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By I M. van Waveren, F Hasibuan, M J. Crow

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Two Hg-Au occurrences west of Bangko, Sumatra occur within the West Sumatra Permian Volcanic Plutonic Arc. The Melipun Hg-Au occurrence was exploited in the past and mineralisation occurs within a hydrothermally altered cupola of a buried intrusion. The Salak Hg-Au occurrence occurs within the outcrop of the Dusunbaru pluton, likely within the remnants of a caldera in which hydrothermal mineralisation was developed. Both occurrences formed late in the history of the volcanic arc, probably between the Triassic and early Jurassic. The Melipun occurrence may have potential at depth, but that at Salak is small and lies within the area of a proposed Geopark.CITATION:Crow, M J, van Waveren, I M and Hasibuan, F, 2015. Two Hg-Au occurrences in the west Sumatra Permian volcanic-plutonic arc west of Bangko in Sumatra, Indonesia , in Proceedings PACRIM 2015 Congress, pp 573–578 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Modelling Channel Scale Flow in Heap Leaching Using Smooth Particle Hydrodynamics (SPH)

Sep 13, 2010

By G J. Corbett, P Magner, M McKenzie

Structures formed during ductile deformation have been reactivated during the later brittle mineralisation process. Two generations of folding are classified as: early recumbent megascopic FI folds and FI shears which transpose the hinge regions, and later upright F2 folds. S1 is folded about F2 folds which contain axial planar S2 crenulation cleavage. Vergence relationships between S1 and bedding indicate that many of the mineralised structures occupy sites of FI folds which have acted as plumbing systems for later gold mineralisation (eg Blackwater mine). The Globe-Progress gold mineralisation is localised by a major jog formed by sinistral strike-slip movement on two FI fault segments and mineralisation also occurs in smaller jogs along strike (eg Sir Francis Drake, Happy Valley-Merrijigs, Cumberland).   The lodes of ribbon quartz which exploit the FI shears and local bedding planes, are inferred to have mostly formed after the peak of metamorphism, possibly related to the emplacement of Carboniferous granites. This was followed by a sequence of vein deposition and wallrock alteration which consists of quartz-As/Fe sulphides ? carbonate - stibnite ¦ trace base metal sulphides and Bi-sulphosalts ? illitic clay/sericite-chlorite. Gold at Globe-Progress is mainly encapsulated in arsenopyrite. At Blackwater, free high fineness gold occurs in partings in lode quartz with late sericite-chlorite. The above sequence of events is comparable to that encountered in many intrusion-related gold systems throughout the Southwest Pacific region. There is a spatial relationship between gold mineralisation and dykes variably described as diabase, dolerite or lamprophyre. Alkaline rocks occur in many Pacific rim and older goldfields and may possibly be related to a magmatic source for gold mineralisation.

Jan 1, 1997

Following the Coalbrook Colliery disaster in 1960, Salamon and Munro (1967) established the well known empirical coal pillar strength formula in South Africa. This formula has prevented further violent multiple pillar failures. In 1996, a back analysis of the collapsed and uncollapsed cases in Australia led to the development of the Australian empirical coal pillar strength formulae. The original collapsed and uncollapsed coal pillar database of Salamon and Munro (1967) was updated in 2006. This study introduced various strength formulae for different coalfields and seams in South Africa through back analyses of collapsed and uncollapsed cases. Today, the resultant pillar strength formulae from these previous studies and the behaviour of coal pillars are mostly well understood and applied with confidence. However, it was assumed in the previous studies that the behaviour of pillars is not time dependent; therefore, the formulae established do not provide an associated time to failure of coal pillars. This paper attempts to evaluate the so called 'Geometrical Limits' concept to provide the Australian coal mining industry with a tool to assess the long-term behaviour of bord and pillar workings where the pillars are prone to failure due to spalling of ribs. In order to achieve this outcome, the principles of the safety factor concept and the probability of failure calculated using the coal pillar strength formulae have also been evaluated and practical design examples are presented in this paper.

