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It is extraordinary that while Australia depends heavily on mineral wealth for its economic well-being, most Australians have no appreciation of the traditions and principles which drive and govern the mineral industry. Their understanding has been largely provided by those who campaign against the industry in one way or another and is therefore quite unrepresentative.

Jan 1, 1993

By Sturgul J. R

A major electricity generating authority have a proposal to construct a Power Station. An understanding of the operation of the bunker system is of importance to the designers and a computer simulation model of the operation was constructed. The computer language used was GPSS/PC which is a recent form of the language designed for the per- sonal computer. The model simulated trains arriving at the power sta- tion and unloading onto conveyors which carry coal to the power station bunker. Coal was drawn from the bunker at a specified feed rate to the power station. Numerous restrictions were placed on the model, if the bunker level got too high dozers would pull coal out of the bunker onto the stockpile, and if the level got too low the dozers would push coal back into the bunker. The conveyors and dozers were unavailable due to breakdown'at various times and trains would arrive randomly about a mean interarrival time. The system was simulated for 30 years of oper- ation and the model used a basic time unit of 30 minutes so that the system was updated 525,600 times during the simulation. The results of the simu- lation gave the designers a greater understanding of the critical factors in the operation, which may now be engineered to minimise adverse Effects.

Jan 1, 1988

By Neville WE, Parkinson J

One of the earliest recorded risk management schemes was implemented by the boatmen of the Yangtze river some 4,000 years ago.. Between them they arranged for shipments to be split up in such a way that a load was divided five ways: if one was lost, then 80% of the shipment got through. Bottomry contracts were in vogue in Babylonian times with similar systems being used in India, in 60OBC and 4th century Greece. One of the first accepted mutual insurance ideas came in 1835 when a mill owner in America negotiated a lower insurance premium in return for installed fire safety measures. Approximately 20 years ago risk management as a philosophy was developed in the U.S.A., the philosophy followed to England and hence to Australia about 10 years ago. The business climate which induced the philosophy of risk management was that of "tight money". The definition of "assets" was then broadened to include earning capacity, skilled personnel and in a negative sense, a corporation's liabilities. In more affluent days losses were comfortably absorbed into the ongoing business expenses, the more prudent managers took out insurance which "covered everything" at a suitable premium. Statistics are available to indicate that a high percentage, (over 60%) of businesses which suffer massive plant damage due to fire, do not restart operations, or in the event of restarting have closed operations within the next 2 to 3 years - in spite of collecting an insurance payout.

Jan 1, 1986

By J Kleynhans, D Vermeulen, V Cogho

A number of rehabilitated open cast coalmines in SA are already decanting. The paper focuses on the situation at one of these mines where the following information exist: monthly decant rates and rainfall; sulfate concentrations of the decanting water; water level measurements inside the mine prior to decanting; ABA analyses; information about the rehabilitation (drainage slope, vegetation, soil used). A 2D-model was constructed for the mine and calibrated against six years of flow data. About 85 per cent of the decant outflow rate comes from direct recharge on top of the rehabilitated mine while the other 15 per cent is derived from lateral groundwater inflows. The estimated recharge value was 17 per cent of the rainfall. Measured sulfate values showed that the sulfate generation rate for the mine was in the order of 7 kg/ha/d. Conclusions from the study are:most of the water decanting from rehabilitated open cast coal mines is derived from recharge via rainfall; given a specific sulfate generation rate, then: the lower the recharge the less the decant rate but the higher the sulfate concentration of the decanting water and vice versa; future prediction of the decant rate must be stochastic according to expected percentile monthly rainfall values; and as a first assessment of the predicted sulfate concentration of decant water from rehabilitated open case mines, the 7 kg/ha/d sulfate generation rate can be used.

