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By Wymer DG

The concept of hydro power in deep mines is based on the exploitation of the hydrostatic head that can be gained as refrigerated cooling water descends in shaft pipe columns from the surface, to provide hydraulic power for machines at the working face. This paper describes the work done on two important aspects of the controlled distribu-tion of the high pressure water within a mine, namely the control of pressure under normal operating conditions, and the control of flow in an emergency situation following a pipe breakage. Suitable methods of control have been determined using theoretical techniques to model the steady and unsteady flow behaviour of the water in the pipeline, and taking into consideration the environmental constraints on the types of control devices that can be used. The preferred approach is one in which the high pressure water itself is used as the control medium. The control valves themselves can be fairly conventional in design, but in the case of pipe break protection it is shown that a less conventional approach based on the use of a hydraulic fuse gives improved control performance.

Jan 1, 1985

The paper presents an overview of the mining industry of Papua New Guinea. Although the Bougainville problem is still unresolved, new mines like Ok Tedi, Misima and Porgera, which have come on stream during recent past, have raised hopes of sustained growth period in the industry. Kutubu Oilfield is also being developed in the Southern Highlands and the oil production has commenced from July 1992. Government revenue from these mega projects will increase five-fold during 1993 and 1994. A new mine which is being planned is the fabulous Lihir Deposit, on an island renowned to be full of gold. Gold occurs within a volcano which still contains high temperature ground water because the system which created the deposit is still geothermally active.In Papua New Guinea, problems of environmental management are far easier to tackle than those of a socio-political and economic nature involving compensation payments to the landowners and the distribution of royalties and taxes between the national and provincial governments. At the socio-political level, the country has not been able to resolve the problems of land rights versus mining rights. Whenever mining starts in a big way, it raises people's expectations to a very high level, which then becomes the focal point of dispute between landowners, provincial governments, national government and mining companies. A new system called 'Forum' has been tried to bring all parties together and son out the issues. The system appears to be working well in new mines like Ok Icdi, Porgera, Misima and Kutubu Oilfields.

Jan 1, 1993

By Schmidt CG

Parameters affecting gold elution using the AARL process are reviewed and critically analyzed in an attempt to optimise metallurgical efficiency and minimise costs in both current and future carbon adsorption operations. Such factors as acid washing, column geometry, elution temperatures and pretreatment reagents are discussed together with eluant water quality and eluate flowrates. Hot acid washing of carbon prior to gold elution has many benefits. Besides improving elution efficiency when eluting with regional water, a hot acid treatment preheats the carbon without causing any gold leakage. Laboratory data indicated that hot acid washing reduces the mass loss of carbon during thermal regeneration. The eluate going to either zinc precipitation or electrowinning is also relatively free of troublesome impurities (organic contaminants and ferrocyanides in particular). Because of the chromatographic character of the AARL elution where an ionic strength gradient is used to inhibit the readsorption of gold, column geometry plays a significant role. While practical considerations and capital costs may restrain the length of the elution column, high length/diameter ratios are advocated in order to promote the plug flow of column eluate. From both a metallurgical and costing viewpoint, the two significant factors affect- ing the AARL gold elution are temperature and cyanide addition. High temperature and high reagent additions within prescribed limits will improve metallurgical efficiencies, but a balance between energy and reagent costs is required in order to minimise overall elution costs. As pretreatment reagents constitute a considerable portion of the total elution costs, both the addition and consumption of sodium cyanide must be carefully considered. Lower cyanide additions may be effective in certain instances, but the more practical use of 0,6 bed volume of a 2-3 per cent NaCN reagent containing 2 per cent NaOH is advocated. This is equivalent to an addition of 20-30 kg NaCN and 20 kg NaOH per ton carbon Treated.

Jan 1, 1986

The South Junction deposit of St Barbara Mines Limited was discovered in 1989 by the geologists of Ross Atkins Mining.The deposit occurs in the lower part of the Gabanintha Formation of the Lukes Creek Group in the Mt Magnet -Meekatharra greenstone belt. Country rock is predominantly talc-chlorite schist. Gold mineralisation is associated with north-south shear zones, quartz-carbonate-fuchsite alteration of the ultramafic rocks and in particular close to deeply weathered quartz-albite porphyry. For a detailed description of the geology of the South Junction Deposit see Fiala (1992).

