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By P G. Rutherford, A W. McOnie

A volcanic sequence is described from the Golden Cross Mine, Waihi, New Zealand. The sequence includes seven lithostratigraphic units comprising flow and pyroclastic units of Coromandel Group andesite and dacite and overlying Whitianga Group dacite and rhyolite which is intruded by the Golden Cross dacite porphyry and rhyolite dykes. The sequence is mineralised and is unconformably overlain by two post-mineral units, the lacustrine Waitekauri beds and Omahine Subgroup andesite.   Detailed structural analysis of mine data has identified four deformational events (D 1-D4) and related these to the gold-silver mineralising events. Faulting was coeval with the mineralization and directly controlled the development, localisation, style and geometry of the ore shoots. Mineralization developed in competent lithologies where dilation occurred during faulting. The Empire Fault is the master shear which controlled fluid flow. Mineralised veining developed in response to tectonic pulses occurring at slightly different stages as represented by the underground Empire vein complex and the open pit vein array. The mineralising events culminated with the deposition of barren calcite veins. Post-mineral movement along the Western Boundary fault appears to have offset the orebody.

Jan 1, 1995

IN this paper an attempt is made to describe the sluicing operations on the tin fields of north-eastern Tasmania. No claim is made to completeness, for much of the ground has already been covered, and nothing is to be gained by needless repetition. On this account some portions of the subject have obviously received but attention in order that others may be rather more fully dealt with; for instance, referring to the accuracy of various methods of valuing alluvial deposits, particulars of efficiencies, and water duties on both overburden and drift; also, the system of recording water distribution, &c. The plans of the tin-streaming shed, sluice and feed race, and overburden tail-race represent types of the most modern design.GEOLOGY. The principal alluvial dcposits being worked at the present time are situated either in the ancient or modern bed of the Ringarooma River or its tributaries. This river flowed in a north-easterly direction, receiving numerous tributaries on either bank...

Jan 1, 1910

By Hindmarsh J. W, McCoy A. E R

Instantaneous outbursts of coal and gas have occurred at various times in several working districts of Metropolitan Colliery, N.S.W.They have occurred in headings only, under both hand and mechanised conditions, and with seam gas ranging from mainly methane to nearly pure carbon dioxide. A modification of inducer shotfiring using a shear cut was introduced in 1955, and in 1961 full face firing both to a machine cut shear and off the solid was introduced. The current series of outbursts -1961 to 1963 - has been induced under these systems with full control of the time of outburst, but without prediction, and with some disappointing production features.Various aspects of current conditions and practices at Metropolitan are considered singular, such as the coarse granulometry of outburst coal, the prevalence of floor heave, the absence of strong structures at outburst sites, the possibility of outburst at any stage in pillar formation up to the last few yards, the effect of rate of advance on outburst occurrence, and the mildness of many outbursts experienced.It is concluded that inducer shotfiring is a reliable control but it suffers by comparison with outburst-free conditions, and that control by preyention would be preferable.INTRODUCTIONThe phenomenon of instantaneous outbursts of coal and gas has been described in detail previously (Hargraves, 1958). Briefly, it is a combined gas and stress hazard of deep coal mining, usually occurring in virgin work and during active face advance, when coal and seam gas burst from the face into the workings.Instantaneous outbursts have occurred sporadically at Metropolitan Colliery, N.S.W., since 1895. Early outbursts were recorded as firedamp and recent outbursts are of blackdamp.Mining methods used have been conventional hand work, with progressive and relatively complete mechanisation over the past 25 years to substantially conventional...

Jan 1, 1964

By Hoskings R

Conceptual studies of the run of mine stockpiling and reclaiming requirements at Thiess Bros Pty Ltd South Blackwater coal mine commenced in 1975.Final selection of equipment was made in 1978 and the equipment was commissioncd in June 1979. Equipment selection was made after extensive investigation and visits to existing facilities throughout the world.The equipment selected is described and compared with the alternatives. Foundations were designed to minimise clean up effort and to ensure stabilily of equipment under design wind loading without storm bays. Programmable logic control enables the stacking and reclaiming facility to provide a blended feed to the coal preparation plant.

