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By M I. Pownceby, A Torpy, C Johnson, N C. Wilson

To extract uranium from low-grade, calcrete-hosted uranium (CHU) ore is challenging owing to the presence of carbonate and swelling clay gangue minerals that require an alkaline lixiviant to be used. Western Australia possesses ~75 000 U3O8 t in CHU resources. Improvements to alkaline leach extraction practices would improve the economic potential of these deposits.A column leach study of CHU ore was run for 105 days using an alkaline carbonate-bicarbonate lixiviant. The uranium content of the liquor plateaued after 75 days at ~275 mg U/L; the calculated maximum solution capacity was 800 mg U/L. Spiked peaks and troughs were seen in the data set beyond the 60th day, where concentrations ranged from 220 - 290 mg U/L, indicating possible cyclic uptake and loss of uranium from the solution.Pristine and leached ore samples were geochemically analysed and mineralogically characterised at high resolution using a field emission gun-electron probe micro-analyser (FEG-EPMA). Results showed that leached ore samples from the top of the column contained less carnotite than pristine ore. In contrast, leached ore samples from the column base contained regions with more carnotite than pristine ore, indicating precipitation. Three carnotite grain micro-structures were identified in the leached ore; fan-spherulite, granular and core-shell cubes, with evidence for multiple growth phases.Evidence of carnotite precipitation was seen at the edge of and in pore spaces within montmorillonite and dolomite grains. The point of zero charge of both minerals is lower than the pH of the lixiviant (pH 10.8), thus the mineral surfaces are negatively charged and would not attract UO2(CO3)34- ions out of solution. Similarly, the decrease in the uranium content of the lixiviant is not attributed to super-saturation, as this was unlikely to have been achieved. Work is ongoing to understand the reason for carnotite precipitation and the fluctuations in the lixiviant uranium concentration that are seen.CITATION:Johnson, C, Pownceby, M I, Wilson, N C and Torpy, A, 2013. Microscale characterisation of pristine and processed ore - implications for leaching calcrete-hosted uranium ore, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 303-316 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

The Gympie Goldfield was the sixth largest producer of gold in historic terms in Australia. The Joint Venture Agreement between BHP Gold Mines Limited and Devex Limited was signed in January 1987. Since that time, some $20 million have been spent on underground and surface exploration work in the southern portion of the goldfield. The project is of considerable interest as the dewatering, rehabilitation and equipping of an old rectangular timber-lined shaft has been undertaken. The project is located in Gympie, a city of 10,000 people. The issues of dealing with urbanisation and associated environmental aspects are vital to the success of the project. An outline of the project and the geology of the mineralised structures follows:

Jan 1, 1989

By V Srinivasan, P Knights, C T. Farrelly

By 2025, with the widespread industry adoption of remote operation centres and advanced analytics, mining companies will find themselves making better, more informed decisions across the value chain. Process automation will drive significant business integration and reorganisation. Better collaboration between functions will make cross value chain optimisation a reality. Wherever possible decisions will be automated, based on analytical models and embedded in an enterprise decision management (EDM) architecture. This will take care of many of the minor day-to-day or the minute-to-minute decisions that consume operators and managers today. More flexible information technologies and architectures derived from the extensions to Web 2.0 and service oriented architecture (SOA) will solve many of the integration issues of today. The ongoing business imperatives for doing more with less people will make true collaboration with partners such as mining contractors, equipment vendors, transport providers, suppliers and maintenance contractors commonplace throughout the industry. All these organisations will be linked in and share common goals and objectives in real-time while providing visibility of internal constraints and available capability, allowing optimised decisions to be made across the extended enterprise. Humans will increasingly move to a more supervisory role and will use advanced collaboration to quickly solve complex abnormal issues that span the value chain out to the extended enterprise. The open collaboration and communication models instilled in the workforce through the widespread use of social networking technologies will drive thought leadership far beyond current æbest practiceÆ thinking. This will encourage the mining industry to extract the business value from rapidly converging fields of study such as environmental sciences, neuroscience, psychology, engineering, information technology and business finance. The future of mining will see a more uniform distribution of data savvy workers between the ages of 20 - 40, forcing a change in current operations. This group will drive the adoption of ubiquitous computing, augmented reality, presence and digital labelling. The enterprise will shift from a relatively static disparate set of functions to a digitally aware, integrated and interactive environment with information available, in context and just in time, to those who need it. The networked virtual enterprise will therefore be a reality.

