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By Mike Sharwood

This subject is to be discussed in greater depth by Mike Sharwood. It has also been the subject of a mini-symposium by the Melbourne Branch of the AusIMM in October, 1993. The papers from this symposium were distributed to the membership late last year "to raise their consciousness and to promote greater awareness and understanding of the wide range of liabilities that may arise". An introductory paper by Nicholson outlined the many areas in which liability may arise with particular emphasis on expert reports, eg: Takeovers Schemes of arrangement Acquisitions from associates Prospectuses Related party transactions Directors' duties Continuous disclosure Other influences (environmental, occupational health and safety, trade practices)

Jan 1, 1994

By Williams DJ

Preliminary calculations suggest that spoil piles in the Bowen Basin will undergo approximately 4 m settlement as the ground water table recovers after mining is abandoned. Approximately 1 m of differential settlement is possible. Superimposed on this will be a long term creep settlement of 1-3 m/log cycle of time. Depending on the nature of the spoil material, partially submerged spoil piles could be sufficiently stable although to ensure stability during long term creep it may be necessary to flatten the final spoil pile face to approximately 25¦.

Jan 1, 1987

The continuously growing coal mining industry of India presently includes shovel dumper combinations in open cast mines, sometimes with dragline mining of overburden, together with the whole range of longwall and bord and pillar underground mining, continuously undergoing fuller mechanisation. This transition from "low tech" to "high tech" systems is now monitored for reliability and provides bases for comparisons of downtime relative to age and make of equipment, whether imported or indigenous, including spare parts, as well as frequencies of particular failures to allow analysis and progressive improvement. Varying geologies complicate technology and equipment requirements, especially in underground mine,s with minimal technological standardisation, but now, reliability in South Eastern Coalfields Limited has been given more importance and superior technological back-up is being developed.

Jan 1, 1991

By Quast K. B, Newell R, Caterford J. H

The most common reason for gold-bearing deposits being refractory is the presence of sulphides; in many cases these interfering minerals contain arsenic, antimony, or other environmentally-sensitive elements. A number of processes have been proposed or developed for pre-oxidation of interfering minerals. In most cases developers have focussed on gold recovery and capital costs, with relatively little data on the deportment or form of these potentially harmful elements. This paper surveys recent work connected with pressure pre-oxidation processes. Data from pilot plant treatment of refractory gold materials, using the nitric acid Redox process, is discussed along with the attendant flowsheet and engineering implications. Four refractory gold-bearing materials have also been tested at the University of South Australia for arsenic and antimony deportments.

Jan 1, 1991

By W Lunwongsa, S Meffre, S Nuanla-ong, K Zaw, R James, A Salam

Gold and silver mineralisation at the Chatree low sulfidation deposit is hosted in andesitic volcanic and volcaniclastic rocks and characterised by multiple hydrothermal alteration assemblages and quartz-carbonate (chlorite-adularia) replacements, veins and breccias. The ore-bearing veins are influenced by intersecting structures and host rock lithologies. Emplacement of the host succession occurred at 250 ¦ 6 Ma (dated with laser ablation ICP-MS U-Pb zircon techniques), which was closely followed by mineralisation at 250.9 ¦ 0.8 Ma based on the analysis of adularia from coarse-grained quartz-sulfide (chalcopyrite-pyrite- sphalerite) veins using laser ablation Ar-Ar methods. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

This paper addresses; land use, rehabilitation and the State/Federal regulatory process, in light of Australia signing various international conventions and agreements in the area of environmental protection. The conventions on biological diversity, climate change and the implications of the Rio and Agenda 21 declarations are examined. The implementation of these initiatives through the Inter-Governmental Agreement on the Environment, and through legistlative mechanisms at Federal and State level is explored.Particular attention is given to the biodiversity strategy in context of the need to integrate economic aspirations and environmental concerns as a basis for sustsainable development. The paper concludes with a brief comparison of the major approval processes in each State, relating to mining environmental issues.

Jan 1, 1992

By Jensen B

The approach of using the Coward Triangle for the analysis of flammable mine gas mixtures has been examined for its application, to the flammability of coal dust/gas/air mixtures. Explosible lean limit and rich limit concentration data for dust/methane/air mixtures are examined and illustrated using co-ordinate geometry. It is concluded that a three-dimensional envelope representing hybrid explosible mixtures can be drawn. The dimensions of this explosive zone will vary with the characteristics of the coal dust and the gaseous composition of the mine atmosphere. Further research is needed to establish these dimensions for important mined seams.

