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By Boland J

Prediction of rock cuttability by various excavation machines such as tunnel boring machines, road headers, rippers, picks, roller disc cutters, excavators, etc is of major concern to both civil and mining engineers and rock mechanics. In principle, the design of a rock cutting tool is based on achieving maximum excavation with minimum input energy, minimum applied force, minimum equipment weight and volume and, more importantly, minimum tool wear. When a rock material is indented by the force of a cutting tool and then unloaded several material zones form underneath and around the tool. As the tool moves into the rock the volume of its associated rock cavity (ie volume of displaced rock) expands and depending on the indenter's shape various phenomena may occur. Immediately beneath the tool a small zone in which the stress state is more or less hydrostatic, is formed which is underlain by an inelastic, or damaged, material zone. Both size and shape of this damaged zone control the magnitude of the indentation force and the chip formation mechanism during unloading. The rock is unable to store the whole strain energy induced by the tool and consequently the extra energy is expended either in forming new fracture surfaces and/or in plastic deformation in the damaged zone. Therefore, it is not surprising to see that both perfect-elastic and rigid-plastic constitutive models are not generally suitable for modelling indentation of rocks. In contrast elastoplastic constitutive models are more appropriate as they can include both elastic and plastic deformations (Kral et al, 1993). Elastic solutions for several half-space indentation problems can be found in most text books on elasticity and in particular in Timoshenko and Goodier (1951), Sneddon, (1951), Poulos and Davis (1974) and Johnson (1985a). If a failure criterion, eg the Mohr-Coulomb failure criterion, is applied to delimit elastic solutions for indentation problems, a lower bound limit of the applied indentation force (for a given indentation depth) can be estimated. It may be noted that elastic analyses, without any delimiting failure criteria, normally overestimate the indentation force. Plastic solutions for a few indentation problems may be found in Hill (1950), Johnson, (1985a) and Alehossein et al (1992). When analysing the behaviour of indented rocks the choice of an appropriate constitutive model describing effectively the behaviour of the rock at various stages and phases during indentation is a challenging issue. Several questions need to be answered before starting an effective analysis. The first question is of course: Which one of these is more appropriate for modelling zones underneath and around a cutter, elasticity or plasticity theory, continuum damage mechanics or fracture mechanics, and what is the bridging link between these various theories? Which mode is more dominant in fracturing rock, tensile or shear mode? What governs the mechanism of chip formation? What is the function, shape and the behaviour of the pulverised zone that forms just underneath a cutter? Is the hydrostatic stress state assumption reasonable for this zone? How does the rock change during the absorption and dissipation of the input energy and how does the indentation energy vary with rock type and depth of penetration? How can we model the damaged zone under the indenter? Furthermore does a plastic material form beneath the pulverised zone? When and how do radial and ring cracks form around and under an indenter?

