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By R Strand, L Reading, G Keir

A major challenge in managing coal seam gas (CSG) water is predicting how much water will be produced as the industry develops. Klohn Crippen Berger Ltd (KCB) was commissioned by the Queensland Department of Natural Resources and Mines (DNRM) to develop a tool to forecast where, when and how much CSG water will be produced in the Surat and Southern Bowen Basins under various industry expansion scenarios.The water production tool (WPT) uses the Theis equation, a non-equilibrium groundwater flow equation that accounts for the effect of pumping time on well yield in confined aquifers, to predict water production volumes. Where multiple pumping wells are in close proximity, the required pumping rates for coal seam depressurisation are reduced. Therefore, pumping effects are projected spatially to assess interference effects between wells. Water production is then upscaled to the projected scale of the CSG industry within the Surat and Southern Bowen Basins.Two modifications were made to address the dual phase nature of CSG extraction (a transmissivity reduction factor) and the impact of weathering at the eastern margin of the Surat Basin (a ænear edge effectÆ factor). These factors modify relevant hydrogeological parameters in a consistent and defensible manner to more closely match observed water production.The WPT was verified by comparing results to equivalent Theis equation calculations and to type curves provided by CSG proponents. Calibration was achieved by varying the spatial distribution and intensity of the near edge effect factor in conjunction with a chi-squared analysis of residuals.The tool, which is now being maintained and further developed by the Centre for Water in the Minerals Industry (CWiMI), was built to balance numerical complexity against relative flexibility and simulation speed. The result is a tool that can produce statistically relevant results of prescribed scenarios to plan water handling and treatment requirements in discrete zones of operation.CITATION:Strand, R, Reading, L and Keir, G, 2013. Water production simulation tool for coal seam gas operations in Bowen and Surat basins, in Proceedings Water in Mining 2013 , pp 311-320 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By See G. T

Bentonites and fuller's earths from seven localities in N.S.W. have been analysed with respect to occurrence, mineralogy and physical properties and areas for future prospecting have been indicated.INTRODUCTIONThe rapid expansion of Australian industry in the postwar years has been accompanied by an ever increasing demand for fuller's earth and bentonite, but in New South Wales at least the demand has been met principally by imports. However, some local and generally inferior active earths have been won to blend with imported materials to reduce costs. The important discovery of the widespread distribution of bentonite clays in the Northern Coal Measures, made recently by Grim (Booker, 1956), has givenimpetus to the further search for material comparable in quality to the imported active earths.Bentonite may be defined as a highly plastic clay, generally possessing swelling properties, composed essentially of montmorillonite and derived from the alteration of volcanic ash. Fuller's earth refers to any clay which, with or without chemical treatment, is capable of decolourizing mineral or vegetable oils and is, therefore of economic value. Montmorillonite is the active component of most fuller's earths, though palygorskite-, halloysite- and even kaolinite-rich clays have been used.Previous literature related to the New South Wales deposits has been confined to general descriptions and little technical data beyond an occasional chemical analysIs have been available. Bentonites and fuller's earths from seven...

Jan 1, 1959

By F Weir, B Estrada

The impact of seismic loading on open pit slope stability in Australia is often only considered where the slopes are located adjacent to tailings facilities or other major infrastructure. The debate regarding application of seismic loading in open pit design in Australia is usually founded on limited reporting on significant damage of open pit operations during earthquakes, the common perception that earthquakes do not occur in Australia or that they are unlikely to occur during the mine life of the mine. It is frequently overlooked that pit slopes that have withstood strong earthquakes in highly active seismic regions are often designed under strict seismic guidelines. This paper discusses the factors that impact earthquake performance of open mine slopes. These factors include topography, slope geometry, rock material and mass properties, water management and intrinsic pit design. Further, the paper presents insights into the characteristics of earthquake activity in Australia such as magnitude distribution, earthquake depths, areas prone of earthquake activity and general seismic hazard that are relevant to pit design. Guidelines are provided on the conditions and circumstances under which earthquake design in open pit mining should be considered. In addition, this paper provides recommendation on the applicable methods for assessment of the impacts of earthquake loading on pit slope stability.

