RECOVERY OF HIGH PURITY TRINIOBIUM OCTACHLORIDE FROM NIOBIUM-TITANIUM ALLOY SCRAP OR FERRONIOBIUM

摘要

PURPOSE:To recover Nb3Cl8 of high purity by chlorinating NbTi alloy scraps or ferroniobium at elevated temperature and hydrogenating NbCl5 to remove Ta. CONSTITUTION:NbTi alloy or ferroniobium is directly chlorinated over 250 deg.C, preferably at 300 to 500 deg.C, and the chlorination is continued utilizing the reaction heat. Formed high boiling chlorides of Fe, Al, Ni, W or the like are separated, then low-boiling chlorides such as TiCl4, SiCl4 or other chlorides are distilled off, thus NbCl5 is purified by distillation at 254 deg.C. The purified NbCl5 is reduced with hydrogen gas at 400 to 600 deg.C, preferably at 580 deg.C to exclude out TaCl5 boiling at 242 deg.C from the system to recover Nb3Cl8 of high purity free from Ta.