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By A Sinuhaji, R Poedjono, G Flumerfelt

PT Freeport Indonesia is currently building the DOZ mine. It is a 25 000 tonne/day block caving operation which is scheduled to reach designed production levels by the fourth quarter of 2002. This paper describes some of the issues and challenges faced by the operation when introducing a new undercut method part way through the project. Advantages and disadvantages are discussed as well as the expected benefits of the new method.

Jan 1, 2002

By Hollis R. G, Tuppurainen J. M I

Improved control of non-ferrous sintering operations requires the on-line measurement of sinter quality. No on-line measure of sinter quality is currently available, however, previous work has shown that the raw mix chemistry and peak sintering temperature determine the mineral phases formed and hence the resulting Blast Furnace behaviour. Control of these factors should therefore lead to improved quality control. In this paper, the development of a simplified heat and mass balance model of the Sinter Plant at Mt Isa is described. The model used available plant data to calculate raw mix composition and a simplified reaction scheme to predict sinter composition. The extent of reaction is inferred from the flue gas analyses. Off-line testing of a dynamic version demonstrated that actual plant performance could be predicted with reasonable accuracy.

Jan 1, 1989

By M T Roche

The Cannington deposit is one of the largest accumulations of silver-lead known. Located 135 km southeast of Cloncurry in North West Queensland (Figure 1), Australia, the deposit is currently in the feasibility stage of its development. The deposit is named after the nearby Cannington Pastoral Property which runs some 25 000 sheep on 'downs' country. The investigations of the Cannington deposit are carried out under the authority of Mineral Development Licences 139 and 144 and Exploration Permit for Minerals 6788, Answer Downs. Exploration for Broken Hill Type (BHT) silver-lead-zinc deposits in the Mt Isa region has been undertaken by The Broken Hill Proprietary Company Limited's Minerals Division (BHPM) since the early 1980s following in-house research which showed that the Eastern Succession of the Mt Isa Block exhibits characteristics which were favourable for hosting BHT

Jan 1, 1994

By Morrison R. S, Doennilan N

Recent mapping (1989-1992) by the Northern Territory Geological Survey in the Tennant Creek 1:250 000 map sheet area has resulted in substantial revision of the lithostratigraphy of the Tennant Creek Block (Donnellan, Hussey, and Morrison, in press). Briefly, the former Warramunga Group (Dunnet and Harding, 1967; Dodson and Gardener, 1978) is divided into the Warramunga Formation, and an overlying less deformed volcano-sedimentary succession, the Flynn Subgroup. The latter is conformably overlain by the Tomkinson Creek Subgroup of the Tomkinson Creek province in the north of the Tennant Creek Inlier. These two Subgroups constitute the Churchills Head Group which is essentially equivalent to the Hatches Creek Group of the Davenport province to the south of the Inlier.

Jan 1, 1994

By K Karmawan, T Casten

The PT Freeport Indonesiaæs Deep Ore Zone (DOZ) copper deposit is located in the province of Irian-Jaya, Indonesia. Currently, a block cave mine is being developed around this deposit. Production is scheduled to start the fourth-quarter of year 2000 and to ramp up to 25 000 tpd by year 2003. The air quantity requirement for this mine is equal to 780 m3/s. To supply this quantity, the mine will require five centrifugal fans (one 450 and four 750 kW fans). This study summarises the technical aspects related to the installation and commissioning of two of these fans. The fans were installed on the surface in parallel arrangement with two others. Each has a design capacity of 240 m3/s of air at 2.2 kPa of static pressure. The study presents the installation details from the underground shaft excavation and portal development through fan testing and commissioning. It also presents the results of a monitoring system that was installed to determine the fan duties.

