Recovery of Acid and Ferrous Chloride from leach liquor of reduced ilmenite by hydrothermal process

Abstract

Ilmenite is the most abundant mineral for the extraction of titanium. It contains more than 50% TiO2 along with iron, silica and alumina. The spinel structure of ilmenite (FeO.TiO2) is so that iron is bounded in the lattice of TiO2 matrix. To remove iron from the ilmenite is a major task for process metallurgists. Various processes have been applied to remove this iron. One of them is reduction and leaching. The carbon containing pellets and environment of jhama coal reduces the iron oxide to metallic state. This metallic iron in then leached in dilute hydrochloric acid (20 vol%) and a greenish color leach liquor is obtained. The pH of the leach liquor solution is found 0.31. This leach liquor contains hydrochloric acid and iron as ferrous chloride. These acid and solid mass was separated by hydrothermal process in the present investigation. The residue containing ferrous chloride was characterized with the help of XRD and EPMA. During experiment it was found that complete separation of HCl and FeCl2 has done. The final pH of separated HCl is found 1.66 and it is suitable for reuse in the leaching of reduced ilmenite and process make a loop. The purity of ferrous chloride is in line with commercial grade which is a sellable product.