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A modular computer-based monitoring system for mines is dis-cussed. The system consists of the following modules : production moni-toring system HADES, methane monitoring system CMC, seismoacoustic and seismometric systems SAK and SYLOK, communication systems. The system enables one to compose flexible,` economic structures according to the specification of a mine. Application of microcomputer-based monitoring and control systems in coal preparation plants also is discussed.

Jan 1, 1985

By P Cepuritis, G Chitombo a, I Brunton

There is a significant amount of past evidence that links blasting and occurrences of slope failure. Particularly of great concern at Telfer Gold Mine is the effect of open pit blasting on the stability of the footwall slope above the underground portal and the stability of underground structures. For this reason, Newcrest Mining Ltd invited JKMRC to conduct necessary field measurements and numerical modelling with the following objectives:assess the dynamic stability of the footwall slope above the portal; assess the characteristics of current and future blasts in the open pit; and prepare open pit blasting guidelines that will minimise the detrimental effect of blasting on slope stability. To achieve these tasks it was necessary to develop a scaled distance attenuation curve for blast vibrations. In order to validate the developed vibration attenuation curves it was necessary to monitor vibrations from a production blast. Using JKMRC blast design software tools, the vibration of the production blast was also modelled from the blast design and vibration results from single hole blasts. The intention was, assuming that the observed and modelled vibrations were close in terms of frequency and amplitude, to use the software tools to model the vibrations of future blasts and assess their likely effect on slope stability. Numerical modelling of the dynamic stability of the footwall slope was done using the FLAC finite difference code and the UDEC distinct element code. The results of the numerical modelling and of the field measurements of the blast induced ground vibrations were combined into the blast design rules that relate distance between the slope and the blast, charge weight per delay and number of blasts necessary to cause failure of the slope.

Jan 1, 1999

Although the effects of sea level changes on ore concentration processes are to some extent obvious with certain deposits, e.g. beach placer deposits, they have been largely overlooked with others such as Mississippi Valley type lead-zinc deposits. It is contended that sea level variations may have more profound effects on a wide range of deposits than has previously been appreciated. These deposits include not only placer'and residual deposits but also stratiform copper deposits, Mississippi Valley type deposits, stratiform manganese deposits and Minette type iron deposits. Sea levels in paralic basins profoundly affect the influx of 'detrital sediment, and this has to be suppressed to allow for the accumulation of thick rich deposits of coal evaporites, phosphate or metalliferous sediment. Emergence can be associated with oxidized waters, erosion, and,solution of soluble rocks. Submergence can reverse the Eh trend and can lead to preservation of ores. Both realms of surficial sedimentary environments and subsurface diagenetic environments can be affected by changes in water pressure, gas pressure (pC02), Eh, pH, and temperature as sea levels fluctuate. Even relatively small sea level changes may have profound effects. For example, there is some evidence to suggest that when the level dropped below 100 metres about 10,000 years ago, the Red Sea became isolated by the sill at Bab el Mandeb in the south, and evaporated away to leave a series of shallow lakes. The Red Sea is 1 to 2 km deep. It was at times such as this that the well-known copper-zinc mineralization developed in the Red Sea trough. Changes in sea level also affect the stability field of gas hydrates which can yield large volumes of gas leading to mass movements on the sea floor (Warnke, 1986).

Jan 1, 1987

By K Hskansson

In earlier studies along a mining region recipient (the river VormbScken, northern Sweden), the fraction of certain trace metals recovered in the particulate phase has been found to increase with increasing concentrations of particulate iron. This study was conducted to see if the pattern could be reproduced by adding minor amounts of ferrous iron, simulating groundwater inputs. When the iron is oxidised in the near neutral river water, it will form iron oxyhydroxides and precipitate. Trace metals may be either co-precipitated along with the iron, or adsorbed onto the freshly formed precipitates. If this is the case, such a mechanism may be incorporated as a part of a final polishing step in a mine drainage treatment system based on natural attenuation processes. The experiments were performed at 0¦C and 22¦C, on authentic river waters collected during the winter and summer of 2002, respectively. In order to investigate the influence of particles and bacteria initially present, filtered river waters (4 solution were added to the experimental beakers, increasing the iron content of the waters by 0 - 1.5 mg/L. The oxidation and precipitation processes were followed by means of filtration (0.2 ¦m) for up to seven days. In order to be able to compare the experimental results with the actual field situation, on both experimental occasions, surface water samples were collected also from three stations situated along the river. The samples collected were analysed for iron, calcium, and trace metals by AAS and ICP-MS. The iron oxyhydroxides formed in the experiment did not influence the partitioning of As, Cu, and Pb to the same extent as the particulate iron encountered along the river appeared to do. Cd and Zn were recovered mainly in the dissolved (

