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By Sanders GJ

Coals from the Southern Coalfield of New South Wales treated in the Port Kembla coal preparation plants of Australian Iron and Steel Pty Ltd differ substantially in their characteristics. Knowledge of, performance not only enables comparison and promotes better control, but also provides the means for predicting results. Evaluation of performance of cleaning equipment has been made in terms of probable error (Ep.) Results for Baum jigs, a Chance cone, heavy medium cyclones and water washing cyclones are examined. The efficiency factors derived from the probable error are applied to the float and sink analysis, mathematically simulating operating conditions. This method is applied to the Balgownie seam. The Balgownie seam lies between the Bulli and Wongawilli seams in the Coal measures of the South Coast and mining on a large scale began recently in the Bulli area. It is known locally as the Four Foot seam and exhibits er difficult washability characteristics, due to a comparatively high middlings content. These properties and the tively high inherent ash make careful selection of cleaning equipment essential for optimum recovery. The prediction technique is used to determine the possible results when this coal is cleaned in the Port Kembla plants. Predicted values are compared with results from full scale trial washings demonstrating the validity and accuracy of the technique. Applications of result forecasting are listed.

Jan 1, 1970

This paper discusses the significant land use changes that have occurred in the Latrobe Valley during 150 years of white occupation. The developments and changes were haphazard and made with little thought as to their setting or their environmental consequences. As a result many landscape and land management problems have not been addressed.This paper contends that the mistakes will continue unless an overall plan for the landscape of the area is developed and implemented. The concept of 'Greening the Valley' is introduced. It aims to provide focus for a comprehensive co-ordinated plan which caters for the need to restore the landscape and the need to provide for future land use. The plan will seek to draw on three major landscape features of the Latrobe Valley: the natural setting of the hills, rivers, valleys and forests; the agricultural land use including the forestry plantations; and the industrial complexes and urban areas.Rehabilitation of mining areas is a key element of the plan but must be put in a regional context and not be treated as an isolated function of a single organisation. A major challenge will be to integrate the worked out areas into useful and significant landscapes. The paper concludes by explaining the process that will be followed in an attempt to realise the concept.

Jan 1, 1992

By Worner H. K

The paper briefly summarises the work of the Titanium Research Section in the Metallurgy Department of the University of Melbourne and mentions the development of a new electrolytic process for titanium production. This process utilises the "hot-spot" cathode technique and titanium carbide anodes. An introduction is given to three further papers on titanium metallurgy to be presented to the Institute.INTRODUCTIONThe unique combination of strength, lightness and corrosion resistance possessed :by titanium and its, alloy has made them of great interest to engineers. However, high cost, difficulties of production and limited knowledge of techniques of application restrict their usage at present almost exclusively to high priority armaments.The cost of the metal is divided between extraction and processing and much research has been carried out to devise new and cheaper methods for winning the metal from its ores. Processing costs will be reduced when production volume increases.Extraction research is proceeding rapidly overseas and Kellogg (1955, p. 72) reports that 'at least seventeen companies in the U.S.A. are interested in titanium production. Of these, two are producing the metal by a modified Kroll process, three are building Kroll plants and the remainder are in various stages of research activity. The Horizons Corporation alone is contemplating electrolytic extraction and is building a pilot plant. Steinberg et aI. (1955, p. 252, p. 332) have reported the early work done by the HorizonsCorporation on electrolysis of potassium fluotitanate and titanium monoxide in fused salt electrolytes. Of these two, the former appears to be the more attractive process.

Jan 1, 1956

By A D. Bugarski, B R. Conard, G H. Sc

The objective, of the Diesel Emissions Evaluation Program (DEEP)-sponsored project at IncoÆs Stobie mine, was to conduct a long-term field evaluation of selected diesel particulate filter (DPF) systems, available to the underground mining industry. Nine state-of-the-art DPF systems were retrofitted to heavy-duty and light-duty vehicles and were subjected to extensive long-term in-mine evaluation. Periodic efficiency tests were conducted at various stages of the study (in 2001, 2002 and 2004) to establish in-use efficiencies and durabilities of the tested DPF systems. During efficiency tests, the vehicles/engines were operated over several steady-state operating conditions. Various instruments were used to measure particulate and gaseous emissions upstream and downstream of the filter systems. The results were used to assess the effects of the filter systems on the concentrations of diesel particulate matter (DPM), nitric oxide, nitrogen dioxide and carbon monoxide in the vehicle exhaust. Experience with the operational issues related to deployment of the filter systems on underground mining vehicles, coupled with the assessment of the filtration efficiencies, were the primary objectives of the study. The variety of filtration systems and regeneration concepts used in this study offered the opportunity to investigate the advantages and disadvantages of the various types. Some of the major issues studied were criteria for selecting the filter media, means of regeneration, the long-term operational reliability, and the occurrence of unwanted secondary emissions.

