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Many operating hard-rock sulfide mines are predicted to require perpetual post-closure management to prevent environmental degradation. Causes include evaporative concentration of metals and other solutes in pit lakes, and acid rock drainage from sulfide waste-rock, tailings, and pit benches. Dilemmas posed by the prospect of perpetual management include: uncertainty in predictive models typically prevents reliable bounding on forecasts for the timing or magnitude of environmental impacts; comprehensive closure designs that can meet environmental standards may not be economically possible, particularly when applied retroactively to mines permitted under less stringent closure requirements; the publication of site-specific environmental analyses in peer-reviewed journals are discouraged in the current regulatory environment, hindering scientific advancement; and the durability of financial and government institutions cannot be assured for the long-time horizons over which mine impacts are predicted to occur. Re-evaluating mine closure in a framework of sustainable development (as proposed by the Mining Mineral Sustainable Development forum), can resolve, in part, these dilemmas. Key sustainability goals include: assurance of the social and economic well-being of the local community; assurance of the long-term environmental integrity of the region; and establishment of institutions capable of addressing (and learning from) long-term environmental management. Under a sustainability framework, impractical plans for immediate attainment of perpetually-stable closure may be replaced with a fund for long-term management of environmental impacts (eg through contaminant migration controls and exposure barriers), and a set-aside long-term growth reserve intended to eventually fund more complete closure. Fund expenditures would follow Adaptive Managementùa template for environmental-management institutions in which knowledge accumulated and uncertainty acknowledged explicitly. Under adaptive management, trusts would be flexible entities, supporting an evolving program of monitoring, predictive model refinement, and treatment. Periodic value of information analyses would target data collection efforts, refining the balance between predictable cost and uncertainty. This framework could overcome present-day financial shortcomings, enhance the field of environmental science, and meet the needs of future generations through the propagation of capita.

Jan 1, 2003

By G, F Beach, D Jazzini, R Rounsley

Over the past 20 years within Australia, there have been a number of incidents at mine sites where ammonium nitrate-based explosives have reacted with certain rock types containing sulfide minerals. These rocks have commonly been referred to as æreactive groundÆ. These reactions have frequently led to fires (particularly in ground susceptible to spontaneous combustion) or premature detonation of the ammonium nitrate-based explosives. Clearly, this introduces an element of risk when using ammonium nitrate-based explosives in these areas. Dyno Nobel has been proactive in developing ammonium nitrate-based explosive products that can be used in these types of æreactive groundÆ environments that minimise the risk of premature detonations occurring. A system for assessing æreactivityÆ of sulfide containing rocks has been developed that can be used in the field. Previous literature has been reviewed, identifying Differential Thermal Analysis (DTA) as the most common method for determining the æreactivityÆ of the ground. In the present investigation, DTA has been rejected as a suitable technique for determining ground reactivity, since it measures thermal reactions at higher temperatures over short time periods, conditions that are unlike those in the field. For example, ground at ambient temperature has been found to react with ammonium nitrate-based explosives over long time periods, reactions that are unable to be evaluated using DTA. Other more suitable techniques have been developed to monitor rock conditions that can be measured in the field and give a good indication of potential ground æreactivityÆ with ammonium nitrate-based explosives. Dyno Nobel is currently investigating the reaction mechanisms of spontaneous combustion in reactive ground, the decomposition mechanisms of ammonium nitrate and the role of inhibitors in ammonium nitrate-based explosives. Once complete, this fundamental research will lead to the further development of even lower risk ammonium nitrate-based explosive products for use in æreactive groundsÆ in a variety of mine environments.

