Method for separating lithium from salt lake raw brine

文档序号：846234 发布日期：2021-03-16 浏览：15次中文

阅读说明：本技术 一种从盐湖原卤卤水中分离锂的方法 (Method for separating lithium from salt lake raw brine ) 是由侯昭飞冯志军昝超毛新宇唐发满谭晓龙李增荣张大义王冕解安福罗志于 2020-11-30 设计创作，主要内容包括：本发明公开了一种从盐湖原卤卤水中分离锂的方法,以盐湖原卤卤水为原料,将原料与装填在吸附柱内的吸附材料进行接触,通过吸附过程、顶液过程和解析过程实现原卤卤水中锂与镁、钾、钠的分离,卤水中锂的收率为70％～85％；通过控制吸附、顶液、解析进料流速获得锂盐溶液。本发明缩短了现有分离锂的工艺路线,规避了修建大面积盐田或经过提钾等工艺过程,减少盐田滩晒过程中锂的损失。直接用原卤卤水为原料,以吸附材料为基础,采用吸附、顶液、解析等简单实用的新工艺路线,一步实现锂的分离,原卤卤水中锂收率由原来的30％～35％提升到70％～85％,提高资源的利用率,简单易操作,具有很好的应用前景。(The invention discloses a method for separating lithium from salt lake raw brine, which takes the salt lake raw brine as a raw material, the raw material is contacted with an adsorption material filled in an adsorption column, the separation of lithium from magnesium, potassium and sodium in the raw brine is realized through an adsorption process, a liquid ejection process and an analysis process, and the yield of lithium in the brine is 70-85%; lithium salt solution is obtained by controlling the flow rate of adsorption, top liquid and desorption feeding. The invention shortens the existing lithium separation process route, avoids the process of constructing a large-area salt field or extracting potassium and the like, and reduces the loss of lithium in the beach solarization process of the salt field. The raw bittern is directly used as a raw material, an adsorption material is used as a basis, a new simple and practical process route such as adsorption, liquid ejection and analysis is adopted, the separation of lithium is realized in one step, the lithium yield in the raw bittern is improved to 70-85% from the original 30-35%, the utilization rate of resources is improved, and the method is simple and easy to operate and has a good application prospect.)

1. A method for separating lithium from salt lake raw brine is characterized by comprising the following steps:

s1, taking salt lake raw brine as a raw material, contacting the raw material with an adsorption material filled in an adsorption column, and separating lithium from magnesium, potassium and sodium in the raw brine through an adsorption process, a liquid ejection process and an analysis process, wherein the yield of lithium in the brine is 70-85%;

and S2, obtaining the lithium salt solution by controlling the flow rates of the adsorption, the top liquid and the desorption feeding.

2. The method for separating lithium from salt lake raw brine according to claim 1, wherein step S1 specifically comprises:

s101, adsorbing brine with different component characteristics by an adsorption column filled with an adsorbing material, wherein the content of lithium ions in tail liquid after adsorption is 0.05-0.08 g/L, and sending the collected tail liquid into a salt pan or recovering other ions with additional values;

s102, switching the adsorption column which is subjected to adsorption saturation in the step S101 to a liquid-topping area, and generating one or a mixture of more of tap water, desalted water, distilled water, RO, 0.05-40% (w/w) electrolyte water, 0.05-40% (w/w) brine and 0.05-40% (w/w) lithium-containing solution; feeding the brine into an adsorption column from a feed pipe of the adsorption column, performing liquid ejection work, ejecting the residual brine in the adsorption column from a discharge pipe of the adsorption column, collecting the top liquid, returning the top liquid to be mixed with the raw brine, and feeding the mixture into the adsorption column again for adsorption;

s103, switching the adsorption column with qualified top liquid in the step S102 to an analysis area, and generating one or a mixture of more of tap water, desalted water, distilled water, RO, 0.05-40% (w/w) electrolyte water, 0.05-40% (w/w) brine and 0.05-40% (w/w) lithium-containing solution; and (4) analyzing the lithium ions adsorbed on the adsorbing material in the adsorption column into an analysis solution, and collecting the analysis solution as a product solution.