Jan 1, 1981

THE Yallourn chimney has aroused interest, as it is, for the time being, the tallest structural erection in Australia. Its height was not decided on, however, with the object of breaking records, but is purely incidental to the purpose which it serves. Theboiler plant at the briquetting works (first instalment) consists of five Babcock and Wilcox land-type water-tube boilers, each of 4510 sq ft. heating su:r£ace and 225 sq. ft. grate area in the form of step grates. Four boilers will normally produce 73,000 lb. of steam per hour at a gauge pressure of 265 lb. and a temperature of 6500 F., the fifth boiler being a reserve. Each boiler will consume about 100 tons of Yallourn coal per 24 hours. Provision is made for future installation of economizers, should it be found desirable. Designing for this condition, and allowing for a waste gas temperature of 3500 F. and an air temperature exceeding 1000 it was found necessary to have a draft of about 1.3 in. (water gauge) at the base of the chimney, and to deal with about 2000 cub. ft. of gases per second. Estimates were made of the cost of providing the necessary draught by means of fans and by means of a tall chill).ney. The annual charges of the two methods differed only slightly, and the tall chimney wasselected as being the more general practice in briquetting factories.Estimates were prepared for brick and concrete chiIlllleys. Yallourn bricks at that time were hand-made, and, while very suitable for domestic work, were not capable of withstanding high compressive stresses. The chimney design to suit these bricks thus required to be on very ample lines, resulting in high cost. Machine-made bricks from Melbourne would cost about £5 10s. per thousand on the site, with extra for radials, so that high cost again resulted. On the score...

Jan 1, 1924

The Kalgoorlie Tailings Retreatment Project (or "Kaltails") involves the reclamation and retreatment of approximately 50 million tonnes of gold tailing situated on the Golden Mile at Kalgoorlie, Western Australia. Tailing is reclaimed and retreated at the rate of 42 million tonnes per annum. The project is a Joint Venture between Poseidon Limited and Gold Corporation, with Poseidon being the major participant (90%) and manager of the operation through its wholly owned subsidiary Kaltails Mining Services Pty Ltd. The marginal nature of the tailing retreatment project dictated that a detailed feasibility study be undertaken. Extensive sampling and metallurgical testing of the tailing permitted the development of an optimum economic processing route. A sensitivity analysis undertaken as part of the feasibility study indicated the project to be very sensitive to gold price and unit operating cost variations, and relatively insensitive to capital cost variations.

Jan 1, 1990

The key to the successful debt funding of a new mining project, whether in economically established or developing nations, is the submission of a comprehensive feasibility study. The feasibility study forms the basis from which the resource banker can construct financial models which govern the amount of available funds, the conditions which control the supply of such funds and the time period over which the loan may be repaid. The bank will wish to ensure that the feasibility study is the best representation and confirmation of reality possible because this model is the basis of the loan security package. Thus the study will be vigorously interrogated by independent experts in all its elements including the ore reserve, mineability, metallurgy, operating and capital cost profile, environmental factors and management. A well constructed feasibility study, undertaken by well recognised and respected independent consultants can save the client company a great deal of real and opportunity costs especially in relation to project timing. Once constructed and operating, the mining project may face one or more completion tests in relation to the loans provided. The genetics of such tests often relate to either the ability of the operating company to become solely responsible for the repayment of the loan or to be rewarded by lower interest rates or some other mechanism. Strong professionalism, accessible records, good checking procedures and high quality, competent site management will greatly assist the client company passing these tests. A record of well established technical competence with its bankers may well assist a company in the establishment of a mezzanine loan for the early development of its next project, thus allowing an earlier return of dividends to shareholders.