Jan 1, 1993

By Nickson NM, Lancucki CJ

X-ray diffraction and differential thermal methodshave been used to determine the mineralogy of some clays used by the heavy clay industry in the Adelaide area. A detailed analysis has been made of the mineralogy and. particle size distribution of eighteen samples from beds' in two pits in~the Recent seaiinents in the Adelaide plains, of six white clays.: developed from the weathering of the Adelaide series of `sediments and, of ,four -Recent alluvial clays from a pit in the Mount Lofty ranges south of Adelaide. Structural clay products 'in the Adelaide area are manufactured from mixtures of these clays:, so the mineralogy and particle size distribution have been determined of eighteen clay mixtures used to make red bricks, cream bricks,. facing bricks, pipes and tiles. Knowledge of this mineralogy is important in understanding the ceramic behaviour of the clays.

Jan 1, 1963

By D McInnes

Rather than look at the problems associated with sampling, this paper deals with the issue of sampling and blending to optimise revenue û predominantly in the mining industry. An example of the use of this methodology in the agriculture industry is also presented. Mining companies, in particular, are experiencing a boom in commodity prices and many believe the industry is in the middle of a æsuper cycleÆ. Production levels are being escalated dramatically to meet the demand coming from China and India. This in turn has further stretched the capacity of our rail and port infrastructure û resulting in significant shipping queues around most Australian commercial ports and increased demurrage costs for the producers. Mining companies are now looking for effective scheduling, planning and blending to maximise production and reduce demurrage charges û given the current infrastructure constraints. Mining companies can no longer use spreadsheets to run their business. This paper further looks at how these outcomes can be met by optimised blending using an integrated supply chain management system such as MineTrak together with effective sampling and analysis.

Jan 1, 2005

By X Yang

White phosphorus (P4) is a critical element in industry, but its current production from phosphate rock using the carbothermal reduction method raises significant environmental and health concerns. This pressing issue necessitates the development of new technologies that facilitate the sustainable production of P4. In response, my team is actively developing an innovative, coke-free approach for white phosphorus production. This method involves the dissolution of phosphate rock in molten CaCl2, followed by the extraction of P4 through electrochemistry at relatively low temperatures. Moreover, this approach has the potential to utilise phosphate-bearing solid wastes as raw materials, further enhancing its environmental benefits. By employing this cutting-edge technique, we aim to revolutionise the phosphorus chemical industry towards greener and more sustainable practices. This paper provides evidence of the feasibility and effectiveness of our proposed approach.

Aug 21, 2024

By D McLaughlin

This paper points to the timely importance of commencing a centrally recognised perpetual collection of mineral specimens in the Northern Territory which has as one of its objectives the collection and preservation of Northern Territory minerals of scientific, educational and heritage value. Currently in the Northern Territory there is no government department or institution that has a resourced coordinated state-wide objective to collect and document collectable mineral specimens. Specimens held in storage by the Department of Mines and Energy and the Museum and Art Galleries of the NT are not catalogued and owe their existence to fortuitous circumstances, not as a result of a planned systematic scientific approach to mineralogy. Northern Territory mineral species and unique specimens have and will continue to be driven to extinction while no central and active, recognised repository exists. This situation persists despite the fact mineral production is the Territory's largest income earner. The paper presents the arguments that hopefully will assist decision-makers to commence development of a state mineral collection lodged within an appropriate institution in the Northern Territory.

Jan 1, 1994

By Yu-Jun Z

According to site measurement and labora- tory experiment, the authors suggest a new mathematical model of grouted rock bolts. The rock bolt is taken as an elastic bar, and the grout is substituted by a set of springs the rigidity of which is given as K. Based on certain assumptions, a simplified formula is deduced. When the category of rock, depth of tunnel, the spacing of rock bolts and the rigidity of springs K values are given, so that we can calculate the radius of plastic zone, and subsequently the convergence of rock at the tunnel inner surface u, and the resis- tance exerted by the rock bolt p. Finally, the length of rock bolt can be determined.

