Search Documents

By J Arif, J Proffett

Copper and gold mineralisation at Batu Hijau is directly related to quartz veining and wall rock alteration that developed in close spatial and temporal association with multiple tonalite porphyry intrusions. To its advantage with respect to the study and better understanding of the evolution of the porphyry system, Batu Hijau has comparatively minor late alteration and mineralisation overprints. This paper summarises results of detailed geological logging, petrographic studies and geochemical analyses of diamond drill cores from the deeper sections of the Batu Hijau porphyry system (ie its roots). An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Renison Limited produces high and low grade tin concentrates at an annual rate of 5000 tonnes of contained tin metal. In spite of the fine average cassiterite grain size, emphasis is placed on gravity concentration methods to produce a high grade final product. Cassiterite flotation is considered and operated as a gravity circuit scavenger responsible for approximately 15 percent of recovered tin metal as a fine grained low grade concentrate. Metallurgical problems mainly result from ore-type variations which may be aggravated by a number of circulating loads. The rationalisation of circuitry is being studied to provide more effective control by operators and to allow exploitation of current control and modelling techniques.

Jan 1, 1977

The design and operating characteristics of the hydraulic cyclone elutriator were described in detail by Kelsall and McAdam (1963), and the method of operation of the commercially available version, the Cyclosizer, is described in the manufacturer's pamphlet (Anon). Complete details of the operating procedure are given in the relevant operating manual (Anon, 1964).The cyclones which form the basis of the Cyclosizer (Fig. 1) under normal operating conditions produce typical cut sizes of 44, 33, 23, 15, and 10 µm for cyclones one to five respectively for material with a specific gravity of 2·7. At the end of the selected elutriation period each sized fraction is discharged and collected for subsequent assay or analysis but all material rejected by the fifth cyclone (e.g. minus 10 \lm quartz) normally passes to waste. When this material is needed for separate study, although its amount and average analyses can be calculated by difference, it may be necessary to collect more than 250 I. of very dilute suspension, flocculate the solids, allow to settle, and decant off the supernatant liquid.This procedure is cumbersome and inconvenient and the simple technique to be described may offer some advantages. The temperature of the water fed to the Cyclosizer is maintained at a constant value for added reproducibility.PROCEDUREThe present overall treatment of the subsieve material (minus 37 \lm) fed to the Cyclosizer incorporated several refinements compared with normal operation and these may be best illustrated by anactual example. Material to be cyclosized (25 to 100 g depending on size distributIOn and specific gravity) is completely dispersed in water at 23 QC by vigorous stirrmg, using suitable dispersants if necessary, in a...

Jan 1, 1974

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

Jan 1, 1981

By Lilly PA, Kavetsky AP

An empirical, kinematic model is developed which calculates the trajectory of individual blocks of rock in a blast, their point of impact in the muckpile and the final shape of the muckpile. The method is based on the determination of initial block velocity and requires input on stemming length, bench height, subdrill, burden, spacing, energy of explosive per unit length of blasthole, energy attenuation rate and resistance to movement. The model, which will form part of a comprehensive blast simulation package, has application in open cut mining in predicting muckpile geometry and the movement of grade blocks during blasting, which in turn impact on shovel productivity and grade control.

Jan 1, 1986

By I Ritchie, A Johnston, D Yataco

Marcobre SAC (Marcobre) is developing the Mina Justa copper mine project, located in the Ica region of Peru. The Mina Justa IOCG orebody comprises of a sulfide mass overlain by an oxide cap with a sharp transitional zone between the sulfide and oxide masses. The primary target metal is copper, but there are minor amounts of gold and silver. The oxide will be treated by HPGR, crushing and vat leaching, whereas the sulfide will be treated by HPGR, milling and froth flotation. The processing selections are due to some unusual ore characteristics which have required relatively unconventional solutions.Vat leaching was chosen over heap leaching and other processes after detailed trade-off studies found it to be the most attractive, primarily due to the high acid consumption of the ore. The sulfide flotation produces a wide range of concentrate grades due to the complex nature of the mineralogy. The selection of HPGR circuits for both the oxide and sulfide ore is due to the extremely hard and competent nature of the deposit. These factors and others have contributed to a unique process selection for this resource.The selection process for the oxide and sulfide ores, and an overview of the technology, equipment selection and geometallurgy, will be discussed.CITATION:Johnston, A, Ritchie, I and Yataco, D, 2017. Process development for the Mina Justa project, in Proceedings MetPlant 2017, pp 207–217 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By P J. Handley

