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By J Bohm, B Csoke, I Tarjan

In process technology, especially in coal preparation, it is often necessary to have a continuous knowledge of the average density of granular material in order to achieve both quality control and process control. The paper presents a new method and means supported by laboratory measurements for the rapid, practically continuous, determination of the average density of continuously supplied granular material through frequent sampling.

Jan 1, 1993

Strong markets for metals and energy over the past five years have supported equity and debt market funding to enable a new group of mining juniors to emerge in control of economic resources, some in regions with high investment risk. As companies drive these projects to development, production and positive operating cash flow, their Boards and CEOs are confronting important questions:Having achieved initial success, what is our longer term purpose as a company? Does the purpose originally described in the Initial Public Offering to raise equity remain wholly relevant? Given that purpose, how do we understand the available sets of opportunities and related risks? Should we be acquiring new assets or other companies, or developing the existing portfolio? What commodity sectors and geographies should we focus on? Or should we be conserving funds until asset prices or project costs provide greater assurance of value to shareholders? How do we translate that purpose into tangible goals that shape and direct the work of people in the organisation? How do we get the right work done in the face of high turnover and competition for capable staff? Drawing on the authorÆs career experience and on work undertaken by Heuris Partners, this paper provides a practical CEO framework for strategy development, organisation design and on planning the work of the business in the mining industry.

Jan 1, 2006

By T Napier-Munn, D J. Bradshaw, M Chauhan, L Keeney

An important aspect of geometallurgy is quantifying mineral processing attributes, which leads to improved orebody understanding. One of these attributes is flotation performance. Several methods have been developed as indicators for flotation performance, including batch testing leading to kinetic information and the standard grade-recovery curve. This paper makes a preliminary statistical comparison between a newly proposed geometallurgical batch flotation procedure and the æstandardÆ batch flotation test commonly used to measure flotation performance in the laboratory. The new test uses much less material than the standard test, and is much faster. It is concluded that the new method follows the final recovery of the standard method well, suggesting that it will be effective in reflecting ore variability for geometallurgical purposes. Comparison of the methods based on the full grade-recovery curve shows less agreement, but this may be due to the fact that the curve is sensitive to the particular experimental set-up and conditions, which make such comparisons quantitatively challenging. Further development work is therefore planned.CITATION:Chauhan, M, Napier-Munn, T, Keeney, L and Bradshaw, D J, 2013. Progress in developing a geometallurgy flotation indicator, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 201-206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

In the sixteenth century the Spanish Captain da Alvaro Soavedaro, on a search for the explorer Ferdinand Magellan, came across the main island of New Guinea which he named Isla del Oro (Island of Gold). Since that time exploration for, and mining of, gold has been pursued by many, culminating in . the development of major world-class projects in the latter part of the 20th century. Though various prospectors have panned for gold and small gold mining projects were undertaken through the seventeenth and eighteenth centuries, it was not until the 1880's when mining became a more concerted economic venture. Misima and Woodlark Islands in Milne Bay, Gura-Ackera and Yoada in Oro, and Lakekamu in Gulf Province and Keveri in Central Province were all gold producers by late nineteenth century. It was in the 1920's that corporations began mining in PNG and with the commencement of production at Panguna in Bougainville in 1972 a new era of mega-project mining began.' Today there are two large mining projects producing mainly gold and copper. The first, already mentioned, is Panguna on Bougainville Island. This project has provided Government with $US 475 million in taxes. ok Tedi is the second large mine development located in Western Province. It began production in 1984 with the extraction of the deposit's "gold Cap".

Jan 1, 1987

By Saghafi A, Kelly M, Williams R. J

A two year program of research into the feasibility of long-hole drilling for improved gas emission control has been undertaken at Appin Colliery. State of the art equipment was employed involving cableless electronic surveying and down-hole motor drilling. The project involved the drilling of 1000 m long, in-seam boreholes in the Bulli seam and boreholes of similar length drilled cross measure and then in-seam along the underlying Balgownie seam. A new concept for gas drainage was defined, employing long-holes for both predrainage and post drainage.