Nov 25, 2010

In a field test at Mount Isa Mines Ltd., a system developed by ICI Australia Ltd. for bulk loading "MOLANITE", an ammonium nitrate slurry blasting agent into ring drilled holes of wblcvel open stopes, was shown to be satisfactory. The fragmentation produced by the slurry was a significant improvement over ANFO and the stope production rate was increased by approximately 50%. Indications are that the charging rate and labour costs will not be greatly changed if a slurry system is used.

Jan 1, 1973

By Branagan D. F

The geology of the area studied is briefly described, together with the prospecting methods used in the search for copper, lead, zinc and uranium ore bodies.Four prospects, Mt. Corella, Yanasinga, Lawlor's and Greenmount, which were diamond-drilled, are described in detail and geochemical results are discussed in relation to the mineralization found. Copper anomalies were found wherever intrusive rocks were mapped, and showed a much closer relation to geology and mineralization than did the predominantly lead and zinc anomalies.Geochemical prospecting aids in the overall mineral search programme because of its speed and economy, as it helps to pinpoint areas worthy of detailed geological examination. Geochemical anomalies are a guide to favourable zones but may not indicate the presence of ore.INTRODUCTIONDuring 1953-55 the National Lead Company of New York carried out a search for minerals in an area south and west of Cloncurry (Fig. 1) in rocks of Precambrian age. After reconnaissance mapping, a number of prospects were chosen for closer examination by detailed geological mapping and geochemical sampling, and from these prospects, five sites were selected for drilling.This paper records the salient features of the exploration programme and discusses the geology and geochemistry of four of the prospects-Mt. Corella, Yanasinga, Lawlor's and Greenmount. Practically all the prospects examined showed high zinc "anomalies" or "dispersion" trains. Greta, Mt. Corella and Lawlor's prospects showed some copper anomalies and, to a lesser extent, lead anomalies. In particular, Greenmount exhibited striking copper anomalies.

Jan 1, 1960

By L Klemettinen, J Biswas, W Malan, D Sukhomlinov, D Lindberg

In order to mitigate the effects of climate change, our society must be able to drastically reduce its CO2 emissions. As the metallurgical industry is a considerable contributor to these emissions, new greener technologies must be invented and developed. One option could be the direct production of metals from oxides using renewable electricity. The aim of this study was to investigate the possibility of using high-temperature molten oxide electrolysis (MOE) for iron and ferrochrome production. FactSage™, ver 8.2 (by Thermfact Ltd and GTT-Technologies) was utilised for estimating a feasible equilibrium electrolyte composition, and the experiments were conducted at 1550–1580°C in conical alumina crucibles with iridium wire as the cathode and platinum wire as the anode. The sources of iron and chromium were either pure FeO powder or industrial chromite pellets. Voltage was applied to the electrolysis cell for 6 hrs and the resulting current was measured, along with oxygen concentration in the off-gas line. The electrolyte comprised of SiO2, Al2O3, MgO and CaO. First, the effect of FeO concentration on iron reduction efficiency was investigated using only pure oxide powders as starting materials. The results indicated that 10 wt per cent FeO mixed with the electrolyte resulted in more efficient iron reduction compared to 20 wt per cent. In further experiments, industrial chromite pellets were ground and mixed with the CaO-free electrolyte. Iron and chromium reduction efficiencies were higher when approximately 19 wt per cent of the total sample mass consisted of pellets compared to increasing the pellet amount to 37 wt per cent. Generally, the chromium solubility in the liquid electrolyte was relatively low, and most of the chromium was confined to the spinel solid solution, from where its dissolution to the liquid electrolyte was very slow, resulting in slow reduction kinetics. For larger scale applications, economically more viable electrode materials should be investigated.

Jun 19, 2024

Thermodynamic properties of the solutions of hydrogen in metals and carbon in austenite were investigated and it is possible to predict the interstitial solubility in these systems over relatively wide ranges of temperature and solute activity. Monte Carlo methods were used to compute the arrangements of interstitial atoms on the tetrahedral sites in body centred cubic metals and the octahedral sites in face centred cubic metals. It was shown that the non-configurational entropies of solution of hydrogen in metals can be interpreted as being principally vibrational and on this basis the potential value of the isotopic solubility ratio theory in indicating the compositional variation of these non-configurational entropies was discussed. The need for future work along these lines is pointed out.

