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By Iwu GO, Almond DP, Joasoo _

The gravimetric integral Knudsen effusion method was used to measure cadmium activity values in binary liquid In-Cd alloys in the range 523 to 573 K. The activity measurements together with other studies from the literature indicate that special bonding conditions exist in the melts near a composition corresponding to InCd3. Sound velocities in In-Cd melts were also measured using a precision pulse-echo over- lap method in the range 404 to 953 K. The frac- tional deviation of experimental and ideal isentropic compressibilities at 623K shows a functional dependence on composition with a pronounced maximum near the composition 75 at.%.

Jan 1, 1980

By E Philippa, J Vitanza, C Hawtin, B Miller

B Miller , E Philippa , C Hawtin and J Vitanza

Mar 22, 2022

By M A. Wells

A new approach to more reliably predict the Ni (and Fe, Mg) composition of Ni laterites was tested for RC samples from the (siliceous) oxide–style, Siberia North deposit, Kalgoorlie Nickel Project (KNP), in the north-eastern Yilgarn (WA) using partial least squares regression (PLSR) analysis of diffuse reflectance spectra over the 380 - 2500 nm wavelength range with a multi–element chemistry data set. PLSR cross-validation models were developed to predict FeO, MgO and Ni contents in composite samples with bulk composition limits of >0.08 wt per cent Ni and <6 wt per cent MgO. Calibration and validation models showed a strong, linear trend for predicting FeO and, to a lesser extent, Ni content, whereas PLSR models for predicting Mg content were less reliable. This reflected the prevailing mineralogy and associated element deportment within the oxide laterite profile. For example, Fe and Ni distribution is controlled by relatively few minerals, predominantly goethite and, to a lesser extent, the Fe3+-bearing smectite, nontronite. Magnesium is associated with a range of Mg-bearing minerals, some of which are compositionally complex (eg serpentine, talc, chlorite, smectite and carbonates). Magnesium chemistry alone does not reflect the varied mineralogy of samples with relatively high (5 - 6 wt per cent) MgO contents, which can be spectrally distinct. Hence, samples with similar Mg contents, though comprising Mg-bearing minerals with distinct reflectance spectra, were difficult to model (eg smectite versus Mg-carbonates). The findings of this study demonstrate that characterisation of Ni laterite composition may be achieved as part of routine logging of either drill chips or diamond drill core using PLSR analysis, but that a detailed understanding of the mineral-element association is essential for reliable predictive analysis. This has particular relevance to characterising the geometallurgy of Ni laterites, especially where deposits may be classed as the same type, but have distinct compositional and mineralogical differences.

Sep 5, 2011

By S Kowalczuk, S V. L Barrett

The potential for adverse surface settlement during tunnelling in soil and rock poses a significant risk to the successful completion of any tunnelling project. Undesirable ground movement may lead to unacceptable level of damage to surface infrastructure, buildings and the environment, resulting in safety concerns as well as causing significant delays and costs to a project. One of the empirical methods which is commonly used to predict surface settlement in the early stages of a project’s development is the volume loss approach as described by Mair, Taylor and Burland, 1996. This method was developed for use in soft ground; however it has also been applied in weathered and soft rock to provide an initial indication of potential surface settlements along a proposed tunnel alignment. This paper presents some initial thoughts on the use of this method in weathered and soft rock and the associated limitations which need to be taken into consideration when interpreting the results. This includes complex weathering profile cases where the strength and stiffness of the ground does not necessarily increase with depth.CITATION:Kowalczuk, S and Barrett, S V L, 2014. Initial thoughts on application of the volume loss approach for estimates of surface settlement due to tunnelling in weathered rock, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 641–646 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By A Galli

