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By Semple DG, Leach TM

A continued exploration programme has further defined the geology of the Tolukuma vein system, verified the resource indicated by Newmont, and identified potential for additional mineralisation. The resource at Tolukuma Hill, designated as Zone C, is a measured 440,000t @ 17g/t Au and 46g/t Ag with an additional indicated resource of 120,000t @ 16g/t Au. A diatreme breccia localised at an intersection of structures, and a relationship of gold to base metal sulphides, are highly indicative of a porphyry association. Typical epi-thermal features such as crustiform banded quartz and quartz pseudomorphing. platy calcite are also present and locally contain lesser gold mineral-isation. Pre-existing dilatant structures have acted as a host to the ore fluids, resulting in the formation of the semi-continuous Tolukuma-Gulbadi veins over a 1100m strike. A fluid flow model suggests that mineralising fluids were sourced from the diatreme margins and migrated laterally along dilatant structures. Bonanza gold grades are derived through fluid quenching in the flexure between a hanging wall split which hosts much of the Tolukuma Hill resource and the feeder graben structure. Thus, the relationship between the pre-mineral structural geometry and fluid upflow at the margins of a diatreme breccia, controls the ore setting. Potential for more ore remains within the Gufinis and the 120 veins as well as in the outlying Prospects.

Jan 1, 1994

Silver-lead ores are widely distributed through- out the Mount Lofty and Flinders Ranges, but none of the deposits is large. Historically the Glen Osmond Mines are the most significant as the site of the first metalliferous mining in Australia, but Talisker was one of the three largest producers of silver-lead in a state whose mining history is dom- inated by copper. The mine is located in a magnificent natural setting on Talisker Conservation Park, near Cape Jervis, southwest of Adelaide (Figure 1). It is exempt from the operations of the Mining Act and listed on the Register of State Heritage Items. The mine and associated township of Silverton were dominated by Cornish influences during the period of principal activity between 1862 and 1872. Silverton, located on a ridge overlooking the mine, grew to a population of about 300 at its peak in 1870 and the area was very much another 'little Cornwall'.

Jan 1, 1987

By Glaessner M. F

The island chains of the Western Pacific (Fig. 1), on account of their related origin, and the similarity of the rocks that compose them, constitute in the main a most homogeneous mineral province. They lie in a complex "mobile" zone of the earth's crust, that formed a geosynclinal area separating the continental margins of Australia and South-Eastern Asia (the so-called Sundaland) from each other, and from the margin of the Pacific Ocean proper (FIg. 2). The whole region was drowned at the close of the Ice Age, as a result of the rise of sea-level that accompanied the melting of the great ice caps in the polar regions, leaving only the higher portions as islands and peninsulas, many of them separated only by shallow seas or "shelves."The geosyncline was infilled with Mesozoic and Tertiary sediments that have undergone varying intensities of folding and metamorphism, and has been subject to intermittent periods of volcanic activity, continuing into the present. Midway between the two continental margins there is a narrow belt of pronounced negative gravity anomalies, with an extraordinary S-shaped convolution in the vicinity of the Banda Sea and Celebes, that marks the core of this unstable region. The folding within the "mobile" zonetrends parallel to it, so that the islands in its vicinity, which are regions elevated by folding, are all elongated in the strike direction of the folds. This explains not only the linear shape of Sumatra and Java, but the arc of islands enclosing the Banda Sea, and the peculiar shape of Celebes.Parallel to the belt of negative anomalies, at a close remove from it, is the line of Recent, or active volcanoes, that extends along the whole length of Sumatra and Java...

