Search Documents

The middle-Devonian Dulladerry Volcanics is a complex of A-type, predominantly rhyolitic ignimbrites, lavas and breccias. They form a NNW trending belt some 90 km long and 10-20 km wide, east of Parkes, NSW. The volcanics are dominated by widespread ignimbrite units with minor basalts, sediments and rarer andesites. The volcanics were deposited in a sub-aerial, possibly continental rift setting and are similar in chemistry and age to the Eden - Comerong - Yalwal Volcanic Zone (EVZ) on the NSW south coast. The volcanics exhibit an unusual Atype chemistry (high Zr, Y, Nb, REE, Ga). This distinctive composition illustrates that the volcanics are not comagmatic with the adjacent Yeoval Granite Complex or Eugowra Granite, which show typical I-type fractionation trends. Epithermal gold veins occur in basalt and andesite in the Dulladerry Volcanics at Mt Aubrey (Hopf, 1992), near Baldry. Alteration also occurs in the Glen Isla and Red Hill areas, with epithermal sinter recognised at Glen Isla. Copper and minor gold mineralisation occurs at the contact of rhyolite and andesite at Reedy Creek, but is not of epithermal origin. The analogous EVZ also contains several epithermal gold fields and it is this style of mineralisation which provides the most prospective targets in the Dulladerry Volcanics. Although the Dulladerry Volcanics also contain high background levels of REE and metals such as Zn and Pb, the general lack of fractionation and water-undersaturated character of A-type magmas does not lend itself to the development of significant concentrations of these elements into a fluid phase and mineralisation. The prospectivity of A-type volcanics in general could not be regarded as high. However, an indicator of some fractionation in the Dulladerry Volcanics is provided by the fairly low abundance (average 230 ppm) and wide range (

Jan 1, 1995

The Middleback Ranges are a series of parallel northsouth ridges on the eastern side of the Eyre Peninsula, South Australia, about 20 miles inland from the Spencer Gulf, as shown in Fig. 1. They extend for some 20 miles across the centre of the County of York. North of them, on the same line of strike, in, the County of Manchester, is a disconnected series of lesser which ends in the Iron Monarch-Iron Knob ridge, the principal iron ore locality. These ridges are referred to in the following pages as an integral part of the Middleback Ranges.The deposits of hematite which outcrop in these ranges (Fig. 1) form the most important group of iron ore bodies in Australia, and are exploited by the Broken Hill Proprietary Company. The largest of them is the Iron Monarch (Fig. 6) .H: The next largest are the Iron Duke, the Iron Prince and Iron Baron. The Iron Knob, Iron Duchess, the North and South Iron Knights, Iron Queen, and the small body south of it, the Kimba Lease, and the deposits in the Cook's and Ash Leases, are all smaller.Numerous small lens-like bodies of hematite occur throughout the ridges, but are not of sufficient size to be of commercial use. At present only the Iron Monarch and the Iron Prince bodies are being worked. The Iron Knob was quarried previously, but its remaining supply is held in reserve.*Published by permission of the Council for Scientific and Industrial Research.

Jan 1, 1936

By P Joyce, A S. Ray, P S. Thomas, J Haggman

Climate change and global warming present a significant challenge as unsustainable levels of greenhouse gas emissions arising from human activities continue to be emitted. The cement industry is responsible for between five and ten per cent of annual world carbon dioxide emissions; most arising from the manufacture of Portland cement (PC). An effective way of reducing emissions is by incorporating supplementary cementitious materials (SCMs) as partial PC replacements. SCMs are silicate or aluminosilicate based pozzolanic materials which, in finely divided form, combine with water and calcium hydroxide (lime), liberated by cement hydration, to form compounds exhibiting cementitious properties. Pitchstone is such an aluminosilicate and has the potential to act as an effective pozzolan for partial replacement of PC. In North Queensland, Australia, a vast deposit of pitchstone is mined and processed for expandable perlite aggregate. During the classification stage of the excavated natural material, waste pitchstone fines (PF) less than 0.5 mm in size are generated. This study evaluates the waste PF as a viable, eco-friendly pozzolan for the partial replacement of PC. The reactivity of the PF is compared to fly ash (FA), using the pozzolanic compressive strength activity index (SAI) after seven, 28, and 91 days ageing at 20 per cent and 40 per cent PC substitutions. PF was found to be comparable to FA as a pozzolan at 20 per cent PC substitution at all ages tested. However, for the 40 per cent substitution blends significant strength was only achieved at 91 days ageing for the FA blend. The pozzolanic reactivity was also investigated using thermogravimetric analysis to determine the degree of free lime present after 91 days. In all cases where an SCM was added, the free lime was observed to be consumed with increasing age.

