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By Michael J. Sapko, William D. Monaghan, Michael A. Trevits

Mine seals are used extensively in underground coal mines to segregate mined-out areas and to isolate fire zones or underground areas that are susceptible to spontaneous combustion. Over the years, 30,000 mine seals have been erected in underground coal mines in the United States. Mine seals, along with rock dusting and ventilation, represent the fundamental means of preventing underground coal mine explosions. In this study the National Institute for Occupational Safety and Health (NIOSH) used ground penetrating radar (GPR) technology to determine if each of three test mine seals were uniformly constructed. Three mine seals representing different construction methods and materials (cast-in-place foamed cement; solid block, polyurethane foam and gravel; and wire mesh, rebar and gunite) were erected at the NIOSH Lake Lynn Laboratory’s underground mine as part of an on-going research program. The seals were imaged using GPR with 400-, 500-, 900-, and 1,000-MHz antennas. We found that variations in uniformity existed in the material for the cast-in-place foamed cement seal. Variations in uniformity also existed in the seal made from solid block, polyurethane foam and gravel. The post-processed radar records correlated closely with recovered core samples (areas of gravel and polyurethane foam, and areas containing only polyurethane foam). Finally, the radar records of the seal made of wire mesh, rebar and gunite showed the various components. The results of this work suggest that GPR could be used as a tool to evaluate mine seal characteristics and construction uniformity.

By K. Biswas, S. Iverson, S. J. Jung

Computer modeling of rock flow in ore passes is being investigated and compared using MSC Soft-ware’s Working Model 2D1 (WM2D) and Itasca Corp.’s Particle Flow Code in Two Dimensions (PFC2D). This work is being carried out by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health to determine the usefulness of computer modeling to improve ore pass design. The types of tests included pendulum tests to validate WM2D simulations and simulated single-rock drop tests in both WM2D and PFC2D to understand their contact models. Simulated rock impacts at the ore pass chute and the use of inclined ore passes and doglegs were investigated in both programs. A PFC2D simulation showed that dynamic loads at the chute gate were reduced significantly when a dogleg transition was used, and simulations in which the ore pass was inclined showed significant reductions in chute impact loads compared to simulations of a vertical ore pass. A released hang-up was simulated using PFC2D.

By J. R. Menasce

Mechanization in low-stope panels situated in hard rock infers roof support by tensile bolting to allow free passage of trackless mining equipment in the production areas. This is in sharp contrast to conventional mining, where compressive roof supports?such as timber and grout packs?have traditionally been used, up to 1.5 metres from the production face. Bolting is a hazardous operation because material is dislodged from the roof during the drilling activity. Even with temporary roof support installed, small pieces of rock are dislodged by the percussive action of the drifter. Operations with the man situated directly under the drill, during the drilling activity, are hazardous. The only way to remove the hazard is to move the man away from the machine for as much as possible throughout the complete cycle Costs associated with safety cannot be quantified, but need to form part of the decision-making process. Machine selections based on purchase and running costs alone do not justify the investment cost of mechanized bolters. The equipment selection process needs to take into account the total cost of mining as well as the human safety impact and loss of production costs from having to re-bolt roofs in a production panel to prevent falls of ground. Labour costs in mechanized low-stope bolting are between one-quarter and half the labour costs of non-mechanized bolting. This paper reviews the mechanized bolting option versus handheld bolting from a mining process and cost perspective in a hard rock, low-stope room-and-pillar mining operation in the platinum and chrome industries.