Jan 1, 2003

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

Evidence for Middle-Late Triassic large-scale, silicic volcanism characteristic of extensional continental terranes is widespread in the Tasman Orogenic Zone in Eastern Australia. Detailed study of an area of south-east Queensland has defined the eroded remnants of a large collapse caldera and an associated area of rhyolite dome building and regional downsag which may be a second caldera (Stephens, 1986). The silicic volcanics and minor basaltic to andesitic products have been assigned to the Aranbanga Volcanic Group (Cranfield, in prep.) and the associated granite complex has been named the Mungore Complex (Ellis, 1968). Published isotopic age dates on the Mungore Complex are 212-219 m.y. (K-Ar Biotite; Ellis, 1968) and 226 m.y. (pooled Rb-Sr on several similar plutons in the region; Webb and McDougall, 1967). Basalts within the area have been dated at 219 m.y. (GSQ Annual Rpt., 1986). The collapse caldera (Mungore Caldera) lies on the intersection of 4 major structural features: 1) the Mt. Perry Lineament, a meridional fault zone extending for over 600 kilometres in a NNW-SSE direction and which has faulted the eastern part of the caldera 5 kilometres sinistrally. The lineament has been active at least from mid-Permian to Late Triassic and has localised activity into the Tertiary. Granite plutons of the same age as'the Mungore Complex- are topographically prominent and largely concentrated east of the Mt. Perry Lineament and its extensions (Nash, 1986); 2) the extension of the Darling River Lineament, a continental-scale, ENE trending feature which correlates with regional structural discontinuities but which lacks expression as faults within the Tasman Orogenic Zone;

Jan 1, 1987

Oxy-ACETYLENE system of welding and cutting is at present practised in two forms, which may be described as the high and lowpressure systems. In the high-pressure system the two gases, oxygen and acetylene, are delivered. to the blow-pipe under pressure from properly constructed trade cylinders. Oxygen cylinders are in two sizes, each containing 100 and 200 cub. ft. of gas respectively. These cylinders are charged to a pressure of 120 atmospheres, or 1800 lb. per sq. in. approximately. The acetylene cylinders are made in one size as far as the writer knows, and contain 200 cub. ft. of acetylene gas at a pressure of 10 atmospheres. Each cylinder is provided with a valve and connection for attaching a regulator to "break down" the high pressure in the cylinders to the necessary low working pressure of the blow-pipes, and to deliver the two gases at a constant pressure irrespective of the variable pressures in the cylinders. These regulators can be adjusted down to as low as 1 lb. and are provided with two pressure gaugesone reading the contents of the cylinder in atmospheres, and the other the working pressure in lb. per sq. in. The high-pressure, or "two cylinder" system is compact and can readily be transported from place to place in the works. For this purpose the two cylinders are mounted on an easy-running 4-wheeled truck, which the operator and assistant find no difficulty in manipulating. In the low-pressure system the two gases are delivered to the blow-pipe, one from the oxygen cylinder and the other from the acetylene gas generating plant, which consists of the following:Generating cylinder, half filled with water, into which the cathoide is plunged. The generated gas is passed through a filter to the gasometer, then through a water washer on to the hydraullic seal...

Jan 1, 1922

By D Jordan, R Wilmoth, J LeFever

Exposed, open pit mine highwalls contribute significantly to the production of acid mine drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Four innovative technologies were evaluated under the US Environmental Protection AgencyÆs, Mine Waste Technology (MWTP), Prevention of AMD Generation from Open Pit Highwalls Demonstration Project. This project is funded by the US Environmental Protection Agency (EPA) and jointly administered by the EPA and the US Department of Energy (DOE) through an Interagency Agreement. The objective of the field demonstration was to evaluate the technologies ability to decrease or eliminate acid generation from treated areas of the highwall in comparison an untreated highwall area. The field demonstration was performed at the Golden Sunlight Mine (GSM) a subsidiary of Placer Dome US, located near Whitehall, Montana. GSM is an operating gold mine. The highwall at GSM was divided into five plots measuring 15.24 by 15.24 m and each technology was assigned a plot with the fifth plot being used for comparison as a background control plot. The four technologies were spray-applied. The applied in situ treatment technologies included: a modified, furfuryl alcohol resin sealant, utilising wood and agricultural by-products to coat the rock surface; EcobondTM ARD, a phosphate based process that forms a stable, insoluble compound, coating the rock surface; and two AMD passivation technologies, magnesium oxide and the Dupont technology developed to create an inert layer/coating on the pyrite, preventing oxidation. The technologies were evaluated using the following methods: ASTM D 5744-96, accelerated weathering of solid materials using a modified humidity cells; mine wall residual wall rinse sampling; microscopy; and core drilling followed by water injection testing. The following paper describes the technologies used for passivation of acid generation from the highwall, the field demonstration, and the testing results from the background and each technology plot.

