توليد اقتصادي پودر تنگستن ازقراضه هاي كاربيد تنگستن

The Production of Economical Tungsten Powders from Tungsten Carbide Scrap

Tungsten is one of the important refractory materials based on its properties & high temperature applications .it is necessary to do some investment for recycling of this strategic metal, due to their wide rang industrial applications ,and lag of their extraction in our country. In this research the recycling of tungsten carbide scrap examined by alkaline melting method. The tungsten carbide was mixed with sodium nitride in different proportions and heated up to 750 °C for 1 hour of time. Sodium tungstat, the product of alkaline melt were mixed with calcium chloride, to form calcium tungstat and Tungstic acid was formed by addition of HC1 to it. Tungstic acid is then converted to tungsten oxide powders by calcining process. The tungsten oxide powders were reduced at 850°C for hour in pure hydrogen atmosphere to form tungsten powder. Particle size analyzing by optical microscope & XRD examination were performed on reduced powders. Average particle size of tungsten powders were measured about <4jnm in size.