Jan 1, 2008

By G King, Q Shu, W Cao, F Gyakwaa, H Singh, S Wang, M Huttula, T Fabritius

Metallurgical slag, such as refining slag, is essential to enhance or promote steel cleanliness. The CaO–MgO–Al2O3–SiO2 system is the primary source of oxides-based inclusions. It plays a vital role in applications in various pyrometallurgical processes. Numerous thermodynamic databases and physicochemical properties of slag studies mainly focus on quenched samples and measurements at room temperature. Consequently, the present study explored the physicochemical, structural properties and crystallisation evolution for CaO–MgO–Al2O3–SiO2 glassy slags via in situ hightemperature Raman spectroscopy and synchrotron X-ray diffraction. The study was carried out by synthesising CaO–MgO–Al2O3–SiO2 slag with varying Al2O3/SiO2 ratios. The results from the in situ high-temperature measurement demonstrated a pattern showing a transformation of a broad peak from the glassy matrix to crystalline peaks. The study showed crystallisation of dominant phases such as Ca2SiO4, Ca2Al2SiO7 and CaAl2O4 that correspond and are attributable to changes of structural units during in situ high-temperature measurements. The results further showed a correlation between an increase and transformation in crystalline phases observed from the spectra obtained from non-isothermal heating of the samples.

Jun 19, 2024

The Canada Centre for Mineral and Energy Technology (CANMET) /Calgary Coal Research Laboratory and the National Research Council in Ottawa established a joint working research group with industry to develop and test various computer models for application in surface coal mining operations in western Canada.The first part of the paper deals with the problems the group experienced during the past two years especially having model specification and requirements defined and understand site management practices.The second part of the paper deals with site specific development of general mine model for TransAlta Utilities' Highvale Mine in Alberta. Described here are the development of an interactive truck/shovel model for their three pit operation, selection and application of dragline model for tandem operation with the extended bench method, criteria for operational model of the five seams operation with selec-tive mining approach.

Jan 1, 1985

By E Amini, N Beaton

Application of ore pre-treatment technologies such as Grade Engineering and in-pit ore treatment require comprehensive analysis to show proven value is being generated by switching away from the current practices. Considering most mining operations last several decades; the pre-treatment technologies must be investigated over life of mine (LOM) to truly show value was generated or lost. Therefore, a value chain flowsheet model has been usually developed to run those analysis/simulations over LOM using a set of defined ore characteristics and the operating equipment capacities. The Integrated Extraction Simulator (IES) has been used for this type of LOM simulations as it has the necessary flexibility to accommodate the whole mining value chain flowsheet in one platform and provide essential computation power to run mass simulations for the given scenarios using the resource block model. This allows to forecast the value chain response over the LOM for all given scenarios in a feasible amount of time. The traditionally developed flowsheets for the analysis/simulations are usually limited to the mineral processing plant and were developed based on a single audit conducted on the plant in a very short time, e.g. several hours. The process plant is being operated with a certain ore at a certain condition during the short audits which would not reveal the true capacity of the operation equipment when ore characteristics changes. Therefore, it would be impossible to define the true capacity of the equipment and identify the constraints along the value chain. In this study, a methodology was developed to identify the constraints along the value chain and implement those in the IES flowsheet using process information. Also, the equipment models were fine-tuned to represent the true capacity of the equipment in the flowsheet using the same data set. The methodology was tested over five process plant in two operations and showed the performance forecast was significantly improved over the traditional methods being used so far. Then those high-fidelity flowsheets were used to evaluate the ore pre-treatment technologies proposed by the relevant resource company experts.

