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Paiam is a new township in the high mountains of Papua New Guinea built in association with the Porgera Joint Venture mine, one of the world's largest and most remote open cut gold mines. The Paiam town project is an interesting and genuine attempt at building sustainability into a community associated with a mine. A result of a tri-party agreement between a resource developer, government and land owners, this town is a good example of appropriate utilisation of benefits, obtained from resource development, directed at achieving a sustainable environment at local and regional levels.   Mining brought technology and income to the region, although as most mine staff fly directly in and out, local landowners considered there was a limited flow of benefits within the nearby townships. An agreement with government and mine was reached that more mine personnel and their families be housed locally. In 1998, we, a firm of Landscape Architects and Heritage Consultants based in Cairns, Queensland, were engaged to assist develop the fledgling town of Paiam into a livable and sustainable town and to produce material that would convey that information to stakeholders.   The design focused on establishing a sustainable town, with livability, urban form, aesthetics and opportunities for economic, social and cultural development. Aiming to be a livable town for locals and mine staff it included a market place designed as a focus for town life, essential for social cohesion and economic opportunities.   Located at 2200 m on steep rainforest clad topography, the town development has been laid out using an appropriate urban form based on organic village layouts. Clusters of houses allow for a common public area so children's play is monitored assisting with a sense of community similar to a traditional defensible village. Aesthetical consideration helps in developing community pride whilst maximising potential for development of a tourist industry.   Opportunities for ongoing economic development were incorporated in the design and construction process. These included developing skills and trades to service the region and to provide skills, development, income opportunities and infrastructure to last beyond mine closure. Administration procedures were set in place to form the basis of good governance.   The shift from traditional subsistence lifestyle to a sustainable community with traditional attributes was the project's goal and is being achieved.

Jun 1, 2010

By D M. Marques, J F. C L Costa

The estimation of process plant head grade is not trivial and is a source of constant dispute within the mining industry. Grade estimates informed by the short term mine planning are frequently not reproduced by sampling the continuous flow of ore at the plant. Head grades are normally obtained by periodically sampling the continuous flow during a day or shift, and taking the average of the multiple increments collected. The standard error of this mean grade depends on the ore variability and the frequency (number) of aliquots extracted. The more increments are taken the higher is the precision on the calculated mean. Variographic experiments are normally used to map grade variability along a certain period of time and the extension variance is derived from this variogram. This experiment is time consuming, expensive and cumbersome. Mining industry personnel rarely apply this approach. Additionally, a temporal variogram can vary from day to day as different ores are mined along the life of the mine. This paper investigates a novel approach based on simulating the grades feeding the processing plant. In situ 3D grade models are built using geostatistical simulations. Grade spatial continuity and variability are reproduced in models that mimic the real deposit. These models are used in mine planning and scheduling transforming a 3D block model into an one dimensional string of values feeding the plant (one dimension flow). These grades have the statistical characteristics of the unknown real grades and can be sampled to emulate a variographic experiment. The results showed consistency and adequacy to estimate the sampling error (Gy, 1998 p 31) for various sampling intervals using the simulated grades. Also the results show a variographic experiment can change significantly from time to time, as ore changes and a selected sampling protocol can become obsolete if not adjusted for ore variability.CITATION:Costa, J F C L and Marques, D M, 2012. Defining a sampling strategy for a continuous flow supported by geostatistical simulations, in Proceedings Sampling 2012 , pp 3-8 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

