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By Adeloju S, McQuade CV, Riley SJ

Metal contamination of sediments can be an issue for minesites discharging water. Water sampling of receiving waters is frequently undertaken. Sampling and analysis of sediment is less common. The variability of receiving environments makes the formulation of a generic sediment sampling strategy virtually impossible. Each situation needs to be carefully assessed before sampling is undertaken. This paper outlines the approach taken for one such survey.The main factors that need to be considered in a survey of surficial sediments are sample representativeness and sample variability. A simple data set from one site within a regional survey is used to illustrate the importance of these factors. The metal content of sediment is shown to vary significantly over small spatial scales.The variability associated with the spatial distribution of samples within a site is shown to be the most significant source of variability in the study. This variability could bias the results of a study if not planned for in the sampling methodology. Taking multiple samples from within each site (sub-site samples) and combining the data gives a more representative indicator of overall conditions than a single sample. The optimum number of sub-site samples to be taken from each sampling site was found to be 15.It is shown that a composite of sub-site samples can give a good indication of the average site metal content, while considerably reducing the sample preparation and analysis effort.

Jan 1, 1998

By Wills BA, Barley RW

A brief description of viscosity measuring devices used in Dense Media Separation (DMS) plants is given, including a new On-line viscometer system. The various factors which affect suspension viscosity are identified. The effect of temperature variation on viscosity and viscosity measurement is examined in detail. Practical problems in using a modified Stormer viscometer for laboratory testwork are noted. Likely problems of continuous viscosity measurements are also discussed.

Jan 1, 1987

By Wilson CJN

The central Taupo Volcanic Zone is a region of intense Quaternary silicic volcanism accompanying rapid crustal extension. Modem central TVZ is the most frequently active and productive silicic volcanic system on Earth, erupting rhyolite at c. 0.28 m' s'. The rhyolites show no major compositional changes with time, but the total extent of magma chamber zonation has changed with the advent of rifting and crustal extension at c.0.7 Ma. At least 34 caldera-forming ignimbrite eruptions have formed a complex sequence of relatively short-lived, nested and/or overlapping volcanic centres in central TVZ. Taupo contrasts with other large silicic magmatic systems in the exceptionally high frequency, but small size, of caldera- forming eruptions. This contrast reflects the thin, rifted nature of the TVZ crust, that precludes the development of long- term magmatic cycles at Taupo.Within central TVZ, non-rhyolitic compositions have been erupted apparently irregularly in time and space; in particular there is no evidence for a geographic separation of basalts from andesites. TVZ is a rifted arc, but its segmented nature, high thermal flux and voluminous rhyolitic volcanism make it unique on Earth.

Jan 1, 1995

By Lean P. J

The present The Zinc ODrporation, Limited and New Broken Hill Consolidated Limited (ZC/NBHC) tailing dam (Site C) is expected to reach its terminal capacity late in 1985. Planning and design of new facilities for disposal of tailing after 1985 which includes new tailing dams (Site D) commenced during 1980. This paper briefly describes planning guidelines and specifications, location considerations, environmental aspects, operating strategy, engineering specifications, envirormental aspects and scheduling of works.

Jan 1, 1983

The goal of the Bureau of Mines, U. S. De- partment of the Interior, diesel engine research program is to reduce exhaust emissions and mini- mize the risk of fires and explosions caused by the use of diesel-powered equipment in under- ground mines. Significant results of research conducted during the last 5 years are briefly described, with references to published reports on specific topics. Topics covered here include brief discussions of a newly completed diesel research laboratory, the effects of a fuel addi- tive on diesel exhaust particulate matter, the effect of diesel engine maintenance on emis- sions, a diesel particulate filter for equipment used in underground metal and nonmetal, and coal mines, and lastly, the prototype hydrogen- powered mine vehicle. These research accomplishments could favor- ably affect the mining industry by reducing the health and safety hazards associated with the use of diesel-powered equipment in underground Mines.

