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Ventilation characteristics of a three h -nc longwall development panel in a 1/100th tale hydraulic model using dispersion mechanics are the first applications of its Find in ventilation. Dispersion mechanics gives additional and important ventilation parameters such as degree of mixing, bypassing, -ecirculation etc. These are not obtainable the traditional pressure-volume methods. Experimentally, the model work investigates entilation characteristics of different stopping layouts, including leaky stopping,, cut-throughs and return roadway, brattice tyre ventilation and the effects of flow rate reduction on air distribution in the headings. Additionally, a model of methane generation at the face provides results used to calculate the dispersion characteristics in the return airways. It is concluded that the model resui,s -trongly suggest that dispersion mechanics could be applied to mine ventilation surveys to provide quantitative flow pattern data and details of effective dispersion '?_C!,r riro ò `b' eritilat.ing air.

Jan 1, 1983

The results of a systematic geochemical survey of rare elements are applied to elucidate genetic relations in a suite of rocks and to predict the probability of mineralization. The geology, radioactivity, major element geochemistry and classification of the main intrusives are described. The distribution of a group of rare elements, their concentration trends and the bearing these have on the emplacement sequence of the rocks are considered in some detail. The guides for exploration in the Pilanesberg that emerge are listed and some areas which substantiate predictions are described briefly. It is concluded that a study of rare element trends can make a considerable contribution as an exploration tool and for clarifying relations between the members of rock suites.

Jan 1, 1986

The Kangiara mine is located within the Middle to Upper Silurian Hawkins Volcanics of the Douro Group near Yass, New South Wales. The deposit is a po1ymetallic type within a rhyolitic tuff.The ore minerals comprise pyrite, sphalerite, botryoidal sphalerite, galena, chalcopyrite, marcasite, tetrahedrite, bismuthinite, bismuth, silver, electrum, chalcocite, covellite, and digenite. The gangue minerals are quartz, barite, calcite, and the host rock. Locally sericite occurs.Several distinct ore types can be recognized, mainly on the basis of their macroscopic textural appearance, and it is inferred from these general features that the mineralization had a submarine volcanic-sedimentary origin similar to that of the Kuroko deposits in Japan.

Jan 1, 1976

By M Ljunggren, M Lundh

Dissolved air flotation (DAF) in wastewater treatment as a separation process of submillimetre biological flocs is based on the generation of bubble/floc aggregates. DAF is a complex process but has got advantages, such as allowing a high hydraulic load, compared to sedimentation. A thorough knowledge of the physics of the DAF process is, however, still lacking. This paper will present results of experimental studies on three aspects of significance to the separation process û the flow structure in the flotation tank, rise velocities of aggregates, influence of floc size on the separation efficiency. Flow structure. Measurements were performed in a pilot plant mapping and visualising the velocity field. The dispersion water (bubbles) had a decisive influence on the flow structure due to the effect of the bubbles on the bulk water density. Stratified conditions with a less dense, bubble-containing upper layer and a clear water, denser bottom layer were important for a good separation. A simple model of the stratified flow structure was elaborated making it possible to interpret the function of the aggregate rise velocities. Bubble/floc aggregates. The dynamics of single flocs, bubbles, aggregates were visualised using a borescope + CCD video camera + digital recorder + image analysis. Sequences of video frames made it possible to determine the rise velocities of the single aggregates. These velocities were found to be in the range 1 - 9 mm/s with a tendency for large flocs to have higher rise velocities. Separation versus floc size. The floc size distribution was measured in the DAF process. Data from three different DAF cases showed, that large flocs (> about 100 ¦m) were entirely separated, whereas small flocs experienced a less good separation. It was, moreover, found, that a very significant separation of flocs took place in the very upstream end of the separation zone in a pilot plant case.

Jan 1, 2005

EnergyAustralia is a state-owned corporation in the state of New South Wales, whose responsibility includes ownership and management of an electricity distribution network. Expansion of the high voltage distribution network in the Sydney central business district (CBD) includes the requirement to run an additional five 132 kV feeders over 1.7 km from south of the CBD to a new 132 kV substation in the northern section of the CBD. A driven tunnel is currently being excavated in Sydney sandstone beneath Darling Harbour to contain the new 132 kV feeders. Tunnel construction methods involve both roadheader and tunnel boring machine (TBM) excavation. This paper describes the design development of the cable tunnel, discusses the use of a geotechnical baseline report as an integral part of the contract documentation and provides an update of the current construction works.  

