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By Kam KM, Tran B

Statistical techniques of Box and Jenkins (1976) have been used to assess the existing control schemes and determine the dynamics of flash smelting furnace at the Kalgoorlie Nickel Smelter. Pertinent process variables, such as, oxygen flow, flux flow, matte grade and iron to silica ratio in slag, were considered in the analysis using routine operating data collected over two periods of operation. Results indicate inadequate control of some of the important variables. Dynamic characteristic parameters (dead time and response time) between a set of input and output variables were identified to improve optimisation of the existing thermodynamic model used for flash furnace control.

Jan 1, 1996

By Weber D, Knox PR

The criteria developed for the Argyle Diamond Mine process plant control system are reviewed. The control system installed is described along with a discussion of the method of implementation adopted. The control system was extensively tested prior to instal- lation at site. This approach led to signi- ficant time savings during plant commissioning and facilitated rapid escalation of plant production. The control system has performed satisfactorily with a high level of operator acceptance and basically satisfies the criteria Developed.

Jan 1, 1986

By S Hapugoda, H Han, L Lu

Sinter quality depends heavily on the mineral phases, textures and physical structure of the sinter, which are formed upon solidification of the sinter melt. The interaction of sinter initial melt with its surrounding materials will impact the properties of the sinter melt and consequently the solidified structure and quality of resultant sinter. Spreading and penetration are two important phenomena dictating the interaction of the initial melt with its surrounding materials, such as nuclei and adhering fines. In the present study, the penetration behaviour of an initial melt into various natural iron ore substrates of different ore types during sintering was studied using a laboratory scale penetration testing procedure. The penetration depth and width were found to increase with temperature and vary with the type of iron ore due to their unique pore structure and mineralogical texture.

Nov 8, 2021

The BHP Billiton Cannington mine uses sequential flotation to treat a silver, lead and zinc ore supplied from an underground mine. The final products from the process plant are a silver rich lead concentrate and a zinc concentrate. Operational history of plant performance highlighted that the majority of valuable metal losses to final tailing occurred in the -5 ¦m fraction. Research completed on the flotation characteristics of this size fraction in plant feed resulted in the development of a split flotation process to improve the silver and lead mineral recoveries. Construction of a $A 9.5 million brownfield project to install the new split flotation circuit at Cannington was completed in July 2002. The circuit consists of three stages of cyclone classification to recover the ultra fine material to a final cyclone overflow stream, conditioning of this pulp to achieve optimal process conditions, and conventional rougher and three stage cleaner flotation to produce a silver rich lead concentrate. The rougher tail from the new circuit is recombined with the cyclone underflow streams and processed through the original lead-zinc flotation circuit. This paper discusses the circuit design, material properties, material selection for components of the circuit, operational practices and requirements to ensure the circuit succeeded in meeting production targets. The technology is subject of a number of patent applications including international application No PCT/AU02/00400.

Jan 1, 2003

By T J. Orr

The changing demographics of the mining industry make successful passing of knowledge and skills to the next generation critical. Training methods and technologies are being developed to meet this need. Twenty years ago classroom training was largely a one-way transfer of knowledge through instructor lectures. In contrast, instructors today can use virtual reality technologies to guide trainees as they fully participate in learning experiences. Trainees can interact with the virtual work environment, co-workers, and equipment without being exposed to workplace hazards. The speed of advancement in mine safety, health, and production training shows no sign of slowing in the next 20 years. Researchers at the National Institute for Occupational Safety and Health have studied and participated in the evolution of miner training. A look at training materials they have created in the past and those they are currently developing reveals changes in methods and technologies over time and also key characteristics which have remained constant. Possibilities for the future can be discussed in the framework of an implementation of virtual reality in new miner training sessions. The example computer-based training package teaches new miners to read mine maps and provides opportunity to practice navigation skills in a virtual mine. With this æserious gameÆ, trainees experience the look and feel of moving through an underground coal mine while in the safety of their classroom. During field-testing in 2007, trainees and instructors responded very favourably to this new way of learning. The software was usable by mine trainers with even limited computer expertise and could be installed on the affordable computers they were using for their more traditional slide presentations. The Underground Coal Mine Map Reading TrainingÆs foundation on past successful development strategies and its acceptance by todayÆs instructors and trainees provide valuable lessons for developing training materials, strategies, and technologies for miningÆs future.

