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By D Brett

"Mine waste storages including tailings dams and waste rock dumps represent arguably the biggest risk on a mine site from both physical and geochemical viewpoints, related firstly to structural stability and the consequences of failure and secondly from potential on-going seepage or run-off of acid and metalliferous drainage (AMD). The risks are most likely to increase during operations and continue through the closure and post-closure phases, with the waste storages likely to be the most difficult features to resolve in the mine closure process. Contaminated water quality from tailings dams and waste rock dumps can require treatment "in perpetuity" at a cost of hundreds of millions of dollars. The problem is increasing with ever larger mine operations and waste generation volumes. This paper identifies leading practice methodologies in planning and operating mines and process plants to minimise the risks from tailings storages and how this might also affect waste rock management and even the design of mine excavations. These methodologies require a "big-picture" approach to develop an understanding of the overall issues and identify synergies between the different operational areas on a mine site that can reduce overall risk. With a conservative approach and realistic allowance for future costs it is possible to facilitate decisions at the mine planning stage that can reduce risk and save cost over the long term. This is in contrast to the common approach where each operational area is looking to minimise its own costs with a short-term view. Incorrect mine methodologies can be developed by allowing net present value (NPV) accounting methods to trivialise future closure issues.Methodologies discussed include: Integrated Waste Management - Significant structural improvements to tailings dams can be achieved if the structures can be incorporated into the waste rock dumps. Risk of AMD can also be reduced by utilising the tailings and waste rock effectively. This could go even further to consider the placement of wastes to limit mine void environmental issues; Process Optimisation - Water quality and the nature of potential tailings dam structures can be highly influenced by the geo-chemistry of the tailings. This can be modified by processing, where simple changes such as maintaining separate streams of geo-chemically different tailings rather than recombining them or by initiating further processing to remove problematic minerals such as sulphides; Enhancing Geophysical Properties - The geochemical performance of waste repositories can be greatly influenced by the geophysical properties of the stored materials, particularly the air-water characteristics, which are influenced by particle size, density and permeability. The geotechnical properties can be enhanced by strategic paddock dumping, blending and compaction.These methodologies are demonstrated by case histories.CITATION:Brett, D, 2013. Mine waste risk minimisation by integrated waste management and process optimisation, in Proceedings MetPlant 2013, pp 247-258 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Methods for Improving the Flotation Recovery of the Coarse Fraction of a Nickel Ore

Sep 13, 2010

By Camier R. J, Perry G. J

Extensive deposits of brown coal exist in the Gippsland Basin, primarily in the Latrobe Valley. The total quantities of economically winnable coal in this region of Victoria and in other smaller fields are large enough to adequately assure Victoria's future electricity needs and to also provide large quantities for alternative applications, including liquefaction. As a result of the recent conflict in the Middle East attention has again been focussed on the production of synthetic fuels from coal. There have been many investigations over the years into the production of oil from Victorian brown coal. The purpose of this paper is to summarise the scope, objectives and major findings of these studies, with the emphasis on the direct hydrogenation route for converting brown coal to oil. The principal alternative processes are carboniastion and hydrotreatment of the product tar, or gasification and Fischer Tropsch synthesis of liquids from the product gas. The attractions of Victorian brown coal which have encouraged these studies include: ò the vast reserves of Victorian brown coal and the favourable conditions for low cost mining, ò the high quality of the coal (low ash, sulphur and nitrogen contents), ò the high reactivity of the coal giving high yields of product in hydrogenation to liquid fuels, ò the extensive data base available on the resource and its characteristics, and ò the availability of a skilled workforce and extensive infrastructure in the Latrobe Region to support a major resource development project. These advantages have been partially offset by: ò the high moisture content of the brown coal and the cost of drying, and ò the priority previously given to electricity generation in the allocation of the brown coal resource.