Jan 1, 2003

The Lennard Shelf is an Upper Devonian carbonate reef complex striking northwest for 350 km along the northeast margin of the Canning Basin. Numerous small Mississippi Valley type (MVT) Pb-Zn prospects occur within this belt, including the Wagon Pass prospect, located 105 km east of Derby in the Napier Range. At Wagon Pass, the base of the Upper Devonian sequence is a cobbly, dolomitic sandstone, the Van Emmerick Conglomerate. This is conformably overlain by the Frasnian to Famennian Pillara cycle Lower Napier Formation fore-reef deposits. These are characterized by red algal wackestones and terrigenous stylo- bedded packstones, with common dolomitization. The conformably overlying Famennian Nullara cycle contains a classic reefal assemblage, consisting of flat lying Nullara Limestone back-reef, fore-stepping massive Windjana Reef, and steep basinward dipping Upper Napier Formation marginal slope. The Nullara cycle is not dolomitized. The Wagon Pass mineralization is hosted by Lower Napier Formation dolomite. Mineral- ization consists of complex intergrowths and semi-massive assemblages of sphalerite and galena, with subordinate pyrite, marcasite, chalcopyrite, bornite, digenite, covellite and bravoite. Ore textures include granular and colloform. Gangue minerals are dolomite and very fine grained green chloritic clay. Although mineralization commonly occurs as reticulate fracture fillings, its overall distribution is stratabound. Ore paragenesis involved early "diagenetic" dolomitization, followed by breccia formation with chloritic and granular dolomite matrices. Main stage galena-sphalerite mineralization then occurred, accompanied by pervasive chloritization of silty units. Ore genesis was probably related to basin-derived "oil field" brines, with open space textures in the mineralization quite comparable to textures seen in Canning Basin dolomitic hydrocarbon reservoirs. Fluid inclusions in the host dolomite have typical MVT homogenization temperatures of 70-1150 C, and contain minor organic phases. The Van Emmerick Conglomerate, with its high porosity, dolomitization and weak Pb-Zn anomalism, was probably the aquifer for the mineralizing brines. Access of ore solutions to the Wagon

Jan 1, 1986

By Hargraves A. J

At 4 MPa gas pres ure and 30°C the sorptive capacity of 10 selected Australian dried coal ranges from 17 to 23 m3/tonne of CH4 and 27 to 36 m3/tonne of CO2. Values for moist coals are about 25 per cent less. At 20°C, sorptive capacities are about 18 per cent greater. No clear relationship between coal rank and sorptive capacity was established.The permeability of coal to gas is dramatically reduced by progressive hydrostatic confinement. No single 'permeability' for a coal can be established because of relative affinities of coals and the gases (Ar, CH4 and CO2) used in experiments. Bedding plane permeability is significantly greater than permeability normal to bedding. Dependent on gas/coal combinations, permeabilities without confinement ranged from 150 to 0.05 millidarcies, and with 8 MPa hydrostatic confinement from 1.0 to 0.001 md. Generally, permeability is increased by reduction in temperature, and reduced by increase in moisture as one changes from Ar through CH4 to CO2. In retrospect, it is preferable to ubject permeability sample to 8 MPa hydrostatic stress only once, because changes occur in the samples and it is difficult to use other gases successively.The initial rate of desorption, DP, does not appear to be a reliable index of proneness to instantaneou outbursts for Australian coals.The methods used for determining quantitative gas-coal properties appear suitable and reliable for testing other coals.

Jan 1, 1985

By M Thomas, M Caccetta, C Laukamp, A Hacket, M Jones, A Rodger, M Verrall, R Hewson

A mineral systems approach was used to interpret precompetitive airborne mineral mapping geoscience data for iron oxide copper gold (IOCG) exploration in the Starra area, Eastern Succession, Mount Isa Inlier. Selected minerals were chosen to map possible source rocks/fluids as well as intersecting structural/fluid pathways that could have transported mineralising fluids into domains of contrasting rocks/fluids where there was potential for physicochemical gradients to precipitate metals. Ferric and ferrous iron contents and white mica abundance were useful mineral criteria to identify theMount Dore Granite of theWilliams-Naraku Batholith as a potential source of æoxidisedÆ fluids rich in Fe, K and potentially Cu-Au. The Mount Dore Shear Zone (MDSZ) intersects the western margin of this granite with the highest contents and changes in composition of the white mica are peripheral to this contact within the granite. This together, with the fact that the entire N-S length of the MDSZ in the study area (~16 km) is abundant in white mica are evidence of K-rich fluids had preferentially moved along this pathway. To the south, the MDSZ intersects a domain comprising massive ironstone bodies as well as numerous graphitic horizons. This interpreted æreducedÆ domain is well mapped using the æopaqueÆ mineral products, as well as by white mica, which is pervasively developed and extends 2 km either side of the MDSZ fault into the meta-sedimentary sequences. The chemistry of this white mica also changes progressively away from the MDSZ, becoming more Si-rich (longer wavelength) towards the contact with massive ironstone bodies in the west and the graphitic units in the east, both of which represent sites of known Cu-Au mineralisation. Beyond these contact zones of interpreted æoxidised fluidsÆ with reduced rocks/fluids, there is either a rapid change to Si-poor white mica and/or no white mica developed, ie major æchemicalÆ gradient change. These mineral mapping results provide evidence for a direct link between possible source rocks and sites of IOCG metal deposition as well as extending the associated alteration zonation which had previously been mapped/published at the metre-scale to the kilometre-scale. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

