Mineral resource classification
Encyclopedia
Mineral resource classification is the classification of mineral deposits based on their geologic certainty and economic value.
Mineral deposits can be classified as:
In common mining terminology, an "ore deposit" by definition must have an 'ore reserve', and may or may not have additional 'resources'.
Classification, because it is an economic function, is governed by statutes, regulations and industry
best practice
norms. There are several classification schemes worldwide, however the Canadian CIM
classification (see NI 43-101), the Australasian Joint Ore Reserves Committee Code (JORC Code), and the South African Code for the Reporting of Mineral Resources and Mineral Reserves (SAMREC) are the general standards.
because of "proximity"; a concept that something valuable may be found near these occurrences because it has been in the past due to a similar geological environment. Often, such occurrences of mineralisation are the peripheral manifestations of nearby ore deposits.
"Ore deposit" applies specifically to economic mineral occurrences that could be mined at a profit after consideration of all factors affecting a mining operation.
Note that this distinction between amounts of raw material available as either a resource or reserve also applies to other materials considered to be minerals. This can include natural gas (legally defined as a mineral in some states of the United States) and hydrocarbons.
, because the economics of the mineral deposit may not have been fully evaluated.
Indicated resources are simply economic mineral occurrences that have been sampled (from locations such as outcrops, trenches, pits and drillholes
) to a point where an estimate has been made, at a reasonable level of confidence, of their contained metal, grade, tonnage, shape, densities, physical characteristics.
Measured resources are indicated resources that have undergone enough further sampling that a 'competent person' (defined by the norms of the relevant mining code; usually a geologist
) has declared them to be an acceptable estimate, at a high degree of confidence, of the grade, tonnage, shape, densities, physical characteristics and mineral content of the mineral occurrence.
Resources may also make up portions of a mineral deposit classified as a mineral reserve, but:
Mineral deposits can be classified as:
- Mineral occurrences or prospects of geological interest but not necessarily of economic interest
- Mineral resources that are potentially valuable, and for which reasonable prospects exist for eventual economic extraction.
- Mineral reserves or Ore reserves that are valuable and legally and economically and technically feasible to extract
In common mining terminology, an "ore deposit" by definition must have an 'ore reserve', and may or may not have additional 'resources'.
Classification, because it is an economic function, is governed by statutes, regulations and industry
Industry
Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...
best practice
Best practice
A best practice is a method or technique that has consistently shown results superior to those achieved with other means, and that is used as a benchmark...
norms. There are several classification schemes worldwide, however the Canadian CIM
Canadian Institute of Mining, Metallurgy and Petroleum
The Canadian Institute of Mining, Metallurgy and Petroleum is a technical society of professionals in the Canadian minerals, metals, materials and energy industries. It was founded in 1898. In 2006, the organization had 12,000 national members...
classification (see NI 43-101), the Australasian Joint Ore Reserves Committee Code (JORC Code), and the South African Code for the Reporting of Mineral Resources and Mineral Reserves (SAMREC) are the general standards.
Mineral occurrences, prospects
These classifications of mineral occurrences are generally the least important and least economic. They include all known occurrences of minerals of economic interest, including obviously uneconomic outcrops and manifestations. However, these are often mentioned in a company prospectusProspectus
Prospectus may refer to:* Prospectus * Prospectus * Prospectus * Parkland College's newspaper...
because of "proximity"; a concept that something valuable may be found near these occurrences because it has been in the past due to a similar geological environment. Often, such occurrences of mineralisation are the peripheral manifestations of nearby ore deposits.
"Ore deposit" applies specifically to economic mineral occurrences that could be mined at a profit after consideration of all factors affecting a mining operation.
Note that this distinction between amounts of raw material available as either a resource or reserve also applies to other materials considered to be minerals. This can include natural gas (legally defined as a mineral in some states of the United States) and hydrocarbons.
Mineral resources
Mineral resources are those economic mineral concentrations that have undergone enough scrutiny to quantify their contained metal to a certain degree. None of these resources are oreOre
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
, because the economics of the mineral deposit may not have been fully evaluated.
Indicated resources are simply economic mineral occurrences that have been sampled (from locations such as outcrops, trenches, pits and drillholes
Borehole
A borehole is the generalized term for any narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water or other liquid or gases , as part of a geotechnical investigation, environmental site...
) to a point where an estimate has been made, at a reasonable level of confidence, of their contained metal, grade, tonnage, shape, densities, physical characteristics.
Measured resources are indicated resources that have undergone enough further sampling that a 'competent person' (defined by the norms of the relevant mining code; usually a geologist
Geologist
A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...
) has declared them to be an acceptable estimate, at a high degree of confidence, of the grade, tonnage, shape, densities, physical characteristics and mineral content of the mineral occurrence.
Resources may also make up portions of a mineral deposit classified as a mineral reserve, but:
- Have not been sufficiently drilled out to qualify for Reserve status; or
- Have yet to meet all criteria for Reserve status
Mineral reserves
Mineral reserves are resources known to be economically feasible for extraction. Reserves are either Probable Reserves or Proven Reserves. Generally the conversion of resources into reserves requires the application of various modifying factors, including:- mining and geological factors, such as knowledge of the geology of the deposit sufficient that it is predictable and verifiable; extraction and mineMiningMining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
plans based on ore models; quantification of geotechnical risk—basically, managing the geological faults, joints, and ground fractures so the mine does not collapse; and consideration of technical risk—essentially, statistical and variography to ensure the ore is sampled properly: - metallurgical factorsMetallurgyMetallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use...
, including scrutiny of assayAssayAn assay is a procedure in molecular biology for testing or measuring the activity of a drug or biochemical in an organism or organic sample. A quantitative assay may also measure the amount of a substance in a sample. Bioassays and immunoassays are among the many varieties of specialized...
data to ensure accuracy of the information supplied by the laboratoryLaboratoryA laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories...
—required because ore reserves are bankable. Essentially, once a deposit is elevated to reserve status, it is an economic entity and an asset upon which loans and equity can be drawn—generally to pay for its extraction at (hopefully) a profit; - economic factors;
- environmental factors;
- marketing factors;
- legal factors;
- governmental factors;and
- social factors
See also
- Mineral explorationMineral explorationMineral exploration is the process of finding ore to mine. Mineral exploration is a much more intensive, organized and professional form of mineral prospecting and, though it frequently uses the services of prospecting, the process of mineral exploration on the whole is much more involved.-Stages...
- Ore genesisOre genesisThe various theories of ore genesis explain how the various types of mineral deposits form within the Earth's crust. Ore genesis theories are very dependent on the mineral or commodity....
- OreOreAn ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....
- Drilling rigDrilling rigA drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...
- National Instrument 43-101National Instrument 43-101National Instrument 43-101 is a mineral resource classification scheme used for the public disclosure of information relating to mineral properties in Canada...
External links
- JORC Code
- University of Western Australia Mining Law Centre
- U.S. Geological Survey Circular 831, Principles of a Resource/Reserve Classification for Minerals
- Canadian Institute of Mining, Metallurgy and Petroleum - CIM Definition Standards - On Mineral Resources and Mineral Reserves (PDF Format)
- The Canadian Council of Professional Geoscientists CCPG
- NI 43-101 Guidelines
- The South African SAMVAL and SAMREC Codes