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Managing project exposure and risk has numerous viewpoints, including those of engineers, owners, bankers and insurers. Fewer stakeholders are involved in early stages, though with wider risk management techniques and tools available. The costs and sometimes benefits of the occurrence of risk and uncertainty have different contingent outcomes for different stakeholders. For some, the impact of risk outcomes can be mitigated or managed. Some sectors and stakeholders can manage resources project risks more completely, by choice or by externally imposed forces, opportunities and constraints. The core to resources project risk management lies in the identification and analysis of project risks, the examination of project management risk options and alternatives, and the determination of which risks are able to be controlled, managed or laid off to third parties. Without prior risk identification and knowledge, the wildcard of previously unidentified or unconsidered project risk impact has the potential for fatal impact to one or more stakeholders. A range of case studies is reviewed, from exploration projects to development and operating projects, with relevant learning experiences, from the risk management lessons available from the oil and gas sector as well as the mining sector. For many cases, the emphasis focuses on the risk analysis modus operandi and on risk management and risk mitigation techniques that can be and in some cases have recently been implemented for resources project and related debt, capital markets and equity project fundings.

Jan 1, 2003

By Coates J. R, Firth I. C

The Imperial Smelting Furnace at Cockle Creek, NSW, was constructed in 1961 and is the oldest facility using the Imperial Smelting process in operation. In recent years there have been significant improvements in many areas of the operation, including production, safety, hygiene and environmental performance. Steps taken to achieve these improvements are described. Plans to secure a profitable future while meeting environmental requirements are outlined.

Jan 1, 1993

By C P. Kramers

The need to provide a sufficient quality and quantity of backfill continues to increase in South Africa, particularly as related to the increasing depth of mining. More and more applications require well designed fill systems either as classified or cemented backfill, and in some applications even tailings/aggregate based backfills. The paper discusses developments in backfill technology in South Africa with special emphasis on reliable system designs and operations, particularly as related to the preparation and hydraulic transportation aspects. Approaches for the alleviation of previous problems associated with premature pipe failures in vertical shaft columns for the distribution of tailings based backfills are discussed. Resulting from CSIRÆs developmental work, reliable full-flow systems, which can operate at low system pressures, have become a common practice, provided that backfill flowrates and internal pipe sizes are well matched. This aspect is reviewed. With regard to the tailings/aggregate based backfills the paper reviews some of the results of comprehensive in situ monitoring and the development of such systems. It is shown that a thorough understanding of the effects of aggregate top size, fines content and slurry relative density is required in order to ensure the restartability of temporarily shut-down pipelines. Some innovative technologies for the comminution of development waste underground to yield aggregate products potentially suitable or hydraulic transportation and backfilling, are briefly discussed.

Jan 1, 1998

Traditional methods for monitoring, and hence controlling, pyrometallurgical processes rely heavily upon the skill and experience of operators. A skilled operator will usually achieve consistent, though often conservative, results, whilst an un-skilled operator will require considerable time and training to achieve the same results. Semtech Metallurgy AB have demonstrated that continuous and precise control of pyrometallurgical processes can be achieved through on-line analysis of pyrometallurgical flame off-gas using optical spectroscopy. The feasibility of the technology has been demonstrated on a large number of full-scale tests at production plants and by several commercial installations. Evidence suggests that installation of this technology, called Semtech Optical Production Control (OPC), has resulted in considerable economic benefits to the plant efficiency and asset life. These economic benefits are believed to be a direct result of improved objective on-line control. Technically the following benefits have been demonstrated: improved metal grade control, reduced metal losses, reduced processing time, and improved personnel safety. SemtechÆs OPC is a non-intrusive technology which relies on the fact that the composition of the vapour phase above a high temperature melt is closely related to the instantaneous status of the melt. This enables on-line real-time analysis of the furnace melt to accurately determine melt status and in particular reaction endpoints. Originally developed for on-line monitoring of copper converting in a Pierce-Smith vessel the field of applications for the technology is steadily growing. This paper introduces the Semtech OPC technology; discusses various applications and outlines the demonstrated benefits.

