6 Ways to Make Metal Tungsten Powder
views, posted on April 13, 2020 by aemmetal
Tungsten powder is the primary raw material for processing P / M tungsten products and tungsten alloys. Pure tungsten powder can be made into wire, rod, tube, plate, and other processing materials and certain shape products. Tungsten powder can be mixed with other metal powder to make various tungsten alloys. More than 70% of tungsten powder is used in cemented carbide production. At present, the main methods of producing tungsten powder are as follows:
1. Hydrogen reduction of tungsten oxide
The process is, using H2 as a reducing agent to lower tungsten oxide to tungsten powder. Taking the reduction of WO₃hydrogen as an example, the total reaction is as follows:
At present, tungsten oxides used as raw materials for hydrogen reduction are mainly yellow tungsten oxide (WO3), blue tungsten oxide (mainly WO2.9) and purple tungsten oxide (WO2.72).
The hydrogen reduction of tungsten oxide is the primary method to produce tungsten powder.
2. Hydrogen reduction of tungsten halide
The method of reducing tungsten halides (such as tungsten chloride and tungsten fluoride) to tungsten metal using H2 as a reducing agent. For example, for the hydrogen reduction of WCl6, the total reaction is as follows:
The hydrogen reduction process of tungsten halide is a gas-phase reaction, mainly used in the preparation of ultrafine tungsten powder or tungsten coating by chemical vapor deposition. At present, the chloride reduction method of tungsten halide is only used in small-scale production.
3. Tungsten oxide carbon reduction method
When the mixture of tungsten oxide and carbon is heated to a specific temperature, tungsten oxide is reduced to tungsten powder. Taking the reduction of WO3 carbon as an example, the total reaction is as follows:
Sometimes a small amount of hydrogen is introduced into the furnace to promote the carbon reduction process. Due to the high carbon content of the tungsten powder towel made by this method, it is not suitable for tungsten products. At present, the technology of producing tungsten powder by carbon reduction method is less. However, it has more use in tungsten carbide's direct production, especially ultrafine tungsten carbide powder and tungsten carbide composite powder.
4. Molten salt electrolysis
5. Zn reduction
6. Plasma hydrogen reduction
The last three methods are not going to be explained here to avoid complexity and extra content. You are welcome to contact us for further consultation.