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By I Özen, G Chitumbura

A paper identifying anticipated challenges in the extraction of the N3500 Orebody at Glencore Xstrata Copper’s Mount Isa Copper Operations was written in 2007. The paper identified the depth of the deposit, the anticipated high stresses, talc alteration and issues with ground support as factors that may affect production. A number of strategies were planned to cope with these issues. After six years of extraction those strategies are evaluated and additional measures taken are outlined. Strategies to cope with the limited mine life are presented, and methods to overcome additional challenges encountered during production are described.CITATION:Chitumbura, G, Matthews, D, Özen, I and Jackson, S, 2014. One mile underground – mining the N3500 orebody at Mount Isa Mines, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 265–282 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

This paper discusses the recently com- pleted TBM-driven pressure tunnel at the Sand Bar Hydroelectric Power Project. The Sand Bar Project is a diversion scheme situated on the middle fork of the Stanislaus River in the Western Sierra Nevada, California, U.S.A. As part of the project, a 5.6 km long and 3.71 m diameter unlined pressure tunnel was bored by a Jarva TBM at the average rate of .37.5 m/ day. This report deals with construction aspects of the tunnel, including TBM performance, lining design, and remedial support measures. Correlations between TBM performance, geologic conditions, and rock properities are made, and the Contractor's mode of operations are discussed. Advance rate prediction, and the impact of these excellent advance rates attainable in hard rock using the new machines are discussed.

Jan 1, 1987

By S Girard, L Rowland, V Lawson, Y Shields

Since 1948, ValeÆs Matte Separation Plant has been successfully using magnetic separation and froth flotation to separate the copper sulfide, nickel sulfide and Ni-Cu metallic alloy contained in Bessemer matte for downstream processing. Though some equipment upgrades have been performed over the years, the flow sheet has generally remained unchanged since the early 1970s. The need to improve metallurgical performance led to the trial of a scalping flotation column to produce a final copper concentrate ahead of the cleaner circuit feed to take advantage of a high degree of copper mineral liberation, reduce cleaner-recleaner circulating loads and decrease the associated loss of selectivity. Plant results indicated that 50 per cent of copper contained in the rougher concentrate could be recovered at final grade target. Results indicate that up to a 1.5 per cent increase in copper recovery to copper concentrate was achieved during the scalper trial due to a reduction in the generation of fine chalcocite which has historically been observed to report to flotation tailings due to surface contamination. Deficiencies are currently being addressed and a long-term trial is scheduled to confirm the benefits of copper scalping.CITATION:Girard, S, Rowland, L, Shields, Y and Lawson, V, 2012. Copper scalping at ValeÆs matte separation plant, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 299-308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By G B. Smith

Barrick (Australia Pacific) Limited initiated a trial of Caterpillar’s Minegem autonomous loader technology in 2009 at the Kanowna Belle mine in Kalgoorlie. Autonomous loader technology offers the potential to improve loader productivity, reduce operating costs and improve safety through removing personnel from the mine operating environment. This paper discusses the implementation of the technology at the mine site, the data collected during the trial and quantifies the benefits of using automated loader technology in comparison with teleremote loader operation. The lessons learned from the trial and work planned for the future in respect of this technology is also discussed.

Mar 21, 2011

By D Capstick, M B. Ebell

This paper describes the test work, process design, commissioning and operation of a processing system at the Ergo gold operation that improves the extraction efficiency from gold tailings material. The improvement in recovery is derived from the separation of the gold contained within the sulfides of the tailings material and a dedicated process stream to recover that gold.The sulfides are separated by means of a flotation circuit and that resulting concentrate is subjected to a regrind of below 20 ¦m to enable a greater liberation of the gold. The ultra-fine material is then subjected to a dedicated leach circuit to recover the now exposed gold particles.The case study is an example of the challenges of introducing new technology and methodologies to a well-established operation and thereby attaining improved efficiencies and tangible business benefits.CITATION:Ebell, M B and Capstick, D, 2013. Improving extraction efficiency from Witwatersrand gold tailings using flotation and ultra-fine grinding of concentrates, in Proceedings World Gold 2013 , pp 301-306 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By A Takahashi, Y Uchisawa, M Hayashi, T Watanabe, M Susa

