Search Documents

The recent description provided by Scott (1981) of the Ardlethan alteration systems is of particular interest as it draws attention to the analogy between Ardlethan and the porphyry tin systems of Bolivia (Sillitoe et aI, 1975).During 1978-1979 a parallel study of the mineralization confirmed that the extensive alteration pattern relates to a series of breccia pipes which provide access channelways for the mineralizing solutions (Clarke, 1979). Many of the results reported by Scott are difficult to interpret without this concept and this short discussion is intended to provide additional perspective to the proposed porphyry tin model.The breccia pipe systems are centred upon each of the major mineralized zones (Wild Cherry, Carpathia, Stackpool and White Crystal) and with the exception of the White Crystal collapse breccia the major pipes are of the hydrothermal intrusive type. They range considerably in size and shape and at least two ages of formation are revealed by their cross cutting relationships at the Stackpool, Carpathia and Ardwest regions. Individual pipes or groups of pipes have distinctive alteration/infill characteristics and the entire system can be viewed as a complex porphyry tin system evolving with time. The recognition of pipes of different types and ages reveals a situation considerably more complex than suspected by Scott, and hence both the geochemical data and modelling require reinterpretation.For instance, the geochemical data contained within Tables 2 and 3 (Scott, 1981) relate to two separate breccia pipes which correspond to the South Cherry and Ardwest ore zones respectively. Although it is probable that both pipes are temporarily identical it is important that the geochemical data be viewed in context. The brecciation is extremely difficult to recognize and it is probable that the chemical compositions given represent mixtures of altered fragments and rock flour, together with material precipitated from solution as matrix, along microfractures, within small vughs, etc.

Jan 1, 1982

By B Cooper

During the design of a new production facility for a greenfields or significant brownfields expansion many design decisions are made driven by an unquestioning objective to achieve 'lowest cash-cost' production costs. In many cases this translates to a design and operating philosophy based on largest-available, single-line equipment. Although acknowledged as an approach that is efficient from an operating cost perspective does this approach always maximise shareholder value? There is an increasing awareness in the mining industry of the value of project flexibility, robustness and value options. The design of a new production facility creates a window of opportunity which should be structured to ensure that project value options and robustness are understood and exploited. This requires the use of emerging valuation methodologies, such as Value-at-Risk and Real Options, as well as tried and trusted NPV/IRR approaches. The paper provides an overview of the basis and application of these less well known techniques in the context of metallurgical plant design. Design guidelines that demonstrate how value options and flexibility can be quantified from both a risk and value perspective are presented. Issues such as use of single versus multiple line equipment, optimum cut-off grade and improved exploitation of the inherent variability of the orebody are also examined. Finally the management issues and approaches to achieving this will be briefly discussed; for example it is common during project development to drive towards increasing certainty as rapidly as possible to facilitate 'accurate' estimation of costs. Understanding and exploiting value options requires a project culture that tolerates, and revels in, ambiguity and uncertainty û something that would make many project teams uncomfortable!

Jan 1, 2008

DIVERSITY There are plenty of examples to show that diversity has been the fundamental downfall of many organisations, particularly when you consider the international position. What about core business, the return of companies to key competence directions and market focus. The stockmarket for instance defines groups and companies in key groups of core business. The expectation is that companies toe the line and do not diversify across their areas of defined expertise. In essence, the market has given notice that the requirements are to focus and stick to our core business. So what right does the conference have to suggest that diversity is the key to prosperity. Hasn't the organiser read the book, studied the history, listened to the market - obviously not. Have they got it wrong, My feeling and belief is no - the organisers have got it right. However, the matter is not as simple as first perceived. What is Diversity, or Diversification as I would prefer? Is it a product position? Is it a geographic position? Is it an expansion or change in services offered? Does a gold mining company diversify into copper or diamonds or aluminium or nickel? Does a gold miner in Australia diversify into China or Kazakhstan or West Africa? How do the two relate? They don't. A successful company will always possess a 'core competence' not so much a 'core business'. The best example of this is the service company extraordinaire - McDonalds. They don't sell hamburgers or french fries, they sell a service, a convenience, a lifestyle. The core business is hamburgers and if McDonalds were to diversify further into new styles of hamburgers, I suggest to you they would fail. But if McDonalds were to diversify into other products based on their 'core competence', provision of service, then I would suggest to you they would be very successful. The service procedure, service machine, service system, the formula, stava the rnnetant the nrnrlnrte -