Jan 1, 1992

Near-Infrared Spectroscopy (NIRS) Sorting in the Upgrading and Processing of Skorpion Non-Sulfide Zinc Ore In 2008 Anglo American sponsored a research project at RWTH Aachen University to assess the feasibility of the use of near-infrared spectroscopy (NIRS) for ore waste discrimination at the Skorpion zinc mine. The Skorpion mine is an open pit zinc mine located in Namibia, owned by Anglo American with an annual production of 150 000 t/a of super high grade pure zinc. Opportunities for the implementation of NIRS sorting for the Skorpion process exist to upgrade currently subeconomic material, including the marginal dump (over 2000 000 tonnes, av grade of 2.5 per cent Zn). NIRS sorting is not yet implemented or established in the minerals industry however it is a proven technology in the plastics recycling industry, where more than 2000 NIRS sorters have already been installed. NIRS sorting, a type of sensor-based sorting, is a single particle sorting technique which classifies the particles based on the absorbed/reflected radiation in the near-infrared (NIR) region. A disadvantage of NIRS is that it is a surface measurement technique, but NIRS sorting shows overall great potential for the minerals industry. Skorpion ore minerals include zinc bearing phases such as sauconite, hemimorphite, smithsonite, and hydrozincite. These display diagnostic responses in the near-infrared. There are three major absorption features that characterise the reflectance spectra of the ore bearing minerals. These are due to OH and H2O molecular bonds. The spectral response of the waste material is caused by other minerals such as non-zinc-bearing clay minerals, calcite and impure quartz. Test work showed that it is theoretically possible to separate ore material from most waste material based on spectral response in the NIR region. In addition to upgrading material by removal of waste it is also potentially feasible to classify the material based on zinc grade. A tentative correlation between zinc grade and spectral response seems to exist for the sample test suite in the NIR region.

Sep 13, 2010

By S McKinley

"The White Mountain sediment-hosted gold deposit is located in north-eastern China. Mineralisation is associated with silica–hematite–altered polymict breccias that occur within dolomite at or near the contact with overlying sandstone. Economic gold grades are controlled by the distribution of the polymict breccias and can transition rapidly to low or zero grade over short distances. This results in sharp and highly irregular ore contacts on whose accuracy proper stope design and ore control is reliant at this blasthole underground mine.Short-term planning and ore control utilise a grade control model created from infill drilling and grade control sampling (ie face and wall sampling). Typically, the grade control model was maintained by time-consuming manual editing of earlier made contacts to incorporate any new data. This approach also was quite error-prone due to: the complexity of the breccia and ore grade contacts irregularly oriented and/or insufficiently dense drill holes inconsistent incorporation of grade control sampling. These errors resulted in unplanned dilution and ore loss due to inaccurate interpretation of the ore contacts.The primary advantage to implicit geological models over conventional, manually-built wireframe models is that they can be updated very quickly and frequently. In a mine setting, the power and efficiency of using an implicit model is greatest where the use of manual inputs or editing can be minimised. Recently a workflow was set-up for the mine geology team to create an implicitly-modelled ore shape for short-term planning needs by using all data, especially all grade control samples. The resultant 3D shapes provided metre-scale accuracy and consistently reconciled complex ore geometries much faster and to a higher degree of quality relative to the wireframe model. The mine stakeholders can now obtain an accurate ore model that will always be in sync with available data.CITATION:McKinley, S, 2017. Application of implicit geological modelling to improve the grade control process at White Mountain gold mine, Jilin Province, China, in Proceedings Tenth International Mining Geology Conference 2017, pp 385–392 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 20, 2017

