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By H Kundapen, B R. Bolton, H Davies

The Ok Tedi porphyry copper-gold mine is located in the Star Mountains of Western Province, Papua New Guinea. Open-cut mine commenced in 1984 and is due to cease around 2010. The mine produces a total of 88 Mt of waste annually including 58 Mt overburden and 30 Mt tailings, which are discharged directly in to the Ok Tedi River. Mine derived wastes are transported downstream and deposited within the river channel in a variety of bar forms. The prevailing hydrogeological conditions including, velocity, competency, capacity, gradient, grain size and specific gravity, control the deposition and segregation of these sediments. Periodic exposure of the reactive sulfides to oxygen during fluctuations in the river discharge may result in oxidation, localised acid generation and liberation of metals into solution. To evaluate the significance of this issue, Ok Tedi Mining Limited initiated an investigation of the sediments deposited in the upper Ok Tedi River as part of its overall ARD Management Program. The specific objectives were to: evaluate the acid-forming characteristics of identified high sulfide river deposited sediments; characterise geochemically the waters in contact with sulfide-bearing river deposited sediments; map and monitor exposure areas and oxidation depth of deposited potentially acid forming (PAF) sediments; determine the depositional processes controlling sulfide distribution; and assess lag period, oxidation and metal release rates for the sediments. This work included the analysis of sediment and water samples collected on a 50 + 50 metre grid at six gravel/sand bars. The sediment samples were analysed for total sulfur, ANC, NAG, total sulfur and total copper. Water samples were tested for general water quality parameters, sulfate and a suite of dissolved metals including; Al, Ca, Cd, Cu, Fe-sol, K, Mg, Mn, Na, S and Zn. This paper presents the results of these investigations with particular emphasis on the geochemistry of the river sediments and associated contact waters.

Jan 1, 2003

By B M. H Sharp, R P. Hide, S P. Devine

Uncertainty and debate currently pervade the mining industry in New Zealand. The operational uncertainties, whether external (eg gold prices, the exchange rate), or internal (eg coal expansion difficulties), are large. In addition, many wider factors which influence mining are in a state of flux. State Coal Mines, the operating branch of the Mines Division of the Ministry of Energy I may be made a state corporation, with the remaining Mines Division functions being revamped. The agencies administering environmental legislation are to be restructured. Mining legislation amendments have been proposed and then dropped, and the area is now to be reviewed (The Press, 31 July 1985). Some mining licences have been withdrawn, and become the subject of heated debate in the community (The Press, 19 July 1985, and subsequent letters to the editor).

Jan 1, 1985

By A Mirzaghorbnali, D Gilbert, R Burton, J Nemcik, N Aziz

Glass-reinforced polymer bolts, commonly known as fibreglass dowels and fibre-reinforced polymer or plastic bolts or plastic dowels are increasingly applied for strata reinforcement in mines as well as in concrete reinforcement in civil engineering. The most popular dowels used in coalmines are the 22?mm diameter fully threaded type. Fibreglass and plastic bolts are cuttable, easy to handle, lightweight and corrosive resistant. A series of tests were undertaken to evaluate various strength properties of fibreglass dowels. These included tensile failure tests by the double-embedment method, a single guillotine shear test and a double shear test, carried out on dowels installed in concrete blocks, and with punch shear tests. Punch shear tests were used to evaluate the dowel shear strength parallel and perpendicular to the fibreglass strands or elements direction of extrusion. The study found that the tensile strength of the 22?mm diameter fibreglass dowels was in the order of 30?t. In the shear testing, the peak shear load was influenced by the encapsulation grout type and the level of fibreglass axial pretension. Also, there was a nearly fivefold difference in the shear strength value of fibreglass dowels tested parallel as against perpendicular to the dowel axis.CITATION:Aziz, N, Gilbert, D, Nemcik, J, Mirzaghorbnali, A and Burton, R, 2014. The strength properties of fibreglass and other polymer-based dowels for strata reinforcement in coalmines, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 263–268 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Offler R, Lau J, Lea J. F

The stratiform and vein-type pyritic silver-Iead-zinc-copper sulphide deposits of Sunny Corner, NSW are hosted by acid volcanic and clastic sedimentary rocks of Middle Silurian to Early Devonian age. The rocks have been subjected to low-grade regional metamorphism (prehnite-pumpellyite facies) and three phases of folding and four faulting events are recognised. Pyrite is intensely fractured, indicating brittle deformation. Chalcopyrite and galena exhibit deformation twins and slip planes indicating ductile deformation; sphalerite and chalcopyrite show straight and curved grain boundaries and dihedral angles of 120° as evidence of annealing recryslallisation. Sulphur isotope ratios for 22 samples from five deposits range from 1.7 to 10.7 per mil and average 7.4 per mil. Sulphur isotope data are similar to those from other stratiform sulphide deposits in acid volcanic rocks of Late Silurian age in the eastern Lachlan Fold Belt, especially Woodlawn and Captains Flat and together with other features of the mineralisation, suggest a volcanic exhalative origin for the Sunny Corner deposits.

