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By R B. Venugopal, P Staples

The selection of the mode of transport for moving bulk materials is never a simple task as there are various concerns/considerations applied to the selection of the most practical and cost-effective mode of transport to be used to move bulk materials. This paper examines various alternatives for moving ore from a mine at the top of a mountain to a process plant below (some 5000 m apart and a vertical drop of 650 m). The terrain of the mountain section of the route has added its own specific requirements, resulting in the final selection of a pipe conveyor for this application. The paper further addresses the final selection of hardware used in the implementation of the solution.

Jan 1, 2005

By B Upton, J Mitchell

The use of hydro scaling and in-cycle shotcrete to replace conventional jumbo scaling, mesh and bolting as the primary method of ground control for run of mine development has been investigated through extensive trials at the Waroonga mine, Agnew Gold Mining Company.These trials have progressed from investigating the productivity aspects of the method through to a three month mine-wide trial, which may yet lead to the adoption of this potentially best practice ground control technique at Agnew.Ov erseas trials and research have shown that hydro scaling results in a significant improvement in the shotcrete-rock bond strength. Good adhesive bond strength ensures that the shear strength of the shotcrete layer rather than itÆs flexural or tensile strength is fully mobilised as rock mass reinforcement.This maximises shotcretes ground reinforcement capability and it is suggested that a bolt-less fibrecrete support design is feasible using the hydro scaling technique.

Jan 1, 2005

By N Guresin, A Cooper, L Lorenzen, H Muller, S C. Dominy

Sampling and metallurgical test work during various phases of engineering?studies?is of?paramount importance for a robust processing plant design. When developing a process flow sheet, risks in achieving desirable financial outcomes are minimised by ensuring appropriate sampling and adequate metallurgical test work supports the engineering and cost estimation at each phase of project development.The quality and type of samples used for metallurgical test work are just as important as the metallurgical test work itself. The key characteristic required of any sample is that it represents some defined portion of a mineral deposit. Representivity should take into account the spatial orientation, lithology, alteration, degree of oxidation, mineralogy and competency of the ore such as hardness and abrasiveness. Statistically representative sampling procedures and an appropriate metallurgical test work program should be designed to bring metallurgical understanding up to feasibility study standard and to give a basis for process plant design.Snowden has observed that the quality of sampling and quantity of metallurgical test work carried out during the various phases of engineering studies are often insufficient to truly support a robust plant design. Some designs are often the result of the plant design based on benchmarks of apparently similar orebodies or buoyant metal prices supporting cash flows until rectifications can be implemented.The paper will discuss important aspects of sampling and test work required for engineering studies in designing process plants based on industrial case studies.CITATION:Guresin, N, Lorenzen, L, Dominy, S C, Muller, H and Cooper, A, 2012. Importance of effective sampling and test work protocols for process plant design, in Proceedings Sampling 2012 , pp 95-108 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By Lock PR

The Silver Swan nickel mine is located at the Black Swan Nickel Project, 53 kin north east of Kalgoorlie, Western Australia. The Silver Swan orebody is a massive sulphide nickel deposit dipping 70¦ east with an average in situ grade of 14 per cent. Mining of the massive orebody is by Mechanised Ramp Cut and Fill (MRCF). A mining recovery of 98 per cent and minimising dilution are primary goals in extracting the high-grade ore. Placing a distinguishable marker bed (working platform) on rock fill was identified as a key method to achieving these goals. Gravel from a pit located onsite was considered the most suitable material for the marker beds. Research undertaken to design the marker beds using the gravel revealed conventional methods used in mining would not suffice, but that road stabilisation methods could be a viable alternative. Trials used a road recycler to mix cement and gravel in situ and several test beds were constructed on the surface to determine the final design. The trials attempted to replicate a marker bed's life cycle of construction and placement and mucking of ore from the marker bed.