Jan 1, 1996

By Wu H. W, Just G. D

Australia's mineral resources boom in the two decades up to 1980 saw the establishment of about 25 new mining towns across the continent Quality housing and a high standard of community services were incorporated to attract a labour force for the major mine or mines i eing serviced. Town construction costs were high and were principally born by the private enterprise mine developer. There has been a change in the pattern in recent years and over 20 new mine developers have adopted a fly-in fly-out arrangement rather than construct new towns. Employees are drawn from a home base which is typically a large city, coastal community or established mining town and flown to the mine site for intensive work periods of about two weeks. The change has occurred for many reasons. Mining companies have been unwilling to support the high construction costs of towns, short life and smallermining operations do not justify a town, fast jet aircraft are available and there is a better perceived family lifestyle in established (coastal) communities. On the other hand reduced permanent development at new mine sites does not assist Australia's perceived need for decentralization. There have been questions as to the social problems which may develop from the artificial separation of the "breadwinner" from his family. The paper reviews a recent survey of the attitude of Australian mining companies employees, governments and unions to fly-in fly-out arrange- ments. The support for this approach is analysed and conclusions drawn that the concept is likely to be with the Australian mining industry for some time in the future.

Jan 1, 1991

By Broome A

In a technologically oriented industry, it is important to understand and apply technology very consciously to create competitive advantage. Technology is not an activity which is simply restricted to CSIRO or the research and technology department. Technology improvement is a part of everyone's role. It is a way of life - the technology facet of continuous improvement. For this reason, The AusIMM has organised this Travelling Technology Forum - a series of presentations about automation in mining. To make the message more accessible, The AusIMM had originally planned to take the Forum to four regional mining centres: Mackay/Townsville, Singleton, Burnie and Kalgoorlie, but only one seminar was held, ie at Singleton in March 1997. Seminars at other locations were cancelled because of insufficient registrants. The presentation by Andrew Logan of BHP Cannington was not available for the Singleton forum. The aims of the forum were: ò to heighten awareness of the key technologies and their impact in the minerals industry in the medium term; ò to foster creative thinking; ò to encourage people to broaden their technical and commercial skills and develop individual networks and linkages based on an interest in these key technologies; ò to share information on the application of these technologies in the industry; ò to promote an enhanced appreciation of the need for an innovative culture; and ò to encourage staff to consider post graduate courses in technology management. The AusIMM wanted to not only raise awareness about `automation in mining' issues, but also to get technology in a more general sense back onto `centre stage'. The Forum was generously supported by CSIRO, Western Mining Corporation Ltd, BHP Coal Ltd, Aberfoyle Limited, Goldfields Ltd, Novacoal Australia Pty Ltd, Pasminco Ltd, and RGC Limited. The program was endorsed by the Centre for Mining Technology and Equipment (CMTE). Copies of the full papers are available from the authors, see `References'.

Jan 1, 1997

The Inglewood Gold Project consists of several titles in and around the Inglewood and Wedderburn Goldfields which were purchased from Strata Mining Corporation (now Excalibur Mining Corporation). The Inglewood goldfield has a historical production of approximately 160 000 tonnes at 23 grams per tonne. The company has reopened and developed the Maxwells reef, picking up a high-grade shoot (Max Shoot) identified and worked by Goldquest et al up until 1994. Production ceased on a low gold price, rapidly reducing vein size and a requirement for further development. Greater Bendigo Gold Mines Ltd (GBM) has undertaken the development and encountered the mineralised vein in an increasing size setting with high grades and the existing mine development has access to a further shoot to the north (Max North Shoot). The Maxwells reef also contains the Woolf shoot south of the Maxwells shaft and an inferred resource of ~20 000 ounces is contained from 60 m below surface. Best intersection 2.9 m at 50 g/t. The Maxwells reef area produced approximately 20 per cent of the Inglewood goldfields production and GBM is preparing to increase its exploration efforts across the rest of the field. A processing plant has been constructed at the Maxwells mine site, which is capable of treating tailings, hard rock and alluvial material utilising gravity recovery. The existing Maxwells tailings have been excavated and treatment commenced. It is intended to produce a sand product from the tailings for resale and to reduce the storage requirements per tonne. Several large water dams constructed by Goldquest in the 1990s are being re-engineered to enable storage of significant tonnages of tailings. A level of surface and underground production is planned for 2008 and this is to be expanded into 2009 and beyond. The long-term future at Inglewood is envisaged as structural repeats at depth below the current workings and a project plan to gain deep access will be prepared on successful drilling results.