Traditionally pit optimisation and scheduling is carried out assuming that the resources, the commodity prices and production costs are all known. Once the pit contour and the mining schedule have been determined, geostatistical simulations can be used to assess the impact of the uncertainty in the resources on the pit design and the schedule, and likewise stochastic simulations can be used to test its robustness to fluctuations in costs and prices. But it would be more interesting to have a dynamic procedure for optimising the pit as the resources become better known and as economic factors such as commodity prices and costs evolve over time. This paper presents a novel approach for doing this. Rather than working with millions of small selective mining units, it was decided to work with large blocks, called macro-blocks. Mining sequences are defined as the quantities to be extracted from each macro-block in each time period. Feasible mining sequences are mining sequences that respect the accessibility constraints, and also the geometric constraints on the amounts that can be extracted from any one block over time, or from all the active blocks at a given time. Having defined feasible mining sequences, their mathematical properties were studied. It was found that natural breakpoints occur in the sequences when one set of blocks have been completely mined out, thereby opening up access to others. It was discovered that families of sequences exist, and that they are convex and closed under certain types of row permutation operations. Convexity is an advantage when optimising. The closure property opens up the possibility of mixing and matching subsequences of rows in the sequences. Another interesting property is that the sequences form branching families, rather like the binomial and trinomial trees used to model prices in finance and in real options.It is easy to generate large numbers of feasible mining sequences randomly. A two-step procedure is used to find the best one (or the best few) using three economic criteria: expected NPV,the probability of a negative NPV, and the percentage of years when the cash flow is negative. The procedure was tested on a synthetic gold mine based on the characteristics of the Essakane mine in Burkina Faso. The results were encouraging.

Sep 26, 2011

By C Itotoh, K O’Halloran, L Karlson

Global methods used to explore for minerals have progressed relatively slowly since the development of the first diamond core drill in 1863. Since then, key developments such as wireline geophysics (1920s), the tricone drill bit (1930s) and aeromagnetic surveys (1940s) all occurred in response to global events. In this project, BHP’s WAIO Geoscience operations team hypothesise that a global movement towards a greener future as well as an increasing intolerance for safety events will drive another step change in exploration methods. We have leveraged our relationships with exploration contractor partners and industry leaders to develop a realistic vision for 2033 and beyond, where drill rigs, earthworks and geophysical units are operated and maintained remotely; emissions of dust and waste are eliminated; hazardous energy sources are controlled; procurement is based on sustainability rather than cost and carbon emissions are tracked with the same rigour as production metrics. We have combined these visions into a series of graphical illustrations with the aim of inspiring ourselves, our vendors and our peers to collaborate further on producing a step change in our industry.

Sep 18, 2023

By C te Kloot, Z Liu

Blast performance and the resulting drawpoint condition and volume of oversize has the potential to impact operator safety and mine productivity. Underground measurements showed that approximately 14 per cent of production rings in the Ernest Henry Mine (EHM) sublevel caving (SLC) operation had either overbreak in the brow or left collars. There were also oversize rocks reporting to approximately 30 per cent of drawpoints, which accounted for over 7 per cent of total production and significantly impacted production rates. A series of trials were conducted in 2015–2016 at EHM to test changes to certain charge parameters in an attempt to optimise blasting results and, in particular, reduce oversize and overbreak. The detailed analysis conducted included field observations, hole surveying, blast monitor analysis and blast modelling. There were a total of nine charge parameters tested in the project, which fell into two major categories: energy distribution and inter-hole delay. These were based on observations made in establishing baseline data and those parameters most likely to have a significant impact on overbreak and oversize.Key results from the project included oversize reduction and improved brow conditions when energy distribution was reduced through changing charge lengths in certain holes in the standard charge plan. Similar benefits were also seen when the inter-hole delay between blastholes was reduced from 50 ms to 25 ms. Based on these results both changes were made to the standard production ring charge plan at EHM.Moving forward, the aim is to continue monitoring the results from the changes made on all levels to ensure efficiencies are being realised and sustained. A 3 per cent improvement in oversize as a percentage of total tonnes and improved brow conditions not only has a positive impact on production rates, but removes people from any potentially hazardous situations and contributes to a safer working environment.CITATION:te Kloot, C and Liu, Z, 2017. The evolution of production blasts at Ernest Henry Mine, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 33–38 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By K Jupp, T J. Howard