Nov 10, 2020

By Moeller T

The Bottle Creek mine, when opened next month, will consist of three open cuts, Emu, VB and Boags, feeding ore to a central mill. The open cuts cover a strike length of 4.5 kilometres which forms part of a linear structure, which can be traced geochemically for 26.0 kilometres. With the exception of a few small gossanous outcrops at Emu, the deposits are completely covered with insitu laterite and alluvial overburden. Since its discovery in 1984, the deposit has been subjected to three major reverse circulation (RC) drilling programmes which have successively closed up the drill spacing on the main mineralized zone to 25m horizontally and less than 25m vertically. All resource calculations have been based primarily on samples of RC drill cuttings from these programmes. Ore reserve calculations have been completed after each drilling phase. They began with a simple polygonal technique, progressed through two sectional half-distance calculations and are now being completed with a 3-D geostatistical technique. Because of the style of mineralization, Norgold personnel paid particular attention to assessing the variability of the mineralization by using repeat samples, repeat analysis and diamond drill vs RC comparisons. In addition, close attention has been paid to obtaining an accurate estimate of the global SG of the ore bodies. Particular care has been taken to obtain complete drill intersections of the orebody and to maximize wet sample recoveries. Extensive re-sampling and re-analysis of samples has confirmed that Bottle Creek is unusual for an oxidized gold deposit in that all the gold appears to be very fine grained, and evenly distributed within the mineralized zone.

Jan 1, 1987

By D R. Swinbourne, T Lehner

Study of the distribution of minor elements between copper matte andfayalite slag is important in determining appropriate methods tomaximise the recovery of valuable metals and the rejection of harmfulelements. Boliden Mineral AB operate a large copper smelter in northern Sweden, where they had noted that the loss of silver to the slag in the settling furnace appeared to be a direct function of the tin content of the slag. This work was aimed at determining whether or not this was a cause-and-effect relationship. Copper matte containing approximately 50 wt per cent copper and small amounts of silver and tin was equilibrated with silica-saturated fayalite slag at 1250¦C, then quenched. The matte and slag were then analysed for their silver and tin contents. It was found that there was no relationship between the silver distribution and the tin distribution. The silver matte/slag distribution ratio had a value of 120 ¦ 40 while that for tin was 2.8 ¦ 0.3. It is suggested that the most likely cause of the relationship observed at the Boliden smelter was matte entrainment in the slag.

Jan 1, 1999

By D S Wallis

Northern Australia leads in world-class mineral deposits' is a bold statement. First there must be a starting point. Land north of the Tropic of Capricorn (23¦ 26' 5") will be regarded as Northern Australia covering nearly 40 per cent of the land surface of Australia. As opposed to land south of the Tropic of Capricorn, it should be regarded as Tropical Northern Australia and for the sake of brevity, (TNA) Refer Figure 1. Apart from the tyranny of distance from centres of power and population in the temperate zone, it suffered in the past from the belief that the tropics are unsuited for European workers and from the lack of infrastructure. Outstanding mineral deposits of iron, base metals, gold and diamonds, discovered and developed in the past three decades, provided the substance for the title. There are many world-class mines producing and there are mineral deposits neutralised through Government policy. TNA can maintain its lead in world-class mineral deposits provided Government policy will stop partitioning the land and decreasing that available for exploration. Let's look at what we have that is world-class. In Western TNA iron ore deposits at Paraburdoo, Mt Tom Price, Marandoo, gold at Telfer, diamonds at Argyle. In central TNA uranium at Ranger and Jabiluka, lead-zinc-silver at McArthur River, gold at the Tanami, manganese at Groote Eylandt and bauxite at Gove. In eastern TNA Mt Isa, Hilton, Century zinc-lead, bauxite at Weipa, gold at Kidston, Mt Leyshon, magnesite at Yamba and coal mines in the Bowen Basin. Those mines or deposits stand out yet are only an indication of the numerous lesser mines and of mineral deposits depending for development on market demand and/or changes in Government policy, eg 'The Three Mines' policy. Very large areas of mineral rich structures in the western, central and eastern parts of TNA are concealed below flat lying comparatively young unmineralised sediments. The Great Artisan basin sediments in eastern TNA can and do host oil shale and non metallic minerals. Nearly 40 per cent of western TNA is covered by the Great Sandy Desert. The Canning Track, with a series of 54 wells, was constructed by surveyor Alfred Canning in 1908 - 1910 with great difficulty. It extends 1700 kilometres from Halls Creek in the north to the gold town of Wiluna in the south, through the Great and Little Sandy Deserts. Gold explorers are following favourable structures extending to the north east below the sediments and sand hills covering the track. Half of central TNA's mineral structures are concealed by the Tanami desert and the Cretaceous sediments covering the pastoral regions of the Barkly Tableland and the Daly Waters to Top Springs pastoral areas. The Georgina Basin in the south eastern section is part of the concealment.

