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Due to the reduction in frictional resistance, the characteristics of joint infill have a major role to play on rock mass instability. This paper elucidates the laboratory behaviour of graphite infilled joints based on a large-scale shear apparatus under constant normal stiffness (CNS). Discontinuities in a graphite mine have been simulated using high strength gypsum plaster, with the joints infilled with compressed graphite layers. The Fourier series was employed to characterize the joint surface, and the method of using the Fourier coefficients for the prediction of dilation and normal stress with displacement is explained. Die Charateristik von Verbindungsfüllungen hat einen wichtigen Einfluss auf Felsmassenstabilität aufgrund der Verringerung des Reibwiderstandes. Diese Veröffentlichung untersucht das Verhalten von Graphit gefüllten Verbindungen im Labormaßstab mit einer Methode die auf einem gross-umfang Apparateprinzip unter konstanter Normal-Steifheit beruht. Unregelmässigkeiten in einer Graphit Mine wurden mit Gypsum Gips von hoher Festigkeit simuliert, die Verbindungen wurden mit kompressierten Graphitschichten gefüllt. Fourier Reihen wurden angewandt um die Verbindungs Fläche zu Characterisieren. Die Methode die verwendet wurde um die Ausdehnung und Normalkraft mit der Verschiebung mit Hilfe von Fourierkoeffizienten zu bestimmen wird beschrieben. Due à diminution des résistances par frottements, les caractéristiques des joints de remplissage joue un rôle majeur sur les instabilités de la roche. Cet article étudie le comportement en laboratoire des joints de remplissage en graphite à partir d’un dispositif de friction à grande échelle sous rigidité normale constante. Les discontinuités dans une mine de graphite ont été simulées grâce à un plâtre à haute teneur en gypse, dont les joints ont été remplis de couches de graphite compressées. La caractérisation de la surface des joints a été réalisée avec les séries de Fourier. La méthode utilisant le coefficient de Fourrier pour la prédiction de la dilatation et de la compression en fonction du déplacement est également expliquée.

Jan 1, 2003

By John R. Hawley

"This paper is intended as a review of the progress that has been made in the Province of Ontario in the field of acid drainage waste treatment technology.Three years ago, at the Third Annual Meeting of the Canadian Mineral Processors, we presented a paper entitled ""The Problem of Acid Mine Drainage in Ontario"". At that time I was working for the Ontario Water Resources Commission. The paper turned out to be the very beginning of the Commission's acid mine drainage control program. In the intervening three years, the Ontario Water Resources Commission has been amalgamated with other government groups and has evolved into the present Ontario Ministry of the Environment. Today the Ministry is involved in running one of the most advanced acid mine waste control programs in the world.As a part of its mining program, the Ontario Ministry of the Environment has published three major reports which deal directly and specifically with the industrial waste disposal problems that may arise at a mining operation. In order of publication, these reports are as follows:(1) ""The Problem of Acid Mine Drainage in the Province of Ontario"".This 338-page report covers all aspects of the problem of acid mine drainage and includes detailed sections on acid flow detection, acid flow chemistry and acid flow treatment.(2) ""The Use, Characteristics and Toxicity of Mine-Mill Reagents in the Province of Ontario"".This report, 244 pages in length, gives the chemistry and toxicity of nearly all of the chemicals that find common use in the Canadian mining industry. Most of the toxicity figures quoted are the result of a comprehensive bioassay program that was initiated by the Ministry."

Jan 1, 1974

By Steve Kral

After years of cutbacks, closures and layoffs, the mining industry is beginning to expand again. Metals prices are up and so is investor interest and confidence in the industry. Gold prices began to slowly move up in January2003 and finally cracked the $12.86/g ($400/oz) mark in early December. Silver, too, is up, as is copper. So the mining industry is feeling good about itself again and many companies are expanding existing mines and developing new ones. One side benefit to mining’s improved outlook is that companies are beginning to send more of their employees to industry conferences. Such was the case at the109th Northwest Mining Association meeting in Spokane, WA. The meeting was held in early December and attracted 1,100 attendees and 84 exhibiting companies. That is up from 2002’s attendance of about 900 people and 65 exhibitors. The theme was “A Partnership into the Future.”

Jan 1, 2004

By J. M. Krese

This paper gives an overview of the National REAP program emphasizing the program's current status and future plans. A brief historical review of the program will be given containing roof-fall accident trends and statistics. The latest developments in roof control technology and training as it affects the REAP program will be presented. A brief discussion concerning some effects of the implementation of the amendments to Part 75, CFR, concerning roof support is included.

