Production process of lithium hydroxide monohydrate

A lithium hydroxide, production process technology, applied in the direction of lithium oxide;/hydroxide, lithium sulfate/sulfite, sulfate/bisulfate preparation, etc., can solve the problem of reducing production costs, long process routes, Reduce lithium loss and other issues, achieve high guiding significance, shorten the process route, and reduce production costs

CN1214981CInactive Publication Date: 2005-08-17JIANGSU RONGHUI GENERAL LITHIUM IND CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2005-08-17
Estimated Expiration
Not applicable · inactive patent

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Abstract

In the production process of lithium hydroxide monohydrate, lithium sulfate solution and caustic soda are made to produce metathetic reaction to form mixture solution of sodium sulfate and lithium hydroxide, and sodium sulfate and lithium hydroxide monohydrate are then separated by means of the obvious difference in low temperature solubility. The production process includes the following steps: adding sodium hydroxide into lithium sulfate solution obtained through serial production steps to obtain mixture solution of sodium sulfate and lithium hydroxide; cooling to minus 10 deg.c to 5 deg.c for the crystallization and separation of sodium sulfate; heating to concentrate the separated clear liquid; crystallization and separation to obtain coarse lithium hydroxide monohydrate product; water dissolving coarse lithium hydroxide monohydrate, adding barium hydroxide to form insoluble barium sulfate, filtering, concentrating filtrate, crystallizing to separate wet lithium hydroxide monohydrate; and drying.
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Description

technical field

[0001] The invention relates to a production process of lithium hydroxide monohydrate. In particular, it is a new process for directly producing products from lithium sulfate solution and realizing product separation by using the characteristics of different chemical reaction characteristics and solubility of lithium hydroxide monohydrate and its by-products. Background technique

[0002] The main technique of producing lithium hydroxide monohydrate in the prior art has following two kinds:

[0003] 1. Lithium carbonate causticization method. That is, lithium carbonate is causticized with calcium hydroxide to form an easily separated calcium carbonate and lithium hydroxide solution. It can be classified according to the raw material source of lithium carbonate, and now there are mainly two sources:

[0004] (1), using spodumene, the principle of this method is to decompose β-spodumene with sulfuric acid according to the following reaction formula at a temp...

Examples

Embodiment 1

[0039] Embodiment 1, with reference to figure 1 :

[0040] 1. The front-end production process of lithium sulfate solution from lithium concentrate through roasting, acidification, pulping, leaching and preliminary concentration still uses the existing production process. The lithium sulfate solution produced in the middle is directly used in the new process.

[0041] 2. Ingredients (prefabricated liquid): Li which has been preliminarily evaporated 2 O concentration in the 45 ~ 55g / l concentrate, and Li 2 The crude mother liquor with an O concentration of 55-65g / l, according to the expected Li 2 O content 50g / l preparation. Add sodium hydroxide, keep heating, and adjust the pH value to 12-14, heat to 90-95°C, stand still for a period of time, and discharge. The still feed liquid is pumped into the plate-and-frame filter press to filter, and various impurities such as Ca, Fe, Mn, etc. are removed, which is the prefabricated liquid, which flows to the intermediate storage t...

Embodiment 2

[0073] Embodiment 2 is basically the same as Embodiment 1, but the temperature control index of the freezing and crystallizing tank solution is: -5~-1°C.