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By P Martin, A Somarin, S Bailey

Field-based research was conducted to investigate the performance of field portable X-ray fluorescence (FPXRF) in the analysis of reverse circulation (RC) drill chips in iron ore exploration. For years, FPXRF has been considered unsuitable for iron ore exploration due to the limitations of the elements it is capable of analysing for, in particular its inability to measure light elements (Mg, Al, Si, P, S). With the advent of the use of silicon drift detectors (SDD) in FPXRF, light elements are now measurable elements. However, doubt over the appropriate use of this new technology still exists due to the absence of reliable comparative field data. These doubts concerned the ability of the FPXRF data to correlate strongly with the laboratory assay of the same samples. It was believed that inconsistent grain size and other variables not being controlled would contribute greatly to this perceived unreliability.We tested RC chip samples on-site in the Pilbara, with the portable Thermo Scientific Niton XL3t X-ray fluorescence (XRF) analyser for a range of elements including Fe, Mn, Al, Si and S and then compared the results with laboratory assay data. A strong correlation indicates that the FPXRF results are reliable. Furthermore, to show the effect of simple sample preparation, we also analysed pulps of the same samples in the same way.The correlations were good for all of the elements of interest for the RC chip samples (R2 values between 0.82 and 0.9), and excellent for the pulps (R2 values between 0.89 and 1). The results also showed a direct correlation between sample preparation and improved quality of results with the FPXRF. This indicates that FPXRF can produce data from unprepared RC chips for Al and Si that, when compared with laboratory assays, is reliable for a field application in drilling and grade control. CITATION:Somarin, A, Martin, P and Bailey, S, 2013. Non-destructive analysis of diamond core for light elements using Niton field portable x-ray fluorescence, in Proceedings Iron Ore 2013 , pp 117-230 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Whitworth NR, Fox MJ, Henley RG

The coal mass flow monitor was developed to measure the instantaneous mass flow rate of pulverised coal to the copper reverberatory furnace at Mount Isa. The instrument was calibrated with an isokinetic coal sampler which was installed immediately downstream from the coal mass flow monitor. Readings from the coal mass flow monitor were used to control the feedrate of coal to the furnace and this helped to stabilise the furnace operation.Coal samples obtained from the isokinetic coal sampler were also sized using a Leeds and Northrup Microtrac analyser. The coal size was critical to reverberatory furnace performance. These developments significantly improved the overall combustion control of the furnace and gains of ten percent were made in the furnace thermal efficiency. Testwork on an auxiliary arch coal burner is also reported.

Jan 1, 1985

The safety of mine winder systems with regard to overwind, underwind, rope factors of safety, winder brakes and the like is discussed. Many misunderstandings and poten- tially unsafe practices are discussed as well as variations between requirements of various Mines Departments. Various methods to improve safety are suggested and the formation of an industry committee to review present practice and foster development of improved safety and economy is also suggested.

Jan 1, 1984

By Noreen D

At Bougainville Copper Limited comparison testwork was conducted between "horizontal" cycloning and conventional vertical cycloning. Horizontal cycloning reduces circulating load and allows increased ball mill throughput. Cyclone efficiency is the same or better as a result of the reduction of fines short-circuiting to the underflow. Operationally, horizontal cyclones are less likely to suffer from blocked spigots and high cyclone feed pump sump levels. Cyclone feed pumping power is reduced. High horizontal cyclone underflow density provides the option to optimise grind by manipulating water addition to the ball mill feed.

Jan 1, 1988

By Shining Z

The strength and deformation of more than two hundred coal samples have been tested in the condition of triaxial compression. The regression equation showing the relationship between coal strength and pressure in the pores, as well as confining pressure, was obtained. The appropriate calculation for stress-strain curve was carried out. Further, an analysis shows the variation of coal strength and its modulus of elasticity in methane medium.

