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I want to explore whether it is valid or even useful to talk about sustainable corporations. After 20 years of focus on sustainable development, the concept of a sustainable corporation is not particularly helpful and it may in fact be profoundly misleading. Why? û because it obscures the need for corporations to be recognised as part of a sustainable society, rather than achieving some kind of corporate nirvana divorced from the social, political and environmental reality. It is more helpful to ask whether corporations are ready to recognise that they are one player among many within society û with the demands this would place on them in terms of transparency, accountability and social responsibility. The achievement of sustainable development has become the new corporate orthodoxy of many large corporations. It has become a clichT to argue that corporations must become æsustainableÆ. The achievement of æsustainabilityÆ is encouraged, as the ultimate step in some form of corporate evolution. We are failing to recognise that sustainability a process û not an end in itself. An enormous array of instruments is being developed to measure when sustainability is or is not being achieved. For example, corporate reporting has burgeoned into an art form, which describes æsustainabilityÆ in a variety of ways. There is no external standard applied to such reporting. These descriptions are quite partial and often place the best possible gloss on the companyÆs activities. I have become increasingly uneasy about this rhetoric and this paper has allowed me the luxury of sorting out my unease. I will discuss, largely in the Australian context, the current debate and literature and describe the way some global mining corporations are dealing with these questions, and finally, offer some suggestions which might be helpful at the operational level.

Jan 1, 2002

By S W. Robertson, A Vercuil, P Craven

Mintek is currently developing a design approach for the heap leaching of low-grade primary copper sulphide material. Since the leaching of chalcopyrite requires elevated temperatures, the generation and management of heat within the heap is crucial. Furthermore, the precipitation of iron needs to be managed to prevent premature blinding of the heap, and acid consumption needs to be limited to contain cost and limit the dissolution of gangue impurities. Standard column tests using jacketed 1-m and/or 6-m columns do not allow accurate prediction of temperature changes and heat generation in an actual heap. Mintek therefore utilizes a computer model to calculate the energy balance and heat generation with time, based on the measured sulphide oxidation rates in the column. The temperature in the column is then adjusted to reflect the computer-predicted temperature in an actual heap. Using this approach, an overall copper extraction of 70% was achieved in 120 days, using 1-metre columns, when treating an ore blend containing 1.36% chalcopyrite, 0.23% chalcocite, 0.07% covellite, 3.8% pyrite and silicate gangue (92%). The chalcopyrite contribution to the total copper content in the feed was 75%. This was followed by 6-m columns using a similar approach, and the column results will be validated on a 23,000 tonne test heap. Key Words: heap; bioleach; chalcopyrite

Jan 1, 2005

Steady increases in longwall production have required operators to apply greater quantities of ventilating air in an effort to control and dilute respirable dust. Significant increases in shearer speeds necessitate that longwall supports also be advanced at a faster rate. Both of these factors may contribute to overall respirable dust levels on the longwall face because as supports are lowered and advanced, broken material falling from the top of the canopy is entrained directly into the air stream. To address this issue, the Pittsburgh Research Laboratory collected respirable dust samples from four longwall faces to characterize shield-generated dust. This paper investigates the influence of air velocity and shield advance rates on respirable dust levels. Also discussed are engineering controls currently used to reduce shield dust and alternative controls being investigated by the National Institute for Occupational Safety and Health (NIOSH).

Jan 4, 2010

By N F. Fraser

Seafield ResourcesÆ offshore placer gold project covers c.10 000 km2 of the Westland continental shelf between Karamea and Jacksons Head, from the low-water mark out to the 120 m isobath (Figure 1). De Beers Marine (DBM), the marine diamond subsidiary of the De Beers Group, will carry out the project with geological input from Placer Solutions (PSL). DBM bring a wealth of expertise and advanced technology to the project, developed during their 20 years of exploration and mining of diamond placers on the Atlantic shelf of southern Africa, where they have also maintained a strong environmental record.   Glaciers and high-energy rivers emanating from the Southern Alps have transported substantial quantities of gold bearing sediment onto the Westland continental shelf during Pleistocene glacial periods, when fluvial gradients are steeper, sea level is c.120 m lower and most of the shelf is exposed. These deposits have been extensively reworked by the advancing shoreline and marine processes during interglacial marine transgressions, and most are now buried beneath a variable thickness of post-glacial marine sand, silt and mud. DBM will use side-scan sonar, swath bathymetry, Chirp sub-bottom profiling and a magnetometer to map the sea floor and sediments beneath it, guided by PSLÆs predictive geological model for gold distribution on the shelf. Cactus grab and vibro-core samples will be used to ground-truth the geophysics and provide stratigraphic, sedimentological and gold distribution data for incorporation into the geological model. Areas of interest identified by the geophysical and sampling data will be investigated in more detail, with closer-spaced geophysics and Mega-drill sampling to a maximum sediment depth of 20 m beneath the sea floor. These samples will be raised to the ship with air-lift suction technology, processed onboard for mineralogical and grade information, then returned to the sea floor. Environmental baseline data will be gathered from Van Veen grab samples of seabed sediment taken throughout the area during the prospecting programme.

