Kangwon National University University-Industry Cooperation Foundation

Young Jun Song

Disclosed is a method of producing high-purity lithium carbonate and barium sulfate from discarded lithium secondary batteries, including: a first process for producing high-purity lithium phosphate from a discarded battery; and a second process for producing lithium sulfate from the lithium phosphate and producing lithium carbonate and barium sulfate from the lithium sulfate. The second process has steps of (a) producing a liquid mixture of lithium phosphate and sulfuric acid, (b) obtaining lithium sulfate by condensing the liquid mixture, (c) dissolving the lithium sulfate in water or a sodium hydroxide aqueous solution, depositing phosphoric acid as lithium phosphate, and performing solid-liquid separation (d) depositing lithium carbonate and performing solid-liquid separation to obtain lithium carbonate, (e) finely grinding the lithium carbonate and classifying the particles, (f) controlling a particle size and shape by dissolving edges of particles or minute particles, (g) performing solid-liquid separation, and (h) depositing barium sulfate.

Method of producing high-purity lithium carbonate and barium sulfate from discarded lithium secondary batteries

Disclosed is a method of producing high-purity lithium carbonate from low-purity crude lithium carbonate. The method includes: (a) producing crude lithium carbonate slurry by mixing crude lithium carbonate having a polycrystalline state and a size of 20 to 200 &#x3bc;m with water; (b) carbonating and dissolving the crude lithium carbonate slurry; (c) performing primary solid-liquid separation to obtain a filtrate; (d) adding soluble barium salts to the filtrate to deposit barium sulfate; (e) performing secondary solid-liquid separation for the filtrate containing the deposited barium sulfate to obtain a filtrate; (f) mixing lithium carbonate seed crystals with the filtrate obtained from the secondary solid-liquid separation and precipitating lithium carbonate dissolved in the filtrate on surfaces of the lithium carbonate seed crystals to produce high-purity lithium carbonate slurry containing high-purity lithium carbonate by controlling a particle size; and (g) carbonating the high-purity lithium carbonate slurry to produce high-purity lithium carbonate.

Method of producing high-plurality lithium carbonate by controlling particle size, particle size distribution, and particle shape

Provided is a method of manufacturing a high-purity lithium phosphate by utilizing a lithium waste liquid of a wasted battery. Lithium phosphate is manufactured and refined by using a minimized amount of sodium hydroxide and by using phosphate, lithium hydroxide, and an optimized pH condition, so that it is possible to manufacture high-purity lithium phosphate from which fine impurities which cannot be removed by cleaning are effective removed. A waste water treatment process of processing waste water as to be immediately discharged is integrated, so that the method is very efficient and environment-friendly. Therefore, since the high-purity lithium phosphate can be manufactured by utilizing a lithium waste liquid discarded in a wasted battery recycling process, the method has an effect in that the method is applied to a wasted battery recycling industry to prevent environmental pollution and facilitate recycling resources.

Manufacturing method of high purity lithium phosphate from the waste liquid of the exhausted lithium-ion battery

Provided is a method of manufacturing high-purity, high-quality manganese sulfate which can be immediately used for manufacturing a lithium ion secondary battery from manganese sulfate waste liquid of a wasted battery. Since impurities are removed from the manganese sulfate waste liquid by using sulfides causing no secondary contamination in the manganese sulfate waste liquid and the manganese sulfate is manufactured by performing evaporation concentration through heating, the manufacturing method is very environment-friendly and economical. Since the manganese recovering process improving the manufacturing yield of the manganese sulfate and the waste water treatment process capable of recycling the source materials and discharging waste water are integrated, the manufacturing method is very efficient and environment-friendly. The manufacturing method is applied to the recycling industry, and thus, it is possible to obtain effects of preventing environmental pollution and facilitating recycling the resources.

Growing community of inventors

Gangwon-do, South Korea

Young Jun Song