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By M A. Noppé

Mining is inherently a risk-based business and risk governance is an integral part of corporate assurance and business decision-making. Mineral Resources and Ore Reserves are the key assets for a minerals company and senior management/company boards require assurance regarding the likely accuracy of estimated and reported technical information. Reviews and audits improve the level of assurance in the reliability of estimated short-term (grade control) estimates, reconciliation, Mineral Resources and Ore Reserves.Peer reviews and audits contribute not only to governance processes, but also provide valuable technical improvement opportunities, as well as mentoring and professional development guidance to those whose work is being reviewed. Technical review is particularly crucial at a time in the industry when companies are running lean or perhaps inexperienced teams, with limited technical or management oversight.Despite both industry guidance and some companies’ standards expecting or requiring reviews and/or audits of Mineral Resource and Ore Reserve generation and reporting processes, it is surprising how infrequently or ineffectively these are actually carried out. Examples of governance systems are presented, which include appropriate peer review processes that if effectively applied, can identify shortcomings in technical processes and provide timely correction to prevent, or mitigate against, erroneous outcomes.Peer reviews are ideally carried out concurrently with the preparation of data, selection of estimation procedures and validation of outputs from Mineral Resource and Ore Reserve estimation prior to the handover of results between disciplines, or the final reporting of results. Audits, on the other hand, are generally retrospective reviews by independent and/or external reviewers who rate the risks inherent with an already completed process, identifying opportunities for improvements in the future.This paper outlines the main components of peer reviews and audits, discussing how a combination of these can provide a structured and objective assurance system leading to systematic and disciplined processes to improve the effectiveness of, and confidence in, grade control, reconciliation, Mineral Resource and Ore Reserve risk management, and support good governance.CITATION:Noppé, M A, 2017. Improved assurance for Mineral Resource and Ore Reserve estimates and reporting through peer review and auditing, in Proceedings Tenth International Mining Geology Conference 2017, pp 143–148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By N Anderson

The world-class Golden Mile gold deposit in the Eastern Goldfields of Western Australia is part of the Kalgoorlie Consolidated Gold Mines (KCGM) operation, which is wholly owned by Northern Star Resources Limited. Current mining operations across the Golden Mile is dominated by the large Fimiston Open Pit, which is over 4 km long, 1 km wide and 600 m deep. It is part of a larger mineralised system that stretches over 8 km and includes the Mt Charlotte Underground Mine, which is also operated by KCGM, as well as numerous historical open pit and underground mines. This mineralised system has been continuously mined for over 125 years and is set to continue well into the future. The Golden Mile deposit is in the Norseman Wiluna Greenstone Belt which is made up of a series of mafic volcanic and sedimentary rocks that have been structurally deformed and intruded by granitic rocks. There are two main styles of mineralisation across the Golden Mile. Firstly, the Fimiston style, which consists of shear hosted Golden Mile lodes with abundant sulfides and tellurides and secondly, the Charlotte style that comprises younger stockwork veins. Fimiston style mineralisation is the primary style of mineralisation within the Fimiston Open Pit. Historically, in excess of 3500 m of underground development and over 755 stopes were mined prior to the consolidation of the area and the commencement of Fimiston Open Pit operation. Old underground workings, known as voids, are either empty or backfilled and extend to more than 1.2 km below surface. Although they are a routine part of mining operations at KCGM, voids pose a significant challenge for the geology team in terms of planning and executing exploration and grade control drilling, geological modelling, grade and tonnage estimation, drill and blast design and execution, marking up ore block designs, mining, and reconciliation. This paper will discuss the various challenges faced by the geology team due to the presence of voids, solutions used to overcome some of these challenges and the results of these activities.