Jan 1, 2003

By T Cutts

Since 1989 Kalgoorlie Consolidated Gold Mines has managed the Kalgoorlie gold operations of joint venture partners Normandy Mining Ltd and Homestake Gold of Australia Ltd. Current production from the Fimiston Open Pit is approximately 650 000 ounces per annum. The mine incorporates a multitude of narrow shear hosted, subvertical lodes, predominantly within Golden Mile Dolerite. Traditionally KCGM has used blasthole based grade control in the Fimiston pits. A single sample is taken from vertical production blastholes, drilled on ten metre benches. This process was improved with the addition of infill drilling along blasthole rows to provide additional samples across strike. However the limitations of adequately defining subvertical mineralised structures with vertical blastholes remain. In 1997 the first of two trial areas were drilled with close spaced, inclined Reverse Circulation (RC) drilling. These tests indicated that RC based grade control had the potential to provide significant advantages. These include:improved delineation of mineralised structures, particularly across strike; reliable short-term mine schedules based on the advance data available from drilling over three benches; and the angled RC drilling is capable of providing samples of near stope and stope fill material which often remains unsampled by blasthole drills due to the safety constraints around unstable underground openings. Based on the success of this initial work RC based grade control was gradually implemented across production areas commencing September 1998. Some of the many challenges faced include:development of effective procedures and systems for the planning, logging, interpretation and modelling of the RC data; obtaining adequate drill coverage due to mine scheduling constraints and restricted access around underground openings; requirement for integrated systems to handle either blast hole or RC data; and development of effective methods to evaluate the performance of RC grade control. RC based grade control is delivering significantly improved lode definition, grade estimation and subsequent ore classification.

Jan 1, 2000

Presidential Address Today I want to couple that prediction with a discussion on competitiveness and changing employment roles in our industry. A crude analysis of the intensity of use of metals in developed and undeveloped nations was undertaken by dividing the weight of copper, zinc, lead and aluminium used in countries by the population. In the developed countries which were basically the Western European States, USA, Canada, Australia and Japan, approximately 38 kilograms are used per annum. In the developing countries which were basically the South-East Asian country Korea, India, Pakistan and Taiwan, the usage is 5.3 kilograms. Thus, if the developing world is to catch up with the developed world, the intensity of use of metals will have to increase seven times. The usage of metals in the developed world is increasing at the rate of 1.5 per cent per annum while the rate of increase in the developing world is about 5.8 per cent. In this analysis, the population of the developed world was 850 million and the developing world 1.5 billion. Note that this analysis did not include Russia, China and most of the countries of South America and South Africa. I am sure that with time, these undeveloped countries will move into the developing category. In the long-term there is obviously great opportunity for us both in the primary and secondary processing required to meet world demand. Turning now to competitiveness and changing employment roles. I am sure that everyone here present is aware of the urgent need for Australia to improve its competitiveness. I want to try and relate unionism and industrial relations, management and tertiary education to our competitiveness. I wish to talk on these items as I see them in the past, the present and the future. So firstly unionism and industrial relations. It has been unfortunate for Australia that unionism was based on the United Kingdom craft system. It is not surprising that it was because UK has been the basis for almost ' all of our institutions and that has generally been of very great value to us. The craft system in our trade unions has lead to the demarcation problems of which we have all been well aware. This has been extremely limiting to the individual; it has limited his or her ability to broaden their scope of knowledge and far worse it has limited their ability to maximise their satisfaction at work as they have only been able to undertake part of a job, rather than being able to undertake a role in totality.

