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The evolution of the Oaky Creek mining complex provides a good example of the mining cycle in practice. Oaky Creek has been innovative in its choice of mining methods, with virtually the full range of coal mining methods having been used as workings have progressed down dip. The history of the mine is traced through its development (and ownership changes), progressive selection of mining methods as depths of cover to seams being mined have increased, and rehabilitation. This allows the different mining methods to be described and illustrates the concept of æwall-to-wall miningÆ.

Jan 1, 1998

By K Verbeken, D Seveno, A Maslov, I Bellemans

Recycling and decarbonisation current metallurgical processes is key for our planet’s future and in both cases, digital twinning will play an important role. However, the various modelling techniques being used for digital twinning require a lot of input values on variables such as viscosities, diffusion coefficients and surface energies that need to be known as a function of temperature, atmosphere and composition, but which are not widely available, such as in databases, for molten slag phases. The need for more accurate data on physical slag properties is clear and will be extremely relevant for making more realistic and quantitative simulations. Some of these properties are difficult to determine, which is inherent to the very high pyrometallurgical temperatures. Therefore, this work focuses on some aspects related to determining electrical conductivities, viscosities and surface tensions of slags via a combined experimental-modelling method. Besides experimental work, molecular dynamics (MD) simulations can be used to investigate oxidic slag physical properties. With MD simulations, one can follow the time evolution of a system (consisting of atoms or molecules) by integrating Newton’s equation of motion. The input for an MD simulation mainly consists of a force field as well as initial positions, velocities and mass of each atom. The determination of the transport properties in existing literature of MD simulations in oxidic systems, is typically based on incorrect assumptions. For example, to determine the ionic conductivity, the frequently-used Einstein-Stokes equation fails to take into account all ionic types and neglects correlated motion. Furthermore, the viscosity determination via the Einstein-Stokes formula also assumes independent motion of the different ions. This paper gives a brief overview of the opportunities and challenges related to the use of MD simulations for oxidic slag systems.

Jun 19, 2024

By Chen J, Zhu D

A detailed study on oil agglomeration of fine metal oxide particles is presented in this paper. The major content embraces several aspects which may possibly reflect the current trends in oil agglomeration such as the effect of chemical and physical parameters, the activation of target minerals and the deactivation of gangue particles, the mechanisim of bridging liquid and the kinetics of oil agglomeration process. Systems of ilmenite-feldspar, manganese dioxide - quartz were seperated successfully through oil agglomeration followed by decantation or flotation technique respectively. A triple mixture of vandium-bearing titanomagnetite ilmenite and feldspar was processed satisfactorily using a composite technology: oil agglomeration-decantation-magnetic concentration.

Jan 1, 1993

Magneto flotation is a recently developed method aimed at simultaneous utilisation of the magnetic and flotation properties of minerals in separation processes. In this method, magnetic minerals are prevented from reporting to the froth product while non-magnetic minerals are being floated. With suitable ores, this makes it possible to reduce or entirely eliminate the cleaning and scavenging operations that are otherwise necessary in conventional flotation and magnetic separation systems. This paper describes the testing of magneto flotation on a Canadian magnetite ore. The ore sample used in the experimental work contained a total of 32.89 per cent Fe of which 87.60 per cent was magnetic in the form of magnetite. Magnetoflotation yielded, in a single step, a final concentrate assaying 69.10 per cent Fe and with an overall recovery of 84.84 per cent representing a magnetic iron recovery of 96.39 per cent. Comprehensive comparisons were made with conventional magnetic separation and flotation, and it was found that with these methods at least four processing steps were required to achieve results similar to those obtained with single-stage Magnetoflotation.

Jan 1, 1993

By Swann CA

In order to meet export sales requirements from 1983 onwards, Amcoal developed a new underground mine in the Witbank area of the Transvaal. The mine was required to produce 5 million tons of run of mine coal per annum giving rise to 4 million tons of saleable products. A description of the coal processing plant is given with comments on design philosophy and design parameters. Main features of the coal processing plant are the raw coal handling facilities, centralised control and data capture and the loadout station. The management systems applied during the commissioning period are described. The difficulties experienced and their solutions are discussed. Commissioning was concluded with an independent plant performance test.

Jan 1, 1986

By R C. Owen, M A. Ward

The paper describes the application of New Zealand's environmental impact assessment procedures to a proposed gold and silver mine in the North Island of New Zealand. The project is described and a summary is provided of the statutory permits or consents that are required prior to operation of the project. Emphasis is given to the requirement for environmental impact assessment and the preparation of a formal environmental impact report. The company's approach to impact assessment is described, with examples of how this assessment and the identification of management alternatives influenced the engineering design of the project. This paper was prepared as a contribution to a working session of the International Association of Impact Assessment VII Annual Conference, July 1988.

