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By Harris J. W

Mr. Gillie and Mr. Harris have given us a wealth of information and food for thought on the vital subject of information and food fo rthought on the vital subject of reducing costs and mention considerable saving in some of the larger items. There are a number of points on which I would like further information, but I will confine my remarks to a relatively small saving which is of particular interest in view of another paper to be presented this afternoon.Mention is made of a 50 per cent reduction in the amount of zinc used in the precipitation of gold slime from the pregnant solution. Would Mr. Harris enlarge on the methods by which they obtained this reduction; and could he give an actual figure of zinc consumption either by ton of ore treated or per ounce of bullion recovered.AuthorsWe consider the reduction of zinc is due to improved clarification of the pregnant solutions. The sand clarifiers used prior to the installation of the 50 ft. -thickener were not satisfactory due mainly to the blending of the hessian and matting under the sand. Under these conditions the leaf clarifiers were fed with overflow solution from the clarifiers and were overloaded in consequence. The addition of Calgon has also been beneficial.The present consumption of zinc per ton of solution treated is 088 lb. per ton.A. L. "Keats (No,rth Broken Hill Limited)In the operation of milling equipment there is a progressive increase in maintenance expenditure during the life of a machine, so that when comparing the cost of operating old equipment with the cost of operating new equip...

Jan 1, 1956

By Hanley J

Coal winning in the Latrobe Valley exceeds 45 mtpa uses a small number of Bucket Wheel Excavators and high speed conveyor systems. While this equipment offers many advantages in the production cycle, incorrect use can lead to low productivity and risks to the safety of the operators and equipment. The mining equipment is of high capital value and easily damaged when used outside the correct operating range. In the extreme case, this can result in total machine collapse, having major implications for personnel safety as well as production and costs. With an active productivity improvement program in the Latrobe Valley in the last two years resulting in a 50 per cent reduction of personnel, many experienced operators have retired. Mine management are facing the urgent need to rapidly train new operators to maintain high productivity levels and reduce the risk of accidents to personnel and high capital cost plant. With the assistance of the Central Gippsland College of TAFE a Certificate Level course has been developed for open cut operators. The course covers all essential training needs for the Latrobe Valley mines. The training is developed from National Competency Standards, allowing transfer of skills, and is flexible to suit other enterprises. It has been written for self-paced learning with the total job understanding, and to have competency-based learning outcomes, training tasks and assessments built-in to modules. With the introduction of this new training program, management is convinced that the element of risk within the mine will be significantly reduced. For these reasons it is an ideal training model for other enterprises.

Jan 1, 1994

By M Freeman

In a visionary move, the Planning Commission and the Ministry for Planning in Western Australia decided to invite three extractive industry quarry operators, local government councils and State Government departments (Minerals and Energy, Environmental Protection, South West Development Commission) to contribute jointly to study the impacts of blasting on areas surrounding basalt quarries in the Bunbury region of WA. The results of the study will help establish suitable zones in which land uses will be controlled under a proposed Greater Bunbury Region Scheme and in local planning schemes, to minimise conflicting land uses. This paper discusses the blasting program conducted to characterise and model the vibration behaviour of the rock under the effects of pilot-scale and full production blasting, and highlights some of the benefits achievable when a thorough blasting impact program and assessment is conducted at the planning stages of land-use establishment.

Jan 1, 2001

This paper describes the MillMapper technology developed for condition monitoring of liners and other operational parameters in grinding mills used for mineral comminution, by presenting a case study of its application. MillMapper provides maintenance engineers, operations managers and process and plant metallurgists with quantitative, accurate and reliable condition monitoring data for informed decision making regarding the maintenance and metallurgical aspects of such mills. MillMapper uses calibrated laser scanners for the capture of three-dimensional surface representations inside a mill during a shutdown so as to determine shell, feed and discharge liner thickness at a resolution of several million data points, a procedure that nominally takes five minutes to complete. Once several data sets over time have been collected inside a mill, MillMapper can be used for liner wear, liner wear zone, liner weight, ball charge volume, ball charge weight and intelligent profile tracking over time. Liner tracking in combination with site defined reline and failure criteria and with throughput tonnage data is utilised for change out prediction of each separate liner segment type.

