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By R Zhang, J Xu, X Lv, C Bai, S Zhang

This paper studies the grinding behaviour of vanadium-titanium magnetite concentrate in a ball mill. The grinding kinetics, surface morphology, lattice distortion, wettability and moisture capacity were analysed. Grinding kinetics equation was established based on population balances model with the size distribution data from a laser diffraction technique. The SEM photos of the ground concentrate showed that the surface gets rough with increasing grind time. Agglomeration of fine particles was enhanced when the grinding time reached 30 minutes. X-ray diffraction results showed that a loss in crystalline occurred with increasing the grinding time. The peaks of the X-ray diffraction patterns are significantly broadened with increasing grinding time. Wettability, characterised by contact angle between the material and water, improved due to the fact that the surface roughness increased with increasing grinding time. Moisture capacity of concentrate ascends abruptly in the first three minutes and then changed slowly with increasing grinding time. The water transfer coefficient in the particles increased rapidly in the first six minutes and then decreased quickly until grinding time reached 12 minutes.CITATION:Zhang, R, Lv, X, Bai, C, Xu, J and Zhang, S, 2013. Wet grinding of ?vanadium-titanium magnetite concentrate in a ball mill, in Proceedings Iron Ore 2013 , pp 511-518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By J Bryant

In recent years the mining industry has suffered from skill shortages in a range of disciplines including mine geology. As a consequence, many businesses operate with incompletely filled organisation charts and technical professionals are frequently thrust into roles earlier than previous generations of geologists, engineers and metallurgists. Exacerbating the difficulties managers face with recruiting suitably experienced professionals is the churn of people through roles. Churn may be caused by internal pressures related to the rapid increase in projects and opportunities within a company or by external factors including the high workforce mobility resulting from the advent of fly-in, fly-out (FIFO). Historically, new entrants into the mine geology profession often received on-the-job training from their more experienced colleagues. This training, supplemented with targeted skills and knowledge enhancement through dedicated short courses, ensured the wide range of skills, knowledge and abilities required in the complex role of mine geology were continually renewed. Faced with an influx of new graduates and a dearth of mine geology professionals in the critical ten to 15 year experience range, the industry needs to develop new paradigms to ensure that the full business benefit of the mine geology function is delivered. This is increasingly important as the complexity of business planning built on geologically-based variables grows. Mine geologists are now faced with the potential incorporation of geometallurgy and waste characterisation along with energy efficiency, carbon-economy and other environmental issues into their roles. Providing baseline data, models, operational control and reconciliation for a wider range of variables further stretches the already limited geological resources available to the industry and exposes personnel with relatively low levels of experience to potentially business transforming decision processes. This paper outlines a successful approach to mentoring at the individual and team level. It discusses what went well and what could have been done differently from both the mentor and menteeÆs perspective with examples from case studies and offers insights into a new approach to dealing with gaps in organisation charts and high turnover of personnel.

Jan 1, 2009

By L C. Thompson

BioLix is the term for a new class of biologically-derived lixiviants for precious metals (gold and silver) recovery. BioLix can be used as an alternative to cyanide on virgin and spent ores. The BioLix process is based on inducing microbial enzymatic reactions that generate organo-lixiviant chemicals. The bioprocess involves a two-stage culture strategy. First, specialty microorganisms are cultured to generate a high biomass. Then, a food-grade quality amendment is introduced that forces the microorganisms to produce the organo-lixiviant. The second-stage culture is applied to the ore where the microbial/lixiviant system acts on mineral surfaces to extract precious metals. The process operates at ambient temperatures and near neutral pH. This paper will examine the BioLix process through an extensive laboratory development and demonstration project. Laboratory development consisted of identifying and isolating specialty microorganisms and inducing agents for the production of the organo-lixiviant solutions. A demonstration was performed on low-grade and high-grade oxidised ore from the Buffalo Valley mine in Nevada, USA. Results indicate that the BioLix process was comparable to cyanide in terms of gold recovery and operated at near neutral pH and ambient temperatures. Applications for the BioLix process will be discussed including spent-ore re-leaching, cyanide replacement for virgin ore, and in situ mining.

