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By G Richmond, J R. Glen

Western Metals Mt Gordon Operation is a copper mine and processing plant situated 120 kilometres north of Mt Isa. The unique Mt Gordon copper process utilises a whole of ore acid/ferric pressure leach to produce copper cathode from the Esperanza massive sulfide copper orebody. Esperanza ore contains chalcocite, covellite and minor chalcopyrite hosted in a massive pyrite matrix. These ore stocks will be depleted in late 2003. Recently the process circuit has been upgraded to allow the treatment of lower grade Mammoth ores. These include the installation of a ball mill to complement the existing SAG mill, a single stage rougher flotation circuit and a tailings thickener. The leach bleed neutralisation plant was also upgraded at this time. Commissioning of these new circuits occurred in March 2003 and involved all the challenges of ensuring current production levels were successfully maintained while new process steps were incorporated into the whole circuit. This paper explains the background flow sheet of the patented Mt Gordon process and the reasoning behind the enhancements required for an already successful copper leaching circuit. Included are discussion of the influences of the new ores on individual process components such as comminution, leach chemistry and solid/liquid separation. Longer term ore processing options are also discussed.

Jan 1, 2003

By J D. Pease, J M. I Tuppurainen, P D. Munro

This paper examines how legislation and regulation can be external drivers of technical change in mineral processing and extractive metallurgy and how the industry can respond. Two examples are considered; the production of copper metal from concentrates and the cyanide process for gold production.The Clean Air Act (1970) in the USA initiated a wave of attempted innovations in the extractive metallurgy of processing copper sulfide concentrates to meet forthcoming standards on sulfur dioxide emissions. Interestingly, a satisfactory technical solution existed (flash smelting and gas capture) but had not been widely adopted.Nearly fifty years later the primary copper industry finds itself with new challenges. One major challenge is how to deal with the increasing level of arsenic in copper concentrates. Most countries impose an upper limit on arsenic in imported concentrate; typically, 0.5% As or less. Higher arsenic concentrates can be blended with cleaner ones to meet the limit, but this tactic cannot be used indefinitely as the average arsenic level of global concentrates rises inexorably. Further, smelters (often in urban locations) cannot be expected to deal with both ever-increasing arsenic in the feed and stricter restrictions on emissions and disposal. A rising “inventory” of primary copper deposits are already constrained from development by high arsenic concentrate. These deposits will need to be developed if future copper demand is to be met. An economic and technical solution to arsenic is needed. The gold industry may also face challenges in the use of cyanide, by far the dominant lixiviant used in gold and silver production. Public perception has driven restrictions on the use or transport of cyanide in some jurisdictions. History suggests that such pressure is only likely to increase. While there are several alternative lixiviants, none can yet match the utility and economics of cyanide.Such important issues will not be resolved by incremental change or new equipment items. They require development of new process technology - a tectonic event rather than an incremental change. It requires sustained effort (and expenditure) over decades and is very unlikely to result from “business as usual” for producers, suppliers or academics. Past major process developments were driven by a dire need for economic survival or by legislative change. What will drive the future changes?CITATION:Munro, P D, Pease, J D and Tuppurainen, J M I, 2017. Technology change by regulation – a cresting wave?, in Proceedings MetPlant 2017, pp 45–58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Most compact bucket wheel excavators in use are in the small to medium range. Large compact bucket wheel excavators compete directly with con- ventional longer boom excavators which have operational advantages over the large compact. There are, however, situations where the large com- pact excavator is viable. In the development of these large compacts there are a number of technical features to be addressed. In addition the SECV now propose to expand the concept to a large compact bucket wheel excavator with a bridge and loading unit for their Loy Yang Open Cut.

