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By Muge F, Pereira H

In the early stages of the planning of a new exploitation, the error in ore reserve estimation is an important factor that must not be disregarded. As this error can be computed by geostatistical methods, the risk of the venture can be calculated for different recognition patterns in a certain assumption of economical conditions. A case story is described for an open pit phosphate deposit in which grade/tonnage curves and their confidence intervals are related to an economic function for three drilling patterns and decisions are taken on the basis of cost and value of supplementary information.

Jan 1, 1977

Diversity is a key strength for Western Mining Corporation. An international corporation with assets of about $A10 billion, WMC is engaged in both mining and downstream processing of minerals including nickel, gold, alumina, copper and talc, as well as having interests in oil and gas production and agricultural fertiliser. The company is focusing on several core commodities that will maintain its strength in the years ahead. Although most current mineral assets are within Australia, it plans to have 25 per cent of its operations off-shore by the turn of the century, and be a major producer in at least six core commodities. WMC's strategic and management focus has shifted from a regional approach to a commodity focus so that it can more readily cater for different markets with differing sensitivities. This document is an ABSTRACT ONLY - no paper was published for this presentation

Jan 1, 1996

By D L. Richardson, B Tiedt, C D. Morgan

Following residentsÆ concerns that the ongoing operations of Collinsville Coal (CCP) mine may be resulting in the release of contaminants, including products of acid mine drainage (AMD), into downstream environments, the Queensland Environmental Protection Agency (QEPA) issued CCP with a Notice to Conduct or Commission an Environmental Evaluation at Three Mile Creek. A key objective of the Environmental Evaluation was to assess the extent and magnitude of impacts to aquatic communities and their habitats. A multidisciplinary investigation examined a suite of physical, chemical and biological indicators to meet this objective. The study also aimed to identify contaminants of concern and the location of potential pollutant sources. Potential indicators of AMD, including elevated dissolved solids concentrations and low pH, were evident within the mine lease. However, significant differences in concentration of these indicators upstream and downstream of the confluence with Three Mile Creek were not observed. Although only proxy indicators of AMD contamination, these results suggest that the extent of impacts downstream is minimal. For the purpose of this study, physio-chemical indicators were selected on the basis of those best likely to provide an understanding of the likelihood of contamination, within the constraints of readily available long-term monitoring data. Ecosystem health indicators were adopted to supplement the existing data set and provide a more æroundedÆ perspective of water quality attributes within the system, generally unattainable by standard physio-chemical assessments. In contrast to AMD products, sediments were considered more likely to have a widespread impact on aquatic ecosystems. Waterways throughout the study region, including those unaffected by mining, have been affected by broad-scale sedimentation and were typically highly turbid. Due to the many diffuse sources of sediment potentially liberated within the catchment, the contribution of the mine compared to other land uses on total sediment loads entering streams is difficult to determine. This is clearly a major management issue for mines throughout the Bowen Basin. Streams of the central Queensland region display enormous variability in water flows and physio-chemical characteristics over a range of spatial and temporal scales. This variability presents major difficulties in distinguishing anthropogenic impacts from natural variability (noise). Despite this variability, impact monitoring by mines in the central Queensland district has tended to focus almost entirely upon physio-chemical indicators. The results of the present study indicate that a multiple indicator approach to environmental assessment is more useful for separating mine related impacts from natural ænoiseÆ and impacts from other land uses. In the absence of such information, by adopting the precautionary principle of Ecologically Sustainable Development (ESD), there is potential for an environmental impact to be incorrectly attributed to mining when other activities in the catchment may be contributing to changes in stream æhealthÆ.