Jan 1, 1998

For the mineral industry, sustainability seems to mean socially positive and ecologically neutral mineral extraction. Mines are financed and developed in response to demand for their products. The purpose of my paper is to indicate the potential dimension of demand. As part of an unrelated study which I undertook ten years ago, it became apparent that there is a persistent relationship within communities between infant mortality and mineral use; greater mineral use corresponds to a lower rate of infant mortality. This comes as no surprise; sufficient potable water, a reliable supply of food, hygienic waste disposal, hot water and refrigeration all improve the chances of survival of the more vulnerable members of any community. The predictable provision of these facilities requires the application of minerals. This relationship is supported by a table (Appendix 1) included in the UNICEF publication, æThe State of the WorldÆs Children 2001Æ. This table lists regional infant mortality rate (IMR) statistics from around the world, including a listing for æindustrialised countriesÆ. Such countries experience an IMR lower by an order of magnitude than any other region. æIndustrialisedÆ inevitably involves the use of metallic and energy minerals. The principal use of copper is in the generation and distribution of power; it is fundamental to any industrialisation. IMR is a valuable connection because it quantifies caring for the young, a vital strategic driver of human behaviour independent of time, place, fashion or economic circumstances. I have tabulated the population, IMR and the copper demand per head of population for countries containing over 99 per cent of the population of the world in the years 1950, 1960, 1970, 1980, 1989, and 1999. These countries have been consolidated into four groups, Very High, High, Medium and Low rates of infant mortality (UNICEF has used this terminology; the Low group includes all the æindustrialised countriesÆ). The purpose of this consolidation was to reduce the volume of work, to dampen out the impact of regional wars and business cycles, and to dampen out the variable quality of information. Based on the pattern of the copper demand, population and IMR over the last 50 years, I have projected the likely copper demand in 50 years time. A dominant feature of my tabulation is the increase per decade in copper use per head and a corresponding reduction of the IMR. The word æuseÆ is preferred to æconsumptionÆ because it is estimated that over 80 per cent of all the copper ever mined is still in circulation There are two major influences at work; one is the absolute increase in population (UN estimates for 2050 are updated periodically) and the second is the movement of countries into a higher pattern of use and lower IMR. For example the Medium group in 1989 had an infant mortality rate approximating that of the Low group in 1960. With the population of the Medium group (which includes Russia and China) forecast to reach 2.6 billion in 2050, the world copper demand in that year will be significantly greater than the present figure. Nevertheless it will not be as great relatively as the increase of over 300 per cent in the last 50 years.

Jan 1, 2002

By B Mohanty, D Zwaan

Systematic near-field vibration monitoring of stope blasts was carried out in a large, deep underground mine. A total of 31 production blasts were studied in order to investigate the effectiveness of existing blast designs. This involved the vertical retreat mining method, which requires drilling a raise bore or blasting a slot raise (typically 1.22 m in diameter) using large diameter boreholes (165 mm). The diagnostic technique employed multistation near-field monitoring of blasts with high-g (100 g) and high-frequency (>10 kHz) triaxial accelerometers. The amplitude of the vibrations is correlated with the strain energy transmitted from each explosive deck. The results showed that more than 30 per cent of the explosive decks contributed little energy to the rock breakage process in these blasts, and an equal number contributed only inadequately. These findings are indicative of serious blast malfunctions. The problems can be traced to inadequate deck blast design and possibly to drill hole deviation. The various causes for such malfunctions are discussed and remedial measures suggested.CITATION:Mohanty, B and Zwaan, D, 2015. Assessment of underground production blast designs and blasting performance, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 607–616 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By T J. McGavin

This paper examines the fire life systems implemented in two existing tunnels and discusses whether the standards used were appropriate. It focuses on the Terrace Tunnel as this upgrade and refurbishment is complete.The New Zealand Transport Agency (NZTA) manages six tunnels on the State Highway network with two of these built in the last seven years. The Terrace Tunnel, opened in 1978, was refurbished with modern fire life safety systems in 2010–2012. An interim upgrade of the Mt Victoria Tunnel, opened in 1931, was also carried out at this time.In present times, few existing tunnels have undergone significant upgrades and refurbishments. The Terrace Tunnel required: new power supplies, control buildings, lighting, wall panels and jet fans, a deluge system, emergency exit lights and way-finding lights, a public address (PA) system, a radio rebroadcast system, lane control sign (LCS) and variable message sign (VMS), an over-height detection system (OHD) and a new tunnel management system.In the absence of suitable guidelines, various standards were used to carry out the refurbishment. The Austroad Guide to Road Tunnels and AS4825 Tunnel Fire Safety, although designed for new tunnels and not specifically intended for existing tunnels, provided a framework. A multi-criteria assessment of risk (MCAT) was carried out to determine the systems to be provided.The Terrace Tunnel has perhaps set a benchmark for refurbishing existing tunnels as few projects of this type have been completed recently. This paper examines the process and the outcomes.CITATION:McGavin, T J, 2014. The refurbishment of the Terrace and Mt Victoria Tunnels, Wellington, New Zealand, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 87–94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M Tsai

