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In preparation of this Paper, the emphasis has been laid on the commercial rather than on the technical and scientific aspects of coal evaluation. It is intended to describe and comment on the principal factors which currently determine the selection and procurement of coking coal for the steel industry, and is not based on the results of any original research by the author. Evaluation of different coals for strictly thermal uses, for gas production or other chemical applications has not been attempted, and comparisons of coal with other fuels have been excluded: the paper is concerned only with coals for the production of blast furnace coke. The discussion is strongly related to, and illustrated by, British, and to some extent, other Western European practice, but it is hoped that the general conclusions may have a wider application.

Jan 1, 1975

Neutralisation, normally using lime, is the most widely used method for treating high flows of acid mine drainage (AMD). Lime costs can be very high however. If carbonate sources could be used to achieve pH values above six, costs could be greatly reduced. For example, use of locally quarried limestone at Mt Lyell could potentially reduce alkali costs from about $A 3.5 to $A 1 million/year. Methods for enhancing the effectiveness of limestone and magnesite for neutralising Mt Lyell and Savage River AMD respectively have been examined through a series of investigations. Small-scale testwork found that the maximum pH economically achievable with ground limestone was about five, due to slow dissolution rates and surface armouring. The problems of surface armouring were greatly reduced by the use of crushed limestone or magnesite at high pulp densities (75 per cent solids w/w), enabling pH values >6 to be achieved in a practical time frame. The use of particle sizes in the range 6 mm and finer also reduces costs by avoiding the need for grinding, and reduces the problems of solid-liquid separation and solid recycling that arise if large additions of ground carbonate are used. Pilot scale tests were carried out using tumbling drum reactors with limestone and Mt Lyell AMD and a pulsed-bed static reactor with magnesite and Savage River AMD. pH values averaging 6.2 and 6.4 were achieved with Mt Lyell and Savage River AMD respectively. Approximately 80 per cent of feed acidity was neutralised. A preliminary engineering design and cost estimate has been completed on the pulsed-bed reactor and shows that the concept is technically feasible and, if results are confirmed, economically attractive. Further pilot testing is planned.

Jan 1, 2002

Australia, with its fast-growing economy and high standard of a~ living, has a high and rapidly increasing per capita consumption of energyIn total terms, Australia's energy requirements are doubling every 15 years, and among mature Western economies Australia ranks behind only Italy-and Japan in the rate of increase of energy consumption.The use of energy is often accepted as a yardstick of development and on this basis Australia might well congratulate itself on its high energy consumption. However, it is less well recognised that the resources absorbed in the production of energy represent a real cost to the* community, and that just as we strive for industrial efficiency or farm productivity we should strive for economy in the use of energy fuels.Australians spend annually an estimated ú500 million.on all forms of energy, a sum which represents about seven per cent of the Gross National Product. In all, energy production and distribution absorb the employment of more than 100,000 persons. In addition, the annual capital investment by.the oil industry amounts to some E55 millions, by the coal industry about ú12 millions, and by electrical and gas authorities some E108 millions, in total representing more than ten per cent of annual investment in other than private motor cars and housing,

Jan 1, 1962

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 Kavetsy A

In surface mining operations, the ease with which a muckpile may be dug is a dominant factor in mining efficiency. Within broad limits this is largely independent of the fragment size dis- tribution, since the equipment used to move the broken rock is generally larger than in underground mines. In such cases, muck- pile shape and voids ratio within a muckpile heavily influence mine productivity. In a particular operation, the muckpile shape after blasting should be tailored to the digging equipment being used. A front- end loader is best suited to a low, flat-lying, loose muckpile, because of its fairly good mobility and small break-out force with its bucket. In contrast, a rope shovel lacks mobility, generates a much larger break-out force with its bucket, and fills its bucket in a vertical filling motion. Therefore, it is ideally suited to well fragmented, steep faces. In situations where a dragline is used, the requirement for a suitable muckpile depends on the operat- ing scheme of the dragline. For a conventional highwall key method the preferred work- ing level of the dragline is the same as the highwall, so that the dragline may sit over its key. In this situation, the ideal muck- pile shape involves relatively little displacement of the fragmented rock, with a minimal "power trough" at the back of the blast. In throw blasting, on the other hand, it is desirable to cast as much of the spoil as possible across the pit. It is then necessary to optimize the blast design by maximizing the throw percentage under any necessary constraints (e.g. damage, vibration, flyrock, explosive cost).