Jan 1, 2003

By H Zahiri

Utilisation of the InSAR technique for monitoring of subsidence in mining areas, employing open pit and underground mining methods, has large potential due to sensitivity and safety issues associated with usage of the classical surveying techniques. InSAR can also be very competitive concerning the cost of provided results. However, there are a few issues that may significantly limit InSAR applicability for subsidence monitoring in mining areas. The altered terrain topography, involving steep slopes and deep pits, may lead to the layover of radar signal for specific satellite and pit geometry. Also, the highly dynamic character of subsidence induced by mining, especially using mass mining methods, may lead to issues such as apparent heave and ambiguous results. In this paper the authors analyse the above-mentioned issues and demonstrate how InSAR technology was applied, as a supporting system, to monitor large scale and highly dynamic subsidence for a real case study in Western Australia.

Jan 1, 2008

By Giedl JG

Technical applications of computers within the coal industry are expanding rapidly with an increase in the number of users and user locations. Collinsville Coal Company Pty Ltd is an example of a remote and growing user company which has a Telecom link to MIM's ICL mainframe computer in Brisbane. The Planning Department is one of the technical user departments at Collinsville, with a variety of VDU, plotting and screen graphics hardware supported by the MIM Computing network. Current applications involve the storage, retrieval and manipulation of borehole information, plan and map production, volume calculations from survey data and mine ventilation modelling for underground Operations.

Jan 1, 1983

By Choulaj D

Mining and petroleum continue to be the two most vita components of our nation's development, says Sir Julius Char in the Australian Journal of Mining (Nov-Dec 1996). In fact the} account for 71.6% of export earnings, and 21.2% of Gros; Domestic Product in Papua New Guinea. The Misima and Porger, Mines, along with the Kutubu oil project, have essentially rescues PNG's economic viability since the loss of income from Panguna Though the industry cannot create employment in the manner o. intensive industries such as agriculture, it does provid( opportunities to local communities in terms of jobs, financia compensation, and infrastructure. Many ventures take many years and enormous capital investment to set up. There are three phases: exploration, feasibility, an( operations. The operations phase sees a massive development o infrastructure, or the actual `building' of the mine. For mining companies to commit to such lengthy time frames and high level: of investment, without returns, requires confidence and a degree of commitment from government on a number of levels - legislative stability, monitoring social development, and the provision o social infrastructure.

Jan 1, 1997

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 T Gibbons, M Korte, C Brent, K Runge

The Barrick Osborne concentrator has gone through a number of upgrades since commissioning and steadily increased production from the original 119 t/h design capacity to 265 t/h milling throughput in 2008. This was achieved incrementally over several years, by maximising operating efficiencies, in order to minimise capital expenditure, and take advantages of economies of scale; but more importantly it was reached with no measurable loss of recovery. Osborne currently processes a blend of under- ground with open pit material from the nearby Trekelano deposit. Following primary/secondary crushing, the material is processed through a rod/ball mill grinding circuit ahead of rougher/scavenger flotation that produces a copper concentrate.Osborne was seeking a further increase in plant throughput of the order of 15 per cent, but at more sustainable levels of secondary crusher plant utilisation. In early 2008, Osborne contracted Metso Minerals Process Technology Asia-Pacific and South America (MMPT) to review the entire process from run-of-mine feed to final copper concentrate. This review would be done concurrently, with surveys of both the crushing/ grinding and flotation circuits being performed at the same time. The outcome would be a steady-state model of the complete flow sheet allowing the crushing/grinding model to interact with the flotation circuit model such that overall process optimisation was possible. Two key outcomes for the operation are exploration of the operating limits of the currently installed plant, and projection of the logical next stage of potential capital plant expansions. This paper covers Part B or the flotation component of the project. A separate paper discussing Part A or crushing and grinding is also being presented at this conference. Surveys of the Osborne flotation circuit were performed along with a comprehensive review of the cell characteristics including measurements of the gas and froth phases of individual flotation cells. These data resulted in a size-by-size floatability component model of the complete circuit. This circuit model was then used to perform steady-state simulat- ions to evaluate options to improve both overall circuit and individual cell performance. The grinding circuit model discussed in a separate paper or Part A of this project was then used interactively with the flotation circuit model to recommend the best operating regime to maximise overall efficiency. For example, the balance between increased crushing and grinding costs versus higher copper recovery and final concentrate grade. Due to changes in market conditions in the fourth quarter of 2008, the focus was shifted to prioritising operational changes rather than capital expansion modifications, in order to improve circuit performance.