Jan 1, 2005

By E. Munnik

The Chambishi Metals Cobalt Plant in Zambia has recently installed a novel oxidation/precipitation pressure leach process as part of the COSAC (CObalt from Slag And Copper as by-product) Project. Aniron-cobalt-copper alloy, produced by the carbothermic reduction of slag, is atomized and pumped to the COSAC Leach Plant, where cobalt and copper are recovered as dissolved sulphate salts, andiron is rejected primarily as hematite. Cobalt and copper are subsequently recovered as cathode metal in the existing Chambish ioperation by conventional electrowinning. This paper examines the challenges faced during the design and subsequent successful commissioning of the COSAC Leach Plant. The challenges discussed include alloy handling, autoclave design, autoclave cooler design, residue liquor recovery and the water balance design. Keywords: Chambishi, Avmin, COSAC, Zambia, Copperbelt, cobalt, copper, alloy handling, pressure leach, autoclaves, cooling, filtration.

Jan 1, 2003

By S. H. Ash

THE INVESTIGATION of barrier pillars in the Western Middle field is part of the comprehensive study of the mine-water problem in the anthra¬cite region of Pennsylvania by the Federal Bureau of Mines (1, 2, 5, 6, 7, 8,9,10,11,1,2,15,16).8 The Western Middle field is in Schuylkill, Columbia, and Northumberland Counties in eastern Pennsylvania. It has an area of 120 square miles, is 42 miles long from Delano on the east to Trevorton on the west, and is 2 to 5 miles wide. In the Western Middle field are 58 underground water pools containing 38 billion gallons of water (5). Some of the pools overflow to the surface, and the water from others seeps into adjacent mines through permeable barrier pillars separating them from abandoned mines. Several active mines are interconnected to workings in abandoned mines, which are partly filled with water. These mines are separated by barrier pillars that are considered effective only below the altitude of the connections. In some abandoned mines, pumping stations maintain the water at altitudes where the hydrostatic pressure against the barrier pillars is not excessive and does not endanger adjacent active mines. If water in these abandoned mines is allowed to rise to where it can overflow into the active mines, it must be pumped from the active mines at lower altitudes; this materially increases the cost of pumping. It is estimated that from 1944 to 1948 approximately 30 percent of the water pumped to the surface was from abandoned mines.

Jan 1, 1953

By S. Rolseth, J. Thonstad

The traditional electrolyte for aluminium electrolysis is based on molten cryolite (Na3AlF6), acting as solvent for the raw material, alumina (Al2O3). Over the years there has been a trend to increase the content of excess aluminium fluoride (AlF3) to the cryolite-based electrolyte, in order to enhance the current efficiency of the process. In most cases one has ended up at 11?13 wt% excess AlF3because higher contents makes it difficult to control the heat balance of the process. This problem may be overcome if sensors are developed that will allow online control of electrolyte temperature and composition, and we may then see a surge towards still higher AlF3contents. In the development of new anode materials to replace the carbon anode with inert, oxygen-evolving anodes, focus is on anode corrosion, and a low electrolyte temperature is then highly desirable. While the conventional process operates at around 960°C, electrolyte temperatures as low as 750°C are being tested. This is achieved by having large excess contents of AlF3(40 wt%). The consequences of using such electrolyte compositions are discussed.

Jan 1, 2004

By M. Maccagni, J. Nielsen

"Engitec developed the EZINEX® Technology some years ago to recover zinc from oxidized secondary sources. This process works at neutral pH and can take into solution any kind of metal, but iron is rejected and remains in the leach residue. Engitec has also developed the FLUOBORATE System, which is able to recover lead and copper from relevant concentrates. Some iron is leached into solution, but it is controlled through a solution purification bleed treatment. In this paper, we present the two above mentioned technologies. They are very different with regards to the chemical environments and the methods used to control the build-up of iron in solution, but both systems are suitable to treat iron bearing feeds.INTRODUCTIONIn the design of hydrometallurgical processes, the most important issues are the water balance, the filtration and the control of impurities. This is particularly important when the process includes an electrowinning unit. Iron has been one of the most problematic elements to remove, especially in acidic environments.Engitec Technologies has developed several hydrometallurgical processes divided in two different electrolyte lines: the Fluoborate Technology for the recovery of lead and copper from primary and secondary sources and the Ammonium Chloride System based on a chloride electrolyte for the recovery of different non-ferrous metals, among which zinc and lead are the most important. In both cases, iron is present in the feed and needs to be eliminated from the solution. It is not a problem for the quality of the metal produced, but when present in solution, it consumes the basic electrolyte reducing its free concentration which is very important both for both the leaching and electrowinning unit operations. Both process systems are very peculiar, the fluoborate case being much more intriguing."

