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By K R. Vining, T E. Norgate

A study was carried out to compare the environmental impacts of the two major iron ore agglomeration processes, sintering and pelletising, using life cycle assessment (LCA) methodology. The following agglomeration processing routes, with the fuel options shown, were investigated:sintering with combined natural gas/coke breeze or charcoal as fuel, grate-kiln pelletising with combined natural gas/coke breeze as fuel, and straight-grate pelletising with combined natural gas/coke breeze as fuel. Inventory data for each process derived from the literature, and in some instances supplemented by additional simulations and calculations, were used in the study and the environmental impact categories considered were gross energy requirement (GER), global warming potential (GWP) and acidification potential (AP). The results of the study showed that the GER, GWP and AP for a sinter plant are higher than those for a pellet plant for the same amount of metallic iron in the agglomerated products. These results are partly due to higher consumption of solid fuel and flux in the sintering process. However, it should be pointed out that the study only compared substantially fluxed sinters with acid pellets that may require additional flux (and hence potentially more greenhouse gases emissions) to be a balanced blast furnace feedstock. Extending the LCA to the blast furnace process stage was beyond the scope of the current study. Within the sinter plant, the sintering stage itself is the largest contributor to the GER, GWP and AP. In the case of pellet plant, the pellet induration stage is the largest contributor to the various environmental impacts. The GER and GWP of a straight-grate pellet plant are marginally higher than those of a grate-kiln pellet plant due to the higher electrical power required by the straight grate system. The substitution of coke breeze with charcoal in the sintering process results in an increase in GER but a decrease in GWP. However, a substantial proportion of the GER is derived from renewable sources (wood), resulting in a decrease in the non-renewable components of this environmental impact. Given the source of the inventory data and the assumptions and approximations made in carrying out the LCAs, it is emphasised that the results presented in this paper should be considered as indicative rather than as definitive results for the two iron ore agglomeration processing routes considered.

Jan 1, 2006

By S Dorrington, J Olsen, N Kinkaid

Several studies have been conducted on the economic analysis of mining near-Earth asteroids for resources for use in Earth orbit. While these studies use detailed economic figures of merit, they often use many invalid assumptions in the trajectory design. Factors such as the energy and propellant requirements are estimated with analytic methods, however, the stay-time at the asteroid and the spacing of repeated launch opportunities are not taken into account. The work outlined in this paper attempts to combine detailed trajectory design methods with newly defined economic figures of merit to improve the economic assessment of asteroid mining missions. The study focuses on asteroid 2014 EK24, a near-Earth asteroid with very Earth-similar orbital properties.CITATION:Dorrington, S, Kinkaid, N and Olsen, J, 2015. Trajectory design and economic analysis of asteroid mining missions to asteroid 2014 EK24, in Proceedings Third International Future Mining Conference, pp 281–288 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Fraser CJ

Stability control plays a prominent part in the planning and execution of coal winning in the deep open cuts in the Latrobe Valley operated by the State Electricity Commission of Victoria (SECV). Different stability mechanisms affect the individual overburden and coal faces. These are the classical rotational slip in overburden and the three-dimensional tetra- hedral wedge or planar block slip in the coal faces. The stability of the overall batters is affected by the so-called "block sliding" mechanism, which is unique in Australian open cuts. The basal stability of the open cuts is affected by pressure from water in confined aquifers underlying the coal being excavated. This paper describes each of these mechanisms and the current monitoring and con- trol techniques practised by the SECV.