Jan 1, 2009

As economic, technological, regulatory and other forces continue to present the global mining industry with new opportunities and challenges, agile mining equipment manufacturers are stepping up their efforts to anticipate and meet the evolving needs of surface and underground mining operations. Operational excellence û the pursuit of efficient, lowest-possible-cost production û is a prime objective for all mines. As mineral commodity markets experience cyclical price highs and lows, mine operators, increasingly, look to their equipment suppliers for equipment and support that can help reduce multiple tangible and intangible operating costs. This paper explores how two mining equipment manufacturers û P&H Mining Equipment, a supplier of surface mining equipment and Joy Mining Machinery, a supplier of machinery for underground mining û are responding to the mining industryÆs aggressive pursuit of obtaining reduced operating cost with innovative products and support programs.

Jan 1, 2000

By C Nucifora, M Landers, J Jones, G Maddocks, K Mandaran, A Forbes, W Wilson, S Newman

Glencore’s Mount Isa Mines Limited (MIM) operates the Mount Isa open cut and underground copper (Cu) and zinc-lead (Zn/Pb) mines near Mount Isa in Queensland, Australia. Tailings from processed Cu and Zn-Pb ore is contained in a 1,315 ha shallow (< 35 m deep) multi-cell valley fill tailings storage facility (TSF). Static geochemical testing conducted by MIM over the life of mine (LoM) verifies that the Cu, and Zn-Pb tailings has a wide range in sulfide content and diverse mineralogy with significant acid neutralising capacity (ANC) in some samples. The tailings are predominantly classified as potentially acid forming (PAF) using static analytical methods. Kinetic leach testing using free draining columns and humidity cell tests simulating tailings placed on the surface of the TSF suggest that the tailings samples are likely to remain non-acid forming (NAF) for 10 to 40 years under aerial exposure, and much longer than this under saturated conditions within the TSF. During this period of weathering, as ANC is depleted, the neutral pH drainage may contain elevated concentrations of some elements including sulfate, manganese and zinc. Only when the ANC is depleted would the tailings then begin to produce acid drainage. CITATION:Mandaran, K, Jones, J, Nucifora, C, Maddocks, G, Landers, M, Forbes, A, Wilson, W and Newman, S, 2018. Mount Isa Mines Rehabilitation Materials Sampling and Analysis program for closure planning, in Proceedings Life-of-Mine 2018, pp 138–140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

I take it the character of addresses to conventions, should, following precedent, avoid details, and treat subjects rather from a philosophical point of view so far as they will permit.In the subject about to be treated on, an endeavour will be made to find here we stand as regards the past, in order that we may the better, hope to look correctly in the direction to be followed.It may be assumed that the main object of the Institute is to forward mining interests and the ways in which engineers can aid those interests are many. If all of us were to try to follow many of those interests we should become like" jacks of all trades and masters of none". Mining engineering is consequently subdivided, all are necessary to the common end, and it is on one of those divisions I have undertaken to address you. The subject or steam pumping is a large one, and I regret, not having received such longer notice as would have enabled me to do better justice to the subject, and more respectful regard for yourselves. I must, however, under the circumstances, crave your generous consideration, and hope the topics mentioned may furnish material for discussion and future papers of far more value than this one, Ind.eed, the subject is so illtimately and historically associated with mining that if treated on its merits would be highly interesting or could be made so in more capable hands.