This paper examines the broader implications of recent and ongoing changes in mineral resource managementå and reporting practices and the impact that these might have on mining companies. It is likely that an International Reporting Code will be developed in the near future, based on a number of National codes produced in recent years. However, this is only part of the reporting story, as an International Code brings with it a range of further issues to resolve. For the Code to be effective, there needs to be international recognition and perhaps licensing of Competent Persons and an expanded base of sponsoring professional bodies. Also, in an increasingly global business, shareholders, regulators and other interested parties need to know and understand the general processes involved in resource and reserve estimation and reporting in order to recognise companies that maintain the highest standards. There is a current trend towards greater scrutiny of company performance in a range of areas under the banner of corporate governance, and many changes are happening that will place greater disclosure burdens on all companies in the future. Good corporate governance means management of company assets for the benefit of the stakeholders. For a mining company, there is no greater asset than its mineral resources and reserves and directors are just as responsible for effective management of their mineral resources as they are for financial good practice. The paper looks at the relevance of corporate governance principles to mineral resource management and the changes that this could bring to the way that companies deal with regulators, shareholders, financiers and others. Finally, increased scrutiny and further regulation inevitably means greater effort by the industry and higher costs. Despite this the author believes that there are substantial offsetting benefits to be gained by companies prepared to take the initiative in improving resource management practices and communicating these improvements to shareholders. In order to achieve the benefits however, the industry needs to fully engage in the changes that are taking place û setting its own standards and working with the regulators rather than sitting back and being legislated against. Mineral resource reporting provides a good model of how this process can work and there will be other opportunities in the coming years as the industry seeks to develop best practice in mineral resource management. The author is an employee of Rio Tinto but wishes to point out that the views expressed in this paper are his own and not necessarily those of Rio Tinto.

Jan 1, 2002

Mineral exploration and development can have a significant impact on the environment and local communities, in some circumstances extending well beyond the mine site. Poor environmental performance and consequent social impacts by some companies have affected the reputation of the whole industry to the extent that the principal public concern about mining is its impact on the environment. This is consistent with public attitudes about other major natural resource sectors such as forestry and commercial fishing. Traditionally the community has relied on governments to set the benchmark for acceptable environmental and social performance through establishing and revising regulations governing the mining industry. This however assumes that regulations keep pace with community expectations. It also does not take into account those circumstances where governments can have conflicting roles as both watchdog and project partner. Government regulations and industry self-regulation are not in of themselves sufficient for the minerals sector to demonstrate that it has adequately addressed environmental and social issues associated with the sector. For the minerals sector to improve its reputation it must first improve its environmental and social performance. To do this requires the sector to operate to acceptable standards of environmental and social performance and for the sector to be able to credibly communicate this to its stakeholders such as investors, non-government organisations (NGOs), customers, staff, regulators and local communities. Independent third party certification of environmental and social performance (æcertificationÆ), already operational in forest and fisheries management, is proposed as a mechanism to enable the minerals sector to achieve this. World Wide Fund for Nature (WWF) and industry partners will be collaborating in a project to ascertain the applicability of æcertificationÆ to the minerals sector. A number of economic, social and environmental benefits are identified that could accrue should mining companies be able to differentiate themselves on the basis of environmental and social performance, an attribute evident in æcertificationÆ schemes. External audiences are seeking increasing levels of information and data on environmental and social performance of mining companies, be it local communities, investors, financial institutions or NGOs. Environmental and social reporting should be a key communications device that stakeholders can rely on as a reliable, credible source of information on environmental and social performance. WWFÆs contribution to the debate about environmental and social reporting has been to develop a process to assess the quality of environmental and social reports against reporting ingredients which WWF believe are important if a report is to be an accurate reflection of the reporting entitiesÆ environmental and social performance.

