Method for preparing lithium carbonate by using lithium aluminum-containing rock

Abstract

The invention discloses a method for preparing lithium carbonate by using lithium aluminum-containing rock. The method comprises the following steps: S1) the lithium aluminum-containing rock and a sulfur phosphor mixed acid leaching agent are mixed, a mixture is leached, the mixture is filtered to obtain a lithium-containing leachate; S2) hydrogen peroxide is added, then the materials are continuously stirred, an ammonium hydroxide solution is added for adjusting the pH value, water is added for dilution, the material is filtered to obtain a lithium-containing purified solution; S3) the lithium-containing purified solution is subjected to evaporative concentration to form a hot saturated solution, the hot saturated solution is cooled for crystallization, and mixed crystals of ammonium sulfate and ammonium biphosphate can be precipitated to obtain a lithium-containing concentrate; and S4) finally magnesium chloride is added, the pH value is adjusted by gradually adding a sodium hydroxide solution, the materials are stirred and reacted under normal temperature, filtration is carried after the reaction is finished, and the material can be filtered to obtain a phosphate-removing filtrate. and S5) the phosphate-removing filtrate is heated for concentration, solid sodium carbonate is added, after the reaction is finished, filtration is carried out while hot, the hot water is used for washing the precipitates, and the precipitates are dried to obtain the lithium carbonate. The method employs a chemical precipitation method, ammoniacal liquor is taken as a precipitating agent, magnesium salt is taken as a phosphor precipitating agent, lithium and aluminium separation is realized, lithium and phosphor separation is realized, and the lithium carbonate can be finally prepared.

Description

technical field [0001] The invention belongs to the technical field of lithium salt preparation, and relates to a new method for preparing lithium carbonate, in particular to a method for preparing lithium carbonate by utilizing lithium-containing aluminum rock. Background technique [0002] In recent years, the application of lithium and lithium products in high-tech fields has been continuously developed, and the strategic position has been continuously improved. Lithium resources can be mined and processed to produce a variety of lithium products, mainly including lithium carbonate, lithium hydroxide, lithium chloride, lithium phosphate, lithium bromide, lithium dihydrogen phosphate, etc. Among them, lithium carbonate is the most important lithium product. The basic raw materials of industry can not only be used directly, but also can be used as raw materials to react with other compounds to produce other lithium products. They are widely used in lithium batteries, cerami...

AI Technical Summary

Problems solved by technology

In this study, lithium-containing aluminum rocks were used as raw materials, and sulfur-phosphorus mixed acid was used as the leaching agent. The salient feature of the leaching solution is that the content of aluminum ions is high, while the content of lithium ions is low, and the lithium-containing concentrated solution contains a large amount of phosphorus. Sodium will generate lithium phosphate with lower solubility. To produce lithium carbonate, phosphorus needs to be removed before lithium precipitation. The two lead to difficulties in the preparation of lithium carbonate