Exploration and discovery of Australia's copper,nickel, lead and zinc resources 1976–2005

Examination of copper, nickel, lead and zinc (base metals) exploration expenditure and discovery in Australia over the period 1976–2005 reveals some significant trends. Australia's base metal resource inventory grew substantially as a consequence of successful exploration over the period, both through addition of resources at known deposits and new discoveries, notably a small number of very large deposits that underpin the resource base. In 2005, Australia had the world's largest economic demonstrated resources (EDR) of nickel, lead and zinc, and the second largest EDR of copper. Growth in nickel resources has been especially strong owing to discovery of large laterite resources in the late 1990s. Resource life, in average terms based on current EDR and production, is approximately 30 years for lead and zinc, 40 years for nickel sulphide (120 years for all nickel EDR) and 50 years for copper. Despite this success, major increases in production over the period (copper, nickel and zinc output increasing 3–4 fold, lead output doubling) and a fall in discovery rates during much of the 1990s means that resource life for lead and zinc is lower and nickel sulphide comparable now to that in 1976; only the resource life of copper has grown substantially over the period. Current published ore reserves are sufficient for at least 15 years operations at current production levels, but only a small number of the largest deposits currently being mined are likely to still be in production in 20 years. However, several mines have substantial inferred resources that may allow production beyond current mine reserves and there is a substantial number of undeveloped deposits that may provide the foundation for extended or new mining operations. The discovery record is strongly cyclical with resource growth for all the base metals punctuated by the discovery of giant (world-class) deposits each decade: these underpin current and future production. Recent higher metal prices and renewed interest in base metals, especially nickel, has reversed a 10 year decline in base metal exploration attended by reduced rates of discovery and resulted in record expenditure, new nickel, copper and zinc discoveries, and increased resources at a number of existing deposits, notably the Olympic Dam copper–uranium–gold deposit. With the exception of the Prominent Hill copper–gold and West Musgrave nickel–copper deposits, most of the recent discoveries, especially zinc (-lead) deposits, are of small tonnage (some of high grade). Nevertheless, these new discoveries have helped stimulate further exploration and also highlight the potential for further discoveries in little-explored provinces, especially those under regolith and shallow sedimentary cover.     

Metal scarcity and sustainability,analyzing the necessity to reduce the extraction of scarce metals

There is debate whether or not further growth of metal extraction from the earth's crust will be sustainable in connection with geologic scarcity. Will future generations possibly face a depletion of specific metals? We study whether, for which metals and to what extent the extraction rate would need to be reduced in order to be sustainable. To do so, we propose an operational definition for the sustainable extraction rate of metals. We have divided 42 metals in 4 groups according to their geologic scarcity. Applying the proposed sustainability definition to the 17 scarcest metals, shows that for almost all considered metals the global consumption of primary resources needs to be reduced to stay within sustainable limits as defined in our analysis. The 8 geologically scarcest metals are antimony, bismuth, boron, copper, gold, molybdenum, rhenium and zinc.     

Some observations on copper yields and ore grades

The paper examines trends in the average copper content of mined ores over the years. It has tended to decline over the long term, but by no means evenly. US averages are not typical of global averages, at least in the past four decades. Those have been both higher, and less volatile than in the US. One reason for falling averages is a change in the type of deposit mined, with a rise in the share of relatively low grade porphyry deposits. The different nature of their deposits is reflected in marked differences in grades between the different continents. African and Australian average grades are higher than the global average, and changes in the share of Central Africa in global output have affected the global average grade. Yields are have been consistently lower in North America than elsewhere, and Latin American average grades have trended downwards, reflecting both the ageing of mines and the rising share of production from porphyry deposits. Typically the yield of mines declines over time as mining proceeds. The average copper content of ore deposits is usually below the average yield of the ore accessed in the early years of production. The initial grades of new mines have not declined over the past forty years, and there has been no perceptible tendency for the average grade of porphyry deposits brought into production to decline over time. There is no apparent correlation between average grade and deposit size, but mine operators tend to exploit economies of scale to offset low grades. The relationship between the annual percentage yields (the head grade) and the reserve grades of deposits is not static. In recent years head grades have fallen closer to reserve grades. The relationship may be affected by movements in metal prices. Although the evidence about the influence of prices is not clear-cut, it does suggest that prices and cut-off grades may be inversely related. As many ores contain other valuable metals besides copper, copper yields will sometimes be subordinated to the extraction of these other metals. Copper equivalent grades have not moved in the same way as copper grades alone.     