Jan 1, 2008

By Upfold RW, Velzeboer MD

An underground mine fire will influence the ventilation equilibrium in several ways which results in a redistribution of the ventilating quantities and pressures throughout the whole mine. The ventilation carries the combustion products which constitute the greatest danger of mine fires through the mine and provides the oxygen on which the intensity of the fire depends. However, as a result of the ventilat- ion disturbances created by the fire, changes in airflow patterns can take place which are not always obvious, especially when the mine is being served by several fans. The use of com- puter simulation techniques allow for the likely effects to be tested and the different ventilation options to be evaluated as an integral part of the overall emergency/rescue planning and control procedures.

Jan 1, 1981

By Erceg MM

The Red Dome deposit is located about 15 kilometres by road west of Chillagoe in far north Queensland. The deposit is within a well known band of mineralisation which is adjacent to the Chillagoe - Mungana railway line. Earlier this century several mines were operating in this area, some of which were supplying feed-stock to the copper smelters which were operating in Chillagoe at that time.The area around Chillagoe has long been an interesting geological region with numerous locations exhibiting significant gold and base metal mineralisation.The Red Dome area of some time, however it was not became involved that the apparent. The upsurge in seventies added further investment.mineralisation had been known for until Noel Adam, a prospector,true potential of the area became the gold price in the late encouragement for additional

Jan 1, 1986

WINDING engines are one of the most important units in the equipment of a mine. Upon the winding machinery depends not only the output of the mine, but it supplies in most cases the only means by which workmen enter and return from the mine, and consequently the utmost care and attention is desirable in its design. The efficiency of a direct acting winding engine, as a machine is very low. In other words, the proportion between the useful work performed and the actual work the engine is capable of performing (under the most favourable conditions) is very small. The reasons for this are:-1. The intermittent nature of the work; the engine is stopped from 20 to 25 %(or even more) of the time which would constitute a useful day's work.2. The large amount of power that is absorbed applying the brakes to bring the load to rest.3. That the net useful load raised is small in comparison with dead load to be lifted, and the parts to be set in motion.4. That, owing to the frequent stops, initial condensation in the cylinders is always greater than in a continuously running engine, whilst radiation from steam pipes, valve chests, &c., goes on whether the engine is running or...

Jan 1, 1911

By P A. Williams, P Leverett

Many of the worldÆs stibnite deposits are found in orogenic zones and are mesothermal or epithermal in origin. They commonly occur near contacts between intrusives and metasediments. However, the spatial extent of anomalous Sb levels around such deposits is not well documented. This project has aimed to gain a better understanding of the mineralogy and geochemistry of Sb by deriving solubility and thermochemical data for some of the most common secondary Sb minerals. This has then been applied in field exploration for Sb ore deposits. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Hayward N, Sutherland D, Wilkie G

A pilot plant study has been made of the liberation characteristics of a nickel ore under different milling conditions. A series of runs were made ranging from fully autogenous grinding to semi-autogenous grinding with a ball load of 8%. The mill products were sized and assayed then analysed by QEM4SEM. This enabled a full liberation analysis to be carried out to see whether the autogenous grinding leads to improved liberation by promoting selective breakage. Though it is frequently claimed that fully autogenous grinding yields superior liberation this could not be detected in the present study.

