Studies on the recovery of tungsten from a composite wolframite-scheelite concentrate

Studies on the recovery of tungsten from a multi-metal tin-tungsten ore fro m Kreghystan were carried out by a combination of physical beneficiation ar id soda ash roast-aqueous leach technique. Cassiterite, wolframite and sche elite are the main valuable minerals in this ore. However, a significant am ount of wolframite occurs finely disseminated in scheelite. This composite nature of mineralisation has limited the scope of using physical separation methods in generating individual concentrates of either wolframite or sche elite with economical recovery. In view of this, a combined tungsten minera ls concentrate which is free of majority of other heavy mineral - cassiteri te was first obtained by physical up-gradation methods and was later subjec ted to tungsten extraction by soda ash roast-aqueous leach technique. The e ffect of process variables such as: roasting time, temperature and feed-to- alkali ratio were studied. At optimum roasting and leaching conditions, abo ut 95% of WO3 values were extracted. (C) 2000 Elsevier Science B.V. All rig hts reserved.