LITHIUM RECOVERY AND PURIFICATION

Abstract

A process for recovering lithium chloride from a lithium sulfate (Li.sub.2SO.sub.4)-containing mixture is described, comprising a step of sulfate removal using barium chloride (BaCl.sub.2). In embodiments, the process may further comprise one or more steps to reduce the level of one or more metals other than lithium and to reduce the level of sulfate by increasing the pH of the (Li.sub.2SO.sub.4)-containing mixture, e.g., using a calcium salt. In embodiments, treatments to reduce the level of one or more metals other than lithium, sulfate, and other components (e.g., calcium if used) may be used, producing a solution substantially comprising Li.sub.2SO.sub.4 for barium chloride (BaCl.sub.2) treatment, to form a precipitate comprising barium sulfate (BaSO.sub.4) and a solution substantially comprising lithium chloride.

Claims

1. A process for recovering lithium chloride from an initial aqueous solution comprising lithium sulfate (Li.sub.2SO.sub.4), the process comprising: increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to reduce the level of species of one or more metals other than lithium and to remove sulfate; treating the solution after the reducing of the one or more metals other than lithium and the removal of sulfate with a material to remove calcium and to produce a solution substantially comprising Li.sub.2SO.sub.4; treating the solution substantially comprising Li.sub.2SO.sub.4 with barium chloride (BaCl.sub.2) to form a precipitate comprising barium sulfate (BaSO.sub.4) and a solution substantially comprising lithium chloride; and recovering the lithium chloride (LiCl) from the solution following BaSO.sub.4 precipitation; wherein the aqueous solution comprising lithium sulfate (Li.sub.2SO.sub.4) is derived from a natural source or mineral deposit comprising a lithium species or from a synthetic or non-natural source comprising a lithium species.

2. The process of claim 1, wherein the lithium chloride is recovered in the form of lithium chloride or a hydrate thereof.

3. The process of claim 1 or 2, wherein the initial aqueous solution comprising lithium sulfate is derived from a natural source or mineral deposit comprising a lithium species.

4. The process of any one of claims 1 to 3, wherein the natural source or mineral deposit comprising the lithium species is an ore, clay or brine.

5. The process of any one of claims 1 to 4, wherein the natural source or mineral deposit comprising the lithium species is not a sulfide ore body.

6. The process of claim 4 or 5, wherein the ore or clay comprises lepidolite, hectorite, jaderite, spodumene, petalite and/or amblygonite.

7. The process of claim 4 or 5, wherein the brine comprises continental brine, geothermal brine and/or oilfield brine.

8. The process of claim 1 or 2, wherein the aqueous solution comprising lithium sulfate is derived from a synthetic or non-natural source comprising a lithium species.

9. The process of claim 8, wherein the synthetic or non-natural source comprising the lithium species comprises materials produced during recycling of lithium-ion batteries or other lithium bearing materials.

10. The process of claim 9, wherein the materials produced during recycling of lithium-ion batteries comprise lithium-ion battery electrode materials.

11. The process of claim 9 or 10, wherein the materials produced during recycling of lithium-ion batteries and/or lithium-ion battery electrode materials comprise lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and/or lithium nickel manganese cobalt oxide.

12. The process of any one of claims 1 to 11, further comprising producing the initial Li.sub.2SO.sub.4-comprising aqueous solution via treatment of a metal-comprising mixture with sulfuric acid (H.sub.2SO.sub.4).

13. The process of claim 12, wherein the metal-comprising mixture is the natural source or mineral deposit comprising the lithium species or the synthetic or non-natural source comprising the lithium species, or is a derivative of the natural source or mineral deposit comprising the lithium species or the synthetic or non-natural source comprising the lithium species.

14. The process of claim 12 or 13, wherein the metal-comprising mixture comprises lithium oxide (Li.sub.2O).

15. The process of any one of claims 1 to 14, wherein the initial Li.sub.2SO.sub.4-comprising aqueous solution has a pH of about 4.0 or less.

16. The process of claim 15, wherein the initial Li.sub.2SO.sub.4-comprising aqueous solution has a pH of about 2.0 to about 3.0.

17. The process of any one of claims 1 to 16, wherein the initial Li.sub.2SO.sub.4-comprising aqueous solution further comprises one or more metal sulfates of one or more metals other than lithium.

18. The process of any one of claims 12 to 17, wherein the metal-comprising mixture further comprises one or more metals other than lithium.

19. The process of claim 17 or 18, wherein the one or more metals other than lithium are one or more of Group I metals (other than lithium), Group Il metals, transition metals and/or post-transition metals.

20. The process of any one of claims 17 to 19, wherein the one or more metals other than lithium are one or more of calcium, sodium, magnesium, potassium, aluminum and iron.

21. The process of any one of claims 1 to 20, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 3.0 or higher.

22. The process of claim 21, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 4.0 to about 5.5.

23. The process of claim 21 or 22, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 7.0 or higher.

24. The process of claim 23, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to be about 9.0 to about 12.0.

25. The process of any one of claims 1 to 24, wherein the reducing the level of species of the one or more metals other than lithium by increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is performed in single step.

26. The process of claim 25, wherein the single step comprises increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to be about 3.0 or higher.

27. The process of claim 26, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 4.0 to about 5.5.

28. The process of claim 25, wherein the single step comprises increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to about 7.0 or higher.

29. The process of claim 28, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 9.0 to about 12.0.

30. The process of any one of claims 1 to 24, wherein the reducing the level of species of the one or more metals other than lithium by increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution comprises multiple steps.

31. The process of claim 30, wherein the multiple steps comprise a first step of increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to a pH of about 3.0 or higher to produce a first Li.sub.2SO.sub.4-comprising aqueous solution comprising reduced levels of metals other than lithium, followed by increasing the pH of the first Li.sub.2SO.sub.4-comprising aqueous solution to a pH of about 7.0 or higher to produce a second Li.sub.2SO.sub.4-comprising aqueous solution comprising further reduced levels of metals other than lithium.

32. The process of any one of claims 1 to 31, wherein increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution comprises treating with an alkaline material.

33. The process of claim 32, wherein the alkaline material comprises lime.

34. The process of claim 33, wherein the lime is in the form of a lime slurry or solid lime powder.

35. The process of any one of claims 1 to 34, wherein calcium removal comprises treating with a carbonate source to form a precipitate comprising one or more metal carbonates, wherein the lithium species is recovered from the solution remaining after precipitation of the one or more metal carbonates.

36. The process of claim 35, wherein the carbonate source is a carbonate salt or CO.sub.2 gas.

37. The process of claim 36, wherein the carbonate salt is at least one of sodium carbonate (Na.sub.2CO.sub.3) or lithium carbonate (Li.sub.2CO.sub.3).

38. The process of any one of claims 35 to 37, wherein the one or more metal carbonates are one or more of calcium carbonate and magnesium carbonate.

39. The process of any one of claims 25 to 31, wherein increasing the pH comprises treating the initial Li.sub.2SO.sub.4-comprising aqueous solution with one or more calcium salts.

40. The process of claim 39, wherein the treatment of the Li.sub.2SO.sub.4-comprising aqueous solution with the one or more calcium salts produces a precipitate comprising calcium sulfate (CaSO.sub.4).

41. The process of claim 40, wherein the precipitate further comprises magnesium and/or base metal oxides and/or hydroxides.

42. The process of any one of claims 1 to 41, wherein the treatment with barium chloride to form a precipitate comprising barium sulfate is performed at a pH of about 6.0 or higher.

43. The process of claim 42, wherein the treatment with barium chloride to form a precipitate comprising barium sulfate is performed at a pH of about 9.0 to about 12.0.

44. The process of any one of claims 1 to 43, wherein the barium chloride is added at a molar ratio of barium to sulfate of about 0.1 to about 3.0.

45. The process of claim 44, wherein the barium chloride is added at a molar ratio of barium to sulfate of about 0.8 to about 1.5.

46. The process of claim 45, wherein the barium chloride is added at a molar ratio of barium to sulfate of about 0.95 to about 1.1.

47. The process of any one of claims 1 to 46, wherein the lithium chloride is recovered by crystallization from the aqueous solution.

48. The process of claim 47, comprising at least one of heat treatment or subjecting the aqueous solution to reduced pressure to remove at least a part of the water from the aqueous solution.

49. The process of claim 48, wherein at least about 10% of the water is removed.

50. The process of claim 49, wherein at least about 15% of the water is removed.

51. The process of any one of claims 1 to 50, wherein the recovered lithium species is a hydrate of LiCl.

52. The process of any one of claims 1 to 51, further comprising subjecting the BaSO.sub.4 to a treatment to generate barium salts including barium oxide, barium hydroxide or barium carbonate and to recover sulfur as sodium sulfide, sodium hydrosulfide, sulfuric acid, or elemental sulfur.

