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It is commonly accepted that govern ments have a role in the financing of mineral development. The reasons for government involve- ment are examined in general and in the light of the current situation in Aust- ralia, particularly having regard to the ownership of resources. A brief introduction is given to the new Australian Government bodies, the Petroleum and Minerals Authority and the Australian Industry Development Cor- poration, designed to fill a new role in mineral development, and to the basic changes brought about by the Australian Government's decision to become involved in the future development of the country's mineral resources. It is generally accepted that governments do have a role in financing mineral development. This acceptance does not seem to be confined to Aust- ralia alone but is more a worldwide phenomenon. Mineral development has traditionally been regarded as the pre- serve of private enterprise and there- fore is presumed-to be profitable, and so it is instructive to ask why there is this special role for governments.

Jan 1, 1974

By W Lunwongsa, S Meffre, S Nuanla-ong, K Zaw, R James, A Salam

Gold and silver mineralisation at the Chatree low sulfidation deposit is hosted in andesitic volcanic and volcaniclastic rocks and characterised by multiple hydrothermal alteration assemblages and quartz-carbonate (chlorite-adularia) replacements, veins and breccias. The ore-bearing veins are influenced by intersecting structures and host rock lithologies. Emplacement of the host succession occurred at 250 ¦ 6 Ma (dated with laser ablation ICP-MS U-Pb zircon techniques), which was closely followed by mineralisation at 250.9 ¦ 0.8 Ma based on the analysis of adularia from coarse-grained quartz-sulfide (chalcopyrite-pyrite- sphalerite) veins using laser ablation Ar-Ar methods. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Carbonation of reinforced concrete is a potential durability issue for vehicular tunnels. This is particularly the case where elevated carbon dioxide concentrations exist and when the design life is 100 years or more. The process of carbonation can result in loss of passive protection to embedded steel reinforcement and initiation of corrosion. Therefore, tunnel design needs to consider the potential for carbonation on internal surfaces and how design life can be achieved in severe environments. This paper examines methods for predicting carbonation and how deterioration can be mitigated through appropriate concrete mix design and construction practices.

Jan 1, 2008

By Georgi H, Farquhar J. W, Lorrigan A. N

The potential for major new lenses of Volcanic Hosted Massive Sulphide (VHMS) beneath the existing Rosebery Deposit is extremely high. Recent deep drill hole intersections of massive sulphides, including 22 in true thickness at 24 per cent Zn, may significantly extend the life of the Rosebery Mine. The Rosebery Ore Deposit is located within Australia's most prospective VHMS mining district, the Mount Read Volcanic (MRV) arc of western Tasmania (Figure 1). The MRVs are a 10 - 15 krn wide arcuate belt of lavas, related intrusives and volcaniclastics. Rosebery is a major Cambrian volcanic hosted Zn-Pb-Cu-Ag-Au rich deposit which has been over-printed by Devonian deformation and granitoid alteration resulting in local rcmobilisation of the ore. The Rosebery Mine Sequence is composed of an east dipping and east facing, predominately felsic sequence of rhyo-dacitic volcaniclastics, epiclastics, sediments and shale lenses more than 500 in thick. This sequence is bounded by two, low angle (35 - 40¦), east dipping thrust faults, the Rosebery Fault to the west and the Mount Black Fault to the cast. The Rosebery Mine lithologies are summarised in the following table: Hangingwall (HW) Polymictic, quartz, feldspar-phyric epiclastics. Black Slates Graphitic, pyritic mudstones. Host Rocks Turbiditic mudstones and sandstones. Footwall (FW) Feldspar-phyric, pumiceous, mass-flow breccias. Cambrian, quartz-feldspar, porphyritic sills intrude this sequence at all levels. Thin, Jurassic, dolerite dykes also occur throughout the mine. Widespread quartz, sericite and chlorite alteration occurs in the FW. This alteration is manifested as quartz-augen schists beneath the orebody. The Host Rocks are pervasively altered with silica, sericite, chlorite and pyrite. Intense carbonate alteration occurs within the orebody, whereas chlorite and pyrite alteration is commonly concentrated directly beneath it. Cambrian volcanogenic alteration is over-printed by three major Devonian, granite-derived, assemblages. These are massive to quartz veined tourmaline, pyrrhotite-pyrite and magnetite-chalcopyrite. Though the Devonian granite has not been intersected in deep drill holes or in mine workings, there is good evidence that it exists within a kilometre of the deposit. The Rosebery orebody is structurally complex when compared to many other VHMS deposits. Evidence for Cambrian growth faulting has been found at the North End of the mine (B lens) where displacement of ore lenses occurs without corresponding displacement of the overlying Black Slates. A well defined cleavage exists throughout the mine, dipping at 28 to 50¦E. East dipping shear zones are also obvious in all parts of the mine workings and reverse movement is evident on many of these.