Jan 1, 2005

By Keys NJ

The so-called COMAT process provides a method for leaching low grade sulphide mattes in an acidic ferric sulphate medium in such a way that non ferrous base metals such as Ni,Cu and Co are substantially all dissolved; the concentration of residual acid and dissolved iron remaining in the leaching solution is low, and a large portion of the sulphide sulphur is converted to elemental sulphur. Thus the quantity of neutralising agents required to remove residual acid and dissolved iron from the leach solution prior to subsequent recovery of the dissolved base metals is greatly reduced. The leach residue and iron precip- itate report in a readily filterable form. In this paper results obtained on a pilot plant scale are presented for the leaching of a typical low grade matte in the manner describ- ed above; for the solvent extraction and elec- trowinning of copper, and for the removal of residual acid, copper and iron from the copper solvent extraction raffinate. Processes tested on a laboratory scale for the further recovery of cobalt and nickel by solvent extraction and electrowinning, and for the recovery of sulphuric acid and ammonium hydr- oxide from the dissolved ammonium sulphate salt contained in the final plant effluent, are also briefly described.

Jan 1, 1986

The able address on the currency question given by the Right Honorable A. J. Balfour, M.P., late leader of the Government, at the Mansion House lately, before a large and influential audience, will strike a key-note that will resound throughout the world. It is high time that gentlemen of position and influence should come forward and express their views on this subject, so as to cause the matter to be,more seriously considered than it has been. The question can be no longer ignored or treated with indifference by bankers, financiers, merchants, miners, and others interested in the settlment on some basis the relative values gold and silver bear to each other. It is gratifying to not that such a great leader of political opinion as Mr. Balfour has given serious attention to this important question.The address created a deep impression ,on the minds of many who probably had not given the matter much att.ention, and Mr. Balfour's words will re-echo over a wide range of thought with such effect that I have no doubt they will materially help to check the downward tendency of the value and uses of silver. As a mining engineer, interested in the development of our mining resources for increasing gold aud silver for currency, and having devoted much attention to the subject, I cordially approve of the views set forth by Mr. Balfouf, and I think the general body of all interested in the production of gold and silver will do the same.

Water is a key resource input to copper heap leach operations in both quality and quantity. A number of recent developments in analysis of the technology have shown that water consumption can be optimised. The leach consumption has been generally considered in terms of minimisation of the evaporative loss by changing the application method (drippers or wobblers). Modelling of the irrigation effects on leach rate has shown that the poorer surface coverage from drippers has an adverse effect on the leach extraction rate. This is particularly evident in the early part of the leach. The use of different irrigation systems during alternate parts of the leach cycle can have benefits in minimising the water consumption without an unacceptable outcome from extended extraction times. By combining the leach rate effect with the evaporative loss estimates, an economic decision matrix can be generated to allow the operator to select an appropriate leach irrigation strategy, combining both irrigation delivery and irrigation rate. In the SX-EW plant, the total quantity of EW bleed and SX scrub stage bleed (both for iron control) can be reduced to an absolute minimum. The economic minimum may be different depending on the cost of producing the high-quality water used to replace the bleed streams. Adjustment of the SX process, in particular use of multiple entrainment control steps, can provide significant reductions in the total bleed and make up requirements.

Jan 1, 2003

The Tregoora Gold Project is centred around the old Mitchell River Antimony Field located 100 kilometres west-northwest of Cairns, North Queensland. The project is currently the subject of a joint venture between Strategic Minerals Corporation N.L. and Hawk Investments Limited.Historical BackgroundThe Tregoora area was first prospected for antimony and gold around 1890. During the periods 1905 to 1914 and 1937 and 1944 approximately 100 tonnes of antimony and an unknown quantity of gold were won from a number of small mines the principal one being the "Retina". A strong increase in the demand for antimony in the early 1970's resulted in renewed exploration activity in the region and the re-development of the Retina Mine. Despite the intermittent interest in the region for antimony it was not until 1984 that the potential of the area for hosting gold resources was realised with the delineation by Strategic Minerals Corporation N.L. of a significant gold deposit now referred to as the Black Knight.

Jan 1, 1986

By Eoffe SW

The wide application of computers in beneficiation plants has resulted in the creation of a number of complex automatic control systems at all stages of ore dressing processes. To create such systems it is necessary to solve complex problems of analysis and calculation. The application of computers to solve these problems demands development of simple and effective methods of investigation and simulation of ore dressing process dynamics because all the known methods are complicated in usage and cannot guarantee the desired accuracy and quality of process control. A new grapho-analytical method of investigation and calculation of ore dressing flow sheet dynamics, worked out by the authors of this paper, is based on proportion method development and is used to construct dynamic characteristics of the investigated processes. It is possible to use the given method for investigating benefication schemes with flotation machines having non-linear static characteristics and circulating loads. The suggested method of investigation of concentration flow sheet dynamics allows us to obtain dynamic characteristics of technological process parameters in both linear and non-linear systems. Moreover, the final result can be obtained without labour consuming analytical calculations by a simple graphical construction based on the static characteristics of the known equipment and processes.