Jan 1, 1988

The initially cautious approach taken towards ground support and reinforcement at the Porgera Underground Gold Mine in the Highlands of Papua New Guinea has evolved rapidly in the two years since stoping commenced. The confidence to continue the evolution process has grown from an increasing knowledge of mining conditions as stoping has progressed, to the extent that reinforcement requirements have decreased by 50 to 75 per cent depending on local circumstances. Changes to mining practices have significantly assisted and influenced this process.Empirical observations of ground behaviour, assisted by a deliberately selective extensometer monitoring program, provided the stimulus for early changes to ground support and reinforcement practices. Further optimisation of the ground support and reinforcement effort is being pursued through an active monitoring, measuring and analysis program. Ultimately, situation rather than site specific design will ensure continuing high quality ground support and reinforcement installations. However, local structural and lithological factors will continue to become more critical as the optimum position is reached.

Jan 1, 1993

By Whittaker B. N, Reddish D. J

This paper presents the physical modelling results of subsurface fracture development associated with Iongwall mining operations and an application of image processing techniques to interpretion of the results. Physical modelling results haióbeen obtained by employing a large sand and plaster model loaded purely by gravity as a means of fracturing the subsurface strata above the longwall excavation. The results have shown fracture development and crack propagation as a longwall face advances and demonstrated that the strength of stratified rocks, the presence and position of a weak band-, and the extraction thickness, have significant effects upon the overall fracture patterns above the excavation. Binary images of fracture patterns were scanned from the black and white photographs of the tested models using an image analyser coupled to a video camels. These images were manipulated by a custom written C program which allows the images to be processed in both vertical and horizontal direction. The images were filtered to quantitatively differentiate between vertical and horizontal fracture intensities. The vertical fracture intensity is particularly important as vertical fractures are considered to provide the main avenues for surface and subsurface water inflow into the excavation. The use of the image analysis techniques has shown a promising improvement in image enhancement and in model results interpretation in a quantitative manner. The numerical nature of the image analysis results will allow further statistical comparison with other modelling techniques to be undertaken and significantly increase the scope for use of the modelling technique results.

Jan 1, 1992

By Takagi T, Seetharam R, Sie SH, Naito K

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medical/high-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnSZ), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

By Glenn R. J

Treatment processes are outlined for the recovery of rutile and zircon from the heavy mineral-bearing sands on the east coast of Australia. With the exhaustion of the higher grade deposits and the imposition of more rigid specifications for the finished products, strict metallurgical control has become necessary.A description is given of the methods used by The Titanium Alloy Manufacturing Co. Pty. Limited to control the operation of suction dredging, of wet concentration using fans and spirals, and of dry separation using high tension and electromagnetic processes. By applying these methods a plant designed for an output of 15,000 tons of rutile per year has been tuned to produce over 20,000 tons of rutile and a corresponding amount of zircon.Details are given of (a) the method of drilling to determine the extent and grade of the ore bodies, (b) a simple electrically-timed pneumatic automatic sampler, and (c) the methods developed for the physical estimation of quartz, rutile, zircon, ilmenite and "others" in the products of plant operation.The method used for calculating the metallurgical balance and the forms used for the reporting of production results are presented.Examples are given which show the value of this detailed production and metallurgical control of plant operation.INTRODUCTIONThe organization which is now known as "The Titanium Alloy Manufacturing Co. Pty. Limited" (T.A.M.Co.)-a subsidiary of National Lead Company-commenced operating at Yamba, N.S.W., in 1935. A mixed natural concentrate was at first simply dried and bagged and later was upgraded by the removal of silica and the lighter heavy minerals on shaking tables and, after air-drying, was bagged for export. At that time zircon was the most wanted constituent.