Jan 1, 1984

By S Wangchai, D B. Hastie, P W. Wypych, A P. Grima

Industries that handle and process ‘dusty’ ores are facing increasingly difficult challenges to ensure sustainable operation and development. Most existing dust-control measures treat only the symptoms of dust generation and do not deal with the root cause/s of the problem. Many of these methods are also relatively inefficient in terms of controlling dust emissions. This paper summarises the various existing options available for dust control and some of their features, advantages and disadvantages. It then describes some of the new technologies that are being researched, developed and employed to minimise dust emissions by addressing dustability or dustiness and the dust generation mechanisms found in industry. Recent research results and case studies are presented to demonstrate some interesting findings obtained from this work. With improved understanding and modelling of dust generation mechanisms and bulk material dustiness, it is possible to achieve a step-change improvement in the design, troubleshooting and application of more efficient dust-control technologies.CITATION:Wypych, P W, Hastie, D B, Wangchai, S and Grima, A P, 2015. Research and application of new dust control technologies for the iron ore industry, in Proceedings Iron Ore 2015, pp 529–536 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

With the burgeoning opportunities for new gold mines to be developed the opportunity now exists for a reassessment of the optimal processing path for these gold ores. Projects have traditionally followed the path of whole ore cyanidation with either Carbon In Pulp (CIP), Carbon In Leach (CIL) or Merrill Crowe. The challenge ahead is whether these traditional processing methods are the best option for stakeholders, or to go beyond CIP and use a combination of currently available technologies that can be used to provide gold recovery at a significantly reduced capital cost and minimal deleterious impact on the environment. Either stand alone or combinations of gravity concentration and flotation, can produce a gold bearing concentrate that can then be fed directly to a batch or continuous intensive cyanidation unit. Treatment of a gravity/flotation concentrate by intensive cyanidation may be processed by the InLine Leach Reactor (ILR) developed by Gekko Systems of Australia. The advantages of the technology combining gravity/flotation followed by intensive cyanidation are significantly reduced capital costs; improved safety due to reduced cyanide inventories; the majority of tailings un-contaminated by cyanide; less energy required due to an opportunity for an increase in grind size û reducing green house gas emissions; detoxification of concentrate tailings can minimise tailings disposal and containment requirements.

Jan 1, 2004

By G Barla

In Europe, a major interest in the infrastructure and tunnelling fields is in the new crossings of Alps in the form of base tunnels, which are important components of the high-speed (for passengers)/high-capacity (for freight) Trans European railway corridors. These tunnels cross the mountain belt at the elevation of the main cities and basins located all around the Alps and are longer (up to 57 km) and deeper (up to 2500 m) than all tunnels constructed in the centuries before. The excavation of the first Alpine railway and road traffi c tunnels could in general be carried out successfully by conventional excavation methods. With the great lengths of the new base tunnels, mechanised excavation by using tunnel boring machines (TBMs) is imperative as it contributes significantly to savings in construction time and costs. Questions are however posed on the adoption of such a systematic tunnel construction method given the severe ground conditions which are some time anticipated along the tunnel alignment, with possible major geological hazards such as water inflow in heterogeneous fractured or karstifi ed rock masses, stress-induced tensile failure of hard rocks, and plastic shear failure and squeezing of weak rocks, etc. This lecture is to briefly review the current state-of-the-art in the understanding and modelling of two such critical hazards as spalling/bursting and squeezing ground behaviour. With the present interest in the design of mechanised tunnelling with TBMs in such conditions, the complex interaction between the rock mass, the tunnel machine and its system components, and the tunnel support is studied in detail by numerical modelling. The research and development efforts presently underway with the intention to provide the designer with a novel three-dimensional (3D) simulator of mechanised tunnel excavation are presented. Case examples are discussed with reference to the Lyon-Turin Base Tunnel design.

