METHOD OF PRODUCING ZIRCONIUM DIOXIDE Russian patent published in 1999 - IPC

FIELD: hydrometallurgy, in particular, process of production of zirconium dioxide used for manufacture of ceramic articles used in metallurgical and chemical engineering. SUBSTANCE: method consists in that zirconium dioxide is produced from oxychlorine solutions by electrochemical and heat treatment. Electrochemical treatment of oxychloride solution is carried out in cathode chamber of three-chamber electrolyzer in which middle chamber is separated from cathode chamber by anion-exchange membrane, and from anode chamber is separated by cation-exchange membrane with current density of 0.5-10.0 A/sq. dm and catholyte pH 2.0-2.8. In this case middle chamber is filled with distilled water, while anode chamber, with 1-5-% solution of any oxygen-containing acid. The method provides full decomposition of salt, higher recovery of zirconium into sediment of zirconyl hydroxide up to 99.8-99.9%, reduced content of chlorine in sediment down to 0.001-0.016% and utilized chlorine ion in the form of acid solutions containing up to 200 g/l of HCl. EFFECT: higher efficiency. 1 tbl