Jan 1, 1982

The Mary Kathleen uranium deposit occurs in 1740-1780 M yr-old calc-silicate melasedimentary and mela-igneous rocks of lhe Corella Formalion which have been tightly folded into lhe Mary Kathleen Syncline. The Corella Formation consists of malic and felsic tuffaceous(?) calc-silicates, quartzile, and minor marble, conglomerate and basic volcanics. Garnet-rich rocks form semi-concordant and transgressive masses in the middle and upper portion of the sequence. Granite, gabbro and acid porphyry dykes also occur in the syncline.Uranium-rare earth mineralisation is closely associated with certain malic rocks and occurs wilhin or close to garnet-rich masses. At Mary Kathleen, uraninite grains are enclosed mainly by allanite which is dislribuled through massive garnet as an irregular honeycomb of interconnected shoot and lenses. The mineralisation occurs along strike from dioritic rocks and conglomerate and lies close to the axis of the Mary Kathleen yncline and adjacent to a major faull zone. All other localities allanite-uraninile mineralisation is broadly stratiform.The mineralisation is interpreted to occur at or near centres of basic volcanism. Garnet formation and uranium-rare earth concentrations are believed to be caused by the volcanism, and to be contemporaneous with it. The former is seen as alteration of a hot, saturated pile of volcano-sedimentary material and the latter as intermittent hydrothermal exhalation.Deposition, volcanism, garnet formation, uranium and rare-earth mineralisation, granile and gabbro formation, and tectonism are seen as a continuum of interrelated processes which operated throughout the period of format ion of the rocks in the Mary Kathleen Syncline.

Jan 1, 1985

The process selection and design aspects to treat primary ore in a new carbon-in-pulp (C.I.P.) plant while utilizing, where possible, existing equipment and infra- structure are discussed. The existing crushing plant, water supply, reagents, laboratory and infrastructure facilities from the heap leach have been upgraded and expanded to meet the C.I.P. plant requirements. The new power supply is from the North Queensland grid system. A series of metallurgical tests was carried out and a review of the data showed that the primary ore was amenable to conventional cyanide leaching. Following feasibility studies, a new process plant which included grinding mills, leaching, and adsorption tanks, thickener, desorption and gold roam facilities was constructed.

Jan 1, 1989

By D J. Williams, A K. Kho, A Shokouhi, N Tucker

The disposal of dewatered coalmine tailings and coarse reject within spoil piles is gaining popularity as a means of eliminating separate surface tailings storage facilities or dams. The contrasting characteristics of coalmine spoil, coarse reject and tailings are somewhat complimentary, making the co-disposal of dewatered tailings within spoil piles geotechnically feasible and environmentally attractive. However, the impacts of mixing plant rejects within spoil piles are not well understood; in particular, the effects of water draining from the mixed plant rejects on the moisture content of the surrounding spoil. Changes in moisture content can cause additional collapse and degradation settlements of the spoil pile. A series of laboratory tests has been undertaken on mixtures of dewatered coalmine tailings, coarse reject and spoil. The results of these tests have been incorporated into a spreadsheet-based settlement prediction tool to investigate the effects of incorporating mixed plant rejects on total spoil pile settlements. This paper presents the laboratory tests undertaken, the incorporation of the test data into the settlement prediction tool, and settlement estimates for the various mixtures at different stages of construction.CITATION:Kho, A K, Tucker, N, Williams, D J and Shokouhi, A, 2015. Impact of co-disposing mixed plant rejects on spoil pile settlements, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 51–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By N Pranoto, E Lawell, T Dean, M Grant

The Goonyella Riverside Mine is located 30 km north of Moranbah in Central Queensland, Australia. Recent mining activities have exposed the north–south striking Kenya and Zimbabwe thrust Faults. These faults vertically offset coal seams by up to 25 m and locally thicken coal packages through imbrication of coal seams. The presence of back-thrusts add to the geotechnical complexity of maintaining highwall stability. The Kenya and Zimbabwe Faults have provided multiple challenges to the mining operation, with an unplanned additional 240 kt of coal tonnes being mined from imbrication of coals seams or from the refinement to local scale geological models. These additional coal tonnes have been either identified during the mining of the coal seam or just prior to overburden removal above the coal seam. These faults can also negatively impacted highwall stability with highwall failures, lowering the overall slope angle for pit designs and increasing stand-off distances for hazardous highwall conditions. Unmanned Aerial Vehicles are used to scan exposed highwalls and enable geological mapping via high-quality 3D images. Measure while drill data from drill and blast rigs can provide local-scale intersections of the faults and coal seams. Mine Geologists utilise these and other data sets to create localised geological models refined position of the fault planes and coal seams. These models are utilised by relevant mine site teams to ensure the safe and efficient mining of coal around these faults.

