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By Kametani H

Since pyrite is a semiconductor, the relationship between the leaching rate and the semiconducting properties is of interest. In order to investigate this relationship, a pyrite concentrate (95% FeS2) was oxidized at 90¦C (363 K) in an acid solution containing 100 g/dm3 H2SO4 and 1.0 to 25.1 g/dm3 total Fe. The suspension potential (Pt vs. SCE) was maintained at the desired values, within the range 0.40 to 0.70 V, by controlled additions of a KMn04 solution during leaching. The results were analyzed using a simplified kinetic expression. The rate constant was independent of the Fe concentration, while it increased with suspension potential. Partly oxidized samples were then prepared at varying fractions of reaction. After removing the elemental sulphur formed, they underwent thermoelectric power measurements using a packed bed lying in a temperature gradient. The value of thermo- electric power increased from about 0 to 30 pV/K in the early stages of oxidation. The results obtained are compared with those for chalco- pyrite reported in a previous paper.

Jan 1, 1987

By J Say, M Hawtin, L Carlon, P Cann

Historically, production from sublevels of the Ernest Henry Mine (EHM) started from blind uphole rises at the end of slot drives. Where previous investigations considered removing these slot drives and starting production with independent ore drives, any development savings were consumed when drives were extended to minimise ore loss. Since 2017, EHM and Orica have been investigating opportunities to optimise drill and blast practices by implementing Orica’s Wireless Electronic Blasting System (WEBS). To reduce ore drive development metres, a novel design was proposed utilising the WebGen™ 100 system to combine a rise with pre-charged widening firings. Initially these new rise and widening firings achieved results similar to previous EHM designs, achieving on average 81 per cent of design height and width. Due to poor performance of the fourth trial a significant re-design was required. Modifications included drill hole re-positioning, in-hole primer relocation and initiation delay adjustments. Since the re-design a step change in rise performance has been observed with rise and pre-charged widening shots averaging 95 per cent of design height and width. With rise and widening performance exceeding expectations, the removal of slot drives has allowed a substantial reduction in lateral development. Development savings of 165 m and 169 m from the RL1325 and RL1300 levels have been achieved. Primary draw and ore recovery has also increased due to the later addition of pre charged forward stripping rings. Level design changes have also significantly improved the mining cycle by allowing for a reduction in required ground support, improved secondary ventilation, a reduction of critical path development, simpler production scheduling and less wear and tear on machinery. Future mine level designs now incorporate key learnings and are proving beneficial to a variety of scenarios including changing orebody boundaries at depth.

Mar 15, 2021

By P Ottenio, B CarrT

In the last 40 years, the froth flotation process widely spread in the paper industry becoming the dominant technology for ink removal from recovered paper slurries and cellulose fibres recovery. Most of current models used to describe the flotation deinking process are based on hydrodynamic and statistical theories of ink particles collision/attachment to air bubbles. The complexity of these theoretical models, together with the variability of the recovered papers composition, does not allow to define a set of æeasy to handleÆ equations to be used for modelling industrial flotation cells. This main limiting aspect makes that, in several deinking process modelling tools, basic parameters used to characterise the flotation unit, ie yield, ink removal efficiency, water loss, are constant parameters. Although in some process simulation tools the flotation yield/efficiency is adapted to process control parameters (air ratio, pulp flow, pulp consistency), physicochemical variables (namely the pulp frothing aptitude, the pulp surface tension and the ink adhesion energy to air bubbles) are not taken into account to adjust the flotation yield/efficiency. Data collected during recent laboratory and pilot plant experiments focusing on the role of surface active substances on the flotation efficiency were therefore interpreted and used to identify general trends that could be described with simple semi-empirical models. A set of model equations using surface tension and froth removal height as main variables was then defined in order to describe the behaviour of a pilot flotation cell. Trends obtained during the dynamic simulation of the deinking pilot plant were in good agreement with experimental data obtained under similar experimental conditions, thus indicating that developed equations can forecast with good approximation the behaviour of a flotation deinking unit.

