The melting furnace is the core equipment in rock wool production, designed to melt raw materials (such as basalt and slag) at high temperatures into a molten state. Currently, there are three main types of melting furnaces:

1. Electric Furnace: Uses electric heating for precise temperature control, offering high environmental compatibility, making it suitable for regions with strict emission requirements.

2. Gas Furnace: Operates on natural gas or liquefied gas, providing high thermal efficiency, though the technology is relatively less mature.

3. Cupola Furnace: Utilizes coke combustion for melting, featuring large production capacity and stable operation, making it the most widely used furnace type in the rock wool industry.

Each melting method has distinct advantages, allowing users to select the most suitable furnace based on production needs, energy costs, and environmental standards.

The electric furnace system utilizes a three-phase AC arc heating principle, generating a high-temperature melting zone up to 2000°C through graphite electrodes. Equipped with an advanced PLC closed-loop temperature control system, it achieves a molten pool temperature accuracy of ±2°C, ensuring uniform melt composition. The multi-layer composite refractory lining design delivers a thermal efficiency of 82%-85%, with specific energy consumption of 1.1-1.3 kWh/kg. Particularly suitable for producing high-acidity coefficient (MK≥1.8) premium rock wool products that meet EN 13162 standards. The integrated electromagnetic stirring system effectively controls melt viscosity within the range of 150-200 Pa·s.

This gas melting system employs regenerative high-temperature air combustion (HTAC) technology, featuring dual-passage alternating regenerative chambers capable of preheating air to 1100°C. The combustion chamber adopts a corundum-mullite composite refractory structure with a design lifespan exceeding 15 months. A laser gas analyzer monitors O₂/CO ratios in real time, maintaining combustion efficiency between 78%-82%. Specially designed multi-stage swirl burners ensure temperature uniformity within ±15°C in the furnace, making it ideal for producing rock wool products with densities ranging from 60-150 kg/m³.

The cupola furnace system features a vertical water-cooled wall structure with an adjustable inner diameter of 1.2-2.0m, incorporating a 22-channel oxygen-enriched air supply system with intelligent oxygen concentration adjustment (21%-28%). The patented dual-spiral charging device maintains a stable coke-to-iron ratio of 1:8-1:10. The smelting zone reaches temperatures of 1750-1850°C, while the discharge port is equipped with an infrared temperature measurement system and hydraulic tilting mechanism for precise flow control. The integrated waste gas treatment system includes a heat recovery boiler and bag filter, complying with GB26453-2020 emission standards. Specifically designed for large-scale continuous production, the maximum single-furnace capacity reaches 15 t/h.