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By Kennedy G. L, Evans D. G

The development of the carbonization of brown coal briquettes to produce a hard char suitable for use in place of imported hard coke has continued in Victoria, and an experimental carbonization plant has recently been commissioned at Morwell by the Gas and Fuel Corpora.tion to assess the prospects for the commercial production and marketing of hard char in Victoria. The char offers advantages in its very low ash content and its uniform lump size, while the indications are that it could be marketed at a price competitive with that of imported hard coke. The hard char is unique amongst metallurgical fuels in combining a high reactivity with high physical strength, and research by the University of Melbourne into its utilization in foundry cupolas for melting iron has shown how modifications could be made to take advantage of these properties. An 18 inch experimental cupola has been built to test in practice the predictions made from this fundamental research.INTRODUCTIONSteady development has continued in Victoria from the promising laboratory researches at the University of Melbourne which were reported to the 1955 Annual Conference of The Institute (Worner, 1956). This work had shown that a hard lump char could be produced by the high temperature carbonization of standard industrial briquettes by careful control of the heating conditions, and that the special briquetting techniques adopted in Germany were unnecessary with Yallourn brown coal. Continuation of this research has led to the refinement of carbonization techniques and has increased the strength of the char until it has equalled that of conventional metallurgical cokes.

Jan 1, 1960

By J Fut=

The rotary drilling of rocks is widespread technology in mining and in tunnelling. The paper describes the results of research by aim to find relationships between optimal drilling and sound signal of drilling machine. The optimisation criterion has been formulated as the minimisation of specific energy with maximal effective speed of drilling in process of the rock disintegration. The research in this field has been made on experimental drilling stand. Our monitoring system has measured following variables: the pressing force of core drill, the revolutions of drilling head, the length of drilling, the time, the power, and the acoustic signals. For measurement of acoustic signals have been used very sensitively sound meter MEDIATOR 2238. From this measurements have been processed acoustic spectrums. Then we are found relationships between optimal control of drilling and composition of acoustic spectrum. On base of experimental results, we can formulate the optimal control following: æTo achieve the minimum difference between the equivalent sound level at the load and idle modes only at the representative frequency (f = 1000 Hz)Æ. The representative frequency dependences on type of the rock New method based on these relationships enables the optimal control of drilling machine by using measured acoustic signals only.

Jan 1, 2003

Factors of importance in the ntilization of coal fines are mentioned, and the results of flotation tests on coal fines from three important coal seams in New South Wales are presented.INTRODUCTIONEconomic utilization of fine coal is an important problem in the Australian coal industry, particularly as the proportion of fines mined is increasing with progressive mechanization.While the use of uncleaned coal fines may be economic, it may be preferable to beneficiate them, but the most economic process must be selected.For beneficiating coal finer than about 28 mesh, froth flotation can be applied, but mining engineers should avoid practices that may be detrimental to flotation. Such practices include the indiscriminate use of water, particularly that containing a wetting' agent, for dust suppression. In addition, clay stemming in wet conditions may produce slimes which could adsorb on coal surfaces, while the use of oils and greases as well as the application of stone dust and chlorides in roadway consolidation may influence adversely fine coal beneficiation.This paper deals with the application of flotation to samples of fine coal from the Bulli, Greta, and Victoria Tunnel seams. In addition a discussion is given of the mineralogical constitution, size analysis, and degree of liberation of ash constituents of the various samples.COAL SAMPLESRepresentative samples of coal from the Bulli, Greta, and Victoria Tunnel seams were obtained for testing.

Jan 1, 1961

Urban development to the south of Sydney is approaching areas of current and proposed coal mining. Already some structures and residential areas are affected by mining subsidence.Subsidence resulting from either conventional pillar extraction methods or longwall mining has been monitored for 15 years to enable the characteristics of the surface deformation to be determined.The vertical and horizontal displacements of survey stations on the surface are monitored and the results arc used to calculate subsidence, changes in slope of the surface, curvatures along the subsidence profile, and the ensile and compressive strains. These features are in turn related to the underground extraction to give a description of surface subsidence and the development of subsidence with time.Subsidence investigations have been carried out over all or part of the workings of six collieries in the Southern Coalfield.Two case histories illustrate the procedure in the investigation of subsidence phenomena. The first example is the study of the subsidence over a series of longwall panels in one seam and the second is a study of subsidence over pillar extraction in two seams one above the other. From the results of the investigations the effects of panel widths on subsidence are determined.This and other information assists mine planning in areas where surface movement and deformation are important considerations.