Jan 1, 1960

The key concepts relating to the calculation of recoverable reserves for selective mining in open pit gold operations are discussed. While the general concepts are relevant to a wide range of gold ore bodies, their application is specific to particular ore bodies.The important factors contributing to the recoverable reserves aregeology, mining method, dilution, ore loss, sampling methods and theultimate bench height used in production.The implications of current methods of computing recoverable reservesare reviewed and some alternative approaches to recoverable reservecomputation based on production experience are presented.

Jan 1, 1986

Longwall mining has historically been considered an application for only deep reserves. This has changed in the recent past as longwall has become competitive with surface mining. Many resources marked for stripping now he in the domain of longwall. Today, the best longwall mines compete with strip mines operating in even the lowest stripping ratios. Longwall mining has become more widely applicable than it ever has been in the past and it is now generally considered the method of choice in situations where high levels of coal production are required. But the best way to use longwall mining has become less certain with the opportunities that highwall access provides. Wall-to-wall mining is the use of retreating longwall developed from and retreating toward a highwall. As a surface mine reaches its ultimate highwall, the opportunity for longwall punch mining or wall-to-wall mining is obvious. There are several clear operating advantages to operating a longwall in this way and where highwalls are available, the best economic decision will generally favor planning a direct approach. Yet wall-to-wall is not applicable in every situation even when highwalls are available. Moreover, the advantages of wall-to-wall mining do not always justify the cost of trenching or box cuts to access coal . However, many tactical advantages of operating from the highwall can be realized with the use of specially equipped blind drilled or raised bored shafts. This paper discusses novel techniques for a shaft assisted mining system which permits the addition of conveyor structure and mine systems from the surface to the face for advance and retreat mining with longwall, shortwall or room and pillar panels.

Jan 1, 1998

By P Hollings, J Holliday

Porphyry copper, gold and molybdenum deposits form in subduction-related settings in association with calc-alkalic or alkalic magmatism. Hydrothermal alteration assemblages are zoned, with potassic cores and propylitic haloes overlain by extensive domains of clay alteration and silicification (lithocaps). Copper sulfides, gold and molybdenite typically occur in veins or hydrothermal breccias, and less significantly as wall rock replacements. Epithermal deposits may form above or to the side of porphyry systems, and may be juxtaposed into the core of a porphyry deposit if rapid uplift and exhumation occur through the life of the magmatic-hydrothermal system. Volcanichydrothermal breccia pipes (ædiatremesÆ) commonly form late in the life of a porphyry system. They may contain clasts of porphyry-style mineralisation, and can host significant epithermal gold resources. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

The reasons for selecting two stage pebble milling in preference to conventional methods of grinding are discussed. Commissioning of the first section was completed in October, 1969. Improvements in both the operating and engineering aspects were then incorporated in the section commiss ioned in March, 1971.

Jan 1, 1975

By Bowden MW

Sintering of lead-zinc concentrates is practised by Sulphide Corporation to provide both desulfurised lump sinter feed, for simultaneous reduction to zinc and lead in the Imperial Smelting Process blast furnace, and sulfur dioxide gas for sulfuric acid manufacture.Moisture control of feed mixes is of paramount importance in the sintering operation and improvements in this area have realised increases in overall plant performance.

Jan 1, 1985

By T Raynlyn, R J. Holmes, J R. Manuel, A Poliakov, L Lu

The prediction of sintering performance of iron ore fines and the possibility of targeted optimisation of specific sinter properties are very important for both the iron ore industry and related research organisations. Physical pilot-scale sinter runs require large amounts of raw materials and are expensive, so it is critical to target large test work programs with many different sintering parameters effectively. To predict values for sintering performance parameters such as tumble index (TI), low temperature reduction disintegration index (RDI) and productivity, a comprehensive database of pilot-scale sintering experimental results has been established and empirical modeling conducted. Similarly to earlier work, physical, chemical and mineralogical characteristics of the iron ores have been considered. However, in contrast to the previous work where only one textural parameter was taken into account, namely the proportion of dense haematite ore texture, the current model includes the abundances of several different textures which were combined into different textural factors corresponding to different sinter properties. Coefficients for the variables within specific regression equations can provide a better understanding of the effect of the variables on the corresponding sintering performance. The modelling results have also been used for predicting the sintering performance of mixtures that were not part of the database used for establishing the models. Comparison of experimental and modeling results for the verification test data is also reported in this paper.

