mineral deposit

Deposit is a term used in applied geology and mining in certain areas of the earth's crust, in which natural concentrations of solid, liquid or gaseous materials are, their degradation is economically worthwhile ( bauwürdige deposit ) or pay off in the future could ( usable deposit ). Natural accumulations of useful ores, minerals and rocks, their degradation is uneconomical called occurrences. In the legal context, one speaks of natural resources.

Basics

Despite the fact that the geology is a science that studies the geological processes that lead to the accumulation of raw materials in the earth's crust, the term deposit is defined purely market economically or technically. Commodity markets are generally regarded as the world markets.

In the English -speaking world, the German term deposit is common as a foreign word, but he called there a particularly rich fossil deposit. The correct English translation for deposit is instead: mineral deposit (which term, however, is sometimes limited to ore deposits ). The economically interesting part of a reservoir is called the resource ( stock or resource). However, More would be: non renewable resource ( non-renewable supplies ).

Overall rating factors

As is common in most world markets results in the price of raw materials from the interplay of supply and demand. The demand for a particular commodity is determined by its uses. If there are cheap method for producing the desired end products, as demand increases. Can the raw material, however, easily be replaced by other materials, or recycled from waste, so it sinks. The raw material resources available for offer, can be represented in the McKelvey diagram: in this case the cost of a deposit is plotted against the degree of geological certainty. The evaluation of such security occurs after certain stock categories; see below.

The minimum content (cut -off grade), in which the degradation of a deposit is worth it depends on not only on the quality of raw materials, but also by many economic, technical and even political factors.

• The development costs through remote location of occurrence, extreme weather conditions or poor infrastructure increase significantly, for example.
• The mining costs depend, among other things, the depth of the earth's crust ( depth ), the quantity of waste mountain and groundwater, the energy requirements of the production and the properties of the raw materials. Sometimes can even prevent the degradation quite an unfavorable metallurgy. This meant that the 1956 discovered polymetallic deposits McArthur River in Australia despite its high metal content still not been exploited because the minerals can not be processed metallurgically due to the extremely small grain size.
• The marketing costs of a reservoir are mainly determined by the length of the transport paths to the customers.
• In densely populated and industrially developed areas are often competing interests of riparian ( land, water rights, conservation, etc.) crucial for the official denial of degradation.
• In some countries, the government levies such high taxes on the extraction of raw materials that an economic loss is no longer possible. Even in countries where political unrest prevail, or which are known for their expropriation policy, rarely settles on an important mining industry. However, other countries are trying to promote the mining industry with tax incentives. In the 1960s, for example, granted the Republic of Ireland to foreign investors complete tax exemption for the first few years. In some cases, this led to intense overexploitation and extremely short periods of operation of the new mines before the investors withdrew again from the country.
• Since it is a highly capital intensive industry in mining, operators rely on extensive investment. In 1997, the scandal led to the Canadian exploration company Bre -X Minerals to a huge loss of confidence by investors in the natural resource industry. As a result, there was a wave of bankruptcies of small exploration and mining companies around the world.

All these factors must be considered in relation to net realizable value. On the other hand, can turn unprofitable deposits unexpectedly in deposits technological innovations. So the Nchaga Consolidated Copper Mines could win 80,000 tonnes of copper in Zambia after the introduction of a metal extraction process from nine million tonnes of overburden.

Classification

Commodity categories

Deposits are divided into groups according to their most economically important mineral constituent:

• Element raw materials for the production of certain elements for metallurgy, chemistry, etc. Ore deposits: these are expected enrichments of metals or metal-containing minerals, such as gold, iron ore ( hematite, etc. ), galena, sphalerite and many others.
• A subset of the ore deposits are the Spatlagerstätten of fluorite and barite, from which one can win fluorine and barium.
• Salt deposits: as halite, potash, saltpetre, borates, nitrates, etc.
• Deposits of elemental sulfur.

• Energy Resources Deposits of hydrocarbons such as oil and gas. These also provide raw materials such as asphalt, earth wax, bitumen, oil shale, etc., are connected.
• Coal deposits and Kaustobiolithe. Here include peat, lignite, bituminous coal and anthracite.
• A special case are here uranium deposits, provide the raw material for the production of nuclear energy. With good reason, they could also be counted among the ore deposits.
• In its broadest sense includes the geothermal energy, as a natural resource, in this group.

• Property resources Industrial minerals such as kaolin ( clay), mica, asbestos, feldspar, quartz and quartzite, graphite, talc, magnesite, alum, vitriol; Diamonds of lower quality than abrasives etc.
• Deposits of usable rocks, called stones and earth, or ground raw materials, such as limestone, dolomite, decoration stones; Sand, gravel, clay, tuff and gypsum for the manufacture of building materials; Bentonite, earth colors, phosphate, diatomaceous earth, etc. This group overlaps with the previous occur.
• Deposits of precious stones, such as diamond, emerald, ruby ​​, garnet, amber, etc.

