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By King R. L

Low-enthalpy geothermal groundwater resources occur at relatively shallow depths in the Upper Cretaceous/1'ertiary sedimentary sequence in the on-shore Gippsland Basin. The main stratigraphic unit containing hot groundwater is the Latrobe Group. Groundwater temperatures in the range 30 to 70¦C have been recorded from depths between 500 and 1000 m. The hottest groundwater is in the Latrobe Valley and Lake Wellington depressions. Geothermal gradients in these areas range from less than 2¦C/100 m to over 10¦C/100 m (compared to a world average of about 3¦C/100 m). A number of theories have been advanced to explain the geothermal anomalies including exothermic reaction such as oxidation of coal, mixing with deeper, hotter groundwater and high geothermal fluxes along fault zones. Variations in geothermal gradients can also result from type and thickness (and hence thermal conductivities) of the sedimentary pile, depth to consolidated basement rocks, and influence of groundwater flow patterns including proximity to recharge zones. The hot groundwater in the Gippsland Basin has substantial potential as a source of energy for direct heat applications such as process heating, space and water heating for buildings, and agricultural and aquaculture. Geothermal energy has a number of environmental advantages over traditional sources of energy. It is clean, safe, causes minimal land disturbances and in most cases is naturally renewable.

Jan 1, 1992

THE township of Costerfield is situated in the parish of Costerfield, county of Dalhousie, and lies 6 miles east of Heathcote and 30 miles south-east of Bendigo. It is separated from Heathcote by the Mt. Ida Range, which forms the western boundary of the Silurian formation. It is situated at the head-waters of Tin-pot Creek, a small southerly tributary of the Deegay Ponds Creek, which flows east to the Goulburn River.The field was discovered in 1860 by two prospectors, Coster and Field, who were guided there by a shepherd, M Nicol Coster and Field had already discovered an antimony lode about three miles nearer Heathcote, when M Nicol offered to guide them to the larger outcrop. The main Costerfield reef at that time projected above the surface, and was white through oxidation, though the bluey sulphide showed on fracture. No alluvial gold of any consequence was obtained at Costerfield, but a little was obtained, at Redcastle, 7 miles to the north, and in some of the gullies to the east.Following its discovery there came a period of prosperity to Costerfield, while the mining operations were confined to the oxidized zone. The early success of mining at Costerfield was due to the gold values, and it is probable that the oxidized zone was secondarily enriched. The earliest available record of values is a crushing of Coster and Co. on the Antimony reef (now known as the Costerfield reef), when 200 tons from a depth of 70 ft. averaged 4 oz. per ton in July, 1861. At this time a crushing mill had not yet been erected at Costerfield, and the ore was carted and treated at Redcastle. The massive antimony ore, consisting of mixed oxides and sulphides, was separated by hand-picking as "marketable ore," and the remainder crushed for gold. A higher average is recorded from South Costerfield in September, 1861, when a 15' cwt. parcel...

Jan 1, 1922

The Effects of Collector and Grinding Environment on the Flotation Selectivity of Rosh Pinah Pb/Zn Ore

Sep 13, 2010

The mining industry is generally regarded as a high risk industry, mainly because of the difficulties in estimating the tonnage and grade of mineral resources, the fluctuations in metal prices, mining problems and other problems which occur with mining in offshore and remote locations, such as appropriation or disruption to supply. As a consequence, finance providers require a high reward from mining projects. In the past two decades, the development of "mega" projects has led to the packaging of the finance becoming more sophisticated. Some would see this move as a measure of the evolution of banking rather than an intrinsic facet of mining finance itself. Project financial managers now require a thorough knowledge of all the financial tools which are available and have to be aware of the funding options so that they can put together a finance package which minimises the cost of the financing with the risk spread adequately between the partners of the financing. The different sources and types of finance for mining projects are described herein along with the factors which determine their costs. To understand the ramifications of financing mining projects, it is essential to appreciate the fundamental difference between debt and equity, which illustrates the importance of gearing. Costs of finance are determined by the interaction of supply and demand forces. Bankers and other financiers have become more adept at isolating a wide selection of risk elements and have devised a formidable range of insurance mechanisms. There is still a lot of money looking for good project risks and if a good project is properly presented and structured, financing can be obtained in today's market.

