MINERALIZATION METHOD OF CALCIUM CHLORIDE-TYPE FROM LITHIUM-CONTAINING SALT LAKE BRINE BY EVAPORATION AND BRINE MIXING

Abstract

The invention discloses a mineralization method of a calcium chloride-type from lithium-containing salt lake brine by evaporation and brine mixing, comprising the following steps of: (1) naturally evaporating the calcium chloride-type from lithium-containing salt lake brine to precipitate sodium salt and potassium-containing mixed salt; and (2) when calcium in the brine is saturated, adding saturated solution of magnesium chloride in a certain proportion for brine mixing operation, and then naturally evaporating to precipitate carnallite, wherein a lithium-containing old brine with low potassium and sodium contents is obtained when magnesium in the brine is saturated. The method has the characteristics of simple process, simple and convenient operation, high potassium yield and easy extraction of lithium from lithium-containing brine, and has practical significance for the development and utilization of potassium and lithium resources in calcium chloride salt lakes.

Claims

1. A mineralization method of a calcium chloride-type lithium-containing salt lake brine by evaporation and brine mixing, comprising the following steps of: (1) naturally evaporating a calcium chloride-type lithium-containing salt lake brine to precipitate a sodium salt and a potassium-containing mixed salt; and (2) adding a saturated solution of magnesium chloride in a proportion into the brine when calcium is saturated for brine mixing, and then performing naturally evaporation to precipitate carnallite, wherein a lithium-containing old brine with low potassium and sodium contents is obtained when magnesium in the brine is saturated; wherein in step (1), the calcium chloride-type lithium-containing salt lake brine is located in a potassium chloride area in a phase diagram of a quinary salt-water system Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+//Cl.sup.?H.sub.2O, at 25? C., and a mass ratio of Ca/Mg is 2 to 50; wherein in step (2), a proportion for brine mixing is such that the saturated solution of magnesium chloride is added according to a total Mg/K molar ratio of a calcium-saturated brine and the saturated solution of magnesium chloride of 2 to 10; and when magnesium in the brine is saturated, the brine with K.sup.+ between 0.5 g/L and 5 g/L, Ca.sup.2+ between 140 g/L and 200 g/L and Mg.sup.2+ between 30 g/L and 80 g/L is the lithium-containing old brine with low potassium and sodium contents.

2. The mineralization method of the calcium chloride-type lithium-containing salt lake brine by evaporation and brine mixing according to claim 1, wherein in step (1), after the calcium chloride-type lithium-containing salt lake brine is naturally evaporated to precipitate sodium chloride, when potassium in the brine in a sodium chloride pool is saturated, the brine is pumped into a potassium mixed salt pool for evaporating continuously to precipitate the potassium-containing mixed salt.

3. (canceled)

4. The mineralization method of the calcium chloride-type lithium-containing salt lake brine by evaporation and brine mixing according to claim 2, wherein in step (1), when the potassium in the brine is saturated, K.sup.+ is between 23 g/L and 28 g/L, Ca.sup.2+ is between 120 g/L and 180 g/L, and Mg.sup.2+ is between 3 g/L and 8 g/L.

5. The mineralization method of the calcium chloride-type lithium-containing salt lake brine by evaporation and brine mixing according to claim 1, wherein in step (2), when the calcium in the brine is saturated, K.sup.+ is between 22 g/L and 35 g/L, Ca.sup.2+ is between 140 g/L and 240 g/L, and Mg.sup.2+ is between 4 g/L and 9 g/L.

6. (canceled)

7. The mineralization method of the calcium chloride-type lithium-containing salt lake brine by evaporation and brine mixing according to claim 1, wherein in step (2), the proportion for brine mixing is such that the saturated solution of magnesium chloride is added according to a total Mg/K molar ratio of the calcium-saturated brine and the saturated magnesium chloride solution of 2.5 to 7.5.

8. (canceled)

9. A lithium-containing old brine prepared by the mineralization method according to claim 1.

10. A battery-grade lithium carbonate, wherein the battery-grade lithium carbonate is obtained by a method comprising: separating the lithium-containing old brine of claim 9 by an electrodialysis membrane method or a nanofiltration membrane, then subjecting to evaporation and concentration, impurity removal and lithium precipitation to obtain a crude lithium carbonate, and then washing, drying and demagnetizing the crude lithium carbonate.