Jan 1, 2005

The objectives of mining grade control are presented and examples of the techniques used in various open pit and underground mines are used to define the attributes of good grade control. Reasons are discussed for the success of various improved practices. The progressive development of grade control is presented and the balance between quantitative and qualitative data is analysed. The skills and resources required for grade control on mine sites that are using best practice are also presented. A number of problems in grade control have been solved recently however there are still issues that need to be addressed. Examination of the grade control process frequently stops after sample quality has been examined. There is much more beyond this that can now be optimised using conditional simulation models. Other future directions of mining grade control are also suggested. An extensive bibliography of published papers on grade control is included that will be maintained and updated on a website.

Jan 1, 2000

By M Erskine, R Mills

This paper approaches tailings dam risk management from the perspective of how other high hazard industries approach the management of their catastrophic event risks, with the aim to provide recommendations from these learnings for the industry to adopt.

Jul 1, 2021

By S Natsui, Y Goto, S Kawanishi, J Takahashi, H Nogami

The demand for copper increases yearly, and further improvements in copper smelting efficiency using flash furnaces are required. This study was conducted to understand and promote the interfacial reaction associated with the collision of silica flux and iron oxide particles, ie the formation reaction of fayalite slag, in the reaction shaft of the flash furnace. High-temperature microscopy was used to observe the reaction behaviour of a 2 mm granular SiO2 reagent in contact with micrometreorder- sized FeO reagents in situ. When the amount of FeO was lower than the stoichiometric amount with SiO2, the molten slag formed at the interface between FeO and SiO2 diffused into the SiO2 particle before dissolving the remaining FeO particles. It did not contribute to the subsequent reaction, and despite having the lowest amount of FeO among the samples in this study, many unreacted FeO particles remained on the surface of the samples after testing. On the other hand, under conditions with high FeO content and close to the eutectic composition of the FeO-SiO2 system, a liquid phase formed from low temperatures, gradually increasing in volume and eventually completely dissolving the 2 mm SiO2 grain. These results indicate that the early-stage slag is essential in increasing the interfacial area between FeO and SiO2 and facilitating the supply of FeO to SiO2. In other words, the FeO/SiO2 determines the amount of liquid phase and significantly influences the subsequent interfacial reaction rate between FeO and SiO2. Therefore, the local FeO/SiO2 of the particles falling down the reaction shaft should also be optimised to ensure early slag formation. Meanwhile, the time required for 2 mm SiO2 to complete the reaction for the temperature history employed in this study was significantly longer than the particle residence time in the reaction shaft. Further detailed investigation of the effects of silica flux particle size, composition, and reaction temperature on the reaction time will help find the conditions under which the reaction of silica flux can be completed in the reaction shaft. These kinetic approaches could contribute to future innovations in the copper smelting process using flash furnaces.

Jun 19, 2024

By D Misra, R Ganguli, S Bandopadhyay

The objective of this paper is to assess the accuracy and applicability of recent state-of-art methods such as the machine learning algorithms (MLA) for mineral resource estimation. Conventional methods such as geostatistics have been predominantly used in the mining industry for this purpose with varying success. Recent advances in the use of MLA have provided a fresh approach to obtain improved accuracy in the estimation of mineral resources. Two MLA methods: the neural network (NN) and the support vector machine (SVM) have been used to estimate a polymetallic ore deposit in Alaska.The general characteristic of SVM and NN emphasises the fact that they can approximate any multivariate non-linear relation among variables. Although neural network models are able to capture the nonlinear spatial relationships that may be present in the data, they are usually difficult to optimise under sparse data settings. Of the various NN alternatives, despite their effectiveness, the model selection and estimation process is typically difficult as it involves solving complex integration and optimisation of parameters. In support vector modelling (SVM), estimating of parameters involves optimisation of a convex cost function. The working principle of SVM makes it robust against noisy and extreme value data. At the same time, it can capture the spatial distribution of ore grade more effectively with careful modelling and selection of SVM parameters.The outcome of the MLA methods were compared to those of the geostatistical ordinary kriging (OK) application to study their generalisation ability. The comparison was made using the following goodness of fit criteria: mean-squared error; mean absolute error; mean error; and coefficient of determination. The results indicated that the MLA methods may improve the predictability of ore deposits and thereby reduce the inherent risk in mineral resource estimation.