Jan 1, 2006

By S. Y. Tshipeng, A. T. Kaniki

"RÉSUMÉ La lixiviation acide d’un minerai oxydé cupro-cobaltifère en milieu non réducteur et en milieu réducteur en utilisant le Fe2+ et le métabisulfite de sodium (SMBS) a été étudiée et les résultats ont été comparés. Les tests de lixiviation ont été effectués à température ambiante, dans une pulpe à 30 % solide, avec une vitesse d’agitation de 600 tr/min, un potentiel redox de 350 mV pour les tests en milieu réducteur, et un pH de 1,8. Les tests de lixiviation avec usage du SMBS comme réducteur ont donné la meilleure cinétique de lixiviation du cuivre. Pour le cobalt, c’est l’usage du Fe2+ qui a donné la meilleure cinétique de lixiviation. L’augmentation de la dose du fer dans la solution au-delà de 5 g/L a influencé négativement les rendements de lixiviation du cuivre et du cobalt. ABSTRACT Acid leaching of a copper-cobaltiferous oxide ore in a non-reducing environment and in a reducing environment using Fe2+ and sodium metabisulfite (SMBS) was studied and the results compa¬red. The leaching tests were performed at room temperature, in a 30% solids pulp, with a shaking speed of 600 rpm, a redox potential of 350 mV for the tests performed in the reducing environment, and a pH of 1.8. The leaching tests using the SMBS as a reducing agent produced the best copper leaching kinetics. As for cobalt, the best leaching kinetics was achieved using Fe2+. An increase in the amount of iron in the solution above 5 g/L negatively influenced copper and cobalt leaching yields. INTRODUCTION La République Démocratique du Congo (RDC) est un pays reconnu dans le monde pour son sous-sol qui regorge d’énormes quantités de cuivre et de cobalt (USGS, 2014; Palisade Research, 2016). La technique qui semble être la plus recommandée pour extraire à la fois le cuivre et le cobalt des minerais oxydés cupro-cobaltifères est la lixivia-tion acide en milieu réducteur. Cette technique est appliquée par la majorité des sociétés minières qui exploitent ces minerais dans l’ex-province du Katanga en RDC, à savoir: Tenke Fungurume Mining, Mutanda Mining, Kamoto Cop¬per Company, Sicomines, Gécamines, Boss Mining, Chemaf, Ruashi Mining et Somika. L’usage d’un agent réducteur est indispensable pour l’obtention d’un bon rendement de lixiviation du cobalt. En effet, plusieurs chercheurs s’accordent sur le fait que le cobalt trivalent de l’hétérogénite (CoO·2Co2O3·6H2O) est insoluble à l’action de l’acide seul; il ne devient soluble qu’après réduction en cobalt bivalent (Mwema, Mpoyo, & Kafumbila, 2002; Mulaba-Bafubiandi, Ndalamo, & Mamba, 2007; Ferron, 2008; Seo, Choi, Kim, & Tran, 2013; Stuurnam, Ndlovu, & Sibanda, 2014)."

Jan 1, 2018

By Dean Nichols, Matt Ortel

Explosive accidents in the United States have brought increased attention to emergency operation plans (EOP) at all facilities that manufacture, transport, or store hazardous materials – particularly explosive materials. Explosions are sudden, powerful, and complex events that are difficult to characterize in terms of the thermal, over pressure, and debris effects. Industry, regulatory, and public officials require emergency response planners to not only anticipate the blast effects of an explosion, but also to prepare an appropriate response.

Jan 1, 2016

By Floyd G. Anderson

This report reviews and summarizes information on prevention and suppression of dust in mining, tunneling, and quarrying published in the United States from 1961 through 1967. Unpublished pertinent data developed or assembled by the Bureau of Mines during this period also are included.

Jan 1, 1969

By M. A. Reyes, L. Yan

Heat and humidity buildup withn refuge alternatives (RAs) may expose occupants to physiological hazards such as heat stress. The Mine Safety and Health Administration (MSHA) regulations require RAs in underground coal mines to provide a lifesustaining environment for miners trapped underground when escape is impossible. RAs are required to sustain life for 96 h while maintaining an apparent temperature (AT) below 95 °F (35 °C). The National Institute for Occupational Safety and Health (NIOSH) tested a 10-person tent-type RA, a 23-person tent-type RA, and a 6-person metal-type RA in its underground coal mine facilities to investigate the thermal environment over a 96-h period. The test results showed that mine air and mine strata temperatures surrounding an RA occupied by simulated miners (SMs) increased over the 96-h test period. The test results suggest that RA manufacturers should consider this increase in temperatures when calculating and evaluating RA components during surface and laboratory tests. The findings can equip stakeholders with additional considerations for calculating the interior heat and humidity temperature profiles for occupied RAs not tested in situ.

By B. Lueger, D. Shen, M. Sedighy, R. Rand, R. Saleh, J. Cheung, M. Rifai, I. Khan, W. Sauri, D. Setianto

The world’s first active power demand stabilization system for a 3-electrode electric arc smelting furnace was commissioned at PT Vale Indonesia in December 2012 on Furnace No. 2 using an SPLC (Smart Predictive Line Controller). The SPLC technology in combination with the Furnace No. 2 rebuild and other upgrades has enabled PT Vale to increase the electrical input to the furnace by up to 20% on a stable and sustainable basis by eliminating peak powers that overload and trip out the electrical equipment, and by reducing power unbalances. The SPLC technology maintains smooth arc power using a continuously variable thyristor controlled series reactor. The SPLC compensates variations in the furnace arc with predictive changes in the circuit reactance at a speed of up to 60 times a second. The system started up quickly and has been shown to be easy to operate and maintain by PT Vale. PT Vale’s Operations Team has been testing the new system at set points of up to 90 MW on the newly re-built Furnace No. 2. Over the last 12 months, the throughput of Line 2 has increased by approximately 10% on an annual average; however, debottlenecking in other design areas of the operation is required in order to achieve 90MW operation on a sustainable basis. This outstanding success results from a combination of the furnace and other upgrades, the SPLC active power stabilization, and the skill of PT Vale in quickly adopting new technologies and maximizing the combined benefits of each technology in their operation.

