Thermal Beneficiation of low grade ore from Enuconda deposits, West Godavari District, Andhra Pradesh

Abstract

A Low grade chrome ore from Enuconda mimes of West Godavari District, Andhra Pradesh, which could not be upgrade to meet the specifications for metallurgical grade by conventional physical ore-dressing methods, has been successfully beneficiated by thermal beneficiation methods. A Table concentrates of the ore containing 40.83% Cr2O3, 22.19 % total iron, 16.9% Al2O3, 3.22% SiO2, 7.5% MgO, 1.2%CaO and initial Ce: Fe ratio of 1.23:1 was used for the beneficiation tests. It was possible to increase the Ce: Fe ratio of the ore to well above 10:1 with more than 90% chromium recovery by preferential solid state reduction of chrome ore and subsequent removal of reduced iron by acid leaching. The briquettes containing -100 mesh (B.S.S.) ore and -170 mesh (B.S.S.) coke were reacted at 1250°c for 2 hours and the reduced ore was leached with dilute sulphuric acid at 100°c. Controlled leaching conditions have also been found to yield a metallurgically suitable beneficiated product with almost full chromium recovery.