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By J E. Wajon

This paper discusses the background, requirements, need and content of plans for management of drinking water self-supplied to mining-related operations, including construction camps, especially in remote areas of Western Australia. The paper discusses the importance of cooperation between regulators, the mine site operator and the consultant in preparing a plan fully compliant with the Australian Drinking Water Guidelines to protect the quality and safety of drinking water supplied to mine sites. The paper outlines some of the issues that need to be addressed in preparing a drinking water quality management plan, such as hazard identification, risk assessment, the multiple-barrier approach and the concept of critical control points. Data requirements, monitoring, incident management, training and reporting are also covered.CITATION:Wajon, J E, 2013. Drinking water quality management for mining operations in Western Australia, in Proceedings Water in Mining 2013 , pp 321-328 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By A Reschke

The Thiess John Holland Group is undertaking the design and construction of Brisbane’s Airport Link Project, the largest single investment in transportation infrastructure in Australian history. Twin Herrenknecht TBMs are being used to bore parallel road tunnels from Kalinga Part in Toombul through to Lutwyche, a distance of 2.45 km. At 12.48 m, these tunnel boring machines (TBM) are the largest diameter machines, outside of Japan, to incorporate annular two-component type grouting through the tailskins.Grout design, preparation and injection have been given particular attention in this project in order to push the boundaries of achievement. Laboratory testing was conducted on various mix designs to ensure the contract specifi cations for grout strength could be met. To study the mechanics of the grout injection process, Herrenknecht supplied a test rig which duplicates the grout injection systems on the TBMs. Multiple recipes were tested, carefully selected to balance the requirements of rapid strength development with high mobility (to completely fill the void between the segmental lining and the ground) and minimal bleed.Team Mixing Technologies, Canada, was selected as the grout plant provider based on the technical performance of their high shear colloidal mill mixers. Field results have shown that the colloidal mixer prepared grout gives almost double the strength of an identical grout prepared by a paddle mixer.

Mar 8, 2011

By R G. Richards

Although most New Zealand coals are low in ash, there are situations where high ash coals could be won. Not all high ash coals can be upgraded by physical means, since the ash is either inherent in the coal or bound in such a way to make its physical removal either impractical or uneconomic. Nevertheless, the authors believe, the situations where high amounts of ash can be economically removed by physical means to make a saleable product are considerable.

Jan 1, 1979

By D Price

Mining at the Tuckabianna Mining Centre in the Murchison district of Western Australia ceased in 1997, after the production of 550 000 ounces of gold at an average grade of 2.5 g/t from 22 separate open pits (Tectonic Resources, 2006). Like many historic mining camps in WA, Tuckabianna was considered exhausted of gold, such that an economic project could not be sustained on the existing resources. Since 1997, three separate companies have owned the Tuckabianna leases. Each of these companies completed minor exploration and some form of mining study to determine if mining could be sustained. All three companies concluded that the remaining resources were insufficient to support an economic project. Silver Lake Resources acquired the adjacent Tuckabianna, Comet and Moyagee projects in 2007 with a combined resource base of 693 000 ounces of gold in 11 separate deposits. In September 2009, Silver Lake commenced exploration in the Murchison targeting extensions to the main resources at the three project centres and completing targeted regional exploration across the lease holding. At the same time, a detailed evaluation of all historic drill data was completed and all resources re-estimated. This has culminated in the resource base increasing to 1.5 million ounces of gold in 20 separate deposits, with two new discoveries being made. In August 2010, a mining feasibility study was commissioned. Preliminary results from the study indicate that an economic stand alone project can be sustained for a minimum of five years. The ability to bring the remaining resource from a once unloved project into production is due to a number of factors: historically high gold price, combining adjacent projects into a single operation, evaluation of all resources regardless of size and grade, and well funded exploration directed to both resource extensions and new discoveries. Using the Tuckabianna Project as an example, this paper attempts to outline the strategy Silver Lake used to define the resources to justify the capital expenditure required for production, and give a summary of some of the successes and failures made as the projects progress towards mining. Examples of where being too rigid and over exuberant have resulted in less than optimal use of expenditure are used to high-light the difficulties in exploring in mature terrains. Evaluation of the success of a company’s exploration strategy at all scales from project acquisition to target selection is critical to the success of future project development. This paper has been part of that process for Silver Lake with some interesting discussions and insights being made. It is hoped that some of the points discussed can be applied to other projects to help achieve the best outcome from the assets available to a company.

