Symposium of the Extraction-and-Processing-Division (EPD) held during 140th TMS Annual Meeting and Exhibition, California, United States Of America, 27 February - 03 March 2011, pp.1031-1035
In this study, the recycling conditions of waste liquor obtained after the production of tungsten boride powder from calcium tungstate by self-propagating high temperature synthesis (SHS) and the following hydrochloric acid leaching were investigated in detail. Environmentally unfriendly and extremely acidic (pH similar to -0.3) liquor consisting of calcium, magnesium, and boron ions was treated with 1 M sodium carbonate solution to precipitate magnesium carbonate and calcium carbonate phases. The obtained amorphous precipitates were heated up to the temperature of 400 degrees C for re-crystallization. As a result, MgO, CaCO3 and CaMg(CO3)(2) phases were obtained, while sodium, boron, chlorine ions were remain in the solution. The present study is still in progress.