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By Wood W, Bell A

Brown coal production in Victoria's Latrobe Valley Region (Figure 1) continues to rise and currently stands at around 50 Mt per annum. With the exception of around 2 Mt used to produce some 700 Kt of brown coal briquettes, this coal is mined by the State Electricity Commission to fuel large thermal power stations with a total installed capacity of just over 5 000 Megawatts. The moisture content of the coal as mined typically exceeds 60 per cent, making Latrobe Valley coal a markedly low rank fuel. The lack of heating value is, however, compensated for through power station design and by the fact that ash yield is very low, usually within the range of one per cent to four per cent on a dry basis. This means that compared with most other coals, the burning of Latrobe Valley brown coal produces relatively small quantities of waste products and discharges a minimal level of pollutants into the atmosphere. Even so, the inherent quality of Latrobe Valley coal does vary significantly from one area to another (Gloe, 1991; Barton et al, 1992) both on a local and a regional scale. Such variations need to be recognised and understood in order to not only realise efficiency gains in existing power stations but to properly assess resource potential for future utilisation and the application of new technologies. The principal aim of this paper is not to describe coal quality variation in detail or to speculate on the nature of and reasons for such variation. Rather, it is to simply underscore that significant differences do occur and that this is clearly a factor which needs to be considered in any evaluation of Latrobe Valley brown coal as a resource for the future.

Jan 1, 1992

This paper describes a proposal to reopen the Sylvia gold mine for underground exploration and development for an initial production of 10 000 tpa. A combination of trackless mining equipment and railtrack would be utilised for development with ore extraction being carried out by undercut and fill methods. The use of the smallest LHD units for mucking, and rail track for the main haulage together with airleg drilling will form the basis for development and stoping. The proposal has been subjected to an environmental impact assessment report to evaluate the impacts of the proposal on the natural and social environment in the area.

Jan 1, 1987

By Madan M. Singh

Section 516 of Public Law (PL) 95-87, commonly known as the Surface Mining Control and Reclamation Act of 1977 (SMCRA), requires that underground coal mine operators must "adopt measures consistent with known technology in order to prevent subsidence causing material damage to the extent technologically and economically feasible, maximize mine stability, and maintain the value and reasonable foreseeable use of such surface lands, except in those instances where the mining technology used requires planned subsidence in a predictable and controlled manner..." Implied in the constraints of Section 516(b)(1) of SMCRA is a determination of what constitutes "material damage" to surface structures, renewable resource lands, and the capacity for sequential land use following underground mining. The authors have already briefly addressed the subject of damage criteria in relation to surface structures (Bhattacharya et al, 1984). In this paper, an attempt is made to provide quantitative guidelines to ascertain material damage to renewable resource lands, although the data available to establish these criteria are considerably more limited than is the case for surface structures. Besides, many more variables influence the severity of the impact at a given site, making the task of assigning stringent ground movement limits even more complex. This often necessitated use of professional judgement and occasional reverting to a qualitative approach. Hence the reader is cautioned at the very outset that the quantitative limits presented herein are approximate and are primarily intended to serve as rough guides for ascertaining the extent of damage to the renewable resource lands under consideration, and that depending on site-specific conditions the actual damage incurred may differ significantly from that predicted by the proposed criteria. The authors, however, feel that the criteria suggested are somewhat conservative, but realistic. The actual damage observed should generally be less severe than predicted by these criteria. It may also be clarified here that the term "subsidence", as used in this paper, implies the total phenomenon of surface and subsurface effects associated with the mining of minerals and not only the vertical displacement of the surface as is sometimes inferred in the literature.

Jan 1, 1984

By Swapan Bhattacharya

United States federal and state regulatory authorities require underground mine operators to adopt adequate measures to minimize material damage to the surface caused by nine subsidence. This paper presents an approach to define and determine the extent of material damage due to subsidence from underground coal mining. The basic steps involved in the development of adequate criteria have been enumerated together with the approaches and methodologies used.

Jan 1, 1984

By Richard R. Brochu

At the International Society ofExplosives Engineers Annual Conference held in Nashville, Tennessee in February 1995, a Seismograph Standards Committee was established. The purpose of this wmmittee was to develop objective performance specifications for vibration measurement instrumentation and field use practices. It was also understood that due to geology, temperature, and moisture in the soils, it is not possible to design and build an instrument to give ‘results which are absolutely comparable for ground vibration. It was, however, considered essential to standardize instrumentation by which vibration can be measured under closely defined conditions so that results obtained by users of seismographs are always the same ,&thin stated tolerances.