Mar 8, 2011

By T Hicks

Designers of mining facilities play a significant role in defining the overall mine greenhouse gas emissions performance. This demands an appreciation of all the greenhouse gas emissions sources, including Scope 3 emissions, which will form an increasing fraction of the emissions as we transition our generation sources to renewable energy. Traditionally overland conveyors are designed to operate as fast as practical, and through this approach, achieve relative minimisation of: conveyor belt tensions; belt width; mechanical equipment masses; structural steel quantities; and concrete quantities. It is well understood that higher belt speeds reduce capital cost and improve project economics. Operating at higher speeds introduces operating costs through system energy losses and increased wear rates. This paper assesses the life cycle greenhouse gas emissions for a typical iron ore overland conveyor to demonstrate how the design criteria and engineering decisions impact greenhouse gas emissions and project economics. An analysis of the decarbonisation potential and project economics using a range of operational parameters has been completed, developing a marginal abatement cost for each system configuration, creating a basis for integration of low emission overland conveyor designs as part of the broader facility decarbonisation strategy.

Sep 1, 2024

Successful evaluation and exploitation of resources and reserves relies on the collection of high quality sample data. The quality of the sample data must be maintained through the application of a robust quality assurance and quality control (QAQC) program, including documentation of sampling procedures, training of sampling personnel and the regular monitoring of control samples. However, the application of QAQC programs in the minerals industry is often poor and the purpose misunderstood. It is all too common to have good quality control data collected, but no analysis work carried out until after drilling is completed. In a lengthy drill program, this can lead to problems not being discovered and corrected as they happen. Moreover, rectifying problems afterwards will be costly in terms of time and money, if not impossible. The consequences of poor quality sample data are many and include such effects as over- or underestimation of block grades, misclassification of ore and waste, and lower confidence in the resource/reserve models. The purpose of this paper is to highlight, using case studies, the importance of good QAQC practices to monitor the quality of sampling and laboratory sample preparation and analysis.

Mar 1, 2010

By Kobe HW, Balance PF, Black PM, Sporli KB, Smith IEM, Locke CA

The Hauraki Goldfield consists of a large number of volcanic-associated epithermal gold deposits within the Coromandel Volcanic Zone (CVZ), North Island , New Zealand; it is the most accessible and most studied of the Southwest Pacific gold regions. The deposits occur generally as steeply dipping quartz veins and breccia sheets in faults and fractures.From a tectonic perspective, the CVZ is generally considered a Neogene convergent volcanic arc constructed under an extensional tectonic regime; the common tectonic setting for epithermal mineralisation. The gold deposits are mostly hosted in subaerial andesitic arc-type volcanic rocks. Temporally, however, mineralisation is associated with rhyolitic rocks of a bimodal volcanic suite that may represent a back-arc environment. Rifting and calderas may be important components of the latter regime, but this is not yet clear; the general structural framework controlling the location of CVZ gold deposits remains poorly understood. Geophysics, particularly aeromagnetics, has a role in mapping regional fault patterns in the CVZ

Jan 1, 1990

By Liu Wenyong, Huang Yucheng, Yang Ba

High-water rapid-solidifying material, called æhigh-water materialÆ, is a new material developed by the authors over many years. The material can solidify nine times its volume of water into solid. The material is a fine kind of binder with special properties. The solidifying body of high-water material with water has quite a high early strength. The compressive strength of the material within three days can reach the same strength as conventional Portland in 28 days. One ton of the material can replace three tons of conventional Portland cement as binder. Some important achievements have been made in application of high-water material. In metal mines, based on the material, a new full-tailing cemented backfill technology has been developed. The characteristic of the new technology is that high-water material is used as binder and full tailing or alluvial sand is used as backfill aggregate. Because of the application of the new technology, major technical problems in backfill technology such as classifying of tailing, dewatering, transportation of pulp, low strength of backfill body, environmental contamination and so on, have been solved.

Jan 1, 1998

The Ramu chromite deposit occurs in the Marum Ophiolite complex and is the most economically attractive chrom-ite deposit in Papua New Guinea. Its lateritic nickel, chromite and cobalt potential has attracted several compan-ies to prospect the deposit.In the present work, the compositions of chromite in the Ramu lateritic deposit and coexisting olivine-chromite pairs in Marum Ophiolite dunite were analysed with the electron microprobe for Fe, Mg, Cr and Al. The results were used to determine the relationship between the cations in the tetrahedral and octahedral structures of the chromite. In addition, the Fe, Mg, Cr and Al cations of the coexisting olivine-chromite pairs were used to calculate the equilibrated temperatures of crystallisation of the chromite. The variation of Fe", Mg and Cr cation values of the chromite in relation to the calculated temperatures was studied by regression analysis.

