WO2003037794A1

WO2003037794A1 - Method for recovering lithium chloride from brine and installation for carrying out said method

Info

Publication number: WO2003037794A1
Application number: PCT/DE2001/004061
Authority: WO
Inventors: Alexander Rybtsev; Valeriy Titarenko; Larisa Menzheres; Natalya Kotsupalo; Elizaveta Guschina; Luydmila Serikova; Piter Shinkarenko; Sergey Sudarev; Nikolay Nemkov
Original assignee: Eurosina Technology Consulting & Project Development Gmbh
Priority date: 2001-10-25
Filing date: 2001-10-25
Publication date: 2003-05-08
Also published as: CN1558871A; CN1263678C; DE10197021D2

Abstract

The invention relates to a method for recovering lithium chloride from brine and to an installation for carrying out said method. The method for recovering LiCl from brine using selective sorptive extraction of the lithium substantially comprises the following steps: obtaining a solution enriched with LiCl in a sorption/desorption complex by means of a desorption liquid and an LiCl solution obtained in circulation operation, said LiCl solution having a concentration of 10 kg/m3 to 17 kg/m3; carrying out an ion exchange purification of the enriched solution of Ca and Mg admixtures; concentrating the purified eluates according to the electrodialysis method up to an LiCl concentration of 100 kg/m3 to 150 kg/m3 while obtaining a desalted solution having an LiCl concentration of 0.2 kg/m3 to 0.5 kg/m3 that is used for lithium desorption from the sorption agent; washing and drying the LiCl crystals obtained by evaporation of the solution concentrated to an LiCl content of 600 kg/m3 to 800 kg/m3 and cooling. The water-free lithium thus obtained has a high degree of purity and is suitable for the production of metal lithium and the alloys thereof.

Description

Process for the production of lithium chloride from brine and plant for

Execution of the procedure

The inventions relate to a process for the production of lithium chloride from brine and a plant for carrying out the process. They generally relate to the field of wet lithium metallurgy, in particular the extraction of lithium chloride from its solutions and from natural brine.

A method is known for obtaining lithium chloride from solutions (US Pat. No. 4,291,001), for example from brine based on crystalline lithium aluminate LiCl 2AI (OH) ₃ nH ₂ O, synthesized in the macropores of an ion exchange resin, and for using this sorbent in the sorption columns with the resting filter layer of the sorbent on the way of lithium elution (desorption) and subsequent concentration of the eluate via a column system. For this purpose, the salt of a non-competitive metal, e.g. NaCI or CaCI ₂ , is added to the eluate. The column system is operated with brine heating up to a temperature of 60 ° C or more. The use of salt for the eluate concentration leads to additional reagent consumption and to eluate contamination by sodium chloride and calcium chloride.

US Pat. No. 4,291,001 describes a plant for the production of lithium chloride from brine, consisting of a device for the production of lithium chloride and a device for concentrating the eluate - lithium chloride solution, which includes three columns filled with sorbent, which together, with the brine source and the container for fresh water by means of a piping system. In addition, the system has a salt metering device and a device for the removal of the concentrated lithium chloride.

With the help of the device mentioned, the lithium selective extraction from the brine in the first column, the elution of the lithium chloride from the sorbent and its subsequent concentration in two further columns.

The system described can only be used in discontinuous operation using the fixed bed sorbent. In the plants of this type, no lithium chloride concentrate can be obtained without foreign components because its contamination by the salts which are introduced into the eluate in the course of the concentration is unavoidable.

In addition, the known system takes up an important production area and has a high metal requirement and a complicated control system for process control.

From WO 94/19280 a process for the production of lithium chloride from brine is known as a sorption-desorption complex (hereinafter referred to as SDK), which the sorption extraction of the lithium from the brine by contacting with the granular sorbent selective for lithium according to RU 2050330, produced according to the process according to RU 2113405 and RU 2050184, as well as the lithium desorption by means of the demineralized water with the extraction of the lithium chloride solution as an eluate and its subsequent concentration. According to this invention, the chloride form of the double hydroxide of aluminum and lithium in the composition LiCl 2AI (OH) ₃ nH ₂ O is used as the sorbent. The lithium sorption and desorption is carried out in step countercurrent operation. The duration of the residence time of the sorbent in the sorption zone is chosen as it is required for complete sorbent saturation with the lithium chloride. The duration of the residence time in the desorption zone is determined by the time required for a complete extraction of lithium chloride from the sorbent. Before desorption, the sorbent saturated in the equilibrium with the lithium in equilibrium takes place in the step by countercurrent contact with the ascending flow of the lithium chloride solution of the specified concentration and within the specified time, which the sorbent after-saturation with the lithium chloride up to the limit capacity with the simultaneous washing of the Sorbent granules guaranteed from the foreign components.

The sorption duration is specified on the basis of the condition of the equivalent saturation of the sorbent initial charge volume with the lithium, which is equal to the volume of the new sorbent charge. The sorbent post-saturation with the lithium up to the limit value is carried out while ensuring the maximum possible concentration of lithium chloride in the sorbent during sorption and corresponding to the maximum possible concentration in the solution in the course of the phase contacts during desorption.

The concentration of the eluate of the lithium chloride produced in the known method is carried out by electrodialysis in the presence of an ion exchange resin, which not only causes a concentration of the solution of the lithium chloride, but also allows its post-cleaning of calcium and magnesium admixtures.

The sorbent used for the selective sorption of lithium from the brine with high mineralization is based on the chloride form of the double hydroxide of aluminum and lithium LiCI 2AI (OH) ₃ nH ₂ O (hereinafter called DHAL-CI) with construction defects and lithium deficiency in its composition prepared, which corresponds to the sorption capacity of 6 i 1 mg lithium per 1 gram of sorbent. The sorbent granulation takes place according to a method described in RU 2050184 and WO 94/19513.

WO 94/19280 describes a process with a plant for the sorption of lithium in the form of its chloride. A component of the plant is the sorption-desorption complex (hereinafter referred to as SDK), which is a Higgens column type with a U-shaped cylinder body filled with granulated sorbent.

The SDK has ball valves that are mounted in the sorption and desorption areas of the column and are used in the column body for the passage of sorbent. The intersections of the sorption and desorption zones are 1.5: 1.0. In the SDK are arranged: pipes for the supply of the starting brine into the sorption zone and for the discharge of the brine from it, pipes for the supply of the elution liquid into the desorption zone and for the eluate discharge from it, pipes for the discharge of the regenerated sorbent from the desorption zone and For the supply of the regenerated sorbent into the sorption area from the SDK and a pipeline for the supply of the solution for the re-saturation and the washing of the sorbent, which is mounted under the pipeline for the supply of the starting brine in the sorption zone.

