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The influence of pulp potential on the flotation behaviour of sulphide minerals in laboratory batch flotation tests is discussed in terms of self-induced flota- tion, collector-induced flotation, and depression.' Assuming that the pulp poten- tial is controlled by the same factors that determine the genuine redox poten- tial, an attempt is made to interpret the experimental results in terms of potential-dependent reactions based on bulk thermodynamic data. Self-induced flotation is displayed by many sulphides in moderately oxidizing solutions but not in reducing solutions. The available evidence suggests that the hydrophobic entity could be sulphur produced by superficial oxidation of the mineral but this has not been established beyond dispute. In general, flotation is observed near the potentials at which sul- phur would be expected to form and the minerals which produce sulphur seem to float the most strongly. Collector-induced flotation is most conveniently studied on minerals which have only slight self-induced floatab- ility. The mineral-collector interaction is potential-dependent hence flotation is generally only observed in limited ranges of potentials. While the general form of the floatability-potential relationship is similar to that predicted from thermody- namic data close correspondence between predicted and experimental results is not always observed.

Jan 1, 1984

By P F. Knights

Mining companies are striving to achieve new levels of operational maturity and drive process improvement across the organisation in the face of unprecedented demand and limited supply of experienced human resources. Advanced analytics techniques can help overcome these fundamental challenges by applying data techniques not previously applied in mining. Today, decisions are usually locally optimised but do not achieve optimum capability for the value chain. Although more information is collected then ever before, it is difficult to link many sources of data together in the same place in real-time, for example plant history, maintenance, mine planning, logistics and engineering data. Consequently complex analysis of data is time consuming and requires specialist skills and knowledge, and is often neglected in the decision-making process. In the future, analytics will close the loop between analysing data and taking action. Analytics will become embedded in the business and routinely applied to improve decision making across the organisation, from senior management to operations and maintenance workers, but will not require specialist skills or be time consuming to analyse data. As analytics becomes embedded in the business process, decisions are supported by data (not on gut feel), and critically, data from many sources are integrated in real-time to improve the quality of decisions. Ultimately, predictive tools will help suggest, or even in some cases automate, courses of action. The main opportunities for analytics exist where the enterprise requires supporting technology to enable it to continue to evolve to higher level of maturity. This will be in the areas of asset management, rapid reconciliation and adaptive planning, and the inbound and outbound supply chains. Advanced analytics are also a key enabler for increasing the effectiveness and realising the true value of Remote Operations Centres to safely and efficiently support operations in remote locations with smaller workforces.

Jan 1, 2008

By D Whitworth

The Golden Pig mine has embarked on a diamond drill program design philosophy that increases flexibility of the program by greatly increased drill pattern densities. The use of standard broad pattern diamond drilling at the Golden Pig mine has previously lead to operational inefficiencies and impacted significantly on the costs of the mine. The diamond drill program philosophy and its interaction with mine planning is explained. The case study of the E lode mining as used to internally justify the increased drill densities is detailed.

Jan 1, 2002

The area (330 sq. miles) shown on the map of the Brocks Creek District (Fig. 1), was mapped by the Northern Territory geological party of the Aerial, Geological and Geophysical Survey of Northern Australia. This work was done in two stages:-(i) In 1935, an area of 30 sq. miles around the Golden Dyke mine was mapped by P. S. Hossfeld, Senior Geologist, and A. H. Voisey, Assistant Geologist. The results were described in a detailed report (10).(ii) In 1939, an area of 300 sq. miles in the Brocks Creek district was mapped by C. J. Sullivan (Senior Assistant Geologist), and V. M. Cottle and S. N. Kiek (Assistant Geologists) under the general supervision of P. S. Hossfeld (Senior Geologist).An outline structural map, together with some geological notes was published (1), but that map does not show the amphibolites, and the relationship between ore occurrence and general geology is not emphasised. The publication of the detailed maps and reportwas postponed indefinitely as a result of war. The original mapping was based on air photographs with a scale of approximately 1 in. to 1,200 ft., and all detail which could be shown at that scale was mapped. Features recorded included rock types, details of structure, mineralisation, and surface workings, creeks and soil boundaries. Underground mapping was also carried out. The present map is much simplified from the original, but it is hoped that it shows sufficient information to reveal close relationship between structure, granite, sills of amphibolite and gold occurrence. About 50 per cent. of the area is covered by deep soil or alluvium, and in these portions the geology of the underlying rocks was not determined with accuracy, though in many places strike trends could be deduced from air photographs.Because the A.G. & G.S.N.A. had published the geological notes and map referred to above, and because the publication of the detailed report and maps is still postponed indefinitely, approval has been given by the Bureau of Mineral Resources, Geology and Geophysics (which took over the affairs of the A.G. & G.S.N.A. at the termination of its operations) to the preparation of the present paper so that information would be available to the public.The views expressed in this report are those of author. The results of the investigation suggest that in areas where granites are predominantly concordant with bedding, ore deposits may be found at approximately the same stratigraphic horizon. It is thus important to correlate beds even though their relationship may have been obscured by faulting and folding.

