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The McArthur lead-zinc-silver deposit is of the stratiform type. It consists essentially of a mineralized bituminous shale sequence that incorporates tuffites, numerous graded beds, and isolated but massive slump breccia horizons.The principal sulphides are' pyrite, sphalerite, and galena. These occur mostly in the shales. The accompanying turbidites contain only minor mineralization.The geochemistry of the deposit has been investigated in relation to the stratigraphic column and mineralogy of the sediments.A sedimentary origin is proposed for the deposit. Volcanism, thermal spring activity, salinity, regional faulting, and climate are examined as possible factors that may have contributed to sulphide formation and which could be used as criteria for mineral exploration.The metallurgy 'of the McArthur deposit is discussed in terms of its geological history.

Jan 1, 1972

By K Heiskanen, R A. Grau

Gas velocity (Jg) measurements conducted close to the froth-pulp interface over the cross-section of a flotation cell reveal how efficiently the incoming air is being dispersed throughout the volume of the cell. Furthermore, measurements of Jg at deepest locations in the cell provide valuable information about air recirculation and dispersion conditions in the bulk volume of the cell. Gas velocity in flotation cells has predominantly been measured by a transient capture of gas in a graduated probe. In this project, a new sensor for measuring gas velocity in an on-line manner was developed. A probe is partially immersed in the flotation machine, below the froth-liquid interface. The probe is used to collect the rising air bubbles from the liquid phase. The liquid-froth interface is shifted into the probe under vacuum. A controlled vacuum is kept inside the probe. As air bubbles burst inside the probe, the excess of air is continuously removed from the probe via suction. The removed air is measured using a mass flow meter. The fully automated sensor allows us to continuously measure Jg at different location in a flotation machine. An experimental programme was carried out in a 10 cm diameter laboratory flotation column to determine the accuracy and repeatability of the automated sensor. The new sensor was used for evaluating gas dispersion conditions in a 215 litre transparent laboratory scale flotation cell. Gas velocity distributions along the radial and axial directions of the cell were measured over a wide range of operating conditions. The operating conditions in the cell were modified by altering impeller speed and air flow rate. Two different rotor-stator mechanisms were utilised to disperse the air in the cell, the MultiMix and the FreeFlow mechanism. In this paper, a description of the gas velocity sensor is given, and the results of the experimental work are discussed in detail.

Jan 1, 2005

Perhaps no aspect of the investigation of an ore-deposit is of greater importance to the mining geologist and engineer than a consideration of its geological structure. A thorough understanding of the type, size, shape, and arrangement of any ore-body is essential to the proper conduct of exploratory, developmental, and mining, operations. Significant as these remarks are' in relationship to ore-deposits in general, they become of paramount moment when a complex structure such as the Broken Hill Lode is in question. In this connection the use of the term "lode" as applied to the Broken Hill ore-bodies may terid to confusion of ideas among those not familiar with the field or with the literature pertaining thereto, by reason of the fact that it is generally understood that a "lode" is characterised by simple, tabular form, regular outline, defined walls, and persistent attitude. However, as the terminology is well established by common usage, itsretention appears desirable, and, for the purpose of this paper, the name "The Broken Hill Lode" refers to that complex unit which includes pre-eminently the famous ore-bodies exposed in the workings from the North Mine on the one extreme to the South Blocks (Zinc Corporation) Mine on the other.That the practical value of geological investigation, of the ore-bodies was realised by the Geological Sub-Committee of the late Scientific Society of Broken Hill is attested by the...