Jan 1, 1988

By Millen M. J, Rainey S, Sowerby B. D

The control of size reduction in grinding machines and circuits may be enhanced by a continuous and accurate measurement of the particle size of solids in appropriate process streams. This paper presents a brief review of commercial particle s

Jan 1, 1997

By K Hines

Anglo Platinum is the worldÆs largest producer of platinum group metals, and also produces large quantities of nickel, copper and cobalt at its Refining complex in Rustenburg, South Africa. In 1995 Anglo Platinum embarked on a smelter modernisation project, primarily to reduce site emissions to below the guideline limit of 20 tonnes per day SO2, but also to increase the converting capacity in line with future projected production profiles. To achieve these requirements the existing Pierce Smith converters were replaced with a single large Ausmelt converter and a new acid plant. This was the first time that an Ausmelt furnace had been used for converting, but it had the advantages of being a very robust furnace and was fully enclosed, giving good gas capture. It was thus considered the most appropriate technology from both a process and an environmental perspective. It also enabled the smelting and converting furnaces to be decoupled. The plant was commissioned from late 2001 and the first tap was in June 2002. Despite being a new technology, ramp-up has been similar to other large scale pyrometallurgical operations. Numerous process improvements have been made since start-up, most notably a change from two-stage batch to fully continuous, resulting in the plant now operating above design in terms of throughput. Optimisation of freeboard accretion control was also a major component of the ramp-up activity. This paper discusses the commissioning and ramp-up issues of the new Ausmelt converting furnace, concentrating on the design and process changes, and summarises current operating performance against the original design objectives.

Jan 1, 2005

By A B. Christie

In Northland, Coromandel, Taupo and Canterbury, weathering and hydrothermal alteration of Cenozoic volcanic rocks has resulted in the formation of various types of clay deposits. Subtropical weathering of rhyolite in the Matauri Bay area (Matauri and Mahimahi deposits) in Northland has formed high quality halloysite deposits. The Matauri Bay halloysite is mined and processed to produce reputedly æthe world's whitest clayÆ that commands a high price in niche ceramic markets. In the Coromandel, some argillic alteration zones contain kaolinite clays (at Hahei) and advanced argillic alteration zones contain kaolinite-gibbsite-pyrophyllite assemblages (at Pumpkin Hill and Lookout Rocks). In addition to known halloysite and kaolinite clay deposits, there is also economic potential for smectite clays produced by hydrothermal alteration of volcanic rocks. Bentonite (mainly ferriferous-beidellite) is mined from weathered basaltic ash in Miocene lake beds at Coalgate in Canterbury.   We have compiled interim mineral deposit profiles for bentonite in basaltic ash, halloysite in rhyolite, kaolinite in altered rhyolitic rocks, kaolinite-gibbsite-pyrophyllite clays in advanced argillic alteration zones and for smectite clays in argillic alteration zones. These deposit profiles include geological and mineralogical attributes, which are linked to the underlying volcanic, hydrothermal and weathering processes that have produced the clay minerals from their source volcanic rocks. Further work on refining the deposit profiles includes characterising the composition of selected deposits to determine spatial trends in mineralogy and geochemistry.

Jan 1, 2007

The Closure Risk model was developed as a new tool to aid decision makers in the complex area of mine closure. It uses a simple analytical technique that allows the decision maker to simplify what is often a complex mine closure process into more easily managed sub components. This systematic approach ensures that critical factors in the closure process are not overlooked. It also allows the most important issues to be highlighted. The model can also be used to produce quantitative estimates of risk by weighting and prioritising the issues to produce the Closure Risk Factor (CRF). Field trials at several mine sites in the Northern Territory of Australia in 2001 tested the model. The trials confirmed that the model has significant potential as a tool for decision-makers to assess in a structured, systematic manner, the major closure risks at individual mine sites. The risks include not only environmental impacts but safety and health, community, legal, financial, technical and other issues. The trials confirmed the value of a team-based approach and the inputs of key staff including environmental, production, mine planning, and community liaison personnel as well as mine management. Although the usefulness of the qualitative component of the model was established, it was found that, due to the influence of subjectivity, the utility of the prototype model to determine quantitative risk was of limited value. Using a continuous improvement approach, improvements to the model were sought. A refined model, incorporating the Australian Standard 4360 definition of risk and facilitated in-house risk assessment sessions was developed and tested against the data obtained in the field trial. This model, while maintaining the qualitative strengths of the original, allows more accurate absolute and relative quantitative scores to be calculated. This in turn facilitates comparisons between the issues at a single site as well as between different mines.

