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By A Richmond

"In some lode-style gold deposits the geological (lithological) uncertainty may have similar economic significance as the grade uncertainty. In the absence of precise knowledge of the deposit geology, geological models of these types of deposits that are used to constrain spatially the estimated (or simulated) grade values may influence significantly the contained metal. Methods for assessing geological uncertainty quantitatively are rarely considered due to their perceived inability to consider exhaustive geological interpretations, and resulting models that often appear geologically unrealistic. Furthermore, should the lodes have been subjected to folding, or where the mineralisation continuity does not follow a planar orientation along strike or down dip, standard methods of variography and interpolation using linear vectors in space often do not provide a good representation of continuity. An alternative approach is to relate spatial samples from adjacent drill holes using an unfolding plane.The paper demonstrates conditional simulation of the geometry and gold grades of a folded lode-style deposit where:simulation of lode geometry considers explicitly the geologistÆs interpretation, andsimulation of gold grade values that consider explicitly the folded nature of the lodes.The results are contrasted to the traditional approach of linear vectors in real space for a single lode interpretation.CITATION:Richmond, A, 2012. Conditional simulation of a folded lode-style gold deposit, in Proceedings Narrow Vein Mining 2012 , pp 149-154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By Stuedel J

Starting from comprehensive programme systems for monitoring tasks of any kind, this paper follows the steps of the programme system hierarchy from top to bottom. The monitoring and control centres for entire production units, the subordinate centres, i.e. district control centres, the microcomputer based autonomous control systems, and data input by mobile terminals are discussed. To an increasing extent, the main emphasis is shifted from monitoring and control of individual machinery to optimized operation of extremely complex comprehensive systems. Network displays, for instance displays of production, transport, supply- and evacuation-networks as well as of safety systems, gain increasing importance. Personnel deployment systemsand planning networks as well as stocktaking and accounting are more and more closely linked with the above-mentioned networks. In order to keep development and application (purchasing) costs low, and to assure compatibility, the use of standard modules is to be assigned particular importance. New module developments are introduced, and the design of standard interfaces for computer and module coupling are discussed.For conclusion, a short view is given on the opinion of the line manage-ments on how future hierarchic systems should be featured in terms of individual units and overall systems, and used.

Jan 1, 1985

By A S. Bamber

Mining is the oldest industrial practice on the planet with a history dating back over 3000 years. Since the early iron age ores have been extracted for use in a variety of contexts by humankind, from domestic to military, transport and more recently for complex industrial applications. Mineral exploration and extraction has evolved from the early exploitation of primary metal occurrences in relatively small quantities such as iron, gold, coal and copper, to the bulk mining and extraction of highly complex polymetallic oxides and sulfides today. Since the industrial revolution, mining practice has evolved substantially to support an increasing range and quantity of required metals and to accommodate the increasing scarcity of high-quality sources of these metals. A common response to the increasing scarcity of mineral resources has been to expand production through simple economies of scale, thus diluting fixed costs. This approach, however, is increasingly ineffective in the face of current trends, that include increasingly complex mineralogy, increasing pressure on environmental footprint - energy in particular, and increasing scarcity of capital for the construction of presently popular æmega-minesÆ. This paper examines historical trends and current practice in mineral exploitation in the light of the current global revolution in social, environmental and economic values as the projects move towards a vastly different topology for the industry for continued success in years to come.CITATION:Bamber, A S, 2012. The mining industry needs to be shaken and stirred, in Proceedings Narrow Vein Mining 2012 , pp 3-14 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

A substitute for rutile can be produced by leaching natural or pre-treated ilmenite in hydrochloric acid. Ilmenite in its natural form is an extraordinarily inactive mineral from which the selective removal of iron is rather difficult. The reactivity of ilmenite so that it can be leached with dilute hydro- chloric acid (=2O% w/w) can be enhanced by pre-treatment steps of oxidation and re- duction. The temperatures at which oxidation and reduction are carried out have an effect on both the kinetics of these steps and the leaching kinetics and optimum temperatures for oxidation and reduction are 950 and 850¦C respectively. The mechanism of leaching of iron from pretreated ilmenite and the effects of rate of agitation, temperature, acid con- centration and addition of ferrous chloride to hydrochloric acid on leaching kinetics and production of fines are discussed in the paper.

