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This paper looks at the various stages of development of open stope drilling techniques. Due to the structural nature of the orebodies mined by open stoping it has been necessary to review mining methods. In-the-hole hammer drilling proved to be the solution to many problems encountered in horizontal percussion drilling.

Jan 1, 1977

This is the seventh major symposium organised by Illawarra Branch over the past five years and the fifth dealing with various aspects of coal. It is clear that all of you here need no convincing that black is beautiful! This symposium is on a broader canvas, covering the overall field of occurrence, preparation and utilization of black coal throughout Australia. It is thus the most comprehensive treatment of the subject by the Institute since the symposium organized in 1950 by the Sydney Branch with the co-operation of the then newly formed branches in Newcastle, Illawarra, Central Western N.S.W. and Southern Queensland, all of which shared coal as a major interest. The 1950 symposium was adopted as a volume in the series of seven published by the Fifth Empire Mining and Metallurgical Congress in 1953. This historical reminiscence brings to our minds the circumstances in which these new Institute branches were formed. This happened in the year of the presidency of the late Frank Hockey, and at the time the Australian black coal industry was in many ways at a very low ebb. It was the time of extreme shortage of coal following World War II, and the industry was beset by industrial unrest on such a scale that daily bulletins were posted listing the number of idle pits, of idle miners and of tons of lost production. There could not, of course, be any thought of export marketing. Some of the more picturesque bulletins recorded the number of pits at which the ceremonial emptying of billies took place, and the number of pits at which the aroma of the horses' breath was insupportable. At an Institute conference at the time it is on record that the late lamented Austin Edwards, that tireless mineral researcher, author and editor, in his gentle way chided the personnel of the industry and the members of the Institute for having allowed a situation to develop in which a whole generation of Australian children could grow up without ever having seen coal or knowing what it was. It is sad that most children and most Australians have still never seen coal, and think of it as something dirty and uninteresting. The desperate situation of the black coal industry inspired moves by people in industry and in governments, whose plans and efforts have been recorded elsewhere, to modernize coal mining methods, to introduce coal preparation, and generally to restore the mines and the mining communities and to re-cast the steel industry and electricity generation. Amelioration of the traditionally troubled industrial relations was an integral part of this overall programme, and whilst one would wish this aspect had progressed further the situation has, in fact, improved immensely. New investment in exploration, mining, preparation, transport and utilization both by the existing coal mining groups and by new entrants, Australian and overseas, have played a large part in bringing about the transformation of the industry to such a point that Australian needs are being fully met and a large export market is being supplied - a situation that few would have dared to hope for in those dark post-war days. Forecasts of exports from New South Wales and Queensland show coal becoming a dominant foreign exchange earner for an indefinite term. Old King Cole may have vanished from our children's nursery rhymes but King Coal is here to stay, providingthat costs in the industry can be kept within competitive limits. It is all too easy for an industry to price itself out of the export market by inflation, by increased costs for a variety of reasons, and through currency readjustments. A second proviso is that we must continue to encourage a balanced attitude to environmental matters.

Jan 1, 1975

The impact of moves to introduce Abori- ginal land rights was felt in the Northern Territory as early as 1972 when the Federal Government froze the processing of all appli- cations for mining interests over vacant Crown land. The Aboriginal Land Rights (Northern Territory) Act was finally proclaimed on Aust- ralia Day 1977 and since that date the mining industry and the Territory legislature have struggled to make the Act work. Despite these efforts long delays have been experienced by those required to negotiate mining and explor- ation agreements under the Act. In fact explor- ation on Aboriginal land has been effectively stiffled since the introduction of the Abori- ginal Land Rights Act. The Northern Territory government and the mining industry have both sought amendment to the Act to remedy some of its more onerous problems. These efforts have generally been fruitless. Some of the recommendations put forward by Mr Justice Toohey following his recent review of the Act would provide relief in some important areas. However, any such improvements are more than offset by a number of Mr Justice Toohey's recommendations which would severely disadvantage the vast majority of Territorians. A recent survey of mining companies seeking exploration licences over Aboriginal land indicates that many of the existing diffi- culties could be overcome without significant amendment to the Act but rather by the adoption of a positive administrative approach by the Land Councils. It is now up to the Commonwealth and the Land Councils to demonstrate that their Act can work without crippling the Northern Territory economy and its mining industry.

