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By Shiels O. J

The paper reviews developments in general galvanising in Australia, including a brief history of the industry and its technology. The changes in galvanising process technology are covered, as well as developments in galvanising bath design, materials handling and pre-treatment. Developments in zinc management through the use of aluminium and nickel alloys are discussed. The paper addresses the cost components of general galvanising and relates this to the competitive position of general galvanising against other coatings used for protecting steel. The environmental aspects of the general galvanising industry in Australia are outlined with respect to the utilisation of process chemicals, problems associated with their disposal and developments in filtering and regeneration of process solutions. The current status of the industry is assessed in terms of zinc usage and usage trends. Likely changes in technology which may impact on the general galvanising industry in the future are reviewed.

Jan 1, 1993

By E Kunz

Decreasing the gas content in the worked seam by degassing before the start of winning has proven its worth in some areas of German hard coal mines. On the one hand, it removes the risk of gas/coal outbursts and on the other hand it reduces the gas inflow into the longwall. The underground experiences of the last 30 years have led to a æhit listÆ of coal seams with respect to their suitability to predegassing. Trials in the DMT laboratory and also results gained in the deposit show that the suitability of a seam for predegassing depends on its rank. In seams with volatile matter of 20 - 30 per cent, high efficiency ratings are achieved as a rule, with lower ratings both in seams with lower and with higher content of volatile matter.If the rock pressure is unusually high, the efficiency rating of the predegassing is lower, even in seams which would normally be suitable for this process. Under unfavourable conditions, for example below or above residual pillars, in-seam boreholes cannot be drilled successfully and the method is not practical. But if the worked seam was already stress relieved, the predegassing has an optimal efficiency. Latest investigations show that the distance between the in-seam boreholes can be extended. But in that case, the time necessary to reach the same reduction of the gas content increases considerably.

Jan 1, 2005

By Johnson CR, Wilkie G

The aim of the study was to use quantitative mineralogical measurements to predict the processing characteristics of an ore. Samples were taken from a wide range of concentrators processing ores of lead, zinc, copper and nickel. QEM'SEM was used to measure the characteristics of the ore feeding the plant. Concentrate product samples, together with plant operating data were used to give concentrate grade, recovery and grind size information. It was found that the mineralogical measurements correlated well with the metallurgical parameters indicating that these techniques will be very useful for making predictions in feasibility studies and simple plant optimization.

Jan 1, 1989

By A Struminski

The principles of occupational risk evaluation resulting from the improper ventilation of the underground mines were presented. It was shown that the risk level implies the appropriate planning and usage of prevention methods. That approach is fundamental in the ventilation, fire and climate safety management in the copper ore mines. The paper uses the adequately modified Risk Score method.

Jan 1, 2003

The Inquiry into the 1994 accident at Moura No. 2 Colliery included in it's findings that mine escape and rescue options for persons in underground coal mines were in need of review. The Inquiry recommended the establishment of industry working groups to report to the Queensland Chief Inspector of Coal Mines on matters including escape strategy and life support for escape from mines.One of these task groups examined issues relevant to self-escape from Australian underground coal mines and formulated recommendations and guidelines in response to the terms of reference and scope.

Jan 1, 1998

By Jones

Extractive metallurgy in the mining industry in Western Australia has diversified and increased in the last 11 years. Before 1980, the industry mainly produced alumina, nickel, mineral sands and iron ore, with the gold industry restricted to five operating plants using Merrill-Crowe technology. In 1981 Carbon-in-pulp (C]P) plants were commissioned at Kambalda, Kalgoorlie and Meekatharra.Currently, the gold industry has some seventy CIP plants in operation, production of synthetic rutile has increased tenfold to 500 000 tpa, alumina production has doubled and production of copper, lead and zinc concentrates has begun. Other extractive metallurgy plants recover tin, niobium and tantalum, silicon, titanium dioxide and zirconia. Current proposals include vanadium, steel and rare earths.

Jan 1, 1992

The concentrated efforts now being directed towards the development and application of monitoring and control techniques have now resulted in their widespread use in UK mines together with evidence of benefits resulting from their application. There is little doubt that the longwall method of producing deep mined coal will continue but will be made more reliable and efficient with the aid of control technology. The major fields of research and development work are concerned with planning and design of mines and mining equipment; management and engineering information; and automation of coalface, tunnelling and transport systems. The principal achievements now in widespread use are: the standard computer system MINOS, widely applied to mine transport, coalfaces and mine environment; extensive use of machine condition monitoring leading to condition-based maintenance; underground automation of conveyor systems and guidance systems for ranging drum shearers and boom-type roadheaders are being widely introduced.