Jan 1, 2008

Basicity(aO2−) has been known to affect the physicochemical properties of molten slags in the metallurgical processes. However, because of the impossibility of direct measurement of single-ion activity, various indirect measures such as capacity, redox equilibrium of transition metal ions, activity of basic oxides, and (theoretical) optical basicity have been proposed; but these basicity measures have been restricted within slag systems and the interaction between measuring elements and slag components has affected the quantitative estimation of slag basicity. Recently, since it was reported that solubility of noble metals in molten slags could be an indirect measure of basicity, the influence of slag basicity on the solubility of platinum and silver has been reported. The reaction mechanism of platinum dissolution into basic slags has been reported, whilst that in acidic slags has not (Nakamura and Sano, 1997; Sano and Nakamura, 1997; Nakamura et al, 1998). Richardson reported that the solubility of metals such as cupper, gold, silver, and lead in the CaO-SiO2-Al2O3 slag was presumably dependent on the atomic radius and the accommodation ability of the silicate network (Richardson, 1974). Swinbourne and You measured silver solubility in the Na2O-SiO2 slag over a wide range of oxygen partial pressure and suggested that silver would be present as both Ago and Ag0.5 in the slags (Swinbourne and You, 1999). For brevity, these previous works discussed the dissolution mechanism of silver into the slags based on the existence of silver as a neutral or molecular species. However, because the almost chemical reactions occurring in the slag are affected by the basicity, the reaction formula with O2- ion is required based on the ionic characteristics of the slag such as desulphurisation and dephosphorisation reactions as given in Equations 1 and 2, respectively.

Jan 1, 2000

The mining industry was one of the first to be directly regulated by legislation in the 19th century when British public opinion was mobilised by reformers seeking social change. In the next wave of mining safety legislation, account was taken of technological advances in the industry, but again, the amendments were in large measure driven by public expectations following a series of disastrous mining accidents with great loss of life. The result was the prescriptive and detailed type of regulation that has, to a great extent, remained with and become a way of life in the mining industry of today. In 1970, the then British Government appointed Lord Robens, a former Chairman of the National Coal Board, to head a Committee of Inquiry to consider the arrangements then in place for preserving the safety and health of people at work and to consider and make recommendations on the need for change in the legislation governing such matters. The result was the 1972 report Safety and Health at Work which, in turn, resulted in the Health and Safety at Work etc Act 1974 (UK). This Act, which embodied the now familiar concepts of consultation with the workforce on matters relating to health and safety and the statutory application of the previously existing Common Law concept of the duty of care, became the model for much occupational health and safety legislation in many places around the world, including the various States of Australia. As a result of the `Robens style' of legislation, the regulators of the mining industry have had the opportunity to become less prescriptive and to introduce an `enabling' style in their statutes. This has not always been welcomed by the industry which has, to some extent, missed the comfort of knowing exactly what is required of it in order to ensure compliance with the legislation while appreciating the `self-regulatory' opportunities that the new style of regulation offered.