Jan 1, 1988

The resource industry must prepare for the inevitable shift towards automation as an operational objective. Although this may seem like a distant concern, many mining companies and equipment manufacturers are already conducting full-scale automation trials. The necessary technology is advancing at a rapid pace yet the training of people to support it at the trade level lags far behind. Those given the responsibility of installing and maintaining automated equipment in the mining environment require a unique set of skills and knowledge. These training needs demand attention to ensure that the wider uptake of automation is sustainable and achieves its full potential.   This paper documents work undertaken by CRCMining and the Mining Industry Skills Centre towards establishing a training framework seeking to address the needs of trade level personnel tasked with the support of automation equipment. A comprehensive definition of the skills and knowledge required by the hypothetical automation-specialised tradesperson is presented. The training pathway identified for these personnel is also described. This work forms part of the Mining Industry Skills Centre's Automation Skills Formation Strategy, funded by the Queensland Department of Education and Training.

Jun 1, 2010

By M. Brozek, W. Pawlos

"The separation of raw materials in the separator with ferromagnetic liquid occurs due to differences in magnetic and gravitational properties of respective components in relation to each other and to the liquid. In the separator with wedge-shaped pole shoes and the working space axis inclined at a certain angle to the horizontal direction, the paths of grain movement at fixed separation conditions depend on its physical properties. Due to this, the levels of grains outlet from the separator working space are differentiated according to differences in their physical properties. The distance between the levels of outlets from the separator working chamber depends on magnetization of the liquid which is proportional to the liquid density, on the magnetic field intensity and the inclination angle of the separator working passage to the horizontal axis. The separation accuracy is higher the larger is the distance between the outlet levels.The paper will present the methods of visual observation and recording of movement paths of coal grains of different physical properties in the paramagnetic liquid which was the water solution of manganese chloride. The paths were recorded with a video camera in the working chamber by means of a specially constructed device, acting as a periscope, which were then transformed into digital images. Experimental movement paths were confronted to the paths obtained in a theoretical way by means of solving differential equations of movement by a numerical method, achieving good compatibility of experimental and theoretical results. The equations of movement were solved with taking into consideration the drag force, expressed by formula for laminar and dynamic conditions of motion.The course of the path of grain movement depends on grain and liquid physical properties, magnetic field intensity and inclination angle of the working space to the horizontal direction. The two latter parameters can continuously control the process of separation."

Jan 1, 2003

By Fabian Kirsch

Cyclic behaviour of axially loaded piles has been an issue since studies revealed that the capability to transfer skin friction into the ground is highly depending on the level and the number of load cycles the pile is subjected. It has been shown that degradation of skin friction due to axial cyclic loading leads to accumulating displacements and a severe reduction in pile capacity. In Germany the DIN 1054 as well as the Recommendations of the Working Group 2.1 ?Piles? of the German Geotechnical Society (EA-Pfähle) require the consideration of cyclic loading for the assessment of both the displacements and the capacity. Up to now no broadly accepted design method exists, which enables the engineer to give a reliable judgement on the pile capacity under axial cyclic loading and the displacements respectively. Instead numerous design charts make it possible to distinguish between stable and instable loading levels in order to ensure a design on the safe side. A newly developed design approach based on engineering models is presented which delivers a calculation algorithm for the remaining axial pile capacity after a defined number of load cycles to allow for the analysis of stability of the foundation. Furthermore the computation of accumulating displacements is made possible. The results are verified with pile load tests undertaken at Dunkirk, France and showed that the axial capacity after cyclic loading calculated with the newly developed design approach predicts actual capacity with an accuracy of ±20%.

Jan 1, 2011

By L. Li

The performance of microemulsified diesel and conventional diesel collectors in coal flotation was compared by flotation indicators, including combustible recovery, ash content of the clean coal, and the flotation index. An efficient separation with lower dosage was obtained using the microemulsified diesel collector. Under optimum separation conditions, the microemulsion consumption was 100 g/t less compared with diesel. The saving in diesel consumption using the microemulsion reached about 70%, disregarding the consumption of the surfactant and cosurfactant. Frothing tests showed that the frother dosage was decreased by using the microemulsion collector, because of the surfactant and cosurfactant added during preparation. The microemulsified diesel collector is superior to the conventional diesel collector in terms of diesel consumption and separation efficiency, but the selectivity requires further improvement. Keywords froth flotation, microemulsified collector, coal.

