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By T Belligoi

Diamond cores and drill chips provide the only direct physical evidence for ore containing rocks. Early characterisation of cores and drill chips is important as it provides critical information for downstream processing. Traditional characterisation techniques include visual logging by a geologist or analytic and spectroscopic methods but they are time consuming and can miss some important textural or geomechanical features.The goal of this work is to evaluate the application of image analysis to iron ore cores and drill chips and to suggest improvements to existing core-scanning and chip monitoring systems. Two samples of massive ore differing by their mineralogy and texture, as well as two different batches of drill chips, have been imaged and analysed. Results are compared in function of the imaging system and the classification algorithms.As a conclusion, despite the necessity for more testing and improvements in calibration and lighting, it is obvious that image analysis technologies can bring a lot of useful information in the perspective of a geometallurgical mapping of the deposit.

Jul 11, 2011

By S Henderson

The Otago Goldfield has produced approximately 8 million ounces of alluvial gold and over 2.5 million ounces of hard rock gold and is currently home to New ZealandÆs largest producing gold mine. In the eyes of explorers this production history makes the goldfield a good place to explore.   Modern exploration in the Otago Goldfield commenced in the late 1970s with the exploration for tungsten. However, a rapid rise of the gold price in the early 1980s saw the focus shift to the exploration for gold which lead to the discovery of the Macraes Gold Project in 1984, which since it came into production in 1990 has been New ZealandÆs largest producing gold mine. With the exception of the Macraes Gold Project, exploration continued in the Otago Goldfield for a further 20 years without further success.   In 2006, Glass Earth (NZ) Limited (Glass Earth) reviewed all the exploration technologies applied to the Otago region and available geological data, including the 1996 OceanaGold Helicopter Electro-Magnetic (HEM) data, and concluded that combined magnetics and HEM were able to delineate the Hyde Macraes Shear Zone (HMSZ) which hosts the Macraes Gold Project. Unlike previous explorers who explored the Otago region in a piecemeal manner, Glass Earth opted to collect a new, region-wide dataset which could be integrated with all previous collected geological information to come up with new exploration concepts and targets. As part of this process, Glass Earth applied in mid 2006 for New ZealandÆs largest on-shore gold Prospecting Permit, PP39-322 which was subsequently granted in November 2006. In mid January 2007, Glass Earth commenced acquisition of approximately 50 000 line kilometres of HEM data, making the Otago regional aerial geophysical survey (survey) the largest aerial geophysical survey ever undertaken in New Zealand.   This paper will report on the progress of the Otago Regional aerial geophysical survey and outline some of the preliminary findings from what is still a work in progress.

Jan 1, 2007

The Mt Keith Mining Alliance operates a fleet of large capacity hydraulic face shovels and more than 40 X 240 t capacity haul trucks to deliver annual production in excess of 40 Mbcm per annum. The Mt Keith Nickel mine is currently operating at a depth to 300 m below surface with a planned final depth of the order of 500 m. As is the case with any large open pit managing the health of the workforce on continuous shift operations is of critical importance to achieving outstanding safety and production outcomes. Fatigue management at Mt Keith is effectively managed by the personnel operating the mining equipment, with assistance and understanding of the management team and supervisors. The program has been driven through the introduction of Fatigue Champions and a comprehensive management plan that includes education, individual health plans and the use of new technologies. Mt Keith has been instrumental in trialling new technology which assists in monitoring fatigue in operations personnel. Insight into these developments is provided in the context of the overall fatigue management plan. The field trials of the OptAlert(TM) system and how it assists in measuring fatigue is explained. The implications for individual operators and the context for a fleet wide approach to fatigue management is also discussed. Mt Keith has recently completed the second phase of trials with the result that this new and exciting technology is being considered for adoption globally across BHP BillitonÆs open pit mining operations.