Jan 1, 2004

By Smith T

Bacterial oxidation is often attributed with the advantage that a high level of gold recovery can be obtained at a relatively low level of sulphur oxidation. This is sometimes attributed to the bacteria "tunneling" towards gold inclusions, however it is often due to the presence of two or more sulphides of differing gold content which leach at different rates. Gold is liberated from the individual sul- phides linearly with oxidation. The distribution of gold between pyrite and arsenopyrite in two samples taken from a prospective gold resource was examined. The two samples showed differing responses to bacterial oxida tion and it was shown that this was due to differing intrinsic gold grades in the mineral phases and differing proportions of the minerals in the two samples.

Jan 1, 1991

Mining of narrow vein mineralisation, invariably depending on the mining method selected, involves the extraction of both ore and waste rock. The level to which mining of waste rock can be minimised depends on numerous factors, but particularly the thickness and dip of the deposit. Resue mining is a method of mining that allows split face firing within stopes to allow waste and ore to be mined separately, allowing dilution to be minimised. This paper examines the technique of resue firing and its applicability to the mining of narrow vein deposits. Particular emphasis is placed on the conditions in which resue mining presents a suitable option for mining of narrow veins.

Jan 1, 2008

Mechanical and electrical (M&E) systems in road tunnels are constrained by the traffic envelope and the construction profile. Whilst these spatial constraints are often ælocked inÆ early in the design process, the detailed M&E design continues for some considerable time after key civil engineering issues have been resolved. Ventilation design criteria for both normal and emergency operation often involves considerable negotiation with a wide range of stakeholders. Final system performance and spatial requirements are only finally resolved when suppliers are selected following the tender process. Lighting design is dependent upon a wide range of factors including tunnel lining materials and associated colours as well as agreed maintenance regimes. Cabling systems can only be developed when the general arrangement for power distribution is agreed and a system of substation, switchrooms and equipment rooms is in place. Many other systems such as fire protection and communications facilities fill the available space beyond the traffic envelope, where physical, structural and æsight lineÆ requirements must all be accommodated. The more co-ordinated civil engineering and M&E design is and the earlier the process starts the better the outcomes for all parties.

Jan 1, 1999

By N Kusuma

Recoverable copper and gold estimates for resource models and ore control routing decisions at Batu Hijau were initially based on flotation testwork from several commercial laboratories. Due to the greater number of copper and gold assay grade available, regression relationships were developed between assay grades and flotation recoveries. Other recovery controlling variables such as oxidation and lithology were included to improve the regression models. With additional drilling, more flotation work was carried out and the regression models were revised to include the new flotation data, also alteration classification and in situ pH. The regression models were replaced in favour of spatially derived models for ore control and short range mine planning. To harness local variability in the block model, blast hole flotation testing is carried out in unison with routine grade assaying. Recovery data are processed (kriged) simultaneously with grade assay data prior to ore polygon delineation. Short range mine planning utilises this model in conjunction with a spatial recovery model derived from drill core flotation data. Long range mine planning utilises the æhybridÆ recovery model whereby the globally robust regression recovery models are overprinted by a spatial (kriged) recovery estimate where flotation data density is adequate (Phase II reserve).

Jan 1, 2002

By R Fleming, G Jones

An ocean outfall is currently under construction in Christchurch, New Zealand to transfer treated wastewater from the existing treatment ponds at the city wastewater treatment plant to diffusers located 3 km offshore. The New Zealand $85 million project comprises a new pump station and 5 km of 1800 mm diameter pipeline with a design capacity of 6.0 cumecs. The pipeline comprises 2.3 km of concrete pipe installed by microtunnelling and 2.7 km of polyethene marine pipe installed by dredge and lay. This paper describes the consent process, key environmental and community constraints, the tender process, risk provisions included in the contract, the type of contract, partnering provisions, geotechnical design issues and the pipejacking construction activities and issues.