Jan 1, 2000

Hydraulic backfill is generally retained in stopes using permeable barricades. Mitchell et al (1975), Mitchell (1992) and Grice (1989) have shown that under normal drainage conditions, barricades experience low levels of loading. Cowling et al (1988) have also shown that barricades are susceptible to piping failures if excess water has ponded on the upper backfill surface and if leakage of backfill from the barricades has occurred. During 1997, six hydraulic backfill barricades failed in four different Australian mines. Fortunately, in each case, the quantity of backfill slurry released was small, and no injuries to personnel nor damage occurred. Detailed investigation of two of the incidents showed that the primary cause of failure could be attributed to the delivery of excess quantities of transport water from the low-density slurry. For each of the incidents investigated there was evidence of the development of piping failures, which resulted in hydrostatic loading conditions on the barricades from the ponded water on the upper backfill surface. The circular failure surfaces in the barricades were characteristic of the application of point loading conditions. This paper discusses the circumstances that led to these incidents and analyses the modes of failure. The standards for the safe operating of hydraulic backfill systems are reviewed along with requirements for ongoing management and control. The design requirements of barricade construction are analysed and some appropriate guidelines introduced.

Jan 1, 1998

By M Johnson, M Horrigan

The scope of this report is to examine the aforementioned hypothesis by performing a detailed analytical comparison of a P&H electric rope shovel to an O&K diesel powered hydraulic excavator. In order to complement the integrity of the concluding results, two different size categories will be analysed in order to demonstrate that the findings can be extrapolated and applied to all the machinesÆ size classes. These two size classes are categorised by their bucket sizes and they are in the range of 43 - 58 cubic metres and 23 - 26 cubic metres. It should be noted that electric powered hydraulic excavators will not be considered in this report. In order to compare the electric and hydraulic types, the machine variants that will be analysed are commercial cost-effectiveness and operational flexibility. Although operational flexibility can be an ambiguous characteristic, a clear and thorough definition describing its exact meaning has been included. In order to simplify this study, all the data collected for this comparison have been for overburden removal, eliminating the variation that occurs with the movements of the shovel when selectively mining in the ore deposit. Thus, it ensures that all the data that is compared stems from a common origin for all the shovels. In other words the information will be compared when digging in the same material, loading into the same sized haul trucks, and when possible, with the same operators. Theoretical data received form the respective manufacturers, and actual data obtained from Mount Whaleback, was used for this comparison. This leads to the final comparison, where the operational flexibility and the cost-effectiveness are evaluated, with respect to their individual importance, ultimately influencing the final recommendation.

Jan 1, 2002

By H Masoumi, I Canbulat, Y Zhao, J Oh, H Lin

Borehole breakout is a drilling induced phenomenon caused by overstress of rock around the borehole. Its depth usually aligns with the minimum horizontal principal stress direction. For this reason, it has been used to determine stress orientations and a series of researchers also argued its dimensions can be indicative of stress magnitudes. If the stress dependencies of breakout geometries are well understood, it is possible to estimate stress magnitudes based on these data. This paper investigates the influences of critical parameters on breakout dimensions, including absolute stress magnitudes, stress ratios and borehole diameter. Several experiments have been conducted on cubic (120 x 120 x 120 mm3) sandstone samples with pre-drilled holes (22 mm and 30 mm) under true tri-axial loading conditions using UNSW self-designed equipment. Experimental results confirm the increasing maximum horizontal principal stress magnitudes result in larger angular span and longer breakout depth at constant minimum horizontal and vertical principal stresses. There is also a considerable discrepancy observed between experimental results and the analytical model. Findings of this study imply a potential on the estimation of stress magnitudes using borehole breakout. CITATION:Lin, H, Oh, J, Canbulat, I, Masoumi, H and Zhao, Y, 2018. Experimental investigation on borehole beakout and its implication on stress magnitudes, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 266–273 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By T QUINLAN

A resource estimate uses data obtained by sampling an orebody. An example is described in which a random drilling pattern did not provide a representative set of assays, and the estimated resource was significantly less than the mine production. It is believed that a better estimate would have been made if the exploration holes had been drilled on a regular grid.

