Beneficiation studies of tungsten ores - A review

Scheelite (CaWO4) and wolframite ((Fe, Mn)WO4) are the only tungsten minerals mined commercially and are mainly found in five types of deposits: skarn, vein/stockwork, porphyry, disseminated and stratabound. Gravity concentration and flotation are the beneficiation techniques most commonly applied to scheelite ore, and gravity and/or magnetic separation for wolframite ore. With increasing exploitation, the primary tungsten resources become poorer in grade, finer in grain size and more complex in mineralogy, which makes the processing of the tungsten ores more difficult. Research and investigations into various approaches to improving the beneficiation efficiency of tungsten ores are reviewed in this paper, including selective flotation of scheelite from other calcium containing minerals such as calcite and fluorite using more selective reagents, very fine scheelite and wolframite flotation, optimization of concentration of complex tungsten ores by a combined gravity-magnetic-flotation process and recovery of associated Mo, Cu and Bi sulphides from tungsten ores.