Jan 1, 2002

Over the last decade mineral exploration in New South Wales has increased markedly. This is due to various factors including the influx of overseas companies an. capital, increase and stabilization of metal prices and improvements in exploration techniques. The initiation of full-scale petroleum exploration and recent discoveries of large mineral deposits in the west, north-west and north of Australia has increased overseas capital, and brought scientists and technicians into the country. Naturally there has been an overflow into New South Wales, which is less attractive as an area for new and large-scale discoveries. In some fields, rise in metal prices and price stabilization has largely contributed to the intensif- ication of exploration. Increased tin production in New South Wales since 1963 is a direct result of price rise and stabilization, and rise in the price of silver has revived an interest in silver prospecting in recent Years,

Jan 1, 1969

By Blom MS

Two well-developed styles of mineralization occur in the Nevados del Famatina mining district, Famatina ranges, La Rioja province, Argentina. Porphyry molybdenum- copper-gold mineralization and high level acid sulphate alteration/mineralization (Nevados del Famatina) are related to intrusion of the Pliocene Mogote rhyodacite porphyry complex. High sulphidation epithermal mineralization (La Mejicana) is developed peripheral to the Nevados del Famatina deposit. Both are hosted mainly by the Ordovician Negro Peinado metapelites.At Nevados del Famatina, five mineralized fracture events have been identified and correlated with four distinct alteration assemblages. Stage I (barren quartz) and stage II (molybdenite¦sphalerite¦pyrite) mineralization are associated with a K-silicate alteration assemblage of K-feldspar+biotite+quartz+magneti te¦ilmenite¦anhydrite. Stage III (bornite+pyrite+sphalerite+molybdenite ¦chalcopyrite¦idaite) and stage IV (chalcopyrite+pyrite +sphalerite+gold¦tennantite-tetrahedrite) mineralization are related to a quartz-sericite assemblage of quartz +phengite+illite+pyrite+rutile. Stage V mineralization is divided into two substages. Stage Va (chalcopyrite +pyrite+sphalerite¦ tennantite-tetrahedrite ¦ tellurides ¦ gold ¦enargite¦famatinite¦stibnite¦molybdenite) is related to a sericite-clay assemblage of quartz+illite+kaolinite ¦montmorillonite¦alunite. Alunite-kaolinite alteration (alunite+pyrophyllite+kaolinite+ aluminum - phosphate -sulphate minerals ¦illite¦fluorite¦corundum¦anhydrite) occurs in the upper part of Nevados del Famatina associated with the later stage Vb (quartz+famatinite +chalcopyrite+covellite + chalcocite ¦ marcasite ¦ enargite ¦ luzonite¦sphalerite¦melnikovite) mineralization.

Jan 1, 1990

By Shining Z

The strength and deformation of more than two hundred coal samples have been tested in the condition of triaxial compression. The regression equation showing the relationship between coal strength and pressure in the pores, as well as confining pressure, was obtained. The appropriate calculation for stress-strain curve was carried out. Further, an analysis shows the variation of coal strength and its modulus of elasticity in methane medium.

Jan 1, 1992

During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within North America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The traditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

Jan 1, 2005

The desire for minimising impacts of mining activities on the environment, and in particular, water resources; is usually tempered by the costs and practicalities of implementing æbest practiceÆ measures. This paper briefly discusses the theoretical and practical options for water management for typical mines and quarries in a range of environments to assess if adverse impacts can be completely eliminated or at least be perceived as doing so. The regulatory requirements for water resources management are usually an essential part of mine planning and operations that can be a primary focus for all stakeholders. As such they can distract attention from implementing best practice in water management for the benefit of the environment and the community for altruistic reasons that have a long-term benefit for the mining industry as a whole. Cost-effective options for supply, demand and quality management of water that comply with basic regulatory requirements are readily available. Making a mine æinvisibleÆ in a practical sense, in terms of impacts on water resources would require eliminating potentially contaminated discharges, minimising demand, maximising reuse and recycling and putting back a healthy proportion of the clean water that is taken out of the natural environment for use in mine operations. This may sound simple enough and there are many well-known standard approaches that are usually applied. But which are the most effective, and who benefits? New approaches to water management are becoming more affordable and can benefit the bottom line as well as the environment, but can they make a mine ædisappearÆ? The perception of whether a mine is æinvisibleÆ in terms of its impacts on water resources is as important as the actions taken to try to achieve such an objective. The viewpoints and thresholds of perceptions of the different stakeholders are therefore relevant to how ævisibleÆ mining activities become.