Jan 1, 1980

Antimony ore samples (mean assay 18·7 per cent antimony) from Endeavour Inlet, Marlborough Sounds New Zealand, were tested for upgrading by flotation to a saleable product (60 per cent antimony).The effects of activating agents, collectors, frothers, pH, conditioning time, and particle size on the recovery and grade of a stibnite flotation concentrate were determined using HaIlimond tube and laboratory flotationcell test apparatus. Optimum flotation conditions for the ore were thereby established. A stibnite concentrate grading 63 per cent antimony and an overall recovery of 90 per cent is obtainable in a two-stage process.

Jan 1, 1977

Samples of a refractory copper ore were examined to test their response to segregation roasting, flotation, and acetonitrile leaching. Recoveries in the segregation roasting stage were between 60 and 100 per cent, while flotation recoveries varied between 60 and 85 per cent in cleaner concentrates assaying 25-40 per cent copper.The fraction of the copper which could be leached from the concentrate by an acetonitrile/sulphuric acid/cupric ion leach solution varied from 16 to 97 per cent, the lower recoveries being correlated with the presence of sulphide in the concentrate.

Jan 1, 1973

The Heavy Media Separation plant operated at Lidsdale siding, eight miles from Lithgow, by the N.S.W. Mining Co. is a product of the Western Machinery Company, of D.S.A.This mill, designed to use finely ground magnetite as the heavy medium, was prefabricated in America and shipped to Australia for erection.First operated early in December, 1951 it has worked on a two-shift basis since. Designed for an input rate of 330 tons per hour, this mill is capable of washing 4 in. x /u in. coal down to its inherent ash by removing all heavy material, including high-ash coal.The principle is quite simple. A stream of raw coal is fed into the separatory vessel which contains a liquid medium, the density of which is adjusted to produce the desired split between coal and refuse. In this bath the lightest coal floats, and all material heavier than the specific gravity of the medium sinks, and is removed separately. Such a system is,. ideally suited to Western coal, as there is no definite splitting point between coal and refuse. Inherent ash of the coal fed to the plant ranges from 8 to 25%, the corresponding density range being from 1.28 up to 1.8.Generally speaking, the higher the density the higher the ash content of the coal.The density in the separatory vessel (hereafter called the cone) can be quickly and easily adjusted throughout the above range to any desired value. Customer requirements, coupled with the economics of washing, dictate the proper specific gravity to be maintained. At present this is held at 1.52...

Jan 1, 1954

The presence of gold or tin in a particular place in payable quantities may be suspected from geological and prospE;cting reports. It behoves the engineer by judiciously spaced boreholes or pits to establish whether the place is exploitable with profit, and it is the purpose of this paper to set out the ways in which this is done. The various types of deposit to be considered occur in Malaya, Thafland and Borneo, in which countries the writer spent four years in estimating alluvials.The methods described were used in actual practice both by the writer and previous engineers for the same company. The subsequent exploitation of the alluvials evaluated by the methods given below shows that the recovery was as good as, and sometimes higher than, expected. No claims are made to the originality of the methods, but it is 'felt that they may be new to some engineers and< interesting to others contemplating alluvial testing.