Mar 22, 2022

Maps of mineral grade used to assess mineral reserves are most commonly generated using one of the many estimation methods available such as inverse distance weighting or ordinary kriging. Most such maps incorporate a degree of spatial smoothing which is an integral part of the averaging process. In deposits with highly variable grade which include many gold deposits, this smoothing can mask the detailed geometry of the mineralization at the economic cutoff grades being considered. In underground mining, a knowledge of this geometry is important in the choice of mining method and thus in the assessment of the minable reserves.The method of conditional simulation in geostatistics can be used to generate maps of grade which reflect the actual spatial variability of grade as measured through the variograms of the drill hole data. Simulated maps can provide a number of equiprobable images of the mineralization geometry from which a more appropriate mining model of the mineralization can be developed. Multiple simulations can also be used to assess the uncertainty existing in the current knowledge of the reserves.

Jan 1, 1990

By B Nielsen, H Lehto, B Musuku

"The demand for fine and ultra-fine grinding associated with the processing of more challenging, finer grained orebodies and the global driver of minimising energy consumption has been an increased focus in our industry. Outotec’s stirred milling technology, the high intensity grinding mill (HIGmill™), was launched in 2012 in response to this industry need. First Quantum Minerals Ltd selected HIGmill™ technology for its Kevitsa mine in Northern Finland. The 700 kW mill is grinding copper rougher concentrate to improve copper/nickel separation and copper recovery. Selection of the HIGmill™ followed mineralogy analysis and laboratory and pilot testing for HIG milling in parallel with flotation tests to determine optimum grind size and energy input.The paper discusses the challenges and successes of the test work, manufacture, installation, commissioning and subsequent operation of the mill. Grinding performance is presented and a comparison between predicted and operating energy efficiency is made. In addition, the various steps to optimise wear rate and minimise maintenance and downtime are made, with particular reference to internal geometry of the mill.Citation:Nielsen, B, Lehto, H and Musuku, B, 2016. Design, Installation, Commissioning and Operation of Fine Grinding Technology at the Kevitsa Mine, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 59–66 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Ward M

The current and future requirements for an underground mine information management system are being met with a flexible, value-engineered approach to mine information/communication infrastructures. El-Equip has developed and delivered to over fifty mines around the world an integrated, high capacity, radio-based leaky feeder communication system called MultiCOM. To meet the requirements of recently developed advanced information management technologies, such as production and ventilation management, the system has evolved to support simultaneous mobile and fixed information delivery services over an integrated single cable system. The following paper will review how MultiCOM is enabling information/communications technology to cost-effectively implement mine monitoring and control applications. Applications described in this paper include mobile vehicle production tracking, vehicle location, ventilation system monitoring and control with integrated ventilation system simulation. The techniques described are leading the world in terms of flexible and value-engineered applications of technology in the underground mine.

Jan 1, 1995

By G Lumley

PlannersÆ optimism (or maybe commercial necessity) means that most mine plans use equipment rates that are rarely achieved (Lumley and Beckman, 2009). This lack of understanding of what equipment actually moves is causing erroneous equipment forecasts, leading to incorrect mine development plans and economic evaluations. Compounding this problem is a downward trend in actual equipment performance in some areas. Consequently, the presentation of realistic mine plans that are actually achieved in practice is not a common occurrence. However, rational, fact-based mine planning is available to those who want it. Hundreds of millions of cycles of data from open cut mining equipment has been collected from mines around the world since 1992. This unique and highly valuable databank is growing at an exponential rate and is being used by a number of our big miners to support rational and fact-based decision-making. However, neither the use nor the appreciation of the value of this data is universal. There is a challenge to everyone in the mining industry - how do you access value from it? The databank was drilled into and the results analysed for, the Australasian Mining and Metallurgical Operating Practices (AMMOP) publication (Lumley, in press). For this paper the analysis has been extended to include interpretation of trends for draglines, shovels, excavators and trucks. It investigates trends between coal and non-coal mines and across geographic areas. It is known that mining equipment performance in most sections of the industry is falling. This paper attempts to quantify the fall and provide explanations. The trends are analysed to extract the reasons behind the changes and most importantly, what can be done about it.CITATION:Lumley, G, 2012. Understanding trends in performance of open cut mining equipment, in Proceedings Project Evaluation 2012 , pp 203-224 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