Jan 1, 1988

Traditionally, the predominant drilling method in open pit mining has been large hole rotary drilling using cumbersome, inflexible equipment offering merely limited scope for improvements in pit design and overall costs. By contrast, the recent development of comparatively light high-pressure down-the-hole hammer crawlers has paved the way for new ideas and trends. High penetration rates coupled with superior mobility and fast set-ups contributing to substantial productivity gains have resulted in a renascence for this drilling method in open pits. The ability to cover a wide range of hole diameters and angles gives designers unique drill pattern possibilities especially when establishing steep and stable pit slopes. As pre-split holes, buffer holes and production holes all can be drilled by using the same equipment, there are, there are obvious advantages in production scheduling as well as in materials handling and service. This paper presents some case stories, which will demonstrate the benefits and improvements that the introduction of new drilling methods and equipment has brought to open pit mining operations.

Jan 1, 2003

By P A Ferenczi

The Proterozoic iron oxide related Au-Cu-Bi (Tenant Creek style') deposits at Tennant Creek can be classified as syntectonic polymetallic hydrothermal replacement type mineralisation. These deposits have characteristics in common with a number of other Proterozoic iron oxide (Cu-U-Au-REE) hosted deposits in regions which include Southeast Missouri, USA; the Kiruna district, Sweden; the Great Bear Magmatic Zone, Canada; the Stuart Shelf, South Australia; and the Wemecke Mountains, Canada. Similarities between these and Tennant Creek style deposits include: 1. Tectonic Setting: Formed at shallow crustal levels (

Jan 1, 1994

By A W. Bewsher, T C. McCu, D B. Mapleson

The Miitel nickel sulfide deposit has been overprinted by a family of late stage structures that have acted as conduits for fluids that have contaminated the orebody with arsenic minerals. This has resulted in highly variable and unpredictable arsenic grades throughout the Miitel orebody. The ore produced from Miitel is processed under a toll-treatment agreement with Western Mining Resources Kambalda Nickel Concentrator. Part of this arrangement includes a financial penalty if monthly average arsenic grades in ore delivered exceed 800 ppm. This constraint has provided an extra challenge to the Miitel mine geologist in addition to daily underground duties. Routine development and stope mapping, close spaced sampling and cross-sectional interpretation were used in building an understanding of the structural controls of arsenic mineralisation and ore repetition at the Miitel nickel mine, and in providing maximum input to mine planning and scheduling. The distribution of structures responsible for arsenic introduction is now well understood from detailed mapping, sampling, and interpretation. By applying these insights to mine scheduling, the operation has successfully managed arsenic levels within the required specifications. Geological mapping has also improved the understanding of the structural complexity of the ore deposit, leading to the addition of ore tonnes and an increased confidence in resource modelling. Regular sampling and tight controls on data quality provided confidence in a strongly skewed arsenic data set. Multiple Indicator Kriging has been used for resource estimation of the arsenic contaminated nickel ore since it allows explicit control of the spatial influence of extreme grades in the positively skewed arsenic sample population. Both the grade control and exploration data sets are used to model the arsenic distribution.

Jan 1, 2003

By Barrett D

The paper discusses the justification for the Open Pit Mining Operation at Central Norseman Gold Corporation Limited's North Royal facility.Open pit mining history is outlined together with production statistics and associated costs. Underground mining practice is discussed together with an outline of the problems with mining in oxidised ground.

Jan 1, 1984

By Nilmani M, Fountain CR

Injection of gases into slag-melt mixtures produces various zones as a result of bubble formation and disintegration within the melt. The extent of these zones depends on the type of reactor used. When compared with ferrous processes, non ferrous processes are character- ised by large bubbles formed adjacent to the tuyeres, low flowrates and shallow tuyere sub- mergence. These features can result in a greater proportion of reaction occurring above the bath, more refractory wear and tuyere blockage with more splashing. The large bubble zone adjacent to the tuyeres has been investigated using the tech- niques of physical modelling, mathematical modelling and plant trials. Large bubble form- ation in physical models was recorded using a high speed camera and a rapid response pressure transducer coupled to an oscilloscope and data recorder. It was found that the bubble volume (Vb) could be correlated at low flowrates using the single bubble model Vb = 1.378 Q6/5 g-3/5 Deviations from this correlation occurred with increasing gas jet momentum. Plant trials were carried out on a copper converter at Mount Isa Mines during five different charges. Pressure measurements were made through the tuyeres during the slag blow and commencement of the copper blow. The power spectrum density showed that the dominant pulse amplitude occurred at a frequency of approximately 3 pulses/sec. Plant data from this and other converters were correlated using the same relationship as for physical modelling. De- viations occurred due to the state of the re- fractory, bath composition or bath circulation effects.