Jan 1, 1993

Competitive commercial circumstances internationally provide a prime impetus for miners to seek new technologies as a means to profitability and survival. Engineering and project management activities play a vital role in establishing, operating and developing the capital facilities used by miners. Computer based technologies are the single most important technology for maintain- ing competitiveness in engineering and project management into the future. Current applications of computers in engineering design and drafting are finding economic applications, computer-aids are more readily introduced, accepted and profitable. Computing technology is advancing very rapidly and on a broad front in hardware, software and communications. This technology advance is improving the ability of engineers and project managers to provide a high quality, responsive and low cost service which will improve in parallel with computer technology. As this technology advances, a key challenge is created for managers in selecting hardware and software, in developing people and organisations and in marketing the technology to advantage. While the future holds many exciting developments, people will still hold the key roles. While the nature of their roles may change, the final acceptance or rejection of technology will be by people, whether as users or owners, who will judge on the basis of whether their stake is improved or not.

Jan 1, 1986

By Blom MS

Two well-developed styles of mineralization occur in the Nevados del Famatina mining district, Famatina ranges, La Rioja province, Argentina. Porphyry molybdenum- copper-gold mineralization and high level acid sulphate alteration/mineralization (Nevados del Famatina) are related to intrusion of the Pliocene Mogote rhyodacite porphyry complex. High sulphidation epithermal mineralization (La Mejicana) is developed peripheral to the Nevados del Famatina deposit. Both are hosted mainly by the Ordovician Negro Peinado metapelites.At Nevados del Famatina, five mineralized fracture events have been identified and correlated with four distinct alteration assemblages. Stage I (barren quartz) and stage II (molybdenite¦sphalerite¦pyrite) mineralization are associated with a K-silicate alteration assemblage of K-feldspar+biotite+quartz+magneti te¦ilmenite¦anhydrite. Stage III (bornite+pyrite+sphalerite+molybdenite ¦chalcopyrite¦idaite) and stage IV (chalcopyrite+pyrite +sphalerite+gold¦tennantite-tetrahedrite) mineralization are related to a quartz-sericite assemblage of quartz +phengite+illite+pyrite+rutile. Stage V mineralization is divided into two substages. Stage Va (chalcopyrite +pyrite+sphalerite¦ tennantite-tetrahedrite ¦ tellurides ¦ gold ¦enargite¦famatinite¦stibnite¦molybdenite) is related to a sericite-clay assemblage of quartz+illite+kaolinite ¦montmorillonite¦alunite. Alunite-kaolinite alteration (alunite+pyrophyllite+kaolinite+ aluminum - phosphate -sulphate minerals ¦illite¦fluorite¦corundum¦anhydrite) occurs in the upper part of Nevados del Famatina associated with the later stage Vb (quartz+famatinite +chalcopyrite+covellite + chalcocite ¦ marcasite ¦ enargite ¦ luzonite¦sphalerite¦melnikovite) mineralization.

Jan 1, 1990

By Quast K. B

The effects of metal ion addition rates and contact time on the activation of synthetic sphalerite using copper, cadmium and silver ions were determined in order to investigate the exchange characteristics at the mineral surface. The stoichiometry of the adsorption indicated that the activation of sphalerite involved both a simple ion exchange and redox process in which the activating ion and oxygen were reduced, and the mixed-sulphide surface was oxidised to produce elemental sulphur and a metal-deficient sulphide surface. Unactivated sphalerite was shown to be relatively hydrophilic, with recoveries usually less than 20 per cent for a five-minute float. Activated sphalerite could be readily floated without the use of a conventional collector. This inherent flotability of the activated sphalerite had previously been associated with the formation of a metal-deficient sulphide layer; however, this study emphasizses the significance of the surface oxidation processes occurring.

Jan 1, 1993

By R Dimitrakopoulos

Optimisation and mathematical formulations for open pit design and long-term production scheduling have been available since the 1960s. There are two main concerns in the application of existing mixed integer programming (MIP) models in open pit mines: a. the feasibility of generating both optimal solutions and practically mineable scheduling patterns and b. the inability to deal with in situ variability in orebodies and account for uncertainty. In dealing with these issues, a general open pit production scheduling method for multi-element deposits is presented and subsequently used to optimise the long-term production schedule in a nickel laterite deposit. The application shows the weaknesses of MIP formulations in terms of generating optimal solutions as well as practically feasible mining patterns. The application of the same formulation in the presence of in situ orebody variability and uncertainty uncovers a major reason for deviations of scheduled production from actual production, and outlines additional limits of traditional optimisation formulations as well as future needs.

