Quartz Grade Abrasive Industry

Quartz exhibits high hardness (7 mohs). It is harder than most other natural substances. Therefore, it is an excellent abrasive material. It is used for sand blasting, sanding as well as a component in scouring cleansers.
Silica sand and quartz are used in the manufacture of silicon carbide grains. The sand should for this purpose contain more than 99% SiO2, less than 0.1% each of Fe2O3 and Al2O3, no lime, magnesia and phosphorous. Similarly, quartz should contain 99.50 - 99.75% SiO2, 0.04 - 0.05% Al2O3, 0.05 - 0.10% Fe2O3, 1.10% CaO and MgO.
Another abrasive use of silica sand is sand blasting where by sand is fired under pressure usually in the presence of water to suppress the dust against the material to be polished. For this purpose the chemical composition of the sand is relatively unimportant but size frequency distribution and the absence of clay clogging materials are very important.