Search Documents

Entry of personnel under a vertical raise bored hole is not standard practice in Australia. Where access is required below a rise, mining operations must be confident that they understand the capacity of the ground control specified and installed. Physical modelling was conducted on Callie mine to evaluate the performance of 5 mm steel wire weldmesh secured to the base of a vertical raise bored hole of 1.4 m diameter. Joint orientation data was used with Unwedge to calculate a series of potential wedges likely to form within the rise. The mass of the most likely wedges were then replicated by collecting rocks in 5 kg increments (¦10 per cent), which were allowed to freefall onto installed mesh at the base of a 40 m vertical rise. The results indicate that two sheets of mesh can retain a freefalling rock of at least 20 kg mass although rupture of strands can result. This paper outlines the test conditions, expected results based on theoretical calculations and actual outcomes of the testing.

Nov 25, 2010

Beaches contain the residue of eroded rocks which have resisted weathering, and it is common to find in all beaches some of the harder, heavy minerals. The natural sorting action of waves and winds tends to concentrate the heavy minerals into banded deposits.The value of such deposits is extremely variable. Even amongst the more concentrated deposits, the principal minerals, in the vast majority of cases, are magnetic, titaniferous magnetite and other forms of iron oxide, which, in the present state of mineral economics and technology, are of little or no value.Valuable minerals of fairly common occurrence in beach sand deposits are rutile, zircon, ilmenite, monazite and chromite, and each of these minerals, as well as others of less common occurrence, is obtained from beach deposits in various parts of the world.Along a stretch of 300 miles of coast from Coff's Harbour in New South Wales to North Stradbroke Island in Queensland, occur unique concentrations of heavy minerals. The principal minerals which occur are rutile, zircon and ilmenite, and for some years these deposits have contributed half to three-quarters of the world's consumption of rutile and zircon 1, ,2. The only other notable beach sand concentrations in Australia are at a number of places in the southwest of Western Australia, where deposits containing highgrade ilmenite are being developed.

Jan 1, 1950

Project developent proceeds by increasingly detailed studies addressing overall project returns through an analysis of the substance, risks and costs associated with the following elements: ò Reserves ò Mining ò Processing ò Infrastructure ò Environmental Impact ò Product Market Computer-based expertise has a potential to ò Capture perishable expertise, making this available for shared access and so reducing the cost of human experience ò Consolidate know-how for optimising process operations, bringing consistency of judgement and advice to decision- making by making the rules, facts and preferences explicit ò Allow assignment of the basis and authority of decisions, so experts can pass routine expertise down the line, freeing their time to generate more. ò Force a review of expertise when creating the knowledge base.

Jan 1, 1989

By Dunlop GA

Pilot Plant confirmatory testing of the treatment route developed in the Metallurgical Laboratory is an essential factor in the development of complex ore bodies. Objectives should be well defined to permit the efficient planning and cost effective operation of the pilot plant project. The primary objective for the pilot plant should be to confirm the viability of the developed flowsheet on a continuous basis, examining only major variables such as ore types, quantum changes in grind, comparison between bulk and sequential flotation circuits, use of flotation columns, evaluation of autogenous grinding and production of samples of concentrates for market evaluation. Secondary objectives may include the collection of engineering design data and the production of a comprehensive report to Bankable Document standards to provide technical support for capital financing. The complexity of the ore body and the scale of the final operating project together with the pilot plant objectives will determine the extent of the pilot plant operations. The level of expenditure associated with a pilot plant can vary, in total cost and as a percentage of the total development capital investment required to take the prospect from exploration to a producing mine. Factors contributing to expenditure are discussed. Associated with cost considerations is the level of confidence mining company investors can have that their capital investment will return dividends.

