Ore is a kind of rock containing minerals and other important elements, such as metals, which can be extracted for commercial trading. The ores are removed from the Earth’s surface through mining and then refined.
Metals ores include silicates, sulfides, oxides, noble metals, or other native metals, such as native copper. The ores are processed to separate the corresponding metal from the waste rock and other ore minerals. Ore bodies, or ore deposits, are usually formed through a number of geological processes. The process of the formation of ore deposits is known as ore genesis.
Ore deposits have been found in both rocks beneath the ocean, and rocks that form the continents. However, the deposits that actually have been mined include continental rocks. Ore deposits are classified into different types based on several factors studied through ore genesis, which include:
- Sedimentary deposits
- Volcanic deposits
- Magmatic deposits
- Granite related hydrothermal deposits
- Hydrothermal epigenetic deposits
- Carbonatite-alkaline igneous related deposits
- Sedimentary hydrothermal deposits
Extraction of Ores
After the exploration of ore bodies, geologists conduct resource estimation to determine the size and grade of the ore deposits. Following this, a feasibility study is carried out to evaluate financial and technical risks involved in the mineral recovery process.
The method of ore extraction depends on the reactivity of the metal to be recovered. Electrolysis is one of the most powerful and expensive extraction methods. It is used to extract aluminum and sodium from rock salt. Extraction of iron from iron ores can be carried out by heating the ore with carbon monoxide in the blast furnace. Copper is extracted by roasting the copper ore in air.
Sources and Further Reading