METHOD FOR PRODUCING FINE TUNGSTEN CARBIDE POWDER

摘要

PROBLEM TO BE SOLVED: To provide a production method of novel fine tungsten carbide powder produced with due consideration in terms of safety.;SOLUTION: A method for producing fine tungsten carbide powder is provided which comprises a step (a) of producing tungsten trioxide powder from a raw material, a step (b) of mixing the tungsten trioxide powder with carbon powders and heating and reducing the mixture under a reducing atmosphere to produce β-W (W₃O) powder, and a step (c) of carbonizing the β-W powder with carbon co-existent under a reducing atmosphere or an inert atmosphere to produce tungsten carbide powder, in this order. In the step (a), tungstic acid (WO₃ H₂O) is calcined at 350 to 500°C under an air atmosphere or an inert atmosphere. In the step (b), the tungsten trioxide powder is heated and reduced under a hydrogen atmosphere at a temperature of 500°C or lower. In the step (c), the β-W powder is carbonized under a hydrogen atmosphere or an inert atmosphere at 1000°C or higher.;SELECTED DRAWING: None;COPYRIGHT: (C)2019,JPO&INPIT