3. The method for separating lithium from salt lake raw brine according to claim 2, wherein the treatment time of step S1 is 7-11 h.

4. The method of claim 2, wherein in step S101, the raw brine contains 0.26-0.45 g/L of lithium ions, 0.3-0.4 g/L of boron ions, 10-13 g/L of potassium ions, 23-30 g/L of magnesium ions, 65-80 g/L of sodium ions, 160-190 g/L of chloride ions, and 7-10g/L of sulfate ions.

5. The method for separating lithium from salt lake raw brine according to claim 2, wherein in steps S102 and S103, the top liquid is preferably RO produced water, and the temperature is controlled to be 10-40 ℃.

6. The method for separating lithium from salt lake raw brine according to claim 5, wherein the temperature is controlled to be 20-30 ℃.

7. The method for separating lithium from salt lake raw brine according to claim 1, wherein in the step S2, the flow rate of feed adsorption is 0.5-3.5 BV/h.

8. The method for separating lithium from salt lake raw brine according to claim 1, wherein in step S2, the flow rate of the top liquid is 1-3 BV/h.

9. The method for separating lithium from salt lake raw brine according to claim 1, wherein in step S2, the desorption flow rate is 0.5-4 BV/h.

10. The method of claim 1, wherein the lithium salt solution obtained in step S2 contains a solution/product solution having a lithium ion concentration of 0.22-0.36 g/L, a magnesium ion concentration of 0.35-0.6 g/L, a sodium concentration of 0.1-0.25 g/L, a potassium concentration of 0.01-0.040 g/L, and a boron concentration of 0.01-0.04 g/L.

Technical Field

The invention belongs to the technical field of development and application of new energy raw materials of lithium batteries, and particularly relates to a method for separating lithium from salt lake raw brine.

Background

Lithium and its compounds are widely used in many fields such as electronics, metallurgy, chemical engineering, medicine, energy and the like due to their excellent properties, and have a very important position in national economy and national defense construction. In particular, in recent years, lithium is widely used as a battery anode and a ternary material, the vigorous development of the international lithium market is driven, the battery is endowed with the name of metal monosodium glutamate, the lithium is used as a novel strategic energy source in the 21 st century, the production of high-quality lithium salt becomes the main direction, and the focus and the hot point of attention and development are realized. There are two main types of currently explored terrestrial lithium resources: according to statistics, the reserve of the salt lake lithium resource accounts for about 70-80% of the total amount of the lithium resource, while the lithium resource in China is rich and famous world prosperous, wherein the lithium in the salt lake brine accounts for 71% of the reserve of the lithium resource in China. The lithium-containing raw material is mainly distributed in Qinghai, Xinjiang, Tibet and the like, but the lithium resource has low general grade, and the raw halogen has high content of impurities such as magnesium, sodium, potassium, sulfate radical, boron, silicon and the like, thereby bringing certain challenge to the development of the lithium resource by directly adopting the raw halogen.

