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Anglo American Platinum practices fine grinding in its processing plants to enhance the liberation of valuable minerals. If the fine particles of valuable minerals generated during fine grinding are not recovered during the flotation process, this could significantly contribute to the overall losses. This study examines the flotability of fine moncheite (PGE mineral) particles in a controlled environment (moncheite size distribution, concentration and liberation). A barren Norite ore ground to 40% and 80% passing 53µm was spiked, with four different size fractions of moncheite (-5, -10+5, -25+10 and -53+25µm) in order to evaluate the effect of particle size on flotation. The investigation also included the effect of energy input and collector dosage on the flotation of two moncheite size fractions, namely -5µm and -10+5µm. The results showed that the moncheite particle size has a significant impact on flotation. Coarse particles (-53+25µm) showed the highest Pt flotation kinetics and overall recoveries. The -5µm size fraction of moncheite could also be recovered by flotation, however, at a lower rate compared to the other size classes investigated. The increased collector dosage of 300g/t at the finer Norite grind of 80% passing 53µm enhanced the flotation rate of the -5µm size fraction of moncheite when compared to the lower collector dosage of 150g/t. The higher energy input during laboratory flotation, at an impeller speed of 1000rpm also increased the flotation rate of the -5µm size range, however, at a lower concentrate grade, when compared to the lower impeller speed of 700rpm. More favourable Pt flotation kinetics data was obtained for the -53 +25µm size fraction of moncheite at the fine Norite grind when compared to the coarse Norite grind. Keywords: flotation, moncheite, particle size, energy input and SIBX

Sep 1, 2012

By A. Vidyadhar

Printed circuit boards (PCBs) constitute a majorpart of electrical and electronic equipment containing valuable metals such as Cu, Ni, Au, Ag, Pd, Fe, Sn, Pb, etc. The concentration of base and precious metals in PCBs is observed to be several times more than those in their respective ores. Therefore, the recycling of PCBs is necessary to recover the valuable materials. However, the ultrafine particles pose a big challenge. Removal of them is suggested prior to processing by flotation. Froth flotation is observed to be a promising technique for rejecting the plastics from the comminution product. In the present work, enrichment of ground 1.0 mm PCB powder was investigated through flotation route by varying the operating variables such as frother dosage, pulp density, air flow rate and rotational speed of the impeller. The liberation studies indicate that excellent liberation of metal values is achieved from the non-metallic constituents at -1.0 mm size and below. The particulate system is quite rich in metal value with about 23% total metal content. The non-metallic constituents such as plastics are observed to possess strong hydrophobicity while the metal particles in the pulverized mass are hydrophilic in nature. Froth flotation kinetics is studied in depth with a view to facilitate high rejection of plastics and identify optimum operating conditions for the same. A number of experiments are performed to establish the influence of the operating variables on flotation performance. The conditions for achieving higher yield of the metal-rich fraction with respect to a specified grade are discussed in the light of the experimental results. It is found that the requirement of reagents is negligible which could be a very important factor from the commercial stand point. Single-stage flotation increases the metal content from 23% to over 32% with a mass yield of around 75% and over 90% recovery of metal values. 32% of the materials in the feed could be effectively rejected in the float fraction losing less than 4% metal values. The dependence of kinetics on the process variables is also discussed. It was concluded that a high rotor speed helps in efficiently rejecting the plastics. Frother should be added to help stabilize the froth and enhance the kinetics. A moderate air flow is required while pulp density must be kept low for efficient pre-concentration. It is established that the entire -1.0 mm comminution product could be treated by flotation for generating a pre-concentrate. Keywords: printed circuit boards, recycling, froth flotation, kinetics, recovery

Sep 1, 2012

Dielectrophoresis is a separation technique that uses a non-uniform electrical field to separate particles on the basis of their permittivity. There are many areas of mineral processing that might benefit from the application of dielectrophoresis. These include: coarse removal of gangue, recovery of ultrafine particles, upgrading of flotation concentrates or simply as a laboratory analysis technique. In order to determine the potential value of dielectrophoresis to the mineral processing industry, the response of composite particles was investigated. The electrical properties of composites involve complex relationships between the shape, distribution and permittivity of the individual grains within the rock. The relationship between mineral composition and dielectrophoretic force was measured on single particles from two ore types. The results were used to populate a model that could predict the separation characteristics of the ore. The insights gained from this model separator allowed potential applications of the technology to be examined and their performance evaluated.

