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By U JSger

The Westerschelde tunnel will be the first permanent road link between the Dutch regions of South Beveland and South Flanders. Two tunnel tubes, each 6.6 km long, will be driven using the shield tunnelling method. The difficult ground conditions and a water pressure of up to 6.5 bar make great demands on the design. This paper describes the problems and their solutions.

Jan 1, 1999

There are a number of methodologies which can be used for the preparation of environ- mental impact statements. Selection of a method depends upon the type of project and the environmental characteristics of the area where it is to be built. Most methods are satisfactory for assessing impacts on the physical environment but less so for the biological. Major problems may arise in deal ing with sociological issues because value judgements are involved. Several methods of approaching problems of this nature have been tried with some limited success.

Jan 1, 1976

By Tapp BA

Australia, considered an energy and mineral resource rich country, is poised on the verge of a major mineral industry 'boom'. It has been repeatedly emphasised that this growth in the mineral industry will form the basis of future economic development. Currently the mining and mineral processing industries use some 32% of the annual primary energy consumption in Australia. This share, although large even now, will increase with the realisation of the 1980's production expansions to 40% by 1985. Two metal industries dominate the energy scenario; iron and steel and aluminium. Major expansions in the local industry will be dominated by the aluminium industry. This highly energy intensive industry has planned major increases in metal production throughout the eighties. The implications of exporting cheap energy to pay for expensive oil imports, the ramifications on Australia's infrastructural ability to supply these major energy needs and the other options that might be

Jan 1, 1981

Access to secure and reliable water resources is fundamental to the minerals industry. In recognition of that requirement, and cognisant of extensive contemporary public water debate and reform initiatives in Australia, the Minerals Council of Australia (MCA) approached the Ministerial Council on Mineral and Petroleum Resources (MCMPR) proposing the establishment of a Joint Working Group to prepare a framework of strategic principles to ensure responsible water management at a site and corporate level, manage risks and identify opportunities. The Framework provides high-level guidance on issues that should be addressed in water decision making across Australia in relation to mining and associated processing operations. It identifies principles and objectives for adoption in four areas, viz: valuing water, strategic water planning, implementation, and engaging stakeholders. Given the high level nature of the Framework, and its national application, it does not seek to replicate detailed guidelines already widely available in each state and territory on operational water management practices and associated regulatory issues at mine sites. The Framework includes a series of case studies from across Australia that demonstrate where strategic thinking, wise water management and close consultation with stakeholders has delivered better water use, more profitable operations and excellent community/stakeholder relationships. The Framework was formally launched on behalf of MCMPR by the Western Australian Minister for Resources at the MCAÆs Sustainable Development Conference in Perth in October 2006. No full paper available for this extended abstract

Jan 1, 2006

By Miller J. D

The mechanism of adsorption of gold from alkaline cyanide solutions by carbon has been the subject of much research over the past decade. In this paper, the nature of the gold cyanide adsorption phenomenon is investigated, particularly with respect to carbon substrates and associated surface adsorp- tion sites.

Jan 1, 1991

Geochemical data on Australian granites and pegmatites9 and the.,mineral.components of these rocks, is presented and compared with that obtained in similar studies in.the U.S.òS.R and:.elsewhere.The petrochemical character of tin granites and the trace.-chemistry of their component minerals, particularly biotites, have some significance as ore guides in prospectingfor tin.The primary geochemical dispersion of tin can be readily tested both in the laboratory and field by colourimetric methods, after volatilization with ammonium iodide, using modifications of.the method described by Wood (1958).Secondary dispersions of tin in residual soils or.alluvia can likewise be readily tested by rapid colourimetric methods in the field, but simple hydraulic methods,.handling larger-. sample volumes, give reliable outlines of dispersion patterns.

Jan 1, 1963

Although geophysical methods of prospecting have proved indispensable in the search or oil deposits elsewhere; it is only 'in recent years that they have been used to any significant extent in Australia. The increase in their use has been quite remarkable over the past two or three years, due in Sao small measure to the encouragement given by means of Commonwealth subsidy. There is no doubt that the use of' geophysical methods will coxi-tinue to increase and this increase could be greatly accelerated as and when oil is discovered in commercial quantities,This review of their use A in Australia and the remarks and statistics are confined to work on the mainland. There has been, a substantial amount of geophysical work in Papua, but as operating conditions are so very different to the mainland Papua has been regarded as a separate province.

