Recycling of tungsten based heavy alloy scrap

The recovery of tungsten from heavy alloy scrap has been explored oxidation of tungsten heavy alloy using oxygen and its subsequent reduction with hydrogen was studied. The oxidation behaviour of the scrap was investigated by simultaneous TG/DTA. Oxidation studies showed a weight gain of 26% and the enthalpy of oxidation was found to be -625 kJ/mol of tungsten. The X-ray diffraction of the oxidised powder has shown the formation of WO3, Fe2WO6 and NiWO4 phases. The reduction of the oxidized material in hydrogen atmosphere at 1000 C yielded a pure tungsten phase in powder form with an approximate weight loss of 25%.