Jan 1, 1991

By Massy-Greene RB

Limited recourse financing techniques reduce the financial exposure of equity holders to major mining projects by transfering some of the risks to the banks which provide loan funds for project development. This can only be achieved by a clear understanding of the principles involved. Engineering and management decisions on how the resource is to be developed and extracted must be made in the light of lender's requirements. The structure of sales contracts, joint venture agreements and many other documents can be important in limited recourse financing. If projections show that the debt can be repaid from project cash flow, loan agreements and other arrangements can restrict lenders ability to look to the equity holders for repayment of project loans.

Jan 1, 1981

Organic dyes such as nigrosine and sun yellow act as depressants for carbonaceous particles in the, flotation of sulphide ores. Depression is achieved when initially hydrophobic organic surfaces are made hydrophilic by preferential adsorption of dye molecules. Experimental studies, mainly on Mount Isa ores, indicate that dyes are adsorbed as planar anionic micelles attached to carbonaceous surfaces by van der Waals and ion exchange attractive interactions. Relationships appear to exist between the amount of organic matter on the surface of ground particles, the surface area of the particles, the "saturation" adsorptions of dyes, and the degree of difficulty experienced during froth flotation.

Jan 1, 1975

The role of metals in the economy is discussed with regard to the flow of metals through to final demand and is illustrated by data for seven metals. Factors influencing the changing pattern of metal consumption are described, including relative prices. A des- cription and discussion of current metal demand forecasting methodologies precedes a discussion firstly of broad economic trends and secondly of the evolving pattern of metal consumption relative to GDP (metal consumption intensity), as technology and other factors change and as economies mature. The tendency for metal consumption intensity to plateau and decline when economies reach a certain region of per capita GDP, following a rapid rise early in the industrial- ization process, is shown in comparative data for seven metals and six countries.

Jan 1, 1979

People in the work environment (and often elsewhere) are seen as a commodity (we use them for our purposes).The general accepted view of a Company is that shareholders are "The Company" and that they employ people to utilise their money in a particular field to generate more money to give a return on investment. To achieve this, capital equipment is purchased to fulfil a task and people are employed to use this equipment. Equipment and people are commodities purchased with money.The focus of this approach is MONEY. The equipment and people, and the use of them, determines the amount of money that can be generated. In this approach people are motivated by financial concerns. The harder the times the more money becomes the focus.

Jan 1, 1998

Brunswick Mining and Smelting Corporation Limited operates a large base metal property near Bathurst, New Brunswick in eastern Canada. Nominal capacity for the underground mining operation and concentrator is 10 250 DMT/day. Four concentrates are produced by differential flotation technology to recover minerals containing copper, lead, zinc and silver. Two characteristics of the Brunswick ores have a major impact on mineral processing operations. The mineralogy of the ore is complex with a total sulphide mineral content of 85 per cent. In addition, the ore is extremely fine-grained, and satisfactory liberation is difficult to achieve. These characteristics directly influence flotation selectivity and thereby affect metallurgical performance. Significant improvements in metallurgical performance have been achieved through the application of basic grinding and flotation principles using conventional milling equipment. Current operating practice and the metallurgical advancements are detailed.

Jan 1, 1993

By Boyes B. A, Haydon D. J

The Paddington project is a gold mining and processing operation located 35 km north of Kalgoorlie in the Eastern Goldfields region of Western Australia (Figure 1). The project, which is operated by Pancontinental Goldmining Areas Pty Ltd, treats 1.25 Mtpa of oxidised gold ore, derived mainly from open cuts adjacent to the plant, with minor tonnages from other pits in the region treated on a custom-milling basis. Gold is recovered using a conventional CIL process. The process raw water supply of 3 500 kUd is derived from the local groundwater system. Average salinity of the raw water is around 90 000 - 100 000 mg/L total dissolved solids. A small portion of the raw water is passed through a vacuum distillation desalination plant to produce the project's 200 kUd requirement for high quality water for potable use and gold recovery.