Jan 1, 1990

By Robinson KJ

Education in Australia now has to respond to a very wide political and policy agenda. The political emphasis is upon increasing participation and retention rates with a view to greater graduation rates in `high-tech' disciplines. There is an implied linkage between `education' and `economic well-being'. Our argument is that equalitarianism in education tends towards mediocrity. In this context many Geoscience educators view the future with pessimism. The argument is that science has been `sold short' and needs revitalising. We contend that Geoscience coursework should be a feature of both secondary and tertiary education in Australia. To this end we propose six policy initiatives to increase the content of Geoscience in education programmes.

Jan 1, 1989

The addition of cement to underground backfill at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited, Broken Hill commenced in 1967. A deterioration in metallurgical performance at each concentrator occurred as a result, with increased loss of lead and zinc to residues. Investigations to determine the reasons for this problem and methods to counteract it have been undertaken. This paper outlines the effects of cement on lead-zinc beneficiation at Broken Hill and presents an interim report on attempts to overcome the metallurgical deterioration.

Jan 1, 1971

By P Mulvey

"Currently mine process studies and geochemical waste characterisation are considered as two interdependent studies, necessary for the development of the mine and inclusion in the environmental impact statement (EIS). Geochemical waste characterisation will utilise the simulated tailings produced by the mine process studies team to understand the behaviour of the tailings, but the two teams rarely integrate these to develop a coherent and agreed final design.Thorough mine waste geochemical assessments can develop processes to minimise environmental harm, resulting in substantial savings in the decommissioning, closure and rehabilitation phases, and may also be able to address changes in mineral processing methods that can result in substantial savings in process inputs, or even recovery of metal concentrates.Based on geochemical waste characterisation, the full cost of waste management can be calculated and incorporated into the costing of milling.  This allows for a more effective evaluation of the metallurgy.  A number of examples are presented in which substantial improvements have been made from the collaboration of both the metallurgical and geochemical teams during planning and the metallurgical team and environmental team during operations.*This paper is only available for individual download. It is not included in the conference proceedings*CITATION:Mulvey, P, 2013. Optimising metallurgy at the planning stage to minimise environmental impact - a feedback loop from geochemical waste characterisation, presented to MetPlant 2013 Conference (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

Treatment of Gold-Bearing Oxide High-Clayish Ores The analysis of modern state of treatment technologies of gold-bearing oxide high-clayish ores showed that the main method applied both in Russia and abroad is sorption leaching and heap leaching with preliminary granulating. The use of any of these processes depends on many factors including average gold grade, site and area of a deposit, clay content and etc. The two processes are often used at the same deposit. In this case, rich ores are treated according to a plant technology, poor ores and ores with cut-off grade are treated with heap leaching. Both technologies possess their own advantages and disadvantages. A plant technology is characterised by high recovery with higher capital and operating costs at the same time. Lower recovery during heap leaching can be attributed to an unstable quality of ore granulating due to both technological and weather conditions. In case of poor high-clayish ores, the use of a combined ore treatment is possible and profitable. It includes the ore disintegration and a clayish fraction treatment by using a heap leaching. In this case, capital and operating costs reduce in comparison with a plant technology and the recovery increases in comparison with heap leaching. Sometimes it reaches a plant recovery. These ores possess special features. As a rule, gold is associated with ore fraction, so it liberates readily from the association with ore ore-forming minerals even with relatively coarse grinding explain their high solution velocity in a hydrometallurgical cycle. Clayish ores are characterised by high sorption activity to gold cyanide complexes as well as extremely low velocity of filtration and thickening of slimic pulps at the same time. The paper describes the options of oxidised high-clayish ores treatment, such as, a plant technology (PIP and CIP process), heap leaching and a combined technology (disintegration, heap leaching of a crystalline fraction and sorption cyanidation). The obtained results were used when selecting a treatment technology and during construction of a plant for oxidised high-clayish ores treatment.

Sep 13, 2010

Conventional hand drawn isopach maps of the cover of the Bulli Seam are too eomplex for use in the delineation of large domains of similar cover. Isopach maps prepared from trend surfaces fitted to the cover data are much simpler in form and so provide a convenient method of delineating broad domains of similar cover.