The Main Seam occurs in two 'pods', termed North and South, separated by an east-west oriented 'want' zone (most probably a palaeo-channel). The seam on either side of the 'want' area reaches thicknesses of over 30 metres but the North Main Seam adjacent to the 'want' zone has been split into multiple seams of 10 to 15 m thickness. Rock types in the inter-burden of this area are characterised by inter-bedded sandstones and carbonaceous mudstones varying in thickness from 0.5 to 5 m. In the South Main Seam, an area of un-split coal exists and is characterised by few inorganic partings. Overburden in this area varies geographically from relatively thick mudstones in the south and east part of the coal deposit to inter-bedded sandstones and carbonaceous mudstones adjacent to the 'want' area. The sandstone/mudstone overburden probably represents a splay or splay-channel complex emanating from the larger 'want' area palaeo-channel. Modelling lithological variability is of use because it is one of the factors used in predicting cavability and roof support system design. The coal in both the north and south deposits were found to exhibit highly predictable quality and breakage parameters in relation to the coal geometry. Although ash yield and sulphur are mostly low and not variable, volatile matter and thus fixed carbon, varied in relation to seam thickness. In general, volatile matter (dat) decreased and moisture increased with decreasing seam thickness whereas moisture increased with decreasing seam thickness. In addition to these parameters it was found that the energy needed to crush the coal was lowest at the top and bottom of the seam and, on a whole seam basis, decreased with seam thickness. All of these parameters were found to vary in relation to the vitrain band content of the coal which itself was controlled by seam geometry. These parameters can therefore be modelled and inputted into mining plans and quality control operations.

Jan 1, 1996

The Greymouth Coal field is situated on the West Coast of New Zealand's South Island and has been mined for coal for more than 120 years. The area covered in this paper is within the Rapahoe Sector of this field and contains >200 million tonnes of low ash, low sulphur, bituminous rank coal. Paper No 6, presented to the 19th Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy in Christchurch in August 1985 by R G Bowman, explained 'A Geologist's View' of the 'Economic Potential of the Greymouth Coalfield', and describes previous geological assessments of the Rapahoe Sector.

Jan 1, 1989

By P Cavieres, R Dunlop, S Gaete

El Teniente Mine started the exploitation of the primary rock in the beginning of the 1980s decade, using caving methods. Since the beginning the mining activities have induced seismicity including some occasional rockbursts. Owing to the relevant damages, the mining operations were stopped in some production sectors. This paper describes the concepts that have been used in order to control the induced seismicity based on the strategies for controlling the rockmass breaking process, which depend on mining parameters. It also presents the main concepts applied in the Teniente Sub6 sector design and the experience collected during its sector exploitation.

Jan 1, 2000

By Jiricek F

Legislative change has reformed the licensing process in Victoria. The Mineral Resources Development Act 1990 and the two stage system of licensing with the authority to commence work is discussed. A key part is the requirements of planning consent, being either an Environmental Effects Statement or the issue of a Planning Permit prior to the issue of an authority to commence work for mineral extraction. Examples of recent experience is discussed.

Jan 1, 1997

By D Ryan

Following a long period of increase, there has been a reduction in exploration expenditure and activity in Australia over the past two years. During the post Second World War period, exploration was largely driven by mining companies seeking resources to satisfy an increase in world demand, while increasing their asset base as a result of mineral discoveries. In general, return on investment to shareholders was not the major driving force. With the exception of gold the mining industry has been faced with a long-term fall of metal prices in real terms. As a result the net profit return on average shareholderÆs funds in the Australian minerals industry has fallen from over 20 per cent in 1990 to less than five per cent today. Mining is now competing for funds with communication and finance based industries yielding high returns on shareholder investment. Shareholders and superannuation fund managers seeking a high return on short-term investments have indirectly reduced the funds available to the mining industry. Globalisation of the mining industry is leading to the rationalisation of the Australian mining industry as witnessed by mergers and acquisitions of local companies by foreign investors. The return on capital invested in the Australian mineral exploration industry must improve if the industry is to be competitive on a worldwide basis. Failure to achieve this will result in capital flowing overseas or to other industries. Relatively short-term upswings in metal prices which are generally driven by threats to the supply base (eg strikes, mine closures, increases in country risk) often lead to increased capital raisings for exploration funding. As a consequence of the time taken to raise the capital and increase exploration activity, measured exploration activity lags the metal price increases. There are also lags between commencement of exploration and discovery and ore production. In the case of gold exploration expenditure peaked six years after the price rise of 1980 Companies persevering with exploration in the current difficult period will be rewarded because they will be able to capitalise on future metal price rises and a minimised time lag.

