Quartz sand is a kind of hard, wear-resistant and chemically stable silicate mineral. Its main mineral composition is SiO2. The color of quartz sand is milky white, or colorless, translucent, hardness 7, brittle without cleavage, shell fracture, grease luster, density 2.65, bulk density (1.6 ~ 1.8 for 1-20 mesh), and 1.5 for 20-200 mesh It is insoluble in acid, slightly soluble in KOH solution, melting point 1750 ℃.