Jan 1, 1988

Detailed cash flow forecasts have always been almost essential as a basis for judging the viability of proposed new mining projects. In recent years attempts have been made explicitly to take account, in such forecasts, of the uncertainties surrounding the assumptions upon which they are based. With the risk analysis approach, Monte Carlo simulation of the cash flows indicates in probability terms the combined effect of these uncertain basic assumptions. While the use of risk analysis has been widely discussed, few specific applications to real projects have been reported. The application of such an analysis in the feasibility study of the large new Deelkraal gold mine presently being established on the Far West Witwatersrand gold fields by the Gold Fields Group in South Africa is described in the paper. The paper also indicates how one of the major sources of uncertainty, namely the gold content of the ore, can be`quantified in objective probability terms. This feature distinguishes the application fran other published accounts in which only subjective probability assessments have been utilised.

Jan 1, 1977

By Martins V, Dunne R

A re-evaluation of the Hampton Boulder prospect in the early eighties resulted in a decision to proceed with mine development in December 1985. A 500 000 tpa gold treatment plant was commissioned in December 1986. The treatment facility was expanded to 1 600 000 tpa in July 1988. A tailings treatment plant to improve recoveries from harder gold bearing sulphide ores was built in December 1990. The development of an underground mine in 1991 meant that a source of sand for backfill was required. A sands plant to fulfil this requirement was commissioned during November 1991.As of June 1992 a total of 7 710 487 tonnes of ore have been treated through the New Celebration gold plant. Total gold production from inception of the new mine until June 1992 is 545 470 ounces obtained at an average recovery of 90.1 per cent from an average gold head grade of 2.4 g/t. The combined quoted ore reserves at the end of December 1991 was 14Mt grading 1.8 g/t gold

Jan 1, 1992

By R Farana

The future challenges in mining instrumentation, mainly on future intelligent mines, are to continue providing instruments with the highest level of reliability at the lowest possible cost, and also to take advantage of technology existing in other industries and to adapt it to the mining context. New wireless instruments (smart sensors, smart actuators, smart controllers) would also be very useful, as well as instruments fully adapted to the monitoring of large movements that are observed, in both underground and open pit mines. Mining instrumentation is found to various degrees in most mines, both open pit and underground. Smart mining instruments present a certain number of aspects specific to the environment in which the instruments are installed. Namely, the instruments can be installed either for short-term or long-term purposes. The mining industry is always looking for useful instruments that can provide relevant information on ground behaviour adjacent to mining stopes or permanent infrastructure. The instruments must meet the various criteria, and must also evolve with the new mining technologies that are continuously being implemented. A strong collaboration between the mining industry, research organisations, and instrument manufacturers is the key to meeting these objectives. This contribution describes the current trends on smart sensors and smart instrumentation with Wireless LAN support.

Jan 1, 2003

By Rashkovski GB

Until recently amalgamation has been the main process forextracting large gold particles from gravity concentrates obtainedduring the dressing of ores and placer gold deposits.Development of new technology for treating the gravityconcentrates was necessary because of the harmful effect ofmercury on subsequent production processes and theenvironment. The harmful effect of mercury is particularlyevident in the resin-in-pulp process that is widely applied inRussia.

Jan 1, 1993

The equipment and general smelter layout for the Mount Isa Copper Smelter were designed by engineers associated with the American Smelting and Refining Company and by Mount Isa staff engineers. The final notice of site was dictated by the need for 'building the smelter near the existing Mount Isa power house to enable full use to be made of the steam from the waste heat boilers. Although much excavation work was necessary before concrete foundations could be poured, the location lends itself to further expansion should it become necessary. The plant is designed and constructed to involve straight line smelting operations which include the following major steps in the overall scheme.1. Charge make-up.2. Roasthig.3. Reverberatory smelting.4. Converting.5. Refining.6. Casting.CHARGE MAKE-UPA system of proportioning bins is provided for preparing the feed mixture for the roasters, Sulphide concentrate containing 24% copper wiil be delivered by belt conveyor from the filter plant to the smelter storage patio. This is a large roofed concrete floor that provides a maximum storage capacity of 8,000 tons of concentrate. Eight proportioning bins located below but adjacent to the south end of the patio will be used for actual charge make-up from which concentrate, ore and flux will be proportioned to the feed belt and conveyed to the roaster feed hoppers. Four of the proportioning bins, 80 tons capacity each, will receive...

