SYSTEM FOR THE PRODUCTION OF LITHIUM HYDROXIDE (LIOH) DIRECTLY FROM LITHIUM CHLORIDE (LICI), WITHOUT THE NEED FOR THE INTERMEDIATE PRODUCTION OF LITHIUM CARBONATE OR THE LIKE

Abstract

This invention patent application relates to a system for the production of lithium hydroxide (LiOH) directly from lithium chloride (LiCl), without the need for an intermediate production of lithium carbonate or the like. Specifically, the invention refers to a system consisting of the equipment and arrangement necessary for the direct production of lithium hydroxide from lithium chloride. The system comprises interconnected main sub-systems, a subsystem for the production of high-purity LiOH.Math.H2O, which comprises conversion and crystallization units, and subsystem for the production of NaCl, consisting of causticization and crystallization units, all of which enable the production of high-purity lithium hydroxide monohydrate, and sodium chloride as a byproduct of the system.

Claims

1. System for the production of lithium hydroxide (LiOH) directly from lithium chloride (LiCl), without requiring the intermediate production of lithium carbonate or any other similar compound, Wherein it is comprises by two sub-systems, a high purity LiOH.Math.H.sub.2O production sub-system and a NaCl production sub-system, in that said system comprises a LiCl brine tank and a NaCl liquor tank, which are connected to the high purity LiOH.Math.H2O production sub-system, which comprises an equipment for the conversion of LiCl to crude LiOH.Math.H2O; where the conversion equipment is connected to a solid-liquid separation equipment and the latter to a reception tank and where, additionally, the solid-liquid separation equipment is connected to a crude LiOH.Math.H2O dilution tank, and this dilution tank is connected to at least one LiOH.Math.H2O crystallizer equipment, where the high purity LiOH.Math.H2O is produced; where the high purity LiOH crystallizer equipment is connected to a second solid-liquid separation equipment, which is connected to a crystal dryer; and a tank containing pure LiOH liquor which can be recycled; where the NaCl production sub-system is composed by a reception tank and a NaOH tank, in which both tanks, in turn, are connected to a causticizing equipment, which is connected to, at least, one NaCl crystallization evaporation system, from which a NaCl liquor pipe is connected, which is connected to a NaCl liquor tank, and such NaCl liquor tank is connected to initial NaCl liquor tank; and a second connection of concentrate NaCl, which is connected to at least one solid-liquid separation equipment from which the separation of the NaCl crystals occurs, and the same are stored in a NaCl crystal tank; where said NaCl liquor tank is connected to initial NaCl liquor tank; and thus, both sub-systemsthe system for the production of high purity LiOH.Math.H2O and the system for the production of NaClare connected.

2. System for the production of lithium hydroxide monohydrated (LiOH.Math.H2O) directly from lithium chloride (LiCl), in accordance with claim 1, Wherein said conversion equipment is a crystallizer equipment that generates a stream of crude LiOH.Math.H2O.

3. System for the production of lithium hydroxide monohydrated (LiOH.Math.H2O) directly from lithium chloride (LiCl), in accordance with claim 1, Wherein said high purity LiOH.Math.H2O production sub-system additionally comprises at least one equipment for the crystallization of crude LiOH.Math.H2O.

4. System for the production of lithium hydroxide monohydrated (LiOH.Math.H2O) directly from lithium chloride (LiCl), in accordance with claim 3, Wherein said crude LiOH crystallization equipment can be arranged in series with another crystallizer equipment.

5. System for the production of lithium hydroxide monohydrated (LiOH.Math.H2O) directly from lithium chloride (LiCl), in accordance with claim 4, Wherein one of said crude LiOH crystallization equipment is connected to said solid-liquid separation equipment, from which it connects to the reception tank.

6. System for the production of lithium hydroxide monohydrated (LiOH.Math.H2O) directly from lithium chloride (LiCl), in accordance with claim 1, Wherein said high purity LiOH production sub-system additionally comprises at least one equipment for the crystallization of high purity LiOH.Math.H2O.

7. System for the production of lithium hydroxide monohydrated (LiOH.Math.H2O) directly from lithium chloride (LiCl) in accordance with claim 1, Wherein said NaCl production sub-system, additionally comprises multiple evaporators equipment connected in series and a crystallizer, where such causticizing equipmentwhich, in turn, is connected to the reception tank and to the NaOH tank that feeds said causticizing equipmentis connected to the NaCl crystallization equipment.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0021] FIG. 1: It represents an isometric view of the invention's general system, where all the equipment composing the system for the direct production of LiOH.Math.H2O from LiCl is shown.

[0022] FIG. 2: It represents an isometric view of a preferred embodiment of the system of the invention in which the high purity LiOH.Math.H2O production sub-system is composed of at least two crude LiOH.Math.H2O crystallizers and at least one high purity LiOH.Math.H2O crystallizer.

[0023] FIG. 3: It is an isometric view showing the high purity LiOH.Math.H2O production sub-system.

[0024] FIG. 4: It is an isometric view of a preferred embodiment of the system of the invention in which the NaCl production sub-system comprising an evaporation or water removal system and at least one NaCl crystallizer is illustrated.