Jan 1, 2008

By J Carrillo, A King

Gravity recoverable gold (GRG) is largely distinguished from other gold by its non-mineralised, metallic form, its high degree of liberation from the ore and its appreciable particle size. The gold mining industry has so widely accepted the use of batch centrifugal concentrators (BCC) and intensive cyanidation (IC) systems for the recovery of GRG that these may well be considered requirements of any plant processing ore containing appreciable GRG. The recovery of gold by gravity is quick, easy and cheap by comparison to alternatives. However, there are cases where attributes of the ore make recovery of gold by gravity and IC unusually challenging. This paper describes three examples where such challenges have been encountered and met, including those where the ore contains cyanide soluble base metals and where fine GRG is to be recovered from flotation concentrate.CITATION:King, A and Carrillo, J, 2018. Addressing challenging applications of intensive cyanidation in gravity gold recovery, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 283–290 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By R Stosch, D Lohberger, J Rodler, E Schnell and A Bassler, H Ramseier

In the last two decades three-dimensional (3D) computational fluid dynamics (CFD) simulations have become an important tool in engineering sciences. More recently, the safety requirements in underground railway stations have increased with regard to incidents. For this reason, existing underground stations (eg Munich, Strasbourg and Berlin) are being equipped with smoke extraction facilities to protect passengers from smoke and visibility impairment in the event of fire. In addition, designs of planned underground stations (eg Karlsruhe, Doha) also include these facilities.For the commissioning of ventilation engineering systems with complex structures, the functional testing of the whole technical installation are important, as are the acceptance tests of ventilation and equipment parts. This functional testing includes not only the technical inspection of the equipment but also the acceptance measurements of the capability of the equipment and the execution of hot- or cold-smoke tests to confirm the effectiveness of the ventilation system.Due to the fact that the overhead contact line and other sensitive installations were already installed in the tunnel roof at the time that smoke tests were proposed, hot-smoke tests with fire loads up to a maximum of 1 MW could only be executed. Therefore, the evidence of the attainability of the safety objective had to be provided computationally in this special case with a fire scenario of a heat release of 10 MW using CFD simulations.This paper presents the interplay between the results from acceptance testing and smoke tests and the use of 3D CFD simulation and virtual reality using the example of Allmend station, which was repositioned underground and is part of a new section of track from Lucerne railway station to Kriens in the Zentralbahn network. The steps of the verification and validation of the computer model are presented with the real tests and measurements.CITATION:Stosch, R, Ramseier, H, Lohberger, D, Rodler, J, Schnell, E and Bassler, A, 2014. Safety in underground railway stations – an example of the interplay between testing and 3D computational fluid dynamics simulation, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 103–112 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By T D. H McGrath, O Baker, W P. Staunton, C Ypelaan

"The carbon-in-pulp process has been used extensively in the gold industry since the late 1970s to recovery leached gold from solution. Despite more than 30 years of experience in operating carbon circuits, average gold solution loss has remained at an average of 0.02–0.03 ppm (mg/L), higher than the ‘best practice’ target of 0.01 ppm.Process modelling, such as SIMCIL developed by the Curtin Gold Technology Group (GTG), can provide information on optimum set points; however, manual control of the circuit limits the potential benefits.An automated carbon measurement device, the Scout Carbon Meter, has been developed to allow for automation of carbon concentration measurement, and automated control of the carbon transfer pumps. This paper describes the results from the evaluation of the first two prototypes of the meter.Citation:Staunton, W P, McGrath, T D H, Ypelaan, C, Baker, O and Eksteen, J J, 2016. Optimising Carbon Management - Increasing Gold Recovery and Decreasing Costs with the Carbon Scout, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 225–228 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By J L. Merritt

