Studies on the leaching of tungsten from composite barite-scheelite concentrate

Studies on the recovery of tungsten from a composite barite-scheelite concentrate ore were conducted utilizing a soda-silicon roast-Na2CO3 solution leach technique. Scheelite and barite mainly compose this ore with a slight trace of other impure components. A high tungsten recovery ratio is not achievable by physical separation by beneficiation or caustic autoclaving procedures as a significant amount of scheelite and barite occur in an interspersed state. Soda-silicon roast-Na2CO3 solution leach is then proposed to extract tungsten from this special ore with effects of the roasting and leaching process tested under variables such as roasting time, temperature, Na2CO3 amount and leaching conditions. Approximately 95.93% of W was dissolved into the solution under optimum roasting conditions of temperature 850 °C, reactive time 2 h, molar ratio of Na2CO3/W 3 and 10% SiO2 dosage of feed mass with leaching conditions of temperature 60 °C, stirrer speed 300 rpm, leaching time 1 h, liquid/solid ratio 4 and in 10 g/l Na2CO3 solution.