How to Improve the Particle Size of Tungsten Powder

Tungsten powder is widely used in cemented carbide, tungsten products, chemical industry and steel industry. Tungsten powder is used as raw material for cemented carbide products and other tungsten products. Its particle size and size distribution have an important impact on product performance.

In the existing technology, the preparation method of tungsten powder is generally to reduce raw tungsten in hydrogen to obtain tungsten powder. This method has less boat capacity, low production efficiency, and wide particle size distribution range, which is not conducive to the subsequent preparation of WC powder. Therefore, the academia has been improving the reduction method of tungsten powder to control the particle size of tungsten carbide powder.

Recently, some scholars have proposed a preparation method of ultra-fine tungsten powder to improve particle size distribution and production efficiency. The process is: grinding blue tungsten powder in ball mill for 3-5 hours, ball-to-material ratio 5.0-10.0:1, ball-milling medium is deionized water, and slurry is obtained. After 20-30 minutes homogeneous mixing of slurry and blue tungsten powder, the mixed materials were scrubbed by Disk Scrubber and rolled on the granulator. After drying, the blue tungsten granular material with particle size of 0.8-1.5mm was obtained. The reduction temperature was 810-910 C and the loading capacity was 3.0 kg. The particle size of tungsten powder Fsss was 1.4-1.8um and the median diameter was 0.88-1.16um. Under the same reduction conditions, the loading capacity of traditional craft is only 0.75-1.50 kg, and the particle size of tungsten powder Fsss is 1.10-3.16 micron. The improved craft not only increases the loading capacity several times, but also has more uniform particle size.

In the production process, the loading capacity is the key factor affecting the quality of tungsten powder. By reducing the loading capacity to ensure the particle size of tungsten powder, the production efficiency is greatly reduced. The idea is changed. Starting from the raw material powder, some raw materials are first prepared into slurry, then mixed with the remaining raw materials to granulate, the raw materials are prepared into millimeter-sized granular materials, and then the reduction reaction is carried out. The permeability of the feeding layer is conducive to the infiltration of hydrogen into the material and the removal of water vapor from the reaction product, which can greatly shorten the reduction time. Therefore, under the same reduction conditions, the loading capacity can be doubled and the production efficiency can be significantly improved.

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