Project Overview
WSHT Mining Group designed and delivered a specialized high-purity quartz processing facility for a solar panel manufacturer in the state of Minas Gerais, Brazil. The plant produces 50,000 tonnes per year of +99.9% SiO2 quartz concentrate for PV-grade silicon production, supporting the growing solar energy industry.
Technical Challenge
High-purity quartz (HPQ) production requires extremely precise processing to remove trace mineral impurities that would compromise semiconductor and solar cell performance. The client's quartz deposit required:
- Careful liberation of quartz from associated minerals
- Removal of iron, aluminum and titanium impurities
- Strict control of particle size distribution
- Chemical treatment for final purification
Process Design
Crushing and Milling:
- Primary crushing to -50mm
- Dry grinding in rod mills to -1mm
- Classification to remove oversize
- Avoiding contamination from grinding media
Flotation Circuit:
- Quartz flotation using cationic collectors
- Desliming to remove fine impurities
- Multiple cleaning stages for purity
- Magnetic separation for iron removal
Chemical Treatment:
- Acid leaching for metal impurity removal
- Hydrofluoric acid treatment for silica purification
- Neutralization and washing
- Drying and packaging
High-Purity Quartz Processing — Brazil
Key Equipment
- Primary Jaw Crusher PE-600×900 (ceramic-lined)
- Rod Mill 3.0m × 4.5m (ceramic grinding media)
- flotation cells (8 units)
- Wet high-intensity magnetic separator
- Acid leach reactors (stainless steel)
- Filter press for product dewatering
- Rotary dryer (gas-fired)
Quality Results
- Product Grade: 99.95% SiO2 (design 99.9%)
- Iron Content: < 50 ppm
- Aluminum Content: < 200 ppm
- Throughput: 52,000 tpa (design 50,000 tpa)
- Recovery: 78% of quartz in feed
Project Highlights
Contamination Control: Special attention was paid to material selection and equipment design to prevent contamination of the high-purity product — ceramic-lined equipment, stainless steel tanks and careful process water treatment.
Environmental Compliance: The project included comprehensive wastewater treatment and acid recovery systems to meet strict Brazilian environmental regulations.
The plant has been operating successfully for over four years, supplying HPQ to both the client's own silicon smelter and to other solar industry customers in the region.