Jan 1, 2008

By Gao K, Wu C, Xia J, Burdett M

X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques have been adopted in this study, to investigate the structure of carbonaceous materials such as graphite, brown coal char as well as coke, in order to explain their dissolution performance during ironmaking. These materials have been selected for study since they are commonly used recarburizers in the metallurgical industry. It was concluded that the crystal structure in a carbonaceous material can have a significant influence on its dissolution into iron melts. The material with the highest degree of ordering, which is graphite, showed the best dissolution performance. In contrast, the material with the lowest degree of ordering, which is brown coal char, showed the worst dissolution performance.

Jan 1, 1996

By Fabjanczyk MW, Guy RJ, Tarrant GC

The design of the reinforcement systems required to stabilise mine roadways has developed through the application of field measurement techniques. These techniques have allowed the level of security of a given opening to be determined from an assessment of the loading within the reinforcement, the extent of roof deformation and experience. The design systems developed are now used extensively in a wide variety of geological environment. Recent interpretative techniques have been developed to improve the level of confidence when designing roadway reinforcement. The techniques are particularly applicable for roadways subject to either weak materials or extreme stress levels. A second area of application is where roadway advance rates and hence the timing of reinforcement placement are critical. The newly developed techniques include both analytical and computational models. The validated computational techniques allow a more rational approach to investigation of the effect of varying reinforcement type, timing of placement and density on the level of stability achieved.

Jan 1, 1992

By Koppe J. C, Costa J. F C L

This paper compares different results for overburden volume estimation assisted by geoestatistics, particularly using kriging methods. The main goal is to obtain the most reliable digital terrain model for the calculation of the overburden volume. The data was collected on an irregularly spaced grid and interpolated values were calculated to provide a denser, more regular data set before volume estimation. The field work was developed at the Butia-Leste Coal Mine, southern most Brazil, where an accurate survey was done using a total station theodolite with electronic data collector. The study was developed in five main steps: data acquisition, exploratory data analysis, spatial continuity measurements, point and block kriging estimation and verification of the results. Data acquisition was carried out on a 5 x 5 in grid. This dense grid provides an exhaustive data set of the real terrain against which data subsets can be compared for the various interpolation procedures and volume calculation. This provides an interesting insight into the influence of the number of data on the estimation error. Univariate statistics were used to compare each data subset and the exhaustive dataset. Ordinary kriging on the data subsets followed by contouring was carried out using Geoeas and Surfer software respectively. A subroutine written in C provided the link between the files generated in Geoeas and subsequent contouring routines embedded into the Surfer package. Omnidirectional and directional variograms were modelled defining the parameters for kriging estimation using Geoeas. Different variogram models were checked through cross validation prior to kriging. A comparison between the magnitude of the differences in volumes calculated with the different DTMs was attained. These final result indicates the sensitivity of the volume obtained to the number of data points. As the number of data points increases the estimation error decreases, but at some point there is no significant decrease in the final volume with the collection of additional data.

Jan 1, 1995

The program, WASTRT 70, was set up specifically to handle the design of tunnel liners and underground structures where inter- action between rock and structure significantly affects the design. It may however be used for any mass/R.C. structure capable of being simulated by straight line elements between modes and with loading restricted to nodes. The analysis system adopts typical elastic/stiffness matrix methods. Two main mass/R.C. design segments are utilized (1) Design of section depth based on maximum required stresses and optimum steel/concrete ratios. (2) Design of reinforcement for a given section depth with concrete stresses given for mass and water code structures. Each design segment covers shear, minimum principal stress on ~ , heavy compression as per code (columns), heavy compression one-face steel (tunnel liners), tension and water code requirements for all moment/thrust/section depth ratios on rectangular sections.

Jan 1, 1976

In line with mining operations throughout Australia, Western Mining Corporation Limiter' is striving to increase productivity by intro-ducing mechanized mining techniques wherever possible. Kambalda Nickel Operations' (K.N.O.) largest operating nickel mine, Long Shaft, is currently introducing mechanized cut and fill methods which must provide flexibility to cater for an orebody that variesconsiderably in width, both along the strike and up dip.This has resulted in modifications to the previous approach to primary level develop-ment, and intermediate stope development, and in the type of development and production equipment being employed. Electric-hydraulic diesel jumbos and diesel loaders have now been mated with conventional rail equipment and production airtrack machines are being utilized.The transition to mechanized methods is in its preliminary phase and is being monitored closely to ensure any productivity gains are not offset by a substantial drop in mine grade. The precise method ofmechanized mining has not been finalized and selective methods will be used, according to the ore width and ground conditions, which vary throughout the mine.

