Battery-grade lithium carbonate preparation method based on phase transformation

Abstract

The invention relates to a battery-grade lithium carbonate preparation method based on phase transformation, belonging to the technical field of the preparation of inorganic chemical materials. The preparation method comprises the following steps: by taking lithium concentrate as a raw material, first mixing the lithium concentrate and water to prepare 10 to 50% serous fluid, then adding a phase transformation agent, and reacting for 0.5 to 5 hours at 10 to 100 DEG C to obtain a high-concentration lithium salt solution; then mixing the lithium salt solution and inorganic alkali, and reacting to obtain a high-concentration causticization solution; introducing the causticization solution into a cation exchange column to obtain a refined causticization solution, and then introducing carbon dioxide into the refined causticization solution to obtain crude lithium carbonate; and finally mixing the crude lithium carbonate and an appropriate amount of composite refined impurity removal agent in water, and reacting to obtain a battery-grade lithium carbonate product with a main content more than or equal to 99.5 percent by weight. By adopting the phase transformation method, the concentration of the lithium salt solution is remarkably increased, the high-concentration causticization and carbonization can be realized, the preparation efficiency of the battery-grade lithium carbonate is increased, and a novel way is provided for the industrialized preparation of the battery-grade lithium carbonate.

Description

technical field [0001] The invention relates to a method for preparing battery-grade lithium carbonate based on phase transformation, and belongs to the technical field of preparation of inorganic chemical materials. Background technique [0002] The increasing demand for green new energy sources such as lithium-ion batteries in modern society has promoted the rapid development of related high-purity basic lithium salts and lithium battery materials. [0003] As a basic lithium salt material, battery-grade lithium carbonate is mainly used to manufacture positive electrode materials for lithium batteries. Lithium batteries have the advantages of good chemical properties, strong power storage capacity, long life, and small self-discharge, and are widely used in electric vehicles, notebook computers, portable phones and other fields. As the world's largest consumer of lithium, my country's demand for battery-grade lithium carbonate is increasing year by year. However, due to t...

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Problems solved by technology

[0012] Therefore, the existing hydrogenation method and causticization method are both low-concentration reaction systems, which have problems such as low efficiency and high cost.

[0013] There are also bibliographical reports to use lithium chloride or lithium hydroxide as raw material, prepare battery-grade lithium carbonate with carbonate precipitation method (Li Liangbin, Hu Naigen, Huang Xuewu, Ge Yuwei, Zhu Shigui, Xiong Xunman, Ma Zhenqian, a kind of lithium chloride solution is used to prepare battery The method of grade lithium carbonate, CN101609888; Ma Jin, Ma Aijun, Xu Zhongji, He Guocai, Yi Chao, Lu Xingwu, Cheng Liang, Li Yuliang, Ji Wuren, Gong Dalei, Shao Chuanbing, Li Shourong, Zhang Enyu, Li Yu, Xue Yingying, A preparation process of battery-grade lithium carbonate, CN103351010A), the disadvantage of this method is that the purity of raw materials is very high, and it cannot handle heterogeneous lithium carbonate raw materials

[0014] In short, although the predecessors have done a lot of work in the preparation of battery-grade lithium carbonate, the existing processes have problems such as low efficiency, high raw material requirements, and high costs, which restrict the large-scale industrial development of these technologies

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