Cold Slag Rock Wool Electric Furnace – Equipment Introduction & Main Parameters

I. Core Equipment Introduction

1. Basic Definition & Working Principle

• Type: Three-phase electric arc resistance furnace (submerged arc)
• Principle: Three graphite electrodes are inserted into the furnace charge. The arc heat and resistance heat between the electrodes and the charge heat raw materials in the furnace to a high temperature of 1600–2000℃ for melting, forming uniform and stable high-temperature melt (1450–1600℃). The melt is then sent to a centrifuge through a launder for fiber formation.
• "Cold Slag" Feature: Specially designed to directly process cold blast furnace slag, mineral slag, waste wool, fly ash and other solid cold materials without preheating, realizing efficient recycling of solid waste.

2. Equipment Structure

1. Furnace Body System
   • Furnace shell (steel plate welded) + multi-layer composite refractory and thermal insulation lining (high-alumina bricks, magnesia-chrome bricks, castable)
   • Furnace bottom cooling system (air/water cooling), furnace wall water cooling structure
   
   
2. Electrode System
   • Three graphite electrodes, electrode lifting/pressing device, conductive cross arm, collector ring
   
   
3. Power Supply System
   • Electric furnace transformer (voltage regulation), short network, reactive power compensation (SVC/SVG)
   
   
4. Feeding System
   • Automatic batching, closed top feeding, distributed charging mechanism
   
   
5. Tapping & Launder System
   • Side overflow port, water-cooled launder, precise melt flow control
   
   
6. Control System
   • Full-automatic PLC control: electrode adjustment, closed-loop temperature/power control, melt level control, safety interlock
   
   
7. Environmental Protection System
   • Furnace top flue gas collection, high-temperature dust removal, waste heat recovery
   
   

3. Core Technical Advantages

• Energy saving & environmental protection: No coke, no CO or dust emission, flue gas volume reduced by 80%, lower power consumption per ton of wool.
• Stable melt: Temperature fluctuation ±10℃, flow fluctuation ±0.2t/h, high fiber-forming quality.
• High solid waste utilization: Can digest 100% of mineral slag, waste wool, fly ash, etc., with low raw material cost.
• Flexible adjustment: Easy to switch acidity coefficient (1.5–2.2), suitable for high-end rock wool/slag wool.

II. Main Technical Parameters (Typical Specifications)

1. Capacity & Production Capacity

2. Electrical & Thermal Parameters

• Secondary Operating Voltage: 120–220 V (multi-stage voltage regulation)
• Electrode Specification:
  • 2500kVA: Φ350 mm graphite
  • 7500kVA: Φ500–600 mm graphite
  • Large furnace: Φ700–850 mm graphite
  
  
• P.C.D. (Pitch Circle Diameter): Φ1.0 m (2500kVA) / Φ2.5–3.5 m (large furnace)
• Melting Temperature: 1600–1800℃ (inside furnace)
• Tapping Temperature: 1450–1550℃ (for centrifuge)
• Power Factor: ≥0.90–0.92 (with compensation)

3. Process & Quality Parameters

• Raw Material Adaptability: Basalt, mineral slag, fly ash, steel slag, waste wool, etc.; particle size ≤50mm
• Acidity Coefficient Control Range: 1.5–2.2 (high precision & stability)
• Melt Temperature Uniformity: ±10℃
• Melt Flow Stability: ±0.2–0.5 t/h
• Furnace Lining Service Life: 1–2 years (continuous operation)

III. Typical Application Cases

• 7500kVA Cold Slag Rock Wool Electric Furnace
  • Capacity: 10–12 t/h
  • Raw materials: Fly ash, blast furnace slag, basalt
  • Features: Full automation, solid waste utilization rate ≥70%, annual output approx. 80,000–100,000 tons
  
  
• Large 30MVA Electric Furnace
  • Capacity: 25–30 t/h
  • Furnace size: Φ10m×4.5m
  • Application: Large-scale rock wool production line (annual output of 300,000 tons)
  
  

IV. Comparison with Traditional Cupola Furnace