Delivered at the University of Sydney, on June 4th, 1954.THE TORCH WE HOLDLast year Our Institute celebrated its Diamond Jubilee, coincident with the holding of the Fifth Empire Mining and Metallurigcal Congress in Australia and New Zealand. We can be proud of our growth over the 61 years since the inaugural meeting in Adelaide in April, 1893, which followed suggestions from a provisional committee of mining men, formed in 1892 in Broken Hill.We can also be proud of our technical achievements in the fields of economic geology, mining and metallurgy.Should we be content with the growth of our mining and metallurgical industries over these years? My answer is in the negative. The discovery of new mineral deposits is essential for the continuance and development of the industries we represent.Let me review the background and trends of our industry in an attempt to emphasise the changing factors influencing the search for minerals and their exploitation.Australia was blessed with the discovery of coal in New South Wales in 1796; copper in South Australia at Kapunda, Burra, Wallaroo and Moonta in the eighteen-forties; gold in Victoria and Eastern Australia in the 'fifties; tin at Mount Bischoff, Tasmania, and gold at Charters Towers, Queensland, in the 'seventies; lead-silver at Broken Hill, New South Wales; gold and copper at Mount Morgan, Queensland, and copper at Mount Lyell, Tasmania, in the 'eighties; and gold at Kalgoorlie, Western Australia, and zinc-lead atRosebery, Tasmania, in the 'nineties. As well, the iron ore deposits of the Middleback Ranges, South Australia, and Yampi Sound, Western Australia, were known before...

Jan 1, 1954

By R A. Lynch

The state-of-the-art in cave seismic monitoring is reviewed, with the latest developments in active seismic monitoring included. Seismic monitoring systems are routinely used by most of the world’s block and panel caving mines to track the cave initiation and progression. The current best practice is to use the cloud of seismic event locations as a proxy for cave growth somewhere below. Problems with event location reliability due to seismic ray bending around the (unknown) cave are side-stepped by using sensors installed above the cave. However, the aseismic gap – the (unknown) distance between actual cave back and seismic event cloud – currently hinders reliable estimation of cave geometry.Velocity inversions using the passive seismic data are inexpensive and should be undertaken more routinely. The straight-ray methods should be used with caution, as the underlying assumptions are invalid in caving environments. The double-difference method is more correct for the caving situation, and there have been some promising results published. Constrained geometric inversions make a lot of sense, but have yet to be demonstrated successfully.Two active seismic source have recently been developed for use in the caving environment: a piezoelectric source for ranges up to a few hundred metres and a pneumatically-powered source for ranges up to a kilometre. These sources produce signals on standard mine seismic sensors that can be used to measure seismic velocity variations down to 0.01 per cent resolution. This allows the cave progression to be monitored by measuring tiny changes to seismic velocities as the rock above the cave is fractured and destressed.CITATION:Lynch, R A, 2016. Active and passive seismic monitoring of cave front evolution, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 217–224 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By B Mack

The cost of water treatment is now more than ever a major consideration for maintaining an environmentally and economically sustainable mining operation. As an industry, we often have to consider water sources that are highly impure and difficult to treat. We are also discovering the value of our waste waters in this regard and using new and improved methods and technology to reclaim and reuse water. In many instances, the water or waste water to be treated is highly acidic and saturated in sparingly soluble salts. Conventional systems used to liberate this type of water typically involve high doses of lime with large volumes of waste sludge produced, and are comparatively complex to operate, to pretreat the water in order to reduce scaling tendency on the reverse osmosis stage. However, if the water is considered valuable for reuse, then why not avoid difficult and cumbersome pretreatment processes and treat the water at low pH to keep the sparingly soluble salts, metals and other dissolved species in solution. This paper describes a patented technology that uses and successfully proves this concept as a cost effective option for certain situations. Results from a treatability study on an Australian groundwater are discussed, along with an economic comparison to a conventional method and discussion on full-scale potential.

Jan 1, 2009

By Wesley, Worner H

During the meeting of the Institute last year at Port Pirie, the opportunity was taken to sample the lead bullion coming from the blast furnace and various stages during the refining process. Also, in the desilverising section, the upper zinc rich phase was sampled as the silver content built up and in the cupellation operation a series of samples was taken as the silver content of the bullion increased. In these two cases, the samples were taken under the supervision of a member of the staff of the Broken Hill AssociatedSmelters.In the following account of the microstructure of the samples taken, only the main phases present have received attention. In this connection deduction from phase diagrams of binary alloys has been used in conjunction with the assays carried out on duplicate samples taken at the same time as those for micro examination.

