High-Purity Quartz Sand Production Process and Production Line

High-purity quartz sand (SiO₂ purity ≥99.99%) is the material foundation for high-end silicon products. It is characterized by excellent chemical stability, high electrical insulation, low thermal expansion coefficient, and is widely used in strategic emerging industries such as new-generation information technology, new materials, and energy-saving and environmental protection sectors.

1. Raw Material Preprocessing

The raw materials for high-purity quartz sand are typically quartzite, quartzite, or natural rock crystal. After mining, the raw ore is washed with water, manually crushed, and preliminarily sorted to remove obvious impurities before being sent to the ore bin.

2. Crushing and Screening

The raw ore is fed into a jaw crusher via a vibrating feeder for coarse crushing. The crushed ore is then conveyed by a belt conveyor to a sand maker for fine crushing. The crushed quartz sand is screened using a circular vibrating screen. Quartz sand below 1mm is sent to a sand washing machine for cleaning, while quartz sand above 6mm is returned to the crushing system, forming a closed-loop cycle.

3. Deep Grinding

Advanced rod mill grinding technology is employed to finely grind the quartz sand to a particle size of 50 to 120 mesh, creating favorable conditions for subsequent purification.

4. Purification Stage

The purification process for high-purity quartz sand includes physical and chemical purification methods:

• Physical Purification: Techniques such as calcination, magnetic separation, and color sorting are used to remove impurities through physical means. For example, high-gradient magnetic separators are used to remove magnetic impurities.

• Chemical Purification: Chemical reactions such as acid leaching and flotation are used to deeply remove trace impurities. For example, a mixture of HCl and HF acids is used to soak the sand for six days to remove acid-soluble metal oxides and some silicate minerals.

5. Drying and Packaging

After purification, the quartz sand is dried using a dryer and then packaged, ready for subsequent applications.

Production Line Technology Features

• High Degree of Automation: China's first fully automated 4N8 high-purity quartz sand production line uses advanced physical and chemical methods. Through multi-stage fine separation and high-temperature sintering technologies, it achieves automated production.

• Environmental Protection and Sustainable Development: While pursuing high purity, strict adherence to environmental policies is maintained. Pollutants generated during the production process are properly treated. For example, a tail gas purification system is introduced to ensure that exhaust gases meet emission standards.

Market and Applications

High-purity quartz sand, as a key basic material, is in high demand in industries such as photovoltaics, semiconductors, optical fiber communication, and aerospace. With the continuous development of these sectors, the requirements for the purity and quality of high-purity quartz sand are also increasing.

In summary, the production process of high-purity quartz sand covers multiple stages from raw material preprocessing to final product. The production line technology is continuously optimized and upgraded to meet the market's high-quality demands for high-purity quartz sand.