Jan 1, 1990

At last year's. annual meeting of The Institute, Sir George Fisher, as President, compared it somewhat nostalgically with a meeting of its kind in the 1920s when comment was expressed on the decline of Australianmining and on the lack of new mineral discoveries.I feel that tonight's annual meeting is even more an occasion for nostalgia, for it represents the seventy-fifth anniversary of the founding of The Australasian Institute of Mining and Metallurgy. I hope, therefore, that I may be allowed to retrace some of the circumstances of this Institute's origin and at the same time to look at some of the broader happenings of those 75 years.From this distance in time it is, of course, much easier to get things in perspective and one of the things that compels enormous admiration in looking back over the history of our Institute is to note the qualities of foresight and keen concern for professional standards which moved the pioneers in this Institute. They had no benefit of hindsight to aid them.Just over 75 years ago, a small group of men met in Broken Hill to discus.s the possibilities of forming an association of mining engineers. The moving spirit was Uriah Dudley, our first secretary, manager of the Umberumberka mine at Silverton. The first formal move to form an association of mining engineers came from the Amalgamated Mining Managers Association of Australasia. At the time, this association was a fairly new group, being 5 years old.It had been formed to try to raise the standard of management throughout the industry. Uriah Dudley and our first provisional president, John Howell, held their first talks in 1891 and further meetings at Broken Hill followed. The inaugural meeting, attended by 200 members, was held in Adelaide in April, 1893.

Jan 1, 1968

Performance of Outotec FloatForce« Flotation Mechanism - A Study in Both Computational Fluid Dynamics and Industrial Scale Measurement

Sep 13, 2010

By Osetzky D, Hesp W. R

The treatment of a hydrobiotite containing 0·64 per cent copper with various soluHons showed that a high percentage (up to 90 per cent) of the copper can be extracted under mild conditions (1 M BCI, 85°C) or withsaline solutions (20 per cent by weight NaCI or NH4F, 400°C). The latter results suggest that the copper is incorporated in the interstratified vermiculite of a vermicuHte-biotite mica and the solutions (NaCl and NH4F) which reacted with the vermiculite without attacking the biotite gave the highest extraction yields.In general, extraction yields with saline solutions increased with the temperature (between 100 and 400°C) and duration (3 or 6 days) of the treatment but were not appreciably affected by the initial pH of solutions.The results of RCI treatment especially may have a bearing on the hydrometallurgical treatment of refractory copper ores where copper is tied to gangue silicates.

Jan 1, 1977

By Blattner P

The Late Miocene gold-silver bearing epithermal system at Waihi has some close similarities in its paleo-thermal and -geochemical structure with modern, volcanic-hosted geothermal systems such as Ohaaki-Broadlands. At Waihi an extensive braided quartz vein system is enveloped by hydrothermally altered andesites with minor tuff breccias and tuffs. A main stage of vein filling consists of multiple phases of chalcedonic quartz and fine to medium grained quartz, which are accompanied by pyrite, sphalerite, galena, chalcopyrite and acanthite below the base of oxidation. Platy calcite is present locally. Fluid inclusion studies indicate that the main stage quartz was deposited at temperatures of 189¦-273¦C from dilute (T¦ of -0.1 to -1.0¦C) fluids that were locally boiling. Homogenisation temperature Th versus T. data points lie within the field enveloped by dilution and boiling/gas loss paths determined for the Ohaaki geothermal field, and indicates that the parent hydrothermal fluid for the Waihi epithermal system had a similar composition to that at Ohaaki, ie 0.2 wt% equiv NaCI and 3.3 wt% equiv CO2. The hydrothermal alteration mineralogy and the isotopic composition of vein calcite indicate that the hydrothermal fluid contained relatively high concentrations of CO 2' as at Ohaaki. Oxygen isotope analyses of main stage quartz range from 6.1 to 11.6 %o and of vein calcite from 2.29 to 9.4% . Calculated d8Ow.½ values for the hydrothermal fluid that deposited the main stage quartz range from - 2.0 to -5.7%c , with a trend to less negative values with depth. They are similar to those in the deep chloride fluid in active geothermal systems with a substantial fluid throughput. A high fluid throughput at Waihi system is also evident from the extensive high intensity hydrothermal alteration and large volume of quartz deposited in the vein system.