Sep 1, 2012

By M. Maldonado

A flotation bank is a serial arrangement of cells. How to optimally operate a bank remains a challenge. This article reviews three reported strategies: air profiling, mass-pull (froth velocity) profiling and Peak Air Recovery (PAR) profiling. These are all ways of manipulating the recovery profile down a bank, which may be the property being exploited. Mathematical analysis has shown that a flat cell-by-cell recovery profile maximizes the separation of two floatable minerals for a given target bank recovery when the relative floatability is constant down the bank. Available bank survey data are analyzed with respect to recovery profiling. Possible variations on recovery profile to minimize entrainment are discussed.

Sep 1, 2012

By B. K. Gorain

Mining of low grade deposits along with the necessity to design and operate flotation plants with high throughput presents unique metallurgical and environmental challenges that need to be addressed to reduce project risks, improve project economics and to sustain the profitability of operations over the life of a mine. Some of the key challenges include poor recovery of valuables and concentrate quality issues due to complex mineralogy, the need to use poor quality water such as brackish or sea water, reduce environmental impact from the process, integrate flotation with hydrometallurgy to maximize precious metals recovery, escalation of capital and operating costs, use of unproven technology and constant use of larger equipment, high ore variability, worldwide constraints on resource availability and an ever increasing need for reliable metallurgical input to financial models to evaluate economic viability of projects. The need to develop effective solutions to these problems in a short time frame is becoming a key to the success of any new project and for sustaining the profitability of a mining operation. An integrated multi-disciplinary approach to problem solving is crucial with the need for a more lateral thinking along with strategic partnerships and collaboration involving the right players. This paper presents some of the key findings based on experiences from a large number of challenging projects and operations focused on solving complex flotation problems Keywords: mineral processing, flotation, flotation problem solving, flotation optimization, plant design, innovation

Sep 1, 2012

By Cagri Emer

In conventional mechanical flotation cells, when the size of particles exceed a particular value, that is of the order of 100 µm for metal sulphides, the recovery of particles decline rapidly. It appears that the turbulence in the agitated vessel is sufficiently intense to rupture the forces of attraction between the particles and the bubbles, so the large particles are flung off the bubbles in the turbulent field. It has recently been suggested, that a fluidized bed would be a very favorable environment in which to contact bubbles and the particles. In a fluidized bed, particles are supported by rising flow of fluid, which separates them from each other and allows them to move freely while remaining close together. In this novel method, bubbles injected into the fluidized bed are able to rise through it, colliding with hydrophobic particles, transporting them to the top of the column where they can form a froth layer that overflows into a launder. The flow in a fluidized bed is generally slow and nonturbulent, and preliminary experiments have shown, that it is possible to collect mineral particles as large as 1 mm and coal particles as large as 5.5 mm. If the upper particle size limit can be extended, there could be significant reductions in the overall energy consumption in concentrators. Calculations show for example that if the top size for flotation could be increased from 100 µm to 400 µm, there would be a reduction in grinding energy of the order of 40%. It is therefore, important to study the mechanism of coarse particle capture in fluidized beds. In this work, the factors governing the capture rate of particles, particularly the particle and bubble size, the fluidization velocity and the superficial gas velocity have been investigated, and the results will be presented.