Jan 1, 1992

By S D. Golding

The current study integrates hydrogeochemical and stable isotope results to investigate the sources and evolution of acid mine drainage at the historic Mount Morgan gold mine in Queensland, including the controlling factors and mechanisms of sulfate formation. The open pit and seepage sumps contain acid-sulfate waters and show elevated Al, Cu, Fe, Mn, Pb and Zn values. Samples collected from the Dee River bordering the mine site are less acidic, with lower concentrations of dissolved metals that gradually attenuate downstream from the mine. Concentrated acid mine waters has lead to formation of efflorescences consisting mainly of hydrous Fe-sulfates. The results of the ongoing isotope analyses on water samples show distinctive grouping of the data. The range of the sulfur isotope values for dissolved sulfate in samples from the open pit and sumps (d34S = 2.1 to 3.0 per mil) are similar to those of sulfides in the Main Pipe mineralisation (d34S = - 0.2 to 2.8 per mil). The lack of fractionation between sulfides and sulfate indicates that intermediate oxidation states of sulfur are not significant and makes this technique a useful tracer to identify the sources of sulfate. The Dee River samples, on the other hand, have heavier sulfur isotopes (d34S = 2.8 to 5.0 per mil). These samples may contain dissolved sulfate from æinternal sourcesÆ in the river basin, show local bacterial reduction or indicate a simple mixing trend. Further isotope analyses including oxygen isotopes of dissolved sulfates will enhance the interpretations.

Jan 1, 2003

By Z U Bajwah

During the Palaeoproterozoic, a large number of granitic intrusions were emplaced in the various parts of the Pine Creek Geosyncline (PCG). In the central region, the granitic magmatism is represented either by the coalesced mass, eg the Cullen Batholith, or individual plutons such as the Mount Bundey Granite which together with the Mount Goyder Syenite intrude the metasedimentary strata, causing wide spread contact aureoles. Some of these granitic intrusions are temporally and genetically related to gold (and less commonly base-metals) mineralisation present in the adjacent metasediments. These plutons are characterised by the presence of biotite and homblende which appear late in the paragenetic sequence. Electron microprobe analyses of biotite and homblende show that these minerals are poorly to moderately zoned. Biotites are characterised by a decrease in Fe/(Fe + Mg) ratios when plotted against AIVI. Similarly a modest decrease in Ti from centre to the margins of the biotite crystals has also been observed. Furthermore, an increase in Mg/(Mg + EFe) ratios from centre to the margins as well as in mafic to felsic rocks is also apparent. On the other hand, homblendes from the granitic bodies display less well marked trends and are poorly zoned. However, they show systematic increases in Mg/(Mg + EFe) ratios, and decreases in Fe, Al"' and Fe/(Fe + Mg) ratios, when plotted against Si. Magnetic susceptibility measurements on powdered samples of the plutons give results characterised by high values ranging from 0.8 x 10-4 to 2.0 x 10-3 emu/g which place the granites in magnetite- series field. This indicates that the oxidation state of the magma was high during crystallisation. The range of chemical compositions of the mafic phases indicates a rise in the oxidation state of the magma as it progressively became saturated in H20-volatiles and other metals, not partitioned into the earlier crystallised phases in the final stages of magma consolidation. These variations in chemical compositions also indicate that initially fOz was high and became progressively higher during fractional crystallisation of magmas; this subsequently led to the emanation of hydrothermal fluids responsible for the mineralisation in the adjacent metasediments.

Jan 1, 1994

Virtual reality (VR) simulators represent a powerful tool for training humans to perform tasks which are otherwise expensive or dangerous to duplicate in the real world. The idea is not new. Flight simulators have been used for decades to train pilots for both commercial and military aviation. These systems have advanced to a point that they are integral to both the design and the operation of modern aircraft (Adams, Klowden and Hannaford, 2001; Mastaglio and Callahan, 1995). This technology has been successfully extended and utilised in the mining industry in a range of successful applications (Bise, 1997; Denby and Schofield, 1999a; Schofield, 2005; Henning et al, 2002; Kaiser, Vasak and Suorineni, 2005). There are a number of lessons that can be learned from other industries that have successfully utilised virtual technology for a number of years. Specific rules of thumb regarding the specification, development, application and operation of these simulators can be garnered from other industrial training systems and examined in a minerals industry context (Tromp and Schofield, 2004; Schofield, 2006). This paper intends to discuss some of these generic rules in the context of a number of recently developed virtual reality mining applications.

Jan 1, 2008

I In an optical microscope, mild attack by cyanide solutions on various minerals can be observed by means of colour changes as well as etching patterns. However, the mineral may not be identifiable due to the coloured film. In some cases, a transfer algorithm between mechanical stages enables the surface-altered mineral to be identified in the SEM. A more severe attack may not be so informative, as it is not known whether the mineral attacked has been completely dissolved away. The leaching behaviour of some common minerals is described.