Jan 1, 1995

The small scale alluvial gold mining industry in Papua New Guinea (PNG) is c.irrently the only form of small scale mining carried out in this country. It already contributes significantly to the economy with current production estimated at 2 000-2 500kg per year. Until recently, small scale alluvial gold mining has been confined to simple panning and sluicing of high grade alluvial and colluvial deposits. Traditionally the small scale miner in PNG has only worked gravels with gold grades in excess of 500mg/m3. Grades of this order are required to justify the hard physical labour involved ~n hand operated small scale mining methods. .he introduction of higher throughput technologies such as trommels fed by hydraulic excavators has the effect of altering what constitutes an economically viable deposit. Mechanised techniques allow for the consideration of grades of almost half that level. The potential and opportunities for utilising this type of small scale mechanised mining in PNG are enormous with large areas of ground with gold grades running in excess of 250mg/m3 and often up to 2000mg/m3 throughout the country. An assessment of the current operating economics of this technology in the PNG context is the principal objective of this paper. Small to medium scale mechanised mining can potentially contribute significantly to the PNG economy particularly as it lies within the react-, of many PNG businessmen. Its potential is currently somewhat limited by a general lack of infrastructure and is also constrained by socio-political factors.

Jan 1, 1991

Working in thick coal seams presents many problems, included in these is obtaining the maximum recovery of coal under safe working conditions. In order to obtain maximum extraction it is important to understand the behaviour of pillars left for support purposes. However it is not always the practice to maintain pillar stability it is often required to design for pillar failure. The greatest hazard of pillar mining is uncontrolled pillar collapse. Many major and relatively minor collapses of pillar workings have been recorded in the history of mining. Notable among the collapses was that at Coalbrook Colliery in South Africa in 1960 (Bryan et al 1964). This led to recommendations on the design of bard and pillar workings in South Africa. (Salamon 1967) These design recommendations were based on the statistical analysis of stable and unstable pillar workings and introduced the concept of probability of pillar failure and safety factor. On the basis of this study a safety factor of 1.6 was prescribed for production panels in South Africa. A general review of pillar design procedures, reveals that a new phase of reinterpretation and modification is in progress. This takes into account for instance the effect method of working, whether by conventional drilling and blasting or continuous miner, has on coal pillar strength, and the necessity to review the methods for increasing depth of working. Also, as more is being understood about overall rock mass properties and advanced computer modelling techniques become more readily available, the mine planning engineer is faced with numerous approaches to pillar design.

Jan 1, 1989

The Burra Burra Mine is situated in complexly folded Torrensian dolomites and limestones forming the faulted axial region of a major anticline. The orebody mined was largely of secondary origin and confined between two faults, Kingston's on the west and Tinline's on the east. The orebody occurred at the junction between cherty dolomites and a clastic limestone with a large mass of marble breccia along its western margin. Secondary ore consisted of carbonates and oxides in the breccia and the ore bed and detrital copper minerals deposited as part of a clastic breccia in sinkholes and solution cavities in the dolomites and ore beds.Primary sulphides occur disseminated in the marble breccia and in stratiform habit in the ore bed. Kingston's so-called "lode" may be mineralized marble breccia.The marble breccia appears to be of diapiric or sedimentary origin and there is evidence to support a sedimentary origin for some of the copper sulphides. No igneous rocks have been discovered within 20 miles of the mine and any hydrothermal activities were probably at comparatively low temperature. The possibility of extensive stratiform and disseminated copper sulphide mineralization in the marble breccia and ore bed requires testing by further drilling and geophysical surveys.INTRODUCTIONThe re-interpretation of Burra Burra geology and ore formation discussed in this paper resulted from a comprehensive investigation of the mine and its surrounding district begun in December 1961 and in progress at the time of writing. (February 1963). The decision to investigate Burra Burra was taken after a thorough examination of records and reports of all non-ferrous metal deposits throughout South Australia and was given impetus by a report by Thomson (1963) suggesting a sedimentary origin for the copper mineralization. Although the author does not concur fully with Thomson's interpretation there is no doubt that sedimentary processes have played an important part in the formation of the Burra Burra copper deposit, nor is there any doubt that igneous activity played no part.