Jan 1, 1988

By J D. Bryant

The Ernest Henry Copper-Gold mine, the third largest copper deposit in Australia, is located 35 km NE of Cloncurry in the Mt Isa-Cloncurry mineral district of NW Queensland. Ernest Henry Mining Pty Ltd (EHM), a wholly owned subsidiary of Xstrata Copper Australia, operates the mine. Approximately 10.2 Mt of ore grading 1.12 per cent Cu and 0.56 g/t Au were processed during the 2001 - 2002 financial year. The Ernest Henry plant produces copper-gold concentrate, which is trucked to Mt Isa for smelting. The Ernest Henry deposit is a member of the diverse Fe-oxide-(Cu-Au) class of deposits. The orebody is hosted within a sequence of moderately SSE-dipping, intensely altered Paleoproterozoic intermediate metavolcanic and metasedimentary rocks. Copper (chalcopyrite)-gold mineralisation occurs mainly within the magnetite-biotite-calcite ¦ pyrite matrix of a 250 m + 300 m pipe-like breccia body. The breccia pipe comprises two anastomosing lenses separated by a lower grade, clast-supported breccia zone. Several anastomosing brittle faults affect the macro-geometry of the orebody. Copper grade is proportional to the degree of matrix support in the breccia. The July 2002 Ore Reserve was 88.7 Mt @ 1.0 per cent Cu and 0.5 g/t Au. Resource estimation at Ernest Henry is based on a large database of predominantly diamond drill hole information. Drill spacing is typically 50 m + 50 m. Ordinary kriging is used to estimate Cu, Au, SG and IST (oxidation indicator) into model parent cells of dimension 20 m E + 20 m N + 16 m RL. The block model is comprised of five geological-geochemical domains represented by 3D wireframe surfaces. Zonal control, where samples and blocks are assigned the same domain number, is used to control grade estimation. The geometry of the domains defines hard grade boundaries across strike and soft boundaries along strike A Deep Drilling Project was initiated in August 2002 with the initial aim of testing the down-plunge extension of the orebody to a vertical depth of over 1 km. The encouraging intersections to date have resulted in a significant increase in the mineÆs open pit Mineral Resource together with the identification of an underground Mineral Resource. Added benefits of the project included an expanded and updated geological legend and an improved understanding of the host geological sequence.

Jan 1, 2003

By Linying W

Entropy is an important concept both in natural and social sciences.Considering the preparatory process of the earthquakes as an open system, in view of basic ideas of the Theory of the Dissipative Structure, the seis-mological Entropy is introduced as an order parame-ter, describing the scale of order associated with the earthquake distribution in time, space and mag-nitude. The features of evolution of seismic acti-vities before and after the large earthquakes have been studied by using the seismological entropy.The preliminary results show that the seismological entropy in certain region decreases as the large earthquake is approaching, it means that the distri-bution of earthquakes has turned gradually in order from disorder.It is expectation that the application of the Principle of Entropy in seismological research will deepen the understanding of the physical process of earthquake preparation. Meanwhile, it will also offer some enlightements in studying mitigation of seismic hazard as well as earthquake prediction.

Jan 1, 1990

By D L. Kennedy

Many aspects of the physical layout of manufacturing plants and storage facilities for explosives are governed by so-called quantity-distances tables. Both the British and the American tables were originally derived from an analysis of the injuries and the building damage documented by an early 20th century compilation of significant accidental explosions. However, progressive changes in explosive process technology and in building techniques have reduced the relevance of much of this historic data set. Extensive scientific research has been conducted over recent decades to characterise the potential injuries and damage from accidental explosions under more modern conditions. This presentation will showcase some of this research.**This is an abstract only. No paper was provided for this abstract**

