How can depletion time be extended

There are already examples in the market of consumer behaviour that seemed to be entrenched and impossible to change, but that is seeing a true revolution nowadays. A good example is that of cars, where we are seeing a major shift from private ownership to lease. In this, as in other cases, e.

Actually, the bank would more likely buy the materials from refiners who would take care of recycling the discarded products, but that does not change the basic idea described here. Over a certain period of time, enough metals are aggregated to build up a sufficient stock, ensure supply and price stability. In this way, a metal bank would slowly free the industries out of the hands of speculators, who contribute nothing to the value chain.

An example is that of rare-earth minerals, commonly used to manufacture computer components, wind turbines and electric vehicles. The stocks of easily extractable ores for these finite resources are rapidly diminishing and that is gradually forcing manufacturers to develop recycling methods.

A few countries including Japan have already turned to taking apart items in waste steam such as old cell phones and old computers to recycle minerals within them. In the future, this may also happen to the hybrid vehicles where the electric motor and the battery contains few kilograms of rare-earth material such as neodymium 1 kg per vehicle and lanthanum 10—15 kg per vehicle Stephenson This phenomenon may be at work in other sectors of the mineral commodity market.

Speculation, rumours and probable disinformation distort traditional price—cost relations to an unacceptable extent. Recently, a number of Japanese companies announced their plans to develop facilities for the recovery of rare-earth material business Rare-Earth Separation Facilities—Innovation Metals Corp This automated process is about eight times faster than the manual labour-intensive practice.

Shin-Etsu Chemical also announced plans to extract rare-earth metals from discarded air conditioners and recycle them in magnets. Tokyo-based chemical maker Showa Denko KK opened a plant in Vietnam to begin recycling metals such as dysprosium and didymium, which are used to make magnetic alloys and plans on having an output of t at the Vietnamese recycling factory. These facilities are still under development, but the tendency is clear.

Without reliable and continuous supply, especially with rare-earth metals and semi conductors, our high technology could face a total collapse.

While in the future the problem will be solved only by means of a completely closed-cycle economy, in the near term the fluctuations and the shortages in the availability of metal commodities could be mitigated by stockpiling them.

The proposed concept of a metal bank could manage these stockpiled resources and strengthen the development efforts of developing nations, which often serve only as suppliers of raw materials and do not upgrade their own industries in the value chain. Managing the metallic assets would also mean that the bank will have a dampening influence on irrational price fluctuations in the metal markets. Whether such a bank will be developed in the future remains to be seen, but the unavoidable, gradual depletion of high-grade ores makes such a concept worth investigating already at the present time.

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Jogmec n. Accessed 23 May Jakobi R Strategische Rohstoffe—Warten bis es dunkel wird? Nachr Chem — Jevons WS The coal question, 2nd edn. Macmillan and Co, New York. The increasing uptake of green technology, such as electric vehicles and renewable energy, will also further increase metal demand.

However, the production lifespan of an average mine is far shorter than the timescales of mineral deposit formation, suggesting that metal mining is unsustainable on human timescales. In addition, some research suggests that known primary metal supplies will be exhausted within about 50 years. Here we present an analysis of global metal reserves that suggests that primary metal supplies will not run out on this timescale. Instead, we find that global reserves for most metals have not significantly decreased relative to production over time.

This is the result of the replenishment of exhausted reserves by the further delineation of known orebodies as mineral exploration progresses. We suggest that environmental, social, and governance factors are likely to be the main source of risk in metal and mineral supply over the coming decades, more so than direct reserve depletion. This could potentially lead to increases in resource conflict and decreases in the conversion of resources to reserves and production.

Metal mining is essential to modern life and provides the raw materials that underpin modern society for e. The mining sector also provides the commodities needed for the development and rollout of lower CO 2 technologies 2. This makes metal mining inherently unsustainable on human timescales since economically extractable mineral deposits become exhausted before replenishment by natural processes.

The rate of exhaustion, however, remains controversial, with some researchers 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 suggesting that the available supply of a range of metals will run out within 50 years or less. All of this means that accurately predicting future global metal supply requires an understanding of mineral resources and reserves, the basic metrics that mining companies provide that outline the metal endowment total metal content of a given resource or reserve , grade the concentration of metal in a given resource or reserve , and tonnage the amount of mineralised material present in a given resource or reserve of individual mining projects.

Statistics on global metal reserves and production are compiled annually by the United States Geological Survey USGS and the contained data are frequently interpreted to represent all the metal available for economic extraction. This interpretation often then guides economic policy and key decisions based on the assumption of a finite, fixed stock of extractable metals.

However, reserves in fact represent a subset of the potential metal endowment of a mineralised area, with resources forming a larger proportion of the less well-quantified mineralised material present within individual projects Fig.