53. The process of claim 51 or 52, further comprising subjecting SO.sub.3 to water treatment to form H.sub.2SO.sub.4.

54. The process of claim 53, wherein the H.sub.2SO.sub.4 is used for treating the metal-comprising mixture of claim 12.

55. The process of any one of claims 1 to 54, wherein the solution substantially comprising Li.sub.2SO.sub.4 is treated with barium chloride at a pH of at least about 6, at least about 7, about 6 to about 12, about 7 to about 12, about 8 to about 12, about 9 to about 12, about 10 to about 12, about 6, about 7, about 8, about 9, about 10, about 11, or about 12.

56. The process of claim 39 or 40, wherein treating with the one or more calcium salts is performed at a pH of at least about 3, at least about 4, at least about 5, at least about 6, at least about 7, about 3 to about 12, about 4 to about 12, about 5 to about 12, about 6 to about 12, about 7 to about 12, about 8 to about 12, about 9 to about 12, about 10 to about 12, about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, or about 12.

57. The process of claim 56, wherein treating with the one or more calcium salts is performed at a molar ratio of calcium to sulfate of about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%.

58. The process of any one of claims 1 to 57, wherein the solution comprising substantially Li.sub.2SO.sub.4, is treated with barium chloride at a molar ratio of barium to sulfate of about 10% to about 300%, about 80% to about 150%, about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 95% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%.

59. The process of any one of claims 1 to 58, wherein the solution substantially comprising Li.sub.2SO.sub.4 is treated with barium chloride at a temperature of about 1? C. to about 100? C., about 5? C. to about 75? C., about 5? C. to about 60? C., about 10? C. to about 60? C., about 15? C. to about 60? C., about 20? C. to about 60? C., or at room temperature.

60. The process of any one of claims 35 to 38, wherein the treatment with the carbonate source is performed at a molar ratio of carbonate to the one or more metals of about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%.

61. The process of any one of claims 1 to 60, wherein the concentration of lithium in the initial aqueous solution comprising lithium sulfate (Li.sub.2SO.sub.4) is about 1 to about 25 g/L, about 5 to about 25 g/L, about 5 to about 20 g/L, about 5 to about 15 g/L, about 8 to about 12 g/L, about 5 g/L, about 6 g/L, about 7 g/L, about 8 g/L, about 9 g/L, about 10 g/L, about 11 g/L, about 12 g/L, about 13 g/L, about 14 g/L, or about 15 g/L.

62. The process of any one of claims 1 to 61, wherein at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, 95% or 99% of the lithium is recovered from the initial aqueous solution comprising lithium sulfate.

63. The process of any one of claims 1 to 62, wherein about 50% to about 99%, about 55% to about 99%, about 60% to about 99%, about 65% to about 99%, about 70% to about 99%, about 75% to about 99%, about 80% to about 99%, or about 90% to about 99% of the lithium is recovered from the initial aqueous solution comprising lithium sulfate.

64. A process for recovering lithium chloride from a material comprising a lithium species and species of one or more metals other than lithium, the process comprising: treating the material with sulfuric acid (H.sub.2SO.sub.4) to provide an initial Li.sub.2SO.sub.4-comprising aqueous solution; increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to reduce the level of species of one or more metals other than lithium and to remove sulfate; treating the solution after the reducing of the one or more metals other than lithium and the removal of sulfate with a material to remove calcium and to produce a solution substantially comprising Li.sub.2SO.sub.4; treating the solution substantially comprising Li.sub.2SO.sub.4 with barium chloride to form a precipitate comprising barium sulfate and a solution substantially comprising lithium chloride; and recovering the lithium chloride from the solution remaining following the removal of the barium sulfate comprising precipitate in the form of lithium chloride or a hydrate thereof, via heat treatment and crystallization.

65. The process of claim 64, wherein the reducing the level of species of the one or more metals other than lithium by increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is performed in single step.

66. The process of claim 65, wherein the single step comprises increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to be about 3.0 or higher.

67. The process of claim 66, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 4.0 to about 5.5.

68. The process of claim 67, wherein the single step comprises increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to about 7.0 or higher.

69. The process of claim 68, wherein the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution is increased to about 9.0 to about 12.0.

70. The process of claim 64, wherein the reducing the level of species of the one or more metals other than lithium by increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution comprises multiple steps.

71. The process of claim 70, wherein the multiple steps comprise a first step of increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to a pH of about 3.0 or higher to produce a first Li.sub.2SO.sub.4-comprising aqueous solution comprising reduced levels of metals other than lithium, followed by increasing the pH of the first Li.sub.2SO.sub.4-comprising aqueous solution to a pH of about 7.0 or higher to produce a second Li.sub.2SO.sub.4-comprising aqueous solution comprising further reduced levels of metals other than lithium.

72. The process of any one of claims 64 to 71, wherein increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution comprises treating with an alkaline material.

73. The process of claim 72, wherein the alkaline material comprises lime.

74. The process of claim 73, wherein the lime is in the form of a lime slurry or solid lime powder.

75. The process of any one of claims 64 to 74, wherein calcium removal comprises treating with a carbonate source to form a precipitate comprising one or more metal carbonates, wherein the lithium species is recovered from the solution remaining after precipitation of the one or more metal carbonates.

76. The process of claim 75, wherein the carbonate source is a carbonate salt or CO.sub.2 gas.

77. The process of claim 76, wherein the carbonate salt is at least one of sodium carbonate (Na.sub.2CO.sub.3) or lithium carbonate (Li.sub.2CO.sub.3).

78. The process of any one of claims 75 to 77, wherein the one or more metal carbonates are one or more of calcium carbonate and magnesium carbonate.

79. The process of any one of claims 64 to 71, wherein increasing the pH comprises treating the initial Li.sub.2SO.sub.4-comprising aqueous solution with one or more calcium salts.

80. The process of any one of claims 64 to 79, wherein the material is obtained from a natural source or mineral deposit comprising lithium species.

81. The process of claim 80, wherein the natural source is an ore, clay, brine or other mineral deposit.

82. The process of claim 81, wherein the ore or clay comprises lepidolite, hectorite, jaderite, spodumene, petalite and/or amblygonite.

83. The process of any one of claims 80 to 82, wherein the natural source or mineral deposit comprising lithium species is not a sulfide ore body.

84. The process of claim 81, wherein the brine comprises continental brine, geothermal brine and/or oilfield brine.

85. The process of any one of claims 64 to 79, wherein the material is obtained from a synthetic or non-natural source comprising lithium species.

86. The process of claim 85, wherein the synthetic or non-natural source comprising lithium species comprises materials produced during recycling of lithium-ion batteries or other lithium bearing materials.

87. The process of claim 86, wherein the materials produced during recycling of lithium-ion batteries comprise lithium-ion battery electrode materials.

88. The process of claim 87, wherein the lithium-ion battery electrode materials comprise lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and/or lithium nickel manganese cobalt oxide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

[0094] The following figures/drawings form part of the present specification and are included to further demonstrate certain aspects of the present specification. The present specification may be better understood by reference to one or more of these figures/drawings in combination with the detailed description. In the appended drawings/figures:

[0095] FIG. 1Illustration of a flowchart illustrating the process for recovering lithium as LiCl from an Li.sub.2SO.sub.4 containing solution in accordance with an embodiment of the present disclosure.

[0096] FIG. 2Illustration of a flowchart illustrating AlFe removal steps in accordance with an embodiment of the present disclosure.

[0097] FIG. 3Illustration of Fe and Al recovery (%) and Li loss (%) at pH=4.75.

[0098] FIG. 4Illustration of an XRD pattern of solid residue from the AlFe removal step.

[0099] FIG. 5Illustration of a flowchart illustrating Mg removal steps in accordance with an embodiment of the present disclosure.

[0100] FIG. 6Illustration of sulfate and Mg removal (%) and Li loss (%) at pH=10 and CaO=5% at T=65? C.

[0101] FIG. 7Illustration of an XRD pattern of solid residue from primary sulfate removal step.

[0102] FIG. 8Illustration of a flowchart illustrating Ca removal steps in accordance with an embodiment of the present disclosure.

[0103] FIG. 9Illustration of Ca removal (%) and Li loss (%) in samples at Na.sub.2CO.sub.3/Ca=2 and at room temperature.

[0104] FIG. 10Illustration of a flowchart illustrating BaSO.sub.4 removal steps in accordance with an embodiment of the present disclosure.

[0105] FIG. 11Illustration of an XRD pattern of the BaSO.sub.4 residue following treatment with BaCl.sub.2.

