[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods of silica, concept of silica

Silica Properties

Silica (SiO2) is one of the most common compounds on the earth and widely exists in nature. It exists mainly in crystalline form, including quartz, flint and opal. Silica is chemically very stable, with a high melting point (about 1710°C) and high hardness (Mohs hardness of 7), making it excellent in a variety of applications. Because of its chemical inertness, silica does not react with most acids, bases and salts, a property that makes it an inert filler and catalyst carrier in many chemical processes.

Silica uses

Silica is widely used and covers many industries. In the architectural and glass industry, silica is a major component of glass and is used to make various types of glass, including float glass, container glass, and optical glass. In the electronics industry, ultrapure silica is used to make integrated circuits and optical fibers. Silica is also an important food additive (E551) to prevent caking of powdered foods. In everyday chemicals, silica is used as an abrasive in toothpaste and as a thickener in skin care products. In the ceramic industry, silica is one of the main raw materials for making refractory materials and ceramic products.

Upstream raw materials

The main raw material for the production of silica is quartz sand. The purity and particle size of quartz sand have an important influence on the quality of the final product. High purity quartz sand is the key to the production of high quality silica. Some chemical companies produce high-purity silicon dioxide through chemical synthesis methods, such as silicon tetrachloride (SiCl4) hydrolysis to generate silicon dioxide. This method can control the purity and particle size of the product to meet the needs of specific applications.

Downstream Products

As the basic raw material, silica has a wide range of downstream products. In the glass manufacturing industry, silica is processed into products such as flat glass, optical glass and glass fiber. In the electronics industry, ultrapure silica is used to produce semiconductor components and fiber optic communications equipment. Silica is also used as a filler and reinforcing agent in rubber and plastic products to improve their mechanical strength and wear resistance. In the cosmetics and pharmaceutical industries, silica is widely used as a thickener, anti-caking agent and adsorbent to improve product stability and user experience.

Production process

The production process of silica mainly includes two methods: natural mineral extraction and chemical synthesis. The natural mineral extraction method is to extract silica from quartz sand, remove impurities by physical and chemical means, and obtain high-purity silica. The chemical synthesis law includes gas phase method, hydrolysis method, etc., in which the gas phase method generates silicon dioxide and chlorine by reacting silicon tetrachloride with oxygen at high temperature, and the hydrolysis law generates silicon dioxide by the hydrolysis reaction of silicon tetrachloride in water. These processes can control the purity and particle size of silica according to different application requirements.

storage method

The storage of silica is relatively simple, but there are some key points to note. Silica should be stored in a dry, ventilated environment to prevent moisture caking. Contact with strong acid and strong alkali should be avoided to prevent chemical reaction. Silica powder is prone to dust, and appropriate dust prevention measures should be taken during storage and handling to protect the health of workers. For specific applications, ultra-pure silica also needs to be stored and handled in a highly clean environment such as a clean room to ensure its purity and performance.

Environmental Protection and Safety

Environmental protection and safety are important considerations in the production and use of silica. Silica dust is irritating to the respiratory system, and long-term exposure may cause silicosis. Therefore, appropriate protective measures should be taken during production and use, such as wearing dust masks and using dust removal equipment. Harmful by-products may be produced during the production of silica, such as chlorine gas from the decomposition of silicon tetrachloride, which need to be properly disposed of to avoid environmental pollution. Enterprises should strictly abide by environmental protection laws and regulations in the production process, adopt clean production technology, reduce waste discharge and protect the ecological environment.

Market Prospects

The silica market is promising and driven by a variety of factors. As the global construction and manufacturing industries continue to grow, the demand for glass and ceramic products is increasing, driving the demand for silica. The development of the electronics industry has increased the demand for high-purity silica, especially with the popularization of 5G technology and the Internet of Things, the demand for fiber optic communications and semiconductor components has increased. The increasing awareness of environmental protection has promoted the demand for renewable materials and environmentally friendly additives, and silica has broad application prospects in these fields.

Conclusion

As an important chemical raw material, silicon dioxide has a wide range of applications and huge market potential. Its excellent physical and chemical properties allow it to play a key role in multiple industries. Although its production and storage are relatively simple, environmental protection and safety issues still need to be paid attention to to ensure its sustainable development. In the future, with the progress of technology and the change of market demand, the application field of silica will continue to expand, providing strong support for the development of related industries.