Jan 1, 1994

This paper will discuss Fordertechnik dawatering screens and their application in process industries. Fordertechnik screens were designed for the dewatering of deslimed, wet fines materials encountered in the mineral beneficiation, sand and coal processing industries. However, these screens have also been used in such industries as municipal waste treatment, paper pulp, chemicals and the food industries. Fordertechnik screens are of simple design and, as a result, offer low capital and maintenance costs. The design is based on the use of twin counter-rotating vibratory motors which provide high frequency, low amplitude linear movement of the screen deck which is essential for high production requirements. Fordertechnik dewatering screens are engineered and manufactured in Australia by Mitchell Cotts Engineering under licence to Fordertechnik GmbH of Mulheim, West Germany

Jan 1, 1984

The Australian mining industry is at an interesting stage in its development. Of the large number of mining companies in Australia, some are still solely domestic in their focus. others have made their first tentative forays offshore, and others are global players of significance in the world industry. It is not long ago that the entire industry was almost exclusively domestic in its focus. Very few companies before the early 1980s had ventured offshore, and those that did so were considered quite risque. The initial moves were made mainly by large companies who could afford to lose the funds expended in getting started in a range of offshore locations.

Jan 1, 1995

Since its beginning, with the works of D. Krige and later, G. Matheron, geostatistics has been analyzing in detail the essential factors at play in ore reserves estimation problems, with the ever-present aim of an optimal use of the available information. Not only do the reserves depend on the geological in situ resources, they also require a correct appraisal of many technical and economical parameters. The objective of the present paper is to show how the method of technical parameterization of reserves, which is at the heart of the geostatistical approach, provides an extremely powerful and versatile tool for characterizing a mining project. After a review of the main properties of the technique, its use in the economic optimization of a project will be examined. Two examples from copper and gold deposits will be given.

Jan 1, 1987

The role played by lawyers in business has, in the course of the last 15 to 20 years, changed perceptively. This development has coincided with, and indeed has been a reflection of, the changing nature of Australian business, especially as the mining industry established its predominance in the Australian economy. The nature and extent of governmental regulation of business, too, has changed markedly. As a consequence, there has been a qualitative'change in the nature of commercial law practice. For the needs of business to be met, lawyers have had to develop specialist skills in new areas. Furthermore, there has been the emergence of the "in-house" lawyer, who increasingly plays a primary rather than a subordinate role in corporate law practice. There is no evidence to suggest that this trend, which is by now so well established, will prove to be ephemeral. Instead, with all indications pointing towards even greater governmental regulation of business activities, the intimate role of the lawyer in business seems entrenched.

Jan 1, 1980

By Stubbs B

In conjunction with Charles Copeman, we have arranged the presentation of a paper by Charles with a support paper by myself presenting alternatives to currentaccepted legal concepts involving the ownership of minerals by the Crown and the absence of ownership in any minerals or entitlement to benefit therefrom by the owner of the land on or under which the minerals occur.2. The current situation has its historical route in the concept of gold and silver being royal metals and belonging wherever situated in the Kingdom to the King and it is submitted it can be'seen as being archaic in nature perhaps even feudal and perhaps worthy in this day and age of reconsideration.Our purpose in these papers is to present an alternative view supported by argument challenging the present system and hopefully, creating room for comment and interchange amongst those involved in the industry. My solutions are not Charles Copeman's solutions and vice-versa. However, we do share a common belief that the present system may not be the best system.

Jan 1, 1990

By L Gladysiewicz

This paper deals with the current situation in the mining industry in Poland. An overview of typical transport systems working in the different branches of mining is provided. The transport systems currently used in lignite mining, particularly in the Belchat=w mine û the largest brown coal mine in Poland, and those operating in copper mines are described in detail. New designs of belt conveyors used in underground hard coal and copper mining are presented.

Jan 1, 2003

By L Crew, S Jackson

A trial of an Adept Online Ore Sizer (OOS) was undertaken at the WMC Leinster Nickel Operation (LNO) in the first half of 2000. During this time the On Line Ore Sizer has been shown to be a robust and accurate instrument for measuring mill feed ore size. Data collected during the trial indicates significant variation in the F80 of the SAG mill feed. The effects of feed size on milling parameters such as mill weight, mill power draw and mill efficiency appears to be dependent on the ore blend treated. With some ore blends a weak positive correlation was found between ore size and mill weight and milling efficiency but with others no correlation is evident. It is believed that the OOS will become a vital piece of equipment in the future as LNO continues to optimises its milling circuit.