Jan 1, 2008

By B Petrie, D J. MacKenzie

The Macraes mine is producing 175 000 ounces Au/year from a mesothermal deposit with total resource of at least five million ounces. The deposit is hosted in greenschist facies Otago Schist, a widespread Mesozoic metasedimentary sequence that forms the basement of the South Island of New Zealand. Mineralisation was controlled by a late metamorphic shear zone which had both brittle and ductile structures accompanying mineralisation. The shear zone dips shallowly (about 15¦), subparallel to the shallow-dipping regional foliation, and mineralization occurred during southwesterly-directed thrust motion. Mineralisation occurred under greenschist facies conditions (about 350¦C) during uplift of the Otago Schist in the late Jurassic. No syn- or late-metamorphic igneous bodies occur within the schist belt. The hosting shear zone is up to 120 m thick, and is traceable for more than 30 km along strike. The shear zone is truncated by an underlying low angle normal fault that juxtaposes mineralised lower greenschist facies rocks on to unmineralised upper greenschist facies rocks.

Jan 1, 2004

By Feilding C

Vitrinite of humic source (often designated as vitrinite A) is the maceral by which the rank of a coal ought to be determined. Therefore its recognition, and the precise identification of other vitrinites is essential. The majority of Australian petrologists are not differentiating between the vitrinite group macerals in maturation studies, the results of which have led to unexplained phenomena in coal characterisations and evaluation, such as 'reactive inertinites' and inaccurate predictions in petroleum source rock studies. The Callide coal has been chosen as a case study, with examples from other coals. The coal seams from the Callide Coal Measures show variation in the predominance of some macerals, indicating successions of environmental changes. The application of transmission electron microscopy (TEM) to the study of the Callide coal has enabled a better understanding of the nature and origin of some of the less understood macerals such as micrinite and vitrinite B. Two forms of vitrinite have been observed, each with a distinct reflectance range. The wood-sourced vitrinite A displays an average reflectance of 0.56 per cent, and a range of 05. - 0.7, implying a higher rank than the 0.49 per cent Ro total vitrinite reflectance recorded in previous publications. Vitrinite B is one of the most commonly-occurring macerals in the Callide coal. The lower-reflecting vitrinite B which forms bands, often several hundred microns in thickness, in TEM appears to be electron transparent lipid rich. Vitrinite B is interpreted to represent accumulations of leaves, and is believed to be a major source of hydrocarbons in Australian sedimentary basins. The Callide coal has entered the oil window, and oil has been generated from some exinite, cutinite, and resinite, as evident from the amber to light brown fluorescence of exinite and the presence of exsudatinite in cell cavities and cleats. However vitrinite B, the major potential source of oil, is seen under the microscope to be generating oil, thus placing this coal at the top of the oil window. Micrinite, the origin of which has been much debated, occurs as cell filling or infill of spaces between laminations in vitrinite B.

Jan 1, 1991

High resolution seismic profiling has proved a cost effective tool for defining the structure and seam geometry of Late Cretaceous-Late Miocene age lignite deposits in the South Island of New Zealand since 1981.In 1985 a total of 45 km of Mini Sosie seismic reflection was carried out in the Benhar, Hawkdun and Ashers-Waituna deposits as part of a major multidisciplinary resource investigation funded by the Liquid Fuels Trust Board. For each deposit the seismic programme involved integrating four or more intersecting Mini Sosie traverses with a grid of 1000 m spaced geophysically logged drillholes. The objective was to detect faults, with displacements ranging 30 - 100 m, which might impede mining using bucket wheel excavator systems at depths down to 300 m below surface.In general the quality of processed seismic data was high and with the assistance of ynthetic seismograms and other geological information, it was possible to identify a number of significant previously unknown faults. The success of this seismic programme ha shown that high resolution seismic profiling, used in conjunction with relatively low density drilling, can produce valuable structural and tratigraphic information at an early stage of open pit mining investigation.

