Ecologically sate and resource-saving methods for recycling waste tungsten, niobium carbide-cobalt cermets and extraction of tungsten and niobium from concentrates

A range of potentials in which the cobalt-tungsten alloy phase is selectively dissolved in the solutions of phosphoric acid to form soluble compounds of these metals while the tungsten carbide phase remains in the precipitate is determined. It is shown that tungsten ores and concentrates are decomposed at temperatures of 1050 to 1100 degrees C in sodium chloride-sodium metasilicate melts to form two immiscible phases: halide-tungstate, which contains 96 to 99 %, and silicate, which contains 90 % of the ore components.