Jan 1, 1932

By Loo R

The Paper discusses the size and extent of in-pit dust suppression problems created by iron ore mining in the Pilbara region of Western Australia. Dust problems associated with drilling, loading, hauling and tipping are discussed indicating the large quantities of water which can be applied for dust control and attempts that have been made to rationalise this water usage to obtain maximum benefits from the applied water. The magnitude of the problem and the quantities of water involved can be appreciated when one realises that 275 000 tonnes of rock are moved on Mt. Whaleback each day and that there are 40 km of haulroad within the open pit. Initially dust suppression was limited to the spraying of haulroads by large water tankers. Now dust suppression is practiced during drilling and after blasting, wind blown dust is reduced by application, using water cannons,of large quantities of water to floor stocks prior to loading operations as well as by the installation of 16 km of automatically controlled fixed sprinkler reticulation on the main semi-permanent haulroads. The methods used to assess the water requirements for in-pit dust suppression are discussed and the extensive development testing used to evolve the present installations are 1. Environmental Superintendent Mt. Newman Mining Co. Pty. Ltd. Newman, W.A. 2. Chartered Consulting Engineer, Perth, W.A.

Jan 1, 1979

A large body of porphyry-type copper mineralization occurs at Panguna in southern BougainviIle. It is associated with the intrusion of quartz diorite/granodiorite into andesites, particularly with the contact zone. Metasomatism of both intrusives and andesite resulted in the formation of biotite pseudomorphing hornblende and the veining of the resultant biotite diorite and biotitized andesite by quartz-chalcopyrite veins with pink orthoclase and dark biotite selvages, respectively.The orientation of intrusives and veins appears to be controlled by premineralization fault-joint patterns in the intruded andesitic Kieta Volcanics.

Jan 1, 1968

The chief use of manganese ore is in the production of ferromanganese alloys for steelmaking. Manganese ores generally occur in tropical areas, which influences the type of treatment required. Present methods of treatment are relatively unsophist- icated but demands by customers for tighter specifications will necessitate the installation of gravity concentrator at many mines At present only limited tonnages of minus j in. product can be sold hence future development will centre around methods of producing an agglomerate satisfactory to the smelter.

Jan 1, 1969

Expansion of the B.H.P. Co. Ltd. mater ials handling facilities, at their Newcastle Steelworks, began in 1964 and continued until 1970. The present complex handles the annual iron ore requirement of some three million tons for the Sinter Plant and Blast Furnaces. Iron ore is discharged from ore carriers and conveyed at rates up to 3,000 t.p.h. to either of two 180,000 ton capacity storage yards, where it is blended using boom stackers. Material is reclaimed from these yards at rates up to 1,000 t.p.h. using a slewing boom bucket-wheel reclaimer and fed to a screening station. Oversize material is scalped out and crushed in a closed circuit cone crusher. Undersize material is sized on double-deck vibratory screens which separate at 1/4in (6mm). The two fractions are blended in two of four 70,000 ton capacity blending yards using slewing boom travelling stackers. Bridge-mounted bucket-wheel reclaimers reclaim the blended piles at 1,000 t.p.h. Fine ore is conveyed to the Sinter Plant and lump ore to a second screening station, for rescreening, before passing to the Blast Furnace.

Jan 1, 1972

IF a straight line should be drawn on the map (See 1, page 96) through the northern half of the South Island of New Zealand, from Mt. Domett in the north to Arthur's Pass in the south, and another line drawn parallel to it and at a distance of ten miles to the west, according to the topographic scale, it will be found that within the belt thus drawn across the country all the most important mines, past and present, of the South Island are situated, with the exception of a few in Otago.The most important product of this tract being gold, and Reefton, the most important southern mining field, being situated at about its central portion, the zone may aptly be termed "The Great Reefton Gold Belt." The occurrence of so many gold mines along this particular strip of country is not at all a matter of chance, but is the outcome of cause and effect. Running along the eastern side of the gold belt are the Brunner and Victoria Ranges, which are chiefly composed of crystalline schists and metamorphic granite of probably Cambrian or Silurian age; between these and the gold-bearing series there are interposed at one or two places some beds of slates, limestones, and...

Jan 1, 1910

By De Carvalho J

The average installed refrigeration capacity on South African gold mines has increased by about eighteen per cent annually for the past 15 years; both the number of installations and their duties have increased. One consequence of these large refrigeration installations is that careful attention must be paid to the system for distributing cold water. In these distribution systems, devices which minimize the temperature rise of the water delivered to the underground workings and which also reduce the pumping requirements for returning the water back to surface are used. In this paper the suitability of these various devices are examined and with the aid of a specially developed computer program their optimum operating conditions are determined. In addition the optimum combination of surface and underground refrigeration plants is examined for a hypothetical mine at various depths and the importance of pump efficiency on total distribution costs is discussed.