Jun 22, 2022

Tunnels are being built around the world using TBMs and prefabricated segments or in situ concrete as linings. Clients demand high quality of these linings to guarantee a long-term stability and density of the tunnels. This paper describes the development and the use of segmental lining systems, including joints, important design criteria, installation procedures, possible mistakes and consequences, repair works and final results for different sites in Europe and around the world. The experience on these sites shows that damages may occur, if some essential aspects are not considered. These aspects include:parameters of the TBMs and back-up equipment such as fixation of jacking rams, movement of the back-up on the lining or ring reformer;parameters of the segments such as quality of moulds, quantity of reinforcement or structure of the joints; andparameters of the tunnel drive such as advance rate, ring-gap grouting or experience of the tunnel crew.All these aspects have to be considered very carefully in detail to get a good lining accepted in total.

Jan 1, 1999

By X L. Liu, W Huang, J M. Zhu, S L. Wu

The shape, position and thickness of the cohesive zone have a great influence on the operational performance of the blast furnace. Many researchers have found that the high temperature properties of iron ores determine the formation of the cohesive zone. The results of this work show that sinter of high basicity interacts with lump ores and acid pellets due to the difference in chemical compositions. The softening and melting properties and the primary slag formation behaviours in the cohesive zone are improved by the high temperature interactions. The high temperature interaction is mainly influenced by the chemical compositions, porosity, interfaces and so on. Although the softening and melting properties and primary slag formation behaviours of lump ore A (a typical limonite lump ore from Australia) is the poorest of the iron ores studied, the high temperature properties of integrated burden A (consisting of sinter and lump ore A) is no worse than the other integrated burdens due to the high interaction between the sinter and lump ore A. It is useful to apply the results in the optimisation of blast furnace burden.CITATION:Liu, X L, Wu, S L, Huang, W and Zhu, J M, 2015. High temperature interactivity of iron ores in the cohesive zone of the blast furnace, in Proceedings Iron Ore 2015, pp 363–366 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

The discovery since 1990 of four major orebodies in the Mt Isa Inlier - Century Zn-Pb, Osborne Cu-Au, Cannington Pb-Zn and Ernest Henry Cu-Au - only serves to enhance the already high stature of the Inlier in world mining importance. Currently the known mineral resources of the Inlier represent about 11 per cent of the world's Pb-Zn resources, five per cent of the world's Ag resources, and one per cent of the world's Cu resources. More can be expected to be added to these impressive figures given that two-thirds of the Inlier remains obscured by younger cover. Individually, projects such as Century and Cannington may ultimately achieve `world's best' status; Century's proposed production of 450 000 tpa of Zn metal would rank it close to number one with Cominco's expanded Red Dog project in Alaska. Cannington, with projected production of 660 tpa Ag, could become the world's biggest producer of silver. For comparison, Mt Isa produced 170 000 t of zinc metal and 335 t of silver in 1995. The apparent physical diversity of deposits in the Mt Isa Inlier is matched by a great diversity of opinion as to their origins. Because Ernest Henry is hosted by `porphyries', it is described by some as a porphyry copper deposit, despite mineralisation age possibly post-dating volcanic age by 200 Ma. Cannington Pb-Zn could be a Broken Hill-type (BHT) exhalitive deposit, or a late epigenetic replacement `regional skarn'. Mt Isa - Hilton Pb-Zn deposits appear to have experienced all deformational events and he syn-diagenetic in origin, or may have experienced little of the above and be epigenetic replacement deposits formed late in the major Isan orogeny, some 150 Ma after deposition.

