EXPERIMENTAL STUDY ON TUNGSTEN LEACHING FROM SCHEELITE-WOLFRAMITE MIXED CONCENTRATE ORE BY HOT PRESSING LEACHING

Experiment of tungsten leaching from scheelite-wolframite mixed concentrate by hot pressing leaching is implemented,focusing on the influence factors of alkali ore ratio,caustic soda,liquid-solid ratio,oxygen pressure,leaching temperature and leaching time on tungsten leach rate.The results show that tungsten leach ratio increases with alkali ore ratio increasing from 20% to 45%;when caustic soda addition is higher than 390 g,tungsten leach ratio reaches above 93% and tungsten leach ratio increases with caustic soda dosage;with increasing of liquid-solid ratio,tungsten leach ratio increases from 87.43% to above 95%,but the optimization of liquid-solid ratio is 3∶ 1 which can improve the leaching ability of concentrate.Oxygen addition is not beneficial for tungsten leaching,the optimization of leaching temperature and leaching time is 160 ℃ and 1 h respectively with the tungsten leach ratio reaching 95.55%.