[0106] FIG. 12Titration curve for PLS by 1 M NaOH at room temperature.

[0107] FIGS. 13A and 13BConcentration of the elements in AlFe removal step at different pH.

[0108] FIG. 14Concentration of Fe, Al and Li in kinetic samples at pH=4.5 at room temperature

[0109] FIG. 15Fe and Al recovery (%) and Li loss (%) at pH=4.5 at room temperature.

[0110] FIG. 16Concentration of Fe, Al and Li in kinetic samples at pH=5 at room temperature.

[0111] FIG. 17Fe and Al recovery (%) and Li loss (%) at pH=5 at room temperature.

[0112] FIG. 18Effect of time and pH on Li loss at room temperature.

[0113] FIG. 19Concentration of Fe, Al and Li in kinetic samples at pH=4.75 and T=Room T.

[0114] FIG. 20Fe and Al recovery (%) and Li loss (%) at pH=4.75 and T=Room T.

[0115] FIG. 21Concentration of Fe, Al and Li in kinetic samples at pH=4.75 and T=45? C.

[0116] FIG. 22Fe and Al recovery (%) and Li loss (%) at pH=4.75 and T=45? C.

[0117] FIG. 23Concentration of Fe, Al and Li in kinetic samples at pH=4.75 and T=65? C.

[0118] FIG. 24Fe and Al recovery (%) and Li loss (%) at pH=4.75 and T=65? C.

[0119] FIG. 25Concentration of Fe, Al and Li in kinetic samples at pH=4.75 and T=85? C.

[0120] FIG. 26Fe and Al recovery (%) and Li loss (%) at pH=4.75 and T=85? C.

[0121] FIG. 27Effect of time and Temperature on Li loss.

[0122] FIG. 28Concentration of Fe, Al and Li in kinetic samples at pH=4.75 and T=65? C. with 10% CaO.

[0123] FIG. 29Fe and Al recovery (%) and Li loss (%) at pH=4.75 and T=65? C. with 10% CaO.

[0124] FIG. 30Concentration of the elements in kinetic samples at pH=7 and CaO=5% at room temperature.

[0125] FIG. 31Mg and sulfate removal (%) and Li loss (%) at pH=7 and CaO=5% at room temperature.

[0126] FIG. 32Concentration of the elements in kinetic samples at pH=8 and CaO=5% at room temperature.

[0127] FIG. 33Mg and sulfate removal (%) and Li loss (%) at pH=8 and CaO=5% at room temperature.

[0128] FIG. 34Concentration of the elements in kinetic samples at pH=9 and CaO=5% at room temperature.

[0129] FIG. 35Mg and Sulfate removal (%) and Li loss (%) at pH=9 and CaO=5% at room temperature.

[0130] FIG. 36Concentration of the elements in kinetic samples at pH=9.5 and CaO=5% at room temperature.

[0131] FIG. 37Mg and Sulfate removal (%) and Li loss (%) at pH=9.5 and CaO=5% at room temperature.

[0132] FIG. 38Concentration of the elements in kinetic samples at pH=10 and CaO=5% at room temperature.

[0133] FIG. 39Mg and Sulfate removal (%) and Li loss (%) at pH=10 and CaO=5% at room temperature.

[0134] FIG. 40Effect of time and pH on Mg removal at room temperature.

[0135] FIG. 41Concentration of the elements in kinetic samples at pH=10 and CaO=5% at T=45? C.

[0136] FIG. 42Sulfate removal (%) and Li loss (%) at pH=10 and CaO=5% at T=45? C.

[0137] FIG. 43Concentration of the elements in kinetic samples at pH=10 and CaO=5% at T=65? C.

[0138] FIG. 44Mg and Sulfate removal (%) and Li loss (%) at pH=10 and CaO=5% at T=65? C.

[0139] FIG. 45Concentration of the elements in kinetic samples at pH=10 and CaO=5% at T=85? C.

[0140] FIG. 46Mg and Sulfate removal (%) and Li loss (%) at pH=10 and CaO=5% at T=85? C.

[0141] FIG. 47Effect of time and Temperature on Mg removal %.

[0142] FIG. 48Concentration of the elements in kinetic samples at pH=10 and CaO=1% at room T.

[0143] FIG. 49Mg and Sulfate removal (%) and Li loss (%) at pH=10 and CaO=1% at room T.

[0144] FIG. 50Concentration of the elements in kinetic samples at pH=10 and CaO=10% at room T.

[0145] FIG. 51Mg and Sulfate removal (%) and Li loss (%) at pH=10 and CaO=10% at room T.

[0146] FIG. 52Concentration of the elements in kinetic samples in presence of Amberlite IRC-50 at room temperature.

[0147] FIG. 53Ca removal (%) and Li loss (%) in presence of Amberlite IRC-50 at room temperature.

[0148] FIG. 54Concentration of the elements in kinetic samples at CO.sub.2=0.5 L/min and room T.

[0149] FIG. 55Ca removal (%) and Li loss (%) at CO.sub.2=0.5 L/min and room T.

[0150] FIG. 56Concentration of the elements in kinetic samples at CO.sub.2=1.5 L/min and room T.

[0151] FIG. 57Ca removal (%) and Li loss (%) at CO.sub.2=0.5 L/min and room T.

[0152] FIG. 58Concentration of the elements in kinetic samples at Na.sub.2CO.sub.3=0.363 g/250 ml (Na.sub.2CO.sub.3/Ca=0.9) and room T.

[0153] FIG. 59Ca removal (%) and Li loss (%) at samples at Na.sub.2CO.sub.3=0.363 g/250 ml (Na.sub.2CO.sub.3/Ca=0.9) and room T.

[0154] FIG. 60Concentration of the elements in kinetic samples at Na.sub.2CO.sub.3=0.41 g/250 ml (Na.sub.2CO.sub.3/Ca=1.0) and room T.

[0155] FIG. 61Ca removal (%) and Li loss (%) at samples at Na.sub.2CO.sub.3=0.41 g/250 ml (Na.sub.2CO.sub.3/Ca=1.0) and room T.

[0156] FIG. 62Concentration of the elements in kinetic samples at Na.sub.2CO.sub.3=0.485 g/250 ml (Na.sub.2CO.sub.3/Ca=1.2) and room T.

[0157] FIG. 63Ca removal (%) and Li loss (%) at samples at Na.sub.2CO.sub.3=0.485 g/250 mL (Na.sub.2CO.sub.3/Ca=1.2) and room T.

[0158] FIG. 64Concentration of the elements in kinetic samples at Na.sub.2CO.sub.3=0.605 g/250 ml (Na.sub.2CO.sub.3/Ca=1.5) and room T.

[0159] FIG. 65Ca removal (%) and Li loss (%) at samples at Na.sub.2CO.sub.3=0.605 g/250 ml (Na.sub.2CO.sub.3/Ca=1.5) and room T.

[0160] FIG. 66Concentration of the elements in kinetic samples at Na.sub.2CO.sub.3=0.807 g/250 ml (Na.sub.2CO.sub.3/Ca=2) and room T.

[0161] FIG. 67Ca removal (%) and Li loss (%) in samples at Na.sub.2CO.sub.3=0.807 g/250 ml (Na.sub.2CO.sub.3/Ca=2) and room T.

[0162] FIG. 68Ca removal (%) in presence of different reagents at room T.

[0163] FIG. 69Concentration of elements in kinetic samples at pH=7 and Ba/SO.sub.4=1 at room temperature.

[0164] FIG. 70Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=1 at room temperature.

[0165] FIG. 71Concentration of elements in kinetic samples at pH=10 and Ba/SO.sub.4=1 at room temperature.

[0166] FIG. 72Concentration of elements in kinetic samples at pH=11 and Ba/SO.sub.4=1 at room temperature.

[0167] FIG. 73Concentration of elements in kinetic samples at pH=12 and Ba/SO.sub.4=1 at room temperature.

[0168] FIG. 74Effect of time and pH on sulfate removal at Ba/SO.sub.4=1.

[0169] FIG. 75Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=0.9 at room temperature

[0170] FIG. 76Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=0.95 at room temperature.

[0171] FIG. 77Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=0.98 at room temperature.

[0172] FIG. 78Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=1.02 at room temperature.

[0173] FIG. 79Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=1.05 at room temperature.

[0174] FIG. 80Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=1.1 at room temperature.

[0175] FIG. 81Effect of time and Ba/SO.sub.4 ratio on sulfate removal at pH=9 and room T.

[0176] FIG. 82Effect of time and Ba/SO.sub.4 ratio on dissolved Ba in the solution at pH=9 and room T.

[0177] FIG. 83Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=1.05 at T=45? C.

[0178] FIG. 84Concentration of elements in kinetic samples at pH=9 and Ba/SO.sub.4=1.05 at T=65? C.

