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By Bastias J

The Ranger uranium mine has operated in the Kakadu region of the Northern Territory since 1979. The mine's water management system was designed to cater for the wet-dry monsoonal climate and to satisfy the recommendations of the Ranger Uranium Environmental Inquiry - Second Report, 1977 (The Fox Report) with respect to environment protection. The Fox Report advised that the aquatic ecosystem of the region must be protected and that the mine should collect all runoff from disturbed areas. Furthermore, the mine was to operate as a no-release system until release standards, based on the experience of several years of operation and on the results obtained from monitoring and scientific investigations, could be established. Monitoring and research data have now been collected for a decade. it is evident that lower-than-expected concentrations of chemical constituents are present in the runoff waters which are retained on site. Standards have been established for the release of these waters to the streams when in flood during the wet season. Mine water quality data and release standards are presented. It can be confidently concluded that controlled release will not cause detriment to the aquatic ecosystems of the Kakadu region. The Ranger operation has demonstrated that environmentally responsible management of mine waters is feasible for future mining ventures in the Kakadu region.

Jan 1, 1988

By W. S. Sadik

This paper presents the ventilation design for an underground testing facility in a salt medium. The underground workings consist of two-12 ft. (3.66 m) diameter watertight shafts and approximately 6000 ft. (1830 m) plus of drifting. These facilities are designed for the purpose of providing access for an in-situ testing of a salt horizon in which a variety of hazardous and non-hazardous materials could be temporarily stored or permanently deposited. The ventilation system includes a design basis for gassy mine conditions and provides for the option of bulk air cooling and heating.

Jan 1, 1988

By Fangting Dong

The broken rock zone (BRZ) and the tunnel support theory are investigated. The relationship between the BRZ and the related factors, the interaction between the BRZ and supports, and the function of supports are analyzed in detail based on the authors' underground observations and model taste. A summary of the application of the BRZ theory in the past is also presented.

Jan 1, 1988

By W. E. Wallace, P. S. Raghootama, M. S. Seehra, C. A. Hill, M. J. Keane, P. Mike

"Dipalmitoyl glycerophosphorylcholine (lecithin) dispersed in physiologic saline, a model of the primary component of pulmonary surfactant, is adsorbed by respirable quartz and aluminosilicate dusts. Dust cytotoxicity as measured by erythrocyte hemolysis and pulmonary macrophage enzyme release is suppressed by this adsorption. The degree of suppression of hemolytic potential versus specific adsorption of lecithin from dispersion in saline by respirable quartz, kaolin, and alumina dusts are compared with dusts' BET specific surface areas to interpret the prophylactic effect cf lecithin adsorption. Dust hemolytic potential versus media pH are presented. Fourier transform infrared spectroscopy and photoacoustic spectroscopy of lecithin on quartz and of lecithin on kaolin are presented and reviewed with results of studies of the time course of removal of lecithin adsorbed on mineral surfaces by digestion by phospholipase enzyme. Results are discussed in terms of a model of prompt neutralization of respired mineral dusts by pulmonary surfactant, and a gradual re-toxification by digestive processes acting on the adsorbed prophylactic surfactant coating following phagocytosis.Introduction Quarts dust of respirable size is well known to cause fibrotic lung disease, but numerous questions persist in the understanding of the initiation and' progression of this disease. Our approach concentrates on physical and chemical aspects of mineral dusts early-on in their interactions with living organisms, and we have chosen simplified models to investigate that interaction. In the alveolar spaces of the lung, tissue is coated with a surface-active material (pulmonary surfactant), which, sagas other functions, mechanically stabilises the lung from collapse by reducing the surface tension of water in the alveolar sacs.(1) This surfactant is also the material that is first contacted by a mineral particle that is transported to an alveolus and is impacted there. This surfactant material has been studied extensively. The primary components are known to be proteins (about 11% in dog lavage fluid). and phospholipids (about 88%).(2) Fhosphatidyl cholines constitute roughly 80% of the phospholipid fraction; about 70% of the phosphatidyl choline fraction is dipalaitoyl lecithin (DPL).(2) Respirable aluminosilicate particles are capable of adsorbing dipalmitoyl lecithin from dispersion in physiologic saline, a model for a possible initial event occuring upon deposition of a particle in a pulmonary alveolus.(3)"