Mar 22, 2022

By B Stump

Reliable particle size analysis in minerals processing plants is a critical factor to the economic return of a plant. As recovery of valuable minerals is compromised for particles outside the optimal size range, effective and reliable particle size analysis is more crucial than ever, particularly in the current upswing of the global commodities market. Inefficient particle size analysis can lead to excessive over-grinding, thereby significantly increasing energy consumption and reagent costs, whilst negatively affecting process operation, thickening capacity, water recovery and tailings disposal.Australia’s first installation of a particle size analyser in Iron Ore has been monitored with great interest by the industry. Previously, manual size sampling at Rio Tinto’s Paraburdoo fines processing plant involved off-site sample analysis, with a turnaround measured in days. The Outotec PSI® 500 particle size indicator, commissioned in July 2009, takes approximately three minutes per line at site.The paper will include details on the following:• plant description,• sampling design,• PSI® 500 analyser functionality description, and• key learnings from site.

Jul 11, 2011

By R Van Laeren, G Langerak, S Fityus, K Koosmen

Co-disposal of partly-dewatered mixed-plant rejects (MPR) from coal processing into spoil dumps is gaining favour amongst Australian coalmine operators in preference to conventional tailings disposal methods which require a tailings dam. Owing to their often low permeabilities and high degrees of saturation, MPR materials may be prone to the development of excess pore pressures when covered by spoil during routine dump advancement. The likelihood of dump failure will increase if these pore pressure regimes and the associated delay of shear strength development are not accounted for during waste dump design. To date however, little is known about these pore pressure regimes due to the complexities associated with their in situ measurement.This paper describes the in situ measurement of pore pressures in a cell of MPR placed within a coalmine spoil dump. Four vibrating wire piezometers (VWPs) were placed within a cell that was then filled with MPR and allowed to consolidate under self-weight before advancing an adjacent tiphead across the cell. The VWPs recorded the transient pore pressures during MPR placement and dump construction, and their interpretations are described within the context of laboratory measured parameters. Following analysis of the measured pore pressures, their implications on shear strength and dump design are also discussed.CITATION:Koosmen, K, Langerak, G, Simmons, J, Fityus, S and Van Laeren, R, 2015. Field measurement of transient pore pressures within co-disposed processing rejects placed in a spoil dump, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 63–72 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By T Stambolie

Mine planning processes are continuously evolving, increasing in complexity, and are required to be developed in shorter timeframes, often missing important steps in the process. Underground coal mines are also moving into more challenging environments, with the more favourable resources having been exhausted. In addition to traditional mine planning processes there is an increasing level of complexities associated with parallel systems including the preparation of Joint Ore Reserves Committee (JORC) compliant estimates (JORC, 2012 and Guidelines Review Committee, 2014) or seeking critical regulatory development consent to undertake mining. There is a clear link between geotechnical considerations and success of mining operations, and therefore it is essential that such considerations are elevated in both status and priority. It is obvious that geotechnical considerations are paramount in any mine, however it is imperative to accept that such considerations, and the collection of information relating to such, are undertaken from the onset of any mining project. CITATION:Stambolie, T, 2018. Elevating geotechnical considerations in the Australian underground coal industry and mine planning process, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 383–391 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By M D. Uttarwar, R R. Yerpude

India is the world’s third-largest producer of coal and is endowed with the fifth-largest coal reserves in the world. Surface mining straddles the entire domain of the Indian coal mining industry, yielding over 88 per cent of production. With continually rising domestic demands, it has to shoulder the responsibility of sustaining the requisite increase in coal production and chasing commensurate stripping targets. Such an ambitious task calls for the deployment of smart technologies. In such a demanding situation, cast blasting of overburden has emerged as a promising alternative for enhancing production and productivity of dragline pits.The cast blasting technique reduces stripping costs significantly as it utilises the chemical energy of explosives in place of mechanical energy to move large volumes of overburden quickly. Proper application of cast blasting not only reduces overall mining costs but also increases coal production. This paper investigates and evaluates the potential of the cast blasting technique, with special reference to dragline pits employing the rehandle method of extended bench. The economic feasibility of the technique is also ensured under different scenarios so that considerable benefits would accrue to the individual surface coalmines. To underline the efficacy of the technique, different cast blasting models have been formulated under a range of operational and economic scenarios that resemble present day practices in India. In order to test for economic variability in the application of the technique, a risk analysis of all the formulated cast blasting models is performed using net present value.CITATION:Uttarwar, M D and Yerpude, R R, 2015. Potential of the overburden cast blasting technique in Indian surface coalmines – a modular approach and its financial implications, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 655–664 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By B Murphy

