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Poor ground conditions associated with historical workings have presented significant challenges to the drilling of production downholes at the Sons of Gwalia Mine. The combination of foam and polymer drilling, the use of Aquacrete to drill through voids and the practice of lining completed holes has allowed downholes to be effectively drilled and blasted in delaminated ground.

Jan 1, 2002

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 P. Tsakiris

The increasing social interest for the environmental issues, forces the authorities to enact more rigorous regulations. The mining industry is one of the sectors that concentrate vigorous remonstrance. It is an absolutely justified reaction, as a result of the numerous contaminated and polluted sites that have been inherited by previous operations and they remain unremedied. The lack of a consolidated global legislation, transfers the burden of decisions to the national level. This paper consists of two parts. At the first part, it discusses the critical role of the state to form an effective environmental policy, feasible for the context of the national economy. Afterwards it analyses two of the main points, which must be considered by the regulator for the excavation activity, the abandoned sites and the duration of the mining investment. The aims are to defuse, in the short-term, the public pressure, protecting the economic growth and, at the same time, to form a basic structure for the development of the corporate social responsibility. The second part presents an alternative financial instrument for the Greek regulatory framework, conformed to the characteristics of the Greek Economy, and analyses the expected benefits both for the business and the social welfare.

Jan 1, 2002

By A. D. Davis, C. J. Webb, C. S. Johnson, J. L. Porter

The abandoned Belle Eldridge Mine near Deadwood, South Dakota, is on land controlled by the U.S. Bureau of Land Management (BLM) property. The mine produced primarily lead and zinc during the first half of the twentieth century. The BLM has expressed concern about acidic drainage as well as elevated arsenic levels in tailings and waste rock at the site. The mine site was evaluated for remediation in 1998 and 1999. Recent reclamation and remediation work included substantial regrading of waste rock, removal of material where metal loading were of concern, and re-routing of drainage from an adit. Trenching at the site shoed a greater volume than originally calculated during site characterization. Material was removed to a repository that was constructed at a nearby drainage divide. Because of physical hazards, the BLM has decided to remove some historic structures. However, a search of mine records and an inventory of archival materials were complete to preserve the history of the site.

Jan 1, 2002

By C. Green, J. Uhrie, C. Filippone, A. Guzman

A central aspect of heap leach management and recovery optimization is solution control. Insofar as each heap is unique in physical and metallurgical properties, it is essential to understand the hydraulic parameters that control the migration of solution on a case-by-case basis. Water Management Consultants, as part of an ongoing research effort for Phelps Dodge Process Technology Center, have adapted techniques of parameter estimation for application to data typically resulting from metallurgical column testing. The parameterization is completed within the context of a variably saturated flow model that allows interpretation of available hydraulic information collected during hydrometallurgical column tests. A novel interpretation approach is introduced to extract the necessary hydrodynamic parameters from typical hydrometallurgical data sets. Results from the application of the approach to standard metallurgical test data will be presented together with a discussion of the application of information gained to the design and operation of a heap.

Jan 1, 2002

By B. Cavender

Mining managers trying to rapidly reduce production costs tend to implement a traditional set of topdown managerial practices: reductions in production volume, employee layoffs, renegotiation of supplier contracts, cancellation of employee training, restrictions on travel, reductions in office supplies, and so forth. While these practices do reduce costs, the benefits are often limited in both magnitude and duration, and the workforce is usually left demoralized. Successful cost-cutters take a different approach. They make the continuous reduction of costs a priority for all members of the organization, whether managers or workers. The culture of these firms emphasizes the commitment, voluntarily given, of individuals and work groups to this goal. Cost-cutting practices often reject all of the traditional methods mentioned above, but are far more numerous, innovative and successful. This culture of cost reduction is the result of a set of leadership competencies that establish direction for the organization, align the organization's various constituencies with this direction, and motivate and inspire the organization. Cost reduction then becomes a routine task rather than a heroic achievement.

Jan 1, 2002

By Michael J. Nicol

The teaching of courses in geology, mining and extractive metallurgy in Australian universities is undergoing significant change largely as a result of the initiative taken by the Minerals Council of Australia (MCA). This has resulted in a major program aimed at developing national under- and postgraduate courses in selected areas with the aim of making these available to a consortium of participating universities. Murdoch University, together with the A J Parker CRC for Hydrometallurgy has been commissioned to develop the course in hydrometallurgy. Progress in the development of this course will be discussed in terms of overall philosophy, content and mode of delivery. Aspects of the extension to a Web-based course will also be summarized. Murdoch University has also established a hydrometallurgical pilot plant on the campus and the results of the first continuous operation for several months using under- and postgraduate students as operators will be discussed from the point of view of practical training and providing an interface with the local industry.

