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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 the particular ore type. Most ore deposits are named according to either their location (for example the Witswatersrand, South Africa), or after a discoverer (eg; the kambalda nickel shoots are named after drillers), or after some whimsy, an historical figure, a prominent person, something from mythology (phoenix, kraken, etc) or the code name of the resource company which found it (eg; MKD-5 is the in-house name for the Mount Keith nickel mine).
[edit] Classification of ore deposits
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Main article: Ore genesis
Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis. The classifications below are typical
[edit] Hydrothermal epigenetic deposits
[edit] Granite related hydrothermal
- IOCG or iron-oxide copper-gold, typified by the supergiant Olympic Dam Cu-Au-U deposit
- Porphyry copper +/- gold +/- molybdenum +/- silver deposits
- Intrusive-related copper-gold +/- (tin-tungsten), typified by the Tombstone, Arizona deposits
- Hydromagmatic magnetite iron ore deposits and skarns
- Skarn ore deposits of copper, lead, zinc, tungsten, etcetera
[edit] Nickel-cobalt-platinum deposits
- Magmatic nickel-copper-iron-PGE deposits including
[edit] Volcanic-related deposits
[edit] Metamorphically reworked deposits
[edit] Sedimentary deposits
[edit] Sedimentary hydrothermal deposits
[edit] Astrobleme-related ores
[edit] Extraction
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The basic extraction of ore deposits follows the steps below;
- Prospecting or Exploration to find and then define the extent and value of ore where it is located ("ore body")
- Conduct resource estimation to mathematically estimate the size and grade of the deposit
- Conduct a pre-feasibility study to determine the theoretical economics of the ore deposit. This identifies, early on, whether further investment in estimation and engineering studies is warranted and identifies key risks and areas for further work.
- Conduct a feasibility study to evaluate the financial viability, technical and financial risks and robustness of the project and make a decision as whether to develop or walk away from a proposed mine project. This includes mine planning to evaluate the economically recoverable portion of the deposit, the metallurgy and ore recoverability, marketability and payability of the ore concentrates, engineering, milling and infrastructure costs, finance and equity requirements and a cradle to grave analysis of the possible mine, from the initial excavation all the way through to reclamation.
- Development to create access to an ore body and building of mine plant and equipment
- The operation of the mine in an active sense
- Reclamation to make land where a mine had been suitable for future use
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 yearly 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.
The World Bank reports that China was the top importer of ores and metals in 2005 followed by the USA and Japan.
As compared with 2005-20067 at the end of 2007 - beginning of the year 2008 the Iron ore prices on FOB/CIF terms increased considerably, at least at 50-55%. The prices were increased after CVRD, which is the world's biggest iron ore producer, has agreed to increase its contract prices, continuing its previleged position on this market.[citation needed]
Price FOB Brazil reached 141-144 U$D/MT CIF Europe came up to 185-188 U$D/MT.[citation needed]
[edit] Important ore minerals
[edit] See also
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