Jan 1, 1996

By W Patton, I Minniakhmetov, H Talebi, U Mueller

The sustainability of mining projects is linked to informed investment decisions based on public reporting of exploration and mineral resource estimation results. In Australia, public reporting guidelines are established by the Joint Ore Reserves Committee reporting code through the JORC Code (2012). Although the assessment of uncertainty in the results reported is a requirement, this is often communicated qualitatively and evaluated subjectively. This can become a liability particularly in the early stages of mining projects when spatial domains of geological interpretation and mineralisation envelopes inform resource estimations’ reliability. A recent review of JORC reports found no reports used quantitative assessments of the geological interpretation or mineral resource estimation envelopes, and 27 per cent of reports did not address the question of quality of geological interpretation. Reports that did address the quality used 19 different terms to communicate quality. This work presents methodologies for quantitative uncertainty assessment and communication and explores how they could be applied in public reporting practice. Quantitative uncertainty reporting would benefit mine planning and financial modelling as they normally assume the geology is 100 per cent right (since no error is reported or only a single deterministic model is provided). The complexity, cost, and additional work of doing a quantitative assessment could hinder a straightforward implementation. This could be overcome if mining companies budget for quantitative uncertainty assessment and associated professional development. A compulsory requirement for the inclusion of uncertainty assessments in public reporting or adopting standardised subjective language would improve industry practice.

Mar 22, 2022

By G Collecutt, T O’Beirne, D Humphreys, J Greenwood

Much of our knowledge of the behaviour of underground coal dust explosions has been derived from less than full-scale experimental explosions in facilities as small as 0.25 m diameter pipes. Although a substantial body of research has been undertaken in larger galleries approaching the size of full-scale modern mine roadways, there are still questions regarding the scaling of results to full-sized roadways in modern coalmines. Questions also surround the issue of comparing or scaling results between smooth and rough walled galleries, round and rectangular galleries and galleries with differing wall thermal properties due to different materials of construction.This paper will examine the influence of gallery size, cross-section area and wall roughness and thermal properties upon the characteristics of a coal dust explosion. Data from past explosion research will be examined and assessed for its application to the problem along with theoretical considerations for these factors.Recommendations on the design and minimum appropriate size of explosion galleries for assessing the performance of explosion inerting strategies, passive and active explosion barrier performance and determination of appropriate pressure ratings for ventilation structures will be made.CITATION:Humphreys, D, Collecutt, G, Greenwood, J and O’Beirne, T, 2015. The impact of facility construction and scale on the characteristics of experimental coal dust explosions, in Proceedings The Australian Mine Ventilation Conference, pp 301–308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

Gold deposits in Eastern China have characteristic of belted distribution. The concentrating belts of gold mineralization are about parallel to the island are belt in Western Pacific Ocean. Gold deposits are mainly concentrated in the aged metamorphic rock series on the upwarping zones and upwarping fault zones, and obviously controlled by the deep fractures and their deriva-tive secondary faults. Gold mineralization had genetic relation to the Mesozoic (especially Yanshan period) magmatic activity. The distribution and genesis of gold deposits can be explained by the assumption of wavy structure. The formation of wavy structure is related to the process of Pacific plate and India plate.

Jan 1, 1990

No paper available.

Jan 1, 1996

By A Bax, G Wardell-Johnson, W P. Staunton, J McGrath, J J. Eksteen

Since 2001, the AMIRA P420 gold processing technology project series has been studying the recovery of gold using gravity devices, with particular emphasis on the centrifugal units, Knelson and Falcon concentrators. The work has entailed the surveying of operating gravity circuits in Australia, Africa and North and South America.This paper reviews some of the results and lessons of these studies, including common circuit operating and design factors, which limit gravity recovery; pointers towards effective modelling of gravity circuits; and the contribution of gravity to overall gold recovery.CITATION:Wardell-Johnson, G, Bax, A, Staunton, W P, McGrath, J and Eksteen, J J, 2013. A decade of gravity gold recovery, in Proceedings World Gold 2013 , pp 225-232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By A Ross, B De Rivaz