Jan 1, 1962

By Alvarez A. R, Garcia H. l

A fuzzy expert system, DIME, has been developed, under Matlab v 5.1. to assess the coal and gas outburst risk in underground mining. Expert systems and fuzzy logic are powerful tools to manage information represented by linguistic statements,

Jan 1, 1998

The Court rejected the suggestion that CRAE had actively misled DMR concerning the worth of its tenements. The Court agreed that CRAE remained silent about certain significant information concerning CRAE's own tenement area. It was a significant question as to what duties CRAE'was under, given that it was in joint venture with DMR in respect of one of the tenement areas. Did that joint venture create an obligation on CRAE to disclose everything it knew? The Court said no. The Court said that the fiduciary duties were defined by the terms of the farm-in agreement between DMR and CRAE. When the Court examined the disclosure obligations within the confines of the contract, it held that CRAE had not breached those terms.

Jan 1, 1990

While specific definitions of the main categories of mineral reserves and mineral resources are becoming well established through the efforts of the Australasian Joint Ore Reserves Committee (JORC) and the Combined Reserves International Reporting Standards Committee (CRIRSCO), there has been perhaps less attention paid to the standardisation of language used in the definition and reporting of Mineral Exploration Results and a clear understanding of the transition to Inferred Mineral Resources. This is an area of significant importance to small and medium sized enterprises in the mineral exploration sector as it represents in many cases the only tangible information by which the reader or potential investor can evaluate the future potential of such enterprises. By its very nature information in the Mineral Exploration Results category is incomplete, and frequently complex, and it is open to a broad range of interpretation by readers of various competency levels and disciplines. Many will have a short-term speculative view rather than a long-term perspective, with others out deliberately to misrepresent the information, and as such it can have an enormous impact on investment decisions if the risks associated with this information being reported are not fully understood. Authors of reports on Mineral Exploration Results, who may be Competent Persons or company directors, have to put themselves in the shoes of the reader of the report, second-guessing if you like what the reader will understand by a report, which in many cases will be of a highly technical nature. This raises reporting dilemmas and questions that require to be understood and addressed. Looking at reports on Mineral Exploration Results from the other side, readers have a degree of responsibility as well, particularly if they engage in an advisory or communications role. The tendency of commentators, journalists, analysts, and bulletin board posters to over-exaggerate the significance of a particular exploration result is all too familiar. Questions arise here as well about whether there should be more regulatory supervision and control exercised over those who use this information, all of whom greatly influence investment decisions, and many of whom have no idea there is a Reporting Code, far less an understanding of it. Examples are given and questions raised to illustrate the dilemmas surrounding the reporting of Mineral Exploration Results. In order to retain credibility with markets it is incumbent on companies to be transparent, not to be selective and to report all material information. On the other hand, information has to be taken and read in its proper context in order to avoid fuelling dramatic and unjustified company share price escalation. Timing of course is another factor that can affect the market price of shares, which may be beyond the control of those making the reports. Emotive and imprecise language, however, when reporting Mineral Exploration Results, coupled by speculation, can trigger damaging short runs on shares and destroy credibility where formerly there was long-term promise. The paper will review how Mineral Exploration Results are dealt with in various jurisdictions, and conclude that there has to be a balance between prescription and the tempering of undue optimism on the one hand, and the entrepreneurial spirit, which the industry needs, on the other.

Jan 1, 2002

Severe development difficulties were experienced soon after in-seam mining commenced at Appin Colliery in'1962. Thirteen years later no significant pro- gress had been made in overcoming some aspects of this development problem. Some success had been achieved in destressing roadways both in development and pillar extraction. Longwall retreat mining had shown promise of being highly productive but at an extremely high cost in terms of development requirements both in number of roadways and intensity of support in those roadways. No real advance was made in the problem of driving the first heading of a group of headings under conditions of apparently high stress in directions other than the preferred mining directions, although failure of the roof in this heading did seem to give easier work in the subsequent headings driven particularly if they were driven on narrow centres.