Jan 1, 1942

By H Sofatzis, J Kinal, J Siliezar, B Kirkwood

Ernest Henry Mining (EHM) is a copper, gold and magnetite mining and processing operation located 38 kilometres north east of Cloncurry in the Mount Isa - Cloncurry mineral district of north west Queensland, Australia. The EHM ore body is an iron oxide copper gold deposit with an average grade of 1.1 percent copper, 0.5 g/tonne gold and 22 percent magnetite.At the end of 2009, after a series of promising laboratory test work, EHM converted the ball mill media charge from forged steel to high chrome media. Laboratory test work also indicated that with the use of high chrome media, the pH was able to be reduced with no negative impact on plant performance. At high pH values (above 10.5), the forged media is passivated, so as the pH of the system drops the media corrosion rate increases and floods the system with corrosion products, affecting flotation. As the high chrome media is much more inert, pH has less of an effect on copper flotation response.This paper provides an overview of the effects of reducing the pH in the EHM copper rougher flotation circuit. The pH in the roughers was dropped from 10.6 to 9.6 to determine the impact on the rougher performance and the subsequent performance of the whole copper flotation circuit. It was found that there was a slightly increased improvement in copper recovery and no statistical change in either the rougher or final copper concentrate grades for copper and gold.With the reduction in pH, there was a noticeable reduction in lime usage from 0.85 kg of lime per tonne of ore processed to 0.55 kg/t. This reduction in lime is equivalent to approximately $700,000 per annum at current production rates.CITATION:Kirkwood, B, Kinal, J, Siliezar, J and Sofatzis, H, 2013. Low pH trial in the Ernest Henry Mining copper rougher flotation circuit, in Proceedings MetPlant 2013 , pp 371-377 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The production of metallic titanium and titanium-rich alloys in forms useful to the engineer involves the use of certain techniques not usually necessary in fabricating the commoner metals and alloys. However, not all stages in the handling and shaping of titanium-base materials require the application of unfamiliar methods. It is the purpose of this paper to indicate where the well-known techniques are applicable as well as to outline the unusual operations which are necessitated by certain chemical characteristics of titanium.In brief, the characteristics just mentioned are manifestations of the very great reactivity of titanium, especially at elevated temperatures. Liquid titanium burns vigorously when brought into contact with air. It also reacts with practically all refractories, causing damage to the latter as well as undesirable contamination of the metal. Even solid titanium undergoes serious superficial contamination when heated above 800°C. in air for more than a few minutes. In addition to an oxide skin being formed, oxygen enters into solid solution in the surface of the metal causing the latter to become hardened and eventually embrittled.Up to date, titanium has been made only on a pilot plant scale by methods which produce a spongy or powdered product. Refractory problems have prevented the development of chemical reduction methods for making titanium in the form of a liquid pool from which ingots of useful size could be cast. Therefore the first part of this paper will cover the consolidation of powdered or spongy titanium. The latter portion will provide a brief description of...

Jan 1, 1950

ALTHOUGH the development of the various flotation processes during the last 8 years has been so revolutionary, this development has been, until recently, entirely confined to the separation of the gangue from the mixed metalliferous sulphides.The desirability of finding some method of separating the independent sulphides from such a miXture, by means of flotation, has long been recognized. ThIS need was emphasized when the slimes resulting from the grinding of Broken Hill sulphide ores were for the first time successfully dealt with by the Mineral Separation Company's process on the Central mine. This process proved the practicability of separating the sulphides of lead and zinc as a mixed concentrate from the gangue present in slime. Although this was a very notable achievement, the process has not been generally used, owing to the mixed lead and zinc concentrates resulting from the treatment being acceptable neither to the zinc nor the lead smelters.Although the introduction of eucalyptus oil in minute quantities as an emulsifying agent has simplified the work of the subsequent tabling of mixed sulphide concentrates, rendering unnecessary the burning off or removal of the oil, there will always be a considerable quantity of slimy product too fine to settle on the moving surface of the concentrating machines, and therefore requiring other means for its division into lead and zinc concentrates.

Jan 1, 1912

By K Nilsson, D Connelly

Troy Resources acquired the Karouni Gold Project in Guyana, South America in 2014 and immediately proceeded to a Pre-Feasibility Study and project implementation. The study considered two open pit mines feeding a conventional carbon in leach (CIL) gold plant with a capacity of 1Mtpa. The study assumed a total of 2.61 million tonnes of ore with an average grade of 3.84 g/t gold with a recovered gold production of 303,526 ounces over a three year mine life.The project development involved drilling metallurgical test holes, securing second-hand major pieces of equipment where suitable, and arranging shipping to Guyana. The remote location meant logistical considerations were paramount. The plant consists of conventional two-stage crushing with single stage ball milling and a gravity circuit. The tailings circuit includes DETOX.The extremely high rainfall presented challenges with water management and the necessity to dispose of clean water to the environment. The DETOX was also mandatory due to the highly sensitive environment and past history in the area. The criticality of this meant that in the design, any cyanide in the tailings would precipitate in a plant shutdown.Lessons were learned and the project has been both profitable and successful for Troy Resources in a new operating location. In addition, the project has created jobs, delivered royalties and brought new skills into an area where previously there was little current mining activity.CITATION:Nilsson, K and Connelly, D, 2015. Karouni Gold Project from drill core to commissioning, in Proceedings MetPlant 2015, pp 197–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