The SDK is connected by means of the pipes and the fitting: to the containers for the starting brine and the brine, for the elution liquid and for the eluate, with the collection container for the solution, which is used as rinsing liquid in the sorbent classification and with the filter for the Sorbent separation method and with the device for concentrating the eluate, which consists of an electrodialyzer and a pulp preparation apparatus, the eluate container, the container for demineralized water and the filter, and the containers for the concentrated solution of lithium chloride and for the Regenerate (solution of magnesium chloride and calcium chloride after resin regeneration in the electrodialyzer are connected.

The main disadvantages of this system are as follows: only eluates with a low lithium chloride concentration (~ 5 kg / m ³ ) can be obtained, in the insufficient purity of the eluate to be fed into the electrochemical apparatus, in the absence of a channel for the return of the liquid the zone for the sorbent transfer into the desorption zone, in a significant sorbent wear due to the slanted device in the column and the different diameter of the device in the soφtions- and the desorption zone; a long drain time of the brine and the rinsing liquid; an uneven supply of brine in the column cross-section, the use of an electrodialyzer with low power for the eluate concentration.

The object of the invention is therefore to provide an improved process for the extraction of

To provide lithium chloride from brine, which is an environmentally friendly extraction of

Lithium chloride with higher purity and yield enables.

Another object of the invention is to provide a plant for carrying out this method.

According to the invention, the object is achieved by a method having the features of claim 1. Advantageous embodiments of the method according to the invention result from the features of claims 2 to 6.

The task of providing the system is achieved according to the invention by a system with the features of claim 7. Preferred configurations of the system according to the invention result from the features of claims 8 to 11.

The process according to the invention is characterized by the following stages and advantages:

The extraction of eluates enriched with lithium chloride (10 g / l to 17 g / l) with a minimum content of magnesium and calcium admixtures up to 1 g / l immediately purified in a sorption-desorption complex (SDK), the extraction of the lithium chloride solution of magnesium and

Calcium admixtures during the ion exchange cleaning of the eluate, the concentration of those cleaned by the electrodialysis process

Lithium chloride solution containing an electrodialysis brine containing

LiCl from 100 kg / m ³ to 150 kg / m ³ and the desalted solution with a LiCl content of 0.2 kg / m ³ to 0.5 kg / m ³ , which is further used for the lithium desorption

Sorbent is used, the possibility of using alternative methods for concentrating the

Lithium chloride solution in a natural way in tanks and graduation towers as well as by concentrating the lithium chloride solution after the freezing process, reducing the sodium admixture in the finished product by the constant

Removal of part of the fugate stream of the enriched sodium chloride after the

Separation of crystals of LiCI H ₂ O, dewatering and drying of the finished product in hand ice quality from LiCI H ₂ O with constant moisture removal.

The technical and economic effect of the method according to the invention is achieved above all by:

the elution of the eluates enriched with lithium chloride directly in the SDK in the course of the lithium desorption in two stages: in the lower zone with the Lithium chloride solution with a concentration of 10 kg / m ³ to 17 kg / m ³ in

Circulation operation with a ratio of the volume flow of the circulating solution to

Sorbent circulation flow of 1, 5 1, 0 with removal of part of the

Lithium chloride solution and in the upper zone in counterflow operation by means of the desalted lithium chloride solution which is conveyed to the inlet of the upper zone by the volume flow which is equal to the volume flow of the lithium chloride solution to be discharged; the cleaning of the lithium chloride solution from calcium and magnesium under

Use of the cation exchanger KY-2 in Li form; The purified eluates are concentrated in two stages according to the electrodialysis process: in the first stage in galvanostatic operation with the generation of a

Electrodialysis salt liquor stream with a LiCl content of 100 kg / m ³ to 150 kg / m ³ and a dialysate stream with a LiCl content of 3.5 kg / m ³ to 4.0 kg / m ³ ; in the second stage in the potentiostatic mode with generation of a

Liquid stream of a desalted solution with a residual LiCI content of 0.2 kg / m ³ to 0.5 kg / m ³ , which in the phase of lithium desorption from the sorbent as

Desorbent is used and the generation of a concentrate flow with a LiCl content of 7 kg / m ³ to 10 kg / m ³ , which is mixed with the purified eluate; the use of natural eluate concentration by evaporation in basins or by freeze-drying at a temperature of -10 ° C to -30 ° C; the subsequent evaporation of the electrodialysis brine or the brine obtained by natural concentration (water evaporation) up to one

Concentration of the LiCl from 600 kg / m ³ to 800 kg / m ³ with subsequent cooling to a temperature of 40 ° C to 60 ° C and with the centrifugation of the LiCI H ₂ O with

Fuga return for further evaporation; to the amount of the admixture of NaCI in the evaporated solution of the LiCl in

Keeping the range from 7.0 kg / m ³ to 7.5 kg / m ³ will result in a current portion of the solution

Separating the crystals of LiCI H ₂ O from the process and for the

Regeneration of the cation exchanger KY-2 and its conversion into the Li form used; the drainage and drying of the LiCI-H ₂ O crystals when heated under the Condition of crystal extraction in vacuum on a surface heated up to a temperature of 100 ° C to 105 ° C.

The technical and economic effects of the method described are also due to the use of the system according to the invention. The system also has a Soφtion-Desorption complex for eluate cleaning (hereinafter referred to as SDKER) with a sorption and a desorption branch whose diameters are 3: 2 to each other, a device for the electrodialysis concentration of the cleaned eluates, consisting of: Electrodialysis concentrator and electrodialysis desalinator, heat exchanger recuperator for preheating the desalinated solution, evaporator and cooler condenser for separating the wet steam with a droplet separator, crystallizer, centrifuge, slanted screw washer and heated screw vacuum dryer. All devices and apparatus are connected to one another by means of pipelines through appropriate containers directly or via pumps.

The technical and economic effects are also achieved in that the main SDK for the selective extraction of lithium from the brine has the same diameters of the sorption and desorption areas. It also has the following assemblies: a device for cross-mixing the washout liquid, arranged in the toroidal part of the column, pipe section with dewatering insert, mounted in the lower part of the container for receiving the regenerated sorbent from the desorption zone and connected to a bypass line for returning the transfer solution into the desorption zone; via a circuit, formed by a drainage system for the eluate discharge, arranged in the lower region of the desorption branch of the SDK above the device for cross-mixing the wash-out liquid, and connected to the container for the eluate circulation.

Furthermore, the effects are also achieved in that a pump is arranged in the device for cross-mixing the wash-out liquid, which is connected via its inlet and outlet pipes to the drainage inserts, which is mounted in the SDK body at the height of the pipe section for the inlet of the wash-out liquid between the drainage inserts. The pump is with the Drainage inserts are preferably connected in such a way that there is a possibility for reversible liquid circulation through the drainage inserts.

The positive effects of LiCI production are further achieved by a preferred embodiment of the system according to the invention, in that an additional dewatering insert is installed in the container for the classification of the regenerated sorbent, which is fed to the SDK, to shorten the duration of the flushing liquid is located above the pipe section for supplying the used brine for classification and is connected to the pipe section for the outflow of the used brine.