Sep 26, 2011

By D Veneziano, J Van Dyck, R Snow, W Pytel, O Zanoli

Best practice standards generally recommend assessment of the environmental and societal risks posed by tailings storage facilities, but they rarely specify how the analysis should be made. As a case study, this paper describes a safety assessment of the Zelazny Most tailings pond operated by the Hydrotechnical Unit of KGHM Polska Miedz SA in Poland. The complete assessment includes a failure mode effect criticality analysis (FMECA) that considers all conceivable failure modes, but this paper focuses on one key mode, the loss of stability during the planned raising of the crest above its current level. Reliability against static dam failure considers uncertainty on the safety factor in a limit equilibrium approach. The threat of dynamic (earthquake induced) instability is assessed by developing a model of future seismicity as a function of the mining plan and considering uncertainty on the induced permanent displacements along critical sliding surfaces. We quantify the additional level of protection against outflow provided by the beach using an event tree with expert-assigned probabilities. Continuous monitoring of the dam for premonitory signs of instability and a set of loss-prevention plans in the case of a spill provide additional layers of protection; their effectiveness is quantified by estimating the fraction of the population that could be evacuated as a function of warning time. The probabilistic analysis indicates that the safety targets are met and produces practical recommendations on how to maintain and improve the safety level while the dam crest is raised above its current level.CITATION:Van Dyck, J, Pytel, W, Veneziano, D, Snow, R and Zanoli, O, 2015. Safety of a tailings storage facility against dam instability, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 253–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By M J. Thurley, L Lindqvist, D Degerfeldt, J Nyström, R Nordenskjöld

Rock breakage is a major component of all mining and mineral processing operations with the particle size distribution linked to productivity through the comminution chain. Optimisation and automatic control of comminution, material handling, and agglomeration processes is a complex task with large potential for gains in productivity, and energy efficiency. A key factor in realising these gains is the requirement for fully-automated online particle size distribution measurement to provide the necessary feedback and input for control. Moreover, to enable automatic control system it is necessary to provide a consistent, reliable size distribution measurement that avoids the significant errors resulting from under-sizing overlapped particles and over-sizing clusters of fine particles. Published literature and observation of commercial systems indicate a body of predominantly 2D photographic based particle size measurement systems that suffer from a number of significant errors except in the simplest case of a monolayer of particles under good illumination with limited colour variation in the material. In order to overcome these limitations a university and industry collaboration developed three-dimensional particle measurement (3DPM) between 2006 and 2012, based on 3D surface profile measurement of the visible material on conveyor. 3DPM avoids particle delineation errors due to variation in material colour and shadows, detects overlapping versus non-overlapping particles, and identifies areas of fine particles as fines and not large rocks. 3DPM measures: the visible material and calculates its particle size distribution, bulk volume, detects boulders, and conveyor belt fill factor in an automated consistent manner. Furthermore, 3DPM’s advanced algorithms allow observation of particle variation that would otherwise be undetected without the capacity to identify visible areas-of-fines and overlapped particles. Boliden Mines has installed 3DPM at three operations for measurement between the stockpile silo and grinding mill, and measurement after the primary crusher. Fragmentation measurements across multiple years of measurement are presented with some observations of plant behaviour. In the future 3DPM results will be incorporated into automatic control strategies for plant optimisation. 3DPM is used across a wide range of material types and applications that also includes; limestone aggregate for quality control in manufacturing, agglomerates for closed-loop automatic control in chemical production, and measurement of coke for size-based blending feed control to the blast furnace in steel production. CITATION:Thurley, M J, Degerfeldt, D, Nyström, J, Nordenskjöld, R and Lindqvist, L, 2018. Automated, online measurement of bulk material size distribution on conveyor using 3D profile imaging at Boliden Mines, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 641–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

