CN108264066A - A kind of new process of salt lake bittern production high-purity lithium chloride - Google Patents

Abstract

The invention discloses a kind of new processes of salt lake bittern production high-purity lithium chloride, include the following steps：1）Mode of operation：The technique is using continuous operation, i.e., by the data of technology Calculation, optimizes each unit scale, preferred mode of operation, the continuous operation of realization, and 2）Raw material：（a）Salt lake bittern, wherein：Li⁺Concentration 0.01 0.20g/L, Mg²⁺Concentration 30 50g/L, Na⁺Concentration 30 45g/L, K⁺9 14g/L of concentration, 200 300g/L of Cl concentration；（b）Salt lake bittern carries old halogen solution after potassium, wherein：Li⁺Concentration 0.25 0.6g/L, Mg²⁺Concentration 100 120g/L, Na⁺Concentration 0.1 0.2g/L, Cl^‑300 400g/L of concentration；3）Product：By the innovation technique, it can be made the qualified chlorination lithium salt solution product of content >=99.5%, the innovation technique includes the technical process such as following 1 ~ 6 altogether, and 4）The chloride containing lithium qualifying liquid that lithium technique is extracted from salt lake bittern and preliminary exquisiteness obtains is carried with ion exchange adsorption, by technical process 1, from salt lake bittern or from salt lake bittern carry potassium after old halogen solution 300：1~600：In 1 old halogen.

Description

A new process for producing high-purity lithium chloride from salt lake brine

technical field

The technical field involved in this innovative process is on the basis of using salt lake brine as raw material to extract lithium by ion exchange adsorption method, according to a large number of small-scale experiments and pilot experiments, using selective adsorption to extract lithium technology, electrodialysis technology, nanofiltration Technology, reverse osmosis (RO) technology, resin adsorption technology, etc., a new process for producing high-purity lithium chloride salt solution.

Background technique

At present, the main production methods of lithium chloride include conversion method, solvent extraction method, ion adsorption exchange method, salting out method, lithium salt conversion method, freezing method, etc., and liquid membrane method. Conversion methods are mainly divided into ore direct conversion method, lithium carbonate or lithium hydroxide conversion method, lithium sulfate conversion method, and lithium hydroxide direct oxidation method. Most lithium chloride production in my country adopts lithium carbonate or lithium hydroxide conversion method. Salt conversion method to produce lithium chloride production process. The ion adsorption exchange method is mainly used to extract lithium from brine, seawater and geothermal brine. The developed adsorbents (exchangers) mainly include aluminum hydroxide adsorbents, manganese dioxide adsorbents, titanium dioxide lithium adsorbents and composite ladder acid adsorbents, and the composite antimony acid adsorbents are mainly used in the extraction of lithium chloride .

Salt lake lithium extraction refers to the extraction of lithium from lithium-containing salt lake brine and the production of lithium products. Lithium extraction from salt lake brine usually undergoes solar evaporation in salt pans, different salts are obtained in stages, and salt solution purification. Finally, lithium salts are separated and extracted from the solution to obtain the required lithium salt products. Extracting lithium from salt lake brine has a simple process and low cost, and has gradually replaced lithium ore to produce lithium. According to statistics, the reserves of lithium resources in salt lake brine account for about 70% to 80% of the total lithium resources. Therefore, lithium extraction from salt lake brine to produce lithium carbonate will become the main direction of lithium salt production. Longitudinal domestic methods for extracting lithium from salt lake brine mainly include precipitation method, extraction method, ion exchange adsorption method, carbonization method, calcination leaching method and electrodialysis method. Among them, the precipitation method, extraction method, ion exchange adsorption method and carbonization method have been studied extensively and in-depth, and are the main methods for extracting lithium from salt lake brine. The biggest advantage of the ion adsorption method is that it has great advantages in terms of economy and environmental protection, and the process is simple, the recovery rate is high, and the selectivity is good. The key to this method is to study an adsorbent with excellent performance, which requires the adsorbent to have excellent selective adsorption for lithium, so as to eliminate the interference of a large number of coexisting alkali metals and alkaline earth metal ions in brine, and the adsorption-elution of the adsorbent The performance should be stable and suitable for large-scale operations. At present, only the American FMC company uses this process to realize industrial production abroad.