Jan 1, 1995

When the Mining Bill came before the Victorian Legislature not so many months ago, the question arose whether mining managers required education, and to what extent. Some members of the House expressed themselves in a way which appeared to leave the impression that mining managers would be all the better if they were not brought up in a scientific school.To try and prove what we owe to science I will give a short history of colonial mining from the earlier period to the present time and compare results.I believe I am right in saying that South Australia is the pioneer colony in mining and to her belongs the credit of not dnly being the first mining colony, but also that her beginning turned out so successful, as the history of the Burra Burra copper mine will testify. At about the same time a little galena mining was carried on nearer to Adelaide, but as this did not prove a success and was only worked by tributing parties, little notice was taken of it.

Base metal sulphide mineralisation on the northern end of Great Barrier Island is spatially associated with hypabyssal intermediate to acidic intrusives, in transgressive structures in indurated, complexly deformed greywackes and argillites. Copper predominates in the mineralisation, with minor accompanying lead and zinc and also some gold and silver. However, in some cases lead or zinc may be the dominant constituent. The mineralisation is generally characterised by only narrow envelopes of weak alteration (propyliticassemblages dominated by chlorite and epidote) and with only minor amounts of quartz accompanying the sulphides, which form a cement in zones of hydraulic fracturing. There are two distinct structural settings to the mineralisation: at MinerÆs Head, in a structurally complex situation in a shell-like zone of crackling in hornfelsed greywacke, in association with both north- and east-striking fractures and rubble breccias associated with the apical part of a large intrusive; and in very narrow, but very strike-persistent, 1inear steeply-dipping fracture zones, exposed on the north coast and inland areas near Tataweka.

Jan 1, 1984

By Pupazzoni P. D, Meissner D. C

Incorporating an iron ore pelletising plant, a MIDREX'"' Direct Reduction Plant, and a mini mill, the conversion of iron ore fines to high- quality steel slabs in Western Australia is among the lowest cost routes in the world. The cost and availability of iron ore and natural gas, government support, and proximity to the growing Southeast Asian market all contribute to the competitive position of the area. Owing to the lead-time required, this is an ideal time to develop a new project to supply semi-finished steel to Asia for rolling to a finished product. A project contracted now will start up in about three years, when the market should have recovered.

Jan 1, 1999

By Creelman C. A

The removal of a horizontal piIlar between Nos. 9 and 11 levels (1,116 feet from the collar of main shaft) was successfully carried out by blast hole drilling, and, to the best of the authors' knowledge, this mass blast of 40,000 tons of ore (requiring the use of 7,150 Ibs. of explosive and 5,385 feet of primacord) was the first occasion on which a task of this magnitude has been carried out underground in an Australian mine.Blast hole drilling was introduced by this company approximately fifteen months ago at New Cobar Mine in sub-level stoping.This experimental drilling and blasting gave very valuable information as to the correct technique to be adopted when the final plans were being prepared for the removal of the horizontal pillar at New Occidental Mine.The dimensions of this pillar were approximately 15 feet long, and from 40 to 60 feet wide, and 65 feet in depth.The block of ore extended to 35 feet above the level and 30 feet below, the upper section being partially excavated to form the bell-hole floor and grizzly chambers used for drawing off the broken ore in the shrink stope above the No. 10 level.Description of Ore-bodyThe main ore-body is situated almost vertically in a well-defined shear zone at the junction of sandstone and slate, the sandstone forming the eastern and the slate the western wall.The ore-body consists of highly silicified slate (chert) sparsely impregnated with sulphides, containing a small percentage of copper and bismuth.The total length of the ore-body is approximately 450 feet, with a maximum width of 60 feet in the main section, which is about 200 feet long.This is the section shown in longitudinal and cross-section (Fig. 1).The ore-body is divided by a horse of mullock in the northern end into two legs, the eastern and western, which are approximately 250 feet long and averaging 25 feet in width.This ore-body is strong, hard and abrasive with extremely strong walls, an ideal proposition for open stoping and mass blasting.MiningIn all levels above No. 9 the cut and fill method of ore extraction was adopted. On Nos. 10 and 11 levels the shrinkage method was introduced with economical results, and no difficulty had ever been experienced with shabby or bad walls.Shrink stoping had been carried upwards from No. 11 level to within 10 feet of No. 10 level, when mining hazards developed, and instead of...

