Nonferrous metallurgy

Introduction

Non-ferrous metal smelting (copper, aluminum, lead, zinc, nickel, etc.) operates under extremely harsh conditions: furnace temperatures typically range from 1300–1600°C, with strong chemical corrosion and penetration from molten metal and slag, combined with frequent thermal shock, mechanical scouring, and drastic changes in oxidizing-reducing atmospheres. Core equipment includes reverberatory furnaces, flash furnaces, electrolytic cells, holding furnaces, and transfer ladles. Any lining failure leads to production downtime, reduced output, and increased energy consumption. Zhengzhou Jinshan Refractory Materials provides highly targeted refractory solutions for different furnace types, focusing on basic refractories (such as chromium-alumina spinel products) and high-performance unshaped materials to help customers significantly extend furnace campaign life, reduce downtime, and lower overall costs.

1. Reverberatory Furnace

Working Conditions: Reverberatory furnaces are widely used in the smelting of aluminum, copper, lead, and zinc, with operating temperatures generally between 1200–1450°C. The lining is in long-term direct contact with molten metal and slag. Aluminum melt penetration is particularly severe during pure aluminum smelting, easily infiltrating brick joints or pores; severe mechanical scouring and abrasion occur at furnace bottom slopes, tapping ports, and launders; frequent temperature fluctuations during charging and discharging easily cause thermal shock cracking and lining spalling.

Recommended Refractory Materials and Advantages:

• High-alumina bricks (Al₂O₃ 80–85%) or mullite/corundum bricks: Offer excellent high-temperature flexural strength and resistance to aluminum melt penetration, with refractoriness above 1790°C. Ideal for furnace bottom and side walls in direct contact with aluminum melt, effectively resisting penetration and chemical erosion while reducing spalling.
• Non-stick alumina castable (with anti-wetting additives): Forms a dense protective layer through special anti-wetting additives, effectively preventing aluminum melt penetration and adhesion. Easy to install and suitable for furnace bottom, launders, and tapping ports, extending lining life by 30–50% compared to conventional materials.
• Silicon carbide-based materials (castables, ramming mixes, mortars): Excellent thermal conductivity and outstanding abrasion resistance, specially designed for high-wear zones such as furnace bottom slopes, aluminum launders, and tapping ports. They also provide good oxidation resistance and thermal shock stability.

2. Flash Furnace / Bath Smelting Furnace

Working Conditions: Flash furnaces are primarily used for copper and nickel smelting, with temperatures reaching 1500–1600°C. The melt is intensely agitated, slag flows rapidly, and erosion/penetration is extremely severe. Frequent switching between oxidizing and reducing atmospheres causes structural loosening and chemical reactions in the lining. The furnace bottom, side walls, and slag line suffer the most damage, with traditional materials often lasting only 3–6 months.

Recommended Refractory Materials and Advantages:

• Fused magnesia-chrome bricks or chromium-alumina spinel bricks: Produced by electric fusion process with high density, offering superior resistance to slag erosion and penetration. Ideal for heavy-duty areas such as furnace bottom and slag line, maintaining structural stability under strong oxidizing-reducing atmospheres and extending service life by over 40% compared to standard magnesia-chrome bricks.
• Direct-bonded magnesia-chrome bricks: Crystals are directly bonded at high temperature, providing excellent thermal shock and erosion resistance. Mainly used in the main furnace bottom and upper side walls to resist slag scouring and penetration.
• Silicon carbide and high-alumina unshaped materials: Fast installation, high density, and suitable for auxiliary areas (such as furnace roof and upper side walls), offering good resistance to high-temperature scouring at lower cost.

3. Electrolytic Cell

Working Conditions: The lining of aluminum electrolytic cells is exposed to 950–980°C high temperatures, cryolite-alumina melt, and strong fluoride corrosion, while also subjected to high electric current. Electrolyte penetration easily occurs at the cathode, causing “bottom heaving.” Side walls must simultaneously meet corrosion resistance and insulation requirements, and the entire lining must maintain stable temperature while minimizing heat loss; otherwise, energy consumption rises sharply.

Recommended Refractory Materials and Advantages:

• Graphite or carbon-based materials: Excellent electrical conductivity and strong resistance to melt penetration, specially used for cathode lining to prevent electrolyte infiltration and maintain stable conductivity.
• High-alumina / corundum bricks + insulating castables: High refractoriness and excellent resistance to fluoride corrosion. Used in side walls and safety lining to resist melt erosion while acting as a protective layer to extend overall service life.
• Lightweight insulating castables (based on mullite and hollow beads): Low thermal conductivity (≤0.5 W/m·K) and low bulk density. Applied in the insulation layer to significantly reduce heat loss, improve energy efficiency, and provide sufficient mechanical strength for construction and service stresses.

4. Holding Furnace / Transfer Ladle

Working Conditions: Holding furnaces and transfer ladles are used for storing and transporting molten aluminum, zinc, or lead. The melt remains for long periods (up to several hours), exposing the lining to prolonged high-temperature immersion. Heat loss is significant, metal penetration risk is high, and the lining must allow quick disassembly and maintenance to accommodate frequent transfer operations.

Recommended Refractory Materials and Advantages:

• Non-stick alumina castable and high-alumina castable: After adding anti-wetting components, they form a dense barrier layer at high temperatures, effectively preventing melt penetration and adhesion. Mainly used in inner linings in direct contact with melt, extending lining life by 1.5–2 times.
• Lightweight insulating castable: Low thermal conductivity and excellent insulation performance. Used in the insulation layer and outer lining to greatly reduce heat loss and save energy, with fast installation suitable for quick repairs of transfer ladles.
• Silicon carbide ramming mixes and plastic refractories: Outstanding abrasion and scouring resistance. Used in high-wear areas such as launders, tapping ports, and ladle bottoms. They can be quickly baked and put into service after installation, minimizing downtime.

5. Other Furnace Types

For other equipment such as blast furnaces, converters, and induction furnaces, we can provide fully customized refractory solutions and technical support according to the specific metal type, process conditions, and furnace structure.

Why Choose Jinshan Refractories?

• Rich experience and technical expertise in non-ferrous metallurgy projects
• Strict quality control system and advanced testing equipment ensuring consistent material performance
• Customized formulations and technical solutions based on actual furnace conditions
• Professional technical support, installation guidance, and comprehensive after-sales service