Jan 1, 2002

By M H. Randell, J B. Haines

The Honeymoon Uranium Project comprises the Honeymoon Deposit,Goulds Dam Deposit and Yarramba Prospect in the Southern Lake Fromeregion, South Australia. Both the Yarramba Prospect and HoneymoonDeposit (which includes Honeymoon and East Kalkaroo orebodies) arelocated in the Yarramba Palaeovalley. The Goulds Dam Deposit is about75 km north west of Honeymoon, in the Billeroo Palaeovalley. Exploration for sediment-hosted uranium began in the area in the late1960s, culminating in the discovery of Honeymoon and Goulds Dam inthe early 1970s. In 1982, a 25 L/s demonstration plant was built atHoneymoon to confirm suitability for in situ leaching. The project was put on hold in 1983 due to changes in government policy. Southern Cross Resources Australia Pty Ltd acquired the project in mid 1997. Roll-front deposits form from a migrating geochemical cell, anadvancing reduction-oxidation interface between oxygenateduranium-bearing groundwater and its reduced aquifer host. The source of metal is uranium-anomalous granites, which were eroded fromsurrounding ranges. The weathered granites and resultant sediments are stripped of uranium by oxidised groundwaters, to form solutions carrying uranyl carbonate complexes. The solutions percolate down-slope through permeable sand zones until contacting a reduced environment where uranium precipitates. Uranium mineralisation occurs interstitially between and as thin coatings on sand grains, usually in the form of uraninite or coffinite. The palaeovalleys (previously termed palaeochannels) are incised intounderlying Cambrian/Precambrian basement rocks and filled withsemi-consolidated, largely un-cemented, Tertiary sediments of the Eyre Formation. The late Palaeocene to middle Eocene Eyre Formation is the basal unit of the Tertiary succession in the Callabonna Sub-basin of the Lake Eyre Basin. Further to the north, the Lake Eyre Basin overlies the Jurassic-Cretaceous Eromanga Basin, which comprises much of the Great Australian Basin. Eyre Formation sediments are in turn overlain by the late Tertiary Namba Formation and terrestrial Quaternary units. At Honeymoon, the Eyre Formation includes immature, pyritic,carbonaceous sands and gravels interbedded with lignite andkaolinite-illite-montmorillonite clays. It was deposited by braidedstreams during epeirogenic uplift of the Olary Ranges, accompanied bysubsidence of the Lake Eyre Basin. The Eyre Formation comprises aconsistent stratigraphy of interbedded sand and clay units that arecontinuous over the Honeymoon Deposit but with local variationindicating some hydrological connection between aquifers.In the Honeymoon orebody, uranium occurs within coarse-grained,pyritic sands where the basal sand pinches out between overlyingcarbonaceous clay and the southern palaeovalley slope. Its characteristics are typical of the well-developed, planar limb of a roll-front uranium deposit. Zonal changes related to the reduction-oxidation interfaces across the deposit are readily observable. The orebody extends for nearly 1000 m along the valley margin, is 400 m wide at its maximum and averages about 6 m in thickness. The East Kalkaroo orebody also lies near the southern margin of theYarramba Palaeovalley. It extends discontinuously for approximately 3.5 km and averages 200 m width, with significant uranium present in the Middle as well as the Basal Member. The Billeroo Palaeovalley extends northward for 40 km sub-parallel tothe western side of the Benagerie Ridge, is up to 5 km wide and hasgently dipping banks. Eyre Formation within the palaeovalley isconcealed beneath 90 m of Quaternary and Namba cover, isapproximately 40 m thick, and is sub-divided into three upward-finingunits, which are remarkably similar to the Yarramba Palaeovalleysequence.

Jan 1, 2001

This paper outlines a range of strategies for steady state optimisation of most types of concentrators. Optimisation is considered in terms of comminution performance, energy efficiency, concentrator strategy and overall mine/concentrator operating philosophies. Application becomes more complex as the range of optimisation is expanded. However, the potential gains also increase. A step by step framework for data collection and analysis is provided. This process is facilitated by powerful simulation and mass balancing programs which are now in common use. Once a sound, steady state rationale for optimisation has been developed, it may be used to provide a fine foundation for process control system development.