Sep 1, 2012

By A. Gülmez

The complex ore deposit containing fluorite, barite and bastnaesite minerals is located in Beylikova Region of Sivrihisar town of Eskisehir Province of Turkey. The ore contains 40.80% CaF2; 35.35% BaSO4; 2.01%Ce; 1.5% La; 0.39% Nd and 0.1% Th. Barite recovery from this ore by flotation of the HCl leached tailings is presented in this paper. Rare earths are recovered by leaching. The leached residue (tailings) containing fluorite and barite is subjected to froth flotation to recover barite. The effect of pH and collector concentration on the flotation of barite have been studied in this work.

Sep 1, 2012

By B W. Atkinson

Full-stream mechanised sampling apparatus, that collect a full cross-sectional increment from the complete screen discharge, will always be the preferred option for sampling screen overflows. However, the reality is that provisions for automated sampling are rarely, if ever, provided at the discharges of individual screens within beneficiation plants.Sampling from the discharge of high capacity vibrating screens, especially multi-slope screens, is subject to sampling bias, due to the stratification of the ore that occurs on the vibrating screen deck. The stratification in the vibrating bed translates to a stratified falling stream at the discharge end of the screen, typically with smaller particles at the back of the falling stream and large particles at the front of the falling stream (Figure 1).The chemical and physical characteristics of heterogeneous ore (mineral or coal) particles vary significantly with particle size. If samples do not correctly reflect the source material size distribution, they will be biased and the resulting analytical/assay data will not reflect the actual physical nor chemical characteristics of the source material.Prior published data for coal preparation research (Australian Coal Association Research Program) has demonstrated that a bias appears to exist for samples collected from high capacity multi-slope screens.A new form of sampling scoop has been developed with the aim of overcoming this issue.Bias was evaluated at a coal preparation plant by comparing the desliming screen overflow size distribution to that for æreferenceÆ coal preparation plant feed samples collected using the recognised stopped-belt technique. The study procured 20 sets of comparison samples in order to ensure statistical relevance.Two forms of sampling device were employed for the multislope screen discharge.A conventional square aperture scoop was demonstrated to exhibit a significant coarse bias, in that the resulting samples exhibited a significantly coarser size distribution compared to the reference samples. In other words it was evident that the conventional scoop æfavouredÆ material from the front of the falling stream.A new æcollapsibleÆ sample scoop was evaluated in parallel, and its samples were found to exhibit no relevant bias.CITATION:Atkinson, B W and Swanson, A R, 2012. A new method for sampling from high capacity screens, in Proceedings Sampling 2012 , pp 89-94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By R Steinhaus, D M. Frantois-Bongarton, P W. Cleary, G K. Robinson, M D. Sinnott

Multotec Process Equipment and Dominique Frantois-Bongarton have a patent for a mineral sampling device, which they call a æTrue-Belt SamplerÆ. This uses a plough, which is rotated about an axis parallel to a conveyor belt to throw material off the belt. A fixed sample cutter takes a sample from the material thrown off the belt.Discrete element modelling has been used to consider a range of plough designs, plough speeds, positions for the cutter relative to the plough, cutter apertures, cutter designs and frictional properties, prior to the building of a physical prototype. This modelling work will be discussed, both as an illustration of the role of modelling in the development of new materials-handling devices and in order to explain the likely strengths and weaknesses of this new type of sampling device.CITATION:Robinson, G K, Sinnott, M D, Cleary, P W, Steinhaus, R and Frantois-Bongarton, D M, 2012. Modelling of a ætrue-belt samplerÆ - A new device for sampling from a conveyor belt, in Proceedings Sampling 2012 , pp 33-40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By M Goers, M Almond