Jan 1, 1984

By McMullen P. H

Mining of copper ore at Mount Lyell has been continuous since 1893. The operation has always been marginal and the depressed copper Market over the last decade has seen mining continue on the basis of a series of short term plans. In 1985 it was determined that the mine would close in 1989 on completion of the 40 Series mining block. Significant changes in the value of the Australian dollar in 1986 and the subsequent effect on profitability dictated a review of the Company's operations. Lower level ore reserves, mining methods and ore handling systems were re-examined and a plan proposed for mining of the 50 and 60 Series mining blocks. The improved economics of this plan, together with workforce and State Government initiatives resulted in an extension of mine life to 1994.

Jan 1, 1988

The accuracy of an ore reserve is only as good as the geologist's understanding of the deposit. The methods that are applied to resource and reserve estimation reflect that understanding. At the Olympic Dam copper-uranium-gold deposit in South Australia, evolution in the understanding of the controls on mineralisation coupled with the changing demands of the project have led to changes in the approach to reserve estimation. The project has moved into a phase where detailed stope mining reserves are now required as distinct from global ore reserves. The complex nature of the mineralisation and the large amount of data demand that all available information be readily accessible in a flexible format. To enable the selective manipulation of geological and assay information and its characterisation, a relational database has been developed. For reserve calculations themselves, initial computations were based on a system derived from that used for the Kambalda nickel orebodies. The Olympic Dam system differed mainly in the use of statistical analyses in the estimation of grade instead of the previous polygonal area of influence weighting method, Three dimensional weighting techniques are now being used for local reserve estimates. Flexible facilities for raw data handling combined with grade estimation techniques which are commensurate with the mine geologist's understanding, produce detailed gridded and contoured ore zone models suitable for reserve calculations and stope designs.

Jan 1, 1987

It is a very great privilege for me to be able to address you tonight and I am deeply sensible of the honour which has been done me. I am equally sensible of the inadequacy of my training for the position of President of your Institute.May I say at once what a very great pleasure it is to have so many members from the mainland States visiting us here in Tasmania. We do hope that you will find pleasure and profit in your stay.Since the Annual Conference is always held in the vicinity of one or other of the great mining fields, it has become the practice for the Presidential address to review the history of the particular field and t(j) indicate its place in the economic structure of the country.I propose to follow this practice and to try and present to you a short picture of thÇ mineral industry as it has existed in Tasmania. None of the information is new it is available in diverse and remote geological reports and in publications such as Witham's Western Tasmania and the more recent Peaks of Lyell. The last composite approach was written twenty years ago by P. B. Nye and published as a Geological Survey Bulletin.I have enjoyed preparing this address because on occasion I find it refreshing to look back and see what was known and what was accomplished in the days when the going was a little tougher than it is now, and to speculate upon the reasons that drove men to do what they did. I shall therefore discuss the search for minerals in this State; the discoveries over the years; the elation with which the new fields are greeted; the disappointments attending some of them; the mines that have come and gone; and the...

Jan 1, 1958

A new least-squares method for inversion of d.c. resistivity soundings from horizontally layered earth is proposed. Powers are used as measured data. Apparent resistivity is generalized and apparent parameters curves are defined. Estimates for parameter errors are often possible even when data errors are unknown or large. Acceptance or rejection of a model is made an easier decision. Total computational effort is often reduced when compared to global least-squares methods, because although several optimizations are needed, few data points are involved in each, and initial guesses are requested only once and not all at the same time. Correlations between parameters may be used to improve solutions. Precise indications for extra needed data points can be conveyed. A test example is worked out and a field sounding, taken by Rijo (1973, personal communication) in an alluvium-filled river valley in north-eastern Brazil, is studied.