Cliffs Natural Resources Pty Ltd (CNR) operates iron ore mines in the Koolyanobbing region of Western Australia, about 50 km north of the town of Southern Cross. Ore is trucked from three geographically isolated sources to the crusher at Koolyanobbing, where it is blended before and during crushing. Lump and fines products are produced and railed to Esperance for ship loading and export to Asian customers. CNR is examining alternative processing paths, from mining to ship loading, with the aim of improving efficiency and reducing costs. Modifications to the system must be consistent with potential future expansions and maintain the low inter-shipment grade variability on which CNR prides itself and has built a strong relationship with its customers. In searching for the optimum process design, many options from mine face to ship loading must be evaluated and compared. Pilot plant studies are infeasible, while complex mineralogical interactions, competing goals and numerous possible system configurations limit the applicability of theoretical analysis. It was therefore concluded that simulation modeling would provide the confidence to take the next step into production trials. This paper describes techniques applied at CNR to simulate grade variability resulting from potential process design changes. The simulation models are easily run Excel-based modules, with each module representing a different part of the process. The modules use extensive Visual Basic macros driven by Excel's user-friendly interfaces. Presentation of the results is enhanced by Excel's excellent graphical capabilities. The simulation software stores and graphically presents time-stamped data from a run, enabling detailed analysis of different process configurations. Final success of a simulation run is measured by inter-shipment variability (standard deviation and process capability) and in-process ore tonnages. Meaningful results from the simulations require the initial input data contain the same correlations present in the real production environment, between the mineral components, production linkages and across time. The data also have to allow simulation of potential changes to mining method and introduction of new pits into the blend. Mining data from the real operations under study are therefore used, with average grades and variability adjusted to match potential future development proposals. It is also necessary to filter out medium and long-term variations from the production data as this variability is best controlled through the conventional medium to long-term mine planning process, not by the process design being studied. The filtering was carried out using a Fourier transform technique, which is described.

Jan 1, 2009

By D Connelly

Silver and gold bearing ore from the Troy Resources NL Casposo Gold-Silver Project, located within the San Juan Province of Argentina contains a complex mix of gold, silver, electrum and silver sulphides in the ore. Casposo is a typical low sulphidation epithermal style gold–silver deposit where mineralisation is hosted within rhyolite – andesite flows and breccias. Veins are typically banded quartz–chalcedony colloform - crustiform banded with quartz - carbonate infill. Mineralisation is associated with an assemblage consisting of quartz, chalcedony, adularia, calcite, illite, sericite and trace sulphides. Gold and silver occur as electrum, native silver, sulfosalts and silver sulphides. This paper presents a case study that describes the process selection, development and engineering of a tailored process plant for the recovery of gold and silver from this ore.The original feasibility study, modelling, metallurgical testwork and engineering studies are outlined. The final flowsheet was based on minimising capital cost, operability, recovery and minimising technical risk.The process flowsheet uses the traditional Merrill Crowe route because of the high silver to gold ratio in the feed and achieves maximum gold and silver recovery while providing a common facility for future ore body treatment.

Aug 8, 2011

By H Law, M Muller

Mount Isa Mines (MIM) Copper Concentrator currently utilises Agitair 120 banks for its roughing flotation circuit. Apart from a rotor change, the only other significant work completed to the Agitair banks since their installation and commissioning over 40 years ago has been a like for like refurbishment in 2016. The Agitair banks at the MIM Copper Concentrator currently utilise the Pipsa rotor design which progressively replaced the original Chile X rotor design in the 1980’s and 90’s in the copper concentrator. Since the development of the Pipsa rotors, modern rotors such as the Dorr-Oliver (DO) high shear rotors have been released to the market with proven recovery and concentrate grade improvements over previous rotor designs. This paper aims to detail the installation, testing and comparison of Pipsa versus Dorr-Oliver rotors in two different flotation sections of the MIM Copper Concentrator.CITATION:Muller, M and Law, H, 2018. High shear rotor trials in the Mount Isa Mines Copper Concentrator, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 393–402 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By K Hooper

Over the past 20 to 30 years statistics as a science has grown in significance. Not a day passes without reference to the latest statistics by the print, audio and audio-visual media. The Northern Territory Government has been part of this growth and like other public and private sector organisations collects a broad range of statistics. The Northern Territory Department of Mines and Energy participates in the government's statistics collection process. Statistics collected and published by the Department of Mines and Energy include geoscientific; mining and exploration tenure; environmental (e.g. mine site waste water management); production of minerals, oil and gas; mining sector employment; and occupational health and safety. The importance of statistics collection to the Northern Territory Government is discussed in the paper.

