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Safety and health at work is about people. It is about people who plan for work, organise work and perform work. It is about those who come in contact with the workplace and those who are responsible for the workplace. There are wider ranging safety and health obligations that are imposed on the industry stakeholders that span all phases of the production process. In all cases, those responsible for discharging the obligations must ask the questions: Is what we propose safe?, can it be done safer? and are we sure? What we learn from recent legal cases before the courts is that it is essential that all stakeholders work together in a collaborative way when discharging these obligations. Safety and health at work cannot become an issue that is viewed only through the eyes of a single stakeholder group. The reason for this is quite simple. The interrelatedness of the responsibilities that are imposed on each of the stakeholder groups, means that the performance based legislation simply wont work, where an active model of communication and consultation is not in place.

Jan 1, 2005

By D Mcleod, S Brindley, S Green

The design and engineering of flotation circuits is driven by numerous inputs, including (in no particular order) testwork outcomes, site considerations, type of separation required, energy sensitivity of the flotation response, personal experience and preference for flotation machines, maintenance access requirements, operability, level of automation and capital constraints.This paper discusses these and other issues in the Australian context and covers the flotation of copper/gold ores and polymetallic (copper/lead/zinc) ores. The paper discusses aspects of the following: how should testwork be done and what are the important inputs and outcomes? how should testwork results be interpreted and how does this impact on equipment selection? what processes can have a critical impact on flotation circuit performance, eg thickening and regrind? what options are available with the typical æflatÆ Australia site? how do you minimise capital cost and what impact can this have on flotation circuit operation and maintenance? how should circuits be controlled and operated? Particular focus is placed on some practical aspects of process design and engineering and the potential impact that engineering decisions can have on flotation plant operation.

Jan 1, 2005

By Hyunsuk Yoon, Kiho Lee, Juhyng Lee, Younghoon Jung, Junboum Park

"The environmental double pile method is presented as a device to improve the engineering properties and to clean up contamination of low-permeability soil. This method is one of the novel technologies based on the concept of one step process. It can be applied to low permeable contaminated ground for site reuse. It uses piles to improve drainage, contaminant remediation, and bearing capacity of the ground. To evaluate the on-site applicability of this technology, drainage and strength properties of the environmental double pile were assessed by a series of experiments and numerical analysis. Environmental double pile was found to be a feasible alternative method to improve contaminated soft ground.Korea is a peninsula with many coastal industrial zones. These zones are located in regions mostly underlain by soft ground with low permeability and adjacent to industrial areas that can be contaminated. Therefore, a new region-specific remediation method is required to achieve environmentally sustainable development. This research introduces the Environmental Double Pile (hereinafter, refer to as EDP) for the lowpermeability contaminated ground and focused on both contaminant remediation and soft ground improvement. Basically, the EDP is quite similar to sand compaction pile (SCP). The SCP has been studied extensively to improve soft ground (Braja 1999; Hansbo 1994; Madhav and others 1978; Taylor 1948). But unlike SCP, EDP is filled with oyster shells instead of sand and an inner pile is inserted in the center of this oyster shell filled-zone. Therefore, it is a double pile consisting of the oyster shell pile and the inner pile, as depicted in Fig. 1."

Jan 1, 2005

This report will differ slightly from the traditional scientific and technical discussions given at this type of conference. It will focus on the personal experiences and choices that I undertook when deciding on my graduate position and location after completing university studies. Throughout the duration of my course I had experience in both fly-in, fly-out operations in the Pilbara and residential operations in the West Australian Goldfields. These experiences, though limited, allowed me to explore the two different methods and their pros and cons, and consequently to make my choice for graduate employment. Throughout the duration of my degree I believed it was important to gain a basic understanding of the two methods, focusing on lifestyle and personal interactions. The decision that a residential site suited my personality and lifestyle then allowed me to refine my job applications to a more specific list of mine sites and companies, resulting in a residential position with BHP Billiton at their Iron Ore operations in the Pilbara, Western Australia.

Jan 1, 2005

By G. Deissman, S. Kistinger

For the last 15 years environmental Life-Cycle Assessments (LCA) have increasingly been used to evaluate the environmental performance of industrial processes and products and have been employed as a basis in decision making processes in the public and industrial sector. However, assessment methodologies for environmental protection measures and reclamation/remediation measures with respect to their consumption of natural resources are generally poorly developed. In this presentation a methodology for LCA of environmental protection measures and remedial actions, respectively is suggested, using the remediation/reclamation of mining sites as an example. Key aspect of this approach is the development of an evaluation method appropriate for environmental protection measures, which links the various impact indicators recognised in the impact assessments and allows their integrated assessment.