Jan 1, 1988

By M. Remillard, M. Garon, D. Hodouin, M. Therien

"Nineteen streams in the copper and zinc flotation units of the concentrator of the Matagami Division of Noranda Inc. have been sampled f or particle size distributions, chemical assays, and gold and silver contents in each particle size interval. The data are upgraded by the mass balance package BILMA T. These results, in conjunction with microprobe analyses, are used to quantify the silver losses in the copper cleaning flotation stages and to determine how over-all silver and three silver-bearing minerals are recovered in the plant final products. RESUMEDix-neuf produits des circuits de flottation du cuivre et du zinc de la division Matagami de Noranda Inc. ont été échantillonnés pour leur distribution granulométrique, leurs analyses chimiques et Ie contenu d'argent et d'or des fractions granulométriques. Le bilan métallurgique a été obtenu à l'aide du programme BILMA T. Ces résultats, couples avec une étude minéralogique a fa microsonde, sont utilisés pour quantifier les pertes argentières aux diverses étapes de nettoyage du circuit de cuivre et pour déterminer la répartition de l'argent et des trois minéraux argentifères dans les produits finals de l'usine."

Jan 1, 1988

By C. M. K. Boldt

The Bureau of Mines surveyed waste disposal sites at 18 metal and non-metal mines and conducted laboratory and full-scale field tests to de-termine the effects of tailings deposition techniques on physical properties of tailings pond beaches. Survey data included measurements of beach slopes, descriptions of deposition techniques, and measurements of beach physical properties taken at various distances from the point of discharge. Laboratory tests involved depositing two types of tailings, each with different grain-size distributions, into a settling trough and determining the resultant physical properties of settled materials along the length of the beach. Side confinement and the closeness of the water pool to the point of deposition caused the laboratory results to be inconclusive. Full-scale field deposition tests conducted at the tailings pond of a cooperating mine showed that there were similarities in relationships between exit velocities of tailings slurry and physical properties of the settled tailings on the beach.

Jan 1, 1988

By Russell E. Griffen

With the development of larger mine-haulage trucks in recent years, the visual field of the driver has diminished correspondingly. Specifically, the operator's lack of direct vision in the right front area and directly to the rear constitutes a serious hazard to personnel in nearby small utility vehicles. Recently developed electronic technology has made it possible to supplement the use of mirrors and fresnel lenses to warn the operator of specific collision dangers in the truck's blind areas. This Bureau of Mines report describes the results of a coordinated contract and in-house research program to develop and test in-mine prototype electronic systems to detect the presence of smaller vehicles within the blind areas of large mine-haulage trucks. Each system utilized transmitters installed on the smaller vehicles and receivers installed on the haulage trucks. Transmitting techniques tested included both low-and high-frequency radio waves. On-vehicle testing established the engineering feasibility of each approach. Further private sector product development to improve reliability and reduce system costs is recommended. Mining companies should consider the advantages of each type of system.

Jan 1, 1988

By H. N. Maleki

The results of five years of geotechnical investigations are presented to develop productive and stable longwall layouts for the Foidel Creek Mine. The program was initiated during the pre-mining stage, and has continuously provided the data required for mine design. From several stress determinations at the mine, the relationship between geologic structure and the stress field/depth was established. The results were used for orienting the entries for improved stability. Cave conditions and load transfer to panel boundaries were evaluated from closely monitored full extraction mining and computer analysis. Back-analyses of ground movements, as compared with the actual measurements, indicated that cave conditions were favorable in spite of the presence of competent, thick-bedded sandstones in the mine roof. Gate pillar design using a yield-rigid concept was developed through computer analyses and underground instrumentation, resulting in 35 and 75 ft wide pillars. The influence of a slickensided bedding plane at the roof contact on pillar yield zones, core confinement, and pillar behavior was evaluated.