Jan 1, 1938

With a price slowly rising above US$35 per ounce gold became a mineral worthy of prospecting and mining endeavour in the early to mid 1970s. Fortune therefore appeared to smile onNew Zealand with its favourable geological environment for gold and past record of major gold production from both hard rock and placer deposits. This was a particularly welcome development as the post war years, including both the base metal exploration boom of 1967/1971 (which produced major nickel, iron and bauxite mines in Australia) and the earlier period of uranium exploration failed to produce any mines in New Zealand with the exception of the small Tui Mine and iron sand mining. Whilst hard rock mining now appears imminent it is 15 years further along the track since the 1967/1971 exploration boom and eight years since the upsurge in prospecting for gold in 1978. New Zealand still has no hard rock base or precious metal mining. This is not for want of proven or potential gold mining situations for these clearly exist at Waihi, Monowai Reef, Golden Cross, MacRaes Flat and elsewhere.

Jan 1, 1986

By J Hall, A Gallardo, M Strizek

Mineralogy and coproponents Sino Iron, International Minerals and Austeel are in the process of developing four world class magnetite iron ore mines with multiple open pits along a 25 km strike length of Brockman Iron Formation to the south of Cape Preston on the West Pilbara coast. The close proximity of the proposed pits raises some challenging project approvals and environmental management issues relating to the impacts of dewatering at individual projects and the cumulative impacts of progressive development on local and regional groundwater resources, which includes a large fresh water aquifer system in the Fortescue River alluvium.This paper presents an outline of the hydro-environmental impact assessment process adopted and the key result that the cumulative impacts of dewatering at all four projects on the local brackish groundwater system in the basement rocks is only marginally more than the impact of any one project on its own, and that the impact on the Fortescue River alluvium aquifer is negligible. The paper also presents an outline of the proposed integrated water management approach that will involve coordinated monitoring, ongoing impact assessment and management, and reporting programs for all projects.

Jan 1, 2009

THE art of mine surveying has made very great progress in recent years, and is still advancing, perhaps faster than any other branch of surveying. The scope of the mine surveyor's duties has greatly increased, his instruments and methods have improved, the responsibility of his position is greater, and the end is not yet in sight.It might be supposed that such a steadily growing subject would have an adequate literature, but this is by no means the case and outsiders commonly judge mine surveyors by their text-books. Hardly any condemnation can be too strong for most of these books. The English books truckle to the antiquated and crude methods apparently still in use in England, and thereby largely aid in perpetuating them; they commonly in illustrative examples give the distances in fathoms, feet, and inches; they spend page after page discoursing on instruments that should have been forgotten long ago; they try to antagonize theory and practice by detailing such calculations as that a certain vein will contain 2,003.907 pounds of galena per square fathom, and then reduce this amazing quantity to hundredweights, quarters, and pounds. Nothing can be more unscientific, or, for that matter, less businesslike, than unwarranted assumptions of accuracy; it is, perhaps, the greatest curse of applied science. Here we have a calculation to thethousandth part of a pound, when there is probably an unavoidable error of two hundred pounds. What shall we say of a man who explains how to measure the depths of shafts to the hundredth part of an inch by means of short brass rods screwed together...