"The use of reverse circulation (RC) drilling for grade control sample collection was selected by the Pueblo Viejo Mine Geology department at the recommencement of the operation in 2010. This method was selected because it allows: for multi-bench drilling (60 m hole depth, four benches of mining) to aid mine planning and provide a detailed close spaced drill data comparison with the reserve model angled drill holes to optimise the drill hole interception of the vertically controlled mineralisation dry sample collection in areas of excessive surface and groundwater mining operations to commence with the long assay return period (due to the need for the samples to be shipped overseas for analysis) until the on-site laboratory is operational.To date, 118 302 m of drilling has been completed throughout the operations of two open pits: Monte Negro and Moore. Two drill rigs (contractor and site-owned and operated) with three generations of sampling systems have been used to date. Throughout the drilling a 20 per cent quality assurance, quality control (QAQC) sample check (blanks, field duplicates and standards) have been used to check the drilling and laboratories performance. In addition, a total of 1104 fines samples were collected to compare the drill chip samples collected and the fines lost with two of the sample systems used.The drilling to date has highlighted the need for a complete and coordinated system to be used before sufficient confidence in the quality of the samples collected is achieved.The complete system must be set-up and coordinated to obtain the best quality sample possible. This complete package includes: drill bit size and shape for the rock being drilled and mineralisation targeted face sampling hammers with the correctly sized hammer shrouds sample hose routing to reduce sample flow turbulence and choking blow-down valves to eliminate drill hole water that has entered the drill string during rod changes correct drilling techniques targeting sample quality a sample system that captures the fines for inclusion into the sample.These improvements can be obtained without reducing the drilling rates.The measurements required to demonstrate the improvement in the sample quality will be the focus of future work within the department.CITATION:Goers, M and Almond, M, 2012. Bit to bag - The importance of a total coordinated system in reverse circulation drilling, in Proceedings Sampling 2012, pp 65-72 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

By V Rasouli, G Cavanough, A Mokaramian

The sampling time, the costs and its quality are the three factors that determine the best method of drilling in mineral exploration. The two principal methods of reverse circulation (RC) and diamond core drilling are often used in combination by mine operators. RC is used for drilling shallow holes and in-pit grade control, and core drilling for deeper holes to identify future resources. The RC method is faster and more flexible than coring and provides virtually uncontaminated cuttings (ranges from dust to 25 mm chips) to the surface cyclone suitable for geochemical anomalies. The diamond coring produces core samples to increase the level of geological knowledge and the 3D extension and distribution of the orebody. However, both of these methods are subjected to certain limitations and inefficiencies in reaching deeper depths and drilling complex hole geometries. Examples of such shortcomings include the inability to provide enough air pressure for RC drilling and high friction between drill pipe and the hole wall in diamond core drilling.Considering that delivering large volume of reliable samples from deep zones to the surface in shortest possible time is of paramount importance in mineral exploration, and assuming that obtaining core samples over whole overburden is not always essential, then drilling small size holes as fast as possible and delivering the small chip samples to the surface would be a good alternative with several advantages over conventional drilling methods for deep hard rocks mineral exploration. As a result, the use of coiled tube (CT) drilling technology has been proposed recently for such applications. CT is a continuous length of ductile steel or composite tube stored and transported on a large reel; and allows fast drilling by eliminating the connection time and providing continuous circulation during drilling. This enables quick access to the zone of interest to collect the cuttings or obtain core samples. CT is advantageous particularly in drilling directional boreholes and multi-laterals. In this paper, feasibility of using CT delivering reliable samples is discussed for deep mineral exploration. In addition, recent developments and practices are presented that make CT a reliable drilling technology to drill cheaper, faster and deeper and to deliver more continuous and reliable data and samples from deep formations.CITATION:Mokaramian, A, Rasouli, V and Cavanough, G, 2012. Quality sampling using coiled tubing drilling in deep mineral exploration, in Proceedings Sampling 2012 , pp 73-80 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By D M. Frantois-Bongarton

