1. Raw Material Preparation Equipment
Crushers and Mills:
Jaw crushers, hammer mills, or ball mills to crush quartz/silica (SiO₂) and carbonaceous materials (coal, coke) into fine particles.
Screening Equipment:
Vibrating screens or sieves to ensure uniform particle size for optimal furnace reactions.
Drying Equipment:
Rotary dryers to remove moisture from raw materials (prevents furnace explosions).
2. Submerged Arc Furnace (SAF) System
Core Equipment:
Electric arc furnace (large refractory-lined furnace) operating at 1,800–2,000°C.
Electrodes:
Graphite/Söderberg electrodes (self-baking or pre-baked) to conduct electricity and generate heat.
Raw Material Feeding System:
Conveyor belts, hoppers, and chutes to continuously feed silica and carbon into the furnace.
3. Gas and Dust Collection System
Off-Gas Treatment:
Bag filters, electrostatic precipitators, or scrubbers to capture CO gas and silica dust.
CO Gas Recycling:
Gas purification systems to reuse CO as fuel or for chemical synthesis (optional).
4. Casting and Cooling Equipment
Tapping System:
Ladles or runners to collect molten silicon from the furnace.
Molds:
Cast iron or graphite molds to solidify molten silicon into ingots or lumps.
Cooling Chambers:
Water-cooled or air-cooled systems to rapidly cool solidified silicon.
5. Crushing and Sorting Equipment
Primary Crushers:
Jaw crushers or cone crushers to break large silicon blocks into smaller pieces.
Screening and Grading:
Vibrating screens to classify silicon into different sizes (e.g., lumps, granules).
Magnetic Separators:
Remove iron impurities from crushed silicon.
6. Power Supply System
High-Voltage Transformers:
Convert grid electricity to the high current (50–150 kA) required for the furnace.
Rectifiers (DC Furnaces):
Convert AC to DC for improved energy efficiency (optional).
7. Cooling Water System
Cooling Towers and Pumps:
Circulate water to cool furnace walls, electrodes, and other high-temperature components.
8. Automation and Control Systems
PLC/DCS Systems:
Monitor and control temperature, electrode position, raw material feed rates, and power input.
Sensors:
Thermocouples, pressure sensors, and gas analyzers for real-time process optimization.
9. Post-Processing Equipment (For High-Purity Silicon)
Leaching Tanks:
Acid (HCl/HF) leaching to remove impurities (Al, Fe, Ca) for solar/electronic-grade silicon.
Vacuum Distillation Furnaces:
Further purify silicon by removing volatile contaminants.