Jan 1, 1992

By R M. Tosdal

The Manantial Espejo district (Argentina) hosts a low-sulfidation epithermal Ag (-Au) deposit with a proven and probable reserve of 38 Moz Ag and 0.55 Moz Au. The district lies along the southern rim of the Deseado Massif in the Middle to Late Jurassic Chon Aike Province, a large bimodal igneous province dominated by silicic volcanic rocks that were formed during the initial extension leading to the opening of the South Atlantic Ocean. The district stratigraphy consists of 162 to 161 Ma old rhyodacitic to rhyolitic volcaniclastic rocks of the Chon Aike and La Matilde Formations, followed by 160 to 157 Ma old andesites and dacites of the informally called intermediate formation. The main stage of normal faulting post-dates the volcanic activity and coincides with the formation of the precious metal veins that were dated by 40Ar/39Ar on hydrothermal adularia with ages between 152.8 ¦ 0.8 Ma and 156.6 ¦ 0.8 Ma. Economically important hydrothermal veins show characteristic features of a low-sulfidation epithermal deposit with crustiform and colloform banding, bladed calcite replaced by quartz and abundant adularia. In the Maria Vein, the major orebody of the district, six hydrothermal stages are identified, but only stages one and four contributed metal. Lead isotope ratios in hydrothermal sulfides show a close relationship to ratios in feldspars from the district Chon Aike Formation, suggesting a common source for the Pb and possibly the precious metals in both the magmatic and hydrothermal products, or that the Pb in the hydrothermal veins was derived from the volcanic rocks. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By d&apos, Alton AJ, Rigden DT

Modern petroleum refining offers a complexity of environments, each requiring different metals for the satisfactory performance of-the various sections of the refinery, and this paper first outlines the varied enva.x¦on-ments thus met.It follows that the metal types in use will also vary to suit each particular environment, and the paper' consequently covers the use of ferrous-metals, ranging from plan carbon steels to the high alloy types and the non-ferrous metals, particularly copper and its alloys.The failures of some,of these metals and alloys are then illustrated by experiences it Kwinana. These failures are duo to (a) corrosion, (b) erosion, (c) faulty welding, and (d) mechanical defects,' of which the first is by far the most prevalent. The protective measures taken to prevent subsequent failures are then given under one or other of the following headings :(1) alterations in process conditions, (2) the use of alternative ,alloys,(3) suitable heat treatment, (4) redesign of the failed section, (5) cathodic protection, and (6) use of corrosion inhibitors.Reference is then made to the use of specialised metals and alloys.Metals, generally in the form of oxides or salts, are also used as catalysts in refining processes. Activated alumina is used, combined with silica .forScracking' of heavy oils, and as a support -for platinum, cobalt, molybdenum, nickel and similar metals, which catalyse hydro-genation and dehydrogenation-processes. .In the final formulation of petroleum products metallic compounds may be added. Reference is made to the large quantities of lead used by the petroleum industry and to the use of metallic soaps and detergents in the formulation of lubricating oils and greases.

Jan 1, 1962

Statistical frequency distributions may be used to characterize the overall variation of grade in orebodies. Special types of distribution (e.g. lognormal, log-type A) are necessary to describe skewness inthe case of rare metals. Also needed (but for the most part hitherto neglected) is the serial correlation function which describes the tendency for grades near together in an orebody to be closer together than grades at points relatively far apart.The sampling problem for orebodies is interpreted in statistical terms. Different methods are reviewed, and the effect of serial correlation discussed.A discussion is given, based on experiments and observations made by the author, of biases arising in the minei:l material by such methods as chip sampling and grab sampling due to such causes as nonrepresentative selection by the sampler.INTRODUCTIONMiners have always recognized the large element of chance in their operations. Chance is the raw material of statistical theory and, provided there is some recognizable pattern or underlying regularity in a set of data arising from the operation of chance events, statisticians are able to formulate mathematical models to study them. Mining engineers, geologists, and statisticians have gone a long way between them towards finding general statistical rules which describe the distribution of minerals and metals in orebodies, and even the distribution of orebodies over the earth's surface.These rules do not have the force of physical laws, though they obviously derive from them and have been used to throw light on them. From statistical theory it is possible to find methods of estimating from sampling some of the characteristics of orebodies which are of importance to...

Jan 1, 1962

By Hematian J

A high horizontal stress field has significant effect on the stability of underground roadways and influences the design of a support system in this environment. The high horizontal stresses at E1lalong Colliery, NSW, Australia provided the environment for this study. Samples of coal measures 'rock were collected and tested to determine their mechanical properties. The lithology, stress state, geometry and conditions prevailing in particular areas of the mine were obtained from geotechnical reports available at the mine and by field observation. The results of a series of finite element models constructed and tested under various conditions provided a basis for comparison with field observations. Analysis of the results indicated sufficient correspondence to provide a basis for the proposed design of an optimum support system. It is not suggested that finite analysis provides 'exact answers', but it does show the relative importance and interaction of various parameters.

