WATER USE AND WATER CONSERVATION BY THE COPPER MINING INDUSTRY1

ABSTRACT: This paper examines the use of water by copper mines for treating low grade ores. The froth flotation process for treating sulphide ore and the heap leaching process for treating oxide ore are described, and ways of reducing the amount of water used in these processes are discussed. Estimates of the costs reducing water consumption are given. Finally, the circumstances in which it would be desirable for a copper mine to reduce its level of water consumption are considered.     

Economic rent : Incidence in selected metals and minerals

The magnitude of the ‘economic rent’ and its distribution among producing countries, mineral exploitation companies and consumers has become a dominant issue in national and international policy formulation, but the difficulties in measuring the rent add to the problems of determining its equitable distribution. This paper examines the nature of the rent and estimates its incidence in bauxite, copper, iron ore, phosphate rock, tin and petroleum. Rents were found to be low for bauxite and iron ore. Bauxite, phosphates and petroleum producers have increased their share of the rent, though this trend now seems to be reversing for bauxite and phosphates. Only in tin, and to a lesser extent petroleum, have the exporting countries captured significant shares in total rent. Otherwise, the rent is largely concentrated at the processing stage, which suggests that processing plant would have to shift to the producing countries if they are to claim a larger share.     

The effects of higher energy prices and declining ore quality: Copper—aluminium substitution and recycling in the USA

An econometric model of the US copper and aluminium industries is simulated to evaluate the impact that higher energy prices and declining ore quality will have on copper–aluminium substitution and recycling in the USA in the next decade. The unique features of the model described here include the calculation of elasticities of substitution between copper and aluminium from the production functions of the using sectors, the use of statistical (not engineering) cost functions for both the primary and the secondary industries, and the explicit consideration of ore- quality deterioration as primary production progresses.     

World phosphate supply

The Bureau of Mines investigated the resources, costs, capacities, market relationships, and short- and long-run supply of phosphate rock and phosphoric acid. The 206 mines and deposits evaluated in 30 market economy countries (MECs) contain an estimated 35.1 billion tonnes of recoverable phosphate rock (demonstrated resource level). US resources are sufficient to satisfy both the domestic market and an export market for phosphate products well beyond 2000. Resource depletion at current producers, however, means new property development (with higher costs) will be required if US production levels are to be maintained. Existing worldwide capacity can satisfy expected demand through the early 1990s. Expansion at existing mines or low demand growth could mean no new property development is required before the late 1990s. Worldwide, almost $8 billion could be required for the development of new phosphate rock properties between now and 2000, given 3% annual growth in demand. Though profit may not be the principal motivation for development of government-owned operations, most properties that could develop in the 1990s would require price increases of 20–50% to break even. To earn a 15% rate of return on investment, prices must rise to nearly double the $23–271 tonne US price level of 1988. Current US phosphate rock and phosphoric acid producers appear to be competitive (on a variable cost basis) with many other suppliers in major markets. New US properties will have higher variable costs than current producers; however, they are competitive with most projected new foreign development. The US phosphoric acid industry will most likely face increased competition as more of the foreign phosphate rock producers develop the capacity to process rock into phosphoric acid and other fertilizer products.     

Leaching characteristics of copper flotation waste before and after vitrification

Copper flotation waste from copper production using a pyrometallurgical process contains toxic metals such as Cu, Zn, Co and Pb. Because of the presence of trace amounts of these highly toxic metals, copper flotation waste contributes to environmental pollution. In this study, the leaching characteristics of copper flotation waste from the Black Sea Copper Works in Samsun, Turkey have been investigated before and after vitrification. Samples obtained from the factory were subjected to toxicity tests such as the extraction procedure toxicity test (EP Tox), the toxicity characteristic leaching procedure (TCLP) and the "method A" extraction procedure of the American Society of Testing and Materials. The leaching tests showed that the content of some elements in the waste before vitrification exceed the regulatory limits and cannot be disposed of in the present form. Therefore, a stabilization or inertization treatment is necessary prior to disposal. Vitrification was found to stabilize heavy metals in the copper flotation waste successfully and leaching of these metals was largely reduced. Therefore, vitrification can be an acceptable method for disposal of copper flotation waste.     

Investment policies in the base metal mining industries and their impact on price cycles

Investment in increased capacity of the major metal producers is examined in the light of changing metal prices and the business cycle. Historically, as metal prices rise, the producers have invested in new mine capacity. This process results in increased production which often comes on stream just as the business cycle is beginning to wane. During the present business cycle the investment pattern of the major mining companies appears to have broken with this historical pattern in that investment strategies are less directed toward increasing capacity.     