Jan 1, 1994

By D Suppel, Y Miezitis, S Jaireth

The competition between various options for the use of land is ever increasing. Commonly in Australia large tracts of land were un-encumbered by sweeping land use option limitations, but this situation has been rapidly altering in recent decades as governments are obliged to maximise the utility of the land for a broad range of competing interests. While the interests of miners have always been considered, the effects on limiting access to land for exploration and possible mining have not always been effectively incorporated into decision-making processes. As a result the challenge for national and state organisations representing these interests has been to develop a transparent process to allow for the mineral potential of an area to be systematically assessed and for information to be presented for use by specialists and non-specialists. Government agencies are called upon to implement government policy but also to provide accurate and meaningful advice which can assist in policy and land use decisions. Commonly timeframes are short and information can be less than complete. Nevertheless on-going decisions are made based upon the best available understanding. It is in this operational framework that the methods described in this paper are set. The paper describes a process for quickly and systematically providing advice on mineral potential for use by government agencies and ultimately the community within tight time and resource constraints. It is a method of combining the accumulated knowledge about mineral resources and their potential and presenting this information in an easily accessible form which can be used in a negotiation and policy development environment. Development of the method was undertaken to meet the needs of the Regional Forestry Agreement process in Australia. The method has been applied to study areas in New South Wales, Tasmania, Western Australia and elsewhere. Examples in this paper are taken from north eastern New South Wales.

Jan 1, 1999

By Hoffmann CF

Thermal conditions at depths of several k.i'-.r.,etres in hydrothermal systems are a major (actor controlling gold transport into the epithermal environment. Understanding of the coupling of thermal, metal and ligand (HZZ S) sources in the root zones of hydrothermal systems therefore becomes important for the application of tectonic and igneous petrochem- ical studies to regional scale precious metal exploration. The evaluation of favourable conditions in this source zone and application to explor- ation rests on a detailed knowledge of the gases, H2S, CO2 hydrocarbons and other trace components preserved in fluid inclusions. Recent developments in analytical techniques now permit examination of these components and the recognition of complex hydrocarbons in rluid inclusions from epithermal and other lydrothermal systems appears promising for ieoosit-source correlation.

Jan 1, 1987

By B Howard, M Jones, D Pershke

"Current closure objectives and criteria are often difficult to achieve and are not delivering value for money outcomes at closure. Current mine closure processes tend to focus on rehabilitation and revegetation of landform structures to as close to premining condition as possible, rather than focusing on the functions of those structures and values they provided. Because mining has highly disturbed the environment, premining conditions and vegetation are often not achievable and objectives and criteria aimed at achieving close to these conditions have been shown to be very costly.The authors have developed a broader approach to developing mine closure plans that is based on environmental risk and gaining post-closure social, environmental and economic value. We think the focus should shift from trying to return the original landscape to returning functions and values provided on- and off-site. If it is not possible to return values on-site in a cost-effective manner, investment should be provided to deliver equivalent values elsewhere.This process can provide better stakeholder acceptance, deliver better environmental outcomes on the tenement and within the catchment and significantly reduce costs, whist fulfilling closure obligations.This framework should enable closure teams to: focus on the functions and services that are important to achieve as outcomes post-closure, rather than a focus on revegetation and replacing the premining biophysical structure engage meaningfully with stakeholders regarding closure outcomes and link outcomes to stakeholder values conduct transparent option evaluations that enable stakeholders to clearly understand the costs and benefits associated with each option and to participate in dialogue on option selection.We present examples of how the framework could be applied to identify alternate closure options that achieve equivalent value outcomes while reducing the costs of closing the mines.CITATION:Howard, B, Pershke, D and Jones, M, 2014. Achieving better mine closure outcomes for less money, in Proceedings Life-of-Mine 2014, pp 615–620 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By D Kent, D Eisner