Jan 1, 1987

By Voermans F. M, Hoyle M. W H

The Archean geological sequence in the West Pilbara region (Fig 1), a deformed greenstone volcano-sedimentary succession regionally intruded by layered mafic/ultramafic lopoliths, batholithic granites, granite stocks and transected by swarms of dolerite dykes, has prompted several companies to search for a variety of base metals and and platinoids (Fig 2). In the first instance, detailed aeromagnetic surveying was completed, producing patterns of marked magnetic anomalism which proved substantially successful in the demarcation of areas warranting geological reconnaissance and detailed follow-up. Revelant to this paper were the obvious magnetic features overlying outcropping and buried mafic/ultramafic bodies which ultimately were proven to be host to Ni-Cu sulphides, pgm, Ti, V, Cr and, more recently, Ag and Au mineralisation. Routine stream sediment, soil sampling and ground geophysical techniques of the day appear, in most cases, to have been adequate in the detection of mineralisation, except in the case of Radio Hill massive sulphides where the Turam E.M. (1972) signal essentially failed to detect the blind conductor (Peters, de Angelis 1987).

Jan 1, 1988

By Chia A. H

This paper presents an overview of the development and operation of the PT Adaro Indonesia coal mining project. This operation is an initial two million tonne per annum mine, located in South Kalimantan, Indonesia.The paper places emphasis on some of the more unique infrastructure development and operational challenges that exist in such a remote location environment.A brief summary is also given of the Indonesian coal industry, its direction and position as a significant coal producing competitor for Australia.

Jan 1, 1992

By M E. Trim, J J. Johnson, W Cranston

The Brightwater conveyance system is located near Seattle, Washington in the north-western United States. The East Contract portion of the system consists of a 4.3 km long, 5.9 m diameter tunnel in soft ground and two large shafts constructed in challenging soil conditions. The two shafts are situated side-by-side in an urban valley. One will house an influent structure to direct incoming sewage and outgoing treated effluent, while the other will house a 645 megalitre per day (ML/d) influent pump station. The tunnel contains four pipelines: two force mains to convey untreated wastewater eastward from the new pump station to a new treatment plant, one gravity-pressure pipeline to convey treated effluent westward to a new outfall in Puget Sound, and one high-pressure pipeline to convey reclaimed water from the treatment plant to downstream distribution points. The shafts and the tunnel presented many design challenges. Groundwater is near the surface in the area surrounding the shafts, and compressible peat and clay soils preclude dewatering during construction. These and other challenges were encountered during design of the pump station shaft and multiple-pipe tunnel. The challenges were addressed by a design that includes a dual intersecting circular cell shaft (referred to as æthe peanutÆ) and a single tunnel into which stacked pipes will be æstuffedÆ. This paper discusses the design approach and design details for both elements.

Jan 1, 2008

By Szpindler G

The results of pot-furnace tests with 35 bituminous coals from 20 seams in New South Wales and Queensland were used to establish the relationship between coal properties, as determined by standard laboratory tests, and the combustion process. The rate of combustion is influenced chiefly by the expansion of the fuel bed, but this cannot be accurately predicted from the crucible swelling number of the coal.The effects of various other factors, such as calorific value and ash yield, were investigated and statistical analysis of the results shows that the coals could be classified satisfactorily according to two experimentally derived parameters, namely heat-release rate at an air flow rate of 260 lb/sq.ft/hr and air flow rate giving stoichiometric combustion. The grouping obtained is shown to be related to ash yield and swelling number.INTRODUCTIQNThe rate of heat release from the fuel bed of a travelling grate stoker and the efficiency with which the heat is used depend upon the design and method of operation of the furnace as well as upon the properties of the fuel. It is difficult to draw general conclusions concerning the influence of fuel properties from tests on a single stoker installation. In the pot-furnace test, on the other hand, a part of the same combustion process as occurs on a travelling grate is carried out in isolation, uninfluenced by furnace design variables, and consequently the effects of coal properties and of the method of pretreatment can readily be demonstrated.While the combustion pot provides a rapid method of assessing the combustion characteristics of a fuel during the ignition and burn-out stages under standard conditions, and of predicting changes in performance with changes in fuel or in air flow rate, it is unable to simulate certain features of furnace design and operation. Data from combustion pot...