Jan 1, 2005

By A. Plumtree

The morphology of environmentally assisted cracks in stressed pipeline steel has been investigated. For a dilute and neutral solution (NS4) simulating ground water in contact with the steel, semi-elliptical cracks grow faster on the surface (2c) than in the depth (a), hence, the aspect ratio (a/c) decreases. This is explained using a deterministic concept since corrosion is dominant and the primary constraint is the conservation of charge. By contrast, when mechanistic conditions prevail, significant growth occurs in the depth. When underloads are imposed in the loading history, temporary accelerations in crack growth occur because corrosion rather than mechanical effects become dominant.

Jan 1, 2005

By Vivian M. Troughton, Clifford J. Wren, Tony P. Suckling

"Secant pile walls are used for the construction of deep basement walls and earth retaining structures. Risk associated with secant pile walls is commonly perceived as being the safety of site personnel and the public during piling operations, or safety used in design. It is recognized that both of these are of paramount importance, but additional risks associated with the construction methods must also be considered to complete the risk management profile for any project. For the particular case of secant pile walls, if Clients take a ""back seat"" they may be unaware of the total risk package they are procuring. The authors argue that the piling contractor should be involved at the earliest stage giving input into the overall risk management process. Such early involvement within the professional team will maximise cost benefits to the Client and minimise the delays and cost increases sometimes associated with these works. A consistent methodology for identifying and then managing all the risks associated with secant pile walls is proposed. An example is used to demonstrate how this methodology should be employed. INTRODUCTIONThis paper discusses the value of a complete and integrated risk management process for structures with basements formed using a secant pile wall.The risk associated with any secant pile wall can be consicfered as comprising four components;1. Safety of people on site2. Safety of design or design methodology3. Construction risks4. Commercial risksAny risk management system needs to fully consider and integrate each of these four components to maximise the likelihood of a successful outcome for the basement.This paper concentrates on the construction risks for secant pile walls, as these are not often understood by the Client (in this paper the term ""Client"" also includes the main contractor, principal contractor, Engineer, Planning Supervisor, quantity surveyor and cost consultant)."

Jan 1, 2005

By B. Andreaus

In spite of tremendous efforts in research and development of polymer electrolyte fuel cells (PEFCs), essential properties of the actual catalyst material, supported Pt or Pt-alloy nanoparticles, are not yet well understood. Fundamental understanding of the catalyst structure and the prevailing kinetic mechanisms is, however, of utmost importance for further progress. In the present study, we investigate catalyst activity for CO oxidation from a theoretical point of view. Electrochemical CO oxidation serves as an important test reaction for the study of the fundamental properties of supported Pt nanoparticles. Recent experiments have revealed strong effects of catalyst particle size and supporting material on catalytic activity. It was found, that the activity towards CO oxidation decreases significantly when the particle diameter drops below 2.5 nm. We perform kinetic Monte Carlo simulations of CO oxidation on supported catalyst particles to elucidate this particle-size effect. The simulations are based on the active site concept, highlighting the role of active site formation and finite surface mobility of adsorbed electroactive species for catalyst activity. For comparison with experimental results, potential step experiments were simulated. The Monte Carlo simulations consistently reproduce effects of particle size and electrode potential found experimentally. In comparison with our simulations, analytical mean field models and nucleation and growth models exhibit inferior agreement with experimental data. In summary, our findings support an oxidation mechanism via active site formation. The reason for the slow reaction kinetics on catalyst particles with diameters below 2.5 nm is a rather low CO surface diffusivity. The rates of active site formation, diffusion and CO oxidation via recombination with adsorbed OH can be determined from the simulations.

Jan 1, 2005

By S K. Ray

Open fire in a mine gallery causes large-scale damage to property and sometimes precious lives. Such fires produce two distinct effects, the throttle effect and the buoyancy effect. These effects disturb the ventilation system of the mine. To understand the complex dynamic phenomenon of open fire and its effect on ventilation systems, a mine fire model gallery has been designed and constructed at Central Mining Research Institute, Dhanbad. Two sets of experiments at air velocities of 1 and 1.5 m/s were conducted in the gallery using coal samples from the Dobrana seam of the Raniganj coalfields. After about an hour of development of fully-fledged fire, heavy backlash, with smoke and fumes, was observed. At the time of backlash occurring the gallery was divided into two zones. In the region of the gallery from the base up to 1.4 m the airflow was normal, in the remaining upper portion the airflow was the reverse. Air quantity reduced substantially, while pressure dropped across the fire zone, the products of combustion (POC) and temperature increased during the period of the throttle effect. It has been revealed from these studies that with an increase in airflow, pressure drops across the fire zone, POC, temperature and reduction in airflow increases. This paper addresses the important design features of the gallery, the instrumentation system, the experimental procedure and assesses the effect of open fires on mine ventilation systems.