Jan 1, 1998

By Dave Minney

The South African mines health and safety regulations require that mine management establish a quality management system for rock support material. Quality control of resin capsules used as a support medium in South Africa is specified under SA National Standards No 1534. Experience has shown that this specification, while addressing the chemical and physical aspects of the products, but does not address the required performance criteria. In order to address this shortcoming, the industry has put a lot of emphasis on short encapsulation pull tests, performed insitu, in the underground workings of the mine. This is also fraught with many shortcomings, particularly as regards site availability, cost and repeatability of results. To try and address these issues, the Department of Mechanical and Aeronautical Engineering at Pretoria University were approached to develop equipment and machinery that could produce reliable, repeatable results in a laboratory environment which reasonably simulates installation practice underground. The test method is based on the ASTM F432-95 Strength Index test, but modified to use push test rather than pull tests. The paper describes development of the test method and the preliminary results and findings of the work.

Jan 1, 2007

By Staff

Introduction As the Sherritt Gordon property is still in the development stage, . it is rather difficult to write a proper account of the mining methods and milling practice that will be used. While the general scheme of operation will remain the same, there will undoubtedly be many minor changes to meet special conditions which we cannot forsee at the present time. Most of the work accomplished to date has followed the usual routine of preliminary development in the Canadian North. However, we have learned a few things which might be of use to others operating under similar conditions. The most important of these is the saving in power cost made possible by the use of Diesels as against steam power when using wood fuel, and the movement of freight by tractors when rail transportation is not available. Location The property i6 located about 90 miles north of The Pas, or 40 miles northeast of the Flin Flon mine. A branch line from Cranberry Portage, on the?C. N. railway, between Flin Flon and The Pas, connects the property with the outside.

Jan 1, 1930

By B Bamford

High speed diamond cutting has extensive applications in civil and mining engineering. A project involving the diamond sawing of black granite is investigating the nature of the diamond cutting process. A sawing machine was devised to adjust the cutting load and measure cutting speed. Cuttings were collected for size distribution analysis. The surface produced by interaction between diamond. grits and the rock was subjected to microscopic investigation. Increasing load prompts the proportional increase in the cutting rate. But the mean size of cuttings shows little change. The photomicrographs of the cutting tracks indicate neither patterns of crack formation nor signs of the ductile behaviour of the rock. A diamond cutting model for hard rock is formulated on these observations. Diamond cutting is a process of surface failure, which advances in four stages. The polycrystalline characteristics of a hard rock and the action of high-speed diamond grits guarantee the creation of crack nuclei which develop into cracks in various directions. This network crisscrossing cracks enable the stripping of this surface layer from the rock.

Jan 1, 1992

By N H. Jansen, H L. Bridgwater

Field portable X-ray fluorescence (XRF) and near infrared (NIR) instruments are proven technologies in the minerals industry. The in-field results of these instruments can add value early in the project life, leading to cost-effective decision-making compared to their equivalent laboratory based techniques. However, in order to add value to a project, it is crucial that the instruments are employed correctly.Orientation studies should be carried out prior to initiating a sampling program to achieve the highest level of quality assurance and control for the results. Hence, an appropriate sampling workflow begins with considering what outcomes are required, including level of precision, accuracy, reliability for elements and minerals of interest, and sampling errors. The workflows proposed include soil sampling and reverse circulation and diamond drilling sampling techniques, and laboratory based techniques. They are practical and flexible workflows using available portable XRF and NIR technologies that can be applied to current sampling and drilling methods.The combined technologies have the ability to create large, integrated geochemical and mineralogical data sets that can provide cost savings for every stage of the mining chain from exploration to prefeasibility, mineral processing and environmental remediation.CITATION:Jansen, N H and Bridgwater, H L, 2017. Proposed workflows for portable X-ray fluorescence and near infrared instruments for soil and drill hole sampling, in Proceedings Eighth World Conference on Sampling and Blending , pp 219–228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The development of research activities at Risdon and the implementing of a policy of instrumentation in plant processes have, in recent years, entailed a considerable increase in research staff and created an urgent need for more space and modern laboratory facilities. The existing laboratories have been in use for 25 years and are now inadequate. New buildings have been authorized.The new buildings will comprise, firstly, a laboratory building of three floors giving a totai .floor space of approximately 11,000 sq.ft., and a pilot plant building as an annexe to the laboratory building, of approximately 4,900 sq.ft. The laboratory building will accommodate from 20 to 22 research workers, and additional plant operatives will be used for the control of processes in the pilot plant building. The new buildings are designed to provide facilities for three principal functions; the investigation and improvementof existing processes, the development of new processes up to the pilot plant stage, and the control and maintenance of instruments.LOCALITY AND ORIENTATION OF BUILDINGSThe site of the buildings is elevated ground on the eastern side of the main plant, near the main entrance and general office building. There will be no obstruction to sunshine at any time of the day, and the laboratory building will command views of wide radius from wooded hills across the River Derwentto the open sea on the south-eastern quarter.The buildings are located to provide space for future extensions. The main laboratory building faces approx...

