[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods, characteristics of tin dioxide

1. Tin dioxide properties

1.1 chemical properties

Tin dioxide (SnO₂), also known as tin oxide, is a colorless crystal with relatively stable chemical properties. Its crystal structure is tetragonal with a high melting point (1630°C) and boiling point (1800°C). Tin dioxide is not soluble in water, but can be dissolved in concentrated sulfuric acid and strong alkali solution. Due to the stability of Sn￣ + ions, tin dioxide shows strong oxidizing properties.

1.2 physical properties

Tin dioxide has a density of about 6.95g/cm³ and has excellent electrical conductivity and optical properties. Its color is white or light yellow in the pure state, but the color may change under the influence of different impurities. It has good light transmission in the ultraviolet and visible light range, and shows a certain photocatalytic activity under light conditions.

2. Tin dioxide use

2.1 photoelectric materials

Tin dioxide is widely used in the manufacture of optoelectronic materials such as transparent conducting oxides (TCOs). It is used as a transparent electrode material in solar cells, liquid crystal displays (LCDs) and touch screens. Its excellent conductivity and transparency make it an indispensable material for these applications.

2.2 catalysts and catalyst carriers

Tin dioxide is also used as a catalyst and catalyst carrier in the chemical industry, especially in air purification and exhaust gas treatment processes. It exhibits efficient catalytic performance in the oxidation of hydrocarbons such as methane and propane. Tin dioxide is also used in automobile exhaust purification catalysts to help reduce harmful gas emissions.

2.3 gas sensor

Due to its sensitivity to a variety of gases, tin dioxide is widely used in gas sensors, especially in the detection of combustible and toxic gases. SnO₂-based gas sensors can detect carbon monoxide, hydrogen, ammonia, etc., with fast response and high sensitivity.

2.4 coatings and ceramics

In the coatings and ceramics industry, tin dioxide as an additive can improve the hardness, wear resistance and corrosion resistance of materials. It is often used in glazes and enamels to enhance the gloss and stability of the surface.

3. Tin dioxide upstream and downstream raw materials

3.1 upstream feedstock

The production of tin dioxide mainly depends on tin ore (mainly cassiterite, chemical formula SnO₂). Cassiterite through beneficiation, roasting and other steps to obtain refined tin, and then through chemical reaction or physical process into tin dioxide. The main production methods include direct oxidation and solution chemical precipitation.

3.1.1 Direct oxidation method

The method is by directly oxidizing metal tin at high temperature to produce tin dioxide. This process is simple, but the energy consumption is high.

3.1.2 Solution chemical precipitation method

The method is through the tin compound (such as tin chloride) dissolved in water, and then through the chemical precipitation reaction to generate tin dioxide precipitation, after washing, drying and calcination to obtain pure tin dioxide.

3.2 downstream applications

The downstream applications of tin dioxide are mainly concentrated in the electronics industry, chemical industry and environmental protection. In the electronics industry, it is mainly used to make transparent conductive films and gas sensors; in the chemical industry, it is used as catalyst and catalyst carrier; in the field of environmental protection, it is used for exhaust gas treatment and air purification equipment.

4. Tin dioxide storage method

4.1 storage environment requirements

Tin dioxide should be stored in a dry, cool, well-ventilated environment. Avoid mixed storage with strong acid, strong alkali and other chemicals to prevent chemical reactions. Storage areas should be kept away from ignition and heat sources to prevent decomposition of the material.

4.2 Packaging Requirements

Tin dioxide is usually used in double-layer packaging, the inner layer uses a sealed plastic bag, and the outer layer uses a moisture-proof carton or iron drum packaging. The packaging should have good moisture resistance to prevent moisture absorption and caking or other adverse reactions.

4.3 Safety Precautions

Pay attention to safety when storing and handling tin dioxide, avoid dust inhalation and skin contact. Operators should wear appropriate personal protective equipment such as dust masks and gloves. In the process of handling and storage, it should be handled with ease to prevent material leakage caused by damaged packaging.

Conclusion

As an important inorganic compound, tin dioxide plays an important role in various industrial fields because of its superior chemical and physical properties. From the extraction and production process of upstream raw materials, to the wide range of downstream applications, to its storage methods, every link affects the performance and use of tin dioxide. With the advancement of technology and the continuous expansion of applications, the market demand for tin dioxide will continue to grow, and its industrial prospects are also very broad.