Ore classification is the systematic process of categorizing mined or in-situ material according to defined criteria such as grade, mineralogy, processing route, or economic value, enabling mine operators to make informed decisions about how different material should be handled, processed, or stockpiled. At the most fundamental level, ore classification distinguishes ore, material with sufficient valuable mineral content to be economically processed, from waste rock, which lacks sufficient value to justify processing costs, based on a defined cut-off grade. Beyond this basic distinction, ore is often further classified into sub-categories based on processing characteristics; for example, iron ore may be classified into lump, fines, or pellet feed categories based on particle size and chemical specification, while bauxite may be classified by alumina-to-silica ratio into different quality grades suited to different refinery requirements. Gold ore is commonly classified as oxide, transitional, or fresh sulphide material, or as free-milling versus refractory, reflecting differences in required processing routes and expected recovery rates. Diamond-bearing ore may be classified by kimberlite facies or weathering zone, which correlates with expected diamond grade and quality. Ore classification relies on data from exploration drilling, grade control sampling, and ore body models, and is fundamental to mine planning, scheduling, blending strategies, and accurate financial reporting of mineral resources and reserves.
