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By K Eglinton

The extractive industries response to community engagement due to social and political pressures in the 1980s and 1990s was the starting point of development leading to the modern function of corporate social responsibility.Challenged by communities who have greater access to information, demand greater transparency and responsibility of corporate organisations and who possess greater awareness of the communities they participate in, the mining sector faces another step change in how it approaches and integrates corporate social responsibility, transparency and engagement.Mining is seeking reserves of lower grades, in more sensitive environments and in countries with minimal transparency and governance. Not only are the locations changing but so to the stakeholders to engage with and issues to contend with. An increasingly savvy opposition, including not just the ‘green hippies’ but the Gen-Ys interested in the wider sustainability debate and Baby Boomers moving to life style environments, are now questioning mining’s behaviour and encroachment into ‘their space’. Issues including effect on lifestyle amenity, property value, energy efficiency, social provision; concepts such as ‘doing more with less’, participatory engagement, increasing transparency and balancing economic, environment, cultural and social aspects are becoming the norm.The traditional model of supporting local communities, communicating plans and providing employment, community investment and indigenous support programs is not enough. Our industry faces challenges on multiple fronts. It must now be able to address these from a personal/community perspective if it is to remain relevant within communities and play a role in addressing the global sustainability issues.This paper draws on corporate social responsibility trends, integrated functions and implementation approaches through the application of activities within Newmont operations across Asia Pacific.The approach presented works on the philosophy that communities do not necessarily have to like what we do, but should be able to identify and recognise the way in which we involve them in decision making, communicate our intentions and respond to issues.

Nov 22, 2011

This presentation addresses the sources and weighting of project risk in coarse gold deposits with relevance to experiences at the Ballarat mine and Castlemaine goldfield. With sample representation and reliability often a source of great error in the resource estimation of coarse gold deposits, it follows that this matter should be of greatest risk to a mining project - but is it? What are the costs and efforts required to best quantify the sampling error due to nuggetty effect? After all, the main problem in Victorian gold mining ventures in the current decade is not the amount of gold available, but defi ning which portion of it can be converted to Ore Reserves or more so profitable gold bars. The author postulates that greater risk to the project lies in the geological interpretation and matching resource spatial parameters to mining methods, than the degree of uncertainty related to grade due to nuggetty gold. Recent experience in the Victorian goldfi elds is that the investor market has already severely discounted Mineral Resources reported in accordance with The JORC Code - so if they don't believe in the capacity to upgrade the resource why should we? To this end, Castlemaine Goldfi elds Ltd at its Ballarat gold project does not intend to estimate its gold mineralisation for public release, instead choosing to focus on the geological interpretation and mine planning elements. So with coarse gold deposits, is your Mineral Resource reported with The JORC Code a glass half full or half empty? Our mining forefathers in Victoria had no predictive tools which could define resources to any degree and yet were successful. By over emphasis on the definition of mineral resources and particularly the sampling error, are we ignoring the basics of cost control, solid geological interpretations and maximum mining flexibility. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Aug 1, 2010

New ZealandÆs share of global greenhouse gas emissions, at about one fifth of one per cent, is very small. But the profile of those emissions is unique among OECD countries; more than half come from methane and nitrous oxide associated with livestock agriculture. Consequently, fulfilling its obligations under the Kyoto Protocol is potentially quite onerous for New Zealand.In this paper we use a single region, static general equilibrium model to assess the implications for New Zealand of various climate change policy options. The energy and agriculture sectors are modeled in a detailed manner to enable realistic simulations to be carried out.Choosing an optimal set of policies is made more difficult by the fact that New Zealand relies heavily on emission intensive sectors for much of its export earnings. For example, one emission intensive sector alone, dairy, accounts for over 20 per cent of all merchandise exports. Avoiding carbon leakage is therefore an important consideration in selecting appropriate greenhouse policies.Our analysis shows the degree of sectoral adjustment required is substantial. In addition, the total costs depend on the uncertain level of variables such as the global carbon price and the level of afforestation activities in New Zealand, ie the rate of new forest planting.