Jan 1, 1968

By Y Zhu, W Liang, P Knights

In recent years, Chinese companies have invested billions in Australian mineral exploration, development and processing. In 2008 - 2009 alone, the Foreign Investment Review Board approved $26.4 B of investment. Much of this investment has been by merger and acquisition (M&A) of Australian resources companies. This paper sets out to investigate how Australian CEOs perceive the cultural and institutional challenges in operating Australia mining companies recently acquired by Chinese interests. HofstedeÆs cultural dimensions and institutional theory from management science were used to develop a structured questionnaire, which was subsequently used to conduct telephone interview of the CEOs of six recently acquired mining companies. Analysis of the survey results indicated that, in all cases, few changes were made to the operational management of the Australian companies post-M&A. The three major benefits for Australian companies as a result of the M&A are the ability to; access long-term debt at lower cost; secure finance for growth plans in financially volatile times; and maintain existing management structures. Some perceived negatives involved longer and more convoluted decision-making as a result of Chinese state approval required for investment decisions. The study identified building æGuanxiÆ and an aversion to losing æfaceÆ as important cultural learnings for Australian CEOs. Maintaining effective communications is regarded as key for successful cultural integration.CITATION:Liang, W, Zhu, Y and Knights, P, 2012. Cultural challenges in Chinese/Australian mining mergers and acquisitions - A CEOÆs perspective, in Proceedings International Mine Management 2012, pp 251-260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

The Northland region of New Zealand has a complex geological history which has long been the subject of considerable controversy. Small mineral deposits have been discovered in the past, and some have been mined. Except for aggregates and very high quality china clay, mining is virtually nonexistent at present. Mercury mining is proposed from small deposits in the Kaeo area. Intensive exploration for epithermal precious metals deposits in the past seven years, combined with some recent geological mapping undertaken by the Geological Survey and University thesis students has added greatly to an understanding of Northland's geology. Mapping of the Whangaroa-Kaikohe map sheet at a scale of 1:100 000 by Brown and Laurenson Limited has enabled new geological information to be collated for the first time since 1961, when the last geological map was published. The 'Northland Allochthon' is now observed to be a series of four or more thrust sheets each containing predictable formations. High angle faulting contemporaneous with overthrusting has modified the thrust sheets, and established a series of horsts and grabens. The Pirau Fault is considered to be a major earth fracture.

Jan 1, 1987

The mechanization of the coal industry in New South Wales involved the introduction of large face and transport machines. The trend is towards still higher capacity units with .greater horsepower and it became apparent that a potential risk of damage to the hearing of workmen existed. In order to assess whether the sound levels were SUfficiently high to impair the hearing of workmen a sound level survey of all major operations in the industry was carried out by the Mining Engineering Division of the Joint Coal Board.The results indicated ·that the operations could be classified into three categories of risk, probably hazardous, of doubtful hazard due to the intermittency of the operations, and of low hazard.Legislation has subsequently been enacted requiring the wearing of hearing preservation aids in some of the probable risk operations.

Jan 1, 1974

The Misima open pit gold mine is a 20Mt per annum operation. Blasthole drilling is used to sample all material at a uniform 5m square pattern, and representative sub- sampling of the blast holes enables assay samples to be collected over the full 10m bench height. Samples are assayed for gold, silver and copper at the Company's laboratory at the mine site and the assays are provided to geologists as a written assay report and on floppy disc. Surveyed blasthole locations and assay results are transferred via personal computers (PCs) to a SUN mini-computer where results are stored by bench, blasthole assays are kriged, and plot files are created. A geologist selects grade boundaries from the kriged data, adjusting the boundaries towards the raw blasthole data where hard boundaries are recognised. Surveyors peg the resultant boundaries in the pit using a system of colour-coded pegs to display the different material types. A daily plan also shows boundaries and face positions.