Australian gold exploration 1976–2003

The Australian gold industry has grown enormously over the past 25 years. Australian mine production of gold in 2003 was 284 t, similar to that of the USA, and behind South Africa, the world's largest gold-producing nation. Gold is Australia's third largest commodity export, worth an estimated A$5.3 billion in 2003–2004.Underpinning the industry is a solid resource base that has grown by successful exploration over the past three decades. Australia ranks third in the world after South Africa and the USA in terms of its economic gold resources. The growth in Australia's gold resources has been underpinned by high levels of exploration and innovations in gold processing technologies, specifically the development of carbon-based gold extraction methods that allowed commercial treatment of low grade ores. It has been supported by advances in gold exploration methods, especially exploration geochemistry.New resources were added at existing deposits and new deposits were found, including several of world class (>100 t contained gold), in each decade over the 25-year-period but resource growth since the 1990s has been dominated by brownfields additions rather than new discoveries. Average costs of discovery have now plateauxed at around A$20–25/oz, after falling sharply during the early to mid-1990s when a number of new discoveries were made, notably in the Yandal belt in Western Australia and the Lachlan Fold Belt in New South Wales. Current gold reserve/production and gold EDR/production ratios are 12 and 19 years, respectively, and indicate that the long-term future of the Australian gold industry depends on continued high levels of exploration and the discovery of new deposits to replace mines that are currently being depleted.     

The legal environmental risk analysis (LERA) sample of mining and the environment in Turkish legislation

As advancing technology and increasing demands for natural resources continue to mount pressure on the environment, environmental conservation and sustainable management have become ever more important. Individual countries have been increasingly taking action to reduce environmental destruction caused by human activities in an attempt to find a balance in between the necessary exploitation of resources and environmental conservation. In Turkey, the struggle between environmental conservation and mining activities is set within the legal context, with the requisite legal regulations (which describe various procedures) in the midst of being updated or renewed. The legal environmental risk analysis (LERA), beginning by discussing the main legal regulations of environmental conservation in relation to mining activities, defines basic environmental components which form the basis of environmental conservation in relation to mining, and analyzes the impact of mining on each component. The analysis (LERA) finishes with an evaluation of the components as they currently stand and makes some suggestions for the improvement of insufficient regulations.     

Quantifying the impacts of primary metal resource use in life cycle assessment based on recent mining data

The quantification of impacts in the abiotic resource category in life cycle assessment is still controversial. However, this is a pertinent issue because of the growing dependence of our industrial society on these resources, particularly on metal resources. One of the important shortcomings of the existing assessment methods used today is that characterization factors are not based on actual mining practice data. In this paper, a new characterization factor derived from recent (1998–2010) and representative (more than 50% coverage of global primary metal production) mining data was established for nine metals: copper, zinc, lead, nickel, molybdenum, gold, silver, platinum and palladium. The quantification of this new characterization factor is based on the annual increase in mass of ore required per unit mass of metal in the ore. This quantification relies on the concept that the mining of resources is threatened not by lack of ores but by changing ore characteristics, e.g., the percentage of metal in the ore, mineral type and location. The characterization factors determined in this study ranged from below 0.1 kg ore kg⁻¹ y⁻¹ for zinc to more than 15,000 kg ore kg⁻¹ y⁻¹ for gold. These results indicate that in 1999, 370,000 kg of ore was required per kg of gold in the ore, whereas in 2008, 530,000 kg of ore was required per kg of gold in the ore (an increase of approximately 4% per annum). When comparing these results with traditional life cycle impact assessment methods, it was found that in all but one method gold, palladium and platinum have the highest characterization factors among the nine metals. In all methods based on ore grade changes lead and zinc are the metals with the lowest characterization factors. However, an important difference in the proposed method is that it assigns higher relative values to precious metals. This suggests that the supply of precious metals may be under more pressure than indicated by other methods, which in the framework of the proposed method implies greater efforts in mining and mineral processing. There is still scope for improvement of the proposed method if more data become readily available.     

