PROCESS FOR THE RECOVERY OF LI, NI AND CO

Abstract

Process for the separation of Li from oxides of one or more of Co and Ni contained in a feed, comprising the steps of: contacting, in aqueous medium, the feed with a quantity of sulfidizing agent, sufficient to convert a major part of the Co and/or Ni to sulfides, and a quantity of mineral acid sufficient to reach a pH of 1 to 5, thereby forming an aqueous slurry containing solid Co and/or Ni sulfides, and a solution containing Li; and, separating the solids from the solution, thereby obtaining solids containing Co and/or Ni sulfides, and a solution containing at least 70% of the Li. This process allows to convert Co and Ni to solid sulfides and at the same time to efficiently separate them from soluble compounds such as Li, Mn and other impurities.

Claims

1-15. (canceled)

16. Process for the separation of Li from oxides of one or more of Co and Ni contained in a feed, comprising the steps of: contacting, in an aqueous medium, the feed with a quantity of sulfidizing agent, sufficient to convert a major part of the Co and/or Ni to sulfides, and a quantity of mineral acid sufficient to reach a pH of 1 to 3, at an absolute pressure of less than 0.3 MPa, thereby forming an aqueous slurry containing solid Co and/or Ni sulfides, and a solution containing Li; and, separating the solids from the solution, thereby obtaining solids containing Co and/or Ni sulfides, and a solution containing at least 70% of the Li.

17. The process according to claim 16, wherein the sulfidizing agent used in the step of contacting is one or more of H.sub.2S, NaHS, and Li.sub.2S.

18. The process according to claim 16, wherein the sulfidizing agent used in the step of contacting is generated in situ, by adding elemental sulfur under reducing conditions.

19. The process according to claim 16, wherein in the step of contacting, the quantity of mineral acid is at least partially generated in situ by addition of a solution containing dissolved Co and/or Ni.

20. The process according to claim 16, wherein the step of contacting is performed at an absolute pressure of less than 0.1 MPa.

21. The process according to claim 16, wherein the solids obtained in the step of separating comprise at least 70% of the Co and/or Ni.

22. The process according to claim 16, wherein the solution obtained in the step of separating, comprises at least 85% of the Li.

23. The process according to claim 16, wherein the feed further contains oxides of Mn, and wherein the Mn is dissolved together with the lithium, thereby obtaining a solution containing the major part of the lithium and the major part of the manganese.

24. The process according to claim 23, wherein said solution comprises at least 70% of the Mn.

25. The process according to claim 16, wherein at least the metal oxides contained in the feed are in the form of a powder.

26. The process according to claim 16, wherein the feed is derived from Li-ion batteries, battery scrap and/or their production waste.

27. The process according to claim 16, wherein the process is performed at a temperature of 80 C. or less.

28. The process according to claim 16, wherein the quantity of mineral acid is predetermined according to stoichiometric reactions, the addition being performed in at least 2 steps, the first addition step being limited to at most 80% of the predetermined amount.

29. The process according to claim 28, wherein the first addition step is terminated at a pH of above 3.3, and wherein the second or any subsequent addition step is terminated at a pH between 1.5 and 3.

30. The process according to claim 16, wherein the Co and/or Ni sulfides obtained in the step of separating the solids are used as starting material in a subsequent hydrometallurgical refining process.

Description

EXAMPLE 1: USE OF H.SUB.2.S AT 60 C. ON PYROLYZED BLACK MASS

[0076] 250 g of black mass is added in a beaker. 0.8 L of water is added and the mixture is agitated. The black mass originates from end-of-life batteries and has been pyrolyzed at 550 C. for 3 h under N.sub.2-atmosphere in order to liberate the cathode powder from the alumina foil. Black mass is obtained after comminution and sieving. The black mass comprises 12% Ni, 7.2% Mn, 3.3% Co, 3.1% Li, 3.8% Al, 1.5% Cu and 1.8% F. The rest of the mass mainly comprises C, P, and O.

[0077] H.sub.2S is injected in the slurry at a constant rate of 10 g/h. The temperature is adjusted to 60 C. H.sub.2SO.sub.4 solution (1000 g/L) is added at a constant rate of 15 g/h. During the experiment, the temperature is maintained at 60 C., pressure in the reactor is maintained at 0.95 bar and H.sub.2S is continuously injected at the specified rate. A sample of the slurry is taken each hour. The samples are cooled to 40 C. and purged with N.sub.2 for 30 minutes before measuring the pH. The addition of H.sub.2SO.sub.4 is stopped when the pH of the slurry reaches 2.1, after about 15 h.