Jan 1, 1947

China has abundant bauxite resources, but these resources are mostly of a diaspore, which has a feature of low Al2O3 to SiO2 mass ratio, typically ranging from four to six. Compared to other materials, this kind of raw materials consumes more alkaline and energy in the process of metallurgy, and incurred a high alumina production cost. To solve this problem, researchers in China have done a lot of work on removing of the silicon from bauxite. Under the impetus of these works, in 2003, the first flotation plant of diasporic bauxite in the world was constructed in Zhongzhou, Henan, China. Seven years of operating experience shows that this technology can signifi cantly reduce the costs of following-metallurgy processing. These efforts are an important reference for the processing of similar resource. In general, for Western scholars it is diffi cult to fully understand these works because most of them are published in Chinese. In this paper, a detail introduction for the research progress on China bauxite de-silica flotation was presented, these works involved crystal chemistry, wettability of bauxite minerals, collector and modifi er in bauxite fl otation and flotation practice, etc.

Sep 13, 2010

The InLine Pressure Jig represents a breakthrough in digging technology Its design incorporates a unique combination of features previously utilised in conventional jig design. In particular, a moveable screen and circular bed are used to excellent effect. However, a major design innovation is the encapsulation of the circular bed within a vessel - allowing the equipment to operate under pressure. This innovation eliminates free water surface, improves the dynamics within the separation layer (crossflow) and provides significant cost savings in the handling of slurries. Recent research results have indicated its capacity to achieve high recoveries and upgrade ratios in the gravity separation of Minerals.

Jan 1, 1997

By Raudsepp R

Since 1991, the Porgera Joint Venture has processed refractory sulphide flotation concentrate by pressure oxidation with the subsequent gold recovery, from the washed residue, via a conventional leach/carbon-in- pulp (CIP) circuit. The capacity

Jan 1, 1997

By Remilton D, Raston GR

The low price of nickel which has prevailed since 1982 has dictated that unit production costs must be minimised. Early in the crisis, a decision was made within Western Mining Corporation to reduce unit costs by increased rates of production, not by a significant reduction in manpower. This paper details developments which have taken place at Kalgoorlie Nickel Smelter to enable the higher production rates to be achieved, or to increase energy efficiency. It is significant that most developments were achieved without the need for capital expenditure.

Jan 1, 1985

By O Dahl, I M. Platten, E J. Sides

Many narrow-vein gold deposits are characterised by a high to extreme nugget effect and the presence of coarse gold. They rank amongst the most difficult of deposits to produce an accurate and precise resource estimate. This contribution presents a case study from the Nalunaq Gold Mine in Southern Greenland. The mine commenced operation in May 2004 and is currently operating at a rate of 400 tonnes per day, to produce about 100 000 oz gold per annum from a total resource base of 1.2 Moz. Mineralisation is characterised by quartz veins that are hosted within a shear zone that is continuous over about 1000 m. The principal orebody is the Main Vein structure, which ranges up to 3 m in width, maintains an average dip of 35¦SE, and contains significant gold grades (1000s g/t Au). Gold particles are often visible, with 25 per cent being greater than 250 microns in size. Variography using underground development samples indicates a nugget effect of about 75 per cent. For the 2005 resource estimate, a 2D metal accumulation ordinary kriged block model was used to produce a global grade for the Target and South Blocks of the Main Vein. Grade control chip-channel samples are collected from æshantyÆ drive footwalls, and used as the basis for both the kriged block model and to determine the grade of individual stope blocks by peripheral weighted averages. Geology plays a key role in mining efficiency, given the locally variable nature of the ore zone.

Jan 1, 2006

By I F. Wood

Planning for flooding and assessment of flood impacts are important requirements for mining projects, as they are also for other types of development. With more intense development and concern from the community, supported by government regulatory requirements, assessment of flood concerns and impacts has become of increasing importance. To ensure that flooding issues are fully understood and results presented in an appropriate format, advanced hydraulic analysis procedures have been developed and are beginning to be applied. These procedures must be rigorous in an engineering context but the results must also be readily understood by the community and government agencies. Advanced two-dimensional hydraulic modelling is becoming accepted as an important means of assessing flooding issues for mining projects. With presentation of results from hydraulic models with Geographic Information Systems (GIS), flood impacts can be analysed rigorously and presented clearly. This paper discusses the application of advanced hydraulic modelling in the planning and impact assessment of a major mining project located on a floodplain where there is extensive inundation. The analysis provides for both input to the planning of the project and for detailed assessment of potential impacts. This case study illustrates some important aspects of the application of hydraulic modelling using a two-dimensional modelling to a critical flood design.

