Search Documents

By Ellis WK, Greenwood-Smith R

A nuclear technique for the analysis of copper in bulk materials has been developed and successfully field tested at Mount Isa Mines Limited. The technique utilises the gamma-ray resonance scattering process. A bulk analyser based on this technique gives a rapid and accurate measurement of the percentage by weight of copper or nickel aver- aged over a large mass of sample, typically 20 kg. The only sample preparation required for accurate analysis is crushing to -2.5 cm. At Mount Isa over 100 mineral samples covering a wide range of rock types and copper contents were analysed. Bulk analyser assays and chemical laboratory assays agreed closely for underground pillar-extraction and geolog- ical chip samples, conveyor belt samples, and finely ground samples from the ore concentrator. For the concentrator samples, the root mean square deviation between bulk analyser and chem- ical laboratory assays was 0.06 wt.% copper. The chemical assay errors for these samples were about 0.06 wt.%

Jan 1, 1975

By Satayev IS, Shepelev DV

Various ways for applying the X-ray fluorescent method to process lump-by lump separation of secondary aluminium raw materials (scrap, slags, waste) as well as ferrosilicon and ferrochromium are being considered and physically demonstrated. A commercial X-ray radiometric sorter has been developed for processing secondary raw materials. Marketable quantities of aluminium scrap with appropriate copper and zinc content have been produced for smelting with a minimal additional of pure aluminium. An industrial complex for scrap processing, incorporating two X-ray radiometric sorters from the Hammermils company is successfully operating at one of the works in Russia.

Jan 1, 1993

By M Chappell

This paper describes the design of the steel fibre reinforced precast concrete (SFRC) segmental lining for the intake and discharge tunnels for the Gold Coast desalination plant in Queensland. In addition, the key design requirements and design methods for the lining of these 2 km long, 2.8 m internal diameter tunnels, including structural, durability and maintenance requirements are discussed. Details of the segment configuration and erection process are presented along with information on the manufacture and trial testing of the concrete for the segments. The paper also gives a brief introduction to steel fibre reinforced concrete behaviour. Construction of the tunnels commenced in April 2007, and the authors believe this is the first application of this technology in Australia.

Jan 1, 2008

By V N. Rudashevsky, N S. Rudashevsky

Characterisation of platinum-group element (PGE) deposits and their process products has many challenges for the process or applied mineralogist. It is now well established that the PGE distribution for such samples is variably divided between submicroscopic concentrations of PGE in sulfides, tellurides and related minerals occurring as discrete platinum-group minerals (PGM), of which there are a large number of species, many with partial replacement between the PGE and between anions. Each PGE deposit type requires a targeted approach but fundamentally, there are two general methodologies in vogue. One way is to make a large number of polished or polished thin sections for detailed scanning electron microscopy (SEM)/optical examination to determine the PGM distribution and their associations and grain sizes. The other is to make concentrates of representative crushed or processed samples, thus having fewer subsamples to examine. Our method of choice is to use hydroseparation (HS) for concentration. HS provides representative concentrates of sizes down to ~10 ¦m, not possible by other techniques. Various microbeam methods have been used for analysis of trace quantities of PGE (EPMA, micro-PIXE, SIMS and LAM-ICPMS). We prefer LAM-ICPMS (laser ablation microprobe û inductively coupled mass spectrometry) because of the relatively large analytical volume sampled, the ability to measure all the PGE, monitor up to 20 elements, together with detection levels in the tens to a few hundreds of ppb. We provide typical results derived in studies of stratiform PGE ores and tailings, and a massive Ni-Cu sulfide ore.

Jan 1, 2008

By Wheatley MR

Answers to the questions "which rocks contain diamonds?" and "which indicator minerals should diamond explorers look for?" are no longer so easily obtained, now that diamonds are known to occur in lamproites and various types of lamprophyres, as well as their traditional source of kimberlites. One way of isolating those factors (host-rock"geochemistry, geographical or tectonic location, xenolith minerals, etc.) which are most critical in determining the diamond potential of a given pipe, is a detailed and critical re-examination of the huge volumes of accumulated data on kimberlites, lamproites and related rocks. A large analytical database to this end has been set up on an Apple Macintosh II microcomputer using the quasi-relational database management system 4th Dimension. Currently, it contains data for up to 90 major and trace elements, isotopic ratios and contained mineral compositions for some 4,000 rock specimens from all over the world. Many experiences in setting up this database are probably relevant to other geologists setting up their own systems: they include determining the relationships between data items; the advantages of codes over free text in representing categorical variables such as rock types; the need for rigorous error trapping and data validation; and the problem of missing data values and ambiguities thereof. The working system is now being used in a rigorous statistical assessment of the criteria which distinguish diamondiferous from non-diamondiferous rocks.

