Oxides and Peroxides

Silica is the most abundant of all minerals. Silica in nature is called silica, which accounts for about 12% of the total weight of the earth's crust. There are three different crystal forms of silica: quartz, scaly quartz and cristobalite. Quartz is the most stable at room temperature and the other two are stable at high temperature. They also exist at room temperature because of their slow transformation into quartz.

It is used as flux for silicate decomposition, dopant for semiconductor materials, fire-resistant additive for heat-resistant glassware and paint. It is the raw material for preparing elemental boron and various boron compounds. It is used in the production of alloy steel in metallurgical industry. It can also be used as catalyst for organic synthesis, additive of lubricant for high temperature and chemical reagent.

Used as raw material for making tungsten metal. Used for making hard alloy, tungsten wire, powder metallurgy, X-ray screen and fireproof fabric. It can also be used as colorant and analytical reagent of ceramic ware.

Copper oxide is an inorganic substance with the chemical formula Cuo. It is a black oxide of copper, slightly amphoteric and slightly hygroscopic. It is insoluble in water and soluble in acid. It can decompose oxygen under high temperature. Hydrogen or carbon monoxide can be reduced to copper at high temperature. Copper oxide is heated in air and releases oxygen at about 1050 ℃ to reduce to cuprous oxide. If in the gas stream of hydrogen or carbon monoxide, it is easy to be reduced to metal copper even below 250 ℃. Although copper oxide is insoluble in water, it can be dissolved in aqueous alkali metal hydroxide solution. It is used as colorant in glass, enamel and ceramic industry, anti Zou agent in paint and polishing agent for optical glass. It is used in the manufacture of dyes, organic catalyst supports and copper compounds. It is also used in rayon manufacturing industry and as a desulfurizer for grease. It is used as the raw material for manufacturing other copper salts and artificial gemstones.

It is mainly used as bleaching agent and oxidation agent, as well as detergent, cleaning agent and bactericide in chemical industry, papermaking, textile, dyeing and finishing, food, medicine, health and other departments.