Jan 1, 2000

By Gillies A. D S, Lee A. H

Water is an integral component of a mining operation. To-date water management has received a low profile in the overall management of mining operations. To cost effectively meet the requirements of government environmental legislation the man

Jan 1, 1994

By D Matthews

Increases in mining and production capacities can have a major impact on the productivity of a mining and production facility during the construction and commissioning period. With minimised production loss in mind, a multi-phase modular plant design was implemented on the Khumani Mine in the Northern Cape, South Africa. The first phase involved a run-of-mine (ROM) crushing facility and the subsequent modular processing facility with capacity for 8.4 million tons per annum (Mt/a) product. An interim phase comprising modular additions to the processing facility increased capacity to 10 Mt/a product, with tie-ins occurring during maintenance periods. The second phase involves a second ROM crushing facility and modular additions to the processing facility, increasing capacity to 16 Mt/a product. This paper outlines the design considerations and limitations with modular design that need to be considered and shows how effectively construction and commissioning were implemented within shut-down and maintenance periods.

Jul 11, 2011

By D Morton, G Wallace

"Evolution Mining is the sole owner of the Mt Rawdon open cut operation, located 75 km south-west of Bundaberg in Queensland, Australia (Figure 1). It is a massive, volcanically hosted, low-grade gold deposit that exhibits excellent characteristics conducive to low cost mining and treatment.In 2014, Mt Rawdon began investigating initiatives to deliver higher mill throughputs without any significant capital expenditure or modifications to the existing processing plant. Various studies have shown throughput increases are possible by applying more blast energy, essentially by reducing feed size through blasting and leaving less work for the comminution circuits (Brent et al, 2013; Ziemski, 2011; Workman and Eloranta, 2003).Given that 53 per cent of energy used on a mine site is consumed by the comminution circuit, with only two per cent being consumed by drill and blast (Smith, 2013), it makes logical sense for a mining operation to align their drill and blast with their processing plant. The term commonly used when exploring this relationship is a ‘Mine to Mill’ program.Over nearly 12 months, various blasting options and Mine to Mill methodologies were tested at Mt Rawdon. Throughout the journey, it was abundantly clear that the Mine to Mill initiative is not as simple as making one technical or physical change and expecting an improvement. Rather, true sustainable improvements demand a paradigm shift across both the mining and processing cultures, where all departments are aligned and working towards the one outcome. This true overarching Mine to Mill mentality, enabled by Vistis™ 250 high energy bulk explosive, ultimately led to a sustained increase in throughput and profitability of the Mt Rawdon operation.Citation:Wallace, G and Morton, D, 2016. High Energy Bulk Explosives and Mine to Mill Focus – the Mt Rawdon Story, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 60–69 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By J-P Franzidis

A technique for determining the recovery of attached particles across the froth phase in flotation that relies on measuring the rate at which bubble-particle aggregates enter the froth is used to investigate the selectivity of attached particles across the froth phase. Combining these measurements with those of other techniques for determining the froth recovery of attached particles provides an insight into the different subprocesses of particle rejection in the froth phase. The results of experiments conducted in a 3 m3 Outokumpu tank cell show that the detachment of particles from aggregates in the froth phase occurs largely at the pulp-froth interface. In particular it is shown that the pulp-froth interface selectively detaches particles from aggregates according to their physical attributes.

Jan 1, 2005

By Buizen M

The results of calibration trials conducted on parachute stoppings under a recently completed NERD&DC grant are presented. Applications of parachute stoppings, for rapid regulation and control of ventilation networks are described including use in mine recoveries, sealing sections and rescue work. Parachute stoppings are one of a series of non-rigid ventilation control structures specifically designed for quick installation in emergency situations, for use in high production/rapid advance areas and areas suffering roof-floor convergence.