The methods reported at present for extracting lithium from salt lake brine include precipitation crystallization, calcination leaching, carbonization, electrochemical method, solvent extraction, adsorption and the like. The precipitation method, the extraction method, the adsorption method and the carbonization method are widely and deeply researched, and are the main methods for extracting lithium from the salt lake brine. The method is characterized in that ions such as magnesium, sodium, potassium, sulfate radicals, silicon, calcium and the like exist in brine, the separation difficulty of lithium is greatly increased, the lithium is pretreated before being separated from other impurities, namely tail liquid or raw brine after potassium extraction is subjected to solarization in a salt field, through pretreatment processes such as natural evaporation concentration, frozen saltpeter and the like, one or more ions of the ions such as magnesium, potassium, sodium, boron, sulfate radicals and the like are removed to form old brine with different intrinsic characteristics, and then the process of separating the lithium from the old brine and the impurities is carried out by combining one or more processes. In the pretreatment process, because of the influence of uncontrollable factors such as entrainment, leakage and the like in the process of beach drying and concentration of brine, the comprehensive lithium yield is only 30-35 percent, the concentration is influenced by the natural environment, and the exploitation utilization rate of the lithium resources in the salt lake is low.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for separating lithium from salt lake raw brine aiming at the defects in the prior art, and the method is characterized in that an adsorption material with strong anti-interference capability of potassium, sodium, magnesium and other ions and good lithium selectivity is selected, then a new process is explored by using the separation material to realize the process of directly separating lithium from sodium, potassium, magnesium, boron and other ions in the raw brine, and the problems that in the prior art, the lithium yield is low, brine concentration is influenced by the natural environment, the content of magnesium, potassium, boron, sodium and other impurities in the raw brine is high, the difficulty in separating lithium from magnesium, sodium and potassium impurities is high and the like due to the influences of uncontrollable factors such as entrainment, leakage and the like in the process of solarization of the concentrated brine in a salt field are solved, and the series of engineering problems and high production and treatment costs are caused by the large difficulty in separating lithium.

The invention adopts the following technical scheme:

a method for separating lithium from salt lake raw brine, comprising the steps of:

and S2, obtaining the lithium salt solution by controlling the flow rates of the adsorption, the top liquid and the desorption feeding.

Specifically, step S1 specifically includes:

Furthermore, the processing time of the step S1 is 7-11 h.

Further, in step S101, the raw halogen brine contains 0.26-0.45 g/L of lithium ions, 0.3-0.4 g/L of boron ions, 10-13 g/L of potassium ions, 23-30 g/L of magnesium ions, 65-80 g/L of sodium ions, 160-190 g/L of chloride ions and 7-10g/L of sulfate ions.

Further, in the steps S102 and S103, RO water is preferably selected as the top liquid, and the temperature is controlled to be 10-40 ℃.

Furthermore, the temperature is controlled to be 20-30 ℃.

Specifically, in the step S2, the flow rate of the feed adsorption is 0.5-3.5 BV/h.

Specifically, in step S2, the flow rate of the top liquid is 1-3 BV/h.

Specifically, in step S2, the analysis flow rate is 0.5-4 BV/h.

Specifically, in the lithium salt solution obtained in step S2, the lithium ion concentration is 0.22-0.36 g/L, the magnesium ion concentration is 0.35-0.6 g/L, the sodium concentration is 0.1-0.25 g/L, the potassium concentration is 0.01-0.040 g/L, and the boron concentration is 0.01-0.04 g/L.

Compared with the prior art, the invention has at least the following beneficial effects:

the invention discloses an adsorption technology for directly separating lithium from salt lake raw brine, which solves the problems of low lithium recovery rate and the like caused by uncontrollable factors such as entrainment, leakage and the like of concentrated brine in a salt field beach solarization process in the original process, and the series of engineering problems caused by high content of impurities such as magnesium, potassium, boron, sodium and the like in the raw brine, high difficulty in separating lithium from impurities such as magnesium, potassium, sodium and the like. The adsorption separation of lithium is directly carried out from the original bittern by adopting an adsorption method, is not limited by the intrinsic characteristics of the original bittern components, can be carried out even under the condition of lower lithium ions, and has the advantages of simple process, short process flow, one-step realization of the separation of lithium and other impurities, high lithium recovery rate, low cost, good product quality and the like, and is not limited by natural conditions.

Furthermore, the setting of the head liquor medium and the temperature completely replaces the residual brine which is not completely absorbed in the process, and simultaneously reduces the loss rate of lithium.