Owing to the deterioration of iron ore, the Al2O3 concentration in iron ore increases, and thus it is important to investigate the effect of increment in Al2O3 concentration on the microstructures of iron ore sinters. During the sintering process, a melt is present in the sinter for only a few minutes, and therefore the microstructure of the sinter doesn’t reach thermodynamic equilibrium. Nevertheless, the formation process of the microstructures can be interpreted and predicted to some extent from the equilibrium phase diagram. This study investigated the liquidus isotherm in the CaO-SiO2-Fe2O3- 5 mass% Al2O3 system at 1240°C in air and the phase equilibria of silico-ferrite of calcium and aluminium (denoted by SFCA) and SFCA-I by XRD (X-ray diffraction analysis) and electron probe micro analyzer (EPMA). The following results were obtained: 1. The ferrite melt region with a high Fe2O3 concentration shifts to the lower Fe2O3 side than the liquidus isotherm in the CaO-SiO2-Fe2O3 system. 2. The compositional region of SFCA extends in the CaOꞏ3Fe2O3-4CaOꞏ3SiO2 direction than the silico-ferrite of calcium (denoted by SFC) composition region with a 0 mass% Al2O3. 3. SFCA-I is observed in the present system, which suggests that the increment in the Al2O3 concentration contributes to the stability of SFCA-I. These results imply that an increment in Al2O3 concentration in iron ore leads to a decrement in the volume fraction of the bonding phase and that the fraction of the SFCA phase increases, and those of 2CaOꞏSiO2 and slag phases decrease in the bonging phase. The SFCA-I phase is also precipitated from the slag with an Al2O3 concentration around 5 mass%.

Jun 19, 2024

By M Haest

This study demonstrates the application of HyLogging™ technologies for mineralogical characterisation of different iron ore types throughout the Hamersley Province (Western Australia), including a channel iron deposit (Murchison Metals Ltd) and bedded iron deposits in the Brockman and Marra Mamba Iron Formations (BHP Billiton Ltd).Drill core from these deposits was analysed using CSIRO’s hyperspectral drill core logging systems (HyLogging systems), which are commercially available at the AMDEL and AMMTEC laboratories in Perth (Western Australia), through a leasing agreement. These HyLogging systems provide high resolution photographs at 0.1 mm pixel resolution as well as visible and infrared spectroscopic refl ectance data at 1 cm spatial resolution. The minerals identified include haematite, goethite and its subtypes (ie vitreous and ochreous goethite), AlOH-clays (kaolinite, Al-smectite and white mica), carbonates, gibbsite, chlorite, amphibole and hydrated silica as well as water content. The abundance and composition of these minerals was established from the spectral data and was validated against XRF analyses.The full potential of HyLogging systems in the iron ore industry is only starting to be unveiled, but some major benefits have already been demonstrated:• HyLogging systems can delineate different ore zones by mapping the vitreous and ochreous goethites. This has a potentially large impact in mine planning and operations, as hard, vitreous goethite and soft, powdery, ochreous goethite have different processing characteristics that can affect plant throughput if not carefully managed.• HyLogging mineralogy can also be used to support stratigraphic interpretations of the host, for example in subdividing the Dales Gorge 1 - 4 submembers of the Brockman Iron Formation.• HyLogging can have a potentially signifi cant impact on waste rock characterisation, as many of the waste materials can be identifi ed and quantifi ed with hyperspectral data (eg clay-type,• hydration state).• HyLogging can provide accurate three-dimensional (3D) mineralogy to iron ore companies that will empower them to improve future exploration and resource planning.• Application of high resolution photography to further improve ore deposit domaining is also to be considered.

