CN-121976060-A - Comprehensive utilization method of salt lake brine

CN121976060ACN 121976060 ACN121976060 ACN 121976060ACN-121976060-A

Abstract

The application relates to the technical field of salt lake brine resource utilization, in particular to a comprehensive utilization method of salt lake brine. The comprehensive utilization method is suitable for salt lake brine with high alkaline carbonate content, and for the salt lake brine, the method adopts a mode of adding carbonate to adjust until the relative mass concentration of carbonate ions and lithium ions is 50-100:1, so as to obtain salt lake brine with high carbonate concentration, and then nano-filtering, adsorbing and evaporating the salt lake brine with high carbonate concentration to obtain lithium concentrated solution with high concentration and lower content of definite impurities. According to the application, various resources in the salt lake brine are synchronously extracted by adopting a reasonably arranged extraction system, so that the high-quality lithium concentrated solution is obtained, and meanwhile, medicament, fresh water and electric heating resources are greatly saved.

Inventors

CAI JIANGUO
SHI HONGYAN
ZHOU FENG
WANG BING

Assignees

江苏海普功能材料有限公司

Dates

Publication Date: 20260505
Application Date: 20251230

Claims (12)

1. The comprehensive utilization method of the salt lake brine is characterized in that the composition of the salt lake brine meets any one of the following conditions (1) and (2); (1) The pH is more than 7, and the sum of the mass concentration of carbonate ions and bicarbonate ions is more than or equal to 10g/L; (2) The pH value is more than or equal to 10, and the mass concentration of carbonate ions is more than or equal to 3g/L; The comprehensive utilization method comprises the following steps: S110, taking salt lake brine of an M batch, optionally adding carbonate until the relative mass concentration of carbonate ions and lithium ions is 50-100:1, and obtaining high carbonate concentration salt lake brine M , wherein the high carbonate concentration salt lake brine M is subjected to nanofiltration treatment to obtain nanofiltration concentrated water M and nanofiltration fresh water M ; S120, carrying out adsorption and lithium extraction treatment on the nanofiltration concentrated water M by a titanium-based adsorbent to obtain a lithium-containing desorption solution M ; S130, after the nanofiltration fresh water M and the lithium-containing desorption solution M are mixed, regulating the pH to 6-8, evaporating and concentrating to obtain a lithium concentrated solution M and crude salt M , and collecting condensed water formed by evaporating and concentrating as fresh water M ; S140, dissolving the crude salt M , and then carrying out nanofiltration treatment to obtain nanofiltration concentrated water MM and nanofiltration fresh water MM ; s150, carrying out chelating resin adsorption impurity removal treatment on the nanofiltration fresh water MM to obtain a sodium chloride solution M ; s160, carrying out electrolytic treatment on the sodium chloride solution M to obtain hydrochloric acid M and sodium base M ; S210, taking salt lake brine of the M+1th batch, optionally adding carbonate until the relative mass concentration of carbonate ions and lithium ions is 50-100:1, and obtaining salt lake brine M+1 with high carbonate concentration, wherein the salt lake brine M+1 with high carbonate concentration is subjected to nanofiltration treatment to obtain nanofiltration concentrated water M+1 and nanofiltration fresh water M+1 , and fresh water required in the nanofiltration treatment process is from the fresh water M ; S220, mixing the nanofiltration concentrated water MM and the nanofiltration concentrated water M+1 , and performing adsorption and lithium extraction treatment by using a titanium-based adsorbent to obtain a lithium-containing desorption liquid M+1 , wherein fresh water required in the adsorption and lithium extraction treatment process of the titanium-based adsorbent is from the fresh water M , and acid required in the adsorption and lithium extraction treatment process is from the hydrochloric acid M ; S230, after the nanofiltration fresh water M+1 and the lithium-containing desorption liquid M+1 are mixed, regulating the pH to 6-8, evaporating and concentrating to obtain a lithium concentrated solution M+1 and crude salt M+1 , and collecting condensate water formed by evaporating and concentrating as fresh water M+1 , wherein alkali required for regulating the pH is sodium alkali M ; S240, dissolving the crude salt M+1 , and performing nanofiltration treatment to obtain nanofiltration concentrated water MM+1 and nanofiltration fresh water MM+1 , wherein fresh water required in the nanofiltration treatment process is from the fresh water M and/or the fresh water M+1 ; S250, carrying out chelating resin adsorption and impurity removal treatment on the nanofiltration fresh water MM+1 to obtain a sodium chloride solution M+1 , wherein fresh water required in the chelating resin adsorption and impurity removal treatment process is from the fresh water M and/or the fresh water M+1 , and acid required in the chelating resin adsorption and impurity removal treatment process is from the hydrochloric acid M ; S260, carrying out electrolytic treatment on the sodium chloride solution M+1 to obtain hydrochloric acid M+1 and sodium base M+1 ; Wherein the definition of the nanofiltration concentrated water M+1 is the same as the nanofiltration concentrated water M , the definition of the nanofiltration fresh water M+1 is the same as the nanofiltration fresh water M , the definition of the lithium-containing desorption liquid M+1 is the same as the lithium-containing desorption liquid M , and the definition of the lithium concentrate M+1 is the same as the lithium concentrate M ; The nanofiltration concentrated water MM+1 is defined as the nanofiltration concentrated water MM , the nanofiltration fresh water MM+1 is defined as the nanofiltration fresh water MM , the crude salt M+1 is defined as the crude salt M , the fresh water M+1 is defined as the fresh water M , the sodium chloride solution M+1 is defined as the sodium chloride solution M , the hydrochloric acid M+1 is defined as the hydrochloric acid M , and the sodium base M+1 is defined as the sodium base M .