Jan 1, 2003

By H Bartosiewi, M Kuruppu, F Mashiri

Wire ropes are one of the most heavily used components in a dragline. They are subjected to harsh conditions during the regular usage of a dragline in a mining operation. Hoist ropes are subjected to fatigue due to the cyclic nature of load handling as well as due to rope bending over the sheaves and the drum under load. This leads to wire breaks due to fatigue. Accumulation of a number of wire breaks close to each other can have a detrimental effect on the rope. Furthermore, to allow for the increasing demand for higher load capacity coupled with the inconvenience of having very large ropes, the factor of safety is often compromised, which increases the wear rate. Drag ropes are also subjected to heavy loads. More importantly, they are allowed to drag along the rough mine surface subjecting them to external physical abrasion. This makes the life of drag ropes one of the lowest among those used in a dragline. Suspension and IBS ropes are relatively uniformly loaded during their regular usage although they need to withstand dynamic load cycles as well as bending. Hence they tend to last for a number of years on average. The paper analyses the wear types and their severity of each of these rope applications, and suggests methods to determine rope wear rates and the resulting rope life. The paper further gives suggestions for good operating and maintenance practice that can extend the rope life and help reduce the large expenditure associated with every major rope change in a dragline.

Jan 1, 2005

By Quan P. M

The great advances made in the application of solvent extraction to the recovery of copper from low grade ore sources over the past 15 to 20 years are well known. Solvent extraction is an essential step in the recovery and purification of copper from dilute sulphate leach solutions by which some one million tonnes of copper are now electrowon annually. A reagent is also available for the selective recovery of copper from chloride leach solutions and this may hold the key to the processing of complex sulphide ore concentrates. By comparison, the use of solvent extraction in the recovery and processing of zinc has as yet found little favour and is confined to only a few specific and comparatively small applications. This is despite the ready availability of a large number of low grade zinc sources and zinc-bearing wastes and residues. It is suggested that this difference is due in large part to the absence of suitable reagents having the particular features required to enable them to fit into a solvent extraction - electrowinning based process for zinc. Ideally, for the recovery of zinc from dilute sulphate solution, an extractant should operate on a proton exchange principle and be strong for zinc in the same way that o-hydroxyaryloxime reagents are strong towards copper. It should load efficiently with zinc at the pH of typical sulphate feed streams without the need for neutralisation and yet be stripped efficiently by spent zinc electrolyte. Another factor of major importance for many applications, however, is that it should be highly selective for zinc over ferric iron. These features have now been realised in a development extractant DS5846, which is a formulation of a novel class of reagent currently under investigation by Zeneca Specialties. The properties of this reagent are described with respect to selectivity, isotherms and how they compare with phosphoric and thiophosphoric acids that have been previously proposed for the extraction of zinc. For the recovery of zinc from concentrated chloride solutions a solvating or neutral donor type of extractant is required which again should ideally have high selectivity for zinc over a number of other metals, particularly iron. The new reagent Acorga ZNX50 is based on a formulation of a novel class of compound developed specifically for this purpose. It gives efficient extraction of zinc from feed solutions that are four to six molar in chloride ion but is readily stripped at 60 - 65¦C using either water, dilute brine, or spent zinc chloride electrolyte. The reagent is highly selective for zinc over iron and a range of other metals including cadmium, arsenic, lead and magnesium.

