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A programme began in 1970 to eliminate the charging of fine materials into the copper blast furnace of The Electrolytic Refining and Smelting Company of Australia Ltd. at Port Kembla, N.S.W. A disc pelletiser and drying plant has been installed as part of this programme. Feed material for the plant is a blended mixture of copper concentrates, fine copper-bearing residues, and blast furnace cyclone dust. The operating parameters for the disc have been calculated by comparing the perform- ance of three other discs on the plant. Re- search work on choice of binder, feed moisture and drying conditions has led to the production of reasonably high strength pellets. A description of the pellet plant and modifications necessary to overcome the initial performance problems is given.

Jan 1, 1974

By M van Kampen

The Resource Management Act 1991 has been amended on a number of separate occasions since its enactment in 1991, and has recently be subject to further amendment by way of the Resource Management Amendment Act 2005. The amendments as proposed in the Resource Management and Electricity Legislation Bill would have had revolutionary and far-reaching consequences. However, as finally enacted, the amendments are a greatly watered down version of what was initially proposed.   Nonetheless, the Resource Management Amendment Act 2005 has provided for a number of amendments that will impact on the minerals industry to varying degrees. This paper discusses in particular the changes and impact of the changes to the definition of æcontaminated landÆ, clarification with respect to the duty to consult, amendments to the provisions relating to National Environmental Standards, and to the council and Environment Court hearing process.

Jan 1, 2005

By R Heath, P Rose, L Coetser

A sustained eight-year major research effort has been undertaken in South Africa to develop integrated passive water treatment systems for the sustainable removal of sulfates, while simultaneously addressing the removal of metals and acidity. The research effort addressed the problem both at a fundamental science level and at the more empirical pilot plant level. Whereas there are numerous anaerobic sulfate reducing reactors in operation on mine waters that remove some sulfate together with metals and acidity, these are typically plagued by low sulfate removal efficiency and gradual reductions in overall reactor efficiency with time. The South African research effort has focused on understanding the fundamental microbiological and biochemical reactions that occur in anaerobic reactors filled with lignocellulosic material and subjected to high sulfate water. Hypotheses have been developed that differentiate the reactions occurring in such a reactor into groups that should be individually optimised and these hypotheses have been verified through rigorous laboratory and pilot scale studies. The results of this research are incorporated into a patented multi-stage integrated passive treatment system that is capable of sustained high rate removal of sulfates, metals and acidity.

Jan 1, 2003

By Casale G

This paper discusses a long range mine plan development at the Santa Fe Pacific Gold Twin Creeks Mine based on the reserves of Mega pit. The key constraints of the schedule development included two types of mill ore targets (sulphide and oxide mill ore), consideration of blending of six chemical constituents (sulphide sulphur, carbonate, organic carbon, the ratio of iron/[arsenic, antimony]), and mining of acid generating and acid neutralizing waste at pre-defined proportions. Solution approaches, selected results, and project experiences are discussed.

Jan 1, 1995

By Waghorn EP, Gleeson HB

The Loy Yang Optr, Cut is a brown coal mine bring developed in the Latrobe Valley region located some 160 kin south-east of Melbourne, Victoria. The mine has been designed to supply a mine mouth power station at a rate that will rise to 32 million tonnes per year by the mid 1990's. Continuous mining metnuds are employed using bucket Whtel excav- ators and conveyors. This paper describes the basis of the design of the Loy Yang continuous mining system ano cne experience of four years of initial operation.

Jan 1, 1987

This paper deals with the extension of Post Office telecommunications (telephone, data, leased private lines etc.) network to mining communities in remote areas of Australia. The evolution of the "Spur Line" policy and its application is referred to together with comments on the engineering of telecommunication Facilities.