Jan 1, 1984

By C M. Stewart, P Bowen

McArthur River Mine, in the Gulf Country of the Northern Territory, exploits one of worldÆs largest deposits of zinc, lead and silver. It was officially opened in September 1995, 40 years after its discovery in 1955. This paper describes the geological, engineering and metallurgical assessments which made up the feasibility study. It then relates how these study components compare with the first two years of operation. The challenges that had to be overcome before the McArthur River Mine became economically viable included the metallurgical problems associated with extremely fine grained ore and the development of an effective mining process.

Jan 1, 1998

By L C. Thompson

A new understanding of the formation of black organic shales in the Illinois Basin has contributed to insights on how to produce methane from these complex reservoirs. These shales are far from simple shallow derived sediments but are in fact the result of a complex series of events which include the intermixing of volcanic detritus and the marine organic material, onlap successions and low energy turbiditic intraformational activity. This has led to a review of the commercial significance of the mid Devonian shales in the sedimentary basins of the eastern half of the USA. These shale sequences are also characterised by very little contribution from the underlying Lower Palaeozoic carbonate formations. The later diagenetic influences and the interaction of sea floor bacteria especially since the mid Devonian have lead to the creation of a major source of energy in the form of methane. Vast areas measured in 1000s of square kilometres are known to contain biogenically derived natural gas as methane. However, this vast resource produces very little gas due to abundance of illite which acts as a major adsorption mineral and creates a refractory situation where though there is abundant gas present the rate of release is clearly subeconomic. This paper will present the results of recent laboratory trials which have indicated that it is possible to create microfracturing using bacteria within the gas bearing shale sequence and also restart the methanogenesis process. As most coal bed methane environments have similar organically derived shales in direct relationship to the coal beds themselves then this paper has ramifications for this industry as well.

Jan 1, 2004

By J Kleynhans, D Vermeulen, V Cogho

A number of rehabilitated open cast coalmines in SA are already decanting. The paper focuses on the situation at one of these mines where the following information exist: monthly decant rates and rainfall; sulfate concentrations of the decanting water; water level measurements inside the mine prior to decanting; ABA analyses; information about the rehabilitation (drainage slope, vegetation, soil used). A 2D-model was constructed for the mine and calibrated against six years of flow data. About 85 per cent of the decant outflow rate comes from direct recharge on top of the rehabilitated mine while the other 15 per cent is derived from lateral groundwater inflows. The estimated recharge value was 17 per cent of the rainfall. Measured sulfate values showed that the sulfate generation rate for the mine was in the order of 7 kg/ha/d. Conclusions from the study are:most of the water decanting from rehabilitated open cast coal mines is derived from recharge via rainfall; given a specific sulfate generation rate, then: the lower the recharge the less the decant rate but the higher the sulfate concentration of the decanting water and vice versa; future prediction of the decant rate must be stochastic according to expected percentile monthly rainfall values; and as a first assessment of the predicted sulfate concentration of decant water from rehabilitated open case mines, the 7 kg/ha/d sulfate generation rate can be used.

Jan 1, 2003

In the last eight years inclined conveyor haulage systems have established themselves in the mainstream for hard rock underground mine haulage. This leaves the question; what else might be on the horizon for mine haulage and how do we address the process of selecting haulage systems for new mines? This paper considers the identification of viable haulage technologies for underground mines and explores an approach for assessing existing and potential technologies. The example of a large deep mine is considered here. The evaluation of existing haulage systems relies on precedence and the assessment of the system capacity to meet the haulage requirements envisaged for a particular mining project. The assessment of potential technologies for mine haulage relies on the capacity to deliver a viable production-scale system within the timeline envisaged for developing a mining project. The haulage technologies addressed in this paper include: shaft hoisting,conveyor haulage,truck haulage,vertical conveyors, andhydraulic hoisting. This paper does not consider rail haulage out of a mine. This is simply because Australian topography typically has insufficient relief to bring them into consideration. However, rail haulage is a widely used and effective haulage solution in situations where significant topographical relief is present. The assessment of haulage system capability focuses on the following fundamental questions: How reliable are they? What is the degree of technical risk in a business context?What levels of flexibility do they offer?How capital effective are they? What returns are indicated by the balance of capital and operating cost estimates?