The results of full-scale tests on precast segment made at University of Roma are presented. The segments were cast using fibre-reinforced concrete produced without any traditional reinforcement, by using fiber made in high-strength steel and a new type of anchorage.Bending tests were performed in order to check the bearing capacity of the segments under the flexural actions; these occur during de-moulding, handling, storage phases as well as in the in situ condition (due to asymmetric soil pressure). Furthermore, point load tests simulating the TBM thrust were performed, in order to study the construction phase (excavation).The results show that the segment response largely respects the material testing and design advice according to the Fib Model Code 2010. Providing engineers, precast operators and builders confidence in material strengths and design methodology.CITATION:De Rivaz, B and Ross, A, 2014. Full-scale tests on precast tunnel segments made in concrete reinforced with high-strength steel fibres, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 469–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By E N. Sparg, O D. A Deuchar, F Needham

Decline shafts are an attractive option to both new and existing mining operations where there is a need to access an inclined orebody deposit via on-reef development so as to generate a return in the shortest possible time. There are many different technologies that are available to transport men, material and rock in incline shafts. This paper focuses on the applicability of two hoisting technologies for decline shafts, namely endless and direct rope systems. The pros and cons of each system are reviewed. A common concern with direct rope haulage systems is the possibility of generating slack rope during deceleration. This paper illustrates the issues involved in designing a system so as to avoid the possibility of slack rope. In conclusion, the key factors relevant to the selection of endless or direct rope haulages for a particular decline application are reviewed. The paper is a joint submission by FFE Minerals-Vecor and Qualter Hall UK.

Jan 1, 2005

The Teutonic Bore deposit lies in a major greenstone belt within the Archaean Yilgarn craton of Western Australia. It occurs towards the base of a suite of tholeiitic basalts, some 100 m above a felsic volcanic pile of rhyolitic composition. Sediments comprise a minor, albeit important, percentage of the mine stratigraphy.The deposit consists of a single, steeply dipping lens of massive sulphides totalling 1.4 million tonnes grading 4.16 per cent Cu, 16.4 per cent Zn, 1.22 per cent Pb and 203 g/t Ag. In addition, cross cutting "stringer" mineralisation in the footwall contributes a further 0.75 million tonnes at 2.38 per cent Cu, 1.92 per cent Zn and 52 g/t Ag to the mining reserves. Principal primary sulphides in massive and disseminated mineralisation are sphalerite, pyrite, chalcopyrite and galena, while minor amounts of arsenopyrite and argentiferous tetrahedrite are also present. Weathering has affected the primary mineralogy down to at least 90 m, resulting in a strongly leached oxide profile to about 85 m, overlying a thin, erratic zone of chalcocite supergene enrichment.Lateral metal zoning is marked both in massive sulphide and stringer mineralisation, with Cu/Zn ratios decreasing away from the centre of the orebody. Alteration is well developed in association with footwall stringer mineralisation, changing from a central Fe-Mg carbonate, chlorite and silica alteration zone below the massive sulphides to an outer halo of sericitisation. The spatial distribution of these minerals is patchy. Geochemically, the footwall alteration zone is characterised by central Cao, Na20 and Sr depletion (with less regular enrichment of SiO2 , Fe and MgO), surrounded by a peripheral zone of K20 enrichment.Evidence supports a classic volcanic-exhalative origin, involving submarine discharge on the flanks of a rhyolitic dome and accumulation of the massive sulphides in a local palaeotopographic depression. The sulphides overlie their feeder zone as shown by alteration and stringer mineralisation. Tholeiitic wallrocks are thought to be genetically unrelated to the mineralising solutions, although their presence as a cap over the felsic volcanics may have permitted the build up of a circulating metalliferous brine system prior to sulphide deposition.