Jan 1, 1973

By Boyce WH

Earthquakes are the most frightening and devastating natural phenomena known to mankind. They strike without warning and their consequences can be disastrous in terms of the toll of human life, financial crises related to the damage or destruction of man-made structures and the social and economic effects on a wide spectrum of the affected communities in the aftermath of the event. Such situations can be widely attested to by most areas around the Pacific Rim. Indeed, the threat of earthquakes is always imminent because of the geological-tectonic nature of the region as manifested by past experiences. It is patently obvious that earthquake occurrences are not only a geological hazard but also pose a serious social danger. When one considers the 19 September 1985 Mexico (Michoacan) earthquake (Mitchell at al., 1986), the necessity of continuing research is of paramount importance. An estimation . of earthquake risk encompasses both qualitative and quantitative aspects and demands a multidisciplinary research effort integrating seismology, tectonics, geology, enginering, sociology, economics, insurance and governmental policies (Bolt, 1978; Booth, 1984). These roles in mitigating such a hazard have been aptly discussed by Press (1985). A series of discussion papers based on an intergovernmental conference covering the whole scenario were published by UNESCO (1978). A comprehensive case history was provided through a workshop on the 1886

Jan 1, 1987

By M Castle, D Mendelawitz

The Marra Mamba iron ore in FortescueÆs Chichester Range project area occurs as a very flat dipping series of waste shale and iron ore beddings. These beddings vary from millimetre thickness to several metres. The ore material generally exhibits a moderate degree of competence when subjected to ultimate compressive strength (UCS) tests, normally failing at up to 60 Mpa. However, the strength of the beddings is markedly less when subjected to the tensile forces imposed by the cutting action of the surface miner. Two surface miners of differing age and sizes were tested over a period of almost three months. These machines produced a product that had not been subjected to dilution by blasting and of such a size that primary crushing is not required. The machines were able to cut all ferrous material presented to them with varying degrees of success. Material containing higher quantities of manganese were broken but caused catastrophic wearing of the picks. During the trial the volume of material produced by the two machines in various strength materials very closely matched the manufacturerÆs estimates. The major impact on costs per tonne related to the wear on bits, which in turn varied with the bit design and composition. Bit design and composition testing is continuing.

Jan 1, 2007

By Christie AB

Stream sediment geochemical analyses from 140 mining company exploration surveys of the Coromandel, Northwest Nelson, Marlborough and Westland regions of New Zealand have been compiled from open file reports and entered on a database called REGCHEM (for Regional Exploration GeoCHEMistry). REGCHEM is supported by GEOEXPL, a custom-written computer software application which operates under the Microsoft Access relational database mangement system on a PC-type computer. The data are plotted as maps using the Maplnfo geographic information system (GIS) package. Thesholds separating anomolous values from background values are determined using the PROBPLOT univariant statistical package, which enables the descrimination and modelling of several populations. Relevant REGCHEM data are being incorporated into a GIS for the Coromandel region as part of ongoing studies to sevelop mineral deposit and metallogenic models for the region, and to assess regional prospectivity.]

Jan 1, 1995

By C Pypno, P Nowakowski, T Opasiak, C

Belt conveyors are machines for continuous transport with most applications in mining industry in Poland. This is a result of simple construction and cheap operating costs. But conveying materials by belt conveyors are often in the powder state (eg small coal, gypsum, etc) and during the transport there is a possibility of polluting the environment around conveyor route. A good solution for this problem is the pipe conveyor, where a belt is closed on the route in circular shape and flat on unloading point. Another problem which is indicated in the paper is dusting on the belt conveyor boosters. In Poland a new solution of booster has been designed, whereby dustiness of transportation powder materials is reduced by up to about 90 per cent.