Jan 1, 1988

By D Teyhan, J Kirsch

Traditionally, most Australian iron ore mining operations have been surface-based. Processing plants were designed to handle dry ores. In recent years mining operations in the Pilbara have progressively moved below the water table exposing wet, sticky ores which have caused lost efficiency in screening operations as particles tend to agglomerate and adhere, blinding screening media. Miners and vibrating screen manufacturers have experimented with a shift from linear motion to elliptical motion screens. Elliptical motion conveys and lifts particles. Effective on flat deck (horizontal and inclined) or sloping decks it can be configured to provide a controlled transport rate, applying pressure in all directions to maximise screening efficiency. In practice, elliptical motion screens have proven to be effective in dislodging sticky particles from screening media, reducing blinding rates and improving screen efficiency. Moisture and clay content change during the life of a mine. These changes are sometimes the effect of seasonal rainfall, in other cases due to increased groundwater and clay content as mining operations go deeper. To compensate for such changes and optimise screen efficiency, changing the ‘shape’ of elliptical screen motion is required. This has traditionally required shutting down processing plants and making mechanical screen adjustments. Plant downtime is costly and machine adjustment has been a ‘trial and error’ practice. This paper will explore the results of a field trial that is currently underway in Brazil of a next generation elliptical motion screen design that allows operators to make changes to exciter rotational direction, speed and screen stroke angle, through electronic drive phase control. The machine’s electronic drive system synchronisation is enhanced for stability with a unique mechanical timing system. Operating at up to 6 g, screen adjustments can be made on the fly without stopping production. Early trial results are showing up to 50 per cent improvement in screen efficiency compared with traditional elliptical motion machines under certain feed conditions.

Nov 8, 2021

The magnesite deposits near Young, N.S.W., occur in decomposed serpentine rock below a soil. and alluvial cover. They show considerable variation in both quality and depth which greatly hampers mining operations. Seismic refraction techniques afford methods of conducting detailed and reconnaissance surveys which yield a depth and velocity analysis of the serpentine/magnesite refractor. The measured seismic velocities may be used as an index of the presence and quality of the deposits. The Seismic Timer which was used in the test surveys is a simplified seismograph which makes use of seismic reciprocity by replacing the conventional seismic shotpoints with geophone stations and the conventional geophone stations with impact points of a sledge hammer. Thi,s enables the use of detailed seismic refraction techniques which yield the depth and velocity analysis of the refractor.INTRODUCTIONThe magnesite deposits near Young, N.S.W., were produced by a process of leaching and enrichment of magnesium in serpentine rock. The magnesite occurs in nodular form emplaced in decomposed rock at shallow depths below soil and alluvium. The depth ranges from close to the surface down to some tens of feet. The deposits are patchy and show considerable variation in both quality and depth, giving riseto considerable difficulties in mining operations.Due to the thorough leaching of the surface material, geochemical tests carried out so far have not proved satisfactory for locating the pockets of magnesite enrichment.It was decided to test the application of detailed shallow seismic refraction methods to the investigation of both the depth and quality of the deposits. The tests were carried out...

Jan 1, 1962

This paper sets out a number of means by which professionals can reduce or eliminate the risk of professional liability whether as directors, employees, partners, independent consultants or contractors. A relationship between client and professional is commonly cited as an example of a fiduciary relationship: the professional "undertakes or agrees to act for or on behalf of or in the interests of' the client "in the exercise of a power or discretion which will affect the interests of that other person in a legal or practical sense."2 As a fiduciary, a professional must ensure that his or her exercise of power does not result in a position of ascendancy or undue influence over the client. Also, a professional must avoid situations where there is scope for even the perception of potential conflict between his or her professional duty to the client and his or her own Interest.