Jan 1, 1987

By T Baumgartl, R Akesseh, M Edraki, B Usher, M Shaygan

With the continuing demand for industrialisation and urbanisation, the rate of mining and processing lower grade ores will also increase, producing large quantities of waste. As extreme weather events associated with global climatic changes are to be expected, the risk from mine tailings management will also increase (Edraki et al., 2014). In sulfide rich tailings, weathering within the critical zone controls the fate and distribution of the contaminants such as copper, zinc, and lead in the environment (Hayes et al., 2014). Tailings evolve geochemically and physically with time as they age under the influence of complex interacting factors. Understanding of the complex interactions between these controlling factors is important for predicting and mitigating the potential risks associated with sulfide tailings such as generation of acid mine drainage (Lindsay et al., 2015). Wetting and drying initiates weathering processes, influencing the hydrological, geochemical and geomechanical properties of the tailings. In semi-arid climates where evaporation exceeds precipitation, salts may precipitate within the pore system as well as on the tailings surface. These salts become the temporal sink of heavy metals until the next episodic rainfall (Nordstrom, 2011, Grover et al., 2016). Therefore, using kinetic and static test to describe the trajectory of these material evolutions without considering the complex interactions could potentially lead to erroneous prediction. In order to understand these relations, the effect of drying and wetting cycles on the hydrological, geochemical and geomechanical properties of ageing tailings was studied to draw conclusions for advanced tailings site rehabilitation and mine closureCITATION:Akesseh, R, Shaygan, M, Usher, B, Edraki, M and Baumgartl, T, 2018. Wetting and drying cycles as a means to determine the effect and consequences of tailings ageing, in Proceedings Life-of-Mine 2018, pp 24–27 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By S W. Richards, J Buys

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Magmatic arcs are prime targets for porphyry- and epithermal-style mineral deposits, although settings within continental arcs and/or tectonically-thickened crust generally tend to be more prospective than intra-oceanic arcs in extensional settings. In this paper, we report new geochemical and geochronological data on igneous rocks of the Western Belt of the Vanuatu intra-oceanic arc. Dating of igneous hornblende (Ar-Ar) and zircon (U-Pb) from the igneous rocks place their formation in the late Eocene to Miocene. In most respects, these are typical arc igneous rocks. However, they contain inherited zircon grains with significant age populations at ca 2.8–2.5 Ga, 2.0–1.8 Ga, 1.75–1.5 Ga, 850–700 Ma, 530–430 Ma and 330–220 Ma. This inheritance signature is unlike anything recognised from the oceanic realm of the south-west Pacific, but, in general, does match the age of the major crustal blocks of the Australian continent. An exception is the significant proportion (~20 per cent) of zircons of Rodinia breakup age (~800 Ma), which previously has not been found in eastern Australia or the south-west Pacific.We propose that part of the Vanuatu arc basement comprises a ribbon of continental material rifted from northern Australia prior to, or during, the Cretaceous. The presence of ancient continental material within the Vanuatu island arc may help reconcile the relatively large thickness and low density of the crust of Vanuatu, and may enhance the prospects for significant porphyry and epithermal ore deposits in the region.CITATION:Spandler, C, Buys, J, Holm, R J and Richards, S W, 2015. Remnants of ancient Australia in Vanuatu – implications for south-west Pacific tectonics and mineralisation potential, in Proceedings PACRIM 2015 Congress, pp 183–188 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Blain CF

For all mineral resource-based companies, it is important to reach the right balance of investment between acquisition and exploration to allow the best chance of achieving long-term corporate goals. The Broken Hill Proprietary Company Limited (BHP) provides an excellent example of success from generative exploration and supports the belief that exploration can be justified, not only in terms of investment criteria, but also because it is essential to a company wishing to build a dynamic profitable growth path based on world-class deposits as cheaply as possible. BHP was incorporated in 1885 to mine a lead/zinc/silver discovery at Broken Hill. The Company has since gone through a steel development phase (1911-1965) and is now in a major phase of growth partly based on exploration success. This third phase was marked by decisions taken in the 1950's to search actively for mineral and energy resources above and beyond the requirements of the steel industry. The commercial successes of this period have been Bass Strait oil and gas, Groote Eylandt manganese, Deepdale iron ore, Gregory coal and Carnilya East nickel. In total at least 22 new resource discoveries have been made in the last 25 years, of which 11 have been developed and several are undergoing feasibility studies. A financial analysis shows that the real value of the returns seeded by discovery covers the real exploration cost many times over. Moreover, the major discoveries have had a spectacular impact on the growth and development of the Company. BHP's present exploration effort is directed towards geological targets which most frequently meet attractive financial criteria and also promote diversification from steel-related earnings.