Jan 1, 2003

By A J. Moore

The Australian Coal Association Research Program (ACARP) funded project, No C14057, entitled æEffect of Blasting on InfrastructureÆ, has been carried out with the objectives of providing methodologies for the assessment of the strength of infrastructure types and the establishment of responsible and realistic limits. Personnel from Melbourne, Newcastle and Swinburne Universities and Terrock Consulting Engineers conducted the project. Infrastructure types including: conveyors; power transmission towers; wooden power poles; electrical substations; pipelines, bridges; public access roads and underground workings have been investigated by both field studies and structural analysis. Railways, underground telecom cables, dams and industrial buildings have been reviewed using general structural analysis. This paper has been prepared for the mining industry to provide a progress report on the project.

Jan 1, 2007

By Henderson J, Ward RG

Dissolved oxygen has been measured directly using a rugged, reliable, accurate electrochemical probe system developed for steelworks application by B.H.P. Central Research Laboratories. Furnace measurements show that the steel is generally supersaturated with oxygen and that oxygen contents vary considerably from heat. to heat. Ladle measurements also show considerable heat-to-heat variations. Analysis in terms of ladle deoxidation chemistry differentiates between carbon monoxide controlled and manganese silicate controlled oxygen levels. Deviations from these levels are sometimes due to aluminium present in other added ladle alloys but in some cases the plant applicability of laboratory derived equilibria is questionable.

Jan 1, 1972

By Ellicott C, Webb N

In November 1996 the NSW Minister for Mineral Resources, Hon Bob Martin MP, commissioned ACiL Economics and Policy Pty Ltd to conduct a wide ranging review of safety within the New South Wales mining industry.The review was a response to a disturbing number of fatalities which had occurred in the industry during the Minister's term of office together with a number of alarming near misses where serious failures in mining systems had occurred. Shortly after the review was commissioned, four mine workers died at Gretley Colliery near Newcastle. An inquiry is currently being conducted into the incident.

Jan 1, 1998

Changes in prices and costs change the mineable grade and the profitabil- ity of an ore reserve. In a static world the grade required for an ore reserve is measured by the ratio: Cost/tonne of ore x 100 Price received/tonne of product and profitability by the ratio:- Price received/tonne of product Cost/tonne of product If the words cost and price refer to average cost and average price over some suitable period, say 3 to 5 years, the above ratios express the convent- ional wisdom of the mining engineer, and assume there will be no change in technology or politics.

Jan 1, 1979

By N J. Betts

This paper aims to build on the strong emphasis that was placed on safety in the Sydney AITES-ITA Congress in March 2002. It will do this by comparing safety records from some major tunnelling projects in Europe and Australia over a period commencing in the second half of the 19th century to the second half of the 20th century and examining reasons for the apparent marked improvement that appeared in the 1980s. Further by looking at the relationship between this improvement and current trends in the australian industry by means of a detailed review of the safety record for the Northside Storage Tunnel project in Sydney which was completed in mid-2000. The paper will conclude by providing a summary of the progressive approach adopted by the minerals industry in australia and summarising the current state of tunnelling and underground construction in australia with respect to recently completed projects and potential major initiatives.

Jan 1, 2003

THE alkaline method for the estimation of zinc cannot, in the writer's opinion, be relied. upon to within very narrow limits between two assayers on unknown quantities of zinc. The end point is not decisive enough, and allows the personal factor toenter largely into the assay. The following investigation was undertaken to see how accurate the acid method is on Broken Hill concentrates and ores, and what should be the limit between the results of two assayers. The method adopted is as follows:Weigh sufficient amount of ore to give titration (between 20 and 50 cc.), place in tall 400 cc. beaker, cover, add 7 cc. nitric acid and heat till brown fumes cease to be evolved. Wash dock glass into assay, add potassium chlorate, evaporate to dryness on a slow fire with the beaker uncovered. When no smell of chlorine or nitric acid is observed, remove and cool. Add 100 cc. boiling water, then 7 grm. ammonium chloride, W cc. ammonia (.880 sp. gr.), boil for five minutes, filter, wash...