Jan 1, 1995

By P Albert, S Crispin, J Hertrijana

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Martabe gold mine is Indonesia’s largest precious metals-only producer and is also one of few significant hard rock mine developments in the past 15 years. Martabe is located on the west coast of the island of Sumatra in the North Sumatra province. The mine commenced operation in mid-2012, producing over 280 koz of gold and 1.5 Moz of silver in its first full year of production.Martabe consists of a cluster of six currently identified high-sulfidation epithermal deposits. The deposits lie in a north–south corridor with an approximately 8 km strike length and 1.5 km width. The total Measured, Indicated and Inferred Mineral Resource Estimate of the deposits is currently 8.2 Moz of gold and over 75 Moz of silver.The exploration program at Martabe has added more than 2 Moz of gold and 15 Moz of silver to the Mineral Resource estimates (Measured, Indicated and Inferred categories) since G-Resources acquired the project in 2009. This has been achieved at an average cost of US$17 in exploration expenditure per ounce of resource added, which includes helicopter-supported drilling programs in rugged forest terrain.The factors that led to this exploration success at Martabe include: in the first instance and most importantly, recognition of the geological potential of the mineralised system continually updating and improving ‘orebody knowledge’ and applying new ideas to the exploration program ongoing engagement and consultation by world professionals with geological expertise in similar systems ongoing executive management support for the program the high quality of work completed by previous owners a strong focus on quality control, staff development and operational safety, with the JORC Code (in particular Table 1 of the Code) as the underlying basis for quality control continual and positive engagement with government, community and other external stakeholders.This paper will discuss in detail the first of these two factors. It is important for the modern exploration team to recognise that mineral potential on its own is not sufficient for exploration success, so this paper will touch on the other factors as secondary but crucial considerations.CITATION:Crispin, S, Hertrijana, J and Albert, P, 2015. Exploration success at the Martabe gold mine, Indonesia, in Proceedings PACRIM 2015 Congress, pp 567–572 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Evidence abounds for sea-level change having occurred throughout geological and recent time. Driven by climatic changes, by cycles of glaciation and deglaciations, and by tectonics the position of sea-level relative to the crust has been going up and down since oceans first formed. Rates of these differential movements have been as high as 10 mm/year during the last major deglaciation as sea-level rose by about 150 m in about 15000 years. Tectonic processes can also produce change in sea-level relative to the crust of several mm/year as in, for example, the uplift of the Huon Peninsula in Papua New Guinea. To understand what is happening to sea-level today and what may be happening in the future it is necessary to understand the geological and climatic processes that have caused sea-level to change in the past and the best laboratory for the study of these processes is the geological and geomorphological record. Evidence for observations of sea-level change throughout Late Pleistocene and Holocene time is plentiful in the Australian region. Temporal variability is characterized by a low-stand, at more than 100 m below the present level, at about 20 000-18 000 years ago followed by a rapid rise and transgression of the continental margin up to about 6000 years ago. After this time sea-levels remained within a few metres of their present value but the patterns of change are not everywhere the same. The depth of the low stand at about 18 000 years ago does not appear to have been the same everywhere. Nor does the time at which sea-level first reached its present value appear to have been everywhere the same. The fluctuations about present sea-level during the past 6000 years appear to have been different in different localities. As yet there has not been a wholly satisfactory quantitative explanation for this spatial variability. How much, if any, is indicative of vertical tectonics? How much is the result of the Earth's response to the changing surface loads as mass is exchanged between ice sheets and the oceans? Can any of it be attributed to past changes in global climate? Or are the observations just wrong?

Jan 1, 1990

By Denby B, Miles N. J

The underlying theory behind the construction of an on-line size analysis system is described together with an introduction to the Artificial Intelligent techniques that it is founded on. Previous systems based on more traditional technology such as edge detection and dilation algorithms have been restricted by the significant processing power they require, this has resulted in the production of systems with either reduced functionality or severe hardware requirements. A neural network approach offered a new perspective to the problem of size analysis; the ability of a network to learn and recognise subtle patterns in training data before on-line processing is initiated opened up the possibility for the production of a fully functioning practical system. The format of the training data had to be carefully analysed prior to its implementation in a neural network as the capability of a neural network solution depends as much upon a suitable data preparation as it does on the system architecture. To facilitate experimentation with various profile quantification techniques such as fourier and fractal analysis an Image Profile Analysis System was constructed (IPAS) in software on a personal computer. The IPAS system was produced with the aim of pre-processing image data to create data sets for experimenting with external neural network packages. The system allows the analysis of both real images obtained by image capture and simulated images created by an in-built in simulator. A measurement comparison scheme is also included together with a case study concerned with the frequency analysis of simulated images. The power of neural networks combined with the data compression provided by profiling removes the need for direct measurement of individual particles. This has obvious implications on the level of hardware necessary, and ultimately the expense of a stand alone system. The extrusive nature of data collection via an image analysis system will also permit simple installation of a shipped system; eliminating any requirement for interference with existing machinery.

Jan 1, 1995

By M Simpson, K Brodie, J L. Mauk

Subaqueous water-rock reactions that occur at the pit wall/lake water interface can affect the pH of pit lakes. Many pit lake water chemistry models neglect subaqueous reactions, which may create inaccurate predictions over time. A mineral quantification method is presented that defines the wall rock mineralogy of active open pit mines, using samples collected from the Martha Mine, a low-sulfidation epithermal Au-Ag deposit in Waihi, New Zealand. The mineral quantification method has five components: field observations and sampling, X-ray diffraction analyses, selection of representative samples, geochemical analyses, and mineral accounting. Predicted mineral concentrations closely match observed mineral concentrations visually estimated using petrographic techniques. Results of the method can be incorporated into a geochemical model of long-range pit lake water quality resulting from subaqueous water-rock reactions.