2. The method of integrated utilization of claim 1, wherein the salt lake brine has at least one of the following characteristics: (1) The mass concentration of magnesium ions is 0.5 g/L-200 g/L; (2) The mass concentration of calcium ions is 0.5 mg/L-500 mg/L; (3) The mass concentration of lithium ions is 0.02 g/L-3 g/L; (4) The mass concentration of sodium ions is 0.5 g/L-200 g/L; (5) The mass concentration of sulfate ions is 0.2 g/L-3 g/L; (6) The mass concentration of carbonate ions is 0.5 g/L-200 g/L; (7) The sum of the mass concentration of the carbonate ions and the bicarbonate ions is 0.5g/L to 200g/L.
3. The integrated utilization method of claim 2, wherein the nanofiltration fresh water M satisfies at least one of the following conditions: (1) Compared with the salt lake brine, the total mass of the nanofiltration fresh water M containing high-valence ions is reduced by 80% -99%; (2) The nanofiltration fresh water M contains the total mass concentration of high-valence ions <0.2g/L; wherein the high valence ions include calcium ions and magnesium ions.
4. The integrated utilization method of claim 3, wherein the nanofiltration fresh water M satisfies at least one of the following conditions: (1) The relative mass concentration of lithium and magnesium is >1; (2) The total mass concentration of carbonate ions and bicarbonate ions is <0.2g/L; (3) The sulfate ion mass concentration is <0.2g/L.
5. The integrated utilization method of claim 2, wherein the lithium-containing desorption liquid M has at least one of the following characteristics: (1) The relative mass concentration of lithium and sodium is >0.5; (2) The relative mass concentration of lithium and magnesium is >10; (3) The total mass concentration of the high valence ions is less than 0.2g/L; (4) The mass concentration of sulfate ions is less than 0.02g/L; wherein the high valence ions include calcium ions and magnesium ions.
6. The integrated utilization method of claim 2, wherein the lithium concentrate M has at least one of the following characteristics: (1) The relative mass concentration of lithium and sodium is >10; (2) The relative mass concentration of lithium and magnesium is >10; (3) The total mass concentration of the high valence ions is less than 1g/L; (4) The mass concentration of sulfate ions is less than 0.2g/L; wherein the high valence ions include calcium ions and magnesium ions.
7. The comprehensive utilization method according to any one of claims 1 to 6, wherein the adsorption lithium extraction treatment of the titanium-based adsorbent in step S220 comprises: after the titanium-based adsorbent fully adsorbs lithium ions, the fresh water M is used for flushing the titanium-based adsorbent, and then the solution prepared by the hydrochloric acid M and the fresh water M is used for flushing the titanium-based adsorbent, so that the lithium ions adsorbed on the titanium-based adsorbent are combined with chloride ions in the solution and then desorbed.
8. The comprehensive utilization method according to claim 7, wherein the titanium-based adsorbent is a spherical titanium-based adsorbent material with a particle size of 0.8-2.0 mm; the titanium-based adsorbent has the ability to selectively adsorb lithium ions.
9. The comprehensive utilization method according to any one of claims 2 to 6, wherein in step S250, the chelating resin adsorption and impurity removal treatment includes: After the chelating resin fully adsorbs high-valence ions, the chelating resin is washed by a solution prepared from the hydrochloric acid M , the fresh water M and/or the fresh water M+1 , so that the high-valence ions are replaced and desorbed by hydrogen ions in the solution; the high valence ions include calcium ions and magnesium ions.
10. The comprehensive utilization method according to claim 9, wherein the chelating resin is spherical chelating resin with a particle size of 0.35-1.2 mm; chelating resins have the ability to selectively remove high valence ions.
11. The comprehensive utilization method according to any one of claims 1 to 6, wherein the lithium concentrated solution M satisfies at least one of the following characteristics with respect to the mth batch of salt lake brine: (1) The recovery rate of lithium ions is more than or equal to 90 percent, and the removal rate of carbonate ions is more than or equal to 95 percent; (2) The volume is reduced by 5% -60%; (3) The concentration of the lithium ions is enlarged by 1.5-20 times.
12. The method of claim 2 to 6, wherein the lithium concentrate M has a lithium ion recovery rate of 90% or more, a carbonate ion removal rate of 95% or more, a magnesium ion removal rate of 80% or more, a calcium ion removal rate of 70% or more, a sulfate ion removal rate of 95% or more, and a carbonate ion removal rate of 95% or more, relative to the salt lake brine of the mth batch.

