American Journal of Materials Science and Engineering. 2013, 1(1), 1-5DOI:
Abstract: Tungsten alloys are the subject of many recycling studies due to the scarcity of the tungsten sources and environmental considerations to reuse metal scraps. In the current investigation, direct recovery of tungsten from W-10.5 wt.% powder metallurgy parts were performed by FeCl3 selective digestion of copper binder. The experiments were performed at different salt concentrations, times of digestion, pH values, temperatures and scrap particle sizes. The copper was effectively driven out from W-Cu scrap with increase in FeCl3 concentration. FeCl3 to scrap weight ratio of 2/1 at room temperature for 24 h, yielded 97% copper removal and tungsten recovery was raised to 75.2%. Complete removal of copper was occurred at elevated temperature accompanied with acidic conditions. However the tungsten direct recovery efficiency fall as low as 50%. XRD analysis indicated the formation of tungsten oxide while turnings attacked by FeCl3. Tungsten oxide corroded at high temperatures and low pH values and reduced tungsten recovery.