Jan 1, 1993

By D S. Nicholson, T Marshall

Reserves of high-grade quartz gravel, lignite and timber suitable for the production of silicon metal and ferrosilicon on large scale occur within 40 miles of Bluff Harbour. Undeveloped hydroelectric power resources on the Clutha River are located within 50 miles of the most promising quartz gravel deposits while opencastable lignite, potentially suitable for electric power production, occurs in the same locality as the quartz gravels. A preliminary study of production economics indicates that the commercial feasibility of silicon/ferro-silicon production would depend mainly on the cost of electric power, total capital cost of plant, and the market value of the products. The proximity of Bluff Harbour is advantageous for the export of products.

Jan 1, 1971

By M J. Saynor, W D. Erskine an, D R. Moliere

The Jabiluka uranium mine was constructed in the Ngarradj catchment, a right bank tributary of Magela Creek in the Northern Territory. The Jabiluka Mineral Lease is adjacent to Kakadu National Park, near an area listed as Wetlands of International Importance under the Ramsar Convention and recognised under the World Heritage Convention. In the late dry season of 1998 and prior to the 1998 - 1999 wet season, a stream-monitoring program was implemented in the Ngarradj catchment to collect baseline data on sediment transport within the catchment to assess and proactively manage associated impacts caused by mining at Jabiluka. Stream suspended mud concentration, stream discharge and rainfall data were collected for four wet seasons (1998 - 2002) giving an almost continuous data set. The stream system has high natural variability dependent on rainfall intensity and subsequent discharge and pre-wet season fire distribution and intensity. In general, mud concentration is elevated at the commencement of the wet season until about February. This is caused by first-flush removal of surface material detached during the dry season by agents such as bioturbation (including anthropogenic activity), wind erosion and surface desiccation. Water quality trigger values downstream of the mine were derived using upstream percentiles and the before-after-control-impact, paired site design. Both analyses showed no observable impact from mine construction in 1998 or during the study period. However, the impacts of dry season fires could be clearly detected. The data set provides good baseline information for future assessment at Jabiluka and demonstrates the need to view measured parameter values on a catchment-wide basis with knowledge of rainfall, discharge and fire distribution.

Jan 1, 2004

Ventilation characteristics of a three h -nc longwall development panel in a 1/100th tale hydraulic model using dispersion mechanics are the first applications of its Find in ventilation. Dispersion mechanics gives additional and important ventilation parameters such as degree of mixing, bypassing, -ecirculation etc. These are not obtainable the traditional pressure-volume methods. Experimentally, the model work investigates entilation characteristics of different stopping layouts, including leaky stopping,, cut-throughs and return roadway, brattice tyre ventilation and the effects of flow rate reduction on air distribution in the headings. Additionally, a model of methane generation at the face provides results used to calculate the dispersion characteristics in the return airways. It is concluded that the model resui,s -trongly suggest that dispersion mechanics could be applied to mine ventilation surveys to provide quantitative flow pattern data and details of effective dispersion '?_C!,r riro ò `b' eritilat.ing air.

Jan 1, 1983

By Lawrence L. J

The Australian Broken Hill Consols Mine, situated some 600 yd east of the main Broken Hill line of lode, is noted for its rich ores of silver. In contrast to the vast conformable orebodies of the Broken Hill field, the Consols lode occupies a narrow fissure dipping to the south west at angles increasing from 240 through to vertical and transgressing the strike of the metamorphosed country rock at an oblique angle. This feature, together with the abundance of calcite and siderite and the virtual absence of silicate minerals in the gangue, has led to its classification as an orebody of the Thackeringa type (King, 1953). Recorded production during the period 1890 to 1903 is given as 845,000 oz of silver and 20 tons of lead.The unusually rich silver values of the Consols lode were concentrated at the intersection of the fissure with beds of amphibolite, whereas in the adjacent schists and gneisses the lode became markedly impoverished. From the surface to a depth of some 120 ft extensive surface oxidation had occurred, resulting in the breakdown of siderite and its replacement by limonite and associated manganese oxides.Silver halides, dyscrasite, acanthite and partly oxidised tetrahedrite were the main silver minerals in this zone. With increasing depth the lode material gradually reverted to minerals representative of the hypogene zone.The only previous work specifically on the mineralogy of the Consols lode is that by Smith (1922), one time manager of the mine. His zeal as a mineral collector resulted in much valuable information being available on the distribution of the minerals. More recently, Garretty (1943) noted the...

