| Three-Phase AC Electric Arc Furnace | Three graphite electrodes create three arcs between the electrodes and the metallic charge. The design commonly includes a tilting shell, water-cooled panels, roof, transformer, and fume-extraction system. | Approximately 10–300+ metric tonnes per heat, depending on furnace design and steelmaking route. | Medium- to ultra-high-power operation; commonly supplied by a high-current, low-voltage transformer. Electrical demand varies substantially with furnace size, scrap quality, and tap-to-tap target. | Carbon steel Stainless steel Alloy steel Steel scrap | Integrated steel mills, mini-mills, foundries, structural steel production, reinforcing bar, billet, slab, and special steel manufacturing. | High productivity, flexible scrap charging, broad capacity range, strong suitability for recycled steel, and well-established operating practices. | Requires substantial electrical infrastructure, water cooling, electrode consumption control, dust collection, arc-furnace transformer capacity, and measures for voltage flicker and harmonic distortion. |
| DC Electric Arc Furnace | Usually uses one graphite electrode above the bath and a conductive bottom electrode or bottom-contact system. The single main arc can provide a relatively stable heat pattern. | Approximately 20–200+ metric tonnes per heat in common steelmaking installations. | Direct-current power supplied through a rectifier and furnace transformer. The electrical configuration differs from AC systems and requires specialized bottom-electrode maintenance. | Carbon steel Low-alloy steel Stainless steel Mixed scrap | High-efficiency mini-mills, scrap-based steel production, billet production, and operations seeking lower electrode consumption or reduced electrical disturbance. | Often lower graphite-electrode consumption than comparable AC operation, reduced phase imbalance, and potentially lower network flicker when correctly engineered. | Higher initial system complexity, rectifier investment, and bottom-electrode wear or leakage risk. Availability of maintenance expertise and spare components should be assessed before purchase. |
| Submerged Arc Furnace | Electrodes are immersed or partially submerged in a conductive burden. Melting and reduction occur below the surface, with the furnace often operated as a continuous or semi-continuous process. | Commonly designed for continuous production from several tonnes per day to several hundred tonnes per day, depending on product and furnace power. | AC or DC power may be used. Operation typically involves high current and relatively low voltage, with power ratings ranging from several megawatts to many tens of megawatts. | Ferroalloys Silicon metal Calcium carbide Phosphorus materials Mineral products | Ferroalloy production, silicon and manganese alloys, carbide manufacturing, mineral reduction, and other processes requiring a reducing atmosphere and high-temperature burden treatment. | Efficient bulk processing, strong thermal utilization within the burden, and suitability for continuous high-volume production. | Generally not the first choice for clean batch melting of conventional steel. Requires carefully controlled burden chemistry, electrode regulation, off-gas handling, and raw-material sizing. |
| Plasma Arc Melting Furnace | Uses a plasma arc generated by a high-temperature ionized gas. The system can operate with an inert or controlled atmosphere and may use a water-cooled hearth or crucible. | Commonly from laboratory and pilot scale up to approximately 1–20 metric tonnes per heat, with larger systems available for specialized production. | DC power is frequently used; power may range from hundreds of kilowatts to several megawatts, depending on the furnace volume and material. | Reactive metals Titanium alloys Nickel alloys Refractory metals Specialty scrap | Aerospace materials, specialty alloy development, high-purity melting, difficult-to-melt feedstock, hazardous waste treatment, and applications requiring controlled atmosphere processing. | High arc temperature, precise atmosphere control, low contamination potential, and flexibility for materials that are difficult to process in conventional furnaces. | Higher capital and operating costs, more complex gas and control systems, and lower productivity for standard bulk steelmaking. Gas purity and chamber sealing are important buying criteria. |
| Vacuum Arc Remelting Furnace | A consumable electrode is melted by an electric arc under vacuum or controlled low-pressure conditions and resolidifies in a water-cooled copper mold. | Commonly approximately 0.1–30 metric tonnes per ingot, depending on alloy, electrode size, and remelting objective. | Usually DC arc power with controlled current and voltage. The process is designed for stable melting and solidification rather than rapid bulk scrap melting. | Titanium alloys Nickel superalloys Cobalt alloys High-alloy steels Reactive metals | Aerospace, power-generation components, medical alloys, high-performance tooling, and applications requiring improved cleanliness, homogeneity, and solidification control. | Reduces dissolved gases and non-metallic inclusions while improving ingot structure and chemical uniformity. | It is a secondary remelting process, not normally a primary scrap-melting furnace. It requires suitable consumable electrodes, vacuum equipment, water-cooled molds, and strict process control. |
| Electroslag Remelting Furnace | A consumable electrode is melted through a conductive molten slag layer. The refined metal solidifies directionally in a water-cooled mold. | Commonly approximately 0.5–100 metric tonnes per ingot, depending on section size and alloy family. | Typically uses low-voltage, high-current AC or DC power. Electrical requirements are lower than those of bulk primary steelmaking furnaces but demand stable control. | Tool steel Bearing steel Die steel Heavy alloy steel Nickel alloys | Premium forgings, large tools and dies, pressure-vessel materials, bearing components, and alloy products requiring improved internal quality. | Excellent control of solidification, improved cleanliness, reduced segregation, and good surface quality for suitable electrode materials. | Requires controlled slag chemistry and consumable electrodes. It is intended for refining and remelting rather than direct melting of unsorted scrap. |
| Small Batch Tilting Arc Furnace | A compact AC or DC arc furnace with a tilting shell for pouring. It may be equipped with a basic roof, water-cooled panels, hydraulic tilting, and local fume extraction. | Approximately 0.1–10 metric tonnes per heat, with some specialized units outside this range. | Commonly hundreds of kilowatts to several megawatts, depending on batch size, melting time, charge density, and required tapping temperature. | Cast iron Carbon steel Stainless steel Copper alloys Experimental alloys | Jobbing foundries, universities, pilot plants, small alloy batches, recycling operations, and facilities requiring flexible production rather than maximum throughput. | Lower installation scale, flexible batch sizes, relatively simple material changeover, and convenient pouring for foundry operations. | Lower productivity than large furnaces and potentially higher specific energy consumption. The buyer should verify electrode access, shell lining life, charging method, and extraction capacity. |
| Selection note: Actual capacity, power consumption, melting rate, electrode consumption, refractory life, and emissions performance depend on furnace geometry, charge composition, scrap density, operating practice, transformer loading, cooling-water conditions, and local electrical and environmental requirements. Figures shown are typical engineering ranges for preliminary comparison, not guaranteed performance values. |