Jan 1, 2008

Computers and other microprocessor technology lead the world of technological change. Nevertheless, the real advances in the world at large are not necessarily in the computer industry, but in the industries whose economics benefit most by the advances that this computer revolution makes possible. The minerals industry has always been in the forefront of this advance. Technological change in the era preceding the industrial revolution, and the mining industry's part in it, provides an instructive lesson for what is happening today. Strong parallels can be drawn for predicting future advances. With each technological advance allowing more efficient production comes a re-alignment of economics - absolute and relative changes to prices, to quantities demanded, and to other market characteristics. This re-alignment applies not only to the mineral industry, but also to the world at large. Adaptability, rather than technical advancement per se is the key to survival and growth in a changing world. 'Adaptability' as a concept is easy to support. As an operational philosophy it is not so easy to implement. As a goal for planning, it is much harder to quantify. A fixed scenario of a future world may provide helpful guidelines, but a scenario that demands adaptability to an uncertain future world is much less definite. Of course, everyone else in the world is also uncertain about the future, and they are making their plans using different assumptions. This virtually guarantees that our future will turn out different to our expectations. This is in part what Hayek (1945) calls the 'knowledge' problem. Until now, most of the planning and technical research undertaken in the world has ignored this problem. This ignorance is a luxury that we can no longer afford. The paper looks at the history of technological change and highlights the characteristics of successful technological revolutions. 'Adaptability' to unforeseen circumstances is the key to success in this environment. The paper examines the knowledge problem from the perspective of the mineral industry, and suggests a number of directions for maximising the returns from application of computer technology in this important area.

Jan 1, 1995

In the- past, at Great Boulder Gold Mines Ltd,, ,' s.. number of attempts ' ha'tre been made to remove water ' `solublo copper and' iron sa'lt's from calcined pyritic concentrates, but various problems have arisen and the methodsi ve been abandoned. A method of rapid washing has now been developed,, and although some problems still. exist,, a workable `process has boreh established .which. has; resulted in 'substantial savings of 'reagents used for. the. cyanidation of calcine

Jan 1, 1964

By R Knight

The spatial variability of geometallurgical characteristics in a mineral deposit can have significant impact on financial and mine planning, mineral processing, concentrate quality and tailings composition throughout the life of a project. These characteristics that may determine the success of a project are not readily apparent to geologists unless they are integrated with deposit geology and assay data, modelled in 3D and incorporated into resource block models.One of the primary objectives of geometallurgy is to integrate and incorporate various geologic, geotechnical and geometallurgical parameters into resource block models, which typically are limited to in situ tonnes and grade of economic metals. Critical attributes, such as concentration of deleterious elements that affect the project viability need to be identified and integrated into the resource block model early in the exploration stage to predict project profitability and address potential environmental impacts.Using data from a volcanogenic massive sulfide deposit we present an example of the integration of ore geochemistry (cadmium, arsenic and antimony) with the results of preliminary, bench-scale metallurgical test work in a 3D geometallurgical model that predicts subdomains of poor-quality concentrate and tailings containing environmentally-sensitive elements. This critical information was incorporated into the existing resource block model in order to inform both financial modelling and mine planning.This example demonstrates that geometallurgical data can be effectively integrated with geological and assay data using Leapfrog MiningTM software (Leapfrog Mining) early in the exploration stage of a project. Three-dimensional representations of geometallurgical data can be created directly using primary additive data, as well as from proxies of non-additive parameters. Resource block models can be updated continually with new information as the project passes from exploration through production. In addition, the software allows for 3D visualisation of the characteristics of the materials that will eventually constitute the mill concentrate, tailings, and waste. This study emphasises the critical importance of establishing a systematic geometallurgical approach early in the exploration stage that can be continuously updated with new information throughout the life of the project. In the example that we present, sulfide ore that had otherwise been identified as high-value (in the absence of geochemical and metallurgical data) turns out to be low-value ore due to concentrate penalties and increased environmental impact.