Jan 1, 2003

Secondary steelmaking (or ladle metallurgy) has been developed as a post- steelmaking ladle treatment to produce steel of superior quality. Its rapid growth has resulted from quality improvements, productivity increase, operational flexibility and process route economics. Advances in secondary steelmaking are very impressive during the past decade, and many commercial systems have been developed for performing one or more of the following unit operations: degassing, atmosphere regulation, reheating, refining with synthetic slag, rinsing gas treatment, injection of solid materials and alloying. The metallurgical requirements imposed by the current competitive steel market include more precise analysis tolerances, minimum level of detrimental elements, improved cleanness, demanding service performance and better processability. In most cases, these requirements could only be realized by the application of appropriate secondary refining facilities. Continuing developments in simplicity of design, cost advantage, quick cycle time, improvements in peripheral services such as refractories, instrumentation and in-situ analysis, extensive exploration of new applications, and the use of computer, can be expected. An exciting future is predicted for the widespread adoption of secondary steelmaking to perform most of the major refining functions over a variety of steel quality. It will also become a vital link in the total steelmaking process for production of tonnage steel at the large integrated steelworks and the mini-steelmills.

Jan 1, 1986

By Artone E

screening equipment installed in e Hamersley Iron operation is described, and tails of operating parameters and screening - Iia in use are given. Tests were carried out on full-size reens in the operating plants to study the Meets of mat aperture size, feed size distri 1,ution, feed rate, screen speed and throw, angle of inclination, and feed moisture content n screen performance. Sampling equipment was signed so that undersize samples could be htained from various locations along the length of the screen, thus providing information pout the quantity and size of particles passing òhro gh the screen at any point. Conclusions derived from the testwork and relevance of these to the Hamersley Iron aeration are discussed.

Jan 1, 1984

By P J. Scales, D Boger

Technological advancements in mineral processing have increased the feasibility of refining low-grade ores. Because of this progression and continual depletion of high-grade ore deposits, much larger volumes of waste material are produced. At the same time, increasing environmental legislation and cost competitiveness dictate that these wastes be disposed of in a manner that is both environmentally acceptable and economically viable. To achieve these criteria, many mineral processing industries are dewatering waste streams in order to reduce the volume of tailings and increase water and reagent recovery. The subsequent dry disposal of these highly concentrated mineral tailings requires a thorough understanding of the effects of dewatering on the flow characteristics. Dry disposal represents a paradigm shift in engineering. The tailings are engineered to suit the disposal requirements, as opposed to engineering a facility to accommodate the tailings. It is therefore important to understand how the material properties and operational parameters can be modified to produce the desired tailings flow and deposition characteristics. As concentrated suspensions usually exhibit non-Newtonian behaviour, determination of the disposal plant operating conditions requires a thorough understanding of the rheological characteristics of the material. The implementation and optimisation of dry disposal methods involves three concurrent and interdependent rheological studies to determine:the concentration required to achieve the optimum spreading and drying characteristics of the tailings once deposited; the optimum conditions for pipeline transport; and the feasibility of dewatering the slurry to the required concentration. The paper presents an overview of the issues pertinent to management of the flow properties and processing of dewatered waste streams.

Jan 1, 2002

In 1939 at the annual meeting of the Australasian Association for the Advancement of Science, held at Canberra, a paper was contributed by E. de C: Clarke and H. A. Ellist in which a plea was made for more "facts" concerning metasomatism near ore-bodies in Western Australia. From time to time writers here, and in other parts of the world, have discussed the alterations in wall rocks of various reefs and lodes, but little has yet been attempted in the matter of accumulation of quantitative data, both chemical and mineralogical, and in the correlation and comparative study of this data. Such a detailed comparative study is needed to determine the economic value of a practical application of our accumulated knowledge of the phenomena of metasomatism.When in 1939 the opportunity offered for an examination of the core from 4 bores recently put down by the Big Bell Mines Ltd., to explore the ore-body of the Corinthian G.M. 10 miles N.W. of Southern Cross, Western Australia it was hoped that some small beginnings might be made of an accumulation of comparative and quantitative data regarding the metasomatism of the wall rock immediately adjacent to this ore-body.By the courtesy of the Big Bell Mines Ltd., the core from the 4 bores was delivered to Survey Headquarters, Perth;in the middle of June, 1939 and copies of assay plans of part of the underground workings at Corinthian, and of the results of assays of the bore cores, were also supplied by the management of the above company.It was not, however, until March, 1940, that it was 'found possible to investigate the core. At that time the writer's colleague, Mr. R. S. Matheson, conducted a: megascopic examination of all the bores and selected material from two of these for possible future chemical analyses. Late in 1940 the writer commenced a microscopic petrological examination of this material.AIM OF THE INVESTIGATIONThe object of the petrological part of this investigation was to determine whether from a megascopic and microscopic examination of the core, any evidence could be obtained indicating changes, in mineralogical composition...