Jan 1, 1992

By Noller B. N, McGill R. A

The Alligator Rivers Region has been the scene of one of Australia's most intensive environmental monitoring efforts since the current generation of uranium mining was mooted in the 1970s. Prior to mining, the local environment and the nature of potential impacts were not well known. The initial monitoring programs therefore included large baseline characterisation and research components. After some 15 years, water, soil and sediment monitoring programs have been reduced to a fraction of their early size, as the mining and natural systems became better known and characterised, and the actual nature of the environmental impacts were established. Modem techniques allow much more rapid and thorough identification of chemical species and elements of concern, allowing much more focused monitoring programs to be designed. In the 1980s data collection was emphasised at the expense of interpretation, and monitoring programs were maintained at much higher levels than were in fact required. It is now clear that investigations are important and should be distinguished from monitoring programs, and that the timely interpretation of investigations and implementation of recommendations can greatly reduce the effort and expense that can be involved in a monitoring program. Monitoring programs based on a sound understanding of potential environmental impact may then be efficient and cost-effective, yet provide sufficient information to assess the environmental impact of mining, guide further environmental protection measures when problems are detected, and demonstrate compliance with regulatory requirements.

Jan 1, 1994

By V A. Diemar

The Chatree Gold Project represents a greenfields discovery of metallurgically clean shallow gold mineralisation in a logistically simple terrain. Total Measured, Indicated and Inferred Resources are currently 31 tonnes of gold and 160 tonnes of silver. Gold occurs in an adularia-sericite epithermal system within quartz-calcite-adularia veins, breccias and stockworks. Host rocks are volcanic arc porphyritic latite-trachyte flows, their pyroclastic equivalents and volcaniclastics of upper Permian to upper Triassic age. The mineralisation was deposited in dilated zones during repeated reactivation of pre-existing structures. To-date five mineralised prospects have been defined by drilling with three reaching JORC Code Mineral Resources status. The project is in its definitive feasibility stage and is anticipated to be in construction during 2000.

Jan 1, 1999

Late Cretaceous and early Tertiary coals in the Greymouth, Ohai and Kaitangata coalfields represent a major national energy resource comprising-up to 2500 x 106 tonnes of coal in ground. The three coalfields are closely related in terms of age and sedimentary and structural character. The most striking feature common to all is the complexity of the geology which has severely restricted exploration and mining of these coal resources. This complexity is manifest in the irregular lensoid nature of coal seams and by the incidence of unpredictable medium and small scale faulting and folding. There are many geological similarities between these coalfields which are considered to arise from a common origin which can be related to the plate tectonic evolution of the southwest Pacific region. In order to efficiently assess and exploit these coal resources it will be necessary to know their geology in great detail. This can he achieved by increasing the understanding of the sedimentary and structural evolution of the coal bearing basins. This knowledge may be gained by the application of traditional (ie drilling, field mapping) and innovative techniques (ie high resolution seismic, in seam seismic) with on going research-oriented studies (ie basin analysis, coal petrography).

Jan 1, 1987

By Y Wei, H-B Mnhlhaus

Particles are by far the easiest objects to simulate, because their dynamics is simple. Determining the motion of particles and their interaction, a wide variety of deformable structures can be constructed by connecting particles that have mass, position, and velocity, and that respond to forces. Starting from this simple idea we have derived what we call the particle-lattice method for the solutions of boundary value problems of deformation and fracture of solid mass. The problem of rock breaking by blasting operations as well as fracture and flow of rocks fragments involve momentum transfer between solid and fluid; gas flow and reactive mass transfer. In this paper we outline the method and describe briefly the salient features of the algorithm. We derive relationships between the contact properties for the discrete model and the properties of the underlying continuum and fluid flow coupling procedure. Finally we illustrate the potential of the method by means of example solutions related to the dynamic fracture and flow in jointed rock by blasting.