Jan 1, 1949

By Denis Labrie

Le minage en profondeur sous contrainte modérée à élevée présente de nombreux défis aux opérateurs et aux ingénieurs de mine notamment au niveau du contrôle de terrain et de l?environnement minier souterrain, pour assurer la sécurité des travailleurs sous terre et la continuité du cycle d?opération. Des conditions de contrainte élevée signifient une pression accrue au front de taille et sur les structures minières tels les piliers de mine et les fins de zone, un risque de rupture violente ou de coup de toit plus élevé, des zones de rupture plus grandes au pourtour des excavations, des charges accrues sur le support de terrain, etc. Le présent article fournit un aperçu du travail fait à l?intérieur du Programme de Contrôle de terrain de CANMET au cours des sept (7) dernières années, entre 1995 et 2001, pour comprendre et suivre l?évolution des niveaux de contrainte à l?intérieur des structures minières. Les propriétés déterminées en laboratoire sur des échantillons rocheux et les prévisions effectuées au moment de la conception sont comparées avec les observations effectuées en chantier à la paroi des excavations et à l?intérieur de la masse rocheuse. La plupart des cas discutés ici montrent une corrélation satisfaisante entre les observations effectuées en chantier d?une part, et les résultats d?essai obtenus en laboratoire et les calculs réalisés lors de la conception d?autre part. Ces observations peuvent donc être considérées comme des moyens relativement sûrs pour vérifier et suivre l?évolution des niveaux de contrainte présents à l?intérieur des structures minières.

May 1, 2002

By Oscar Concha

El presente texto describe la exploración, geología, controles estructurales, mineralización y los tipos de alteración hidrotermal del yacimiento minero Cuajone, situado al sur de la Cordillera Occidental de los Andes y en el flanco Andino de Moquegua. En 1937, se inicia su exploración a través de una campaña exploratorla de la empresa Cerro de Pasco, donde se determina la zona como un proyecto potencial de cobre porfirítico de baja ley. Posteriormente en 1942, se inicia la primera campaña de perforación diamantina exploratoria y en 1969, se inicia la etapa de construcción y desbroce de material para preparar la mina. De otro lado, se ha desarrollado un modelo de la evolución del yacimiento desde las rocas preminerales del Grupo Toquepala, de las cuales la andesita basáltica fue una gran receptora de la mineralización de cobre originada por la intrusión de un primer pulso de latita porfirítica.

Apr 26, 1999

As a result of the world depression and the consequent heavy fall in the price of tin, Malaya joined with other great tin producing: countries of the world in a restriction scheme that heavily restricted production from its individual mines. This condition, together with the knowledge that it was becoming more and more difficult in, Malaya to acquire further areas and so prolong the existence of a specific company's activities, induced Mr. H. G. Scott, managing director for the Siamese Tin Syndicate Ltd., to consider other possible sources of production. Mainly because of the conditions that obtained in Tasmania, he turned his attention to that country, where, not only could mining be carried on without restriction as to output, but where the incidence of the exchange position created favourable conditions for operation. The district selected for examination was that of St. Helens, on the East Coast of Tasmania, which district had behind it a long record of successful tin mining operations.PRELIMINARY OPERATIONS OF SIAMESE TIN SYNDICATE LTD. AT ST. HELENS.First of all the district was examined, and there was no lack of evidence to show that tin existed, although it was impossible to get down to quantities and values without an extensive prospecting campaign. For one thing, the physical features of the country seemed to be all wrong. There were no extensive alluvial flats such as a mining engineer...

Jan 1, 1934

By Lever R. R

The paper discusses assay methods generally used when prospecting for gold, and also the applicability of various chemical methods, it describes a new paper chromatographic technique.for making fairly rapid semi-quantitative assays for very fine gold. Testing of the method in field work shows that this simple method could have applications in geologic work, in prospecting and in certain routine mine sampling work. It is not yet a method that can be used to detect anomalies in traces of gold dispersed around an orebody, as is general practice in geochemical prospecting.INTRODUCTIONAccording to the English economist Harrod (1958), "the acute shortage of gold in the world-because currency value has not been adjusted in line with the fall in the goods value of the various currencies-has been a familiar fact for some time now". Harrod calculates that a rise in the price of gold to double its present value is necessary to rectify this condition, and that, if this rise were to take place, increase in production and reduction in private hoarding might well bring annual accretion to world stocks from the presentaverage of about $464 million to a figure close to the $2,000 million that would probably eiiminate these shortages.Any increase in the price of gold is bound to lead to a great increase in prospecting at working mines, in abandoned areas and possibly in untouched country. Prospecting, techniques for base metal orebodies have improved greatly in the last thirty years; but methods available to detect gold occurring without accessory metals have not received the same attention. With this in mind a paper chromatographic method of assaying for gold has been developed by Lever (1958). In the field this semi-quantitative method has proved...