Jan 1, 1970

By Sharpe E. J

The Triton lode is a schistose feldspar biotite chlorite rock with quartz, carbonate, pyrite and some pyrrhotite. Its more chloritic sections strongly resemble the enclosing greenstones, its more feldspathic portions are indistinguishable from the flne-grained phases of the porphyry dyke into which the southern extremity of the ore body merges. The ore body' has a length of 880 ft. and an average width of I2t ft.; in places this widens to as much as 30 ft.The average dip is 85° west and pitch of the ore shoot 75° south.METHOD OF SAMPLING.With the exception of a limited amount of channel sampling (a reference to which is made elsewhere in this paper) all the sampling is by chip sample.The samplers use a hammer weighing approximately 11 lb. and chip directly into the sample bags. Sampling is generally carried out over 3-ft. sections and portions thereof to the nearest half foot-thus a face 8t ft. wide is divided up into two sections of 3 ft. each and one section of 2 ft.-no measurements of less than 4 ft. are used and calculations are all in feet and dwt. per long ton.In the oxidised stopes wp.ere the lode is much narrower, .i.e., 6 ft., sampling is over 2-ft. sections. All borehole samples are over 2-ft. sections, this corresponding approximately to steel changes.(a) DEVELOPMENT SAMPLING.Driving.-This is done by following the east wall and each face is sampled-this corresponding to an advance of 5 ft. If the full width o,f the lode is not exposed boreholes...

Jan 1, 1938

Techniques have been developed for the dissolution of a wide range of rocks and minerals by a sodium peroxide sinter process. A olarge number of elements are determined by atomic absorption spectroscopy, and other elements such as arsenic and sulphur are determined by chemical analytical methods. The methods adopted to overcome inter-element and ionization effects on the atomic absorption results are discussed.

Jan 1, 1974

Pipe Flow Stability of Concentrated Coal-Water Suspensions in the Presence of an Electric Field

Sep 13, 2010

There is an increasing demand for refrigeration as mines progress deeper. Mine refrigeration plants have special requirements in terms of their duty and application. There are no national or international standards applicable for the testing of these plants. There have been numerous examples of plants failing to meet their required nominal capacity, but with the plant owner being unable to enforce the design duty on the manufacturer, due to a failure to unambiguously specify testing or accepting criteria. This paper discusses some of the reasons for performance shortcomings and describes a methodology for developing and specifying performance criteria, when inviting design and/or construction tenders, and a method of performance and acceptance testing once the plant has been built and commissioned. These guidelines encompass the full range of performance duties expected from a mine plant, including stable operation at maximum and minimum plant capacity, and under the various combinations of extremes of high and low condensing and evaporating pressures. A description of a methodology for developing a computer-based mine refrigeration plant model is also presented as part of the performance testing criteria. The methodology is illustrated with reference to the actual performance and acceptance testing process used on the worldÆs largest bulk air cooler (R67) at the Enterprise mine at Mount Isa, Australia.

Jan 1, 2005

By Worner H. K

Education has always been a topic to rouse the interest of mining and metallurgical engineers, but the recent activities of the Education Committee of the Australasian Institute of Mining and Metallurgy 1, 2, together with the moves throughout the Commonwealth to extend the field of technological education, have made the subject a very live one at the present time. The authors have felt it would be appropriate that on the occasion of the First Ordinary Meeting for 1950, in Victoria, some contribution should be forthcoming concerning the history, present status and possible future trends of mining and metallurgical education in this State. As for the past, the time approaches when there will be none having personal recollections of the beginning of Victorian mining schools or of the men who started them. As for the future, it is obvious that rapidly expanding metal-producing and metalconsuming industries will demand a greater output of competent graduates and diplomates. The era immediately ahead seems to be bristling with opportunities, but mining educators need to temper their enthusiasm for various policies and programmes with the realisation that they are helping to train men who will be leaders 15-20 years hence when the problems of industry and trials of life generally may be very different from what they are to-day.