Jan 1, 2002

By Alice DiDonna

The heating and cooling of buildings worldwide represent a large amount of a country?s energy needs and are major sources of CO2. Therefore, decreasing the environmental impact of residential and office buildings is of crucial importance. Energy pile foundations are a sustainable solution to this problem and constitute a local, renewable and environmentally friendly resource. They are also in accordance with current energy policies. A system of pipes installed within the concrete with a heat carrier fluid that circulates through it can extract heat from the ground to satisfy the need for heat during the winter and expel excess heat resulting from air conditioning during the summer. Consequently, the foundation is subjected to a thermal load, which results in additional stresses and strains that must be considered in the design process. Despite the fast spread of this technology in the last decade, there is still a lack of knowledge about the thermo-mechanical behavior of energy pile foundations. Consequently, design approaches and guidelines are limited. Here, a new geotechnical method for the design of energy piles is illustrated based on the quantification of the additional thermal effects that appear inside the foundations. The method is based on the load-transfer curves approach and has been implemented into a numerical tool called ThermoPile. The software is presented and validated through a developed analytical solution and the results are compared with real in situ experimental tests.

Jan 1, 2011

By Boleslav Taraba, Antonín Taufer

Thermovision monitoring of surface temperature has been examined for the purpose of detection of spontaneous combustion of early stage. Measurements were carried out in bituminous and subbituminous coal mines. It was found that surface temperature heterogenities can be considered as common phenomenon in mine openings. However, the most of the observed temperature heterogenities were not connected with coal spontaneous combustion of early stage. These, so called [non-spontaneous combustion] temperature heterogenities in surface of mine openings were found to be caused by: l. Different conditions of heat transfer between opening surface and air stream; 2. Low temperature (natural) oxidation of coal; 3. Dissipated heat loses of working machine. Sites of early stage spontaneous combustion of coal were characterized by: 1. More significant, local rise in surface temperature comparing with low temperature coal oxidation; 2. Evolution of carbon monoxide with local concentration near the surface of such site more than about 15 ppm (bituminous coals) or 30 ppm (subbituminous coals). INTRODUCTION Mine fires are a serious hazard to life and result in a considerable loss of coal reserves. Thus, great attention is paid to investigation of new methods enabling already early detection of self-heating of coal. The earlier a fire is observed, the easier would it be to deal with. Detection methods used in coal mines are mainly based on: 1. [Mine air analysis]. Changes in composition of mine air are examined. Products of spontaneous heating of coal, not being present in mine air under normal conditions, are considered as indicators of anomalous behaviour of coal (carbon monoxide, unsaturated hydrocarbons) (Mackenzie-Wood and Strang, 1990). 2. [Temperature measurements]. Sites of higher temperature level comparing surroundings are looking for underground using various direct or indirect methods of temperature measurements. This paper summarizes experience from thermovision monitoring, as one of the latest indirect temperature measurement technique, used for the purpose of early detection of self-heating of coal in mine openings. INFRARED THERMOVISION Infrared thermovision device of AGEMA Infrared systems AB (Sweden) was used for the in situ measurements. The constant value of emissivity factor, 0.95, was pre-set as the most probable level of emissivities of coal and rocks in mine conditions.

Jan 1, 1993

By J. A. Rowland

Magnesium alloys containing nickel, nickel and manganese, lithium, lithium and manganese, and lithium and aluminum were investigated. Melting, casting, and mechanical working techniques and the heat treatment of various compositions were studied. Amenability to cold and hot working was shown for many compositions. The magnesium-nickel and magnesium-nickel-manganese alloys failed to develop superior mechanical properties and were very low in resistance to corrosion. The magnesium-lithium series, although entirely plastic, had low strength properties. The addition of small amounts of aluminum to the Mg-Li base did not affect greatly either the ductility or the strength; further additions developed increased strength, but only at room temperature, and the alloys became brittle with age. Continued study, concentrating on the ductile lithium-rich beta phase as a base composition for ternary and quaternary systems, is recommended.

Jan 1, 1956

By Foster Fraas

The objective of this research was separation of one highly conductive mineral from a second conductive mineral , a procedure which is impractical in commercial electrostatic separators using metal rolls . Such separators permit separation of nonconductive from conductive minerals . A new technique involved use of carrier electrode rolls specially prepared by anodizing and / or oxidizing at high temperatures to form suitable oxide surfaces . Specific oxides included aluminum , copper , and nickel . The significant result provided by the new surfaces was the extension of the separation range to higher conductivities , an extension in relative mineral conductivity from 10-14 mhos . The results are in accordance with the blocking- layer theory .

