Patent ID: 6852304
Filing Date: 2005-02-08
Classification: C01B,C01P

Abstract:
1. A process for producing a tungsten carbide powder, comprising the steps of: (a) mixing an aqueous ammonium tungstate solution with a carbon powder in a proportion to reduce and carburize ammonium tungstate to form a slurry, (b) drying the slurry to prepare a precursor, (c) subjecting the precursor to a reduction and carburization by heating to a temperature, at which a reduction and carburization proceeds, in a non-oxidizing gas atmosphere to form a reduced and carburized product, (d) mixing the reduced and carburized product with a carbon powder in a proportion required to carburize a W (e) subjecting the reduced and carburized product mixed with the carbon powder to a carburization by heating to a temperature, at which a carburization proceeds, in a hydrogen atmosphere, wherein an amount of the carbon (C) powder in step (a) with respect to the tungsten (W) component in ammonium tungstate by atomic ratio C/W is within a range of 3-4.