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By K Henley

One of the greatest practical difficulties of measuring airblast occurs when a significant wind is blowing onto the microphone. Small windscreens are usually used to mitigate the wind noise on the microphone, but in some wind conditions, sound pressure levels (SPL) of over 120 decibel (linear) are frequently recorded. There are no specific procedures to mitigate the effect of wind noise when measuring airblast in any of the standards or guidelines pertaining to the measurement of airblast from blasting operations, other than the requirement to use an effective windscreen. A search for relevant literature was undertaken and measurements were taken over a period of six months at a test site using alternative microphone measurement methods. Previous researchers’ experiments with windscreens in silenced wind tunnels showed that wind noise can be reduced through the use of large diameter windscreens, and that at low frequencies, the windscreen size and the material type makes no difference to measured SPL values. Other researchers found that wind turbulence caused significant SPL measurement problems. A comparison with field data failed to explain the extremely high SPL recorded by the field microphones at wind velocities much lower than those used in wind tunnel testing. It has been concluded that turbulent airflow over and behind the microphone is a significant contributor to extraneous noise in airblast measurements in windy conditions. This turbulence can be generated by objects upwind of the microphone or by the microphone itself if the windscreen is ineffective. Reducing the wind speed over the microphone by placing it on the ground is the approach required by the international standard for the measurement of noise from wind turbine generators (IEC 61400–11). This paper presents data that illustrates the extent of the problem, reports on the trial of three different microphone mounting locations for measuring airblast from blasting and concludes that in windy conditions, microphones placed on the ground substantially avoid wind problems and do not reduce the measured SPL of the airblast.CITATION:Henley, K, 2015. Reducing the effect of wind on airblast measurement during blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 485–492 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

A series of petrological studies were carried out on the characteristics of alteration and mineralisation in mainly structural-controlled (Deep Star, Meikle, Deep Post) and predominantly lithological-controlled (Post-Betze-Screamer and West Leeville) gold deposits in the northern district of the Carlin trend, Nevada. Alteration and mineralisation in these deposits are hosted in a sequence of calcareous clastic units of the Devonian Popovich Formation, into which have been emplaced a number of Jurassic intrusions, and syn- to post-mineral Eocene dikes. Four hydrothermal events have been recognised in these deposits: an initial Devonian base metal system and early diagenesis; a Mississippian stage of alteration in conjunction with burial metamorphism; contact and hydrothermal alteration and base metal-gold mineralisation associated with the emplacement of the Jurassic intrusions; and a Carlin-style gold system related to Eocene magmatism.

Jan 1, 2004

By L C. P J Fonteneau, B Godel, E R. Ramanaidou

The Hamersley Province in Western Australia hosts large iron ore deposits. Each deposit displays various iron ore types that were defined on their metallurgical properties, especially in terms of porosity and mineralogy. Conventional porosity and mineralogy information on iron ore types are provided on 2D thin sections using automated image analysis with scanning electron microscopy (SEM)-based techniques combined with chemical analyses. However these techniques cannot accurately quantify the 3D porosity. High-resolution X-ray computed tomography (HRXCT) is a non-destructive technique providing a 3D image of the sample with a resolution close to 0.5 - 0.7 ¦m for samples size of up to few centimetres in length. 3D image analysis using customised algorithms now provide accurate quantitative porosity and mineralogy of iron ore types.CITATION:Fonteneau, L C P J, Godel, B and Ramanaidou, E R, 2013. Application of high-resolution x-ray computed tomography to iron ore characterisation, in Proceedings Iron Ore 2013 , pp 243-250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By P Valenzuela