[0078] The slurry is filtered on a Buchner filter, resulting in a solution and solid residue. 156 g dry solid residue and 0.9 L solution is obtained.

[0079] The mass balance of the complete experiment can be found in Table 1 below.

TABLE-US-00001 TABLE 1 Metal input and yields (in g) in solid residue and solution at pH 2.1 Input Solid residue Solution Ni 30 27.8 2.2 Mn 18 0.9 17.1 Co 8.2 7.6 0.6 Li 7.7 0.3 7.4 Al 9.5 2.4 7.1 Cu 4.5 4.5 0.0 Fe 13.8 0.5 13.3

[0080] This experiment shows that under the current process conditions, 95% or more of the Li and Mn dissolve, while 90% or more of Ni and Co is in the solid residue and the dissolution of Ni and Co is minimized.

EXAMPLE 2: USE OF H.SUB.2.S AT 40 C. ON PYROLYZED BLACK MASS

[0081] 300 g of black mass is added in a beaker. 0.8 L of water is added and the mixture is agitated. The black mass originates from end-of-life batteries and has been pyrolyzed at 550 C. for 3 h under N.sub.2-atmosphere in order to liberate the cathode powder from the alumina foil. Black mass is obtained after comminution and sieving. The black mass comprises 20% Ni, 12.4% Mn, 10.5% Co, 4.55% Li, 5.2% Al, 6.1% Cu and 2.6% F. The rest of the mass mainly comprises C, P and O.

[0082] H.sub.2S is injected in the slurry at a constant rate of 10 g/h. The temperature is adjusted to 40 C. H.sub.2SO.sub.4 solution (1000 g/L) is added with a constant rate of 24 g/h over a period of 15 h. During this period, the temperature is maintained at 40 C. and H.sub.2S is continuously injected at the specified rate. After this period, the pH of slurry is 2.8.

[0083] The slurry is filtered on a Buchner filter, resulting in a solution and a solid residue. 194 g dry solid residue and 0.95 L solution is obtained. The mass balance of the complete experiment can be found in Table 2 below.

TABLE-US-00002 TABLE 2 Metal input and yields (in g) in solid residue and solution Input Solid residue Solution Ni 60.0 58.6 1.4 Mn 37.2 1.1 36.1 Co 31.5 29.2 2.3 Li 13.7 0.6 13.1 Al 15.6 5.1 10.5 Cu 18.3 18.3 0

[0084] This experiment demonstrates that the yields obtained at 40 C. are similar to those obtained in Example 1 at 60 C.

EXAMPLE 3: USE OF NAHS AND H.SUB.2.SO.SUB.4 .AT 80 C. ON MECHANICAL BLACK MASS

[0085] 300 g of black mass is added in a beaker. 0.8 L of water is added and the mixture is agitated. The mechanical black mass is battery production scrap that is obtained after comminution (wet crushing) and sieving. The black mass comprises 18% Ni, 6.5% Mn, 6.5% Co, 3.8% Li, 1.5% Al, 0.4% Cu and 0.8% F. The rest of the mass mainly comprises C and O.

[0086] NaHS solution (300 g/L) is injected in the slurry at a constant rate of 115 g/h. The temperature is adjusted to 80 C. H.sub.2SO.sub.4 solution (1000 g/L) is added with a constant rate of 45 g/h over a period of 7 h. During this period, the temperature is maintained at 80 C. and NaHS is continuously injected at the specified rate. After this period, the pH of slurry is 3.

[0087] The slurry is filtered on a Buchner filter, resulting in a solution and solid residue. 302 g dry solid residue and 1.4 L solution is obtained. The mass balance of the complete experiment can be found in Table 3 below.

TABLE-US-00003 TABLE 3 Metal input and yields (in g) in solid residue and solution Input Solid residue Solution Ni 54 53.9 0.1 Mn 19.5 0.7 18.8 Co 19.5 19.4 0.1 Li 11.4 0.2 11.2 Al 4.5 4.0 0.5 Cu 1.1 1.1 0.0 F 2.4 2.3 0.1

[0088] This experiment demonstrates that NaHS can be used as sulfidizing agent instead of H.sub.2S.