Jan 1, 2003

Most of you who are attending this conference are probably Student Members of The Institute and well aware of the advantages which flow from student membership. You will probably agree that the major benefits are: ò Low and subsidised membership fees;

Jan 1, 1994

While reaction to immediate demands may be required from time to time, the principal concerns of a Geological 'Survey should be proaction, with respect to the systematic production of maps, reports and data in order to meet exploration needs in the longer term, and interaction, which involves a complex matrix of relationships - firstly within the Department between disciplines and at various levels of responsibility, secondly with the exploration industry, thirdly with Commonwealth authorities particularly the Bureau of Mineral Resources (BMR), and fourthly with university researchers in related fields.

Jan 1, 1987

The successful operation of diesel equipment underground does not entirely depend on selection of robust, reliable, easily maintained machines. Results are also heavily influenced by the following factors: Design and condition of the operating area. Skill of operators. Correct maintenance facilities. Experience, skill and initiative of maintenance personnel. If the mine layout does not allow access to a central workshop area, the effect of any shortcomings will be magnified. The best results will only be obtained by close co-operation between mining and maintenance departments right from the initial planning stages.

Jan 1, 1977

The expense of mine environmental and planning process approvals is a fundamental and proper part of mine planning and feasibility costs. It is not a cost that should be the subject of challenge nor is it a cost that should be avoided. However the additional process approval costs incurred by bureaucratic delay, process duplication and administrative incompetence is a scandal and a deterrent to investment.

Jan 1, 1992

By Dalzell R. W

A Conveyor Belt Fire Test Program was initiated in 1985 by the Approval and Certification Center (A&CC), Mine Safety and Health Administration (MSHA), U.S. Department of Labor. The purpose was to evaluate the effect of entry air velocities on the burning properties of mine conveyor belts and assess fire test data from large- and small-scale tests. Belts meeting the fire-resistant standards of MSHA and agencies of other countries were tested in small- and large- scale fire tests.

Jan 1, 1988

Australians have always been great travellers but, traditionally Australian companies have been very conservative in contrast to more daring individual Australians. During the 1960s, '1970s and 1980s, the Australian companies spent much of their time exploring in Australia. It was only some of the major companies like CRA and BHP that had explored in places like Bougainville and Chile. However, during the mid-1980s some of the smaller companies started looking beyond their shore towards other opportunities in other countries. Why did they do this? Were they pushed or did they jump? And where did they go?

Jan 1, 1996

An attempt was made to determine the lateral extent of analcite in the Newcastle Coal Measure sediments of the Sydney Basin. From an examination of the cores of eleven bores it was concluded that the mineral is concentrated in the western sector of the original Newcastle Basin and this presumably was the region of greatest sodium concentration and aridity. The distribution of the analcite is such that it appears to have little correlative value.