Jul 11, 2011

By J Seppelt, G S. Lane, E Wang

Newcrest’s Cadia concentrator operated from 1998 to 2012 with a traditional SABC grinding circuit treating Cadia open pit ore. The Cadia comminution circuit was well characterised through surveys and data that are available in the public domain, and became a benchmark standard for the industry and practitioners modelling large SAG mill based circuits. In 2012, the HPGR-based crushing circuit was introduced in front of the SAG mill to increase throughput when treating the Cadia East ore that was derived from an underground block cave. This ore was expected to be more competent and have a coarser run-of-mine size distribution.Numerous previous papers have described the design and commissioning of the Cadia HPGR-based circuit.This paper describes the improvement in comminution energy consumption resulting from the introduction of the HPGR, including identifying the impact of process complexity and an increase in ancillary energy consumption for conveyors, screening, and crushing.CITATION:Lane, G S, Seppelt, J and Wang, E, 2018. Quantifying the energy efficiency transformation at Cadia due to HPGR crushing, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 141–152 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By J Young, S Yu, P Moyo, M Powell, A Musunuri, B Bonfils, S Kanchibotla, P Yaroshak, V Jokovic

The appropriate design of liners continues to be an issue on many mills worldwide. Loss of milling capacity especially at liner change, uneven wear lives along the mill, substantial scrap on worn liners, excess mill down-time, undesirably short and unreliable wear lives are all common issues. This paper presents a designed approach to liner optimisation that follows a logical path of initial design and step-wise improvements based on liner wear monitoring. The target is to have a good liner design from start-up, then tune the profiles, heights and thicknesses based on wear monitoring. This is conducted as a team of liner specialist, site personnel and liner supplier. The application to the Pustynnoye SAG mill of JSC Altynalmas in Kazakhstan is presented. The increase in liner life by around 50% along with increased mill throughput of over 20% illustrate the huge benefit of the cooperative triumvirate approach through the gains that can be made in productivity and reduced liner costs.CITATION:Powell, M, Kanchibotla, S, Jokovic, V, Hilden, M, Bonfils, B, Musunuri, A, Moyo, P, Yu, S, Young, J, Yaroshak, P, Yalcin, E and Gorain, B, 2018. Advanced mine to mill application at the Barrick Cortez mine, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 177–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By R E. McIvor, K M. Bartholomew

Classification system efficiency (CSE) is a simple, powerful metric that provides a comprehensive measure of classification system performance. CSE directly quantifies the amount of coarse solids in the mill, and as a result, also directly quantifies the percentage of mill power being used effectively. In this manner, it is an effective, practical grinding energy efficiency metric.Three independent variables drive CSE: circulating load ratio, sharpness of classification, and classifier bypass. Due to practical downstream constrains on per cent solids, improvements realised by increasing circulating load reach diminishing returns as sharpness of classification and bypass deteriorate in the most commonly used classification device, the hydrocyclone. This combination of effects leads to the use of CSE, and its relationship to operational economics, as an objective circuit optimisation criterion.Its simplicity in measurement makes CSE a useful tool for the plant metallurgist, and it is not subject to a great amount of experimental error. CSE provides the plant operator a fast, simple, and effective means to evaluate the performance of the plant classification system. Improvements in CSE relate directly to circuit throughput and energy efficiency. This paper, through description and plant case studies demonstrates the power and utility of this emerging grinding system optimisation metric.CITATION:Bartholomew, K M and McIvor, R E, 2013. Classification system efficiency - a comprehensive closed-circuit grinding optimisation metric, in Proceedings World Gold 2013 , pp 389-394 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By J S. J van Deventer

