Large-Capacity White Fused Alumina Arc Furnace

Equipment Introduction & Parameters

1. Core Equipment Structure

1.1 Furnace System

• Furnace Shell: Welded with 20g boiler steel plate, thickness 18–25 mm, circular structure without stiffeners, ensuring tightness and strength.
• Furnace Lining: Constructed with high-alumina refractory bricks or castables, resistant to temperatures above 2200℃, corrosion and erosion, with adequate permeability to prevent melt blowback.
• Furnace Cover: Water-cooled composite steel structure, cylindrical type, equipped with electrode holes, charging holes and observation ports, rotatable and liftable.
• Tilting Mechanism: Fixed type (block furnace) or hydraulic tilting type, tilting angle 0–45°, convenient for slag and block discharge.

1.2 Electrode System

• Electrodes: High-power graphite electrodes, commonly Φ300–Φ450 mm for large-capacity furnaces, arranged in an equilateral triangle.
• Lifting Device: Driven by variable-frequency motor, lifting speed 1.5–2.5 m/min, stroke 1600–2200 mm, with automatic constant-current / constant-power regulation.
• Clamping System: Belt-type or hydraulic chucks, water-cooled, ensuring reliable conductivity and clamping.

1.3 Electrical System (Core)

• Transformer: Special on-load voltage-regulating rectifier transformer, commonly 6000–10000 kVA (6–10 MVA) for large-capacity models.
• Short Network: Composed of water-cooled cables, copper bars and conductive cross-arms, arranged in triangular form with three-phase impedance unbalance < 8% to reduce energy consumption.
• Control System: Fully automatic PLC control, monitoring current, voltage, power, temperature and electrode position.

1.4 Auxiliary Systems

• Cooling System: Spray cooling for furnace walls, internal water cooling for furnace cover, electrodes and short network; water consumption 150–300 t/h, equipped with pressure and temperature alarms.
• Charging System: Top furnace bin / charging tank, automatic or semi-batch feeding.
• Flue Gas Dedusting: Fully sealed gas hood with bag filter to meet environmental emission standards.
• Oxygen Injection: Top-blowing oxygen device for auxiliary melting, stirring and impurity removal.

2. Typical Large-Capacity Specifications

3. Working Principle & Process

• Raw Material: Industrial alumina powder (Al₂O₃ ≥ 98.5%), with strict control of Na₂O, SiO₂ and Fe₂O₃ impurities.
• Arc Ignition: Electrodes lower down and energize to start arcing, raising furnace temperature to 2200–2300℃.
• Smelting: Batch feeding with closed-chamber method (thick material layer) for high thermal efficiency and low energy consumption.
• Refining: Holding for 4–6 hours to separate and remove impurities; β-Al₂O₃ (sodium impurities) segregated and eliminated.
• Cooling: Natural cooling for 24–36 hours after power-off to form dense white fused alumina clinkers.
• Post-Treatment: Crushing, sieving, acid washing and sorting to obtain finished product with Al₂O₃ ≥ 99%.

4. Performance Features

• High Purity: Product Al₂O₃ ≥ 99.0%, high whiteness and low impurities.
• High Output: 10000 kVA furnace achieves daily output of 30–35 tons, suitable for mass production.
• Low Energy Consumption: Higher thermal efficiency in large-capacity furnaces, unit power consumption 5–10% lower than small furnaces.
• Stability & Reliability: High automation, long furnace lining life, stable continuous operation.
• Environmental Protection: Fully sealed structure with high-efficiency dust removal, flue gas meets emission standards.

5. Main Applications

• Abrasives & Grinding Tools: Ceramic / resin abrasives, sandpaper, abrasive belts, grinding powders for precision grinding and polishing.
• Refractory Materials: High-grade refractory bricks, castables, nozzles, sliding plates for metallurgical, building materials and petrochemical high-temperature kilns.
• Functional Ceramics: Electronic ceramics, ceramic cutting tools, high-temperature structural components.
• Others: Precision casting sand, sandblasting media, anti-corrosion fillers, refractory fibers, etc.