The mining industry seeks to engage with and respond to stakeholders through open consultation processes during the various phases of a mining project (Department of Industry, Tourism and Resources, 2006). Two Australian Coal Association Research Program (ACARP) funded projects conducted in the Bowen Basin coalfields in Central Queensland investigated the use of a stakeholder panel for the evaluation of mine site rehabilitation. The panel members were drawn from the local and regional area, and represented neighbouring landholders, traditional owners, AgForce, local government, conservation groups and non-governmental organisations (NGOs) such as Greening Australia and the Fitzroy Basin Association. The approach of utilising stakeholders to establish rehabilitation criteria was proposed as an alternative to the established practice of assessing rehabilitated areas against a suite of quantitative completion criteria; eg >70 per cent vegetative ground cover or <5 t/ha/a soil loss. The basis of this approach recognises the reality that the definition of completion criteria has proved problematic over the last 40 years with no broad consensus reached on the suite, let alone the metrics; eg the exact cover level that will benchmark acceptance of the mine site rehabilitation.CITATION:Merritt, J L, 2016. Zooming out – learning to see rehabilitation through stakeholders’ eyes, in Proceedings Life-of-Mine 2016 Conference, pp 163–165 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

The recent trend of installing flotation cells with volumes as large as 200 m3 in concentrators is driven mainly by economic considerations such as lower capital, operating and maintenance costs. Despite the economic advantages, the metallurgical benefits from these large cells have not yet been fully realised by the industry. This is mainly due to the lack of understanding of cell operation, viz cell mixing and hydrodynamics, gas dispersion and froth transportation behaviour in large cells. There is still no rational basis for selecting optimum cell operating conditions and down-the-bank operating profiles. The relationship between cell operating conditions and metallurgy is not well established. This has resulted in poor utilisation of cell capacity in many operations. The present trend of installation of fewer cells in a bank requires each cell to be operated very efficiently. Optimisation of cell operation provides an opportunity for significant metallurgical improvements in a flotation circuit with minimal capital expenditure. Extensive work on optimising of cell performance has been carried out at various Teck Cominco operations in Canada, Peru and USA. Three different levels were involved in this work. The first level was aimed at identification of cell operating conditions for optimum mixing and hydrodynamics, gas dispersion, entrainment and froth flow behaviour in individual cells. The objective of the second level was to identify the optimum bank operating profile for cells down the bank in a circuit. The third level then focused on controlling these cell operating conditions and bank operating profiles for tighter control of concentrate grade and recovery for optimum bank metallurgy. This paper presents some of the major findings at all three levels and demonstrates the importance of each level in optimising the performance of flotation banks installed with large cells.

Jan 1, 2005

By S G. Gatehouse

Extensive gold mining activity û dominantly alluvial û has taken place in the Sofala-Wattle Flat district since the 1850s.This work will have located most, if not all, of the visible sources for the gold in current stream systems.Also, there are many gold bearing elevated Tertiary alluvial terraces in the district which may confuse possible gold signals from primary hard rock sources in the streams.Associated element signatures eg As and other chalcophiles, will discriminate non-alluvial signatures but will not necessarily distinguish non gold bearing mineralisation.Both trace elements and conventional gold analyses will dominantly re-identify known occurrences. Conventional BCL sampling is considered misleading as experience from the Oberon area to the south of Sofala demonstrated that BCL sampling was very sensitive û perhaps too sensitive.All occurrences û major or minor û of gold will be detected (Gatehouse, 1992). To improve on BCL sampling, a small, -120# sample with selective duplication was recommended to screen coarse-grained gold anomalism and a program of sampling covering an area thought to be prospective was enacted.Samples returning anomalous Au were analysed in duplicate and if the results demonstrated reproducibility, indicating fine gold only, the sample site was assigned a high priority.It was found that most of the reproducible samples clustered in one area û Spring Gully. The results of this sampling program led to immediate identification and, ultimately, the successful delineation of the Spring Gully gold deposit near Wattle Flat.

