ore

An ore is a naturally occurring solid material from which a valuable substance can be profitably extracted. Most commonly this term refers to metallic ores containing metal compounds. Ore minerals such as hematite and magnetite for iron; chalcopyrite for copper; and bauxite for aluminum are typical examples. If the concentration of the valuable constituent is too low to cover mining and processing costs, the body is not considered an ore.

Ore deposits are found in varied geological settings and come as primary metal ores, or secondary ores formed by enrichment processes. Ore grade describes the concentration of the valuable constituent; cut-off grade is the minimum grade for mining to be economically viable. Ore bodies can be large or small, tabular or irregular, and often occur with gangue minerals.

Formation and types: Metallic ore deposits form by magmatic differentiation, hydrothermal activity, metasomatic processes, or sedimentary deposition; carbonate-hosted, sulfide, oxide, and laterite types are common classifications. Non-metallic or industrial ore deposits include phosphate, limestone, gypsum, and salt sources, used for construction and chemical industries.

Processing and economics: After extraction, ore undergoes beneficiation to increase the concentration of the desired material (crushing, grinding, flotation, magnetic separation). Metal extraction often requires smelting and refining. The economic viability depends on ore grade, metal price, energy costs, and environmental considerations; mining operations aim to minimize environmental impact and manage tailings and waste.