Joint mapping is a fundamental input for rock mass characterisation and slope stability analysis. The usual way to do it is using a compass in the field or digitising structures on a screen, with a software package.In this paper a method to identify and map joints automatically along a rock face is presented; it is called the Concentric Shells (CS) algorithm. The method scans a point cloud sequentially, tests if selected points are ‘true pivots’ within an inner shell, and then it searches for points inside a wider sphere (outer shell).The algorithm, developed by the author, was applied in real data. It reproduces the main features obtained from conventional (compass) and digital mapping (software package). Execution times are approximately 45 seconds for two point sets holding of 3.1 million points. Obtaining the same results via digital mapping takes approximately 3–4 working days.Key advantages of this method are: significant time reductions; elimination of mapping bias; and the ability to manage very large data sets (>2 million points) without the need of scanning the cloud on the screen. These advantages make this method an attractive tool for engineers and geologists wanting to increase productivity.CITATION:Valenzuela, P, 2017. Automated joint mapping using the concentric shells algorithm, in Proceedings Tenth International Mining Geology Conference 2017, pp 257–262 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By P Clark

This paper discusses the challenges, solutions and lessons learnt as tunnelling work continues on the Melbourne Main Sewer Replacement (MMSR) project.The MMSR project is a $220 million dollar project for the Melbourne Water Corporation. It involves the construction of approximately 4.2 km of new sewer from the southern fringe of the CBD through the inner metropolitan suburbs of Port Melbourne and South Melbourne.Of the 4.2 km of sewer currently in construction approximately 2.2 km will be constructed using a 2.95 m diameter Lovat EPB tunnel boring machine (TBM) with approximately 1.9 km of small diameter (300 to 600 mm) reticulation sewers constructed using trenchless techniques.These sewers are being constructed in a dense urban environment, which means that the tunnels and shafts are often in close proximity to buildings and structures. The underground constructionof the sewer is further complicated by the variable geology of the ancient Yarra River delta which includes weathered basalts, the infamous Coode island silt formation and fine loose sands.Some of the key challenges and lessons learnt so far during construction include:· steering and alignment control of the TBM through very soft silt with little residual strength,· development and refinement of a monitoring and alarm system for leaving the machine dormant on a day works only project,· control and measurement of tunnel lining defl ection during ring build and grouting,· prediction and monitoring of surface settlements during tunnel excavation,· improved understanding of the geology and hydrogeology at this previously unchartered area of Melbourne,· consolidation settlement due to dewatering at shafts required careful construction controls, and· ground support and excavation in close proximity to the existing 110 year old sewer which requiredvery detailed risk control measures.

Mar 8, 2011

By D J. Black

The process of excavating and mining coal causes fractures in the overlying and underlying strata. The fractures provide pathways for gas released from coal seams and other gas-bearing strata to flow into the mine workings. Coal seam gas typically contains high concentrations of methane with lesser concentrations of carbon dioxide. Low concentrations of other gases such as nitrogen, hydrogen sulfide and ethane may also be present in some coal seams. In certain geological settings, particularly in close proximity to geological structures, such as faults and dykes, the concentration of gases contained in a coal seam can vary significantly between methane-rich to carbon dioxide-rich.In mine design and planning it is vital that mining engineers gather sufficient information to accurately determine the content and composition of the gas present in the coal seam and develop an understanding of changes in these parameters within the planned mining area.The longwall method of mining coal causes fracturing of the overlying and underlying strata behind the retreating longwall face. Where coal seams and other gas-bearing strata are present within the caving zone, gas will be released from the strata leading to contamination of the mine workings. If the rate of gas emission exceeds the diluting capacity of the mine ventilation, the concentration of gas in the mine may exceed the statutory limit, resulting in production delays and potentially unsafe conditions.CITATION:Black, D J, 2016. Planning effective management of gas emissions in an underground coalmine, in Proceedings Life-of-Mine 2016 Conference, pp 44–47 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Gordon N