Chlorine as a lixiviant for gold possesses a number of significant chemical and Idnetic advantages over cyanide but because of its corrosive and vaporous nature the method of implementation needs to be significantly modified. At comparable reagent concentrations the dissolution rate for gold in the C12/Cl- systems is some 10 - 100 times that achieved in the 02/CN system. The dissolution rate in the chlorine system is largely a function of the concentration of C12, Cl- and pH. Under conditions of low Cl', (less than 50 g/1), the dissolution rate begins to drop off dramatically over the pH range from 3 - 4. Increasing the level of dissolved chloride ions shifts the pH of this rate reduction to around pH 5 at 100 g/l NaCl, and to around pH 6 at 300 g/l NaCl.

Jan 1, 1991

By C McIntosh, M van Dam, N Whetter, R Lane, M McCulloch

Mine geology is understood through synthesising large amounts of structural, lithological, geochemical and geophysical data derived from the original topographic surface, drilling and surfaces exposed and removed during open cut and underground excavations. Computer- generated 3D geological models of any mine environment need to incorporate large amounts of information but also should be regularly updated with typically frequent influxes of new data. Geologists with the local knowledge should also be involved in the model construction, enhancement and interpretation, placing ease-of-use functionality high on modelling software requirements. Implicit-style modelling is a fast-growing area of 3D geological software development where interpolated surfaces such as lithology boundaries and bedding orientations are defined mathematically as functions rather than explicitly through coordinate meshes. The functions are constrained only by the data and not by an artificially imposed grid; therefore, implicit 3D modelling can process a lot of information quickly and routinely operate on original data (such as observed contacts and structural data) rather than on evolved iterations and interpretations. 3D mine geology models can be readily updated with new data, which can be automatically reprocessed to test ideas in near-real time. Implicit, function-based 3D modelling software has been applied to the Globe-Progress mine in West Coast, New Zealand. This structurally- hosted gold mine has some geometrical conundrums that are in part being resolved as excavation of the open pit proceeds. The relationship of the Globe-Progress ore shoots to hanging wall and footwall structure is still not fully understood, however, and 3D geological modelling is assisting with visualisation and testing of structural hypotheses. The modelling is also capable of predicting areas of bedding defect slope failure in yet-to-be excavated parts of the mine.

Jan 1, 2009

Underground measurements, observations and computed simulations, started a long time ago were concerning the study of : - occurence of typical rockburst, - inducing, stretching of main fractures in the roof of caved longwalls. They made obvious a foundamental phenomenon of inducing of strata fractures involving contact be- tween two layers quite different in their elastic characteristics : coalseam and rocklayer.. The start of primary cracks in maximum abutment zone takes place in the rock near the contact surface. It is opening of crevasses induced by traction stress component resulting of difference of rigidity of both materials and no sliding on in- terface. Occurence and stretching of these crevas- ses are a rheological phenomenon so that the rate of advance and stops of the face influence the distance between the crevasses and the stretching of these ones. The characteristics of these cracks in space and time affect mining conditions. So it is for fractures proximity and expan- sion inducing eventual blocks formation in longwall roofs in front of faces, for depth and delay of road- ways ribsides fracturing, inducing some rockbursts. In longwalls roofs, cracks initiated in front of a face can be either quite close or quite distant each from the other one, according to the depth of crushed coal in front of the face, which af- fects also extension of the cracks.

Jan 1, 1988

The Palaeozoic succession of Victoria contains one of the world's major gold provinces with a total production of 2500 tonnes of gold. Larger deposits, including Bendigo (over 800 tonnes Au), are related to Ordovician slates and greywackes, but a wide range of metamorphosed sedimentary and igneous rock types are host to significant gold deposits. Most, if not all, deposits demonstrate structural control, although the controlling structural features are variable between deposits: a majority of deposits comprise quartz veins. It is suggested here that a major factor in making Victoria such a gold-rich province might be a particularly high geothermal gradient in central Victoria during the Tabberabberan orogeny (360-380 my). This generated auriferous metamorphic fluids from underlying successions (?Cambrian) which migrated upwards along active structural pathways. One cause of gold deposition appears to have been fluid reduction by carbon, but other methods are suspected. This model is considerably simpler than the plethora of syngenetic, granite magmatic and lamprophyre-related models that have been proposed recently, but is in basic agreement with Cox et al. (1983). Exploration models for similar gold deposits both within Victoria and elsewhere should take account of the negligible evidence for a major syngenetic contribution to Victorian gold production, and the lack of any clear genetic relationship to particular igneous rock types. A real opportunity exists for new deposit types not identified by the early prospectors.

