Method for preparing lithium hydroxide monohydrate by using lithium carbonate

Abstract

The invention relates to a method for preparing lithium hydroxide monohydrate by using lithium carbonate. The method comprises the steps: adopting industrial grade lithium carbonate as a raw material,performing a reaction on suspension of the lithium carbonate, calcium oxide and water under the conditions of heating, pressurizing and stirring for 90-110 min, and performing filtration, purification, elution crystallization, drying and the like so as to obtain lithium hydroxide monohydrate. The method has the advantages that industrialization can be realized easily through adoption of industrial grade lithium carbonate to prepare the lithium hydroxide monohydrate, and improvement of the reaction speed and shortening of the reaction time are achieved by adopting a pressurized mode to increase the reaction temperature, so that the conversion rate of lithium carbonate is achieved; by adopting the elution crystallization method, the problems that a previously adopted evaporative crystallization method has large energy consumption and a high temperature, and lithium hydroxide is easily converted into lithium carbonate during evaporation are solved, and conversion, caused by water loss, of lithium hydroxide monohydrate into anhydrous lithium hydroxide can be prevented during evaporation; the product has stable quality and high purity, and organic solvents used during the elution crystallization can be recycled, so that discharge without solid and liquid waste is achieved.

Description

technical field [0001] The invention relates to the technical field of lithium hydroxide monohydrate, in particular to a method for preparing lithium hydroxide monohydrate by utilizing lithium carbonate. Background technique [0002] Lithium compounds have unique physical and chemical properties, and have been widely used in the fields of energy, chemical industry, metallurgy, ceramics, semiconductors, batteries, lubricants, and pharmaceutical industries. In recent years, rechargeable lithium batteries have attracted attention as the main power source of hybrid and electric vehicles. [0003] my country has abundant salt lake lithium resources. In recent years, Qinghai Salt Lake Industry Co., Ltd., Qinghai CITIC Guoan Technology Development Co., Ltd., and Qinghai Lithium Industry Co., Ltd. have adopted adsorption, calcination, and ion selective migration methods to realize the industrialization of lithium extraction technology from salt lake brine with high magnesium-to-lit...

AI Technical Summary

Problems solved by technology

However, lithium carbonate, calcium oxide and water are typical endothermic reactions, and using a lower reaction temperature will lead to problems such as low conversion rate of lithium carbonate and long reaction time.

Moreover, the above patents for the preparation of lithium hydroxide all adopt the method of evaporation and crystallization to obtain lithium hydroxide products. Evaporation and crystallization consumes a lot of energy and has a high temperature. During the evaporation process, lithium hydroxide is easily converted into lithium carbonate, and the prepared lithium hydroxide is also Often a mixture of lithium hydroxide monohydrate and lithium hydroxide anhydrous

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