[0179] FIG. 85Effect of time and T on sulfate removal at pH=9 and Ba/SO.sub.4=1.05.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

1. Glossary/Definitions

[0180] The word a or an when used in conjunction with the term comprising in the claims and/or the specification may mean one, but it is also consistent with the meaning of one or more, at least one, and one or more than one unless the content clearly dictates otherwise. Similarly, the word another may mean at least a second or more unless the content clearly dictates otherwise.

[0181] As used in this specification and claim(s), the words comprising (and any form of comprising, such as comprise and comprises), having (and any form of having, such as have and has), including (and any form of including, such as include and includes) or containing (and any form of containing, such as contain and contains), are inclusive or open-ended and do not exclude additional, unrecited elements or process steps.

[0182] As used in this specification and claim(s), the word consisting and its derivatives, are intended to be close ended terms that specify the presence of stated features, elements, components, groups, integers, and/or steps, and also exclude the presence of other unstated features, elements, components, groups, integers and/or steps.

[0183] The term consisting essentially of, as used herein, is intended to specify the presence of the stated features, elements, components, groups, integers, and/or steps as well as those that do not materially affect the basic and novel characteristic(s) of these features, elements, components, groups, integers, and/or steps.

[0184] The terms about, substantially and approximately as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. These terms of degree should be construed as including a deviation of at least ?5% of the modified term if this deviation would not negate the meaning of the word it modifies.

[0185] All methods or processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. Further, in embodiments, various steps may be repeated, for example to increase recovery and/or purification.

[0186] The use of any and all examples, or exemplary language (e.g., such as) provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed.

[0187] No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.

[0188] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by the person of ordinary skill in the art (POSITA) to which this disclosure belongs.

[0189] In an aspect, the present disclosure relates to a process for recovering lithium chloride from an initial aqueous solution comprising lithium sulfate (Li.sub.2SO.sub.4), the process comprising: increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to reduce the level of species of one or more metals other than lithium and to remove sulfate; treating the solution after the reducing of the one or more metals other than lithium and the removal of sulfate with a material to remove calcium and to produce a solution substantially comprising Li.sub.2SO.sub.4; treating the solution substantially comprising Li.sub.2SO.sub.4 with barium chloride (BaCl.sub.2) to form a precipitate comprising barium sulfate (BaSO.sub.4) and a solution substantially comprising lithium chloride; and recovering the lithium chloride (LiCl) from the solution following BaSO.sub.4 precipitation; wherein the aqueous solution comprising lithium sulfate (Li.sub.2SO.sub.4) is derived from a natural source or mineral deposit comprising a lithium species or from a synthetic or non-natural source comprising a lithium species.

[0190] Precipitation is understood in the chemical field to relate to the process by which one state is ejected or formed from another state, such as the creation of a solid from a solution, e.g., via a reaction that creates an insoluble product. The resulting precipitate or solid may remain in solution, may settle by gravity, or may be separated from the solution by other means, such as by sedimentation/centrifugation or filtration. The resulting liquid or solution remaining after sedimentation/centrifugation is often referred to as a supernate or supernatant; the resulting liquid or solution remaining after filtration is often referred to as a filtrate. In embodiments described herein, such resulting liquid or solution remaining after precipitation may be subjected to further treatments in a stepwise recovery or purification process. Similarly, in embodiments the precipitates may be treated to generate compounds for various uses, such as the recycling steps described herein. In embodiments, the precipitate may be subjected to one or more washes (e.g., with water), and the wash liquid may also be subjected to further treatments in a stepwise recovery or purification process (e.g., in combination with the resulting liquid or solution remaining after precipitation).

[0191] In an embodiment of the present disclosure, the lithium species may be recovered in the form of lithium chloride (LiCl) or a hydrate thereof, such as LiCl.Math.H.sub.2O.

2. Preparation of Li.SUB.2.SO.SUB.4.-Comprising Aqueous Solution

[0192] In an embodiment of the present disclosure, the process further comprises preparing the Li.sub.2SO.sub.4-comprising aqueous solution via treatment of a metal-comprising material with sulfuric acid (H.sub.2SO.sub.4) (e.g., via sulfuric acid leaching). In embodiments, the metal-comprising material comprises metal species other than lithium species, and recovery of the lithium species from such a material comprises obtaining a preparation enriched in lithium species and having reduced amounts of metal species other than lithium species, relative to the starting mixture. In embodiments, such metal species other than lithium comprise one or more Group I metals (other than lithium), Group Il metals, transition metals and/or post-transition metals. In embodiments, such metals other than lithium comprise one or more of calcium, sodium, magnesium, potassium, aluminum and iron.

[0193] In embodiments of the present disclosure, the Li.sub.2SO.sub.4-comprising aqueous solution has a pH of about 4.0 or less, in a further embodiment of about 3.5 or less, in a further embodiment of about 3.0 or less, in further embodiments of about 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, or 2.5 or less. In further embodiments the Li.sub.2SO.sub.4-comprising aqueous solution has a pH of about 2.0 to about 3.0, about 2.1 to about 2.9, about 2.2 to about 2.8, about 2.3 to about 2.7, about 2.4 to about 2.6, or about 2.5.

3. Removal of Metal Species Other than Lithium Species

[0194] In embodiments of the present disclosure, the reduction of the amount/removal of metal species other than lithium species (e.g., Al, Fe, Mg, etc.) present in the Li.sub.2SO.sub.4-comprising aqueous solution may be accomplished by increasing the pH of the Li.sub.2SO.sub.4-comprising aqueous solution. In embodiments of the present disclosure, the reduction of the amount/removal of metal species other than lithium species present in the Li.sub.2SO.sub.4-comprising aqueous solution may be accomplished in a single step (e.g., a single pH increase) or in multiple steps (e.g., multiple pH increases). In embodiments of the present disclosure, the pH is increased by treatment with an alkaline material (e.g., lime, for example as a lime slurry or solid lime powder). In embodiments of the present disclosure, the pH is increased by treatment with one or more calcium salts, either in a single step or in multiple steps. In embodiments, the pH of the Li.sub.2SO.sub.4-comprising aqueous solution is adjusted to be about 3.0 or higher, in a further embodiment to be about 7.0 or higher, in a further embodiment about 3.0 to about 12.0, in a further embodiment about 3.0 to about 7.0, in a further embodiment about 9.0 to about 12.0, in a further embodiment about 3.0 to about 6.0, in a further embodiment about 3.5 to about 5.5, in a further embodiment about 4.0 to about 5.5, in a further embodiment about 4.5 to about 5.0, in a further embodiment about 4.6 to about 4.8 in further embodiments, about 4.5, about 4.75 or about 5.0.

[0195] In embodiments of the present disclosure, the metal species other than lithium, if in reduced form, may be treated with oxygen or other oxidants to be oxidized to more oxidized forms, prior to removal via pH adjustment.

[0196] In embodiments of the present disclosure, the reduction of the amount/removal of metal species other than lithium species may be performed at ambient temperature (e.g., about 22-25? C.) or higher, in a further embodiment at about 20? C. to about 30? C., in a further embodiment at about 25? C. to about 100? C., in a further embodiment at about 30? C. or higher, in a further embodiment at about 30? C. to about 100? C., in a further embodiment at about 35? C. or higher, in a further embodiment at about 35? C. to about 100? C., in a further embodiment about 40? C. or higher, in a further embodiment about 40? C. to about 100? C., in a further embodiment at about 45? C. or higher, in a further embodiment at about 45? C. to about 100? C., in a further embodiment at about 50? C. or higher, in a further embodiment at about 50? C. to about 100? C., in a further embodiment about 55? C. or higher, in a further embodiment about 55? C. to about 100? C., in a further embodiment at about 60? C. or higher, in a further embodiment at about 60? C. to about 100? C., in a further embodiment at about 65? C. or higher, in a further embodiment at about 65? C. to about 100? C., in a further embodiment about 70? C. or higher, in a further embodiment about 70? C. to about 100? C., in a further embodiment at about 75? C. or higher, in a further embodiment at about 75? C. to about 100? C., in a further embodiment at about 80? C. or higher, in a further embodiment at about 80? C. to about 100? C., in a further embodiment about 85? C. or higher, in a further embodiment about 85? C. to about 100? C., in a further embodiment at about 90? C. or higher, in a further embodiment at about 90? C. to about 100? C., in a further embodiment at about 95? C. or higher, in a further embodiment at about 95? C. to about 100? C., in a further embodiment at about 40? C. to about 50? C., in a further embodiment at about 60? C. to about 70? C., in a further embodiment at about 80? C. to about 90? C.

