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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 Sheard SN, Tucker DH

Sampling procedures are an important aspect of geophysical exploration survey design. It is good practice that the selection of survey parameters ensures that the signal to noise ratio is optimised, while minimising survey cost.Sampling considerations for any geophysical method include the size of the target, scale of observation, aliasing associated with station and line spacing, nature and extent of overburden, and the presentation of data.As a guide to survey design, the specifics are discussed for three geophysical techniques in common use in mineral exploration; these include the magnetic method, transient electromagnetics and induced polarisation.

Jan 1, 1976

By Emerson J

Drilling has always been one of the most important parts of the exploration process with most companies spending around 25% of their budget on drilling. Although superficially there appears to be little difference in drills and drilling practice a number of major refinements have taken place over the last decade that have significantly changed the drilling scene. One of the most important advances has been in hydraulic engineering giving rise to the Dual Purpose top drive drilling rigs. These have led to significant productivity increases with the high rotation speeds and longer fleets. Downhole technology has also advanced with better hammers, stronger drill rods, impregnated coring bits and improved drilling fluids. Although geologists continue to measure drilling performance on a cost per metre basis, greater consideration is at last being paid to the quality of sample produced. This is particularly the case with RC drilling where quite sophisticated automatic and semi automatic splitting devices have been developed. Drill operators are now required to be experienced in both Diamond coring and air drilling and be better qualified to maintain the more sophisticated machinery. Management of drilling companies or drilling divisions has also had to change to accommodate both the high capital cost of equipment and the demands of keeping drilling a cost effective exercise.

Jan 1, 1987

The major coalfields of Australia are almost unique in the occurrence in some areas of CO partly or almost completely replacing CH4,t1e normal seam gas from metamorphism of coal due to time and depth of burial. This CO2 situation has some benefits but mostly it introduces particular safety problems result- ing from the high density of CO2 relative to air, magnifying problems of gas dilution in ventilation, and the greater affinity which coal has for CO2 than for CH4 increasing proneness to gas-dynamic phenomena. The occurrence of most CO2 seam gas can be directly related to igneous intrusion and to its associated pneumatolytic injections. Whilst intrusions locally increase the rank of coal by their contact metamorphic effect, normal coal metamorphism due to time and depth of burial continues after intrusion and injection together with the ongoing metamorph- ic production of CH . This new CH slowly displaces any CO to leave some present-day intruded coals with seam gas with reduced CO2 or even without any significant CO2 associat- ions. The seam gas maps of the Bowen and Sydney Basins and more detailed maps of specific areas exemplify these situations. Mining progress, plus more searching studies of igneous-coal relationships provide improved understanding of the factors involved.

Jan 1, 1986

By Gluch KD

The current Mining Act has been the mechanism for administering and encouraging the State's mining industry through the 1970's up to the present. Although it has been subjected to considerable amendment there continues to be judicial challenge as well as criticism in relation to ambiguity of interpretation. Expansion of the mining industry and pressures placed upon "it by the ever increasing interaction with other land users have highlighted deficiencies in the current legislation and the need for a strong and progressive Act covering the rights and obligations of miners and their relationships with those outside the industry. - It is considered that the most positive results can be achieved by a complete redrafting of Queensland's mining administrative legislation.

Jan 1, 1987

The Sydney Coalfield, Nova Scotia contains extensive undersea longwall mining operations which are expected to continue well into the 21st Century. A long term research program has been initiated by the Cape Breton Coal Research Laboratory to investigate the full spectrum of problems associated with undersea mining and develop specific guidelines for use by the mine operator. At present, research is centred on the detailed evaluation of existing undersea sub- sidence guidelines, the identification and development of instrumentation capable of moni- toring seafloor subsidence profiles and the effective sealing of offshore exploration boreholes. In addition, work is also planned to examine in situ strata permeability changes occurring between the mining horizon and seabed and the feasibility of using artificial islands.

Jan 1, 1986

The purpose of any feasibility study is to determine whether a particular investment or management program will enhance shareholder wealth by, for example, producing an economic return in excess of the cost of equity capital.The threshold rate of return conventionally used in gold feasibility studies is higher than the cost of equity capital, meaning that some viable projects are wrongly described as being sub-economic with their development deferred.Is the industry failing to fully realise its potential? Aside from important technical considerations that determine the cost of exploiting inground inventories, feasibility studies need to incorporate expectations about future gold prices, exchange rates, interest rates and tax rates.Rather than revert to speculation, insights from capital markets give a rigorous framework in which these parameters can be determined for feasibility purposes. Separate questions sometimes, and then inadequately, addressed by feasibility studies include: ò Is it optimum? Many projects are expanded soon after project commissioning - what does this say about the quality of the initial feasibility study? Moreover, does the rate of extraction really matter? ò What is it worth? Although feasibility studies are designed to address viability rather than valuation, such studies are never- theless used by the industry as further evidence that the equity markets have got it wrong again! More likely the problem is with the financial slide rule being used. ò Can it be debt financed? The bankable feasibility study has entered the vocabulary of the gold mining industry but what does it mean? Does it matter anyway how the project is to be Financed?

