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By C Ausa, Nyunt Htay, A, L Deiparine

The main tectonic elements in Myanmar are a late Mesozoic and Cenozoic magmatic arc system in the west, repeated in northern Myanmar by more than 300 km of dextral movement on the Sagaing Fault, and the back-arc continental region affected by early and late Mesozoic orogenies, in the east. Historically most lode gold production has been from latest Cretaceous high-grade mesothermal veins and derived placers in the Wuntho and Tagaung-Myitkyina segments of the magmatic arc. Placer deposits in the Ayerwaddy River north of Myitkyina are currently worked by more than 100-bucket dredges. South of Wuntho, the magmatic arc and Pegu Yoma fold belt host epithermal gold with associated As, Sb and Zn in mid-Tertiary marine sediments. MyanmarÆs most productive lode gold deposit, the Kyaukpahto mine, lies within a north-trending district east of the magmatic arc and north of Mandalay. Here mineralisation and associated jasperoidal silica occur in Eocene sandstones and Permian and Triassic carbonates. Possibly this district continues southeastwards, across the Sagaing Fault, as sediment-hosted Sb Au and locally skarn Au mineralisation within a 1100 km long fold-thrust belt. Also present in the back-arc region are sandstone-hosted Au Cu in a Palaeozoic slate belt, and gold and stratabound gold-base metal mineralisation in the medial metamorphic belt. While untested targets remain in the magmatic arc, particularly for high sulphidation Au, the best potential is clearly within the back-arc slate and fold-thrust belts in the western part of the Shan Plateau and in northeastern-most Myanmar.

Jan 1, 1999

By A N. Parry, G van Wyk

"Sensor based automatic ore sorting technologies are used in the minerals industries to efficiently remove waste and submarginal grade material from crushed and screened run-of-mine (ROM) ore, producing a coarse (typically >10 mm) upgraded preconcentrate at an early stage in the mineral processing circuit. This avoids additional energy intensive downstream processing of this rejected component of the ROM feed, leading to lower unit operating costs and reduced tailings disposal volumes.Test work on bulk low-grade gold ore stockpile samples from Central Norseman Gold Proprietary Limited has been conducted, indicating high gold recoveries as well as high material rejection rates. A financial model, based on these results, evaluates grade sensitivity and identifies a minimum stockpile grade for adequate financial returns. The base case modelling estimates that the ex-stockpile grade (including the fines bypassed fraction) can be more than doubled through ore sorting and that the project will be highly viable with strong cash flow generation at stockpile grades as low as 0.7 g/t gold. The modelling will enable the company to benchmark ore sorting options against stockpile reclaim and screening operations currently employed. Citation:Parry, A N and van Wyk, G, 2016. Upgrading Low-grade Gold Ore Stockpiles by Preconcentration Using Ore Sorting - an Assessment of the Economic Impact and Viability, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 179–190 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By J Tien, J Huang, N Haque, M O’Brien

Coal preparation is an integral part of producing coal for thermal powerplants and metallurgical processing plants. Coal processing plants use various unit processes to separate gangue and ash content from mineral coal, thus increasing the specific energy content.A flow sheet and a simulation model was established for a typical coal processing plant using Microsoft Excel. This model used the mass balance and split factors for run-of-mine (ROM) coal, tailings and water usage from a typical, generic coalmine.The common method of coal preparation initially involves several stages of crushing to reduce the size of coal. It is then sent to the processing plant for further washing. The typical method in Australia for coarse coal material processing is the use of dense medium cyclone (DMC) (Kininmonth and Baafi, 2009). Flotation cells are used for processing of fine coal. The fine products are utilised for coking coal only. In our case study, the intended coal product is for thermal powerplants. Therefore, the fine coal processing utilised spirals instead of flotation, which is typical for the industry.CITATION:Huang, J, Haque, N, O'Brien, M, O'Brien G and Tien, J, 2016. Development, simulation, economic and environmental evaluation of a coal processing flow sheet, in Proceedings Life-of-Mine 2016 Conference , pp 48–51 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By S Leichliter