Jan 1, 1993

Interrelated data for five fundamental features of production processes would help promote the- development of the discipline and profession of extractive metallurgy. The features are the input materials, the products, equilibria, kinetics" and movement of materials within the reactor. Aspects of overall process performance that could be developed in these terms include quantitative comparison of reactor engineering options, process dynamics, interruptions to operations, and recycling. The ability to be able to forecast these and other aspects of process performance would be valued by most metallurgists. Although data have been reported for each of these aspects they have been more relevant to process economics than process fundamentals. The data have not often been interrelated via the fundamental features for a particular raw material-process system; nor have ~ similar data been related for different systems.

Jan 1, 1986

By D Jones

The development, piloting and engineering design of an innovative water treatment system for process water produced by a uranium mine mill are described. The process incorporates lime/carbonate softening (Stage 1), reverse osmosis (Stage 2) and biopolishing (Stage 3) to produce water of quality suitable for release to the receiving environment. Comprehensive performance data are presented for each stage. The unique features of the proposed process are: recycle of the lime/CO2 softening sludge to the uranium mill as a neutralant; potential use of power station off-gas for carbonation; and the potential recovery and recycle of ammonia from the RO reject stream.

Jan 1, 2003

Explosives have been an important tool for unlocking minearl wealth from the earth's crust for several countries. In'the past, innovation in explosives technology, spurred on by industry needs has assisted the Mining Industry to improve productivity and reduce costs. A symbolic relationship exists between Explosives and Mining. Australia has vast mineral wealth. Our Mining Industry is of major importance to the Economy., The value of mineral produc- tion in 1987 was $25 million or 10% of GDP. Australian Mining is a business depending on international markets. The Mining Industry is our leading export earner, generating 44% of all export income. 60% of mineral production is exported. About half of these minerals are extracted using explosives. Explosives rank as one of the top three consumable expenditures for a mine. For example: A major open-cut iron or coal mine can spend $6 million dollar per annum on explosives.

Jan 1, 1988

During the last 20 years, manufacturers of Australian iron have given increasing attention to development of external markets for processed blast furnace slag. Slag has been in widespread use overseas and data on the performance of Australian slag in concrete lave shown it is suitable for that use. Chemical and physical properties of typical Australian slag products including air cooled, granulated and pelletised slag are discussed and compared with local natural aggregates. Special attention is given to pumping achieve- ments with slag concretes and the observed durability of concrete after many years service. More'recent applications for granulated slag as a sand replacement are discussed. It is concluded that'whilst more wide- spread use of slag is possible, the cost of marketing and transporting slag are likely to restrict opportunities unless for local usage.

Jan 1, 1979

By Jensen B

The approach of using the Coward Triangle for the analysis of flammable mine gas mixtures has been examined for its application, to the flammability of coal dust/gas/air mixtures. Explosible lean limit and rich limit concentration data for dust/methane/air mixtures are examined and illustrated using co-ordinate geometry. It is concluded that a three-dimensional envelope representing hybrid explosible mixtures can be drawn. The dimensions of this explosive zone will vary with the characteristics of the coal dust and the gaseous composition of the mine atmosphere. Further research is needed to establish these dimensions for important mined seams.

Jan 1, 1994

By E Villaescusa

This paper describes a methodology for the design of mine pillars at the McArthur River Mine. The pillar strength is calculated using a method that accounts for confinement, pillar geometry and intact rock properties. The average pillar stress was calculated using in situ measurements of vertical stresses at shallow depth and the tributary area method in conjunction with numerical modelling. Observations of pillar behaviour indicate that an existing pillar stability graph may be slightly conservative and further adjustments for the local rockmass conditions are needed. The results to-date indicate that all mine pillars are stable for a range of mining geometries at McArthur River Mine.