Safescape Laddertube provides an improved system for emergency egress in ventilation shafts. The addition of Laddertube in a rise has very little impact on ventilation flow, studies have indicated that the difference in flow velocities are difficult to measure due to the minimal impact. Due to the size and open-ended nature of Laddertube, the air velocity inside and out of the Laddertube is mostly linear. Laddertube can be used either permanently or during an emergency as a secondary ventilation duct. One project involved a 385 m ladder installed in a surface return air raise that could be made to bypass the primary circuit and supply fresh air to a sea container fresh air base at the bottom of the raise. Laddertube has been designed to be installed to any feasible length and can be fitted with a climb assist system ensuring enhanced speed and reduced fatigue during ascent. The climb assist used in association with Laddertube is a Tractelift system which applies a weight relief of up to 36 kg off the climber’s body weight when using the ladder. This system has successfully been tested for ladders up to 600 m in length and is currently in use for a ladder of 185 m length. The use of refuge chambers in underground coalmines has long been a contentious issue due to the concern that while it may provide temporary shelter, the risk of being exposed to high heat or the inability for rescuers to access them due to fire or explosive atmosphere means that they may be effectively trapped. The additional application for coal environments includes Laddertube installed alongside a refuge chamber concealed behind a blast proof door ensuring a secondary means of emergency egress. In certain operations designs may allow for this chamber to be provided withpositive pressure fresh air.

Oct 12, 2022

By M McGrory, A Rodolfo, J Paredes, L E. Manguba, K A Villaspir, G Webb, R Setiagani, H Cardenas

"OceanaGold’s Didipio operation has been in operation for three years. Integral to the flow sheet design is a flash flotation circuit treating a portion of cyclone underflow, consisting of an Outotec SK-500 flash rougher and an Outotec TC10 flash cleaner and a SB-2500 falcon treating flash rougher concentrate to recover fine free gold.Flash copper recovery has been holding steady at 60 per cent, while flash gold recovery at 50 per cent. Gold recovery from the gravity circuit is 22 per cent, bringing the overall flash plus gravity gold recovery to 72 per cent.Operation of the flash rougher is mainly by pulp level control. Control of copper grade in the flash cleaner is mainly controlled by air inflow and flash cleaner pulp level control drives copper recovery. Gold recovery around the circuit is mainly driven by gold head grade.SB-2500 concentrate is scalped with a 250 micron screen with the coarse fraction reporting to a SB-250 falcon, concentrate of which combines with the screen fine fraction to a Gemini table.Citation:Cardenas, H, McGrory, M, Webb, G, Paredes, J, Setiagani, R, Villaspir, K A, Manguba, L E and Rodolfo, A, 2016. Didipio Flash Flotation and Gravity Recovery Circuit, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 123–126 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Beer G

The recent re-emergence of an Integral Pressure Stripping system which operates with both cell and column in closed circuit at elevated temperature and pressure, requires no cyanide in the eluate solution and has greatly reduced carbon reactivation requirements in seen as a progressive step in this area. Several of these re-configured IPS systems have been placed in service in Australia and overseas in the last three years, with the first of the new generation units constructed and commissioned by Como Engineers Pty. Ltd. at Mt. Fisher in the East Murchison of W.A. in September 1987. This plant was relocated to a new ore body at Darlot W.A. in February 1989. Use is made of a data base of raw plant performance figures from both Mr. Fisher and Darlot and its performance compared with other operating plants. Initial commissioning difficulties of the Mt. Fisher prototype and dis- cussed together with the modifications and operational procedures required to overcome these problems. Stripping times of less than 6 hours at 145 degrees have been achieved with barren carbon values less than l O ppm from loaded carbon values above 3000 ppm and with cell pass efficiencies reaching 90 per cent.