Jan 1, 1994

By A J. Morrison, K Demir, J Kohmuench, K Runge, C Evans

The Eriez HydroFloat® is a flotation device capable of recovering significantly coarser and lessliberated particles than is possible using a conventional mechanical flotation cell. Originally developed for industrial and bulk mineral beneficiation, the HydroFloat® is attracting increasing interest as a means of increasing the required grind size for metalliferous ore flotation. Doing so would reduce the costs of processing complex ores, either by decreasing the energy required to grind the flotation feed or by increasing the throughput achievable with a given comminution circuit. Processing coarser particles would also result in coarser waste streams, potentially improving the mechanical and hydraulic performance of the waste dams that they are sent to. Recent work at pilot – and industrial-scale has proven the potential of the HydroFloat® technology to achieve these gains in metalliferous applications. However, in order to realise the full potential of the HydroFloat® technology, it is necessary to understand not just its performance but also the drivers for that performance. Doing so will allow the design and operation of HydroFloat® devices to be optimised for different ores and applications. For this work, a HydroFloat® pilot rig was deployed to a coppergold plant in Australia and was used to investigate the effect of stream and operating conditions for treating the tailings stream of one of the plant’s rougher flotation cells. Under each set of operating conditions, samples were taken of the HydroFloat® feed, tailings and concentrate streams, and processed to yield the grade and recovery achieved by the device. At the same time, the bubble size and bed behaviour inside the device were measured. This paper presents preliminary relationships observed between the operating conditions and the performance of the HydroFloat® cell, and thus suggests a range of possible drivers for the measured coarse particle flotation performance.

Aug 24, 2022

In May 1977 a new dam was commissioned for disposal of 600,000 metric tonnes/year of tailings. Design basis, costs and construction problems are described. Problems arose, assoc- iated with lack of experience in building such a dam "from scratch". Solutions are described land costs given.

Jan 1, 1978

By Neville WE, Parkinson J

One of the earliest recorded risk management schemes was implemented by the boatmen of the Yangtze river some 4,000 years ago.. Between them they arranged for shipments to be split up in such a way that a load was divided five ways: if one was lost, then 80% of the shipment got through. Bottomry contracts were in vogue in Babylonian times with similar systems being used in India, in 60OBC and 4th century Greece. One of the first accepted mutual insurance ideas came in 1835 when a mill owner in America negotiated a lower insurance premium in return for installed fire safety measures. Approximately 20 years ago risk management as a philosophy was developed in the U.S.A., the philosophy followed to England and hence to Australia about 10 years ago. The business climate which induced the philosophy of risk management was that of "tight money". The definition of "assets" was then broadened to include earning capacity, skilled personnel and in a negative sense, a corporation's liabilities. In more affluent days losses were comfortably absorbed into the ongoing business expenses, the more prudent managers took out insurance which "covered everything" at a suitable premium. Statistics are available to indicate that a high percentage, (over 60%) of businesses which suffer massive plant damage due to fire, do not restart operations, or in the event of restarting have closed operations within the next 2 to 3 years - in spite of collecting an insurance payout.

Jan 1, 1986

Early in 1950 a new laboratory was set up to deal with problems in mineragraphy, petrology and metallography. This paper describes the equipment, the organisation and association of the laboratory with the various departments of the company, the work that has been done and future plans.At Mount Isa it was soon realised that the microscope would play a most important role in mineral dressing problems and aiding geological research.As early as 1928, R. J. Colony submitted a petrographic report on Black Star ore for Consolidated Limited; much later, in 1934-5 Dr. Grondijs published for Mount Isa Mines Limited a preliminary study of the Mount Isa orebody, followed by a mineragraphicinvestigation of mill products, and in 1937 a Study of Mount Isa Ores by H. GrondIjs and C. Schouten appeared in Economic Geology, for June-July. Other papers dealing with the petrology and mineragraphy of Mount Isa ores are appended at the end of the paper.The mill research metallurgical staff has endeavoured to incorporate mineragraphy in solving milling problems and determining the effectiveness of laboratory as well as examining minerals sent in by the geological department.For many years the amount of equipment available was limited and much of it was locally made or improvised. An improvised briquetting machine, and grinding and polishing lap gave moderate results in conjunction with an old, but serviceable, Leitz microscope. However, for more detailed and accurate work not possible with improvised equipment, many mineragraphic problems were sent to specialist in.