Jan 1, 1962

By J Rapkoch, M Cerna

As long as the tendency of Chilean copper ores continues to feature high levels of impurities, the smelters will tend to produce high-impurity mattes. The most notable impurities include As, Sb, Pb and Zn. Producing high-quality copper with such materials is a major challenge to metallurgical engineers and operators. More investigations into process optimisations and/or alternatives are needed, using both theoretical knowledge and operational skill. Converting of matte in Chile depends on the matte grade using established technologies. Mattes up to 66 per cent Cu, such as those from Outokumpu Flash furnaces, are converted in two stages, while typical Teniente Converter mattes, ranging from 70 - 74 per cent Cu are converted in one blow, directly to copper. In this paper thermodynamic data are used to evaluate possible variations in the use of traditional technologies applied to smelt copper concentrates with high impurity levels. The results of this analysis help to predict the impurity distributions between matte-slag-gas during the slag blow, and between copper-slag-gas during the copper blow. For converting high-impurity white metal, the effectiveness of volatilisation in the slag blow is analysed. In the copper blow, the type and the amount of flux (SiO2, CaO and others) are altered with the aim of optimising impurity distribution to the slag and gas.

Jan 1, 2005

By Donchak P. J, Champion D. C, Fordham B. G, Domagala J

The Hodgkinson Province forms the northern part of the Tasman Orogen and contains the most extensive outcrops of Silurian - Devonian rocks in Queensland. Deep-water, marine siliciclastic sequences (mainly turbidites) dominate most of the province except near the western margin where mafic volcanics and fossiliferous limestones characterise much of the succession. It is difficult to apply normal stratigraphic mapping techniques to the Hodgkinson Province because of extensive stratal disruption by numerous thrust faults, the general lack of stratigraphic and structural markers, and the unfossiliferous nature of much of the succession. Nevertheless, several distinct units have been delineated although their internal stratigraphy or boundary or superpositional relationships are uncertain. Ordovician strata, as well as two major unconformities have been recognised in the western part of the province. Several models have been proposed to explain the evolution of the Hodgkinson Province. Although there is no general agreement most recent researchers favour an extensional tectonic regime.

Jan 1, 1990

By Dunne R. C

Column flotation is receiving increased interest from both an industrial and research perspective in Australia. The traditional overseas application as a molybdenum cleaning cell is being expanded and a number of new applications as cleaners, scavengers and roughers are emerging in Australia. The success of column flotation has hinged on the new understanding developing from the work of Finch- and coworkers at McGill University, Canada, particularly in relation to scale-up parameters and model development. The aspiring column flotation user in Australia now a has wealth of experience to draw on when deciding on the correct procedure to follow during the process evaluation and plant installation stages of development. However, some aspects relating to column design, such as aeration mechanisms, require careful evaluation.

Jan 1, 1987

By Kolarczyk M

When controlling the ventilation process in a deep mine some knowledge of the sensitivity of the air volume output to changes in the resistances of network side branches is of great advantage.Sensitivity is taken to mean the limit of the differential quotient AV /ART where AV. is the change in air output in the i--h side branch caused by a change of resistance LI R in the r-th side branch. A method Is presen- ted for determining any arbitrary co- lumn of the sensitivity matrix. A network interpretation of this met- hod was developed in which an ancilla- ry network additional the basic network is constructed and solved, giving an analysis of the sensitivity signs de- pending on the structure of the network.