"Conventional wisdom is that gold not assayable is not recoverable or does not exist. There has been no formal study on the possibility that gold assays using advanced spectroscopy such as mass spectrometry and neutron activation could grossly underestimate the gold recoverable by proprietary extraction techniques. Such gold is not considered here to be æinvisibleÆ to detection but rather æabnormalÆ or ædistortedÆ at atomic level. Large-scale extraction of gold from æabnormalÆ ores has not been demonstrated, hence this emerging field still lacks credibility and acceptance. For fear of harming their reputation, few academic researchers or companies are expected to venture into this field until it is well proven. This paper aims to create awareness amongst metallurgists of the potential of æabnormalÆ gold ores by reviewing unconventional observations, the pseudoscience mainly available in non-peer reviewed web sites, and hypotheses for the recovery of ænon-assayableÆ gold, including: the occurrence of high levels of nano-sized gold in clays detectable by high-precision analytical instruments, which represents æinvisibleÆ gold accounts of ambient transmutation of elements, mainly using thermal methods orbitally rearranged monoatomic elements (ORMEs), which are virtually undetectable by conventional means, and their conversion to normal metals the possibility of a æhigh spinÆ state of transition metals the formation of microclusters altering the chemical behaviour of gold and the possibility of clustering with other elements. It is suggested here that gold in ores displays a range of clustering, from ænormalÆ gold amenable to conventional extraction to the ORME state. The concepts of æintermolecular waterÆ in forming complex salts locking up precious metals, electro-dissolution in strong acids, and electrowinning at both the anode and cathode are discussed as a means of treating æabnormalÆ gold ores. It is also possible that the gas phase extraction of gold chlorides under controlled temperature and pressure conditions, as well as transferred-arc plasma fuming of gold through carbothermic reduction of sulfides, could be used as a basis for extraction of gold from æabnormalÆ ores.CITATION:van Deventer, J S J, 2013. Is there gold that we do not recognise?, in Proceedings World Gold 2013, pp 27-34 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

By Baafi E. Y

A heuristic approach for the optimisation of the stope geometry is presented. The heuristic method uses economic model of a given deposit to search for the best combination of mining blocks that results in the maximum profit while imposing geo

Jan 1, 1998

During late 1953 and early 1954, tests were carried out in Sydney metropolitan brickpits in order to determine if some improvement might not be effected in the personal shock, fly rock and possible ground displacement accompanying daily blasting occurrences in the numerous quarrying activities of the metropolitan area. As a result of this preliminary work (Reid, 1954), the Department of Mines decided to further investigate the problem with a view to placing this type of blasting on a sound economical and safe basis for both operator and nearby residents alike. To assist in the work, a Cambridge Universal vibrograph was acquired.Human safety was the first consideration followed by property damage to homes and factories in the extractive areas. Although most of the actual field work has been confined to the Sydney metropolitan area and in particular to the large clay-shale quarries, many cities and country towns have blasting problems associated with the extractive industries, engineering projects both above and below ground level, and in building excavations to which the results may apply.The following figures illustrate how much activity of this type is located around cities and towns:Sydney Metropolitan Area:

Jan 1, 1958

A nine-month investigation was conducted into the effect on coke quality and blast furnace operation of the addition of bentonite and southern coal to the northern coal fed to the coke ovens at the Newcastle steelworks.Additions of 0·3 per cent bentonite or 25 per cent southern coal to the northern coal increased the coke strength from 15-20 A.S.T.M. stability to 25-30 A.S.T.M. stability. It is likely that improved mixing and blending facilities would, in both cases, give a coke of over 30 A.S.T.M. stability.For the same coke strength, the use of 0 3 per cent imported Wyoming bentonite was considerably cheaper than the use of 25 per cent southern coal, but the use of Australian bentonite promises the same coke strength for still lower costs. Other additives such as coke breeze, charcoal, iron ore fines, and certain other finely divided materials, gave relatively minor improvements in coke quality.There appeared to be sufficient improvement in blast furnace operation and production to justify full scale addition of bentonite to improve coke quality, although other variables, particularly iron ore physical quality, overshadowed on many occasions the effect of coke quality. Further coke trials with southern or bentonite will be carried out when ore quality has been improved by the introduction of ore sintering at Newcastle.INTRODUCTIONDuring the period of operation of the Newcastle coke ovens and blast furnaces from April 1960 (when No. 3 blast furnace was blown in after rebuilding) to December 1960, a bentonite coke trial was carried out based on earlier research findings (Gregory, 1959a, 1959b; Felton and Gregory, 1960; Gregory, 1960) that as little as 0 3 per cent to 05 per cent bentonite clay added to northern N.S.W. high volatile coking coals gave a significant increase in coke strength. The bentonite coke trial was followed by trials...