Jan 1, 1999

By G K. Robinson

Variations in many aspects of physical and chemical grade are often of concern to mining operations and mineral processing plants. In most circumstances these amounts of variation are predictable. At the time of planning new operations, we should be able to predict the amount of sampling and testing variation which our sampling devices, laboratory procedures and on-stream analysis devices will achieve. We should know how well our stockpiles, reclaimers and bins will homogenise material (or whether segregation will actually increase the amount of variation). We should be able to predict the amounts of variation that will occur on the important time or tonnage scales at the crucial p oints in our proposed operation. And once these amounts of variation are reliably known, mine planning will seem a little bit more like dealing with known knowns rather than like dealing with unknown unknowns.The first step towards quantifying amounts of variation for planned operations is to assess amounts of variation for existing operations. How many operations have estimates of amounts of variation in their databases? How often are people able to partition amounts of variation into amounts due to sampling error, amounts due to sample preparation, amounts due to assaying, and the amount of real variation in the stream of material?CITATION:Robinson, G K, 2012. Making sure that the amount of grade variation is a known known, in Proceedings Project Evaluation 2012 , pp 159-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

The Energy Authority of NSW has wide powers and responsibilities conferred by its Act which are pertinent to the State's coal industry and its development into the next century. With respect to coal, the broad objective is to maximise the benefits to NSW and its people derived from the State's coal resources. The initial focus of the Authority's coal-related activities in the late 70's and early 80's was on petroleum substitutes from coal. Research was supported, especially on hydrogenation, and the Authority participated in the Joint Australia/Federal Republic of Germany coal-to-oil feasibility study. It also co-ordinated a State Government initiative to involve the private sector in examining the possible establishment of a synthetic fuels industry based on Hunter Valley coal. With a short-fall in world-wide petroleum supply now seen as less likely for some years, the Authority is looking also at ways of working towards the broad objective in the field of coal utilisation on both domestic and export markets. Areas of interest include possibilities for using washery rejects, means of making NSW coal more competitive as an energy source, use of coal-seam gas and new or special technologies for burning coal. The future is expected to see renewed interest in producing petroleum substitutes, and coal - as the State's major energy resource - is seen as a strong contender as a basis for such an industry. Developments in coal-based power generation are also expected to have an impact, with advanced technologies having a possible place here as well as Overseas.

Jan 1, 1987

By E Vargas, A Egana, M Alarcon, X Emery, A Barberan, A Lopez, N Morales, C Friedrich

"As the cost in time and money of data from sensors and small-scale tests has reduced, additional challenges have arisen. Although many mine data sets are not big relative to those in other disciplines, they are complex in other ways, and becoming too large to manage efficiently on personal computers. In order to take advantage of the opportunity offered by increased data, a diverse team from Universidad de Chile and CSIRO Mineral Resources has developed a virtual geometallurgical laboratory to support the computational requirements linking data acquisition with data-driven business decisions. A particular focus to date has been the development of user-guided workflow ensembles to enable comparison between plausible geometallurgical hypotheses.A case study has been undertaken using publicly available data from the Rocklea Dome iron deposit in Western Australia. A hypothetical mining schedule was produced from geochemical and hyperspectral drill core/chips data via the following steps: data preprocessing, exploratory data analysis, geochemical interpolation, block modelling, ultimate open pit design and scheduling. The key outcome of this study was the integration of workflow stages through new plug-in methods or modification of existing software. Outcomes from this study will be described in the paper in terms of geological and metallurgical data quality, analytical software support and ongoing computing infrastructure requirements.CITATION:Lopez, A, Barberan, A, Alarcon, M, Vargas, E, Ortiz, J, Morales, N, Emery, X, Egana, A, McFarlane, A and Friedrich, C, 2016. Progress towards Data-driven Mine Planning via a Virtual Geometallurgical Laboratory, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 287–294 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By N Power, A D. Costar