Jan 1, 1998

In preparation of this Paper, the emphasis has been laid on the commercial rather than on the technical and scientific aspects of coal evaluation. It is intended to describe and comment on the principal factors which currently determine the selection and procurement of coking coal for the steel industry, and is not based on the results of any original research by the author. Evaluation of different coals for strictly thermal uses, for gas production or other chemical applications has not been attempted, and comparisons of coal with other fuels have been excluded: the paper is concerned only with coals for the production of blast furnace coke. The discussion is strongly related to, and illustrated by, British, and to some extent, other Western European practice, but it is hoped that the general conclusions may have a wider application.

Jan 1, 1975

The excessively high cost of production in underground coal mines has made the survival of many coal mines around the globe economically non-viable. The global competitive coal market speaks itself of the desirability of a lower operating cost in conjunction with a higher productivity performance, particularly in underground coal mines, and calls for an optimal production planning under a host of constraints. Such a task of optimal planning is not an easy exercise like that of traditional planning based merely on intuition, experience and subjective judgement. It essentially demands a thorough understanding of the complex interaction of mine sub-systems for judicious application of optimisation tools and techniques available with operations research. A few large mines around the globe have made an effective use of a sizeable number of operations research packaged programs for optimal decision-making (Grayson, 1989). The success of practical applications of operations research techniques made in a variety of mining problems in large mines in different parts of the world will hopefully make inroads to smaller mines in years to come. The present paper is an addition in the series of such applications of operations research tools to mining problems, particularly with reference to an underground coal mine in India. The paper is based on research work (Jawed, 1990) and deals with the development and use of a mathematical model for production planning in underground coal mines under multiple objective environment subject to a host of constraints.

Jan 1, 1995

By C J. Noack, P B. Ganza

The concept of large trucks underground has been around for some time. While the road train concept is gaining momentum, there are underground mining applications where these trucks have not been suitable. Unfortunately few of the ægreenfieldsÆ projects that are most suited to the road train concept have come æon lineÆ since the underground road train was first introduced to Australia in 2001 so that the trucks have generally been adapted to existing operations. As at December 2004, there were 17 road trains operating underground in Australia, one being rebuilt and one under construction. This paper addresses the necessity for the mining industry to have an integrated ore transport system that starts at the underground load haul dump unit (LHD) in the stope production area and finishes at the crusher feed at the processing plant. Chute and orepass designs are investigated, as well as feeders to determine the best load and haul system for large-scale trucking. The paper also discusses potential developments in the large truck scene. The paper highlights the cost and productivity gains by introducing large trucks and associated integrated ore transport systems underground. While 400 vertical metres was seen as the limit of vertical hauling in the 1970s, one kilometre is a common discussion point for trucking limits today. In real terms the cost of underground trucking (including ownership costs) has decreased from $1.50 - $2.00/t.km in the mid-1990s to $1.00 - $1.20/t.km at present.

Jan 1, 2005

The Queensland Department of Mines believes it is in the best interests of the gold mining industry to reduce and control the environmental impacts from gold mining since that is the community expectation.The Department of Mines has set as a special condition of many recently granted Mining Leases the requirement to submit a "Description of Operations" for the approval of the Minister, prior to commencing initial mining operations. In order to facilitate compliance by lessees with this condition an explanation is given of the reasons for this condition and how it is intended to achieve the objective of environmental protection.Environmental impact is operations dependent. Impact on a lease will vary quite significantly with the scale and methods employed. Before a lease can be granted and mined it is therefore necessary to have this information. The parameters of operations most critical both in terms of environment impact and economic viability are worked out and agreed with the lessee before the lease is granted. An approved description of operations which is required now, prior to the start of mining, provides the details of that agreement for the security and benefit of the lessee and the inspectors. It also provides the details of operations and environmental controls which were not required prior to the grant of the lease but are nevertheless required and necessary for compliance with the environmental standards.

Jan 1, 1986

Strata bolting/dowelling reinforcement techniques are being reintroduced into the mines of the National Coal Board. There are strong reasons for the selection of the full hole anchorage principle of bolting and for the development of the wood/resin dowel. There are strong reasons also for the measurement of strata bed separation as the method of assessing the effectiveness of a roof bolting system. There are several designs of bolts. Instruments have been developed for investigation and control purposes. Different drilling and bolting machines have been employed in trial sites. In addition comparative laboratory model work has been conducted on simple non-bolted and bolted systems.

Jan 1, 1971