Large areas of ground are permanently supported on coal pillars, both in extensive old workings and current drivages in active mining operations. Continued growth of civil infrastructure is resulting in more surface development above old bord and pillar mines and an increased need for mine development beneath existing surface structures and features. The result is a greater likelihood of conflict between miners, developers and regulatory bodies. However, over the last 40 years there has also been significant improvement in the general level of understanding of pillar behaviour and stability, both in Australia and overseas. This paper examines some of the issues to be considered when undermining surface structures or undertaking surface development above old workings. The Factor of Safety (FoS) methodology widely employed for the assessment of pillar stability is reviewed, including the key geometrical, geological and statistical concepts associated with the probability of pillar failure; local and international experiences are examined and significant parameters isolated. Common concerns are addressed in the context of actual practical experience, utilising a risk management approach. Recent advances in methods for the assessment of pillar stability are put forward, along with criteria for arriving at rational design outcomes.

Jan 1, 2005

By S Lakemond, L I. Ku, J Vaughan

Conventional processing of poly-metallic gold containing flotation concentrates are challenging for a number of reasons. One reason is that substantial copper and zinc in the cyanide leach solution compete with gold and silver for carbon adsorption sites. In this study, metal-cyanide adsorption kinetics and equilibrium are measured on three samples of coconut derived activated carbon and one sample of synthetic carbon. Loading selectivity was confirmed to be in the order gold>silver>copper>zinc for all carbon samples. The synthetic carbon tested showed promising results in terms of loading kinetics and capacity for precious metals.CITATION:Lakemond, S, Ku, L I and Vaughan, J, 2013. Effect of carbon type on adsorption of Cu, Zn, Ag and Au from mixed cyanide solution, in Proceedings World Gold 2013 , pp 411-418 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By P B. Hills, R J. Walton

Geotechnical instrumentation has been implemented as a key step for monitoring and optimising an engineered mine design for managing seismicity at the Beaconsfield Gold Mine. Measurements of displacement, stress change, ground control element load and seismic response of the rock mass allow for back analysis and calibration of critical parameters for feedback into the engineering design loop. Instrument clusters are installed in strategic locations prior to the commencement of stoping in order to determine the nature of the response of the rock mass to stoping. A selection of instruments including instrumented cable bolts and rod extensometers, resistance wire extensometers, hollow inclusion stress cells, vibrating wire stress meters and resistance wire extensometers are used to gather data through a data logging system. The rate at which data is recorded is adjusted to provide more information during periods of anticipated rapid change such as around stope firings or during periods of high seismic activity, and less information during periods of anticipated quiescence. The twofold purpose of the instrumentation is to calibrate the numerical modelling output which forms the basis of the engineered mine design, and to provide an alert mechanism where the behaviour of the rock mass is not what was anticipated, or where the impact of that behaviour may compromise the integrity of the engineered ground control system. The paper describes the location of instrument clusters with respect to stoping, the type of instruments employed and the method of data acquisition. It provides examples of results obtained and illustrates the way in which that information is used to optimise the mine design and manage seismicity.