Jan 1, 2003

By Getliffe RK

It is becoming more and more difficult to operate mineral and metal processes profitably, as operating costs rise, quality demands in-crease, international competition becomes more fierce and Government charges remain at their current levels. Profitability today depends upon efficient operations, which can only be achieved through precise and dependable con-trol of each process unit comprising thetotal plant.Modern process control systems utilise distributed architecture with microprocessor-based controllers, data acquisition devices and VDU operator stations. Honeywell intro-duced this control technology in 1975 with the "Total Distributed Control" System. Now, building on the proven performance and re-liability inherent in TDC hiway modules, Honeywell has extended the TDC system to inte-grate both management information and control by providing distributed processing modules on the new TDC 3000 Local Control Network (LCN).

Jan 1, 1985

By Williams RC

Overlying the coal deposits of the Sydney Basin are several lakes and other bodies of water. These include the Pacific Ocean, Lake Macquarie, the Tuggerah Lakes and the stored waters of the dams of the New South Wales Metropolitan Water Sewerage and Drainage Board. The coal beneath these bodies of water amounts to hundreds of millions of tons. Colliery workings have approached these areas of water and in some instances first 1"orkings of bord and pillar have taken place oi_eshh the water. he problem which now faces mine manage- and other interested authorities involves the determination of the maximum ;mount of coal which can be safely extracted from beneath the water. There are many factors to be considered including the depth of cover, seam thickness, geological details and strata movements.

Jan 1, 1972

The Escondida Porphyry Copper Deposit, located in Chile's II Region 160 Km to the southeast of the city of Antofagasta, is currently owned by Minera Escondida Limitada, a company comprising The Broken Hill Proprietary (57.5%), Rio Tinto Zinc (30%) a group of Japanese companies represented by Mitsubishi Corporation (10%), and the International Financing Corporation of the World Bank (2.5%) (Fig.l)By 1983, most of the reconnaissance drilling was completed and prefeasibility studies were regularly updated as new drilling results were reported and project concepts re-evaluated (Fig.2). In October 1982 the project was transferred from Exploration Management to Operations. By the end of 1984 project pre-development activities, including inpit development drilling, geological exploration, water resource definition, an underground bulk sampling program and the initial project feasibility report, were completed.

Jan 1, 1990

The original leases making up today's North Kalgurli Mines were developed by independent companies on an ad hoc basis. The major disadvantage which now arises is the varying levels of mining horizons. From Kalgurli Shaft in the south, through main Shaft and to Croesus Shaft in the north, there are three separate sets of levels. work has commenced to link the three areas with either common levels or new development which will facilitate common access and haulage via Main Shaft.Generally, the workings at North Kalgurli were established at the turn of the century. The introduction of techniques and equipment to bring the mine into the 20th Century has been difficult and slow. The general size of openings, a widespread workforce and complex ore distribution often make innovation and change more than a challenge.

Jan 1, 1985

By Walker G. S

Infrared and Raman spectroscopy have been used to study a range of solid state and aqueous solution species which are of interest in extractive metallurgy. In the solid state new Cu(II)/CN'/NH3 complexes have been detected, iron impurities in kaolin characterised, aluminium substitution in hematite and goethite quantified, and the crystallinity and orientation of zircon determined in heterogeneous crystals. In aqueous solution metal cyanide complexes and equilibria were readily characterised, the thermal decomposition of SO2 monitored and products identified, and complexation of AI(III) by hydroxycarboxylates observed. Attempts to monitor the early stages of the gelling of silicate solutions were less successful, with only changes in the gel being detected. However, the degradation of 12-tungstosilicic acid was readily monitored as a function of both time and pH.

Jan 1, 1996

This report chronicles the historical development of longwall mining in the United States and speculates on future developments to the turn of the century. Five eras of technological development during the modern period are described and analyzed. These eras discuss the development of (1) mechanized extraction, (2) self advancing roof supports, (3) high capacity roof supports, (4) shield supports, and (5) system automation. Current trends are analyzed in terms of: longwall utilization, production capability, support capacity, face widths, and new technological developments. From these analyses, the future of longwall mining to the year 2000 is speculated. It is concluded that longwall mining will continue to grow in importance during the next decade and that the next major technological milestone will be the realization of a fully automated longwall mining system.