"Predicting how coal seams will be beneficiated through the coal handling processing plant (CHPP) has long been challenging within BHP Coal. Various coal seams from different areas are mined and stockpiled separately, often depending upon a deleterious coal quality parameter; high/low trace elements for example. These stockpiles are then fed in different ratios into the CHPP to produce the desired product/s. In understanding the washability characteristics of the feed source, mine geologists and process engineers work together to improve the beneficiation of different coal materials through the CHPP.For the majority of the BHP Coal deposits, the washability data is available for the coal seams across the deposits. However, no previous standardised modelling and prediction technique existed that could ensure the correct information was available for forecasting and refining CHPP processes. This paper will discuss the steps undertaken to implement a geometallurgical prediction tool that simplified and streamlined the washability modelling and yield estimation process. The value realised to the BHP Coal assets resulting from this process was: improved compliance to plan increased throughput increased CHPP recovery through improved efficiencies and increased revenues.CITATION:Handley, P J, 2017. Washability modelling and estimation techniques used to improve coal handling preparation plant beneficiation, in Proceedings Tenth International Mining Geology Conference 2017, pp 327–336 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 20, 2017

At Hilton Mine, 18 kilometres north of Mount Isa, the silver-lead-zinc sulphide bodies have undergone strong deformation in the form of folding and later faulting and brecciation in the hangingwall region of the mine. Variation in grades and widths over compara- tively short distances causes problems regarding accurate sampling of orebody exposures in underground development, and in defining confidence limits for the extrapolation of ore intersections in ore reserve calculations. The paper gives a preliminary insight into the problem of obtaining representative samples for exposed orebodies and discusses the sampling techniques employed. Results gained from these sampling methods could not be verified due to lack of individual bulk samples for comparison but strong evidence for precision was provided. INTRODUCTION In a developing mine like Hilton, accurate grade information is of extreme importance. Original grade information for a potentially viable ore deposit is gained from surface drilling, and initial ore estimates are calculated from the resultant ore widths and grades. After underground development has proceeded, the opportunity arises for detailed examination of orebody exposures, and the resultant assay grades and widths from sampling of these exposures may, in the long term,

Jan 1, 1976

HoistEM is a helicopter-towed time domain electromagnetic system. This paper presents details of the towed array structure (the Hoist) as well as a description of the instrumentation. A comparison between HoistEM and ground TDEM (from which HoistEM was derived) is given. Over 50 000 line kilometres of HoistEM have been completed to date and datasets for structural mapping, nickel, base metals, manganese, ground water and bathymetry are presented and discussed.

Jan 1, 2004

Universal Resources Ltd has acquired a large portfolio of high quality exploration projects in two of Australia's most prospective regions for base and precious metal exploration: the Mt Isa Inlier (the Mt Isa-Cloncurry area) of North West Queensland, and the southern Lachlan Fold Belt in New South Wales. Drilling techniques commonly employed by the company for mineral exploration include diamond core drilling, air core drilling, reverse circulation (RC) drilling, and rotary air blast (RAB) drilling. Using examples from these two regions, each drilling technique is briefly described and compared, with particular reference to the specific advantages and disadvantages of each method for: sampling size, sample representivity, recovery, integrity and potential contamination. The applicability and implications of the different drilling techniques described for subsequent mineralogical and metallurgical evaluation work are discussed.