Jan 1, 1953

By F Anthes, U Barow

Two tunnels are being bored using a æHydroshieldÆ in section 3.1 of the extension of the Underground railway line 5. At the end of the two tunnels, directly in front of the Hotel Adlon, the shields cannot be retrieved. The steel shell of the shield will be left in place within a sealed concrete block and the reusable components taken out through the completed tunnel. For the first time in Germany, an Underground tunnel is being lined solely by means of UNI rings. BerlinÆs Underground network is 165 km long and has 167 stations. Some 450 million passengers are transported annually. On account of the urban planning modifications that followed reunification, the network has to be adjusted, particularly in the city centre. The most significant project is the extension of the U5 from Alexanderplatz to the Lehrter Bahnhof. After completion, the U5 will be a continuous east-west traffic artery. It will provide a direct link with the new parliamentary and government district, open up new business districts and the cultural centre of the city.

Jan 1, 1999

In Australia, current production of rare earth element (REE) minerals, monazite and xenotime, occurs as by-product from titanium-enriched placers and beach sands. Undeveloped REE resources are associated with carbonatites, alkaline igneous rocks, pegmatites, phosphorites, cemented fluvial sandstones, and uranium mineralisations. The REE are held within a range of minerals including silicates, phosphates, a1uminophosphates, carbonates, and oxides. The development of these REE resources may require new processing and extraction methods. The distribution of REE in the currently mined ore minerals, monazite and bastnaesite, does not match that requested by the market. Exploration for new REE resources should be focused on ores with more marketable REE distributions, particularly with heavy REE, neodymium, samarium, europium and yttrium enrichments. Such ores occur within alkaline igneous rocks, in laterites overlying carbonatites and alkaline igneous rocks, and in placers derived from low-grade regional and contact metamorphic sediments. Lateritic REE deposits may be easily and economically mined by shovel in open pits and are unlikely to require extensive crushing and milling. In addition, lateritic REE clay deposits may be processed by simple hydrometallurgicaltreatment mehtods.

Jan 1, 1991

Before proceeding I wish to say that the excellent diagrams by which my paper is illustrated are the work of Mr. C. H. Barnes, Constructing Engineer of the Kalgurli Gold Mines Limited, and I am also much indebted to Mr. F. A. Moss, manager of the mine and for the privilege piIling information not previously made public.The limited time at my disposal has coolled to, curtail the scope of my paper to a few practices in ore treatment which are being worked on the Kalgurli Mine, but which I believe are of more than ordinary interest to thp~e Goncerned in modern treatment of gold ores. As an introduction to my subject it is, necessary that I should give a brief outline of the process by whiGh the gold is won from the complex sulpho-telluride ore of the Kalguili mine.My business is not to enter into any discussion as to the relative merits of the two rival sulpho-telluride ore treatment processes at work on the Kalgoorlie field, viz, the treatment of the unroasted ore after shining by solutions of bromocyanide, as against the treatment of the ore-after roasting by solutions of potassium or sodium cyanide either in filter presses or percolating sand vats. Even if reliable costs and percentages of extractions were obtainable in each case, it would not constitute an infallible basis of comparison, as the larger plants would necessarily have an advantage in cost per ton as against the small plants, and the other conditions obtaining are in many Cases dissimilar.