EXAMPLE 4: USE OF H.SUB.2.S AND HCL AT 60 C. ON MECHANICAL BLACK MASS

[0089] 250 g of black mass is added in a beaker. 0.8 L of water is added and the mixture is agitated. The black mass is battery production scrap and is obtained after comminution and sieving. The black mass comprises 18% Ni, 6.5% Mn, 6.5% Co, 3.8% Li, 1.5% Al, 0.4% Cu and 0.8% F. The rest of the mass mainly comprises C and O.

[0090] H.sub.2S is injected in the slurry at a constant rate of 15 g/h. The temperature is adjusted to 60 C. HCl solution (430 g/L) is added with a constant rate of 14.3 g/h over a period of 15 h. During this period, the temperature is maintained at 60 C. and H.sub.2S is continuously injected at the specified rate. After this period, the pH of slurry is 2.2.

[0091] The slurry is filtered on a Buchner filter, resulting in a solution and solid residue. 227 g dry solid residue and 0.95 L solution is obtained. The mass balance of the complete experiment can be found in Table 4 below.

TABLE-US-00004 TABLE 4 Metal input and yields (in g) in solid residue and solution Input Solid residue Solution Ni 45 39 6 Mn 16 1 15 Co 16 14 2 Li 10 1 9 Al 3.8 3.4 0.4 Cu 0.9 0.9 0.0

[0092] This experiment demonstrates that HCl can be used as mineral acid instead of H.sub.2SO.sub.4.

EXAMPLE 5: USE OF H.SUB.2.S AND H.SUB.2.SO.SUB.4 .AT 60 C. ON MECHANICAL BLACK MASS

[0093] 116 g H.sub.2SO.sub.4 solution (1000 g/L) and 0.95 L water is added to the reactor. H.sub.2S is injected in the solution at a constant rate of 15 g/h. The temperature is adjusted to 60 C. Black mass is added to the reactor with a constant mass flow of 12.5 g/h for 12 h. The black mass is end-of-life battery scrap and is obtained after comminution and sieving. The black mass comprises 23% Ni, 6.4% Mn, 6.5% Co, 4% Li, 1.8% Al, 2.1% Cu and 1.1% F. The rest of the mass mainly comprises C, P and O.

[0094] During the 12 h in which the black mass is added, the temperature is maintained at 60 C. and H.sub.2S is continuously injected. After adding the last quantity of black mass, H.sub.2S is added for another 2 h at the specified rate. After this period, the pH of slurry is 2.2.

[0095] The slurry is filtered on a Buchner filter, resulting in a solution and solid residue. 167 g dry solid residue and 1.2 L solution is obtained. The mass balance of the complete experiment can be found in Table 5 below.

TABLE-US-00005 TABLE 5 Metal input and yields (in g) in solid residue and solution Input Solid residue Solution N 34.5 31 3.5 Mn 9.6 0.2 9.4 Co 9.8 9 0.8 Li 6.0 0.4 5.6 Al 2.7 2.2 0.5 Cu 3.2 3.2 0.0 F 1.7 1.0 0.7

[0096] This experiment demonstrates that the order of addition does not significantly affect the dissolution yield of Li and Mn or the overall outcome of the experiment.

EXAMPLE 6 (COMPARATIVE): USE OF H.SUB.2.S AND H.SUB.2.SO.SUB.4 .AT 60 C. ON PYROLYZED BLACK MASS

[0097] The experimental conditions and input feed are identical as in example 1, only the added amount of sulfuric acid is different. In total 110 g H.sub.2SO.sub.4 solution (1000 g/L) is added to the slurry in order to reach pH 4.4 (compared to pH 2.1 in Example 1).

[0098] The slurry is filtered on a Buchner filter, resulting in a solution and solid residue. 153 g dry solid residue and 0.86 L solution is obtained. The mass balance over the complete experiment can be found in Table 6 below.

TABLE-US-00006 TABLE 6 Metal input and yields (in g) in solid residue and solution Input Solid residue Solution Ni 30 30.0 0.0 Mn 18 3.4 14.6 Co 8.2 8.2 0.0 Li 7.7 0.7 7.0 Al 9.5 8.4 1.1 Cu 4.5 4.5 0.0

[0099] Working at a pH of 4.4 results in the dissolution of 80% of the Mn and 90% of the Li. This is lower than in Example 1, where Mn and Li are dissolved for 95% or more.