Jan 1, 1985

By M Fahey, A B. Fourie

Over the past ten years, the mining industry has witnessed the introduction of a new and innovative mine filling technique known as paste fill, which consists of placing full stream tailings with small amounts of binder and water into underground stopes. Paste fill has benefits over traditional backfill methods, such as higher solids contents than hydraulic fill and easier transportation than rock fill. From a geotechnical perspective, the behaviour of very fine material in a fully saturated state can be complex, particularly when binder is added. Previously, there has been no rigorous solution to understanding the paste fill deposition process, resulting in uncertainty regarding critical aspects such as barricade load calculations. This uncertainty has the obvious consequences of potential barricade failures (including at least 12 over the past four years), and for many operations attempts to deal with this uncertainty has led to excessively conservative filling schedules, restricting production. This paper presents an application of Minefill-2D, the first rigorous model capable of representing the paste fill deposition process. The model couples the processes of material accretion, consolidation and cement hydration to calculate the distribution of stress around a stope (including the total stress applied to barricade structures) during filling. Minefill-2D is a finite element numerical program, which has been verified using laboratory element tests, centrifuge tests and in situ measurements (Helinski, 2008). The authors present a sensitivity analysis, carried out using the model, to demonstrate some of the critical and less critical aspects relating to paste backfill deposition. The results of this sensitivity analysis are used to devise a fill management strategy that can be utilised to minimise the risk of barricade failures and maximise fill rates where appropriate.

Jan 1, 2008

The use of black and white and colour infrared film in remote sensing of natural resources, is reviewed. In heavily-forested areas such as New Zealand, the main value of the method is in surveying the vegetation cover to detect the existence of plant communities characteristic of specific geological formations, By contrast, in and areas of Australia where the vegetation cover is sparse and where rocks and soils are well exposed, the method can be used in detecting different rock types or other geological differences.

Jan 1, 1971

By M Mee, R L. Gwyther

Accurate measurement of rock mass response during the mining of massive underground orebodies is essential, as mines become larger and deeper. These measurements enable: provision of quantitative data for optimal pit slope design and engineering; monitoring of the stability of deep pit slopes, the long-term integrity of shafts and large-scale underground infrastructure, and long-term measurements of deformation or rock mass creep following the mining process for environmental management. Strainmeters traditionally used for deformation measurement have neither the long-term stability nor the high sensitivity to perform measurements in these applications. This paper describes a new precision borehole strain monitoring system (GTS) currently deployed by CSIRO Exploration and Mining, which has the potential to solve these new issues in rock mass deformation monitoring. This technology was originally developed for use in hard rock mines (Gladwin, 1977) and refined considerably for earthquake research (Gladwin et al, 1994; Gwyther et al, 1992). A case study of the use of the GTS in monitoring longwall coal mining over the period 1993 - 1998 is presented.

Jan 1, 2000

By Holcombe R. J, Dobos S. K, Little T. R

Blue amphibole-bearing rocks in the North D'aguilar Block of southeast Queensland occur either as relict pods and lenses within regionally extensive greenschist facies phyllites and schists or as blocks entrained in serpentinite-matrix melange. Epidote + crossite-bearing varieties predominate and formed under conditions consistent with underplating and high P:T metamorphism in a subduction-related tectonic environment. Neither lawsonite nor jadeite has been observed and metamorphic conditions are estimated at 380-4500C for pressures of 0.5-0.8 GPa. High P:T metamorphism occurred during the earliest stages of deformation and was superimposed upon protoliths of inferred Late Devonian - Early Carboniferous age, including mafic volcanics, tuffs and coarse volcaniclastic breccias as well as pelagic and henipelagic sediments, all of which have undergone varying degrees of over-printing to the greenschist facies. Greenschist facies metamorphism occurred during the second phase of deformation and was associated with the formation of mainly flat-lying or subhorizontal structures; it followed the cessation of subduction and occurred in response to either thermal relaxation during uplift or the imposition of regional heating induced by crustal thickening and/or synkinanatic granite emplacement. Uplift and cooling of the high P:T rocks was completed by 260-265 Ma and may have occurred in response to the same extensional processes which gave rise to the onset of rifting in the adjacent Esk Trough.

Jan 1, 1990

By C Mark

Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past two years, three US coal miners were killed in two coal bursts, following a six-year period during which there were zero burst fatalities.This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major longwall mining coalfields that have struggled with bursts for decades. The Utah experience displays many of the ‘classic’ burst characteristics, including deep cover, strong roof and floor rock, and a direct association between bursts and mining activity. In Colorado, the longwalls of the North Fork Valley (NFV) also work at great depth, but their roof and floor strengths are moderate, and most bursts have occurred during entry development or in headgates, bleeders or other outbye locations. The NFV bursts also are more likely to be associated with geologic structures and large magnitude seismic events. The paper closes with a brief discussion of how US longwalls have managed the burst risk.CITATION:Mark, C, 2014. Coal bursts in the deep longwall mines of the United States, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 33–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By G Nicholas, S Coward, J Vann, R Wolff, S Jackson, S Moayer, A Bye