GOLD-MINING EFFECTS ON HEAVY METALS IN STREAMS,CIRCLE QUADRANGLE,ALASKA1

Placer gold mining, which extracts gold from buried or exposed alluvia, is often conducted on or near streams. Such mining has the potential to adversely affect water quality. Other heavy metals associated with the gold (such as arsenic, cadmium, lead, zinc, and copper) may be freed to enter streams. Mercury may also enter streams if miners are using it to recover fine particles of gold. These heavy metals are toxic and thus may be harmful to the aquatic life of the streams receiving effluent or runoff from placer mines. In 1982 we sampled two streams intensively - one heavily mined and one unmined - for total recoverable arsenic, mercury, lead, zinc, and copper. Only mercury was not significantly higher in concentration in the mined streams. In 1983 we sampled two stream pairs three times, and 10 other sites at least once, for total and dissolved arsenic, cadmium, mercury, lead, zinc, and copper. Mercury and cadmium were not significantly elevated in mined streams, but the concentrations of total arsenic, lead, zinc, and copper, and dissolved arsenic and zinc were significantly higher in streams below active placer mining sites than in these that were not being mined or those that had never been mined. Additionally, total arsenic, lead, zinc, and copper and dissolved arsenic and copper became elevated after mining began in 1983 on a previously unmined stream.     

EVALUATION OF PHILODINA ACUTICORNIS (ROTIFERA) AS A BIOASSAY ORGANISM FOR HEAVY METALS1

ABSTRACT: A technique for using the rotifer Philodina acuticornis as a bioassay organism is described. The rotifer was exposed to a range of concentrations for each of 14 toxicants. The effects of the heavy metals cadmium, chromium, cobalt, copper, lead, mercury, nickel, silver and zinc were studied. Based upon 96 hours exposure in soft water the sensitivity of the rotifer to the metals from the most toxic to least toxic was: cadmium, mercury and copper, zinc, silver, nickel (chloride), chromium, nickel (sulfate), lead and colbalt. In hard water with 96 hours exposure the most to least toxic respectively were: cadmium, copper, mercury, chromium and lead. The 48 hour EC₅₀ value suggests that zinc will follow mercury in relative toxicity when Philodina is tested in hard water. In a comparison of the toxicity of the chloride and sulfate salts of cadmium, nickel and zinc in soft water cadmium sulfate and zinc sulfate were more toxic after 96 hours; nickelous chloride was more toxic than nickelous sulfate. Increased water hardness decreased the toxicity of the heavy metals studied. The results suggest that this rotifer may be more sensitive than the bluegill sunfish to the salts of cadmium, copper, nickel, zinc and chromium and less sensitive to lead. Data for cobalt, silver and mercury were not available. Philodina was extremely tolerant of ammonium chloride and phenol. The feasibility and economics of using an inexpensive, readily cultured and available organism such as Philodina acuticornis as a bioassay organism were discussed.     