Jan 1, 1995

A feasibility study will fail its objective if it does not identify and then correctly assess, all the risks which could have a substantial impact on the financial viability of a project. Before this assessment can be undertaken, one needs to understand the risk profile of the entity which is making the decision about the project. Some of the commonly encountered issues when assessing project risk are related to the problem of not being able to see the wood for the trees. In any risk analysis it is important that conservatism does not strangle a viable project; that the variables are internally consistent with each other, that reality checks are carried out and that appropriate expertise is used. Sensitivity analysis forms a part of the overall project risk assessment; however, it can only test those variables which have already been identified in the financial model. The most useful tool in performing a sensitivity analysis is Monte Carlo simulation. When properly used, it provides a more real world scenario than the simple adjustment of key variables by ¦ 10 per cent one at a time. Monte Carlo can provide valuable information about the robustness of a project. Project risk and sensitivity assessment is prone to the analysis paralysis syndrome. The focus should be on quality rather than quantity.

Jan 1, 1997

Declining from surface provides access, haulageway, ventilation and provision for ser- vices for stoping and development. Three boom jumbos and 3.8 m3 capacity diesel loaders are used in decline development, the majority of which is driven at a gradient of 1 in 9. Primary ventilation is drawn from the mine through raisebored airways and high pressure contra rotating fans provide secondary ventil- ation. To meet schedules a special decline crew was formed on similar lines to a mining con- tractor. The basis of payment for the mining party was changed and the net effect was to accelerate development. Ground conditions demand constant support and this is achieved with chemical anchor rock bolts, multistrand grouted bolts and shotcrete. Major local shear zones are encountered and when they are to be driven through, a combina- tion of the above methods, involving a spiling technique, is used.

Jan 1, 1977

The Coke Ovens Laboratory at Australian Iron & Steel, Port Kembla has been involved in the analysis of seam gases and mine airs for approximately twenty (20) years. This period has seen many developments and changes in the techniques used to the point when the current techniques are equal to other labora- tories involved in similar analyses. The laboratory has NATA registration for the analysis of mine airs and gases. Apart from routine testing of seam gases, ventilation airs and gases emmitted from coal bore cores a number of projects have been undertaken. These have served a twofold purpose, one to provide information to the customer, generally Collieries Research and Technology and secondly in developing the skills and capabilities of the Coke Ovens Laboratory. This paper discusses the development and services available at the Coke Ovens Laboratory for the analysis of gases and airs from collieries.

Jan 1, 1983

By Richards AB

This paper describes the ENVIB software system, which has been developed in a menu-driven form to aid in the monitoring and assess- ment of vibration caused by routine blasting operations and for research and development projects. The paper gives an outline of the capabilities of the system by means of screen-dumps and a general descriptive commentary. Technical notes have been added where appropriate to further describe the system. The ENVIB system covers: I . Analysis of blast vibration results, and preparation of graphs and tables for control and estimation purposes. 2. Effects of atmospheric conditions and air vibration propagation. 3. Real-time acquisition and analysis of analogue blast vibration sig- nals directly from transducer equipment or from FM tapes. 4. Analysis of digital files on floppy disc or transferred via the serial port from blast monitoring equipment. 5. Transfer function calculation for structure response studies.

Jan 1, 1988

By Haigh C. J

A process has been developed to recover at least 75% of the 2-naphthol contained in cobalt precipitate produced during the removal of cobalt from electrolytic zinc plant solution. The recovered material is in a form suitable for recycling to precipitate further cobalt from solution. The process consists essentially of two steps. The first involves leaching of cobalt precipitate in 400 g/l sodium hydroxide solution at 95¦C in the presence of an additive. The second step involves treating the filtrate from the leaching stage with sodium sulphide to precipitate cobalt as the sulphide thereby re- generating the sodium hydroxide for recycling. The process is only marginally profitable at present 2-naphthol prices, giving a net return of 20% on a capital investment of $1 200 000. A reaction mechanism is proposed which accounts for the 25% loss of the 2-naphthol in the recovery process.