Jan 1, 1911

A simple and rapid method for delennining gold and silver in carbon samples is described. The method involves dissolution of carbon ash in a strong oxidising medium of aqua regia and hydrofluoric acid. Gold and silver are determined in the resultant solution using atomic absorption speetrometry (AAS). The method is efficient and reproducible. Gold results are comparable to the standard fire assay results, with agreement of results within ± 5 per cent. The co-efficients of variation for gold and silver are 0.37 and 0.39 per cent respectively for six replicate analyses. The analysis of gold and silver in a batch of ten carbon samples can be completed in approximately four hours.

Jan 1, 1992

By M Simpson, K Brodie, J L. Mauk

Subaqueous water-rock reactions that occur at the pit wall/lake water interface can affect the pH of pit lakes. Many pit lake water chemistry models neglect subaqueous reactions, which may create inaccurate predictions over time. A mineral quantification method is presented that defines the wall rock mineralogy of active open pit mines, using samples collected from the Martha Mine, a low-sulfidation epithermal Au-Ag deposit in Waihi, New Zealand. The mineral quantification method has five components: field observations and sampling, X-ray diffraction analyses, selection of representative samples, geochemical analyses, and mineral accounting. Predicted mineral concentrations closely match observed mineral concentrations visually estimated using petrographic techniques. Results of the method can be incorporated into a geochemical model of long-range pit lake water quality resulting from subaqueous water-rock reactions.

Jan 1, 2003

By L Crew, S Jackson

A trial of an Adept Online Ore Sizer (OOS) was undertaken at the WMC Leinster Nickel Operation (LNO) in the first half of 2000. During this time the On Line Ore Sizer has been shown to be a robust and accurate instrument for measuring mill feed ore size. Data collected during the trial indicates significant variation in the F80 of the SAG mill feed. The effects of feed size on milling parameters such as mill weight, mill power draw and mill efficiency appears to be dependent on the ore blend treated. With some ore blends a weak positive correlation was found between ore size and mill weight and milling efficiency but with others no correlation is evident. It is believed that the OOS will become a vital piece of equipment in the future as LNO continues to optimises its milling circuit.

Jan 1, 2000

Uranium minerals were found in Australia as early as 1869, but it was not until the 1940's that a search specifically for uranium was begun. Instrument types and techniques used in early exploration are still used today, but have been developed into more sophisticated and portable types. Recent improvements in exploration have been the introduction of the gamma ray spectrometer, radon sampling and geochemical surveys. The environments of presently defined uranium deposits are predominantly sedimentary. Known deposits in igneous environments are usually small. The size of targets which are likely to provide economic deposits is of the order of 10,000 tons U308, producible at a cost of less than $10 per pound. Such targets are most likely to be in Precambrian sediments or in granitic masses. Recent exploration in Australia has included investigation of Precambrian sediments, Precambrian and Palaeozoic granites, Mesozoic and Tertiary sediments, Precambrian volcanic rocks and brecciated masses of unknown age. The origin and method of emplacement of uranium in these environments is not well known but there are indications that syngenetic sedimentary processes are important, and volcanic rocks may make a major contribution to the supply of uranium.

Jan 1, 1970

By Ehlers HK

Mount Isa Mines Limited has 25 rod and ball mills of various sizes installed in two Concentrators at Mount Isa. A continuing investigation into installation, design and materials of liners for these mills has been in progress since the early sixties. Both manual and mechanical methods of liner installation are used and described. Materials for the various applications have been evaluated, mainly by field trials. Design of liners has also been evaluated by field trials and the history of trials in No.4 Concentrator is given. The purpose of the investigation has been to reduce the cost of mill lining and the life of many linings has been greatly increased as a result of this work.

Jan 1, 1978

By S Blackburn, T Veasey

The physical and mechanical properties of rock can be measured by a variety of standard tests, and studies have shown that there should be a fundamental connection between breakage in comminution and rock æstrengthÆ. The current study aims to develop the ring-loaded strength test, used as an industry standard for the characterisation of brittle ceramics, for determination of comminution behaviour from exploration borehole core samples. The test procedure is simple, reproducible and can yield 250 separate measurements from a one metre length of drill core. The effects of material grain size and fabric on the degree of scatter of results have been investigated with respect to the ring-loaded strength test. This study has also compared the ring loaded strength to the chevron bend test used to determine the Mode I fracture toughness. A wide range of rock materials have been studied and with further work it is conceivable that an operational work index could be obtained directly from exploration drill cores tested via the ring-loaded disc test.

Jan 1, 2000