[0197] In embodiments of the present disclosure, the reduction of the amount/removal of metal species other than lithium species results in a removal of at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, at least 99.5% of metal species other than lithium species.

[0198] In embodiments of the present disclosure, the step of reduction of the amount/removal of metal species other than lithium species results in less than about 10%, less than about 9%, less than about 8%, less than about 7%, less than about 6%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, less than about 1%, or less than about 0.5% of lithium species being removed.

4. Further Removal of Metal Species Other than Lithium Species

[0199] In embodiments of the present disclosure, a further step for the reduction of the amount/removal of metal species other than lithium species may be performed, to for example remove other metals other than lithium species, for example via treatment with alkaline material (e.g., lime, for example as a lime slurry or solid lime powder) to increase the pH of the solution, for example to be about 7.0 or higher, in a further embodiment about 7.5 or higher, in a further embodiment about 8.0 or higher, in a further embodiment about 8.5 or higher, in a further embodiment about 9 or higher, in a further embodiment, about 9.5 to about 12.5, in a further embodiment about 9.0 to about 12.0, in a further embodiment, about 9.2 to about 12.0, in a further embodiment, about 9.0 to about 11.0, in a further embodiment, about 9.2 to about 10.8, in a further embodiment, about 9.4 to about 10.6, in a further embodiment, about 9.5 to about 10.5, in a further embodiment, about 9.6 to about 10.4, in a further embodiment, about 9.8 to about 10.2, in further embodiments about 9.0, about 9.5, about 10.0, about 10.5, about 11.0, about 11.5 or about 12.0.

[0200] In embodiments of the present disclosure, the further reduction of the amount/removal of metal species other than lithium species may be performed at ambient temperature (e.g., about 22-25? C.) or higher, in a further embodiment at about 20? C. to about 30? C., in a further embodiment at about 25? C. to about 100? C., in a further embodiment at about 30? C. or higher, in a further embodiment at about 30? C. to about 100? C., in a further embodiment at about 35? C. or higher, in a further embodiment at about 35? C. to about 100? C., in a further embodiment about 40? C. or higher, in a further embodiment about 40? C. to about 100? C., in a further embodiment at about 45? C. or higher, in a further embodiment at about 45? C. to about 100? C., in a further embodiment at about 50? C. or higher, in a further embodiment at about 50? C. to about 100? C., in a further embodiment about 55? C. or higher, in a further embodiment about 55? C. to about 100? C., in a further embodiment at about 60? C. or higher, in a further embodiment at about 60? C. to about 100? C., in a further embodiment at about 65? C. or higher, in a further embodiment at about 65? C. to about 100? C., in a further embodiment about 70? C. or higher, in a further embodiment about 70? C. to about 100? C., in a further embodiment at about 75? C. or higher, in a further embodiment at about 75? C. to about 100? C., in a further embodiment at about 80? C. or higher, in a further embodiment at about 80? C. to about 100? C., in a further embodiment about 85? C. or higher, in a further embodiment about 85? C. to about 100? C., in a further embodiment at about 90? C. or higher, in a further embodiment at about 90? C. to about 100? C., in a further embodiment at about 95? C. or higher, in a further embodiment at about 95? C. to about 100? C., in a further embodiment at about 40? C. to about 50? C., in a further embodiment at about 60? C. to about 70? C., in a further embodiment at about 62? C. to about 68? C., in a further embodiment at about 63? C. to about 67? C., in a further embodiment at about 80? C. to about 90? C.

[0201] In embodiments of the present disclosure, different sources of such a metal-comprising mixture may be used in the processes described herein. For example, natural sources or mineral deposits may be used, such as an ore, clay or brine comprising lithium species. In embodiments, such ores or clays comprise for example minerals such as lepidolite, hectorite, jaderite, spodumene, petalite and/or amblygonite. Brines include for example continental brines, geothermal brines and oilfield brines.

[0202] In an embodiment of the present disclosure, the natural source or mineral deposit is not a sulfide ore body.

[0203] In a further embodiment of the present disclosure, synthetic, non-natural, processed or man-made sources may be used as a starting material for the processes described herein, such as materials produced during recycling of lithium-ion batteries, e.g., from the electrode materials thereof (which in embodiments comprise lithium species such as lithium cobalt oxide (LiCoO.sub.2), lithium manganese oxide (LiMn.sub.2O.sub.4), lithium iron phosphate (LiFePO.sub.4), lithium nickel manganese Cobalt (NMC; Li(NiMnCo)O.sub.2).

[0204] In embodiments of the present disclosure, such natural or synthetic/non-natural sources may be treated by hydrometallurgy, pyrometallurgy and/or electrometallurgy processes. In embodiments, such natural or synthetic/non-natural sources may be treated by processes such as calcination, roasting, alkali or acid treatment, and leaching (with water to generate an aqueous solution comprising metal salts).

[0205] In an embodiment of the present disclosure, the starting mixture (metal-comprising mixture) is not obtained by electrolysis.

[0206] In an embodiment of the present disclosure, the starting mixture (metal-comprising mixture) comprises lithium species in the form of lithium oxide (Li.sub.2O).

[0207] In embodiments of the present disclosure, the precipitation of barium sulfate may be performed using barium chloride (BaCl.sub.2) or hydrates thereof, such as BaCl.sub.2.Math.2H.sub.2O.

5. Primary Sulfate Removal

[0208] In embodiments of the present disclosure, a primary sulfate removal step (e.g., in addition to and prior to the sulfate removal using BaCl.sub.2) is implemented via precipitation with a salt other than barium chloride, such as one or more calcium salts. In an embodiment, the process described herein further comprises treating the Li.sub.2SO.sub.4-comprising aqueous solution with one or more calcium salts to form a precipitate comprising calcium sulfate (CaSO.sub.4). This step is carried out prior to precipitation with barium chloride and prior to precipitation with a carbonate source (e.g., the solution remaining after CaSO.sub.4 and carbonate precipitation is treated with barium chloride to form the precipitate comprising BaSO.sub.4).

[0209] In embodiments of the present disclosure, such a primary step of sulfate removal, prior to treatment with barium chloride, is performed via treatment with a salt other than barium chloride, such as one or more calcium salts, such as in the form of an alkaline material (e.g., lime, for example as a lime slurry or solid lime powder) to increase the pH of the solution, for example to be about 3.0 or higher, or to be about 7.0 or higher, in a further embodiment 4.5 or higher, in a further embodiment 5.0 or higher, in a further embodiment 5.5 or higher, in a further embodiment 6.0 or higher, in a further embodiment 6.5 or higher, in a further embodiment 7.0 or higher, in a further embodiment about 7.5 or higher, in a further embodiment about 8.0 or higher, in a further embodiment about 8.5 or higher, in a further embodiment about 9 or higher, in a further embodiment, in a further embodiment about 3.0 to about 12.0, in a further embodiment about 3.0 to about 7.0, in a further embodiment about 9.5 to about 12.0, in a further embodiment about 9.0 to about 12.0, in a further embodiment, about 9.2 to about 12.0, in a further embodiment, about 9.0 to about 10.0, in a further embodiment, about 9.0 to about 11.0, in a further embodiment, about 9.5 to about 10.5, in further embodiments about 9.0, about 9.5, about 10.0, about 10.5, about 11.0, about 11.5 or about 12.0. In embodiments of the present disclosure, the primary step of sulfate removal may be accomplished in a single step (e.g., a single pH increase) or in multiple steps (e.g., multiple pH increases). In an embodiment of the present disclosure, such a primary step of sulfate removal also results in the further reduction of the amount/removal of metal species other than lithium species. In embodiments of the present disclosure, the steps of further removal of metal species other than lithium species and primary sulfate removal may be combined into one step.

[0210] In embodiments of the present disclosure, the steps of removal of metal species other than lithium species and primary sulfate removal may be combined into one step, via direct treatment of the Li.sub.2SO.sub.4-comprising aqueous solution with one or more calcium salts in the form of an alkaline material (e.g., lime, for example as a lime slurry or solid lime powder) to increase the pH of the solution as noted above, thus resulting in both removal of metal species other than lithium species and primary sulfate precipitation in a single step.

[0211] Following treatment with one or more calcium salts, gypsum is produced as a by-product. In embodiments of the present disclosure, the gypsum may be recycled for other purposes. In such cases, it is preferred to perform the removal of the metal species other than lithium species and primary sulfate removal in separate steps, such that the gypsum produced is of greater purity and has fewer metal contaminants. For greater clarity, in such cases, the pH is increased by treatment with one or more calcium salts in the form of an alkaline material (e.g., lime, for example as a lime slurry or solid lime powder), in multiple steps. For example, a first removal step may be carried out at a pH of about 4.0 to about 5.5 to produce a first gypsum-containing mixture which also contains metal species other than lithium species (e.g., Al, Fe), followed by a second removal step at a pH of about 9 to 11 to produce a second gypsum-containing mixture, wherein the gypsum in the second gypsum-containing mixture is of greater purity and has fewer metal contaminants relative to that of the first gypsum-containing mixture.