Furthermore, it has proven to be advantageous in a preferred embodiment that a drainage insert is mounted in the container for receiving the regenerated sorbent from the desorption zone of the SDK, connected to the lower pipeline for the discharge of the transfer solution directly and by means of a bypass system for the return the transfer solution from the container into the desorption zone and with the upper pipeline for the discharge of the transfer solution for the purpose of its return to the desorption zone.

The system proposed according to the invention for the production of lithium chloride from brine ensures the step-countercurrent flow of the contact phases in the sorption-desorption complex, which runs in two operating stages, firstly the brine filtration (sorption) through the sorbent and the sorbent transfer with a closed sorbent circuit and one effective washing of the granules of foreign matter using a cross line for mixing the washing water and secondly concentrating the eluate directly in the column by introducing a circuit for the eluate recirculation and the return flow of the eluent liquid from the zone of sorbent transfer to the upper desorption zone, which is a Eluate dilution prevented.

The eluate with the concentration of LiCl, which is close to equilibrium, is fed to the ion exchange column (SDKER) for the purification of Ca ions and Mg ions. Then it is directed to two-stage electrodialysis concentrating. The salt-free water thus obtained is led into the desorption branch of the SDK and the electrodialysis salt liquor of the LiCl is evaporated by the heat treatment for the subsequent crystallization of the LiCI H ₂ O and for the production of the anhydrous lithium chloride.

The inventions are to be explained in more detail below with the aid of drawings and examples. Show it:

1 shows a graphical representation of the dependence of the eluate concentration on the circulation circuit by means of the circulation solutions of the recirculation of the desorption branch from the SDK with a ratio of the liquid phase to the solid phase of 1.5: 1, 0;

Fig. 2 graphical representation of the isotherm of lithium desorption from

Sorbs means;

Fig. 3 graphical representation of the eluate concentration in

Electrodialysis machine with galvanostatic operation and different current densities (A / dm ² ): a - 3.3; b - 5.9; c - 7.2;

Fig. 4 graphical representation of the eluent salting in the galvanostatic

Operation up to the optimal LiCl content in the dialysate under different current densities (A / dm ² ): a - 3.3; b - 4.6; c - 5.9; d - 7.2;

Fig. 5 graphical representation of desalination after the 1st stage of

Eluate concentration in potentiostatic operation;

Fig. 6 graphical representation of the dependence of the water content on the

Duration and temperature when LiCl H ₂ O dries out at a temperature of a - 105 ° C and b - 100 ° C;

Fig. 7 graphical representation of the eluate concentration by

Freeze-drying;

Fig. 8-1, 8-2, 8-3 Schematic representation of the plant for the production of lithium chloride from brine.

The method proposed according to the invention for the production of lithium chloride and the Plant for its implementation are realized thanks to the interaction of the following basic processes:

1) selective extraction of the lithium from the brine by obtaining the eluates of the lithium chloride;

2) deep ion exchange purification of the eluates of Mg ²⁺ and Ca ²⁺ admixtures;

3) concentrating the solution of the lithium chloride by methods known per se, including electrochemical methods;

4) thermal evaporation of the LiCI solution after the previous concentration up to 150 kg / m ³ LiCl;

5) cooling and crystallization of the lithium chloride monohydrate with its subsequent separation and the removal of part of the fugate, enriched with NaCl;

6) Obtaining the anhydrous lithium chloride in hand ice quality by drying the product in a vacuum.

The SDK, hereinafter referred to as the column, has a number of zones through which the sorbent is continuously passed and which correspond to the following processes: hydraulic sorbent classification (I), sorption (II), washing and post-saturation (III, IV), desorption ( V and VI). After the lithium desorption, the sorbent is passed into the container (VII) and then into the zone for the hydraulic classification (I), which forms a closed circuit. According to FIG. 8, the sorbent is passed on under compressed air pulses.

In zone (I), a small fraction (the products of the sorbent decay) is removed from the column by hydraulic classification in the ascending flow of the liquid, whereby the resistance of the hydraulic resistance of the sorbent layer is achieved.

After sorbent saturation in the sorption zone (II), the sorbent is led into the washing and post-saturation zone of the LiCI solution (III, IV). Here the sorbent is washed off from the salt contained in the brine by the additional cross-mixing with the washing liquid. In the intermediate zone (IV), sorbents reach and solution (desorbate) the point at which the maximum lithium content is determined both in the sorbent and in the solution. The eluate is removed at this point. During the forwarding of the sorbent into the desorption area of the SDK, the sorbent runs through the first desorption zone (V), through which the eluate circulates, and further through the second desorption zone (VI), where the lithium is deeply desorbed with the salt-free desorption solution.

The sequence of the processes described makes it possible to use eluates with a LiCl content of 10 kg / m ³ to 17 kg / m ³ and MgCl ₂ and CaCl ₂ admixtures in the range from 0.1 g / l to 0.3 g / l to obtain.

The mentioned LiCI concentration is reached during the eluate recirculation in the desorption zone. 1 shows the dependence of the LiCI concentration on the number of cycles (passes) through the recirculation circuit. As follows from FIG. 1, the LiCI concentration practically reaches an equilibrium state after only 2 to 4 cycles (FIG. 2).

After the SDK, the eluate is fed into the ion exchange column (SDKER), which is filled with the cation exchange resin KY-2 in Li form and works according to the SDK principle, i.e. in counter-current operation.

The small resin fraction is separated off in zone (I) by means of hydraulic classification. In the sorption zone (II) the resin is saturated with the Ca and Mg ions from the eluate, during which the lithium ions pass into the solution.

The resin KY-2 runs from the sorption zone into the transition zone (III), where the Li ions are further displaced from the resin into the solution and replaced by Ca and Mg ions, the concentration of which compared to their concentration in Starting eluate of the sorption zone is somewhat higher. At the exit of zone (III) the sorbent is completely saturated with the Ca and Mg ions and the regeneration solution (LiCI solution) running in the opposite direction reaches the point at which the concentration of calcium and magnesium in the sorbent and in the solution is at a maximum is. Of From this point, the used regeneration solution is removed, which contains up to 100 kg / m ³ CaCl ₂ and MgCl ₂ as well as approximately 2 kg / m ³ LiCl.

When passing through Zone IV, the Ca and Mg ions in the resin are replaced by lithium ions, the concentration of which in the regeneration solution (lithium chloride solution) is almost ten times higher than in the starting eluate and 1.5 to 2.5 M (64 kg / m ³ to 100 kg / m ³ ). The regenerated sorbent is transferred to Zone V and Classification Section I closes the technological cycle.

The described construction of the ion exchange column allows eluates with a content of Ca ²⁺ and Mg ²⁺ to be obtained up to 0.001 kg / m ³ and 0.003 kg / m ³ . The lithium chloride content increases somewhat to 13 kg / m ³ to 18 kg / m ³ because of the lithium transition from the resin into the solution. The lithium chloride solution is used to concentrate electrodialysis: stage I - production of the electrodialysis salt solution 100 kg / m ³ to 150 kg / m ³ LiCl and the dialysate 3.5 kg / m ³ to 4.0 kg / m ³ , and stage II - concentration of the Dialysates from stage I to 7.0 kg / m ³ to 10.0 kg / m ³ LiCl with recovery of the Li concentrate and the desalted solution with a LiCl content of 0.2 kg / m ³ to 0.5 kg / m ³ , which is conducted as a desorbent in the desorption zone from the SDK for lithium desorption from the granulated sorbent.

