alumíniumérc

Alumíniumérc refers to naturally occurring rocks or mineral deposits from which aluminum can be extracted economically. The primary and most commercially significant source of aluminum is bauxite. Bauxite is not a single mineral but rather a mixture of aluminum hydroxide minerals, predominantly gibbsite, boehmite, and diaspore, along with impurities such as iron oxides, silica, and titanium dioxide. These deposits typically form from the weathering of aluminum-rich rocks in tropical or subtropical climates.

The process of obtaining aluminum from bauxite is energy-intensive and involves two main stages. The first stage is the Bayer process, a chemical refinement that purifies the bauxite into aluminum oxide, commonly known as alumina. This process involves crushing the bauxite, treating it with a hot solution of sodium hydroxide to dissolve the aluminum compounds, and then precipitating pure alumina. The second stage is the Hall-Héroult process, an electrolytic reduction method where alumina is dissolved in molten cryolite and then passed through an electric current. This electric current separates the oxygen from the aluminum, yielding molten aluminum metal. Other less common aluminum-containing minerals, such as nepheline syenite and alunite, can also be considered aluminum ores, but their extraction is generally less economically viable than that of bauxite.