Jan 1, 1989

By Balint F

The Izok massive sulphide deposits are located in the Northwest Territories of the remote western Canadian Arctic. Together they represent one of the highest grade undeveloped zinc-copper resources in North America. Metall Mining Corporation is presently engaged in a feasibility study on developing the Izok property as well as actively exploring for additional reserves. The Izok deposits are Archean-aged, volcanogenic massive sulphide (VMS) bodies hosted within and near the top of a thick sequence of predominantly felsic pyroclastic rocks. The hangingwall package includes additional felsic volcanoclastics, dacitic and basaltic flows, thin sulphide-rich iron formations, and turbiditic sediments. The felsic volcanics are intruded by syn- to late-hydrothermal dacitic dykes and sills and post-hydrothermal gabbroic dykes and sills. Both intrusives are interpreted to be volcanic feeders to overlying flows. All lithologies are cut by much later irregular granitic pegmatite dykes and regionally metamorphosed to pyroxene homfels grade. The deposits occur within a large kilometre-scale soda-depleted alteration zone. The immediate footwall and hangingwall rocks to the deposits are characterised by zones of muscovite-biotite (with or without sillimanite), lesser chlorite-biotite-cordierite (with or without anthophyllite), and locally intense silicificified and albitised zones. All lithologies have been affected by a later calcic metasomatic alteration. As currently defined, the Izok Zn-Cu-Pb-Ag deposits comprise a cluster of four complexly-zoned composite lenses: the Northwest, North, Central, and newly discovered Inukshuk deposits. The first three deposits are amenable to open pit mining while development of the Inukshuk deposit will require underground methods. The combined mineral inventory of the Northwest, North, Central and Inukshuk deposits at present totals 15.6 million tonnes with a grade of 2.4 per cent Cu, 13.8 per cent Zn, 1.4 per cent Pb, and 74.6 g/t Ag.

Jan 1, 1993

By Y Wei, H-B Mnhlhaus

Particles are by far the easiest objects to simulate, because their dynamics is simple. Determining the motion of particles and their interaction, a wide variety of deformable structures can be constructed by connecting particles that have mass, position, and velocity, and that respond to forces. Starting from this simple idea we have derived what we call the particle-lattice method for the solutions of boundary value problems of deformation and fracture of solid mass. The problem of rock breaking by blasting operations as well as fracture and flow of rocks fragments involve momentum transfer between solid and fluid; gas flow and reactive mass transfer. In this paper we outline the method and describe briefly the salient features of the algorithm. We derive relationships between the contact properties for the discrete model and the properties of the underlying continuum and fluid flow coupling procedure. Finally we illustrate the potential of the method by means of example solutions related to the dynamic fracture and flow in jointed rock by blasting.

Jan 1, 1999

Ore reserve estimates form a basis for strategic mine planning at Argyle Diamonds open pit and alluvial operations. Most ore reserve statements are mainly concerned with resource tonnage and grade. Because diamond deposits are low grade, high value resources, diamond quality ($/carat) is also an important parameter. Relatively large variations in quality and/or grade can occur. These variations must be taken into account before the resource potential can be fully assessed. Computers (HP9000 and PC's) are utilised to compile resource inventories. Resource inventories are then ranked on an economic basis. This paper discusses the methods used to compile resource inventories and explains how these are then used to present ore reserve estimates in terms of resource potential.

Jan 1, 1990

Instantaneous outbursts of coal and gas have occurred in Australia in the Sydney Coal Basin since 1895 and in the Bowen Coal Basin since 1954. The largest has been about 500 tonnes of coal and so their magnitude and character have not approached those experienced in some other countries. The occurrence of CO2 with some Australian cases provides some similarity with the worst affected areas in France and Poland.The proneness of seams depends on coal rank and seam gas composition, among other factors. The proneness of places depends on depth, structure, intrusion, tectonism and other factors affecting the geometric, physical and chemical uniformity as well as details of mining. As a phenomenon due to gas and stress, prevention can be achieved by relief of high gas and/or stress condition. Alternatively, controls can be applied to render mining safe for personnel. Unfortunately day-to-day prediction is not widely and reliably achieved to allow selective use of prevention or control. The initial rate of desorption is the most promising day-to-day indicator.Various researches include gas conditions and parameters, stress and failure conditions and parameters, coal variables and geological variables in relation to prediction, prevention and control. Some assistance in research may derive from study of analogous phenomena of instantaneous outbursts of salt and other rocks and gas. It is concluded that in the Sydney and Bowen Basins, any coals with less than 30 per cent Volatile Matter (VM) ash free dry (afd) at depths over 200 m could be prone. Proneness increases with depth, with lower volatile content, with geological disturbance including faulting, intrusion and recent tectonics, with increased CO2 in seam gas, with narrow work and with other factors. Much more research is needed.Unfortunately outbursts are needed too, to provide the research with realistic data. With the problems of mechanism and prediction still being unsolved much research remains to be done. No present aspect of research is satisfactorily resolved.

