Which indicator of metallurgical carbon black is the most important? Can cemented carbide and graphite be used as insulating materials?

In the cemented carbide system based on tungsten carbide and titanium carbide, in industrial production, even if Taihei is used as the carbon material, carbon black is also used as the heat insulation material of the graphite tube resistance furnace. Practice shows that the lower the impure substances (such as moisture, ash, volatile matter, sulfur content, etc.) in Taihei, the better, especially the effect of sulfur content on the single crystal grain size and cemented carbide structure The structure has obvious influence. When the sulfur content of carbon black is low, the particle size of tungsten carbide is more uniform, and the bending resistance of the alloy is higher. The sulfur content in the metallurgical industry is not more than 0.02%-0.5%, which can be used in metallurgical alloys.

Other carbides, such as silicon carbide, boron carbide, and zirconium carbide are the main raw materials for lighting engineering ceramics or high-temperature ceramic refractory materials. Traditional silicon carbide is produced by making silicon raw materials such as quartz sand and carbonaceous raw materials such as coke and anthracite in a high-temperature electric furnace (the temperature of the furnace core is 2700 degrees). Its raw material price is low, the reaction operation is simple, and it is easy to prepare x-SiC with stable performance. The disadvantage is that the energy consumption is high, and the resulting silicon carbide block is hard and low in purity. It takes a long time to crush and repeated purification to meet the requirements of particle size and purity. . There are also problems such as powder size distribution and uneven grain shape.

In order to reduce the reaction temperature, improve the particle size of silicon carbide products. Crystal formation and activity, people have made many improvements, such as using too black below 2000 degrees, reducing SiO2 powder with a particle size below 10um to b-sic in a non-oxidizing aerosol, so that it will not be pulverized, after (or without) desorption Silicon and decarburization can be used as raw materials for sintering engineering ceramics.

As a carbide raw material, the requirements for carbon black are mainly high purity, less impurities, especially sweating materials, and easy dispersion.