The Upgrading of Ha Tinh Ilmenite to Synthetic Rutile by Becher Process

Abstract

Becher process was applied for upgrading Ha Tinh ilmenite concentrate (54-55% TiO2) to synthetic rutile. The process includes reduction of ilmenite concentrate using anthracite coal as reductant, followed by aeration of reduced ilmenite in ammonium chloride solution (NH4Cl). The controlled parameters were temperature and NH4Cl concentration. The results showed that the degree of iron metallization was 83% after 4 hours of reduction at 1150 °C. Most of the metallic iron (98%) was successfully rust after 9 hours of aeration at 70°C, 7/1 of liquid/solid ratio (L/R), 4 liter/minutes (L/min) of air flow rate and 0.5% of NH4Cl concentration. The addition of acetic acid or citric acid in to the aeration solution has facilitated the aeration process. The aeration time could be vastly reduced when ammonium chloride solution used in aeration was replaced by the mixture of CH3COOH 0.075M and CH3COONa. Leaching with H2SO4 15% has improved TiO2 content from 82% in the aerated ilmenite to approximately 89% in synthetic rutile. The research work has proved that Becher process is applicable for the beneficiation of Ha Tinh ilmenite concentrate.