Jan 1, 1989

By K Williams, A Lavrinec, V Gurung, D Ilic

The moisture content of iron ore during handling can range from the dust extinction moisture at the point of arrival at the port to the transportable moisture limit at the point of loading ships for maritime transport. Moisture content and ore composition, specifically fines content, have a large influence on ore flowability. Typically, elevated moisture can result in bottlenecks, downtime and lost productivity due to build-up, conveyor carry-back and blockages, increasing maintenance costs. On the other hand, low moisture can result in increased dust emissions influencing the environmental footprint and product losses. Managing the use of water across the supply chain is therefore critical for service life of equipment, productivity, but also has environmental and social impacts, affecting the social license to operate. Previously, experiments have shown that oscillations induced in iron ore during handling and transport can result in movement of moisture through the ore. This kind of moisture migration depends on the nature of these oscillations, such as the undulation of idlers during conveying, the inherent ore properties and the initial moisture content. Moisture has been observed to move either upwards and/or towards the bottom of the burden. These effects can be exploited to remove excess water from the ore influencing handleability and operation, however, the actual mechanisms of moisture migration are currently poorly understood. The study presented herein involves the use of simulation to examine moisture and ore interactions. Simulations using discrete element method (DEM) and coupled with smoothed particle hydrodynamics (SPH) are implemented to investigate the behaviour of moisture in wet ore in the presence of oscillation. This is conducted at a fundamental level first using glass beads and water which is then compared to iron ore at high moisture content. The results of the modelling are discussed in view of experiments conducted.

Sep 18, 2023

By D Eschebach, D Mathewson

A belt press filter (BPF) handbook containing practical information for the reference of plant designers and operators has been created as part of Australian Coal Association Research Program project C23040. The handbook combines research and experience with newer generations of equipment and circuitry. BPFs are increasingly finding application in the dewatering of thickener underflow tailings slurries due to changing environmental regulations, difficulty obtaining tailings storage facility approvals and limited water availability. Sources of BPF inefficiency and low availability stem from a lack of understanding of the key operational parameters that affect their performance. This lack of understanding typically leads to increased operational expenditure due to suboptimal reagent dose rates and increased maintenance costs, or decreases in plant availability due to excessively high filter product water contents and equipment failure. It is essential for the continued economically competitive operation of Australian coal handling and preparation plants that complex factors affecting BPF operational performance are clearly defined and understood. Installation and operation handbooks are often provided to sites with new installations, but these manuals are manufacturer- or even model-specific and are often focused on mechanical maintenance. The handbook identifies industry ‘best practice’ and improvements developed by other sites, such as extra spray bars, air system bleed valves, guarding designs, feed and filtrate protection screens and roller tensioning systems. Equations to predict optimum operating conditions – such as free moisture, belt tension and reagent dose rates, with simple feed-specific variable inputs – have been developed from site-specific test work. The correlations developed provide a benchmark for plants to attempt to achieve. This provides operators and process engineers with a tool to explain BPFs and assist them in optimising the performance of BPF dewatering plants of both contemporary and less modern design.CITATION:Mathewson, D and Eschebach, D, 2015. ACARP belt press filter design, operation and maintenance handbook, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 73–82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Robinson T

The paper describes a spreadsheet system that enables selection of projects and companies that meet the user's corporate exploration and/or acquisition philosophy. A regularly maintained commercially available database has been used as the basis for this system. It provides an easily accessible efficient com- prehensive search method. The technique enables ranking by various criteria, both technical and financial, to provide groups of projects/companies that are of interest. Initially, target size parameters such as reserves, production and mine life are applied together with geological criteria such as age and deposit type; the significance of the targets in the context of the Australian gold industry is addressed.

Jan 1, 1988

By Tamura S, Maekawa M, Nagai C, Deguchi M

Heavy fuel oil has been injected into blast furnaces in order to reduce the coke rate, to improve productivity and to control the furnace heat condition. However, in the first oil crisis at the end of 1973, it became necessary to develop an injection technique of new fuels into blast furnaces to reduce oil consumption. In Kobe Steel, Ltd., it was thought that the injection of a coal-oil mixture (COM) into blast furnaces could be developed in a shorter time than pulverised coal injection. The development of this technique was under- taken in 1974, and COM was injected through two tuyeres of the No.3 blast furnace at the Kobe works in 1977 and 1978. In addition, in order to study the combust- ibility of COM and the phenomena in the tuyere zone, the development of a gas sampling method was under- taken in 1975. In this paper, the results of the injection tests and gas sampling tests are reported.