Jan 1, 1984

By S McGregor, J Sharp, I Entezari, T Boulter

The piezocone penetration test (CPTu) is one of the primary screening tools used by the mining industry to evaluate whether tailings are susceptible to liquefaction (static or cyclic). Liquefaction analysis using the CPTu is influenced by the fines content of the soil, and most CPT screening tools empirically use the behaviour type index (Ic) to correct for fines. The issue with this approach is that such empirical relationships have been developed using data collected from natural soils and their applicability to different tailings deposits needs to be studied. In this paper, we explore the use of machine learning to develop a site-specific model to estimate fines content of tailings using gamma piezocone penetration testing (GCPTu) measurements. The results are then compared to the fines content derived from the soil behavior type index (Ic) proposed by Robertson and Wride (1998). A dataset of paired GCPTu and laboratory results were compiled and a support vector machine (SVM) algorithm was employed to calibrate a model to estimate tailings fines content from in-situ GCPTu data. We calibrated GCPTu data to geotechnical 75 μm fines content measured in the laboratory. The geotechnical fines content is the fines content as a percentage of solids. The development dataset was comprised of paired GCPTu-laboratory results collected in 2009-2019 from a mining area with predominately clay mineral and quartz sand tailings. Results show that the developed model predicts the geotechnical 75 μm fines content of the studied deposits with 7.8% error. The Ic based method estimates the fines content with 31% error. Evidently, the Ic method is not applicable to the studied tailings deposits. It is appreciated that many tailings fines do not contain clay, and that the success on this program may not be repeatable everywhere. However, the authors wish to point out that the application of site-specific machine learning algorithms may be used to significantly improve empirical geotechnical parameters.

Jul 1, 2021

By S J. Schafrik, C Keles, C Schlosser, E S. Gilliland, A K. Louk, N S. Ripepi, S Keim, J Amante, E Diminick

Three legacy coalbed methane production wells have been converted to injection wells for a one-year carbon dioxide (CO2) injection test to evaluate the potential for CO2 storage in the coal reservoir and the potential for enhanced gas production at offset wells. The injection reservoir is composed of 15–20 individual coal seams with an average thickness of 30 cm (1.0 ft), spanning a depth range of approximately 240 (800 ft) to 670 m (2200 ft).The monitoring program for this test includes gas and water sampling of the three injection wells, three dedicated monitoring wells and approximately 20 offset production wells. Key technologies used for monitoring the study area include time-lapse GPS and interferometric synthetic aperture radar (InSAR) acquisitions for surface deformation measurement, a 28-station buried passive microseismic monitoring array, real-time downhole pressure and temperature sensing and perfluorocarbon tracer fluids, which will be injected with the CO2 stream. The schedule for the monitoring program includes pre- (baseline), during- and post-injection data collection. This schedule will allow data to be analysed for time-lapse changes and trends, which are important for understanding the migration of gas and fluid phases in the reservoir – including CO2, methane, other hydrocarbons and water – and for observing the changing distributions of reservoir pressures and stresses.The results of the monitoring efforts for this study have implications for monitoring mining operations. The combined use of GPS and InSAR geospatial data to evaluate elevation changes across and beyond the study area may prove to be an accurate option for measuring surface deformation, including mining-induced subsidence, in unstable terrain. Long-term microseismic monitoring using high-sensitivity instruments has several applications in mining operations, including rock stability monitoring, production monitoring and miner location detection during emergencies. Tracer studies and short-term microseismic monitoring used to assess methane extraction can also be used to develop and optimise degasification systems for underground coalmines.CITATION:Gilliland, E S, Ripepi, N S, Schafrik, S J, Schlosser, C, Amante, J, Louk, A K, Diminick, E, Keim, S, Keles, C and Karmis, M, 2015. Monitoring design and data management for a multiwell CO2 storage/enhanced coalbed methane test in a stacked coal reservoir, Buchanan County, Virginia, USA, in Proceedings Third International Future Mining Conference, pp 47–56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

At the outset, I guess we should define what we mean by "com- modities". In the 20 minutes or so which I have for this paper, it is impossible to tackle all commodities -one would need to con- sider not only the base metals but also the ferrous iron and steel products as well as energy commodities such as coal, oil and even uranium. For the purpose of this address however, I would prefer to refer to the principal non-ferrous commodities: copper, lead, zinc, aluminium and nickel and, I would like to consider some of the changes which have taken place in the industry over the past 20 years-and the likely reasons for these changes. I would also like to dwell a little on the future and some of the key issues which-may influence the future path and direction of the metals industry.