Jan 1, 1964

By G. W. Jones

The determination of the ignition temperature of diethyl ether and ethylene in air and omen which is described in this report was made primarily for comparison with similar determinations of other compounds in the same apparatus and using the see laboratory technique. The investigation was conducted at the Pittsburgh Experiment Station of the United States Bureau of Mines with the cooperation of Merck & Co., Inc.

Jan 1, 1935

Train services through the Channel Tunnel linking Britain and France where scheduled to be fully restored in February 2009 following several months of repairs after a major fire in the tunnel on Sept. 11, 2008. A lorry caught fire on a shuttle train carrying heavy goods vehicles bound for France through the 50-km- (31-mile-) long northern tunnel. The fire, that spread to other vehicles, raged for about 16 hours. The extreme temperatures of up to 1,000º C (1,832° F) caused extensive damage to about 600 m (2,000 ft) of the 7.6-m- (25-ft-) diameter tunnel?s concrete lining, approximately 11 km (7 miles) in from the French entrance. The Channel Tunnel operator, Eurotunnel, awarded the repair con-tract, estimated to be between ?50 to 60 million, to a consortium of Freyssinet, Eurovia Travaux Ferroviaires (ETF) and Vinci Energies. Freyssinet was appointed to look after the civil engineering works, while ETF would be responsible for track and overhead wire restoration and Vinci Energies responsible for other equipment. The technique of hydrodemolition, which uses high-pressure water jets to remove concrete from various structures, was specified as the method to remove the fire damaged concrete. Freyssinet subcontracted the concrete removal to the specialist hydrodemolition and industrial cleaning contractor Philip Lasserat.

Jan 1, 2009

By A. Zarei-Hanzaki, O. Golmahalleh, S. M. H. Hosseini, H. Azizi-Alizamini

The main importance of acicular ferrite microstructures arises from their desired combination of mechanical properties in comparison with the bainite and ferrite-pearlite microstructures. Several factors affect the microstructural transition from bainite microstructure into the acicular ferrite one. As is well established any factor corrupting the prior austenitc grain boundaries nucleation potential, such as the thin layer of allotriomorph ferrite and the austenitc deformation inhomogenities may promote the acicular ferrite formation instead of bainite. Accordingly, this study deals with the effects of the aforementioned features on the acicular ferrite formation in low carbon microalloyed steel. The results indicate that the formation of strain-induced ferrite at the prior austenite grain boundaries accompanied by deformation inhomogenities in the austenite grains change the effectiveness of allotriomorph ferrite on acicular ferrite formation from active to inert one.

Jan 1, 2004

By J. Alexis, G. Ye, E. Burström

Over the past twenty years the 3 MW DC arc furnace at MEFOS has been frequently used for development of new processes. These processes include recovery of valuable metals from slag, sludge and dust from steel and other metallurgical industry, treatment of ashes from power plant and incinerators, smelting reduction of minerals and zinc recovery from EAF dust. The process characteristics of the DC arc furnace operation in terms of: ? selective reduction, ? total reduction, ? process stability and flexibility, ? dust carry-over, ? thermodynamic conditions provided in the hot spot area, ? precision in composing slag products These are analysed and described in this paper based on technical results from selected test campaigns over the years and thermodynamic considerations. The electromagnetic properties of DC arcs beneath the electrode have been studied by CFD simulation. The calculated result enables us to understand some interesting technical phenomena observed. The heat balance has also been considered based on data obtained from test campaigns and heat balance calculation.

Jan 1, 2004

By S J. Kim, S W. Kim, L Tomas da Rocha, S Jung

Al2O3 has been regarded as a harmful gangue component in iron ore, especially causing reduction degradation in industrial sintering of iron ore. The current study aimed to utilise low-grade iron ore containing high Al2O3 content in sintering process. In order to counteract the adverse effect of Al2O3 on reduction behaviour of iron ore sinter, mill-scale and calcined dolomite were chosen as FeO- and MgO-bearing materials. Firstly, mill-scale was added to high Al2O3 sinter and addition was optimised as 10 wt per cent, then calcined dolomite was added further. Magnetite and magnesio-ferrite were identified as the major phases in iron ore sinter when adding mill-scale and calcined dolomite. As the dosage of calcined dolomite increased beyond 4 wt per cent of in sinter mix, unreacted MgO particles were observed, which is ascribed to the limitation of MgO dissolution into magnetite matrix. Both mill-scale and calcined dolomite were effective in improving compressive load and Reduction Disintegration Index (RDI) of iron ore sinter although its reduction degree was highly decreased. The addition of both FeO and MgO-bearing materials to high Al2O3 sinter has a potential to improve the sinter quality, also contribute to the recycling of industrial by-product. However, the amount should be optimised in views of phase development and deterioration of reducibility.

