Search Documents

By M Clay, J Dunlop

Thermal and metallurgical coal mining in Queensland has resulted in mines which contain voids due to open cut mining. While there are several proposals for greenfield coalmines or expansions to existing operations, many existing open cut coalmines are reaching maturity and most will leave one or more residual voids in place. The rehabilitation of mine voids is challenging. Water held in voids will evaporate over time leaving solutes to concentrate. This is likely to lead to poor water quality with limited practical use. The most basic practices to rehabilitate voids have historically involved stabilising the high and low walls, bunding to provide flood protection, and preventing public access. Regulatory reforms for mine rehabilitation were introduced in Queensland as part of the Mineral and Energy Resources (Financial Provisioning) Act 2018, and aimed to strengthen progressive rehabilitation planning, limit risks to the environment and improve outcomes for local and regional communities. Under the reforms, the goal for rehabilitation of voids is to achieve a safe, stable, and non-polluting landform, which can sustain a post-mining land use (PMLU). The reforms also introduced a requirement to describe rehabilitation of mined land in Progressive Rehabilitation and Closure (PRC) plans, replacing the description of such plans in Environmental Authorities (EAs). The reforms are not retrospective and recognise historic approvals for voids, meaning established voids will remain in the landscape as non-use management areas (NUMAs). The objectives of this study were to outline historic void rehabilitation planning practices, describe water quality limitations of Queensland mine voids and identify possible opportunities for improved planning

Aug 2, 2023

At Pasminco Mining's South concentrator. which was commissioned in 1952. an expansion. modernisation and efficiency improvement program commenced in 1986 with a coarse ore stockpile and grinding circuit expansion. the replacement of small flotation cells and the upgrading of reagent mixing and metering equipment. The program continued with the installation of a TDC 3000 based process control system (1988) and concentrate thickeners (1990). By mid-1991 a further grinding expansion and the installation of zinc flotation feed regrind ball mills and zinc recleaner column cells will be complete. leaving the use of ceramic disc fillers and development of process control strategies as probably the remaining major avenues for improved process efficiency at present.

Jan 1, 1991

By S Ellis

In January 2008 Chirano Gold Mines Limited committed to expansion of the Chirano Gold Project from its existing design capacity of 2 Mtpa ROM ore to a new design value of 3.5 Mtpa. In addition to increased throughput, the design had to contend with increasing ore hardness and competency, while at the same time make cost effective use of existing equipment with minimum disruption to existing production. The solution adopted involved some novel approaches including tertiary crushing and operation of the SABC circuit in overflow ball mill mode and parallel elution with a common acid wash column. This paper describes the approach taken to the design of these elements to achieve a cost effective and safe capacity expansion.

Aug 8, 2011

Vertical retreat open stoping (VROS) is a variation of sublevel open stoping (SLOS) that has been introduced at Cannington to minimise the influence of subvertical geological structures during stope extraction. The first application of VROS is described, where structures within the stope resulted in a change in firing sequence and the extraction of two complete sublevels in a single blast. The use of electronic detonators is critical to the success of VROS and their application is described. Numerous benefits of using VROS have been identified and are described. To date, eight stopes have been successfully mined using VROS. In addition to the first application of VROS, two further case studies are described.

Jan 1, 2005

By I Jabou, D G. Blazak, L C. S Hogarth

The R70 test is a good indicator of coal reactivity to oxygen and is commonly used to provide a rating of propensity for self-heating. Tests performed by The University of Queensland Spontaneous Combustion Testing Laboratory have resulted in the development of a large database that shows the impact of coal quality on this parameter. From these results it is possible to infer an R70 value, which can be used to gain an appreciation of the intrinsic coal reactivity before it is even tested. However, any interpretation of R70 values must consider the influences of coal rank, mineral matter and moisture content to provide a better understanding of the spontaneous combustion risk of a particular coal.

Jan 1, 2005

By M Jara, R Nuñez

As the global interest in sustainable energy sources has increased, lithium has emerged as a vital resource, playing a crucial role in the transition towards a cleaner and more efficient economy, but with this comes important challenges, especially associated to health, safety, and environmental matters. So, it is imperative for the lithium industry to prioritise HSE measures to protect workers, environment and surrounding communities. Implementing robust safety protocols and technology helps ensure the sustainability of mining operations and contributes to the overall responsible development of the industry. In this work we present how the Chilean lithium mining industry becomes a safer and more compliant industry using digital transformation (Cochilco, 2018; Bradley et al, 2013; Cabello, 2022).

