Materials Science Forum Vol. 978

Abstract: In countries like Australia and South Africa, even less than 2% grade THM samples are being mined and processed for recovery of heavy minerals. In this paper, an attempt has been made to recover heavies from lean deposits of Brahmagiri coast of India. The Brahamagiri coast contains substantial amount of heavy minerals. Still at some locations of this coast, the heavy mineral deposit is very low. The present paper deals with the recovery of values from these lean deposits. Initially, a composite sample was prepared from samples containing less than 3 % heavy minerals. The composite sample is subjected to spiral concentrator in stages to recover total heavy minerals. The results of the investigation reveal that 12 stages of spiral concentrator are essential to recover a concentrate of 90.3% grade, 1.95% yield and 99 % recovery from a composite sample containing 2.9 % heavy minerals.

Abstract: NALCO is mining the bauxite ore of 63.4 lakh tones per annum for the production of alumina 21.57 lakh of tonnes per annum. During mining of bauxite, partially laterized khondalite (PLK) and kaolinised khondalite rocks are excavated and dumped at mining area or can be used for backfilling. The sample ground and classified to recover fines which are suitable for paper industry. Further, the overflow sample is subjected to leaching studies. Leaching studies were carried out at different concentration, time and temperatures. The experiment shows that the optimum conditions are 1.5M oxalic acid, 70oC temperature and 4 hours time. This product can be used as a coating material on paper industry to increase the brightness. The product is fine and no grit present in it. The iron oxide in the product is 0.72% with brightness is 75%. The product specifications compared with BIS standard for raw material using in paper industry. The other characterization of the product indicates that the raw material is suitable for paper industry.