Плавка кварц-лейкоксенового концентрата при рассредоточенном дуговом нагреве

Abstract

Separation of titanium and silicon oxides in the melt of quartz-leucoxene concentrate of the Yarega deposit under diffuse arc heating was investigated. Melting was carried out in argon at atmospheric pressure at direct current in a graphite crucible with an arc power of ≈ 25 kW. The crucible with the material was the anode of the arc. The arc heating was dispersed by applying an axial magnetic field. At the same time, a diffuse anode spot with a current density of 8 A/cm2 was formed on the surface of the material. The current-voltage parameters of the diffuse arc were investigated. As a result of melting, an oxide ingot consisting of two phases was obtained, one of which is enriched with titanium oxide, the other with silicon oxide. However, the separation of these oxides did not occur completely due to the high cooling rate of the melt. Despite the low current density in the heating spot, the melt evaporated intensively. Evaporation occurred congruently. Due to the high temperature of the bath mirror, no volatile titanium oxide evaporated along with the volatile silicon oxide. Condensation of the evaporated material occurred selectively. A condensate, consisting almost entirely of SiO2, was formed in the form of powder on the cooled surfaces near the crucible. A specific surface area of the powder was 120 m2/g. The evaporated TiO2 was removed with the exhaust gas.