La Colosa, Colombia is a large gold-porphyry deposit currently undergoing feasibility studies by AngloGold Ashanti. This period of development allows the opportunity to apply innovative and emerging testing and modelling methods to provide a predictive geometallurgical recovery model for the deposit. By partnering with the AMIRA P843A Geometallurgical Mapping and Mine Modelling (GeMIII) research project, the geological and mineralogical data are analysed with respect to liberation and recovery methods. This will allow the variability in the geology and mineralogy of the deposit and key relationships recognised in the data to be included in the development of a model to help predict recoveries of the gold. Many aspects of the gold mineralisation such as gold paragenesis, associations, grain size and texture are determined and analysed using optical microscopy, Mineral Liberation Analysis (MLA), and laser ablation (LA-ICP-MS). At La Colosa the gold has been located in sulfides (eg pyrite, pyrrhotite, and chalcopyrite), silicates, along silicate phase boundaries, and among the pyrite-rich intermediate argillic alteration. Further testing and analysis will also determine if ‘invisible’ gold is present in the pyrite, pyrrhotite, and chalcopyrite. Recovery methods can also be determined and tested after combining the results of mineralogy tests with other data (eg results of comminution tests). Indices for the mineralisation and recovery are developed using image analysis and analytical testing. These indices are correlated with recovery data from the company to develop a predictive block model for recovery. The goal is to develop cost-effective, efficient methods to analyse the mineralogy and geology of the deposit; understand the variability in the mineralogy, geology, and recovery; and construct a predictive geometallurgical recovery model.

Sep 5, 2011

By D Henderson, M Germain

The beneficiation of iron ore deposits to yield haematite and magnetite concentrates for steel making processes typically require the use of one or a combination of wet processing techniques based on gravity, magnetic or froth flotation processes. With the need for more cost-effective technologies with a lower water demand, a re-examination of dry processing techniques has been initiated. For example, a dry processing capability may offer an advantage where suitable quality and quantity of process water hinders the development of a particular resource. This paper describes recent laboratory test work for the production of high grade concentrates using dry electrostatic techniques for -300 ¦m haematite and magnetite ores and compares them with magnetic separation techniques.

Jan 1, 2009

Dragline performance drops considerably when chop-down and double handling of material is needed due to increasing overburden thick- ness or total pit depth. Beyond a certain pit depth the dragline needs support by a pre- stripping system in the upper portion of the overburden. In soft to medium hard ground the bucket wheel excavator can be used for pre- stripping, whereby several methods of material transport are investigated. Conveyor transport around the pit and dumping by stackers is the best solution from the technical point of view. Cross pit transport and dumping by means of a conveying bridge is the method with the lowest costs per volume moved. Cross pit transport by use of a beltwagon with overlong discharge boom is both, poor from the technical point of view and high in overall costs.

Jan 1, 1981

By N Elith

The explosives demolition of a post-stressed, steel reinforced, concrete road bridge in Australia’s capital city, Canberra. The bridge was 50 m from the new replacement bridge, 320 m from community structures and within five kilometres of the national parliament buildings. The job required multiple overlays of risk assessment, public relations, safe work procedures, specialised blast design, environmental predictions and flyrock controls. Project stakeholders included Worksafe, Roads ACT, bridge owners, consulting structural engineers, community groups and road users. The bridge precincts, including a major road underneath, had to remain operational to peak traffic in the days leading up to the demolition. The break-up and removal of debris had to be executed in just two days from Friday to have the road beneath re-opened for Monday morning city-bound traffic.In Canberra, all explosives demolitions are now viewed with particular caution after a demolition in 1997, during which a young girl was killed. Any approval requires that Explosives Regulations, AS2187 2006 and Worksafe processes are satisfied, and a convincing case presented for blasting as a safe and viable option.Our design used specialised shaped cutting and blasting charges to sever in situ concrete beams and tendons and to shatter components of the stressed concrete bridge assembly. We include comments on structural engineering reports dealing with pre-weakening mechanisms. The benefit of pre-weakening is that it reduces the amount of explosives needed to safely complete the job and facilitates quick removal of debris after the shot. The complementary skills of the team, each one an expert in his field, resulted in a highly successful demolition, praised by authorities as an outstanding example of controlled use of explosives.