Tube bundle gas monitoring systems have been used in the mining industry for over 50 years. The initial design was based on four individual gas analysers along with a series of solenoid valves, gas sample conditioning and flow control mechanisms to ensure the correct gas flow stream volume to the analyser. Simtars staff have identified flow control issues when providing operational support to coalmines on numerous occasions. The accuracy of the oxygen analysis is dependent on control of the gas flow to the analyser. Oxygen is one of the parameters used in calculating Graham’s ratio which is used for the detection of spontaneous combustion activity in coalmines. This paper will provide data which identifies the flow control issues by comparing mine site records for the two surface sample lines in the analyser room and the gas cage. Mine sites will be deidentified within the paper. The paper will discuss some of the changes that have been made in modern tube bundle systems and compare the change to the initial design specification developed by the UK National Coal Board, investigate possible operational impacts and provide a technical fix to solve the current flow issues being experienced at some mines.

Oct 12, 2022

By J Krnmmelbein, T Raab

In Lusatia, lignite mining causes major disturbances on the landscape scale. Reclamation procedures are applied to recover the reconstructed landscape for different land use options. In this study we investigate soil physical properties of an agricultural reclamation/recultivation site directly after site restoration and the development of selected parameters within the first years after site restoration depending on varying recultivation strategies.The sandy substrates used for recultivation stem from depths of several meters. They are unstructured, free of recent organic matter and have high contents of calcium carbonate. During reconstruction and most of all during surface levelling with heavy crawlers, the substrate?undergoes high mechanical stresses. This leads to partly severe soil or substrate compaction, depending amongst others on substrate water content and mechanical stresses during site construction. We investigate the effect of different organic soil amendments, different crop rotations and partly subsoiling on the development of soil structure. We compare results of laboratory measurements directly after site construction before any reclamation measures had been applied to results we gained after three and four years of recultivation. The results show that after the earthworks are completed, the site is strongly heterogeneous in relation to mechanical stability, permeability for air and water, pore volume and bulk density. The results after three and four years show that the heterogeneity of soil physical parameters decreases. The selection of suitable crop rotations superimposes the affects of other reclamation measures, eg varying organic fertilisers or deep loosening.CITATION:Krnmmelbein, J and Raab, T, 2012. Reclaimed lignite mining areas A73 in Lusatia - Development of soil physical parameters of an agricultural site within the first years after site reconstruction, in Proceedings Life-of-Mine 2012 , pp 117-122 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By T A. Short, P L. Brown

Kestrel Mine co-disposes around 1.5 Mt of fine (2SO4/t and to date around 9 Mt has been deposited. The mine plans to co-dispose of approximately 39 Mt of material, creating a dump with a maximum height of 35 m and a disturbance footprint of 260 ha. Benign materials suitable for rehabilitation are severely limited and no successful rehabilitation strategy has yet been demonstrated. A rigorous measurement and modelling program is resolving outstanding issues associated with acid rock drainage (ARD). The objective of the program is to develop and validate a strategy for dump rehabilitation that will control ARD and allow for mine closure. The strategy includes using a soil cover to reduce water flux into the dump to control the overall oxidation rate and to control effluent release. Monitoring of the oxygen distribution and water flux in the uncovered material commenced in February 2001 and monitoring in waste under a trial cover commenced in February 2002. Carbonaceous and sulfidic oxidation rates have been measured. Initial modelling indicates that the carbonaceous material has the general effect of slowing the rate of pyrite oxidation, lowering the maximum sulfate production rate and extending the time to oxidise all the sulfides. The combined approach of measurement and modelling provides a sound basis for assessing the performance of the trial cover and predicting the long-term quality and quantity of effluent at the base of the rehabilitated waste dump.

Jan 1, 2003

By W Angerer

This paper describes the design of the marine riser structures, including the design measures for sealing and protection from flooding, dewatering and connection to the main tunnels, for the Gold Coast desalination plant in Queensland. The risers connect the intake and discharge tunnels to the ocean. Construction commenced on both in April 2007. The paper describes the key design criteria for the risers, the construction constraints that influenced the design and the design of the main elements of the risers and the connections to the tunnels.

Jan 1, 2008

By A Lim

"As Abel Mine continues to expand and increase production, the requirements of the ventilationsystem have also increased. This paper will outline the stages undertaken to increase the AbelMine ventilation system from an operating position of 110 m3/s and 500 Pa to the current operating position of 220 m3/s and 1.6 kPa and outline steps to be taken to ensure all future requirements will be able to be ventilated."