Effects of Metal Mining and Milling on Boundary Waters of Yellowstone National Park, USA

/ Aquatic resources in Soda Butte Creek within Yellowstone National Park, USA, continue to be threatened by heavy metals from historical mining and milling activities that occurred upstream of the park's boundary. This includes the residue of gold, silver, and copper ore mining and processing in the early 1900s near Cooke City, Montana, just downstream of the creek's headwaters. Toxicity tests, using surrogate test species, and analyses of metals in water, sediments, and macroinvertebrate tissue were conducted from 1993 to 1995. Chronic toxicity to test species was greater in the spring than the fall and metal concentrations were elevated in the spring with copper exceeding water quality criteria in 1995. Tests with amphipods using pore water and whole sediment from the creek and copper concentrations in the tissue of macroinvertebrates and fish also suggest that copper is the metal of concern in the watershed. In order to understand current conditions in Soda Butte Creek, heavy metals, especially copper, must be considered important factors in the aquatic and riparian ecosystems within and along the creek extending into Yellowstone National Park.KEY WORDS: Mining; Metals; Toxicity; Biomonitoring; Copper; Yellowstone National Park     

The macroeconomic determinants of volatility in precious metals markets

This paper models the monthly price volatilities of four precious metals (gold, silver, platinum and palladium prices) and investigates the macroeconomic determinants (business cycle, monetary environment and financial market sentiment) of these volatilities. Gold volatility is shown to be explained by monetary variables, but this is not true for silver. Overall, there is limited evidence that the same macroeconomic factors jointly influence the volatility processes of the four precious metal price series, although there is evidence of volatility feedback between the precious metals. These results are consistent with the view that precious metals are too distinct to be considered a single asset class, or represented by a single index. This finding is of importance for portfolio managers and investors.     

Aggregates in England—Economic contribution and environmental cost of indigenous supply

Aggregates represent one of the largest material flows in the UK economy; however, the importance of these minerals in underpinning economic activity is frequently not recognised. Features such as the spatial imbalance between resources and demand centres, exacerbated by changes in demographics and public perception, are placing increased pressure on the planning system to maintain supply. This paper sets out the direct and indirect economic contributions made by the indigenous aggregates industry to the English economy through Gross Value Added and employment sustained. It describes the key role of aggregates in construction activities, assesses the links between infrastructure development and economic growth. In 2005, aggregates extraction directly contributed £810 million of Gross Value Added to the English economy. Primary aggregates are, however, extracted at a cost to the environment and this cost, based on amenity value reduction, is estimated by updating previously published contingent valuation data. Estimates for the costs associated with carbon dioxide emissions are derived from values published by the European Union and, separately, by the UK Government. These two elements combined result in an environmental cost of indigenous extraction of £445 million in 2005. Additionally, an examination of the potential for a significant increase in the level of aggregate imports into England is made and the consequences assessed. This includes an evaluation of shipping costs and port capacity, and concludes that there are significant barriers to any substantial increase in the level of aggregate imports into England. As a consequence, indigenous supply is likely to predominate into the foreseeable future.     

A regional environmental information system for analyzing and predicting the impacts of nonferrous mining on an agricultural environment

Mineral exploitation is a necessary component of China's economic development goals. Such exploitation brings with it the potential for serious environmental degradation. Careful environmental impact assessments of mining projects are required in order to implement China's environmental protection law and identify measures for protecting surrounding agricultural environments. This article describes an environmental information system that has been developed for the purpose of assisting with the environmental impact assessment of nonferrous mining operations with a particular focus on agricultural impacts. An application of the environmental information system to the Yongping copper mine, located in Jiangxi Province, is discussed. The role of the environmental information system is analyzing and predicting soil contamination from heavy metals and other types of impacts from this mining operation is described. The environmental information system is designed for implementation on an IBM PC/XT microcomputer. The experience gained from the Yongping copper mine application and the growing popularity of microcomputers in China indicate a significant potential for the effective use of a microcomputer-based environmental information system in other parts of China.     