Jan 1, 1989

The importance of the minerals industry to Australia is briefly reviewed and the professional specialists essential for the industry identified. The average first degree graduation numbers in geoscience, mining engineering, metallurgy/materials and chemical engineering are shown and compared with the postgraduate numbers. Demographic trends in population are reviewed and the implications for the required numbers of trained specialists indicated. Short/medium and long-term possible solutions to potential shortages of trained personnel are canvassed.

Jan 1, 1997

By T Hayward, G Lane, M Phillips

In December 2004 Phu Bia Mining Ltd commissioned Ausenco International Limited to conduct a feasibility study for its Phu Kham copper-gold project located in Laos. The feasibility study for a mining and processing operation treating 12 Mtpa of ore averaging 0.56 per cent copper and 0.25 g/t gold to produce an anticipated annual average 200 000 t of concentrate containing 25 per cent copper was completed in early 2006. The plant design incorporates a single processing line and includes a gyratory crusher, overland conveyor, coarse ore stockpile, SAG and ball mill grinding circuit, flotation circuit including regrind and three stages of cleaning, concentrate dewatering and concentrate load-out facilities. The Phu Kham copper-gold mineralisation comprises two principal styles: stockwork-disseminated and banded-massive sulfide within skarn limits. Primary copper in both mineralisation styles occurs as chalcopyrite and secondary copper sulfide minerals. Skarn includes the copper and gold mineralisation contained in pyrite, silicate, magnetite and haematite skarns, and in quartz-pyrite altered sediments. Both the stockwork-disseminated and banded-massive sulfide ores contain relatively high proportions of pyrite relative to the copper and gold mineralisation. Thus, the flotation metallurgy of the Phu Kham orebody is characterised by the need to reject a high proportion of the pyrite during differential flotation to yield a concentrate grade of approximately 25 per cent copper. The rejection of pyrite is accompanied by the rejection of some copper and gold and can result in modest metallurgical recovery. Consequently, the greater the pyrite content, the lower the expected copper and gold recoveries. The relative pyrite content is expressed on the basis of sulfur:copper ratio. For Phu Kham ores, the sulfur:copper ratios are in the range eight to 14 on a blended annual basis, but can be greater than 20 in the skarn components. Higher grades of copper and gold are also present in the skarn mineralisation. The design concepts for the concentrator were influenced by the need to provide a low capital cost approach for the project due to the relatively low grade of the ore and the modest metallurgical recovery. The concepts used to minimise capital cost whilst retaining operating and maintenance flexibility are discussed, together with the metallurgical challenges imposed by the high pyrite mineralisation.

Jan 1, 2007

By Barclay C, Jacobsen M, Towsey C

The Emperor Gold mine at Vatukoula, Fiji, is a nine million ounce gold telluride deposit. In January 1992, the mine was on the verge of closure when the current management team took charge. Losses had been incurred for two consecutive years and the published resource amounted to less than five years of production. Relationships with the workforce, the government and the general public were poor. Today, the mine has recorded three consecutive years of profit, has resources that will support the operation for at least 20 years and has excellent relationships with employees, government and the general public.

Jan 1, 1997

By Sheer T. J

The increasing demand for underground cooling in South African gold mines has resulted in various cooling methods being con- sidered, including the use of ice. Two main areas in connection with ice cooling systems are being investigated. The first concerns the efficient and cost effective production of ice on a larger scale than previously required for any other application. The second con- cerns the transportation of ice in pipes from surface ice-making machines to underground melting sites.

Jan 1, 1988

Education and Training for the minerals industry has been identified as one of the key priorities by the AusIMM and many closely related groups. The AusIMM Education Taskforce has been engaged, through a visioning exercise, in evaluating what minerals education and training should look like by 2025. A common recurring theme is that for minerals education and training to be efficient and effective into the future, it needs to be comprehensive and inclusive. Some previous attempts to achieve efficiency and effectiveness have had limited success, mainly due to approaching the issues involved from a narrow, singular perspective. This paper outlines that the achievement of the desired outcome may require an approach that parallels the same techniques that are used for multi-dimensional mine planning, treating tertiary minerals education and training in a similar way to the planning involved for a complex orebody. Just as efficient and effective mine planning requires engagement and understanding of many factors, so too does engagement with tertiary minerals education and training. The major factors that need to be considered are outlined in the paper, including: levels of tertiary education and training; Australian Qualifications Framework (AQF), Levels 1 to 13: systems of minerals education and training, such as higher education, (mainly universities), industry/professional associations and licencing requirements, vocational education, (mainly TAFE) and workplace programs; types of minerals or mining methods involved; volume of delivery; stage in the flow sheet, (geology, mining, beneficiation, extraction, refining). For comprehensive mine planning there is the need to develop links or roadways and openings between different levels of a mine. Similarly, to achieve a comprehensive tertiary minerals education and training model, there is a need to develop pathways, recognition and credit transfer between the various levels and components of minerals tertiary education and training.