Jan 1, 1991

The hoisting system at the Newcrest Telfer mine is designed for a final duty of 7.35 million tonnes per annum at a hoisting distance of 1450 m. In terms of hoisting capacity (t/h) times hoisting distance it is one of the largest friction hoist installations. Initially, the hoist will be equipped for hoisting 6.5 Mtpa from 1100 m depth. This new drive technology is now well proven by ABB for mine hoist applications with the first installation in commercial operation since July 2001. To date 17 systems for medium voltage drives and another five for low voltage drives have been purchased from ABB for mine hoists. This paper will also deal with skip design and powerful data loggers with diagnostics for local and remote monitoring that are installed in the Telfer mine hoist.

Jan 1, 2005

By Sullivan TD, Redman PG

AND INTRODUCTION The Lochiel coal deposit, a large Tertiary soft brown coal deposit in the mid north of South Australia, is currently being investigated by the Electricity Trust of South Australia (ETSA) as a potential source of fuel for a base load power station. Feasibility studies indicated that the proposed dragline method of overburden removal was viable but economically sensitive to both highwail and dump batter angles. The unusual properties of the unconsolidated overburden sediments and the groundwater regime posed a number of intimately related hydrogeological and geotechnical questions which were addressed before and during the excavation of a trial pit. All strata at Lochiel are of soil strength, and artesian aquifers occur above and below the coal. From the initial evaluation of the deposit a number of hydrogeological questions were defined. These related to the rate at which the pore pressure in the silts is reduced by dewatering, the extent of the reduction in pore pressure due to prestripping, and the feasibility of dewatering and depressurising carbonaceous silty sand sequences. The site of the trial pit was selected to answer these and other questions from the basis of a detailed geological, hydrogeological and geotechnical understanding. The trial pit dewatering system simulated a full scale mine dewatering system and included ten pumped wells, twenty drainage wells, and nearly 400 monitoring instruments. It operated from September 1986 to June 1987. The excavation was carried out between February and May 1987.

Jan 1, 1988

The objective in design of an excavation in a jointed rock mass is to achieve a prescribed degree of control of rock mass displacement around the excavation. Any excavation in jointed rock usually involves slip and separation along discontinuities as well as translation and ro- tation of constituent rock blocks. Thus, any acceptable model of behavior around an excava- tion must be capable of simulating the force displacement paths followed by the constituent elements, including rigid body translation and rotation. The distinct element method models such behavior by simulating the rock mass as an assemblage of rock blocks which interact through corner and edge contacts. Discontinuities are regarded as boundary interactions between blocks with joint behavior prescribed for these inter- actions. Introduction of structural element logic allows a variety of installed support sys- tems to be modeled. The response of the support to axial, transverse, and flexural loads is based on explicit algorithms similar to those used in the distinct element formulation. This allows large displacements and rotations and general non-linear constitutive behavior for both the support elements and the interface with the rock. This paper describes both the distinct element and structural element formulations and demonstrates several applications involving sup- port interaction with jointed rock.

Jan 1, 1987

The explosion at Appin Colliery on July 24th, 1979, demonstrated the need for a large scale facility to simulate an underground type explosion and study its effects. The effects of an explosion cannot be established quantitat- ively using small scale models. A gallery was constructed for this purpose at Londonderry Centre and commissioned in Feb- ruary, 1980. It is 50 metres long, 2.7 metres in diameter, capable of withstanding an internal pressure of 210 kPa and is the only facility available for this purpose in Australia. The gallery has provided valuable inform- ation on blast effects of explosions in tunnels and is to be used for testing the performance of explosion arresting devices, further invest- igation of explosion effects, research into basic explosion phenomena and instrumentation development. Additionally, it will provide a demonstration facility for training purposes.

