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By Eaton R. A

The design of most underground mining machines shows little evidence of regard for ergonomic principles and operator comfort. Likewise, efficiency and ease of operation often appear to have been given little consideration in machines where ruggedness and simplicity have tended to dictate the configuration. Improvements in productivity are amongst the benefits to be gained by a different approach to machine design. The paper describes the philosophy and features of a test bed Load-Haul-Dump Vehicle undergoing trials at Mount Isa Mines. This machine is the outcome of a Research and Development Programme conducted by the Department of Mechanical Engineering at the University of Queensland and Mount Isa Mines Limited. The diesel powered test bed features an enclosed, air conditioned cabin, with a suspended operator's control station and electrically operated controls. An electronically controlled hydrostatic transmission incorporating wheel slip control, is another innovation. The performance and operator acceptance of the machine has led to adoption of most of the concepts in a new machine now being put into production.

Jan 1, 1987

By Clarke B. N

The Olympic mine is currently and development to 1988. The mine practice is, and number of factors. Dam copper-uranium-gold undergoing construction start production in May ventilation design and will be determined by a These include: 1. Mining method and degree of mechanization. 2. Presence of radon emanating material. 3. High virgin rock temperatures at relatively shallow depths. 4. High ambient air temperatures in Summer.

Jan 1, 1988

An underground storage and filling distribution system is presently being established at North Broken Hill Limited in the No.3 Shaft area. This has been necessitat- ed by the dependence of the present filling system on the No.2 Shaft and its imminent closure due to cessation of production. The storage will consist of three tanks excavated in low grade ore, between the No.20 and No.21 levels, at approximately 2700 feet below the surface. The tanks will each have a capacity of 1500 cu yds. Consideration was given for surface storage, although under- ground storage was thought to have greater merits. Two tanks have been excavated, and are in operation. Three or more outlets are installed beneath each tank, with horizontal connections into the No.21 level 'mixing box'. Water decants from the top of the fill in the tanks, and passes into a decant water sump, at the bottom of which is a borehole to the No.21 level. This is then connected to the mixing box and water used as make-up water with the semiwet solids for transport into the existing pipe distribution system. Preliminary results of the system have been satisfactory and it is envisaged that this system will readily cope with the filling demands of the future.

Jan 1, 1973

By T Klinge, P Field, N Sugden, D Trenberth

Mining remains one of the key industries in Australia and many other countries with mineral wealth. In Australia, mining contributes 8.8 per cent to the countryÆs gross domestic product (McKay et al, 2000). In Queensland alone, mineral and petroleum industries contribute approximately $9.4 billion to the StatesÆ gross state product (2001/02) (Young, 2003). Increasing pressure on mining companies to perform in a global marketing environment requires mine management to consider more innovative ways to manage their resources û human, plant and equipment û which includes the gathering and analysis of operations data and information for improved decision making. For any mining operation utilising rubber tyred equipment such as trucks, front-end loaders and ancillary equipment, annual expenditure on tyres and related items can be significant. Even a small reduction in tyre operating costs can have a real effect on the business bottom line performance in the short term. Tyre Application Risk Management (TYREARMÖ) can provide substantial benefits in the long term across a number of KPIs not just through reduction in direct tyre expenditure but through flow-on improvements in safety, productivity and reduced environmental impacts. Several accidents involving tyres have also highlighted an increased need to consider the hazards and resultant risks arising from operations of rubber tyred mining fleets (Torlach and Johnston, 1990). This paper presents the process and results of achieving sustained safety and business improvement through the strategic alliance between an earthmover tyre management service provider, Klinge and Co (Klinge) and a BHP Billiton coal mine. The accompanying case study demonstrates in some detail the overall methodology, and the tools and technologies used where active management of data, its analysis and decisions taken have resulted in a 43 per cent improvement in tyre cost performance and a corresponding reduction in tyre-related downtime since the beginning of the alliance.

Jan 1, 2003

By Guo H

The importance of using disc cutters for rock excavation is reflected by their wide application in hard rock cutting machines such as tunnel boring machines and raise borers. The forces involved in the cutting process are those due mainly to thrust and rolling forces and are greater than that required by cutting picks. An interesting feature of cutting with discs is the formation of surface crushing, surface and sub-surface chipping and primary crack formation. Experimental, as well as analytical, work has been carried out to determine the optimum spacing between the disc cutters to control primary crack orientation. Wedge bit indenters were used to simulate disc cutters. The paper concludes by proposing a new approach to rock excavation by hybrid cutting based on controlling the primary crack Orientation.