Furthermore, setting of analysis media and temperature, selecting media which are easy to obtain and do not contain or contain a small amount of magnesium, sodium, potassium and boron as analysis liquid, analyzing the target ion lithium adsorbed on the adsorption material in the process into product liquid, and improving the lithium-containing quality of the analysis liquid/product liquid.

Furthermore, the time for adsorption, liquid ejection and analysis control is 7-11 h, and the maximum yield of target ion lithium in the whole process is ensured depending on the effective contact time of the adsorption material in the adsorption bed layer in the adsorption column in each sub-step.

Further, in order to increase the recovery rate of the target ion lithium in the process, the discharge amount of lithium in the tail liquid is reduced.

Furthermore, in order to better replace the raw bittern remained in the adsorption column during the process.

Furthermore, the target ions lithium adsorbed on the adsorbing material in the process can be better resolved into the desorption solution.

Further, a product liquid/analytic liquid with high relative lithium content and low relative impurity content is obtained, and the product liquid/analytic liquid is determined by the salt content of the connecting pipe, the equipment investment and the operation cost of a process route for purifying the target ion lithium in the next procedure.

In conclusion, the invention shortens the existing lithium separation process route, avoids the process of constructing a large-area salt pan or extracting potassium and the like, and reduces the lithium loss in the beach solarization process of the salt pan. The raw bittern is directly used as a raw material, an adsorption material is used as a basis, a new simple and practical process route such as adsorption, liquid ejection and analysis is adopted, the separation of lithium is realized in one step, the lithium yield in the raw bittern is improved to 70-85% from the original 30-35%, the utilization rate of resources is improved, and the method has the characteristics of simplicity, easiness in operation and the like, and has a good application prospect.

The technical solution of the present invention is further described in detail by the following examples.

Detailed Description

The invention provides a method for separating lithium from salt lake raw brine, which combines untreated salt lake raw brine with an adsorption material, utilizes continuous ion exchange equipment, and realizes the separation of lithium and other impurities at one time through three steps of adsorption, desorption, liquid topping and the like.

The invention relates to a method for separating lithium from salt lake raw brine, which comprises the following steps:

s101, adsorbing brine with different component characteristics through an adsorption column filled with an adsorbing material, wherein the content of lithium ions in tail liquid after adsorption is 0.05-0.08 g/L, collecting and then sending the brine into a salt pan or recovering other ions with additional values, and the raw brine contains 0.26-0.45 g/L of lithium ions, 0.3-0.4 g/L of boron ions, 10-13 g/L of potassium ions, 23-30 g/L of magnesium ions, 65-80 g/L of sodium ions, 160-190 g/L of chloride ions and 7-10g/L of sulfate ions;

s102, switching the adsorption column which is subjected to adsorption saturation in the step S101 to a liquid-topping area, and generating one or a mixture of more of tap water, desalted water, distilled water, RO, 0.05-40% (w/w) electrolyte water, 0.05-40% (w/w) brine and 0.05-40% (w/w) lithium-containing solution; the method comprises the following steps of (1) entering an adsorption column from an adsorption column feed pipe, performing liquid ejection work, ejecting residual brine in the adsorption column from an adsorption column discharge pipe, collecting and returning top liquid, mixing the top liquid with raw brine, entering the adsorption column again for adsorption, preferably selecting RO (reverse osmosis) produced water as the top liquid, controlling the temperature to be 10-40 ℃, controlling the temperature to be 20-30 ℃, and preferably selecting 25 ℃;

s103, switching the adsorption column with qualified top liquid in the step S102 to an analysis area, and generating one or a mixture of more of tap water, desalted water, distilled water, RO, 0.05-40% (w/w) electrolyte water, 0.05-40% (w/w) brine and 0.05-40% (w/w) lithium-containing solution; and (3) resolving, resolving the lithium ions absorbed on the absorbing material in the absorbing column into a resolving solution, collecting the resolving solution as a product solution, preferably selecting RO water as a top solution, controlling the temperature to be 10-40 ℃, controlling the temperature to be 20-30 ℃, and preferably selecting 25 ℃.

