Method for preparing battery grade lithium carbonate by using impulse type hydrogenated industrial grade lithium carbonate

Abstract

The invention discloses a method for preparing battery grade lithium carbonate by using impulse type hydrogenated industrial grade lithium carbonate. The method comprises the steps of preparing the industrial grade lithium carbonate and common pure water into slurry according to a certain proportion, adding high-purity CO2 in a pulse mode, controlling reaction temperature to be within a range of 20-25 DEG C until the solution is converted into clearer liquid, and filtering the liquid; injecting filtrate into a decomposition reaction kettle, decomposing the filtrate, then transferring the decomposed filtrate into a causticizing reaction kettle, adding a right amount of a Ca(OH)2 solution into the causticizing reaction kettle, controlling reaction temperature to be within a range of 90-100 DEG C, and filtering and washing the solution while the solution is hot; injecting filtrate into a concentration kettle, and removing impurities such as Ca and Mg of concentrated liquor by using ion exchange resin; then, injecting the concentrated liquor without the impurities into a synthesis kettle, and replenishing the synthesis kettle with the high-purity CO2 gas so as to further prepare the high-purity battery grade lithium carbonate. The method utilizes the advantage of hydrogenation of lithium carbonate so as to effectively utilize the high-purity CO2 gas and avoid the loss of CO2 as much as possible in a reaction process, and enables the hydrogenation to be carried out smoothly.

Description

technical field [0001] The invention relates to a method for preparing high-purity battery-grade lithium carbonate, in particular to a method for preparing battery-grade lithium carbonate by pulse-type hydrogenation of industrial-grade lithium carbonate. Background technique [0002] As an important compound of lithium salt, lithium carbonate has many industrial uses. According to GB / T 11075-2013, YS / T582-2013 and other relevant national and industry standards, industrial grade Li 2 CO 3 Content less than 99.5%, battery grade Li 2 CO 3 Content 99.5% ~ 99.9%. [0003] Lithium carbonate is widely used in glass ceramics, new energy vehicles, alloys, and medicine. In recent years, with my country's policy of advocating low-carbon and environmental protection, the new energy industry has developed rapidly. The most notable is the rapid growth of the lithium battery industry. Lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt oxide, lithium iron phosphate and ...

AI Technical Summary

Problems solved by technology

[0005] For example, the hydrogenation process is used in Chinese patent 200710019052.3 "A Process for Producing High-purity Lithium Carbonate Using Salt Lake Lithium Resources". The salt lake brine is used as raw material to prepare industrial-grade lithium carbonate, and CO 2 Gas hydrogenation, after the relevant impurity removal process, decomposes lithium bicarbonate under negative pressure conditions, and washes it several times to prepare battery-grade lithium carbonate; 2011.7, 25, Wu Jian) ​​pointed out that 10 g of lithium carbonate and carbon dioxide had a flow rate of 1L / min, reacted at 25°C for 40 minutes, and the utilization rate of carbon dioxide obtained was only 7.6%; Salt Industry, 2013.8, 8, Li Yanru) chose 10 g of lithium carbonate to react with 1L / min carbon dioxide at 20°C for 150 min, and the utilization rate of carbon dioxide was 2.02%. The amount of dissolved carbon dioxide is very small, which affects the mass transfer process, which in turn affects the CO 2 Gas utilization, resulting in waste of gas raw materials

Images