Jan 1, 2007

By Davies K. E

Several nuclear techniques have been assessed for application to online conveyor belt analysis of oil yield from Rundle oil shale. The most favourable technique is neutron inelastic scattering which determines the total carbon content of bulk shale samples. Correlations of chemical laboratory assays for 540 Rundle oil shale samples show that oil yield can be predicted from total carbon to within 11 litre/tonne.Laboratory experimental work on 17 bulk samples of Rundle oil shale indicated that carbon and oil yield can be determined to within 0.6 wt per cent and 9 litre/tonne, respectively, using the neutron inelastic scatter technique. A practical neutron inelastic scatter gauge for application on a 23 mm thick reinforced conveyor belt could consist of a 5 curie 241 Am-Be neutron source and a 150 mm diameter x 100 mm thick Nal(TI) detector. With this gauge, the analysis time to achieve a counting statistical error of 6 litre/tonne should be about five minutes.

Jan 1, 1985

By Shinnosuke U, Zhang HE, Qian X

In this paper it is recommended that pyrite is to be separated as froth from arsenopyrite by selective depression of arsenopyrite in strong alkaline medium (1), by oxidation with chlorinated lime (II), by co-use of chlorinated lime with sodium carbonate (III), and by modification with `L' reagent (know-how) without filtering to get rid of residual copper ions after Cu activation (IV). The corresponding principles of these (new) effective methods were briefly discussed. The artificial mixture (1:1) of pyrite and arsenopyrite could be successfully separated, and concentrates of pyrite containing 2.12 per cent (I), 7.00 per cent (II), 2.60 per cent (III) and 3.16 per cent (IV) arsenic with recovery of 90.9 per cent (1), 89.5 per cent (II), 89.0 per cent (III) and 81.4 per cent (IV) respectively can be obtained by only one flotation. Some effective precautions were suggested to improve the separation of arsenopyrite and pyrite (or other sulphides) by flotation.

Jan 1, 1993

By D P. Sainsbury, J Western, B L. Sainsbury, V Mutton, P E. Petrie

Remnant rib pillars at Castlemaine Goldfields Ltd’s Ballarat Gold Project have been sterilised by the placement of loose rock fill in production stopes. The application of selectively injecting low-viscosity grout into the backfilled stopes to form a stabilised material has enabled recovery of the previously sterilised pillars. This paper outlines the engineering design, quality control and quality assurance program implemented to ensure the safe and efficient recovery of the rib pillars. The successful program included laboratory testing, numerical exposure stability modelling and in situ monitoring.CITATION:Sainsbury, B L, Sainsbury, D P, Western, J, Petrie, P E and Mutton, V, 2014. Pillar recovery adjacent to stabilised rock fill at the Ballarat Gold Project, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 77–86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By A Li, H Jinto, M Laxman

The behaviour of tailings under cyclic loading has an impact on the stability and deformation of tailings dams and a good understanding of the cyclic behaviour of the tailings under earthquakes is important for tailings engineers and tailings operators for the design and safe operation of tailings dams. This paper presents an investigation into the cyclic behaviour of tailings using both laboratory cyclic direct simple shear (DSS) testing and numerical modelling. The laboratory testing involved cyclic DSS tests on gold tailings and zinc-copper tailings under different loadings and loading frequencies. The gold tailings specimen tested at a higher loading frequency and a higher cyclic stress ratio experienced spontaneous liquefaction during cyclic shearing and the zinc-copper tailings specimen tested at a lower loading frequency and a similar cyclic stress ratio exhibited ductile behaviour and liquefied due to cyclic mobility. The liquefaction behaviour of the tailings was modelled using an advanced constitutive model (UBCSAND), which was developed specifically to model soil liquefaction and strain softening under cyclic loading. The constitutive soil model presents the nonlinear soil behaviour under dynamic loading using a hyperbolic stress-strain relation. Dynamic analyses were carried out using a finite difference program FLAC. The cyclic stress-induced excess pore water pressures measured in the laboratory were modelled using numerical simulations of the laboratory tests under different loading conditions. The results of the non-linear dynamic analyses demonstrated the capability of numerical modelling of cyclic shearing induced excess pore water pressure and the onset of the spontaneous liquefaction. The laboratory investigation and numerical modelling technique provided the key properties and parameters for the dynamic analyses to assess the stability and deformation of tailings dams under design earthquake events. More importantly, the laboratory tests and numerical modelling provided some insights into liquefaction behaviour of the tailings during earthquakes. CITATION:Li, A, Laxman, M and Jinto, H, 2018. Liquefaction behaviour of tailings under cyclic simple shear testing, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 250–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Drinkwater DJ, Watsford RMS, Johnson NW, Munro PD

