1)high purity 99.5%,no dust,snow white 2)size:800/1000 ... structure orderly transition from disorder to order ,products with high whitness,stable chemical property,uniform particle size distribution,better mobility ... silica rubber,engineering plastic,sealant,adhesive,dental materials,cosmetic,high-grade electronic,high-grade ceramic,special ceramics,special refractory materials,shielding materials ...