The in situ behaviour of claystone floors associated with the Wallarah, Great Northern and Fassifem Seams has been studied using a comprehensive suite of stress and displacement monitors. The instrumentation was supplemented by in situ and laboratory testing of the claystone materials. The instrumentation demonstrated that the presence of claystone floors is associated with floor heave, extra rib spall, and settlement of the pillar into the floor. Horizontal floor extensometers showed that the depth of extrusion of clay was limited to 1-2 in. A pore pressure transducer installed in a claystone floor demonstrated the possible existence of short-term undrained behaviour of the claystone. Long term swelling of destressed claystone was also documented. Settlement of pillars into claystone floors can be analysed using simple elastic theory. The assumption of plane strain is valid for most claystone thickness/pillar width aspect ratios. Floor heave can be analysed using bearing capacity concepts. However, it is considered that heave is the result of local bearing capacity failure in the rib spall zone. The advantage of this model is that the bearing capacity equation can be applied without resort to unrealistically high factors of safety.

Jan 1, 1992

By G R. Ballantyne, B Putland, I Lovatt, M Di Trento

The Tropicana Gold Mine, owned by AngloGold Ashanti Australia Ltd (70% owned and managed) and Independence Group NL (30%) is located 330 kilometres east-northeast of Kalgoorlie, Australia, in the newly developed Albany-Fraser Orogen. Following extensive feasibility studies, a high pressure grinding roll (HPGR)-ball milling circuit was selected based on the reduced power requirements and thus reduced operating expenses. The HPGR-ball mill circuit was estimated to require 75% of the energy of a standard semi-autogenous grinding (SAG) mill circuit. Even with an anticipated greater capital cost, the HPGR-ball mill circuit was found to give significantly better financial returns in all cases investigated in the feasibility study. A comparison between the specific energy requirements of the HPGR, crush and SAG based circuits (SABC) from the feasibility work was conducted and the HPGR circuit was found to be considerably more energy efficient. A survey was conducted and the efficiency of the HPGR was similar to both the overall circuit design and the HPGR laboratory results, reflecting the accuracy that is possible for design and operation of HPGR circuits.Between 2015 to 2016, the Tropicana circuit has achieved a 20% increase in throughput from 780 to 930 t/h, and this increase has been maintained in 2017. This improvement can largely be attributed to upgrades to material handling processes, increased HPGR speed and smaller HPGR screen apertures. The result of these changes has been to increase the ball mill capacity by increasing the breakage conducted by the HPGR.CITATION:Ballantyne, G R, Di Trento, M, Lovatt, I and Putland, B, 2017. Recent improvements in the milling circuit at Tropicana mine, in Proceedings MetPlant 2017, pp 73–83 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

Mine site restoration, involving the re-establishment of original ecosystems, is a far greater challenge than revegetation, which simply aims to stabilise the site and to give it a green appearance. One of the challenges is to establish a simple yet effective measure of restoration success. A potentially useful approach is to focus on particular groups of plants or animals which are likely to provide a general indication of the state of the ecosystem in which they occur. Ants have been used extensively by the mining industry in this context, particularly in northern Australia. Ants are likely to be useful bioindicators because of their general importance in the Australian environment, and because of the many linkages they have with other parts of the ecosystem. Moreover, ant community structure responds to stress and disturbance in predictable ways, and therefore provides an interpretable measure of ecosystem change. This is illustrated by a study of ant recolonisation at Ranger uranium mine. However, the extent to which ants reflect the responses of other ecosystem components is poorly documented. This is currently the subject of a collaborative project between OSS and CSIRO.

Jan 1, 1994

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 J Cronin, R Burgess-Limerick, T Horberry, L Steiner

"Automation offers the mining industry great potential for improvements in productivity and safety. However, the experience of introducing automation in other industries has been that the full potential of new technology is not always realised. Designers are surprised, for example, to find that automation does not eliminate human errors. Unwanted and unexpected consequences also arise if the introduction of automation fails to consider how people will adapt to the new technology. A focus on the technical aspects of automation is necessary but not sufficient for success. The potential for improvements in productivity and safety promised by automation will only be achieved if the joint cognitive system that emerges from the combination of humans and automation is designed to perform the functions required for system success. This case study describes the human factors issues associated with the introduction of automation generally, and describes a case study of the successful implementation of loader automation at Northparkes mine.Information obtained through a site visit and interviews with operators, safety staff and the project manager revealed the following strategies for successful design and implementation of the automation system: involve the people who will be impacted encourage constant communication between operators and designers provide operators with essential information avoid providing non-essential information provide the operators with flexibility empower operators to take action take advantage of the new possibilities automation provides.CITATION:Burgess-Limerick, R, Horberry, T, Steiner, L and Cronin, J, 2017. Mining automation human-systems integration – CMOC-Northparkes case study, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 93–98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 16, 2017