Jan 1, 1991

By B Roache

Ground support installation into the face of development headings has become an accepted practice at many Australian hard rock mines. Ground support is installed in the development face to reduce personnel exposure to rockfall while conducting work tasks such as marking up, installing lifter tubes, charging, and face sampling. The ground support system installed in the face is typically friction bolts and mesh. This support system can be effective at reducing rockfall occurrence, but it also increases the cost of development per metre, in terms of capital for the ground support, jumbo and operator capital allocation and the installation time slowing each drill and blast cycle. Other issues associated with meshing and bolting the development face include management of rock bolts and mesh sheets in the fired dirt of every cut, damage to services such as vent duct, geometry issues when installing ground support onto irregular development profiles and operator error. Fibrecrete installation onto the development face for support is an option considered by many mines, but it can be difficult to manage due to the removal of visual indications of misfires and slowing the mining cycle due to the wait time for fibrecrete curing. The use of Thin Spray Liner (TSL) products in underground hard rock mines has been relatively infrequent in the past, mainly due to issues with cost, health and safety, and liner strength. Kanmantoo Mine investigated the use of TSLs for the purpose of development face support, while collecting data on the costs and practicalities associated with their use. Several TSL products were trialled and a preferred TSL product was selected for use as face support. Cost savings, drill and blast cycle timing improvements and other benefits were achieved while meeting the requirement to reduce rockfall risk.

Mar 29, 2023

By A R. McKinnon

The recently opened Hera Au-Pb-Zn-Ag mine in central New South Wales has provided an ideal opportunity to demonstrate the calculation of sulfide ore mineralogy using normative methods. Normative mineralogy applies a set of sequential rules based on the species likely to be present to assign the chemical components of a sample to their respective mineral components. The dominant sulfide mineral assemblage present at Hera is galena, iron-bearing sphalerite, chalcopyrite, pyrrhotite and pyrite. A normative technique for estimating the relative abundance of each of these species from drill hole, grade control and metallurgical assay data sets has been developed. This includes a process for deriving a gangue iron value and differentiating pyrrhotite from pyrite using sulfur/iron ratios. A calculated total sulfide volume value has been utilised at the mine to improve interpretation of lode boundaries. Normative drill hole values have also been used for domaining within the orebody, with large scale mineralogical trends evident. Dry bulk density (BD) values calculated using a normative species-weighted method show good correlation with measured BD values (R2 = 0.895) and are a significant improvement on the Pb+Zn+Cu regression method (R2 = 0.646) previously used. Application of these calculations to identify errors in assay databases is demonstrated, with specific reference to the data set for the nearby Nymagee copper deposit. Validation of block model grades is also explored and a method to improve resource estimates using direct normative mineral interpolation is proposed. The integration of the normative data into the production and metallurgical data sets at Hera is described and the relationship of the normative minerals to other economic elements such as gold and silver is discussed.CITATION:McKinnon, A R, 2017. Application of normative ore mineralogy to geological and metallurgical data sets at the Hera Au-Pb-Zn-Ag mine, New South Wales, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 63–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Hoffmann CF

Thermal conditions at depths of several k.i'-.r.,etres in hydrothermal systems are a major (actor controlling gold transport into the epithermal environment. Understanding of the coupling of thermal, metal and ligand (HZZ S) sources in the root zones of hydrothermal systems therefore becomes important for the application of tectonic and igneous petrochem- ical studies to regional scale precious metal exploration. The evaluation of favourable conditions in this source zone and application to explor- ation rests on a detailed knowledge of the gases, H2S, CO2 hydrocarbons and other trace components preserved in fluid inclusions. Recent developments in analytical techniques now permit examination of these components and the recognition of complex hydrocarbons in rluid inclusions from epithermal and other lydrothermal systems appears promising for ieoosit-source correlation.