A lot of talk has been generated about the so called ‘Internet of Things’ (IoT) and its potential to transform the way we interact with our homes and devices. But the true potential and value of IoT is not going to be realised by the general consumer but by businesses.This paper outlines the application of IoT in mining and how it is a natural extension to the base networks becoming commonplace in both surface and underground mines. The potential for ubiquitous monitoring throughout a mining operation at low capital and support costs will transform the ability to monitor, analyse, report and manage all of the key processes involved in a mining operation.Importantly, the paper will discuss the practical applications that the IoT offers mining and explain how this really is transformative technology, not just the latest buzz words from the information technology (IT) world. If leveraged correctly the impact on mining, its cost base and efficiencies, is enormous.CITATION:Kent, D and Eisner, D, 2015. What the internet of things means to mining, in Proceedings Third International Future Mining Conference, pp 65–70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Chaturvedula V. K

Pillar extraction carried out using various methods (split and lift, Wongawilli and Old Ben) involves the formation of narrow fenders (commonly 7 m of coal) formed by driving "splits" for lifting off with a continuous miner. The strata above a split and fender adjacent to the goaf consists of a cantilever beam (usually >3 m thick) that extends from the solid coal and bridges across the fender. Lifting off the fender from the split in safe conditions depends upon the bridging capability of the cantilever and the fender strength. The nature and competence of the immediate and near roof, the support capability of the coal fender and the presence of faults and or joints can adversely affect the bridging behaviour of the cantilever. Insufficient knowledge of these parameters can lead to extraction under dangerous conditions. Remnants of fenders ("stooks") also support the cantilever and their dimensions are critical to obtain regular caving and goaf falls. Stook area, goaf roof span and roof stand-up time after lifting can be related and only a relatively small increase in stook area of 10-15 m2 can lead to a significantly increased stand-up time, especially under a massive roof. Such conditions strongly influence the re- distribution of abutment stresses and can create increased outbye pillar loading. Based on detailed underground geotechnical investigations, it is concluded that strata caveability, roof cantilever behaviour, fender H:W ratio and remnant stook size are all critical parameters for successful and safe pillar extraction.

Jan 1, 1992

By L MacDonald, D Molver, D Pepper

Increasing contamination/impurity levels (including arsenic, antimony, mercury etc.) of concentrates is an issue of global commercial and health / environmental significance. With increasing environmental pressures at smelters, penalties for contaminants in concentrates continue to rise, accompanied by lower reject limits. There is a strong incentive for miners to investigate alternative means to remove contaminants in order to increase the value of complex ores and concentrates. This paper discusses the global problem of contamination in complex ores and concentrates, how the Toowong Process technology is a potential solution to this problem, and the opportunities this technology brings to the business of dealing with deleterious elements. CITATION: MacDonald, L, Molver, D and Pepper, D, 2018. The Toowong process for treatment of complex ores, in Proceedings Complex Orebodies Conference 2018, pp 119–121 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Singh BN, Chakravarty PK, Chatterjee LM

Indian blast furnaces operate with coke gener- ally containing 24 to 28% ash compared to 10-15% ash in coke in most other parts of the world. The operating problems are further aggravated by the high alumina content and the adverse alumina to silica ratio in the ore. The above factors not only increase the coke rate but, at the same time, increase the flush slag volume, make the bosh slag highly limey and thereby viscous, and produce a flush slag containing 24 to 26% alumina. Relative- ly low flame temperatures (RAFT) make conditions more difficult. The high basicity of the bosh slag limits the maximum flush slag basicity to around 1.0, beyond which the burden movement is adversely affected by the viscosity of the bosh slag: This effect is partly controlled by operating blast furnaces with high MgO in the flush slag (around.10%), which also improves the desulphurizing power of slag. Steps are underway in some plants to inject lime through theòtuyeres to control the bosh slag basicity and also to neutralise the large quantity of silica which is released at the tuyere level from the coke ash, so that the silicon content of the hot metal can also be controlled. High bosh slag basicity coupled with the characteristics of iron ore/aggolmerates, widens the softening-melting zone and alters the shape of the softening-melting zone. This leads to operat- ing difficulties and poor hot metal quality. This paper discusses the above aspects of Indian blast furnace operation and steps being taken to surmount some of the above difficulties.