Nov 1, 2013

By C. Anderson, Mike Michaelis

Ammonium Nitrate (AN) - based commercial explosives are non-ideal explosives. This is because the chemical and physical structure is heterogeneous on a distance scale comparable to, and in many cases larger than, the reaction zone in the detonating explosive. Such systems consist of inter-molecular fuel-oxidizer systems. Attempts have been made to minimize the heterogeneous nature (inter-molecular distances) of these explosives; emulsion systems are the latest examples of these commercialized AN-based explosives which balance cost, utility and performance. This latter factor (increased performance) is a direct result of increasing the contact between oxidizer and fuel.

Jan 1, 2003

By C Haughy, F F. Pitard

Blue Mountain Minerals is a large supplier of calcium carbonate products used by various manufacturers as a major raw material. Very small amounts of free carbon in the rock can have a huge impact in carbon-sensitive applications. The marble in the deposit at Blue Mountain Minerals contains variable amounts of free carbon in the form of trace amounts of the mineral graphite.To make quality improvements, variography was used to measure the impact of non-ideal sampling practices at the Blue Mountain Minerals operations in Columbia, California in the United States. A major investment in correct sampling systems and sampling protocols was implemented over a one-year period. Subsequent variography was used to measure the improvement on the predictability of the graphite content in marble produced by the quarry and as it is processed as an acceptable raw material for extremely carbon-sensitive applications. The improvements of the sampling protocols, control of long-range changes and better knowledge of process cycles are easily noticeable on variograms when they happen to exist. The economic impacts are discussed.CITATION:Haughy, C and Pitard, F F, 2017. Use of variography to measure improvement of sampling practices for the quality control of graphite consistency in marble used for carbon-sensitive applications, in Proceedings Eighth World Conference on Sampling and Blending , pp 255–260 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Ernest Baafi

A simulation model RoadSIM using the ARENA modelling system has been developed to evaluate roadway development options for a given development panel configuration. The RoadSIM simulation system has provisions for variability/randomness in operations including cutting and loading at the face, tramming and discharge of coal to the boot end and availability of equipment. The modelling system provides a means for assessing the operational limitations of roadway development practices at a particular coalmine. It is a ?what if? tool that allows a range of equipment, configurations and operating practices to be assessed in terms of achievable advance rates and equipment utilisation. Output from the system is in the form of a dynamic visualisation as well as summary reports and detailed logs of operations over time.

Oct 1, 2009

By Steven J. Schatzel, Robert B. Krog

Frictional ignitions are defined as the ignition of a flammable mixture of methane and air that is initiated by frictional heating. Ignitions created through the addition of energy from open flames and exposed electrical circuits are not included in this analysis. Energy released in a roof fall that creates a spark and ignites a methane mixture would be considered a frictional ignition. Frictional ignitions represent the majority of all ignitions in underground coal mines. Over the study period of 1983 to 2005, a total of 1993 ignitions were reported in underground bituminous coal mines in the United States, of which 1589 were frictional ignitions. Reportable ignitions to the Mine Safety and Health Administration (MSHA) are any unintentional occurrences of flame underground regardless of duration. Frictional ignitions were reported in 155 mines and 13 states. Continuous miners represented the largest source for frictional ignitions with 1090 (68.6% of all frictional ignitions). Longwall mining operations represented the highest concentration of frictional ignitions during this study period with 1365 frictional ignitions (85.9% of all frictional ignitions). The 17 mines with the most frictional ignitions were all longwall mining operations and had 1130 frictional ignitions (307 from the shearer) that represented 71.1% of the total. In 1983, mines with frictional ignitions represented 6.9% of operating underground mines and 36.6% of total underground coal production. The percentage of operating underground mines with frictional ignitions and their total production has increased steadily and in 2005 represented 9.8% of active mines and 46.2% of underground coal production. The three coalbeds with the highest number of frictional ignitions (Blue Creek, Pittsburgh No 8, and Pocahontas No 3) had 1049 ignitions that represented 66.0% of all frictional ignitions. The three states with the highest number of frictional ignitions were Alabama (710), Virginia (247), and Pennsylvania (242) that represented 75.5% of the total. Frictional ignitions peaked in 1991 with a high of 114. In 2005, only 34 frictional ignitions were reported. If only frictional ignitions that occur at the face are considered, there have been no fatalities since 1983. Since this time, there were 33 ignitions that caused 53 workers to lose a total of 2912 working days. When including ground falls, then there have been four frictional ignitions with one incident causing two fatalities and injuring eight workers. From 1983-1991, underground productivity and the number of frictional ignitions increased. However, productivity continued to increase from 1991-2000 while total frictional ignitions fell, thereby disproving this connection between productivity and frequency of frictional ignitions. Ninety percent of all frictional ignitions occurred in underground coal mines that liberated more than 393 L/s (1.2 MMcfd million cubic feet per day) of methane through the main ventilation system. Although methane production is not the determining factor for the occurrence of frictional ignitions, it is a good indicator of the anticipated frequency.