Jan 1, 1994

By P J. Hawke, M F. Flis

The Hamersley Basin of Western Australia holds significant tonnages of detrital iron deposits. Formed by a cyclic weathering and eroding sequence of nominally barren banded iron formation, they may form rich proximal accumulations of iron cemented gravels distal from any obvious hard-rock iron mineralisation. While generally small, they nonetheless represent excellent economic targets as they are near surface and easy to mine. The relatively high density of iron detritals, when compared with their sedimentary hosts, makes the gravity method the primary method of exploring for these blind deposits. Identification of possible trap sites is used as a precursor to gravity surveying, with magnetics used as an ancillary method prior to drilling. Application of the gravity method in this terrain is not straightforward. Detrital trap sites are best developed next to the spectacular cliffs that form the range fronts to the Hamersley Ranges. Precise terrain corrections and use of first vertical derivatives are routinely applied to gravity data in an effort to map every possible gravity high that may reflect the presence of a detrital accumulation. Extensions to Hamersley Iron Pty LimitedÆs BS2D deposit were discovered by the routine application of gravity. This methodology has been used to create a model by which exploration for detrital deposits continue to the present day.

Jan 1, 2002

By M Gasparon, J Harris, T Baumgartl, D J. Williams, M Edraki, P A. Kirsch, D Rowe

RISKGATE, an Australian Coal Association Research Program-funded (ACARP) initiative, has been designed to assist the Australian coal mining industry in improving minimum standards for safety performance, efficiency, operating practice and training. The online system is innovative in that it is built upon a foundation of industry expert knowledge gathered through action research workshops, which is further supported by a broad array of industry, academic and technical resources. In operation, RISKGATE offers a continuum for knowledge transfer and communication of current practice in risk identification, assessment and management in the coal mining industry. The primary mission of RISKGATE is to focus industry attention on prioritising control management as a way to achieve acceptable risk.A Coal Mine Tailings Dam Module has recently been added to the RISKGATE suite. The key risk, or initiating event, associated with coalmine tailings dams is catastrophic failure of the dam, leading to the release of tailings and water. This can occur due to geotechnical instability of the dam itself or of its foundation, overtopping and erosion of the dam, and piping failure of the dam itself or of its foundation. Coalmine tailings dams are also prone to seepage into the foundation and through the dam, particularly during operation when large volumes of water are discharged with the tailings. The most significant risk associated with seepage is the release of potentially contaminated water to the environment. Contamination can take the form of elevated salinity, acidity and dissolved metals. Run-off from coalmine tailings can cause erosion and can also potentially contain contaminants. Desiccation of the tailings surface can result in dust generation and dispersion.The paper presents the background and context of the RISKGATE project, the need for the addition of the RISKGATE Coal Mine Tailings Dam Module, and a description of the developed module, including the five initiating events considered, their causes and associated preventive controls, and their consequences and associated mitigating controls. This paper concludes with a discussion of the ways in which Australia’s coal mining companies are starting to apply the RISKGATE body of knowledge at their sites, which will flow onto the management of their tailings dams.CITATION:Williams, D J, Kirsch, P A, Gasparon, M, Baumgartl, T, Edraki, M, Rowe, D and Harris, J, ?2014. Application of RISKGATE to coal mine tailings dams, in Proceedings Life-of-Mine 2014 , pp 219–230 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By T Ireland, S Eratne, W Newns, P Spies