Aug 22, 2011

By H J. Dalstra

High-grade iron ore may be derived from banded iron formation (BIF) through four fundamentally different processes:1. syngenetic precipitation of chert free BIF,2. residual enrichment by removal of gangue minerals from BIF to form bedded (residual) ironore,3. mechanical erosion of iron oxide and chert from bedded iron ore or BIF and re-deposition andupgrading as detrital iron ore, and4. chemical removal of iron from BIF and precipitation elsewhere as a secondary (channel) irondeposit.Finally, the BIF itself may constitute iron ore if a high-grade concentrate utilised for pellets or sinters can be derived from it through mechanical (industrial) separation of iron oxide by means of crushing/milling and mineral separation.Historically, exploration for high-grade BIF hosted iron ores was focused on the residual (bedded) deposits and driven by supergene concepts. Exploration for detrital and channel type iron ores was mostly secondary to exploration for bedded deposits, but recently, a more focused exploration effort has led to the discovery of enormous moderate to low iron grade deposits in the Pilbara region of Western Australia. Exploration for high-grade iron ores using syngenetic concepts has been limited,but together with exploration using hypogene concepts offers the best hope of fi nding concealed deposits. Exploration for BIF sources suitable for concentrate ores commenced in the ‘old’ iron ore provinces after the high-grade resources were depleted and has only recently gained importance in Australian BIF provinces, mainly as a result of high iron ore prices in the last decade.

Jul 11, 2011

By A B. Christie

The Institute of Geological and Nuclear Sciences' Mineral Resources Programme is currently carrying out research under two major projects:   HAREM (Hauraki Andesite Rhyolite Epithennal Mineralisation) The Hauraki Goldfield lies within a belt of andesite-dacite-rhyolite volcanics of Miocene Pliocene age which is underlain by a basement of Mesozoic greywacke. It contains some 50 separate epithermal gold deposits and is a world-class gold and silver producer. The HAREM project is aimed at improving models of the epithermal gold mineralisation, and to better understand the processes and controls of origin, transport and deposition of the gold.   MARGO - (Marlborough Gold) The MARGO project is aimed at determining the geological factors that controlled the formation of the Mesozoic mesothermal gold-antimony-tungsten deposits in the Marlborough Schist belt. Following reconnaissance work on 12 deposits, our current work is concentrated on deposits in the Wakamarina valley.

Jan 1, 1994

By K Blay, C McCamley, P Petrucci

The Newmont Boddington Gold (NBG) processing plant was designed for 35Mt/y with ball mills expected to deliver a combined new mill feed rate of 4837 tonnes/hr. Since beginning commercial production in late 2009, the plant has steadily increased throughput to meet design capacity in 2014 and reached 37 Mt/y in 2015. Through improved efficiencies, changes to the milling circuit have taken place since commissioning to take the plant beyond its design to an actual throughput of 39.0 Mt in 2017 and a budgeted throughput of 39.4 Mt/y this year.The NBG milling circuit has four parallel ball mills, each consisting of a 7.9 x 13.4 m ball mill with twin 7.5 MW fixed speed motors in closed circuit with twelve 650 mm cyclones. Each mill is fed by two wet screens with the undersize gravitating to a mill discharge hopper where it is combined with the ball mill discharge and pumped to hydrocyclones for classification. The cyclone underflow is re-ground to a target P80 of 150 µm.This paper will focus on process improvements made to the NBG milling circuit which include cyclone reconfiguration, fine screen panel redesign, implementation of an expert control system, mill power draw increase and grinding media changes to take NBG beyond its design throughput.CITATION:McCamley, C, Petrucci, P and Blay, K, 2018. Going beyond design at Newmont Boddington Gold, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 497–508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By A Hughes, J Agius, T Ferguson, A Parbhakar-Fox, D Lester, L M. Jackson