Jan 1, 1909

By H Firdausi, I Pasek, T Chenier

The Grasberg Block Cave (GBC) Mine is one of the future underground mines of PT Freeport Indonesia (PTFI). Located in the remote highlands of Papua, Indonesia, the GBC mine is scheduled to start production in 2017 reaching its peak production capacity of 160 000 t/d in 2023.In order to reach planned production capacity, the GBC mine will utilise an ore handling system consisting of rail haulage, crushing and conveying. The rail haulage system will utilise over 20 km of track while crushing is accomplished by way of three gyratory crushers each with a capacity of 3300 t/h. Nine conveyors operating in two parallel systems, each system over 3 km in length, will move the ore from the crushers to the stockpiles. These systems require a network of larger tunnels and mass excavations to accommodate the planned production facilities.This paper will describe the ore handling system, tunnel and mass excavation methodology as well as some of the challenges encountered with ground conditions and excavation quality during the execution of the project. A combination of lateral and vertical development methodologies and equipment, including drill jumbos, mechanised raise climbers and specialised ground support equipment, have proven successful in the development of a quality ore handling system.CITATION:Pasek, I, Firdausi, H and Chenier, T, 2016. Development of the ore handling system at the Grasberg block cave mine, Indonesia, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 599–608 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By G D. Price

Scheelite mineralisation east of the main divide in' the Southern Alps of New Zealand was originally identified by Royden Thompson who is now a geologist with the NZ Geological Survey. This mineralisation was brought to the attention of CRA in 1978. Reconnaissance surveys were carried out in 1979 to delineate the extent of the mineralisation. This was undertaken using ultraviolet light examination of the sediments within the major drainages in the Southern Alps. This defined tentative zones of prospective mineralisation. As a result of this, preliminary reconnaissance, exploration licences were applied for -those areas in which indications of scheelite mineralisation were strongest. A total of 1737 km2 of ground was applied for within four exploration licences. These covered the main Southern Alps mountain chain between the Haast/Wanaka highway and the Mt Cook National Park.

Jan 1, 1983

The nature of the specialty glass and ceramic business magnifies the dependency of the ultimate product on the unique properties of their raw materials used to make them. This dependency has implications in the management of risk in the supply process which requires a special procurement organization and program commitment to be successful. The Coming system of managing critical materials and factors in development of alternate new suppliers and products is discussed.

Jan 1, 1989

CONTENTSSummary.Introduction.Location and Geology.Historical and Exploitation.Part 1. Washability Characteristics of the Liddell.Seam.Foybrook Open Cut, Top Bench.Sampling.Size and Ash Distribution.Washability Data.Washery Separations.Part 2. Washability Characteristics of the LiddellSeam.Foybrook Open Cut, Bottom Bench.Sampling.Size and Ash Distribution.Washability Data.Washery Separations.Acknowledgments.References.INTRODUCTIONThe washability characteristics, size-range and chemical analyses of the screening from the Liddell Seam are matters of growing interest in view of the increased exploitation of this seam over the last few years, and also since the Newdell Coal preparation plant of the New South Wales Mining Company Proprietary Limited, utilizing magnetite heavy media separation, commenced...

Jan 1, 1954

By L Maw

New ZealandÆs largest gold producersÆ OceanaGold Macraes Mine is characterised by a large tonnage and relatively low grade operation. To survive in diminishing real gold prices, the operation must focus on a culture of continuous improvement. This paper presents the outcome of a supplier sponsored continuous improvement project known as the Orica Advanced Mining Services project.   In March 2004 OceanaGold (then GRD Macraes) entered into an Advanced Mining Services (AMS) project with Orica Mining Services. The motivating factor behind OceanaGoldÆs need to improve bulk waste productivity and SAG mill throughput was the planned increase in production from five million to 5.4 million tonnes per annum. A stripping ratio of ten to one meant that optimisation of the drill, blast and production functions was paramount.   The primary focus of the project was to optimise the drill and blast parameters to suit the variable rock conditions throughout the mines main operating pit (Frasers Pit). Fragmentation of the ore for presentation at the SAG mill, and cost reduction on the mining of bulk waste movement, were the primary objectives. A number of additional initiatives complimenting the interface between drill, blast and ore production were also established. These included; +        reduced ore loss through delineation of ore boundaries to allow for blast movement; +        established blasting parameters for variable geological conditions, resulting in improved fragmentation; and +        improved asset utilisation by establishing a blasting regime that angled grade control holes to be used as blastholes in the stockworks area.   A year into the project, the philosophy of continuous improvement is now in-grained at the Macraes minesite. As the project continues, the focus is on the further refining of those procedures established, to ensure a continued focus on lower unit mining production costs.