Jan 1, 1942

A major new mine to be developed at Pike River during 2005 has been designed to have a minimal impact upon the environment, and an overall net conservation gain. The Pike River Coalfield is located on the West Coast of the South Island of New Zealand on the top of the Paparoa Range approximately 46 km north east of the coastal town of Greymouth. Pike River Coal Company Ltd (PRCC) holds a 40 year mining permit over the coalfield.   In October 2004, the Minister of Conservation granted PRCC access through 1.25 km of Department of Conservation land via an access agreement, and the Environment Court issued a number of consents for the development and operation of the mine, in addition to some existing consents.   The underground mine at Pike River is located under land administered by Department of Conservation, and has been designed to avoid or mitigate adverse environmental effects and integrate into the natural bush surroundings. The mine process has been designed to operate within an environmentally sensitive area and will incorporate technologically advanced methods of mining and processing. The mine process involves hydro mining of the coal, and transportation via a 12 km coal water slurry pipeline, to a dewatering complex located on PRCC land. This will ensure that traffic in the Pike River Catchment up to the mine is minimised.   An extensive series of management plans and monitoring programmes will be used to ensure that the environmental effects of the mine activities are minimised, by evaluating the performance of managerial procedures, and physical mechanisms in place to avoid or mitigate the effects. Trial mining and substance management plans in conjunction with an orthophoto and surface monitoring protocol will ensure that surface features, and water ways are protected from any adverse effects. The Blue Duck enhancement, and pest and predator control programme will help ensure that an overall net conservation gain is achieved.   Developing transparent working relationships and good communication with Department of Conservation, Iwi (Ngati Waewae and Ngai Tahu), and local environment groups has been and remains very important in the development of this project.

Jan 1, 2005

'Industrial Minerals - their mining and use in New Zealand' is the theme of the 1978 Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy. This paper describes the use of phosphate rock, sulphur and potassium chloride (potash) - three industrial minerals which have enabled the farmers of New Zealand to increase production to current levels. The growth of imports of these raw materials for the New Zealand fertiliser industry is well documented in NZ Fertiliser Statistics 1977. This is the most recent of the Ministry of Agriculture and Fisheries annual publications on this Subject prepared from the detailed returns of fertiliser manufacture and sales from each fertiliser works. There are now 12 of these works in New Zealand one of the most recently established being in Whangarie where this conference is being held. Its capacity to manufacture superphosphate will shortly be 300 000 tonnes twice that when it opened late in 1964. New grinding and manufacturing equipment comes on stream early in 1979. This paper illustrates the interdependence of two primary industries, agriculture and mining. New Zealand's economy in the foreseeable future will be based on agriculture so that our standard of living is dependent on the overseas prices and freight costs of the bulk raw materials from which our fertilisers are made. For the year ended 31 March 1978 New Zealand's total exports were $3395 million, of this total $2413 million (71%) came from the products of pastoral agriculture (wheat, wool, dairy and other animal products), $291 million from forest products and $501 (15%) from manufactured exports. Approximately half of the pastoral receipts can be attributed to the fertilisers applied at a total cost of about $200 million including subsidy.