Jan 1, 1950

By D Craw, C E. Martin, C Smith, C Rufaut

Wangaloa Coal Mine opened in 1945, and by the time of its closure in 1989, had produced 750 000 tonnes of coal and disturbed an area of 75 ha. The original mining licence required land rehabilitation to exotic forestry, however the current owner, Solid Energy, has worked with Crown Minerals and local councils to write a new rehabilitation objective. The site is now being stabilised and replanted with native species, and may be available for public use before the coal mining licence expires in 2007. Site discharge permits expire in 2017, and by that time, it is anticipated that discharge water chemistry will be similar to background levels. MWH are currently contracted for management of the mine rehabilitation project. The Kaitangata coal unit mined at Wangaloa is sulfurous lignite with associated pyrite. Kaitangata coal contains 3.2 wt per cent sulfur, which is higher than most New Zealand coals. Initial analyses at Wangaloa indicate low pH (2.56.2) values in soil, groundwater and surface waters as a result of acid rock drainage (ARD) processes, leading to increased metal mobility and challenging conditions for vegetation. Pilot studies indicate pinus radiata needles contain up to 67 mg/kg boron, and elevated As, Cu and Zn concentrations in surface waters. The main lake at the site has a pH of approximately 4.9, despite lime dosage in 2002. There is a real need for a complete geochemical model of the Wangaloa coal mine. Such a model could be applied to similar restoration projects, and would assist by pinpointing geochemical processes and toxic metal relationships most harmful to the receiving environments. Using this model, rehabilitation in the future will be targeted and more efficient. This project is part of a larger scheme to characterise and model the Wangaloa mine site restoration, including waters, soil, vegetation, geology and invertebrates.

Jan 1, 2003

Present roof bolting practices in the collieries of Australian Iron and Steel Pty. Ltd. are outlined. Roof support has been improved since introducing roof bolts and it is hoped to increase the reliability of the bolts still further.Expansion-shell, and split and wedge roof bolts five to eight feet long are placed by "Atlas Falcon" and "Fletcher" roof bolters. Both anchorage and tightening have presented some problems.Good panel supervision is required if systematic roof bolting is to be properly co-ordinated with coal production without unnecessary delay to either. Successful roof bolting can only be the product of conscientious men and supervisors who are all convinced of its value. A rigid operational code should be established early and maintained.INTRODUCTIONRoof bolting is a method of support which is permanent and reduces or eliminates the need for other support; The method was pioneered in America and was first experimentally investigated in Australian collieries at Elrington in 1949 (McKensey, 1953). Pneumatic installation methods were employed. Subsequently, a method of using standard hand-held electric coal drills was developed at John Darling Colliery (Horseman, 1954). Pneumatic roof bolting equipment was first operated in the collieries of Australian Ironand Steel Pty. Ltd (A.I. &. S.) in 1951. Since then various hydraulically operated mobile machines have been installed in Australian collieries and these, together with improved pneumatic equipment, form the two present basic methods of placing ,roof bolts. Roof bolt anchorage is achieved by either split and wedge or expansion-shell bolts.The two broad types of roof bolting are 1. consolidation of strata, and 2. suspension support.