"A new approach to mineral project evaluation is described called Scenario-Based Project Evaluation (SBPE). SBPE incorporates well established æscenario planningÆ and æscenario thinkingÆ approaches, which are used extensively in other industries,?most notably the?petroleum industry. While most scenario planning is qualitative and non-probabilistic, the approach described here includes both quantitative and qualitative aspects. SBPE is complementary to optimisation approaches and allows mining firms to build and operate projects that are more robust in the face of adverse changes as well as proactively respond and exploit the upside offered by a realistic assessment of variability. The approach has potential to improve project performance and decrease operational risk. It also has important applications for currently operating mines.Conventional evaluation of metalliferous mineral deposits uses estimates of metal grades and deleterious attributes in singular æorebody modelsÆ, usually 3D block models, which fail to capture two critical aspects that underpin the realised value of mining projects: the inherent uncertainty of the estimated attributes the spatial variability of attributes, at the scale of mining selection, which impact on downstream processing steps and fundamentally drive realised value. While singular models are appropriate for estimating block averages, conditional simulation (CS) models of the relevant attributes are needed to represent uncertainty and capture spatial variability. Any attributes that can be either built into CS models and/or modelled in the envisaged mining/processing steps, can be evaluated fully through to highly ægranularÆ (ie detailed and un-smoothed) cash flows. A complete view of SBPE relies on selected strategies being tested against plausible æscenariosÆ of factors external to the project and thus outside management control. æExternalitiesÆ captured in such scenarios include market prices, costs and taxes. Via SBPE, project managers may demonstrate that there is material value in preserving or purchasing options that provide future flexibility to respond to the changing externalities or changes in orebody performance. Such flexibility generally comes at a cost but is very difficult to value. It is argued that full value chain evaluation using SBPE can help to value these options for a mining company. A case study for a gold mine is presented.CITATION:Vann, J, Jackson, S, Bye, A, Coward, S, Moayer, S, Nicholas, G and Wolff, R, 2012. Scenario thinking - A powerful tool for strategic planning and evaluation of mining projects and operations, in Proceedings Project Evaluation 2012, pp 5-14 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

May 24, 2012

By M Titley, M NoppT

A study on the feasibility of mining the recently discovered Wallaby gold deposit is due for completion by mid-2000. Open pit mining is the favoured method. Determination of the impact of mining bench height on the recovery of ore, including the estimation of dilution and ore loss, is critical to the economics of the operation. Conditional simulation was used to derive a number of gold estimation scenarios within a typical volume of the deposit. These scenarios were interrogated for a selection of mining bench heights and ore block dimensions. The results were reported as a range of grade tonnage relationships and compared to the kriged resource model. This allowed the resource model to be calibrated to a specific mining bench height and ore block size. Once calibrated, more realistic dilution and ore loss values for a number of mining bench heights were calculated from the resource model. These values were then used to determine the economic sensitivity of particular mining methods. The spread of results from the simulations also provided an indication of the confidence in the kriged grade estimates for the different zones of mineralisation within the deposit and highlighted areas of any significant uncertainty.

Jan 1, 2000

By Jaques A. L, Heinrich C. A

Mt Todd lies towards the south end of the Pine Creek Geosyncline, sandwiched between the Cullen Batholith and the Edith Falls Basin, in an area of regionally metamorphosed sandstones, siltstones and shales. The Batman deposit, some 3 km west of Mt Todd is a sheeted quartz vein system hosted within greywackes of the Palaeoproterozoic Burrell Creek Formation (Finniss River Group). The gold-bearing quartz veins, trending 010¦-020¦ and dipping 60¦-70¦E, are commonly 0.5 to 5 cm wide and occur at intervals which are from 10 cm to 1 m apart. Gold tends to be restricted to the quartz veinlets and immediately adjacent country rock. Grade Control utilises two 4 m 'collar' samples which are collected from each 8 m production blasthole. The irregular distribution of the quartz veins and erratic gold mineralisation has resulted in a disseminated 'salt and pepper' type of gold occurrence, with only a poorly defined footwall. Delineation of ore and waste blocks for mining uses an approach which combines the smoothing effect of kriging with a pragmatic view of the raw data. Large ore blocks with simple geometry help to minimise mining dilution, reduce block variance and give good reconciliations to interpreted ore tonnes and grade. Daily mine face advance is reported against truck counts and provides continual comparison with budgeted production. All data processing uses Gemcom software, together with Lotus spreadsheets.