Apr 16, 2024

By D H. Lee, J F, J H. Rubinstein

This paper examines the problem of optimising the life-of-mine costs of an underground mine, focussing particularly on the costs associated with the underground development needed to provide access to and haulage from the ore zones. This mine optimisation problem is modelled as a network and a solution technique is outlined. The effectiveness of this solution technique is then demonstrated by applying it to a prototype test example and some actual case studies. Finally, extensions of this technique to other underground mining problems are discussed.

Jan 1, 2000

By D Elder, S Bell

Over the last five years Solid Energy New Zealand (SENZ) has gone through a series of changes in response to both external and internal factors. These changes have included corporate reorganisation and funding restructure, as well as modifications to medium and long term business objectives. The nature and size of its coal reserves and markets requires SENZ to continue developing new mines as existing mines are depleted. As well, there are opportunities to develop new mines as coal markets change or to realise value from existing coal resources. To assist in this process, a set of mine project assessment guidelines which are relevant to the size and scale of anticipated mine developments have been developed for SENZ. These project guidelines are structured to operate from the early stages of project or resource review through to final feasibility study stage. The guidelines provide both a basis for planning and budgeting, and a control mechanism within the company. They also enable clear understanding of the status of individual projects and provide a framework for comparison between projects. SENZ now has a defined method to plan, monitor and control this important aspect of its business. The paper explains the development and structure of the guidelines, as well as providing examples of their application. and use. It demonstrates how SENZ integrates its long term planning, five year planning, annual planning, project planning and risk management to maximise the value of individual projects, business units and the company overall in a consistent manner.

Jan 1, 2002

By D Moss, P Ganza

There are continuing developments in underground narrow vein mining, from innovative mining methods using low-profile equipment to adaptations of current mining methods using equipment such as road-headers. The development of new mining methods and mining equipment has one purpose in mind û to extract narrow reef orebodies keeping dilution to a minimum, whilst maximising mining recovery. Achieving this will increase the head grade of the ore mined and reduce the tonnes delivered to the mill. Narrow vein mining in Australia has been limited to traditional hand held or mechanised drill and blast methods using existing æoff the shelfÆ equipment. Numerous trials have been undertaken using rock cutting technology and lower profile equipment, but these mining trials have not resulted in the full implementation of any new mining method or the adoption of low profile equipment in narrow vein mines as an accepted mining methodology. Mine operators in Canada and South Africa have teamed up with a number of equipment manufacturers and have taken steps to further mechanise and automate the mining of narrow vein orebodies, in particular to increase safety and productivity. The challenge to Australian narrow vein mining projects is to capitalise on work undertaken by overseas mining companies and equipment suppliers and to investigate the adaptation of low profile coal mining machinery to specialised metalliferous mining. With the inevitable fall in metal prices, it is necessary for Australian mine owners and mining contractors to apply these specialised methods and equipment to make narrow vein mining profitable.

Jan 1, 2005

Exploration risk increases with time, due to a general decrease in prospectivity as the more accessible deposits are found, and be- cause of rising costs and demands due to an improving standard of living. Risk is separated into financial risk, which increases sharply at the development stage, and the risk of failure which is at its peak at the outset of exploration. Risk is also divided into internal and external factors; some of the latter cannot be offset, viz. the systematic overall risk for any enterprise. The recently emergent risk embodied in withdrawal of large areas from exploration access is discussed. An appeal is made for objective multiple land-use policies to be applied so that land remains available at reasonable cost and with appropriate environ- mental safeguard conditions. Risks specific to gold exploration are discussed. As gold now accounts for over 50% of all mineral exploration, and most other metals are depressed, any sharp decline in gold will have grave effects on the ex- ploration industry. Gold exploration will become more difficult and expensive in about five years, after most of the readily accessible deposits in Australia are found. Government's role is important in pro- viding stability and basic data at reasonable cost. Exploration for specific minerals or of particular areas could be stimulated by extending the 150%.tax deductibility of R & D to aspects of exploration of strategic im- portance, particularly in the event of a downturn. Exploration is classic scientific research, at least through to the proving Stages.