Jan 1, 2003

By P Mackenzie, S Askraba

Pyritic black shales present several challenges to mining operations due to their reactivity. The risk of predetonation of explosives in blastholes, spontaneous combustion of fractured rock and the generation of acid rock drainage must be managed for safety, operational and environmental reasons. At the Mt Tom Price iron ore mine there is a need to differentiate between reactive and non-reactive shale in order to assess risk and make decisions on materials handling. The current approach uses a combination of stratigraphic information and sulfur analysis of blasthole samples. The time taken for sulfur analyses can be a constraining factor on mine production. A new instrument developed by ANSTO Minerals overcomes some of the current limitations on material characterisation. The IOR MeterÖ measures the intrinsic oxidation rate (IOR) of samples of broken rock by circulating air through a sample and monitoring the oxygen concentration over time. The intrinsic oxidation rate is given by the rate at which oxygen is consumed per unit mass of sample, in units of kg(oxygen) kg-1(sample) s-1. Up to eight samples can be measured simultaneously and the turn-around time can be less than 12 hours. Initial trials of the IOR MeterÖ were undertaken at the Mt Tom Price mine in July 2004. The measured IOR of samples from a blasthole pattern spanning different geological layers containing black shale, correlated strongly with the expected reactivity of those layers. The correlation between position in the geological sequence (detailed stratigraphy) and IOR MeterÖ results were much stronger than that between stratigraphy and sulfur content. The new characterisation technique offers the prospect of improving the ability to identify and predict the behaviour of reactive black shales and to differentiate more precisely between different materials. Mine planning, operations, safety and environment all stand to benefit from the success of further trials of the technique.

Jan 1, 2005

By J Mavrogenes, C J. Spandler, S M. Eggins, K Worden

Major occurrences of platinum group minerals (PGM) are in crustally-contaminated, huge, layered igneous complexes (Bushveld and Stillwater) and gabbroic intrusions (Norilsk); relatively minor occurrences include arc-related æzoned Alaskan ultramaficsÆ. In terms of arc-related provenances, the recognition of alluvial PGM in river and beach deposits of southern South Island (Mitchell, 1995), in situ in the Longwoods (Cowden et al, 1990), and the ultramafic-mafic layered Greenhills Complex at Bluff (Spandler et al, 2000) raise the possibility that some economically-significant PGM deposits may exist in New Zealand. The Longwoods and Greenhills are in the Brook Street Terrane which is a remnant of a primitive intra-oceanic arc system of Late Permian-Early Triassic age. The Terrane comprises volcanogenic sequences containing plagioclase- and clinopyroxenephyric basalts, high-MgO ankaramite and dolerite dikes, trondhjemite plutons, and basaltic to andesitic volcaniclastic and sedimentary rocks. The cumulate complexes contain early-formed olivine- and clinopyroxene-rich ultramafic cumulates overlain by anorthite and hornblende-bearing gabbros. Primary (isoferroplatinum) and secondary (sperrylite) platinum group minerals are preserved in chrome-rich spinel pods in basal dunite of the Greenhills Complex. Saturation during early fractionation of primitive high-MgO magmas rather than magma mixing seems likely for the primary PGM. Together with correlative terranes in Queensland and New Caledonia, the Brooks Street Terrane is an exposed cross-section of an extensive Permo-Triassic island-arc system. Most parental magmas were primitive island-arc tholeiites, but other primary magma-types include high-MgO ankaramites and trondhjemites û the latter formed by partial melting of lower crustal clinopyroxene-rich cumulates and gabbros, respectively. The parental ankaramites fractionated to form mafic-ultramafic cumulates and primitive to evolved melts of high-Al basalt to andesite compositions (Takitimus). The Brook Street Terrane is an analogue for modern intra-oceanic islandarc systems and allows detailed study of subvolcanic arc processes.

Jan 1, 2005

By R Berthelsen

The Peak Gold Mines Pty Ltd (PGM) operations are located approximately 9 km south of Cobar, NSW. PGM currently mines and treats ore from three separate orebodies within 5 km of the original plant. Production from the original Peak orebody ceased in April 2002, with ore currently sourced from underground at New Occidental and Perseverance, while New Cobar supplies ore from an open cut mine. In March 2003, Wheaton Minerals Asia Pacific purchased the operation from Rio Tinto who operated the mine for around ten years. The Perseverance deposit is situated between 600 and 1000 m south of the Peak orebody. Access is via shaft from Peak to 630 m below surface and then by decline to the northern end of the deposit locally known as Zone A. Development of the resource commenced mid 2002 to set up for a long hole open stoping operation at 25 m level spacing. The first production stope was successfully brought on line December 2003. The Perseverance deposit is hosted by sediments and volcanics along the eastern margin of the Devonian Cobar basin and is one of many deposits with the Cobar Gold Field. The Cobar Gold Field has produced approximately 2.5 million ounces of gold since 1880. The Perseverance area had long been considered prospective due to the presence of old workings at the southern extensions of Peak line of lode. Significant mineralisation was first discovered at Perseverance in 1994 when PGM drilled a hole targeted 950 m below the historic workings. The target was based on an apparent plunge to the stratigraphic controls to the Peak Orebody. Subsequent exploration within and around the ægreaterÆ Perseverance area has been significantly aided through the use of downhole electro-magnetic surveys due to the close spatial association between gold and sulfide mineralisation.

