Phosphorus slag powder exists in the form of silicate glass, and its main composition is SiO2Al2O3 fe2o3mgo Cao Nao. Silica fume is also called micro silica powder, or micro silica powder or ultra-fine silica powder, generally referred to as silica fume. Silica fume is a kind of ultra-fine silicon powder material, which is formed by the rapid oxidation and condensation of SiO2 and Si gas produced in smelting ferrosilicon and industrial silicon with oxygen in the air.