Jan 1, 1962

Recovery of tin and copper from concen trates containing cassiterite, stannite and chalcopyrite was studied in laboratory-scale tests designed to simulate continuous operation of the matte fuming process in which tin is recovered as SnS fume while copper accumulates in the matte. Charges made up of 300g of mixtures of the concentrate and siliceous flux were added at a uniform rate in pelletized form to crucibles containing 300g of matte and 50g of slag (both of which were recovered from previous tests), while blowing through the matte with air or oxygen-nitrogen mixtures at a rate of 3 to 5 1/min. Accurate material balances enabled the effects of process operating conditions on tin recovery and sulfur utilization to be deter- mined. When operated correctly, the matte fuming process gave tin recoveries exceeding 90 percent in spite of wide variations in the copper content of the matte and in the operat- ing conditions. Deterioration of tin recovery was associated with undersaturation of the slag with respect to silica, and with high partial pressure of sulfur dioxide (greater than approx- imately 0.2) brought about by oxygen enrichment of the blowing air. The utilization of sulfur varied widely in low grade mattes. Copper in excess of approx- imately 10% promoted formation of SO2 by the commonly accepted reaction: FeS + 1-120 2= FeO + S02 while in copper-free and lower grade mattes a substantial fraction of the oxygen was consumed in the alternative reaction FeS + i 02 = FeO + z S2.

Jan 1, 1980

Supercritical fluids are gases compressed to near liquid densities and, as such, have unique properties compared to liquids: low viscosity; zero latent heat; high diffusivity and pressure-dependent, solvation characteristics. These properties are being utilised in new processes and current research is delineating areas where such processes may be applicable to extractive metallurgy. The processes and areas of interest are as follows: Supercritical Fluid Extraction in which substrates are dissolved at high pressure and fractionated at successively lower pressures. Areas of interest include extraction of organic materials for regeneration of activated carbon for the CIP process and for upgrading alumina industry products and, separation of transition metal chlorides. ò Supercritical Water Oxidation in which high pressure gaseous water acts as a medium in which substrates are oxidised while suspended or dissolved. This process may be of use for oxidation of organics in Bayer liquor and oxidation of mine waters etc. ò Supercritical Fluid Reactions where reactions occur in a supercritical fluid medium, particularly when the medium itself is a reactant. This may be of use in treating refractory or carbon-aqueous auriferous ores and in lower-temperature chlorination of transition metal oxides. Research is described which is aimed at chlorination and separation of transition metal oxides by two supercritical operations.

Jan 1, 1991

By J Siliézar

The Ernest Henry Mine (EHM) is situated 38 km north-east of Cloncurry in the Mount Isa – Cloncurry mineral district of northwest Queensland. The EHM orebody is an iron oxide copper gold deposit with an average grade of one per cent copper, 0.5 g/t gold and 23 per cent magnetite, with current reserves of approximately 88 Mt.The copper concentrator is a single line plant with a nominal throughput rate of 1300 tonnes per hour. An average of 350 000 tonnes of concentrate is produced each year containing around 100 000 tonnes of copper metal and 120 000 troy ounces of gold.In December 2009, Xstrata Copper announced approval of a $589 M investment to extend the life of EHM to at least 2024, through the transformation of open pit mining operations to a major underground mine together with the construction of an associated magnetite extraction plant.The EHM magnetite plant extracts the magnetite from the copper concentrator’s tailings stream. It will produce approximately 1.2 Mt of magnetite concentrate per annum at full capacity for export to Asia, making EHM Queensland’s first iron ore concentrate exporter. Construction of the magnetite extraction plant commenced in July 2010 and was completed in January 2011.This paper gives an overview of the development of the EHM magnetite extraction plant flow sheet from the early mineralogy and laboratory test work through to the plant commissioning and early operation of the base plant. It has a major focus on the commissioning learnings from the plant start-up and includes a review of the operational performance of the plant versus original design and expectations.