Jan 1, 1981

By M John

The Kwinana Industrial Area (KIA) is by far the largest and most diverse industrial processing region (with supporting industries) in Western Australia. As with elsewhere in Australia (and globally), the KIA is facing sustainability challenges on various fronts, such as increasing water and energy scarcity, climate change, an aging workforce, and growing community expectations. Through the Kwinana Industries Council (KIC) the industries within Kwinana are working closely on common issues in the KIA, including the sustainable development of the region. Over the past decade, significant progress has been made by the industries towards the improvement of the sustainability performance at the company and regional level. Given the ever increasing sustainability pressures, there is strong desire to address sustainability challenges in the KIA, through a pro-active and collaborative industry approach. A sustainability roadmap is being developed to assist the KIC and its industry members with strategic decision making on the long-term sustainability of there. At the heart of the roadmap is a set of key performance indicators for each of seven priority themes or focus areas (water use, by-products produced, greenhouse gas emissions and energy use, economic performance, environment, community impacts and sustainable workforce). Aspirational targets and subsequent strategies are being developed for those activities where the KIC has an influence and can make a positive impact. The indicators and their targets enable constructive stakeholder discussions (eg with government and community) on emerging local issues and possible future directions for the KIA. The paper will report on the development process and the preliminary results of the sustainability roadmap for the KIA, including a historical perspective on milestones achieved so far and future aspirations.

Jan 1, 2009

By J Penman, N Turner, H Liu

This paper aims to present a snapshot of the risk profile for tailings storage facilities within Western Australia by comparing the spatial distribution of known facilities against common geohazards such as cyclonic activity, climate, and peak ground accelerations from earthquakes. The analysis also includes an assessment of proximity to populations at risk including towns and sensitive receptors including significant river systems and wetlands.

Jul 1, 2021

By P Myers, T Elkington, S Wonday

Sierra Rutile LimitedÆs (SRL) heavy mineral sand mining operation in Sierra Leone, West Africa, is embarking on a new phase of its life. After confronting many challenges during the 1990s and 2000s, SRL is embarking on a strategy of growth to recover maximum value from the mine over the rest of its life. Sophisticated linear programming techniques have been used to develop an optimum strategy for extracting SRLÆs many known deposits of economic grade, while considering options for expansion and for a variety of mining and processing methods and combinations. CITATION:Myers, P, Elkington, T and Wonday, S, 2012. Strategic optimisation at Sierra Rutile - A case study in maximising project value, in Proceedings Project Evaluation 2012 , pp 59-66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By B Flynn, P Knights

Low-loaders or 'floats' for relocating equipment in surface mines are limited to a capacity of approximately 350 t. In the iron ore industry it is desirable to be able to rapidly relocate excavators in order to maintain production rates within appropriate quality limits. In addition, the ability to rapidly relocate heavy equipment raises the possibility of improving the quality of repairs by performing maintenance in controlled shop conditions. However, many iron ore operations operate hydraulic excavators in the 600 to 800 t range, with newly released excavator models exceeding 800 t. These excavators are too large to float using conventional technology. This paper examines the potential for using multi-bogie transporters to relocate large hydraulic excavators in surface mines. Recent innovations have seen the development of modular transporters which can be coupled together to achieve larger platform areas. When separated, and with their drive bogies neutralised, these units are able to be towed behind prime movers and relocated between mines via public roads. The potential cost savings for relocating a Terex RH170 excavator in an open pit coal mine are examined. In the first six months of 2008, the analysis showed the potential for a 38 per cent reduction in total travel time with a corresponding revenue increase of approximately $350 k. The paper recommends that a feasibility study be conducted into offering a heavy equipment relocation service within the Pilbara region.