Jan 1, 1961

By J L. Lett, I Brunton, T Thornhill

Block cave fragmentation has been documented in the literature to have a significant impact on mine design, performance and downstream material handling and comminution processes. Due to this impact, emphasis is placed on the premining prediction and subsequent quantification of primary and secondary fragmentation distribution. This paper discusses the fragmentation prediction and assessment methodology employed at the Ridgeway Deeps (RWD) and Cadia East PC1 (CEPC1) cave operations.Prediction of drawpoint fragmentation was based on an iterative process, which relied on an improved quantitative and qualitative understanding of the rock mass as the mining project developed. In particular, the collection of scanline mapping data provided detailed information in relation to discontinuity trace length, persistence, termination characteristics and large-scale planarity. This allowed an improved estimation of select modelling input parameters, in particular ‘block forming’ discontinuity orientation and strength characteristics.With the start of production, drawpoint fragmentation assessment was undertaken using digital image processing (DIP) techniques for drawpoint extracted tonnes up to 61 000 t. This technique provided a consistent methodology to estimate changes in fragmentation as the block cave matured. It can generally be concluded that the measured mean fragmentation distribution became finer as drawpoint tonnage increased. The incremental change in fragmentation distribution (per 10 000 t) was not uniform, with step changes evident. In addition, for a given geotechnical domain and drawpoint tonnage, the measured fragmentation distribution range was found to vary significantly. A possible explanation for these observations may relate to the disturbed flow behaviour noted from marker experiments at RWD and CEPC1. These experiments indicate that material reporting at the drawpoints (for any given tonnage extracted) may be sourced from highly variable heights within the cave, with finer material preferentially reporting.A comparison between predicted and measured drawpoint fragmentation distribution indicated two general findingsa close match between predicted and measured distributions for material greater than 1.0 m3an under prediction of finer material passing 0.5 m3 relative to measured.The findings would indicate that the fragmentation modelling frameworks utilised at both RWD and CEPC1 were deficient at predicting the percentage of finer material for both primary and secondary fragmentation.The wide range in fragmentation distributions observed in the measured results, and the discrepancy between modelled and measured fines should be considered in the design of mine (material flow, extraction level geometry and draw rate), material handling (crushing and material movement), and downstream milling (comminution and metal recovery) processes for future block cave mines at the Cadia Valley Operations (CVO). With respect to fragmentation distribution range, a sensitivity analysis should be undertaken for these design considerations, with a range in predicted fragmentation distributions investigated (for example, lower quartile, mean and upper quartile). For future mines with similar geotechnical and mining conditions, the calibration of fines should be considered in any fragmentation distribution prediction to match those measured previously.CITATION:Brunton, I, Lett, J L and Thornhill, T, 2016. Fragmentation prediction and assessment at the Ridgeway Deeps and Cadia East cave operations, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 151–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

In 1953, Dr. N. H. Fisher of the Bureau of Mineral Resources, acting on behalf of the Society of Economic Geologists, which is considering the sponsoring of a uniform system of nomenclature for ore reserves, enquired from the Australasian Institute of Mining and Metallurgy whether it had ever considered this subject and particularly whether it had ever set up any standard definitions or specifications with regard to ore reserves.As this had not been done, but was thought to be desirable, the Council of the Institute appointed a Committee consisting of H. H. Dunkin, Associate, Professor of Mining Engineering, University of Melbourne (Convenor), E. A. Rudd, Professor of Economic Geology, University of Adelaide, I. N. Campbell, Chief Geologist of Western Mining Corporation; and the writer to consider and report on this supject.In December 1953, the Committee submitted its first report to the council and this report (reproduced here as an Appendix) was widely circulated among member companies, and engineers, with an invitation to comment on the proposal. A large number of, replies was received and studied.After studying the replies the Committee issued a second report in part as follows:-From these replies we have learned that the suggestions made in the first teport of the Committee are unacceptable to most of those interested, on one or all, of the following grounds;-(a) number of categories,(b) definition of categories;(c) nomenclature.

Jan 1, 1955

The contiguous Kotre Basantpur and Pachmo (KBP) coal blocks in the Hazaribagh District of Jharkhand State in east India are being developed by Tata Steel Limited (Tata Steel) to supply coking coal to a new steel mill at Kalinganagar in Orissa.The planning challenges are many. The multiple coal seams range in thickness up to 6 m and extend to nearly 500 m depth, with dips up to 25¦ and highly variable quality. Several normal faults with throws up to 150 m intersect the deposit. There is little room for waste dumping on the lease, several large nalas (seasonal creeks) cross the blocks, and the KBP leases are not contiguous with Tata Steel's existing mining operations at West Bokaro. Geotechnical conditions, while not well defined at this stage, are largely unfavourable. There are several villages on the blocks, and extensive paddy fields. In 2009, Adelaide Mining Consultants Pty Ltd (AMC) completed a Detailed Project Report (DPR) for a production level of 8 Mt/a. A terrace mining system was proposed using 28 m3 hydraulic excavators and 185 t trucks working horizontal up-dip slices. Subsequently the viability of in-pit crushing and conveying was assessed, but the full results were not available for this paper.It is planned to extract a total of 147 Mt of raw coal at a strip ratio of 5.2 bank cubic metres per tonne (bcm/t). The planned maximum pit depth is over 300 m.The project includes a washery, a 2 + 25 MW fluidised bed power station to utilise all the coarse washery rejects, and a railway spur line to carry the washed coal to the railhead some 7 km distant.

