Search Documents

By Sorokin AP

The main regularities of the tectonic history of the Circumpacific belt's Asian segment are discussed. The established longitudinal metallogenic zoning is characterized by essential copper specialization being replaced in the.continentward direction by tin-tungsten and then by copper-gold-molybdenum and-tin-lead- zinc ones. The zones indicated show specific magmatism and ore forming fluid composition. The eastern margin of Eurasia experienced specific tectonic history and exhibits a wide variety of mineral deposits. It is composed of the Siberian and Sino-Korean cratons and of the largest mobile elements of tectonosphere like the Hyperborean, Urals-Mongolian, Mediterranean and Circumpacific belts. The Earth's Atlantic segment mobile features show deep penetration of their geosyncline-fold systems into the eastern margin of Asia. A good example is the Urals-Mongolian belt, its Intra-Asian branch being located within the continental margin. The Intra-Asian structural features have WE and NE trending, while folding process moved southward : Karelides and Baikalides are found in the Transbaikalia and the Soviet Far East (Stanovoy, Bodaibo-Patom, Baikal- Vitim, Selenga-Yablonovy fold regions)

Jan 1, 1987

A review of major mineral processing and extractive metallurgical developments is made and current areas for research are discussed.

Jan 1, 1975

In those days no one worried - there were plenty of other things to do. But in'these days it is different. Everyone worries- and. because there is so much worry, emotion has entered the picture. And, worse than that, capital is being made in political circles. People who were quite unaware, five years ago, that any problem existed, have now become experts on the subject, and shout to high heaven that something should be done - and yet they go on using the leaded high octane petrol they deplore so much. And even scientists, who should know better, adduce only such evidence as fits the argument in hand. And the Press is not without blame - some of its reportings is open to serious question, whatever may be the excellence of its motives. The point is made that one should know what one is talking about. And make sure that the evidence quoted is fact - and make sure too, that all the evidence is used, not only that which suita the argument.

Jan 1, 1971

Metal grades and contents of ore deposits should be measured in an unbiased manner, and with a degree of precision that reduces to an acceptable level the risk to put into production inviable prospects. The additive property of variances for metal grades and contents is used to assess the accuracy and precision characteristics of this measurement process. Each stage in the process of extracting different types of samples from ore deposits, preparing test samples from drill core sections, drill chips or crushed ore, and collecting and assaying test portions, contributes a variance component to the intrinsic variability of a metal's distribution in its matrix. Deducting such extrinsic variances results in more precise estimates for metal grades and contents of elementary units. The cumulative metal content for a set of elementary units of in-situ ore, and the sum of the variances for metal contents of all units in the set, can be used to calculate confidence intervals and confidence ranges at different probability levels as measures for risk.

Jan 1, 1976

By Y Wu, F-J Ping

Today, coal production accounts for about 65 per cent of the nationÆs gross energy in China. By the year 2010, the output of coal is planned to increase to 1.65 billion tonnes and by the year 2020 to 1.9 - 2.0 billion tonnes. To meet these energy needs the Chinese coal industry is developing underground coal production on a massive scale. The new drive introduced by using direct torque control (DTC) is now proven technology for mine shaft hoisting. The drive offers unequalled speed and torque control performance as well as a low impact on the supply network by controlling the power factor to unity with a minimum of harmonics distortion.

Jan 1, 2005

The Prospero orebody is a part of the Helene mine at Cosmos and was scheduled to begin production in March 2008 after the exhaustion of the Tapinos orebody in the same mine. Treatment of the Tapinos orebody was challenging and it was envisaged that Prospero would have similar properties given that it was also anomalous in deleterious elements and would be of a similar mineral hosting. It was deemed necessary to undertake a metallurgical test work program to identify any potential processing issues, complex mineralogy or significant metallurgical domains. The paper discusses the processes which were employed to undertake the metallurgical test work program and describes the aspects that can be employed by other developers to quickly and effectively assess potential future orebodies. It will demonstrate that the work was successful at determining expected metallurgical behaviour, providing direction for mining operations and highlighting areas for more extensive research.

Jan 1, 2009

By Restarick CJ

A compound cylinder-cyclone system, fitted with a flow control valve between the cylinder and cyclone, has been used for coal slurry sizing experiments in the range approximately 100 to 300 micrometres. An important feature of the system is the ability to adjust the cut size of the separation over wide limits by adjustment of the flow control valve. Results have been compared with typical fine screening operations. Under roughly equivalent conditions the compound cyclone system can achieve better elimination of extreme fines, but is not as sharp as the screen for coarser size cut-off. Simulations of systems involving combinations of the cylinder-cyclone system with screens indicate that the advantages of both sizing devices can be combined to yield accurately sized products for fine coal cleaning, at much less cost than using screens alone.

Jan 1, 1984

By P Sutton

The global goal of Sustainable Development is not achievable without major changes in the way goods and services are delivered and material needs are satisfied, which requires tremendous innovation in the supply chains and life cycles in which minerals and energy processing take part. Values derived from minerals and metals processing need to be delivered with a fraction of current ecological impacts, which means removing technical obstacles to eliminating waste and emissions in the minerals cycle. The challenge is to find economically attractive ways to get there, through eco-efficiency gains in existing operations, capturing regional synergies, streamlining and greening the materials supply chain, and commercialising new process technology and new products. This paper summarises the outcomes of the Sustainable Resource Processing project, which was designed to provide a strategic analysis of what sustainability means for minerals and metals processing and how that can be effectively translated into technical and business innovation.