Sep 5, 2011

By C Simpson, J M. F Clout, G Plummer

Detrital iron deposits (‘DID’) in the Hamersley Province of Western Australia have been successfully mined and processed as small quantities of saleable standalone or blended lump and fine ore products over many decades. Despite their past, present, and potential future exploitation, they have received far less geological attention than the economically more significant higher grade bedded iron deposits (BID) or channel iron deposits (CID). DID are composed of Pliocene to Quaternary unconsolidated colluvial/alluvial hematite gravels with minor sand, silt, and ferruginous clay, as well as minor iron rich hematite clast conglomerates. DID mineralisation at Solomon has been subdivided into six distinct stratigraphic units, DID-5 (lowermost) to DID-0 (uppermost) based on differences in clast and matrix textures and mineralogy, degree of consolidation/lithification, particle size distribution and replacement textures. The most significant accumulations of DID-1 to DID-5 are in tributary valleys that have been cut through the Joffre Member of the Brockman Iron Formation on either side of the main Kings-Queens valley which contains the CID. DID-5 and DID-4 are ferruginous conglomerate, referred to as canga, with four subtypes recognised. DID-4 is composed of BID hematite clasts cemented by hematite or goethite. DID-5 is characterised by partial to complete replacement of BID hematite clasts and matrix by the yellow ochreous and brown to black vitreous forms of goethite. DID-3 to DID-0 are unconsolidated hematite detritals composed of largely (>80 weight per cent) fine to coarse gravel, minor sand and little silt or clay. The gravel clasts are largely composed of hematite and hydrohematite that replace BID, micro-nanoplaty hematite-martite-ochreous goethite (m-nplH-M-oG) BID, reworked canga, hematite pisoids, siliceous hematite BID (micro-nanoplaty hematite-martite-quartz, m-nplH-M-quartz), chert (~10–20 per cent) and minor (<5 per cent) Banded Iron Formation (BIF). Hematite abundance decreases from DID-3 to DID-0 whilst siliceous hematite BID is highest in abundance in DID-0 and lowest in DID-3. A key finding of the study is that >90 per cent of mineralised detrital clasts are derived from hypogene altered BID micro-nanoplaty hematite-martite with subsequent later supergene ochreous goethite mineralisation hosted by the Joffre Member. The DID genesis model entails interpreted Palaeoproterozoic siliceous hematite hypogene microplaty BID mineralisation of the Joffre Member undergoing Cenozoic supergene leaching of quartz and replacement by ochreous goethite to form low phosphorous BID micro-nanoplaty hematite-martite-ochreous goethite clasts. BID martitenanoplaty hematite-martite-ochreous goethite clasts and detritus eroded from hill slopes were deposited in the valleys as an initial single DID-5-DID-4 unit over a weathered pre-CID basal conglomerate. DID-5 and DID-4 underwent goethite cementation of the matrix followed by replacement by hydrohematite, hematite, and maghemite. DID-3 formed during subsequent periods of erosion of largely DID-4 hematite clasts and pisoids. Groundwater flow-through hematite canga resulted in partial to complete hydration replacement of DID-4 hematite clasts and matrix by ochreous and vitreous goethite to form DID-5. Deposition of DID-2 to DID-0 was via reworking and deposition of DID-5 to DID-4 canga and DID-3 as clasts and pisoids/ooids, as well as siliceous hematite and BIF sourced from the Joffre Member in the hill slopes.