Jan 1, 2002

By David Newman

The Southern Appalachian coalfield has a long history of coal bumps that are attributable to a unique combination of topography, geology, and multiple seam mining. The high pillar stresses that generate a coal bump result from: i. mountainous topography where the overburden commonly exceeds 1,500 feet beneath ridges, ii. multiple seam mining, iii. thin interburden between active and abandoned mines, iv. thick beds of competent sandstone and sandy shale strata throughout the stratigraphic section, v. strong coal seams, and vi. irregular pillar and mining geometry in older room-and¬pillar mines. Coal has been intensively mined for more than 100 years in Eastern Kentucky, Southwestern Virginia, and Southern West Virginia. As a result, it is commonplace to have abandoned mines above and/or below active operations. Therefore, those conditions that generate coal bumps will be more prevalent in the future, as underground mining continues in Southern Appalachia. The focus of this paper concerns two coal bumps that occurred in the Kellioka seam where both undermining and overmining had occurred. The purpose of the investigation is to determine the magnitude and distribution of vertical stress that initiated the bumps, to identify bump-prone areas in the unmined reserve, and to recommend pillar centers and mining layouts to avoid future bumps. The state of stress in three vertically adjacent seams was examined using the LAMODEL boundary element program. Large, detailed numerical models were constructed of both bump areas and of the remaining unmined reserve block. The results of the numerical analyses were compared with those obtained using analytical equations.

Jan 1, 2002

By Heinz Brandl

Box-shaped pile and diaphragm wall foundations have proved suitable for transferring heavy loads of bridges, power plants, tanks, towers or other buildings in a concentrated form into the ground. The bearing-deformation behaviour and the earthquake resistance of such "box-foundations" are superior to those of conventional pile groups. The reason lies in the reduction of lateral soil displacement and in the composite effect between concrete elements and the enclosed soil. The paper describes results of comprehensive model tests and in situ measurements, theoretical aspects and case histories.

Jan 1, 2002

Accretions of dust on the walls of the offtakes from furnaces and in the waste heat boiler are a cause of significant operating and maintenance problems in non-ferrous smelters. The dust originates from entrained solids in the gas stream and vaporised species that condense during gas cooling. Control of dust formation is very important for minimising the formation of accretions and reducing the severity of environmental problems caused by toxic species, such as those containing arsenic, in the dust. The present paper discusses the formation of accretions and the condensation of dust in copper smelting from a thermodynamic viewpoint. Changes, in gas composition and the amounts and identities of the condensed species in the dust are calculated using computational thermodynamics. Interactions between dust species to form accretions are considered in the light of appropriate phase equilibria. The results show that the nature of the dust formed varies greatly, depending on the temperature and the amount of oxygen present during cooling. Control of the amount of oxygen is required if offtake and waste heat boiler accretion problems are to be minimised.

Jan 1, 2002

By H. E. Bartlett

In the operation of some flotation plants treating platinum ores it was found that there were imbalances between the inputs and outputs. The inputs and outputs were sampled as slurries and it was determined that the imbalances arose from biases in the sampling, despite the samplers having been designed according to well-established rules. The launders feeding the sample cutters, and the sample cutters themselves were redesigned using finite element analysis to model the flows. A new set of design rules were formulated. The application of a Components of Variance Analysis, to determine the variance of primary and secondary sampling and of analysis in the lab for a concentrate is presented to illustrate the need for frequent sampling of process streams.

Jan 1, 2002

By R. Du Plessis, J. D. Miller, D. G. Kotlyar

The low potential hydrophobic state of pyrite in amyl xanthate flotation with nitrogen is of particular interest with regard to the N2TEC flotation technology currently being used for the recovery of auriferous pyrite at Newmont’s Lone Tree Plant in Nevada. The N2TEC system had been found to operate satisfactorily, but cyanide in the flotation mill water appeared to be responsible for a loss in pyrite recovery. This supposition was confirmed with laboratory experiments and a program was initiated to study flotation chemistry variables by electrochemically controlled contact angle measurements. Experimental results show that activation of pyrite in such cyanide solutions can be achieved more effectively with lead than with copper. Subsequently, based on these fundamental studies, significant improvement at the Lone Tree Plant was achieved by lead activation, in which case the recovery increased to expected levels. The effect of activator is particularly significant not only with respect to pyrite depression by residual cyanide, but also with respect to collector (PAX) consumption and the initial state of the pyrite surface. Each of these issues is being studied in detail and research progress is discussed herein.