This paper describes the use of modelling and simulation techniques in the analysis and optimisation of grinding circuits at the Lead/Zinc Concentrator of Mount Isa Mines Limited.The objectives of the studies were to: -1. improve primary grinding circuit performance by reducing the production of -0.006 mm galena fines.2. maximise the fineness of grind in the second existing grinding power and pumping capacitie The study has shown that quantitative models can operations. The models described plant operation,,and simulated the effect of process changes on plant performanc The use of automated scanning electron microscope technology tcliberation characteristics of the major minerals in the Mount isa Lead/Li ore is also described.

Jan 1, 1985

The Goonumbla district of central-west New South Wales, Australia, hosts four significant porphyry Cu-Au deposits that contain a combined probable ore reserve of 71.7 million tonnes at 1.2 per cent Cu and 0.5 g/t Au. Mineralisation in the Goonumbla deposits is associated with narrow, pipe-like intrusions of quartz monzonite porphyry, in which several intrusive phases have been recognised. Five textural characteristics have been used to distinguish the various intrusive phases recognised in the Goonumbla porphyry deposits: (1) phenocryst abundance; (2) nature of the groundmass; (3 and 4) proportion and mineralogy of the mafic and non-mafic phenocrysts; and (5) the presence or absence of anhedral quartz grains in the groundmass. In addition, each intrusive phase is classified according to its estimated original quartz, alkali feldspar and plagioclase contents. Features common to all of the intrusions are that they contain two types of plagioclase and two or three types of K-feldspar phenocrysts in variable proportions. Most of the intrusions also contain apatite micro-phenocrysts. The groundmass textures range from aphanitic through granular to euhedral K-feldspar in a quartz matrix. With only one exception, all of the intrusive phases recognised are either quartz monzonite porphyry or mafic (>5 per cent mafic minerals) quartz monzonite porphyry. The exception is a biotite - phyric monzodiorite, which occurs in the basal portions of one of the deposits. Textural variants of intrusive phases at Goonumbla have been investigated to establish whether specific combinations of characteristics indicate mineralised intrusions, while others suggest barren ones. Some correlations between intrusion types and Cu and Au grade have been recognised. The most important textural characteristic that relates to high grade mineralisation appears to be the low proportion of mafic minerals, because the quartz monzonite porphyry intrusions hosting most of the mineralisation in the two deposits studied contain

Jan 1, 1999

The experiments described in this paper were carried out as a preliminary to a comprehensive study of the factors which affect the behaviour of lead during and subsequent to deformation by rolling and pressing. These observations are therefore to be considered as introductory to a further paper dealing more specifically with the above-mentioned variables.EXPERIMENTALThe rolling was carried out in a small mill with six-inch diameter surface ground rolls, both of which were electrically driven at 15 r.p.m. The average draft per pass approximated 0·03 in. The pressing was performed between platens in the compression unit of a 30-ton Amsler machine. The flat faces used had a ground finish comparable with the surface of the rolls. All hardness measurements were made with a Herbert "dead load" Brinell machine. The following te'sting conditions were maintained: ball diameter-5 mm.; load-10 kgms.; duration of loading-30 seconds; temperature of testing-16 to 18°C. The hardness values which are given are the mean of two or more impressions made at corresponding positions on the test specimens.PREVIOUS WORKSince the researches of Tresca (1):j: into the nature of the plastic flow of metals during various forging and extrusion...