Variograms can be powerful tools for the analysis and control of process streams and their sampling. Their uses and proper utilisation have been described somewhat unclearly to date, and their limitations and precautions of use are too rarely mentioned. The general meaning and properties of the variogram tool and its use in geostatistics are therefore reviewed in details to derive a critical view of its proper use for process control: what to expect from it and what it cannot deliver and which uses are illusory or potentially misleading. A summary of GyÆs seminal work accompanies this essay to put the concepts into historical perspective.CITATION:Frantois-Bongarton, D M, 2012. Review of variogram properties and remarks on its use in process control, in Proceedings Sampling 2012 , pp 175-180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By C D. Rose

"The primary objective of this paper is to demonstrate a different approach to predicting and verifying mechanical sampling system precision. Early in the year 2011 an experiment was conducted to evaluate the sampling precision being obtained by a three-stage falling-stream mechanical sampling system for coal owned and operated by Peabody Energy. This system collects samples from lots averaging approximately 14000 t being loaded onto rail cars at a flow rate averaging about 9000 t/h. In phase 1 of the experiment, a total of 60 increments were collected in a two day period at preassigned intervals using a cross-belt sampler located on a conveyor belt feeding a silo upstream of the sampling system under evaluation. Coal variability parameters were calculated from the resulting laboratory analysis data using the gauge-invariant fractal model developed by the author.Estimates of precision of the three-stage system as a function of the number of increments were calculated using the variability parameters determined in phase 1. In phase 2 of the experiment, duplicate samples of 30 lots of coal were taken by the three-stage sampling system, enabling calculations of the precision being achieved by the system. Phase 2 precision estimates are in reasonable agreement with those of phase 1. Conclusions drawn from the experiment include the following: Experimental variograms or the equivalent correlograms are essential in understanding sampling issues and for designing a sampling system to meet specific precision requirements. Consensus coal sampling standards provided by ISO and ASTM may be improved by treating all stages of a mechanical sampling system as æsamplingÆ rather than considering downstream sampling stages as æsample preparationÆ, to be treated in a separate part of the document. The coal industry would profit from use of methodology for routinely monitoring the overall measurement precision and the precision of the individual components of measurement: sampling, sample preparation and laboratory testing. This would not only give necessary credence to the measurement results but would also no doubt, lead to more efficient sampling system designs.CITATION:Rose, C D, 2012. Evaluation of precision being obtained by a three-stage sampling system for coal, in Proceedings Sampling 2012, pp 115-124 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

By D M. Frantois-Bongarton

"A few situations are first reviewed where practical shortcuts lead to acceptable solutions where none seemed to be possible. These include: The solving of many complex sampling optimisation problems with the simple approach of the worst case policy (WCP). A simple approach to single-stage sampling problems will be mentioned at continuation. In the plants, minimising the impact of border effects in incorrect samplers, so that the resulting samples are approximately correct and acceptable in practice because the bias risk attached to them is controlled. Examples are given, as well as practical tools and a general methodology.Finally, some sources of undue conservatism are reviewed with general recommendations aiming at eliminating them.CITATION:Frantois-Bongarton, D M, 2012. Practical considerations and shortcuts in sampling, in Proceedings Sampling 2012, pp 171-174 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 21, 2012

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 I T. Ross

Sampling drawpoints in block cave mines has been a contentious issue for many years. Doubts have been expressed as to the validity of the process used at most mines. This paper outlines the sampling practice commonly in use, discusses the resulting issues associated with reconciliation and drawpoint closure decisions. The paper also looks to the future and highlights issues for some block cave mining operations currently planned to have in the order of one thousand active drawpoints. It is likely that these operations will require a new approach to drawpoint sampling. There are several potential technologies currently available although some appear to be better suited than others to replace the current approaches. CITATION:Ross, I T, 2012. Sampling in block cave mines, in Proceedings Sampling 2012 , pp 81-86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By T Baumgartl, B Richards