Jan 1, 1986

The transgressive sedimentary sequence of the Notnnea Basin contains rhyolitic lavas and less voluminous mafic and intermediate volcanims of shoshonitic affinities which erupted simultaneously during the late Cretaceous. The shoshonitic volcanism shows a trend from early inafic to younger evolved intermediate lithologies. The rhyolites are consistently calc- alkaline. There is no evidence of 'mixing, of, the two magma types. The shoshonitic volcanism is the result of a short-lived subduction event related to sprcadime in the New Caledonia Basin and involved reactivation of an earlier Mesozoic subduction zone.

Jan 1, 1995

By M, C A. RosiFre, R C. Figueiredo e Silva

Jaspilites and underlying basalt contacts of the Archaean volcano- sedimentary Grpo Parß Group, Carajßs, host giant iron mineralisation in the ~100-km long, E-W trending Carajßs fold. Preliminary, unpublished geochronological data point to a Palaeoproterozoic mineralisation event. Geochemically, jaspilites are typical volcanogenic banded iron formations. Basalts exhibit evidence of spilitic seawater interaction. Iron-associated hydrothermal alteration of mafic rocks was induced by fluid infiltration in amygdales, with development of chlorite- and hematite-dominated zones. In the case of jaspilites, iron mineralisation encompasses: partial replacement of jaspilitic microcrystalline hematite by blasts of martitic magnetite; jasper recrystallisation, producing fine-grained, hematite-free granoblastic quartz; martite recrystallisation, forming lobate¦subhedral hematite; pervasive porosity development by quartz-chert leaching; incipient cavity filling by microlamellar hematite; and advanced filling by coarser, euhedral and comb-textured, tabular- shaped hematite.Peak hydrothermal ore textures indicate typical epithermal-crust conditions, supported by preliminary fluid-inclusion calculations at 160 - 200¦C. Such temperatures and extreme fluid-to-rock ratios during alteration must have exceeded the ambient metamorphic conditions, with the infiltrating fluid relatively hot and capable of leaching SiO2. Therefore, mineralisation developed over exhumed, Archaean, brittly deformed rocks, with mineral associations representative of very low- to low-grade metamorphism. Considering that chlorite (¦talc) abounds in mafic rocks; hydrothermal albite is developed; dolomite fills veins and vugs; the typical rare-earth-element (REE) pattern of jaspilites is significantly modified in higher-grade hard hematite ores (higher LREE); pyrite, copper sulfide minerals and rare gold occur in association with carbonate-quartz-rich alteration zones, it is suggested that an alkaline, H2O-Fe-CO2 mineralising fluid dominated, also containing species like S¦Cu¦Au. Peak-mineralising conditions are likely to have resulted from a single, evolving fluid, via incipient- through advanced-stage alteration phases. The porous, high-grade soft hematite-type ore (SH), rich in microlamellar and anhedral hematite, must have derived from interaction with this relatively hot SiO2-leaching fluid, whereas the high-grade massive hard hematite-type ore (MH) developed due to closer fluid-rock temperature equilibrium conditions, attained by mineral reactions, with relative increase in the Fe/Σcations ratios allowing the precipitation of subhedral-tabular hematite that partially cements the soft-hematite ore. SH and MH hematite ore types must thus reflect intermediate and high fluid:rock ratios, respectively. Since the N5 deposit is to date understood to contain the largest amount of the MH ore, its units are interpreted as the loci of the highest fluid:rock ratios in the district. Preliminary mineralogical information regarding the S11 deposit of the Serra Sul (south range) implies higher-temperature conditions. The near-equant grain size and the granoblastic intergrain relationship, coupled with the presence of riebeckite, augitic pyroxene and garnet, suggest hornfels textures. The data collected, though still relatively sparse, permit the speculation that the immense driving force for the Carajßs world-class iron deposits was a relatively shallow, igneous-related hydrothermal system. If such a model is correct, then the Carajßs Palaeoproterozoic iron deposits could represent an end-member of the iron oxide-copper-gold hydrothermal system in the province.

Jan 1, 2005

By A K. Bayer

When the human eye fails in the evaluation of quality parameters in the extraction of minerals the use of laser-induced fluorescence analysis (LIF) can supply more detailed information on the composition of rocks. On the basis of measurements of selected raw materials engineering concepts for the use of this method in the mining industry as an innovative system for horizon control of mining machines will be described and the most important analysis parameters, influencing factors and interference variables are presented.

