1.Significant Potential for Energy Efficiency and Equipment in China’s Aluminum Industry
China has not only become a major global producer of primary aluminum but also possesses the industrial foundation to transform into a leading aluminum powerhouse. However, China’s aluminum industry faces challenges such as low capacity utilization, high energy consumption, and emissions. Compared with global leaders in the aluminum industry, China’s aluminum industry lags in resource allocation capabilities, industrial concentration, technological equipment levels, product competitiveness, and innovation capabilities. A new type of nano insulation material is emerging in energy-saving and emission reduction activities in the aluminum industry.
2.Energy Savings and Space Efficiency of Nano Microporous Insulation Panels in Aluminum Industry Equipment
Nano microporous insulation panels are high-efficiency thermal insulation materials made by direct compression molding using nano-silica, with appropriate additives, through a special dry pressing process.
Due to their unique nano-microporous structure and the synergistic effect of various additives, these materials significantly inhibit heat conduction, convection, and radiation within different temperature ranges, outperforming all traditional insulation materials such as lightweight insulating bricks, mineral wool, calcium silicate, and ceramic fibers. In most temperature ranges, the thermal conductivity of nano microporous insulation panels is even lower than that of static air (Figure 1).
Given their superior insulation performance, they can achieve lower external wall temperatures with the same insulation layer thickness, thus saving energy. Alternatively, they can provide excellent insulation with thinner layers in confined spaces. Additionally, nano microporous insulation panels are green and environmentally friendly insulation materials characterized by safety, efficiency, and long-lasting efficacy. During production, they do not generate substances, waste, or emissions harmful to the environment and human health, unlike traditional insulation materials that consume significant energy and pose risks to production personnel.
In summary, nano microporous insulation panels are ultra-insulating, ultra-thin, and highly eco-friendly new insulation materials.
Figure 1: Comparison of thermal conductivity of various main insulation materials in different temperature ranges
For applications in the aluminum industry we can offer MIP-950 and MIP-800 products, suitable for use up to 1000°C and 850°C respectively. For details, please refer to our datasheets or consult a sales engineer.
3.Application Examples of Nano Microporous Insulation Panels in the Aluminum Industry
3.1 Application in Aluminum Melting Furnaces
In the aluminum industry, aluminum melting furnaces are a crucial part of the production process. These furnaces need to maintain optimal temperature distribution to ensure uniform liquid metal, which in turn guarantees the quality of the final product for customers. The refractory insulation system is extremely important for ensuring proper temperature control in aluminum melting furnaces.
MIP-950 or MIP-800 flexible panels can be used for this purpose to reduce heat loss, improve product quality, and lower operating costs. MIP-800 is completely covered with aluminum foil to prevent performance degradation caused by moisture absorption from casting materials. MIP-800 materials can be bonded to the lining of the package with high-temperature adhesives. Compared with aluminum melting furnaces using traditional insulation materials (such as glass wool, mineral wool, and ceramic fibers), the use of nano microporous insulation panels can significantly save space or energy.
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3.2 Application in Aluminum Transfer Ladles
The aluminum processing industry expects high production flexibility and low production costs. Many aluminum processors use transfer ladles to efficiently transport molten aluminum between plants. Road transport of transfer ladles allows efficient transportation of aluminum melt. In China, the current trend is for aluminum casting plants to gradually concentrate around electrolytic aluminum plants, directly processing products from molten aluminum without the energy-wasting process of cooling ingots and re-melting.
The temperature of molten aluminum is about 750°C.
MIP-800 Solution
The interface diagram of the lining system (Figure 5) is as follows:
Figure 5: Application of MIP-800 in Aluminum Transfer Ladles
The thickness depends on the specific configuration and size of the ladle. MIP-800 is completely covered with aluminum foil to prevent performance degradation caused by moisture absorption from casting materials. MIP-800 materials can be bonded to the lining of the package with high-temperature adhesives.
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3.3 Application in Aluminum Launders
To transfer molten aluminum from the melter to the casting facilities, aluminum processors use launder systems to distribute the molten aluminum and remove bubbles, thus improving processing quality. To prevent “freezing” of the molten aluminum and ensure consistent flow in the distribution system, an insulation system is required to maintain the melt temperature. The temperature of the aluminum melt is about 750°C. Additionally, using insulation materials minimizes heat loss in the launder, reducing the need for excessive reheating of the aluminum melt.
Application of MIP-800 in Launders (Figure 7)
Figure 7: Application ofMIP-800 in Aluminum Launders
MIP-800 can be used for this purpose. The thickness depends on the specific configuration and size of the launder. MIP-800 is completely covered with aluminum foil to prevent performance degradation caused by moisture absorption from casting materials. MIP-800 materials can be bonded to the lining of the package with high-temperature adhesives.
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3.4 Application in Electrolyzer
The tank voltage of the new cathode structure electrolyzer is generally in the range of 3.70-3.75V, which is about 0.3V lower than that of the conventional electrolyzer. If the tank voltage is reduced by 0.3V, it is equivalent to a reduction of about 13% in the electrical energy input to the new cathode structure electrolyzer for resistance heating. At this time, the heat dissipated from the heat balance system of the new cathode electrolytic structure must also be reduced by about 13% in order to maintain the heat balance required for normal production at normal electrolysis temperature. Therefore, the insulation of the electrolyzer, especially the insulation of the new electrolyzer, is very important for reducing energy consumption and maintaining the thermal balance of the process.
Figure 8 Electrolytic aluminum electrolysis cell, using MIP-950 heat insulation plate
Due to the constraints of the electrolyzer structure design, the space for assembling the thermal insulation material is 10-12mm on the side wall, and the space for the end part is only about 15mm, and the thermal insulation temperature is 950-960°C. Therefore, it is very suitable for the use of nano-micropore thermal insulation material both in terms of the geometric scale and the working condition. After using the nano-microporous heat insulation plate, it is obvious that it has achieved the effects of reducing power consumption, improving current density and applying stable voltage.
However, the structure of the electrolytic tank and the process operating conditions are relatively complex, and it is necessary to determine a reasonable thermal insulation program through comprehensive design and calculation. Generally, the present insulation requirement is the bottom of the tank moderate insulation; electrolyzer side should not be too much insulation, in the electrolyzer cathode steel rod below the bottom of the tank above the belt-shaped lining to strengthen the insulation; but in the four corners of the electrolyzer, need to strengthen the insulation.