Nov 8, 2011

By J B. Pateiro-Fernßndez, M Fuchsschwanz, G Deissmann, S Ahmad

Quang Ninh province is the most significant coal producing region in the north of Vietnam. The Nui Beo Coal Company (NBCC) operates open pit mines in Quang Ninh province and the waste overburden produced is dumped as sidehill fill in the Chinh Bac waste dump site. In the past, no special consideration has been given to the environmental impacts during the dumping operations. The mine waste is transported in trucks from the mine site to the dumping site and the loading, hauling and dumping operations are the main sources of dust emission. Rain events, especially during the rainy season, cause the generation of contaminated surface water as well as seepage of water through the dump at a number of locations. The existence of cracks at the top of the dump can pose serious stability problems with heavy rain events leading to failure of slopes which can potentially disturb vast areas of land currently used for agricultural purposes and human settlement. For sustainable development at the Chinh Bac waste dump site in the future, apart from the social and economic considerations to be assessed, there is an absolute necessity for environmental protection measures to be in place both during and after the dumping of the mine waste overburden. Research Association Mining and Environment in Vietnam (RAME) is working to develop and implement concepts for the mitigation of environmental problems emerging from dust, contaminated water and lacking slope stability to ensure successful rehabilitation of the coal mine waste dumps in the north of Vietnam. Within the framework of RAME, the Institute of Mining Engineering I (RWTH Aachen University) is managing and working to develop the stabilisation concepts for the solid mine waste dump in collaboration with the Chair of Geotechnical Engineering (RWTH Aachen University), Brenk Systemplanung and the Vietnamese group of companies VINACOMIN (Vietnam National Coal-Mineral Industries Group). The most economical and environmentally sound operations, as well as locally adaptable environmental protection measures, are essential for the sustainable development of the dumping operations at Chinh Bac dump. This paper describes the dump site and the sustainable development possibilities with an emphasis on the environmental protection and stability problems at the Chinh Bac waste dump.

Jan 1, 2009

By Lynch K. S, Street R. P

Hamersley Iron's pellet plant at Dampier involves ore drying, dry grind- ing in ball mills, disc balling and, indurating by use of the straight grate system. After five years of operation, the plant's output has been increased from the design capacity level of 2 M.T.P.Y. to 2.5 M.T.P.Y. Steps taken in equipment modifica- tion, improvements in process control, and changes in maintenance procedures are described.

Jan 1, 1973

By D David

Geometallurgy is often a misunderstood and poorly defined concept. The first thing the paper will attempt is to provide a definition of geometallurgy. Ultimately this paper has been written to provide guidance to geologists, mining engineers and processing professionals as to what geometallurgy means in the crucial early phases of a potential mining project between the time of discovery and the time of commencing construction, should this occur. The paper covers the options available for conducting a geometallurgical study of a resource or orebody, appropriate to the level of definition required in the projectÆs development cycle. The paper will then describe how the geometallurgical information generated is subsequently used in calculations, planning and preparation of reports designed to inform and reassure stakeholders, such as the market. Ultimately in a successful project, appropriate options adopted in the development phase will form the basis of an ongoing geometallurgical program that links the major site disciplines for the good of the operation.CITATION:David, D, 2013. Geometallurgical guidelines for miners, geologists and process engineers - discovery to design, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 129-132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By K Eglinton