Jan 1, 1993

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

The writers of these notes, having conducted some tests on the steam consumption of air compressors under varying conditions, believe that the detailed results of such tests will be of interest to the members of the Institute, and may lead to the contribution of further and more valuable information, of benefit both to manufacturers and users of this class of machinery-to the manufacturer in that he frequently has the opportunity of giving a very thorough test to the machine in the shop, and-tothe user or purchaser by making clear to him what may be reasonably demanded of a high-class machine. It must be remembered that, though of the highest importance, a low steam consumption is but one of the many features of a high-classmachine; for the present, however, it has been considered advisable to confine the paper chiefly to the first-mentioned aspect, with such information concerning the air ends as is obtained along with the steam consumption tests. Unfortunately, too few of these tests are conducted, and but few results are published, therefore the writers feel that no apology is needed in bringing their results before the members.Some nine months ago the Brilliant Extended G. M. Co. was supplied with a compressor by Messrs. Thompson and Co., of Castlemaine, and with the object of testing its actual performance.

Jan 1, 1907

By Davies L, Jeffreys J

The Broken Hill Proprietary Company Limited (BHP) has been successfully using mini computers in its open cut strip and pit coal planning for the past six years. A recent development within the computerised Seam deposit User oriented Mine Planning System (SUMPS) provides the facility for the generation, evaluation, and simulation of colliery workings.Existing computer programs for collieries were studied, but none met the requirements of BHP's underground mine planners.Consequently, it was decided to develop programs, based on those existing within BHP for open cut strip and open cut pit mine planning. The new planning facility was designed to enable any number of proposed colliery developments and operating plans to be evaluated against optimistic, most likely and pessimistic geological lease area interpretations.In mine planning, sensitivity studies should be conducted to determine the likely effects on production, development costs and colliery economics of changes in mine design and budgeted equipment productivity. By automating the manual calculations involved, the computer programs provide the ability to conduct numerous and extensive sensitivity studies. Hence an optimum mine design for budgeting purposes can be derived quickly with an improved degree of confidence in the long term viability of the proposed development.

Jan 1, 1982

By M Ruhrberg, J Grassmann, C Bauer

Within the context of acid mine drainage (AMD) associated with mining activities worldwide there has been a tremendous research effort to determine the extent of AMD and assess the influencing factors controlling this process. However, the majority of the current approaches focus on local and regional scale case studies and do not provide a global scale picture of AMD potentials. This study attempts to develop a method aiming at a global environmental impact assessment related to AMD. To confine the complex topic this study concentrates on acidic emissions from heaps in consequence of copper mining processes. In order to pursue this approach two factors are of significant advantage: a comprehensive environmental data base of more then 600 copper sites worldwide and a method which has been developed and proven to be successful in assessing environmental impacts related to land use. Current and future research efforts focus on using this background knowledge to enable both a comparison between sites and a categorisation of sites according to emission estimates.

Jan 1, 2003

By Seeley D, Buckley N, Goodall J

Improving the performance and reducing the costs associated with export logistics chains is critical to the competitiveness of export coal mines. The fundamental practices associated with the use of export logistics chains made up of mine, trucking, rail and port operations are being challenged by the advent of third party operators on rail systems and the use of the Internet.Whilst individual mines can improve their processes to drive down their mining costs, they face major challenges in their endeavour to improve the performance of export logistics chains and reduce the significant logistics costs of moving coal from the mine to export ships, via the shared infrastructure of rail systems and ports. There is an increasing realisation that global competition is not only between mines but between coal export regions that are defined by their rail system and ports infrastructure.

Jan 1, 1998

Cleaner Production stands for a proactive and preventive approach to industrial environmental management and aims for process- and/or product-integrated solutions that are both ecologically and economically efficient (æeco-efficiencyÆ). Pioneers in the field were large manufacturing and processing industries in the USA (since the late-1970s), but it took until the early-1990s before Cleaner Production was generally recognised as a valuable approach for large and medium sized enterprises. The application of Cleaner Production in mining and minerals, metals and energy production appears to lag behind other sectors, such as manufacturing and processing. This paper starts with a discussion of the Cleaner Production concept and provides examples of its application from a few selected Australian mining and minerals processing industries. This evidences that Cleaner Production can achieve significant reductions in environmental impact, in terms of reduced waste and emission generation and in terms of conservation of materials, energy and water, while simultaneously reducing operating costs. The paper then investigates a number of key issues pertaining to the implementation of Cleaner Production; ie organisation and management of Cleaner Production activities, effective tools for mastering the Cleaner Production concept as a way of life, and performance measurement.