Jan 1, 1981

By B Gyngell, P Culvenor

Large language models (LLMs) have generated a lot of hype since ChatGPT was released in early 2023. In essence, they allow people to interact with computer systems through natural language and have the ability to generate highly complex text, images and videos (Patil and Gudivada, 2024). It is clear that this technology has significant potential, however most mining companies have not yet found practical applications for it within their operations. In this paper, we present a range of such applications along with the tactical considerations associated with developing and implementing them. We have identified use cases across a variety of operational and functional areas within the mining industry and evaluated them based on their potential business value and ease of implementation. Firstly, we provide an overview of how LLMs work and a review of how LLMs are being applied in other industries to provide best practice inspiration for mining. Next, we present a list of possible applications in mining and a critical assessment of each use case. This section also includes a technical deep dive into the different methodologies for developing the technologies as well as an analysis of barriers to adoption within mining organisations. Finally, we share a discussion of the potential path forward for LLMs in mining and the impact they could have on the industry. We analyse the potential differences between early adopters and laggards in the artificial intelligence (AI) space. This research draws on interviews and surveys with artificial intelligence experts as well as mining subject matter experts to connect cutting edge thought leadership with the specific problems faced by our industry.

Sep 1, 2024

It is indeed a pleasure to be here this morning to open the 4th Mill Operators' Conference. It is no mean feat to organise such an event and I would like to congratulate the committee for the work that they have done. I am sure that the Conference will be an outstanding success. I welcome overseas visitors and hope that they gain and share in the openness of this Conference. There is personal satisfaction for me to speak to you as a mining engineer addressing a large group of metallurgists and mill operators. I would have thought that it would be impossible for a mere mining engineer to inform a metallurgist of anything. I will desist from using such derogatory terms as "xanthate munchers", "bubble makers" and "glorified mathematicians". Terms of endearment as these may not be seen with much equanimity. Such is the warm association that the two professions have enjoyed over the years. The economic climate that we at present face is a major problem to all of us. I wonder how many people here come from mining operations that are in trouble financially or that are cutting back in one form or another. This is the recession that we needed to have. When the world's greatest treasurer can tell us that then we truly have a lot to fear. The present downturn can be seen as a normal adjustment in the cycle of our business. Yet the world does not experience such severe adjustments as frequently as we experience ours. The root cause for the regular adjustments can be placed at the feet of inflation. Until the politicians of this country of ours can come to grips with inflation, we will continue to experience downturns on a 5 to 7 year cycle. This, in my opinion, is the basic reason why we appear to experience more downturns than the rest of the world. We simply price ourselves out of the market. This takes about 5 to 7 years to be highlighted and then we need to make adjustments. However, this recession is worldwide. The adjustments usually take the form of redundancies, retrenchments and early retirements. What is the solution?

Jan 1, 1991

By Stitt P. H

This paper provides a brief historical review of the invention of the spiral separator and its adoption into Australian metallurgical practice. The purpose of the review is to demonstrate that spiral development to date appears to have been a largely empirical process, and that the cur- rent resurgence of interest in the spiral, especially in the coal industry, warrants an increased fundamental research effort. Current research work concentrating on empirical modelling is outlined, while some preliminary experimental results of a more fundamental nature are presented and some research of other disciplines interested in particle transport introduced in order to stimulate further work and discussion.

Jan 1, 1988

By Garland W

Access to geoscience reference informa- tion including mining and mineral processing has increased considerably in the last five years in Australia. This has been due principally to the use of computer-based information storage and retrieval systems. The main reference data base for the mineral and petroleum industries and disciplines in Australia is the Australian Earth Sciences Information System (AESIS), cooperatively developed and coordinated by the Australian Mineral Foundation (AMF). AESIS is created on the CSIRO computing network (CSIRONET) which has a CYBER 76 host computer located at the CSIRO Division of Computing Research (DCR) at Canberra. Data entry was until recently carried out by AMF using a dedicated line through the Adelaide CSIRONET node to the CYBER 76 interactive system. Data entry is now done directly at the AMF on a DEC PDP 11/44 mini computer that is also a host work station on CSIRONET. Data collection via magnetic tape media input from other computer-based systems is under development. The software used for data entry and management of the data base was developed by CSIRO CILES Systems Development Group. For public interactive online use the AESIS data base is transferred by tape to AUSINET - the Australian information net- work run by ACI Computer Services, Melbourne, where the data base is converted to a form suitable for the IBM STAIRS software. CSIRO facilities at DCR Canberra are used to produce computer type-set camera ready products and output in microform, on magnetic tape or as graphic display. Keywords: Earth sciences information, Computer applications, Information storage and retrieval, AESIS, Data bases, Australia.