11. A lithium-containing old brine prepared by the mineralization method according to claim 2.

12. (canceled)

13. A lithium-containing old brine prepared by the mineralization method according to claim 4.

14. A lithium-containing old brine prepared by the mineralization method according to claim 5.

15. (canceled)

16. A lithium-containing old brine prepared by the mineralization method according to claim 7.

17. (canceled)

18. A battery-grade lithium carbonate, wherein the battery-grade lithium carbonate is obtained by a method comprising: separating the lithium-containing old brine of claim 11 by an electrodialysis membrane method or a nanofiltration membrane, then subjecting to evaporation and concentration, impurity removal and lithium precipitation to obtain a crude lithium carbonate, and then washing, drying and demagnetizing the crude lithium carbonate.

19. A battery-grade lithium carbonate, wherein the battery-grade lithium carbonate is obtained by a method comprising: separating the lithium-containing old brine of claim 13 by an electrodialysis membrane method or a nanofiltration membrane, then subjecting to evaporation and concentration, impurity removal and lithium precipitation to obtain a crude lithium carbonate, and then washing, drying and demagnetizing the crude lithium carbonate.

20. A battery-grade lithium carbonate, wherein the battery-grade lithium carbonate is obtained by a method comprising: separating the lithium-containing old brine of claim 14 by an electrodialysis membrane method or a nanofiltration membrane, then subjecting to evaporation and concentration, impurity removal and lithium precipitation to obtain a crude lithium carbonate, and then washing, drying and demagnetizing the crude lithium carbonate.

21. A battery-grade lithium carbonate, wherein the battery-grade lithium carbonate is obtained by a method comprising: separating the lithium-containing old brine of claim 16 by an electrodialysis membrane method or a nanofiltration membrane, then subjecting to evaporation and concentration, impurity removal and lithium precipitation to obtain a crude lithium carbonate, and then washing, drying and demagnetizing the crude lithium carbonate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a process flowchart of the invention;

[0019] FIG. 2 is a phase diagram of a five-component water-salt system containing Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+//Cl.sup.?H.sub.2O, wherein the points in Area A is the salting-out route before brine mixing, and the points in Area B is the salting-out route after brine mixing;

[0020] FIG. 3A is the enlarged drawing of area A in FIG. 2, and FIG. 3B is the enlarged drawing of area B in FIG. 2.

DETAILED DESCRIPTION

[0021] The invention will be further explained in detail by taking the following 3Q Salt Lake brine in Argentina as an example to evaporate and mix brine to prepare a potassic salt ore and a lithium-containing old brine with low potassium and sodium contents with reference to the specific examples of the invention. In the examples, lithium, calcium, potassium, sodium, magnesium and boron in the brine are determined by inductively coupled plasma atomic emission spectrometry (ICP-OES), and chloride ions are determined by argentometry.

[0022] The invention will be further described in detail below with reference to the specific examples.

Example 1

[0023] The raw material of Example 1 was brine taken from Well PB1 of 3Q Salt Lake in Argentina, which had the chemical compositions shown in Table 1-1, and belonged to a calcium chloride salt lake brine system. As shown in FIG. 2, FIG. 3A and FIG. 3B, a brine composition point of the brine was located in the potassium chloride area in a phase diagram of a five-component water-salt system containing Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+//Cl.sup.?H.sub.2O at 25? C.

TABLE-US-00001 TABLE 1-1 Component content table of calcium-saturated brine Ion content (g/L) Density Item Li.sup.+ Na.sup.+ K.sup.+ Mg.sup.2+ Ca.sup.2+ Cl.sup.? (g/ml) Ca/Mg Content 1.220 60.610 13.48 2.235 61.27 219.39 1.2000 27.41

[0024] As shown in FIG. 1, a mineralization method of a calcium chloride-type from lithium-containing salt lake brine by evaporation and brine mixing, including the following steps of: [0025] (1) taking 35 kg of raw material, and naturally evaporating the raw materials in a sodium chloride pool to precipitate sodium chloride, and when K.sup.+ was 27.06 g/L, Mg.sup.2+ was 5.607 g/L and Ca.sup.2+ was 138.70 g/L, carrying out solid-liquid separation to obtain 4.22 kg of sodium chloride solid; [0026] (2) pumping the liquid separated in step (1) into a potassium mixed salt pool, naturally evaporating the liquid continuously to precipitate potassium-containing mixed salt minerals, and when K.sup.+ was 30.44 g/L, Mg.sup.2+ was 7.130 g/L and Ca.sup.2+ was 196.70 g/L, carrying out solid-liquid separation, wherein minerals obtained were mixed salts of sodium chloride, potassium chloride and carnallite, which were called potassium mixed salt minerals; 0.67 kg of potassium mixed salt mineral were precipitated, and meanwhile, 15.40 kg of calcium-saturated brine were obtained; [0027] (3) pumping 15.40 kg of calcium-saturated brine into a brine-mixing tank, then adding saturated solution of magnesium chloride according to a molar ratio of total Mg/K of 4.27 for brine mixing, and then directly pumping the brine into a carnallite pool for natural evaporation to precipitate carnallite; and [0028] (4) when K.sup.+ was 1.47 g/L, Mg.sup.2+ was 51.60 g/L and Ca.sup.2+ was 161.17 g/L, carrying out solid-liquid separation and pumping the separated liquid into an old brine pool, wherein minerals obtained were mixed salts composed of sodium chloride, epsomite and carnallite, which were called carnallite; 1.91 kg of carnallite were precipitated, and meanwhile, 14.51 kg of lithium-containing old brine with low potassium and sodium contents were obtained.