Jun 19, 2024

By V. N. Kolesnikov

The gold-silver deposits of the northern Primorye region are located in the eastern part of the East Sikhote-Alin volcanic belt, where the belt overlaps the Kema island-arc terrain of the Aptian-Albian age. There have been four deposits and numerous mineralization points found in the NE-trending Kema metallogenic belt that is about 1000 km long and 100 km wide. The known mineralization is of epithermal type, controlled by faults, and concentrated in quartz, quartz-fluorite-adularia, and, less commonly, sulfide-quartz vein systems hosted by the Upper Cretaceous-Lower Tertiary volcanic rocks. The vein systems extend for hundreds meters along strike, varying from tens centimeters to 50-60 meters in width. They are surrounded by wide zones of low-temperature hydrothermal alteration containing some gold-silver mineralization for which the commercial value was not studied during the early exploration. The ore bodies contain from 1 to 50-80 ppm of Au and from 1 to 1000 ppm of Ag. Gold is native, associated with quartz, and represented by particles from tens of microns to 1 mm in size. Silver occurs in native form as a constituent of argentite, pyrargyrite, stephanite, and other sulfosalts. The test work carried out for three vein systems 20 years ago showed that gold might be easily and almost completely recovered from the ore by cyanide treatment. The paper describes the geology and mineralogy of the deposits, Salut and Primorskoye, that are the most studied properties of the Kema belt. It also presents the data available on disseminated gold-silver mineralization in stockworks, altered explosive breccias, and wide zones of low-temperature hydrothermal alteration. This mineralization should be explored for possible exploitation as large open-pit, heap-leach deposits.

Jan 1, 1998

By Victor Kalcevic

A gas-flow retort for thermal processing of oil shale to recover shale oil was developed by the Bureau of Mines at its Oil-Shale Demonstration Plant, Rifle, Colo., from 1948 to 1952. The retort is a crossflow gas-to-broken-solids heat exchanger. The heating medium is the gas produced in the shale retorting process. The gas is heated in specially designed stoves outside the retort and recycled to the retort. Oil shale from the Mahogany ledge section of the Green River formation in northwestern Colorado was the material processed. Indicated maximum oil recoveries for 20-to 25-gallon-per-ton shale in a l2-inch-thick shale bed and a 20-inch bed are 96 and 91 weight-percent of Fischer assay, respectively. Heat requirements for maximum recovery are 600 to 750 B.t.u. per pound of shale. Properties of the recovered shale oil are affected slightly by shale-bed thickness and extent of retorting. Oil recovery from oil shales assaying over 30 gallons per ton is lower than that from leaner shales.

Jan 1, 1959

The development and introduction of a preventive maintenance scheme in the coke ovens department, coal preparation section, of The Broken Hill Proprietary Co. Ltd., Newcastle steelworks, is described together with its operation and the results achieved during the first 12 months.'fhe scheme consists essentially of an engineering analysis of the plant to establish maintenance schedules, and to record the details on reference cards.Items are reviewed progressively and a weekly work schedule is prepared, from which work orders are passed on to the maintenance foremen. These foremen in turn originate action orders and issue inspection sheets as required. Results are then reported back to the maintenance planner and used to revise norms, practices, and cycles.INTRODUCTIONWhat is maintenance? Some people consider maintenance to be the work involved in putting things together again after they have fallen apart. The author regards it as the mechanical care and repair of plant machinery and equipment to keep it operating in sound mechanical condition, without undue interference with production processes.Maintenance may be organized or haphazard, and, too often, what has been fondly imagined to be nicely controlled and organized maintenance proves, under pressure, to be more correctly described as haphazard. Haphazard maintenance deals with breakdowns as they occur, and frequently finds itself confronted with more breakdowns than can be handled. Even organized maintenance, if not based on sound planning, can, at times, be found in a chaotic state, because of unexpected and unanticipated breakdown.Properly planned and scheduled maintenance permits an orderly and controlled approach to the problem of maintain...