Jan 1, 1978

By D Langberg, R Taylor

Many metallurgical operations produce fine residues and dusts as by-products which can be difficult to handle and offer little direct financial incentive to treat. There is a growing imperative to deal with these materials particularly since land fill is fast becoming an uncertain long term solution. One possible means of treatment is to extract the valuable metals while fusing the remainder into a slag. In this way valuable metal components of the material can be recovered and the less valuable components be converted into useful products, eg cements and inorganic polymers which have a high environmental stability and a growing market. The aim of this project is to establish solids injection and fusion in a slag bath as a viable method of treating industrial wastes and residues. The benefits of this approach are expected to be: the ability to treat a wide range of organic and inorganic residue materials, ease of recovery of volatile and valuable elements and the production of final materials which could be used in other industries. In ongoing experimental work at the CSIRO Minerals a 250 kg slag bath reactor has been used to test the injection of Paragoethite residue into an iron silicate based slag. An experimental apparatus has been designed and commissioned to pneumatically inject solid material at feed rates of up to 80 kg/hour. The capture efficiency of injected solids by the slag bath was calculated by monitoring the composition of the slag. Using this method of treatment, the zinc contained in the residue can be recovered as a fume by varying the oxidation state of the slag. Other valuable elements could be recovered by creating a matte or metal phase in the reactor with the final material being used in the production of cement. A capture efficiency of injected solid paragoethite particles in the slag bath of up to 97 per cent was achieved. Under the conditions of the experimental work capture efficiency was found to be independent of injection velocity and slag depth. The rate of fuming during injection was found to increase slightly with injection velocity and was independent of slag depth.

Jan 1, 2002

THE absence of any locality maps of the district of Morobe has been seriously felt by mining engineers engaged on the goldfields, and as it was evident at the beginning of operations that the administration would be unable to make good this deficiency, ascheme for making rapid traverses was worked out, and in all subsequent travelling the necessary records were kept for the construction of a reliable reconnaissance map of the Bulolo goldfield and its approaches (see Plate 1.). Since all the field work had tobe carried out without encroaching on primary duties, the compilation of sufficient data was a somewhat lengthy business. It was found that in this r;ough country a pedometer was useless, as it was impossible to calibrate it for the variation in length ofpace between climbing semi-precipices and walking over level country. Further, the native tracks "meander" so excessively that the only method of calculating air-line distance is by timing, and a knowledge of what the timing represents, and until a 10kg experience had been gained in the time taken to cover known distances in various types of-country, one could not feel competent to estimate sufficiently accurately. It was found that reliability could be attained only when walking at nearly top pace. Inregard to aeroplane traverses, results were reliable only when the air was fairly still.BEARINGSIn arriving at the bearing between main traverse points, the method used was to keep a "boy" about two chains- behind when marching and sight back on him, standing, at about two-chain intervals. These bearings were averaged into the field book at the end of the day, each line being averaged separately. As the roads became known, it was possible to get a considerable amount...

Jan 1, 1928

By Hanley J

Coal winning in the Latrobe Valley exceeds 45 mtpa uses a small number of Bucket Wheel Excavators and high speed conveyor systems. While this equipment offers many advantages in the production cycle, incorrect use can lead to low productivity and risks to the safety of the operators and equipment. The mining equipment is of high capital value and easily damaged when used outside the correct operating range. In the extreme case, this can result in total machine collapse, having major implications for personnel safety as well as production and costs. With an active productivity improvement program in the Latrobe Valley in the last two years resulting in a 50 per cent reduction of personnel, many experienced operators have retired. Mine management are facing the urgent need to rapidly train new operators to maintain high productivity levels and reduce the risk of accidents to personnel and high capital cost plant. With the assistance of the Central Gippsland College of TAFE a Certificate Level course has been developed for open cut operators. The course covers all essential training needs for the Latrobe Valley mines. The training is developed from National Competency Standards, allowing transfer of skills, and is flexible to suit other enterprises. It has been written for self-paced learning with the total job understanding, and to have competency-based learning outcomes, training tasks and assessments built-in to modules. With the introduction of this new training program, management is convinced that the element of risk within the mine will be significantly reduced. For these reasons it is an ideal training model for other enterprises.

Jan 1, 1994

Projected cooling requirements for ERPM led to the first proposals for the large- scale use of ice for mine cooling in the early 1980's. Following successful research into ice conveying and ice melting a large ice plant was commissioned at Harmony in 1985 and a much larger 6000 ton per day plant is presently under construction at ERPM. A brief description of the mining project is given, followed by general descriptions of the surface ice plants and the ice conveying system, the systems for using the ice for mine cooling, and the control of the whole ice cooling System.

Jan 1, 1988

The Beaconsfield gold mine processing plant is a complex operation and utilises crushing, grinding, gravity gold concentration, sulfide flotation, bacterial oxidation, cyanidation and zinc cementation to recover gold from the partially refractory ore. This paper discusses the challenges, developments and advancements throughout the processing plant since start up, which have culminated in a 25 per cent increase in the mill throughput over the nameplate design and a concomitant gold recovery increase from 75 to 92 per cent. The improvements have been attained via advancements in mechanical integrity, metallurgical review, process control and operator training, resulting in the current operation producing over 630 000 ounces of gold to date.

Jan 1, 2007