The Devonian Mount Morgan gold-copper deposit was situated on the western margin of the Calliope Volcanic Are assemblage, in the northern New England Orogen. Recorded production from commencement of mining in 1882 to mine closure in 1989 stand

Jan 1, 1994

By Z Tong, M Gao, X Wang

In response to the need for improved magnetic separators for beneficiation of fine grained iron ores that have been finely ground to liberate the iron minerals from the gangue, a series of high efficiency wet drum permanent magnetic separators (T-GCT) has been developed by Maanshan Tiangong Technology Co Ltd. These magnetic separators have high efficiency for separating superfine strongly magnetic minerals and the ability to produce high-grade concentrates with high recovery. They are ideal replacements for conventional drum magnetic separators, especially for treating superfine particles.

Jan 1, 2009

By D Bertoldi, C Haines

"The Waihi Gold Mine (WGM) operated by OceanaGold New Zealand Limited is a wholly owned subsidiary of the OceanaGold Corporation of Australia. Traditionally WGM has stockpiled and processed separate campaigns of open pit and underground ore. The ore is processed via a conventional semi-autonomous grinding (SAG) / ball circuit (SABC). The low aspect SAG mill operates in a closed circuit with two 20" cyclones, whilst the ball mill is also a closed circuit with a 10" cyclone cluster. A major wall movement in April 2015 ceased open pit operations indefinitely, 18 months ahead of the mining plan. This immediately reduced the forecast mill tonnage leaving two options: begin campaign milling or change the operating strategy and target lower throughput. Additional cost pressures necessitated improved milling cost efficiency. The immediate ore restriction limited processing alternatives to within the existing major infrastructure. Available comminution circuit survey data laid the foundation for developing a comminution model using the JKSimMet™ software package (version 6, created by KJTech). A number of flow sheet variants were then evaluated based on predicted throughput and efficiency. The comminution models suggested opportunities for improved efficiency lay in reducing throughput and increasing utilisation rather than on/off campaign milling under the existing operating philosophy. A series of process alterations followed, delivering new cost efficiencies that maintained the current $/t processing cost. This paper aims to review the change in circuit performance and examine the decisions and challenges faced following the transition from a high tonnage SABC circuit to lower tonnage SABC circuit.Citation:Haines, C and Bertoldi, D, 2016. The Transition from Semi-autogenous to Autogenous Milling at Waihi Gold, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 303–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By F Sinaga, E Widijanto

PT Freeport IndonesiaÆs Deep Ore Zone (DOZ) mine is the new underground block caving mine within the East Ertsberg Skarn System (EESS) which started production in mid-2000. The DOZ will produce 25 000 tpd using mechanised block cave mining method and will be the fourth underground mine opened within the EESS deposit. A review of the DOZ extraction bolting design was conducted in November 2000. The aim of this review was to re-evaluate the effectiveness of the current design in relation to bolt length and spacing and to challenge some questions about the technical background of the design. For instance, the influence of the rock condition on the design. To review this bolting design, several books and papers are reviewed and several experienced people have been contacted to give their opinion. The methodology used for this review is:reviewing the technical background of current design; collecting ideas and alternatives; collecting data from books and personal communication and conducting analysis; and conclusion and proposed design.

Jan 1, 2002

By Clarici E, Marsden J. R, Calderbank P. A

Evaluation of previous studies of multi-layer perceptron type artificial neural networks in the modelling of the deformability behaviour of rock have suggested that a deviation from the standard method of laboratory testing of rock under triaxial loading at constant confining stresses and constant axial strain rates may be inappropriate when the data produced are used to train an artificial neural network. In this paper, preliminary results of adopting such a strategy are reported. Of specific concern is the establishment of a suitable schedule for the stress path during testing. Furthermore, the training element of back propagation optimisation was directed towards prediction of new stresses given old stresses and old strain increments. Adoption of this method of supervisation in artificial neural network training facilitates the integration of the trained neural network within existing numerical methods used in rock mechanics. The target code was a finite difference Lagrangian formulation for the analysis of continua. Sandstone rock taken from a quarry in the UK was used in the study which showed that the method has great potential.