Jan 1, 2004

By G Gibson

Realising that current roadway development performance levels were unlikely to sustain new generation high-capacity (15 Mt/a) longwall mines then being planned, the Australian Coal Association Research Program (ACARP) established a Roadway Development Task Group (RDTG) in 2005 to develop a research strategy targeted at improving roadway development performance in Australian longwall mines. The initial phase of the project identified a number of factors that differentiated best practice mines from others, and proposed a multi-faceted research strategy encompassing both short- and long-term research initiatives, including:conducting regular benchmarking studies across the industry to identify factors contributing to improved performance and to monitor performance trends,conducting regular industry roadway development operatorsÆ workshops to facilitate the transfer of successful roadway development improvement initiatives throughout the industry and facilitate networking between development practitioners,development of alternative skin reinforcement and containment measures that would eliminate the use of steel mesh and enable face support systems to be fully automated,development of automated bolting and mesh handling systems that would enable operators to be removed from the immediate face area,development of a body of knowledge of industry roadway development practice,development of a web-based information management system to capture and transfer emerging developments in roadway development practice and technology,reviewing the Australian civil tunnelling and underground metalliferous mining sectors to identify practices and technologies that could potentially be utilised to improve roadway development performance, anddeveloping a new generation high-capacity mining system capable of +10 metres per operating hour for 20 or more hours per day (CM2010). The paper reports on the progress of the above initiatives and outlines strategies to continue the pursuit for improved roadway development performance.

Jan 1, 2008

By J Szymanski, S Planeta

Extensive rockfill cylinder testing was performed to determine the effect that aggregate size, aggregate moisture, Portland cement, fly ash and cement dispersant addition has on compressive strength of a cemented backfill. In this paper ætwo-level factorialÆ and æcentral compositeÆ designs were used to determine the single and interaction effects that each factor have on the overall strength. The results from the designwork indicated that the per cent of aggregate fines had the greatest influence on the compressive strength of the rockfill cylinders. From the factorial design results, a compressive strength estimation equation was derived, which enables the strength to be estimated, given varying input values.

Jan 1, 1998

The St George orebodies are situated within the tectonically disrupted eastern limb of the Boogardie Syncline.Highly disturbed rafts of banded chert formations occur within a sequence of felsic volcanic tuffs. The chert forms the hostrock for the gold mineralization.The gold distribution within the irregular and narrow banded chert formations is erratic and patchy. The average gold content of the two orebodies is between 3 - 4 g/t Au.Economic mining of these relative small, irregular and low grade St. George orebodies can be carried out by using a highly selective mining method.The highly selective mining method uses an excavator as the principle mining tool. Blasting, breaking and loading of the rocks is done in a different way than by using a front-end loader as with the conventional mining method. Simple, and therefore cheaper, blasting breaks the rocks and lifts them up without major displacements.

Jan 1, 1984

Both blast furnace and steel furnace slags have been used extensively and successfully on main line railroads in the United States for more than 25 years. Annually, these slags are being used as ballast at the rate of about 4 million tonnes of blast furnace slag and 1 mil- lion tonnes of steel furnace slag, much of it on main line with 90 metric tonne car loadings. More steel furnace slag would be used if it was available. Both slags meet all the specification limits of the American Railway Engineering Association. Actual use on high density rail- roads has confirmed the long range economics of their use. Comparison of laboratory tests, such as Los Angeles abrasion, with actual field per- formance has shown conclusively that commonly used laboratory tests can not be used to accu- rately compare the quality of various types of ballast materials.