[0212] In embodiments of the present disclosure, the Li.sub.2SO.sub.4-comprising aqueous solution is treated with the one or more calcium salts at a molar ratio of calcium to sulfate of about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%.

6. Calcium Removal

[0213] In embodiments of the present disclosure, a calcium removal step (e.g., in addition to and prior to the sulfate removal using BaCl.sub.2) is implemented via precipitation with a carbonate source in the form of a carbonate salt or CO.sub.2 gas. In an embodiment, the process described herein further comprises treating the Li.sub.2SO.sub.4-comprising aqueous solution, following primary sulfate removal, with one or more carbonate salts to form a precipitate comprising one or more metal carbonates. In particular embodiments of the present disclosure, the carbonate salt is at least one of sodium carbonate (Na.sub.2CO.sub.3) or lithium carbonate (Li.sub.2CO.sub.3) and the one or more metal carbonates are one or more of calcium carbonate and magnesium carbonate. This step is carried out prior to precipitation with barium chloride and following primary sulfate removal (e.g., the solution remaining after CaSO.sub.4 precipitation is treated with a carbonate source).

[0214] In embodiments of the present disclosure, the calcium removal step may be performed at a pH of about 7.0 or higher, in a further embodiment about 7.5 or higher, in a further embodiment about 8.0 or higher, in a further embodiment about 8.5 or higher, in a further embodiment about 9 or higher, in a further embodiment, about 9.5 to about 12.5, in a further embodiment, about 9.5 to about 12.5, in a further embodiment about 8.0 to about 10.0, in a further embodiment, about 8.2 to about 9.8, in a further embodiment, about 8.4 to about 9.6, in a further embodiment, about 8.5 to about 9.5, in a further embodiment, about 8.6 to about 9.4, in a further embodiment, about 8.7 to about 9.3, in a further embodiment, about 9.2 to about 12.0, in a further embodiment, about 9.0 to about 11.0, in a further embodiment, about 9.2 to about 10.8, in a further embodiment, about 9.4 to about 10.6, in a further embodiment, about 9.5 to about 10.5, in a further embodiment, about 9.6 to about 10.4, in a further embodiment, about 9.8 to about 10.2, in further embodiments about 9.0, about 9.5, about 10.0, about 10.5, about 11.0, about 11.5 or about 12.0.

[0215] In embodiments of the present disclosure, the further reduction of the amount/removal of metal species other than lithium species may be performed at ambient temperature (e.g., about 22 to about 25? C.) or higher, in a further embodiment at about 20? C. to about 25? C. in a further embodiment at about 20? C. to about 30? C., in a further embodiment at about 25? C. to about 100? C., in a further embodiment at about 30? C. or higher, in a further embodiment at about 30? C. to about 100? C., in a further embodiment at about 35? C. or higher, in a further embodiment at about 35? C. to about 100? C., in a further embodiment about 40? C. or higher, in a further embodiment about 40? C. to about 100? C., in a further embodiment at about 45? C. or higher, in a further embodiment at about 45? C. to about 100? C., in a further embodiment at about 50? C. or higher, in a further embodiment at about 50? C. to about 100? C., in a further embodiment about 55? C. or higher, in a further embodiment about 55? C. to about 100? C., in a further embodiment at about 60? C. or higher, in a further embodiment at about 60? C. to about 100? C., in a further embodiment at about 65? C. or higher, in a further embodiment at about 65? C. to about 100? C., in a further embodiment about 70? C. or higher, in a further embodiment about 70? C. to about 100? C., in a further embodiment at about 75? C. or higher, in a further embodiment at about 75? C. to about 100? C., in a further embodiment at about 80? C. or higher, in a further embodiment at about 80? C. to about 100? C., in a further embodiment about 85? C. or higher, in a further embodiment about 85? C. to about 100? C., in a further embodiment at about 90? C. or higher, in a further embodiment at about 90? C. to about 100? C., in a further embodiment at about 95? C. or higher, in a further embodiment at about 95? C. to about 100? C., in a further embodiment at about 40? C. to about 50? C., in a further embodiment at about 60? C. to about 70? C., in a further embodiment at about 62? C. to about 68? C., in a further embodiment at about 63? C. to about 67? C., in a further embodiment at about 80? C. to about 90? C.

[0216] In embodiments of the present disclosure, the treatment with the carbonate source is performed at a molar ratio of carbonate to calcium of about 80% to about 250% about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%, of about 80% to about 2500%, about 150% to about 250%, about 175% to about 225%, about 180% to about 220%, about 190% to about 210%, about 195% to about 205%, or about 200%.

[0217] In embodiments of the present disclosure, the treatment with the carbonate source is performed at a molar ratio of carbonate to one or more metals (e.g. calcium and/or magnesium) of about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%.

7. Secondary Sulfate Removal with Barium Chloride

[0218] In embodiments of the present disclosure, the Li.sub.2SO.sub.4-comprising aqueous solution, following removal of the metal species other than lithium species, primary sulfate removal and calcium removal, is treated with barium chloride at a pH of about 6.0 or higher, in a further embodiment about 7.0 or higher, in a further embodiment about 7.5 or higher, in a further embodiment about 8.0 or higher, in a further embodiment about 8.5 or higher, in a further embodiment about 9 or higher, in a further embodiment, about 8.0 to about 10.0, in a further embodiment, about 8.5 to about 9.5, in a further embodiment, about 8.6 to about 9.4, in a further embodiment, about 8.7 to about 9.3, in a further embodiment, about 8.8 to about 9.2, in a further embodiment, about 8.9 to about 9.1, in a further embodiment, about 9.5 to about 12.0, in a further embodiment about 9.0 to about 12.0, in a further embodiment, about 9.2 to about 12.0, in a further embodiment, about 9.0 to about 11.0, in a further embodiment, about 9.0 to about 10.0, in a further embodiment, about 9.5 to about 10.5, in further embodiments about 9.0, about 9.5, about 10.0, about 10.5, about 11.0, about 11.5 or about 12.0. In an embodiment of the present disclosure, BaSO.sub.4 precipitation may be performed without adjusting the pH of the mixture prior to the addition of the barium chloride.

[0219] In embodiments, the barium chloride is added at a molar ratio of barium to sulfate at a ratio of about 0.1 to about 3.0, at a ratio of about 0.8 to about 1.5, at a ratio of about 0.9 to about 1.2, at a ratio of about 0.9 to about 1.1, at a ratio of about 0.95 to about 1.1, at a ratio of about 0.95 to about 1.05, at a ratio of about 0.98 to about 1.02, at a ratio of about 1.0 to about 1.2, at a ratio of about 1.0 to about 1.1, at a ratio of about 1.0 to about 1.05, in further embodiments at a ratio of about 0.9, 0.95, 0.98, 1.0, 1.02 1.05, 1.08 or 1.10.

[0220] In embodiments of the present disclosure, the Li.sub.2SO.sub.4-comprising aqueous solution is treated with barium chloride at a molar ratio of barium to sulfate of about 10% to about 300%, about 80% to about 150%, about 80% to about 120%, about 90% to about 120%, about 100% to about 120%, about 90% to about 110%, about 95% to about 110%, about 80%, about 90%, about 100%, about 110% or about 120%.

[0221] In embodiments of the present disclosure, the Li.sub.2SO.sub.4-comprising aqueous solution is treated with barium chloride at a temperature of about 1? C. to about 100? C., about 5? C. to about 75? C., about 5? C. to about 60? C., about 10? C. to about 60? C., about 15? C. to about 60? C., about 20? C. to about 60? C., about 20? C. to about 30? C., or at room temperature (e.g., about 25? C.).

[0222] In embodiments of the present disclosure, the concentration of lithium in the Li.sub.2SO.sub.4-comprising aqueous solution is about 1 to about 25 g/L, about 5 to about 25 g/L, about 5 to about 20 g/L, about 5 to about 15 g/L, about 8 to about 12 g/L about 5 g/L, about 6 g/L, about 7 g/L, about 8 g/L, about 9 g/L, about 10 g/L, about 11 g/L, about 12 g/L, about 13 g/L, about 14 g/L, or about 15 g/L.

[0223] In embodiments of the present disclosure, at least about 50%, 55%, 60%, 65%, 70%, 75%, 80%, 90%, 95% or 99% of the lithium species is recovered from the Li.sub.2SO.sub.4-comprising aqueous solution. In embodiments, about 50% to about 99%, about 55% to about 99%, about 60% to about 99%, about 65% to about 99%, about 70% to about 99%, about 75% to about 99%, about 80% to about 99%, or about 90% to about 99% of the lithium species is recovered from the Li.sub.2SO.sub.4-comprising aqueous solution.