Jan 1, 1995

By M Stewart, J Vann, S Dunham

Geometallurgy is an emerging, cross-disciplinary field that integrates spatial models of rock properties with time-based outcomes of mining and treatment processes. Geometallurgical variables include any rock property that has a positive or negative effect on the business. Some of the more critical geometallurgical variables include recovery, grindability, throughput, power consumption, mineralogy and content of deleterious materials. These variables drive project costs and revenues in a fundamental way and thus geometallurgy has potential to positively impact on the value of strategic and tactical decisions across many mining organisations. Geometallurgical models, like traditional grade-only models are based on samples collected from the mineralised and non-mineralised regions of the deposit. The nature of some non-grade variables, particularly those that are dependent on the ore treatment processes, requires special consideration during sampling and subsequent spatial modelling. Failing to objectively consider the characteristics of variables may seriously compromise the validity of the sample selection, sample treatment, data models and the subsequent decisions. In addition to addressing the vexed question of collecting an æunbiased and representativeÆ sample, the sampling and modelling approach must consider issues of scale, both geostatistical support and also the relationship between bench-scale data and operational-scale mineral processing performance. This paper proposes a framework (the Primary-Response framework) for the classification of geometallurgical variables. This framework is designed to assist with developing sampling approaches and identifying the most appropriate spatial modelling approach. The proposed framework can also help identify the risks associated with designing, sampling and modelling of both types of geometallurgical variables. The Primary-Response framework divides variables into two categories; primary variables and response variables. How a variable is classified in this framework depends on the degree to which the variable reflects either an intrinsic attribute of the rock (æprimaryÆ) or its response to measurement processes (æresponseÆ). Depending on the classification in this framework, appropriate sampling and modelling decisions can be made to minimise the risk associated with the incorrect treatment of the variable. In particular, the authors argue that for response variables, the approach taken to building spatial models may need to be different to conventional linear averaging approaches (for example kriging).

Jan 1, 2009

The Australian mining industry is at an interesting stage in its development. Of the large number of mining companies in Australia, some are still solely domestic in their focus. others have made their first tentative forays offshore, and others are global players of significance in the world industry. It is not long ago that the entire industry was almost exclusively domestic in its focus. Very few companies before the early 1980s had ventured offshore, and those that did so were considered quite risque. The initial moves were made mainly by large companies who could afford to lose the funds expended in getting started in a range of offshore locations.

Jan 1, 1995

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

By King MN, Travis IC

PISCES - the Planning and Information System for Coal Export Services has been developed by Port Waratah Coal Services (PWCS) to ensure the efficient and economic operation of the Hunter Valley Coal Chain. PISCES is a computer based integrated information and management system to coordinate operations commencing at minesites through the coal chain to shiploading at the Port. The PISCES system comprises a central database around which a number of planning modules interact. These include interactive programs for train planning and timetabling, stockpile management, berthing analysis and a coal shippers enquiry system. PWCS has previously developed - number of computer based systems for planning, controlling and monitoring complex coal handling operations and the extension of the PISCES system to the Hunter Valley Coal Chain is another initiative to assist the Hunter Valley Coal Export Industry in looking confidently towards the Future.

Jan 1, 1987

Until early-1997, Mount Isa Mines Limited (MIM) generated electrical power for most of north-west Queensland. The discoveries of many new orebodies in the region meant the inevitable increase in power generation requirements for the new mines. In addition, the expansion at Mount Isa itself meant that MIM had to invest in new generating capacity or utilise the existing generating plant more effectively. Using its generating plant more effectively required MIM to undertake rigorous energy management within its own operations. A personal computer based system with a wide area network was installed as the basis for energy management. The result was that energy consumption was reduced, the need for additional generating plant was curtailed, and capital outlay for the generating plant that was required was delayed. As a direct result of energy management, carbon dioxide emissions were reduced substantially.

Jan 1, 1998

THERE are few industrial and metallurgieal processes which do not require the application of heat energy, and the modern demand for increased working efficiency has resulted in attention being paid to temperature control as a means of ensuring fuel economy and more efficient plant operation. In general, mill accuracy required is not very contant in laboratory work, and few industrial operations are controlled to within less than 5° while in many cases greater limits are allowable. Almost every thermal property of matter has been suggested as a basis for the construction of pyrometers, but the thermo-electric type finds by far the widest application, and hence this paper will deal only with the principles, construction, and uses of this type of instrument. THERMOELECTRIC PYROMETRY.In the year 1821 Seebeek discovered that if the ends of two dissimilar metal wires were joined and one junction heated, a current flowed in the circuit, and the KMF (electro-motion force) set up could be measured by inserting a galvanometer at the cold junction. The phenomenon was not thoroughly investigated for many years, but, as the demand for high-temperature thermometers increased, several investigators, of whom Le Chatelier was one of the pioneers, successfully endeavoured to utilize the principle in pnometric construction. The couples which gave the most satisfactory results were discovered, improvements were made in material and design and the present-day type of instrument gradually evolved. The apparatus consists of three main parts, viz. (1) The thermo-couple itself of two dissimilar metal or alloy wires together at one end. (2) The leads which connect the terminal of the thermo-couple with the measuring instrument.

