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CN-121976059-A - Fresh water-saving brine lithium extraction method

CN121976059ACN 121976059 ACN121976059 ACN 121976059ACN-121976059-A

Abstract

The application relates to the technical field of lithium resource recovery and extraction, in particular to a method for extracting lithium from brine saving fresh water, which comprises the steps of nanofiltration of lithium-containing aqueous solution meeting preset conditions to obtain nanofiltration concentrated water and nanofiltration fresh water, and then the nanofiltration concentrated water is adsorbed by a direct lithium extraction adsorption system, then desorption is carried out by desorption liquid to obtain lithium-containing desorption liquid, and then the nanofiltration fresh water and the lithium-containing desorption liquid are evaporated and concentrated together to obtain fresh water and lithium concentrated solution. The method can realize self-sufficiency of fresh water without additional consumption of fresh water resources, and simultaneously realizes impurity removal and concentration, and has the advantages of high efficiency, low cost and low water consumption.

Inventors

  • CAI JIANGUO
  • SHI HONGYAN
  • ZHOU FENG
  • LI JINPENG

Assignees

  • 江苏海普功能材料有限公司

Dates

Publication Date
20260505
Application Date
20251230

Claims (7)

  1. 1. A method for extracting lithium from brine saving fresh water is characterized in that the magnesium-lithium ratio of the brine is (3-30) 1, and the pH value is 3-7; The brine lithium extraction method comprises the following steps: S1, taking the brine of an M batch, adjusting turbidity to be less than 1.0NTU, and carrying out nanofiltration treatment to obtain nanofiltration concentrated water M and nanofiltration fresh water M , wherein M is an integer which is more than or equal to 1, the magnesium-lithium ratio of the nanofiltration concentrated water M is (10-150): 1, and the magnesium-lithium ratio of the nanofiltration fresh water M is (0.6-1.5): 1; s2, carrying out adsorption and lithium extraction treatment on the nanofiltration concentrated water M by an aluminum-based adsorbent to obtain a lithium-containing desorption solution M , wherein the ratio of magnesium to lithium in the lithium-containing desorption solution M is (0.1-0.4): 1; S3, mixing the nanofiltration fresh water M with the lithium-containing desorption liquid M , evaporating and concentrating to obtain a lithium concentrated solution M , wherein the ratio of magnesium to lithium in the lithium concentrated solution M is (0.1-2): 1, and collecting condensed water formed by evaporating and concentrating as spare fresh water M ; And S4, carrying out deep processing treatment on the lithium concentrated solution M to obtain a lithium product, wherein fresh water required in the deep processing treatment process is from the fresh water M , and the lithium product comprises at least one of lithium carbonate, lithium hydroxide and lithium chloride.
  2. 2. The method for extracting lithium from brine according to claim 1, further comprising the steps of: S5, taking the M+1st batch of brine, adjusting the turbidity to be less than 1.0NTU, and carrying out nanofiltration treatment to obtain nanofiltration concentrated water M+1 and nanofiltration fresh water M+1 , wherein fresh water required in the nanofiltration treatment process is from the fresh water M ; s6, carrying out lithium extraction treatment on the nanofiltration concentrated water M+1 by using an aluminum-based adsorbent to obtain a lithium-containing desorption solution M+1 , wherein fresh water required in the lithium extraction treatment process is from the fresh water M ; S7, mixing the nanofiltration fresh water M+1 with the lithium-containing desorption liquid M+1 , evaporating and concentrating to obtain a lithium concentrated solution M+1 , and collecting condensed water formed by evaporating and concentrating as spare fresh water M+1 ; S8, carrying out deep processing treatment on the lithium concentrated solution M+1 to obtain the lithium product, wherein fresh water required in the deep processing treatment process is from the fresh water M and/or the fresh water 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 .
  3. 3. The method for extracting lithium from brine saving fresh water according to claim 1, wherein the mass concentration of lithium ions in the brine is 0.3g/L to 4.0g/L; the mass concentration of lithium ions in the nanofiltration fresh water M is 0.3 g/L-4.4 g/L; the mass concentration of lithium ions in the nanofiltration concentrated water M is 0.2 g/L-3.2 g/L; The mass concentration of lithium ions in the lithium-containing desorption solution M is 0.8 g/L-1.2 g/L; the mass concentration of lithium ions in the lithium concentrated solution M is 1 g/L-6.5 g/L.
  4. 4. The method for extracting lithium from brine saving fresh water according to any one of claims 1 to 3, wherein the aluminum-based adsorbent is a spherical average particle aluminum-based adsorbent with a particle size of 10-20 meshes.
  5. 5. The method for extracting lithium from brine saving fresh water according to any one of claims 1 to 3, wherein the adsorption and extraction treatment of the aluminum-based adsorbent in the step S2 comprises: After the aluminum-based adsorbent is fully adsorbed, washing the aluminum-based adsorbent by using leacheate, and discarding the liquid washed by the leacheate; Washing the aluminum-based adsorbent by using an eluent, and collecting the liquid washed by the eluent; the composition of the eluent comprises fresh water, and optionally, the eluent contains lithium ions with mass concentration of 0.1-2 g/L.
  6. 6. The method for extracting lithium from brine saving fresh water according to any one of claims 1 to 3, wherein the further processing in step S4 or step S8 comprises one or more of adsorption, reverse osmosis, electrodialysis, evaporation, precipitation and washing processes to obtain the lithium product, wherein the lithium product comprises at least one of lithium carbonate, lithium hydroxide and lithium chloride.
  7. 7. The method for extracting lithium from fresh water-saving brine according to any one of claims 1 to 3, wherein the volume of the lithium concentrate M is reduced by 9% -59% and/or the mass concentration of lithium ions is increased by 1.6-10 times relative to the brine of the mth batch.