Jan 1, 2004

By J Addai-Mensah, W Skinner, C Kelsey, J R. Kelly, E Baawuah

Comminution continues to be the most capital-intensive unit operation in mineral processing. The fundamental purpose of comminution is to liberate the valuable minerals so that they can be economically concentrated into saleable products. Declining ore quality characterised by lower grade and increased complexity requires significant energy consumption for comminution. Low-grade magnetite ores are typically fine-grained and require fine to ultra-fine grinding (P80 ~ 30 - 40 µm) to enhance its liberation from the typically siliceous gangue matrix. Historically, this has been achieved using multi-stage crushing and grinding technologies, which require high energy consumption with low energy efficiency. This motivated innovations in energy efficient technologies for comminution. Such technology has been developed in the IMPTEC super-fine crusher. It is an innovative, dry (with the potential to be operated wet), media-free, energy efficient crusher that can to reduce 10 mm feed particles to 19 – 30 µm with very low recycle loads. In this study, the mineralogical and physicochemical characteristics of crushed magnetite ore using the IMPTEC super-fine crusher have been investigated in comparison with those of rod milling. The super-fine crusher generated higher liberated magnetite minerals in the – 300 + 212 µm and < 45 µm size fractions compared to rod mill. Both comminution devices generated large low-grade hematite and goethite middlings. However, the rod mill produced higher locked/unliberated hematite and goethite compared to that of the super-fine crusher. Quartz mineral had the highest liberation irrespective of the comminution device used. The super-fine crusher generated higher entrapment of other minerals within the silica matrix compared to the rod mill. The breakage mechanism of the super-fine crusher which is predominantly through high compression with shear, generated improved mineral liberation in the coarse size fractions compared to the predominant abrasion and attrition breakage mechanisms of rod milling. The higher mineral liberation generated by the rod mill is potentially due to the prolonged batch milling of the ore compared to the single-pass open circuit of the super-fine crusher.CITATION:Baawuah, E, Kelsey, C, Kelly, J R, Addai-Mensah, J and Skinner, W, 2018. Mineral liberation studies of IMPTEC super-fine crusher – 130 crushed product, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 313–326 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By A Hoyle, P Walker, D Bennett

The Phu Kham copper-gold operation located in Laos People’s Democratic Republic (PDR) is owned and operated by Phu Bia Mining Limited. PanAust Limited, based in Brisbane Australia, holds a 90 per cent interest in Phu Bia Mining Limited, with the remaining 10 per cent held by the Government of Laos PDR.The 12Mt/y copper-gold concentrator at Phu Kham commenced production in April 2008. Flotation copper and gold recovery from commissioning was consistently poor, due to the high levels of pyrite and problematic secondary and oxide copper species and non-sulfide gangue.The low recoveries of copper and gold from Phu Kham were recognised during the feasibility study design phase. A bulk sulfide flotation regime in roughing produced high recoveries, however a large capacity cleaning circuit was required and there was risk of not meeting saleable concentrate grade specifications. The installed design offered a capital efficient compromise to ensure that a concentrate grade of 24% copper could be achieved at acceptable recoveries.Incremental improvements in copper recovery were achieved by 2011 through conversion of conditioning cells to flotation cells in both roughing and first cleaning and increased cleaner capacity through the installation of a Jameson cell. In 2012 the Phu Kham Upgrade Project was commissioned to increase mill throughput, along with additional rougher and cleaner capacity to increase residence times at the nominal 16 Mt/y throughput. The marginal reduction in primary grind size due to the additional ball milling power also provided a small recovery improvement.This paper presents the development, design, implementation, and performance of the Increased Recovery Project commissioned in April 2013 which targeted the major causes of copper loss from the circuit. Based on fundamental and detailed test work and mineralogical analysis of concentrator streams, an optimised design was developed which has increased copper and gold recoveries by over 5% and 10% respectively. The Increased Recovery Project has positioned the concentrator to process high pyrite ores that were previously considered untreatable, and opened further opportunities for maximising flotation recovery by de-bottlenecking plant regrind and cleaning capacity.CITATION:Hoyle, A, Bennett, D and Walker, P, 2015. The increased recovery project at the Phu Kham copper-gold operation, Laos PDR, in Proceedings MetPlant 2015, pp 246–265 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By D Kentwell