Jan 1, 1944

By B E. Hall, D B. Kahler

"'Optimisation' has become a catchcry among many mining companies looking to tell the market how mining businesses will be improved and shareholder value increased. Consequently, the term 'optimisation' has been adopted by many service providers as they look to assist mining companies in achieving their objectives. But the explosion of services and products being offered with the label 'optimisation' has created some confusion. Mining companies ask for help in 'optimising' and service providers offer their assistance because they have a product that has the word 'optimisation' in its title. This is of course an over-simplification, but not by much! The authors' discussions in recent years with both mining companies and service providers have uncovered a number of very different definitions of optimisation.This paper provides a framework for identifying the scope and approach of different mining optimisation products and services, particularly the distinction between optimisation of components of the operation and the business as a whole. The different types of business optimisation are discussed, highlighting the failings of the mining industry's typical approach of strategy selection (as opposed to strategy optimisation). Mining business optimisation is discussed as a wicked problem, with the implication of this on how strategy optimisation models should be used and what the objectives of a business optimisation study should be.Case studies are also included to illustrate how fully flexible strategy optimisation models have been applied to assist decision-makers understand the impacts of changes in one part of the operation on the whole mining and treatment process, from geological models to the sale of product to customers.CITATION:Kahler, D B and Hall, B E, 2016. Strategic decision-making in mining – business optimisation using flexible evaluation models, in Proceedings Project Evaluation 2016, pp 215–225 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

Factual data about the sedimentation in the Newcastle Coal Measures are presented. Data concerning the total coal measure sequence (isopachs, sand/shale ratio, and total coal thickness variation), data about three coal seams (Borehole, Dudley, and Victoria Tunnel) and data about interseam conglomerate units are discussed.From this data conclusions are drawn about the coal measure environment. The western edge of the coal basin, the Lochinvar Dome, although a high feature, was apparently stable during coal measure time. Despite its height it apparently supplied little sediment to the basin.The northern and north-eastern edge, which was unstable, supplied most of the coarse detritus (including the conglomerates) to the basin. The conglomerates show patterns of fluvial origin but after a period of "normal" variations in pattern they become restricted to two parallel zones evidently tectonically controlled. Deposition of conglomerates is episodic and separated by periods of coal formation when deformation was apparently slight. Formation of each of the three seams considered followed a rather similar pattern- each show development of thick coal around the basin edge and poor thin coal in the "axial" region of the present synclinal structure.Evidence of ill situ formation of some areas of the seams is discussed and periodic deformation of the basin during coal measure time is postulated.The unusual character of this coal basin, in particular the very coarse units, is stressed, despite the presence of many "normal "coal basin features.

Jan 1, 1970

A study of the accessory opaque iron-titanium oxide minerals of the Oiles Complex, central Australia, was an Important complement to an investigation of the magnetic properties of the Complex. These minerals constitute no more than 10 per cent of the rocks sampled, and generally less than 1 per cent of the ultramafic rocks ("magnetite" concentrations were not sampled for magnetic investigation).Titanomagnetite is the main opaque mineral present, although ilmenite exsolution has been widely developed. High-temperature oxidation of these produced mainly titanohematite, pseudobrookite and rutile. Both exsolution and high-temperature oxidation developed along specific crystallographic directions (along {111}), and in Irregular patches. Low-temperature oxidation is generally not well-developed, indicating the small degree of weathering in the rocks sampled.Although the Oiles Complex is layered, no apparent overall preferred orientation of the iron-titanium oxide minerals was observed, other than crystallographically controlled alignment of very fine grains within pyroxene crystals. Other textural features of the opaque oxides are restricted to symplectic intergrowths mainly with the ferromagnesian silicates.