Jun 1, 2012

By G Pitkin, D Sorley

The purpose of any consultancy is to provide a superior service for their client. Organisational structure is a key element in providing this service and differentiating between consultants.In an organic organisation the emphasis is on effectiveness, problem solving, responsiveness, flexibility, adaptability, creativity and innovation. Such an organisation is able to respond in a timely manner to change because employees are empowered to be creative, to experiment and to suggest new ideas. The process of innovation is triggered by employees throughout the organisation in a collaborative manner.Problem solving becomes a core competence of the consultancy. A multidisciplined approach arrives at superior solutions that are rigorous, holistic, achievable and often novel. It allows the mining consultancy to extract the most from a very talented and experienced team.This paper highlights the advantages of an organic structure for a mining consultancy and how to implement such a structure. It draws on examples of innovative problem solving from feasibility and strategic studies carried out in Australia and Africa.CITATION:Pitkin, G and Sorley, D, 2016. Organic management structure – its advantages in a mining consultancy, in Proceedings International Mine Management Conference, pp 155-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

Pike River Coal Limited is in the process of developing the Pike River Coal Mine in the Paparoa Ranges of New ZealandÆs South Island. The mine will be developed to extract a coking coal deposit of the Brunner Seam, some 46 km north-east of Greymouth, using a combination of continuous miners and hydraulic extraction. The mining area is located within Department of Conservation (DOC) land and is adjacent to the escarpment of the Paparoa Range and the Paparoa National Park.   As such, the major restriction to planned extraction is protection of: +        the western escarpment, +        vertical and sub-vertical rock faces, +        permanent water courses, +        significant vegetation, and +        steep slopes.   The mine will use its elevation advantage to hydraulically flume coal from the working faces to the pit bottom area where it will be slurried to approximately 35 per cent density of solids and pumps down a slurry line to the coal prep plant some 10.5 km down the Pike River Valley. The coal will be sold on the export market as a high quality coking coal for international steel making.

Jan 1, 2006

By Tilley H. L

The 90 m deep Yallourn Open Cut brown coal mine in the Latrobe Valley, Victoria is developing into an area close to a reverse fault. A major batter stabilisation program, matched to ongoing operations, has com- menced to maximise coal recovery where the fault is within 100 m of the Open Cut. The various mine development options considered during the planning stages are outlined. These options were formulated in a back- ground of geotechnical constraints and the need to maintain continuous and reliable coal supply at a time when a new coal field would be developed. The geotechnical investigations and analysis procedures under- taken to determine stability of the batters during their excavation are presented. The geotechnical constraints on the mine design and opera- tions required to ensure safe working conditions are detailed. Current operational and batter stability conditions are considered satisfactory.

Jan 1, 1989

By A M. L Smith, W E. Dubbin, K A. Hudson-Edwards

Jarosites (KFe3(SO4)2(OH)6) are examples of minerals that are highly effective scavengers of toxic elements, and are abundant in acid rock drainage systems, acid sulfate soils, metallurgical wastes and other contaminated sites. The K, Fe and S sites can be filled by toxic elements such as Cd, Cu and Zn, but the mechanisms of this incorporation are not well understood.We have used atomistic simulation methods to model the jarosite (102) surface and its interactions with Cd, Zn and Cu, in order to understand the mechanisms by which these potentially toxic elements are incorporated into the K-jarosite structure. Our results suggest that incorporation via a defect complex consisting of an impurity cation at the K site charge balanced by a K vacancy stabilises the (102) surface in the order Cu>Zn>Cd.

Jan 1, 2008

By P Williams

The Sunrise deposit is one of AustraliaÆs largest and most profitable gold deposits. It has consistently and spectacularly outperformed every resource model created. Currently over the life of the Sunrise pit there has been a 50 per cent under estimation of ounces mined. Without a solid basis for predicting the tonnes and grade or the spatial location of mineralisation, mine planning becomes problematic. Recently, through a better understanding of the mineralising processes the reconciliation of the resource model has improved to be in the order of ten per cent under on ounces mined. This paper will describe how the mine geologists at Placer Granny Smith have implemented the changes required to improve the resource model. Work began with the development of a three-dimensional lithological and structural model based on historical drilling and pit mapping. Continual updating of the geological model with grade control logging, assays and in pit face mapping, now allows for the on-going improvement of the resource model and the planning of mine development drilling.

