A new pathway for preparing ultrafine tungsten powder via non-contact carbon reduction followed by hydrogen reduction

Ultrafine tungsten (W) powder was prepared by a non-contact carbon reduction followed by hydrogen reduction method. In this process, WO3 and activated carbon were separated by a porous plate and the reduction of tungsten oxide was achieved by carbon atoms diffusion at high temperature. This method can stably prepare violet tungsten oxide powder with low carbon content (194 ppm) using activated carbon as a reducing agent. It avoids the problem that the high residual carbon in reduction products in traditional carbon reduction experiment. Then, ultrafine tungsten powder with an average particle size of less than 100 nm was prepared by hydrogen reduction of violet tungsten oxide.