Mar 1, 2010

Expert systems are a product of Artificial Intelligence (AI), a field of long standing, dedicated to the study of problem solving using heuristics, construction of symbolic representations of knowledge about the world, communications proce

Jan 1, 1998

Recent and on-going studies on the leaching of gold, the properties and activity of carbon, developments in the elution of gold from carbon, and methods of recovering gold from solution are reviewed. Emphasis is placed on Australian contributions, and their impact on gold metallurgy. Consideration is given to the future development of selective solvent extractants, ion exchange resins or alternative reagents for cyanide.

Jan 1, 1987

By W Wu

The prospect of discrete element modelling (DEM) being used as an everyday design tool for transfer chutes in the iron ore mining industry is becoming more and more probable. However, much care needs to be taken to ensure accurate results are obtained. Whilst there are many publications in industry portraying the potential of DEM, there is little evidence of where it has been validated against a real set of experimental results. The purpose of this investigation was to gauge whether the incorporation of the physical properties of a specific bulk material at the DEM pre-processing stage can yield visually and numerically accurate simulations for a simple flow case. Effects such as irregular particle shapes, varying frictional properties and coefficients of restitution, all found through experimentation were investigated. Video analysis was used to compare simulations to real flow cases. It was found the most critical attributes in determining the accuracy of the simulations were particle shape and wall friction. Keeping the particle-to-wall friction factor constant was not sufficient to describe the flow accurately. But by introducing the varying effects of wall friction with consolidation stress, the correct results were simulated.

Jan 1, 2007

By Kuganathan K, Potvin Y

Enterprise Mine at Mount Isa is to expand ore production from the current 1.4 to 3.5 mtpa by mining the 3500 Orebody, from which production is scheduled to start in February 1998 making this the deepest underground mine in Australia with its lowest mining horizon at nearly 1.6 km below surface. The following fill requirements were defined for the 3500 Orebody during the feasibility study: 1. a minimum filling rate of 250 ma/h, 2. a curing time of 28 days, and 3. minimum free fill water. This paper mainly describes the investigation of high density and paste fills for the 3500 Orebody. The investigation covered all the key issues relating to fill option selection, including design criteria, material supply and demand assessment, drainage modelling, tailing dewatering method, mix design and a pump loop test. Results of the investigation indicate that both high density fill and paste fill are technically feasible. The investigation has led to the selection of a blended tailing paste for the 3500 Orebody as the paste option has significant advantages over high density fill in stope filling rates and fill reticulation. The blended tailing for paste fill is finer than Isa deslimed tailing but coarser than full plant tailing. The paste fill selected has minimum binder and tailing dewatering requirements while a relatively high filling rate is achieved.

Jan 1, 1998

By J Boshoff, D Reid

It has been recognised worldwide that the liquefaction risk of unconstrained tailings stacks or cyclone underflow embankments requires careful consideration. The stability of a tailings deposit where the perimeter embankments are made up of hydraulic fill is often governed by post-liquefaction stability.Cyclones are frequently used around the world to classify tailings into a coarse underflow for building a tailings impoundment wall and a finer fraction that is disposed of into the basin. The shear strength of the tailings that form the outer embankment of a tailings storage facility (TSF) and the location of the phreatic surface are the two most significant factors influencing the structural integrity of the facility. The coarse underflow is placed in such a way as to contain the overflow, which is finer, has low strength and is often poorly consolidated.A cyclone field trial was undertaken at a gold mine in Western Australia to assess the feasibility of using the cyclone deposition method to optimise and increase the capacity of an existing tailings cell. The aim of the cyclone trial was to collect information to demonstrate to the client and the regulators that cyclone deposition was a feasible option for raising TSF embankments. The cyclone trial provided an opportunity to assess the cyclone under field conditions and the quantity and quality of the underflow fraction produced on-site. A variety of methods were used to assess the flow liquefaction susceptibility of the tailings underflow sample produced during the cyclone field trial.The field trial, laboratory testing and analysis will be discussed in this paper.CITATION:Boshoff, J and Reid, D, 2015. The resistance of cyclone underflow material to flow liquefaction, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 151–156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Zharinov SE