Jan 1, 2002

By Keith Orgeron, Tibor Rozgonyi, Graham Mustoe, Vilem Petr

This paper presents the results of an experimental and numerical investigation of the shock wave energy transmission and reflection through boundary layers (joints, fractures) or between inhomogeneous geomedium with different physical properties. The conclusions drawn significantly clarify the dynamic failure mechanics because of shock wave energy transmission and reflection through different rock materials and their jointed interfaces. Thorough studies were performed to document the transient, two dimensional deformation characteristics, the normal and shear stress fields for inhomogeneous geomedium focusing on the influence of the internal geometrical shapes, relative density variations and packing of the grain boundaries.

Jan 1, 2002

By K M. Brodie, D I. K McLeod, J Ruddock

Environmental incidents involving mine tailings and waste rock inevitably become highly publicised and serve to damage the credibility of the entire industry. The recent serious incident involving a spill from a Romanian mine, was blamed for triggering æone of the worst environmental catastrophes in Eastern EuropeÆ. It is important to clearly demonstrate to the general public that these incidents are not representative of the industry as a whole. Where such incidents have occurred, the causes are generally related to poor design and/or construction, inadequate supervision and/or monitoring and maintenance, lack of independent expertise, inadequate risk identification and treatment and no provision to ensure that rehabilitation and long term management of the site occurs. Many people are unaware that these issues have been considered and provided for at the Martha Mine. Despite the fact that the first tailings storage facility has performed very well over fifteen years of operation, the long term safety and security of the tailings storage facilities continues to be questioned and debated by the public. The best way to address this is to provide quality information to enable a better understanding amongst the general public.

Jan 1, 2002

By Brian P. Waagner

Construction law in general and the law of deep foundations in particular continues to develop rapidly, particularly in the areas of risk allocation. Public and private owners are increasingly using contractual disclaimers to shift the risk of differing site conditions to contractors, and courts are increasingly willing to enforce these contractual devices. Perhaps also in an effort to control costs, public and private owners are turning to design-build contracting techniques. While design-build offers many advantages over traditional project delivery systems, it does not answer all of the risk-allocation questions that frequently arise. Even in design-build, problems with unanticipated subsurface conditions and defective design are not easily addressed. Finally, developments in electronic commerce present the potential to transform the construction industry.

Jan 1, 2002

By K Brown, J Webster-Brown

Coal mining activity first began on the West Coast in 1864 and has since led to the exposure of large areas of coal and host rock to chemical weathering. These exposed abandoned workings have led to the formation of acid mine drainage, which flows into selected rivers and streams impacting on the natural environment. A previous study conducted for the West Coast Regional Council identified four catchments receiving mine drainage which had elevated arsenic concentrations. The aim of this research is to expand on this initial study by determining the spatial distribution and attenuation of the arsenic within the sediment and water column in each stream of concern. Cannel Creek is influenced from drainage from the Bellevue coal mine adit and exhibits a low pH of ~3, elevated sulfate concentrations and high arsenic and iron concentrations in the sediments. This pattern is repeated in the Rapid Stream and Soldiers Creek catchments, which are also affected by adit inflows from the Sullivan and Blackball coal mines respectively. Soldiers Creek also has significantly high arsenic in the waters, with an accompanying pH of ~5.5. Snowy River exhibits a similar trait with a pH also of ~5.5, but with very low sulfate concentrations. Arsenic concentrations in the waters are consistently around 30 ppb, with sediment concentrations up to 900 ppm. These sediment values might be partially attributable to the operation of the Snowy battery gold ore production facility, but the consistently high As concentrations in the water column and in the sediment upstream of the battery have an as yet unconfirmed source.

Jan 1, 2002

By B. Elevli

This paper deals with the selection of alternative accesses to a podiform chromite orebody in Turkey. The most important alternatives studied in a related project have been stated as a new vertical shaft and a ramp system. The comparison of these alternatives have been carried out on the basis of total investment costs, ore transport unit cost and net present value (NPV) of overall project for various depth. The results show that up to the depth of 700 m, the total investment cost and NPV favours the ramp access while unit ore transport cost make the shaft access preferable.