Jan 1, 1923

By Guoqing Cao, Xinghong Wang, Fuqiang Liu, Rong Shen, Xiaoping Yuan

In this paper, an approach is proposed to monitor the rate of lump coal based on image processing. Using this method, we effectively improve rate of lump coal on comprehensive mechanised coal face.

Jan 1, 1998

By Scott RM

The project management and construction plans adopted by Davy McKee for the Cooper Basin Liquids Project resulted in a project notable for the Relatively short duration from initiation of the design through to liquids production. Two locations were involved, one at Moomba in the far northeast of South Australia some 800 km from Adelaide, and the other at Port Bonython some 40 km from Whyalla. Total expenditure by the owners at the two sites was in excess of $600 million. Matters covered include organisation, transport, construction, industrial relations, project services and commissioning.

Jan 1, 1986

Underground mechanized excavation in New Zealand has become more commonplace in civil and mining applications during the last three years. At one stage up to seven Dosco Road- header machines were being used on different projects around the country. The Huntly West Mine Drifts inclined at one in four were by far the most severe grade conditions that the machines were subjected to; however, other operations posed their own particular problems for the machines. Two major interrelated factors became evident as soon as the machines commenced at Huntly. These were traction problems on the grade and control of water, particularly on the invert.

Jan 1, 1978

In an earlier paper(l) details of a laboratory method of extracting and separating tantalum and columbium oxides from tantalite have been given. In view of the fact that Australia may have need to be self sufficient in this field it was decided to erect a pilot plant for the production of tantalum oxide in the Metallurgy School, University of Melbourne. The plant was designed for treating about 40 lb. of ore in a batch over a period of two weeks, although; because of the sectionalized nature of the process, the capacity of the plant was 40 lb. ore per week.Australia is fortunate in possessing some very rich tantalite and columbite deposits, particularly in the Pilbara District in Western Australia. The ore used in this work was obtained from a small but high grade deposit near Greenbushes, Western Australia, and consisted of lumps, weighing up to 8 lb. each, of almost pure ferro-tantalite with occasional thin veins of the very' rare' mineral stibiotantalite.The main constituents were:

Jan 1, 1946

By A J. Moore

The Australian Coal Association Research Program (ACARP) funded project, No C14057, entitled æEffect of Blasting on InfrastructureÆ, has been carried out with the objectives of providing methodologies for the assessment of the strength of infrastructure types and the establishment of responsible and realistic limits. Personnel from Melbourne, Newcastle and Swinburne Universities and Terrock Consulting Engineers conducted the project. Infrastructure types including: conveyors; power transmission towers; wooden power poles; electrical substations; pipelines, bridges; public access roads and underground workings have been investigated by both field studies and structural analysis. Railways, underground telecom cables, dams and industrial buildings have been reviewed using general structural analysis. This paper has been prepared for the mining industry to provide a progress report on the project.

Jan 1, 2007

By Lane D. P, Malone J. G

The slag fuming furnaces are the major bottleneck in the BHAS zinc production flowsheet. Intensification of the fuming process could significantly reduce this production restriction. Oxygen enrichment was proven to be a means of intensifying the fuming process. This procedure resulted in higher slag bath temperatures, and development work was undertaken towards obtaining accurate slag bath temperature measurement and control. Slag bath temperature measurement techniques were evaluated, with infra red optical pyrometry established as the system with the most potential for continuous temperature measurement and control. Oxygen enrichment resulted in a zinc production capacity increase of 1 000 tonnes per year. An oxygen enrichment technique was developed which both minimized the risk of furnace damage and made the most efficient use of the enrichment oxygen.

Jan 1, 1989