Jan 1, 1950

By Walker E. R

IN the early age of steel it was made hy what is known as the cementation proeess, in which wrought iron was embedded in charcoal and heated in a mufflc furnace to a tcmperature of approximately 1100° C. for varying lengths of time, the length of time depending upon the amount of carbon (or better known in thosedays as the degree of hardness) required in the finished product.By this process the resultant product obtained was not of uniform quality, and because of this uncertainty of quality Huntsman was induced, in the year 1740, to introduee what is known as the crucible process.This process consisted of cutting into small pieces the product of the cementation process, placing these pieces in a crucible, and melting them down with the aid of a eoke-fired furnace, after which the molten metal was cast into suitahly shaped ingots, from which could be hammered any desired shape.A section of crucible furnace is shown in Fig. 1. By this means a product, very uniform in character, was produced.The process is still in use, but, owing to its high operating cost, it is mostly eonfined to the production of very high-grade carhon and alloy steels. Its position to-day as a producer of these high-grade steels is, however, being very seriously challenged by the electric process.It was owing to the excessive cost of crucible steels and the need of producing a steel in commercial quantities and at a reasonable cost, that led Sir Henry Bessemer to introduce what is known as the Bessemer process.

Jan 1, 1930

By D Porta, E Grigolato, K Behrens

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Aug 12, 2013

Secondary steelmaking (or ladle metallurgy) has been developed as a post- steelmaking ladle treatment to produce steel of superior quality. Its rapid growth has resulted from quality improvements, productivity increase, operational flexibility and process route economics. Advances in secondary steelmaking are very impressive during the past decade, and many commercial systems have been developed for performing one or more of the following unit operations: degassing, atmosphere regulation, reheating, refining with synthetic slag, rinsing gas treatment, injection of solid materials and alloying. The metallurgical requirements imposed by the current competitive steel market include more precise analysis tolerances, minimum level of detrimental elements, improved cleanness, demanding service performance and better processability. In most cases, these requirements could only be realized by the application of appropriate secondary refining facilities. Continuing developments in simplicity of design, cost advantage, quick cycle time, improvements in peripheral services such as refractories, instrumentation and in-situ analysis, extensive exploration of new applications, and the use of computer, can be expected. An exciting future is predicted for the widespread adoption of secondary steelmaking to perform most of the major refining functions over a variety of steel quality. It will also become a vital link in the total steelmaking process for production of tonnage steel at the large integrated steelworks and the mini-steelmills.

Jan 1, 1986

This paper describes some of the challenges and opportunities of contract mining overseas, based on the experiences of Byrnecut Mining Pty Ltd over recent years. It seeks to highlight the advantages Australian miners have compared to competitors around the world, and the opportunities that arise from that. A number of pitfalls and how to avoid them are also discussed.

Jan 1, 2002

Refractory gold concentrates and their roasted products have been examined by mineralogical and chemical methods, and the distribution of gold in the tailings after leaching has been Investigated.

Jan 1, 1989

By C A. Locke, M Stevens, P Vidanovich, J Cassidy, J L. Mauk

The Karangahake adularia-sericite epithermal gold-silver deposit, located at the southern end of the Waitekauri Corridor, Hauraki Goldfield, occurs as quartz veins with associated alteration haloes. Integrated geophysical studies were undertaken to determine the expression, location, and extent of these alteration zones. Aeromagnetic data show an extensive, magnetic æquietÆ zone over Karangahake and the southern Rahu Ridge that represents a zone of magnetite destruction resulting from hydrothermal alteration. Analytic signal data are used to define the boundary of this zone; the resulting 6 km2 area is elongate north-south with an irregular boundary. A detailed gravity survey over the area reveals a positive residual gravity anomaly, up to 30 gu in amplitude, over the Karangahake deposit. Density measurements on near-surface rocks give low values indicating that the source of this positive gravity anomaly must be deep; possible causative bodies include an igneous intrusion or dense sulfide mineralisation. To the west and east of the host Waipupu Formation, strong gravity gradients of 100 gu/km and 65 gu/km reflect the faulted boundary of the Hauraki Rift, and the edge of the Waihi Basin respectively. High resolution airborne radiometric data define a 2.2 km2 area of potassium enrichment. This area is elongate north-south and has an irregular boundary. It coincides approximately with the centre of the magnetic quiet zone and the peak of the gravity high, and correlates with known areas of intense mineralisation. Anomalously high potassium counts and elevated K/Th ratios correlate with areas of potassic alteration that have undergone K-metasomatism. Underexplored portions of this zone may indicate areas of gold-silver prospectivity. Combined geophysical data therefore reveal the extent of hydrothermal alteration, and the central zone of Kmetasomatism that is most likely to contain orebodies.