Jan 1, 1988

By Ray Heater, Qian Liu, Alan Bauer

The channel effect is a phenomenon that takes place with decoupling explosive charges; an air shock wave propagating ahead of the detonation wave in the annular space around the explosive charge compresses the charge so that the process of detonation is modified and even stopped. For commercial explosives, such as AN/FO slurries and emulsions, the channel effect causes partial detonation under certain conditions. To simulate and evaluate the phenomenon, a hydrodynamic model was developed based on the assumption that the pre-shock wave is produced by Mach reflection at the tube walls. Based on instrumented experimental studies with the above explosives in diameters ranging from 25 to 90 mm in pipe sizes ranging from 35 to 127 mm, it has been possible to demonstrate that a criterion for failure based on a critical impulse concept fits the experimental data well. Critical impulse values for the various explosives tested are presented along with the necessary correlations between charge and borehole diameter required to produce this.

Jan 1, 1988

By C. R. Zegarra

Extraction of manganese, gold, and silver from a low-grade manganiferous-silver ore was investigated by thiourea leaching followed by standard cyanidation. The levels of reagent concentrations in this investigation were 0.0 -1.0 M thiourea and 0.0 -1.0 M sulfuric acid. Temperature and agitation speed were maintained at Z5 °c and 300 rpm, respectively. The dissolution of gold, and silver was shown to be dependent mainly on sulfuric acid and thiourea concentrations. In general, 50.0 % Ag, 98.0 % Au, and 75 % Mn were recovered from a Mn-Ag ore by thiourea leaching. Overall silver extraction of 98.0 % was obtained by cyanidation after thiourea leaching. Thiourea leaching of sodium bisulfite leach residues was also studied, and the total extraction of gold and silver were 97 % and 40 %, respectively. Finally, a two-stage thiourea leach was also investigated.

Jan 1, 1988

Despite technological improvements and better understanding of the hazards, coal dust explosions stilI occur. Experimental explosions in galleries in various countries extend knowledge with the constant aim of providing safer working conditions. The inadvertent ignition of an accumulation of methane is the traditional initiator of the coal dust explosion.There are specific parameters of coal dust explosibility and explosion propagation, including the important volatile matter in the coal, fineness and dispersibility of the dust and its concentration. Accepting that initiation cannot be absolutely prevented, it is necessary to consider explosion suppression. While both limestone dust and water are the chosen explosion suppressants, in practice water has more limitations to its efficacy when related to the degree of explosion violence. These data give rise to the criteria for explosion suppression, differences in favoured mining geometries, and using the same principles, to differences in suppression treatments.

Jan 1, 1988

By P. R. Richardson

"Milling is the weak link in the process chain of many mineral operations. While this activity accounts for only a relatively small proportion of the direct costs of most mineral processing complexes, there are intangible and indirect costs associated with milling which are extremely large. For example, significant opportunity costs are associated with the relatively low yields which characterize this stage of the process.There are changes abroad in the world which I believe are going to cause us to reformulate the whole concept of milling. Increased competition in mineral markets are going to force managers to look anew at the high mineral values reporting to tailings which are a high opportunity cost for many operations. Tailings recovery plants are not the ultimate solution to this problem. Greater environmental concerns are going to increase the costs associated with tailings disposal and force the mining industry to look for other ways to dispose of waste products. Technology changes currently underway in manufacturing and other process industries, such as the automated 'lights-out' plant are going to be brought into this industry, and the changes will be dramatic.These are major long term changes which probably seem rather remote to many managers and professionals in existing operations which are faced with much more mundane challenges arising from day-to-day operations. However, I believe that milling is increasingly a 'lean and keen' operation involving fewer and fewer people, but who are increasingly skilled and professional. Traditional cost management approaches are no longer adequate and the industry has to take a new look at the nature of cost reduction in this core activity. This stage in the mineral process provides opportunities for value creation leading to a significant unit cost advantage for the corporations willing to adopt a total cost approach."

Jan 1, 1988

By J. F. Edwards

In situ extraction of copper through borehole injection presents a new technology for the mining of copper. For the successful application of this technology, copper recovery at the surface must be specifically designed for borehole injection and the general conditions of the well field. This paper describes the design of a solvent extraction / electrowinning facility specifically designed for in situ leaching of copper. This design is based on commercial solvent extraction / electro-winning with considerations of the requirements of this specific application.