Jul 11, 2011

Attempt has been made to determine the nature of charge on activated carbon surface by studying the electro-kinetic properties of the carbon in the presence of cations, anions and aurocyanide solutions. The zeta-potential measurements were made in the presence of individual ions and also in combinations. The cations and anions chosen were those commonly associated with gold bearing ores in Kalgoorlie area. It was found that the iso-electric point of Norit Carbon was at pH 4.45; below this pH the charge was positive, while above, it was negative. In the absence of gold cyanide solutions and in the presence of individual cations the i.e.p. shifted to the alkaline range (pH 7.2-8.5) while in the presence of anions the i.e.p. was shifted to less than pH 3.5. In the presence of aurocyanide solutions, the iso-electric point was still in the acid region irrespective of whether anions or cations were present. The probable mechanism for such a behaviour has been attempted after measuring the specific conductivities of solutions before and after gold adsorption, by studies using the electron- probe-mirco-analyser, and S.E.M. on the carbon surface.

Jan 1, 1982

By E Niva

The IsaMillÖ is challenging the way that plants are designed and operated. This paper challenges existing designs of concentrator flow sheets, particularly focusing on magnetite circuits.   From what has started out as a small scale ultra fine grinding mill in the pharmaceutical and pigment industries, it has been redesigned and improved upon for mineral processing, and has been the mainstay of fine grinding applications for over ten years. These applications have required energy efficient grinding to succeed, and have been predominately in the base metals industry.   Further development of the IsaMillÖ has now resulted in the machines being able to treat larger tonnages, with higher capacity motors. This development, along with the introduction of purpose designed ceramic media, has allowed the mill to treat courser feed sizes. At the same time, the mill still offers highly efficient grinding, and has enabled it to be operated in coarser tertiary and secondary grinding applications.   The acceptance of the mill in coarser applications, predominately in base metals and PGM applications, has enabled the IsaMillÖ to be a serious contender for beneficiation in other minerals. One such application is the potential for IsaMillsÖ to be part of magnetite flow sheets, which are being considered in Australia to meet the growing iron demand of China. The high energy efficiency of the IsaMillÖ compared to conventional technologies, as well as the smaller infrastructure requirements, provides a great opportunity to reduce the power intensity of magnetite circuits.   This paper will examine the use of IsaMillÖ technology in conventional grinding applications, including recent testwork in a primary grinding base metal circuit, as well as testwork on magnetite ore comparing a lab scale IsaMillÖ with a lab scale Tower Mill.   The growing demand for minerals over the next decade, coupled with higher energy cost, will result in energy efficient technology, such as the IsaMillÖ, being included in standard circuit design.

Jan 1, 2008

To follow the development of the central crushing plant it is necessary briefly to outline the history of the Lake View and Star Limited. This Company, when first constituted, took over the properties of the Lake View Consols, Hannan's Star, and Chaffers Gold Mines.The Company then treated the ore won from these leases at two dry crushing, all-roasting plants, situated adjacent to each other on the site of the present Chaffers Treatment Plant that handles all the ore won by the Lake View and Star Ltd.SUbsequent to the initial union of the three companies mentioned, the Ivanhoe Gold Corporation and the Golden Horse Shoe Ltd. were absorbed. Still later, and after the original crushing plant was erected, the Associated Gold Mines of Australia were purchased.A very extensive development policy was adopted by the Company's management in the late 1920's, and as the underground programme progressed, it became eVident that a large treatment plant would be required. Wet milling of the ore, followed by flotation, was considered desirable, and the necessity of a central crushing plant capable of producing a feed that could be handled by the wet ball mills attached to it was obvious.At this time, each of the properties absorbed had its own crushing station, situated adjacent to the respective...

Jan 1, 1948