The association of specific plants and plant communities with soils developed over underlying superficial orebodies and mineralisation has been long recognised. It has given rise to the use of plant indicators for geobotanical exploration as a regular component of primary minerals reconnaissance where there is an undisturbed vegetation cover. That the chemical composition of indicator plants is a measure of their soil environment has further led to biogeochemical prospecting methods for minerals and its use in the mapping of underlying ore deposits. Where there is a strong surface expression of metal and metalloid anomalies, concentrations of potentially phytotoxic elements may reach a level at which they have strong selective impacts on plant populations. In such circumstances, natural selection has operated in the development of a unique flora composed of plant species and individuals with genetically-based tolerances to the stressed environment in which they continue to survive. These plants are called metallophytes. Metallophytes occur globally on all metalliferous sites, both in pristine undisturbed environments and in areas of mineral workings, ancient and modern. However, the best-developed primary metallophyte vegetation is found in the most ancient areas where there has been a long-term evolutionary impact of the underlying geology through ore weathering and dispersion of metals into the rhizosphere zone. Natural selection of metal-tolerant races of plants in these largely undisturbed areas can eventually lead to speciation and the development of an endemic regional metallophyte flora (Baker et al , 2010). Mineral wastes resulting from mining activities also allow colonisation by metal-tolerant individuals leading to the establishment of metallophyte communities. The distribution and extent of such communities is determined by regional and local factors relating to climate and substrate conditions and the availability of suitable plant resources on which natural selection can operate (Baker, 2009).The ability of metallophytes to tolerate extreme metal concentrations commends them as the optimal choice for ecological restoration of mineral wastes and metal-contaminated sites. Metallophytes have recently also spawned several novel phytotechnologies, including phytoremediation and phytomining (Chaney et al, 2000, 2005; Baker and Whiting, 2008). Action towards conserving the global metallophyte resource base is imperative because many species are under threat of extinction from new and extensive mining activities (Whiting et al, 2004). This has been identified as a priority in the Mining, Minerals and Sustainable Development (MMSD) Project of the Global Mining Initiative in 2002 but positive responses from the minerals industry have been slow. The last decade has, however, seen an ever-increasing interest in metal-tolerant and metal-accumulating plants, both from an academic standpoint and their use in revegetation and phytostabilisation (Tordoff et al, 2000; Baker and Whiting, 2008; Baker, 2009). Few studies have highlighted the need to conserve and develop these unique plants (Whiting et al , 2004). This presentation identifies future research needs for the conservation and exploitation of the global metallophyte biodiversity and its potential in sustainable mine closure. CITATION:Baumgartl, T and Richards, B, 2012. Evaporation and salt transport under variable climatic conditions, in Proceedings Life-of-Mine 2012 , pp 179-186 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By N Kawashima, R St C Smart, A M. Robertson

This paper focuses on a case study at a base metal mine located in a tropical semi-arid area of Western Australia (WA). It is demonstrated that understanding the geochemical nature of the mine tailings forms an integral part of innovative management strategies developed throughout the life-of-mine (LOM) when planning for mine closure. The tailings are currently stored at an above-ground valley fill tailings storage facility (TSF) and one option for long-term management under consideration is leaving the tailings in situ at mine closure and covering using the concept of an enhanced æstore and releaseÆ cover system.Extensive geochemical and mineralogical studies have found that the geochemical behaviour of the tailings in the TSF is significantly more benign than initially predicted. The sulfide content of the tailings is primarily pyrrhotite, which can be acid-forming, acid-neutral or acid-consuming depending on a number of factors including redox conditions. Tailings pore water at depth is pH neutral with excess alkalinity, low concentrations of dissolved metals and elevated sulfate concentration.Recent geochemical tests on tailings samples indicate that a reduction in the acid potential and a corresponding increase in the neutralising potential of the tailings, through partial removal of pyrrhotite at the ore processing stage, has the potential to further reduce the long-term risk of potential impact to the environment from any TSF seepage. The current work program investigates whether partial removal of pyrrhotite is feasible and secondly, whether this approach is necessary to produce a significantly better outcome at mine closure.CITATION:Robertson, A M, Kawashima, N, Smart, R St C and Schumann, R, 2012. Understanding tailings geochemistry - Continuous learning and innovation when planning for mine closure, in Proceedings Life-of-Mine 2012 , pp 287-292 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By A M. Lechner, S Arnold, M J. Gillespie, P D. Erskine, D R. Mulligan, A T. Fletcher, A Gordon