Copper cycle in China and its entropy analysis

Copper cycle analysis approaches have been broadly investigated for sustainable development of copper industry in China. There are four stages in the life cycle of copper products, including mining & processing, fabrication & manufacture, use and reclamation. The 2005 copper cycle in China, analyzed by copper-flow diagram of the copper products life cycle with time factor, indicates that the copper ore index and copper scrap index were 0.78 t/t and 0.063 t/t, respectively; and copper resource efficiency was 1.3 t/t. To ascertain the degree of both aggregating and dispersing of the copper in the life cycle of copper products, the substance flow analysis with the index of entropy and the calculating method of entropy was presented. The variation of entropy along copper cycle was calculated based on the analysis of the life cycle of copper products in China in 2005. The entropies at the five nodes along copper cycle were 0.26, 0.046, 0.24, 0.60 and 0.25, respectively. The variation ratio of relative entropy in the whole system was −2.9%, which showed the copper-contained materials were congregated after the whole products life cycle. The same method was also applied to the variation of entropy along copper products life cycle in China in 2002. The discussion was focused on the results of these two years. The values of entropy at the five nodes along copper cycle in 2005 were all lower than those in 2002. The entropy at the five nodes along copper products life cycle in 2005 was extracted through two scenes under different technical indices, including scene one: 0.26, 0.032, 0.23, 0.60 and 0.17, respectively; and scene two: 0.26, 0.023, 0.23, 0.60 and 0.096, respectively. The values of entropy are effectively reduced, especially from the fourth to the fifth node, which is the obsolete copper products reclaiming stage.     

The copper and aluminum industries: A review of structural changes

In this article the evolution of the aluminium and copper industries is examined, with a view to deriving policy options open to Third World copper producers, which face a declining rate in the growth of consumption. Market structure, company behaviour and performance are analysed for both industries. The impact of energy and general economic crisis in copper and aluminium industries is assessed and market concentration trends are discussed. We conclude that Third World copper producers must change their basic orientation and become seriously involved in market development.     

絮凝浮选剂PS-01的研究

为了提高油田采油（气）污水处理能力,胜利油田开发研制出新型絮凝浮选剂ＰＳ－０１,以聚合铝为主,配以常用的助凝剂二氧化硅气溶胶,工业用硫酸镁等,按比例混合在一起配置而成。在试验中将它们与油田内广泛使用的絮凝浮选剂ＳＧ－０１,ＪＸ－０１,ＮＡ－１等进行比较。结果表明：ＰＳ－０１絮凝浮选剂的原料来源广泛,合成工艺简单,易于操作;对采油（气）污水处理效果好,加药量少,处理成本低;应用的ｐＨ范围较宽,反应迅速,可缩短混合反应时间;适用性强,低温时效果不受影响;对投药设备的腐蚀性小,性质稳定,无沉淀产生;同时各种原料的不同配比对絮凝浮选效果影响很大,要控制好比例。     

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.     

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.     

冷轧废乳化液破乳技术研究进展

冷轧废乳化液是轧钢过程中排放的高浓度难降解废水,治理的关键是破乳技术。主要介绍了混凝工艺、膜分离工艺、电凝聚气浮工艺、Fenton氧化工艺、微电解工艺、微波破乳工艺原理及研究现状,并对每种工艺在乳化液废水破乳中的优缺点进行了阐述。其中混凝破乳和膜分离破乳是目前应用最广泛的技术,其他技术由于运行管理以及成本的原因应用相对较少,今后破乳技术的发展应该是高效、低成本的新技术开发或者对原有破乳技术进行革新。     

Implementation of US Surface Mine and Reclamation Act

The US Congress is currently studying various ways through which legislation similar to that of the Surface Mining Control and Reclamation Act of 1977— which is concerned mainly with coal, can be applied to all minerals other than coal. This study analyses three US mineral industries—copper, iron ore, and phosphate rock - and identifies a number of areas which Congress and other decision makers ought to consider in arriving at such legislation. The author concludes that reclamation costs may affect the economic and financial performance of each of these industries in a different manner; furthermore, their economic behaviour is significantly different from that of coal. The author's main recommendation is that if surface mining regulations are to be legislated, they should be industry- and commodity-specific rather than umbrella legislation for all non-coal minerals.     