Jan 1, 2009

Legislation introduced for Queensland and New South Wales Coal mines provides different levels of prescription regarding specification of mine seals û generally in relation to capacity to withstand overpressure. In Queensland, the Coal Mining Safety and Health Regulation (2001), Section 341 (d) places a further onus on the statutory ventilation officer to æensure all ventilation control devices at the mine are properly constructed and maintainedÆ and that the ventilation officer æmust ensure a ventilation control device mentioned in the regulation à and installed at the mine meets the design criteria statedÆ for the ætype of deviceÆ. Based on the experience of the author, it appears that risk management and life cycle approach to seals has not been adopted to the same extent as for other aspects of operations. Further, because of the number of disciplines and personnel involved that may influence various factors affecting seal integrity, the opportunity for oversight or unclear allocation of responsibility is considerable. While suppliers can provide explosion or design rated seals, this should only be a starting point for application of the product in a coal mine. Application is often considered by mine planning staff (taking into consideration mine environment parameters such as water, control of gas, spontaneous combustion risk, etc) in conjunction with the colliery ventilation officer, and then construction completed by contractors under supervision of operational staff. After construction, seals often are managed by operational personnel with input from the ventilation officer. Input of the geotechnical engineer into pillar design, roadway opening size, ground support specification and most stable seal location is also required. The need for a customised design approach for each seal site is proposed in order to take into account the many and variable factors that may influence a site so that improved seal performance reliability and predictability can be developed. A program of quantitative as well as qualitative monitoring of performance and triggers for rectification or maintenance action is required, and would provide support to the aforementioned proposal. Many mines rely on visual/audible inspection and periodic bag sampling as the primary means of assessment. Other significant factors such as seal material properties, rib degradation, convergence, floor heave, effects of water on both structural integrity of the seal as well as the air tightness of the seal do not generally receive the same level of attention. Based on the above observations, the author has compiled a reference checklist in regard to the above matters, including aspects of and approaches to mine and pillar design, geotechnical modelling and data collection, civil engineering design, site evaluation and practical options available.

Jan 1, 2005

By D Kilkenny

This paper discusses the use of a mechanised shaft sinking machine Herrenknecht Vertical Shaft Sinking Machine (VSM) – to conduct the 93 m presink for the Wira Hoisting Shaft at the Prominent Hill Mine in South Australia. This technology has been widely used in the global construction industry, however, this was the first time it had been used in Australia and the second time in a mining application. The non-entry shaft sinking system eliminates risks associated with a traditional manual method and allows all shaft construction operation to take place from surface. The geology in the upper 100 m at the Prominent Hill mine is conducive to mechanical excavation, with expected rock strengths below 130 MPa. This enabled an alternative shaft construction methodology to be considered. The Herrenknecht VSM system was selected due to its extensive work history and demonstrated performance in similar ground conditions. In collaboration with the operations and design team, the shaft collar and surface configuration were modified to suit the requirements of the VSM, additional equipment, and loading jacks that support the pre-cast lining. Dedicated concrete moulds were designed in Germany and built in Italy. The concrete segments were cast in Adelaide and road freighted to site. This paper outlines each stage of the presink – refurbishment, transportation, logistics, establishment, operation and demobilisation. Selecting this shaft presink excavation methodology, delivered through positive collaboration and communication despite some challenges, shows the benefit to the mining industry of applying new technology and innovation to improve safety and productivity.

Mar 29, 2023

By L Boczek

The term Engineer of Record (EoR) is commonly used in North America and South Africa to define the responsible person for the design, construction and operational phases of a tailings storage facility (TSF). Recently, this role has been elevated in prominence within Australia, but what does it really mean? Recent updates to international TSF guidelines suggests appointing an EoR is good practice, but where does the responsibilities of the EoR start and finish. Interestingly, both Samarco and Mount Polley failures had active EoR’s in place. This suggests that nominating an EoR alone, is not the full answer to mitigating the potential for a TSF failure. Appropriate construction and operational practices are key to the success of the design of TSFs, where all too often, operators ignore the operating plans developed by the designer. To be successful, a key consideration of the EoR role, is involvement in the operational phase of the TSF. This requires ‘buy-in’ from the mine managers and a change in the way TSFs are perceived by site. This paper explores how the roles and responsibilities of the EoR can assist in improving governance of TSFs if implemented effectively and what role the client has to ensure the success of the EoR.