Jan 1, 1992

By Wagland D. G, Guo H

The Mt Whaleback orebody is in a complex geological regime. A good understanding of geological structure is essential during the design and implementation stages. The amount of information on the rock-mass condition available at the design stage is considerably limited. It is essential to validate the rock-mass properties used in the design during implementation. It is important to achieve integrity of the final pit wall during development and to maintain the integrity until the end of its designed life for safe and economical extraction of ore. The original geological model is updated by way of on-going detailed geological face mapping. Original design is reassessed and is modified based on any significant variations to the previously evaluated geotechnical conditions. Information gathered during design implementation provide tools for effective management of the pit walls. Controlled blasting techniques are employed in the final limits blasting. Presplit blasting is used in most limits blasts. Presplit helps to maintain the integrity of the wall by venting excessive gases from the limits blast. This helps to reduce bedding dilation by gas penetration. Also, it helps to define the design batter for the operators for final batter trimming. Pyritic shale needs special attention during blasting due to its reacting nature. Cablebolting is applied in selective areas to secure small-scale potential instabilities. During the development phase, pit wall monitoring instruments are installed. These instruments are used to monitor the performance of the wall during and after excavation of the slope.

Jan 1, 1995

By Yao S, Wang P, Zhang C

The Zhilingtou Au-Ag deposit is situated in the eastern part of the complexly deformed and metamorphosed South China Caledonian Fold Belt. It consists of seven orebodies that are almost exclusively hosted by biotite plagioclase gneiss of the Precambrian Chencai Group. They form an apparent en echelon pattern in both cross-section and level plan. Three different ore types, based on mineralization textures, have been recognized within the Zhilingtou lode. These are Au-Ag-rich quartz veins, Au and Ag-bearing silicified rocks and Au-Ag-containing altered rocks with quartz stockworks. The mineralization is principally composed of electrum, argentite, pyrite and minor sphalerite, galena as well as traces of hessite and chalcopyrite plus a gangue assemblage of quartz, rhodonite, sericite and chlorite. Fluid inclusions related to Au-Ag mineralization yield a wide range of homogenization temperatures from 110 to 447¦C, with two distinctive peak values at 250-300¦C and 350-400¦C respectively. S30Si values of quartz veins and silicification from the three stages of mineralization range from -0.1 to -0.4%o. The mineralization at Zhilingtou is interpreted as forming by recirculated meteoric water extracting ore-forming elements from metamorphic rocks due to Mesozoic volcano-magmatic activity.

Jan 1, 1995

By D Mukendi-Ngalula, G Hearn

Beach sand minerals from the volcanic rock structures of the Drakensberg, Kwazulu-Natal, (South Africa) have been processed. Screening, flotation, spiral concentration and magnetic separation methods were used either separately or successively in an attempt to concentrate monazite minerals. Products thereof and those from a long time (up to 72 hours) microwaves treatment of the finally produced ilmenite-bearing minerals have been studied using the M÷ssbauer effect spectroscopy. The 57Fe M÷ssbauer effect spectroscopy has demonstrated its versatility and power in monitoring the ilmenite internal reduction mechanism and products and, in characterising the iron-bearing phases contained in different products from the beach sand minerals processing. Microwaves heating of ilmenite for up to 38 hours reduced internally the Fe3+ from the ilmeniteÆs structure. A more prolonged microwaves heating (up to 72 hours) re-oxidised the mineral. 61 per cent natural ilmenite recovery was obtained in the floating products of a spiral concentrated -212+106 ¦m screened and beach sand minerals fraction. A preferential concentration of hematite with a 62 per cent recovery was found in the sinking products while the combination of screening-spiral separation-magnetic separation and flotation yielded a floating product with the highest ilmenite and the highest hematite abundanceÆs (71 per cent, 19 per cent respectively). A natural ilmenite containing 87 per cent ilmenite and 13 per cent hematite could be produced and extracted from the sinking products of the flotation process collected subsequently to the spiral concentration and the initial screening.

Jan 1, 2000

The paper examines the possibility of applying the monolithic packing technique developed in the UK to the division of wide development drivages in Australia, so enabling double entries for longwall retreat panels to be created from shortwall units. The monolithic pack of the UK therefore becomes a monolithic partition in this proposed Australian application. A method developed for the analysis of the load development in packs installed behind longwall advancing faces is adapted and used to predict the support performance of the monolithic partition. Conclusions are made regarding partition construction and possible rates of advance.