The Wongawilli system of mining has been in use for over 30 years and has enabled high production rates and acceptable extraction ratios to be achieved in seams less than 4 m in thickness. A modification of the Wongawilli system has been developed to permit the use of a continuous miner and mobile equipment to extract a coal seam 6 m thick. Following physical and mathematical model studies the new mining method is now undergoing field trials at Collinsville, Queensland. Progress of the field trials to date has achieved 99 per cent extraction of the upper slice by remote control operation of the continuous miner and established the feasibility of installing resin grouted wooden dowels in the coal floor to reinforce the coal septum. The method is explained in the text. Monitoring of the goaf gases as an early indication of spontaneous combustion has been incorporated in the mining cycle by placement of tubes in the goaf as the face retreats and continuous analysis of the goaf gases made at the surface by the National Coal Board tube bundle monitoring system.

Jan 1, 1980

By A Unlutepe

The Bosphorus Rail Tunnel Project, located in Istanbul, Turkey, aims to provide a Euro-Asian rail link, via an immersed tube tunnel crossing the Bosphorus Strait, along which will run all commuter, freight and intercity passenger trains of Turkish State Railways (TCDD), as well as the future extension to the European rail network. The total length of upgrading and new railway construction will be approximately 76 km. The main structures include the immersed tube tunnel; mechanised shield tunnels; new Austrian tunnelling method (NATM) tunnels; cut-and-cover, at-grade and retained-cut/fill structures; and some service structures. This paper discusses Phase 1 implementation of the project, one of the major transportation infrastructure projects in the world today, whose varied structures present stimulating engineering and construction challenges.

Jan 1, 2008

Geochemical data on Australian granites and pegmatites, and the mineral components of these rocks, are compared with that obtained in similar studies in the U.S.S.R. and elsewhere.The geochemical character of tin granites and the trace chemistry of their component minerals, particularly biotites, have some significance as ore guides in prospecting for tin.The primary geochemical dispersion of tin can be readily tested both in the laboratory and field by colourimetric methods, after volatilization with ammonium iodide, using modifications of the method described by Wood (1958).Secondary dispersions of tin in residual soils or alluvia can likewise be readly tested by rapid colourimetric methods in the field, but simple hydraulic methods, handling larger sample volumes, give reliable outlines of dispersion patterns.INTRODUCTIONThe search for tin ores, whether lode or placer in type, is usually directed on genetic grounds to country within or adjoining acid intrusives.A long established means of prospecting is to test samples for cassiterite by panning or other hydraulic separation.These methods can be used on crushed lode material or the natural materials from placers.With the advent of new techniques for extraction and for colourimetric analysis for tin (Wood, 1958 and Ross and White, 1961) a means is available for rapid analysis of materials not susceptible to quantitative testing by hydraulic methods because of the fine sizings of cassiterite or the occurrence of tin structurally held in minerals. The new methods thus opened up the field of tin prospecting by extending the search for ore guides to genetically associated rocks and minerals, wall ror-ks of veins and a wider range of superficial deposits.