Management of historic tailings is a major challenge facing the mining industry and its regulators. However, through improved mineralogical and chemical characterisation of such materials the opportunity to develop better rehabilitation strategies arises. Microanalytical techniques including microscopy, mineral liberation analysis and laser ablation inductively coupled plasma mass spectrometry (ICPMS) allow for improved tailings characterisation – but the challenge posed by these techniques is how to use them effectively. Additionally, data sets collected by such techniques must be properly integrated, only then can they assist in the identification of the most appropriate rehabilitation strategies. A study conducted at the Old Tailings Dam (OTD) located at the Savage River Mine, Tasmania allowed for the integrated use of several microanalytical techniques to help evaluate the benefits of a shallow water cover as a potential rehabilitation strategy. Samples (n = 144) from 14 trenches and 11 boring cores (2 m maximum depth) were collected across the OTD. These were subjected to routine acid-base accounting, with a subset subjected to detailed mineralogy using a modified sulfide alteration index (SAI), X-ray diffractometry and mineral liberation analysis (MLA). In addition, representative samples (n = 6) from across the OTD were subjected to laser-ablation ICPMS to characterise the pyrite chemistry. Our results showed that tailings in the northern area submerged under a natural water cover were relatively unoxidised from approximately 1 m depth, with SAI values of 1 to 2. Tailings from the subaerial southern portion were extensively oxidised to approximately 35 cm depth (SAI = maximum 5.8), with fresher materials observed underneath (SAI = 5 to 5.8). Pyrite from across the OTD is enriched in Co, Cu and Ni. Through the integrated application of microanalytical tools, we determined that establishing a water cover of at least 1.5 m depth across the OTD is a suitable rehabilitation option for this historic site. However, consideration for the reprocessing of these tailings to extract Co should be further investigated.CITATION:Jackson, L M, Parbhakar-Fox, A, Hughes, A, Agius, J, Ferguson, T and Lester, D, 2015. Microanalytical evaluations of the savage river old tailings dam, north-?west Tasmania, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 111–124 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Adams R. W

A commercial scale strong acid leaching plant was commissioned at the Risdon plant of the Electrolytic Zinc Company of Australasia Limited, a member of the Pasminco group of companies, in February 1988. It was designed to upgrade the lead/silver residue product from 26% to 37% lead, thus improving the realised value and increasing overall zinc recovery. This in turn enables the lead smelter treating the lead residue to improve its productivity. The equipment consists of two 250m3 bricklined leach tanks and two 6.5m diameter stainless steel high rate thickeners operating with counter current washing at 95¦C and 120 g/L H2SO4. The present filtration and drying equipment is also being replaced. Two 35m2 squeeze action filter presses equipped with horizontal plates are being installed, together with ancillary drying equipment to ensure that the final product complies with the transportable moisture limit. The new filtration plant is due to be commissioned in mid-1989.

Jan 1, 1989

By S Gomez-Hernandez, P D. Munro

Filtered dry stack tailing storage facilities offer many advantages over thickened tailing storage facilities and yet, most of the mining companies still prefer the latter.Some of the advantages of filtered dry stack tailing storage facilities are: increased structural integrity of the tailing storage facility, which is even more critical in areas of high seismicity, close to nearby communities or environmentally sensitive areas; maximised water recovery which is particularly important in arid environments where water is an extremely valuable resource and its supply is regulated; optimised recovery of valuable metals in the process water, avoiding high cyanide concentration going to detoxification (both aspects haven’t been emphasised enough in technical papers on this subject); optimised space to store the tailings in mountainous regions; minimised elevation of embankment height, providing a safe option to store the tailings in places where there is limited area available; simplified license approval to operate where the tailing facility is a big issue; and avoidance of potential problems with nearby communities.Filtered dry stack tailing storage facilities have some disadvantages such as: technology limitations in operations that process high throughputs (eg >50 000 tpd) as they require many filters resulting in high maintenance and operating costs; higher capital cost; low efficiency in the filtration process, particularly in ores with high clay content increasing operating problems and capital cost; the new technology risk with possible debottlenecking issues and a longer time to achieve the design throughput; and the need to treat larger water flow rates when the water balance is negative.This paper analyses: the operating practices of Mexican gold and silver operations using filtered dry stacking storage facilities; implementation issues, advantages and disadvantages; quantifiable reductions in gold and silver losses and actual lower detoxification cost; and current trends to use filtered dry stacking storage facilities in new projects. The data gathered raises questions about (a) the need to collect data on tailings filterability, and; (b) reducing the current high operating cost of tailings filtration.CITATION:Espinosa-Gomez, R, Gomez-Hernandez, S and Munro, P D, 2018. Tailing filtration practices in Mexican gold and silver mines, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 275–282 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By R H DAVIES

Peak Gold Mine is a new gold and base metal mining project being developed by Enterprise Metals (a 100 per cent subsidiary of CRA) at Cobar in the centre of New South Wales. The Cobar district has a long history of copper and gold mining operations stretching back to the 1870s. Extensive gold and base metal mineralisation was discovered at the Peak in 1981 below a series of gold mines which had been active around the turn of the century. Evaluation of the deposit through the 1980s led to CRA's decision to develop the project for production at a capacity of 450 000 tonnes per annum in late 1992. The project has been developed with a green fields approach despite the long history of mining in the local area. This approach has lead to several innovative ideas being trialed at the site which are expected to result in the operation being a low cost producer of gold and base metals.