By Yoshio Nakano

Keywords: Tannin gel, Palladium, Separation, Redox We have developed the novel recovery system of palladium from wastes, which is simple and generates little secondary waste in comparison with the conventional recovery processes, using tannin gel particles synthesized from condensed-tannin molecules. Pd is adsorbed onto the tannin gel particles through inner-sphere redox reaction mechanism: two-electron transfer from tannin gel to Pd(II) species, accompanied by ligand exchange between chloropalladium(II) complexes and tannin molecules. In addition, we propose the separation system of Pd and Au from Pd-Au mixture, which is feasible due to the difference in oxidization and reduction potential between Pd and Au species: PdCl3(H2O)? and PdCl42? are less adsorbable than Pd species containing fewer Cl, such as PdCl2(H2O)2 and PdCl (H2O)3+, while such a distinct difference between Au species is not observed.

Jan 1, 2005

By A Rorke, B Cubitt, R Beeslaar

The recent drop in the value of the South African Rand has resulted in an increased export value for South African coal and has lead to new coal reserves becoming available for mining. Very often these reserves are in close proximity to existing structures and utilities thus calling for stringent blast control measures to keep the risk of vibration, air blast and fly rock damage to a minimum.

Jan 1, 1997

By Gregory A. Johnson

Operations and Maintenance departments have long had an adversarial relationship. The widespread evolution and adoption of modern management techniques such as Reliability Centered Maintenance (RCM) and Lean Production however has driven interest in working co-operatively to optimize overall plant performance. Mining and minerals operations have long adopted RCM in maintenance, and are now adopting Lean throughout the organization. Modern management initiatives like these explicitly call for co-operation between the two disciplines of maintenance and production and many advances have been made in the realms of people and methodology. One area that has lagged behind in supporting these developments however is information systems. Enterprise Asset Management (EAM) systems in maintenance and newer Manufacturing Execution Systems (MES) in operations have not been truly integrated in the way needed. Complicated plants, different software architectures, continually changing conditions and many variables have lead to systems problems which have contributed to the maintenance/operations divide. Master data synchronization (the ?plant tree?) and integrated reporting of real-time data with transactional data are just two of the issues that are being solved by new approaches in information technology including web services and service orientated architectures. New technologies are coming on-stream to enable the final ?bridging of the gap?.

Feb 1, 2008

By N. Iverson, E. Haft, V. T. McLemore, M. Woodard, E. Owen

Present and emerging technologies are renewing interest in domestic rare earth elements (REE) production. REE deposits throughout the North American Cordilleran alkaline-igneous belt are being re-examined for their economic potential. In New Mexico, the mineral deposits found in this belt are associated with Eocene–Oligocene alkaline to calc-alkaline igneous rocks. Four areas in New Mexico have been examined for their REE potential. The chondrite-normalized REE patterns are similar for all four districts, even though different REE minerals are found. Crandallite, xenotime, bastnäsite and brookite are found in fluorite veins and carbonatites at Laughlin Peak. Bastnäsite was extracted during fluorite processing from 1954-1980 from the Gallinas Mountains, where samples as high as 8% total REE are found in fluorite veins. Other REE minerals include agardite, parasite, xenotime, and monazite. Allanite, thorite and as much as 8133 ppm total REE are found in fluorite veins in the Capitan Mountains. In the Cornudas Mountains, exploration along the outer edge of the Wind Mountain nepheline syenite laccolith and within phonolite dikes, plugs, skarns and carbonate-replacement deposits in Chess Draw contain as much as 3110 ppm TREE, hosted in eudialyte, monazite, bastnäsite, and calciocatapleiite.

Feb 1, 2023

By Scott Ellenbecker

Soon New York City will have a new train station. A tunnel project is under construction to extend Line 7 to a new station that is located near the Jacob K. Javits Con-vention Center. This is also part of the Hudson Yards redevelopment project that is intended to aid redevelop-ment of the west side of Midtown Manhattan around the Long Island Railroad?s Caemmerer Railyard. The station, or ?cavern? as it?s called by those excavating it, will be the portal for that growth. In the city, public transportation means high-rise residential proper-ties will have better access to the business district, and those outside the area will have greater access to event facilities ? two factors that are critical for development investment.