The electrodialysis salt liquor LiCl from concentration stage I runs into the heat exchanger recuperator for preheating, then into the evaporator for subsequent evaporation with subsequent cooling of the evaporated solution in the crystallizer and for crystal formation LiCl H ₂ O. The LiCl H ₂ O crystals are in the centrifuge from the remaining solution is separated off and washed in an inclined screw washer, where countercurrent washing takes place with a lithium chloride solution; then the LiCIH ₂ O crystals are fed into the vacuum screw dryer, in which the anhydrous lithium chloride is obtained at a temperature of 100 ° C to 105 ° C and constant removal of the water vapor.

Concentrating the LiCI solution after cleaning the Ca and Mg admixtures can also occur naturally in the basin under the conditions of a mild one warm climates or freeze-drying in areas with a long winter period and very dry air. After the natural concentration or freeze-drying, the concentrated LiCI solution is also passed on to the heat exchanger recuperator and the evaporator for further evaporation and production of the crystalline lithium chloride monohydrate, as already described above.

In the following, the offered invention is explained using examples of its implementation.

example 1

The granulated sorbent based on DHAL-CI was after the selective sorption of the lithium from the brine ( _Sa , _z ≡ 500 g / l; LiCl = 2.5 g / l) with mixing and with the ratio liquid phase: solid phase = 1 , 5 worked with the water. After the lithium desorption with the salt-free water, the eluate contained 5.5 g / l lithium chloride.

A new portion of the lithium-saturated sorbent was processed with the eluate obtained under the same conditions. Several cycles were carried out in this way. The eluates from the previous cycle were used to process the new sorbent portion in the next cycles. The course of the eluate concentration in the recirculation circuit of the desorption branch of the column was thus traced. After the second processing, the lithium chloride concentration in the eluate increased to ~ 9 g / l and after the fourth processing up to 13 g / l. The results of the successive cycles of lithium desorption from the saturated sorbent using the lithium chloride solutions from the previous cycle are shown in FIG. 1. This method makes it possible to obtain a lithium chloride concentration in the eluate of ~ 15 g / l, which corresponds practically to the equally difficult concentration in the solution-sorbent system (see desorption isotherm in FIG. 2).

Example 2 The eluate after its concentration, composed of (in g / l): LiCl = 12.9; NaCI = 0.03; MgCl ₂ = 0.20; CaCI ₂ = 0.28 (or 4.2 millival / l MgCl ₂ and 5.05 meq / l CaCl ₂ ), in a volume of 16.5 l, was passed through the ion exchange column filled with the resin KY-2 in Li form and in a volume of 225 ml. The processing was carried out until Ca ⁺ breakthrough into the solution. After the Ca and Mg ions had been purified, the eluate had the following composition (in g / l): LiCl = 18.0; NaCI = 0.02; MgCl ₂ = 0.003; CaCI ₂ = 0.001. Ca and Mg content in the resin = 153 meq.

Example 3

After the eluate was passed through the cation exchange resin KY-2, it was regenerated with a lithium chloride solution of 70 g / l. Resin regeneration was carried out in the same column before the absence of Ca and Mg in the resin. The regenerated solution used was a solution of magnesium and calcium chloride with a concentration of up to 100 g / l, converted to CaCl ₂ with a LiCl content of ~ 2 g / l, added to the starting salt solution (example 1).

Example 4

The eluate, which had been cleaned of foreign constituents and had a LiCl content of 18 g / l (see Example 2), was subjected to electrodialysis concentration in a 10-chamber cell, of which 5 chambers were used for desalination and 5 chambers for concentration, and the second Electrode chambers, united by a uniform circulation circuit in which the LiCI solution circulated with a concentration of 15 g / l to 20 g / l. The chamber distance was 2 mm. Concentration was carried out in galvanostatic operation at current densities of 3.3 A / dm ² ; 5.9 A / dm ² and 7.2 A / dm ² . The linear velocity of the solution flow through all chambers was 5 cm / s. The process was carried out for the LiCI solution circulating for desalination and concentration.

The process control is based on the change in the LiCI concentration in the desalination circuit and in the concentration circuit. The test results are in Fig. 3 shown. At current densities of 5.9 A / dm ² and 7.2 A / dm ² , concentration was carried out to 130 g / l to 150 g / l (FIGS. 3a and 3b). At a current density of 3.3 A / dm ² , the eluate concentration was carried out down to -100 g / l LiCl (FIG. 3c).

Example 5

The determination of the optimal residual concentration of LiCl in the dialysate during eluate concentration in galvanostatic operation was carried out at the current densities of 3.3 A / dm ² ; 4.6 A / dm ² , 5.9 A / dm ² and 7.2 A / dm ² . The test results are shown in FIG. 4. With the current strength unchanged, the process takes place in a stable manner up to the LiCI concentration in the dialysate of 3.5 g / l (FIG. 4a), 4.5 g / l to 5.0 g / l (FIG. 4b, c) and 6 g / l (Fig. 4d) according to the specified current densities. If the LiCI concentrations in the solution to be desalinated decrease as a result of the membrane polarization, the energy consumption increases very much. The LiCI solutions are optimally concentrated at a current density i = 3.3 A / dm ² to 5.9 A / dm ² , because under these conditions the minimum LiCl content in the dialysate of 3.5 g / l to 5 0 g / l can be obtained with minimal energy consumption.

Example 6

The dialysate with a LiCl content of 3.5 g / l and 5.0 g / l was desalted in an electrodialysis cell, the construction of which is described in Example 4. Desalination was carried out in potentiostatic operation with a voltage drop in the unit cell of 4 V. The process was carried out in the circulating mode of the solution to be desalinated at a linear velocity of the current of 5 cm / s. carried out. The test results are shown in FIG. 5. Desalination took place up to a LiCl content of 0.2 g / l (a) and 0.5 g / l (b) at a starting content of 3.5 g / l and 5.0 g / l. The LiCl content in the concentration range corresponded to ~ 7.5 g / l and 10.0 g / l.

Example 7

The eluate cleaned of foreign constituents with a LiCl content of 100 g / l became after the electrodialysis concentrate in a container which was heated in a water bath with constant mixing in order to follow the evaporation of the LiCI solution under natural conditions. After evaporation four times, a LiCI solution with ~ 400 g / l was obtained. Evaporation of the LiCI solution down to ~ 600 g / l was carried out with an electric cooker. After cooling the solution and forming LiCl H ₂ O crystals, the crystals were separated from the solution and washed three times with smaller amounts of the lithium chloride solution. The content of the basic substance in the lithium chloride monohydrate obtained was 99.9%.