Jan 1, 2000

The purpose of this paper is to look at the costs of tailings disposal, and in particular the comparative costs of different disposal methods in different situations. Costs are often the hidden design parameter. We know that they are important but sometimes feel that it is not very respectable to talk about them in public. It is better from a public relations point of view for it to appear that the decision-making process is driven by environmental factors or best practice rather than looking for the cheapest option. But this presumes that the two are mutually exclusive and this need not be so. These issues are discussed later in the paper. It is also commonplace for the scale of the mining operation to change with time, typically involving increased throughput rates and total tonnage. New ideas in tailings disposal make their appearance. The regulatory attitude can change. Having made a decision about the disposal method at the time of original feasibility study and design it is easy to suppose that the mine is æstuck with itÆ. But that also need not necessarily be so. Careful costing of options may reveal that a switch in method could be cheaper in the long run. The designer will often tend to think in terms of initial earthworks and site development costs. Aspects of power consumption, labour, and periodic campaigns to move tailings pipelines and carry out embankment raises are either overlooked or not given the same emphasis. This can distort the evaluation process. It is productive to think in terms of dollars or cents per tonne as a basis of comparison, not just the total sums. Tailings disposal can cost from as little as 10 - 20 ó/t to over $1.00/t which is a big range. There may be good and unavoidable reasons for the high figure but there would need to be to justify being so far over the industry average. At the same time, mining and processing costs, at least for gold, are around $15 - 20/t. Viewed from this perspective tailings disposal will always be a relatively small component of the annual budget.

Jan 1, 2000

By W P. Breytenbach

"The phased application of statistical process control (SPC) infers that processes are classifiable as pre-SPC (or phase zero), phase I and phase II processes, with different objectives being pursued in the different phases. Phase zero processes, defined as processes affected by assignable causes of variation, are characterised as follows: out-of-control with unknown autocorrelation structure having an unknown statistical distribution not performing consistently on target with minimum variability potentially incapable of conforming to the product specifications. The objectives of phase I SPC is to obtain estimates of the mean (µ), variance (s2), probability density function (f(X)) and the autocorrelation structure, as well as transforming the process into a phase II process (defined as a process conforming to specifications and performing on target with minimum variability). As in any other type of research or pragmatic improvement intervention, sampling is required is to achieve these objectives. The challenge of deciding a phase I sampling plan is multifarious since it has to cope with the aforementioned effects of assignable causes and provide for rigour estimates of the unknown parameters. Furthermore, deciding sampling plans in phase I invariably presents a classical catch-22 situation: appropriate sampling is required to determine the autocorrelation structure of a variable, but knowledge of the autocorrelation structure is required to formulate an appropriate sampling plan. This paper suggests, for random variables, guidelines to formulate sampling plans, and presents a methodology to estimate the inherent process parameters of process variables and an approach to identify assignable causes in phase I. CITATION:Breytenbach, W P, 2014. Rational sampling and standard deviations for random variables in phase i application of statistical process control, in Proceedings Sampling 2014, pp 141–154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 29, 2014

By D A. Kepert, I J. Tehnas, M A. Pudovsk

BHP Billiton (BHPB) was the first company to start iron ore mining in the Pilbara at Mt Goldsworthy in 1966 through Goldsworthy Mining Limited (GML - then Consolidated Goldfields Australia, Cyprus Mines and Utah). Operations later started at Newman on Mt Whaleback in 1969 with the Mt Newman Mining Joint Venture (MNM û then comprising American Metals Climax û AMAX, Colonial Sugar Refineries û CSR and BHP). In 1986 it acquired majority ownership of MNM, and at the same time the previously 100 per cent BHPB owned but undeveloped Yandi property came on board. Purchase of Jimblebar (formerly McCameyÆs Monster) occurred in 1990 and full ownership of Goldsworthy followed in 1991. With the exception of Jimblebar (100 per cent owned), all mines are now 85 per cent BHPB and the balance with Itochu and Mitsui. This evolution of the company resulted in an eclectic mix of mines/ores, each with their varied exploration and evaluation histories. Discussion of some aspects of these histories, and reflections on changes in exploration-related activities with particular reference to discussion of advances in geological understanding since the 1960s forms the basis of this paper. BHPB presently has open cut mines at four main centres û Newman, Jimblebar, Marillana Creek (Yandi) and Yarrie û and is currently developing the former GML Area C near Yandi. With the exception of NewmanÆs Mt Whaleback mine and immediate satellites, all are contract operated. Ore is carried on BHPB railroads (696 km total) for export through the companyÆs Nelson Point or Finucane Island shipping facilities at Port Hedland. Some is directed to the BHPB Boodarie Iron hot briquetted iron plant near Finucane Island. Over 73 Mt of ore was produced by BHPB in calendar 2001, and the company has now mined over 1500 Mt in Western Australia since their operations at Yampi Sound first started in 1956.

Jan 1, 2002