Jan 1, 2005

A study of the effect of nickel on the cupellation process has shown that a very low "nickel limit" must be imposed for cupellation (0·08 grams nickel or 0·05 grams when copper is present). In the presence of slightly greater amounts of nickel, lead tends to spreadon the cupel with detachment of drops from the main lead pool. In crucible fusions nickel contaminates the lead button to a small extent, and this contamination is increased.in the presence of either iron or copper. Nickel also causes "shotting" of the lead, this effect being more apparent in the presence of iron.Both the spreading during cupellation and the shotting during crucible fusion are considered to be caused by adsorption of insoluble NiO at the Pb-PbO interface, lowering the interfacial tension.Excess litharge crucible charges are' fused at 116boC. to eliminate shotting. A brief· soaking in molten basic litharge slag effectively reduces the nickel content of lead buttons. The solubility of silver in litharge slags is considerably decreased in the presence of nickel. Corrections can be applied for silver losses in slags but these corrections are not as accurate as with copper ores.INTRODUCTIONThis paper on the effects of nickel on fire assays for silver is the second of an intended series describing investigations into the fire assaying method.In the first paper, discussing the effect of copper on fire assaying processes (Guerin, 1957), it was shown that certain elements, because of their relatively low affinities for oxygen, will tend to contaminate the lead button during crucible fusion and scorification. Nickel, having a slightly greater affinity for oxygen than has lead, would be expected to be oxidized and slagged readily, and would not be expected to appear in the metal phase (lead button) to any appreciable extent. Thus, judged solely on this basis of...

Jan 1, 1960

By Yesil MM, Bozdag T

The swelling process is an impor- tant problem causing damages to the structures in or on swelling rocks, both during construction and operating life. To understand swelling problem, a number of testing methods have been developed by many researchers. In these studies, the swelling parameters, in most cases, are derived from oedometer tests. The swelling parameters determined from oedometer type tests represent one-dimensional behaviour (one-dimensional swelling law) therefore, it is quite difficult to extrapolate the oedometer type test results to the three-dimensional in-situ conditions. To overcome these problems, a three-dimensional approach is suggested for clay bearing rocks. Results of triaxial swelling tests conducted on marl from Dodurga Lignite Coal Mine are presented. Triaxial swelling characteristics of the marl are presented and design approach for tunnels is described.

Jan 1, 1992

The last decade of national water reform implementation has improved the availability and efficiency of water source allocation in Western Australia. However, it is critical to recognise that the concurrent mining boom witnessed the approach of full water allocation limits, and increasing trends in mineral processing, water infrastructure costs, and wastewater management costs. Water supplies are commonly viewed as absolutely critical to project feasibility in mining, industrial and energy generation projects, even if considered 'non-core business'.   An increasing density of mining projects and industrial estates in Western Australia (WA) creates an opportunity for water infrastructure cost sharing and synergies. The WA government and its agencies have given preliminary consideration to the establishment of independent water utilities in the goldfields (Kalgoorlie), the Pilbara, and Collie regions, and in the Kwinana Industrial Area. The impending Oakajee industrial area and Mid West regional development, and Anketell port in the East Pilbara, could also be considered for common non-municipal water supplies.   The critical issue of apparent commercial risk due to the large scale of water demands and the low customer numbers in the minerals sector relative to other water markets is expected to mandate government partnership in any non-municipal water utility ownership. The commercial feasibility risk is observed as a risk to water supply security for potential mining and industrial customers. Absence of proper water infrastructure planning and governance has the potential to create infrastructure access issues as observed for Pilbara rail developments under the Trade Practices Act 1974.   Other aspects of water cycle management which could be addressed by a non-municipal utility include resumption of mine dewatering water (required changes to WA legislation that are progressing) and consolidated wastewater management for maximising synergy or reuse opportunities and minimising cumulative environmental impacts.   Address of water infrastructure planning for non-municipal water demands must cover commercial and environmental sustainability outcomes to successfully progress minerals sector growth in the State.

Jun 1, 2010

By J C. Macintosh

Capcoal Mine has modified its water use practices over the past 15 years. Two issues have changed the way water was managed:an economic review of water supply options for a planned expansion of the coal handling and preparation plant (CHPP) in the early 1990s, and increasing neighbour concerns about discharge of worked water from the mine into the local streams. These issues resulted in commitment by the site General Manager to cease discharge of worked water from site and to convert from using raw water to worked water in the CHPP. Operational needs, societal demands and continuing dry weather are again demanding change to the siteÆs water management strategy. This paper outlines the drivers for past and future operational change.