Jan 1, 2008

Microorganisms have been used throughout history for the benefit of mankind with some of the earliest applications being in the production of fermented foods and beverages. Reactions involving inorganic substances such as metals, sulphur and sulphide compounds were hardly ever used until the early 1900s when it was discovered that Thiobacillus ferrooxidans was capable of promoting the oxidation of metal sulphides in ores. Today, it is widely recognised that biotechnology has great potential in the minerals industries, particularly in such areas as the leaching of low-grade ores of metals such as copper, gold and uranium; removal of heavy metal ions from process streams and from liquid process wastes; and in the desulphurisation of high-sulphur fuels. Although widespread commercialisation of mineral biotechnology has not yet been achieved, it is estimated that by the Year 2000 mineral biotechnology will have a significant impact on the minerals and metal industry and will probably account for tens of billions of dollars worth of annual production world-wide. This paper examines the actual and possible future applications of biotechnology in the minerals, metal refining and fossil-fuel processing industries. Firstly, the important chemical (and biochemical) principles involved in bio-dissolution of metals from ores and solid wastes, and in bio-accumulation of metals from process and waste solutions are reviewed, including leaching practices - past, present and future. Microbial desulphurisation of coal, and microbially-enhanced oil recovery are also discussed. The practical aspects of genetics and genetic engineering, the types and characteristics of those microorganisms important to mineral biotechnology, and the current research trends are reviewed as well. KEYWORDS: Biotechnology, microbial leaching, bioaccumulation, biosorption, bioleaching, biohydrometallurgy.

Jan 1, 1993

By Somasundaran P

Controlled modification of mineral/liquid interfacial properties by adsorption is critical for mineral processing operations such as flotation, filtration, dispersion and flocculation. Ionic/nonionic surfactant mixtures usually show enhanced surface activity and salt tolerance over ionic surfactants, and this is especially beneficial for flotation of salt type minerals in which case dissolved multivalent cations in high concentrations usually cause loss of anionic surfactants by precipitation. Adsorption of nonionic/anionic surfactant mixtures on kaolinite has been studied with sodium dodecylsulfate as the anionic surfactant and octaethyleneglycol mono-n-dodecylether as the nonionic surfactant. Synergistic interaction between these surfactants was found to cause adsorption of the nonionic surfactant with its hydrophilic chains protruding into the bulk, leading to substantial changes in flotability and dispersion characteristics of kaolinite. Similarly, hydrophobicity changes are observed also' for silica particles upon adsorption of nonionic ethoxylated alcohols owing to possible changes in the orientation of the adsorbed surfactant species at the interface. Also, based on the results obtained with surfactant adsorption, a hydrophobically modified polymer was used successfully to disperse graphite particles in aqueous solution.

Jan 1, 1993

The Ausmelt Catalytic Waste Converter (CWC) has been developed for use in the treatment of industrial wastes and for the recycling of secondary materials. Ausmelt Technology uses a top submerged lance system within a versatile and efficient slag bath reactor. High temperature pyrometallurgical reactions are carefully controlled within an oxidised molten siliceous slag such that metals can be extracted from waste feedstock for recycling, with non-volatile elements reporting to the slag, usually as oxides. Modification of the slag chemistry results in a final slag product that is stable, vitrified and is able to pass standard leach tests such that it is safe to discard or be used in civil engineering applications. Toxic components in the wastes such as organohalides can be completely destroyed and are prevented from reforming. Waste to energy conversion is practiced by the addition of a heat exchanger/steam generator in the converter offgas system. The Ausmelt CWC has been used for recovering zinc from residues and slags, treating spent potliner (SPL) from the aluminium industry and a wide range of electronic and other potentially valuable waste materials. Methods of monitoring the exhaust gases at different stages in the CWC gas handling system are discussed. The assay of these gases prior to emission is used to assist in the control of the converter chemistry to ensure the complete oxidative breakdown of the feedstock.

