Tungsten Oxide Hydrogen Reduction Method

The hydrogen reduction process for producing tungsten powder generally consists of two stages: the first stage, at 500-700℃, reduces tungsten trioxide to tungsten dioxide; the second stage, at 700-900℃, reduces tungsten dioxide to tungsten powder. The reduction reaction is usually carried out in a tubular electric furnace or rotary furnace. This method is only suitable for small-scale industrial production.

Ultrafine tungsten powder is an important raw material for producing cemented carbide, and the low-cost, large-scale production of uniform ultrafine tungsten powder has always been a research hotspot. Currently, industrially, ultrafine tungsten powder is mainly prepared through the hydrogen reduction of tungsten oxide. Blue tungsten is a suitable raw material; by controlling process parameters such as reduction temperature and hydrogen flow rate, uniform ultrafine tungsten powder can be produced. Zhai Yuchun et al. used WO3 as raw material and a closed-loop hydrogen reduction method at 600℃ to obtain tungsten powder with a particle size of 20-60 nm and a purity of 99.76%. The reduction sequence of WO3 powder in a hydrogen atmosphere was as follows:

Liao Chunfa et al. conducted hydrogen reduction experiments on tungsten oxide and studied the hydrogen reduction process of blue tungsten. They found that the hydrogen reduction method of tungsten oxide to prepare ultrafine tungsten powder is simple, has a short process, and is suitable for large-scale industrial production.