Silica powder (Microsilica or silica fume), also called micro-silica powder, the scientific name "silica fume", also known as Silica fume, is an industrial furnace in the high-temperature smelting of industrial silicon and ferrosilicon process, with the smoke escaping from the dust by special trapping devices collected and processed. The scientific name "silica fume", microsilica or silica fume, is an industrial furnace in the high-temperature smelting of industrial silicon and ferrosilicon process, with the smoke escaping from the collection of special trapping devices to deal with. In the escaping smoke, the SiO2 content is about 90% of the total amount of soot, the particle size is very small, the average granularity is almost nanometer level, it is called silica powder.