| Gas-Fired Reverberatory Furnace | 1–30 tonnes per batch | 120,000–400,000 | 700–1,100 kWh equivalent per tonne of aluminium | 35–55% | 250–1,500 kg/h | Higher direct CO₂ and NOₓ emissions; requires exhaust treatment and ventilation | Combustion, gas leakage, hot surfaces, and molten-metal splash risks | Moderate to high | Large-volume melting, foundries, and continuous production | Best for high throughput |
| Electric Resistance Furnace | 100 kg–10 tonnes per batch | 100,000–350,000 | 650–900 kWh per tonne of aluminium | 50–70% | 50–600 kg/h | No on-site combustion emissions; electricity-source emissions vary by grid | Lower combustion risk; electrical isolation and molten-metal protection remain essential | Low to moderate | Clean melting, smaller foundries, remelting ingots, and controlled-temperature work | Best overall balance |
| Coreless Induction Furnace | 100 kg–5 tonnes per batch | 180,000–600,000 | 600–850 kWh per tonne of aluminium | 60–80% | 100–1,000 kg/h | No direct combustion emissions; power-generation emissions depend on the electricity mix | Requires electromagnetic-field controls, refractory monitoring, and strict water-cooling protection | Moderate | Frequent alloy changes, high temperature control, and rapid melting cycles | Best for flexibility |
| Rotary Tilting Furnace | 1–15 tonnes per batch | 150,000–450,000 | 800–1,200 kWh equivalent per tonne of aluminium | 30–50% | 150–1,000 kg/h | Combustion emissions plus increased dross and flux-related exhaust | Tilting movement, molten-metal handling, combustion, and splash hazards require guarded operation | High | Contaminated scrap, chips, turnings, and high-recovery recycling operations | Best for scrap recovery |
| Electric Crucible Furnace | 25–1,000 kg per batch | 30,000–150,000 | 900–1,400 kWh per tonne of aluminium | 35–55% | 15–250 kg/h | No on-site combustion emissions; electricity-source emissions vary by grid | Simple operating concept, but crucible failure and molten-metal exposure must be managed | Low | Laboratories, prototypes, maintenance shops, and low-volume casting | Best for small batches |
| Gas-Fired Crucible Furnace | 25–500 kg per batch | 25,000–120,000 | 1,000–1,500 kWh equivalent per tonne of aluminium | 25–45% | 15–150 kg/h | Direct CO₂ and NOₓ emissions; effective ventilation is required | Open flame, gas supply, hot surfaces, and crucible handling create elevated operating risks | Moderate | Low-cost, low-volume melting where gas is readily available | Best for low initial cost |
| Indicative engineering ranges for aluminium melting equipment. Actual performance depends on furnace size, charge composition, melt temperature, insulation condition, operating schedule, electricity or fuel prices, local installation requirements, and emissions regulations. Energy figures exclude downstream holding, casting, and material-handling equipment. |