Jan 1, 2005

By P Moswate, D Phillpotts, S M. Mantsho, P Strobos

A challenge on many industrial flotation circuits is controlling concentrate mineral grades using measurements that are provided infrequently. The mineral grades in concentrate streams are a critical performance indicator in any industrial flotation circuit. Failure to achieve concentrate mineral grade targets has significant financial consequences on a flotation operation. A violation of gangue mineral grade limits by the concentrator may also result in significant penalties.Online grade analysers which can provide reliable real time grade measurements are essential for effective grade optimisation. The Blue Cube MQi analyser (by Blue Cube Systems) has recently come to prominence for its ability to rapidly determine mineral concentrate grades online and has the benefit of operating in-stream. This has provided excellent insight into the actual process dynamics in the flotation circuit, and hence enabled real-time control and optimisation of concentrate mineral grades.MintekÆs Measurement and Control division, specialising in advanced control solutions for mineral and metallurgical industries, has had the opportunity to link the FloatStar Grade-Recovery Optimiser to the measurements provided by the Blue Cube system at the BCL nickel concentrator plant in Botswana. The project focused on stabilising the final concentrate grade while ensuring the final tailings are minimised, resulting in an improved nickel recovery. This site already had the FloatStar Grade-Recovery Optimiser for several years, but the original grade measurement device was unreliable and ultimately failed. The system was reactivated once the Blue Cube system was installed, replacing the old analyser. The positive results show the advantages of combining reliable real time measurements with an advanced process control system.CITATION:Mantsho, S M, Moswate, P, Strobos, P and Phillpotts, D, 2013. The implementation of floatstar grade-recovery optimisation control solutions using Blue Cube Online grade analysers on industrial flotation circuits, in Proceedings MetPlant 2013 , pp 575-582 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By A J. Scogings, W J. Shaw

The successful development of industrial minerals projects requires an integrated, holistic understanding of the metallurgical and product performance test work in the context of the geological setting of the deposit and applied to mining, processing and marketing of saleable products. The product specifications provide the essential starting point for geometallurgical studies. A sound understanding of the desired product is needed to design and interpret a program of test work. Examples are provided from recent studies on bentonite and graphite deposits.For bentonite projects, the naïve testing of only the cation exchange capacity (CEC) as a measure of purity can lead to unexpected outcomes when the deposit is mined. The CEC attribute may remain the same, while other important properties such as pH and swelling index change markedly with depth, due to weathering and oxidation, leading to disappointing production outcomes.For graphite projects it is not enough to report only total graphitic carbon content (TGC). Knowledge is required of the in situ flake size and textures in addition to purity and flake size distribution of extracted graphite, which may all vary from one domain to another across the deposit. Such geometallurgical attributes of the ore will impact on the ‘basket price’ used to estimate the value of marketable parcels of expected product.Disclosure of such information must be considered part of fully informing the market. As with all new project developments, consideration of the JORC (2012) and VALMIN (2015) Codes requires disclosure of all material information. This includes the geometallurgical characterisation, ie those aspects of the mineralogy that impact on resource evaluation, ore reserve definition and project valuation.CITATION:Shaw, W J and Scogings, A J, 2017. The importance of geometallurgical test work for industrial minerals projects, in Proceedings Tenth International Mining Geology Conference 2017, pp 83–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

An extensive series of tests was carried out on a ball mill-rake classifier circuit in the New Broken Hill Consolidated Ltd. concentrator. The data were used to develop a mathematical model of the operation of a rake classifier and this model has been used in the simulation of the performance of a ball mill-rake classifier circuit on a digital computer. As a result of this simulation it has been possible to develop a technique for the optimization and control of a circuit which includes these units.

Jan 1, 1967