In the context of global resource scarcity and the growing awareness of environmental protection, the recycling and utilization of spent lead-acid batteries have become an important part of achieving sustainable development. In this recycling and smelting system, the rotary furnace, with its excellent performance, has become an indispensable core equipment, making significant contributions to the efficient recovery of lead resources and environmental protection.

Core Role Highlighted, Aiding Efficient Recovery of Lead Resources

The rotary furnace undertakes a number of key tasks in the recycling and smelting system of spent lead-acid batteries. Its treatment and reduction of lead paste can be regarded as a core link. The lead paste in spent lead-acid batteries is mainly composed of lead compounds such as lead sulfate. In the high-temperature environment of the rotary furnace, lead sulfate will undergo a decomposition reaction. Part of it decomposes into lead oxide and sulfur trioxide. The sulfur trioxide is discharged with the flue gas and can be recycled through desulfurization treatment. Under the action of reducing agents such as coke and carbon monoxide, lead oxide will be reduced to metallic lead, which finally flows out in the form of liquid lead, realizing the efficient conversion from lead compounds to metallic lead.

At the same time, the rotary furnace can also effectively separate metals from other impurities. The metal impurities such as copper, antimony, tin, and organic impurities such as plastics and rubber contained in spent lead-acid batteries will be separated due to differences in melting points and densities in the high-temperature environment and unique physical processes of the rotary furnace. Metal impurities will sink in layers, and organic impurities will burn or decompose. After being discharged with the flue gas, they are discharged up to the standard after purification treatment, laying the foundation for the production of high-purity recycled lead.

In addition, the rotary furnace can realize continuous production. Materials can be continuously added, and products such as liquid lead and slag can be continuously discharged. This production method has greatly improved production efficiency. The rotary furnace in large-scale recycling and smelting enterprises can process dozens or even hundreds of tons of waste battery raw materials every day. At the same time, it is conducive to stabilizing process parameters and ensuring the stability and consistency of product quality.

Significant Advantages, Leading Industry Development

The rotary furnace shows many significant advantages in the recycling and smelting process. Its lead recovery rate is relatively high. By precisely controlling parameters such as temperature, atmosphere, and material residence time in the furnace, the lead recovery rate using the rotary furnace in advanced processes can reach more than 95%, which effectively reduces resource waste, improves resource utilization efficiency, and alleviates the shortage of lead ore resources.

In terms of thermal efficiency, the rotary furnace performs excellently. Materials keep rolling in the rotating furnace body and fully contact with the high-temperature furnace wall, realizing efficient heat transfer. At the same time, the furnace body adopts good thermal insulation materials to reduce heat loss. Compared with traditional smelting equipment, it can save about 20%-30% of energy, which meets the environmental protection requirements of energy conservation and emission reduction and reduces the production cost of enterprises.

Moreover, the rotary furnace has strong adaptability to raw materials. Whether it is the mixed material of lead paste and lead grid after preliminary crushing and sorting, or waste batteries with different impurity contents, it can carry out effective smelting treatment by adjusting process parameters, meeting the production needs of different recycling enterprises, and has a broad application prospect in the complex and diverse recycling market of spent lead-acid batteries.

Facing Challenges, Continuous Improvement to Promote Industry Progress

Although the rotary furnace has obvious advantages, it also faces some challenges in the application process. Tail gas treatment is a major problem. The tail gas containing pollutants such as sulfur dioxide, dust, and heavy metals generated during smelting requires complex and costly purification equipment for treatment. To completely achieve up-to-standard discharge, the treatment capacity and operation stability of purification equipment need to be further improved.

At the same time, the problem of equipment corrosion and maintenance cannot be ignored. The rotary furnace works in a high-temperature and highly corrosive environment, and the inside of the furnace body is easily eroded by lead liquid, slag, and high-temperature flue gas, which affects its service life, increases maintenance costs, and may even bring potential safety hazards.

Facing these challenges, the industry is actively exploring improvement directions. In terms of tail gas treatment, more efficient and economical technologies and equipment are being developed, and new desulfurizers and adsorbent materials are being explored to improve the removal efficiency of pollutants and reduce costs. In terms of equipment maintenance, more corrosion-resistant furnace materials are being developed and applied, the structural design is optimized, and daily maintenance and detection are strengthened to ensure the long-term stable operation of the rotary furnace.

As the core equipment in the recycling and smelting system of spent lead-acid batteries, the importance of the rotary furnace is self-evident. With the continuous progress of technology and the gradual implementation of improvement measures, the rotary furnace will certainly play a more important role in promoting the recycling of lead resources and environmental protection, injecting strong impetus into the sustainable development of the industry.