Exploitation of lean grade manganese ores from Joda Mines

Abstract

Out of total 378 million tonnes resources of India, 40% resource is in Orissa and ~85% of total Indian resource is of low grade. Hence, beneficiation of these low grade ores is a necessity to meet the demand. However, the manganese mines of Tata steel belongs to the Bonai Kenojhar manganese belt of Orissa and spreads over a large area in Joda. Characterisation, beneficiation and agglomeration studies were carried out to develop a utilization strategy for typical low grade manganese ores from Odisha.Composite samples of low grade lumps and fines of 0-25mm were collected from mine waste dumps. The major mineral phases found are pyrolusite, hematite, goethite, clay, feldspar and quartz. Washing, crushing (<3mm) and two-stage high intensity magnetic separation (17 & 11k gauss) process can recover 30-40% material of ferromanganese grade with 40-50% Mn recovery. The recovered material was briquetted adding molasses (7%), cement (4%) and bentonite (1%) to use in the submerged arc furnace for metallurgical applications. A cost effective process flow sheet has been developed to utilize these low grade process rejects.