Jan 1, 1991

While the potential for the discovery of new high grade resources exists, it is almost inevitable that the ore resources used to provide society's ongoing demand for primary metals will deteriorate over time as the higher grade reserves are exploited first and are progressively depleted. This deterioration in quality of metallic ore resources will bring about significant interactions with other resources such as energy and water, resulting in an increase in the amount of these resources required per unit of primary metal production. In this paper it is shown that as ores deteriorate in quality, the contributions of the mining and mineral processing stages to the life cycle-based embodied energy and water of primary metal production will increase significantly. Therefore efforts to reduce the impact of deteriorating ore resources on energy and water consumption should focus on these stages.   The results from life cycle assessments of the production of various metals by a number of different processing routes, particularly copper and to a lesser extent nickel, have been used to identify a number of opportunities and technologies for reducing the energy consumption in the mining and mineral processing stages, including: comminution, eg high pressure grinding rolls, stirred mills, ore sorting, preconcentration, advanced blasting techniques, advances in diesel technology for loading and hauling, alternative processing routes, eg heap leaching, in situ leaching, water treatment and re-use, water quality 'fit for purpose', dry processing, floating modules to reduce evaporation, and paste thickeners. All the above and existing developed flotation technologies can impact on the mineralogy of the concentrate supplied to the smelter. Removal of gangue minerals early on in processing may have further downstream process implications on fuel and water requirements. The above technologies are in various stages of development, with some more advanced than others. However, all can be expected to play their part in improving the sustainability of the Australian mining industry.

Jun 1, 2010

Using a Jarrell-Ash "Compact" direct reading spectrometer, analyses were made of a wide variety of rocks ranging from acidic to ultrabasic types. Statistical evaluation suggests that accuracies comparable with the values obtained by the rapid chemical methods used by the United States Geological Survey will be obtained.The spectrographic method involves fusion of the rock with lithium tetraborate, strontium being incorporated in the flux as the internal standard. The resulting bead is ground with graphite and pressed into a pellet. The counts obtained on two standard pellets are used to correct for instrumental drift.Background readings are made at 4109 Å and corrections for background are made to all lines. Corrections for matrix interferences, both by chemical suppression and optical enhancement, are made. The three corrections of drift, background, and matrix are incorporated into one general expression which has been programmed on magnetic cards, each element requiring a separate card. The cards are placed individually into a desk top computer (an Olivetti Programma 101), which enables true counts to be calculated from the "readout" counts, and the element concentration is then obtained from computer-printed tables by referring to the appropriate value of true counts versus concentration. These tables were prepared by making a polynomial regression analysis of the spectrographic results from 50 standard and analysed samples, a curve of best fit being chosen for each element.The regression coefficients, usually of a fourth or fifth degree equation, together with other relevant data, were fed into a large computer, programmed to print out tables of concentration versus true counts. This technique enables the results obtained to be based on mathematically-derived values rather than on hand-drawn calibration graphs, giving greater inherent accuracy. The technique has been shown to give results of good accuracy and acceptable precision suitable for many geological and geochemical exploration programmes involving the analysis of many rock samples of different types.