Jul 1, 2021

By C J. Greet

Oil can enter a flotation circuit from a number of sources (for example, from mining equipment, oil leaks from the grinding equipment and coatings on the grinding media, but to name a few). Folklore generally states that any oil that contaminates the ore entering the flotation circuit is considered to have a negative impact on flotation. That is, a loss in concentrate grade and recovery.This represents a dilemma for some grinding media suppliers, who use a variety of quenching medium (air, polymer, oil or water) to achieve the desired physical properties of the ball. In the case of high chrome grinding media it is necessary, in some instances, to quench in oil to give the ball the right degree of toughness, which invariably leads to these balls having a thin film of oil on their surface. Once the grinding media arrives on site and site personnel recognise that the balls are “covered” in oil, they generally insist that the oil will have a deleterious impact on flotation performance.Obviously, any supplier “worth their salt” would take remedial action at the point of manufacture to minimise this problem. However, does quenching oil actually present a significant “threat” to the flotation process? This paper provides both laboratory and plant data describing the effect quenching oil has on the flotation of copper sulphide ore, with surprising results!

Aug 8, 2011

By F H. Henrfquez, A G. Oroz

Design and operating conditions of large size mechanical flotation cells were evaluated by comparing them with actual operating conditions in a plant. The objective was to determine the time scale-up factor, typically based on empirical rules. Experiments were conducted on the rougher flotation circuit at Minera Escondida Ltd. The circuit consisted of self-aerated mechanical cells of 160 m3, arranged in six parallel banks with nine cells each. The rougher circuit flotation kinetics were evaluated from direct sampling and local mass balances around each cell of the bank. Adjusted overall mass balances were also developed. This information was used to fit different kinetic flotation models, and it was found that the rectangular distribution function was the most appropriate to describe the distributed rate constant for industrial operation. Then, a rougher flotation simulator was developed to describe the actual operation in terms of the operating variables (mass flowrate, solid percentage, feed grade) and the actual volumetric flowrate entering to each cell. In this study feed pulp samples were taken in parallel from the rougher circuit and were simultaneously floated in the laboratory. The kinetic behaviour was then modelled at a laboratory batch scale in order to determine the time scale-up factor between laboratory batch flotation data and industrial size flotation. The time scale-up factor observed for large sized cells, 160 m3, was found to be reasonably similar to those previously determined for self-aerated mechanical cells, but of lower size, operating at similar recoveries. In addition, the relative effect of mixing, between laboratory batch and an industrial flotation bank, was quantified by the parameter, separating the impact that kinetic and mixing changes have on the time scale-up factor. In general, the rougher flotation operation was found to reach the predicted metallurgical target, and the optimal separability criterion was also respected. The diagnostic generates information about the internal state of the process and helps to identify potential improvements for design, operation and control of the circuit.

Jan 1, 2005

An empirical method of estimating dense rock (D.R.E.) equivalent volumes erupted as airfall tephra, described in a companion paper in this volume, is elaborated, and its accuracy discussed. Estimates obtained from a single eruption can be classified as to whether they show positive, negative, or constant relative dispersion. For positively dispersed tephras (estimated volumes increasing with distance), this procedure improves the accuracy of the method. The technique is applied to selected andesitic tephras erupted from Egmont Volcano, New Zealand, during the last 28 000 years, which are found to range in volume from about 1.5 x 107 m3 up to about 2.4 x 108 m3 D.R.E. With a factor of about 16 between the smallest and largest volumes, this contrasts sharply with the rhyolite volcanoes in New Zealand, where the difference factor is usually of the order of 100. The largest tephra eruptions at Egmont are small compared to the largest debris avalanches, which have exceeded 1010 m3 (10 km3) in volume.The magnitude versus frequency relationship, calculated using a maximum likelihood method, establishes the limits of eruption magnitude at Mt Egmont as 107 to 109 m3 D.R.E. For some volcanoes, the magnitude-frequency relationship changes with time, owing to clustering of eruptions, separated by long dormant intervals. Ngauruhoe Volcano, New Zealand, is an example. Within eruptive episodes, the mean interval between eruptions of >_ 105 m3 is about 0.9 ¦ 0.65 years. The mean interval between eruptive episodes in which >_ 106 m3 is erupted, including episodes in which this volume is erupted gradually, is about 25.8 ¦ 6.6 years, and the mean dormant interval between all episodes is about 5.2 ¦ 3.0 years. At present Ngauruhoe is in an unusually prolonged dormant period, 50% longer than any in the historical record, since 1839.