Jan 1, 1963

By Hargraves A. J

With increasing depth, stresses and stress phenomena are becoming more important considerations in Australian coal mining.A large number of compressive and tensile strength tests was made on coal and rock cubes cut from samples taken in various Australian collieries. In addition, an empirical impact strength test was carriedout on fragments of the same samples, to obtain a correlation with compressive strength.In one colliery, flat-jack measurements were taken to assess stresses in coal ribs and in the roof.INTRODUCTIONBy world standards, some of the New South Wales collieries are approaching depths of cover considered a maximum for bord and pillar the normal Australian coal mining method. Several South Coast collieries are winning coal at depths of about 1500 ft., and future operations are being planned at deeper cover. Some areas of these deep workings produce considerable quantities of seam gas.Phenomena associated with high stress and copious gas under pressure in the seam violent phenoma presenting a danger and a nuisance in mine working - have occasionally occurred, and the phenomena are being investigated as a whole (Hargraves, 1958), and separately as a gas problem (Bolt and Innes, 1959; Hargraves, 1962) and as a stress problem. This paper relates to the latter - to investigations into the strengths of coals and coal measure rocks, and into the stresses in and about coal seams...

Jan 1, 1962

The title of this address was selected before I had an opportunity to consider in detail the matters that I would like to discuss. Accordingly, I chose a very broad subject-so broad indeed that it would be foolhardy for me to attempt to deal with more than a few aspects of it. I do not propose to touch. at all on the developments to date of our mining and metallurgical enterprises, beyond paying a sincere tribute'to the skill and enterprise of those who have established an international reputation for Australian mining and metallurgy. I would rather look ahead and discuss certain factors that will play a decisive part in the future development of our mineral resources. I do this in no dogmatic spirit, and I hope that my remarks may lead to discussions which will stimulate action where it is needed.In recent years my colleagues and I have been forced by circumstances to give consideration to problems in the fields of mining and geology, and in process metallurgy, which lie outside the scope of our own research work. People come to us with metallurgical problems because they know of no more appropriate place to go, and it is distressing to have to inform them that it is nobody's job to offer them advice and assistance. I want to suggest to your Institute that it should press strongly for the provision of properresearch facilities for the mining and metallurgical industries, such as aready exist in most enlightened countries. In such countries, those connected with the development of mineral resources are able to obtain information and advice from Geological Surveys, Mines Departments or Bureaux of Mines, which offer far more comprehensive services than are available in this country.Before discussing specific technical problems of the mining and minerals industries, I shall enunciate certain general principles that I believe should be followed in respect to the technical side of the development of all Australian industries. The problem can, I suggest, be considered in three parts-technical education production, and research. I shall confine my remarks mostly to the research aspect, for it is with this that I am most familiar.For the efficient development of any industry in Australia, it is essential firstly that We should learn what is going on abroad, and secondly that we should simultaneously conduct independent research. In the latter sphere the Governmeht'departments and the private companies' or groups of companies should have complementary functions, the former concentrating on problems common to a number of companies or industries, and the latter on their oWn individual problems. It is essential to the continued existence of Australian industry that both company and govern...

Jan 1, 1944

The case study has identified and characterised additional subsidence arising from longwall mining above or under existing longwall goaf. It suggests that the magnitude, mechanisms and prediction methods for such additional subsidence are different between the two mining configurations. This paper presents a proposed method to predict maximum vertical subsidence due to longwall mining under existing longwall goaf. It suggests that, unless different results from further new cases become available, the findings presented in this article, including the aforementioned prediction method, be applicable to the majority of sites in New South Wales, where multi-seam longwall mining is to take place. This article also presents an important concept of 'overburden modification' due to multi-seam mining. A causal relationship between the above-mentioned additional subsidence and 'overburden modification' has been identified as a result of the case studies. Further investigations into the physical processes that cause such overburden modification will be fundamental to the understanding and management of multi-seam subsidence.

Nov 25, 2010

Gippsland has perhaps the most colourful history of exploration of any area in Australia. Hydrocarbons were first discovered in the Gippsland Basin in 1924 when a water well at Lakes Entrance encountered oil and gas shows. In 1942, the Commonwealth and Victorian Governments, in an effort to supplement a wartime oil shortage, sank a shaft near this well and produced 8000 barrels of low gravity oil up to 1956, when the field was abandoned. A total of 64 shallow wells had been drilled in the Lakes Entrance area by that time. Elsewhere in the onshore Gippsland Basin, 30 wells were drilled from 1925 to 1941. In 1960 BHP Ltd was granted an exploration permit covering much of the offshore area of the Gippsland Basin. Esso Australia Ltd joined BHP in 1964 and drilled the Barracouta-1 gas discovery in 1965. Since then over 100 exploration and appraisal wells have been drilled in the basin resulting in the discovery to date of some 3.6 billion barrels of recoverable oil and 8.8 trillion cubic feet of recoverable gas (Current remaining recoverable reserves are 906 million barrels of oil and 5.7 TCF of gas). Exploration in the offshore areas is actively continuing today and new discoveries are still being made.

