Non-ferrous metallurgy industry is one of the important pillar industries of the national economy, involving the extraction, refining and processing of a variety of metals. In these complex metallurgical processes, high temperature environment is common, and refractory materials, as a key material that can withstand high temperatures and maintain physical and chemical stability, play an indispensable role in ensuring the smooth progress of non-ferrous metallurgical production. They not only resist high temperature erosion, but also maintain the structural integrity of the furnace in harsh metallurgical environments, thereby improving production efficiency, reducing production costs and ensuring product quality.
1. The special requirements for refractory materials in the non-ferrous metallurgy industry
1.1. High erosion resistance
The slag produced in the process of non-ferrous metallurgy is complex in composition and has different degrees of corrosiveness. The properties of slag produced by different non-ferrous metal smelting processes are quite different. For example, lead and zinc smelting slag contains more lead, zinc oxide and fluoride, which has strong erosion to refractory materials. The cryolite electrolyte molten liquid in aluminum smelting will also have a special erosion effect on the furnace lining refractory. Therefore, refractories need to have excellent corrosion resistance for different smelting processes and slag compositions.
1.2. Strict purity requirements
In the smelting process of some high-purity metals, such as the production of electronic grade aluminum, the purity of refractory materials is very high. Because impurities in the refractory may enter the metal melt at high temperatures, thus affecting the purity and quality of the metal. Therefore, the refractories used in such processes need to be rigorously purified to ensure that their impurity content is controlled at very low levels.
1.3. Adapt to complex process environment
There are a variety of non-ferrous metallurgy processes, including fire smelting, wet smelting and electrolytic refining. Each process has its own unique operating conditions and environmental requirements. For example, in the process of fire smelting, the temperature is high and the atmosphere is complex, and wet smelting involves the role of corrosive solution. Refractories need to be able to adapt to these different process environments and maintain good performance under a variety of conditions.
1.4. Long life and reliability
Non-ferrous metallurgy production is usually a continuous large-scale production, equipment shutdown maintenance will bring huge economic losses. Therefore, refractories are required to have a long service life and a high degree of reliability in order to reduce the number of shutdowns and maintenance costs caused by refractory damage. This requires refractories to meet high standards in terms of quality, performance stability and construction and installation.
2. The application of common refractory materials in the non-ferrous metallurgy industry
2.1. Alumina refractory material
– Application field: widely used in aluminum smelting industry, such as aluminum electrolytic cell lining. In the process of aluminum electrolysis, the alumina refractory can withstand the erosion and high temperature action of cryolite electrolyte. It has high chemical stability and good high temperature resistance, and can meet the harsh working conditions of aluminum electrolyzer.
– Features and advantages: high alumina content, high hardness, good wear resistance. It has strong corrosion resistance to liquid aluminum and cryolite melt, and has good thermal stability, which can adapt to the frequent change of temperature of aluminum electrolytic cell. In addition, the alumina refractory has better insulation performance, which helps to reduce the electrical energy loss in the electrolytic process.
2.2. Magnesia refractory material
– Application: Often used in copper, nickel and other non-ferrous metal smelting furnace, especially in copper smelting converter, electric furnace and other equipment lining parts. Magnesia refractory has good corrosion resistance to copper and nickel slag, and can maintain the structural integrity of the furnace lining at high temperature and improve the service life of the furnace body.
Features and advantages: It has good high temperature resistance, and its melting point is high, up to about 2800℃. Magnesium refractories have strong alkalinity and can effectively resist the erosion of acidic and neutral slag. At the same time, it also has a certain thermal conductivity, which helps to evenly distribute heat and improve smelting efficiency. However, magnesia refractories are easy to react with water vapor at high temperatures, so it is necessary to pay attention to moisture resistance during use.
2.3. Silicon carbide refractory
Application: It is widely used in zinc smelting, lead smelting and some special high-temperature reactors in the non-ferrous metallurgy industry. For example, in zinc distillation furnaces and lead blast furnaces, silicon carbide refractories can withstand high temperatures and highly corrosive atmospheres, showing excellent performance.