Jan 1, 2006

By Caigen Wang, Wending Ma, Xiexin Mi

The urgent need for the control of surface subsidence caused by longwall coal mining in densely populated areas of China has led to a feasibility study on the effectiveness of longwall goaf cemented backfill. The study is focussed on exploring the potential of longwall goaf cemented backfill practice for surface subsidence control. Specific backfill geometry was designed in view of the characteristics of the longwall coal mining system. Laboratory physical simulated tests were carried out with different backfill material properties and pack size. The tests achieved a marked reduction in surface subsidence by the use of goaf cemented backfill. The system has been shown to be effective in laboratory tests, the challenge now is to overcome the engineering problems to put it into practice.

Jan 1, 1998

By A Boeing

Rock-breaker automation and remote operation improves the safety and efficiency of mining operations. This paper presents an overview of the Rocklogic rock-breaker automation system architecture that provides collision avoidance, automated parking and remote operation functionality. The system consists of a distributed computer control system that interfaces with sensors attached to the rock-breaker, the rock-breaker hydraulics and the site infrastructure. We present results of an automated Transmin rock-breaker installed in a production environment at an underground Australian mine site. The system has been in production use for over 900 days, during which there have been no reported collisions and 100 per cent adoption of the remote operation technology. As a result, Rocklogic has significantly improved the safety of rock-breaking operations and reduced the rock-breaking cycle time, thereby improving the site’s overall throughput.CITATION:Boeing, A and Douglas, E, 2014. A remotely operated robotic rock-breaker with collision avoidance for the mining industry, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 131–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

Computer simulation of the control systems for the heavy media coal washing process have been presented in this paper. The simulation model applies the Simulink module of the Matlab 5.1 software package and allows monitoring of variations of a

Jan 1, 1998

A system of decline mine entries and ore haulages has been designed for the Mt. Windarra mine. This choice was controlled by the nature of the ore- bodies, the mining method chosen and the capital cost of development re- quired for production. Mine entries are being driven 4 metres high and 5.5 metres wide and decline at 11%, to accommodate diesel haulage vehicles of 35 tonnes capacity. The.Mount Windarra haulage system and the design parameters used in its selection and design are discussed, and general design and selection parameters are proposed.

Jan 1, 1973

By R Turner, P Hatherly, T Medhurst

Borehole geophysical logging data are routinely acquired during exploration of coal deposits in Australia. These data are commonly used qualitatively to identify and correlate coal seams and geotechnically significant interburden rock units. Some quantitative analysis, such as using sonic logs for rock strength estimation is becoming increasingly widespread. This paper discusses results from a project aimed at expanding the quantitative approach to more detailed mineralogical and lithological analysis, which leads to improved geotechnical characterisation for mine planning and mining hazard reduction. A standard suite of wireline logs measuring density, natural gamma, sonic and neutron were analysed from three coal mines in the Bowen Basin. Thirty-nine samples from cored sections of the boreholes were analysed by X-ray diffraction, spectral gamma counts and hyperspectral scanning. Using a standard petrophysical approach to calculating porosity, shale and matrix components from a combination of density, natural gamma and neutron logs, a good correlation with observed mineralogy was demonstrated. However, unusual mineralogies such as heavy minerals or low-potassium clays may distort this analysis. Simultaneous evaluation of all available geophysical logs by modern data mining methods was able to show how these ambiguities may be solved.

Jan 1, 2006

A viable flow sheet of the sorption-flotation technology for gold recovery from low-grade ores and concentrates using powdered activated carbon modified by organic compounds as the sorbent-bearer has been developed. The powdered activated carbon, with high kinetic ability and sufficient specific area, was selected as the all-purpose gold cyanide complex-bearing sorbent which is active during flotation. To improve carbon adsorption capacity and to provide the required floatability its porous structure was filled with a quaternary ammonium compound which can extract gold cyanide complexes and render additional flotation properties to the carbon. To optimise the process and to simplify the layout, adsorption and flotation processes were carried out simultaneously in a mechanical flotation cell. The proposed technology was used for extended and pilot-plant tests of sorption-flotation gold recovery from 0.6 g/t Au final tailings and 2.0 g/t Au gravity tailings. The extended tests were carried out on Taseevskaya (Chita Region) flotation tailings, whereas pilot-plant tests were conducted on Kommunarovskaya (Krasnoyarsk Region) gravity tailings passing to cyanidation, followed by processing with filtration technology. Additional gold recovery from Taseevskaya final flotation tailings was 50.8 per cent. Gold recovery from Kommunarovskaya final gravity tailings was 92.5 per cent. Compared to the complete sludge process conventionally used at the plant, gold recovery was increased by 7.5 per cent due to lower gold losses in the liquid phase and conversion of the refractory non-cyanided metal into a carbon concentrate. This paper presents the experimental results of gold adsorption onto powdered activated carbon modified with quaternary ammonium compounds (sorbent-bearer) as well as sorbent-bearer flotation with various collectors from cyanide solutions and pulps.

Jan 1, 2005