Jan 1, 1986

In the Massif du Sud ophiolite complex platinum group elements occur predominantly as ultrafine-grained inclusions of rutheniridosmine, laurite and iridosmine. These form primary inclusions less than 5 to 10 um in diameter within chromite in podiform chromitite fringed by dunite, and emplaced subsequent to solidification of the host harzburgite. There is no specific association with trace inclusions of transition metal sulphides. The crystallization of then: Ir. Os and Ru minerals may have occurred concomitant with hromite, perhaps related to more reducing conditions produced by crystallization of the chromite. The Ir, Os. and Ru show pronounced fractionation from Pd, Pt and Rh expected to be also present in the mantle source rock. The dunite shows evidence of metasomatic origin from adjoining harzburgite, and the possibility of selective crystallization of the Ir sub-group elements suggests that Pd, Pt and Rh may have been transported elsewhere.

Jan 1, 1989

Proposals designed to use stockpiles and buffer stocks to achieve price stabilization and better resource use have a long history. They are super- ficially simple to understand. The benefits seem clear. And yet I am well aware that this is not a simple subject: the more one studies it, the more complex it becomes. Worldwide interest in re- source management, while receiving fresh impetus from the OPEC actions, also has a long and chequered history. Those venturing into such ter- ritories must be forewarned of the traps and pit- falls which abound. Interest in these schemes has waxed and waned over the years with the fluctuating fortunes of the producers or consumers. As I write this paper towards the end of 1977, I am acutely aware of the low ruling prices for zinc, copper, and nickel. These sacrifice prices remind me that it is difficult, for example, for a surveyor, to be calm and rational if he is up to his neck in a swamp full of crocodiles. He might be forgiven for forgetting that the aim was to drain the swamp! I am also aware that when swamps are drained, painful and dangerous stumps sometimes stick out. Hence, in looking at the subject of stockpiles and resource management we must not set our sights too high, perhaps not initially hope for perfec- tion, if we want to secure worthwhile changes. My approach is to acknowledge a bias for the market system. We have, however, had experience (remember the 1930s) of some weaknesses in the untrammelled operation of free markets. Thus our international economic relationships over the past 20 or 30 years have been based on a desire to retain as much as possible of a liberal world trading system backed by such organizations as the GATT, IMF, and the U.N. to ensure the necessary cooperation. Some nations have seen this system work only partially in their best in- terests. GATT, for example, has been reasonably effective in liberalizing trade in many manufac- tured goods but far less so in regard to agricultural or semi-processed goods.

Jan 1, 1978

By Johnson G. D

The typical management systems used to address the issue of operating risk centre around technologies that identify, analyse and evaluate the risk factors. These logical systems such as HAZOPs, Fault Tree Analyses, etc rely heavily on technical considerations and process flow analysis. However, several research projects, across industries and countries have clearly shown that up to 80 per cent `operating risk' is determined by the actions of workers, supervisors and managers. Yet, most of the focus of risk management is on technical and procedural issues. This suggests that a significant imbalance exists in our management systems and that industries are unlikely to show significant improvement on current levels of safety performance. Effective risk management must include the intangible element of the organisation psychology towards risk. A practical and theoretically sound approach had been researched and developed in and for the mining industry. This paper describes the approach and methodologies applied at the Cosmo Howley Gold Mine in the Northern Territory, where an inclusive approach to managing financial and operating risk was followed. The Cosmo Howley Mine showed a dramatic reduction in lost time injuries and improvements in financial indices - providing conclusive evidence of the link between management effectiveness, safety and productivity. This `triangle' has often been the subject of speculation and theory. It is demonstrated in this paper how the management team of Cosmo Howley focused their practices and systems on the improvement of organisational dynamics, ensured tangible and clear focus on parameters of costs and safety and how the improvement process was managed. It is concluded that the improvement process did not require a `major re-engineering' of the organisation. The organisation culture changes that occurred were incremental, planned and effective. It entailed the implementation of sound risk management methodologies, and ensured that a significant emphasis was placed on an aspect that is defined as `organisational dynamics'.