The approach to risk management during the procurement of major projects often has a significant outcome on the ultimate delivery of a project. The NZ$1.4 B Waterview Connection project is the largest and most complex project yet undertaken by the New Zealand Transport Agency (NZTA) and the procurement process for an alliance contract was refined to provide compliance with the International Tunnel Insurance Group (ITIG) Code of Practice for Risk Management of Tunnel Works (TCoP). The principle of shared risk within an alliance incentivises a common understanding of project risks prior to finalising the alliance agreement and therefore enables superior risk management through design, construction and beyond. Risk management practices need to be instigated well in advance of commercial phases, so that commercial competition does not lead to a significant elevation of project risk. In particular the practice of gaining commercial advantage by taking on a potentially unmanageable level of risk is one of the outcomes to be avoided by the TCoP.During the procurement phase the NZTA placed high value on design and construction mitigation measures proposed in order to address ground risks, as is appropriate for a major tunnel project. In order to achieve alignment on the level of geotechnical risks an Alliance Geotechnical Baseline Report (AGBR) process was developed.This paper describes the measures taken during the procurement process to achieve certainty with respect to outcomes and minimise project risks whilst also achieving value for money. Refinements to the procurement process to ensure compliance with the TCoP prepared by the International Tunnel Insurance Group (ITIG) are described along with the AGBR process applied as part of a suite of measures to achieve a successful procurement outcome.CITATION:Ireland, T, Spies, P, Eratne, S and Newns, W, 2014. Risk management and use of a geotechnical baseline report for a competitive alliance procurement?process, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 553–562 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By A Simmons, R Longey, D Brett

The South Deposit Tailings Storage Facility (SDTSF), located at Grange Resources Pty Ltd’s (Grange) Savage River mine in north west Tasmania, has recently begun construction. The facility will provide storage for approximately 37 million cubic metres of tailings, equating to approximately 20 years’ tailings storage.The SDTSF embankment will be constructed entirely out of waste rock won from mining operations, and will feature a flow-through drain constructed from alkaline, non-acid forming (NAF) waste rock. This provides Grange with an economical storage solution for waste management (both tailings and waste rock) and maximises available space on site. The outflows discharged through the alkaline rock ‘flow-through’ will provide a long-term source of alkalinity to Main Creek, subsequently feeding into Savage River. This will provide environmental benefits to the downstream ecology that has long been degraded due to the effects of legacy acid and metalliferous drainage (AMD), caused by historical mining operations.CITATION:Longey, R, Brett, D and Simmons, A, 2015. Integrated mine waste management – South Deposit Tailings Storage Facility, Savage River mine, Tasmania, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 343–352 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By I Sherrell, R Jain

Worldwide iron ore feed grades are trending downwards and will continue to do so with the increasing difficulties of upgrading ores. This has led to operations looking for ways to capture current tailings that still contain valuable material. In the past, these were acceptable to dispose of, but this practice is no longer economically feasible. With the increasing trend of re-mining previous tailings deposits that could be decades old, new equipment designs have been introduced to upgrade current or historic beneficiation plants. These designs can effectively upgrade these tailings to saleable products.Outotec conducted test programs for upgrading iron ore tailings from flotation rejects, thickener underflow or tailings dumps on samples provided by customers around the globe. The studies utilised Outotec’s SLon vertically pulsating high-gradient magnetic separator in combination with preprocessing equipment such as low-intensity magnetic separation, screen or scrubber and flotation for downstream processing of the magnetic concentrate. A review of the equipment required to economically process these tailings is provided, along with testing data and industrial implementation examples. The effect of different operational and design parameters on Fe grade and recovery from processing each tailings sample has been highlighted.CITATION:Jain, R and Sherrell, I, 2015. Iron ore tailings reprocessing to maximise ore production, in Proceedings Iron Ore 2015, pp 149–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