Jan 1, 2008

By J Addai-Mensah, W Skinner, C Kelsey, J R. Kelly, E Baawuah

Comminution continues to be the most capital-intensive unit operation in mineral processing. The fundamental purpose of comminution is to liberate the valuable minerals so that they can be economically concentrated into saleable products. Declining ore quality characterised by lower grade and increased complexity requires significant energy consumption for comminution. Low-grade magnetite ores are typically fine-grained and require fine to ultra-fine grinding (P80 ~ 30 - 40 µm) to enhance its liberation from the typically siliceous gangue matrix. Historically, this has been achieved using multi-stage crushing and grinding technologies, which require high energy consumption with low energy efficiency. This motivated innovations in energy efficient technologies for comminution. Such technology has been developed in the IMPTEC super-fine crusher. It is an innovative, dry (with the potential to be operated wet), media-free, energy efficient crusher that can to reduce 10 mm feed particles to 19 – 30 µm with very low recycle loads. In this study, the mineralogical and physicochemical characteristics of crushed magnetite ore using the IMPTEC super-fine crusher have been investigated in comparison with those of rod milling. The super-fine crusher generated higher liberated magnetite minerals in the – 300 + 212 µm and < 45 µm size fractions compared to rod mill. Both comminution devices generated large low-grade hematite and goethite middlings. However, the rod mill produced higher locked/unliberated hematite and goethite compared to that of the super-fine crusher. Quartz mineral had the highest liberation irrespective of the comminution device used. The super-fine crusher generated higher entrapment of other minerals within the silica matrix compared to the rod mill. The breakage mechanism of the super-fine crusher which is predominantly through high compression with shear, generated improved mineral liberation in the coarse size fractions compared to the predominant abrasion and attrition breakage mechanisms of rod milling. The higher mineral liberation generated by the rod mill is potentially due to the prolonged batch milling of the ore compared to the single-pass open circuit of the super-fine crusher.CITATION:Baawuah, E, Kelsey, C, Kelly, J R, Addai-Mensah, J and Skinner, W, 2018. Mineral liberation studies of IMPTEC super-fine crusher – 130 crushed product, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 313–326 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By D Engelhardt, G Lane

The Cadia mine has shifted from an open pit operation to the Cadia East underground panel cave. The resulting increase in milled tonnes, more competent ore and the decrease in fines production through shifting to panel caving were predicted to require an increase of over 25 per cent in installed power. This expansion was accomplished via the installation of secondary and high pressure grinding rolls (HPGR) crushing of the ore, with the semi-autogenous grinding (SAG) mill receiving a combination of primary, secondary and HPGR crushed feed. This design, criteria and rationale for selection was presented at the SAG Conference 2011. This paper reports on the initial impact of secondary and HPGR crushing on the circuit performance with the new panel cave feed.CITATION:Engelhardt, D, Lane, G and Powell, M S, 2014. Cadia expansion – the impact of installing high pressure grinding rolls prior to a semi-autogenous grinding mill, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 233–240 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By R J. Soriano, S Ciutina

The Masbate gold deposits are situated on the island of Masbate, 350 km south of Manila. A new plant was commissioned in April 2009. The grinding circuit consists of one semi-autogenous (SAG) mill Ø9.75 m × 4.27 m, two ball mills Ø5.6 m × 7.1 m and a pebble crushing circuit, which is usually called a SAG-ball mill-crusher configuration. The SAG mill was originally equipped with radial pulp lifters. The mill runs at fixed speed of 10.9 rev/min, which is approximately 80 per cent of critical speed (per cent CS). Due to the high speed of the mill the original radial design pulp lifters presented a high volume of recirculating load inside the chamber and consequently heavy wear on the outer circle (bottom pan).In order to address the high wear on the pulp lifters a number of avenues were considered in early 2011. The chosen solution was to change the geometry of pulp lifters from radial to curved design. The pre-existing drilling pattern on the discharge end of the mill was a major constraint. A number of designs were considered. The selection of the most suitable option was to be made based on 3D discrete element modelling (DEM) and smoothed particle hydrodynamic (SPH) simulations.The original radial design and two potential solutions for curved pulp lifters were simulated with 3D DEM and SPH software. The main three objectives were predicting the charge dynamics, the expected wear patterns and discharge efficiency. One of the solutions was chosen and implemented during 2012.Observations carried on after installation of the curved pulp lifters have confirmed, as expected, a reduction in wear intensity on the outer pulp lifters. In addition to this, at early stages of operation with curved pulp lifters, the mill operator noticed a reduction in energy consumed by the mill with no detrimental effect on mill performance.This paper is intended to further study the effect of curved pulp lifters on mill energy consumption.CITATION:Ciutina, S and Soriano, R J, 2014. Curved pulp lifters – can they save energy?, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 109–116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By R Sterk, B Reid