This means that although mining should deplete reserves over time, this is not the case as the removal of reserves is balanced by both the conversion of resources to reserves and the delineation of new resources in the same area through ongoing mineral exploration processes 13 , This in turn can increase the total known endowment of metal within a given mining project over time even coincident with increases in production 13 , Combined with the discovery of new deposits, the resulting ongoing increase and growth in reserves and resources suggests a more optimistic outlook for the future than is predicted by some researchers who take reserves to represent all there can be in terms of possible metal extraction 5 , 6 , 7 , 8 , 9 , 10 , 11 , This pessimistic outlook is similar to that outlined for oil by M.

King Hubbert in the s 15 , who determined that the exhaustion of known oil reserves would reach a peak and then inevitably and inexorably decline as oil production depleted known reserves.

Equally important is the fact that a peak in production may not indicate an exhaustion of supply but may indicate a decrease in demand for oil as has happened in recent months , or in fact for any commodity that peak models have been suggested for. Darker colours indicate increased geological confidence and probability of economic extraction. Circles indicate drillholes used for exploration and subsequent resource and reserve estimation, giving an indication of the confidence of the data used to delineate different parts of the mineralised system.

Note that resources and reserves only make up a small part of the true extent of mineralisation; the latter may well be known as a result of field mapping, geological and geochemical sampling, geophysical imaging, and some drilling, but cannot be reported because the geological confidence in the continuity of the mineralisation and associated economic prospects may not be sufficient to meet the criteria needed for resource or reserve reporting.

Exploitation of known reserves would be followed by conversion of resources to reserves and the delineation of more resources from the surrounding poorly delineated mineralisation, extending the initially stated life of mine and causing resources and reserves to remain static or potentially grow coincident with production. Similar arguments for and against peak supply have been made for metals 10 , 22 , 23 , 24 , 25 , 26 , especially as growth in demand for metals has increased rapidly throughout the twentieth century and is expected to continue.

The fact that production of most commodities has increased over time 27 , 28 , 29 to meet demand means that exponential increase in reserves and resources must have continued 13 , 14 albeit with volatility related to short-lived rapid changes in demand or supply, sharply contrasting with predictions of declining metal supply. As a result, while USGS reserves and similar data for e.

This dynamic nature is reflected by the fact that reserves can grow not only through exploration, but also can shrink or revert to resources or worse as a result of economic and environment, social and governance ESG factors, all of which can limit the conversion of resources to reserves or force write-downs of reserves back to resources. This in turn means that improving the understanding of the dynamic nature of reserves and resources is necessary to better assess future global metal supply.

This study examines mineral reserve and production data from to , and uses these data to assess the renewability of reserves coincident with production. In other words, this paper focuses on whether known mineral reserves are being delineated at the same rate as production i. The paper also discusses whether environmental, social, and governance factors are more important limits on metal production as a result of resource and reserve sterilisation i.

Reserves and resources are reported by the global mining industry to indicate the amount of contained metal or other commodities within a given mineral deposit. These terms form the basis for formal codes, guidelines, and legal instruments that are used to determine the value for companies and other entities that own mineral deposits. The approaches outlined in these codes contain strict definitions for resources and reserves, summarised as follows adapted from ref.

Resources are known metal concentrations of economic interest with grade, quality and quantity suggesting reasonable prospects for eventual economic extraction.

Both are subdivided based on the amount of data and increasing levels of confidence in the reported estimates. The approach is effectively probabilistic, although probabilities are not stated explicitly in mineral and metal resource and reserve estimates.

Delineation of resources and reserves in a mineralised system is based on drilling at set spatial intervals, with smaller intervals yielding greater geological confidence in a given area. Resources and reserves also almost invariably form part of a larger area of mineralisation that has not been fully delineated 26 Fig. Furthermore, significant areas of known mineralisation not associated with deposits or mines that publicly report reserves and resources are known to exist.

These deposits contain variable amounts of metal but do not have formally reported reserves or resources as they are typically owned by governments or private companies that are not required to report these data. All of these factors indicate that a viewpoint considering published reserves to represent a fixed stock of metals i.

What can be stated with confidence is that we are currently producing more metals than ever before e. A simple and optimistic outlook like this is, however, compromised to some extent by multiple non-geological factors i.

The potential constraints on metal supply related to reserve depletion can be examined by considering the variation in metal reserves over time compared to metal production. The ratio of reserves to production should decrease if reserves are becoming depleted over time. As mentioned above, the USGS provides the only annual source of global reserves estimates for most minerals over historical time periods 27 including the former U.