Jan 1, 1995

By T Vizcarra, G Sandoval, C L. Evans

One of the challenges in the development of mineral processing simulators is modelling the liberation characteristics of particles produced by comminution circuits. Understanding the mineral characteristics of these particles is one of the keys to predicting their behaviour in separation circuits. While more fundamental research seeks to model the non-random breakage of ores this work examines whether we can move forward now by using observed characteristics of ores to model the composition of particles generated in comminution processes. Several researchers have noted the similarity of the liberation characteristics for a selected size fraction of particulate material, whether the fraction comes from a coarse material, such as the product from a jaw crusher, or a more finely ground material, such as the product from a ball mill. In most cases these observations were reported as an aside and were not the main focus of the published work. This observed behaviour has the potential to be a useful tool for modelling the particle characteristics in mineral comminution and separation circuits, particularly as we move towards the development of multi-component models. However, before the behaviour can be used widely we need to understand which ore types follow the observed pattern and which do not. The current work examines a range of ores and identifies which exhibit the pattern of similarity of composition for particles in a given size class that has been produced as the result of a variety of breakage conditions. The impact of mineralogy and texture on the evolution of liberation characteristics for both valuable and gangue minerals is discussed.

Jan 1, 2008

By M Denton, M Rheinlander, S Mundell, M Broadgate

The manufacturing industry reinvented its approach to the manufacturing process by managing and measuring it end-to-end. This improved returns on production assets, improved information quality and reduced delivery time, resulting in larger net profits through cost reduction and improved cash flow. Today this approach is standard in the manufacturing industry. Resource development has many requirements in common with the manufacturing production line. These include: control of the various steps, transparency of the state of the process to various levels of the organisation and the overall efficiency with which the process is executed. The authors argue that the introduction of manufacturing execution systems (MES) concepts and technologies to resource development processes will lead to similar improvements in control, transparency and efficiency and could improve profitability and enable staff to work more effectively and make better decisions.

Jan 1, 2009

Distillation of the large and growing greenhouse literature indicates that: ò Global warming has occurred over the past century or more; ò Build-up of CO2 (and lesser greenhouse gases) in the atmosphere is a fact; ò This build-up is likely to cause further global warming. It does not appear possible to conclude that the observed C02 build up and observed global warming are linked; nor is it yet possible to forecast global or regional climate variation with conviction. The dominant greenhouse gas is C02 with about half the warming potential of those gases emitted by man's activities; and about 80% of anthropogenic C02 emissions are from the burning of fossil fuels. Fossil-fuel C02 emissions arg divided about equally between the developed countries of OECD and the rest of the world. However C02 output growth over the past decade was about 4% for OECD and some 40% elsewhere. Population growth and pressure for better living standards will ensure continued higher growth outside OECD. Uncertainty about the impact of increasing C02 emissions on climate, and the long lead-times involved in limiting the increase in atmospheric C02 concentrations, are good reasons for taking action now. Australia accounts for about 275 million tonnes a year or just over 1% of the CO2 emitted from the world's consumption of fossil fuels, and the fight to control global emissions will be won or lost elsewhere. Australia's participation will be by wise conselt and by example. In view of the uncertainties involved, it appears premature to take actions that might place an additional financial burden on our hard-pressed country. However, much can be done now that makes good economic sense and has the added benefit of limiting the growth in Australia's CO2 emissions. Natural gas emits less C02 per unit of energy when burned than either coal or oil. Furthermore, new gas-fired power stations utilise energy at considerably higher efficiency than is the case today with coal or oil. Because of much lower capital costs, there is a compelling economic case for permitting natural gas to compete freely with coal in the Australian power generation market.

Jan 1, 1989

The Nelson province was chosen as the prime area for rhenium sampling, based on its mineral associations. Sample preparation involved benefication by grinding and flotation A modification of published procedures for rhenium analysis was developed and the results compared with those obtained for molybdenum on the same samples using atomic absorption spectroscopy. The results of the analysis for both metals is discussed and the relationships between rhenium and the molybdenum mineralisa- tion of this region is commented on. A metal- 1ngenic province is defined for molybdenum and r'.ienium and the tectonic setting for this is discussed. Some consideration has been given to rhenium possibilities in Fiordland and the Coromandel Range.