Geonechanical modelling of island arc sys- tems and their analogs is investigated. Slow seismotectonic movements along the inclined deep fault zone under the compressive horizontal stress conditions are proposed to be the princi- pal mechanism controlling the structures and processes in the active continental margins. A model of shearing surface crack in an elastic half-plane is used for simulation. The main ele- ment of the model is viscous interaction bet- ween the crack sides, the viscosity varying with depth. To describe the stress-strain state of the medium an integro-differential singular equation is derived and solved numerically. The results of simulation are in good agreement with geological and geophysical data on the ac- tive continental margins.

Jan 1, 1987

Traditional methods for the production of transition metals from their ores usually include the electric arc smelting of the ore or concentrate to produce a ferroalloy. This is subsequently refined to produce either a ferroalloy or to produce the metal or metallic carbide. Recent trends in the treatment of iron ores have seen the development of many processes for solid state carbothermic reduction followed by melting of the prereduced iron to produce steel and similar types of processes are under consideration for the production of ferroalloys. There are clear potential savings in energy and control of emissions from such processes. This paper discusses some research which is currently underway at La Trobe University into the solid state carbothermic reduction of chromium and tungsten ores to produce the metallic ferroalloy or the carbide for subsequent further processing. The kinetics of the carbothermic reduction of both chromite and scheelite were found to be dominated by gaseous CO rather than by direct carbon reduction. However the diffusion of carbon into the ore is certainly an important feature of the process. The production of tungsten carbide from the metal is the slow step in tungsten reduction. The development of phases during reduction were studied using a scanning electron microscope and an electron probe and knowledge of the phases produced allows analysis of the reduction process.

Jan 1, 1997

By Box JC

A comprehensive computer simulation has been developed for heap and dump leaching processes. It deals with complex chemical interactions, involving several minerals and reagents, which vary with time and location in the dump. The simulation is generally applic- able to ores of various metals extracted by different reagents. It requires only mineral- ogical data obtainable from drill cores and chemical data obtainable from the literature; there is no curve-fitting with adjustable parameters. Applications in designing testwork programmes, evaluating operating options, transferring experience to new situations and reducing uncertainty in long-term forecasts are described. Specific examples are included illustrating the potential of the simulation.

Jan 1, 1983

By V Novoselov, R Sabirov

Flotation processing technology of water-soluble minerals has made it possible to realise, since the 1960s, the wide scale industrial processing of potash and potassium-magnesium ores (about 200 million tonnes per year) as well as to create the multi-tonnage worldwide production of sylvite (KCl) for industrial and agricultural application. In this paper the particularities of the effect of reagents (blinders, collectors and frothers) during cation flotation in saturated saline solutions are outlined. New reagent modes for activating the effects of alkylamines during the flotation of KCl and the perfecting of technological flow sheets for processing potassium ore have been developed. The results of research on the reverse flotation of carnallite ore, with the help of alkylmorpholine û a new developing technology for benefication carnallite as raw material for the production of metal magnesium and fertilisers are listed. Examples are given of the industrial applications of processed reagent modes at potash flotation factories in Russia.

Jan 1, 2005

By A M. L Smith, W E. Dubbin, K A. Hudson-Edwards

Jarosites (KFe3(SO4)2(OH)6) are examples of minerals that are highly effective scavengers of toxic elements, and are abundant in acid rock drainage systems, acid sulfate soils, metallurgical wastes and other contaminated sites. The K, Fe and S sites can be filled by toxic elements such as Cd, Cu and Zn, but the mechanisms of this incorporation are not well understood.We have used atomistic simulation methods to model the jarosite (102) surface and its interactions with Cd, Zn and Cu, in order to understand the mechanisms by which these potentially toxic elements are incorporated into the K-jarosite structure. Our results suggest that incorporation via a defect complex consisting of an impurity cation at the K site charge balanced by a K vacancy stabilises the (102) surface in the order Cu>Zn>Cd.

Jan 1, 2008