Jan 1, 1971

By H Zhou, T Honeyands, M Zhou

In iron ore sintering, packing the granules onto the sintering strand to form a porous bed with optimum permeability is a complex dynamic process. The packed bed voidage is the key factor determining the flame front speed and the final sinter productivity and quality. Previous studies have found that granules are soft quasi-particles with a typical structure of nuclei with an adhering fines layer. The deformation of the adhering layer greatly affects the bed voidage during packing, which is related to the strength of the adhering layer and the force exerted on the granules. In this study, tablets simulating the particle size distribution in the adhering layer of granules were made for four single ore blends. Both the tensile strength and shear strength properties of these tablets were investigated as a function of water content by the uniaxial compression test and direct shear test respectively. The results of compression tests show that the adhering layer becomes weaker and more compliant with the increase of moisture. The most porous ore has a more rigid adhering layer than the other three tested iron ores at any given moisture content. In direct shear tests, the internal friction angle of the adhering layer ranged from 31° to 37° and varied little with the moisture content or ore type. The cohesion constant is around 1 kPa and is quite small compared to the stress applied to the granules during packing. Combined with the results of granulation and packing experiments, the influence of the adhering fines layer deformation on the degree of voidage loss is specifically discussed.CITATION:Zhou, M, Zhou, H and Honeyands, T, 2017. Tensile strength and shear strength properties of the adhering layer of granules in iron ore sintering, in Proceedings Iron Ore 2017, pp 117–112 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Y Öztas, S McKinley, T Baker

The Kisladag Mine, Turkey, is a large porphyry gold deposit which is mined by open pit methods. In operation for over ten years, Kisladag provides an excellent example of how attention to a geologic feature, namely hydrothermal alteration, became a very effective predictive geological tool for planning and operation. The alteration domains were initially used as a geological tool to assist with establishment of resource model domains and to guide delineation drilling, but they were soon recognised to be correlative to geotechnical characteristics (affecting pit slope angles) and metallurgical performance (heap leach recoveries). Recent developments in spectral processing allow the systematic quantification of complex overlapping alteration phases and have greatly improved the ability to rapidly define internally consistent alteration domains for geotechnical and geometallurgical purposes.Alteration at Kisladag comprises a central core potassic (K-feldspar-biotite) zone, a tourmaline-white mica enveloping zone, an advanced argillic lithocap on the deposit’s eastern side and an overprinting pervasive argillic zone. These alteration zones and their distribution were based initially on strictly qualitative, visual mineralogical logging of diamond drill core. With the need for more accurate and consistent identification of the alteration mineral suites, particularly the phyllosilicate phases, logging was augmented by systematic measurement of spectral data using a Terraspec instrument.Recently the Kisladag spectral database (over 85 000 readings) was reprocessed by the newly developed methodology (aiSIRIS™) that allows relative quantification of the spectrally-responsive minerals. Visualising this transformed spectral mineralogy at various mineral concentration thresholds using implicit modelling software (Leapfrog®) led to the creation of consistent mineralogical and alteration domains that are used for the definition of geotechnical and geometallurgical parameters. An implicit modelling workflow enables these domains to be easily updated as new data is collected while maintaining geological integrity of the model.CITATION:McKinley, S, Baker, T and Öztas, Y, 2017. Alteration at Kisladag gold mine, Turkey – a progressive study in geology, geotechnics and geometallurgy, in Proceedings Tenth International Mining Geology Conference 2017, pp 51–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Many mining operations are uncertain of what costs they should be achieving. The majority of cost estimates are based on historical costs that have added contingency factors. Historical costs are a valuable source of information but a more precise costing method is necessary. There are several alternative methods for predicting costs. A methodology which provides the best indication of the achievable costs is one using a standard inventory list and a bill of quantities. The model is termed a Basic Principles model and addresses basic design principles and engineering constraints.