Jan 1, 1991

The Stawell Goldfield, the westernmost of the main Victorian fields, has produced over a million and a quarter ounces of gold from one and three-quarter million tons of ore. The lodes are quartz reefs and sulphide bodies occurring in sediments of lower Ordovician or upper Cambrian age. The lodes are confined to a relatively narrow suite of weak rocks lying between stronger ones above and below and there is a definite relationship between fold structure, pitch and strength of folding and ore.LOCATION HISTORY AND PAST PRODUCTIONThe town of Stawell, situated 150 miles north-westerly from Melbourne on the main railway and road to Adelaide, is the most westerly of the main gold areas of Victoria. Alluvial gold was found at Pleasant Creek (now Stawell West) in 1853 and the usual "rush" followed. Numerous alluvial leads, some surface, others buried under up to 100 ft. of Tertiary sediments were worked. The alluvial gold was soon exhausted, but in 1857 gold-bearing reefs were found on the slopes of a prominent ridge on the northern edgeof the present town. Early reef mining was by small working parties mining to shallow depths only and treating their ore at public crushing plants. Some of the early returns were very high grade. The next stage was the amalgamation of claims and the formation of companies, with their own treatment plants. This stage continued till the last mine closed in 1921. These companies had, by present standards, small holdings and far too many shafts were sunk, resulting in less efficient prospecting and operation.Since 1921 there have been one or two small scale attempts to revive mining but without success. Of recent years Gold...

Jan 1, 1960

This paper examines some of the fundamental economics of mining - in particular, for optimisation studies, for production rate determination and for reserve estimates.It includes introductory discussion on the principles as to how economics drives mining investment decision-making, applicable to the optimising of pit shapes and production, or truck fleets, or any other part of the mine.The main part of this paper looks at the decision to start-up a mine and why the 'optimum' production rate to start-up a mine is not the point of lowest cost according to traditional discounted cash flow (DCF) analysis. The optimum production rate is usually substantially less than this rate. The paper recognises the difference between typical mining investments and investments in other industries that do not have the unique characteristics of mining and the problem of uncertainty resolution. It examines the marginal revenue effects, the marginal cost of capital and the value of a real option to expand pending uncertainty resolution as determinants of optimum initial production rates.The final part of this paper looks at applying these principles to renewable and non-renewable resources. It examines mine life and reserve estimates from an economic perspective.

Dec 6, 2010

From March to May of 1963, the Bureau of Mineral Resources carried out an experimental aeromagnetic survey at Cobar, New South Wales, to field test a proton-precession magnetometer installation in the Cessna aircraft VH-GEO. The Cobar area was chosen as considerable information was already held on the Earth's magnetic field there, which was known to provide a range of anomalous areas that are not excessively disturbed.A procedure for survey flying and methods for processing data were developed during the survey. Contour maps of the aeromagnetic results were produced in the field. The experimental survey was successful in outlining magnetic anomalies in detail.INTRODUCTIONSince 1951 the Bureau of Mineral Resources, Geology and Geophysics (B.M.R.) has carried out an airborne magnetometer exploration programme with DC.3 aircraft carrying fluxgate magnetometer equipment. Recently a proton-precession magnetometer was developed by the Design and Development Group of the B.M.R. for observatory use. One unit modified for airborne use was installed in the Cessna light aircraft, VH-GEO. The Cessna was modified structurally to take the magnetometer, associated bird, and winch gear.The proton-precession magnetometer has many good features.1. It utilises the transistor and associated solid-state devices in its electronics, and hence is light and small.This is the basic feature allowing its installation in a light aircraft. The transistor circuits have a high reliability factor and owing to the card sub-unit...