Jan 1, 1992

By Morrell S

As more and more autogenous and semi-autogenous mills are run in closed circuit with cyclones the limitations that can be imposed by poor grate and pulp lifter design are becoming increasingly apparent. Relevant literature on the subject is al

Jan 1, 1997

By D Howe

The Athena gold deposit was discovered in 2007 by Gold Fields Australia Ltd, at the St Ives Gold Mine, 35 km southeast of Kambalda, Western Australia. Gold anomalism was identified in sheared Paringa Basalt as a result of a regional scale aircore drilling program, in association with geophysics. In the 18 months following discovery, the deposit was intensely drilled and by June 2009, it was announced that the Athena deposit contained an ore reserve of 1.7 Mt @ 5.6 g/t for 316 koz. This was followed by a feasibility study, and as a result mine development commenced in November 2009.The Athena mineralisation is hosted in a discrete, north-south striking, steep to moderately dipping shear zone within the southwest dipping Paringa Basalt. Vein intensity has a strong correlation to grade and vein type varies from early thin quartz-albite-sulfide (pyrite and/or pyrrhotite) shear parallel veins to strong brecciation and irregular veining with quartz-albite-actinolite-biotite-pyrrhotite infill. The geology preproduction process developed at the Argo mine was refined and improved following a business improvement project. The aim of the process is to construct detailed geological interpretations prior to development allowing informed mining decisions to be made. The process delivers significant cost savings and revenue enhancements.The development of macroscopic classification scheme was critical to determine ore or waste in the early phases of mining. The Style of Deformation, Alteration and Veining (SAV) Code was the result, and has been enhanced as greater geological knowledge is gained over time.

Aug 22, 2011

Most mining operations have been happy to live in blissful ignorance of what their equipment is really capable of. Shareholders have been shown increasing tonnes output per employee (due to rationalising employee numbers). It is now known that the best practice for large mining trucks is 52 per cent higher than average or best practice for excavators is 41 per cent higher than average, or 38 per cent in shovels or 35 per cent with draglines, etc. The data is available. The bell curve of performance is flat. Substantial underperformance is rife. If you are working in or supplying equipment or services to one of the majority of operating mines that donÆt achieve best practice surely you want to know why. Or maybe you donÆt? For many mining people this sort of knowledge could be dangerous to their career so keeping the MD or CEO in the dark is a good option. Many suppliers donÆt want the performance of their equipment benchmarked? Mining consultants donÆt have the data so they are happy to keep guessing. Unfortunately, many Business Improvement or Business Excellence projects are about ticking the participantÆs æcareer boxesÆ. The first step to capacity utilisation is knowing what the capacity is. Even then people and culture will get in the way. People are the biggest hurdle to capacity utilisation. This paper will discuss what the mine of the future (and today) will need to do to utilise the productive capacity of its assets. It is not just benchmarking. It is not just automation. It is not just technology. It is about engaging those people who impact on equipment performance; right from the operator up to the Mine Manager. Doing it better involves a process to facilitate change and a culture which says it is OK to try even if you are wrong.

Jan 1, 2009

Hydraulic mining shovels can be successively used at open-pit mining operation in severe climatic zone with air temperature interval from -700C to +450C typical for some northern region of the world particularly of Russia, Canada and Sweden, if they would be equipped by special preheating facilities for their diesel engine, water, hydraulic oil and lubrication systems. All shovels manufactured by the Komatsu Mining Germany GmbH for operation at ambient air temperatures down to -50¦C have cast and forged structural design elements, bolted connections made of special steel grades, electric cables with special insulation, flexible high-pressure hoses manufactured by ICE-Champion with connectors made of special steel grades.Generally at the temperatures below -25¦C the ordinary machine has to be stopped, the attachment should be placed in the parking position, the generator should be switched on, or the external electrical power supply connected, for the preheating equipment. For rapid start-up in winter after a long shutdown of a hydraulic shovel, there is a procedure for preheating of the main systems. It is applied for the following systems: engine cooling system, engine oil, hydraulic oil, pumps and drive motors of the propel gears, electric cabinets, machinery house, especially near the ventilation inlets and outlets.Start-up of the main drive engine is permitted at a hydraulic oil temperature of -20¦C, when it has a viscosity of 1000 cSt. In this case the rotation speed of the diesel engine crankshaft is lower by two times than the nominal value and this is the most favourable condition of start-up of the engine and hydraulic pumps and motors, which work with half of their rated rotation speed until the hydraulic oil reaches a viscosity from 100 to 10 cSt. After that the hydraulic system and the entire shovel begin to operate under normal conditions.