[0224] In an embodiment, the present disclosure relates to a process for recovering lithium chloride from a material comprising a lithium species and species of one or more metals other than lithium, the process comprising: [0225] treating the material with sulfuric acid (H.sub.2SO.sub.4) to provide an initial Li.sub.2SO.sub.4-comprising aqueous solution; [0226] increasing the pH of the initial Li.sub.2SO.sub.4-comprising aqueous solution to reduce the level of species of one or more metals other than lithium and to remove sulfate; [0227] treating the solution after the reducing of the one or more metals other than lithium and the removal of sulfate with a material to remove calcium and to produce a solution substantially comprising Li.sub.2SO.sub.4; [0228] treating the solution substantially comprising Li.sub.2SO.sub.4 with barium chloride to form a precipitate comprising barium sulfate and a solution substantially comprising lithium chloride; and [0229] recovering the lithium chloride from the solution remaining following the removal of the barium sulfate comprising precipitate in the form of lithium chloride or a hydrate thereof, via heat treatment and crystallization.

[0230] In embodiments, the processes described herein further comprise one or more steps to remove or reduce the level of non-lithium metal species present in the solutions or filtrates obtained during the process. In embodiments, such steps are carried out prior to BaSO.sub.4 and after CaSO.sub.4 precipitation. For greater clarity, such steps are carried out prior to BaSO.sub.4 precipitation and recovery of the lithium species. In embodiments, such further treatment comprises treating the solution remaining after CaSO.sub.4 precipitation with any source of carbonate, such as CO.sub.2 gas, and/or a carbonate salt, to form a precipitate comprising one or more metal carbonates of the one or more metals other than lithium. In embodiments, the carbonate salt is sodium carbonate (Na.sub.2CO.sub.3) or lithium carbonate (Li.sub.2CO.sub.3), or a combination thereof. In embodiments the non-lithium metals include calcium and/or magnesium, in which case treatment with a source of carbonate (e.g., CO.sub.2 gas and/or carbonate) salt shall generate calcium carbonate and/or magnesium carbonate.

[0231] In embodiments of the present disclosure, the process further comprises a step of recovering the lithium species from the solution, for example by crystallization. In embodiments, such a step comprises for example heat treatment to remove or boil off at least a part of the water in the solution. In a further embodiment, such a step may comprise for example subjecting the aqueous solution to reduced pressure (e.g., vacuum treatment). In embodiments, at least about 10% of the water is removed, in a further embodiment, at least about 15% of the water is removed, in a further embodiment, at least about 20% of the water is removed, in a further embodiment, at least about 25% of the water is removed, in a further embodiment, in a further embodiment, at least about 30% of the water is removed, in a further embodiment, at least about 35% of the water is removed, in a further embodiment, at least about 40% of the water is removed, in a further embodiment, at least about 45% of the water is removed, in a further embodiment, at least about 50% of the water is removed, in a further embodiment, at least about 55% of the water is removed, in a further embodiment, at least about 60% of the water is removed, in a further embodiment, at least about 65% of the water is removed, in a further embodiment, at least about 70% of the water is removed, in a further embodiment, at least about 75% of the water is removed, in a further embodiment, at least about 80% of the water is removed, in a further embodiment, at least about 85% of the water is removed, in a further embodiment, at least about 90% of the water is removed, or, in a further embodiment, at least about 95% of the water is removed.

[0232] In embodiments of the present disclosure, various products obtained in one or more steps of the process may be recycled back to a form for use in the process. For example, in embodiments, the BaSO.sub.4 may be treated, e.g. by calcination, to form BaO and SO.sub.3. In embodiments, the regenerated SO.sub.3 may be subjected to water treatment to form H.sub.2SO.sub.4, which can then be used to prepare the Li.sub.2SO.sub.4-comprising aqueous solution, e.g., for treating the starting material described herein.

[0233] BaSO.sub.4 is generated when barium chloride is added to the sulphate solution. The solid barium sulphate precipitate is separated from the lithium solution for example by filtration, centrifugation or by settling in a thickener.

[0234] The present disclosure is illustrated in further detail by the following non-limiting examples.

Example 1AlFe Removal from Li Pregnant Leach Solution (PLS)

[0235] This step comprised treating the PLS from an original pH of about 2 to about 3 to an optimum pH of 4.75 at room temperature (22? C.) using a 5% pulp density lime slurry to precipitate gypsum along with iron and aluminum. The expected reactions in this step are:

[00001]$F{e_2\left(S{O}_4\right)}_3+3C{a\left(OH\right)}_2+6H_{2}O=2F{e\left(OH\right)}_3+3CaS{O}_4.Math.2H_{2}O$$FeS{O}_4+C{a\left(OH\right)}_2+2H_{2}O=F{e\left(OH\right)}_2+CaS{O}_4.Math.2H_{2}O$$A{l_2\left(S{O}_4\right)}_3+3C{a\left(OH\right)}_2+6H_{2}O=2A{l\left(OH\right)}_3+3CaS{O}_4.Math.2H_{2}O$$H_{2}S{O}_4+C{a\left(OH\right)}_2=CaS{O}_4.Math.2H_{2}O$

[0236] The observed results are indicative that a pH of about 4.75 provides for good performance, and there is no need for iron oxidation as it appears that all the iron in solution is ferric and can be easily precipitated. Test conditions and the composition of products are shown in Tables 1-1 and 1-2, and FIGS. 3 and 4. FIG. 4 presents the XRD of the final solid residue, confirming iron and aluminum hydroxides and gypsum. See also FIGS. 13-29.

TABLE-US-00001 TABLE 1-1 AlFe removal test conditions Parameters Terminal Lime slurry T Kinetic Test # pH PD (? C.) samples? 1-1 4 5% 25 Yes 1-2 4.5 5% 25 Yes 1-3 5 5% 25 Yes 1-4 5.5 5% 25 Yes 1-5 6 5% 25 Yes 1-6 4.75 5% 45 Yes 1-7 4.75 5% 65 Yes 1-8 4.75 5% 85 Yes 1-9 4.75 1% 25 Yes 1-10 4.75 10% 25 Yes Optimum 4.75 5% 25 Yes

TABLE-US-00002 TABLE 1-2 Concentration of Fe, Al and Li in kinetic samples at pH = 4.75 Time C Recovery Element (min) (mg/L) (%) Fe 0 143.5 30 0 100 40 0 100 60 0 100 80 0 100 120 0 100 Al 0 2211.6 30 0 100 40 0 100 60 0 100 80 0 100 120 0 100 Li 0 9724 30 8122 1.9 40 8377 0 60 8201 1 80 8094 2.3 120 8262 0

Example 2Mg and Other Base Metal Removal from Li Pregnant Leach Solution (PLS)

[0237] This step comprised treating the PLS with more lime (Mg removal step) to a pH of about 10 (lime saturation condition) at 65? C. using a 5% pulp density lime slurry to precipitate gypsum and Mg(OH).sub.2. The expected reactions in this step are:

[00002]$MgS{O}_4+C{a\left(OH\right)}_2+2H_{2}O=M{g\left(OH\right)}_2+CaS{O}_4.Math.2H_{2}O\left(\mathrm{major}\mathrm{reaction}\right)$$MS{O}_4+C{a\left(OH\right)}_2+2H_{2}O={M\left(OH\right)}_2+CaS{O}_4.Math.2H_{2}O\left(\mathrm{major}\mathrm{reaction};M=Ni,Co,Mn,\mathrm{etc}.\right)$$H_{2}S{O}_4+C{a\left(OH\right)}_2=CaS{O}_4.Math.2H_{2}O\left(\mathrm{minor}\mathrm{reaction}\right)$$L{i}_{2}S{O}_4+C{a\left(OH\right)}_2+2H_{2}O=CaS{O}_4.Math.2H_{2}O+2LiOH\left(\mathrm{minor}\mathrm{reaction}\right)$$F{e_2\left(S{O}_4\right)}_3+3C{a\left(OH\right)}_2+6H_{2}O=2F{e\left(OH\right)}_3+3CaS{O}_4.Math.2H_{2}O\left(\mathrm{if}\mathrm{any}\mathrm{present}\mathrm{in}\mathrm{the}\mathrm{PLS}\right)$$FeS{O}_4+C{a\left(OH\right)}_2+2H_{2}O=F{e\left(OH\right)}_2+CaS{O}_4.Math.2H_{2}O\left(\mathrm{if}\mathrm{any}\mathrm{present}\mathrm{in}\mathrm{the}\mathrm{PLS}\right)$$A{l_2\left(S{O}_4\right)}_3+3C{a\left(OH\right)}_2+6H_{2}O=2A{l\left(OH\right)}_3+3CaS{O}_4.Math.2H_{2}O\left(\mathrm{if}\mathrm{any}\mathrm{present}\mathrm{in}\mathrm{the}\mathrm{PLS}\right)$

[0238] To explore the effects of various process parameters in this step, a precipitation pH range of about 7 to about 10, temperatures from 25 to 85? C. and lime pulp densities of 1, 5 and 10% were tested. Good process performances were observed at a precipitation pH of about 10, a lime pulp density of 5% and a temperature of about 65? C. An indicator of process performance was the % Mg removal. Test conditions and product compositions are shown in Tables 2-1 and 2-2, and FIGS. 6 and 7. FIG. 7 presents the XRD of the final solid residue, confirming gypsum and excess lime are the only major solids present in the residue, confirming a clean gypsum. Based on Table 2-2 and FIG. 5, all Mg in the PLS was precipitated as Mg(OH).sub.2 in the solid residue and insignificant amounts of Li were precipitated as Li.sub.2O.sub.4 in the solid residue. See also FIGS. 30-51.