Jan 1, 1939

By J Mauk, R Ruddock

The Taharoa ironsand deposit is 1600 hectares in size and is located 144 km south of Auckland on the west coast of the North Island, New Zealand. The sand predominantly contains heavy mineral-rich sediments, quartz, and feldspars. One hundred and two samples were collected from all areas of the mine, from the stockpile, black sand areas, tailings and Te Akeake Sands. Samples were collected with the primary focus on the next predicted mining path and secondly on gaining a good geographic spread throughout the mine. All samples were analysed for the dry, wet and particle density, the porosity and the magnetic, non-magnetic and clay minerals content.Stockpile samples had an average magnetic mineral content of 92 percent. Dry, wet and particle density values for stockpile material exceed all values from untreated ironsand samples with average values of 2.8g/cm3, 2.9g/cm3 and 4.4g/cm3 respectively. Black sand samples from the mine came from various areas such as the central area, the forest, the southern area and the benches. All black sand samples are remarkably consistent, with dry and wet density values between 2.3 û 2.5g/cm3 and particle densities that range from 3.7 to 3.9g/cm3. The porosity values are comparable to all other areas of the mine (average 37 per cent). The tailings and Te Akeake Sands have different physical properties due to their different mineral contents. The dry, wet and particle densities are all lower than that of all other areas with averages of 2.1g/cm3, 2.2g/cm3 and 3.3g/cm3 respectively. These lower values reflect the lower magnetic mineral content (average 18 per cent) and the associated increase in non-magnetic mineral content (average 78 per cent).

Jan 1, 2002

By E T. Baker, J A. Resing, S L. Walker, V Ferrini, F Martinez, R Haymon

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Enumerating active sea floor hydrothermal sites has been a challenge since their discovery almost 40 years ago. High-temperature hydrothermal sites are readily discoverable, primarily by detecting mineral-laden plumes, but working at these sites poses severe environmental and operational difficulties. Low-temperature vent fields, which may represent waning of venting from high-temperature systems, may be more accessible but are more difficult to locate. Over the last decade, however, oxidation-reduction potential (ORP; aka Eh) sensors capable of detecting minute concentrations of reduced hydrothermal chemicals have been successfully used to pinpoint such fields. In this extended abstract, we use ORP anomalies observed during continuous (towed sensor) plume surveys to estimate site frequency along four intermediate- to fast-spreading ridge sections. From these data, we estimate site frequencies between five and 16/100 km for these ridge sections. Previous camera surveys on the fast-spreading East Pacific Rise support these frequencies. These rates are much greater than the frequency of ~0.5–5/100 km, generally increasing with spreading rate, derived from well-surveyed ridge sections in the InterRidge database (InterRidge, 2014). The higher frequencies arise because ORP sensors are able to distinguish between sites as close as ~1 km and identify sites with negligible or no optical plume signal.CITATION:Baker, E T, Resing, J A, Martinez, F, Haymon, R, Walker, S L and Ferrini, V, 2015. How leaky are oceanic ridge axes? A new assessment of the spatial density of submarine hydrothermal discharge, in Proceedings PACRIM 2015 Congress, pp 3–8 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By C Linklater, A Garvie, D Kentwell

Various Australian and international regulatory bodies (Environmental Protection Authority, 2015) require an early assessment of the geochemistry of waste rock. This usually includes estimates of the locations and volumes of potentially acid forming (PAF) materials and requires sampling of the waste rock zones as well as submitting the samples for a series of tests. We know that the required number of samples will vary depending on rock type, mean sulfur levels and spatial variability of sulfur as well as total volume. The key question is how do we know when we have enough samples?This extended abstract describes the application of geostatistical methods to examine how sample numbers and sample locations influence the preliminary conclusions that may be drawn for early stage waste characterisation.CITATION:Kentwell, D, Garvie, A and Linklater, C, 2016. Geostatistics and sample numbers from an acid and metalliferous drainage perspective, in Proceedings Life-of-Mine 2016 Conference , pp 12–15 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By W Zirima

A detailed, mine scale non-linear numerical model of Rosebery mine has been built for the purpose of simulating life-of-mine global deformations. The model was calibrated using observations of displacement and damage, and was then used to investigate the correlation between dissipated plastic energy (DPE) and seismic event occurrence. The study is unique because the seismic data was collected over a relatively short period using a temporary portable seismic system. It is the intent to undertake significantly more work, but the analysis of limited data shows that a very good, non-linear relation between DPE and event probability is present. The observed correlation is consistent with measurements from other mines where more data was available. With more data, the strength of the correlation will allow the DPE analysis to be used during the design and sequencing phase of planning to better design the mine to minimise seismic hazards.