Jan 1, 1990

By H Rossiter, C Simpson, J Market, P Jeanneau

Downhole Assay tools are a geophysical method to collect an instigated response from the material surrounding a drill hole and deliver a multielement proxy-assay. They were first tested in the Pilbara at the turn of this century, however since 2011 they have seen a more focused testing and implementation regime with multiple companies across multiple Pilbara mine sites. The increase in the volume of data has led to advances in the measurements and significant improvements to the efficiency of the calibration process. Pulsed Fast and Thermal Neutron Activation Analysis (PFTNA) downhole assay tools collect gamma photon spectra which are characteristic of elemental signatures. One of the key components of the technique is calibrating the spectral signatures to lab assays. Each tool is slightly different due to the organic nature of the crystal detector and therefore responds slightly differently. Environment and hole conditions as well as ore characteristics are among other external influencing factors. Thus, a unique calibration is required for each tool. In addition, not all elements are measured directly, but some are actually characterised by proxy, meaning that if the signal-to-noise ratio for an element is small, it may be easier to identify the mineral or geology in which that element is found and thus infer the concentration of the element. These proxies may differ for each site or geology type within a site. There is a large advantage to build a unique calibration per tool at each site rather than a universal one to be used across the whole province. This then delivers the accuracy and precision of measurements that mining companies require for modern operations. Early work with the tool required several thousand metres of calibration data and several weeks of analysis to build each calibration. This process has now been streamlined to significantly reduce the amount of data required and the analysis time to make it much easier to introduce new tools to a site with an existing model or to create new models. This paper details the calibration process, illustrating the increasing accuracy of the models as training data are acquired as well as the methods for transferring a calibration from one tool to another.

Nov 8, 2021

The Health Tracking project is one of five projects being undertaken as part of the Minerals Industry Cooperation Initiative (MICI) û a national initiative sponsored by the Minerals Council of Australia. The aim of the Health Tracking project is to assess the practicality of ways to demonstrate the monitoring of hazardous exposures and the occurrence of related occupational illness and disease and development of management systems and strategies at a national level. This second stage of the project will be completed in 2005 and will cover four areas: pilot development of a comprehensive job exposure matrix (JEM) for the minerals industry; development of both proactive and reactive occupational illness and disease metrics; recommendations regarding appropriate health tracking models; and provision of best practices guidelines for management of occupational health. The synergies between these areas will establish the path towards an effective national occupational health surveillance system and the development of effective prevention strategies and policies.

Jan 1, 2005

Underground mine ventilation is now com monly simulated on a digital computer. Such a programme, incorporating natural ventilation has been modified by others to account for methane emission and elevated local tempera- tures. At Wollongong University, the pro- gramme was further developed and extensive interactive graphics incorporated such that any view of the three dimensional mine could be viewed, and superimposed upon that view are areas where a nominated parameter has exceeded a particular value - generally at a nominated time after a particular event and usually a fire/explosion of one type or another. A further programme was developed such that up to 20 'times' could be examined at a particu- lar location after say, a fuel rich fire at some other place in the mine. The output from this programme includes a plot of methane 1, smoke 1, temperature, pressure and air flow versus time - a most useful graphic to observe the limits of safe attendance in a particular Airway.

Jan 1, 1983