Jan 1, 2005

Addressing community concerns in relation to an economic activity, particularly when it causes significant community impacts, is especially important for the development of extractive industry projects. Pipelines comprise an integral part of many hydrocarbon developments, which may cause different effects on local economic development, communities and the environment compared with open cast mines. This paper explores community impacts associated with a case study of the oil pipeline æEastern Siberia-Pacific OceanÆ in the Republic of Sakha (Yakutia), Russia. Based on semi-structured interviews, conducted in 2006 - 2008 in Russia, the paper investigates claims of local communities about potential impacts of the pipeline development of their environments and economic activities as well as community claims for greater involvement in sharing the benefits from this major infrastructure project. A community of Indigenous people, Evenk, is likely to be most profoundly affected by the development due to impacts on their traditional activities such as hunting and reindeer herding. The paper examines in detail the regional economic, social, environmental and Indigenous peoples concerns over the construction of the oil pipeline and investigates actions and methods adopted by community organisations to voice their concerns about the pipeline development. Finally, the paper assesses the process of interaction between the pipeline developers and regional stakeholders.

Jan 1, 2009

By Orr C. W

In previous papers (1, 2), the influence on the creep resistance of elements normally found in commercial lead has been recorded. The results in the present paper refer to the influence of calcium, an element which is not found naturally in lead, but which has been used commercially in the form of alloys. It was realised that calcium would act as a deoxidising agent for lead-and in fact it was with this feature in view that both calcium and magnesium were used as additions. Subsequent work (including the results given in the present paper) has tended to diminish the importance which at first seemed to be associated with the presence of oxygen in lead. The structure of the dilute calcium lead alloys has been worked out in detail (S) and the phase diagram shows the existence of limited solid solubility and a compound CaPbs.

Jan 1, 1938

By T Jones, K Karunaratna

The Kalgoorlie Consolidated Gold Mines (KCGM) Fimiston Open Pit is located on the eastern boundary of the Kalgoorlie-Boulder City and is mining an area traditionally known as the Golden Mile. The pit area has been continuously worked since 1893, predominantly by underground mining methods and more recently through open cut mining. There are over 2000 km of old mine headings and numerous stopes under the open pit area. KCGM has interpreted and digitised the underground mine plans and stope sections into a common database. A 2D-model software package, called Pits, was developed in-house and allows old workings to be displayed at any bench level; this is integrated with 3D Vulcan modelling software, which allows triangulated surfaces to be displayed. Almost every mining activity is affected by underground workings. The effective management of the interaction between current mining and the underground workings is very important for safety and production. A specific ævoidÆ management department has been formed and its broad objective is to minimise the impact of underground workings upon production while maximising safety. Special criteria and procedures have been developed and implemented to keep personnel and machinery from being exposed to unsafe ground. It is of primary importance to accurately define the location and outline of underground workings in advance. Probe drilling has been used as the key tool for that purpose. Various geophysical methods have also been trialled on site to detect underground workings; these are discussed in some detail. This paper discusses ævoidÆ management issues such as data integration, void detection and flagging. The impact of underground workings on mine planing, production and slope stability is also discussed.

Jan 1, 2003

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

Particle Mechanics and the Design of Cyclone Tribochargers Triboelectric separation is a dry electrostatic technique that has shown promise in several particle processing applications. A tribocharger uses contact or friction to differentially charge particles of different materials, which are then separated by an electric field. The initial tribocharging process is poorly understood, with tribocharger design and operation largely a matter of trial and error. A better physical understanding of tribocharger operation would therefore be of immense value in the optimisation of triboelectric separation processes. A combination of charge measurements, trajectory modelling and high-speed video has been used to relate charging to particle mechanics in a cylindrical pneumatic cyclone, one of the most effective tribochargers for mineral separation applications, and the preliminary results are presented here. The consequences of these observations for cyclone tribocharger design and operation, and for tribocharger design in general, are discussed.  