Jan 1, 1988

By Jr. Stokowski

Topsoil for revegetation projects is in demand in many urban areas. In this case history, a large aggregate producer manufactured a topsoil from three waste materials. The topsoil was produced in a 200,000 m2 (50-acre) abandoned gravel pit that still had additional gravel under 10 m (30 ft) of overburden uneconomic to strip directly. The topsoil was produced by rotary mixing of sludge, overburden, and a lime admixture; solar drying; and stripping and stockpiling of the product. A major problem was an increase of topsoil drying times for stripping from 40 to over 100 hours when it was rewet by storms. The problem was solved by a research project that evaluated over 50 formulations and over 20 waste materials. . The final formula dried in 15 hours and contained 3-parts sandy mine spoil, 1-part sewage sludge, and 2 % spent-bed, a granular quick-lime produced during power-plant flue-gas desulfurization.

Jan 1, 1988

By D. K. Ingram

In situ horizontal stresses were measured to determine the influences of geologic anomalies on the regional horizontal stress field in two coal mines in southern Illinois. Stress measurements were obtained near a normal fault having a 121-ft displacement at the AMAX Wabash Mine and a large coalbed want at the Kerr-McGee Galatia No.5 Mine. Horizontal stress measurements were completed using a Bureau of Mines borehole deformation gauge. The average maximum and minimum horizontal compressional stresses at the Wabash Mine were 1,400 and 800 psi, with the direction of maximum stress ranging from N 78° W to N 83° E. At the Galatia No.5 Mine, the averages were 1,500 and 500 psi, with the direction of maximum stress ranging from N 85° E to N 75° E. Generally, the geologic anomalies appear to have no dramatic effect of the regional horizontal stresses. However, subtle differences between stress measurements suggest an influence by the fault zone at the Wabash Mine. The larger anisotropic stress conditions at the Galatia No.5 Mine could be responsible for the increase in kink zones and directional roof failures.

Jan 1, 1988

By H. McSorley

"I note that many of you are involved in the production of zinc, lead and copper concentrates and metal, which I am the most familiar with among the non-ferrous metals. This afternoon, I will describe briefly the responsibilities of a commercial manager within a mining/metallurgical company, the basic framework of a non-ferrous metals concentrate agreement and lastly, a brief discussion of the copper, zinc and lead concentrate and metal markets.I hope this talk will contribute to a better understanding of the business between all of us and look forward to a discussion after the presentation.First of all, I work for Noranda Sales, which is the marketing and sales agent for Noranda Minerals' three operating units: Noranda Copper, Noranda Zinc and Mining Corporation. In addition, Noranda Sales acts for other mining companies in the marketing of their raw materials and metals. Noranda Sales is responsible for procuring all raw materials for Noranda's metallurgical plants, such as the Copper Group's Forne and Gaspe smelters, as well as the sale of surplus concentrates and by-products and metal products. In addition, Noranda Sales trades metals and concentrates and owns a metal brokerage business, Rudolf Wolff, a founding member of the London Metal Exchange. It does $3 billion of business in 60 countries, exporting some 80% of Noranda Minerals' output to the world.What are the responsibilities of commercial management in resource marketing to the mine and metal producers?Resource marketing and commercial administration involves assistance in establishing exploration priorities, contributing to feasibility studies, pre-production planning, product promotion and realization of income for many properties and metallurgical plants through completion of supply and sale agreements with other companie"

Jan 1, 1988

By P. D. Kovscek

The Bureau of Mines has tested a low-thrust water-jet-assisted rotary drill. This work was performed to evaluate the performance of a water-jet-assisted drill operated at thrust levels typical of a handheld manual-thrust operation. Prior work by the Bureau had indicated that using water-jet assist with high-thrust drilling applications would increase drilling rate. Small-diameter holes were drilled in five different types of rock. Thrust and water pressure were varied as the drill rate was monitored. The test results indicate that drilling rates increase with increasing water pressure and thrust. The water jet has more effect on reducing the specific energy when drilling in the harder rocks than in softer rocks. Variation in drill rate for a given rock sample is attributable primarily to the material heterogeneity within the sample. One rock type (Greenwich sandstone) could not be drilled efficiently with the water-jet-assisted drill.