Jan 1, 2000

By Aziz NI, Bridgwood EW, Singh RN

One of the major impacts of using modern mechanised systems of mining is the production of large amounts of extraneous dirt intermixed with the Run of Mine output. The paper out- lines a proposed system of utilizing liquid tailings from coal mines to replace imported cementitious materials used in ground control and various other safety measures. A geotech- nical and cost assessment of the proposed system are also included. The paper concludes that it is possible to utilize processed tailings to cost effectively replace imported packing material for ground control.

Jan 1, 1986

Victorian brown coals occur in massive deposits, the quality of which is determined in the first instance by means of samples taken from exploratory bores. As a number of important utilisation characteristics are connected, not with the relatively homogeneous organic mass of the coal, but with minor components such as the ash content and particular constituents of the ash, it is necessary to know how bore samples relate to coal finally used in the process concerned. Tests are described in which the statistical parameters associated with bore sampling, operational sampling and sample reduction and laboratory procedures including a range of coal analytical methods were determined. These indicated properties where analytical errors were relatively high and where sample reduction procedures contributed substantially to imprecision in results. They also showed the effects of the non-homogeneity of brown coals with higher than normal ash contents. A further experiment explored the relationship between samples taken at various stages in the course of test boring, digging, and burning a defined 'block' of coal, and demonstrated an apparent increase in the proportions of adventitious mineral constituents as the 'intensity' of sampling Increased.

Jan 1, 1976

By Eldridge B. J

During recent years, Central Queensland has experienced a boom in its coal mining industry. This has involved many companies in projects requiring large capital expenditure. As with most projects of this size, many operating problems are now being experienced which were unforseen at the feasibility stage. One of these problems is the failure of pit slopes and spoil piles at some of the strip mining operations. There have been serious stability problems associated with Utah Development Company's strip mining operations in Central Queensland, in particular the Goonyella Mine. A field investigation programme was under- taken to determine the cause of highwall and spoilpile slope failures. Spoilpile failures were found to result from weakness near the spoil/floor contact zone. Highwall failures were found to result from a combination of unfavourable bedding plane dips and weakness, and the presence of joints in weak o~erburdep; Satisfactory solutions fa the staiity, problems are difficult to formulate, and-field stability experimentation is still at an early Stage.

Jan 1, 1974

By Strickland R. E J

Heap leaching is establishing itself as an efficient method for the extraction of gold from low grade ore. It has the advantage of low capital costs, low operating costs and rapid startup. However, not all ores are amenable to heap leaching. It is only applicable to well oxidized ores that have reasonable permeability characteristics. Ore with excess fines or clay often display low permeability and are unsuitable for heap leaching.In this study, an attempt has been made to increase the rate of cyanide leach solution percolation by flocculating clay particles or reducing the surface tension of the leach solution. A wetting agent was found to decrease the rate of gold dissolution, possibly by presenting a hydrophobic surface to the gold particle. Flocculation of the clay increased the solution flow rate. The flocculation agent had no affect on the total gold leached but decreased the leaching rate.

Jan 1, 1992

Mt. Whaleback, the property of the Mt. Newman Joint Venturers, contains more than one thousand million long tons of high grade hema- tite averaging 64% Fe, ranging from 70%, the grade of absolutely pure hematite, to 54%. The ore occurs in the Dales Gorge and Joffre Members of the Brockman Iron Formation. The interbedded shale bands common in other orebodies occurring in these horizons are seldom more than a few inches thick and are commonly partially enriched to about-35% Fe. In the generally hard, massive hematite orebody, the gangue minerals tend to break preferentially to the fines, or -6 mm product, and for this reason it is of a somewhat lower grade than the lumpy product. The control of the chemical qualities is concentrated on the fines product for it has been found that maintaining the iron and alumina levels in this product ensures that all chemical specifications are met in both the lump and fines products. Physical qualities are monitored to ensure that the physical quali- ties of decrepitation and degradation of the lumpy product are maintained at levels accept able to the buyers.

Jan 1, 1973

By Bertrand D. L

Although investigations into treatment of Mt. Keast (a hill of tailing) began as early as 1940, it was not until the Imperial Smelting Furnace (I.S.F.) was installed at Cockle Creek by Sulphide Corporation that its treatment became eooncmically feasible. Early investigations and milling operations which began in mid-1976, with their developments are described. Metal recovery involves sulphide flotation, oxide flotation and gravity techniques.

Jan 1, 1983