Jan 1, 1976

By Upfold RW, Nguyen VU

The extraction and utilisation of metals and materials is the basis of modern civilisation, and will remain so for many decades, Traditional metals are facing some challenges and research is needed in specific areas, to improve metal extraction processes, to develop processes for newer metals and minerals, and to develop new applications, The shortage of metallurgists now becoming apparent in Australia is a further significant problem that needs urgent attention, and much more publicity is required for the Mineral Industry, as well as for the utilisation Industries,

Jan 1, 1986

By Granholm S

The current emphasis within the mining industry to reduce the cost of production has stimulated interest in the fields of maintenance and operational reliability of capital intensive mining equipment. From an economic point of view, high reliability is desirable to reduce the maintenance costs of the systems. Two graphical methods consider reliability analysis. The first one, the method of Total Time on Test (177)-plotting deals with the reliability data which are free from trend and serial correlation. The second method which is based on time dependent modelling approach deals with the data which are not free from trends and serial correlation. The examples show how these graphical methods can be used to calculate the optimal maintenance intervals for components or systems.

Jan 1, 1991

By T Iwadachi, T Fujisawa an, G R. Alvear

A large amount of Be2C and BeO is formed during the Cu-Be alloy production process, because beryllium is a highly reactive element. Carbide and oxide formation impairs the production yield and the quality of the Cu-Be alloy products, and therefore should be minimised. As a first step for solving these problems in the process, the following thermodynamic properties of the Cu-Be-C-O system were investigated. Based on the results, the equilibrium relations of the Cu-Be-C-O system were clarified and the operational conditions of the current Cu-Be alloy production process were also examined and discussed.

Jan 1, 2000

Silver and gold bearing ore from the Palmarejo mine, located within the Mexican state of Chihuahua, contains a complex mix of electrum, native silver, silver sulfides and silver chlorides. This paper presents a case study that describes the selection, development and engineering of a tailored process plant for the recovery of silver and gold from this ore. Process circuit feasibility study modelling, metallurgical test work and engineering studies are outlined. Options considered to optimise the recovery of the contained silver and gold are compared, based upon cost, operability, recovery and engineering aspects. Concentration by flotation was found to be the preferred primary recovery route. Intensive leaching of the flotation concentrate resulted in solution grades sufficient to allow direct electrowinning to be evaluated against the more traditional Merrill Crowe process. The flotation tailings stream is processed through a separate leaching stage as there is sufficient economic metal extractable from this stream. The processing flow sheet, which is designed to maximise the recovery from both the flotation concentrate and tailings, and to utilise a common metal production facility, is presented.

Jan 1, 2009

By Masszi D

INTRODUCTION The association of methane with coal has been known almost since coal was first mined and in general it has been considered the curse of underground coal mining. Historically, most of the effort to handle this methane has been directed at diluting it to a safe level and preventing an explosive mixture of methane and oxygen from forming in any part of the mine. This is generally achieved by in-mine activites. This approach has two principal drawbacks, the severity of which are dependent on local conditions. The first is that the activity associated with the handling of the methane is undertaken in the mine and there- fore competes with the mining activity for the limited space available. The second drawback is that the whole methane handling activity is generally a cost to the coal because methane is so diluted that it cannot be used. With the value of energy increasing thi; second drawback is gaining importance so th.u several mines in Europe and North America ;it,, now installing systems to recover the methane in a useful form. Two approaches are

Jan 1, 1982

By X Z. Sun, N Jiang, J H. Zhao, C X. Wang, L Y. Bai

In backfill grouting for underground coalmines, the filling materials strengthen the caving rock and support the overlying strata to reduce surface subsidence. The broken roof strata fail and collapse during mining operations without appropriate supporting measures being taken. It is difficult to perform continuous backfill mining on the working face of such roofs using the existing mining technology. Therefore, in order to solve the above problems, fly ash and mine water are considered as filling materials, and flow characteristics of fly-ash slurry are investigated through laboratory experiments and theoretical analyses. Laws governing the diffusion of fly-ash slurry in the void of caving rock masses and in the void between a caving rock mass and a basic roof are obtained and verified. Based on the results obtained from the above analyses and field conditions at the Zhaoguan coalmine, Shandong Province, China, a cave backfill grouting system of the hauling pipeline is developed and successfully tested at the 1703 working face. The results demonstrate that a filling rate of 43.46 per cent is achieved, and the surface subsidence coefficient of the grouting process is found to be 0.475. Compared to the total caving method, the proposed system is found to achieve a reduction rate of 40.63 per cent. This effectively helps in lowering the value of the surface subsidence coefficient. Fly ash and mine water, considered as primary materials in this study, also play a significant role in improving the air quality and water environment.