There has been significant growth in mining and energy exploration in South Australia, which has identified new major potential opportunities. This sector generates significant economic value to the state and their support remains a priority for the state government. The delivery of this economic and associated community value to the state is dependent on the mining and energy sector being able to access reliable water supplies.The vast majority of priority areas for the mining and energy sectors are located in areas that have traditionally been of low priority from a water-use perspective and hence, data and knowledge levels are generally low.Recent studies have identified a potential increase in demand for water in the mining and energy sector for potential developments from approximately 40 GL to over 170 GL over the next ten years. The studies found that water and water infrastructure is the second highest proportion of planned infrastructure capital investment by resource companies. The South Australian GovernmentÆs Plan for Accelerating Exploration (PACE) initiative (PACE 2020), also identifies addressing the issues of location, use and management of South AustraliaÆs water resources as a key priority for the growth of the mining and energy sector.The Department of Environment, Water and Natural Resources (DEWNR) has developed the facilitating long-term outback water solution (FLOWS) initiative. DEWNR is currently undertaking a suite of programs to provide groundwater information at the regional scale to better target water supply options for mining and energy developments and community water supplies.The Goyder Institute for Water Research has leveraged significant research investment of $3 M to develop methodologies to interpret airborne geophysics to map groundwater sources.The FLOWS Initiative will provide key content for the PACE Water Program and will also assist in the development of water supplies for remote far north communities by identifying alternate groundwater sources to improve water supply security.This paper will discuss how developing an appropriate science and knowledge base will encourage and secure development where appropriate, enable prudent decision-making and policies regarding water allocation, accounting and licensing, whilst ensuring the protection of environmental assets.CITATION:Power, N and Costar, A D, 2013. Finding long-term outback water solutions, in Proceedings Water in Mining 2013 , pp 191-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By M F. L Gibson

The issue of flyrock is very important in the operation of all mineral extraction sites that use blasting. Unlike the other environmental effects of blasting, ground vibrations and air overpressure, flyrock is (or should be) a rare event, with severe consequences which may include damage to property, injury or fatalities. These physical consequences are often matched by a loss in public confidence in the management of the operation, mistrust and bad press. In this work a deterministic analysis of flyrock was carried out using the equations of a particle in motion with drag. The solutions to these equations were used to reproduce the curves of Lundborg et al (1975) for the relationship between flyrock boulder size and maximum ejection distance. A probabilistic approach based on Monte Carlo simulation was built up with the analytical model using published data together with local case study material. A typical quarry blast situation was modelled and estimates of safe standoff distances were determined using risk assessment techniques.

Jan 1, 2001

By S Logan, J Pu, J Milsom, G McDonald

Management of environmental issues is an integral part of the mine decommissioning process. In Queensland, miners must comply with environmental aspects of the Mineral Resources Act and Contaminated Land legislation. Successful decommissioning involves the integration of a final Plan of Operations, decommissioning report addressing the mineÆs commitments included in its Environmental Management Overview Strategy (EMOS), and Site Contamination Report for relinquishment of leases under the Contaminated Land Act (1991). Niugini MiningÆs Red Dome Mine is proceeding through the decommissioning process. This paper discusses the important environmental management issues including sampling programs, management of culturally significant areas, assessment of background concentrations of target analytes, the use of historical reviews and risk assessment techniques, the timing of works, and the remediation/management of large areas of impacted land. The importance of a clear communications plan between key stakeholders is also discussed.

Jan 1, 1998

By B Oostendorp, R van der Merwe, P

In order to assess whether polysaccharide depressants are strongly or weakly and reversibly bound to the surface of talc, a series of experiments was conducted on New York talc in which the floatability of the talc in a microflotation cell was determined. The talc was conditioned in solutions of carboxymethyl cellulose (CMC) or guar gum in 10-2 ionic strength Ca(NO3)2 or Mg(NO3)2. The talc was then washed with four successive aliquots of water, or cation solution, to try to remove the polymer and the flotation response of the talc was assessed. CMCs of different charge (DS) were used to assess the effect of charge on the strength of bonding. The results show that CMC and guar gum could be removed to a large extent from the talc surface by washing with water (the floatability was restored), however very little could be removed from the surface by washing with cation solution. The higher charge CMC was easier to remove from the talc planes in the absence of cations than the lower charge CMC. Thus CMC bonding to talc has been shown to be irreversible or very slowly reversible only if cations are present, implying that cations are necessary to keep the polymer bound to the surface of the planes to effect depression. The presence of ions in solution also had the effect of maintaining surface coverage of the talc by guar gum.

Jan 1, 2005