Qinghai Salt Lake Fozhao Lanke Lithium Industry Co., Ltd., a subsidiary of Qinghai Salt Lake Industry Co., Ltd., used lithium adsorbent to selectively adsorb lithium in high-magnesium and low-lithium brine, and completed the preliminary separation of magnesium and lithium (magnesium-lithium ratio is 500: 1 or higher), and at the same time synthesized a lithium adsorbent with excellent performance, which can eliminate the interference of a large number of coexisting alkali metal and alkaline earth metal ions in brine, and selectively adsorb lithium ions in brine. During more than 3 years of operation, its performance indicators can meet the target requirements. Secondly, the adsorption/desorption performance of the adsorbent is stable, suitable for large-scale operation and use, the preparation method is simple, the price is cheap, and there is no pollution to the environment. However, because the follow-up process of extracting lithium from salt lake is in the research and development stage, there is no successful experience to learn from, and the process of producing high-purity lithium chloride salt solution from salt lake brine is still blank.

New craft content

The purpose of the research and development of this process is to provide a new process for producing high-purity lithium chloride from salt lake brine. Using salt lake brine as raw material, the new process route for producing lithium chloride is based on the extraction of lithium by ion exchange adsorption. This process takes lithium-containing qualified liquid after lithium extraction as raw material, adopts ion sieve adsorption technology, nanofiltration technology, electrodialysis technology, reverse osmosis technology, resin adsorption technology, etc. to produce high-purity lithium chloride salt solution products or for other Downstream lithium products provide raw material lithium chloride solution, which provides a guarantee for the recycling of lithium resources in salt lakes. Its specific characteristics are as follows:

A new process for producing high-purity lithium chloride from salt lake brine, comprising the following steps:

1) Operation mode: The process adopts continuous operation, that is, optimizes the scale of each device through the data calculated by the process, optimizes the operation mode, and realizes continuous operation.

2) Raw materials:

(a) Salt lake brine, in which: Li ⁺ concentration 0.01-0.20g/L, Mg ²⁺ concentration 30-50g/L, Na ⁺ concentration 30-45g/L, K ⁺ concentration 9-14g/L, Cl ^- concentration 200 -300g/L.

(b) Old brine solution after potassium extraction from salt lake brine, in which: Li ⁺ concentration 0.25-0.6g/L, Mg ²⁺ concentration 100-120g/L, Na ⁺ concentration 0.1-0.2g/L, Cl ^- concentration 300-400g /L.

3) Products: Through this innovative process, qualified lithium chloride salt solution products with a content of ≥99.5% can be produced. This innovative process includes the following 1~6 processes.

4) Lithium chloride-containing qualified liquid extracted from salt lake brine and initially refined by ion exchange adsorption lithium extraction process, through process 1, after extracting potassium from salt lake brine or from salt lake brine, old brine solution 300:1～600 In the old brine of 1:1, the selective adsorption, washing and desorption of lithium chloride can be realized, and the qualified lithium chloride liquid with a magnesium-lithium ratio of 3:1-6:1 can be obtained, which can be used for subsequent lithium carbonate or other lithium products. Qualified lithium chloride raw material.

Preferably, the process 1 mainly adopts the adsorption extraction technology with aluminum-based molecular sieve as the adsorbent and the full-cell bed with special liquid distributor as the core technical equipment. The full-cell bed technology used includes but is not limited to Upward full chamber bed technology, downlink full chamber bed technology, the special liquid distributor is customized according to the size and distribution of self-made aluminum-based adsorbent particles, the special liquid distributor can realize selective and uniform liquid distribution and flow limiting functions, and improve the performance of the full chamber bed. The special liquid distributors for adsorption, washing and desorption efficiency are designed and calculated according to the hydrodynamic characteristics of brine and the flow rate and distribution characteristics of the adsorption, washing and desorption processes; To distribute the liquid, the structure of the liquid distributor adopts the method of selectively moving porous and uniform liquid distribution; see Figure 1 for details.

