Production of High Purity APT from Scheelite and Complex Tungsten Raw Materials with a High Mo Content

73% of the tungsten resources in China are scheelite and 41% of themare high molybdenum content ores, respectively, and their dressing becomes increasingly difficult. Such situation calls for new and advanced processes that can treat complex ores and still attain high overall recovery of tungsten. We have developed novel NaOH digestion process and selective precipitation process.The former is universal for leaching tungsten from various tungsten materials, including scheelite concentrate and keeps most of the impurity elements P,As,Si in residue, while the latter is effective for removing impurities such as Mo,Sn. Combined with the traditional ion exchange process, our new process can be used to produce APT that confirms with the Chinese national standard GB10116-88APT-0 with crystallization ratio of 95%.When treating high molybdenum scheelite concentrate from Shizhuyuan deposit with WO3 content of 50-55% , recovery of the new process may reach up to about 95% which is grossly the same as that from the traditional way for treating standard wolframite concentrates.