Jan 1, 1987

Strip mining offers the advantages of high productivity from both human and capital resources as well as high rates of production. Experience suggests that it will be advantageous to extend strip mining to the maximum pos- sible depth in order to minimize costs and maximize the recovery of the in situ coal reserves. Highwall and spoilheap stability pose significant problems. Deep working in strip mines is likely to produce a change from methods which are based upon the elevation of material followed by dumping, to methods involving elevation and horizontal transport. There is considerable scope for optimizing the types of machines and minimizing the amount of double handling.

Jan 1, 1975

By R M. Krek

The haulage system used to convey ore from an underground mine to a surface stockpile at the mine process plant is a vital component of the mine’s overall infrastructure and economic viability. The system selected has a significant impact on the set-up of the mine and the access to the underground mine. In turn, the set-up of the mine and the access to the underground mine have a significant impact on the system.A number of haulage technologies are available to transfer the ore from the underground workings to the surface stockpile, including hoists, conveyors, rail and trucks.This paper focuses on the shaft hoisting and inclined conveyor haulage technologies. These technologies have been used consistently to deliver ore from at depth and/or at high tonnage. Previous reviews of the appropriate vertical haulage systems have nominally been restricted to the respective systems only, with no consideration for any other scope or issues that may affect the selection. The selection of the appropriate vertical haulage system, whether shaft hoisting or inclined conveying, needs to consider numerous key factors.CITATION:Krek, R M and Northcote, A E A, 2014. A holistic viewpoint for selecting the vertical haulage system – shafts and conveyors, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 289–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By D Elmo, M Scoble, Y Liu, B Klein, J Scholar, S Nadolski

A cave-to-mill study being conducted at the New Afton block caving operation demonstrated the potential for sensor-based ore sorting equipment to reject waste and improve the grade of feed to the mill. The lack of selectivity and potential for dilution entry associated with the block cave mining method results in many caving operations having to mine and process material that is below cut-off grade at certain stages of production. Online monitoring and bulk sorting systems have the potential to alleviate this problem and improve the productivity of caving operations while reducing energy and water requirements for each tonne of concentrate produced.As part of the cave-to-mill study, the suitability of a range of sensors, such as X-ray fluorescence and induction-type sensors, to sort mine production at the New Afton mine was investigated. Results showed that the discrimination of ore and waste can potentially be carried out by implementing surficial sensors into the material handling system. The study also showed that a combination of sensor outputs could be used to identify a certain ore type so that pre-emptive changes can be made in the mill to improve beneficiation performance. Overall, the outcomes of the study on implementing sensor systems at block cave mines are considered to be of significant relevance to a number of existing and future caving operations.CITATION:Nadolski, S, Klein, B, Elmo, D, Scoble, M, Liu, Y and Scholar, J, 2016. Investigation into the implementation of sensor-based ore sorting systems at a block caving operation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By A Densten, C Gimber

Surface water management and drainage is a key aspect of mine rehabilitation and closure planning. In the authors’ experience, drainage related problems are amongst the most common forms of failure in mined landscapes. The appropriate design of surface water infrastructure is therefore a key focus of practitioners. While there is currently a trend towards distributed drainage networks and avoiding hard engineered structures, in many situations (especially for existing landforms) engineered drainage structures cannot be avoided. CITATION:Gimber, C and Densten, A, 2018. A risk-based approach to drainage design standard selection for mine rehabilitation and relinquishment, in Proceedings Life-of-Mine 2018, pp 116–118 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By L R. Sousa, M He

Rock burst is common in deep underground excavations and is characterised by a violent ejection of block rocks from excavation walls. It is critical to understand the phenomenon of rock burst and particularly the failure mechanism. Laboratory experiments are one of the ways. For that purpose, a rock burst laboratory test system was developed at the State Key Laboratory for Geomechanics and Deep Underground Engineering at the China University of Mining and Technology, Beijing. A true triaxial test system, designated the Deep Underground Rock Burst Analogue Test Machine, was developed, which can transfer a stress state from three-direction-compression on six surfaces to the compression on five surfaces with one set free. The rock burst experimental system comprises an acquisition of acoustic emission signals, a high-speed recording in order to accurately record the kinetic characteristics of rock fragments ejected during a rock burst event and the possibility of infrared thermography showing the surface temperature of the samples. In this paper, analyses of typical results from rock burst tests are presented with a description of the obtained results. The mechanisms of rock burst are illustrated, and a rock burst classification is proposed based on these laboratory tests. For the control of rock burst, the constant resistance, large deformation (CRLD) bolt or anchor is presented for accommodating the large displacement of surrounding rock masses and absorbing the impact of the sudden release of rock burst while outputting a constant resistant force in response to the external load. The CRLD bolt or anchor has had practical applications in underground mines. Finally, in situ tests performed in a tunnel at Qingshui coalmine, China, are analysed in detail.CITATION:He, M and Sousa, L R, 2014. Experiments on rock burst and its control, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 19–32 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By G Capes