Preferably, the full-cell bed is not filled with inert fillers, and the process can realize functions such as forward washing and backwashing, and realize online rinsing and screening of fine and finely divided adsorbent powders, so as to improve the efficiency and performance of the adsorption bed. The process flow rate is controlled at 5-8m/hr; the adsorption temperature is controlled at 10-25°C, the washing process flow rate is controlled at 10-20m/hr; the washing temperature is controlled at 10-25°C; the flow rate is controlled at 10-20m/hr, desorption The flow rate is controlled at 10-20m/hr, and the flow rate during the desorption process is controlled at 10-20m/hr; the desorption temperature is controlled at 20-40°C.

Preferably, the flow rate of the adsorption process is set to 7m/hr; the adsorption temperature is set to 20°C, the flow rate of the washing process is controlled at 15m/hr; the washing temperature is controlled at 20°C; the flow rate is controlled at 15m/hr, and the desorption flow rate is controlled at 17m /hr, the flow rate of the desorption process is controlled at 18m/hr; the desorption temperature is controlled at 30°C.

Preferably, the washing is divided into 4 steps of washing and 3 steps of desorption; the high-magnesium solution for washing is discharged, and the low-magnesium solution is reused; the high-lithium solution is recovered during the desorption process, and the low-lithium solution is applied mechanically. The washing process uses 5-10% chlorine Wash with sodium chloride solution to remove residual magnesium ions in the adsorption tower and magnesium ions on the surface of the adsorbent. An online conductivity meter is installed during the washing process.

Preferably, the washing process uses 8% sodium chloride solution to wash away the residual magnesium ions in the adsorption tower and the magnesium ions on the surface of the adsorbent.

Preferably, the adsorption, washing, and desorption processes of the process 1 are all operated in an automatic mode, and each operating control parameter can be automatically input and controlled according to the characteristics of the raw material and the calculated yield.

Preferably, the process 2 uses the raw material lithium chloride qualified liquid 102 and the nanofiltration cut-off concentrated solution 302 in the process 3 as feed, and separates calcium and magnesium ions therein by selective electrodialysis, and the purified solution obtains purified lithium chloride Qualified solution 202, the ion-exchange technology for adsorption and removal of calcium and magnesium ions, including strong acid resin, weak acid resin, chelating resin and all resin adsorption technologies that can realize this function.

Preferably, the process 2 adopts combined ion exchange technology to reduce the content of calcium and magnesium ions in the qualified liquid 202 to below 0.5 mg/L or even lower, and obtain the regenerated wastewater desalination pond.

Preferably, the process 3 is to use the raw material lithium chloride qualified liquid 103 as a feed, and the calcium and magnesium ions therein are intercepted by a selective nanofiltration membrane, and the nanofiltration purification liquid is 203; the nanofiltration concentrated solution 302 goes to the process 2 The electrodialysis unit 1 separates and intercepts magnesium ions; the nanofiltration purification solution 203 and the electrodialysis purification solution 202 are mixed to form a qualified solution 3 .

Preferably, the nanofiltration is the separation technology of the main process, and the nanofiltration technology adopted includes but is not limited to medium and low pressure nanofiltration, high pressure nanofiltration and ultrahigh pressure nanofiltration technology and their combination technology, while separating calcium and magnesium ions, It is necessary to control the feeding conditions of the system within the design range, including temperature, PH value, pressure, etc. Nanofiltration can adopt multi-stage multi-stage design, multi-stage is used to increase the concentration multiple and yield, and multi-stage is used to improve the quality of purified liquid .

Preferably, the purified liquid can go to the first-stage water production, and the subsequent multi-stage concentrated product water returns to the first-stage inlet to improve the overall magnesium removal effect and ensure that the magnesium ion content of the purified liquid reaches the set value. The purified liquid Magnesium ion index is controlled below 50mg/L or even lower.

Preferably, the process 4 is to use the qualified liquid 401 as the feed material, and remove trace calcium and magnesium ions therein through an ion exchange process to obtain the crude qualified liquid 402; wherein: Li ⁺ concentration 0.4-0.9g/L, Mg ²⁺ concentration 0.001-0.01g/L, Na ⁺ concentration 0.01-0.1g/L, Cl ^- concentration 2.0-5.0g/L.