By G R. Ballantyne, V Souto, K Bartram

Particle sorting allows partially liberated minerals to be separated prior to energy intensive fine grinding. Sensors select particles for separation and air, water or mechanical ejectors are used to physically deflect those selected. To achieve effective separation there has to be sufficient liberation, accurate detection and presentation of a separated monolayer of particles. These three physical constraints determine the particle size limits, the sorting technology utilised, the separation efficiency, and the throughput that can be achieved. The combination of all these factors controls the effective limits on the degree to which sorting can reduce the specific comminution requirements and increasing energy efficiency. This paper will explore two case studies: the application of sorting in base metal mining and precious metal mining.CITATION:Ballantyne, G R, Hilden, M, Bartram, K and Souto, V, 2018. Characterising energy efficiency of particle sorting, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 531–540 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

Most new engineers in the mining industry do not realise the importance of legal obligations. During investigations the first question you are asked is: Do you have any proof or evidence? The smallest detail in an underground notebook or a diary entry is able to be used as your proof and/or evidence. The importance of a paper trail is often undervalued and overlooked when you first enter the industry. As a new engineer, all too often your legal obligations, including your duty of care are not given enough consideration. Whose job is it to inform you of what your legal obligations are and when do they end? Everyone has legal obligations at every level of the industry, from graduate to mine manager. The level of these responsibilities varies depending on the position that you hold. When you first start in the industry you need to understand what your responsibilities are and how you are expected to discharge them, whether they are memos, databases or senior sign-offs, etc. In order to fulfil your obligations you must first discharge your own obligation, which in turn discharges those of your department and ultimately those of the mine. As a graduate engineer in the mining industry what I have learnt about my own legal obligations has come directly from my own experience, which will form the basis of this paper.

Jan 1, 2007

Anglo American Metallurgical Coal (AAMC) manages five open cut coal mines in Queensland and New South Wales, producing approximately 30 million tonnes per annum. The size and complexity of these mines require efforts by a large and diverse number of personnel to minimise adverse geotechnical events from occurring. To achieve this, the AAMC coal mines in Australia are developing a concept of managing the geotechnical risks associated with open cut coal mines. The overall system utilises a combination of internal training, a management system (operational management systems) and standards, numerical modelling, monitoring, inspections and audits. The development of the standards as well as training and mentoring of exploration personnel, geotechnical engineers, engineering geologists and mining engineers with an interest in the geotechnical aspects of mining, training of the production workforce, mentoring and training of the technical staff create the basis for achieving a pro-active rather than a reactive system. Audits are used to assure that personnel are maintaining the standards and to facilitate cross-mine leanings so that best practices are developed across all sites.

Nov 25, 2010

By W Potma, C Brauhart, S Halley, S Urbisinov, A Scogings

Truly integrated, quantitative, 3D GEOmetallurgical (or mineral system) characterisation, classification and 3D modelling should provide a cradle to grave unifying link across the exploration and mining value chain. All too often, spatially representative (quantitative) characterisation and modelling of a mineral system is delayed until feasibility stage, incurring a significant opportunity cost. The application of robust GEOmet characterisation methods early in the project lifecycle (at exploration stage) improves ground selection, exploration, and Mineral Resource estimation outcomes, long before there is a need for metallurgical test work. The value of this early provision of quantitative 3D mineralogy models is compounded at project feasibility stage, and continues to accrue over the entire project lifecycle, delivering cost savings, improved decision making and early warning of issues and opportunities.CITATION: Potma, W, Halley, S, Scogings, A, Urbisinov, S and Brauhart, C, 2018. Putting the ‘GEO’ back in front of GEOmetallurgy: importance of early implementation of quantitative mineral system characterisation, classification and modelling, in Proceedings Complex Orebodies Conference 2018, pp 55–57 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By I R. F MacCulloch