In 1980 Pancontinental Mining Limited decided that while the Jabiluka uranium project was still a major focus of the company's efforts some diversification was necessary. At this time it was decided to include precious metals in Pancon's exploration and acquisition objectives. As a result the now Paddington Gold tenements were acquired, explored and developed. Today, it rates as the 6th largest gold mine in Australia and at an expanded throughput of 1.2 million tonnes per year of ore it will produce about 110,000 ozs of gold per year. Following extensive exploration activities by Pancon's Exploration Division the Operations Division continued with development drilling finally proving up a reserve of about 8.4 million tonnes at an average grade of 3.2 g/t. An in- house preliminary feasibility study was followed by a two phase feasibility study by Davy McKee. This resulted in a recommendation to the Pancon Board of Directors to develop Paddington with an annual throughput capacity of 875,000 tonnes. This paper describes the acquisition, exploration and development of the Paddington project. It goes on to

Jan 1, 1986

By A Simmons, J Chan, A Li, Q Gu, D M. Brett

The paper presents an example of field density achievements using thin layer deposition and solar drying and compares this with compaction data from laboratory testing and field trials of mechanical densification processes.

Jul 1, 2021

By A F. D C Varajpo, R C. Weba, C Volkmer-Ribeiro, C A. C Varajpo, N S. Gomes

This study relates to the spongillite deposits from the region of Jopo Pinheiro, in the north-west of the State of Minas Gerais, south-eastern Brazil. The deposits occur in shallow ponds (with a maximum depth of 3.5 m) on a karstic planation surface developed on rocks of the Spo Francisco Neoproterozoic Supergroup. Cenozoic detritic covers are associated with this surface. The field study of spongillite deposits from the Preguita and Avipo deposits revealed sedimentological and pedological similarities between the different deposits. They have a lenticular shape and contain different layers of sedimentary spicules intercalated with layers of quartz sand and clay minerals. Representative samples from the different layers investigated by X-ray diffraction, differential and gravimetric thermal analysis and infrared spectroscopy showed a range from three to 80 per cent of amorphous silica (opal) corresponding mostly to the sponge spicules in the sediments. Optical microscopic investigation determined that the spicules predominantly belong to the sponge Metania spinata. This species is represented by smooth megascleres (alpha type), prickly megascleres (beta type) measuring 240 to 450 mm in length, as well as the spiny microscleres; whereby the smooth megascleres are larger and thinner. The morphological variation of the spicules as well as the presence of more fragmented spicules towards the base of the deposits, portray a variation in texture and in the state of their preservation along the profile, suggesting environmental variations at the time of their formation and deposition.

Jan 1, 2008

This paper aims to address the issue of the public's image of the extractive minerals industry. What is it about the industry that incites such negative feelings and are they justified? Are we really the 'rapists of the land' that many would have us believe? Has the industry really not improved since the old gold boom days?   I believe that the fundamental cause for the public's view is lack of knowledge and understanding of the industry as a result of the dislocation of the end production from its source. There are few people who look at a house, car, record, toilet, tooth-brush, bottle of coke or pair of glasses and see the mine site that supplied the source material. But the mine site and its products should be inseparably linked. This is one area where we should be educating the public û it is all very well being anti-development but the population as a whole is not really prepared to live without its 'mineral'-derived necessities. It is very easy to say that we do not want minerals development in New Zealand but are we prepared to live with the consequences, ie go without its products? We have a duty as a global citizen to develop our own resources rather than expect Third World nations desperate for overseas investment, often with governments who are not prepared to constrain or control their development, to be exploited. New Zealand is not the only 'beautiful' place in the world and we should be aware of the impact that our demands for resources have on the countries who supply us. We have a duty to be a good global citizen.   So how does the industry improve its public image? The key here has to be to educate. This does not have to be high powered or expensive but can be as simple as getting a few local kids' hands dirty panning, and gaining some firsthand knowledge of the industry. The industry also needs to be more pro-active in the public arena. Yes, the industry has skeletons, but the industry should be publicly displaying them û admit that things have gone wrong but let's do it ourselves and not leave it up to the environmental groups to accuse, point the finger and put the industry under public scrutiny. The industry should also be publicising its successes, inviting the local press, councils, etc to view the latest area rehabilitated. But more than anything else we must tell the public what the minerals industry means to New Zealand. Can they really live without us?

Jan 1, 1991