Ethical Analysis of the Use of GM Fish: Emerging Issues for Aquaculture Development

Improvements in production methods over the last two decades have resulted in aquaculture becoming a significant contributor to food production in many countries. Increased efficiency and production levels are off-setting unsustainable capture fishing practices and contributing to food security, particularly in a number of developing countries. The challenge for the rapidly growing aquaculture industry is to develop and apply technologies that ensure sustainable production methods that will reduce environmental damage, increase productivity across the sector, and respect the diverse social and cultural dimensions of fish farming that are observed globally. The aquaculture industry currently faces a number of technology trajectories, which include the option to commercially produce genetically modified (GM) fish. The use of genetic modification in aquaculture has the potential to contribute to increased food security and is claimed to be the next logical step for the industry. However, the potential use of these technologies raises a number of important ethical questions. Using an ethical framework, the Ethical Matrix, this paper explores a number of the ethical issues potentially raised by the use of GM technologies in aquaculture. Several key issues have been identified. These include aspects of distributive justice for producers; use of a precautionary approach in the management of environmental risk and food safety; and impacts on the welfare and intrinsic value of the fish. There is a need to conduct a comparative analysis of the full economic cycle of the use of GM fish in aquaculture production for developing countries. There is also a need to initiate an informed dialogue between stakeholders and strenuous efforts should be made to ensure the participation of producers and their representatives from developing nations. An additional concern is that any national licensing of the first generation of GM fish, i.e., in the USA, may initiate and frame an assessment cycle, mediated by the WTO, which could dominate the conditions under which the technology will be applied and regulated globally. Therefore, an integrated analysis of the technology development trajectories, in terms of international policy, IPR, and operational implications, as well as an analysis of a broader range of ethical concerns, is needed.     

Prospects for an iron ore cartel

Recent breakdowns of commodity cartels have been associated with sharp price declines, thereby reversing the increases which accompanied their formation. This suggests that cartelization can significantly affect market prices. This paper examines the factors influencing the economics of a cartel with a view to assessing the chances of success of cartelization in the context of the iron ore industry. The structure of the iron ore market is examined with particular emphasis on the dominant producers and the likely alternative suppliers.     

CHANGING CONCEPTS, APPROACHES AND TECHNIQUES IN MINERAL EXPLORATION

The concepts, approaches and techniques in mineral exploration are changing to meet the demands of society for the discovery of new ore deposits. Recent developments in mineral processing and metal production have made it possible to consider deposits not acceptable before, such as low-grade uranium and copper occurrences, lateritic nickel, iron-rich chromites, lithium in brines, and disseminated beryllium deposits. New concepts on the formation of mineral deposits, as for example the continental drift theory, and new exploration techniques, such as remote sensing, airborne mapping and sampling, electronic data storage and analysis, assure a higher success rate of exploration projects.     

Pig iron production structure in Japan

Japan is the world's largest steel producing country, and around half of its total input requirements for coking coal and iron ore are sourced from Australia. Moreover, around half of Australia's total coking coal and iron ore exports go to Japan each year. Therefore, changes in the demand for these two inputs are likely to have a significant impact on Australia. The purpose of this paper is to investigate the production structure of the blast furnaces in Japan and factors affecting the demand for iron making raw materials. The empirical study is based on the generalized Leontief cost function. Because of its functional flexibility, the model allows testing various hypotheses regarding pig iron production from blast furnaces. Based on the data from 1974 to 1991, the modelling results show that the Japanese ironmaking technology, when considered as an aggregate production process using fuel and iron ore as major inputs, could be characterized by fixed factor proportions, constant returns to scale and technical changes that can be explained by systematic changes in input mix. Moreover, while there is little variation in the iron ore usage rate, variations in fuel usage rate can be explained largely by changes in the make-up of iron ore charge and blast furnace production capacity over the sample period.     

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.     

THE INDUSTRIAL ECONOMICS OF COPPER PROCESSING

Developing countries have increased their activity in smelting and refining of copper in order to retain a greater proportion of the value added and to achieve more control over production and marketing. This article examines the technology and economics of copper smelting and refining and considers the advantages and disadvantages to developing countries of increased investment in copper ore processing.
Les pays en développement ont accru leur activité dans le domaine de la fonte et du raffinage du cuivre dans le but de conserver une part plus grande de la valeur ajoutée et d'établir un contrôle plus efficace sur la production et la commercialisation de cette ressource. Cet article étudie les aspects techniques et économiques de la fonte et du raffinage du cuivre. Il compare les avantages et désavantages, pour les pays en développement, de la croissance des investissements dans le traitement du minerai de cuivre.
Los países en desarrollo han incrementado las actividades de fundición y refinado de cobre con el objeto de retener una porción mayor del valor agregado y de ejercer más control sobre la producción y el mercado. Este artículo examina la tecnología y economía de la fundición y refinado del cobre y considera las ventajas y desventajas de mayores inversiones en el procesado del mineral de cobre por los países en desarrollo.     

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.