In Fig. This group of commodities, including key bulk and ferrous minerals and base, precious, and minor metals, have long-term trends Fig. Descriptive statistics evaluating the variation of the ratios over time for these minerals and metals as well as other selected commodities Table 1 also document either minimal changes or a small decrease in these values.

Bulk and ferrous commodities Fig. Gold and silver ratio trends are similarly flat, whereas the PGE ratio increased sharply prior to and decreased gently after this date Fig. Indeed, the reserve to production data between and or closest available year for some metals , for a wide range of commodities confirm that reserve to production ratio values change little compared to the rapid increase in both production and reserves over this time period Supplementary Table 1.

Another important variable in metal markets is price. Metal prices are compared to production, reserves, and reserve to production ratios over time for the major commodities copper and zinc and the minor commodities cobalt and molybdenum in Fig.

These data indicate steady to dramatic cobalt increases in production for all four metals matched by modest continuous increases in reserves, yielding reserve to production ratios that show almost no overall change over the period in spite of considerable short term variations. None of these metrics correlate closely with price normalised to despite moderate to large price variations.

Some short term changes in the reserve to production ratio appear to correlate with price changes, particularly for copper and zinc, possibly reflecting decreasing exploration and reserve delineation during low price periods.

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Get This Book. Visit NAP. Looking for other ways to read this? No thanks. Page 7 Share Cite. Page 8 Share Cite. Page 9 Share Cite. Estimated World Reserves of Selected Minerals and Metals, ss million metric tons of contained metal, end of decade 1 s s s s s Aluminum 2 1, 3, 11, 22, 23, Copper 91 Lead 86 Zinc Source: Crowson , who compiled data from Minerals Handbook Notes: 1.

Gross weight of bauxite. Bureau of Mines Minerals Yearbooks Page 10 Share Cite. Challenges Concerning Depletion. Page 11 Share Cite. Page 12 Share Cite. This page in the original is blank. Login or Register to save! Stay Connected! Rainwater falling on the mine tailings becomes acidified and can create toxic conditions in the runoff. This can mobilize potentially dangerous heavy metals and kill organisms in the streams draining the tailings.

Questions on this material that could be asked on an exam. Physical Geology. Mineral Resources. Mineral Resources Almost all Earth materials are used by humans for something. In this discussion, we hope to answer the following questions: What constitutes a mineral resource and an ore? What determines whether or not a mineral sources is economical to exploit?

By what processes do ores form? How are mineral resources found and exploited? What happens when a mineral resource become scarce as a result of human consumption? What are the adverse effects of exploiting mineral resource. Examples: The copper concentration in copper ore deposits has shown changes throughout history. Gold prices vary on a daily basis. When gold prices are high, old abandoned mines re-open, when the price drops, gold mines close.

The cost of labor is currently so high in the U. Note that we will not likely ever run out of a useful substance, since we can always find deposits of any substance that have lower concentrations than are currently economical. Origin of Mineral Resources Mineral deposits can be classified on the basis of the mechanism responsible for concentrating the valuable substance. Examples: Pegmatites - During fractional crystallization water and elements that do not enter the minerals separated from the magma by crystallization will end up as the last residue of the original magma.

This residue is rich in silica and water along with elements like the Rare Earth Elements many of which are important for making phosphors in color television picture tubes , Lithium, Tantalum, Niobium, Boron, Beryllium, Gold, and Uranium. This residue is often injected into fractures surrounding the igneous intrusion and crystallizes as a rock called a pegmatite that characteristically consists of large crystals.

Crystal Settling. As minerals crystallize from a magma body, heavy minerals may sink to the bottom of the magma chamber. Such heavy minerals as chromite, olivine, and ilmenite contain high concentrations of Chromium, Titanium, Platinum, Nickel, and Iron.

These elements thus attain higher concentrations in the layers that form on the bottom of the magma chamber. Hydrothermal Ore Deposits - Concentration by hot aqueous water-rich fluids flowing through fractures and pore spaces in rocks. Examples: Massive sulfide deposits at oceanic spreading centers.

Hot fluids circulating above the magma chambers at oceanic ridges can scavenge elements like Sulfur, Copper, and Zinc from the rocks through which they pass. As these hot fluids migrate back toward the seafloor, they come in contact with cold groundwater or sea water and suddenly precipitate these metals as sulfide minerals like sphalerite zinc sulfide and chalcopyrite Copper, Iron sulfide. Vein deposits surrounding igneous intrusions.

Hot water circulating around igneous intrusions scavenges metals and silica from both the intrusions and the surrounding rock. When these fluids are injected into open fractures, they cool rapidly and precipitate mainly quartz, but also a variety of sulfide minerals, and sometimes gold, and silver within the veins of quartz.