[0029] The components of the potassium mixed salt, carnallite and lithium-containing old brine with low potassium and sodium contents obtained were shown in Table 1-2.

TABLE-US-00002 TABLE 1-2 Component contents of old brine and potassium salt after evaporation and brine mixing Ion content (s: % or l: g/L) Density Item Li.sup.+ Na.sup.+ K.sup.+ Mg.sup.2+ Ca.sup.2+ Cl.sup.? (g/ml) Potassium-mixed salt 0.02 22.41 11.27 1.36 0.82 50.25 Carnallite 0.02 0.17 12.74 8.25 1.03 37.82 Lithium-containing old 3.42 1.95 1.47 51.60 161.17 457.43 1.4169 brine

Example 2

[0030] The raw material of Example 2 was brine taken from Well PB3 of 3Q Salt Lake in Argentina, which had the chemical compositions shown in Table 2-1, and belonged to a calcium chloride salt lake brine system. As shown in FIG. 2, FIG. 3A and FIG. 3B, a brine composition point of the brine was located in the potassium chloride area in a phase diagram of a five-component water-salt system containing Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+//Cl.sup.?H.sub.2O at 25? C.

TABLE-US-00003 TABLE 2-1 Component content table of calcium-saturated brine Ion content (g/L) Density Item Li.sup.+ Na.sup.+ K.sup.+ Mg.sup.2+ Ca.sup.2+ Cl.sup.? (g/ml) Ca/Mg Content 1.158 66.900 11.940 2.121 62.970 218.255 1.2372 29.69

[0031] As shown in FIG. 1, a mineralization method of a calcium chloride-type from lithium-containing salt lake brine by evaporation and brine mixing, including the following steps of: [0032] (1) taking 245 kg of raw material, and naturally evaporating the raw materials in a sodium chloride pool to precipitate sodium chloride, and when K.sup.+ was 26.71 g/L, Mg.sup.2+ was 4.97 g/L and Ca.sup.2+ was 141.70 g/L, carrying out solid-liquid separation to obtain 29.73 kg of sodium chloride solid; [0033] (2) pumping the liquid separated in step (1) into a potassium mixed salt pool, naturally evaporating the liquid continuously to precipitate potassium-containing mixed salt minerals, and when K.sup.+ was 26.69 g/L, Mg.sup.2+ was 5.89 g/L and Ca.sup.2+ was 214.90 g/L, carrying out solid-liquid separation, wherein minerals obtained were mixed salts of sodium chloride, potassium chloride and carnallite, which were called potassium mixed salt minerals, 4.45 kg of potassium mixed salt mineral were precipitated, and meanwhile, 79.52 kg of calcium-saturated brine were obtained; [0034] (3) pumping 79.52 kg of calcium-saturated brine into a brine-mixing tank, then adding saturated solution of magnesium chloride according to a molar ratio of total Mg/K of 3.50 for brine mixing, and then directly pumping the brine into a carnallite pool for natural evaporation to precipitate carnallite; and [0035] (4) when K.sup.+ was 2.53 g/L, Mg.sup.2+ was 37.97 g/L and Ca.sup.2+ was 190.05 g/L, carrying out solid-liquid separation and pumping the separated liquid into an old brine pool, wherein minerals obtained were mixed salts composed of sodium chloride, epsomite and carnallite, which were called carnallite; 10.48 kg of carnallite were precipitated, and meanwhile, 86.79 kg of lithium-containing old brine with low potassium and sodium contents were obtained.

[0036] The components of the potassium mixed salt, carnallite and lithium-containing old brine with low potassium and sodium contents obtained were shown in Table 2-2.