Nov 29, 2022

Flue gases from electrical power station boilers, roasting, metallurgical and chemical plants could be treated by flotation using conventional flotation machines. The flue gases are introduced into the pulp instead of the air. The flotation media is a suspension of Ca(OH)2 or CaCO3 or a solution of NH4OH etc containing Na oleate as collector and frother. The SO2 and dust content of the initial flue gases were experimentally reduced by 100 to 1000 times in one flotation operation. The velocity of the flue gases through flotation machines could reach approximatively 0.4 to 0.5 m/s and more against 1.5 m/s reached in scrubber absorbers used for this purpose, but the quality of purification is expected to be better for flotation, which is essential for the cases of heavy polluted metallurgical and chemical flue gases. For some chemical plants the flue gases flotation media may be different and more suitable as compared to the above mentioned media. The proposed flotation method could be used for separation of dry grinded ores in the form of aerosols, with a realisation of flotation from a closed space (gas bubble in the pulp) onto the interface liquid-air where the particles are attached inside the bubbles.

Jan 1, 1993

By V Narayanaswamy

SustainabilityÆs imperative of economic development in tandem with social advancement and environmental protection is widely accepted, but much debate remains about the practical implications for the minerals processing technologies and practices for the future. Experience in other industry sectors however suggests that sustainability can be a value-adding framework for innovation in processing technologies, business models and management systems. This position paper explores how sustainability can drive innovation in minerals processing, by reviewing pertinent ideas and experiences gained in non-minerals sectors. Sustainable innovations can generally be broadly ranked from incremental to transformative, with each category having its own typical improvement potential, timescale and technological and operational challenges. This leads to a æmud mapÆ for sustainable innovation in minerals processing with three distinct tracks: eco-efficient operations; sustainable plant design and sustainable processing. Competing models for the sustainable innovation process through either forecasting or back-casting, have in common the strong reliance on vision, perspective and competency, which in turn highlights the importance of sustainability frameworks. Such sustainability frameworks provide normative goals and option elicitation prompts to assist with the analysis of current processes and scoping of more sustainable alternatives. A comparative analysis of five prominent environmental sustainability frameworks revealed three cross cutting sustainability themes that challenge current resource processing technologies and practices. These are: fate of materials (zero dissipation of materials); compatibility of materials and processes; and materials intensity of industrial products and processes. Although the sustainability concepts presented in this paper have not been extensively road tested in the minerals processing industry, there is ample evidence that recent initiatives in the Australian resource sector illustrate the applicability of the proposed framework. It is therefore argued that more in-depth assessment of sustainable innovation concepts would be a valuable contribution to the sustainable resource processing theory and practice.

Jan 1, 2004

By D Stephenson, N R. Steward

“TerraFlowingTM” is a dewatering process that addresses both the value proposition of Tailings as a Resource™, and the safe storage of tailings. “TerraFlowingTM” incorporates two stages of cyclone dewatering followed by centrifugation of the final dilute tailings stream. In this process three dewatered tailings streams are produced; a primary cyclone underflow, a secondary cyclone underflow and a centrifuge pulp. These three streams can be combined, or used, in various configurations to achieve different outcomes. The ability to vary the cyclone and centrifuge operations and configuration enables this process to deal with tailings feed variations in particle size distribution and mineralogy and deliver consistency, or design variations, in particle size distribution, tailings solids concentrations and recoveries. Water recovery can be up to 85% of the total water in the tailings with a stackable final tailings product achieved if the three tailings streams are combined in the maximum solids concentration configuration. The primary cyclone can be operated to deliver a particle size distribution suitable for tailings storage facility embankment construction or alternatives such as concrete structures or shotcrete for support. The secondary cyclone underflow and centrifuge pulp is suitable for beaching deposition within the tailings storage facility.

Jul 1, 2021