A review of the PGM industry,deposit models and exploration practices: Implications for Australia's PGM potential

Australia is prospective for platinum group metal (PGM) mineralisation (in particular primary magmatic reef, primary magmatic by-product, late magmatic and hydrothermal, and alluvial placer type) but its known PGM endowment is negligible compared to that of South Africa, Russia, the USA and Canada. Most Australian PGM projects are operated by mid-cap or junior companies and form part of larger, more diverse project portfolios held by these explorers. Most projects were ‘hot’ while market conditions were favourable. However, as other metals became ‘fashionable’ and market conditions for PGM changed, so did the focus of these companies. Pure PGM companies are rare in Australia. The search for and development of PGM-only deposits in Australia are high risk business activities. No new primary PGM deposits have been discovered since the mid to late 1980s and none of the significant deposits that were discovered or evaluated in the 1980s have been mined. This review suggests that at least several A$10 million but more likely several A$100 million were sunk into PGM exploration and development projects but none advanced to the mining stage. The viability of Australian PGM projects is very sensitive to (1) metal prices, (2) the US$/A$ exchange rate, and (3) large capital expenditure requirements relative to the small size of Australian PGM-only deposits. Most PGM-only projects were initiated at times of high PGM prices. However, advanced exploration, feasibility studies and project development always lagged behind the price booms. South Africa, Russia and Canada contain approximately 98% of the known global PGM reserves. This situation has a very negative effect on the Australian PGM industry as the well-endowed nations continue to receive the lion's share of exploration spend and new projects.     

The concept and measurement of mineral reserves and resources

The distinction between an exploitable and a non-exploitable mineral deposit is dynamic, varying as a function of changing economic and technological factors. A conceptual framework is proposed: ‘reserves’ are restricted to known currently exploitable deposits; ‘known resources’ are reserves plus currently non-exploitable deposits; ‘total resources’ are known resources plus all deposits not yet discovered. The short-term inadequacy of some mineral reserves requites a policy of accelerated mineral exploration and rapid development of new exploration techniques. Future problems could be avoided if the nature of resources is recognized and new mineral extraction and processing techniques for lower grade and unconventional mineral deposits are developed.     

Non-renewable mineral resources

The natural resources of the earth's crust upon which industry depends for metals, non-metallics and most of its energy, come from deposits in the crust carrying six to over 1000 times the normal content of the required elements. Such deposits have formed over such long periods of geological time that they must be regarded as non-renewable within the span of existence of the human species. These facts are briefly illustrated by reference to the cases of iron, copper, aluminium, titanium, magnesium, lead, zinc, flourine and the fossil fuels. The possibilities of exploiting much lower concentrations when considered in relation to the exponential rise in demand, lead to the conclusion that the scope is limited unless very cheap energy becomes available.     

Recent Evolution of Petroleum Exploration and Exploitation Agreements in Developing Countries: New Approaches to Introduce More Flexibility and Progressivity in the Contractual Terms

Over the last decade rather important changes have occurred in the legal and economic aspects of international petroleum agreements for exploration and exploitation. In the late nineteen seventies, as a consequence of the strong increase in oil prices, there was a general tightening of contractual terms and conditions. With the present oil market imbalance, characterized by sharp price falls, there is a tendency to ease the applicable contractual terms. In such a rapidly changing environment, the economic terms contained in a petroleum agreement should be properly designed to introduce a certain element of flexibility and progressivity in regard to the government take, without unduly complicating the fiscal package or discouraging potential investors. This is the present challenge for international petroleum negotiators.     