Jan 1, 1994

By C McIntosh, M Carder, P M. J Durance

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Disseminated, gold-bearing sulfide minerals hosted in sheared, wall rock metasediments and clay alteration zones comprise one of the dominant styles of Palaeozoic orogenic gold mineralisation within the Reefton Goldfield, and is exemplified by OceanaGold’s Globe Mine. This study begins the exploration and characterisation of the gold-arsenic-antimony mineralisation hosted within the dominant lithologies of the Globe-Progress shear zone. The main gold-bearing sulfides are pyrite, arsenopyrite and stibnite. Pyrite and arsenopyrite are not compositionally uniform across the Globe-Progress shear zone. Pyrite from the mineralised greywacke and argillite has higher As contents than pyrite in the host rock and pug breccia. Furthermore, the mineralised greywacke and argillite pyrite are enriched in As from core to rim. The 3D models based on bulk assays reveal a significant correlation in the distribution of Au, As and Sb. The interpolant for Sb envelops those for Au and As, which in turn are very similar to each other in their vertical and lateral extents across the shear zone. This result is consistent with earlier findings that the occurrence of stibnite represents a separate and likely later phase of mineralisation relative to that represented by the formation of disseminated pyrite and arsenopyrite both of which exert a stronger control on the distribution of As.CITATION:Durance, P M J, Christie, A B, McIntosh, C and Carder, M, 2015. The composition of disseminated, gold-bearing sulfides within the three-dimensional framework of bulk Au, As and Sb in the Globe-Progress orogenic gold deposit, Reefton Goldfield, New Zealand, in Proceedings PACRIM 2015 Congress, pp 327–334 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By P Hollings, J Holliday

Porphyry copper, gold and molybdenum deposits form in subduction-related settings in association with calc-alkalic or alkalic magmatism. Hydrothermal alteration assemblages are zoned, with potassic cores and propylitic haloes overlain by extensive domains of clay alteration and silicification (lithocaps). Copper sulfides, gold and molybdenite typically occur in veins or hydrothermal breccias, and less significantly as wall rock replacements. Epithermal deposits may form above or to the side of porphyry systems, and may be juxtaposed into the core of a porphyry deposit if rapid uplift and exhumation occur through the life of the magmatic-hydrothermal system. Volcanichydrothermal breccia pipes (ædiatremesÆ) commonly form late in the life of a porphyry system. They may contain clasts of porphyry-style mineralisation, and can host significant epithermal gold resources. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Standards in the public reporting of resources and reserves in Australia have dramatically improved since the implementation of the Australasian Code for Reporting of Mineral Resources and Ore Reserves (The JORC Code) in 1989. Whilst the JORC Code states clearly that Mineral Resources and Ore Reserves are imprecise calculations and should be treated as estimates, there is strong evidence that many people regard them as fact, including some accountants, directors, auditors and investors. Mineral Resources and Ore Reserves are key inputs in the valuation of a mining company and the determination of financial performance. Geological knowledge is the foundation upon which Mineral Resources, Ore Reserves and investment decisions are made, however this information carries with it substantial uncertainty. Case studies and company reports have established that errors derived from inadequate geological inputs have led to reduced profitability in operating mines and in extreme cases the premature closure of mine operations. Whilst there are many causes of mine closure and reduced profitability, including commodity prices and exchange rates, the cumulative effect of all geological uncertainty contributes significantly to the erosion of the credibility of mining within the investment community. There are a number of methods used to characterise and model uncertainty in Mineral Resource and Ore Reserve estimation. Empirical mining indexes, sensitivity analyses, Monte Carlo simulations and Conditional simulations are used to identify and estimate geological uncertainty, notably the quantification of uncertainty in grade and tonnage estimates. These techniques have not generally been applied to estimating geological uncertainty associated with key Ore Reserve inputs such as appropriate mining technique, equipment selection, production rate, mining dilution, stability requirements, materials handling, metallurgical processing, product quality and waste storage. New software tools are needed to model the entire mining process with all its geological and other interdependencies, enabling all uncertainties to be separately identified and estimated. By its very nature, mining involves the assumption of significant technical, financial, political, environmental and social risk. Success comes by understanding and managing these risks and consequently the mining industry will never choose to reduce the level of geological uncertainty to nil. The ultimate aim of improved identification and estimation of geological uncertainty is to quantify inputs into the Ore Reserve process, allowing a company to assess the risks and manage these accordingly. This approach is relevant to feasibility studies for new projects as well as life-of-mine planning through to the weekly schedule at existing mines.

Jan 1, 2003

By Hansmire WH

The 14.7 km Mt. MacDonald Tunnel beneath Rogers Pass in Canada used both drill-and-blast and machine boring methods. A unique ventilation system provides for diesel operations. The design featured minimum construction support and an unrei.nforced poured concrete lining. The west heading was excavated in a single-stage drill-and-blast operation. The east heading used a TBM top heading with a drill-and-blast keyhole bench. The choice of methods was controlled by varying geology, with up to 1,700 m rock cover. Construction performance and progress are evaluated.

