PURPOSE: To surely obtain a high-purity oxide in the form of fine particles by melting the oxide consisting of an ore contg. impurities, industrial waste, etc., with a flux contg. alkali metal oxides, B2O3, etc., quenching the melt to vitrify the material and then reheating the vitrified material to crystallize the oxide.
CONSTITUTION: An oxide obtained by the dry or wet beneficiation of an ore or an oxide as the industrial waste, e.g. the calcination product of the iron chloride recovered from a waste steel sheet pickling soln., as the starting material is heated with a flux contg., by weight, 10-70% alkali metal oxide, 20-90% B2O3 and ≤10% of one kind between NaF and NaCl, and the oxide is dissolved in the flux with its impurities. The melt is quenched and vitrified, the vitrified material is heated above the crystallization temp. of the oxide to crystallize the oxide in the glass in the form of fine particles, and the fine particles are cleaned and dried to obtain the fine particles of the high-purity oxide.
INOUE AKIRA
HIDAKA CHIKARA
TANAKA KOGYO