Gravity concentration of fines and ultrafines

Concentration of fines by gravity methods remains one of the challenging problems to the world mineral industry. Considering the increasing losses of mineral values and the search for an economic process, it has been the major concern of the researchers and the practicing engineers to develop an efficient fine gravity separator. The development of some of the recent fine gravity separators with the application of high centrifugal forces has resulted in improvement in the separation efficiency. In the last four de¬cades extensive studies have been carried out at National Metallurgical Laboratory (NML), Jamshedpur to develop gravity based processes for low grade ores, fines and industrial wastes involving the conventional separators to the latest equipment like multi-gravity separator for their economic exploitation. In this paper an attempt has been made to briefly present a review of the gravity concentration processes with a particular reference to the recent advances in the processing of fines. The salient results obtained from the recent studies carried out on beneficiation of lean grade finely disseminated tungsten ore, iron ore slimes and chromite slimes at NML using some fine gravity separators like Bartles-Motley Vanner GEC-duplex concentrator and MGS are discussed