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

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.