Jan 1, 1983

By D Reid, A Fourie, J Ayala

This paper discusses cone penetration test correlations for loose gold tailings that were developed within a critical state soil mechanics framework. The development of a new calibration chamber for cone penetration testing that consists of a modified triaxial cell is described. Some of the early development and commissioning issues that were encountered, as well as the solutions adopted are outlined, including the system to prepare the samples and to acquire high-quality data from the testing. Also, the triaxial laboratory testing required to achieve the critical state line is described, including some of the basic precautions considered necessary as good practice. Additionally, the system adopted for volume tracking of the calibration chamber sample is described, which is essential for ensuring a reliable state parameter comparison against the acquired cone penetration test data. Finally, some laboratory test data from the calibration chamber is plotted against the soil behaviour type charts currently available from various authors.

Jul 1, 2021

By Waqinwright M. S

The underlying principles of dewatering theory have recently achieved considerable practical application in the washing and dewatering of alumina trihydrate in Bayer plants. In particular, the influence on residual cake moisture contents of trace amounts of surfactant added to the wash water reveals that significant energy savings can be achieved. The influence of organic compounds produced by the caustic extraction of bauxite in the Bayer process is shown to be significant. These humic species reduce the cake permeability and the effectiveness of certain surfactants in dewatering operations.

Jan 1, 1989

By R Berry

This paper looks at two ways to estimate the bulk mineralogy of the rocks for assay intervals. The aim is to find an efficient indicator of the most common minerals in the rock. Phase (modal) analysis has traditionally been done using visual methods such as point counting and image analysis. A modern version of this process is the X-ray point counting routine using the SEM-EDS based software. These methods are too slow and expensive for routine analysis of bulk sample mineralogy at the normal assay spacing.Two sources of data were considered that provide information that can be used to determine the mineral abundance in assay samples. The most widely applied method is (semi-) quantitative X-ray diffraction (QXRD). The QXRD method is most applicable to major minerals and has limited application to minerals at low abundance. The nominal detection limit is 0.5 per cent. Values below five per cent have large errors. A second, less common, method is calculation of mineralogy from chemical assay data. Conversion of chemical analyses to mineralogical analyses depends on the unique chemical composition of each mineral. Elements only found in one mineral are easily accounted for, but many compositions are ambiguous. Deciding on the actual mineralogy is not simple. Recalculation of mineral mode from chemical analyses is more accurate than QXRD when the correct minerals, and mineral compositions, are known.Where only a few QXRD analyses are available they can be used to setup a protocol for calculation of mineralogy from assay data. Linear programming works well in this environment. The best results are obtained when both H2O and CO2 are directly measured. Loss-on-ignition (LOI) should be included if these are not available.Where both QXRD and chemical analysis are available for all samples, the best results are obtained using the least squared method to merge the data sets assuming QXRD has much higher analytical errors than chemical assays. The combined method provides more robust results because the high abundance minerals are controlled by the QXRD measurements while the chemical assays improve the precision for low abundance minerals

Sep 5, 2011

Following the Moura No 2 Wardens Court of Inquiry and subsequent changes to the Queensland Mining Legislation there is a requirement in Queensland coal mines for: a person with the recognised competencies to be appointed at each underground coal mine to the position Ventilation Officer; and the person is directly responsible for the implementation of the mine ventilation system and for the establishment of effective standards of ventilation for the mine. The Regulations require that an underground mine must have principal hazard management plans that provide for at the least the following: emergency response, gas management, methane drainage, mine ventilation, spontaneous combustion, and strata control. Other than strata control all the plans require the ventilation officer to have roles and responsibilities to develop, control, monitor and undertake actions in relation to these plans.There are also another 34 Regulations that either directly or indirectly requires the Ventilation Officer to take actions.The purpose of this paper is to outline the information that the regulators look for in sealing plans and the actions the regulators will take if the sealing does not go to plan (TARPs being exceeded).