Jan 1, 2002

Legislation, if it is to be effective, must be enforceable by the state and acceptable to the industry. In the mining industry the relationship between the government inspector on the one hand and the mine management and employees on the other, must be one of full co-operation before the system can be effective. To understand our present system, which is-duplicated in most countries of the world, an examination of the history from which it evolved is necessary.

Jan 1, 1975

This paper describes the characteristics of blasting which set it apart from other methods of breaking rock. The mechanism of rock breakage and the influence of rock proper- ties are then discussed. The strain and fragmentation produced by a cylindrical charge does not change once the charge is longer than 16 blasthole diameters. The influence of bench geometry, charge length and drill diameter are then examined. It is shown that spherical charges have advantages over long slender cylindrical charges. By selection of the appropriate drill diameter, explosive and charge configuration the optimum blasting practice for a given rock to give suitable fragmentation and muckpile profile for sub- sequent handling can be found. The fragmentat- ion depends not only on rock and explosive properties but also on the pattern which dictates how effectively the cracking is utilised. The size distribution of the fragments is given by the Rosin - Rammler equation. Undesirable cracking of the rock in the final wall can be controlled by the careful design of blasts as they approach the final wall. Finally, it is concluded that because of the distance to which blasting can fracture and then displace rock it is suited for the breakage of large volumes of rock.

Jan 1, 1978

X-ray analysis of polycrystalline powder samples has grown beyond its roots in the world of laboratory research and is now regarded as one of the most powerful industrial process-control tools in the field of building materials. This is the key to characterise the element and crystalline phase composition of the material. This is due largely to the development of industrial X-ray analytical systems such as PANalyticalÆs twin solution, which has transformed the advanced analytical techniques born in the laboratory into a robust, workmanlike and easy-to-use tool for todayÆs heavy industries. The increasing use of alternative fuels makes the Bogue method less reliable. Therefore, the real phase quantification by the Rietveld method is the only choice. Additional fine-tuning of the Rietveld method by using alternative methods guarantees the most accurate quantitative results. Moreover, the recent development of ultra high-speed X-ray detectors allows for æon the flyÆ quantitative X-ray diffraction analysis and a truly interactive process and quality control.

Jan 1, 2008

By C Hall, K Williams, B Keogh, S Wong

Cannington mine is a silver lead zinc operation located in north west Queensland. The operation has been in production since 1997. Ore is primarily moved through an underground material handling system comprising of a crusher, conveyor and hoist. The underground crusher and conveyor system were sited in lower grade ore when the mine was first commissioned. As Cannington is now a mature operation, this ore is considered run of mine and stoping progressed into the crusher exclusion zone. As the stoping fronts advanced there was increased damage on the crusher chamber and infrastructure. In response to monitoring data, the crusher monitoring system was significantly upgraded in 2016. The monitoring system included rock mass and infrastructure instrumentation. It improved the understanding of stress impacts and mechanisms driving the damage within the chamber. It allowed the site geotechnical team to respond to changes utilising ground support, mining sequences and increased levels of monitoring. As stoping and damage to the rock mass continued, so did the process of responding to monitoring data. Ultimately, the monitoring system enabled a safe and controlled closure of the chamber. CITATION:Williams, K, Keogh, B, Hall, C and Wong, S, 2018. Monitoring as an input to support and sequence design, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 446–452 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

Mining had a very considerable effect on the country's development. The visual evidence remaining is an integral part of New Zealand history. Early mining for manganese and copper in the 1840s was succeeded by alluvial gold rushes. These gave way to hard rock extraction, hydraulic elevation and dredging. Coal mining dating from the 1850s was fairly widespread. Other minerals were obtained on a small scale. Manufacture of mining' machinery stimulated industrial engineering enterprises. Schools of mines played a significant part in advancing technical skills and several remain as museums. Surviving mine structures and site relics are part of the industrial heritage signifying the technological and economic development of a small isolated nation. Some of these are described. Identification, recording and preservation where practicable is advocated.