Nov 8, 2021

By B J. Hutchison, S Gannon, J Chambers, D Oko-oboh

The Kanmantoo copper mine is located in the Adelaide Hills area of South Australia and is owned and operated by Hillgrove Resources (HGO). The mine is a drill and blast, truck and shovel operation mining sulfide (chalcopyrite) ore located in chloritised andalusite biotite schist. The initial Kanmantoo open pit operation occurred in the 1970s, before falling copper prices closed the mine. In 2010 the mine was reopened by HGO and the Kavanagh cutback of the Kanmantoo pit was undertaken. The Spitfire, Nugent and Emily Star satellite pits were also mined through to 2015 before the latest steep wall Giant pit design was developed to take mining out to 2019.There are no major fault structures and only two significant shear zone structures exposed in the open pit walls. The main Garnet Andalusite Biotite Schist (GABS) unit is quite competent so the pit designs have therefore mainly been controlled by four distinct joint sets. This paper is a case study on the influence of the joint regime on the wall stability of the main GABS unit and how a better understanding of the joint regime and the use of rock reinforcement has allowed the steep wall design to be adopted.The paper also describes the remote geotechnical mapping and slope monitoring techniques used to manage the rockfall risks associated with the steep walled slope design.CITATION:Hutchison, B J, Chambers, J, Gannon, S and Oko-oboh, D, 2017. Case study of joint structure and the design and performance of open pit walls at the Kanmantoo copper mine, in Proceedings Tenth International Mining Geology Conference 2017, pp 355–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Campbell R

The use of a 35mm non-metric SLR camera and an analytical plotter to prepare close range photogrammetric (CRP) plans of a quarry and open pit mine face is described. The plans, at scales ranging from 1:5 -1:1 000, were used to measure the orientation of geological structures and failure surfaces in the exposed faces.Details are provided on the equipment used and the field techniques. The method:ò is quick and relatively cheap to perform,ò allows the accurate orientation of specific geological features to be determined,ò provides survey results of suitable accuracy that may be used for detailed geotechnical analyses of pit wall failures,ò shows great potential as a rapid and accurate technique for monitoring changes in pit wall profiles with time.

Jan 1, 1990

By Watson D. F

P S B Stewart has rightly pointed to a possible obscurity in our paper on drilling patterns, viz. in comparing the improvement of a triangular drilling pattern over a square one, we used percentage improvements without always making clear their base. We hope, however, that other readers, like Stewart, have been able to understand the particular meaning from the context.Although different methods of estimation of an ore deposit will have different local bias (Philip and Watson, 1985), the critical relationship affecting the reliability of estimation of an unsampled location is the scale of local variation of the variable being estimated in comparison with the density and isotropy of sampling. This relationship overrides all other considerations.

Jan 1, 1985

By D Stepanenko, G Stovpchenko, L Lisova, D Togobitskaya, L Medovar

Classical electroslag remelting of consumable electrodes is a drop-by-drop melt feeding through a slag layer into a renewing molten metal bath, slowly solidifying into a homogeneous, dense, defectfree ingot in a copper water-cooled mould. The new look at the additive nature of the electroslag remelting (ESR) process in a protective atmosphere allowed us to formulate the principles of a comprehensive thermodynamic-based model that can predict dynamic changes in slag and metal composition at certain ingot remelting. The model considers drastically different slag-to-metal mass ratios at the beginning and end of remelting and predicts gas, slag and metal composition in a chain of thermodynamic subsystems. Despite consisting of calcium fluoride and stable oxides, the ESR slag can oxidise main and active elements from steel and alloys (primarily aluminium, titanium and silicon) due to chemical reactions between slag and metal. ESR is not an electrochemical process in its nature. However, slags are ionic melts and deviation in their composition causes a change in their properties, affecting both operation mode and ingot quality. Another important understanding derived from the modern metallurgy technological route is that the ability to refine metal from impurities is not a priority for the ESR because consumable electrode has already passed all stages of refining and deep degassing at ladle treatment that changes ESR slags engineering principles. The critical importance became slag’s ability to generate process heat and keep the melting composition in the metal bath unchanged (except for non-metallic inclusions assimilation). Slag engineering for ESR required a compromise between chemical inertness to a metal composition and desired physical properties deriving from technological reasons. The Directed Chemical Bonds Concept (DCBC) in a multicomponent oxide system was used to build predictive models of electric conductivity and the melting temperature of fluoride-oxide slag based on their chemical composition. Both models help to design a customised composition of effective slags for steel and alloy groups or individual grades, and they are significant steps in the development of a comprehensive model of electroslag remelting.