Jan 1, 1992

By F Melcher, M Wiedicke, A Wittenberg

Ferromanganese nodules form a specific category of widespread marine mineral deposits. The tremendous increase in metal prices during the last decade raised new economic interest in their exploration. The German Federal Institute for Geosciences and Natural Resources (BGR), which had been engaged in nodule research in the 1970s and 1980s, renewed its activities on this subject based on an exploration contract with the International Seabed Authority, signed in 2006. BGRÆs licence area û comprising 75 000 km2 û is located between the Clarion and the Clipperton Fracture Zones. In this so-called nodule belt north of the equator the sea floor reaches water depths of >4000 m. About 900 million tonnes of manganese nodules are expected there. In this study the fine-scale distribution of important elements in manganese nodules and crusts from a variety of locations was investigated. Besides 11 samples from the RV SONNE cruise SO-25, numerous samples from additional locations were included in this study for comparison. In general, the sample suite includes two genetic types of precipitates, manganese nodules and Co-rich crusts. A detailed characterisation of the distribution of major, minor and important trace elements in manganese nodules based on in situ microenergy dispersive X-ray fluorescence (¦-EDXRF) analysis is presented here. The data are compared with bulk major, minor and trace element data as well as with quantitative electron probe microanalysis (EMPA) data sets. The element distribution maps and profiles produced by ¦-EDXRF analysis with short or extended (in case of profiles) counting times, allow precise selection of æregions of interestÆ for further detailed investigation using high spatial resolution techniques (eg scanning electron microscope (SEM)-EDAX; laser ablation-inductively coupled plasma mass spectroscopy (LA-ICPMS); isotopic studies).

Jan 1, 2008

By D E. Ralph, D-J Kim, G-J Ahn, Y-H Rhee

The amount of discarded dry batteries are presently found to be increasing globally and waste cathode active materials of the lithium ion battery industry are among them. Hydrometallurgical operations are being applied to recover the valuable metals from these waste batteries. To find an economic and environmentally friendly process, the bioleaching process was applied in the present investigation for recovery of valuable metals. Its principle is the microbial production of sulfuric acid and simultaneous leaching of metals. Bioleaching of spent lithium ion secondary batteries, containing LiCoO2, has been studied in this investigation. A new method for recovery of cobalt, potentially the basis of an economic and environmentally friendly process was examined. The present study has been carried out using chemolithotrophic and acidophilic bacteria Acidithiobacillus ferrooxidans, which utilises elemental sulfur and ferrous ion as the energy source to dissolve metals from spent batteries. Bio-dissolution of cobalt was found to be faster than lithium. The effect of initial Fe(II) concentration, initial pH and solid/liquid (w/v) ratio were studied in detail. Higher Fe(II) concentration showed a decrease in dissolution due to co-precipitation of Fe(III) with the metals in the residues. Similarly, at higher initial pH values and higher solid/liquid ratio (w/v) metal dissolution was found to be inhibited. The optimised conditions for bio-dissolution were solid/liquid (w/v) ratio û 10 g/L, initial Fe(II) concentration û 3 g/L, elemental sulfur û one per cent (w/v) and initial pH û 2.5. In the optimised conditions, cobalt dissolution was observed to be about 60 per cent, whereas that of lithium was ten per cent after 20 days. A first order kinetic model was derived to study the rate of dissolution of both the metals.

Jan 1, 2006

Industrial relations on Australian and New Zealand resource projects can be volatile. Therefore investors have become increasingly aware over the years that sound industrial relations during construction is vital to the overall success of their project. There has been a wide range of actual industrial relations performance, project by project, and the degree. of success often directly correlates with the degree and thoroughness of pre-project planning. However, although many projects have been crippled by delays and cost overruns because of labour disputes, good results are achievable. Total commitment to the project by all parties involved is essential and it is up to the employers to seek out this commitment and not just trust mother luck. Industrial relations must be taken very seriously as the price of failure can render a resource project unviable.

Jan 1, 1983

This paper deals with a few aspects of town planning and town management which affect human relationships within that town. Its scope is limited to the consideration of towns forming an adjunct to a mining operation, and particularly considers these aspects at the Hamersley Iron Pty. Limited, town of Parabur doo, Western Australia. Planning and standards of a new town and amenities are-discussed and related through living comfort to an effect on human relation- ships. Town administration and the promotion of many forms of social activities are dealt with in detail to illustrate the importance of quickly forming a cohesive community from a large number of newly arriving individuals. The results achieved by the planning and administration at Paraburdoo are highlighted by involving many residents by way of answers to a questionnaire.