The extractive industries response to community engagement due to social and political pressures in the 1980s and 1990s was the starting point of development leading to the modern function of corporate social responsibility.Challenged by communities who have greater access to information, demand greater transparency and responsibility of corporate organisations and who possess greater awareness of the communities they participate in, the mining sector faces another step change in how it approaches and integrates corporate social responsibility, transparency and engagement.Mining is seeking reserves of lower grades, in more sensitive environments and in countries with minimal transparency and governance. Not only are the locations changing but so to the stakeholders to engage with and issues to contend with. An increasingly savvy opposition, including not just the ‘green hippies’ but the Gen-Ys interested in the wider sustainability debate and Baby Boomers moving to life style environments, are now questioning mining’s behaviour and encroachment into ‘their space’. Issues including effect on lifestyle amenity, property value, energy efficiency, social provision; concepts such as ‘doing more with less’, participatory engagement, increasing transparency and balancing economic, environment, cultural and social aspects are becoming the norm.The traditional model of supporting local communities, communicating plans and providing employment, community investment and indigenous support programs is not enough. Our industry faces challenges on multiple fronts. It must now be able to address these from a personal/community perspective if it is to remain relevant within communities and play a role in addressing the global sustainability issues.This paper draws on corporate social responsibility trends, integrated functions and implementation approaches through the application of activities within Newmont operations across Asia Pacific.The approach presented works on the philosophy that communities do not necessarily have to like what we do, but should be able to identify and recognise the way in which we involve them in decision making, communicate our intentions and respond to issues.

Nov 22, 2011

By P J. Vardon, L A. van Paassen, Y Yao, A F. van Tol

Thin-lift atmospheric fine drying (AFD) is a technique used to dewater mine and oil sand tailings, which utilises both self-weight consolidation and atmospheric evaporation. The disposed layers undergo a cyclic drying and rewetting process due to precipitation and deposition of additional lifts on top of the dried layer. The current research aims to optimise the deposition process via use of a numerical model and realistic atmospheric conditions, including both periods of drying and wetting. The model is based upon water balance and includes large strain considerations. A number of material behaviours are characterised using empirical fitting curves based upon laboratory measurement of material characteristics, including both the shrinkage and water retention curves for drying and rewetting. The model is able to model multiple lifts, simulating field scale and realistic climatic conditions within timescales suitable for engineering practice (eg seconds or minutes). The model has been previously validated against controlled laboratory experiments and utilised to simulate field tests. A series of simulations are presented to illustrate the ability of the model to be used as a practical tool for the optimisation of a tailings deposition strategy.CITATION:Vardon, P J, Yao, Y, van Paassen, L A and van Tol, A F, 2015. The use of a large-strain drying and consolidation model to optimise multilift tailing deposits, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 263–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By M Barkh, F X. Spachtholz

The mining industry faces significant environmental challenges in managing tailing ponds and wastewater treatment, including the risk of contaminated water, breaches of tailing dams, and energy-intensive treatment processes. Traditional methods involve pumping water to secondary treatment facilities for neutralisation, which is costly and poses operational and environmental risks. In response to these challenges, the Professional Mine Water Action Plan (PMAP) introduces a revolutionary approach that combines cutting-edge AI technology and environmentally friendly reagents for in situ neutralisation of acidic wastewater. PMAP leverages magnesium-based slowrelease reagents and AI-driven intelligent dispensing systems to optimise treatment processes within the tailing pond itself. The unmanned smart dispensing vessel (USDV) conducts bathymetry to gather data on water quality and hydrography, allowing the system to determine the appropriate reagent quantity and injection strategy. This approach transforms the tailing pond into virtual reaction columns, enabling individual and simultaneous water treatment while optimising efficiency. PMAP’s novel reagent demonstrates exceptional efficacy in removing critical metals like cobalt, nickel, and copper, as well as reducing harmful metals such as mercury and manganese to undetectable concentrations. Unlike traditional lime-based treatments, PMAP’s reagent prevents gypsum formation and reduces waste volume significantly, improving reagent utilisation and solid waste handling. Furthermore, PMAP technology offers benefits beyond environmental stewardship. By reducing water treatment costs and improving resource management, it enhances operational efficiency and aligns with broader corporate sustainability goals. Additionally, PMAP expedites permitting processes by eliminating the need for traditional water treatment infrastructure and mitigating risks associated with hazardous reagent transportation. Integrating PMAP as a pre-treatment for existing lime facilities provides further benefits, including optimisation of treatment operations, reduced reagent consumption, and the recovery of valuable metals from generated sludges. Overall, PMAP represents a groundbreaking advancement in mining wastewater management, showcasing the transformative potential of AI and environmentally friendly solutions to foster sustainable and responsible mining practices globally. Its inaugural project in the Yukon Territory aims to demonstrate its capability to remove contaminants from mine water, paving the way for widespread adoption in the industry.