Jan 1, 1994

By Noller B. N, Mine F. J

Modem open cut and underground mining in the tropics inevitably expose partially weathered and unweathered rocks to oxygen and water, leading to weathering and the release of solutes and often acidity as well. Historical monitoring data can demonstrate these phenomena. Three case studies from open cut mines in the north of the Northern Territory illustrate the deterioration in quality of pond water receiving drainage from waste rock dumps. The potential for deterioration of water quality was not recognised in many mine Environmental Impact Statements prepared and accepted in the 1980s. The examples documented indicate the importance of adequately planning for this near inevitable process. Retrofitting a mine water management system to 'no' or minimal release can be very difficult and expensive, and may not be feasible, leading to downstream pollution. The characterisation of acid and solute production potential of ore and waste rock, and improved dumping strategies and water management are very important to minimise the environmental impact of mining in the tropics.

Jan 1, 1994

By J Harris, P Kirsch, R LaBouchardiere

æMining + Health in DevelopmentÆ is a project funded by the International Mining for Development Centre (IM4DC, 2012) to develop a centralised database of corporate sustainability initiatives for managing and improving occupational and public health, based on information extracted from social and environmental reports of major mining, oil and gas (MOG) companies. This register of materials has the potential to increase stakeholder awareness of the unique health risks impacting the minerals industry, employees, their families and surrounding communities, as well as to inform stakeholders on global industry approaches to health management.Data and preliminary outcomes from analysis of different MOG corporate sustainability reports on public health and disease management are presented for six African countries (Democratic Republic of Congo, Ghana, Mozambique, Sudan, Tanzania and Zimbabwe) and six Asia-Pacific countries (Indonesia, Mongolia, Pakistan, Papua New Guinea, Philippines and Vietnam).With the minerals industry facing ongoing rapid growth worldwide, including continuous expansion into developing regions, the æMining+Health in DevelopmentÆ project will inform industry, civil society and regulators of current health management practices and programming among the different sectors of the minerals, oil and gas industries and across various regional operations. This baseline information will serve as a resource for minerals industry managers, providing a forum for sharing best practice health management approaches amongst MOG companies.CITATION:LaBouchardiere, R, Harris, J and Kirsch, P, 2012. Mining and health in development - An inventory of global resource industry health initiatives in developing countries, in Proceedings International Mine Management 2012, pp 75-90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By I Auranen, J Raatikainen

IMA Engineering (IMA) and Mine On-Line Service (MOLS) companies have used on-line sensors for analysing ore and waste rock in mining for more than 25 years. Today IMA on-line sensors are used in various stages of the mining process including on-line analysis of drill cores, drill chips, ore and waste in loader bucket, ROM ore analysis on belt conveyor belt and in bulk ore sorting and in slurry analysis in concentrators. During years of extensive field experience and testing we have found that the waste rock dilution and ore losses create much larger economic and environmental losses than has been previously recognized. According to our studies the main reason is limited number of analysis already in exploration when drill cores or drill cuttings are used in block modelling. The same happens in production because too few and biased samples from benches are used to estimate the ore grade. Much more than today estimated amount of waste enters the mill and considerable volumes of ore losses happen at the same time. The ore grade on the benches and in muck piles is averaged and “homogenized” with averaged and biased samples. These are the main root causes of waste rock dilution and ore losses. Sensor based preconcentration can be the remedy to waste rock dilution and ore losses. This presentation will show examples of the use of on-line sensors in preconcentration when analysing ore and waste rock in drill cores, drill cuttings, on conveyor belt and in bulk ore sorting. Waste rock removal in preconcentration has direct effect on energy consumption in crushing and grinding and chemicals in concentrator. In concentrator waste is separated and goes to tailings pond, however, preconcentration directly reduces the volume of the tailings. In our presentation we will cover cases in base metals and in gold mines.

Nov 10, 2020

By G C. Snedden

Tandem row stator arrangements are common in the last stage of multirow, gas turbine compressors. Tandem row stators, or stator and de-swirler vane combinations are used to relieve the loading on the stator but ensure axial flow leaving the compressor. In this paper a standard 40” (1016 mm) ventilation fan in the Air Blow Fan’s range is modified to utilise the plate support struts on the barrel to relieve the aerodynamic loading on the aerofoil stator. Performance maps for both versions of the fan were generated using computational fluid dynamics and are compared across a wide range of rotor setting angles showing a clear advantage of approximately 2 per cent in efficiency for the tandem blade design. In addition, the area of high efficiency that represents the practically usable area of the map extends over a greater area in terms of flow rate and total pressure rise.

Oct 12, 2022

By Kuster D

Under humid conditions geochemical exploration for rare-metals is, at the reconnaissance level,usually carried out by stream sediment and soil sampling. As the secondary dispersion patterns are distinctly different in arid environ- ments, other exploration methods have to be applied (MATHEIS & KOSTER, 1985).

Jan 1, 1988