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Introduction to Aluminum Refining
Aluminum is a silver-white metal that is both lightweight and strong. It is abundant in nature but is most typically found combined with other elements to form aluminum compounds. Aluminum is non-toxic, non-abrasive and corrodes very slowly. These characteristics make it an ideal material for use in a wide variety of industries, including aerospace and automobile manufacturing, construction, and packaging. As steel, aluminum is preferred for many products because it can be easily machined, stamped, cast, and extruded and is generally less expensive than other metals.
Aluminum is produced from aluminum ore, or bauxite, which contains hematite, silicide, and alumina. The ore is first extracted and then refined to separate the impurities from the pure aluminum. This process, known as aluminum refining, is done at high temperatures and requires a great deal of energy to turn the bauxite into pure aluminum.
Processing
The aluminum refining process begins by heating bauxite in an extremely hot furnace. The furnace is heated to over 1200 degrees Celsius, which causes the bauxite ore to break down into smaller chunks. The chunks are poured into rotating drums, which spin the mixture and separate out any other impurities. The remaining mixture is then cooled and the remaining aluminum is extracted from the mixture.
The extracted aluminum is then heated again in a furnace to purify it further. This additional purification step removes any remaining impurities and results in pure aluminum. The pure aluminum is then smelted and sent to mold factories for product manufacture.
Energy Considerations
The refining process for aluminum is extremely energy intensive. According to the United States Energy Information Administration, aluminum refining accounts for roughly 2% of the nation’s total energy consumption. This is due to the high temperatures required for the bauxite ore to be refined into aluminum. In addition, the smelting process is also very energy intensive due to the extremely high temperatures required.
Environmental Concerns
The aluminum refining process can result in a variety of environmental contamination due to air emissions. Some of the air pollutants generated during the refining process include carbon dioxide, sulfur dioxide, and nitrogen oxides. These pollutants can cause significant air pollution problems in the surrounding areas and can significantly contribute to global warming. In addition, many of the pollutants are toxic and can be hazardous to both human and environmental health.
Conclusion
Aluminum refining is a process used to extract pure aluminum from bauxite ore. This process requires a lot of energy and can result in various environmental pollutants. While aluminum is a popular material for a variety of industries, its refinement should be done with careful consideration of the energy and environmental impacts associated.