Jan 1, 2002

By Tapponnier P

In North Vietnam, large ductile shear zones are observed along the Red river fault and the Dienbien fault. Left-lateral sense of the Red river shear zone is related to the direction of shortening E-W. NE dipping foliation planes is subvertical. Stretching lineation is subhorizontal ( 25¦). Left-lateral slip observed in the Oligocene Yansun granites demonstrates the major tectonic phase in Neogene, The stress field established from microfaults observed in triassic limestones, Oligocene granites and Neogene Conglomerates. Measurements of striations on fault mirors are used for calculating the stress tensor and for separating tectonic phases. Two tectonic phases in tertiary are separated : first tectonic phase related to the compressive direction E-W corresponds to the major tectonic phase represented by NW left-lateral shear zone. Second phase having the compressive direction N-S associated with the right-lateral movement of the Red-river fault zone opening of the Eastern sea and the Red-river and the Red-river delta is associated with the left-lateral movement along the Red-river.

Jan 1, 1990

By S Moradi

The thickener overflow of zinc concentrate, obtained from flotation process in the Angouran plant located in Iran, contains a large quantity of slimes which were transferred to the tailing ponds. These slimes have caused problems of storing and environmental aspects in the Angouran area. The objective of this research is to describe the extraction of zinc from these slimes by leaching method using sulfuric acid in pilot plant scale.Chemical analyses showed that these tailing materials contain 35 per cent of zinc. By XRD analysis, smithsonite is identified as the major constituent. Calcite, dolomite, and cerussite are found as carbonate minerals. A minimal amount of Zn occurs as hemimorphite. Quartz, kaolinite, clinochlore and muscovite are other silicate minerals in the slimes.In the optimal conditions, ie acid leach at pH of 1, temperature of 55¦C, reaction time of 120 minutes and solid-liquid ratio of 1:3 and neutralisation with Ca(OH)2 at pH = 4.5, temperature = 70¦C, time = 90 minutes, the total recovery of zinc obtained was 95 per cent.

Jan 1, 2004

By McGregor GW

The Utah International group of companies has a wide geographic spread of operations, including a significant interest inAustralia's largest coking coal operation in Queensland, steaming and coking coal mines in USA, a copper mine in Canada, a half interest in an iron ore operation in Brazil, a number of smaller operations, and a significant portfolio of undeveloped properties in South America, South Africa and South East Asia.The opportunity to acquire this group of companies presented an immediate problem to BHP in that it was regarded as too large for BHP to absorb by itself. In addition, there was a concern that such an acquisition would increase BHP's coking coal exposures to unacceptable levels. Despite these dilemmas, BHP was keen to acquire Utah.A plan was therefore developed and agreed to by General Electric (GE) (the then owner of Utah) which would give BHP nine months in which to put together a consortium to share in the ownership of the Queensland coal assets (plus coal assets owned by BHP), and to arrange a project financing for use by BHP and the consortium. BHP would own 100% of the rest of the assets.

Jan 1, 1985

By M.E. Crump

Gallium occurs at above background levels in most samples collected from 11 of the major geothermal areas in the Taupo Volcanic Zone. Concentrations of Ga in the 48 samples ranged from 8 to 144 mg kg-' and varies widely from place to place within each geothermal area. Gallium is contained within the alumino-silicate structure of clay in the mud, having substituted mainly for Al. Suggested deposition mechanisms for Ga also involve co-precipitation with Sb, As, and SiO. colloids. Digestion trials, carried out to determine extraction conditions for possible commercial exploitation, showed that heating the mud to 500 -600¦C for 1 hour followed by acid/alkali treatment gave complete recoveries.

Jan 1, 1995

The development of paraprofessional courses in metallurgy and related disciplines, by the Department of Technical and Further Education in New South Wales, is outlined in this paper. The changing nature of metall- urgical educational requirements is summarised, and various attendance patterns discussed. The potential advantages of the sandwich system of College attendance, to the more distant sectors of the mineral processing and metallurgical industry is outlined. Some of the likely future trends in technician education are presented. These include the need to respond to the changing expectations of technician employers, as shown by industrial surveys, the role of experiential learning, the need to integrate courses so that students can build on prev- iously completed courses, the possibility that future technicians will require a multi- disciplinary background and the provision of easier access to technical college facilities by potential students and industries.

Jan 1, 1978

By Arndt MB, Bamberg S

The evaluation of risk is becoming more important in the siting of mining operations in the United States as well as the rest of the world. The determination of environmental, economic, as well as health and safety risks is an important step in the planning of any mining operation. Hydrogeology plays an important role in pre-mine planning and in the determination of these risks. The mine operators must determine if ground water would inhibit mining in any way. Factors which are important to consider include mine dewatering economics, slope stability, and other adverse hydrologic impacts. This paper presents methodologies for the characterization of hydrogeological risks for a mining operation. First of all, the term risk analysis is defined and its utility is addressed. Then, stepwise methods for performing a typical risk analysis are presented. Finally, the application of risk analysis to hydrogeology in mining is given. With slight modification, it is believed that these methodologies can be used to evaluate the hydrogeological risks for any mining operation.