Jan 1, 1991

In the late 1970's Western Mining Corporation, Exploration Division considered the purchase of a major multi-element spectrometer as an adjunct to our existing atomic absorption spectrophotometers. The analytical work proposed for the unit included barium, uranium and rare earth elements from Olympic Dam, uranium, sulphur, vanadium and strontium on Yeelirrie type deposits, major element and whole rock analysis, multi-element analysis of samples from the laterite, chromium and manganese exploration programmes and tin and arsenic analysis. These were all analyses that were not readily or easily performed by flame atomic absorption or were where we expected that a simultaneous multi-element instrument would be an advantage. Also the turnaround times for the commercial laboratories was considered unacceptably long for some determinations. Other factors, important when considering the spectrometer were the ability to ensure confidentiality of results and the ability to assign our own priorities and not to have to rely on commercial laboratories. The two techniques considered were X-ray Fluorescence Spectrometry and Inductively Coupled Plasma Optical Emission Spectrometry. The decision was made in favour of the ICP unit for several reasons. The ICP fitted in with our existing methodology, ie samples digested for atomic absorption or colorimetric techniques would also be suitable for ICP analysis and vice versa. The technique was suitable for water samples and for major element analyses and for rare earth elements. X-ray fluorescence spectrometers were installed at the Kambalda and Belmont laboratories and would be available to us for routine checking and for elements not suitable for ICP analysis. The final consideration was price. ICP was considerably cheaper than XRF.

Jan 1, 1987

By Martin CH

Over the past forty years colliery management has coped with intensive mechanisation and other rationalisation of traditional conditions to accomplish increases to outputs by miners, mines and nationally. The basic managerial function of planning, organising, directing and controlling have adjusted and expanded to current management demands, including the detail of achieving the highest possible efficiency, particularly in forward planning. Although industrial aspects have vastly improved, there are lingering problems. Safety is not necessarily the basic ingredient of any industrial events-which occur but is always paramount. Likewise some legislative changes may have elements of political and particular vested interests and conservation of technical expertise may be threatened by such frustrations. Not only technical excellence is required, but particular attributes of the individual are required in management evolving from "simple owner management to the complete corporate approach required for the multidisciplined operations of to-day".

Jan 1, 1988

Studies of Theological effects in grinding hold promise for improving this energy-intensive process. Six surveys of the Hellyer ball mill were conducted. The stream and sizing data from these surveys were balanced by JKMbal to compare the mill

Jan 1, 1994

A brief review of the problems in ventilating and cooling deep and hot Australian mines is presented. An overview is given on the development of the controlled partial recirculation concept. The main part of this paper describes the first majo

Jan 1, 1994

A good deal of criticism has been levelled at Mines Division over the slowness of processing mining privilege applications, some of which is justified and some which is not. There are many reasons for delays in the processing of applications and not the least of these delays are caused by the applicants themselves.

Jan 1, 1982

Continuing education is recognised as an essential aspect of professional training, but no systematic procedures have hitherto been attempted. The tertiary educational institut- ions are making a valuable contribution without formal financial support. The Australian Mineral Foundation is offering a programme of continuing education in the earth science and related disciplines both by direct initiative and by co-operation with existing tertiary educational institutions.

Jan 1, 1974

A review of the most widely used global extraction sequences in sublevel is undertaken. The review includes techniques used to extract massive as well as single or multiple steeply dipping tabular orebodies. The paper also deals with thick flat lying orebodies suitable for open stoping. Techniques used to minimise the effect of stress redistributions on a global scale are discussed for all the extraction sequences analysed.

Jan 1, 2003

The Mineralogical Researches of Gold Ores and Technological Products at Operating Factory in Olympiada Mine (Russia)

Sep 13, 2010

Naturally occurring organic plastics have been in use for over 2,000 years. Plastics based on chemically modified organic polymers date back only about 100 years, and those based on synthetic polymers about 50 years. The development of ,these two latter groups up to the present day is outlined, and the basic techniques currently available for polymer-building and modi-fication (blending, copolymerisation, quantitative and qualitative struc-tural control, and'si de-group reactions)-are reviewed.

Jan 1, 1962

As the mining industry looks to new technologies for a safe work environment and increased production rates, so should emergency response teams when dealing with organisational incidents. Implementation of technology has transformed the nature of incidents within the international mining community with lower frequency, high impact events replacing high frequency, low impact incidents of the past. In turn the approach to mines rescue response and preparation has naturally diversified. New rescue technologies when applied effectively can only further advance preparation and the response of mine rescues teams. This paper discusses some of the changes associated with mines rescue as the industry embraces technology. It highlights some recent rescue responses and their approach and gives examples of some of the new technologies being used for improved mines rescue.

Jan 1, 2004

The paper looks at those factors which led the Latrobe Valley Community Forum to .focus on shortcomings of the consultative process. that existed around the 1980 period, and the limitations on the ability of the community of the Latrobe Valley to have input to the factors affecting their quality of life. Through a review of the Yallourn East Field Extension project it seeks to demonstrate the changes that have occurred and some of the shortcomings still existant in the consultation process.

Jan 1, 1992

In planning its production and investment activities the mining industry has generally paid too little attention to perceptive analysis of its market environment. The nature of world economic difficulties over the past decade is not a mystery. Essent- ially prolonged affluence has engendered a false sense of security and fostered entrenched vest- ed interests hostile to economic change. The overall outlook remains poor. For mining projects mineral demand affects both product prices and the availability of specific sales outlets. Long-term projection of demand is complex and a key to success is concentrating on analysis of fundamental deter- minants and avoiding mindless extrapolation.

Jan 1, 1983

Operation of the tankhouse at the Electro lytic Refining and Smelting Company's works has been improved, but further automation is re- quired to cut the labour intensive nature of the routine tasks. Anode quality, both chemical and physical, plays an important role in efficient refinery practice, and impurities such as lead, antimony and nickel have required careful monitoring for smooth operation. The gradual replacement of copper blanks by titanium has markedly improved the quality of starting sheets, but problems have been ex- perienced with surface preconditioning of the titanium blanks. Polishing with emery paper proved to be a successful technique.

Jan 1, 1976