Ore is natural rock or sediment that contains desirable minerals, typically metals, that can be extracted from it. Ore is extracted from the earth through mining and refined, often via smelting, to extract the valuable element or elements.
The grade of ore refers to the concentration of the desired material it contains. The value of the metal an ore contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining.
Metal ores are generally oxides, sulfides, silicates, native metals such as copper, or noble metals such as gold. Ores must be processed to extract the elements of interest from the waste rock. Ore bodies are formed by a variety of geological processes generally referred to as ore genesis.
An ore deposit is an accumulation of ore. This is distinct from a mineral resource as defined by the mineral resource classification criteria. An ore deposit is one occurrence of a particular ore type. Most ore deposits are named according to their location (for example, the Witwatersrand, South Africa), or after a discoverer (e.g. the Kambalda nickel shoots are named after drillers), or after some whimsy, a historical figure, a prominent person, something from mythology (phoenix, kraken, serepentleopard, etc.) or the code name of the resource company which found it (e.g. MKD-5 was the in-house name for the Mount Keith nickel sulphide deposit).
Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis. The classifications below are typical.
The basic extraction of ore deposits follows these steps:
Ores (metals) are traded internationally and comprise a sizeable portion of international trade in raw materials both in value and volume. This is because the worldwide distribution of ores is unequal and dislocated from locations of peak demand and from smelting infrastructure.
Most base metals (copper, lead, zinc, nickel) are traded internationally on the London Metal Exchange, with smaller stockpiles and metals exchanges monitored by the COMEX and NYMEX exchanges in the United States and the Shanghai Futures Exchange in China.
Iron ore is traded between customer and producer, though various benchmark prices are set quarterly between the major mining conglomerates and the major consumers, and this sets the stage for smaller participants.
Other, lesser, commodities do not have international clearing houses and benchmark prices, with most prices negotiated between suppliers and customers one-on-one. This generally makes determining the price of ores of this nature opaque and difficult. Such metals include lithium, niobium-tantalum, bismuth, antimony and rare earths. Most of these commodities are also dominated by one or two major suppliers with >60% of the world's reserves. The London Metal Exchange aims to add uranium to its list of metals on warrant.
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