Sep 13, 2010

By M Bloss, B Roberts

BHP Billiton Olympic Dam required a well-tested software product suitable for strategic optimisation and scheduling of options for a potential underground mining project. The company has a standard software package called Blasor® that is used for open pit optimisation of complex deposits such as iron ore, copper-gold-uranium and silver-lead-zinc. It applies a mixed integer programming formulation (MIP) to produce conceptual pushback designs and an optimised pushback sequence. Schedules can then be run on the resulting mine designs. Existing pushback designs can also be imported into the model and an optimum schedule generated. One of the key advantages of Blasor is that multiple strategic mine schedules can be quickly generated according to the various scenarios, options and constraints that are being investigated.It was realised that Blasor, if carefully configured, could be adapted for use in underground planning. The concept of using Blasor as an optimiser for underground strategic scenarios is to represent the underground stope and development data in the form and structure of an open pit mine. In simple terms, underground stoping areas are modelled in the form of pushbacks (phases) with vertical walls. The phase dependency tools in Blasor are used to link mine blocks and their access development drives. These underground phases are imported into the optimiser. Artificial block models are constructed using stope design tonnage and grade data at various fixed cut-offs. A variable cut-off grade model has also been developed using a method of parcels to represent each cut-off grade increment.So far, this approach has been successfully used to investigate the optimum stope design cut-off for various strategic options, the economic potential of a series of mining and processing configurations and to provide guidance on the optimum sequence for developing and mining the various stoping blocks in the resource. Examination of the results has highlighted the most suitable development paths for more detailed study.CITATION:Roberts, B and Bloss, M, 2014. Adaptation of an open pit optimiser for underground strategic planning, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 249–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By George CW

Western Mining Corporation (W.M.C.)operate a 30 000 tpa nickel refinery at Kwinana, W.A. using the Sherritt Gordon Process. Following ammonia/air leaching of sulphideminerals and subsequent copper removal, nickel metal is produced as powder by hydrogen red-uction of the ammonium sulphate-rich solution. Batchwise reduction in pressure autoclaves is preceded by an oxidation/hydrolysis step to ensure nickel powder quality.The reduction process is energy intensive, requiring high temperatures and pressures. Present energy requirement is 24 GJ per tonne of nickel reduced. Of this, 95% represents steam and hydrogen consumption and 5% electric power. The design and operation of the red-uction circuit is reviewed, outlining the main areas of steam and hydrogen usage.

Jan 1, 1985

By J Meinhart, J Rodler, I Katolicky

The ever increasing number of vehicles is leading to slow-moving and even stationary traffic sitting longer in traffic jams over extensive city areas. This traffic situation causes a sharp increase in pollutant emissions from vehicles, and high levels of pollution usually result throughout the built-up area. Reducing the pollution level by using traffic routing measures to speed up the flow of traffic in the existing street network is only possible in exceptional cases.In many cases the only option for achieving a significant improvement in traffic conditions is to shift the traffic underground using a road tunnel or underpass. Such tunnel routes suck off the traffic from large sections of the city, thereby easing the overall traffic flow. Thus on the one hand it produces a sharp reduction in pollution levels in the area of the tunnel route, but on the other hand it can result in locally increased exhaust pollution levels from longer tunnel systems that require mechanical ventilation. The air extracted by the ventilation system is blown out into the atmosphere either directly through the tunnel portal, or via a venting tower. Pollution can therefore occur in the area surrounding such exhaust air outlets.Thus if a tunnel is planned in a city, then closer investigation is required of both aspects: the reduction in pollution in the area of the tunnel route thanks to relocating the traffic and easing congestion, and the increased short-range pollution around the tunnel portals (shafts).

Jan 1, 1999

Circuit alterations and adoption of more compact items of equipment have made it possible to increase the capacity of the King Island Scheelite concentrator, both with regard to head grade and feed tonnage, while at the same time increasing total recovery and reducing maintenance costs. The present operation is described, with particular emphasis being placed on alterations made during the last two years to achieve capacity Goals.

Jan 1, 1977

To secure a sustainable competitive advantage some smelters may need strategies based on flexibility in feed and product ranges depending on immediate future projections of profitability. This paper explores the technical requirements for strategic diversity in smelting, leaving procurement, marketing and contractual considerations aside. The days when a smelting operation is tied specifically to say only processing zinc concentrates are perhaps drawing to a close. While internationally traded mineral concentrates are available, attractive business opportunities must exist for fully diversified custom smelters. Certain new and emerging technologies have inherent characteristics that are evaluated in this context. The paper identifies the basic building blocks that will permit such a scenario and assesses the technical feasibility. The ability to respond flexibly to environmental pressures is highlighted as being of paramount importance.

Jan 1, 1996