Jan 1, 2002

Existing fluid flow techniques may be readily applied to the design of ranges for seam gas drainage. The Reynolds number characterises the flow regime within the pipe and it can be used in conjunction with data on absolute pipe surface roughness to determine the system friction factor. The application of the solution to the isothermal compressible flow equation utili- sing Moody friction factors and the concept of equivalent length of pipe for fittings and valves provides a practical method for sizing gas ranges. The physical capacity of a range can be decreased by the existence of significant quantities of water in the range and also by the ingress of air into the system at poor pipe joints etc. Both problems can be elimin- ated by adequate attention to design detail.

Jan 1, 1982

By J E. Everett, M L. James

When iron ore is crushed and split into lump and fines components, there are systematic differences between the lump and fines grades. Generally the lump product is richer in iron and lower in the other minerals, compared to the fines product. The grade differences between lump and fines, together with the lump percentage, are referred to as the ælump algorithmÆ. Mine estimates of grade, based on exploration or blasthole drilling, relate to head grade. The ælump algorithmÆ predicts lump and fines product grades from the head grade. This knowledge is important when developing mine plans. Different ore types can be expected to have systematically different lump algorithms. Previously, lump algorithms for specific ore types have been estimated by running the crusher with a single ore type over a sample period. This method is costly, interferes with production, and yields results of limited statistical power. It has been found that weighted-least-squares (WLS) multiple regression can be used to ascribe lump algorithms to different ore types, provided sample periods have sufficiently varied ore type mixes. This study discusses the method and its application to the analysis of Mining Area C crusher production records to estimate the separate lump algorithms, which could be applied to the different ore types. The analysis has enabled the set up of lump algorithms in the production system, to improve the grade control of lump and fines product. Some other relevant applications of the WLS multiple regression approach are also considered.

Jan 1, 2005

Pipe Jacking has been a recognised method of tunnelling in the U.K. since the early 1950's, although I understand that pipes were pushed blind by the soldiers in the first World War from trenches on the Allied side to, or adjacent to, trenches on the German side, thus allowing explosives to be used with a certain element of surprise! 'However, on its more conventional to the U.K. in the 1950's, Pipe Jacking made considerable inroads into the tunnelling market place as an alternative to timber supported headings. This success was, unfortunately, fairly short lived because, owing to its simple method of operation, contractors paid insufficient detail to the engineering (or surveying) aspects and as such the system soon had a bad reputation for unreliability and lack of accuracy. Due to these failings, the market was not exploited and, therefore, there was a lack of investment by contractors, pipe manufacturers and also by any client, or research organisation, which is client associated. The effect of this meant that the system stagnated for a number of years and was used generally only for short crossing work (i.e. railways, canals and motorways), and then only in good homogeneous ground. Albeit, a limited number of full scale sewage disposal contracts were carried out, but with the lack of knowledge and experience of the clients, contractors and suppliers, (particularly the pipe suppliers), no reasonable success, either physical or financial, was achieved on any such contract.

Jan 1, 1987

A new plant for grinding limestone was built at the Risdon Works of the Electrolytic Zinc Company of Australasia Limited to meet increasing process demands expected to reach 150 tonne/day of ground limestone. Plant specifications included open- circuit wet grinding, a single ball mill, a feed sizing of minus 6 Tyler mesh, a product sizing of 100 per cent minus 200 and 95 per cent minus 325 Tyler mesh and for the plant to be unmanned during normal running. Main features of plant and equipment are described; grinding performances given, as well as operating experience since commission- ing of the plant in March, 1976.

Jan 1, 1977

By K Lee, K Fernando, S Rayner

Copper-gold ores have been technically difficult and uneconomical to process due to high consumptions of cyanide. Many copper oxide and sulphide minerals react with cyanide to form copper cyanide complexes, partly contributing to the high level of weak-acid dissociable cyanide in the tailings which is normally experienced during the processing of copper-gold ores. The cost for detoxification, if required for treating these tailings, would further inhibit the development of these copper-gold resources unless the cyanide used for leaching was recovered. Several technologies have been proposed to process copper-gold ores, aiming to recover copper as a co-product and cyanide for recycling in conjunction with the leaching process. A critical review of these processes reveals that a pre-concentration stage (solvent extraction or resin ion exchange) is required. Cyanide is recovered by the conventional Acidification-Volatilisation-Regeneration technique in most cases. A critical evaluation is also provided on technical aspects related to the use of Vitrokele Technology and a newly developed Elutech process in processing copper-gold ores, in particular with its application at May Day Mine.

Jan 1, 2000