Jan 1, 2016

By Michael Schaffer

The paper point out how APC (Advanced Process Control) can be implemented in a stepwise fashion, where each step demonstrates a return and builds towards the overall achievable benefit. Initial efforts focus upon areas that demonstrate the highest potential for quick payback. By attacking small, contained scope, the APC solution is manageable from both a commercial and technical perspective. While this approach results in a slower implementation with correspondingly delayed payback, it provides tangible benefit and addressees the fiscal reality of many operations.

Sep 12, 2005

By P Lindsay, J B. Hughes

Underground and opencast coal mining has been ongoing since 1896 on the Stockton Plateau, West Coast, New Zealand. Acid Rock Drainage (ARD) from historic and current mine workings has had an adverse environmental impact on the surrounding aquatic environment. The two main catchments affected by ARD are those of the Mangatini and St Patrick streams. These catchments flow into the Lower Ngakawau River, which holds high amenity value for the local community. Water quality targets set by Solid Energy for 2010 in the Ngakawau River include increased pH and clarity and a decrease in certain dissolved metals.   At-source ARD minimisation options are the first stage in mitigating the effects of mining acid forming rocks and reducing acid loads in the Mangatini and St Patrick stream catchments. ARD minimisation techniques reduce the quantity of acidity generated and thus reduces the treatment required. Treatment will be required for many years at Stockton due to current and historical acid formation. This paper looks at the treatment options that Solid Energy has been investigating including limestone leach beds, engineered wetlands, oxic limestone drains, and limestone dosing of catchment drainage. Particular focus is given to fine limestone dosing of the Mangatini stream and subsequent water quality improvements.

Jan 1, 2007

By V. Bush, T. G. Killingsworth, E. P. Ruffel

Effective and sustained corporate energy management programs are becoming a necessity for energy users as electricity deregulation laws are enacted on a state-by-state basis across the country and environmental regulations pertaining to emissions become more prevalent. The “Total Energy Asset Management” (TEAM) approach has been developed to assist energy end users with the development and implementation of corporate energy management programs designed to reduce energy risks and increase energy cost savings. This paper highlights the ways in which this approach can be applied to the mining industry while minimizing initial program implementation costs and increasing potential program benefits. Nearly the entire mining industry has become very focused on identifying opportunities to reduce costs per unit of yield. The industry as a whole has increasingly faced pricing pressures in large part due to the effects of global competition. The result of international marketplace participation and the emergence of higher efficiency recovery techniques have resulted in flat or even decreased prices for mining products. Thus, opportunities to reduce costs are actually opportunities to gain a competitive edge over similar mining operations. Due to the energy-intensive nature of many mining operations, the costs associated with energy are often a substantial percentage of operating costs. Therefore, it becomes very important to develop the corporate mentality that energy is an asset whose use should be optimized globally. In addition to the cost benefits of the TEAM approach, other benefits may occur such as reductions in facility greenhouse gas emissions.

Jan 1, 2002

By Earl T. Hayes

[This work represents a continuation of the efforts of the Metallurgical Division of the Bureau of Mines to ascertain and apply knowledge of mineral physics to process metallurgy.]

Jan 1, 1941

By Earl T. Hayes

[This work represent a continuation of the efforts of the Metallurgical Division of the Bureau of Mines to ascertain and apply knowledge of miner physics to processes metallurgy.]

Jan 1, 1941

By R Blair

The Domain and Burnley Tunnels, which are major features of the Melbourne City Link Project, are MelbourneÆs first road tunnels. They are 1.6 km and 3.5 km in length respectively and are being constructed through a variety of ground conditions. Deeper sections of the tunnels have been driven through the Silurian mudstone which underlies Melbourne. Other shallower sections of the tunnels pass through a variety of ground conditions including silts, sands, clay and rock and have been constructed using both top-down and bottom-up cut and cover construction techniques. The Yarra River Crossing is a 140 m length of the Domain Tunnel which crosses under the Yarra River on a relatively shallow alignment. The crossing of the river using cut and cover techniques was identified in the early stages of design development as being one of the most challenging stages of the works on the Southern Link. The prevalence of varying geological conditions combined with the need for maintained traffic and stream flow conditions provided a demanding and often conflicting set of criteria for which there appeared to be no one clear solution. A team of designers, constructors, estimators and specialist contractors were involved in a concept evaluation and risk analysis study spanning a period of approximately 12 months. During this study, four concepts were considered as likely contenders. This paper provides a brief outline of the four concepts addressing their relative merits, disadvantages and risks followed by a detailed description of the adopted solution, namely top-down construction using secant pile walling (east bank) and bottom-up in situ construction (west bank).

