CN-122012946-A - Method for extracting and separating lithium from high-sodium-lithium-ratio solution

CN122012946ACN 122012946 ACN122012946 ACN 122012946ACN-122012946-A

Abstract

The application provides a method for extracting and separating lithium from a high-sodium-lithium-ratio solution, and relates to the field of hydrometallurgy. The method for extracting and separating lithium from the high-sodium-lithium-ratio solution comprises the steps of mixing a lithium-containing sodium water phase with an organic phase, extracting, standing and phase-separating to obtain a lithium-loaded organic phase and a raffinate, wherein the organic phase comprises an extractant, a co-extractant and a diluent, the extractant comprises PMBP, the co-extractant comprises TRPO, the diluent comprises at least one of sulfonated kerosene and light white oil, the mass ratio of sodium to lithium in the lithium-containing sodium water phase is greater than or equal to 80, mixing the lithium-loaded organic phase with a washing liquid, washing to remove co-extracted sodium, mixing the washed organic phase with the back-extraction liquid, carrying out back-extraction, and standing and phase-separating to obtain a lithium-rich back-extraction liquid and a regenerated organic phase. The method can realize the high-efficiency separation of lithium and sodium from the solution with high sodium-lithium ratio, and has the advantages of high lithium extraction rate, low sodium co-extraction rate, rapid split phase and complete back extraction.

Inventors

Guo zong
MA HAO
YAN LI
SUN HONGHONG
ZHENG CHAOZHEN

Assignees

矿冶科技集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260213

Claims (10)

1. A method for extracting and separating lithium from a high sodium to lithium ratio solution, comprising: Mixing a lithium-sodium-containing water phase with an organic phase, extracting, standing and phase-separating to obtain a lithium-loaded organic phase and a raffinate, wherein the organic phase comprises an extractant, a co-extractant and a diluent, the extractant comprises PMBP, the co-extractant comprises TRPO, the diluent comprises at least one of sulfonated kerosene and light white oil, and the mass ratio of sodium to lithium in the lithium-sodium-containing water phase is more than or equal to 80; mixing the lithium-loaded organic phase with a washing liquid, and washing to remove co-extracted sodium; And mixing the washed organic phase with the stripping solution, carrying out stripping, standing and phase separation to obtain the lithium-rich stripping solution and the regenerated organic phase.
2. The method for extracting and separating lithium from a high sodium to lithium ratio solution according to claim 1, wherein the concentration of sodium ions in the aqueous phase containing lithium sodium is 100-150 g/L, and the concentration of lithium ions in the aqueous phase containing lithium sodium is 1-2 g/L; And/or the aqueous phase containing lithium and sodium is a salt lake lithium precipitation mother solution.
3. The method for extraction separation of lithium from a high sodium to lithium ratio solution according to claim 1 further comprising adjusting an initial pH of the aqueous sodium lithium containing phase to 10-13 prior to extraction, followed by mixing the aqueous sodium lithium containing phase having an initial pH of 10-13 with the organic phase.
4. The method of claim 1, wherein in the extracting step, the volume ratio O/a of the organic phase to the aqueous phase containing lithium and sodium is 2:1 to 4:1.
5. The method according to claim 4, wherein in the extracting step, the molar ratio of the extractant to lithium in the aqueous phase is 1.0-2.5:1.
6. The method for extracting and separating lithium from a high sodium to lithium ratio solution according to claim 5, wherein the volume concentration of the co-extractant in the organic phase is 10% -35%.
7. The method for extracting and separating lithium from a high sodium to lithium ratio solution according to claim 1, the method is characterized in that the extraction time is 0.5-5 minutes.
8. The method for extracting and separating lithium from a high sodium-lithium ratio solution according to claim 1, wherein the washing solution comprises a hydrochloric acid solution with a concentration of 1% -3%; and/or in the washing step, the volume ratio O/A of the lithium-loaded organic phase to the washing liquid is 10:1-20:1.
9. The method for extracting and separating lithium from a high sodium to lithium ratio solution according to claim 1, wherein the strip liquor comprises a hydrochloric acid solution with a concentration of 20% -30%.
10. The method for extracting and separating lithium from a high-sodium-lithium ratio solution according to claim 1, wherein in the back extraction step, the volume ratio O/a of the washed organic phase to the back extraction solution is 20:1 to 40:1; and/or the method further comprises the step of returning the regenerated organic phase to the extraction step for recycling.