Jan 1, 1987

By Kelley BC, Filmer AO

The chemical oxidation kinetics of sphalerite by Fe(III) was studied at various temperatures and size fractions in sulphate media. The kinetics of Zn extraction followed a pore diffusion control mechanism with an apparent activation energy of 54-58 kJ mole. This figure, although high for a pore diffusion control process, is consistent with other studies carried out in sulphate media. An empirical statistical model, relating the extraction time to % Zn extraction, average particle size and temperature, is described by log 1 = 12.22 - 0.017% Ext. - 1.76 log D Av t - 2954 T Parallel studies were also carried out investigating the biological oxidation of sphalerite utilizing the acidophilic autotrophic bacterium Thiobacillus Ferroxidans. The effect of such kinetic parameters as pulp density, particle size and Fe(III) on bacterial growth rate and consequently zinc extraction rate, were studied and where appropriate, optimum conditions for bacterial growth were specified. Based on the results of chemical and biological leaching studies, it was apparent that rapid zinc extraction from sphalerite was predominently due to oxidation by Fe(III). The biological oxidation process catalyses the oxidation and regeneration of Fe(III). The proposed combined chemical-biological leach system was simulated in semi continuous fashion. The sphalerite oxidation rates obtained in this system were similar to that predicted by the chemical leach empirical model. 1. Senior Research Metallurgist, CRA Research, Boolaroo, N.S.W. 2. Group Leader-Hydrometallurgy, CRA Research, Boolaroo, N.S.W. 3. Senior Research Scientist, Biotechnology Australia, Roseville, N.S.W. 4. Senior Experimental Officer, Biotechnology Australia, Roseville, N.S.W.

Jan 1, 1986

By R B. Wanty

Historically, most investigations of biogeochemical cycling in acid rock drainage systems involved synoptic sampling over longer time periods (one sample per week or month) or intensive time series studies over a few hours or days. However, many important episodic loading events, such as seasonal meltwater and storm events occur on timescales that are rarely observed by these traditional sampling approaches. Monitoring these transient processes, which may contribute the bulk of the annual metal loading, is essential for accurate assessment in acid rock drainage areas. Recent work also has demonstrated dramatic diel (24 hour cycle) variations in trace metal concentrations in response to diel changes in temperature, pH, oxygen, and photochemical cycling (Brick and Moore, 1996; Nimick et al, in prep). To characterise a system that may respond to diel, seasonal, and episodic events, a monitoring program must sample at a frequency that captures the details of these major forcing events. We developed two novel instruments, the Zn-DigiScan and the DigiSampler to examine low and high frequency temporal changes in acid rock drainage areas. The Zn-DigiScan is a battery powered real time in situ chemical analyser designed for long-term deployments with hourly analyses of Zn. Stream physical parameters (temperature, conductivity, dissolved oxygen, pH, turbidity, etc) were measured every 15 minutes with a water quality sonde. The DigiSampler was developed for the long-term daily sampling of biogeochemically active elements and can take either discrete samples or samples integrated over 24 hours. The DigiSampler collects 2 ml samples in a Teflon coil which are separated by 0.2 ml nitrogen bubbles. The sample coil is returned to lab and the 2 ml samples are diluted 1:10 and analysed for trace metals by ICP-MS. Initial results from a three-day deployment at Fisher Creek, MT, USA have successfully demonstrated the ability of the Zn-DigiScan to record Zn concentrations at levels below 100 ¦g/L. Zinc concentrations measured at 30 minute intervals in Fisher Creek showed a diel cycle with low values of ~25 ¦g/L in the late afternoon and increasing to ~60 ¦g/L by early morning. Zn concentrations were inversely related to temperature and pH, suggesting that temperature and pH dependent adsorption was the main factor controlling diel Zn fluctuations. Initial deployment of the DigiSampler also was successful, revealing diel cycles in Zn, Cu, and Mn. Comparison of trace metal samples collected by the DigiSampler showed good agreement with samples collected by an Isco automated water sampler, demonstrating that the DigiSampler can collect clean samples for trace metal analysis at the low ¦g/L range.

Jan 1, 2003

Good morning ladies and gentlemen, and may I thank you for inviting me once again to address your conference. I would first like to welcome you all, especially international delegates and conference speakers. ItÆs a pleasure to be with you all and I hope that you have the time to enjoy the many beautiful sights that the Coromandel and Bay of Plenty have to offer.   Holding your conference in Waihi is particularly apt, especially bearing in mind the conference theme û 'Mining in the Community'. There can be few venues in the world that can boast a world class gold deposit of the likes of Martha Hill located right here in the centre of a rural service town. ItÆs a deposit that has a mining history active now in its third century and that to date has yielded some 7.5 million ounces of gold and 50 million ounces of silver. I doubt that when John McCombie and Robert Lee discovered gold at Martha Hill in 1878 that they had any inkling that their endeavours would be the foundation for a mine that would become such an inseparable part of the economic and social fabric of Waihi for the next 130 years.   This is now my fifth appearance at a New Zealand minerals conference, I especially value such occasions as it allows me to comment on your industryÆs performance over the past year, share my thoughts on matters affecting your industry, and also to give you some feedback from central government.