Jan 1, 2009

A BRIEF account of the water-power potentialities of Tasmania is given, together with possible applications of the power commercially. A short history of the Waddamana development is then given, and the main works are described.WATER POWER POTENTIALITIESTasmania is an island of approximately 24,500 sq. miles area (exclusive of small islands). An area of 12,000 sq. miles is at an elevation of over 1000 ft. above sea-level, and of 2300 sq. miles at over 3000 ft. above sea-level. Average annual rainfall varies from' over 140 in. on West Coast to 20 in. on East Coast, and for the whole island averages 48.5 in. The total water-power available, based on conservative figures for run off and efficiency, is 6,000,000 b.h.p. Only a small percentage of this total will, under present conditions, and under likely conditions in the immediate future, be capable of being developed commercially.An extensive hydro-metric and water-power survey is at present being carried out in order to collect information concerning the most promising water-power schemes. Already 400,000 b.h.p. has been located in different proposals, and there is still a large area of very likely country along the West Coast which has not been investigated yet. Tasmania thus has very vast power potentialities, which, combined with good ports and communications and wonderful mineral and timber resources, should augur well for the establishment of the great key industries, particularly chemical and metallurgical.

Jan 1, 1923

By C Slaughter, J C. Tien

Commonly held ideas about effective training have long emphasised the importance of realism. Realistic training builds better experience among the trainees and a better perspective on the training material, making training more effective. While great strides have been made in this realm for mine safety and mine rescue training there are still areas that can be improved. One possible area is the expanded use of a mine fire simulation program where the migration of gases and smoke can be realistically displayed in an emergency, and outcomes varied as different conditions are being simulated. The use of mine fire simulation software potentially allows for the creation of more realistic scenarios in that smoke advance rates can be measured and recreated in evacuation scenarios, or that gas readings in mine rescue training can be dynamically and realistically changed to show the effect that time has on the fire scenario.CITATION:Slaughter, C and Tien, J C, 2015. The potential use of mine fire simulation software as an enhancement for mine safety and mine rescue training, in Proceedings The Australian Mine Ventilation Conference, pp 285–290 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Fitzpatrick JM

The feed preparation section of the Whyalla iron ore pellet plant includes a screening and crushing plant followed by dry grinding mills. Improvements in the efficiency of the vibrating screen and cone crusher have enabled screening plant throughput to be increased and product size to be decreased. This, in turn, has enabled improvements in the grinding mills' operation.

Jan 1, 1978

By Nightingale R, Johnson B, Bensley C, Vince A, Keast-Jones R

In order to counter the massive increase in the level of near gravity material that would follow the reduction in dense-medium cyclone separation density at B.H.P. Slab and Plate Product Division's B and C coal preparation plants, "wing tank" systems to control medium density to within ¦0.005RD units have been installed. However, despite very precise density control, cyclone metallurgical performance has been less than satisfactory. The approaches taken to identify the causes of this poor performance and to justify alterations in operational and maintenance practices are presented.

Jan 1, 1987

By C Fong

Compliance Planning is an active approach to ensure mining operations align more closely to their longer-term plans. Through Compliance Planning, operations can not only measure their performance on intervals as short as intra-shift, but they can then apply corrective measures to ensure they remain as close as possible to the plans. Compliance Planning targets short-term and execution level teams, as these are the shortest duration planning divisions commonly found in mining operations. Compliance Planning combines live information with intelligent planning capabilities to provide a framework that enables mining operations to realise a significant improvement in reconciliation of plan to actual movements.

Jun 22, 2022