Jan 1, 2002

By Sushil Bhandari

A computer model is developed for the problem of dispersal of dust (suspended particulate matter) resulting from blasting operations in surface mines. Undulated surface (lower boundary) simulation was carried through sixth order polynomial by least square approximation. Segmentwise terrain simulation was linearly added to build ground feature extending either side of the blast location. Assuming the initial dust concentration in the vertical column to. be uniform and treating the finite vertical line sources as a series of point sources to height, H varying from zero to top of the dust mushroom, integration was done of the concentration effects from H = 0 toL tan[0] (L = horizontal distance of the blast location and [0] is the angle of the top of dust cloud from the point of observation). Using frame of reference moving with the mean wind, the ground level 'concentration (GLC) has been computed over the undulated terrain. Standard deviation (s) of concentration has been parameterized based on mixed layer similarity theory in convective boundary layer.

Jan 1, 2002

By Åke Krukka, Heribert F. Broicher

"The iron ores of the Kiruna Mine in Sweden are of exceptional quality but for the phosphorus content in certain zones of the orebody. The prevention of mixing ores high in phosphorus with those low in phosphorus has always been of significant economic importance. The ongoing introduction of tele-mining and automatic haulage by LHDs requires new means in the field of quality control underground, as the experienced miner as well as the underground laboratory assistant no longer are involved in the process. As of 1998 LKAB has been testing prototypes of LIF Analysers for non-contact and real-time measurement of the phosphorus content of ore being transported by LHDs from the stopes to the respective ore pass assigned to a certain ore quality. The principles of the analysis of laser-induced fluorescence, the different test phases and results are described and conclusions made. With bulk sorting of ore underground the mining engineer supports the efforts of the metallurgist in the processing plant.INTRODUCTIONThe Kiruna Mine of LKAB, Sweden is the largest underground iron ore mine in the world. In the early nineties LKAB decided to develop the Kiruna orebody further down from the 775m main level to a new main level at 1045m. This development programme was realised while in the mineral processing section and in the pellet plant further capacity was added (Wyllie 1996).In addition to deepening of the mine, which opened up 330 million tonnes of ore, the exploitation of the so-called lake ore was included in the future planning, adding another 1 15 million tonnes of mineable ore. At an annual production of approximately 20 million tonnes of ore the Kiruna Mine today looks at a developed ore reserve sufficient for the next 20 years.All of the competitors’ ores traded in the world market are from open pit operations. LKAB compensates for the obvious disadvantages by continuous efforts to make the best possible use of her high quality magnetite ore deposit. This objective is realised by combined efforts in the pellet plant, the mineral processing plant and the mine. Propriety processes, latest big scale equipment and high tech solutions for automation lead to high quality sales products at a reasonable cost."

Jan 1, 2002

By W. Duyvesteyn, B. Sabacky, T. Spitler, D. Verhulst

"The Altair TiO2 pigment process is based on hydrochloric acid leaching of ilmenite at high-acid concentration. Titanium is transferred by solvent extraction into a high-purity aqueous stream with a high titanium concentration. HCl gas is recovered by pressure-swing distillation and is used to regenerate the leaching solution.A new method of TiO2 recovery in dense film with simultaneous dehydration and hydrolysis provides great flexibility in adjusting the characteristics of the TiO2 pigment product.Modifications of this method lead to a flexible, low-cost, high-tonnage process first for the production of nano-sized TiO2, and later for stabilized zirconia-based nanomaterials and nano-sized titanates.IntroductionProcesses for the production of TiO2 from ore by a hydrochloric acid route have been proposed in the past. Most of these processes dissolve impurities and recover TiO2 as a residue or as a hydrolyzed phase in the original solution (Turner, 1948; Berkovich, 1975; Morris, 1982; Judd, 1986; Chao, 1993). Solvent extraction of titanium after leaching in aqueous HCl has also been studied (Tsuchida et al., 1982; Narita et al., 1983) or at least mentioned as an alternative (Ellis, 1963). A number of small-scale studies on leaching and solvent extraction in both sulphuric and hydrochloric systems have appeared recently (John et al., 1999; Lanyon et al., 1999; Sole et al., 1999. As far as we know, only Kerr-McGee (Morris, 1982) and a plant in India and one in Malaysia use a hydrochloric acid route (20 wt% HCl) to commercially produce synthetic rutile.The Altair process originated in a search for an economical method to treat high-magnesium ilmenite deposits, while avoiding the production of a waste metal salt by-product. The first attempts aimed at producing pure TiO2 by leaching out the impurities. Further work centred on completely dissolving the ilmenite in concentrated hydrochloric acid and reprecipitating TiO2. To decrease the impurity level in the product, solvent extraction of titanium into a purified stream was introduced. It also became clear that to take full advantage of the increase in leaching efficiency provided by concentrated acid, it was necessary to regenerate HCl gas."

Jan 1, 2002