Jan 1, 1962

By G D. Carman

White Rock is a reduced tungsten-tin skarn deposit near Rye Park, New South Wales. This abstract summarises the depositÆs mining and exploration history, and current exploration by Paradigm Metals Ltd targeting an economic resource at the deposit. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

High resolution seismic profiling has proved a cost effective tool for defining the structure and seam geometry of Late Cretaceous-Late Miocene age lignite deposits in the South Island of New Zealand since 1981.In 1985 a total of 45 km of Mini Sosie seismic reflection was carried out in the Benhar, Hawkdun and Ashers-Waituna deposits as part of a major multidisciplinary resource investigation funded by the Liquid Fuels Trust Board. For each deposit the seismic programme involved integrating four or more intersecting Mini Sosie traverses with a grid of 1000 m spaced geophysically logged drillholes. The objective was to detect faults, with displacements ranging 30 - 100 m, which might impede mining using bucket wheel excavator systems at depths down to 300 m below surface.In general the quality of processed seismic data was high and with the assistance of ynthetic seismograms and other geological information, it was possible to identify a number of significant previously unknown faults. The success of this seismic programme ha shown that high resolution seismic profiling, used in conjunction with relatively low density drilling, can produce valuable structural and tratigraphic information at an early stage of open pit mining investigation.

Jan 1, 1989

The Mineragraphic Section of the Council for Scientific and Industrial Research has had occasion from time to time to examine rocks, ores and concentrates from the Yatukoula goldfield, Fiji. The results of the examinations have been supplied as Mineragraphic Reports and have been supplementary to various investigations carried out by the mining companies on ore treatment, or by visiting geologists on the nature of the rocks and lodes. The presence of tellurides was determined in 1935, though incorrectly as nagyagite. The general absence of lead, except in traces, was soon afterwards discovered, and it came to be recognised as the mines were opened up that the chief telluride minerals on the field were sylvanite and native tellurium. Specimens of the tellurides have been provided from time to time by E. G. Theodore, Managing Director of the Emperor Mines Ltd., and of the Loloma (Fiji) Gold Mines N.L., and further material was recently obtained, as the result of a visit to the field at the invitation of Mr. Theodore.The aim of this paper is to describe the occurrence of the tellurides in these specimens. The work has been carried out as part of the programme of research of the Mineragraphic Section.THE VATUKOULA GOLDFIELDThe Emperor, Loloma and Dolphin mines are situated at Vatukoula, six miles, south of Tavua, on the north coast...

Jan 1, 1949

By Glatthar J. W, Lauder D. W, Manlapig E. V, Mackinnon I. R

The Ok Tedi copper orebody consists of porphyry and skarn orebodies. The skarn orebodies, identified by different mineralogies, are the source of high intermittent fluorine levels in the mill concentrates. This paper discusses the results of t

Jan 1, 1998

By M Denton, M Rheinlander, S Mundell, M Broadgate

The manufacturing industry reinvented its approach to the manufacturing process by managing and measuring it end-to-end. This improved returns on production assets, improved information quality and reduced delivery time, resulting in larger net profits through cost reduction and improved cash flow. Today this approach is standard in the manufacturing industry. Resource development has many requirements in common with the manufacturing production line. These include: control of the various steps, transparency of the state of the process to various levels of the organisation and the overall efficiency with which the process is executed. The authors argue that the introduction of manufacturing execution systems (MES) concepts and technologies to resource development processes will lead to similar improvements in control, transparency and efficiency and could improve profitability and enable staff to work more effectively and make better decisions.

Jan 1, 2009