Jan 1, 1984

By Liu X

The solubility of cobalt oxide in iron silicate slags has been measured at 1573 K by equilibration of silica and alumina saturated slags with liquid Co-Au-Fe alloys, and by equilibration of silica unsaturated slag with solid Co-Fe alloys, at oxygen pressures of either 10-9 or 10-10 atm (1 atm = 1.013 x 105 Pa). The activity coefficient of cobalt oxide has been calculated and compared with previous studies.

Jan 1, 1991

Effective pre-splitting is a key feature of wall control blasting. Most mining operations use historical designs or rules-of-thumb for designing pre-split blasts. If productivity and safety benefits are to be gained, these methods need to be improved in order to accurately predict pre-split performance. This will become more pertinent as overburden depths increase, placing more demands on the pre-split operation. A classical qualitative quasi-static description of pre-splitting (Kutter and Fairhurst, 1968) is presented and it is shown to give some useful insights into the pre-splitting process. In particular, it is clear that the time interval between the initiation of adjacent pre-split holes is a very important factor. In terms of this analysis, it is shown that current techniques which employ detonating cord as the surface initiation system are not optimal. A static quantitative model for pre-split design which has been widely reported is then discussed and its simplifying assumptions and their implications are examined. It is shown that several of the assumptions may be reasonably justified in the light of real pre-split results. It is concluded that the model should yield conservative designs. For this model, the key calculation of the blasthole pressure that is needed to determine the required explosive charge is highlighted. Popular methods employed in the literature for describing the expansion of real detonation products are shown to be inappropriate and an alternative method using the non-ideal detonation code, CPeX, is proposed.

Jan 1, 1995

By Hanna P

Coal geologists are under pressure to minimise exploration expenditure, maximise interpretation confidence and produce the results often too soon. This pressure continues to increase as companies are forced to evaluate borderline economic deposits which are usually deeper and more hazardous, such as the Togara North and Togara South projects in Central Queensland.

Jan 1, 1998

Whilst decisions to commit projects have traditionally been heavily influenced by hurdle rates for d.c.f. analysis, it is suggested that evaluation of competitors' costs may be a desirable additional tool.The MICAS system developed over the past four years is described. This computer system uses standard costs modified by District and Mine factors to allow estimation of individual mine costs. The data base contains more than 15,000 items of data and more than 6000 costs are calculated.Recent applications include use for competitive analysis, predictive analysis, statistical analysis, and comparative assessments with scopes ranging from a few mines to the whole Australian export industry. Some areas where care is necessary are outlined and potential further uses are discussed.

Jan 1, 1985

By Gillies A. D S, Supriyadi

The landed cost of coal to the international customer is a major parameter which determines market competitiveness. Rail, port and shipping charges represent 30 to 50 per cent of landed costs for Australian mines selling to Asia. This prop

Jan 1, 1994

By Ballantyne GH

The Ladolam gold deposit on Lihir Island, in Papua New Guinea, is a large disseminated gold deposit hosted by hydrothermal breccias. The deposit occurs in the cupola zone of a 350,000 year old monzonite stock which is emplaced in the collapsed caldera of a shosho- nitic stratovolcano.

Jan 1, 1987

WMC Resources Ltd has been involved the development and trialling of an automated load haul dump vehicle system since 1997. This paper describes the introduction of the system into the Olympic Dam Operation and its performance compared with existing manual loaders. In certain situations the autotram loader will outperform the manual operation, particularly on the longer distances. There were no personnel injuries associated with the operation of the system during the testing period.

Jan 1, 2005

By Williams RC

Overlying the coal deposits of the Sydney Basin are several lakes and other bodies of water. These include the Pacific Ocean, Lake Macquarie, the Tuggerah Lakes and the stored waters of the dams of the New South Wales Metropolitan Water Sewerage and Drainage Board. The coal beneath these bodies of water amounts to hundreds of millions of tons. Colliery workings have approached these areas of water and in some instances first 1"orkings of bord and pillar have taken place oi_eshh the water. he problem which now faces mine manage- and other interested authorities involves the determination of the maximum ;mount of coal which can be safely extracted from beneath the water. There are many factors to be considered including the depth of cover, seam thickness, geological details and strata movements.

Jan 1, 1972

The number and severity of sulphide dust explosions in underground metalliferous mines have increased in recent years, despite various methods used to prevent or inhibit them. A dust explosion occurs when a cloud of combust- ible dust in an oxidizing atmosphere is exposed to an ignition source with sufficient energy to ignite the dust. A computer blast simulator model was used to investigate the movement of the fractured rock, temperatures and volumes of the explosion gases in a 70 m high, 24 m wide open stope.

Jan 1, 1988