Jan 1, 1963

By Koch D. F A

An electrochemical study of the dissolution of gold in aerated cyanide solution shows that the dissolution rate is determined by the nature of the surface. A passive film (probably a basic cyanide) formed at -0·6 V vs a saturated calomel electrode inhibits both the anodic dissolution of gold and the cathodic reduction of oxygen. Thallium has an "activating" effect on these reaction mechanisms.INTRODUCTIONIn general the dissolution rate of a solid in a liquid is studied by weight loss measurements or analysis of the solution at known time intervals. However, if the solid is a metallic conductor, on which a redox reaction can occur at the metal-solution interface, it can be studied by electrochemical techniques. Electrochemical measurements have the advantage that the overall reaction can be separated into its components, in some cases by electrical measurements alone, and in others by a combination of these with analytical determinations.The overall equation for the dissolution of gold in aerated cyanide solution may be written4Au + 02+ 8CN- + 2H20 = 4Au (CN)2- + 40H- ..... (1)which can be separated into the two electrochemical componentsrepresenting the oxidation of gold and the reductionof ogygen respectively.4Au + 8CN-,= 4Au(CN)2- + 4eand O2+ 2H20 + 4e = 40H- These two reactions occur at the gold-electrolyte interface and it is the purpose of this paper to discuss the mechanism...

Jan 1, 1964

This paper is intended partly as a summary of the conclusions that have been arrived at by various authorities on this matter, and also with a view to initiate some discussion on the subject, especially as most of the quartz gold mines in Victoria are operated without having any proper assay plans or any idea of the real values other than those given by the mining managers, who, from experience in the particular cases, are supposed to be able to arrive at a correct idea of the true values of- the ore, and, in many cases, oppose any other methods than their own, holding the view that no sampling is equal in correctness to the bulk sample of the battery. The necessity of properly sampling and estimating the ore in a mine in every case, perhaps hardly needs to be urged on the members of the Institute, but is not, apparently, so obvious to others.It is proposed to confine this paper to the sampling of ore reserves in a mine, and the various points which have to be taken into consideration in arriving at values, from the assayer's point of view, leaving the methods of sampling metallurgical products out of consideration for the present. "It is advisable to define" ore reserves" as ore exposed on three sides at least, and accessible to the sampler on all three. "Prospective ore" would include all ore not so fully exposed; but which may, from the nature of the case, and the geological conditions prevailing, be reasonably supposed to exist.

Jan 1, 1904

By Lee T. J

The area, A, under a gamma-ray log that passes through a horizontal bed given by: A = gl/k. Here is the equivalent concentration of U3O8 in the body, l the thickness of the body, and k the calibration factor or sensitivityof the logger. The area is independent of the logging speed or logger time constant.This relationship, together with the first moment about the maximum of the log and its value there suflicient to determine the thickness, position of the centre of the bed from the log maximum and the concentration of U3O8.Numerical results obtained from artificial and field data show that the computed results arc as good as those obtained by methods such as the inverse filter technique and the iterative method. The present method yields results that arc easier to feed into an ore reserve data base.

Jan 1, 1981

(This paper reviews the reasons for and the principles followed in designing and constructing complete new surface works at the mine of the Zinc Corporation Limited, Broken Hill, New South Wales, and describes the layout, plant, buildings and services.)The Zinc Corporation mine produces high grade lead, silver and zinc sulphide ore. Lead and zinc concentrates are sent by rail to Port Pirie, where the lead is smelted and the zinc concentrate is shipped to Tasmania, England and other overseas countries.Some time ago consideration was given to the advisability of sinking an additional shaft. For some years the old main shaft had been working at full capacity and developments underground had indicated that the mine would eventually be capable of an output greater than that which could be handled through the shaft. It was therefore decided to sink a new main shaft and the site chosen was in footwall country 900 feet south of the old main shaft. The reason for the move south was so that the new shaft would be opposite the centre of gravity of the ore-bodies at depth. The size of the new shaft is 27 ft. ,6 in. x 15 ft., and the work was put in hand early in 1936.It was intended to haul the whole mine output through this shaft, which was 1,600 feet from the mill then operating. An extensive conveyor system thus became necessary unless a new mill was built near the shaft. A careful study of the situation was made by the management and consideration was given to requirements for expansion, the condition of...

Jan 1, 1940

By Beavis FC, Box JC

The important chemical and fluid flow phenomena in heap, dump and in situ leaching are summarised. Published, quantitative models of these processes are critically reviewed, and their potential applications outlined. Comparison between the independent predictions of one of the models and column leach test data reported by others confirms the potential. Some recent developments by the authors in the fields of fluid flow through unbroken ore and modelling of the more complex chemical systems are briefly Described.

Jan 1, 1981