Jan 1, 2008

By W Assibey-Bonsu

The paper provides a brief review of the multivariate uniform conditioning and the localised multivariate uniform conditioning techniques and presents a case study based on a porphyry copper gold deposit in Peru. Two other important scenarios have been investigated and will be particularly emphasised: The recovered selective mining unit (SMU)s depend on a combination of copper and gold content, which can be expressed by means of ænet smelter returnsÆ (NSR). Two approaches are compared. Firstly, the application of a composite cut-off on NSR on the joint distribution of each grade and the application of uniform conditioning to three variables is investigated, ie for the first approach NSR is used as the main variable. The second approach considers copper as the main variable. In the case of multiple domains the procedure used to apply the technique to process mixed panels is clarified and recommendations are made.

Sep 26, 2011

By S Ellis

In January 2008 Chirano Gold Mines Limited committed to expansion of the Chirano Gold Project from its existing design capacity of 2 Mtpa ROM ore to a new design value of 3.5 Mtpa. In addition to increased throughput, the design had to contend with increasing ore hardness and competency, while at the same time make cost effective use of existing equipment with minimum disruption to existing production. The solution adopted involved some novel approaches including tertiary crushing and operation of the SABC circuit in overflow ball mill mode and parallel elution with a common acid wash column. This paper describes the approach taken to the design of these elements to achieve a cost effective and safe capacity expansion.

Aug 8, 2011

By T Honeyands, L Jelenich

We are currently witnessing large fluctuations in the relative price of ironmaking raw materials brought on by changes in the dynamics of supply and demand, market conditions, environmental regulations and technical factors affecting the iron and steelmaking process. From a customer perspective, it is the behaviour of iron ores in downstream processing that give them their value; their impact on the sintering or pelletising process and subsequently blast furnace ironmaking. It is therefore important to consider this value when developing projects, making mine planning/cut-off grade decisions and in setting price differentials for differing quality.This paper describes the use of the Marx value-in-use model to quantify the downstream value of lump iron ores. The Marx model consists of heat and mass balance modules for sintering and pelletising and a rigorous two-stage heat and mass balance model of blast furnace ironmaking. Mass balance and cost models are applied for steelmaking, casting and rolling. The use of a heat and mass balance allows accurate comparison of the impact of raw material properties on blast furnace operation. The impact of minor elements, such as alumina, silica and phosphorus, and metallurgical properties on ironmaking is described, and examples are given for the calculation of a lump premium.CITATION:Honeyands, T and Jelenich, L, 2015. Lump ore properties and their impact on value-in-use in ironmaking, in Proceedings Iron Ore 2015, pp 359–362 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Z Li, Z Yan, M Yang

Recycled cement paste (RCP) is a kind of CaO-rich recourse, which is separated and recycled from waste concrete. Due to its chemical composition, RCP could partially replace lime as a flux and be loaded into electric arc furnace (EAF) steelmaking process. Rapid RCP assimilation and liquid slag formation have significant effects on EAF steelmaking process. In this study, the dissolution behaviours of RCP and lime at temperatures of 1400°C to 1500°C were investigated using static dissolution experiment. The dissolution rate, interfacial microstructure, as well as dissolution mechanisms were discussed. It was found that the dissolution rate of RCP was much higher than that of lime. RCP could be completely dissolved into slag in 60 secs at 1500°C. The dissolution rate of lime was in range of 3.910-4 g/(cm2ꞏs) to 2.610-3 g/(cm2ꞏs), while that for RCP was in range of 1.510-3 g/(cm2ꞏs) to 4.910-3 g/(cm2ꞏs). As for lime dissolution, a dense layer of dicalcium silicate (C2S) generated at the dissolution interface, and the diffusion of Ca2+ in C2S layer was the limited step for lime dissolution. Some of calcium ferrite could be observed at the interface between lime and C2S layer. As for the RCP dissolution, there is no obvious product layer of C2S formed at the dissolution interface, Fe2+ continuously diffused into RCP layer during the dissolution, and small amount of FeOꞏMgO solid solution generated and gathered at the dissolution interface. The dissolution rate of RCP in EAF slag was quite higher than that of lime, partially add RCP as flux in EAF could accelerate the slag formation process.