The Konongo Gold Project is located on the western margin of the 125 Moz Ashanti Gold Belt in Ghana, West Africa. It is situated 60 km along strike of the world-class mineral system at Obuasi and is interpreted to lie on the same controlling regional shear system.The project is operated by Signature Metals, a subsidiary of the Liongold Corporation, and is managed and funded by the Liongold Corporation.Historic underground operations at Konongo produced 1.6 Moz Au at a head grade of 11.8 g/t Au, from eight operations spread along 16 km of the shear system. Mining focused almost exclusively on free-milling gold in quartz, ignoring the gold-bearing sulfide mineralisation associated with the quartz veins. Underground mining ceased in 1986.In 2013, Signature Metals re-focused the program at Konongo to assess the viability of mining the sulfide ore sustainably. This led to the first campaign review of the historic underground data and resource potential since mine closure. The Obenemase mine was the first of the eight operations to be assessed as part of this campaign.Large amounts of legacy data have survived for Obenemase and several historic resource estimations have been completed based on these data. The data typically consisted of hand-drawn sections and plans, and ledgers of commonly incomplete drilling and sampling data. Some drill core have been lost over time, but a large amount of quarter-core and half-core as well as pulps and rejects are still available. Previous resource estimates had a low confidence value because all the available assay and geological data were integrated effectively with the estimates, resulting in a lack of understanding of both grade and geological continuity.This project built a new geological model for Obenemase that greatly enhances the understanding of the controls on mineralisation using a thorough approach of re-surveying, re-cataloguing and re-logging. This model led to an increased degree of confidence and a subsequent upgrade of resource classification, and created several previously unrecognised strong exploration targets. The resulting resource estimates increased the value of the project by 100 per cent.This paper emphasises and highlights the importance of a well-understood geological model on the confidence of a resource estimate and how this may directly impact on the project’s ‘bottom line’.CITATION:Sterk, R and Reid, B, 2014. The Konongo Gold Project, Ghana – an example of how geology makes all the difference to a resource estimate, in Proceedings Ninth International Mining Geology Conference 2014 , pp 467–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By J Northfield, L Neesham

The GRE46 Underground Project lies beneath the environmentally unique and culturally endowed shore of Lake Cowal. The ore body is open both along strike and at depth and is currently defined to a strike length of 1.5km and depth of 800m. The Warraga exploration decline commenced in March 2019 and represents the first stage of the Project, which is expected to underpin production at Cowal Gold Operations (CGO) for a period exceeding 10 years. Mining operations at Cowal commenced in 2005, following a period of over 20 years of exploration and permitting. In 2015 Evolution Mining (Cowal) Pty Limited (Evolution) acquired the operation from Barrick Gold Ltd (“Barrick”). Barrick had a life of mine plan that anticipated a cessation of operations in 2024 at a processing rate not exceeding 7.5 Mtpa. Evolution have grown the regional endowment considerably and have a currently approved mine life out to 2032 with a currently approved maximum processing rate of 9.8 Mtpa. This paper examines the history, current status and future path of one part of that plan, the GRE-46 Underground Project. Topics for discussion include discovery, Mineral Resource growth under different ownership philosophies, planning, permitting and commissioning of an exploration decline and bulk sampling project, and integration with the possible future mine. Environmental sensitivities affecting regulatory approvals, timeframes, technical challenges, opportunities and solutions are discussed, along with the path required to fast-track production from the existing 14Mt, 1.4Moz Mineral Resource while complying with the requirements of modern, responsible project development stewardship.