Jan 1, 2006

Almost from the beginning of civilisation the inhabitants hadlearned the art of recovering and working copper to produceitems which were of use to society.From the early beginnings of the use of copper which can betraced back 6000 years and more, there has been an evolutionaryprocess accentuated in more recent times in which the art ofproducing alloys particularly with tin and latterly zinc and otherelements, has given society a wide range of useful alloys for usein industrial, domestic and architectural applications.

Jan 1, 1995

By S C. Dominy

A high nugget effect and the presence of coarse gold characterises many vein-gold deposits. The effective sampling of these deposits is often difficult because of the relatively low concentrations involved and erratic nature of the gold. Geological complexity often compounds this effect. Underground development, in-fill drilling and bulk sampling/trial mining are often required to delineate Ore Reserves. Winzing is an historical technique that was used to gather geological and sampling data during underground exploration. It permits access to the mineralised structure below the current datum to help determine viability. Winzing has always been considered an arduous and dangerous task. Modern technology has led to the development of the Mobile Supersucker, essentially a giant vacuum cleaner. This system permits safe and efficient winzing activities, and allows the collection of bulk samples for grade estimation. Bulk samples from horizontal development have long been collected to help define mineable grade. However, when defining blocks below current development, there has been over-reliance on ineffective æsmall sampleÆ drill data. The Mobile Supersucker permits safe and cost-effective development of winzes and off-winze sublevels.

Jan 1, 2003

The various functions of public relations are playing an increasingly important part in the activities of the many companies now engaged in oil exploration in Australia.Several of the larger exploration companies, notably West Australian Petroleum Pty.Limited, Ampol Exploration Limited, Caltex Oil (Australia) PtSr: Limited and Australian Oil and Gas Ltd. (and its American Associate Union-Kern), employ staff or consultant public relations specialists. In, most of the other companies now exploring in Australia, public relations are handled within the company, directed from the highest executive level.The object of public relations in.the oil industry is. to create in the public mind an impression favourable to the industry as a whole and'the company -or group of companies with which the public relations officer is associated.

Jan 1, 1962

By Hatcher MI

Exploration undertaken at Copley diapir has located several occurrences of oxidized supergene and primary sulphide copper mineralization at the margin of the diapir or in adjacent country rocks. The mineraliza- tion is related to carbonate-rich epigenetic solutions which moved along major structural features closely associated with the intru sive diapir.

Jan 1, 1975

The far reaching consequences of designing pillars for coal mines, while retaining concern for safety and economics, are cause for the search for refinement of the existing engineering methods to continue. Coal pillars, while having various functions within the overall mine plan, are the basic structural elements that assure the stability of a mine. Reliable coal pillar design methods take into account criteria which the pillars should meet in specific applications. These applications include typical mining situations such as the partial extraction room and pillar method with and without subsidence considerations, high extraction rate room and pillar, longwall mining chain pillars, and barrier pillars. However coal pillars are onlyu one element of a three element roof-pillar-floor system, weakest element of which system usually determines the stability of the excavations; however, the mining engineer can ony change dimensions of a pillar, properties of the surrounding strata remain beyond his control. The state of the art approach in pillar design places emphasis on recent developments in research. A widely encountered problem in certain coal fields is where pillars are underlain by weak floor strata. The resultant pillar design constantly maintains the perspective of the reliability of the design.

Jan 1, 1991

By Biswas AK

The solubility of nickel in matte smelt- ing slags, both as oxide and in the metallic form, is predicted using the results of a recent experimental work carried out with lime- free iron silicate slags as well as slags containing lime. Predicted solubilities are much lower than the nickel content of smelting slags, indicating that entrapped and possibly dissolved matte could be the major cause of nickel losses in such slags.