Jan 1, 1988

By Alex C. Smith

This report describes laboratory studies conducted by the Bureau of Mines to evaluate the effectiveness of 10 additives to inhibit the self-heating of coal. Aqueous additive solutions were applied to a bituminous coal with a high spontaneous combustion potential, and the minimum self-heating temperatures (SHT's) of the dried coal-additive mixtures were determined in the Bureau's adiabatic heating oven. The relative effectiveness of the additives was determined by the observed changes in the minimum SHT's of the mixtures, or by the time required for the sample temperature to reach 150" C, compared with the untreated coal and a coal-water blank. Sodium nitrate, sodium chloride, and calcium carbonate were found to be the most effective inhibitors, followed by ammonium dihydrogen phosphate, calcium chloride, ammonium chloride, sodium acetate, and potassium chloride. Two additives, sodium formate and sodium phosphate, promoted the self-heating process. Differential scanning calorimetry experiments on the coal-additive mixtures showed that reactions occurred between the coal and some of the additives, but these reactions did not influence the self-heating process.

Jan 1, 1988

This address was delivered at the Annual Conference Presidential Dinner held in Sydney on 11 July 1988.The Australasian Institute of Mining and Metallurgy brings together, voluntarily, people with a professional interest in the disciplines and skills which are employed in the mineral industry, and in relation to that industry.We come together because we have a mutual interest in improving what is done by the mineral industry, in all its aspects. It is this sense of continuing improvement, of doing better, of doing as well as we can, as our knowledge and skills improve, that unites us in creating and fostering a professional association of likeminded people.We know from our professional training and experience that enormous progress has been made, at an ever-increasing rate, in the mineral industry, particularly this century. We know that the mineral industry has played a very major role in providing the means by which so many more people survive to live longer, healthier ,and more interesting lives, than ever before. Indeed, together with the oil and gas industry, which is an integral part of the mineral industry but has achieved its own commercial distinction, it is fair to claim that the mineral industry has played the major role in providing the means for the advancement of the human, quality of life.We do not need to make any great claims on human society in consequence of our statement of these contributions. The facts, for those who are aware of them, speak for themselves. Our more modest interest, as members of our professional association, is to look to the future, while conscious of our heritage as a guide to what more might be done, in that future.We certainly do not claim that this indisputable contribution made to human welfare by the mineral industry gives us some moral position of superiority from which to claim greater support or understanding from the wider community of people.On the other hand we know that as members of the mineral industry we have a responsibility to do what we can to help other people to be aware of, and to understand the significance of, those facts which will only speak for themselves if we take the trouble to make them known. And we have a number of organisations. The Institute itself, The Australian Mining Industry Council, the various State Chambers of Mines, the industrial relations body, The Australian Mines and Metals Association, and others, each of which in its own way endeavours to add strength to the individual efforts which we each should make.We may look at these facts about our mineral industry as simple dry statistics, even with their undoubtedly improving trends, or we can see them, and portray them to others, as expressing something which is much more. We can portray them as expressing the outcomes of our professional determination to strive to do better, whatever it i,s we find ourselves doing in this mineralindustry.We may seek to describe our efforts as being in pursuit of excellence, or by other such high-sounding phrases, but I prefer to describe those efforts as simply our strivings to make everything we do better next time-much as the dedicated golfer tries to do, but with, may I suggest, more evident success achieved in the mineral industry; which is one reason why I don't try to play golf.May I suggest to you that trying to do better, is very simply the true basis of professionalism? We are trained and practised to see the opportunity for improvement-not to be static in a world which we know is changing so rapidly in every aspect around us. We must be dynamic, which means optimistic, about improving the world in which we find ourselves.

Jan 1, 1988

By R. L. Garrett

The quality of mineral additives used in a drilling fluid (mud) can dramatically affect the fluid's properties and the overall cost of drilling an oil or gas well. The principally wed minerals are bentonite, barite, barite/hematite blends, and hematite alone. The high specific gravity minerals, barite and hematite, are used to increase drilling fluid density. Bentonite clay is used to increase drilling fluid viscosity and gel strength and to provide a low permeability filter cake. A multimillion dollar investment in a well and the safety of the personnel on the drilling rig can depend on how effectively these mud additives perform with other constituents in the mud. This paper points out effects caused by small amounts of certain carbonate and sulfide mineral impurities in barite or hematite and how polymeric extender additives in bentonites contribute to unpredictable behavior of a mud. Effects like these are the reason oil companies using these materials sometimes set their own quality standards beyond those already specified in APZ Spec. 13A. Also discussed in this paper are the current standardization activities of API Committee 13 on these minerals.

Jan 1, 1988