Jan 1, 1979

By Thomas E. G

In the economic evaluation of any Australian mining project, changes in taxation can significantly affect viability. Australian tax laws, particularly in the period since early 1973, have undergone many changes which have led to shifts in the profitability of mining companies. This paper examines the sensitivity of a selected, broadly based sample of Australian mining companies to the changes that have occurred, or are reasonably likely to occur, in taxation legislation. In the past, tax systems have been altered for a variety of reasons, such as 1. reduction'in the impact of inflation 2. neutralization of incidence between different sections of the economy 3. as an incentive to encourage expansion and growth in a particular industry or area, and 4. increase in the real "take" of government. In this paper, conventional rate of return analyses are applied in a study of how profitability is affected under various taxation systems.

Jan 1, 1977

By R Trueman

An improved ability to predict dilution for narrow vein deposits enables more accurate economic comparisons between mechanised longhole stoping and other narrow vein mining methods, as well as reducing uncertainty surrounding dilution estimates for deposits at the prefeasibility/ feasibility stage. This paper proposes narrow vein dilution prediction and minimisation strategies for both greenfield sites and operating mines, respectively. The narrow vein dilution method (NVD method) is a tool for more accurately predicting longhole narrow vein dilution. The method is based on a new concept called benchmark stoping width. Benchmark stoping width is based on probabilistic analysis of overbreak distributions from a typical longhole narrow vein mine. The premise for the NVD method is that dilution associated with longhole stoping can be predicted using the benchmark stoping width. In addition to dilution prediction, the NVD method also includes strategies for narrow vein dilution minimisation generally, including; filling, cablebolting, stress relaxation, extraction sequencing and blast overbreak.

Jan 1, 2008

By Yu AB, Azahari HL

Indonesia has the largest coal reserves in the south-east Asian region. According to estimates from the World Energy Confer- ence, it has reserves of 18 billion mt lignite, 4.4 billion mt sub-bituminous coal and 774 million mt bituminous coal (Wyllie,1988). In recent years, substitution of coal for oil in power plants has been the goal of the Indonesian government since proven deposits of coal are about five times as large as national hydrocarbon reserves and most of Indonesia's power stations are still oil fired. Recently a coal fired power plant has been built in Java Barat, which will have a full capacity of about 3000 MW. It is intended to supply coal for this power plant from Bukit Asam mining area (South Sumatra). Coals from Bukit Asam - which are of the lignite or brown coal type - usually contain considerable moisture . It should be noted that reference to moisture in coal pertains to the total moisture content. This is comprised of what is commonly termed as equilibrium moisture and surface moisture. Surface moisture typically affects combustion process as well as pulveriser performance since it possibly influences the relative ease with which coal may be ground. In practice, the surface moisture produces agglomeration of the fines in the pulverising zone and reduces pulveriser drying capacity because of the inability to remove the fines as quickly as they are produced. This agglomeration has also the same effect as coarse coal during the combustion process because the surface area available for the chemical reaction is reduced, hence the combustion efficiency is also reduced. The influence of the moisture of some coals on their grindability (Hardgrove Grindability Index) has been previously correlated by several authors; some of them will be mentioned later. Those correlations, however, could not be immediately applied to any coal since it is still believed that there are other factors which influence the grindability of the coal, such as type and rank of the coal. The relationship between coal moisture content and its grindability has been investigated by Ellmann and Belter (1955). It was found that, for North Dakota lignites, the grindability varied as the moisture content changed. In Britain, Fitton, Hughes and Hurley (1957) stated that, for Bilsthorpe coal, over a wide range of free moisture content (from air-dried to about 30 per cent moisture), the Hardgrove Grindability Index (HGI) remains virtually unchanged. In addition to that, it was suggested that it would be slightly advantageous to dry the coal below its air-dried moisture content (at temperature ¦ 100¦C) to increase the ease with which coal could be ground, especially for low-volatile coal and high-volatile non-caking coal. Furthermore, it was also concluded that a broad relationship appeared between coal rank and Grindability.

Jan 1, 1993