How are oxides used in metal extraction?

Oxides are used in metal extraction through a process called reduction, where a metal is obtained from its oxide.

In more detail, the extraction of metals involves a series of chemical processes. These processes are used to convert the raw metal ore into a usable form. The most common method of metal extraction is through the use of oxides. This is because many metals naturally occur as oxides, due to their reaction with oxygen in the air or water.

The process of using oxides in metal extraction is known as reduction. Reduction is the removal of oxygen from a substance. In the context of metal extraction, it refers to the process where a metal is obtained from its oxide. This is usually achieved by heating the oxide with a reducing agent, such as carbon or hydrogen. The reducing agent combines with the oxygen in the metal oxide, leaving behind the pure metal.

For example, in the extraction of iron from its ore, haematite (iron(III) oxide), carbon is used as the reducing agent. When haematite is heated with carbon, the carbon removes the oxygen from the iron(III) oxide, leaving behind pure iron. This process is carried out in a blast furnace.

Similarly, in the extraction of aluminium from its ore, bauxite (aluminium oxide), an electrolytic reduction process is used. Here, electricity is passed through molten aluminium oxide, causing it to split into aluminium and oxygen. The aluminium is then collected at the bottom of the electrolytic cell.

In summary, oxides play a crucial role in the extraction of metals. They are the starting point in the reduction process, which ultimately leads to the production of pure metals.