Preferably, the process 5 is to use the crude lithium chloride qualified liquid 402 as the feed material, and concentrate it through the reverse osmosis process to obtain the concentrated liquid 502; Here, in addition to the crude lithium chloride qualified liquid 402, the light brine 703 from the electrodialysis 2 of the subsequent process unit 7 returns to the process 5, and together with 402 forms the feed liquid for the reverse osmosis of the process unit 5.

Preferably, the process 1 mainly adopts the membrane concentration technology with reverse osmosis as the main process, and the reverse osmosis technology used includes but is not limited to medium and low pressure reverse osmosis, seawater desalination reverse osmosis, high pressure reverse osmosis and ultra-high pressure Reverse osmosis technology and its combined technology, wherein while concentrating the lithium chloride solution, the feed liquid is the front-end adsorption and magnesium removal qualified liquid 101; the outlet qualified liquid 102 is the Li ⁺ concentration of 4-7g/L, and contains some magnesium ions , calcium ions, boron and organic matter, etc., and the outlet liquid 103 is 85-95% light brine, which is all reused in the previous system, which can greatly reduce the consumption of industrial water. The reverse osmosis for concentration adopts boron-removing reverse osmosis technology, which can separate and remove 85% of boron ions, and the concentrated solution will go to the subsequent process after boron removal.

Preferably, the process 6 uses the reverse osmosis concentrated solution 502 as the feed material, and removes trace amounts of calcium and magnesium ions, and most of the sodium ions and potassium ions through the combined ion exchange process to obtain the qualified lithium chloride solution 6; The regeneration liquid goes to the salt pond.

Preferably, in the process 6, the resin adsorption and its combination technology used to adsorb and remove impurities such as calcium and magnesium ions include weakly acidic resins, chelating resins and other resin adsorption technologies that can realize this function. The content of calcium and magnesium ions is lower than 0.05mg/L or even lower. In process 6, the resin adsorption and its combination technology used to adsorb and remove impurities such as calcium and magnesium ions, and the special liquid distributor full-bed technology can absorb lithium ions The yield is guaranteed to be 99.5% or higher; acid and alkali consumption and product loss are optimized.

Preferably, the process 7 is to use the qualified liquid 602 as a feed, through a homogeneous electrodialysis process, to concentrate the lithium chloride solution; the concentrated high-purity lithium chloride solution 702 is collected as a product, to remove subsequent lithium carbonate, Lithium chloride or lithium hydroxide production workshop; electrodialysis light brine 703 goes to process unit 5, concentrates and removes most boron ions through process unit 5, mainly adopts electrodialysis as the main process of electro-driven ion membrane concentration and purification Technology, reverse osmosis membrane technology combined process technology, the lithium ion yield is 96-98%, and the lithium chloride solution concentration and purification process can have a removal rate of 85-98% for calcium and magnesium ions, boron and organic matter. The lithium chloride solution is pre-concentrated and pre-purified to provide a qualified liquid with higher purity for the subsequent process.

Preferably, the electrodialysis technology includes but not limited to homogeneous ionic membrane technology, heterogeneous ionic membrane technology, selective ionic membrane technology, non-selective ionic membrane technology and combination thereof, while concentrating the lithium chloride solution, further The feed liquid is the qualified liquid 602 of the process 6; the qualified export liquid 702 is a Li ⁺ concentration of 18-24g/L, which is a high-purity lithium chloride salt solution, and the outlet liquid 703 is 75-80% light brine, and contains some The mixed solution of lithium ions, boron and organic matter is returned to the process 5 to be concentrated and recovered by reverse osmosis, and boron ions are selectively removed.

Preferably, the product lithium chloride solution 801 is sent to the subsequent production workshop of lithium carbonate, lithium chloride or lithium hydroxide; the composition of the lithium chloride product solution: Li ⁺ concentration 18-24g/L, Mg ^{2 +} concentration 0.02-0.1 mg/L, Na ⁺ concentration 1.0-4.0g/L, B concentration 100-200g/L, Cl ^- concentration 90-120g/L.

Preferably, the lithium chloride yield in the process 1 yield is 40-60%; the process 2 and 3 yields: 98%; the process 4 yield: 99.5%; the process 5 yield: 98% ; Process 6 yield: 99.5%; Process 7 yield: 96%;. The total yield of lithium chloride is ≥90% (calculated by lithium ions).