The Environmental sustainability of mining in Australia: key mega-trends and looming constraints

At first ‘sustainable mining’ could be perceived as a paradox—minerals are widely held to be finite resources with rising consumption causing pressure on known resources. The true sustainability of mineral resources, however, is a much more complex picture and involves exploration, technology, economics, social and environmental issues, and advancing scientific knowledge—predicting future sustainability is therefore not a simple task. This paper presents the results from a landmark study on historical trends in Australian mining, including ore milled, ore grades, open cut versus underground mining, overburden/waste rock and economic resources. When complete data sets are compiled for specific metals, particular issues stand out with respect to sustainability—technological breakthroughs (e.g. flotation, carbon-in-pulp), new discoveries (e.g. uranium or U), price changes (e.g. Au, boom/bust cycles), social issues (e.g. strikes), etc. All of these issues are of prime importance in moving towards a semi-quantitative sustainability model of mineral resources and the mining industry. For the future, critical issues will continue to be declining ore grades (also ore quality and impurities), increased waste rock and associated liabilities, known economic resources, potential breakthrough technologies, and broader environmental constraints (e.g. carbon costs, water). For this latter area, many companies now report annually on sustainability performance—facilitating analysis of environmental sustainability with respect to production performance. By linking these two commonly disparate aspects—mining production and environmental/sustainability data—it becomes possible to better understand environmental sustainability and predict future constraints such as water requirements, greenhouse emissions, energy and reagent inputs, and the like. This paper will therefore present a range of fundamental data and issues which help towards quantifying the resource and environmental sustainability of mining—with critical implications for the mining industry and society as a whole.     

Electronic waste recycling: A review of U.S. infrastructure and technology options

The useful life of consumer electronic devices is relatively short, and decreasing as a result of rapid changes in equipment features and capabilities. This creates a large waste stream of obsolete electronic equipment, electronic waste (e-waste).Even though there are conventional disposal methods for e-waste, these methods have disadvantages from both the economic and environmental viewpoints. As a result, new e-waste management options need to be considered, for example, recycling. But electronic recycling has a short history, so there is not yet a solid infrastructure in place.In this paper, the first half describes trends in the amount of e-waste, existing recycling programs, and collection methods. The second half describes various methods available to recover materials from e-waste. In particular, various recycling technologies for the glass, plastics, and metals found in e-waste are discussed. For glass, glass-to-glass recycling and glass-to-lead recycling technologies are presented. For plastics, chemical (feedstock) recycling, mechanical recycling, and thermal recycling methods are analyzed. Recovery processes for copper, lead, and precious metals such as silver, gold, platinum, and palladium are reviewed. These processes are described and compared on the basis of available technologies, resources, and material input–output systems.     

The role of price expectations and legal uncertainties in ocean mineral,exploration activities

In this paper, a standard exploration activities model is modified and applied to time series, data from deep seabed mining of a group of minerals where the number of patents is used as a proxy, for the level of mineral exploration activities. In addition to the rational expectations model, price, expectations formation for mineral prices is decomposed into trend and cyclical components using the, HP-filter method. Estimated parameters from the supply and cost functions are used to determine the, shadow price of the minerals. The non-linear instrumental variables estimator is employed to estimate, the exploration activities function. While the rational expectations model shows the importance of, current prices on exploration efforts, the HP-filter model suggests that firms concentrate on the trend, in prices rather than the short-run cyclical fluctuations. Also, while the U.S. refusal to ratify the LOSC, has increased the legal uncertainties surrounding the management of ocean resources and reduced the, incentive to engage in exploration activities, the passage of the ISA's main legislative accomplishment, regarding regulation of the explorations for polymetallic nodules appear to have made a positive effect.     

Copper, Cobalt, Nickel and Manganese Availability from Land-based Endowments A Perspective

Estimates of land-based demonstrated resources of cobalt, copper, manganese, and nickel would indicate adequate supply for many years to come based on current levels of annual consumption. However, when these resource estimates are disaggregated, much of this resource is found to occur in a limited number of producing mines. Almost all of the cobalt in these resources coexists with either nickel or copper, and as such, will be available only to the degree extraction of these two metals from existing mines is economical. Finally, current projections of excess capacity in existing mines for all four metals, coupled with additional inferred resources at these mines and yet to be exploited resources in known economical deposits, would lead one to conclude that, from this perspective, the mining of sea bed nodules is not likely to occur until well into the next century.