Jan 1, 1903

By M Dixon, T OÆShannessy

Melbourne Water (MW) is responsible for a section of existing gravity trunk sewer servicing the Melbourne central business district, Docklands, Port Melbourne and other adjacent areas, known as the Melbourne Main Sewer (MMS). MW has determined that the 2.2 km long 110 year old sewer will not adequately service these areas into the future or provide the level of reliability needed. The Melbourne Main Sewer Replacement project (MMSR) involves the replacement of the MMS with a new gravity sewer main and six key manhole shafts, known as the Melbourne Main Reliever (MMR).The majority of the MMR sewer tunnel is situated south of the Yarra River and will be constructed using an earth pressure balance (EPB) tunnel boring machine (TBM) and will be lined with precast concrete segments. The tunnel will be 2.4 m internal diameter and will have a 1.8 m diameter glass fibre reinforced plastic (GRP) sewer pipe positioned within it. This project represents the first large-scale, modern, mechanised tunnel project in MelbourneÆs Yarra Delta Quaternary sediments. There is little precedence known to the authors of similar scale tunnelling projects in these particular geological units. During the recent detailed investigation and design stages of the project, significant effort has been spent on characterising the geotechnical conditions along the alignment and predicting the effects of the new tunnel on the existing environment. Some of the key design issues that have been identified and managed through the design process include short-term surface settlement due to tunnel excavation and the predicted effects on surface infrastructure, potential spalling of the steel fibre reinforced concrete segments under full TBM ram loads and tunnel lining design in geological units with highly variable stiffness.Construction of the new MMR sewer tunnel is expected to commence in mid-2008 with a capital cost of approximately $160 million. Sewer system commissioning is scheduled for completion by early 2012.

Jan 1, 2008

By Y Zha, J L. Walshe, A Ord, N J. Archibald

The purpose of this paper is to discuss the concept of Geodynamic Modelling as an exploration tool and to provide a specific example, namely, the Century Zinc deposit in Northern Queensland. Geodynamic Modelling is an attempt to become more quantitative in the way we develop exploration models. It is a systems approach to ore genesis which examines the complete four-dimensional mineralising system of interest, rather than individual site specific ore deposits. The goal is to establish a predictive capability that enables the explorer to predict grade, tonnage, mineralogy, alteration patterns and precise location of a potential orebody given a particular exploration model. The process consists of two well-defined stages: firstly, a æsoftÆ modelling stage where all available data on lithospheric architecture, geodynamic history, fluid chemistries, fluid flow mechanisms and mechanisms of metal transport and deposition are collected; and secondly, a æhardÆ modelling stage where the system is modelled using fully coupled deformationûfluid flow-thermal transport-chemical reaction computer codes. In the case of the Century Zinc Deposit we point to its existence on the boundary between two fundamental blocks of Proterozoic mantle lithosphere. This boundary has controlled Pb/Zn mineralisation in Northern Australia from the Proterozoic through into the Paleozoic. Detailed thermal, chemical, fluid flow, deformation modelling of the Century System points to an origin involving mixing of crustal oxidised fluids bearing zinc, with reduced fluids bearing H2S and CO2 from the lower crust or mantle. We use this modelling to define critical exploration criteria for another Century type of deposit.

Jan 1, 2000

The Golden Cross is the first large precious metals mine to be both commissioned and closed in the æmodernÆ era in New Zealand. This paper discusses the life cycle of the Golden Cross mine, with emphasis on the closure process and post closure management.   The closure process has generally been very well managed, and successful, but in spite of that some on-going issues remain unresolved. Nearly nine years after the end of mining the mine owners are still actively managing the site, with no immediate end to that in sight.   The site has been described as atypical, due to the identification of a deep seated landslide below the tailings and waste rock storage facilities. However that should not be given too much emphasis when addressing the overall closure and post-closure management issues, which could well apply to other existing and future mine sites in New Zealand.   The Golden Cross can provide valuable lessons for other miners, and the issues arising at this site should be watched closely by the industry as a whole.