Jan 3, 2010

By Alain Blouin, Mohamad Sabsabi, Aissa Harhira, Paul Bouchard, Greg Lithgow

"The objective of this study was to demonstrate the application of Laser-Induced Breakdown Spectroscopy (LIBS) to the continuous analysis of online monitoring of Al, Mg, Ni, Mn, Si and Fe in nickel ore limonite and saprolite slurry samples. Analysis was performed on slurry samples in air at atmospheric pressure. Two pure samples of limonite and saprolite were used. Mixtures of the two samples in varying proportions were used to build calibration curves, study the influence of solid/liquid ratio, and evaluate short and long term reproducibility. The LIBS measurement of these elements is independent of the water content (from 70-85%, the range allowed by our setup). Repeatability of the measurement and long term reproducibility (from day-to-day) were below 1.2 % and 2% respectively for all the elements studied in our conditions. The results obtained showed that an industrial LIBS analyzer could provide the chemical composition of the six elements Al, Mg, Ni, Mn, Si and Fe within 1-2 minutes.IntroductionThe metal-producing industry faces the major challenge of increasing productivity, reducing costs, and maximizing benefits from existing equipment. By pyrometallurgy, metal making involves the basic steps of charging the furnace, melting the charge and refining. By hydrometallurgy, the metal refining is carried out through the dissolution of the metal by chemical reaction and electrolysis. During refining either by pyrometallurgy or hydrometallurgy, it is critical that operating parameters be adjusted and controlled so that the chemistry of the melt or the solution is within predetermined limits. Presently, the complete turnaround time for sampling, sample transfer, analysis and communication of the results to the operators is often 30 minutes or more."

Jan 1, 2016

By John E. Newby

Washington?s King County is constructing a new regional wastewater treatment facility, called Brightwater, in response to growth in the greater Seattle region. Planning conducted in the late 1950s identified the need for two regional treatment facilities. Constructed in the 1960s, these plants have served the region well. However, an eventual need for a third facility was also recognized. The Brightwater project implements the final phases of the long-term plan. The project includes a new treatment plant and an extensive conveyance system. When completed in 2010, the Brightwater facilities will treat sanitary sewer flows from growing populations living in northern King County and southern Snohomish County. The new system will fulfill commitments to provide wastewater services to local jurisdictions and sewer service providers in the King County Service Area. It will also provide more flexibility in the operation of the King County regional wastewater system. The Brightwater wastewater treatment plant will provide secondary treatment capacity using membrane bioractor technology in 2010 for 36 million gallons per day (mgd), with anticipated expansion in 2040 to 54 mgd, using membrane bioreactor technology. These capacities are for average wet-weather flows. The plant will also accommodate peak hourly flows of 130 mgd by 2010 and 170 mgd by 2040. The Brightwater Conveyance System consists of more than 8.1 km (13 miles) of tunneled influent and effluent conveyance lines, five tunnel portals/shafts, microtunneled influent and outfall connec-

Jan 1, 2007

By Robin Shepherdson

Security concerns have prompted the Department of Homeland Security to investigate the use of recording systems on all vessels holding materials used for blasting; a new regulation is expected in the near future. By measuring the strain developed in the legs of vessels with bolt-on sensors, it is possible to monitor the weight of vessel contents. Several companies make this type of sensor and recent versions give the required accuracy. This paper describes two generations of sensor, the second generation having a simpler method of installation that uses standard power and hand tools. Three types of indicator are available to monitor the material weight. 1) A simple electronic bar-graph indicator with a digital weight display. 2) A touch-screen display showing bar-graphs of multiple silos with digital weight displays plus their associated trend graphs, recent readings and an alarm log. 3) A data acquisition unit which acquires the weight digitally from up to 32 vessels and stores the raw and filtered date and time stamped data in a local computer database. This local computer then transmits the data via an Internet connection to a secure central database which allows the weights of all the storage vessels for a company to be viewed anytime and anywhere via the Internet. Historical trend graphs can be viewed and the data can be uploaded into an Excel file for further processing; for example to determine filling or discharge amounts. In addition, E-mail and SMS (Short Message Service) text alerts can be sent automatically when selected alarm levels are reached. Current research and development includes connection of vessels to the central database by a cellular wireless modem when a local computer or Internet connection is not available, as well as connection of remotely located vessels to a central point via “Wi-Fi bridge" radio data links. Future versions will include digital I/O (Inputs and Outputs) to record, for example, activation of filling and discharge devices as well as opening and closing of doors.

Jan 1, 2015