Jan 1, 1975

By Y Peng, D J. Bradshaw, X Chen

At NewcrestÆs Telfer gold mine, a strategy of regrinding pyrite rougher flotation concentrates has been proposed to increase gold recovery and reduce cyanide consumption in the CIL circuit. The regrinding will be followed by an additional copper/gold flotation stage, where copper minerals need to be separated from pyrite. However, although the minerals are well liberated, the separation of chalcopyrite from pyrite in the cleaner stage is not always straightforward. The surfaces of the fine particles, produced during regrinding, are more easily oxidised and contaminated than coarse particles, directly influencing the particle floatability. The depression of pyrite is difficult in the cleaner stage as well due to copper activation, a process which is also highly dependent on the grinding environment. In this study, different grinding media, including mild steel and stainless steel, was used in the regrinding to produce different regrinding chemistry, such as, pH, Eh, and iron hydroxide contamination. The effects of regrinding conditions on chalcopyrite flotation and its separation from pyrite were studied. It was found that the stainless steel grinding media, which produced an oxidising environment, was more beneficial for the separation of chalcopyrite from pyrite after regrinding. The mild steel grinding media had a detrimental effect on both chalcopyrite and pyrite flotation. This study addresses the importance of choosing suitable regrinding conditions in the pyrite and copper flotation circuit.CITATION:Chen, X, Peng, Y and Bradshaw, D J, 2012. Effect of regrinding conditions on the flotation of chalcopyrite and its separation from pyrite in the cleaner stage, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 279-286 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The Green Parrot and Reward stratabound silver-lead (copper-zinc) deposits are located in the eastern part of the Arunta Block. At Green Parrot, mineralisation is contained within a north-south striking lode horizon comprised of elongate lenses of massive garnet or calcsilicate-carbonate "lode rocks" with intercalated sericite-biotite schist and laminated biotite-feldspar schist. The "lode rocks" are increasingly calcareous to the west. The mineralisation is broadly zoned with an increase in lead content and decreases in copper and silver contents from east to west. The principal sulphide minerals are galena, sphalerite and bornite. The Reward deposit lies adjacent to a lens of massive garnet "lode rock" which is contained within garnetiferous sericite-quartz schist. Primary mineralisation consists of galena, chalcopyrite, sphalerite and pyrite. Both deposits are associated with a substantial thickening of the lode horizon which is narrow and discontinuous along strike from the Green Parrot and Reward deposits.

Jan 1, 1984

The chief use of manganese ore is in the production of ferromanganese alloys for steelmaking. Manganese ores generally occur in tropical areas, which influences the type of treatment required. Present methods of treatment are relatively unsophist- icated but demands by customers for tighter specifications will necessitate the installation of gravity concentrator at many mines At present only limited tonnages of minus j in. product can be sold hence future development will centre around methods of producing an agglomerate satisfactory to the smelter.

Jan 1, 1969

A metallurgical balance drawn around a mineral processing plant or smelter must involve all process streams crossing the plant boundary. Modern sampling theory, as formulated by Gy, and sound statistical method can be used to determine the uncertainties in the observed assays for the set of balance analytes and in the mass flow rates of the process streams for the balance period. These uncertainties can then be used together with the material balance equations to arrive at adjusted component mass flows that satisfy the material balances exactly. To determine whether or not the data is consistent with the level of uncertainty in the data and with the material balance equations, a goodness of fit test is applied. This goodness of fit criterion is the principal tool to quantify the quality of the material balances. The mathematical structure of the statistical material balance problem poses a number of challenges. For example, while the variances of the adjusted component mass flows do not vanish, the variances of the sums of the adjusted component mass flows about each balance node do vanish, simply because the balancing computation demands that the balances close exactly. Even though it can be shown that the variances of the adjusted component mass flows are always lower than the estimates for the corresponding unadjusted component flows, it is still not possible to construct a confidence interval on the component mass flow into (and out of) a balance node using the adjusted component flows. On the face of it, such a confidence interval is exactly what is most desired from the balance calculations. The problem arises because the balance problem is a data adjustment rather than a parameter estimation problem. It is possible, however, to calculate the recovery of a component to a product stream and determine a confidence interval for the recovery value. It is also possible to calculate an uncertainty in the mass flow of any balance species in any process stream, before and after balancing.

Jan 1, 2005

Rare-earth permanent magnetic roll separators, pioneered by our group a few years ago, have distinctly different operation characteristics compared to prior art electromagnetic separators of various types. Many new applications for dry high-intensity (or better: high-force) magnetic separation have been developed in a short time period. It has also been found that the new generation of separators generally are more efficient with regards to removal of weakly magnetic contaminants in glass and ceramic raw materials with minimum loss of valuable product compared to induced magnetic roll (IMR) separators.The latest development is in the area of production of clean magnetic concentrates at high recoveries. It is likely that the PERMROLLR magnetic separator will replace cross-belt and lift-type magnetic separators as a result of this most recent advance.The paper will review the features of the PERMROLLR magnetic separator in comparison with other types of magnetic separators on the market and give examples on applications.

Jan 1, 1990