Aug 21, 2024

By N Haque, S Northey

Water in mining, mineral processing and metal production on a life cycle basis has been at the top of agendas for various industries, government agencies, research organisations, academic institutions and communities. As a result, a number of water footprint assessment methodologies have been developed. However, their practical applications in mining and mineral processing industries with specific case studies are still rare.A key objective of the Minerals Down Under Flagship is to contribute to the long-term sustainability of the Australian mining and mineral industries. Researchers in the Mineral Futures theme have developed robust assessment methods to evaluate the impact of mining and minerals technology development on the environment. The future of mining and the mineral industry is strongly linked with its sustainability - better water management strategies will need to be implemented.Life cycle assessment (LCA) has been a recognised method for measuring the environmental impacts of products, processes and services. It provides a scientifically sound method of comparing products and processes using a common basis and identifies so called æhot spotsÆ and opportunities for reducing environmental impacts. The water footprint of mining, mineral processing and metal production using an LCA basis is still scarce in the literature. Research methodology is now being applied in detail for copper, gold and nickel. A primary focus has been the relationship between ore grade and water use for which mathematical models are being developed. These types of models provide inputs for LCA of mining and mineral processing plants and can identify water saving opportunities through scenarios and process route analysis.CITATION:Northey, S and Haque, N, 2013. Life cycle based water footprints of selected mineral and metal processing routes, in Proceedings Water in Mining 2013 , pp 35-50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By J Vann

Geometallurgy is inherently multidisciplinary and it gains its power to deliver improved outcomes for the minerals industry by bridging silos between disciplines. This cross-disciplinary approach unlocks value, identifies (and avoids) value destruction and provides a pathway to better implementation of an energy efficient and sustainable minerals industry. Despite this promise, we argue that the cross disciplinary approach also represents the greatest threat to the success of geometallurgy. Some key cross disciplinary issues identified are:Geometallurgy has so far evolved in the technical sphere, mainly by collaborations of geologists and metallurgists. Consequently, in many cases the business dimensions and value have not been incorporated. Financial and risk evaluation viewpoints need to be assimilated into the geometallurgical paradigm. In fact, until such measures are integrated into practices, the value cannot be fully demonstrated.The historical and current efforts on geometallurgy have been highly focused on improved sampling and measurement of geometallurgical properties or appropriate proxies. This work has been driven by professional and academic geologists and metallurgical engineers. It is notable that mining engineers (who are critical in the value delivery of geometallurgy through changed planning approaches) have so far been at the margins, or absent. The construction of valid three dimensional (3D) geometallurgical models raises some important organisational, mathematical and geostatistical considerations. The enhancement of resource models to account for geometallurgical aspects must be managed carefully if the full value of geometallurgical thinking is to be realised.The use of 3D geometallurgical models to change business decision making and practices is the real nub of the problem. We believe sophisticated scenario based evaluation methods are required if the potential impacts of spatial rock properties on processes further down the mining value chain are to be realistically evaluated. Such changed practices require ‘whole of value chain thinking’ to embed this change into the business in an ongoing way.Because profitable geometallurgy demands changed approaches to business decision-making and also organisation of the firm (radically changed in some cases), the senior executive viewpoint must be incorporated into the language and thinking of geometallurgy. This is unavoidable if the establishment of a geometallurgical approach to project evaluation, development and operation is to be successful and sustained.A powerful analogy for the problem faced by geometallurgy is the transformation of safety culture in the mining industry in the past 20 years. We argue that, as in the safety revolution, explicit models, cultural change and management of the ‘soft’ dimensions of the problem are pivotal to success of geometallurgy. In light of this, we propose a model (‘the Geomet Curve’) that gives a framework and pathway for geometallurgy in seven steps. The implications of this model for technical and organisational steps required at different stages are discussed.

Sep 5, 2011