Jan 1, 1977

By G D. Cooper

There are no manuals or handbooks for budding mill superintendents or process plant managers. Most who obtain this level of responsibility have gained their training from watching the good and bad of their predecessors and the successful ones have themselves graduated from the school of hard knocks. This paper attempts to provide some helpful guidelines and direction for those who aspire to better manage a mineral processing facility. The authors have 20 years combined experience in senior management roles at nine different mineral processing operations in Australia and overseas, covering gold, base metals and mineral sands. This summary of tips and pitfalls will hopefully benefit future leaders in mineral processing and metallurgy.

Jan 1, 2007

By I F. Wood

Planning for flooding and assessment of flood impacts are important requirements for mining projects, as they are also for other types of development. With more intense development and concern from the community, supported by government regulatory requirements, assessment of flood concerns and impacts has become of increasing importance. To ensure that flooding issues are fully understood and results presented in an appropriate format, advanced hydraulic analysis procedures have been developed and are beginning to be applied. These procedures must be rigorous in an engineering context but the results must also be readily understood by the community and government agencies. Advanced two-dimensional hydraulic modelling is becoming accepted as an important means of assessing flooding issues for mining projects. With presentation of results from hydraulic models with Geographic Information Systems (GIS), flood impacts can be analysed rigorously and presented clearly. This paper discusses the application of advanced hydraulic modelling in the planning and impact assessment of a major mining project located on a floodplain where there is extensive inundation. The analysis provides for both input to the planning of the project and for detailed assessment of potential impacts. This case study illustrates some important aspects of the application of hydraulic modelling using a two-dimensional modelling to a critical flood design.

Jan 1, 2003

By Newman D, Wyslouzil DM

Different conventional and non-conventional flowsheet configurations were examined for the treatment of a number of refractory lead-zinc and copper-lead-zinc ores containing carbonaceous pyrite, flotable non sulphide gangue and pre-activated zinc. The flowsheet configuration for the processing of complex massive sulphide ores has a remarkable effect on the overall metallurgical results. Conventional sequential flowsheets, with circulation of intermediate products for both lead-zinc and copper-lead-zinc ores, gave poor metallurgical results and often saleable concentrates were difficult to produce. The concept of semi-bulk flotation and double bulk flotation with coarser grinding of the ore, followed by single or double-stage regrinding and sequential flotation was established to be most effective in achieving optimum metallurgical results. This flowsheet design gave superior results as compared to the conventional sequential flowsheet, and resulted in a lower reagent consumption, a significant reduction in the circulation load of intermediate products, and improvement in the rate of flotation of valuable minerals. Thus, optimum flotation conditions were provided for different products within the flowsheet.

Jan 1, 1993

By Kallioinen J

This paper discusses different possibilities to enhance coarse particle flotation using forth manipulation and improved flotation cell design. Experiments were carried out in laboratory, pilot and industrial scale ranging from 0.0015 to 100 m3/axle. During the work it could be shown that the conventional idea of one single flotation cell type for both fine, immediate and coarse flotation of coarse and fine particles need different impeller tip speeds and a different froth control objective for effective operation. For optimal operation for coarse feeds the tip speed must be reduced and the froth vertical velocity must be increased to compensate the respective drainage velocity and also the water film thickness must be taken care of. Turbulent eddies below the froth interface should be suppressed. The paper discusses the effects of different froth manipulation variables like froth vertical velocity and froth residence time to the recovery and selectivity. A function has been developed, between the residence time of the froth and the flotation cell's ability to produce an improved concentrate grade as a function of different operating and froth manipulation variables.

Jan 1, 1993

By G H. Luttrell

The use of secondary desliming cyclones ahead of froth flotation cells to reject ultrafine (-45 ¦m) particles has become a popular option in the United States for preparing fine coal feeds for froth flotation circuits. In light of this popularity, several experimental studies have been performed at industrial plant sites to develop a better understanding of the impacts of ultrafine desliming on froth cell performance and, ultimately, overall plant performance. These studies included an evaluation of various circuit configurations incorporating different flotation technologies (conventional machines and column cells) as well as different dewatering systems (disc filters, screen-bowl centrifuges, and thermal dryers). The data obtained from these studies indicate that deslime circuits offer several important benefits including lower product ash, reduced product moisture, better froth handling characteristics, and lower capital and operating costs. In addition, case studies conducted as part of this investigation have been used to develop generic guidelines for how deslime circuits may be successfully applied to improve the overall profitability of fine coal flotation circuits for both the metallurgical and steam coal markets.

Jan 1, 2005