Jan 1, 1964

Demonstration of Solid-Liquid Separations Using Recycled Supernatant that Contains Temperature-Responsive Polymer The effective use of recycled supernatant that contains temperature-responsive flocculant is demonstrated for solid-liquid separations. The recyclability of poly(N-isopropylacrylamide) (PNIPAM) of several different molecular weights and a 15 per cent negatively charged derivative are compared. Batch settling tests of a-alumina suspensions are first conducted at 50¦C, with a subsequent 25¦C period, after which the supernatant is harvested and used to flocculate subsequent suspensions. Using this procedure consecutive separations are obtained with the repeated recycling of uncharged PNIPAM containing supernatant. Batch settling tests indicate that hindered settling rates increase with molecular weight of PNIPAM. Adsorption studies indicate that strong adsorption of PNIPAM onto alumina occurs with PNIPAM at 50¦C and that significant desorption occurs after cooling at 25¦C. However, the extent of desorption decreases with molecular weight resulting in low amounts of PNIPAM for recycling and poor settling behaviour when high molecular weight PNIPAM is recycled. Little recyclability was evident using the negatively charged PNIPAM. On the basis of these findings a recycling-thickener apparatus that uses low molecular weight uncharged PNIPAM is proposed.

Sep 13, 2010

The granulites and related "dry" igneous rocks tend to be passed over during exploration for metals. Preliminary data show that high trace concentrations of eu, Ni, and other metals of economic interest are commonin orthopyroxene and some of the other granulite minerals. During retrograde metamorphism of granulites, pyroxenes are converted to amphiboles or phyllosilicates, and significant quantities of metals are released andbecome available for incorporation into new mineral phases, or may be transported elsewhere. S-rich scapolite is the normal scapolite of granulites. Its retrogression to secondary plagioclase provides much S which scavengesCu and Ni, from pyroxenes undergoing retrogression, thus producing ore-fluids. A full analysis of a scapolite with 5·10 per cent SOg is given.Beryl is unstable in granulites but the rare Be mineral taaffeite (Al4Mg(Be, FeII)Os) with 5·50 per cent BeO occurs in central Australia as a pale green tabular mineral easily confused for chloritoid in hand-specimen.Metamorphic differentiation and mobilization of primary ore concentrations are major factors controlling their post-granulite attitude and grade.Zones of retrograde metamorphism are commonly found cutting or engirdling granulite terranes. As the "volatiles" for the new hydrous minerals of many of these zones are of deep-seated origin and may be juvenile, sulphide mineralization in them may also be of mantle origin. However, it is likely that much of the metal content could be scavenged from the granulites as they are down-graded by juvenile volatiles. Major Bouguer gravity anomalies delineate some granulite terranes (e.g. Fraser Block, Western Australia), and are related to deep-seated geosutures and mantle disturbances.Many granulite terranes are linear belts and appear to be welded to older cratonic blocks.

Jan 1, 1969

By S Hu, P Ni, H Xu, P Chen

Indosinian (T) orogeny amalgamated the Mongolia-Xingan fold zone, the North China continent, the Yangtzi platform and the SE China fold zone into a unified continent. The early to middle Yanshanian (J-K1) orogeny created a Cordilleran type active continental margin in East Asia, reactivated the consolidated East China continent, and generated a large amount of granitoids, calc-alkaline volcanics and W, Sn, Mo, Cu, Au, and U ore deposits. The late Yanshanian (K2) orogeny began a transition to the western Pacific type continental margin. A tensional environment led to the development of peralkaline magmatism and tne formation of continental basins with red beds. The Himalayan (Tr-Q) orogeny was characterised by a backarc spreading and rifting regime. The dominant magmatism was continental basaltic.

Jan 1, 1995

The Karangahake gold-silver deposit is located 11 km west of Waihi in the southern part of the Hauraki Goldfield. Historically it was the second largest bullion producer in the goldfield with a past production (1882 - 1944) of 126.712 tonnes of gold-silver bullion (Au:Ag ratio of 1:3.3) from 1 142 315 tonnes of ore grading 27.4 g/tonne gold equivalents.

Jan 1, 1987