Bacterial oxidation of sulfide minerals is a familiar and commercially available process to enhance gold recovery with problem ores. Pintail Systems, a Colorado, USA based company had developed bio-processes for gold recovery based on natural mineral formation and transformation in a global mineral cycle. The biological recovery of precious metals from ore involves a number of mechanisms that are dependent on the metal-mineralogical association. These processes include: partial bio-oxidation of sulfide ores; oxidation of gangue minerals exposing gold to leaching; surfactant properties of bacteria/nutrient solutions that improve wettability of ores and solution contact with leachable gold and silver; and microbial production and excretion of trace amounts of gold lixiviants, and bio-fracturing or biological alteration of ore minerals. Pintail has demonstrated enhanced recovery of precious metals during cyanide detoxification of spent heaps at the end of mine life. Biological recovery processes also have the potential to be applied to in situ mining technologies. The in situ process application could recover gold from subgrade deposits, small deposits or those ore bodies with uneconomic stripping ratios for conventional mining. In situ biomining can be accomplished at a fraction of the cost of conventional mining and leaching and does not have the environmental liabilities associated with many conventional gold lixiviants.

Jan 1, 2004

The proximity of the Town of Kalgoorlie to the Mount Charlotte mine necessitates that charge weight per delay be limited in order to keep surface vibration levels within acceptable limits and to reduce damage to underground workings. The mining system requires that large mass blasts must be used to recover pillars and therefore a large number of separate delays are needed. Until recently all blasting has been done electrically, fired from mains, but with the introduction of large diameter blastholes (165mm diameter) this firing system was inadequate. Various firing systems were considered, but after extensive trials a non-electric sequential firing system was chosen. This system fulfilled all criteria of blast design, was relatively straight forward in charging technique and had a very simple primary initiation system. Although initially designed for large mass blasts, the non-electric firing system is now used for all large hole blasting and in a simpler form for small (57mn diameter) holes.

Jan 1, 1982

By Ovchinnikov YN, Novikov VS, Spirin NA, Babushkin NM, Mysik AF, Shcherbatskii VB, Kukarkin AS

Laboratory investigations were carried out to determine the resistance coefficient of the flow through beds irrigated with wetting and non-wetting liquids. A formula was obtained which may be used to evaluate the resistance of the irrigated packing. Quantitative investigations were also carried out on operating furnaces at Magnitogorsk. Continuous measurements of the lower pressure drops were made under different furnace conditions. Pressures were measured in the tuyere space and the bosh region. A significant transient behaviour of the pressure drop was observed in the irrigated zone as a function of the accumulation of the liquid phase in the bosh region as smelting progressed. Additionally, transient processes were also investigated in the upper furnace zones. The basic cause of the transient behaviour was shown to be the irregularity of burden descent caused by the casting cycle. It was shown that the rate of burden descent between consecutive casts reflects fairly accurately the accumulation and drainage of the liquid products as a result of which heat transfer, reduction and aerodynamic processes assume transient character. In practically all cases of casting a decrease in blast pressure and that over the furnace height of 0.2 kg/cm2 was observed. The analyses of radial gas composition at the stock line showed that compositional variations connected with the casting cycle are most pronounced in the central and peripheral regions, whilst in the intermediate regions the conditions are relatively stable. Calculations show that as casting progresses there is a decrease in the gas flow rate at the periphery and an increase in the centre of the furnace. The transient nature of the aerodynamic processes in packings revealed the existence of an appreciable reserve capacity. Elimination of transience was tested on the furnace at Magnitogorsk and improved operating and economical furnace parameters obtained.