Jan 1, 1987

By Mitchell G, Clarke C

The high oas emissions which are associated with high production lonowall mining have provided a need to investigate the limitations and reouirements of the various gas control methods. The major relationships between oassiness and various other parameters are presented with computer analysis being adopted to assess the respective correlations. Some of the relationships are studied in detail with emphasis being placed on methods for overcomino the changes in conditions resulting from high production levels. The importance of the various drainage systems which can be adopted to combat high gassiness levels are analysed. Logical and necessary steps are also proposed for gassiness prediction and data monitoring as well as various combinations of gas drainage systems. The gassiness prediction methods which are discussed outline the need for a sound knowledge of the established worldwide methods together with a comprehensive study of the local mining and geological environment in order to develop a system which is adaptable to the changing conditions. This is particularly important in mines where high coal production levels are anticipated and the need for accurate gassiness relationships is essential.

Jan 1, 1988

As near-surface underground mines progress deeper, the inevitable question is whether to convert from truck haulage to shaft hoisting. The desire to defer capital expenditure frequently delays investigation of the shaft option, or deferral of a decision to start shaft sinking, unless the shaft option is clearly significantly better than trucking. By the time increasing depth makes trucking uneconomic, there may then be insufficient resource remaining to justify a shaft, and the mine must close. However, had the shaft been built earlier, its lower operating costs would have permitted the mine to continue to greater depths. This paper presents a methodology for investigating the shaft versus trucks decision. As well as the typical analysis of which option is preferable at the time the analysis is conducted, the process presented illustrates how the timing of the decision to sink a shaft is critical. The paper shows how to identify the latest date at which the decision to sink a shaft can be made, after which time the shaft option will not be economic. It also illustrates how to assess the resource that may be required to justify the shaft. Considering this in conjunction with the latest decision date, implications for the companyÆs exploration program are discussed.

Jan 1, 2005

By D Feng, G C. Lukey, J S. J, R R. Dagastine

An ongoing challenge in the coal industry is pyrite removal using the flotation method for fine particles. The use of a æseparation in frothÆ (SIF) technique to recover coarse particles of up to a few millimetres in size has presented a potential solution. However the commercial success of SIF is still limited due to the poor understanding of the separation mechanism. The particle floatability in SIF is determined by the constructive or destructive stresses resulting from the forces exerted by the particle on the bubble films. Hence, the surfactant properties and the mineral characteristics (eg hydrophobicity, shape, etc) are the key factors that control the interaction between the particle and froth. In the present work, the interaction forces between different particles (ie crushed glass, pyrite and coal) and a single air bubble are measured in a non-ionic surfactant solution (pentaethylene glycol mono n-dodecyl ether, C12E5) using an atomic force microscope (AFM). Experimental results show that the interaction is primarily dependent on the contact angle (ie the degree of hydrophobicity of the minerals). For crushed glass, the transition from repulsion to attraction was observed as the contact angle increased. As the concentration of C12E5 increased, the adhesion force was suppressed due to wrapping effect. For coal and pyrite with much higher hydrophobicity, long-range attraction was observed. The effect of shape factor was only visible at high surfactant coverage where sign of destabilisation became noticeable on the retracting force curve. These results provide a fundamental understanding of the direct interaction forces of a complex real system between an irregular particle of either crushed glass, pyrite or coal and a single air bubble. Theories developed for interpretation and modelling are thus far based upon the study of ideal systems of glass or polystyrene spheres and an air bubble and were incapable of explaining the interactions in complex real systems. The presented measurements were a first approach to the problem of real mineral-bubble interaction in flotation systems. Thus, the results can only best be interpreted semi-quantitatively.

Jan 1, 2005

By R Vleggaar

In addressing a short-term operational need for the relocation of a tailings storage facility reclaim pond, a mine has achieved a host of water management objectives. Through effective planning and adoption of a strategic æwhole of mine lifeÆ approach, the mine has achieved significant environmental, social and economic benefits. A review of all water management aspects across the site identified a host of other interrelated water issues and concerns which, if dealt with individually, would prove too costly for individual operational departments. When considered as a whole, however, the issues became opportunities and provided the stimulus for integration of the site water management system. The development of site water and solute balance models provided the tool by which a number of water management options/strategies could be evaluated. The conceptual design and costing of the proposed water infrastructure further facilitated the evaluation of the multiple benefits to be gained from each option. A business case could then be made to mine management for the preferred option. The recommended water management strategy finally recommended to the mine not only provided a tailings storage facility (TSF) reclaim pond, but also provided for:increased wastewater recovery from the TSF, the capture of all waste rock dump run-off, additional water harvesting from local creeks, increased wastewater reuse, improved environmental water management, infrastructure that could be used by the local community after mine closure, and overall cost savings. This paper illustrates how effective water management planning can provide both short-term economic and environmental benefits, as well as long-term social benefits.

Jan 1, 2006