TABLE-US-00003 TABLE 2-1 Mg removal test conditions Parameters Terminal Lime slurry T Kinetic Test # pH PD (? C.) samples? 2-1 7 5% 25 Yes 2-2 8 5% 25 Yes 2-3 9 5% 25 Yes 2-4 9.5 5% 25 Yes 2-5 10 5% 25 Yes 2-6 10 5% 45 Yes 2-7 10 5% 65 Yes 2-8 10 5% 85 Yes 2-9 10 1% 25 Yes 2-10 10 10% 25 Yes

TABLE-US-00004 TABLE 2-2 Concentration of the elements in kinetic samples at pH = 10 and CaO = 5% at T = 65? C. Time C Recovery Element (min) (mg/L) (%) Ca 0 442 30 602 0 120 590 0 Mg 0 41.7 30 0 100 120 0 100 Li 0 8100 30 8000 98.8 120 7970 98.4 SO.sub.4 0 56700 30 54300 2 120 57722 0 Ba 0 0 30 0 120 0 Al 0 7 30 0 100 120 0 100 Fe 0 0 30 0 120 0 Na 0 499 30 492 1.4 120 500 0

Example 3Ca Removal from PLS Using Na.SUB.2.CO.SUB.3

[0239] This step comprised treating the PLS with Na.sub.2CO.sub.3 (Ca removal step) at room temperature (22? C.) using solid Na.sub.2CO.sub.3 to precipitate Ca as CaCO.sub.3 crystals. The expected reactions in this step are:

[00003]$CaS{O}_{4\left(\mathrm{aq}\right)}+N{a}_{2}C{O}_3=CaC{O}_{3\left(\mathrm{solid}\right)}+N{a}_{2}S{O}_{4\left(\mathrm{aq}\right)}\left(\mathrm{dominant}\mathrm{reaction}\right)$$L{i}_{2}S{O}_4+N{a}_{2}C{O}_3=L{i}_{2}C{O}_{3\left(\mathrm{solid}\right)}+N{a}_{2}S{O}_{4\left(\mathrm{aq}\right)}\left(\mathrm{side}\mathrm{reaction}-\mathrm{not}\mathrm{significant}\right)$

[0240] Good process performances were observed at 22? C., pH of 11 (automatically adjusts to this pH), residence time of 2 hours or less, and CO.sub.2 to Ca molar ratio of 2 (200% stoichiometric requirement). 97% of Ca in the solution was removed by Na.sub.2CO.sub.3 and precipitated as CaCO.sub.3 in the solid residue. Further test conditions and product compositions are shown in Tables 3-1 and 3-2, and FIG. 3-2. It should be noted that Amberlite IRC 50 resin and CO.sub.2 gas addition were also tested, but none were as efficient as the addition of sodium carbonate for calcium removal. See also FIGS. 52-68.

TABLE-US-00005 TABLE 3-1 Ca removal test conditions Parameters Test Resin or CO.sub.2 to Ca Kinetic # pH reagent ratio samples? 3-1 10 Amberlite Yes IRC 50 3-2 10 CO.sub.2 0.5 (L/min) Yes 3-3 10 CO.sub.2 1.5 (L/min) Yes 3-4 10 Na.sub.2CO.sub.3 0.9 Yes 3-5 10 Na.sub.2CO.sub.3 1.0 Yes 3-6 10 Na.sub.2CO.sub.3 1.2 Yes 3-7 10 Na.sub.2CO.sub.3 1.5 Yes 3-8 10 Na.sub.2CO.sub.3 2 Yes

TABLE-US-00006 TABLE 3-2 Concentration of the elements in kinetic samples at Na.sub.2CO.sub.3/Ca = 2 and room temperature. Time C Recovery Element (h) (mg/L) (%) Ca 0 553 2 17 97 Mg 0 0 2 0 Li 0 7960 2 7870 1.1 SO.sub.4 0 61200 2 60900 0.5 Al 0 0 2 0 Fe 0 0 2 0 Na 0 534 2 2200 0

Example 4Sulfate removal from PLS using BaCl.SUB.2

[0241] This step comprised treating the solution following the Ca removal step with BaCl.sub.2 (sulfate removal step) to precipitate sulfate as barium sulfate crystals and produce LiCl liquor (e.g., a clean LiCl solution). The expected reaction in this step is:

[00004]$L{i}_{2}S{O}_4+BaC{l}_2=BaS{O}_{4\left(\mathrm{solid}\right)}+2LiC{l}_{\left(\mathrm{aq}\right)}$

[0242] In this step a final pH ranging from about 7 to about 11.5, a temperature ranging from 25 to 65? C., a Ba/sulfate stoichiometric ratio ranging from about 0.95 to about 1.10 was tested. Good process performances were observed at a pH near 9 (the natural PH of the solution was around 11; pH adjustment was done using sulfuric acid), 25? C., and Ba/sulfate ratio of 1.05 when using high a purity barium chloride salt.

[0243] Further test conditions and product compositions are shown in Tables 4-1 and 4-2, and FIGS. 10 and 11. FIG. 11 presents the XRD of the final solid residue, confirming that barium sulfate is the major solid present in the residue. See also FIGS. 69-85.

TABLE-US-00007 TABLE 4-1 Li.sub.2CO.sub.3 crystallization step Secondary sulfate removal tests - test duration: 1 h Parameters Terminal Ba to SO.sub.4 T Kinetic Test # pH Ba salt molar ratio (? C.) samples? LiCl-4-1 7.0 BaCl.sub.2 1.00 25 Yes LiCl-4-2 9.0 BaCl.sub.2 1.00 25 Yes LiCl-4-3 10.0 BaCl.sub.2 1.00 25 Yes LiCl-4-4 11.0 BaCl.sub.2 1.00 25 Yes LiCl-4-5 12.0 BaCl.sub.2 1.00 25 Yes LiCl-4-6 Opt. pH BaCl.sub.2 0.90 25 Yes LiCl-4-7 Opt. pH BaCl.sub.2 0.95 25 Yes LiCl-4-8 Opt. pH BaCl.sub.2 0.98 25 Yes LiCl-4-9 Opt. pH BaCl.sub.2 1.02 25 Yes LiCl-4-10 Opt. pH BaCl.sub.2 1.05 25 Yes LiCl-4-11 Opt. pH BaCl.sub.2 1.10 25 Yes LiCl-4-12 Opt. pH BaCl.sub.2 Opt. ratio 45 Yes LiCl-4-13 Opt. pH BaCl.sub.2 Opt. ratio 65 Yes LiCl-4-14 9 BaCl.sub.2 1.05 25 Yes

TABLE-US-00008 TABLE 4-2 Concentration of elements in kinetic samples at pH = 9 and Ba/SO.sub.4 = 1.05 at room temperature. Solid Time C Recovery analysis Element (min) (mg/L) (%) (%) Ca 0 15.4 0 30 3.8 75.3 60 6.4 58.4 Mg 0 0 0 30 0 60 0 Li 0 7770 0.42 30 7800 0 60 7890 0 SO.sub.4 0 51300 0.81 30 0.6 100 60 169 99.7 Ba 0 0 0.75 30 260 60 0 Al 0 2.7 0 30 0 100 60 0 100 Fe 0 0 0 30 0 60 0 Na 0 1590 0.15 30 1220 23.3 60 1310 17.6

[0244] All of the processes and process steps disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the processes and process steps of this disclosure have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the processes and process steps described herein without departing from the concept, spirit and scope of the disclosure. All such variations apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.