IGO Ltd’s (IGO) Nova Operation (Nova) is 160 km east-north-east of the town of Norseman in Western Australia (WA). Discovered by Sirius Resources NL (Sirius) in 2012 and acquired by IGO in 2015, the Nova-Bollinger Deposit (Nova-Bollinger) occurs within the Fraser Zone of the AlbanyFraser Orogen. Nova-Bollinger is a complex nickel-copper-cobalt (Ni-Cu-Co) magmatic intrusive sulfide deposit, which is characterised by high-grade folded and undulating breccia lodes that host the bulk of the payable metals. Significant sulfide mineralisation is also found in several magmatic intrusive styles including net-textured, disseminated and blebby styles. A smaller but material volume of sulfides has also been remobilised into the deposit’s footwall rocks as ‘stringer’ bands in metasediments, or as discrete massive sulfide lenses. When interpolating Mineral Resource estimate (MRE) block grades in the presence of locally varying grade connectivity trends, such as folds or undulations, the sample search neighbourhood, which is used to identify the composites subset that is used for each block estimate, should be oriented to match the local trends. In theory, the most robust method of estimation where locally varying angles (LVAs) are applied to search neighbourhoods, are techniques where the composites and the blocks to be estimated are transformed to an unfolded coordinate system (UCS). However, UCS methods can be tedious to implement and require subjective decisions to be made that cannot always be fully defended. An alternative LVA method commonly used in the industry is dynamic anisotropy (DA), which is much simpler to implement and is often assumed (but not that often demonstrated) to result in similar results to UCS-style estimation. In 2018, Nova’s Mine Geology team (MGT) estimated the grades and density of the Nova-Bollinger MRE using the UCS approach. For the 2020 MRE update, Nova’s MGT tested and compared the USC grade interpolation method with the DA approach. As applied to the Nova-Bollinger’s 2020 MRE, the comparison, advantages and disadvantages of the two estimation methods are the subject of this paper

Mar 22, 2022

Any Australian who knows of the poverty of the early settlers in the first few years following the arrival of Captain Arthur Phillip with his "first fleet" at Botany Bay must feel proud of the progress that has been made in the 174 years that have elapsed since that momentous occasionGFor all its attractive appearance as reported by Captain Cook and Sir Joseph Banks, the shores of Botany Bay and of Port Jackson proved most ,inhospitable, and the accessible country surrounding them anything but suitable for sustaining the life of the small settlement. It is well known that during the first 15 or 20 years the hardy colonists and un-tfortunate convicts were close to starvation on several occasions and were only saved by the arrival of supply ships, which were dependent on the vagaries of wind and current, and the hazards of the uncharted seas they had to -navigate-.When Australia was little more than a miserable penal settlement, Great Britain was one of the great-powers of the world, and the U,.S.A. was an independent nation with a growing degree of prosperity that even then gave promise of its mighty awakening to become, as it has, a e.olossus of industry and commerce,-and the. leader in living standards of the world to-day.Australia, from such a shaky, and comparatively recent start, has risen to a position in which its living standards rank very high in comparison with those of most of the nations of Europe and America. Exact com-parisons are hard to fix because of the wide variety of factors involved .but the Institute of Pab?Lic Affairs .(Victoria) places Australia fifthin the world, excelled only by the U.S.A., Canada, Sweden and Switzerland. The next best after Australia are the United Kingdom, West Germany and France.How we achieved such a high standard of living is a vast subject for study but some of the economic aspects of our climb from abject poverty to a position of near affluence can readily be identified.