Example 8

The Lithiumchloridmonohydrat obtained as described in Example 7, with a water content of - 40%, was dried in a vacuum oven at a temperature of 100 ° C to 105 ^C C. The test results are shown in Fig. 6. As can be seen from the graph, the residual moisture is - 7.5% (curve b) at a temperature of 100 ° C and 2% at 105 ° C (curve a). The dried product does not lose its bulk status. The foreign constituents in anhydrous lithium chloride are 0.142%, which corresponds to a lithium chloride with a high degree of purity.

Example 9

250 ml of the eluate cleaned of the foreign constituents (16.1 g / l, mass LiCl - 4.03 g) were frozen at the temperatures -4 ° C., -15 ° C. and -22 ° C. After freezing, the amount of ice in the samples was 84%, 96.8% and 98.5% of the volume of the starting solution, respectively. The LiCI concentration in the remaining brine made 43.0 g / l; 64.4 g / l and 68.7 g / l according to the temperatures given (Fig. 7). This means that the concentration of the LiCI solution was 2.7 to 4.3 times, with the transition into the solution from ~ 60% to 70% of the LiCI mass that was present in the starting solution. During the transition to the industrial plants for freezing the brine, this characteristic value can be increased to 90%. The lithium chloride content was 0.4 g / l to 0.8 g / l after separating the brine produced and defrosting ice, which it was allowed to use such solutions for the lithium desorption of the sorbent.

Example 10

The function of the system will be described below with reference to FIG. 8.

The first loading of the column (SDK) with the sorbent takes place when the sorbent pulp is fed in the LiCl solution (~ 2 g / l), which runs from the container 90 into the container 29. After filling the column with the sorbent, the brine is conveyed into the left Soφtionsbereich II of the column. The starting salt liquor from the container 1 is passed through the pipe section 4 into the SDK 3 by means of the pump 2. When passing through the Soφtionszone (left area of the column), the low in lithium brine is discharged through the pipe section 5 and the filter 26 into the collecting basin for the brine 27. The used brine flows through the used brine disposal system 101. Part of the brine is fed from the tank 27 with the pump 28 through the pipe section 7 into the classification zone of the SDK (tank 3-1), where the crushed sorbent fraction is separated and together with the brine through the pipe section 8 from the SDK (tank 3 -1) is dissipated. The pulp of the shredded sorbent and the brine flow through the filter 26, with which the sorbent constituents are separated: the brine runs into the container 27 and the shredded sorbent is filled into sacks and transported to a plant for producing granulated sorbent for further use. Fresh feeds with granulated sorbent (DHAL-CI) are made by mixing DHAL-CI with the brine that flows from the column (SDK area II) through the pipe section 5 into the container 29; then the pulp with the jet pump 30 is guided through the pipeline and the pipe section 9 into the classification zone of the SDK (container 3-1).

After saturation with the lithium in the sorption branch of the SDK, the granulated sorbent comes into the lower toroidal part of the column, where the water from the container 38 is also pumped through the pipe section 12 with the pump 37. Washing is carried out using the mixing device 13, including the pump 14. The washed sorbent runs into the desorption zone of the sorption-desorption complex (SDK) 3, in which a two-stage lithium desorption is carried out: first by means of the lithium chloride, which is fed from the container 35 through the pipe section 15 with the pump 36; this is followed by deep lithium desorption with the salt-free solution, which is conveyed from the container 40 through the pipe section 17 with the pump 39. After the lithium desorption with the water, the eluate flows into the lower part of the zone, where it is re-saturated with the lithium with the aid of the drainage system 11 of the concentration cycle. The eluate from the container 35 is pumped several times by means of the pump 36 through the sorbent of the lower part of the desorption zone of the SDK 3, which increases the LiCl concentration in the eluate. The eluate saturated with lithium is passed on from the concentration circuit 11 into the container 33 for cleaning calcium and magnesium.

After lithium desorption, the sorbent passes through valve 25 into container 3-2 for receiving the regenerated sorbent; a part of the transfer solution, which came into the container 3-2 during the conveying of the soothing agent, is returned to the column via the bypass system 18-1 and through the pipe sections 19 and 16. The prepared (regenerated) sorbent is conveyed through the valve 24 into the classification zone (container 3-1). After classification, the sorbent is passed through valve 23 into the sorption area of the column (SDK). This closes the sorbent cycle in the SDK 3. The sorbent is conveyed from the container 3-2 into the classification zone with the help of water from the container 38, which is guided through the pipe section 20 by means of the pipe 37 into the container 3-2.

After desorption, the eluate is led from the container 33 by means of the pump 34 through the pipe section 42 into the area II of the ion exchange column 41 (SDKER). The eluate cleaned from Ca ²⁺ and Mg ²⁺ ions runs through the pipe section 43 via the curved sieve 64 into the collecting container 65 for the cleaned eluate. The cation exchanger KY-2 saturated with Ca ²⁺ and Mg ²⁺ ions is conveyed into the toroidal part of the column by means of a compressed air pulse, after which it runs into the region IV of the column and for the desorption of Ca ²⁺ and Mg ²⁺ ions is regenerated there at the same time. For this purpose, the regeneration solution LiCl with a concentration of 70 kg / m ³ to 100 kg / m ^{3 is} fed through the pipe section 52-1. During the passage through the desorption zone, the used regeneration solution, saturated with Ca and Mg chlorides and with a LiCl content of ~ 2 kg / m ³ , is drained through the pipe section 50 and passed into the container 1 with the starting solution. The regenerated cation exchanger KY-2 in Li ⁺ form runs through the valve 60 into the container 41-2, and the solution fed into the container together with the resin is returned to the desorption zone via the bypass system through the pipe sections 54 and 51. From the container 41-2, the resin is conveyed through the valve 59 into the container 41-1 for classification and separation of the small fraction with the aid of the purified eluate coming from the container 65. The resin classification is also carried out by means of the cleaned eluate, which is fed from the container 65 through pipes and the pipe section 45. From the classification zone, the pulp is passed on to the curved screen 64, on which the small resin fraction is separated from the LiCl solution, which runs into the container 65.

