Silica, chemical terms, the pure silica colorless, normal temperature is solid, chemical formula for the SiO ₂, insoluble in water. Does not dissolve in acid, but soluble in hydrofluoric acid and thermal phosphoric acid concentration, the can and molten alkali class work. Exists in the nature, which has two kinds of crystalline silica and amorphous silica. Silica USES a wide range, mainly used in making glass, water glass, ceramics, enamel, refractories, aerogel blanket, ferrosilicon, sand, elemental silicon, cement, etc., in ancient times, silicon dioxide is also used to make porcelain glaze and body. General stone is mainly composed of silica, calcium carbonate.
Silica used in the manufacture of flat glass, glass products, casting sand, glass fiber, ceramic glaze, antirust sandblasting, filter with sand, flux, refractory materials and concrete manufacturing lightweight bubbles. The purpose of the silica is very wide. Sparse nature of the crystal could be used in the manufacture of the important components of the electronic industry, optical instruments and crafts. Silica is the important raw material for manufacturing optical fiber. Generally a pure quartz, can be made from quartz glass. Quartz glass small expansion coefficient, equivalent to 1/18 of the common glass, can withstand the temperature change, good acidproof performance (except for HF), therefore, quartz glass used to make high temperature resistant chemical equipment. Quartz sand used for glass raw materials and building materials.
Silica is made of glass, quartz glass, water glass, optical fiber, the important components of the electronic industry, optical instruments, crafts and refractory raw material, is an important material of scientific research.
When silica crystal perfection is crystal; Silicon dioxide is agate after dehydration; Silicon dioxide aqueous gel after solidification is opal; Silica grain is less than a few microns, chalcedony, flint, secondary quartzite. Physical properties and chemical properties are very stable mineral resources, the crystal of trigonal system oxide mineral, namely low quartz (alpha quartz), is one of the most widely distributed in the quartz mineral mineral species. Generalized quartz include high temperature quartz (beta - quartz). Quartz piece also known as silica, mainly in the production of quartz sand (also known as silica sand) raw materials, and quartz firing ferrosilicon and refractory materials.