Jan 1, 1988

By D Veneziano, J Van Dyck, R Snow, W Pytel, O Zanoli

Best practice standards generally recommend assessment of the environmental and societal risks posed by tailings storage facilities, but they rarely specify how the analysis should be made. As a case study, this paper describes a safety assessment of the Zelazny Most tailings pond operated by the Hydrotechnical Unit of KGHM Polska Miedz SA in Poland. The complete assessment includes a failure mode effect criticality analysis (FMECA) that considers all conceivable failure modes, but this paper focuses on one key mode, the loss of stability during the planned raising of the crest above its current level. Reliability against static dam failure considers uncertainty on the safety factor in a limit equilibrium approach. The threat of dynamic (earthquake induced) instability is assessed by developing a model of future seismicity as a function of the mining plan and considering uncertainty on the induced permanent displacements along critical sliding surfaces. We quantify the additional level of protection against outflow provided by the beach using an event tree with expert-assigned probabilities. Continuous monitoring of the dam for premonitory signs of instability and a set of loss-prevention plans in the case of a spill provide additional layers of protection; their effectiveness is quantified by estimating the fraction of the population that could be evacuated as a function of warning time. The probabilistic analysis indicates that the safety targets are met and produces practical recommendations on how to maintain and improve the safety level while the dam crest is raised above its current level.CITATION:Van Dyck, J, Pytel, W, Veneziano, D, Snow, R and Zanoli, O, 2015. Safety of a tailings storage facility against dam instability, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 253–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

During operations, mining and metallurgical processes may generate effluents such as tailings water, acid mine drainage (AMD) and seepage and process acid streams. Depending on the type of ore and the metallurgical process, these effluents may contain one or more toxic compounds (eg acidity or alkalinity, cyanide, ammonia and/or nitrate, heavy metals, total suspended solids (TSS), sulfate) in elevated concentrations requiring treatment before their discharge to the environment or recycle/reuse in the process. Natural oxidation of sulfide minerals present in mining wastes (eg tailings and waste rock) at mining sites may generate AMD, which is characterised as a low pH, high acidity effluent containing heavy metals and sulfate. If generation of AMD cannot be controlled and/or prevented, AMD needs to be collected and treated for neutralisation of acidity and reduction of metals and TSS to meet regulated water quality standards. It is important to note that some of these compounds may persist in run-off from mine sites, even after the mine and processing facilities are decommissioned. Treatment of mining and metallurgical process effluents can be accomplished by means of various physical, chemical and/or biological methods. The mode of process application may vary from the use of either specifically designed, controlled and automated facilities or passive systems. Lime neutralisation and precipitation is the most common method used in the mining industry to treat AMD. To reduce the problems associated with disposal and long-term storage of the resulting sludge, the use of a high-density sludge process (HDS) has become a preferred option. The use of other chemical reagents, waste or by-products from other industries, and biological sulfate reduction methods can also be considered as viable options for site-specific situations. Recently, several passive treatment systems have been designed and successfully operated, even in the cold North American climate. This paper will discuss available options and provide insights for selecting a suitable method for a given situation using case studies from projects conducted by Golder Associates around the world over the last decade.

Jan 1, 2006

By W. M. LONIE

Address by the President of the Institute (Mr W M Lonie) in making the presentation of the Certificate of Honorary Membership to Sir Ian McLellan, K.C.G.M, K.B.E. Address by Sir Ian McLellan after accepting the award.

Jan 1, 1979