Description of drawings

Fig. 1 is a schematic diagram of the process flow of the present invention.

In the figure: process unit 1, adsorption unit, process unit 2, electrodialysis unit 1, process unit 3, nanofiltration unit, process unit 4, ion exchange unit 1, process unit 5, reverse osmosis unit, process unit 6, ion exchange Unit 2, process unit 7, electrodialysis unit 2, process unit 8, evaporation crystallization unit.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to Figure 1, a new process for producing high-purity lithium chloride from salt lake brine,

Example 1:

Raw material: old brine solution

1) Composition of old brine: Li (mg/L) Mg(g/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 456 120 47 362 2800 35 55

2) Process 1 process:

Ø Adsorption flow rate: 4-8m/h;

Ø Adsorption temperature: 15-25℃

Ø Washing flow rate: 6-15m/h;

Ø Washing temperature: 15-30℃

Ø Desorption flow rate: 6-15m/h;

Ø Desorption temperature: 15-40℃

3) Obtain the initial qualified liquid composition: Li (mg/L) Mg(g/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 658 2660 17 8630 216 28 36

4) Process 2-Process 7 process:

Nanofiltration, reverse osmosis, electrodialysis, resin combination process;

5) The composition of high-purity lithium chloride solution obtained in process 7: Li (mg/L) Mg(mg/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 18500 <0.1 <0.1 59630 1620 13 58

6) Process 8 to obtain high-purity lithium chloride product:

Ø LiCl: >99.3%;

Ø Na: <0.1%;

Ø Ca: <0.003%;

Ø Mg: <0.0003%;

Ø SO ₄ ^2- : <0.008%;

Example 2:

Raw material: brine

1) Composition of brine: Li (mg/L) Mg(g/L) Cl (g/L) Na(mg/L) K(g/L) 220 35 225 72 15

2) Process:

Ø Adsorption flow rate: 4-8m/h;

Ø Adsorption temperature: 15-25℃

Ø Washing flow rate: 6-15m/h;

Ø Washing temperature: 15-30℃

Ø Desorption flow rate: 6-15m/h;

Ø Desorption temperature: 15-40℃

3) Obtain the initial qualified liquid composition: Li (mg/L) Mg(g/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 415 2160 twenty two 9130 1660 1210 32

4) Process 2-Process 7 process:

Nanofiltration, reverse osmosis, electrodialysis, resin combination process;

5) The composition of high-purity lithium chloride solution obtained in process 7: Li (mg/L) Mg(mg/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 16500 <0.1 <0.1 52660 2850 615 69

6) Process 8 to obtain high-purity lithium chloride product:

Ø LiCl: >99.0%;

Ø Na: <0.13%;

Ø Ca: <0.004%;

Ø Mg: <0.0003%;

Ø SO ₄ ^2- : <0.007%;

Example 3:

Raw material: old brine solution

1) Composition of old brine: Li (mg/L) Mg(g/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 550 140 50 421 2920 39 58

2) Process 1 process:

Ø Adsorption flow rate: 4-8m/h;

Ø Adsorption temperature: 15-25℃

Ø Washing flow rate: 6-15m/h;

Ø Washing temperature: 15-30℃

Ø Desorption flow rate: 6-15m/h;

Ø Desorption temperature: 15-40℃

3) Obtain the initial qualified liquid composition: Li (mg/L) Mg(g/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 658 2660 17 8630 216 28 36

4) Process 2-Process 7 process:

Nanofiltration, reverse osmosis, electrodialysis, resin combination process;

5) The composition of high-purity lithium chloride solution obtained in process 7: Li (mg/L) Mg(mg/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 17500 <0.1 <0.1 62140 2970 600 71

6) Process 8 to obtain high-purity lithium chloride product:

Ø LiCl: >99.2%;

Ø Na: <0.14%;

Ø Ca: <0.003%;

Ø Mg: <0.0004%;

Ø SO ₄ ^2- : <0.007%;

Example: 4:

Raw material: brine

1) Composition of brine: Li (mg/L) Mg(g/L) Cl (g/L) Na(mg/L) K(g/L) 310 80 171 58 7

2) Process:

Ø Adsorption flow rate: 4-8m/h;