S2, obtaining a lithium salt solution by controlling the adsorption, solution ejection and analysis feed flow rates, wherein the feed adsorption flow rate is 0.5-3.5 BV/h, the solution ejection flow rate is 1-3 BV/h, and the analysis flow rate is 0.5-4 BV/h, and the obtained lithium salt solution contains 0.22-0.36 g/L of lithium ions, 0.35-0.6 g/L of magnesium ions, 0.1-0.25 g/L of sodium, 0.01-0.040 g/L of potassium and 0.01-0.04 g/L of boron.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. The components of embodiments of the present invention generally shown herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The salt lake raw halogen brine is used as a raw material, wherein the concentration of lithium ions is 0.26-0.45 g/L, the concentration of boron ions is 0.3-0.4 g/L, the concentration of potassium ions is 10-13 g/L, the concentration of magnesium ions is 23-30 g/L, the concentration of sodium ions is 65-80 g/L, the concentration of chloride ions is 160-190 g/L, and the concentration of sulfate ions is 7-10 g/L. Respectively passing through continuous ion exchange equipment filled with an adsorption material, enabling raw material brine to enter the continuous ion exchange equipment through an adsorption inlet pipe, a desorption solution inlet pipe and a top solution inlet pipe, enabling the raw material brine to enter corresponding adsorption separation columns through corresponding pore passages or channels in a central rotary valve system, enabling the raw material brine to pass through an adsorption, top solution and desorption processes, then enabling the raw material brine to pass through an adsorption tail solution discharge pipe, a desorption solution discharge pipe and a top solution discharge pipe, discharging the raw material brine out of the ion exchange equipment, collecting the raw material brine into corresponding storage equipment, obtaining a qualified lithium salt solution product which has high relative concentration of lithium salt and low impurity content and meets the salt content requirement of a rear-end pipe, thereby realizing the continuous operation of the whole process, and enabling the adsorption columns to realize the series connection and the parallel connection of the ion exchange.

Example 1

The salt lake brine consists of 0.26g/L of lithium ion concentration, 0.3g/L of boron ion concentration, 11g/L of potassium ion concentration, 24g/L of magnesium ion concentration, 69g/L of sodium ion concentration, 165g/L of chloride ion concentration and 7.5g/L of sulfate ion concentration.

And S1, controlling the whole process step to realize the time of 7 h.

S2, taking the brine as a raw material, controlling the feeding flow rate at 0.5BV/h, adsorbing, and measuring that the concentration of lithium ions in the discharged tail liquid is 0.053g/L and the recovery rate of lithium is 79.6%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 20 ℃ and the feeding flow rate of 1.0BV/h as a top liquid medium;

s4, switching the adsorption column saturated in S3 to a desorption area, and analyzing the water by RO produced water with the temperature of 20 ℃ and the flow rate of 0.5 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.28 g/L; the average ion concentration of boron is 0.036 g/L; the average concentration of potassium ions is 0.038 g/L; the average concentration of magnesium ions is 0.55 g/L; the average concentration of sodium ions is 0.24g/L

Example 2

The salt lake brine consists of 0.35g/L of lithium ion concentration, 0.35g/L of boron ion concentration, 11.5g/L of potassium ion concentration, 26g/L of magnesium ion concentration, 75g/L of sodium ion concentration, 175g/L of chloride ion concentration and 9g/L of sulfate ion concentration.

And S1, controlling the whole process step to realize the time of 8 h.

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 21 ℃ and the feeding flow rate of 1BV/h as a top liquid medium;

s4, switching the adsorption column saturated in S3 to a desorption area, and analyzing the water by RO produced water with the temperature of 21 ℃ and the flow rate of 0.5 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.32 g/L; the average ion concentration of boron is 0.038 g/L; the average concentration of potassium ions is 0.033 g/L; the average concentration of magnesium ions is 0.54 g/L; the average concentration of sodium ions is 0.21g/L

Example 3

And S1, controlling the whole process step to realize the time of 8 h.

