Blue Tungsten Oxide Preparation -- APT Autoreduction Method
Blue tungsten oxide is one of the important raw materials for making tungsten powder. As an important intermediate of tungsten in modern industry, it has been popular for many years.
The commom methods of preparing blue tungsten oxide are APT closed calcination method and hydrogen mild reduction method etc. Although they have been popularized for many years, they have more or less some environmental safety factors. As a result, people have never abandoned the quest for a more effective and environmentally friendly method for producing blue tungsten oxide.
APT autoreduction method is an upgraded version of the APT hydrogen mild reduction method. What's different between them is that the APT autoreduction method does not add hydrogen or ammonia into the reacting furnace, instead, the heating temperature is increased to 600°C -800°C. APT decomposes hydrogen under high temperature. Hydrogen processes autoreduction with crackate of ammonium paratungstate under high temperature, and gets blue tungsten oxide that meets the requirement.
Some scholars used rotary calciner to test APT hydrogen autoreduction. Through the improvement of process technology and the optimization of process parameters, the following conclusions are obtained, with the increase of temperature, the degree of crystalline water and ammonia out of ammonium paratungstate intensifies. Hydrogen decomposed by ammonia also intensifies under high temperature. The hydrogen atmosphere is increased, the reduction degree of hydrogen to ammonium metatungstate was strengthened. When the temperature reaches 600°C~800°C, rotary furnace speeds at 0.3~2 r/min, delivery rate at 150~300kg/h, and then gets blue tungsten oxide that meets the requirement.
Compared with the traditional methods for preparing blue tungsten oxide, APT autoreduction has three advantages. First, It can reduce ammonia emissions and reduce environmental pollution factors. Second, ammonia and hydrogen are dangerous gases, and there are potential safety problems in the process of production, the APT autoreduction method is less risky. Third, ammonia and hydrogen as auxiliary materials need cost. Autoreduction can eliminate the expenses. Therefore, APT autoreduction method not only has good environmental benefits, but also achieves better economic benefits.
If you have any inquiry of Blue Tungsten Oxide, please feel free to contact us:
Tel.: +86 592 5129696/+86 592 5129595
Fax: +86 592 5129797
Scan QR code of Chinatungsten Wechat platform to follow up the daily latest price and market of tungsten, molybdenum and rare earth.
评论
发表评论