Dec 6, 2010

By S Jahanshahi, D R. Swinbourne

A knowledge of the value of the activity coefficient of cobalt oxide in slag as a function of composition and temperature is necessary if effective strategies are to be devised to maximise the recovery of cobalt in nonferrous smelting processes. This work reviews previous studies and shows that comparison and evaluation of the results is hampered by variations in the choice of standard states for the species. Published results have been recalculated to a common set of standard states with a preferred value for the Gibbs free energy of formation of cobalt oxide. It has been shown that the value of the activity coefficient of cobalt oxide referred to the solid standard state in iron silicate slags is approximately two, at temperatures from 1523 to 1623¦K. It is suggested that some contradictory results are most likely due to errors in the measured partial pressure of oxygen.

Jan 1, 1998

By A R. McKinnon

The recently opened Hera Au-Pb-Zn-Ag mine in central New South Wales has provided an ideal opportunity to demonstrate the calculation of sulfide ore mineralogy using normative methods. Normative mineralogy applies a set of sequential rules based on the species likely to be present to assign the chemical components of a sample to their respective mineral components. The dominant sulfide mineral assemblage present at Hera is galena, iron-bearing sphalerite, chalcopyrite, pyrrhotite and pyrite. A normative technique for estimating the relative abundance of each of these species from drill hole, grade control and metallurgical assay data sets has been developed. This includes a process for deriving a gangue iron value and differentiating pyrrhotite from pyrite using sulfur/iron ratios. A calculated total sulfide volume value has been utilised at the mine to improve interpretation of lode boundaries. Normative drill hole values have also been used for domaining within the orebody, with large scale mineralogical trends evident. Dry bulk density (BD) values calculated using a normative species-weighted method show good correlation with measured BD values (R2 = 0.895) and are a significant improvement on the Pb+Zn+Cu regression method (R2 = 0.646) previously used. Application of these calculations to identify errors in assay databases is demonstrated, with specific reference to the data set for the nearby Nymagee copper deposit. Validation of block model grades is also explored and a method to improve resource estimates using direct normative mineral interpolation is proposed. The integration of the normative data into the production and metallurgical data sets at Hera is described and the relationship of the normative minerals to other economic elements such as gold and silver is discussed.CITATION:McKinnon, A R, 2017. Application of normative ore mineralogy to geological and metallurgical data sets at the Hera Au-Pb-Zn-Ag mine, New South Wales, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 63–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By J R. Leeming

Mining law has developed in Great Britain (GB) over centuries, mainly in response to lessons learned after disasters and other major incidents. This has led to a culture of preventing repeat accidents, rather than predicting and controlling unsafe acts or conditions.This paper explains how, initially in response to a government drive to reduce the burden on industry, the opportunity was taken to review and reform all 48 sets of GB mining-specific law into a single document. The philosophy adopted, the procedure followed and the significant changes that resulted are explained.CITATION:Leeming, J R, 2017. The complete renewal of Great Britain’s mining laws for the 21st century, in Proceedings Australian Mine Vent Conference 2017, pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By J Caron, M Athayde, F Lavoie, R Joyce

Decarbonisation has become a major challenge for the global steelmaking industry, turning towards new technologies aimed at carbon footprint reduction, which on its own accounts for approximately 9 per cent global emissions. The iron and steel industry represents a ‘hard to abate’ sector, where much of efforts are currently being deployed into initiatives aiming to decarbonise the ironmaking through the use of green hydrogen, carbon capture utilisation and storage and state-of-the-art operation of current technologies, while little efforts being deployed to find carbon-efficient solution to iron ore burden preparation, where high-grade iron concentrate will increase in importance to ironmaking regardless of the chosen reduction route. Quebec Iron Ore (QIO), a subsidiary of Champion Iron Limited (Champion), produces high-grade hematite concentrate with one of the lowest carbon global footprints. Still, QIO is partnering with its clients to the development of burden solutions to minimise CO2 emission, in the seek for a decarbonised steel. In a strong technological partnership, Binding Solutions Limited (BSL) has developed a novel, coldbinding technology to provide a cleaner, more cost-effective alternative to induration. The technology allows miners and steel producers to reduce Capex significantly and reduce energy consumption and CO2 emissions by 90 per cent. QIO and BSL have partnered to adapt the disruptive cold binding technology developed by BSL to QIO’s concentrate to produce a high-quality low emissions iron ore agglomerate. This paper describes the efforts taken to further develop BSL’s cold binding technology and its application to QIO’s high-grade iron ore concentrate to produce a hematite cold bonded briquette (hCBB) showing comparable performances with high quality seaborne fired pellets.

Nov 8, 2021

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