Jan 1, 1992

Development of aggregate resources for use in structural concrete has been encouraged in Japan to support infrastructure improvement and national land conservation. Natural aggregate is a valuable resource necessary for sound economic development, and its importance is growing. After completion of aggregate mining projects, planting and afforestation are implemented. But sandy soil in excavation sites is not optimum for the growth of vegetation, and many years are needed before forests are restored. Planting techniques should be improved to support efficient reforestation in a shorter period of time. For this purpose, problems hampering growth of vegetation must to be solved through application of physical and physicochemical techniques to ensure that the environment and the ecosystem will be conserved in project sites.

Dec 6, 2010

By Hookings H. J

UNDER a contract relating to the sale of a Broken Hill concentrate, the differentiation between granular and slime concentrate is determined by the proportion of the material which will pass a 200-mesh (I.M.M. standard) screen, and this has led to considerable attention being devoted to the question of laboratory sizing tests with screens of this order.It was found that many of the screens turned out by the makers during the war, and also since its termination, did not conform with the I.M.M. specifications as closely as some supplied in pre-war days. A perfect screen is hardly to be expected, but when the above contract was framed the parties anticipated that, by special care being taken during manufacture, a screen at least as good as the best pre-war screens would be available. This, however, has not proved to be the case, and the large irregularities in screens recently supplied render them useless for sizing determinations under the contract. The makers were approached through the Institution of Mining and Metallurgy, London, with the view of obtaining a few screens conforming as closely as possible to the 200-mesh I.M.M. standard, and in response to a request twelve pieces of screen were...

Jan 1, 1922

The stability of parallel underground coal mine galleries and pillars have been investigated using two- and three-dimensional (3D) numerical stress analysis. Anisotropic horizontal in situ stresses and the direction of the excavations have been considered in the numerical analysis. The stability of the tunnels driven in a coal seam at various working depths has been investigated taking into account different strata conditions and then results from two- and three-dimensional numerical modelling studies were compared. Maximum principal stress components have been chosen in three various directions: vertical, parallel and perpendicular to the tunnel axis. Analysis have shown that in the anisotropic in situ stress field, the favourable direction of underground mine openings which have different strata conditions depend not only on the horizontal in situ stresses but also on the vertical in situ stresses. Furthermore, 3D numerical modelling studies have been carried out to investigate stability of multiple entry longwall panel gate roads and pillars with various width-to-length ratios (W/L). Results of the modelling studies have shown that the critical dimension of coal pillars depends on their width and the direction of maximum horizontal stresses.

Dec 6, 2010

By K Ehrig

You are a geologist, geometallurgist, or metallurgist/process engineer and are fortunate enough to work for an organisation who asks you to design/execute a geometallurgy program. What seems like a simple request is actually not a trivial exercise. æRecipeÆ style manuals are not readily available. However, many æexpertsÆ are lurking around willing to deliver solutions which will solve all of your problems. Even though similar ore deposit styles (e.g. porphyry Cu, IOCG, Ni-laterites, calcrete hosted U, etc.) have many similar characteristics, each ore deposit is unique. Hence your geometallurgy program needs to be æfit-for-purposeÆ. This paper offers some insights gained via designing and executing geometallurgy programs from exploration through to production, and working at a mine where you are held accountable for your metallurgical performance predictors.CITATION:Ehrig, K, 2013. Geometallurgy - What do you really need to know from exploration through to production?, in Proceedings MetPlant 2013 , pp 28-33 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Triboelectric Separation - Beneficiation of Coal The performance of triboelectric separators is highly sensitive to the selectivity of the particle charging process. This paper presents a quantitative study on triboelectric coal beneficiation. The performance of different charging media was studied. Stainless steel was identified as having a work function between that of coal and silicate gangue and found to be the optimum charging medium for coal beneficiation. Recent results from separation tests were performed where silicate gangue was separated from crude coal using a parallel plate free-fall separator are illustrated.

Sep 13, 2010