Jan 1, 1973

Although technology and circumstances are in a constant state of change, the principles of managing the human element remain constant. The isolated mining community continues to form the backbone of the minerals industry but the nature of the isolation, along with the economic and political environment of the industry, is changing. These changes require new inputs by management to the workforce. Management must determine an effective working relationship with unions on its mine site and concurrently contribute to the build- up of the expertise of the individual worker through training and communication. It must also retain a proper balance, by way of human contribution, in cost and information reporting and in other areas amenable to computerisation. These comprise the aids to management necessary to achieve the desired operating efficiency and profitability.

Jan 1, 1980

The exploration methods used by the British Coal Corporation in 1990 improve the geological reliability of underground coal production. Although some of the techniques in common use have been proved to be effective, their limitations are recognised and concentration has been on the increasing integration of direct and remote sensing techniques. Attention is focussed onto first seam workings in sections of at least 2 metres in the depth range of 400-1200 metres and covers both surface and underground exploration. The case studies of exploration techniques and their effect on mine design at several existing collieries are representative of a wide range of geological environments within the more productive British coalfields. Notwithstanding such improvements in exploration and geological reliability, further new exploration technology is currently being investigated or trialled by British Coal.

Jan 1, 1991

The difficulty of successfully imple menting a landscape policy is almost incom- prehensible. Landscape design is recognised as an essential component in the integration of engineering and architectural projects into the landscape, but the factors which prevent the achievement of a successful result are rarely recognised or assessed. In many cases these prohibiting factors are due to a lack of understanding of the effect of major planning decisions on the existing landscape, the importance of the landscape plan and the significance of appro- priate specified techniques to prevent un- necessary damage and to ensure retention of existing vegetation in a healthy condition. The role of the landscape architect in incorporating new land uses into the landscape provides the background against which factors which inhibit policy achievement can be con- sidered.

Jan 1, 1976

ALTHOUGH discovered as long ago as 1817, by Strohmeyer, the use of cadmium did not become in anyway general for nearly a century. Its properties, although well known, did not recommend it to users of metals generally, and it was, on the whole, regarded more in the light of a nuisance to zinc producers than anything else. Its real value was not appreciated until both the United States of America and Germany, who are entirely dependent on outside sources for their supplies of tin, were faced with the unpleasant fact that their tin stocks were being rapidly depleted, with practically no prospect of having them replenished. This resulted in serious efforts being made in the UnIted States of America to conserve what tin was available, and, as a consequence, several metals were tried in the hope that they would prove satisfactory substitutes for tin. Among these was cadmium, and it was found that cadmium could replace tin in a manner sufficiently satisfactory to permit of its use in many directions where tin had been used before.It is on this ability of cadmium to replace tin that its use became in any way general at first; but since then new avenues of development have been opened up in which its physical and chemical properties are proving their value. It is highly probable that its use will extend very considerably as time goes on. OCCURRENCE OF CADMIUM.There are several cadmium minerals known, but none of them occur in profitable quantities as ores. The cadmium of commerce is derived almost entirely from zinc minerals and ores in which it is almost invariably present in proportions which are usually very small. Cadmium behaves metallurgically almost the same as zinc, and hence constitutes a fraction of 1% of almost all spelter.

Jan 1, 1923

By Elpatyevskaya VP, Arzhanova VS

Main geochemical problems concerning the environment and mining industry interrelation are connected with the transformation of natural water chemistry by mining wastes. The investigation of many mines in Primorye, the southern part of the Russian Far East, showed that their mining waters have high concentrations of heavy metals and aluminium. Water acidity is primarily connected with the amount of acid-forming sulphide minerals in ores and also depends on the neutralising capacity of rocks. Considerable quantity of metals occur in the waters in dissolved form. Metal concentrations in mining waters exceeds the natural levels by 2-5 orders of magnitude and can't be reduced to the background levels even after multiple dilution. It is necessary to develop and put into practice new technologies so that to reduce the geochemical impact upon the environment.

Jan 1, 1995