Jan 1, 1980

The New Zealand experience has shown that the trend in technologi- cal change in gold extraction can be characterised by a systems approach which grows progressively broader with advances in understanding and allowing for an increasing number of factors. The Australian experience has demonstrated that the elements of developing an exportable process include allowing projects to prolifer- ate where substantial entrepreneural involvement is likely to occur. In both countries useful technological breakthroughs were invariably discarded when first tried at operations not well established and under great pressure of achieving and maintaining production. It required the efforts of persistent individuals at operations which had become bedded in and profitable, to follow the initial work up and commercialise it.

Jan 1, 1988

By S Wasi, J Tobiczyk, J Roszkowski

Methane and fire hazards have a vital effect on work safety and continuity of mining plant operation. In the 1990s, the SMP hazards monitoring and ventilation control systems, based on continuous measurement of air parameters, were put into operation at nearly 30 Polish mines. These systems provide continuous measurement of methane concentration within the range of zero to 100 per cent with automatic switching off of electrical energy immediately after detection of potentially explosive conditions. Early detection of coal spontaneous combustion and open fires is made by continuous measurements of CO, CO2, smoke and O2 content in mine air as well as temperature changes in air and rock mass. The essence of the system is intrinsic safety of all underground instrumentation and uninterrupted central power supply from the surface. All abnormal and critical states are signalled to the mine control room. These trigger alarm and emergency procedures. The computer based ventilation monitoring and control system also performs the function of an expert system for fire detection and underground fire fighting. The mine control operator (dispatcher) makes use of stored data in computer escape route schemes and procedures for the safe withdrawal of miners from hazardous areas. The operator can put in motion intrinsically safe alarm signalling units and banners with programmed messages indicating escape routes.

Jan 1, 2005

Bulk mining and handling technologies have been affected in two ways by the soaring costs of oil products in recent years. Firstly, the substition of oil by coal, oil sands and oil shale demands the development of high-capacity mining and handling equipment, and secondly the rising fuel costs favour a trend away from cost-intensive heavy truck transport. To cope with the growing volumes of material in mining and handling, larger equip- ment units have to be designed. This tendency becomes apparent from the examples of the Hambach open pit mine in Germany, and the Port Kembla handling plant in Australia. A combination of the flexibility of heavy truck transport and the cost advantages of belt conveyors is achieved by the system of semi-mobile crushing installations described in this paper.

Jan 1, 1981

By S Meffre, A E. Fallick, K Zaw, I T. Graham, G Giuliani

Dispersed gem corundum is mined from placers, commonly from basalt fields, as occurs along eastern Australian and Asian continental margins. New laser ablation inductively coupled plasma mass spectrometry analysis (LA-ICP-MS) of Australian corundum allows genetic distinctions among these suites and gives clues to their primary lithospheric sources prior to basaltic delivery. Bimodal corundum suites at Barrington Tops, Cudgegong-Gulgong-Macquarie River and Yarrowitch, New South Wales (NSW), include lower Ga, higher Mg æmetamorphicÆ and higher Ga, lower Mg æmagmaticÆ groups. The Barrington Tops æmetamorphicÆ corundum is more Fe-rich (av 4500 - 7100 ppm) than Cudgegong- Macquarie River equivalents (av Fe 1800 - 2100 ppm). Yarrowitch corundum is relatively low in Fe, Ti and Cr. Along with other eastern Australian data (north-east Tasmania; New England, NSW) and from gem fields elsewhere, the combined trace element and O isotope data, reveal considerable geographic and genetic variations within the corundum suites. A few corundum groups contain noticeable Be, Sn, Ta, Nb, a particular genetic message that also precludes easy distinction of treated corundum in the gem trade. Expanding geochemical, inclusion and geochronological data on gem corundum hold promise for characterising derivative gem corundum on both geographic and genetic features.

Jan 1, 2008