A novel open stope design approach is presented that delivered improved performance in a mining area with poor ground conditions at the Olympic Dam mine. During 2019, a large open stope had an unplanned caving event resulting in the inability to extract the planned tonnes and subsequent sterilisation of nearby stopes. A design limitation was the lack of data and understanding around the alteration domain extents, the rock mass strength controls and limits, the failure modes controlling stope stability in the local area, and the use of conventional stope shapes. From the available data and failure observations, it was inferred that the dominant caving failure mode resulted from a blocky rock mass impacted by structure and alteration causing an unravelling failure mechanism. Numerical and empirical analyses were conducted to test this hypothesis and establish strength limits for design. The strength limits for the design were then used to provide a range of outcomes from which future stope design shapes such as chamfered backs could be selected. Three alternate chamfered geometries were selected to trial the innovative designs. The application of this methodology in 2020 resulted in overbreak reduction from >100 per cent in the initial caved stope to

Mar 29, 2023

By I M. Platten

Narrow reef gold deposits are generally less than 4 m in width and relatively complex geological phenomena. They often display variable geometry, attitude, continuity and internal architecture. Economic grades are mostly restricted to specific structural domain(s) and localised within discrete ore shoots that have a nuggety internal grade distribution. On account of the often extended history of geological events, the specific factors localising gold-rich domains are likely to be unique to a particular mine or even reef. These features lead to a high resource risk and require careful management during both evaluation and mining. The gross form, location and global continuity of gold reefs can generally be determined from surface diamond drilling leading to the definition of Inferred Mineral Resources. It is likely that for the definition of Indicated and Measured Mineral Resources underground development and/or close- spaced diamond drilling will be required. Understanding geometry and continuity permits the resource to be more effectively managed, lowering risk/uncertainty. This in turn will allow for well-informed financial and operational decisions. Most importantly, project expectations and milestones can be set at achievable levels.

Jan 1, 2008

By L Thorburn

In 2009, the Queensland Government developed a series of amendments to environmental authorities (EAs) for mines throughout the Fitzroy Basin in response to studies that assessed the cumulative impacts of mine water discharges in the basin. One of the key amendments was the requirement for all mines in the Fitzroy Basin to develop and implement a receiving environment monitoring program (REMP). The intent of the REMPs was to provide baseline information on the condition of the receiving environments of the mines and any impacts resulting from release of mine-affected water. Since this time, the requirement to complete a REMP has been incorporated into new or revised EAs for mines (including metalliferous mines) in other regions, as well as for other industries that discharge to natural watercourses (such as coal seam gas). This paper discusses the approaches that can be used to incorporate biological monitoring and direct toxicity assessments into REMPs. It highlights the importance of collecting biological data using sound experimental design principles to investigate whether releases resulted in environmental harm; and the use of monitoring data, coupled with direct toxicity assessments, for setting more realistic, site-specific trigger values and release limits (compared to the default guidelines such as Australian and New Zealand Environment and Conservation Council (ANZECC), which may not be appropriate to the region). Implementation of a robust REMP can maximise outcomes for both the proponents and the environment.CITATION:Thorburn, L, 2013. Receiving environment monitoring programs - making the most out of biological indicators and direct toxicity assessments for monitoring of aquatic ecosystems, in Proceedings Water in Mining 2013 , pp 143-148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013