Description

Fresh water-saving brine lithium extraction method Technical Field The application relates to the technical field of lithium resource recovery, in particular to a method for extracting lithium from brine by saving fresh water. Background The rapid development of the lithium ion battery industry has driven the large-scale exploration, development and utilization of lithium resources. At present, the production of lithium carbonate mainly depends on salt lake brine, which makes the development of a lithium liquid lithium extraction process with high efficiency, low energy consumption and low pollution particularly important. In selecting a suitable lithium extraction technique, consideration is required to consider the economy, scalability, and potential impact on the environment of the technique. For example, while some techniques may perform well under laboratory conditions, problems with cost, operational complexity, or environmental pollution may be encountered in large scale industrial applications. Therefore, comprehensively considering various factors, selecting the technical route most suitable for specific brine characteristics and application conditions is a key for realizing efficient, economic and environment-friendly lithium extraction. In the method for extracting lithium from a lithium-rich water source, the traditional beach sun concentration method has the problems of high construction cost, long extraction period, high old brine grade influenced by weather and the like, and the problems of high treatment capacity, high treatment difficulty, high project investment cost, high water consumption in operation and production and the like can be encountered when the original brine is directly used for processing and producing. The coupling process of the adsorption and membrane method has the advantages of high efficiency, low cost and environmental protection, however, extra fresh water resources are needed to be used in the process, the fresh water consumption is increased, and the development of the process of the adsorption and membrane method has great implementation difficulty for some areas where fresh water is difficult to draw. Based on the method, the development of a lithium extraction technology with low fresh water consumption becomes a key point of industry development. Disclosure of Invention Based on the above, one or more embodiments of the present application provide a method for extracting lithium from brine saving fresh water, which is capable of extracting lithium resources from brine having a relatively low lithium ion concentration, can be used for extracting lithium from salt lakes, and has the advantages of low fresh water consumption and low cost. The technical scheme of the application comprises the following contents: A method for extracting lithium from brine saving fresh water, wherein the magnesium-lithium ratio of the brine is (3-30) 1, and the pH value is 3-7; The brine lithium extraction method comprises the following steps: S1, taking the brine of an M batch, adjusting turbidity to be less than 1.0NTU, and carrying out nanofiltration treatment to obtain nanofiltration concentrated water M and nanofiltration fresh water M, wherein M is an integer which is more than or equal to 1, the magnesium-lithium ratio of the nanofiltration concentrated water M is (10-150): 1, and the magnesium-lithium ratio of the nanofiltration fresh water M is (0.6-1.5): 1; s2, carrying out adsorption and lithium extraction treatment on the nanofiltration concentrated water M by an aluminum-based adsorbent to obtain a lithium-containing desorption solution M, wherein the ratio of magnesium to lithium in the lithium-containing desorption solution M is (0.1-0.4): 1; S3, mixing the nanofiltration fresh water M with the lithium-containing desorption liquid M, evaporating and concentrating to obtain a lithium concentrated solution M, wherein the ratio of magnesium to lithium in the lithium concentrated solution M is (0.1-2): 1, and collecting condensed water formed by evaporating and concentrating as spare fresh water M; And S4, carrying out deep processing treatment on the lithium concentrated solution M to obtain a lithium product, wherein fresh water required in the deep processing treatment process is from the fresh water M, and the lithium product comprises at least one of lithium carbonate, lithium hydroxide and lithium chloride. In some embodiments, the brine lithium extraction method further comprises the following steps: S5, taking the M+1st batch of brine, adjusting the turbidity to be less than 1.0NTU, and carrying out nanofiltration treatment to obtain nanofiltration concentrated water M+1 and nanofiltration fresh water M+1, wherein fresh water required in the nanofiltration treatment process is from the fresh water M; s6, carrying out lithium extraction treatment on the nanofiltration concentrated water M+1 by using an aluminum-based adsorbent to obtain a lithium-containing desorpt