Jan 1, 1969

By L E. Setiawan

The mining and milling groups at Batu Hijau are tasked with increasing SAG mill throughput by approximately ten per cent. Avenues used for this process are blasting and crushing optimisation, ore blending and predicting SAG mill throughput in relation to the geological model. This is in line with traditional æMine to MillÆ studies. At Batu Hijau, mill and mine sequencing cannot readily be configured to perform the surveys traditionally required by a æMine to MillÆ study while meeting the daily production target of 140 000 tonnes per day and processing from varying ore types in one pit. A program called BOCCOST (blasting optimisation crushing conveying optimising SAG throughput) has been implemented to capture approximately 200 variables from blasting, mining and milling operations and assign them to a common point in space in the geological model in real time. Interpretive analysis of data from BOCCOST is used to model relationships between the 200 variables to determine which and how these factors affect SAG throughput. Once these relationships are determined, the blasting, ore blending and crushing process can be optimised to generate a product that maximises mill throughput. The relationships modelled from BOCCOST are also used to generate a SAG mill throughput estimator, which can be coded into the production block model. The block model can be reconciled with the geological block model for correlation by geological domain. Once this relationship is established, SAG mill throughput domains can then be established for predicting SAG mill throughput. This SAG mill throughput estimator is then used in conjunction with revenue calculations to determine an ore cut-off, which combines these two elements to maximise metal production.

Jan 1, 2002

By J Koppe, J F. Costa

A fundamental error of sampling occurs when a sample is extracted from a larger mass of ore or lot. The act of sampling requires that all particles belonging to the lot have an equal chance of being extracted. This type of sampling is called unbiased sampling. The sampling equipment (herein referred to as the sampler) should be constructed with some additional mechanical characteristics to guarantee that the samples will be unbiased. Samplers, extracting increments from a continuous flow, such as a conveyor belt, collect aliquots at regular time intervals. These time intervals relate to the number of aliquots extracted from a given mass of lot, whilst passing through the continuous flow. The frequency of extractions will influence the precision or the error of the sample (integration error). Further, the ore variability influences the amount collected from the continuous flow. Normally, the sampling protocol utilised is designed for the extractions obtained from the conveyor belt, omitting any error committed during this operation, ie the error of extracting from the continuous flow. This study aims to analyse the error of sampling a continuous flow by using a variogram with added on auxiliary functions. Each different piece of material passing through the flow will exhibit a distinct temporal variogram, which should influence the frequency of the samples being extracted for each chosen sampling error. The methodology used is presented in the form of a case study from a coal processing plant.

Jan 1, 2005

The complete life cycle of a production facility has many phases requiring many different skills and many different personalities. It is not unlike the life cycle of a person and many parallels can be drawn from it. I leave some of these analogous situations to your fertile minds. The author, having worked in operations, plant design, plant commissioning, marketing and many other interesting situations through the industry has drawn from this experience and examples given by many associates in the industry.The phases seen are as follows: Concept Studies û someone has a bright idea of how to make a dollar. Scope Studies û what possible processes/options that could make a dollar. Prefeasibility Study û the æviableÆ scope options are studied to develop feasible options. Feasibility study û defines the concepts that should be designed to make a viable project thus enabling financing and project commitment to be made. Detailed Design û an intermediate step that consolidates the inputs to give a robust plant that can be constructed.Construction û people can see what they thought was going to occur and start to understand the plant. Commissioning û the hand-over of æownershipÆ from the conceiverÆs to the operators. Operations û the ætoyÆ has become reality and money must be made. De-commissioning û the plant has seen out the useful life of the ore deposit, it now goes through a further process required by society.Across these phases of plant design run several countervailing management requirements that can influence the outcome of the plant design. Some of the management rigours that have to be applied to the various phases are as follows: costing basis of the various phases; operational and maintenance reviews; sustainable development; risk assessment; reliability reviews; equipment availability; commissioning time; and environmental review.This paper endeavours to awaken people to the phases that projects require for a successful outcome and the management rigour that has to be applied throughout the phases to ensure the correct intellectual horsepower is applied at the right time to ensure the best outcome.Many of you would be parents and realise this is not unlike the development of children, teenagers, adults, retirees and ongoing.

Jan 1, 2002