Jan 1, 1959

By P. G. Flood

A simplified conceptual model shows how the arc flank to arc fringe areas adjacent to ignimbritic centres form a prospective zone for natural zeolites. Large alkaline lakes that serve as the repository of voluminous ash-fall tuffaceous material provide the ideal chemical setting for pervasive alteration of silicic glass to zeolites. The unusually old age of the Escott deposit demonstrates that any silicic volcanic province that contains low-temperature, unmetamorphosed sequences is a potential zeolite exploration target and that age should not be used as a criterion to exclude potential areas. It has also been demonstrated that heulandite and mordenite, formed by diagenetic alteration of silicic glass, do not always change to analcite and albite through the ageing process

Jan 1, 1991

By V A. Tsukerman

Prospects a new energy saving method for an efficient destruction of the sturdy and hard materials (rocks, ores, frozen soils, concrete blocks, etc) û the Electric Pulse Discharge (EPD) method of materials destruction for green processing in mining and processing of mineral raw materials are considered.The EPD-technologies give additional possibilities for solving ecological problems at the expense of increase of integrated approach of utilisation of minerals and industrial wastes. The scientific and technical level of executed development of EPD method is sufficient for organisation of design work to develop substantially new equipment. A number of plants have been developed and tested, including plants for processing raw material with minerals of jewels, plants for selection of mica from rocks, and plants for processing the merging of artificial mica.

Jan 1, 2002

By M Rattenbur, A B. Christie, S C. Cox

A new minerals initiative to increase the level of understanding of New Zealand's mineral resources and to promote the development of minerals began earlier in the year in a partnership pilot-project between Crown Minerals and the Institute for Geological and Nuclear Sciences (GNS). The project aims to gather a set of comprehensive geoscientific data and build a series of digital GIS packages to highlight New Zealand's mineral prospectivity. The pilot study was carried out at a regional scale, and is focussed on mesothermal gold mineralisation in the South Island. A significant amount of geological data and information was sourced from open file technical reports held by Crown Minerals and from various databases held by GNS and has now been compiled into a single GIS dataset, which will soon be made freely available to interested parties. In addition to this comprehensive data compilation, prospectivity modelling using Weights of Evidence techniques was undertaken to highlight those areas likely to contain ore deposits. It is clear from this study that the South Island of New Zealand remains highly prospective for mesothermal gold mineralisation. Many of the highly prospective areas, which also contain historic mine workings, remain open for exploration. The study not only highlights these areas, but also other areas where the potential for similar mineralisation exists, in all likelihood with no surface expression. The study has also highlighted the value of many of the open-file technical reports held by Crown Minerals and the need to carry out additional studies using this and other available data at a more detailed level, possibly as the basis for a web-based minerals information system.

Jan 1, 2002

By Bruce Gellar

In March, the Prospectors and Developers Association of Canada (PDAC) held its annual conference in Toronto, Ontario. This is the third PDAC meeting the author has attended. The following are some impressions of the meeting. And the author looks forward to the joint meeting of the PDAC and the Canadian Institute of Mining, Metallurgy and Petroleum to be held March 5-10, 2000, entitled Mining Millennium 2000. One of the features of next year’s gathering is a proposed forum of world mining ministers, the first ever to be held anywhere.

Jan 1, 1999

New Zealand has been a significant producer of gold for over a century. Total recorded production is over 850 tonnes. There were three major periods of production: the first and biggest was between 1860 and 1880, the second was between 1895 and 1920 and the third was between 1930 and 1945. After 1945 gold production fell continually until 1980 when the major upward adjustment in gold price led to renewed interest. There have been important new developments in each of the known gold-rich areas: Westland, Otago and Coromandel and exploration for gold in these areas and in previously unprospected regions has reached unprecedented levels.

Jan 1, 1988

By John A. Teeter

"A SHORT WHILE AGO I enquired about The Mining Society of Nova Scotia. In all honesty I was apprehensive about addressing such a body if it was highly geared to the technical aspects of discovering and obtaining mineral resources. I was told that this would not be the case. Rather, there would likely be in attendance a broad cross section of people from business, industry and government and from across Canada and the U.S.A. Thus there would be an interest in a free-wheeling discussion of the prospects for industrial development in Cape Breton. Accordingly - being one who hates to miss an opportunity - I intend to exploit the invitation of your executive by being, over the next short while, frankly promotional. I would like to talk about what I consider to be some of the most important attributes of Cape Breton for industrial development and identify some of those prospects. Secondly, I will quickly review some of the things the Cape Breton Development Corporation is doing these days to stimulate some of that industrial development."

Jan 1, 1972