Jan 1, 2003

The King River Power Development on the West Coast of Tasmania has involved the storage of the waters of the King River in the new Lake Burbury and their diversion through a 7 km tunnel to a 144 MW power station. The last kilometre of this tunnel descends through 160 m under a ridge before emerging from the bank of the King River at the power station site. The decreasing cover over the tunnel as it approaches the power station meant that a steel lining was required in the last few hundred metres of the tunnel. This paper describes the geotechnical investigations which were carried out to establish the necessary length of the steel lining.

Jan 1, 1993

INCREASE OF CATASTROPHE FREQUENCY AND SEVERITYIn the last couple of decades the frequency of natural catastrophes has increased dramatically. This realization results from the statistical analysis of the comprehensive loss data that we have been collecting constantly over the last 30 years and have evaluated in connec-tion with the preparation of our "World Map of Natural Hazards", which is now in its second edition (Munich Re, 1988). Each month brings data on between 30 and 50 new loss events. Fortunately, however, only a few of these have to be added to the list of major natural catastrophes, that is only those involv-ing damage that considerably exceeds what the country or region concerned can handle itself so that substantial na-tional or international aid is required. That is generally the case if the number of dead runs into the hundreds or thousands, if tens or hundreds of thousands of people are rendered home-less and if the total economic loss is in the region of US$ 100 million. These major catastrophes, about which we have fairly comprehensive data even in the case of those that occurred farther back in the past, numbered only 14 in the 1960s but 70 in the 1980s; they there-fore increased over a period of 30 years by a factor of 5. The trend is also very clear when we consider the total economic loss, which - adjusted for in-flation - increased during the same period from an average of US$ 3.7 bil-lion per year to US$ 11.4 billion, i.e. by a factor of 3.1. The insured losses, finally, increased by as much as a fac-tor of 4.8.

Jan 1, 1990

The Big Bend and Cobra molybdenum prospects which occur near the margin of the Karamea Batholith in the Northwest Nelson molybdenum province are compared. The Big Bend Prospect is a 3000 m by 800 m area of disseminated pyrite and anomalous molybdenum associated with Cretaceous porphyry intrusives and later argillic and potassic alteration within Ordovician schists and phyllites adjacent to the batholith margin. The Cobra Prospect is a 1200 m by 1200 m area of weakly disseminated pyrite mineralisation and anomalous molybdenum-in-rock associated with moderate to strong quartz-molybdenite and quartz-orthoclase-molybdenite veining in quartzite.

Jan 1, 1979

Towards Improved Hydrocyclone Models - Contributions from Computational Fluid Dynamics

Sep 13, 2010

By G Fergus, M Hart, S W. Weeks

Rio Tinto Alcan has undertaken feasibility level assessments into the expansion of its bauxite mining operation in an area south of the Embley River in far north Queensland. The project has the potential to extend their Weipa operations by approximately 40 years.The construction and operation of two additional mineral ore processing plants are proposed for the South of Embley project. Golder Associates was engaged to develop and conduct modelling assessments of potential sources of water supply required by mineral ore processing.Two models were developed using GoldSim: a dam yield model and a water balance model. GoldSim is a graphical object-oriented modelling environment with a capacity to carry out dynamic probabilistic simulations. Originally developed by Golder, GoldSim has been applied successfully in a decision support role to a range of mine water management operations.The dam yield model was used to provide estimates of reliability and volume of annual water supply of several potential surface water dams. This information was then used to determine a hierarchy of water supply options for processing plant operations. The water balance model dynamically simulated the water demands of the two production plants and the consequential response in water supply, with respect to the timing and discharges provided by the various source options.Use of the model provided a preliminary operational tool to assist with water supply management decisions. Water quality issues required a blending of water from separate sources and attention paid to scheduling to ensure water supply through the dry season. The model also helped identify risks to water supply in the event of underperformance of one or more water supply sources. This allowed the operational rules to be refined to minimise those risks.The dynamic and stochastic modelling approach provided a method for identification of water supply issues susceptible to seasonal climate variability.CITATION:Weeks, S W, Hart, M and Fergus, G, 2013. A dynamic evaluation of water supply security susceptible to climate seasonality, in Proceedings Water in Mining 2013, pp 197-208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013