S2, adsorbing by using the brine as a raw material and controlling the feeding flow rate at 1.5BV/h, and measuring that the concentration of lithium ions in tail liquid is 0.065g/L and the yield of lithium is 75%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 22 ℃ and the feeding flow rate of 1.4BV/h as a top liquid medium;

s4, switching the adsorption column saturated in S3 to a desorption area, and analyzing the water by RO produced water with the temperature of 22 ℃ and the flow rate of 1.8 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.258 g/L; the average boron ion concentration is 0.032 g/L; the average concentration of potassium ions is 0.031 g/L; the average concentration of magnesium ions is 0.45 g/L; the average concentration of sodium ions is 0.18g/L

Example 4

The composition of the salt lake brine is 0.45g/L of lithium ion concentration, 0.38g/L of boron ion concentration, 12.3g/L of potassium ion concentration, 28.9g/L of magnesium ion concentration, 78.5g/L of sodium ion concentration, 189.7g/L of chloride ion concentration and 9.7g/L of sulfate ion concentration.

And S1, controlling the whole process step to realize the time of 9 h.

S2, adsorbing by using the brine as a raw material and controlling the feeding flow rate at 1.6BV/h, and measuring that the concentration of lithium ions in the discharged tail liquid is 0.074g/L and the recovery rate of lithium is 83.6%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 23 ℃ and the feeding flow rate of 2BV/h as a top liquid medium;

s4, switching the adsorption column saturated in S3 to a desorption area, and analyzing the RO produced water with the temperature of 23 ℃ and the flow rate of 2.1 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.33 g/L; the average boron ion concentration is 0.029 g/L; the average concentration of potassium ions is 0.032 g/L; the average concentration of magnesium ions is 0.476 g/L; the average concentration of sodium ions is 0.22g/L

Example 5

And S1, controlling the whole process step to realize the time of 9 h.

S2, adsorbing by using the brine as a raw material and controlling the feeding flow rate at 3.5BV/h, wherein the lithium ion concentration in the tail liquid is 0.075g/L and the lithium yield is 78.6%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 24 ℃ and the feeding flow rate of 3BV/h as a top liquid medium;

and S4, switching the adsorption column saturated in the S3 adsorption to a desorption area, and analyzing the RO produced water with the temperature of 24 ℃ and the flow rate of 4 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.23 g/L; the average ion concentration of boron is 0.012 g/L; the average concentration of potassium ions is 0.013 g/L; the average concentration of magnesium ions is 0.36 g/L; the average concentration of sodium ions is 0.13g/L

Example 6

And S1, controlling the whole process step to realize time of 10 h.

S2, adsorbing by using the brine as a raw material and controlling the feeding flow rate at 3.5BV/h, wherein the average concentration of lithium ions in the tail liquid is 0.075g/L and the lithium yield is 71.2%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 25 ℃ and the feeding flow rate of 3BV/h as a top liquid medium;

and S4, switching the adsorption column saturated in the S3 adsorption to a desorption area, and analyzing the RO produced water with the temperature of 25 ℃ and the flow rate of 4 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.232 g/L; the average ion concentration of boron is 0.025 g/L; the average concentration of potassium ions is 0.023 g/L; the average concentration of magnesium ions is 0.38 g/L; the average concentration of sodium ions is 0.143g/L

Example 7

And S1, controlling the whole process step to realize time of 10 h.

S2, adsorbing by using the brine as a raw material and controlling the feeding flow rate at 0.51BV/h, and measuring that the concentration of lithium ions in the discharged tail liquid is 0.0695g/L and the recovery rate of lithium is 84.6 percent;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 26 ℃ and the feeding flow rate of 1.1BV/h as a top liquid medium;

s4, switching the adsorption column saturated in S3 to a desorption area, and analyzing the RO produced water with the temperature of 26 ℃ and the flow rate of 0.5 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.35 g/L; the average ion concentration of boron is 0.037 g/L; the average concentration of potassium ions is 0.036 g/L; the average concentration of magnesium ions is 0.58 g/L; the average concentration of sodium ions is 0.24g/L

Example 8

And S1, controlling the whole process step to realize the time of 11 h.

