PROCESSING OF WOLFRAMITE CONCENTRATE

Abstract

The PURPOSE of the article is to study the possibility of wolframite concentrate processing eliminating cake leaching tailings from charge composition while reducing the sintering temperature and obtaining a commercial tungsten trioxide. METHODS. Processing of wolframite concentrate was performed by its sintering with soda, saltpeter and potassium carbonate. The obtained sinter was crushed and subjected to leaching with the production of the solution of sodium tungstate. Measurements of sodium tungstate density allowed to determine its concentration and calculate the forecast extraction of tungsten trioxide. The resulting solution of sodium tungstate was decomposed with the precipitation of “artificial scheelite”, which was decomposed by the hydrochloric acid in order to produce a tungsten acid. The latter was subjected to thermal dissociation to obtain tungsten trioxide. RESULTS. Having conducted a series of laboratory studies on wolframite concentrate processing it was found that the components of charge are to be sintered at the temperature of 450-500ºC at 1:0.45:0.9:1 ratio of wolframite concentrate, soda, potassium carbonate and saltpeter respectively. The powder of tungsten trioxide with a high content of valuable component has been produced. CONCLUSION. The possibility of wolframite concentrate processing with the elimination of cake leaching tailings reducing the tungsten content in the charge from charge composition was studied. The optimal temperature conditions of sintering and the composition of charge to be sintered in order to obtain sodium tungstate were determined. Leaching of the resulting sodium tungstate with the following precipitation of the “artificial scheelite” and the decomposition of the latter by hydrochloric acid allowed to produce the powder of tungsten trioxide with 99.8% content of WO₃ .