METHOD FOR PREPARING HIGH-PURITY AMMONIUM PARATUNGSTATE USING WASTE SUPER HARD METAL SCRAP

摘要

A method for preparing high purity ammonium paratungstate using a waste hard metal scrap according to the present invention comprises the following steps: (a) calcinating and oxidizing a hard metal scrap; (b) crushing a hard metal scrap oxide; (c) mixing a solid flux and the hard metal scrap oxide, and heating the same; (d) dissolving a sodium tungstate (Na_2WO_4)-containing mixture in water (H_2O); (e) filtering the sodium tungstate-containing mixed solution; (f) adding calcium chloride (CaCl_2) in the solution, and heating the same to manufacture a calcium tungstate (CaWO_4)-containing solution; (g) adding acid in the solution, and heating the same to manufacture a tungstate (H_2WO_4)-containing solution; (h) adding ammonia (NH_4OH) in the solution; and (i) solidifying and collecting ammonium paratungstate in the ammonium paratungstate-containing solution. According to the manufacturing method of the present invention, high purity ammonium paratungstate may be manufactured.