The purified eluate is concentrated in series-produced electrodialysis apparatus in filter press design, consisting of the alternating cation and anion exchange membranes that form the chambers for concentrating and desalting. The cleaned eluate is conveyed from the container 67 with the pump 68 into the electrodialysis concentrator 69 for the first stage of the concentration; in the process of concentrating, the solution circulates in the desalination chamber until the LiCl content reaches the value of 3.5 kg / m ³ to 4 kg / m ³ . In the concentration chambers, the LiCl concentration in the electrodialysis brine is simultaneously increased to 100 kg / m ³ to 150 kg / m ³ , which is collected in the container 72. The dialysate produced in the desalination chambers is fed to the container 73 at the second stage of desalination, from which it is pumped into the electrodialysis desalder 75 of a similar design for deeper desalination (to 0.2 kg / m ³ to 0.5 kg / m ³ LiCl) is forwarded. At the same time, concentrate with a LiCl content of ~ 7.5 kg / m ³ to 10.0 kg / m ^{3 is} obtained in the concentration chambers, which is passed from the container 77 into the container 67 and mixed with the purified eluate , The desalted solution with a LiCl content of 0.2 kg / m ³ to 0.5 kg / m ³ runs into the container 40 for use in the lithium desorption stage of the sorbent in the SDK 3. The electrodialysis brine of the lithium chloride is fed from the container 72 with the pump 79 into the heat exchanger recuperator 78, in which the solution is heated with the steam coming from the evaporator 80. After preheating, the LiCI solution runs into the evaporator 80 for further evaporation, in which the water evaporates in vacuo and by means of the heating steam which is passed through the steam supply system 96 and the condensate which has formed in the course of the steam supply. As a result, the LiCI concentration in the brine increases to 750 kg / m ³ to 800 kg / m ³ . The subsequently evaporated LiCl brine is discharged into the crystallizer 85. The wet steam is condensed in the cooler condenser 81 and passed on through the droplet separator 83 into the collecting container 84 for the condensate. The LiCl H ₂ O crystals produced in the crystallizer 85 are separated from the brine in the centrifuge 86 and passed on for washing in the end part of the slanted screw washer 87. The condensate runs out of the container 84 in the top part thereof. After centrifuging the LiCl H ₂ O crystals, the fugate from the centrifuge is partly used in the circuit for the evaporation stage and partly removed from the system and into the container 93-2 for promoted the preparation of the regeneration solution. During the regeneration of the KY-2 resin, the Mg and Ca ions are removed and the resin is transformed into the Li ⁺ form.

After washing and drying in a screw vacuum dryer 88, the LiCl H ₂ O crystals represent an anhydrous lithium chloride of high purity in hand ice quality (the amount of the cation admixtures of Na, K, Mg, Ca is only 0.01 percent by mass to 0.15 percent by mass ).

The technological process according to the invention has no runoff and also does not cause wastes that are harmful to nature and pollute the environment. All the reagents required for the process remain in the described technological system. Thus, the salt-free solution from the process of concentrating the lithium chloride solution is used for the lithium desorption of the sorbent; For the regeneration of the cation exchanger KY-2, the concentrated solution of lithium chloride is used, which is obtained by washing the LiCl H ₂ O crystals; the used regeneration solution, which contains calcium and magnesium chlorides as well as lithium chloride (up to 2 g / l), is used for the stage of lithium sorption after regeneration of the cation exchanger KY-2 used in the SDK.

Based on the examples given, the following additional advantages are associated with the method according to the invention and the system according to the invention:

The introduction of the circuit for the eluate circulation in the desorption branch from the SDK (example 1) makes it possible to increase the lithium chloride concentration in the eluate to about two to three times in relation to eluates which have been obtained according to the known prior art.

The cleaning of the eluates of Ca ²⁺ and Mg ²⁺ ions using the cation exchanger KY-2 is a very effective process for obtaining LiCI solutions which contain magnesium and calcium chlorides in amounts of only 0.0003 percent by mass and 0. Contain 0001 mass percent (Example 2), which is ten times less than according to the prior art described.

The two-stage electrodialysis concentration of the eluates with the subsequent evaporation of the solution and the crystal formation of lithium chloride monohydrate from this solution, and the discontinuous removal of a fugate part saturated with sodium chloride, make it possible to obtain anhydrous lithium chloride with a high degree of purity, which is necessary for the production of metallic lithium and alloys its base is usable. The salt-free solution of the second stage of eluate concentration is used for lithium desorption of the sorbent, which is associated with a significant reduction in fresh water consumption.

It is particularly advantageous that the technical solutions according to the invention can be successfully used to obtain the lithium chloride monohydrate from the lithium-containing natural chloride salt liquors of any type and with any salt concentration and from the technological salt solutions of chemical and biochemical production.

REFERENCE NUMBERS

1 container for the natural starting brine

2 Pump for the brine supply

3 (sorption-desorption complex SDK) for the selective extraction of LiCl from brine

3-1 container for the classification of the regenerated sorbent and its

Feed into the sorption zone 3-2 container for receiving the regenerated sorbent from the

desorption

4 Pipe section for the brine feed to the SDK

5 Pipe piece for the removal of the used brine

6 pipe section for supplying the used brine to classify the regenerated sorbent

7 Pipe piece for the drain of the used brine

8 Pipe piece for the removal of the pulp of the shredded sorbent during the classification

9 Pipe piece for the supply of the fresh sorbent DHAL-CI

10 pipe section for the supply of compressed air

11 Drainage system for the eluate discharge

12 pipe section for the supply of the washing water Device for the cross-mixing of the washing water Pump of the device 13 for the mixing Pipe piece for the supply of the circulating solution of the lithium chloride for desorption Pipe piece for the return of the transfer solution into the desorption zone Pipe piece for the supply of the desalinated solution for the desorption-1 bypass system for the return of the transfer solution the container for the absorption of the regenerated sorbent into the desorption zone -2 lower pipe section with drainage insert for the removal of the transfer solution from the container 3-2 for the reception of the regenerated sorbent upper pipe section for the removal of the transfer solution from the container 3-2 for the reception of the regenerated sorbent pipe section for the supply of the rinsing liquid (water) for the sorbent transfer pipe section for the blowing off pipe section for the supply of compressed air valve for controlling the supply of the rain erated and classified sorbent in the sorption zone valve for controlling the supply of the regenerated sorbent in the classification container 3-1 valve for controlling the transfer of the regenerated sorbent from the desorption zone into the receiving container 3-2 filter for separating the sorbent phase from the solution phase collection container for the used solution pump for supplying the used solution for sorbent classification and for regeneration of the dewatering inserts container for preparing the pulp of the fresh sorbent (DHAL-CI) in the brine (when the column is first loaded in the weakly concentrated LiCl solution) jet pump for feeding the sorbent pulp into the container 3-2 for classifying the regenerated sorbent Pipe piece for the removal of the sorbent from the SDK jet pump for the removal of the sorbent pulp from the SDK collection container for the eluate pump for the eluate supply container for the circulation of the eluate pump for the circulation and discharge of the eluate pump for the water supply for washing and transferring the sorbent Water tank Pump for the supply of the desalted solution for lithium desorption Collection tank for the desalted solution Sorption-desorption complex for eluate cleaning (SDKER), ion exchange column -1 tank for the classification of the regenerated cation exchanger and its feeding into the sorption zone -2 tanks for the reception of the regenerated cation exchanger from the