Jan 1, 1988

Workplace Centred Learning, (WCL), is a learning strategy which helps organisations cope with the constant change in skill requirements that is part of business today. WCL focusses on the specific needs of the workplace and provides the structure and sets the standard whereby the required competencies can be transferred between individuals. Learning is considered part of the job and ownership is achieved by involving individuals in all aspects of the learning system. Each individual in a WCL system is considered both a learner and a teacher. A significant advantage of WCL over conventional training systems is that it responds quickly to changing requirements, and once in place, becomes self-sustaining. That is, once implemented, the system provides mechanisms to detect and respond to changes in skill requirements as they arise. WCL is a competency-based system with multiple levels of validation. It provides a flexible approach to skills development that recognises both the needs of the workplace and the needs of the individual. WCL was developed in collaboration with ALCAN Aust Ltd and is currently being implemented by companies within Australia and overseas.

Jan 1, 1995

By Sheer T. J, Van Rensburg J P

The primary objective of this research was to address the demands imposed on self- contained self-rescuer (SCSR) performance dur- ing simulated escapes. The results clearly indicate that SCSR performance, apart from the inherent technological features, is a function primarily of the physical and anthro- pometric features of the wearer, and of the particular nature of the escape route. These factors consequently play a major role in the planning of any escape strategy, which may vary from mine to mine. It is therefore concluded that each mine would have to formulate its own escape strategy which in turn would depend on the choice of SCSR, and the particular escape Route.

Jan 1, 1988

In 1975, following a programme of solution characterization and small scale laboratory test work, a pilot plant was constructed to treat waste liquors from the Risdon works. The plant was designed basically to neutralize liquor to a desired pH, and to flocculate, thicken and then filter the resultant pulps. The primary objective was to purify waste liquors to stand- ards set by Tasmanian environmental regulations and at the same time to provide design data for construction of a full scale treatment facility. Waste liquors were divided into two groups, those from the Zinc Plant, and those from the Acid and Superphosphate Plants, and were treated independently. To satisfactorily purify Zinc Plant waste liquors the following reaction sequence was required: 1. Neutralization to pH 10.5 (with aeration for Mn removal). 2. Further reaction of neutralized pulp with Na2S at an addition rate of typically 5 mg of S2-/litre of liquor treated to remove Cd.

Jan 1, 1977

Open stoping dimensions are typically controlled by a number of factors including production drilling capacity, scheduling, fill constraints, orebody dimensions and host wall rock conditions. Frequently host wall rock conditions are the key control on stope dimensions. As a new mine is brought into production, there is a steep geotechnical learning curve for those associated with the development of the mine. Initially, the experience and observations gained at other mines is used to guide the stope design. As experience is gained at the new operation, site specific techniques can be validated for use. This has been the case at BHP Cannington, where a heavy emphasis has been placed on the validation of empirical stope stability techniques for site specific conditions and experience. A range of empirical and numerical techniques can be applied during the design of open stopes. The empirical techniques are an experience based application of known performance levels during the design of open stopes. The numerical modelling and structural tools can be used to compliment the empirical techniques so that an understanding can be gained of the likely stress and structurally controlled failure mechanisms.

Jan 1, 2000

Financial markets are subject to constant change and project finance, as a product within these markets, adapts and will continue to adapt with those changes. A meaningful discussion of these adaptations requires an understanding of differences between non-, limited and full recourse project finance. The reasons sponsors seek and lenders provide project finance are also pertinent in this context. Arranging a project, financing package can be a canplex and time consuming task. An important first step is choosing the right advisor for the assignment and then structuring and tailoring the financing before approaching prospective lenders. The last thirty years has seen changes in the needs of sponsors and the ability of lenders to meet them. These shifts in preference may well be a guide to the future. Several major project financings successfully canpleted in Australia in the last few years and more recent examples are broadly discussed. Project finance will be keenly sought in the future and the form and nature it takes will continue to vary.

Jan 1, 1983

The economic future of the Palmer Goldfield lies with both the gold mining and the tourist industries. An equitable solution to the competition between the two involves putting a dollar value on the historical evidence there for our Australian heritage.On 23 October 1986 the Queensland Government gazetted the Palmer River Reserves R16 of 16 200 hectares, in recognition of the competing land uses emerging in the region. The intention is that historically significant gold mining sites and relics will be preserved in situ with provision for continued gold exploration and mining.This paper explores and explains the administrative process of achieving a set of Management Guidelines for Rl6 within the Queensland political milieu. The result of that process is the achievement of some of the highest preservation standards in Australia, prohibiting surface disturbance of defined Category 1 sites, and no mining proposal has yet been refused approval.The Palmer Goldfield R16 experience is a major step in achieving a co-ordinated approach to both current mining and preservation of Queensland's mining heritage.

Jan 1, 1990