Aluminum metal itself is not produced as a white powder from the re-refinement of bauxite. Instead, aluminum is typically extracted from bauxite ore through a two-step process:
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Bayer Process: Bauxite is primarily composed of aluminum oxide (Al₂O₃), and the Bayer process involves crushing the bauxite and treating it with sodium hydroxide at high temperatures. This process separates aluminum oxide from impurities, resulting in a substance known as alumina (aluminum oxide), which is white and powdery.
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Hall-Héroult Process: The alumina obtained from the Bayer process is then subjected to the Hall-Héroult process, where it is electrolyzed in molten cryolite (sodium aluminum fluoride) to produce aluminum metal. This process yields aluminum in its metallic form, which is not a powder but a lightweight, silvery-white metal.
In summary, while alumina (derived from bauxite) is a white powder, the final aluminum metal product is not a powder but a solid metallic form.
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