However, not all silica sand is suitable for industrial use. Each application demands strict specifications regarding purity levels, grain size, and metallic impurity ratios. Consequently, the processing and purification of silica sand are essential stages to ensure the raw material meets the requirements of precision industries, such as transparent glass, solar panels, and advanced electronics.
This article outlines the processing stages of silica sand, the technical standards required for peak quality, and the pioneering role of Zohdy Minerals Egypt (Zohdy Trading) in developing and supplying world-class Egyptian silica sand. Contact Us.
What is Silica Sand and Why is it Industrially Significant?
Silica sand is a natural sand composed of silicon dioxide (SiO2), typically in the form of hard quartz crystals. Its physical and chemical properties make it a strategic material for various fields, including:
- Flat and Automotive Glass.
- Solar Cell Manufacturing.
- Iron and Steel Foundries.
- Ceramics and Advanced Construction Materials.
- Water Filtration and Environmental Treatment Systems.
The primary determinant for its use is the purity level. While 95% SiO2 may suffice for some construction applications, advanced industries require a purity of no less than 99.7%, with iron impurities (Fe2O3) kept below 0.03%.
Stages of Silica Sand Processing and Purification
- Extraction and Primary Preparation
Based on precise geological studies, sites containing high-purity sand are identified. Surface layers are removed to reach the silica-rich strata. The raw sand is then transported to processing units via specialized trucks or conveyor belts, focusing on maintaining grain integrity and minimizing contamination from dust or clay.
- Washing and Mechanical Separation
This is a fundamental step in improving quality. The sand is washed with clean water to remove clay and dust, then passed through a series of screens to separate grains by size. Systems like Hydrocyclones or Attrition Scrubbing are often used to remove clay coatings adhering to the grains, improving Grain Size Distribution (GSD).
- Magnetic Separation and De-ironing
Even trace amounts of iron oxides (Fe2O3) can impair glass transparency or solar panel efficiency. High-intensity magnetic separators attract and isolate magnetic impurities. In advanced cases, a two-stage magnetic separation is employed to reduce iron content to less than 0.03%.
- Chemical Treatment (Acid Leaching)
For ultra-high purity requirements (e.g., electronics or solar energy), Acid Leaching is applied. Diluted acids, such as Hydrochloric (HCl) or Hydrofluoric (HF), are used to remove residual iron and aluminum oxides. The sand is then thoroughly rinsed with pure water and dried in controlled ovens.
- Drying and Packaging
Drying is crucial for quality stability during storage. Sand is dried in thermal ovens at 100°C to 120°C until moisture levels drop below 0.1%. It is then packed in paper bags or Jumbo bags (25kg, 50kg, or 1 ton) or shipped in bulk containers.
Quality Standards and Chemical Analysis
At Zohdy Minerals Egypt, every batch is tested in laboratories equipped with the latest analytical instruments to ensure compliance with local and international standards.
| Property | Target Value | Industrial Importance |
| SiO2 Content | \ge 99.5 \% | Enhances transparency in glass and solar cells |
| Fe2O3 | \le 0.03 \% | Reduces unwanted tinting in glass |
| Al2O3 | \le 0.1 \% | Ensures thermal property stability |
| TiO2 | \le 0.05 \% | Prevents staining in glass and ceramics |
| Moisture | \le 0.1 \% | Facilitates storage and transport |
| Grain Size | 0.1mm – 0.6mm | Tailored to the specific industry |
Industrial Applications of Processed Silica Sand
- Glass Industry: The core component for flat, container, and optical glass.
- Solar Panels: A primary source for extracting pure silicon used in photovoltaic cells.
- Foundries: Provides uniform grains that withstand high temperatures during metal casting.
- Water Treatment: Acts as an inert filtration medium to trap impurities.
Zohdy Minerals Egypt: Commitment to Quality
Zohdy Minerals Egypt has developed an integrated production system that includes:
- High-tech washing, magnetic separation, and chemical treatment units.
- Advanced quality control laboratories.
- Automated packaging lines to ensure product integrity.
- Flexible export services to Arab, European, and Asian markets.
Our products are customized according to client needs (GSD, purity, packaging) and fully comply with international standards such as ISO 9001 and ASTM.
Why Choose Zohdy Minerals Egypt?
- Guaranteed purity exceeding 99.7% SiO2.
- Ultra-low iron impurities (max 0.03%).
- Flexibility in sizing and packaging.
- Expert technical support for optimal application selection.
- Commitment to timely delivery and consistent quality.
The processing of silica sand is a decisive factor in industrial success.
Through long-standing expertise and advanced technologies, Zohdy Minerals Egypt continues to provide high-quality Egyptian silica sand that meets the most demanding global standards. Contact Us.