Jan 1, 1962

By J Fraser, M Scoble

Within the past decade, incidents of mining–community conflicts have grown dramatically and represent one aspect of a phenomenon known as social risk. Research published in 2014 indicates that a lack of social acceptance is now a leading and costly cause of delays for mining projects.The rise of social risk, complemented by the need to earn the trust of an increasing number of stakeholders so that mining projects can be developed effectively, is problematic for the industry. Conflicts are occurring in situations where companies are fully compliant with regulatory and legal requirements, despite initiatives by mining companies to earn social acceptance and despite the proliferation of tools to support corporate social responsibility. Intensifying the impact of social risk is the fact that it has increased during a time in the global mining sector when companies have had to grapple with declining commodity prices, increasing capital costs and debt levels and the challenges of mining lower-grade deposits.This paper will explore a hypothesis that in today’s interconnected society, social risk in the mining sector constitutes a legitimate business risk that must be managed strategically. The reality facing mining companies is that information, once considered confidential, now travels quickly on social networks and via a growing number of groups and individuals that have earned a legitimate right to be classified as stakeholders in projects that affect their communities. To be successful, it is suggested that companies will benefit from increasing internal collaboration and providing training to equip teams to mitigate social risk to mining projects and protect reputation capital. The paper is based upon PhD research being undertaken to assess the points of intersection between social risk and social responsibility during the construction stage of greenfield mining projects.CITATION:Fraser, J and Scoble, M, 2015. Mining–community conflicts – can the future mining sector transform social responsibility?, in Proceedings Third International Future Mining Conference, pp 159–168 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

Exploring for deep shallow dipping orebodies can be very expensive and very difficult. Surface exploration is often not an option and obtaining the best location for underground drilling can cause production delays if drilling is carried out from development headings. The Otter/Juan mine has been in production for approximately 34 years. All of the production is now sourced from more than 1000 metres below the surface from an area known as the Edwards Lode. The orebody is shallow dipping and open at depth. Exploration drilling has been performed from decline stockpiles and from hangingwall drill drives. Drilling from footwall positions (eg decline stockpiles) into shallow dipping orebodies can often produce intersections which are unusually thick thus leading to optimistic resource figures. The decision to develop a dedicated hangingwall drilling position can vastly improve the quality of the data used to generate an orebody model. In 1997 a new extension to the Edwards Lode was discovered and named the æFÆ surface. In 1999 a resource calculation was performed using data obtained from drilling that was carried out from decline stockpiles. In 2002 a dedicated drill drive was developed into the hangingwall of the æFÆ surface to obtain better data to verify the previous resource calculation. For this case study obtaining more representative data reduced the resource estimate by 66 per cent. This information was obtained early enough to allow for alteration to the mine plan and without loss of capital.

Jan 1, 2003

A series of physical tests have been conducted to determine the actual performance of bunton to shaft side wall connections typically used in new shaft construction in South Africa. The test set-up is described, together with the applied loading, which incorporates a cyclical load component and a quasi-static load component, in an attempt to simulate actual conditions in the shaft. The test results are given and it is shown that generally the performance is adequate, provided double-slotted holes are not used. Generally the fatigue performance is found to be good, with the only exception being cases where the bottom of the bunton is lower than the seating level for the bunton to side wall connection. Arising from the tests, typical design values of connection stiffness, strength and fatigue life are proposed and a design procedure including these three key aspects of connections is described.