Aug 21, 2024

This paper describes the application of a three-dimensional finite element modelling tool to help assess the stability of a highwall at a Central Queensland mine following the weakening of its base due to highwall mining. With traditional stability assessment techniques, likely failure modes are identified on the basis of previous experience and structural, sedimentological and geomechanical data and a mechanistic analysis of these individual modes is performed. The value of the full three-dimensional model over these traditional techniques is that it provides a coherent approach to assessing highwall stability without the necessity of initially deciding upon the dominant failure mechanism and gives a useful adjunct to the traditional tools. The three-dimensional model assumes the rock mass is made of elasto-plastic blocks, incorporating possible planes of weakness, separated by near horizontal joints. The model includes the relaxation of stresses due to the excavation of the highwall and incorporates estimates of blast damage near the highwall surface

Jan 1, 1995

By T E. Hayward, D H. English, S J. Smith

Gold mineralisation at Bendigo is exclusively associated with quartz reefs, commonly found within or near anticlinal fold hinges. The gold is typically coarse grained (0.5 mm to 5 mm), free milling and displays a complex, nuggetty distribution within the veins. This ore is highly amenable to gravity recovery processes. As the Bendigo operation is not permitted to treat whole ore by a cyanide leach/CIL circuit, the flow sheet is more complex than conventional gold recovery circuits. Primary gold recovery is from a gravity circuit closing the grinding circuit to a bulk gravity concentrate and from a flotation circuit treating cyclone overflow to a bulk float concentrate. The plant capacity is relatively low by current gold industry standards at 600 000 tpa. Re-establishing gold production at Bendigo has presented several challenging, and sometimes competing, issues in process design and operation. The mine, process plant, associated services and infrastructure are at Kangaroo Flat, a low density, semi-rural zone in the southern urbanisation of the Bendigo metropolitan area. One of the main processing challenges during the design was the competing comminution requirement to avoid over-grinding, which would flatten or smear the characteristic nugget gold and hinder effective gravity gold recovery, whilst also providing sufficiently well liberated particles that would respond well to flotation. Important, non-metallurgical challenges were to minimise impacts on the local community from noise, dust, air emissions, visual impact, water egress and off-site traffic.

Jan 1, 2007

By Ichinose M, Tsuru T, Gotoh K

Since 1980, the Department of Mining Engineering at Kyushu University, in co-operation with the Ikeshima Colliery, Matsushima Coal Mining Co. Ltd., has been conducting a research project into longwall gateroad designs applicable to deep and poor strata conditions. During this period, the economic environment has drastically changed the situation of the domestic coal mining industry. Conventionally, the retreat longwall method, with re-use of gateroad, has been employed as it achieves higher recovery. However, from the view point of production efficiency, this method is not suitable because it requires intensive work in side packing and roadway maintenance. Therefore an interpanel-pillar system, or a two-entry gateroad system, was adopted to identify the factors responsible for excessive vertical closure in longwall gateroads. Field measurements and non-linear finite element analyses were undertaken to confirm the performance of this system. Study results indicate that the stability of the gateroad employing the rib pillar system is comparable to that of the conventional system of re-using Gateroads.

Jan 1, 1992

By Boehme PW, Gregory OR

The results presented here show quite definitely that in the system investigated the intensity of dispersion is enhanced by switching the flow entry from bottom to sides of the packed trough. Since there is no reason to suppose that this would not be true generally then it is not surprising that the blast furnace dispersion data of Standish and Polthier lie above the data for packed columns with bottom fluid entry. In fact, on the basis of the present results, blast furnace dispersion results can never equal standard packed column behaviour but must always be above these. The result that the intensity of dispersion in the trough model is higher closer to the side ports than away from them is at variance with that of Standish and Polthier blast furnace results. Aside from the obvious structural differences between these two systems, it is thought that the presence of raceways and the tortuous path of the gas flow in the furnace may provide an answer. Clearly this is an important difference in the behaviour of the two systems and further investigations designed to clarify the position would have significant practical value. This would also give an indication of how the furnace D/ud values may be decreased along the whole height - assuming of course that this result gives the best overall performance of the furnace. However, there is to date no knowledge whatsoever about this aspect of blast furnace Technology.

Jan 1, 1975