Jan 1, 1999

An Integrated Solid Waste Management Method for Western Macedonia, Greece

Sep 13, 2010

By J Temos

This paper outlines a number of immediate practical approaches to continuous improvement in environmental management in the minerals industry. It puts these into context with longer time-frame step-change approaches whose gestation may take a decade. Examples of improvements and approaches are drawn from WMC operations.

Jan 1, 2002

The safety of personnel is the most important matter during a mine fire. However, there is not enough research on a case when a fire occurs near a shaft and the behavior of the fire gas is not well understood. Therefore, a series of experimental study using a scaled ventilation circuit model was carried out. The behavior of ventilation air during a mine fire near a shaft was investigated. The model consists of two vertical shafts, three horizontal ducts connecting the shafts and an exhaust fan from the shaft bottom. The cross section of the shaft and duct is a square of 200×200mm. The height of the shafts is 3400mm. The length of the ducts is 1540mm. The lower duct is set at the same level as the shaft bottom. The middle and upper duct are set at 750mm and 1760mm above the shaft bottom respectively. The airflow rates through the ducts can be adjusted by regulators installed in each duct. The behavior of the fire gas was measured by anemometer, thermometer, and visualized using laser light .The air was ventilated downward in both shafts before the initiation of the fire. Some amount of fire gas of high temperature rose upward gradually along the shaft wall regardless of the downward ventilation after the initiation of the fire. Then the direction of main ventilation air suddenly reversed upward in the shaft. The direction of ventilation reversed in many places in the model and the fire gas reached even the part not anticipated.

Jan 1, 2009

By Steve Tadolini

Underground roof falls can have devastating effects on the safety of operations personnel, and equipment, and seriously impact production. Immediate steps are usually taken to danger off and secure the area while clean-up efforts are designed and implemented. A critical step, often overlooked due to production demand, is the determination of - why the roof fall occurred so that additional occurrences can be avoided in future developments or what measures can be taken to identify areas that have similar ?symptoms?? Forensic engineering includes the investigation of materials, products, structures or components that fail or do not operate/function as intended. The authors define forensics in ground control engineering as the study of evidence discovered while examining underground roof falls by applying expert observational techniques and established mining engineering principles to determine the probable cause, hypothesize solutions, and design engineering safeguards to prevent reoccurrences. Simply stated, the primary steps in the forensics of underground roof fall techniques are: ? Assess regional and local conditions prior to the event. ? Assess post-event conditions. ? Hypothesize plausible ways in which the pre-event conditions ? became the post-event conditions.Search for evidence that either denies or supports the various ? hypotheses.Apply engineering skill to relate the various facts and evidence into a cohesive scenario of how the event may have occurred. This paper details the proposed technique by utilizing a roof fall case study that required the examination of five primary factors: mine design parameters, excavation geology, method of excavation, method of support, and mining cycle times.

Jan 1, 2009

By Woodhouse M, Andrews D, Drew G

The nickel deposits within the Honeymoon Well project area (26¦ 40'S, 120¦ 25'E), located 45 km south of Wiluna, occur in the northern part of the Agnew-Wiluna belt (Figure 1; Hill et at, 1990). The project area is covered by up to 50 m of transported material which greatly hampers both exploration and an understanding of the bedrock geology. Since 1990 intensive exploration has increased the resource from 10 Mt at one per cent Ni to 134 Mt at 0.76 per cent Ni in five deposits (0.4 per cent Ni cut-off, resources above 300 m depth, December 1994). This includes a massive sulphide resource of 2.5 Mt at 3.4 per cent Ni.

Jan 1, 1996

By Rashmi Ramesh

Zinc oxide nanoparticles and nanostructures form an active area of research in the recent years. It can be doped to modify electronic, optical and other properties. Synthesis and characterization of zinc oxide is of extreme importance in order to understand the structure property relationship in this material which is now being considered of importance next to carbon nanotubes. Microstructure of zinc oxide nanomaterial is extremely sensitive to the preparation conditions. Nanocrystalline pure and Mn and Mg doped zinc oxide samples were prepared by wet-chemical method under different growth conditions. The samples were investigated for crystalline phase, microstructure, morphology and luminescence characteristics. The effect of Mn and Mg doping on the characteristics of ZnO have been discussed.

Jan 1, 2010