Jan 1, 2005

By N Weatherstone

A consistent and reliable international approach to public reporting of a mining companyÆs main assets, its Mineral Resources and Mineral Reserves, has become of increasing importance in recent years with the rapid globalisation of the mining industry. Through the efforts of the Committee for Mineral Reserves International Reporting Standards (CRIRSCO), a committee representing national resource/reserve reporting committees in Australia, South Africa, UK/Ireland/Western Europe, Canada, USA and Chile, the reporting standards in most æwesternÆ countries use almost identical resource and reserve definitions and are generally around 90 - 95 per cent compatible. New codes based on the CRIRSCO model are being developed or considered in other countries, including Peru and the Philippines. This unified approach has provided the mining industry, regulators and investors with a common framework to report and interpret mineral resource and reserve estimates, thereby facilitating funding to the mining industry through improved investor understanding and confidence. The common reporting standards are reflected in the CRIRSCO International Template, available on CRIRSCOÆs web site, a document that is kept æliveÆ by reflecting the best of the most recently published CRIRSCO-type national standards. In a significant exception to this unified industry approach, the USA Securities and Exchange Commission (SEC) requires adherence to its own standard, only partly compatible with CRIRSCO-type standards, with adverse and costly implications for companies listed in the USA. A major industry submission was presented to SEC in April 2005 which, if accepted, would bring about considerable compatibility of CRIRSCO and SEC standards. The UN Economic Commission for Europe (UN-ECE) has, since 1992, been developing its Framework Classification (UNFC) as a single global system for harmonising all existing national and international resource/reserve reporting systems, covering both government and industry requirements and both the hydrocarbon and solid minerals sectors. While few mining companies report their resources and reserves using the UNFC, the system is accepted or is being examined as a basis for reporting by some governments, including those of Russia, China and India. The UN-ECE agreed in 1999 to incorporate CRIRSCO definitions into the UNFC for those categories of resources and reserves used for market-related reporting, but a more recent edition of the UNFC removed or changed the definitions, requiring re-engagement by CRIRSCO to ensure compatibility. Since 2005, CRIRSCO and the Society of Petroleum Engineers (SPE) have been involved in discussions with the International Accounting Standards Board (IASB), which plans to develop a new Accounting Standard for the Extractive Industries as part of its International Financial Reporting Standards. At the request of the IASB, CRIRSCO and SPE have been examining any potential for convergence of resource/reserve definitions between the mining and hydrocarbon industries. Each of these systems is described in this paper and high level comparisons made.

Jan 1, 2006

By J Meinhart, J Rodler, I Katolicky

The ever increasing number of vehicles is leading to slow-moving and even stationary traffic sitting longer in traffic jams over extensive city areas. This traffic situation causes a sharp increase in pollutant emissions from vehicles, and high levels of pollution usually result throughout the built-up area. Reducing the pollution level by using traffic routing measures to speed up the flow of traffic in the existing street network is only possible in exceptional cases.In many cases the only option for achieving a significant improvement in traffic conditions is to shift the traffic underground using a road tunnel or underpass. Such tunnel routes suck off the traffic from large sections of the city, thereby easing the overall traffic flow. Thus on the one hand it produces a sharp reduction in pollution levels in the area of the tunnel route, but on the other hand it can result in locally increased exhaust pollution levels from longer tunnel systems that require mechanical ventilation. The air extracted by the ventilation system is blown out into the atmosphere either directly through the tunnel portal, or via a venting tower. Pollution can therefore occur in the area surrounding such exhaust air outlets.Thus if a tunnel is planned in a city, then closer investigation is required of both aspects: the reduction in pollution in the area of the tunnel route thanks to relocating the traffic and easing congestion, and the increased short-range pollution around the tunnel portals (shafts).

Jan 1, 1999

Existing production facilities are constantly looking at ways to increase capacity. Many recent solutions have focused on the implementation of capital and infrastructure projects. It is accepted that capital expansions are frequently necessary for production gains; however, in many cases existing assets have the potential to deliver substantially better throughput than they are currently achieving. By focusing on automation of production control systems, production reporting and business processes substantial gains can be achieved utilising existing assets. This potential can be realised quickly and has been proven across several sites and industries. In the Pilbara region of Western Australia throughput gains of between two per cent and 25 per cent (translating to millions of tonnes per annum) have been achieved from existing assets using the methodologies discussed. The improvement process involves evaluating the entire production chain from the time the ore arrives at the plant to the time it is dispatched. A technical evaluation of the performance of the control system and plant automation interfaces to upstream and downstream processes is conducted. The relationship of these processes to the business systems and the human interface to the systems is reviewed to ensure a complete picture of the system is understood. Technical evaluation targets include: individual equipment operation, the engineering level of control systems, feed controls, etc; managing recirculating loads, surge capacities, dynamic inventories as well as management of in-feed systems and integration into yard and out-feed systems; and communication flow between control and other systems, data alignment between rail and shipping schedules, yard systems, sales systems and maintenance systems including such fundamentals as truck dispatch links to plant control. In parallel with the technical evaluation, business system evaluation takes place, including analysis of the operational systems, methods and personnel.

Jan 1, 2007