Jan 1, 1985

By Enever J, Walton R, Wold M

Photoelastic and equivalent material model ling techniques for studying stresses and defor- mations and modes of failure in geological and engineering structures are described. The appli- cation of these techniques to the solution of tunnelling design problems is outlined. Models may contain heterogeneous components to simulate geological and man-made structures and may be two- or three-dimensional. Prototype construc- tion procedures and time dependent behaviour may be modelled. Examples of recent model studies carried out for the design of underground railway tunnels are given. Development of photoelastic and equi- valent material modelling techniques and facili- ties at the CSIRO, Division of Applied Geomech- anics are described, including a biaxial and triaxial frame for testing large scale two and three dimensional equivalent material models and components of full scale prototype structures.

Jan 1, 1976

By Lyman GJ

Systems for the routine on-line determination of ash content of process streams in coal preparation plants and handling systems have been in use in Australia for over four years. More recently, monitors for on-line moisture measurement have been developed to complement the ash measurement function. The technology for these systems is reviewed briefly. The development of reliable ash and moisture monitors has made the implementation of automatic systems of coal quality control practical. The emerging philosophies of automatic control in Australian preparation plants are examined with particular emphasis on systems involving dense medium circuit regulation. Related developments in flotation control and coal sorting are noted to complete this overview.

Jan 1, 1987

By Whittaker B. N, Reddish D. J

The rockbolting method of support is employed widely in several countries in different of mines. Hard rock mines use this method extensively. Soft rock mines, such as coal mines, have employed standing supports (steel sets) as the main method, although some countries such as the U.S.A. and Australia have preferred rockbolting. There is increasing interest in extending the rockbolting method in coal mines. The application of rockbolting techniques in an industry which traditionally has not applied such techniques, has required the development of a systematic design approach. This design approach uses extensive monitoring, to asses the viability of the support system in differing conditions. Currently at a number of new and existing mine developments in the U.K., rockbolting is being successfully applied. Although, inevitably some localised geotechnical problems have been encountered and have needed to be taken into account. The effect of faulting on roadway conditions is discussed in this paper and a design approach has been applied using a numerical analysis method, namely the Finite Element Method. The results presented in the paper serve as a useful guide to roadway support designers, and in particular the role played by different bolts in a range of conditions.

Jan 1, 1992

By Beech-Jones J. M

At Port Latta in Tasmania, Savage River Mines operates vertical shaft furnaces for the firing of pelletised magnetite concentrates. At times the temperature profile of the furnace has changed markedly, necessitating the- burning of greater quantities of fuel to maintain good pellet quality. A study of the oxidati=of magnetite concentrates was under- taken because this exothermic process supplies much of the heat required to indurate the pellets. Using the thermal analyses methods, different magnetite concentrates from Australian and overseas were heated in air under identical conditions, to compare rates of oxygen uptake and of heat release. In addition, a compari- son was made of the oxidation behaviour of different particle size fractions of a selected concentrate. Particle size analyses, x-ray diffraction and dilatometer tests were used to aid inter pretation of the thermal analysis traces. The investigation emphasized the importance of particle size and ferrous iron content in determining' oxidation rates from the commencement of heating.

Jan 1, 1974

This paper discusses how the i-kon TM Digital Energy Control System may be deployed by miners of massive underground orebodies to deliver significant advantage in terms of safety, cost and environmental compliance. Digital Energy Control offers an exciting opportunity for mine operators to review their blasting and mining practice to gain the most advantage from this new technology.