Mine ecological monitoring schemes are often conducted only to address compliance and in some cases do not have the sufficient statistical power or understanding of ecological systems to assess, quantitatively, the meeting of rehabilitation targets or mine impacts. Monitoring schemes for rehabilitation commonly rely on analogue sites or premining baselines (reference sites) to assess whether rehabilitation sites are ecologically similar and thus successfully rehabilitated. In the case of monitoring for mine impacts, if the impacted sites diverge from reference data, the site is considered to be impacted. Fundamental to any monitoring scheme is testing the sampling design to ensure that it can detect these differences if they are present through adequate sample sizes (ie statistical power). However, a good understanding of the ecological system is required to ensure that differences detected are ecologically significant. Modelling ecosystem properties can provide a quantitative understanding of how ecosystems change over time and space, in response to natural environmental variations and thus aid in determining significant ecological differences. Furthermore, modelling methods can be used to predict future ecosystem states. Within the ecological literature, guidelines for robust statistical monitoring designs and modelling methods exist but are not routinely being used in the mining industry. This paper uses simple examples to discuss: problems with current compliance monitoring methods; importance of robust statistical techniques; and how modelling can assist rehabilitation assessment and guide monitoring schemes. The aim of this paper is to describe general monitoring and modelling methods that could be potentially used for mine site monitoring and closure assessment. These methods are often considered by mining companies as an extra expense that provide little practical benefit, and the domain of academia; however, engaging these methods may be more cost-effective in the long-run than conducting untargeted monitoring schemes that give no confidence to regulators on whether rehabilitation criteria have been met. Furthermore, monitoring programs in mining contexts provide a good opportunity to better understand long-term ecological patterns and test the application of more rigorous modelling approaches as the life of many mines tends to be greater than ten years.CITATION:Lechner, A M, Arnold, S, Fletcher, A T, Gordon, A, Erskine, P D, Gillespie, M J and Mulligan, D R, 2012. Embracing modern ecological methods - Monitoring and modelling for mine closure, not compliance, in Proceedings Life-of-Mine 2012 , pp 25-32 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By X Li, J Wang, D Liu, Y Liu, K Hu

"Since the adoption of open-door policy 30 years ago, rapid economic growth has resulted in serious resource depletion and environmental destruction, especially in mining areas. As an urgent response to this situation, the central government and the Ministry of Land and Resources (MLR) have adjusted policies with concrete and realistic actions for halting this trend of non-sustainable mining activities in China. æGreen Mine CampaignÆ is one of the actions implemented. In 2010, MLR announced the æGreen Mine CampaignÆ, in which existing and new mines will be evaluated against the æGreen Mine Construction StandardsÆ and certified as æGreen MineÆ if complying with these standards. The standards cover five key aspects: the considerations of science-supported resource exploitation efficient resource utilisation standardised management environmental friendliness harmonious community relationship.Every year, MLR reviews ægreen minesÆ from all provinces. Thirty seven mines, including coal, metal, non-metal, gold, chemical industry and building materials mines, passed the review and were certified as green mines in 2010. In 2011, 187 out of 194 mines that participated in the review were certified as ægreen minesÆ. These mines are viewed as good examples of sustainable mining development in China.CITATION:Liu, Y, Hu, K, Li, X, Liu, Y, Liu, D and Wang, J, 2012. The green mine campaign and sustainable mining in China, in Proceedings Life-of-Mine 2012, pp 339-342 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012