Because of its importance is expected the groundwater to storage sites ( hot springs, mineral water, drinking water).

Stock categories

The sum of all deposits and occurrences in a given region is the local supplies or resources. The basis for the resource calculation, both for whole countries, and for individual deposits, forming a scheme of stock categories, which describes the approximate knowledge about the respective inventories. The ratios are the limit ( FG) and the confidence level (AS). Thus, for example, a resource can be described as sure as much data must be available, that the margin of error no greater than about 10 % and a confidence level of more than 80% is present. That is, when one has so calculated a supply of 100,000 tonnes of ore in a deposit, for example, sampling, drilling, mapping, then the really existing amount 110000-90000 tons should be, and the likelihood that these quantities exceed or be undercut should be less than 20%. The fewer the available data is, the higher the margin of error, and the smaller the confidence level.

The usual classification refers to the inventories as:

• Safe ( proven ): (FG: about 10 % AS :> 80 %) the size and shape of the resource ( for example, a vein or an oil field ) are known.
• Probably (probable ): (FG: about 20 %, AS: 60 to 80%) The extent of the resource is known only incomplete, but there is a connection to a secure resource.
• Possible indicated ( possible, Indicated ): (FG: about 40 %; AS: 40 to 60 %) The resource is known by outcrops at a distance, explored through reliable geophysical measurements or by drilling.
• Suspected ( inferred ): (FG: about 60 % AS: 20 to 40%) The resource is explored only by a few outcrops, or their presence is suspected on the basis of measured data of geophysics or geochemistry.
• Prognosis ( undiscovered ). This is the undiscovered deposits whose discovery but you can expect by comparison with the geology of other well known areas in the future. The prognostic stocks may still hypothetical (AS: 10 to 20 %) and speculative ( AS <10% ) are divided.

According to the North American model, the stock categories are safe and probably collectively measured ( Measured ). Together with the possible resources they form the recognized ( demostrated ) resources. If we add one of the Inferred resource category, we obtain all discovered (identified ) resources. The discovered resources thus include all stocks whose location, content, quality, and quantity are known by specific geological evidence, or can be estimated. This contrasts with the prognostic inventories.

In addition there are numerous other organizations of resources, both in the various countries, as well as for different types of deposits, as well as the individual deposit Kund learning. Sometimes the reserves to be distinguished from the resources. The meaning of the two terms but in different languages ​​so different that a consistent use of the term reserve is almost impossible. In German, it usually means that part of a resource whose economic degradation is possible at the Valuation Point. Often, then, the term resource is equated with unbauwürdigen inventories. With falling world market prices may therefore result from mineable deposits are unbauwürdige occurrence of resources with reserves, and vice versa.

The National Mining Administration of the USA ( United States Geological Survey) provides the following definition:

• Reserve base ( reserve base): That part of an identified resource that meets the specific physical and chemical minimum criteria for the current mining and production practices, including those for content, quality, thickness and depth. The reserve base includes both currently economic reserves as well as reserves, the economic might can be degraded within a given planning period.
• Reserves ( reserves ): That part of the reserve base which could be economically extracted at the time of provision or produced. The term does not mean that extraction systems are installed and working. Reserves include only extractable quantities.

Exploration and examination of deposits

After preparatory literature searches and the first preliminary exploration ( Reconnaissance ) in the terrain begins first phase of prospecting. If the evidence suggests a deposit, you go to special mapping across, scrapes on the surface, or leads first flat exploration drilling.

After a Höffigkeitsgebiet was located, followed by the definition. The detailed investigations ( geological mapping, sampling and drilling in mining, geochemical and mineralogical- petrographic analyzes ) are systematically continued and expanded. In this phase also increased geophysical methods such as gravimetry, seismic, magnetic, electrical and radar procedures are used. At the end of this phase of exploration to estimate the dimensions of the deposit and a first calculation of inventories should be possible.

At best, followed by the actual development. The exploration work will be complemented with technical experiments and find the feasibility study (English: feasability -study ) a provisional conclusion. After that, the actual mining can begin.

Potential for conflict and mining law

The exploration and exploitation of resources is very time consuming and expensive, resulting in extremely high yields, but also expenses in the care and has significant training and after-effects on the environment and surroundings. They can lead to serious conflicts at regional, national and international level. For global mining companies and their employees is the contract and investment security are of great concern, government institutions are interested in the highest possible taxes and duties from the mining business, customer and recipient countries want security of supply and low prices.

Regarding the local ownership of natural resources are two basic interpretations of the law and conflict resolution mechanisms.

Depending on the location, history and development of occurrences and deposits thus also result in conflicts of different legal traditions, local authorities and through contractual arrangements. The discovery and possible development of extensive mineral deposits can aggravate existing territorial conflicts and problematic border demarcation issues as well as contribute to new legal instruments as in the 200 -mile zone in coastal states. Conversely, successful cross -border conflict rules - such as in the ECSC as a forerunner of the EU, the North Sea oil and the Svalbard Treaty - a solid foundation for international cooperation.