Jan 1, 1981

Reverse sensitivity is a critical issue for all extractive activities. Extractive industries can only establish in the location of the particular resource sought to be extracted. Avoiding a location near sensitive activities (such as residential activities) may, therefore, be more difficult for extractive industries, than for other industry (such as dairy factories).   This paper focuses on the following matters: +        principles to be derived from case law, +       district and regional council approaches managing reverse sensitivity effects, and +        avoiding, remedying or mitigating reverse sensitivity effects in the future.

Jan 1, 2006

By G M. Mudd

Mine tailings represent one of the two largest sources of mine waste from the minerals industries (the other being waste rock). Given the problems of declining ore grades and growing production, tailings generation is increasing exponentially across the global mining industry. Common practice is for mines to build large containment dams to store tailings during operations, which are then rehabilitated following mine closure. At some sites, however, the controversial practices of riverine or marine dumping of tailings is still practiced. As recent tailings dam failures have shown, there are legitimate questions being raised about the long-term viability of leaving tailings above ground due to the risks of collapse and failure. At present, it is rare for mines to emplace tailings back into former mine voids following mine closure, most commonly into a former open pit mine void (although a fraction of the tailings may be used for underground mine backfill, this is minor in scale). The approach of in-pit tailings has numerous advantages, such as inherent physical stability, low to negligible acid and metalliferous drainage (AMD) risks, as well as allowing more productive use of formerly mined land. In tropical areas where surface repositories are prone to leakage with potential for AMD and widespread dispersal of radionuclides (in the case of uranium mining), in-pit management provides particularly strong advantages – thorough hydrogeological studies are required, however, to address residual groundwater contamination risks and to establish sound, long-term environmental monitoring regimes for groundwater quality and subsidence issues. This paper presents a study of in-pit tailings management and compares it with surface repositories established in a tropical climate. The comparisons lead to the conclusion that, at least under tropical conditions, in-pit tailings management should be considered as world’s best practice – especially for radioactive uranium tailings.

Aug 8, 2011

By M Berry

Consider these four questions:What is the definition of life-of-mine?When should life-of-mine planning seriously commence?When can life-of-mine planning seriously commence?What is the key input to effective life-of-mine planning?Whilst there is likely to be general consensus on the answers to the first three questions, the answer to the fourth question is open to debate. This author argues that understanding and managing risks and opportunities associated with geological uncertainty is the key input to effective life-of-mine planning, at all stages in the life cycle of a mining project.CITATION:Berry, M, ?2014. Effective life-of-mine planning by understanding and managing risks and opportunities associated with geological uncertainty, in Proceedings Life-of-Mine 2014 , pp 183–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D Oliveira

The use of an equivalent continuum for a rock mass is not always suitable for situations where the failure is structurally controlled by discontinuities as in the case of wedges in the tunnel roof. In these instances, discontinuum approaches are usually preferred. Rock joints that are filled with soft infill are likely to be the weakest planes in a rock mass, having a dominant influence on its overall shear behaviour. In this case, the joint material model adopted for the discontinuities should be able to describe important mechanisms, such as asperity sliding and shearing, post-peak behaviour, asperity deformation, and the effect of the soft infilling. The latest version of a soil-infilled joint model is discussed here. It describes more comprehensively than previous models the occurrence of dilation and compression with lateral displacements, and also represents the hardening mechanism related to asperity interference as observed in the laboratory that cannot be readily captured by the existing joint models. An analytical approach for the analysis of rock wedges structurally controlled by soil infilled joints is presented.The analytical approach presented in this paper for assessment of symmetric rock wedges in the roof of a tunnel demonstrates, that the peak shear strength of the joint may not be fully mobilised before detachment of the wedge. The analysis verifi ed that an overestimation of the factor of safety may be observed when an elastic-perfectly-plastic joint model was assumed, whereas the computed maximum factor of safety was considerably less when adopting an appropriate soil-infilled joint model.

Mar 8, 2011