Sep 1, 2024

This paper presents a rationale for selecting appropriate support elements which combine to form a support system to maintain stability in mines subjected to both strainburst and the shaking that occurs from fault slip. The overall approach was developed during the 'case for safety' study undertaken to allow the then Beaconsfield Gold mine (now Tasmania mine) to resume development and production after the 25 April 2006 ground-fall and fatality that received worldwide publicity. Issues of the sometimes competing requirements of support element performance during dynamic loading are discussed and the need for support flexibility is contrasted with the usual high support element stiffness required when these are used to reinforce rock masses. An example is presented to show the steps and technical details required to design each component of a support system to counter the de-stabilising effects of seismicity.

Nov 25, 2010

By R Peiffer, L van Wyk

The Port of Port Hedland is the largest bulk export terminal in the world and is one of Australia’s most important pieces of economic infrastructure. BHP is the largest Port user to support the export of iron ore products from mines located within the Pilbara region of Western Australia (WA). BHP’s priority is the safety and well-being of its workforce and the communities where it operates. In a recent regulatory application to increase export capacity, BHP committed to the deployment of wind fences to reduce wind erosion from stockpiled ore. Wind erosion from stockpiles was identified through inverse modelling as the most significant dust source compared to other sources such as stackers, reclaimers, shiploaders and transfer stations. The primary cause of dust emissions from stockpiles is dust lift-off during high wind conditions. BHP proposed the installation of wind fences across its Port Hedland operations, targeted at reducing emissions from wind dependent sources, primarily stockpiles, by reducing the wind speed downwind of the wind fence. Modelling predicts that installation of the wind fence will significantly reduce emissions from stockpiles, particularly at BHP’s western operations (Finucane Island). To be effective in shielding stockyards and reducing wind speeds, the wind fences are located upwind and as close as practical to the open stockyards. BHP’s wind fence design incorporates learnings from other existing installations and has been tailored for Port Hedland’s cyclonic conditions. The wind fence will be higher than the stockpile height, with a mesh porosity of approximately 50 per cent. The mesh porosity allows some of the wind to pass through the mesh. This reduces the wind turbulence downstream of the wind fence, as opposed to a solid wind fence, which increases downwind turbulence, resulting in increased dust.

Sep 18, 2023

By H Khoshrou, A Siamaki

Blast designs can have productive and non-productive impacts on downstream stages, mine productivity and operating costs. On the other hand, ground vibration, fragmentation, and back break caused by blasting impose damage and financial penalties and which must be controlled by blast design. One of the significant variables in blast design is the burden. In this study, the potentials of artificial neural network are investigated in prediction of burden in the Sungun copper open-pit mine. Input data were assembled through 18 blasting blocks according to different levels and experimental geomechanical investigation. To construct the model blastability index, uniaxial compression strength, hole diameter, specific weight of rock, rock quality designation and cohesion strength are taken as input parameters, whereas, burden is considered as an output parameter. Mean square error was used as the performance function and back propagation algorithm as the training function, containing four hidden layers and 14 data sets. Four sets of data were used to make sure that correct training had been carried out. This produced the coefficient correlation of 0.662.