TABLE-US-00004 TABLE 2-2 Component contents of old brine and potassium salt after evaporation and brine mixing Ion content (s: % or l: g/L) Density Item Li.sup.+ Na.sup.+ K.sup.+ Mg.sup.2+ Ca.sup.2+ Cl.sup.? (g/ml) Potassium-mixed salt 0.07 16.97 17.60 2.68 3.50 56.49 Carnallite 0.02 1.64 12.28 7.86 1.16 38.76 Lithium-containing old 3.91 2.70 2.53 37.97 190.05 473.40 1.4262 brine

Example 3

[0037] The raw material of Example 3 was brine taken from Well PB7 of 3Q Salt Lake in Argentina, which had the chemical compositions shown in Table 3-1, and belonged to a calcium chloride salt lake brine system. As shown in FIG. 2, FIG. 3A and FIG. 3B, a brine composition point of the brine was located in the potassium chloride area in a phase diagram of a five-component water-salt system containing Na.sup.+, K.sup.+, Mg.sup.2+, Ca.sup.2+//Cl.sup.?H.sub.2O at 25? C.

TABLE-US-00005 TABLE 3-1 Component content table of calcium-saturated brine Ion content (g/L) Density Item Li.sup.+ Na.sup.+ K.sup.+ Mg.sup.2+ Ca.sup.2+ Cl.sup.? (g/ml) Ca/Mg Content 1.346 56.150 12.450 2.333 59.570 213.590 1.2567 25.53

[0038] As shown in FIG. 1, a mineralization method of a calcium chloride-type from lithium-containing salt lake brine by evaporation and brine mixing, including the following steps of: [0039] (1) taking 210 kg of raw material, and naturally evaporating the raw materials in a sodium chloride pool to precipitate sodium chloride, and when K.sup.+ was 24.32 g/L, Mg.sup.2+ was 5.05 g/L and Ca.sup.2+ was 137.40 g/L, carrying out solid-liquid separation to obtain 25.02 kg of sodium chloride solid; [0040] (2) pumping the liquid separated in step (1) into a potassium mixed salt pool, naturally evaporating the liquid continuously to precipitate potassium-containing mixed salt minerals, and when K.sup.+ was 22.32 g/L, Mg.sup.2+ was 6.71 g/L and Ca.sup.2+ was 178.20 g/L, carrying out solid-liquid separation, wherein minerals obtained were mixed salts of sodium chloride, potassium chloride and carnallite, which were called potassium mixed salt minerals, 3.16 kg of potassium mixed salt mineral were precipitated, and meanwhile, 75.18 kg of calcium-saturated brine were obtained; [0041] (3) pumping 75.18 kg of calcium-saturated brine into a brine-mixing tank, then adding saturated solution of magnesium chloride according to a molar ratio of total Mg/K of 5.0 for brine mixing, and then directly pumping the brine into a carnallite pool for natural evaporation to precipitate carnallite; and [0042] (4) when K.sup.+ was 1.40 g/L, Mg.sup.2+ was 51.38 g/L and Ca.sup.2+ was 162.03 g/L, carrying out solid-liquid separation and pumping the separated liquid into an old brine pool, wherein minerals obtained were mixed salts composed of sodium chloride, epsomite and carnallite, which were called carnallite; 8.36 kg of carnallite were precipitated, and meanwhile, 79.53 kg of lithium-containing old brine with low potassium and sodium contents were obtained.

[0043] The components of the potassium mixed salt, carnallite and lithium-containing old brine with low potassium and sodium contents obtained were shown in Table 3-2.

TABLE-US-00006 TABLE 3-2 Component contents of old brine and potassium salt after evaporation and brine mixing Ion content (s: % or l: g/L) Density Item Li.sup.+ Na.sup.+ K.sup.+ Mg.sup.2+ Ca.sup.2+ Cl.sup.? (g/ml) Potassium-mixed salt 0.04 21.00 19.01 0.55 2.14 58.66 Carnallite 0.02 0.02 12.80 8.28 1.04 37.73 Lithium-containing old 3.44 1.92 1.40 51.38 162.03 458.30 1.4191 brine

Example 4

[0044] The battery-grade lithium carbonate was obtained by following process: treating the lithium-containing old brine from any one of Examples 1 to 3 by electrodialysis membrane method or nanofiltration membrane, then obtaining crude lithium carbonate after evaporation and concentration, impurity removal and lithium precipitation, and then washing, drying and demagnetizing the crude lithium carbonate to gain the final product.

[0045] The above examples are preferred examples of the invention, but the examples of the invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and scope of the invention should be equivalent replacement means, and are included in the protection scope of the invention.