Regeneration zone Pipe piece for the eluate supply for cleaning Pipe piece for the discharge of the cleaned eluate Pipe piece for the supply of the cleaned eluate for classifying the cation exchanger Pipe piece for the eluate discharge Pipe piece for the discharge of the pulp of the comminuted cation exchanger in the classification Pipe piece for the feed of the pulp of the fresh cation exchanger Pipe section for the supply of compressed air Pipe section for the discharge of the cation exchanger Pipe section for the discharge of the used regeneration solution Pipe section for the return of the transfer solution via the bypass system -1 Pipe section for the supply of the regeneration solution LiCl -2 Pipe section for the supply of the washing water Lower pipe section with dewatering insert for the removal of the Transfer solution from the container 41-2 for the uptake of the regenerated cation exchanger from the regeneration zone of the upper tube piece for the removal of the transfer solution from the container 41-2 and the uptake of the regenerated cation exchanger from the regeneration zone tube piece for the supply of the rinsing solution into the container 41-2 Pipe section for supplying compressed air Pipe section for venting Valve for controlling the supply of the regenerated and classified cation exchanger into the sorption zone Valve for controlling the supply of the regenerated cation exchanger in the classification tank 41-1 Valve for controlling the supply of the regenerated cation exchanger in the Storage container 41 -2 Container for the preparation of the pulp of the fresh cation exchanger Jet pump for feeding the pulp of the cation exchanger into the SDKER jet pump for removing the pulp of the cation exchange Schers from the SDKER curved screen Collecting container for the cleaned eluate Pump for supplying the cleaned eluate for concentrating the dialysate container Pump for forwarding the dialysate Electrodialysis concentrator Pump for forwarding the electrodialysis salt solution LiCl Container for the electrodialysis salt solution LiCl Collection container for the electrodialysis salt solution 1 Stage pump for the transfer of the dialysate Electrodialysis desalinator Pump for the transfer of the concentrate 77 concentrate container

78 Heat exchanger recuperator for heating the electrodialysis brine

79 Pump for supplying the electrodialysis brine for evaporation

80 evaporators

81 Cooling condenser of wet steam

82 Pipe section for the drainage of the condensate of wet steam

83 droplet separators

84 collection container for the condensate

85 crystallizer

86 centrifuge for the separation of LiCl H ₂ O crystals

87 Slanted snail washer

88 heated screw vacuum dryer

89 collection container for the anhydrous lithium chloride

90 containers for the preparation of the diluted brine of lithium chloride

91 Pump for supplying the lithium chloride solution

92 Pump for supplying the cleaned eluate to the SDKER 93-1 Pump for supplying the regeneration solution

93-2 Container for the preparation of the regeneration solution

94 collection container for the washing solution

95 Pump for supplying the washing solution for evaporation

96 steam supply system

97 Fresh water supply system

98 vacuum system

99 compressed air system

100 brine deposit

101 System of recovery of the used brine

102 Pipe section for blowing off

103 cooling circulation system

Claims

claims

1. Process for the production of lithium chloride from brine with selective sorption extraction of the lithium by contacting a lithium with selective sorbent in step-countercurrent operation with the sorbent remaining in a sorption zone which ensures complete sorbent saturation with lithium chloride; a post-saturation of the sorbent saturated in the sorption zone through its step-countercurrent contact with an ascending flowing lithium chloride solution of a predetermined concentration, which ensures the sorbent post-saturation with the lithium chloride up to the limit capacity with simultaneous washing of the sorbent granules from foreign components and with a lithium chloride desorption from the sorbent in the salt-free water Step countercurrent operation and subsequent concentration of the lithium chloride solution, characterized in

- That the extraction of the solution enriched with the lithium chloride directly in a sorption-desorption complex by the Lithium desorption from the sorbent takes place, first by means of the desorption liquid and then by means of a lithium chloride solution with a concentration of 10 kg / m ³ to 17 kg / m ³ ;

- The lithium chloride solution with a concentration of 10 kg / m ³ to 17 kg / m ^{3 is obtained} in circulation mode, the volume flow of the circulating solution to the sorbent volume flow being 1.5: 1, 0, with the removal of a current part of the lithium chloride solution from the Circulation circuit in the extent which is at least approximately equal to the volume flow of the desorption liquid to be supplied;

then an ion exchange cleaning of the lithium chloride solution of calcium and magnesium takes place;

then the lithium chloride solution is concentrated until LiCl H ₂ O crystals are formed, the LiCl H ₂ O crystals are separated from the brine and the brine is returned to concentrate;

- The LiCl H O crystals are washed with salt-free water in countercurrent to the contact phases, the chloride solution formed during the washing being promoted for concentration and

- The washed LiCl H ₂ 0 crystals are finally dewatered and dried to anhydrous lithium chloride.

A method according to claim 1, characterized in that the cleaning of the LiCI solution is carried out according to the ion exchange method with a cation exchanger of the KY-2 type in Li form.

A method according to claim 1 or 2, characterized in that the concentration of the purified eluates is initially carried out in two stages by an electrodialysis process, one in a first stage in galvanostatic operation Electrodialysis salt solution with a LiCl content of 100 kg / m ³ to 150 kg / m ³ and a dialysate stream with a LiCl content of 3.5 kg / m ³ to 4.0 kg / m ^{3 is} generated and in a second stage in potentiostatic operation a salt-free solution with a residual LiCl content of 0.2 kg / m ³ to 0.5 kg / m ³ , which is used as desorbate in the stage of desorption of lithium for selective sorption, and a concentrate with a LiCl content from 7.0 kg / m ³ to 10.0 kg / m ³ , which is mixed with the purified eluate, can be obtained and then the electrodialysis salt solution with a LiCl content of 100 kg / m ³ to 150 kg / m ³ by evaporation concentrated to a LiCl content of 600 kg / m ³ to 800 kg / m ³ with subsequent cooling to a temperature of 40 ° C to 60 ° C and then the resulting solution is centrifuged with return of the fugate for evaporation, whereby the concentration of the NaCI admixture in the LiCI solution to be evaporated in the range of 7.0 kg / m ³ to 7.5 kg / m ³ and part of the lithium chloride solution is continuously removed after centrifuging and used for the regeneration of the cation exchanger KY-2 and for the conversion of the latter into the Li form.

4. The method according to any one of claims 1 to 3, characterized in that the dewatering and drying of the LiCI H ₂ O by heating under the conditions of promoting crystal formation on surfaces heated to a temperature of 100 ° C to 105 ° C in a vacuum respectively.

5. The method according to any one of claims 1 to 3, characterized in that the concentration of the purified eluates is carried out by natural evaporation of the moisture in basins or graduation towers with subsequent evaporation of the lithium chloride solution.

6. The method according to any one of claims 1 to 3, characterized in that the eluates are concentrated by freeze-drying at a temperature of -10 ° C to -30 ° C.