Jan 1, 2006

By Z W. Orndorff

Excavation through sulfidic geologic materials during construction activities has resulted in acid rock drainage (ARD) related problems at numerous (>40) locations across all five geologic regions of Virginia, USA. Potential acidities ranging from >100 to develop a statewide sulfidic materials risk map; document ARD impacts to soil and water quality and engineered structures; and develop methods to assess site-specific risk potentials within a given highway corridor. A statewide sulfidic materials GIS risk map was developed based upon the state digital geology map which assigned four levels of relative risk to all mapped strata based upon predicted lime requirements and probabilities of encountering highly reactive materials. Non-highway construction activities have also routinely disturbed sulfidic materials, and a recent airport project in northern Virginia resulted in over 150 ha of extremely acidic (pH 45 mg/L) run-off from this site heavily damaged a receiving stream, partially due to the fact that it dissolved the galvanised steel water control structures in stormwater detention basins, leading to direct discharge of run-off and sulfidic sediments. The airport area was treated and revegetated in 2002 with a combination of lime-stabilised biosolids, straw mulch, and acid-tolerant grasses. Water quality in a receiving second-order stream quickly responded to the treatment, but some release of N was also noted as a secondary effect. Collectively, these results point out the importance of accurately assessing the potential for excavation of sulfidic materials in construction environments, and the necessity of developing toxic materials handling strategies similar to those employed in mining environments.

Jan 1, 2003

By Moore A. J

Blasting in mines in an urban environment can be conducted safely and within regulatory vibration limits by careful attention to detail and the application of correct techniques. Factors affecting blast vibration are described using surface and underground mining examples. An understanding of these factors provides an essential base for effective planning and operational control. Techniques are described for assessing and predicting vibration levels and the presentation of data for planning purposes such as environmental impact statements for new projects and the protection of buffer zones around existing operations.

Jan 1, 1997

By K Koskinen, S Ronkainen

The flow field induced in an Outokumpu TankCell and by an OK rotor-stator mixing device in a laboratory and a process size flotation cell was modelled numerically using computational fluid dynamics (CFD). The primary target was to discover and reproduce the various interactions between the flow field and the flotation cell by numerical means. As power consumption depends sensitively on flow field, it can be regarded as a top-level derived quantity (or measure/metric) indicating the validity of the numerically obtained flow field. Having properly validated numerical means to produce the flow field the influence of various design parameters can be captured with certain accuracy. In addition, separate gas and solid phase models for bubbles and solids, respectively, were implemented. The comparisons between velocities and turbulence quantities measured using the laser doppler velocimetry (LDV) technique and CFD modelling were performed. The grid generation was performed with the commercial Gambit 1.3 and the subsequent integration and solving of the resulting algebraic equations with the commercial CFD-code Fluent 6.22. The computationally economic multiple reference frame method was included to model the moving rotor blades. Gas and solid phase models were modified mixture models.

Jan 1, 2005

By S Walters

The emerging discipline of ‘geometallurgy’ is not new but is becoming increasingly recognised as a discrete and high-value activity. Geometallurgy involves a quantified and spatially constrained approach to ore characterisation in terms of relationships to critical processing performance behaviours. A key outcome is enhanced economic optimisation of mining and improved risk management tools.Industry recognition of the need for large-scale, integrated research to support this emerging area resulted in commencement of a major ongoing initiative in mid-2005. The AMIRA International P843 ‘GeMIII’ project (Geometallurgical Mapping and Mine Modelling) is a cross-discipline collaboration involving a number of world-class research organisations supported by over 20 industry sponsors.The project is delivering integrated tools and methods which link intrinsic rock characteristics to prediction of mineral processing performance. These indices must be capable of spatial distribution in 3D resource models and incorporation into mine planning and optimisation. A key aspect is provision of new cost-effective tools and methods which can provide the large numbers of measured and estimated data points required to undertake effective modelling and spatial distribution. The integrated methodology and enabling technologies being developed through the ongoing AMIRA GeMIII project are outlined, together with implications for supporting industry best practice.

Sep 5, 2011