Jan 1, 1975

By J Pearce, R Ramanathan

hortly after the World Health Organization declared COVID-19 a pandemic, the words ‘social distancing’ entered the global lexicon. The effects on the public of social distancing, lockdowns and travel bans are well documented. They also present unique challenges to the mining industry. For Hexagon’s Mining division, this posed a significant challenge. We have built our business – our reputation – on regional, customer-focused service and support. True to Hexagon’s values of being professional, engaged and customer-focused, we innovated to overcome the distance dilemma. Making automation a reality for our customers by implementing and supporting technology projects from a distance has helped deepen partnerships by making it easier to tap into our global experts’ knowledge. For example: • Body cameras were at the heart of a successful safety installation at a mine in Ghana. Despite the pandemic lockdown preventing travel by our South Africa staff into Ghana, the project was completed with minimal delays. • Traditionally, implementation and training for our Blast Movement Technology solution is done physically at the mine site. With COVID-19 travel restrictions in place, we have developed and successfully employed a remote deployment methodology. • Using RealWearTM headsets in the field and utilising the knowledge management platform from HINDSITE, Hexagon workshop technicians have been able to support hardware repairs in local offices, which once would have been undertaken in our overseas offices. • The same headset is being utilised to provide clients with remote mentoring sessions by our skilled team members who are based in our regional locations and unable to travel to their site without extensive quarantine commitments. • In instances where our team members have had to travel to site, we have provided consumer technology such as VR headsets to help them cope with long periods of quarantine to and from site. Post-pandemic, Hexagon will continue to refine and improve this method of working. INTRODUCTION Shortly after the World Health Organization (WHO) declared COVID-19 (COVID) a pandemic, the words ‘social distancing’ entered the global lexicon. As governments, healthcare organisations and the public scrambled to respond to the crisis, one thing became abundantly clear: isolation was and, for most of us, still is the key to maintaining our health. Hexagon, a leader in sensor, software and autonomous solutions, was well positioned to pivot and assist in the global response to the crisis. From simulations of the effects of social distancing to mapping the spread of COVID in real time, to drone technology delivering COVID tests, to providing communities with transparent geospatial information, Hexagon solutions continue to help ensure that innovation is readily available to those who need it most during uncertain times. The effects on the public of social distancing, lockdowns and travel bans are well documented. They also present unique challenges to the mining industry.

Jun 22, 2022

By D J. Williams, E M. Rykaart

Soil cover systems are routinely used to reduce acid rock drainage (ARD) from mine waste rock dumps and tailings impoundments. A technology for the analysis, design, instrumentation and monitoring of barrier-type (oxygen limiting) and store/release-type covers has rapidly developed and the number of covers under construction has grown extensively during the past ten years. Mine operators are currently investing in this relatively new technology with the expectation that these covers will reduce long-term liability with respect to acid generation, drainage and treatment costs. While the design life for cover systems may extend into hundreds of years, we have less than ten years of construction experience and proven performance. Some cover designs appear to be functioning well; however, the performance of many more is now being called into question. The paper presented herein evaluates the integrity of cover systems from a global perspective. Soil cover systems for the control of ARD are being constructed at mine sites located within high rainfall equatorial regions, deserts ranging from low to high latitude, humid temperate regions, and cold-continental climates. While the technology for analysis and design of soil cover systems is well developed, factors that compromise the performance of cover systems (in addition to the paramount issue of climate) relate to material selection and availability, cost and construction practices. Long-term performance is also strongly affected by physical stability (ie erosion), volume change (ie cracking, desiccation, settlement and freeze/thaw cycling), vegetation, soil evolution and ecological stability. This paper provides a review of the application of soil cover systems for the control of ARD. Cases where cover systems have been constructed with both success and failure are illustrated. General criteria and recommendations for cover selection, design, construction, and maintenance are provided.

Jan 1, 2003