Preliminary Studies on the Chloride Recycle from Residue of Fused Salt Chlorination and the Effect of Recycled Chloride on Hydrochloric Acid Leaching of Ilmenite

This work preliminarily studied chloride recycle from residue of fused salt chlorination and the effect of recycled chloride on hydrochloric acid leaching of ilmenite. The results show that the soluble chloride and insoluble oxides in residue of fused salt chlorination can be effectively separated by water leaching. The insoluble residue of water leaching that mainly consists of stable oxides such as Fe₂O₃, （Fe,Mg）₂TiO₅, （Ca,Al,Mg） SiO₃,etc.,is only 11% of mass fraction. It is easy for stockpiling and harmless to the environment. The main chloride in residue of fused salt chlorination,KCl and Na Cl are enriched in the crystalline salts by evaporation of solution of water leaching,and the recovery rate of Cl element exceeds 95%. Adding the recycled chlorides into the system of hydrochloric acid leaching of ilmenite can improve the leaching reactivity. More recycled chlorides are added,synthetic rutile products with higher TiO₂ grade are obtained. The TiO₂ grade of synthetic rutile can increase from 80.8% to 84.5% by adding recycled chlorides with a mass ratio of 50%.