Jan 1, 2005

Aspiring to be excellent makes you a good leader as it shows a capability for strategic thought, defining and implementing a vision, making a job easier, more efficient and effective. Every great business leader can generate additional revenue or cost savings for their company. Becoming excellent requires the desire and action to follow it through. There are many established methods of excellence: benchmarking, target setting, supply chain and market analysis, employee suggestions and knowledge sharing forums. In BHP Billiton, practices benchmarking is a key tool in generating improvements for functional areas such as processing, mine operations and mine planning. Practices Benchmarking involves organisational and technical questions that allow the site to self-assess their maturity and generate a prioritised improvement path. Not only does it benchmark and identify gaps, but the approach also facilitates networking, education and team building. For new leaders it is important to remember that you are not alone. Chances are your problem has been solved before. Networks û internal, external, formal and informal can get you started and often save you time and effort. Any leader can achieve success in excellence through a proper process of problem formulation, data and analysis. Again, using key players can make the process more effective. It is important to remember that the people side of the solution is the key to success and that monitoring will ensure the solution will work. In the words of BHP BillitionÆs CEO, Chip Goodyear: Excellence is a mind set. ItÆs something that comes when people get rewarded forthinking outside the box and applying their skill and knowledge. It happens, not in$50 million chunks, but in hundred thousand and million and $2 million chunks.When you get 35 000 people thinking that way, then youÆve really got somethinggoing.

Jan 1, 2005

By P. Schmieder

"The close vicinity of mining companies to other sites that are used for commercial and residential purposes or to areas under conservation as well as the fact that the people become more and more sensitive to emissions have led to a negative attitude towards mining operations in the neighborhood. It is above all the use of drilling and blasting techniques that give rise to objections, in the course of which demands for more environmentally-friendly production methods have been voiced. It is in this context that production methods without the use of explosives are considered as an option. After all, the use of such production methods is the only alternative for some quarry operators. The question is what are the true benefits of these techniques and what is the relation between a possible improvement of the environmental effects on the one hand and the technological potential as well as the costs on the other. It is intended to assess the mining techniques for solid rock in their entirety. This paper will therefore look at the aspects for assessing mining techniques in the context of their environmental impact and the costs."

Jan 1, 2005

By Jacques F. Abrahamse, Kevin A. Bahe, T. Arthur Palm, Gregory E. McCluskey, Stephen L. Bessinger

Introduction Basis For System San Juan Coal Company (SJCC) is a subsidiary of BHP Billiton. Until recently, BHP Billiton operated three surface mines in northwestern New Mexico: Navajo, San Juan, and La Plata. The San Juan and La Plata Mines supplied the San Juan Generating Station operated by Public Service of New Mexico. Stripping ratios at those operations were increasing, and by 2000 a feasibility study was underway to develop SJCC’s vast underground reserves as a replacement. Early in the evaluation and planning phase for the San Juan Underground Mine, it was determined that the target seams (Fruitland #8 and #9) had a high propensity for spontaneous combustion. Spontaneous combustion was identified as a risk, both to personnel and equipment, and to the ability of SJCC to reliably fulfill its obligation to the power plant. In the last 20 years, several western US coal mines suffered underground spontaneous combustion events and/or mine fires. Included in this group were Colorado Westmoreland’s Orchard Valley Mine (1987), RAG’s Willow Creek Mine (1998 and 2000), Oxbow’s Sanborn Creek Mine (1999), the West Elk Mine of Arch Coal (2000), Arch’s Skyline Mine (2002), Western Fuels’ Deserado Mine (1996), and the West Ridge Mine of Andalex Resources (2003). The cause for the majority of these fires was spontaneous combustion. Fighting the fires required injection of an inert gas or foam. Nitrogen and carbon dioxide were the predominant choices of inert gas. In all cases, the gasses had to be trucked in from considerable distances. Before the inert gas could be used, injection holes had to be drilled into or near the suspected fire locations. This drilling and trucking caused costly delays in the timing of the fire fighting effort, and was not as precise as desirable. Emergency purchasing of gas and pumping services was extremely expensive, running as high as $70,000 per day at one mine. As a result of the experience of other western US coal operators, and the risk inherent with spontaneous combustion at SJCC, it was decided to pursue installation of a nitrogen delivery facility on-site at SJCC. This decision was later expanded to include a continuous supply of nitrogen.

