Silicon dioxide is the raw material for manufacturing glass, quartz glass, water glass, optical fiber, important components of electronic industry, optical instruments, handicrafts and refractories, and is an important material for scientific research.


Applications of silicon dioxide: flat glass, glass products, casting sand, glass fiber, ceramic colored glaze, sand blasting for rust prevention, sand for filtration, flux, refractory materials, and the manufacture of autoclaved lightweight concrete. Silicon dioxide is widely used. Rare crystals in nature can be used to make important components, optical instruments and handicrafts in the electronic industry. Silicon dioxide is an important raw material for manufacturing optical fibers. Generally pure quartz can be used to make quartz glass. The expansion coefficient of quartz glass is very small, which is equivalent to 1/18 of ordinary glass. It can withstand sharp changes in temperature and has good acid resistance (except HF). Therefore, quartz glass is often used to make high temperature resistant chemical instruments. Quartz sand is often used as raw material for glass and building materials.


chemical property

The chemical properties are relatively stable. It is insoluble in water and does not react with water. It is an acidic oxide and does not react with general acids. Gaseous hydrogen fluoride reacts with silicon dioxide to form gaseous silicon tetrafluoride. React with hot concentrated alkali solution or molten alkali to form silicate and water. It reacts with a variety of metal oxides at high temperature to form silicate. It is used for manufacturing quartz glass, optical instruments, chemical vessels, ordinary glass, refractory materials, optical fibers, ceramics, etc. The nature of silicon dioxide is inactive. It does not interact with halogen, hydrogen halide, sulfuric acid, nitric acid and perchloric acid other than fluorine and hydrogen fluoride (except hot concentrated phosphoric acid). Common concentrated phosphoric acid (or pyrophosphoric acid) can corrode silicon dioxide at high temperature and generate heteropoly acids [2]. Molten borate or boric anhydride can also corrode silicon dioxide at high temperature. In view of this property, borate can be used as a flux in ceramic firing. In addition, hydrogen fluoride can also dissolve acids in silicon dioxide to generate fluosilicic acid that is soluble in water: SiO 2 + 4HF = SiF4 ↑ + 2H 2 O