Silica Sand 1.very high purity, SiO2 99.9% min 2.very ... -purity crystal powders, high-purity low OH crystal powder, clear fused quartz glass tube, UV-stop quartz glass tube, none-ozone ... , it can be used as material of producing optical fiber, fused quartz glass tube , rod and crucible which can be used ... )≤1≤1K(*10-6)≤1.5≤3Na(*10-6) quartz silica sand in industry