Sep 26, 2011

By B C. McLellan

The decline of ore grades on land, increasing demand and high prices for various minerals have led to an increased interest in mining the deep ocean sea floor. The potential deep ocean reserves are vast and in some circumstances the grades are high enough to consider mining. However, the consequences of such mining are as yet uncertain. This paper will present the results of a comparative assessment of life cycle impacts of deep ocean minerals. Two alternative extraction technologies from different deep ocean resource types were examined and key commodities are considered. Initial results indicate that the energy requirements will be higher than the average land-based resources, but may fall within the range of the deepest terrestrial mines.CITATION:McLellan, B C, 2015. Comparative life cycle impacts of deep ocean minerals and land-based counterparts, in Proceedings Third International Future Mining Conference, pp 253–260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By A Holmgren, W Forsling

In the present study infrared attenuated total reflection (IR-ATR) was used to monitor the rate of in situ adsorption of heptyl xanthate on a layer of zinc sulfide synthesised on a germanium ATR crystal. The zinc sulfide surface was characterised using x-ray photoelectron spectroscopy (XPS). The absorbance of heptyl xanthate measured increased with increasing bulk concentration of the adsorbate up to an equilibrium plateau value corresponding to a fractional coverage of the surface sites of the substrate. For the adsorption from solutions of concentrations between 10-3 and 10-5 M, the rate of adsorption increased with increasing bulk concentration. At higher concentrations the measured absorbance should be corrected for the absorbance due to the concentration of xanthate in bulk solution. The present work provides a discussion of this correction. Assuming the adsorption stage to be rate-controlling and proportional both to the concentration of the adsorbing species in solution and unreacted surface area, a rate law governing this type of transient adsorption kinetics was derived. By means of absorbance data for the concentrations 0.1 and 0.01 mM, the rate constant of adsorption was calculated. From the initial part of a Langmuir adsorption isotherm, the absorbance at monolayer coverage and the equilibrium constant of adsorption could be estimated.

Jan 1, 2005

By V Pfannenstiel

The United States (US) coal mining industry has been working under comprehensive planning, operating and rehabilitation regulatory requirements for nearly 35 years. The public desire for environmental protection during mining and rehabilitation following mining to achieve post-mining land use and sustainability goals has been a major factor and continues to influence the process. Mining companies have evolved operations to achieve outcomes that address the desired goals and regulatory requirements cost-effectively and successfully. Over the 35 year regulatory period, requirements for more diverse topography, specialised revegetation communities, landform stability and assured sustainability have increased and become more complex. These challenges are effectively met by maximising integration of mine planning and operating with the rehabilitation process. Rehabilitation is then implemented in a more timely and efficient manner and with effective results that achieve desired outcomes, commonly with added value. Peabody Energy (Peabody) has taken this approach in its US operations and this paper discusses an integrated approach and illustrates learnings and results with examples from several of its western US operations.CITATION:Pfannenstiel, V, 2012. Integrated planning, mining and rehabilitation for effective results and sustainable land use - A western United States perspective, in Proceedings Life-of-Mine 2012 , pp 219-232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By E P. O’Dwyer

Segment and gasket lining in tunnel boring machine (TBM) tunnels; and sheet membrane lining systems in driven tunnels are robust waterproofing systems each with a proven history of performance in Australia and further afield. Where an interface between these two systems occurs, the potential for costly failures is vastly increased and additional attention to detail is required in design, planning and construction. TBM cross-passages represent the most common occurrence of this interface, with steel compression flanges and neoprene gaskets being the typical means of connecting the waterproofing systems. There is a large variance in both detailing these flanges and associated outcomes, which makes this an area where there is room for improvement within the industry.The paper will look to tease out the various issues associated with this interface and how they can be dealt with efficiently with appropriate design measures, robust planning and carefully controlled construction methods.The paper will also look to review the new technologies and systems currently being put forward as potential alternatives, including an epoxy tape system, which has recently been successfully trialled on a project in Europe under high-pressure head.CITATION:O’Dwyer, E P, 2014. The challenge of waterproofing cross passages in segmentally lined tunnel boring machine tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 315–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014