Dec 6, 2010

By H Thanasekaran, J Kohmuench, B Seaman

To achieve an efficient separation in the flotation process, valuable particles need to be selectively segregated from the gangue while utilising a minimum number of flotation stages. TodayÆs existing flotation technologies are effective for fine particle size classes; however, limitations due to particle buoyancy and bubble-particle detachment restrict the effectiveness of traditional flotation approaches on coarser particles. As a result, flotation circuits are generally configured to process only fine particle size classes in order to maximise recovery in the primary stages. Eriez has invented a novel flotation technology, the HydroFloat, which overcomes these limitations by carrying-out flotation in a dense, fluidised-bed medium allowing for the recovery of coarse particles (>0.250 mm). Over the last 15 years, this technology has been successfully applied to industrial minerals with several full-scale units installed to recover particles up to and exceeding 3 mm diameter in primary flotation circuits. This paper includes discussions on the history of this technology, process theory, existing applications, and a review of recent sulphide-based laboratory test work conducted for Newcrest mining and others. Benefits of this approach, such as improved recovery, low energy consumption and reduced reagent addition will also be reviewed.CITATION:Kohmuench, J, Thanasekaran, H and Seaman, B, 2013. Advances in coarse particle flotation - Copper and gold, in Proceedings MetPlant 2013 , pp 378-386 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By D Barclay, S Mercer, S Wright

Mine water management is often an afterthought in mine planning processes and can introduce significant risks to projects when studied as a stand alone component at a later stage in the mine design. Incorporation of a mine dewatering and pore pressure dissipation strategy in the early stages of mine planning is imperative in order to minimise constraints on the production schedule, to match designed pit slopes and maximise project value for an open cut mine option such as Olympic Dam. A risk-based mine planning approach was adopted during the project selection phase study whereby water management was introduced into mine planning, scheduling and the development of an operational strategy. Hydrological and hydrogeological studies and outputs were successfully integrated into the various iterations of the mine planning cycle during early selection phase to manage the potential water management risks associated with pit slope depressurisation and access to dry working conditions during rapid advancement of mining phases.An extensive network of vibrating wire piezometer sets and long-term depressurisation testing characterised aquifer conditions and demonstrated that hydraulic connectivity exists within the geological profile due to the presence of structures and resource drill holes which enhance vertical connectivity. This connectivity, along with underdrainage from mining activities contributes up to 100 m of depressurisation in low permeability units.A pit dewatering strategy incorporates the mine planning schedules and accounts for operational constraints as to the location and development of the dewatering wells, storages and pipelines. Numerical modelling generated a range of likely pit inflows and dewatering requirements with the average initial dewatering discharge likely to be 150 L/s and reduce quickly to 50 L/s after five years, depending on the premine schedule.Coupled hydrogeological and geotechnical assessments were also carried out as part of the mine planning cycle and indicate that successful dewatering will go a long way to reduce the pore pressures within key geotechnical units during the rapid mining phase where around 300 m of cover sequence is stripped in five years. However, the residual storage in the primary aquifer and the residual pore pressure in underlying low permeability units will need to be dissipated (in-pit horizontal holes) as the pit floor advances. Pit slope design angles are sensitive to depressurisation and dewatering and up to 70 per cent depressurisation of key geotechnical rock units are required. Whilst an accelerated program of aquifer dewatering supported by lithostatic unloading should drive rapid depressurisation in the lower permeability units, intervention is anticipated in key geotechnical units such as the Tregolana Shale and volcaniclastics. The extent of induced drainage will ultimately depend in part upon the mining rate and geotechnical stability requirements. Practical operability testing addressed the potential for operational constraints to mine depressurisation activities such as congestion and mining schedule development within the pit and identified that depressurisation drilling can be achieved even with reduced access availability. Mine operations and planning groups established design criteria and considered the likely inoperable periods following rainfall events of seven to 14 days to manage the base surge and minimise impact on production. In-pit surface water management options to minimise operational disruptions during and after significant rainfall events were estimated used a stochastic approach.

Jan 1, 2009