Jan 1, 2006

A thermochemical model is developed to study the two-stage smelting reduction process for ironmaking without post-combustion. Steady-state multi-material and heat balance equations are solved simultaneously to study the effect of metallisation, slag basicity, coal rank and heat loss on consumption rates of coal, ore, flux and oxygen and production rate of slag to produce hot metal of a given composition, tapped at a given temperature. The model is applied to the commercial data for a COREX-plant producing a wide range of hot metal compositions, tapped at different temperatures. The computed rates of coal, slag, flux, ore and oxygen were found to be close to the reported ones, but an exact match could not be obtained. It is found that a four per cent change in metallisation brings changes the coal rate by five per cent, flux rate by six per cent, slag rate by eight per cent and oxygen rate by 13 per cent, while a ten per cent change in basicity changes the coal rate by ten per cent, flux rate by 13 per cent and oxygen rate by 22 per cent. Further, it is found that an increase in metallisation decreases the coal rate and export gas. At a given per cent metallisation, the coal rate and the export gas are lowest for anthracite compared to all other types of coal.

Jan 1, 1999

A mineral grain finder is described which is easily constructed to fit onto the stage of a standard reflected light ore microscope.The device is most useful in relocating particular grains or mineral associations on 30 mm diameter polished sections. The use of the grain finder in the teaching of ore microscopy is outlined.

Jan 1, 1988

Mining Automation By Professor Hugh Durrant-Whyte, Australian Centre for Field Robotics and Centre for Mining Technology and Equipment, Department of Mechanical and Mechatronic Engineering, The University of Sydney Professor Hugh Durrant-Whyte summarised why the mining industry needs to automate and reviewed the current automation technology - its risks, costs and benefits. Why automate? The drivers for automation include: safety, productivity, quality control and reduced manning, equipment utilisation, maintenance, and organisation and planning. Durrant-Whyte recommended starting out with a picture of a fully automated mine and working backwards through a systematic analysis of benefit and risk. This also involves looking at the impact of the total automation on current mine design, and identifying the key technologies.

Jan 1, 1997

By Pratt IJ

A report is given of the problems of finance and physical resources that currently affect The University of New South Wales, and of some of the measures adopted to alleviate them. Partly as' a result of review procedures, a School of Mines was formed to amalgamate Applied Geology and Mining Engineering, and to add the skills of extractive metallurgy to produce a group to match the needs of the minerals industry. A review of courses within the School indicated a need for enhanced computer teaching, which is partially negated by a lack of resources. It also shows an overcrowded course whose structure could possibly benefit from a split into managerial and specialist streams.

Jan 1, 1986

The complicated mining-geological conditions in the Kuzbass have led to some difficult mining situations in the past. Now, with historical data, supplemented by geomechanical information and measurements, together with an appropriate kinematic theory, a more reliable basis exists for prediction and control of the geomechanical state during extraction, with caving and with backfilling. Continued progress and improving reliability comes from data banks and computations, and now prediction of geomechanical situations is upgraded by more routing measurements and monitoring. Not only in the Kuzbass, but throughout the USSR, 14 dedicated groups are ready to solve various specific problems of prediction an control of geomechanic situations with assured increase in the quality of mining.

Jan 1, 1991

Transport infrastructure constitutes, since always, an essential link between regions, countries and continents, for economical, commercial and human purposes. Permanently growing mobility needs, which are encountered in the whole world, lead to a more and more clear necessity to increase and modernise these transport infrastructures, as well in quantity as in quality, for all transport modes, and for all what is able to be transported, from people to consumption goods and energy. With only very few exceptions, transport infrastructure achievements have for long been the concern of the sole public authorities, at the various levels, which put them, mostly free of charge or at very low cost, at the disposition of the user or the customer.

Jan 1, 1999

The application of cheap robust microprocessor based units to achieve monitoring and control in an underground mining environment is described. The functional layout of the programmable controller and the methods of multiplexing and processing information from local and remote sources are examined as are features for refrigeration plant control.High noise immunity communication to a remote micro computer uses existing telephone lines and enables display and print of essential data. The development of this system then leads to applications in monitoring compressed air, ore transport and underground fires.In conclusion, the problems of data presentation to different levels of management and the future philosophy of a central multi-reporting system are discussed.

Jan 1, 1985