– Features and advantages: Silicon carbide has high hardness, high strength, high wear resistance and good thermal conductivity. It has good chemical stability and can resist the erosion of most acid-alkali slag at high temperatures. In addition, silicon carbide refractories have small thermal expansion coefficient and excellent thermal stability, which can adapt to the working conditions of acute cooling and acute heating. Its disadvantage is that when used at high temperature in an oxidizing atmosphere, the surface is easy to oxidize to form a silica film, which affects the long-term stability of its performance.
2.4. Silica refractory material
– Application field: Mainly used in glass melting furnace, lead smelting open furnace and other equipment in non-ferrous metallurgy industry. In glass furnace, siliceous refractories can withstand the erosion and scouring of high temperature glass liquid to ensure the normal operation of the furnace. In lead smelting open-hearth furnace, silica refractories can also adapt to the high temperature environment in the furnace and the role of lead slag.
– Features and advantages: The main component of siliceous refractories is silica, which has high refractoriness and good chemical stability. It has strong corrosion resistance to acidic slag and relatively low price. However, the thermal expansion coefficient of siliceous refractories is large, the thermal stability is poor, and it is easy to crack and spalling when the temperature changes rapidly. Therefore, it is necessary to pay attention to controlling the rate of temperature change during use.
3. The development trend of refractory materials in non-ferrous metallurgy industry
3.1. High performance
With the continuous progress of non-ferrous metallurgy technology and the expansion of production scale, the performance requirements of refractory materials are getting higher and higher. In the future, refractory materials will develop in the direction of higher high temperature resistance, stronger erosion resistance, better thermal stability and mechanical strength. For example, through the development of new refractory formulations and production processes, improve the comprehensive performance of refractory materials to meet the increasingly harsh production conditions of non-ferrous metallurgy.
3.2. Functionalization
In addition to traditional functions such as high temperature resistance and corrosion resistance, future refractories will also have more functional characteristics. For example, refractory materials with thermal insulation function can reduce heat loss of furnace body and improve energy utilization efficiency; The refractory with self-healing function can automatically repair small cracks and damage during use, and extend its service life; Refractories with adsorption and purification function can absorb harmful gases and impurities produced in the smelting process and reduce environmental pollution.
3.3. Green
With the enhancement of environmental protection awareness, the environmental protection requirements of refractory materials in the non-ferrous metallurgy industry are also getting higher and higher. In the future, the production and use of refractory materials will pay more attention to green environmental protection. On the one hand, in the production process of refractory materials, a cleaner production process will be used to reduce the emission of pollutants; On the other hand, the development of recyclable refractory materials, reduce resource consumption, reduce the generation of waste. For example, the development of the use of waste refractory materials to prepare new refractory materials technology, to achieve the recycling of resources.
3.4.Intelligentize
With the development of information technology, the application of refractory materials in the non-ferrous metallurgy industry will also move in the direction of intelligence. By implanting intelligent components such as sensors in the refractory, the use status of the refractory can be monitored in real time, such as temperature, pressure, wear degree, etc. According to the monitoring data, the production process parameters can be adjusted in time, the life of refractory materials can be predicted, the preventive maintenance of equipment can be achieved, and the production efficiency and safety can be improved.
Refractories play a vital role in the non-ferrous metallurgy industry. Their performance and quality directly affect the efficiency, cost and product quality of non-ferrous metallurgy production. With the continuous development and progress of non-ferrous metallurgy technology, the requirements for refractories are also increasing. In the future, refractory materials will develop in the direction of high performance, functionalization, green environmental protection and intelligence to better meet the development needs of the non-ferrous metallurgy industry. At the same time, refractory production enterprises and scientific research institutions should strengthen cooperation, continue to innovate, and develop more advanced and applicable refractory materials to provide strong support for the sustainable development of the non-ferrous metallurgy industry.