Nov 8, 2011

The geology and mineral deposits of the West Pilbara Goldfield are described and comparison is made with the Pilbara Goldfield,, In the West Pilbai'a Goldfield two adjacent environments are represented by a predominantly clastic succession and a predominantly volcanic succession. These two successions are lateral equivalents and lithologically they are similar to the classical successions at Warrdiwdbna and Mosquito Creek. How- ever, no evidence of a significant erosional break has been found. It is suggested that the Archaean rocks of: the Pilbara Block represent a single geosynclinal cycle, which culminated in orogenesis, within which-local disconformities have been developed in various places: and that the sub-Mosquito; Creek unconformity at Eastern Creek may be the most widespread of these disconformities, Widespread evidence of'preconsolidation movement, aid the intrusion of igneous rock into. unconsolidated sediment, suggest that tectonism and igneous activity began at a very early stage, This was localised along lines of fracture in an unidentified basement.,.Moveme.nt was primarily vertical and persisted into the older Proterozoic, The sediments were enriched in metal by vulcanicity, chemical sedimentation, and possibly detrit`1' contribution. Diagenesis and metamorphism caused the remobòliyation of the metallic constituents of igneous and sedimentary, rocks which were then localised-in loci of dislocation-formed both before and after consolidation.,.. . . , . .

Jan 1, 1964

By N McKenzie, F Brodbeck

The North-South Bypass Tunnel is the first project to get underway as part of BrisbaneÆs transport plan, which aims to improve the urban road network. The total length to be excavated is 6.8 km, which includes 4.8 km of driven tunnel and associated road connections. Construction commenced in August 2006 with project completion targeted well before the contractual completion date of October 2010. Due to the local geology, in particular the hard Brisbane tuff and neranleigh-fernvale formation, a combination of tunnel excavation methods are used. The majority of the tunnel is excavated by two tunnel boring machines which have a rate of progress of 16 - 20 m per day in rock having a compressive strength of between 80 and 150 MPa. Ten roadheaders operate at a rate of up to 2 m per day excavating the remaining tunnels, such as ramps, access tunnels, cross passages and merges. The tunnel team are managing the challenges and complexities associated with tunnelling through the hard Brisbane rock. A major challenge arose during the planning of the initial mainline excavation underneath the Royal National Association Showground in Bowen Hills. This section contains low rock cover and historical maps indicate that the showground is located within a former topographic depression (alluvial valley), which a creek once flowed through.Due to traffic merge design requirements, both tunnel boring machine (TBM) and roadheader excavation methods were required to be used in this challenging geological profile. The answer was to stabilise the alluvium above both TBM section tunnels from the surface prior to excavation and to operate the TBM in single shield mode with immediate grouting of annular void from the tail shield. In addition, the roadheader section of tunnel required additional support by spiles and canopy tubes installed from the tunnel face.

Jan 1, 2008

Brief summary of results obtained by a French-Japanese cooperative study on the bottom of trenches around Japan. The geophysical prospection, multi beam echo sounding and direct observation with submersible dives of the trench bottom clarified the details of the subduction of oceanic plates. It may be noted, among many new facts found: 1. The subduction and geologic structure resulted from the process is different according to the nature of subducting oceanic plate, and the geology of the land behind the trench. Thus the Nankai trough characterized by the developpement of accretionary prisms is contrasted to that of the Japan Trench where the basement rocks are exposed on the land side cliff of the trench wall. 2. The compressional tectonic situation prevailing in the trench bottom provokes the venting, along the fissures on the bottom, of water contained in sediments. Hydrocarbons contained in the sediments are comming out with water and give nutrients for bacteria. Clams, tube warms, sea slugs and shrimps are taking these bacteria as their food and biological communities with exceptionally dense population for the deep sea of more than 3000 meters in depth are formed on the field of accretionary prism and wall of the land side cliff. 3. An intense compressional tectonic field resulted from the subduction is inducing the transition from the subduction of oceanic plate to the collision of a part of the plate to the continental plate.

Jan 1, 1987