S2, adsorbing by using the brine as a raw material and controlling the feeding flow rate at 1.8BV/h, and measuring that the concentration of lithium ions in tail liquid is 0.069g/L and the yield of lithium is 80.3%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 28 ℃ and the feeding flow rate of 1.7BV/h as a top liquid medium;

and S4, switching the adsorption column saturated in the S3 adsorption to a desorption area, and analyzing the RO produced water with the temperature of 28 ℃ and the flow rate of 2 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.275 g/L; the average boron ion concentration is 0.029 g/L; the average concentration of potassium ions is 0.026 g/L; the average concentration of magnesium ions is 0.48 g/L; the average concentration of sodium ions is 0.18g/L

Example 9

And S1, controlling the whole process step to realize the time of 11 h.

S2, taking the brine as a raw material, controlling the feeding flow rate at 3.5BV/h, adsorbing, and measuring that the concentration of lithium ions in the discharged tail liquid is 0.0795g/L and the recovery rate of lithium is 82.3%;

s3, switching the adsorption column saturated by the S2 to a top liquid area, and carrying out top liquid by taking RO produced water with the temperature of 30 ℃ and the feeding flow rate of 3BV/h as a top liquid medium;

and S4, switching the adsorption column saturated in the S3 adsorption to a desorption area, and analyzing the RO produced water with the temperature of 30 ℃ and the flow rate of 4 BV/h.

The average concentration of lithium ions in the obtained product liquid is 0.29 g/L; the average ion concentration of boron is 0.023 g/L; the average concentration of potassium ions is 0.023 g/L; the average concentration of magnesium ions is 0.403 g/L; the average concentration of sodium ions is 0.18g/L

BV is the volume multiple of the adsorbing material (if the amount of the adsorbing material filled in the adsorption column is 10mL/h, the adsorption flow rate is 10BV, namely the flow rate of the entering feed liquid is 100mL/h, the desorption flow rate is 1BV/h, namely 10mL/h, and the top liquid flow rate is 1BV/h, namely 10 mL/h).

The method is combined with the above cases to know that the method is directly adopted to separate the lithium in the salt lake raw brine, so that the analytic solution or the product solution which is relatively stable and has high lithium purity and low impurity content of magnesium, sodium, potassium and boron can be obtained, the separation of lithium from elements such as sodium, magnesium, potassium, boron and the like in the complex brine components is realized, the worldwide problem that the separation of magnesium, lithium and potassium is difficult is solved, and the method has great significance compared with the lithium extraction technology for separating magnesium, lithium and potassium from single-component lithium in old brine, and the lithium extraction technology has subversive promotion.

In conclusion, the method for separating lithium from the salt lake raw brine provided by the invention avoids the existing process by adopting the technology of directly extracting lithium from raw brine, breaks through the process that the traditional lithium extraction must be carried out by constructing a large-area salt pan, extracting potassium and the like, does not need to carry out long-period evaporation, crystallization and concentration processes on raw materials in the salt pan, reduces the influence on the production process due to natural factors such as weather, temperature and the like, avoids the risk of excessive lithium loss in the salt pan and the maintenance and management cost of the salt pan, and effectively increases the utilization rate of resources. The operation steps are simple, the process stability is stronger, the production period is shorter, and the comprehensive lithium yield is improved to 70-85 percent from 20-30 percent of the traditional process. The separation of lithium from elements such as sodium, potassium, magnesium, boron and the like is realized in one step, the interference of the magnesium, potassium, sodium, boron and other ions of the adsorption material is stronger, and the applicability is wider.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

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