7. Plant for the production of lithium chloride from brine, consisting of a Sorption-desorption complex SDK (3) for the selective extraction of lithium chloride from a brine, with a pipe section (4) for the brine supply by means of a pump (2) from a container (1) with the starting brine, a pipe section (5) for the discharge of used brine, a pipe section (7) for the transport of the used brine for classification, connected by means of a pump (28) to a collecting container (27) for the used brine, a pipe section (8) for the discharge of the pulp of the Classification of crushed sorbent by a filter (26) for separating the solid phase from the used brine, a pipe section (12) for the supply of the wash water, connected to a wash water tank (38), a pipe section (17) for the supply of the salt-free lithium chloride solution Desorption by means of a metering pump (39) from a container (40) containing the salt-free lithium chloride solution, a pipe section ( 31) for the removal of the selective sorbent in the lower toroidal part of the SDK (3), a pipe section (21) for blowing off air into the atmosphere and a raw piece (11) for the removal of the lithium chloride solution (eluate), connected to a collecting container (33) for the lithium chloride solution (eluate) and with devices for heating and concentrating the lithium chloride solution (eluate), characterized in that the system also has:

- A sorption-desorption complex SDKER (41; 41-1; 41-2) for the cleaning of the lithium chloride solution (eluate) from calcium and magnesium with sorption and desorption branches, the diameter of which are 3: 2, connected to pipes and a pipe section (42) for the eluate supply via the pump (34) to the collecting container (33) for the eluate and directly connected to the container (90) for the preparation of the dilute sodium chloride solution of the lithium chloride; connected by means of pipes and the pipe section (43) for the discharge of the cleaned eluate into the container (65) for the cleaned eluate, via the jet pump (62) for feeding the pulp of the starting cation exchanger into the SDKER (41-1) and directly connected with the container (61) for the preparation of the pulp of the starting cation exchanger and with the curved screen (64) and by means of the pipe section (44) for the supply of the cleaned eluates for classifying the cation exchanger in the SDKER (41-1) and by means of the pipe section (45) for the eluate drain; connected by means of the pipe section (46) for the discharge of the pulp of the comminuted cation exchanger formed during the classification in the SDKER (41-2) via the curved sieve (64) to the collecting container (65) for the cleaned eluate; by means of the pipe section (52-1) for the supply of the LiCl regeneration solution via the pump (93-1) with the container (93-2) for the preparation of the regeneration solution; by means of the pipe section (50) for the removal of the used regeneration solution directly with the container (1) of the starting brine; by means of the pipe section (52-2) for supplying the washing water via the pump (39) with the collecting container (40) for the desalinated solution; by means of the pipe section (51) for the return of the transfer solution via a bypass system directly with the upper and the lower pipe section (54; 53) for the discharge of the transfer solution from the container (41-2), by means of the pipe section (55) for the supply the rinsing liquid LiCl in the container (41-2) via the pump (92) directly to the collecting container (65) for the cleaned eluate; by means of the pipe section (56) for supplying the compressed air to the compressed air system (99) and by means of the pipe section (57) for blowing off the air into the atmosphere;

a device for the electrodialysis concentration of the cleaned eluate, consisting of a two-path electrodialysis concentrator (69) of the filter press type, which by means of a pipeline with the container (71) for the electrodialysis salt liquor, the container (67) for the dialysate, with the pump (70) for the transport of the electrodialysis salt liquor and is connected to the pump (68) for the dialysate delivery and which forms independent circulation circuits with the electrodialysis salt liquor and the dialysate section, as well as consisting of a two-section electrodialysis desalinator of the filter press type (75) which is connected to the container by means of pipelines ( 73) for the salt-free solution and the concentrate container (77), with the pump for the supply of the desalinated solution (74) and the concentrate (72) and thereby independent circulation circuits with the desalinated solution and forms the concentrate; The container (71) for the electrodialysis salt liquor and the container (67) for the dialysate are connected via the pump (66) by means of a pipe to the collecting container (65) for the purified eluate, the circuit on the dialysate line is connected to the container by means of a pipe (73) for the salt-free liquid and with the concentrate container (77), the circuit on the route of the electrodialysis salt solution - with the collection container (71) for the electrodialysis solution and the circuit on the route of the salt-free solution - with the collection container (40) for the salt-free solution linked;

an evaporator device, comprising: pump (79) for supplying the electrodialysis brine for evaporation, a heat exchanger (78) for the electrodialysis brine, an evaporator (80), connected to a steam supply (96), a cooler condenser for wet steam (81), connected to a cooling circulation system (103), a droplet separator (83) and a collecting container (84) for the condensate;

a cooled crystallizer (85) directly connected to the cooling circulation system (103) of the evaporator (81) and a centrifuge (86) which in turn is connected to the collecting container (72) for the electrodialysis salt liquor by means of a pipeline;

an inclined screw washer (87), connected by a pipe to the centrifuge (86), a condensate collector (84), the collector for the desalinated solution (40) and a collector (94) for the washing solution, which is connected by a pipe via the pump ( 95) is connected to the collecting container (72) for the electrodialysis salt liquor;

a heatable screw vacuum dryer (88), connected by means of pipes to the slanted screw washer (87), a collecting container (89) for anhydrous lithium chloride, a vacuum system (98), a system of steam supply (96) and the condensate collecting container (84).

8. Plant according to claim 7, characterized in that the sorption-desorption complex SDK (3) for the selective extraction of the lithium from the brine has the same diameter of the sorption and desorption branches and consists of: a device (13) for the Transverse transport of the washing liquid in the toroidal part of the SDK (3), a lower pipe section (18-2) with a drainage insert, arranged in the lower part of the container (3-2) for receiving the regenerated sorbent from the desorption zone and connected to the bypass system (18- 1) for the return of the transfer solution from the container (3-2) for the absorption of the regenerated sorbent from the desorption zone, a circulation circuit consisting of a drainage system (11) for the removal of the eluate, which is in the lower zone of the desorption branch of the SDK (3) above the device (13) for the transverse mixing of the washing liquid is arranged by means of pipeline s and armature via the container (35) and the pump (36) for the eluate circulation with the pipe section (15) for the supply of the lithium chloride solution for desorption is connected.

9. Plant according to claim 7 or 8, characterized in that the device (13) for the transverse mixing of the washing water with the pump (14) by means of pipeline and fitting on its inlet and outlet pipe section is connected to the dewatering inserts in the column body in the height of the pipe section (12) for the supply of the washing water which is installed between the drainage inserts, the pump being connected to the drainage inserts in such a way that there is a possibility of reversible liquid circulation through the drainage inserts.

10. Plant according to one of claims 7 to 9, characterized in that an additional dewatering insert is arranged in the container (3-1) for classifying the regenerated sorbent and feeding it into the sorption zone of the SDK (3). 4) is arranged for supplying the used brine for classification and is connected to the pipe section (5) for the outlet of the used brine.

1. Plant according to one of claims 7 to 10, characterized in that a drainage insert is arranged in the container (3-2) for receiving the regenerated sorbent from the desorption zone of the SDK (3), which with the lower pipe section (18-2 ) for the removal of the transfer solution and directly by means of the bypass system (18-1) for the return of the transfer solution from the receptacle (3-2) of the regenerated sorbent; the drainage replacement is with the upper pipe section (19) for the removal of the transfer solution and with the pipe section (16) for the return

i ι connected to the desorption zone.