Jan 1, 1990

By S M. Mousavi

The issue of estimating evaporation in soils is central to the design of engineered soil caps for mine waste and landfill applications. In general, because evaporation from the soil is difficult to measure in the field, laboratory experiments and empirical methods have been used. Much of the earlier work has been conducted in soil science, although in recent years, geotechnical and geoenvironmental engineers have given great deal effort to this work. The result of this increased interest is the development of numerical models, such as UNSATH and SoilCover for estimating evaporation. In this study laboratory-measured evaporation from soil columns was compared with evaporation predicted using the computer program SoilCover, and the analytical method proposed by Gardner and Hillel. Good agreement among the results was observed. Also the sensitivity of the predicted evaporation to soil hydraulic and geotechnical properties, such as saturated hydraulic conductivity and coefficient of volume change was discussed and the practical implication of the sensitivity were highlighted. The work has application in the design and construction of soil covers over sulfide-bearing mine waste and landfills.

Jan 1, 2003

In the exploration of an area proposed for the establishment of an underground colliery, consideration of all land and mining titles and consents has early priority. Environmental aspects have become more meaningful. Preliminary assessments of previous geological knowledge, together with new geological and geophysical data from surface investigations, condition the decision to proceed with costly diamond drilling programmes. Methods other than fully cored diamond drilling have a useful application in appropriate circumstances. Drilling exploration is conducted in stages of increasing density of-hole spacing to the point where, with holes at 1 km centres, reserves are categorized as measured. The programme is subject to constant review in the light of market changes.

Jan 1, 1976

By Williams SR

Column Flotation cannot be used indiscriminately. Based on extensive pilot plant experience at Lakefield Research, a number of limiting parameters have been identified for the application of column cell flotation. Parameters of importance are the use of wash water, flotable mineral content, pulp viscosity, type of mineral selectivity being sodght and degree of mineral liberation. The paper discusses when wash water should be used and the positioning of a column within the circuit as this is important to maintain a sound water balance for the circuit and prevent excessive circulating loads. Other areas of debate are pulp chemistry, very low and high weight recovery, for which the conventional column is a poor selection of equipment, and treatment of complex ores, where the separation of valuable minerals is more difficult than non-sulphide, sulphide mineral separation. Based on these observations, the application of column flotation must be carefully considered or can be optimised.

Jan 1, 1993

By V S. Vutukuri, K Shariar

This paper present a modification of selected strength criteria for coal and rocks containing weakness planes. The three strength criteria, namely, Murrell (1965), Bieniawski (1974a, 1983) and Hoek and Brown (1980) have been assessed for coal (containing weakness planes) by using triaxial strength tests. Triaxial test results indicated that the strength of coal specimens depends on the weakness plane inclination with respect to the principal stress direction. However it is shown that with increasing confining pressure, the effect of weakness planes inclination on the strength of coal specimens is reduced. The constant parameters in the three failure criteria for coal are determined for each weakness plane inclination by using the Datafit computer program (nonlinear regression analysis) and the results are compared with other rock types.

Jan 1, 1999

By Forssberg KSE

The behaviour of cationic and anionic collector mixtures in the feldspar-quartz flotation system has been investigated througl conductivity, surface tension, zeta-potential and flotation studies. Tht results show the formation of molecular complexes between oppositel; charged collector ions through charge neutralisation. The molecular complexes are found to have a higher surface activity than the individua components. The mole ratio of the mixed composition is found to have, significant effect on flotation. Mole ratio less than unit} (anionic/cationic) of collector mixtures increases the flotation recoveries If the mole fraction of the anionic collector is greater than the moh fraction of cationic collector in a mixed composition, flotation ceases The flotation selectivity principally depends on the inherent differences it the surface charges of feldspar and quartz at the flotation pH values of

Jan 1, 1993