Jan 1, 1983

By Palmer G, Dennis R, Clark A

The Ravenswood Mine in North Queensland is the first gold mine developed by Carpentaria Gold Pty Ltd, a wholly owned subsidiary of MIM Holdings Ltd. Carpentaria Exploration Pty Ltd began exploration at Ravenswood in 1978. However initial exploration of the main gold producing area (Buck Reef East) commenced in March 1987 when exploration rights to four key leases were secured. A rapid, co-ordinated exploration and development program produced gold from a heap leach operation nine months after the first costeans were dug at Buck Reef East. To treat higher grade ore found at depth in the Buck Reef East pit and the metallurgically more difficult Buck Reef West ore, a carbon in pulp plant was commissioned in May 1988. The mine is currently producing at a rate of approximately 40 000 ounces of gold per year. Ore at Ravenswood is hosted by hydrothermally altered diorites and tonalites of the Ravenswood Granodiorite complex. Alteration is controlled by planes of permeability formed by joints, shear zones and dilational breccias. The complex orebody geometry resulting from these controls required very detailed surface and drill exploration for adequate definition. Carpentaria's need for early cash flow meant that economic, mining and metallurgical considerations governed choices of exploration techniques, program timing, material and data collected. The initial reserve of 1.1 mt @ 2.87 g/t Au was defined by sectional polygonal methods. Grade control is based on geologic mapping and blast hole or channel sample assays. Ore is batched through the crusher and sampled to monitor grade control and mining performance. Minimal dilution has occurred. Gold content is greater than predicted by the reserve. Sprinkling of heaps commenced in November 1987. Changes have been made to the pad design and to the method of heap construction. Heap leach ore is treated at a rate of 400 000 tpa.

Jan 1, 1989

By M Berndt

Four siltite-argillite rock samples were characterised (particle size, chemistry, mineralogy) and subjected to laboratory dissolution testing for 36 to 298 weeks. In two samples sulfur (0.99, 1.69 wt per cent) occurred largely as pyrite, and in the other two samples sulfur (0.96, 1.93 wt per cent) occurred predominately as potassium jarosite. The observed rate of sulfate release from the pyritic samples was one to two orders of magnitude greater than that from samples containing potassium jarosite. Drainage pH values from the pyritic samples were one to two units lower and acidities were ten to 70 times higher than associated values from the potassium jarosite samples. Geochemical modelling supported the hypothesis that pH and concentrations of sulfate and potassium in drainage from the potassium jarosite samples were controlled by the limited solubility of potassium jarosite. This dissolution produced an iron-dominated mineral phase, but iron concentrations in the drainage were well below those predicted by ferrihydrite solubility.

Jan 1, 2003

By J Zhou, T D. McGrath, K P. Galvin, C P. Lowes, J J. Eksteen

Pre-concentration of low grade ores can improve the economic and environmental sustainability of an operation significantly, with opportunities for implementation ranging from run-of-mine to mill discharge depending on ore specific characteristics. For a gravity separation, where the performance is fundamentally constrained by mineral liberation, these feeds often represent a very difficult separation given the dominance of the relatively coarse gangue and fine liberation sizes. Thus, building knowledge of the feed through characterisation of the density distribution is critical to assessing amenability before progressing towards lab/pilot-scale test work and full-scale operation. The traditional approach to determining the density distribution typically involved sink/float testing, however, recent developments in hydrodynamic fractionation using inclined channels now offers a more cost-effective alternative with minimal health and environmental risk. A non-hazardous dense liquid, namely an aqueous solution of lithium heteropolytungstates (LST), is supplied as fluidisation to a REFLUXTM Classifier, consisting of a vertical section below a system of inclined channels, operating in semi-batch configuration. Fractionation is achieved by increasing the flow rate incrementally and collecting the particles to form a series of flow fractions. The purpose of this paper is to present this new method in the form of a case study, aimed at assessing the amenability of a low grade gold-bearing sulfide ore to pre-concentration. The robustness in the method is demonstrated through comparison with sink/float data, examining the density distribution and the liberation-limited product grade and recovery achievable. These data are then used as a benchmark to assess water-based continuous gravity separations conducted on the feed using a laboratory-scale REFLUXTM Classifier. This data set is used as the basis for process modelling and empirical validation for the recently established partition surface of the separator.

Nov 10, 2020