Description

Method for extracting and separating lithium from high-sodium-lithium-ratio solution Technical Field The application relates to the field of hydrometallurgy, in particular to a method for extracting and separating lithium from a high-sodium-lithium-ratio solution. Background Lithium is an important strategic resource and is widely used in the fields of batteries, ceramics, glass, lubricants, nuclear industry and the like. Salt lake brine is one of the main storage forms of global lithium resources. After lithium is extracted from salt lake brine in Qinghai and other places in China by a sodium carbonate method, a large amount of lithium-precipitating mother liquor with high sodium-lithium ratio is generated, wherein the concentration of sodium ions is extremely high, the concentration of lithium ions is relatively low, and the mass ratio of sodium to lithium in the lithium-precipitating mother liquor is more than 80. The method has important significance for further recovery of lithium in the mother liquor and improvement of comprehensive recovery rate of lithium resources and reduction of cost. The solvent extraction method is a high-efficiency technology for separating lithium and sodium in the lithium precipitation mother solution. However, the existing extraction method generally has the problems of high sodium co-extraction rate, difficult phase separation, low back extraction efficiency and the like. Disclosure of Invention The application aims to provide a method for extracting and separating lithium from a solution with high sodium-lithium ratio so as to solve the problems. In order to achieve the above purpose, the application adopts the following technical scheme: a method for extracting and separating lithium from a high sodium to lithium ratio solution comprising: Mixing a lithium-sodium-containing water phase with an organic phase, extracting, standing and phase-separating to obtain a lithium-loaded organic phase and a raffinate, wherein the organic phase comprises an extractant, a co-extractant and a diluent, the extractant comprises PMBP, the co-extractant comprises TRPO, the diluent comprises at least one of sulfonated kerosene and light white oil, and the mass ratio of sodium to lithium in the lithium-sodium-containing water phase is more than or equal to 80; mixing the lithium-loaded organic phase with a washing liquid, and washing to remove co-extracted sodium; And mixing the washed organic phase with the stripping solution, carrying out stripping, standing and phase separation to obtain the lithium-rich stripping solution and the regenerated organic phase. According to an embodiment of the application, the concentration of sodium ions in the lithium-sodium-containing aqueous phase is 100-150 g/L, and the concentration of lithium ions in the lithium-sodium-containing aqueous phase is 1-2 g/L; And/or the aqueous phase containing lithium and sodium is a salt lake lithium precipitation mother solution. According to an embodiment of the application, the method further comprises, before the extraction, adjusting the initial pH of the aqueous phase containing lithium sodium to 10-13, and subsequently mixing the aqueous phase containing lithium sodium with an initial pH of 10-13 with the organic phase. According to an embodiment of the application, in the extraction step, the volume ratio O/A of the organic phase to the aqueous phase containing lithium sodium is 2:1 to 4:1. According to an embodiment of the application, in the extraction step, the molar ratio of the extractant to lithium in the aqueous phase is 1.0-2.5:1. According to the embodiment of the application, the volume concentration of the synergistic agent in the organic phase is 10% -35%. According to an embodiment of the application, the extraction time is 0.5-5 minutes. According to the embodiment of the application, the washing liquid comprises a hydrochloric acid solution with the concentration of 1% -3%; and/or in the washing step, the volume ratio O/A of the lithium-loaded organic phase to the washing liquid is 10:1-20:1. According to the embodiment of the application, the stripping solution comprises a hydrochloric acid solution with the concentration of 20% -30%. According to the embodiment of the application, in the back extraction step, the volume ratio O/A of the washed organic phase to the back extraction liquid is 20:1-40:1; and/or the method further comprises the step of returning the regenerated organic phase to the extraction step for recycling. Compared with the prior art, the application has the beneficial effects that: The method can realize the high-efficiency separation of lithium and sodium from the solution with high sodium-lithium ratio, and has the advantages of high lithium extraction rate, low sodium co-extraction rate, rapid split phase and complete back extraction. The method specifically comprises the following steps: 1. the high selectivity is that the lithium extraction rate can reach more than 90 per