Jan 1, 1953

By R W. Shaw

The MTM Process targets treating lower grade and/or problem concentrates that are not attractive to smelters. The process has been developed at laboratory scale for copper and is based on a related development for zinc that has been extensively developed both in the laboratory and through pilot testing. The basis of the process is novel ammonia-ammonium chloride leach chemistry adapted to give high copper extraction whilst being selective over iron, arsenic and many other elements. The preferred flow sheet depends on location, especially infrastructure and utilities. These impact upon the leach and crystallisation stages more than copper reduction.

Aug 24, 2022

The mining of Australia's rich and diverse mineral resources has been central to the development of the continent by "Europeans" over the past two hundred years. Mining has historically been encouraged (to varying degrees) by development-orientated state governments (the. managers of largely Crown-owned resources) and since Federation, by successive Com- monwealth governments (which have seen mineral development as a means of generating export revenue to fund predominantly social-welfare orien- tated budgets). This marriage of convenience between governments and the mining industry has to date served all parties well. However, Australia's entry to a new world economic environment at a time that community percep- tions are changing (owing to an education-inspired challenge to "old" values) is challenging the hitherto held assumption that mining develop- ment is always aligned with the well-being of the State and community. Issues such as the type and extent of State/Commonwealth government taxation, resource ownership and control, the environment, land use con- flict, the extent and desirability of secondary processing and infrastruc- ture funding are being debated in the public arena. Opponents of mining in the community are well-organised and are well funded, articulate and more importantly, they have effective communication channels with most governments, irrespective of political complexion. Apart from some television-orientated corporate image building and recent efforts by AMIC, the industry's response to this challenge has been unco-ordinated, poorly directed and arguably ineffective. Professionals working in the industry are concerned about the community's perception of themselves and their industry. Recognizing that the Australian democratic system ensures that, in the large, government at its various levels, is reflective of and responsive to the views and aspirations of people, the industry's response must be wide- ranging, equally articulate and couched in a form which is politically acceptable. New objectives in providing information to the public and its educators must be formulated. Moreover, professionals are looking for new directions from industry leaders. The Institute is well placed to facilitate this process.

Jan 1, 1988

White Cliffs Opal Field is situated in the Parish of Kirk, County of YulguIgra, New South Wales, about sixty miles from Wilcannia, and the River Darling. It is near the southern edge of the cretaceous basin of the interior of Queensland, New South Wales, and South Australia. Twelve miles south-west of the field, at Tarella station, a well sunk at the homestead reached silurian slates at about 127 feet, getting no water but about three miles north-west from the originally discovered and no central portion of the field, a well was sunk by the Momba, Pastoral cmpany, to a depth of 270 feet all the way through the cretaceous beds. At 250 feet a small supply of water was struck, but so much mineralised as to be quite useless. The temperature also was so high that a man could not keep his hand in it and Mr. Hogarth, the Momba Pastoral Company's manager, informs me that so corrosive was the action of the water, that a shovel left down the well for a fortnight, at the time of sinking, was completely eaten away.The well having now fallen in, I have been unable to obtain any of the water for analysis.The western termination of this portion of the cretaceous basin is situated about twenty miles from the present opal field, at which distance the slates, with (probably) devonian sandstones and quartzites resting unconformably thereon, commence to appear. The opal bearing country, as far as at present known, follows a more or less well defined line running north and south towards the northern end of the field, and north-east and south-west towards the southern extremity.

By J Darbritz

"This paper details the events leading up to a slope failure that occurred at Kalgoorlie Consolidated Gold Mines (KCGM) and the remediation method executed using rope access specialists.n January 2016, KCGM Fimiston Pit experienced a double bench wall failure where approximately 80 000 t of material fell from the wall that blocked access to a ramp and caused minor damage to equipment.The event was triggered by heavy rainfall and occurred along unfavourable eastward dipping structures that lead into weaker shale/porphyry bands, which in turn left more material on the face. A remediation plan was formulated that would allow for the continuation of open pit operations while a full geotechnical assessment of the failure area could be conducted. This was accomplished by means of rope access specialists who abseiled down the wall and blasted off the remaining overhang using a portable drill rig and prepackaged explosives.This paper provides a brief overview of the KCGM operations, how the instability was identified and monitored, details of the failure event, outcomes of the geotechnical assessment and details on the remediation work.Citation:Graf, C and Sullivan, R, 2016. The Journey to Steepening the Pit Slope Angle - Advancing the Effectiveness of Wall Control, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 104–114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016