Jan 1, 1988

A method is proposed for the analysis of tin in cassiterite ores. Tin is volatilised by heating with ammonium iodide. The tin iodide so formed is extracted with hydrochloric acid and the concentration is measured by atomic absorption spectroscopy using an air-hydrogen flame.It is considered that a more efficient extraction of tin and faster reproducible results are obtained than by any other known method.

Jan 1, 1967

THE Company's smelting equipment consists of three blast furnaces, supplied with blast from two sets of vertical piston blowers, each capable of delivering 8000 cub. ft. of air per minute at a pressure of 60 oz. per sq. in. Each blower is belt-driven by a 1:30 h.p. motor. The maximum speed of the blowing engine is 35 r.p.m.No. 1, the largest of the three blast furnaces, has a crucible area of 49.5 sq. ft., and measures 11 ft. 6 in. x 5 ft. at the tuyeres.From tapping floor to feed floor measures 35 ft. 9 in., and holds, when full, 100 tons of charge. Blast enters through thirteen 3-m. tuyeres at 60-oz. pressure. Working normally, this furnace is capable of treating :300 tons of charge, exclusive of returned slag and coke, per 24: hours, with an output of 100 tons of lead. Tapped slag flows into a C.l. forehearth mounted on wheels, where any lead and matte is caught, and the slag overflows into a 3-ton cast-iron pot, in which it is drawn away by an electric locomotive and poured over the dump.

Jan 1, 1918

Quite often the reserve assessor becomes enamored with the numbers gen- erated and forgets the basis for his assessment. The quality of the assess- ment can only be as good as the quality of the input data. The use of seismic data from the Gippsland Basin in assess- ing Esso/BHP's oil and gas reserves is an excellent example of this principle. By significantly improving the quality of seismic data, a much more reliable estimate of a field's reserve potential can be made. In addition, it provides the basis for further delineation drill- ing which, as recent experience in Gippsland has shown, often leads to increased reserves.

Jan 1, 1979

By J Howard

Following discovery in October 2004, commencement of development in February 2007 and first ore production in mid 2007, the Trident gold deposit, located in the Eastern Goldfields of Western Australia, has now been successfully mined for over three years. Three years of operational history has enabled the performance of the Trident underground mine to be reconciled against the mine plan and strategy proposed for the original feasibility study.The Trident deposit, initially based on two lode systems known as the Eastern Zone and Western Zone, has been continuously drilled, interpreted and re-interpreted over the period and as a result the addition of the Athena, Apollo and Artemis lode systems as well as numerous smaller scale lodes has been realised. The first three years has seen the Trident underground mine quickly move up to its 1 Mtpa design production rate. The mine plan and strategy used in the initial feasibility study and subsequently implemented, required sufficient flexibility to enable modification and optimisation to mine plans as ore zones were further defined. The ability to modify the mining plans has enabled Avoca to achieve its mining targets at Trident. With over 250 000 ounces gold produced to January 2010, the company is well positioned to achieve its ten year vision associated with the Higginsville Gold Project.This paper offers an account of operational experiences whilst providing comparison to assumptions and methodologies used in the original feasibility study. The paper is a sequel to a paper presented at the Tenth Underground Operators’ Conference held in Launceston, Tasmania titled Development Strategy of the Trident Underground Gold Mine.