Jan 1, 1988

By Oversby B, Wellman P, Wyborn D, McPhie J, MacKenzie D

The Bureau of Mineral Resources (BMR) and the Queensland Mines Department are engaged in integrated regional- and deposit-scale studies in the Burdekin Falls-"Conway" area, about 100km southeast of Charters Towers (Fig. 1). The regional work augments recent mapping in the Mount Coolon area farther south (Hutton et al., in prep.). These studies are aimed at improving understanding of gold mineralisation and its geological setting in the Drurunond Basin and associated rocks. Knowledge of the regional stratigraphic- structural framework and setting of mineralisation has until now been based on investigations dating from the early to mid 1960's (mainly Bowen 1:250 000 Sheet; e.g. Paine et al., 1974; Wyatt et al., 1971), and on regional syntheses (Olgers, 1972; Levingston, 1981). Some recently explored epithermal gold occurrences in the region have been interpreted on the basis of this early work as being hosted by the Late Carboniferous Bulgonunna Volcanics. The objective of our field research was to refine the regional geology, paying particular attention to the Bulgonunna Volcanics. The results summarised here indicate that unnamed Devonian-Carboniferous volcanics (DCv) of the northern Drummond Basin and mid to late Palaeozoic granitoids are much more extensive, and the Bulgonunna Volcanics much less so, than was previously recognised.

Jan 1, 1989

By Dundon P

The Broken Hill Proprietary Company Limited (BHP) is Australia's largest company with widespread commercial interests ranging from steel productin to minerals, oil and gas recovery. While these interests are worldwide, the Company operates or is partner in more than 30 Australian mining ventures. BHP Engineering (BHPE) is the in-house consultant to BHP but is also the largest consultancy in Australia available to general industry. Australian Groundwater Consultants Pty Limited (AGC) is a large, independent consultancy offering specialist services in all aspects of water resources, waste management and environmental engineering, both in Australia and overseas. AGC is particularly well regarded within the mining industry and has a considerable record of providing solutions for mine water related issues. By drawing on the extensive combined experience of AGC and BHP Engineering, this paper will summarize some of the unique ways in which water interacts with and impacts on mining operations in Australia, particularly in matters such as: Slope Stability Drainage and Dewatering Production Cost (Transport, Drilling, Blasting, etc) Water Supply Water Management Tailings and Waste Management Environmental Issues. The paper will also illustrate the cost benefit of providing major engineering works for reduction in total mining cost. It will be shown that, through advance planning and close interaction between outside experts (ie consultants) and on- site personnel, very significant operational cost savings can be made while at the same time achieving a safe and responsible mining environment.

Jan 1, 1988

By Hosking IA, Mirkov P

Among the solutions currently being considered for improving traffic flow in Sydney are the construction of major road tunnels, principally the Eastern Distributor Tunnels, leading from the end of the Cahill Expressway to Drivers Triangle and South of Taylor Square and the Sydney Harbour Tunnel, which incorporates sections of driven tunnel at the northern and southern sides of the harbour. The Eastern Distributor Tunnels, known as Stages 2 and 3 of the Eastern Distributor Scheme comprise: Stage 2 - A south bound two lane tunnel from north of William Street to Driver's Triangle. The southern end includes two Y junctions (locally 3 to 4 lane widths) with exits into South Dowling Street, Anzac Parade and Moore Park Road. Stage 3 - A north bound, two lane tunnel from Taylor Square to Palmer Street just north of William Street. Further details of the Eastern Distributor Tunnels are given in the paper by Baxter, Chappel and Fishburn (1986) which is included in this conference.

Jan 1, 1987

By Jaczkowski B. M, Cox T. J, Domfeh I. A, Stalker I

Mining and treatment of gold ore in the Ashanti region at Obuasi, Ghana has been continuous for more than 100 years. Earlier production from this world class deposit can be traced far into the history of West Africa's gold trade. As part of a general development and expansion program, Ashanti Goldfields Corporation (Ghana) recently undertook a program to heap leach oxidized near surface ore. Kappes, Cassiday & Associates was given a major role in the design, equipment supply, installation and start-up management of the 3000 tonne/day heap leach. Unusual conditions included a high annual rainfall and an ore which could be characterized as a soft, decomposed, water saturated schist. Production began in March 1990. Startup problems and their solutions are discussed.

Jan 1, 1991