Jan 1, 2000

By D Cotnoir, Q Liu, D Richard, M Ourriban

The difficulty in fine particle flotation has been attributed, among other things, to a low bubble-particle collision efficiency. Many technologies have been developed which aim at increasing bubble-particle collision efficiency, either by generating micro bubbles or by enlarging particle sizes. However, commercial applications of these technologies are limited. Over the last five years COREM has been actively testing fine particle froth flotation technologies with the objective of commercialisation. Several fine particle flotation technologies, such as dissolved air flotation, electro-flotation, floc flotation, selective flocculation-flotation and carrier flotation, were tested on both single minerals and ore samples in order to identify the reasons that prevented these technologies from being used on a commercial scale. It was found that the two most noticeable factors that prevented the successful application of these technologies were: Mechanical entrainment of fine gangue minerals. This was a general problem in fine particle flotation, but was aggravated by these technologies that either generated micro bubbles or enlarged the sizes of hydrophobic particles. Oxidation of (sulfide) minerals that resulted in hydrophilic oxidation product coatings. The oxidised fine particles could not be recovered by these fine particle flotation technologies effectively. Solutions to the two problems, ie gangue entrainment and fine particle oxidation, were proposed and tested. It seems that polymeric depressants with both depression and flocculation functions could significantly reduce gangue entrainment, and hydrophilic surfaces of oxidised fine particles could be modified by high intensity conditioning or controlled sulfidisation, thus increasing the recoveries of fine valuable minerals. The improved fine valuable particle flotation and reduced fine gangue entrainment along with fine particle flotation technologies resulted in much improved flotation separation of fine particles.

Jan 1, 2005

The introduction of large diameter drill holes and mass firings in underground metalliferous mines has led to an increase in the number of reported sulfide dust explosions in Australia and overseas. Adaptation of the coal mining technique of using limestone to inhibit or prevent dust explosions has not been entirely successful as the development and inhibition of a sulfide dust explosion is somewhat different from that of a coal dust explosion. Tests were carried out on two pyritic ore samples, sulfur contents of 41 and 36 per cent, in 8 and 20 litre explosion chambers to evaluate the effect of the addition of limestone on the maximum explosive pressures developed and rates of pressure rise. Significant values were obtained in both chambers with dusts containing 60 per cent ore and 40 per cent limestone. The percentages of limestone required to inhibit the pyritic dusts were considerably higher than those values generally accepted by the mining industry and the current methods used to inhibit sulfide dust explosions should be re-evaluated.

Jan 1, 1986

By Sorokin M, Komkov A, Fyodorov A

The Vanyukov Process is a high-intensity smelting system that has been proven over the last 20 years for various metallurgical operations including the smelting of copper, nickel, copper-zinc, antimony concentrates, municipal waste treatment and pig-iron production. Extensive pilot plant tests on copper and copper-nickel concentrates have provided information for the design of the commercial furnaces. The thermodynamic analysis, design idea and the data obtained from commercial furnaces have shown that Vanyukov Process would be the best choice to smelt copper-nickel and nickel sulphide concentrates as well as oxide nickel ores.

Jan 1, 1996

By Preston JC, Richards DJ

A multicommodity exploration programme was mounted in the 1970s by CRA Exploration Pty. Limited over a major part of the southern Murray Basin in Victoria. Commodities sought were brown and black coal, gold, uranium, diamonds, titanium and zirconium rich heavy minerals, and base metals. An area of 40 000 km2 was held under exploration licences by the Company. Exploration techniques used were literature research, airborne magnetics and gamma ray spectrometry, drilling, and geophysical well logging. Targets were defined in both the Tertiary basin sediments and the underlying Palaeozoic sedimentary and igneous rocks. Although exploration is continuing, large resources of brown coal and low grade titanium rich heavy minerals have already been discovered. Exploration for uranium was abandoned in accordance with statutory requirements. The search for significant resources of the other commodities has not been successful.

Jan 1, 1986

This paper is based on studies made intermittently from 1937 to 1950. Its object is to describe the surface geology and the tin lodes, and to relate the lodes to the structure of the field.PREVIOUS REFERENCESR L. Jack made his first report on the field in 1880, but his principal report was made in 1883. W. E. Cameron described the Great Northern lodes in 1904. Numerous later reports on various mines were made by L. C. Ball, J. H. Reid and C. C. Morton, the most important of which were on the Black King, Good Friday, St. Patrick and the Great Northern Gully Shaft.GENERAL GEOLOGYJensen maps the Herberton area as part of a granite massif intruding rocks of two ages, the Younger Metamorphics of Silurian-Devonian age, and the Older Metamorphics of Older Palaeozoic age. The distinction is apparently based on lithological data. The Older Metamorphic rocks occur as inliers in the granite massif to the west and east of Herberton (Fig. 1).The area described consists of granite traversed by numerous dykes. West of the area, approaching the Older Metamorphic rocks, the granite becomes finer grained as if chilled towards its contact, and the dykes more numerous. To the east, passing from the Nova Scotia mine to Mount Lavery there are numerous dyke rocks, but the outcrops are poor and knowledge of the geology indefinite. The area is the main tin-producing area. To the west there are comparatively small tin lodes in the granite, and the "Copper Firing Line" occurs in the Older Metamorphic...

Jan 1, 1951