Jan 1, 1995

By L Galisson, E Audigé, D Sowers

Establishing a robust geotechnical instrumentation and construction monitoring plan is one of the keys to the successful delivery of the world’s largest soft-ground bored tunnel in Seattle, Washington. The paper describes and provides a return of experience on current and best practice for monitoring tunnelling projects in urban areas. The owner’s contractual approach is discussed to highlight the flexibility of the design-built contract in achieving equal or better solutions by allowing for the use of innovative technics. Special attention is given to the management and involvement of third parties (building owners, utility owners), including the public, to overcome all challenges faced during the installation of the monitoring system in downtown Seattle for over 1000 instruments. Finally, the authors present the strategies implemented for managing the monitoring data and communicating with the owner, contractor and stakeholders.CITATION:Sowers, D, Galisson, L and Audigé, E, 2014. Current and best practice for monitoring tunnelling projects in urban areas – Alaskan Way bored tunnel, Seattle, Washington, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 441–450 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By A D. Price, W J. Germs, O Patterson, T R. Weaver

"Understanding controls on groundwater and surface water flow and quality at mine sites throughout all mine stages is critical to effectively manage environmental impacts over the entire mine life. Monitoring forms is an essential component of this proof of understanding. Typically, monitoring programs at mine sites have been developed in the framework of existing conditions. However; recognition of the challenges of climate change and the performance of mines during recent extreme events in Australia has highlighted the need to develop monitoring programs that are resilient and responsive to changing environmental conditions. Water monitoring programs need to be effective under a range of environmental conditions, potentially not historically experienced.This emerging challenge requires cross-disciplinary teams to work together to understand issues including: representativeness of background conditions to longer-term conditions at the mine site sensitivity of mine and closure designs to changing climate and hydrologic conditions methods of performance (eg water quality or quantity) failure during extreme climate events such as flood or extended drought.These understandings come together in a detailed conceptual and, in many cases, numerical hydrologic model that considers the mine-water environment under a range of conditions. The groundwater, surface water and water quality monitoring programs that are developed from the conceptual model need to be sufficiently responsive to be effective in the face of such changing conditions, with results in turn informing the conceptual model. Extended drought, major floods and changing weather patterns can alter recharge and discharge areas, oxidation profiles and ultimately, the contaminant flux estimates that would have contributed to mine design parameters and performance. Unless these effects are considered in the spatial and temporal design of the monitoring program and within the parameters monitored, the resultant program may fail to capture data that are critical to evaluating environmental impacts from mine sites.Developing and implementing a water monitoring program that considers these issues can build confidence in mine performance under a range of conditions, leading to increased confidence by all stakeholders in long-term mine performance during and after closure.CITATION:Weaver, T R, Price, A D, Patterson, O and Germs, W J, 2013. Developing resilient water monitoring programs in changing climate conditions, in Proceedings Water in Mining 2013, pp 109-114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

The B.R.G.M., through international experience gained over many years, has become very skilled in alluvial prospection, particularly for diamonds. The research laboratories within the B.R.G.M. have also been active in creating new mineral processing equipment,. some of which is directly applicable to such prospection. One such development, the mobile prospection unit, is described and -its application in mineral exploration is demonstrated by a consider- ation of the diamond search in Australia and the general exploration of the Massif Armoricain (France). Because this latter study was fundamental in the development of the concept of "mineral-geochemistry", and its application in mineral exploration, it is also briefly described.

Jan 1, 1980

By Liu Q, Siefken T. C, Misra V. N

Investigation of the differential flotation characteristics between arsenopyrite and pyrite in a ore concentrate have been carried out on a laboratory Leeds flotation cell. Experimental results indicate that some limited separation between arsenopyrite and pyrite is possible by differential flotation under the conditions of high pH and low pulp redox potential. The best performance in this testwork was achieved by using an oxidizing agent at pH 10.7. Of the oxidizing agents tested, NaOCI gave better oxidizing effect than KMnO4. It has also been observed that the pulp redox potential depends on the pulp pH value. At high pH values a hydroxide layer is formed on the arsenopyrite surface, which has the effect of a depressant on the arsenopyrite.

Jan 1, 1992