[0025] The figures are merely illustrative and any extension of system components and auxillary equipment will be understood to be included within the scope of protection.

[0026] Each sub-system may include a purge for the benefit of the quality of the final product.

DESCRIPTION OF THE INVENTION

[0027] The system for the production of lithium hydroxide (LiOH) directly from lithium chloride (LiCl), without the need for intermediate production of lithium carbonate or the like, consists of two sub-systems, a high purity LiOH.Math.H2O production sub-system and a NaCl production sub-system.

[0028] The system comprises a LiCl brine tank (1) and a tank of mother liquor from the NaCl sub-system (2), which are connected to the high purity LiOH production sub-system, which comprises a conversion equipment (3) from LiCl to crude LiOH.Math.H2O. The conversion equipment (3) is a crystallizer equipment that generates a crude LiOH.Math.H2O stream. The conversion equipment (3) is connected to a solid-liquid separation equipment (4) from which two streams are generated: a liquid solution (ML1) composed of mother liquor 1, which is fed from the solid-liquid separation equipment (4) to a tank (9) of mother liquor 1 at the inlet of the NaCl production sub-system; and a second stream composed of crude LiOH.Math.H2O crystals which is fed from the same solid-liquid separation equipment (4) to a dilution tank (5). Equipment (4) can be, for example, a centrifuge equipment. This dilution tank (5) is connected to at least one crystallizing equipment (6) where high purity LiOH, H2O is produced. Similarly, tank (A) provides the necessary water for dissolving crude LiOH.Math.H2O within tank (5). The LiOH.Math.H2O crystallizing equipment is connected to a second solid-liquid separation equipment (7) which has two outputs from which two products are generated: one output with a solid stream of high purity LiOH.Math.H2O crystals which is sent to a crystal drying unit (8); and another output with a liquid stream of pure LiOH liquor which can be recycled directly to crystallizer (6).

[0029] The NaCl production sub-system is made up of said receiving tank (9) of mother liquor 1 and a NaOH tank (16), and both tanks in turn are connected to a causticizing unit (10), which is connected to an evaporation or water withdrawal system from the fed solution, and NaCl crystallizing unit (17). From the latter two outputs are generated; one is NaCl liquor that is connected to the NaCl liquor tank (13), being this NaCl liquor the mother liquor 2 (ML2) that is fed to the ML2 tank; and the other output is a NaCl pulp that is connected to a third solid-liquid separation equipment (11) from where the separation of NaCl crystals that are stored in the NaCl crystals unit (12) takes place. The NaCl or ML2 (13) liquor tank is connected to the initial NaCl liquor tank (2), and, thus, both sub-systemsthe high purity LiOH.Math.H.sub.2O production system and the NaCl production systemare connected via the mother liquor 1 and mother liquor 2 circuits, creating a circular system that enables the production of high-purity LiOH.Math.H.sub.2O directly from LiCl brines, without NaCl co-precipitation.

[0030] In the invention's preferred method of execution, the high purity LiOH.Math.H.sub.2O production sub-system comprises at least two crystallization equipment for crude LiOH.Math.H.sub.2O (21 and 22). The LiOH crystallization tanks can be arranged in series (as illustrated in FIG. 2). Regarding the method shown therein, the crystallization equipment (22) is connected to the centrifuge (4), from which the mother liquor 1 (ML1) outlet is connected with the reception tank (9) of said ML1. In this preferred method of the invention, the high purity LiOH production sub-system additionally comprises at least one high purity LiOH.Math.H.sub.2O crystallization equipment (23). The crystallization equipment (23) is connected to a solid-liquid separation equipment (7), from which two outlets are generated: one corresponding to the high purity LiOH liquor outlet directed to the tank (14), which can recycles the stream directly to crystallization equipment (23); and another outlet corresponding to the high purity LiOH.Math.H.sub.2O crystals, which is connected to the crystal drying unit (8).

[0031] In another preferred method of the invention, the NaCl production sub-system comprises multiple evaporator systems and a crystallizer equipment, as illustrated in FIG. 4. In this preferred method of the invention, the NaCl crystallization sub-system comprises evaporator and crystallization equipment (17), (18) and (19), connected in series, where the causticizing equipment (10)which is connected to the reception tank (9) of mother liquor 1 (ML1) and to the NaOH tank (16) which feed the causticizing equipment (10)is connected to the NaCl evaporation and crystallization system that initiates with the unit (17). Moreover, the last equipment of the NaCl evaporation and crystallization system (19) is connected to a solid-liquid separation equipment (21), from which a solid flow exits towards the NaCl crystal storage equipment (12), since the NaCl liquor outlet of the solid-liquid equipment (21) can be connected directly to the NaCl liquor tank (13) and, from there, directly feed mother liquor 2 (ML2) to the NaCl liquor tank (2) at the start of the system. Likewise, in order to perform the evaporation, the unit (19) has an inlet from a steam generator (V). The cycle is closed with the steam outlet from the unit (17), through the outlet (S).