Jan 1, 2005

By G. T. Lapidus, J. Trejo-Gallardo

A phenomenological model is presented for leaching silver from silver sulfide contained in mineral particles with ammoniacal thiosulfate solutions of copper in stirred reactors. Experimental results were used to adjust the kinetic parameters of the model, such as the reaction order and velocity. The incorporation of the cuprous sulfide-silver sulfide equilibrium at the reaction interface allowed the prediction of the conversion limits for different reagent concentrations. The information obtained from the reactor model was later integrated into a heap leaching simulation, whose results adequately describe tendencies observed in column tests, with respect to variations in copper and thiosulfate concentrations. Comp

Jan 1, 2005

Mine Terex articulated dump trucks are working on a large restoration project of an abandoned open cast coal site in Blacklaw, central Scotland. The project is part of the construction of a 42-turbine wind farm complex. During the scheduled 18-month duration of the project, three 28-t(31-st) Generation 7 TA30 dump trucks and the six 36.5-t (40-st) TA40articulated trucks are estimated to move about 1Mm3 (1.3 million cu yd)of material. The trucks are working12-hour shifts, 5.5days a week.

Jan 1, 2005

By V Kumar, A S. Venkatesh, R K. Upadhya

The enormous iron ore deposits of eastern India are part of the volcano-sedimentary basins containing iron and to some extent manganese deposits that belong to the Iron Ore Group (IOG) of Archaean Singhbhum Craton, occurring as western and eastern limbs of a broad synclinorium. The eastern iron basin contains typically huge amounts of blue dust and powdery ores. There is a remarkable difference between the western flank ores and the eastern flank ores and the present study is part of the eastern flank ores from Noamundi. Demand for sintered fines as blast furnace feed coupled with the higher export price for lumpy ores that produce enormous amounts of fines during processing has created a situation whereby both primary and secondary fines, such as classifier fines, are being increasingly used as sintered feed for blast furnace. Systematic mineralogical and geochemical characterisation indicates that in many cases the ROM and classifier fines have to be processed to increase their Fe content and at the same time reduce their Al, Si and P contents. The fines which are already at micron sizes are amenable for beneficiation using the Mozley mineral separator and sink float test. It was observed that beneficiation was better and significantly greater by the sink float method than the Mozley mineral separator. Mineralogical and chemical studies of the fines reveal that around 80 per cent of alumina bearing minerals (gibbsite, clay and silicates) are present in the liberated form. Microscopic studies confirmed that the iron minerals are well liberated by controlled grinding to -300 mesh sizes with the beneficiation of iron ore fines and low-grade ores carried out using the Mozley mineral separator and sink float test. Beneficiation using the Mozley mineral separator increased the grade of concentrate with increasing flow rate of water as well as increase in amplitude of oscillation of the tray, but not very significantly with the increase in slope of the tray. In this method, though, iron concentration improved from 47 to 63 per cent with a recovery of around 67 per cent. It is not suitable for industry scale operation as only a small quantity of ores can be handled at a time. Beneficiation using the sink float test produced a better result with the Fe content increasing from 47 - 49 per cent to 66 - 68 per cent with a recovery of approximately 58 per cent. Initial feed Al2O3, SiO2 and Fe contents of 9.85 per cent, 15.3 per cent and 49.8 per cent respectively were beneficiated to 2.13 per cent Al2O3, 1.5 per cent SiO2 and 67.5 per cent Fe in the concentrate, with a recovery of 54.1 per cent. In contrast, using the Mozley table resulted in beneficiable contents 66.3 per cent Fe, 3.01 per cent alumina and 2.05 per cent silica. The combined alumina and silica content for the Mozley Table was >5 per cent, which exceeds the industry requirement of