Jan 1, 2005

By S M. C Verryn

Through the application of the Rietveld method, X-ray diffraction analysis has developed into a fully quantitative method for phase analysis of metallurgical products. The Rietveld method itself has progressed from an unstable method that required constant operator intervention to a stable and robust method suited even for routine process control. Knowledge of the crystal structures of the major phases is essential for Rietveld analysis, and these are well known for most minerals and major phases in metallurgical products. It provides the basic structural information necessary for the determination of mineral stoichiometry and for elucidating solid solution behaviour. Modern methods, such as simulated annealing and charge flipping, permits the determination of crystal structures from powder data. Unit cell data can be used where conventional microchemical analysis is unable to provide an answer to the extent of solid solution in ilmenite roasting. Unit cell data (by XRD) is used to determine the amount of roasting necessary for the development of magnetisation to be able to separate chromite from an ilmenite concentrate. Phase quantification is probably the most widely used application of XRD analysis. It is used for materials balance in the minerals and cement industries, and it is finding novel applications in the iron and steel industry. Applications of XRD in high-temperature metallurgical processes are increasing. In this paper the phase chemistry of iron ore sinters, the evaluation of subsolidus reactions in titania slags and the identification of furnace accretions are discussed. Despite the success of the Rietveld method in phase quantification, the method still needs further development in the quantification of closely related or polytypic phases. The quantification of pyrrhotite phases using various Rietveld programs still gives ambiguous results. This is also true for the different SFCA phases in iron ore sinters. Clearly the analysis of similar phases, differing only in the presence of weak superlattice reflections is still problematic.

Jan 1, 2008

INDEX OF CONTENTSIntroductionThe slag samplesGranulated SlagGlass-spinel-magnetite-metallic leadRapidly Chilled SlagSlowly Cooled SlagSpinel - magnetite - zinc melitite (hardystonite) willemite - olivine -lead silicate - metallic lead - lead sulphide - copper sulphide - copper arsenide - nickel arsenide.ConclusionsIllustrationsINTRODUCTIONThis paper presents the results of a mineragraphic examination of representative samples of granulated lead blast furnace slags from the Port Pirie Smelter, and of slowly cooled samples of t:b.e same slags, undertaken at the request of the Broken Hill Associated Smelters Pty. Ltd., as part of the research programme of the Mineragraphic Section of the Commonwealth Scientific and Industrial Research Organization.THE SLAG SAMPLESThe chemical composition of the slags examined is given by the following three analyses of the granulated slags, supplied by the Broken Hill Associated Smelters (Table 1).

Jan 1, 1949

By S Smith

Several styles of copper (Cu) mineralisation are present at Sepon. Large tonnage, low grade skarn and carbonate replacement massive sulfide mineralisation occur within the metamorphic aureole of Permian-aged rhyodacite porphyry intrusions (RDPs). During exhumation and supergene weathering, this primary mineralisation has been upgraded to form high-grade chalcocite enriched zones up to 50 m thick, which comprises the bulk of Cu resources currently being mined at Sepon. Groundwaters remobilise Cu to form exotic accumulations of malachite that are locally hosted in irregular karsts in carbonate rocks, found up to 1000 m from source mineralisation. Khanong is the largest Cu deposit and recent discoveries have been made at Thengkham South, Thengkham North and Phabing. All deposits have formed by similar processes of mineralisation. However, all differ due to local variations in host rock lithology, structural setting, and hydrological conditions. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

This paper discusses a number of examples of how environmental factors have been incorporated into the water management aspects of mining projects. One example is the Kingston Lignite Project in the South-East of South Australia where the most significant environmental issue was considered to be the effect of drawdown from mine dewatering and depressurization upon the use of groundwater. By proposing an alternative mining method - the use of floating dredges rather than a two-pass dragline method - drawdown effects would no longer be a concern. A second example is the Pine Creek Gold Mine in the Northern Territory. In this case the principal area of interest from an environmental viewpoint was water management - in particular effluent disposal, contaminated seepage from overburden and tailings, and project water supply. Through an integrated approach to the management of wastes and water the potential for water quality impairment was significantly reduced and external water supply requirements were also significantly reduced.

Jan 1, 1987