Ø Adsorption temperature: 15-25℃

Ø Washing flow rate: 6-15m/h;

Ø Washing temperature: 15-30℃

Ø Desorption flow rate: 6-15m/h;

Ø Desorption temperature: 15-40℃

3) Obtain the initial qualified liquid composition: Li (mg/L) Mg(g/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 515 2220 26 9130 1780 1310 37

4) Process 2-Process 7 process:

Nanofiltration, reverse osmosis, electrodialysis, resin combination process;

5) The composition of high-purity lithium chloride solution obtained in process 7: Li (mg/L) Mg(mg/L) Ca(mg/L) Cl (g/L) Na(mg/L) K (mg/L) B (mg/L) 16300 <0.1 <0.1 51560 2970 632 71

6) Process 8 to obtain high-purity lithium chloride product:

Ø LiCl: >99.1%;

Ø Na: <0.13%;

Ø Ca: <0.003%;

Ø Mg: <0.0002%;

Ø SO ₄ ^2- : <0.005%;

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (21)

1. a kind of new process of salt lake bittern production high-purity lithium chloride, which is characterized in that include the following steps：

1）Mode of operation：The technique passes through data-optimized each unit scale of technology Calculation, preferred operations using continuous operation Mode, the continuous operation of realization.

2）Raw material：

（a）Salt lake bittern, wherein：Li⁺Concentration 0.01-0.20g/L, Mg²⁺Concentration 30-50g/L, Na⁺Concentration 30-45g/L, K⁺It is dense Spend 9-14g/L, Cl^-Concentration 200-300g/L.

（b）Salt lake bittern carries old halogen solution after potassium, wherein：Li⁺Concentration 0.25-0.6g/L, Mg²⁺Concentration 100-120g/L, Na⁺It is dense Spend 0.1-0.2g/L, Cl^-Concentration 300-400g/L.

3）Product：By the innovation technique, the qualified chlorination lithium salt solution product of content >=99.5%, the innovation technique can be made Include the technical process such as following 1 ~ 6 altogether.

4）The chloride containing lithium qualifying liquid that lithium technique is extracted from salt lake bittern and preliminary exquisiteness obtains is carried with ion exchange adsorption, By technical process 1, from salt lake bittern or from salt lake bittern carry potassium after old halogen solution 300：1~600：In 1 old halogen, realize Selective absorption, washing and the desorption of lithium chloride, it is 3 that Mg/Li ratio, which is made,：1~6：1 lithium chloride qualifying liquid is follow-up lithium carbonate Or other lithium products provide qualified lithium chloride raw material.

2. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：It is described Technical process 1 is mainly employed using aluminium system molecular sieve as adsorbent, is employed using the full chamber bed of special liquid distributor as core technology The absorption method extractive technique of equipment, the full chamber bed technology of use include but not limited to uplink full chamber bed technology, downlink full chamber bed skill Art, special liquid distributor are customized according to self-control aluminium system's absorbent particles size and distribution, and special liquid distributor can realize selectivity Even cloth liquid and current-limiting function improve the absorption, washing and the special liquid distributor of desorption efficiency of full chamber bed according to brine fluid mechanics spy Property and absorption, washing, desorption technical process flow velocity and distribution character requirement design calculate；Full chamber bed adsorption tower is respectively adopted up and down The liquid distributor of different uniformly cloth liquid functions carrys out cloth liquid, and liquid distributor structure type is using alternative mobile porous uniform cloth liquid side Formula；It is specifically shown in legend 1.

3. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 2, it is characterised in that：It is described Full chamber bed does not use inert filler to fill, technical process can realize just washing, the functions such as backwash, the tiny and fine crushing suction of canbe used on line The rinsing and screening of attached dose of powder improve the efficiency and efficiency of adsorbent bed, and adsorption process flow control is in 5-8m/hr；Absorption temperature Degree control is at 10-25 DEG C, and washing process flow control is in 10-20m/hr；Wash temperature is controlled at 10-25 DEG C；Flow control exists 10-20m/hr, desorption flow control is in 10-20m/hr, and desorption process flow control is in 10-20m/hr；The control of desorption temperature exists 20-40℃。

4. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 3, it is characterised in that：It is described Adsorption process flow velocity is set as 7m/hr；Adsorption temp is set as 20 DEG C, and washing process flow control is in 15m/hr；Wash temperature Control is at 20 DEG C；Flow control is in 15m/hr, and desorption flow control is in 17m/hr, and desorption process flow control is in 18m/hr；It is de- Temperature control is inhaled at 30 DEG C.

5. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：It is described Washing is divided into the washing of 4 steps, 3 step desorptions；Wash high magnesium solution discharge, low magnesium solution reuse；The high lithium solution recycling of desorption process, it is low Lithium solution is applied mechanically, and washing process is washed using 5-10% sodium chloride solutions, washes away adsorption tower residual magnesium ion and adsorbent surface magnesium Ion, washing process are equipped with online conductivity meter.

6. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 5, it is characterised in that：It is described Washing process is washed using 8% sodium chloride solution, washes away adsorption tower residual magnesium ion and adsorbent surface magnesium ion.

7. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：It is described The absorption of technical process 1, washing, desorption process employ automatic mode operation, and each operational parameter control can be according to original The realizations such as material characteristic, calculated yield are automatically entered and are controlled.

8. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：It is described Technical process 2 is charging with nanofiltration retention concentrate 302 in raw material lithium chloride qualifying liquid 102 and technical process 3, passes through selectivity Electrodialysis detaches calcium ions and magnesium ions therein, and scavenging solution obtains purification of chlorinated lithium qualifying liquid 202, wherein Adsorption calcium ions and magnesium ions work( The ion exchange technique of energy, including all trees that can realize this function such as highly acidic resin, weakly acidic resin, chelating resin Fat adsorption technology.

9. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：It is described Technical process 2 uses ion exchange combination technique, and calcium ions and magnesium ions content in qualifying liquid 202 can be reduced to below 0.5mg/L Even lower, obtained regenerative wastewater goes to salt pond.

10. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute It is for charging with raw material lithium chloride qualifying liquid 103 to state technical process 3, and calcium ions and magnesium ions therein are retained by selective NF membrane, Nanofiltration scavenging solution is 203；Nanofiltration concentrate 302 removes 2 electrodialysis of technical process Unit 1 separation retention magnesium ion；Nanofiltration scavenging solution 203 and electrodialysis scavenging solution 202 be mixed into qualifying liquid 3.

11. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 10, it is characterised in that：Institute The isolation technics that nanofiltration is main body technology is stated, the nanofiltration of use includes mesolow nanofiltration, high pressure nanofiltration With super-pressure nanofiltration and combinations thereof technology, in separating calcium and magnesium ion simultaneously, the feed liquid feed conditions of control system is needed to exist Scope of design, including temperature, pH value, pressure etc., nanofiltration can be used the design of multistage multisection type, multistage for improve cycles of concentration and Yield, multistage are used to improve scavenging solution quality.

12. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 11, it is characterised in that：Institute Stating scavenging solution can go the first order to produce water, and follow-up multistage concentration production water returns to first order import, to improve whole demagging effect, Ensure that scavenging solution magnesium ion content reaches setting value, the scavenging solution magnesium ion norm controlling is even lower in below 50mg/L.

13. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute It is for charging with qualifying liquid 401 to state technical process 4, and by ion-exchange process, the wherein micro calcium ions and magnesium ions of removal obtain thick Qualifying liquid 402 processed；Wherein：Li⁺Concentration 0.4-0.9g/L, Mg²⁺Concentration 0.001-0.01g/L, Na⁺Concentration 0.01-0.1g/L, Cl^- Concentration 2.0-5.0g/L.

14. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute It is to be concentrated with crude lithium chloride qualifying liquid 402 for charging by reverse osmosis process to state technical process 5, and it is 502 to obtain concentrate； Reverse osmosis produced water is 503, and absorbing process reuse is gone as recycle-water；Here, other than crude lithium chloride qualifying liquid 402, subsequently The light salt brine 703 of 7 electrodialysis 2 of technique unit returns to technical process 5 and 402 and forms the reverse osmosis charging of technique unit 5 together Liquid.

15. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute State that technical process 1 is main to be employed with, the reverse osmosis embrane method concentration technique for main body technology, the reverse osmosis technology of use include but It is not limited to include that low pressure RO, seawater desalination reverse osmosis, high pressure be reverse osmosis and super-pressure reverse osmosis technology and combinations thereof skill Art, wherein in concentration lithium chloride solution simultaneously, feeding liquid is adsorbed for front end and demagging qualifying liquid 101；Outlet qualifying liquid 102 is Li⁺A concentration of 4-7g/L, and qualifying liquid is mixed containing part magnesium ion, calcium ion, boron and organic matter etc., go out oral fluid 103 for 85- In preceding system the consumption of industry water can be greatly lowered, wherein electrodialysis 2 is light in 95% light salt brine, the light salt brine fully recovering Brine concentration removes boron reverse osmosis technology with reverse osmosis employ, and can detach and remove 85% boron ion, except concentrate is gone after boron Subsequent technique process.

16. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute It is for charging with reverse osmosis concentrated liquid 502 to state technical process 6, passes through ion exchange group technology, the wherein micro calcium and magnesium of removal Ion and most of sodium ion and potassium ion, obtain lithium chloride qualifying liquid 6；Regenerated liquid goes to salt pond.

17. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 16, it is characterised in that：Institute It states for the resin adsorptions of impurity function such as Adsorption calcium ions and magnesium ions and combinations thereof technology in technical process 6, including faintly acid All resin adsorption technologies that can realize this function such as resin, chelating resin, control qualifying liquid calcium ions and magnesium ions content are less than 0.05mg/L is even lower, for resin adsorptions of impurity function such as Adsorption calcium ions and magnesium ions and combinations thereof in technical process 6 Technology using special liquid distributor full chamber bed technology, can ensure lithium ion yield even higher 99.5%；Acid and alkali consumption and Product, which loses, to be optimized.

18. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute It is, by homogeneous electrodialysis process, to concentrate lithium chloride solution therein for charging with qualifying liquid 602 to state technical process 7；Concentration High-purity lithium chloride solution 702 is collected as product, removes follow-up lithium carbonate, lithium chloride or lithium hydroxide workshop；Electrodialysis Light salt brine 703 removes technique unit 5, is concentrated by technique unit 5 and removes most of boron ion, mainly employ using electrodialysis as The electrically-driven ion embrane method of main process concentrates and purifies technology, the COMBINED PROCESS of reverse osmosis membrane technology, and lithium ion yield exists 96-98% to lithium chloride solution concentration and purification process, can have calcium ions and magnesium ions, boron and organic matter the removal rate of 85-98%, Pre-concentration and prepurification are carried out to lithium chloride solution, the qualifying liquid of higher degree is provided for subsequent technique process.

19. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 18, it is characterised in that：Institute It states electrodialytic technique and includes but not limited to homogeneous ion membrane technology, different-phase ion membrane technology, selective ion membrane technology, non-selection Property ion membrane technology and combinations thereof technology, in concentration lithium chloride solution simultaneously, feeding liquid is the qualifying liquid 602 of technical process 6；Go out Mouth qualifying liquid 702 is Li⁺A concentration of 18-24g/L is high-purity chlorination lithium salt solution, goes out the light salt that oral fluid 703 is 75-80% Water, and containing mixed liquors such as part lithium ion, boron and organic matters, return in technical process 5 and recycled using reverse osmosis concentration, and select Selecting property removes boron ion.

20. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute Product lithium chloride solution 801 is stated, removes follow-up lithium carbonate, lithium chloride or lithium hydroxide workshop；Lithium chloride products solution composition： Li⁺Concentration 18-24g/L, Mg²⁺Concentration 0.02-0.1mg/L, Na⁺Concentration 1.0-4.0g/L, B concentration 100-200g/L, Cl^-Concentration 90-120g/L。

21. a kind of new process of salt lake bittern production high-purity lithium chloride according to claim 1, it is characterised in that：Institute It is 40-60% to state lithium chloride yield in 1 yield of technical process；2 and 3 yield of technical process：98%；4 yield of technical process：99.5%； 5 yield of technical process：98%；6 yield of technical process：99.5%；7 yield of technical process：96%；.Lithium chloride total recovery >=90%（With Lithium ion calculates）.