Jan 1, 2005

By C. M. Diaz, S. W. Marcuson

In the late 19th century, the discovery of rich nickel-copper sulfide ore bodies in Sudbury and the need for tonnage quantities of the metal to be used in nickel steel armor provided the foundation for establishing the Canadian nickel industry. For almost 50 years, International Nickel was the key player. In 1930, Falconbridge Nickel entered the field. These two companies remain the key Canadian nickel producers. This paper discusses the factors that have influenced the evolution of nickel smelting processes. The initial Sudbury ore smelting and nickel copper separation technologies were imported from abroad. It was only in 1937 that International Nickel established a process research laboratory in Copper Cliff The explosive post WW II industrial development created a strong demand for a broader variety of nickel products. For both International Nickel and Falconbridge, R&D became an essential business tool to succeed in the new market scenery. In the last few decades, new technologies were developed and commercialized to respond to the raising cost of energy, society pressing environmental concerns, the advent of nickel laterites as an important source of new metal, the incorporation of new nickel producers to the market, and, therefore, the need to increase productivity. Canada thus became an important exporter of technology. In this paper, the authors review this history with the objective of highlighting the forces that have triggered the most important changes in Canadian nickel smelting.

Jan 1, 2005

By G. Beckstead, L. Gormely, R. Zimmer, K. Hanneman, B. Nethery

As part of the EIS and permitting activities for the Pogo Mine in Alaska, a risk assessment study for the water management plan was carried out. The basis for the study was a site water volume and contaminant balance model. Probabilistic modeling was carried out using the @Risk Monte Carlo simulation package to investigate the frequency, quantity, and quality of discharges under varying assumptions. The results were used in discussions with regulatory officials as part of the permitting process for the project. The simulation allows probabilistic modeling of key environmental parameters based on input frequency distributions involving both quality and quantity of flow. When combined with predictions of water treatment plant capacities and removal efficiency, this was very useful for defining the likelihood of important regulatory outcomes. Based on the model, certain project modifications were made. Using the simulation as a basis, ongoing dialog with regulators led to consensus that all potential risks have been considered and mitigated for the Pogo Mine according to their likelihood and severity, and that regulatory requirements would be achieved. The paper describes the model and some of the applications for which it was used.

Jan 1, 2005

By Henri Letient, Tom Aley, David Evans

Antamina is a large open-pit copper and zinc mine located within the Central Andes of Northern Peru at an altitude of 4300 masl. The facilities are situated within the headwaters of several watersheds, within the Amazon basin. Nearby villages rely heavily on springs and streams for drinking and irrigation water. The principle source of baseflow during the dry season is from Cretaceous karstic limestone aquifers. Antamina will produce nearly 1.4 billion tonnes of waste rock over its mine life. Finding suitable sites for storing large volumes of waste rock is often a challenging task – especially in karstic, alpine terrain. Detailed hydrogeological investigations are essential for delineating the karstic hydrogeologic watersheds associated with the proposed waste facilities, which are often very different than topographic (hydrologic) watersheds. Contamination vulnerability mapping at Antamina consisted of geological and karst mapping, geophysical surveys, geochemical testing, dye-tracer studies, drilling and aquifer testing. Detailed mapping followed by dye-tracer studies proved to be the most cost-effective methods for characterizing the karst aquifer systems. The results were used to optimize waste rock management at the site to minimize potential impacts on groundwater resources.

Jan 1, 2005

By Steve Kral

Improved metals and other commodity prices have caused the mining industry to open new mines, re-evaluate development opportunities at potential mines and increase production at existing ones. This sense of renewed optimism is being seen at operations and development projects around the world. Except in the United States. The regulatory structure there has not allowed the domestic industry to share much in mining’s resurgence. It can still take up to 10 years to permit a new mine. And, while Clinton-era regulations regarding mill sites have been put on hold, existing mines that wish to expand operations still face significant regulatory and environmental hurdles. But things may begin to improve in the United States.

Jan 1, 2005

There is an increasing demand for refrigeration as mines progress deeper. Mine refrigeration plants have special requirements in terms of their duty and application. There are no national or international standards applicable for the testing of these plants. There have been numerous examples of plants failing to meet their required nominal capacity, but with the plant owner being unable to enforce the design duty on the manufacturer, due to a failure to unambiguously specify testing or accepting criteria. This paper discusses some of the reasons for performance shortcomings and describes a methodology for developing and specifying performance criteria, when inviting design and/or construction tenders, and a method of performance and acceptance testing once the plant has been built and commissioned. These guidelines encompass the full range of performance duties expected from a mine plant, including stable operation at maximum and minimum plant capacity, and under the various combinations of extremes of high and low condensing and evaporating pressures. A description of a methodology for developing a computer-based mine refrigeration plant model is also presented as part of the performance testing criteria. The methodology is illustrated with reference to the actual performance and acceptance testing process used on the worldÆs largest bulk air cooler (R67) at the Enterprise mine at Mount Isa, Australia.

Jan 1, 2005