Description

Comprehensive utilization method of salt lake brine Technical Field The application relates to the technical field of salt lake brine utilization, in particular to a comprehensive utilization method of salt lake brine. Background Under the strategic background of carbon peak and carbon neutralization, the rapid development of new energy industry puts higher demands on new energy battery materials, wherein lithium element shows wide application prospect in the new energy field due to high activity and low electrode potential. Salt lake brine is an important lithium resource, and development and utilization of the salt lake brine are highly valued. In order to meet the quality requirements of new energy battery materials, the development of a salt lake lithium extraction process with high efficiency, low energy consumption and low pollution becomes an important problem in the industry. In the selection of lithium resource extraction technology, the adaptive process needs to be customized according to the characteristics of brine and the regional characteristics. For salt lake brine with high carbonate content and alkalescence, a method combining nanofiltration impurity removal and adsorption lithium extraction is commonly adopted at present, however, the method has larger loss on a filter membrane and an adsorbent, and the problems of high operation cost and large consumption of leaching reagent and regeneration reagent are still existed in spite of the fact that the adsorbent can overcome the dissolution loss caused by alkalinity, and in addition, a large amount of fresh water is required to be consumed for nanofiltration and adsorption. In the current industry context, especially in areas where pharmaceutical, water and thermoelectric resources are scarce, lithium extraction technologies with low water consumption and low pharmaceutical consumption are relatively scarce. Therefore, the development of the full-flow brine treatment process with low medicine consumption and low water consumption has great commercial popularization potential for the areas, and can better adapt to the lithium extraction requirements of different areas and brine types. Disclosure of Invention Based on the above, one or more embodiments of the present application provide a comprehensive utilization method of salt lake brine, which can obtain high-quality lithium concentrate from salt lake brine with high alkali and high carbonate, and simultaneously greatly save medicament, fresh water and electric heating resources. The technical scheme of the application comprises the following contents: a comprehensive utilization method of salt lake brine, wherein the composition of the salt lake brine meets any one of the following conditions (1) and (2); (1) The pH is more than 7, and the sum of the mass concentration of carbonate ions and bicarbonate ions is more than or equal to 10g/L; (2) The pH value is more than or equal to 10, and the mass concentration of carbonate ions is more than or equal to 3g/L; The comprehensive utilization method comprises the following steps: S110, taking salt lake brine of an M batch, optionally adding carbonate until the relative mass concentration of carbonate ions and lithium ions is 50-100:1, and obtaining high carbonate concentration salt lake brine M, wherein the high carbonate concentration salt lake brine M is subjected to nanofiltration treatment to obtain nanofiltration concentrated water M and nanofiltration fresh water M; S120, carrying out adsorption and lithium extraction treatment on the nanofiltration concentrated water M by a titanium-based adsorbent to obtain a lithium-containing desorption solution M; s130, after the nanofiltration fresh water M and the lithium-containing desorption solution M are mixed, regulating the pH value to 6-8, evaporating and concentrating to obtain a lithium concentrated solution M and crude salt M, and collecting condensate water formed by evaporating and concentrating as fresh water M; S140, dissolving the crude salt M, and then carrying out nanofiltration treatment to obtain nanofiltration concentrated water MM and nanofiltration fresh water MM; s150, carrying out chelating resin adsorption impurity removal treatment on the nanofiltration fresh water MM to obtain a sodium chloride solution M; s160, carrying out electrolytic treatment on the sodium chloride solution M to obtain hydrochloric acid M and sodium base M; S210, taking salt lake brine of the M+1th batch, optionally adding carbonate until the relative mass concentration of carbonate ions and lithium ions is 50-100:1, and obtaining salt lake brine M+1 with high carbonate concentration, wherein the salt lake brine M+1 with high carbonate concentration is subjected to nanofiltration treatment to obtain nanofiltration concentrated water M+1 and nanofiltration fresh water M+1, and fresh water required in the nanofiltration treatment process is from the fresh water M; S220, mixing the nanofiltration concentra