Mar 15, 2021

By G Stovpchenko, G Jianjun, L Medovar

Electroslag remelting (ESR) today and into the future, will still be the main process for producing high-quality ingots by suppressing segregation, not just refining chemical composition from impurities. This paper analyses state-of-the-art electroslag refining with a focus on ESR with consumable electrodes, and recent technology with liquid metal supply (ESR LM) in view of their refining abilities and development trends, taking into consideration that the size of the ingots required by industry continues to grow, and the composition of new materials sophisticates to withstand increasingly higher mechanical and temperature loads . The yield of suitable metal in large ingots produced by conventional casting is low due to problems of element segregation by height and crosssection. For example, conventional ingots for nuclear powerplant rotors today reach nearly 700 t in weight. Attempts to directly replace such giant ingots with big-diameter ESR ingots weighing approximately 400 t were also unsuccessful because of growing segregation. Modern ESR equipment and technologies produce 200–250 t of ingots of satisfactory quality, reaching 2.5 m in diameter, implementing the change of consumable electrodes during remelting to increase ingot length. Another way to mitigate segregation is to enlarge the smaller diameter ESR ingot by a 500– 800 mm coaxial layer to the desirable diameter by ESR in the current-supplying mould (CSM). Modelling and experiments prove that refining from impurities and non-metallic inclusions at ESR most effectively occurs at the slag bath and liquid metal pool interface because the ESR LM has provided the same desulfurisation. ESR’s special refining capabilities in CSM come from the much longer time of LM residence shown at titanium purification from hard-melting nitride inclusions that are unremovable in vacuum arc remelting (VAR) and electron beam melting (EBM). Implementation of ESR technologies in CSM, especially with LM supply, is prospective to produce heavy enlarged and hollow forging ingots with prevented development of segregation due to dividing cross-section and reducing overheat of solidifying metal.

Jun 19, 2024

By J Channell, G Phillips

"The Chesney deposit, located 4 km south-east of Cobar consists of three copper-gold rich shoots that lie within a larger, copper dominant lode. A fourth gold rich shoot is located adjacent to the main deposit. The deposit exhibits a strong structural control on mineralisation, as brittle deformation during subvertical extension provided the requisite structural traps to precipitate sulfides from solution. It is postulated that the Great Chesney Fault acted as a fluid conduit, conveying fluids to the site of orebody formation. The continual supply of fluids resulted in cyclic brittle deformation when the fluid pressure exceeded the lithostatic pressure and the tensile strength of the Great Cobar Slate.Evidence supports the hypothesis that ore deposit formation was controlled by: a supply of mineralised fluids transported along the Great Chesney Faulta suitable location for the mineralised fluids to accumulate, accommodated by vertical extension and dilation in certain locationsthe creation of suitable structural traps to capture the sulfides. These traps formed as a result of fault-valve behaviour. Understanding the controls on mineralisation enables prediction of the location of other deposits with similar emplacement history, or extensions of current deposits.CITATION:Channell, J and Phillips, G, 2014. Understanding mineralisation controls – a case study of the Chesney deposit, in Proceedings Ninth International Mining Geology Conference 2014 , pp 301–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By S M. Jowitt, G M. Mudd

"The mining industry is the source for the vast majority of the metal, mineral and energy resources we use on a daily basis. New deposits are discovered over time and are developed into mines before being rehabilitated – a sequence that when repeated can help contribute to the noble notion of ‘sustainable development’, despite the generic concept of mining being the unsustainable consumption of non-renewable resources. The scale of the modern mining industry is immense – from iron ore and coal to base and precious metals, modern mines are sometimes hundreds or thousands of times bigger than their long lost historic ancestors. We also live in a world with emerging and increasing demands for so-called technology metals (aka ‘critical’, ‘e-tech’ or ‘specialty’ metals) that are needed to feed the rapid growth in renewable energy (especially solar photovoltaic panels and wind turbines), consumer electronics, sophisticated military technologies and super alloys, amongst other uses. These elements include the rare earth elements, indium, germanium, tellurium, rhenium, selenium, gallium and many others, most of which had few or no known uses in the recent past. Although the mining industry has been successful in developing ever larger mines and increasing the scale of production, the key issues underlying the future of the industry are declining ore grades, increased tailings and waste rock generation, the presence of toxic or other impurities, balancing the economics of primary and secondary products, stricter environmental conditions, more difficult exploration, increasing community expectations, as well as the processing of more complex or refractory ores, let alone the recent volatility in world commodity markets. Here, we synthesise our recent research on many of these various issues, focusing on the need to link all areas within the mining chain from mineral resources through mining to environmental performance in order to ensure we obtain the most out of our modern mining effort. The paper presents a unique and detailed assessment of the sustainability challenges and opportunities facing modern mining – and geometallurgical thinking is at the heart of this conundrum.CITATION:Mudd, G M, Jowitt, S M, 2016. From Mineral Resources to Sustainable Mining – the Key Trends to Unlock the Holy Grail?, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 37–54 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016