Jan 1, 1967

By D Lau

Traditionally X-ray diffraction (XRD) has not been significantly used by the cultural heritage sector, as the most commonly used technique, X-ray powder diffraction (XRPD), requires sample removal from the artwork or artefact, followed by grinding of the sample to a fine powder. With the development of micro-X-ray diffraction (micro-XRD) and other associated advances, non-destructive, in situ analysis of crystalline pigments on micro-areas of paintings and artefacts has become possible. This is illustrated with the application of this technique to the in situ analysis of propriety paints, paint cross-sections and small paintings. However, workers have noted that XRD can be insufficiently sensitive with pigment mixtures, due to matrix effects. This study obtained X-ray diffractograms of 17 single pigment preparations and determined relative amounts of crystalline content. The purity of single pigments was compared with Joint Committee on Powder Diffraction Standards (JCPDS) database diffractograms. The impact of pigments with high X-ray absorption coefficients on the detection limits of pigments with low X-ray absorption coefficients was further investigated by building on work done with the chromium oxide-zinc oxide series with the preparation of a second series of binary mixtures of zinc oxide (which has a high absorption coefficient and is almost fully crystalline) and ultramarine blue, which has a lower absorption coefficient but which is more crystalline. Semi-quantitative analysis, where baseline and absorption factor corrections are made, confirm detection limits as low as five per cent for chromium oxide and ultramarine blue when in a binary matrix with zinc oxide. However, this type of analysis is very time consuming. So in order to theoretically simulate issues that will be encountered with binary pigment mixtures, the single phase diffractograms were used to theoretically investigate the matrix effects of the three white pigments with the various coloured pigments. This illustrated that detection limits can be as low as five per cent or in non-ideal conditions, such as with partial peak clashes or where there are large differences in relative peak intensity, as high as 50 per cent. These results have significant implications for the analysis of painted surfaces on artworks or artefacts. It has been demonstrated that ideally this method is more suited to the investigation of surfaces where there is minimal mixing of pigments or where there is not a significant difference between the absorption coefficients of the mixed pigments.

Jan 1, 2008

Heavy media separation serves to upgrade mill feed and reduce unit operating costs, allowing ores to be mined which could other wise be uneconomic. At the Aberfoyle mine at Rossarden in north-east Tasmania, a simple heavy media operation using a converted Akins screw classifier as a separating vessel, removes barren quartz from mineralised material. At the Cleveland mine at Luina on the west coast of Tasmania a more complex ore mix requires a versatile operation combining hydro-dynamic and static separation equipment to provide an efficient beneficiation circuit. The two operations are briefly described with a background of basic heavy media separ- ation practice.

Jan 1, 1978

Extensive personal experience in the USA and Australia has shown that Australians working in suitable work environments are capable of world-class performance. To build such work environments, mining leaders need to ditch two common management approaches that have not succeeded. Firstly, stop relying on traditional methods of trying to change people's behaviour simply by using communication alone to change attitudes and then change behaviour. Analysis of human behaviour explains why this approach fails in all industries. Secondly, stop trying to improve productivity by just running harder and increasing capital investment. Understanding work processes explains why this approach has limited success.

Jan 1, 1995

Haematite Recovery from a Tailings Stream Laboratory and pilot scale testing were carried out in 1999 on a tailing sample from a North American iron ore plant using gravity, magnetic and flotation techniques. The ore contained 16 per cent iron mainly in the fine (-38 ¦m) size fraction. Two methods of evaluating the separation efficiency were used; Selectivity Index and Z factor analysis. Tabling and magnetic separation produced poor results, with flotation testing showing some promise, generating concentrates assaying more than 40 per cent Fe. High grade concentrates containing more than 67 per cent Fe were generated using the Kelsey Centrifugal Jig, and it was recommended that this technique be pursued at a larger scale to verify the results obtained.

Sep 13, 2010

By Chaves AP, Delboni H. Jr

Thermal comminution is an industrial process specially suited to very abrasive material, when contamination with Fe from wearing parts of conventional crushing and grinding equipment must be avoided. It involves an initial step of heating the material to be comminuted, followed by sudden cooling (quenching) and finally by a conventional mechanical process to disassemble the particle aggregates. The thermal step is, in fact, a pre-fracturing process. The heating operation causes changes in phase of the minerals and changes in volume of these minerals and other substances included in pores and cracks. The cooling operation causes thermal shock reversions or the phase transformation and consequent generation of internal stresses, high enough to fracture the solid.

Jan 1, 1993