Jan 1, 1961

By Laura A. Sanders

Mineral scale formation is prevalent in numerous mining operations. Such scale formation can occur in the direct-contact heat exchangers ahead of an autoclave. In these heat exchangers, the incoming slurry comes into contact with steam in a stage-wise fashion, which is re-circulated from the downstream flash vessels to heat the slurry in stages ahead of the autoclave. Calcium sulfate scaling causes severe problems in mining operations where increased temperatures are involved due to rising temperatures promoting calcium sulfate scaling through a decreasing solubility. In a number of these operations, the scale formation can occur in the presence of mineral solids, where fine-grained charged particles are at concentrations in excess of 35%. Scale prevention is not difficult in standard aqueous systems; however, the presence of solids leads to significant deficiencies in the prevention of scale due to the adsorption of the polymer onto the charge solids instead of the polymer interaction with the scale. Therefore, a technical solution to prevent mineral scale build up occurring in presence of pulp slurry in mining operations is needed. Several novel antiscalant technologies were developed and evaluated which provided a substantial improvement in the scale prevention in such systems.

May 1, 2013

The common approach of designing blasts on a trial and error basis is quickly coming to an end. When utilizing the full scale blast environment, trial and error can quickly become cost prohibitive and leaves much to be desired in terms of true blast diagnostics. In these situations testing is usually only continued until a perceived improvement is achieved and when the gross undesirables in blast results are removed. This does does not preclude, however, that further improvements of up to 100% or more can not be obtained.

Jan 1, 1991

By R. F. Abernethy

A chemical method of determining microgram quantities of arsenic in coal was investigated by the Bureau of Mines to supplement a semiquantitative spectrographic method of determining arsenic in coal ash. In accordance with a method recommended by the International Organization for Standardization, 1-gram samples of coal are decomposed by wet oxidation with boiling sulfuric acid (H2S04) and nitric acid (HN03) to remove the organic matter. After heating to fumes of SO3 to remove HN03, the arsenic is separated as arsine by the action of zinc in H2S04 solution. The arsine is absorbed in dilute iodine solution in which the arsenic is determined colorimetrically by the molybdenum-blue reaction. Two modifications of the method for obtaining the arsenic in solution, in addition to the wet oxidation method, give satisfactory results. The modifications are (1) furnace ashing with MgO added to the coal, followed by treatment with H2S04, and (2) extraction of arsenic from the coal by dilute HNO3 without ashing. Float-and sink-tests show that arsenic is associated mainly with mineral matter in the three coals examined. High-temperature ashing tests show that very little arsenic is volatilized from coal ash below 1,000° C, but it is virtually all removed from the ash at 1,300° C.

Jan 1, 1968

By T. W. Wloder

During recent studies concerning the effects that various surface treatments, surface imperfections, locked-in residual stresses and metallurgical and geometrical notches have upon the mechanical behaviour of metals and, in particular, upon their tension-bending characteristics under impact loads, it became apparent that specially developed methods and samples would be of great assistance in determining the desired data. This paper describes and discusses a number of different types of double-notched tension-bending impact samples which have been considered and examined for this purpose. The types most suitable for exploratory investigations are proposed for application in the study of the _behaviour of metals, their welds, and, in particular, their surfaces, when subjected to various notch-severities, surface imperfections, strain rates, temperatures, and constrained states of stress (i.e. the relations of the three principal stresses). It is expected that the proposed double-notched tension-bending samples and the proposed test methods will also contribute toward further understanding of the cold brittle behaviour and the notch-sensitivities of metals. The possibilities of introducing the so-called impact notch-sensitivity index and relative impact notch sensitivity of metals are discussed. Data obtained on double-

Jan 1, 1961

By Drew Sinha

Success of the environmentally benign semiconductor manufacturing depends on the cost-effective integration of the principles of reduce, recover, reuse and recycle from source material to final product disposal. Increasing demand combined with current shortage of polysilicon provided unique opportunities to recover the silicon waste, caused by various defects, in wafer manufacturing process. Current practices relating to recovery and reuse of waste silicon produced, from crystal growth process to finally polished and epitaxially deposited silicon wafer, at Mitsubishi Silicon America is presented. Future plan to recycle the process generated silicon fines produced during the intermediate steps of the wafer manufacturing process such as grinding, slicing, lapping and polishing is also discussed.

Jan 1, 1998