Jan 1, 1990

Tin mineralization in both eastern and western Tasmania shows a spatial correlation with middle Palaeozoic biotite granites and adamellites. The range of composition of these granitic rocks is restricted with respect to Mg, K, and Na content. Because this compositional restriction is shown by granitic rocks from other tin provinces, the concept of a genetic relationship between these granites and the associated tin mineralization is reinforced, and similar concentration mechanisms may be involved.Gold mineralization is largely restricted to eastern Tasmania and in contrast to the tin mineralization is rarely spatially associated with the middle Palaeozoic granitic rocks, although most authors have suggested a genetic correlation with hornblende and/or biotite granodiorites.Although few analyses are available, the granodiorites that are spatially associated with gold deposits exhibit similarities to granitic rocks from gold provinces elsewhere. These features suggest a possible genetic relationship between gold mineralization and the granodiorites.The composition of granitic rocks may be used as an aid to exploration in delineating areas of potential tin and gold mineralization in granite terrains.

Jan 1, 1970

By Colwell J. B, Constantine A. E

A unique, regional grid of deep (12 - 14 second record length), seismic reflection and refraction data has been recorded by the Australian Bureau of Mineral Resources (BMR) across the offshore Gippsland Basin and parts of the adjacent Bass Basin, in southeastern Australia. These data have been combined with onshore mapping to produce a new model for the development of the Gippsland and adjacent Bass Strait basins. Overall, the Gippsland Basin contains up to 12 - 14 km of sediment in an ESE-trending depocentre bounded on its north and northwestern margins by a detachment ramp, and on its southern side by a relatively linear, listric fault system. The basin, together with the adjacent Bass and Otway Basins, appears to have formed as part of a linked, largely- strike-slip to 'transtensional' system, which started to extend through Bass Strait, probably during the latest Jurassic. Each of the basins developed by movement on a common detachment or detachment complex, which produced headwall extension at their western ends, in the areas now occupied by the Strzelecki Ranges, Otway Ranges - Torquay Sub-basin, and Robe Trough. Adjustments and reactivation from the mid Cretaceous of several postulated microplates in the region, largely in response to Tasman Basin rifting, gave rise to the wrench-related and compressional structures which form the major petroleum targets in the Gippsland Basin. However, the same process formed largely extensional stuctures in the Bass Basin. Our interpretation of the tectonic history of the Gippsland Basin leads us to the conclusion that there may have been several phases of petroleum generation and migration, and that potential petroleum traps appear to exist in the deeper section, in structures sometimes not reflected at the top or near-top Latrobe Group levels.

Jan 1, 1992

By G W. Wilson, M Aubertin

A desulfurised tailings cover was installed at the Detour Lake Mine in Ontario, Canada, to reduce oxygen penetration into the underlying sulfidic tailings. The cover ranges from one to 1.5 m in thickness and was intended to maintain high water saturation to reduce oxygen diffusion and consume oxygen by oxidation of the residual sulfide minerals. The tailings impoundment was instrumented to measure climatic parameters, water levels and water content profiles within the tailings and single-layer cover. One year of monitoring data was collected. Additional tailings samples were obtained for geotechnical and geochemical characterisation. The average grain size of the cover material was found to be coarser than the underlying tailings. Monitoring also indicated that air entry values of the cover material were lower than the tailings. Numerical modelling was conducted on the cover to predict water content profiles under varying climate conditions together with the depth of oxygen penetration and diffusive oxygen fluxes. Estimates of the diffusion coefficient and kinetic oxidation rates from field data compared well with values obtained by laboratory measurements. Numerical simulations indicate water saturations of less than 85 per cent can be expected under varying climate conditions. Predicted oxygen flux rates through the desulfurised cover over tailings with high acid potential indicate low flux rates reaching these tailings due to either consumption of oxygen by residual sulfur within the cover or saturation of the underlying tailings.

Jan 1, 2003