presence of manganese in the cobalt source to co-derive a solution containing manganese sulfate, manganese dithionate, cobalt sulfate and cobalt dithionate.

9. 9. The method of claim 8, wherein the manganese is recovered by combining with cobaltous carbonate to co-precipitate as manganese carbonate, which is then wholly or partially removed from the liquor by filtration.

10. 9. The method of claim 8, wherein the manganese is recovered by combining it with cobaltous carbonate and lithium carbonate to co-precipitate it as manganese carbonate, which is then removed in whole or in part from the liquor by filtration.

11. 9. The method of claim 8, wherein the manganese is recovered by combining with cobaltous hydroxide to co-precipitate as manganese hydroxide, which is then wholly or partially removed from the liquor by filtration.

12. 10. The method of claim 1 including the presence of nickel in the cobalt source to co-derive a solution containing nickel sulfate, nickel dithionate, cobalt sulfate and cobalt dithionate.

13. 13. The method of claim 12, wherein the nickel is recovered by combining with cobaltous carbonate to co-precipitate as nickel carbonate, which is then wholly or partially removed from the liquor by filtration.

14. 13. The method of claim 12, wherein the nickel is recovered by combining it with cobaltous carbonate and lithium carbonate to co-precipitate it as nickel carbonate, which is then removed in whole or in part from the liquor by filtration.

15. 13. The method of claim 12, wherein the nickel is recovered by combining with cobaltous hydroxide to co-precipitate as nickel hydroxide, which is then wholly or partially removed from the liquor by filtration.

16. 10. The method of claim 1 including the presence of lithium in the cobalt source to co-derive a solution containing lithium sulfate, lithium dithionate, cobalt sulfate and cobalt dithionate, wherein cobalt precipitates as cobalt hydroxide and lithium, still in the solution in step c, is subsequently precipitated from the solution as lithium carbonate by the addition of sodium carbonate.

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