Mar 21, 2011

By Voorhees JS, Bureau G

To operate a mine in California requires compliance with State environmental regulations, including assessment of risks and associated financial assurances for postulated worst case catastrophic event scenarios. Carson Hill Gold Mine, an open pit, heap leach operation, completed new risk assessment catastrophic event analyses in 1988. The risk assessment was performed at the same time that a new leach site (Leach Site 3) was being designed. Leach Site 3 is located about 400 m upslope of New Melones Reservoir, which is a public recreation facility and a source of drinking water. Release of leachate (pregnant solution) or ore containing cyanide and metals from Leach Site 3 into New Melones Reservoir was considered to pose the largest risk of environmental damage.Flow failure of the ore heap, potentially induced as a result of liquefaction of the saturated portion of the ore, and/or overtopping of the leach site containment embankment due to excessive precipitation were found to be the most plausible leachate release scenarios. Yearly combined probabilities of various downstream release volumes were estimated. The release volume corresponding to a yearly probability of 0.05 percent was then used to estimate potential environmental impacts and mitigation costs. The costs include earthwork to restore the geometry of the ore heap and repair the fill slope below the Leach Site 3 containment, and impacts on New Melones Reservoir.

Jan 1, 1990

By K Esmaeili, S Aziznejad

Impact-induced rock fragmentation is a mechanism that is commonly used for rock breakage in drilling and crushing. Additionally, rock fragmentation by blasting is frequently used in rock excavation operations. Experience shows that the presence of discontinuities can significantly influence the impact-induced damage and fragmentation of rock. Quantification of the response of jointed rock masses to impact loads is complicated by the fact that the available laboratory tests are mainly designed for aggregates or intact rocks. It can be argued that neither of these tests adequately represent a jointed rock mass. This paper presents the results of a series of numerical simulations used to investigate the influence of pre-existing discontinuities on the impact-induced fragmentation of rock masses. The methodology includes determination of the static and dynamic mechanical properties of a rock unit by conducting a series of laboratory tests on intact rock samples collected from a quarry in Canada. A 2D distinct element code, Particle Flow Code, was used to generate a bonded particle model in order to simulate both static mechanical properties (uniaxial compressive strength, elastic modulus, Poisson’s ratio and indirect tensile strength) and dynamic mechanical property (drop weight tensile strength) of the intact rock. The calibrated numerical model was then used to construct large-scale synthetic rock mass samples by incorporating discontinuity networks of different intensity into the bonded particle model. Finally, the impact-induced fragmentation inflicted by a rigid projectile particle on the jointed rock mass samples, simulated by a synthetic rock mass model, was determined. More fragmentation was observed for the rock mass samples with higher joint intensity.CITATION:Aziznejad, S and Esmaeili, K, 2015. Effects of joint intensity on rock fragmentation by impact, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 377–384 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

This paper reviews rehabilitation, closure, and post-closure management of the Tui, Golden Cross, and Martha Mines, all of which are located in the Waikato Region of New Zealand. There was no requirement for rehabilitation of the Tui mine, which was abandoned in 1973. There was a requirement to rehabilitate the Golden Cross mine. Mining at that site ceased in 1997, and rehabilitation is now well advanced. When first approved, there were some requirements for rehabilitation of the Martha Mine, but when reconsented in 1998, those were extended, and in addition a requirement for post-closure management was included. As a result, a Trust, funded by the mining company, has been established to take long-term responsibility for the site following completion of closure. The different rehabilitation/closure requirements at each of these sites illustrates that we have learnt something from the experiences of the past.

Jan 1, 2003

By E Baafi, G Brassington

Coal mining operations can impact on various types of surface infrastructure or natural features, including cliff-lines, steep slopes and natural watercourses. Longwall mining leads to a subsidence depression due to the changing geometry of the mined out area. The current regulatory process for managing subsidence in New South Wales (NSW) involves the preparation of a Subsidence Management Plan (SMP). This paper demonstrates the use of a Weights of Evidence (WofE) technique applied within a Geographical Information Systems (GIS) environment to predict potential areas for rockfalls along cliff-lines in the NSW Southern Coalfield. The WofE is a ædata-drivenÆ method that can be used to predict subsidence impacts prior to mining. The WofE method was applied to ten known rockfalls along the Cataract River to evaluate the reduced impact of not mining within 50 m of cliff-lines along the Nepean River. There is significant reduction of probabilities of rockfall occurrence when mining is avoided within 50 m of cliffs.

Jan 1, 2006