Jan 1, 2014

By Leslie C. Richards

Sooner or later the potential miner of industrial minerals reaches the conclusion that of the various factors he must consider, the marketing of his product is. the most important. The sooner he realizes this the better, as successful industrial mineral producers .will confirm. Herein lies a difference between i.ndustria1 mineral mining and metal mining. Often in the latter, technical problems of mining or concentrating are equal to or even surpass those of marketing. This is not meant to imply that there are no problems in mining and beneficiation of industrial minerals, but these usually are outweighed by the problem of marketing. Recentlv. an official of a nationally known corporation :i the elecl.ro-metallurgical industry made an industrial mineral survey in the Pacific Northwest. In the course of his investigation he interviewed producers and potential producers of the various industrial minerals scheduled for use in the plant now being constructed in this area. He stated that he was interested in only three factors: namely, (1) Can your product meet our specifications? (2) Are you able to supply our tonnage requirements? and (3) What will be the delivered price? If there are several sources of supply of sufficient grade and tonnage, as is often the case in the Northwest, then the third factor becomes the important and deciding one. While industrial minerals are usually sold f.0.b. cars with the freight being paid by the buyer, it is the delivered and riot the f.0.b. price that determines the competitive position of the producer and his industrial mineral product. Unfortunately for both the consumers and producers of industrial minerals in the Northwest, the sources are generally a considerable distance from the markets. This necessitates long rail hauls, for which transportation charges make up the largest share of the delivered cost and the delivered price of the product. Is it any wonder then, that rail rates play such an important part in the marketing of industrial minerals? In order to sell his product, the producer must be able to deliver to the market at a competitive price. It must be remembered that his largest cost factor is rail transportation, and that he is limited to markets that he can reach competitively. Since the cost of rail transportation is so important, let us compare various freight rates in the Northwest and attempt to determine their influence on marketing. A study of all rates on all industrial minerals transported in this area, is beyond the scope of this paper. For the purposes of comparison, let us consider limestone (broken, crushed, or ground), and silica rock. These are widely used industrial minerals, and are carried by several different rail routes from.the sources of supply to the centers of consumption in the Pacific Northwest. Markets and Sources of Supply: Limestone has a number of uses in western Oregon and Washington. Among them are agricultural lime for the soils of the Willamette Valley and southwestern Washington; paper rock for the mills in such cities as West Linn, Oregon City, Newberg, St. Helens, and Salem, Oregon, and Camas and Everett, Wash.; chemical and metallurgical-grade limestone for the metallurgical plants centering around Portland, and the Tacoma-Seattle areas'; and sugar rock for the sugar refineries at Toppenish, Wash., and Nyssa, Oregon. Since limestone for cement manufacture is generally processed near the quarry, transportation

Jan 1, 1951

By E. M. Wise

THOUGH known as the platinum-group metal- the sextuplet, platinum, palladium, iridium. rhodium, osmium, ruthenium, might well be called the American metals or perhaps Pan-American metals, as the ore containing them eras first discovered in South America, and in recent years the largest production has come from North America. The South American alluvial deposits, which also, contain gold, are in active production, as are the alluvial platinum deposits of Alaska, but the main production is from the copper-nickel ores of Sudbury, Ontario. The Russian deposits in the Urals were the source of most of the worlds platinum for about 100 years, but since 1934 have assumed second place. For a time considerable amounts of platinum came from several rather rich deposits in South Africa but these were exhausted quickly. However, a tremendous reserve of lower-grade ore exists there, which could be worked profitably if the price of platinum were considerably higher.

Jan 1, 1942

By Charles L. Allie

Since Reserve Mining Co. began commercial operations at Silver Bay, MN, some 25 years ago, major improvements in taconite processing technology have become available. In addition, significant new government standards have been imposed on industrial operations. By implementing a $370-million modernization program, Reserve was able to accomplish two major company objectives: the quality of concentrates produced from the Peter Mitchell mine has improved, and the operation meets both present and foreseeable environmental standards. Process modifications at Reserve were designed to: •Reduce the pellet silica content from 9% to 5%; •Increase the pellet iron content from 62.5% to 65.8%; •Implement a tailings disposal system utilizing "best available technology" water quality controls; and •Reduce air emissions by installing "best available technology" air emission controls. By adding dry cobbing, fine screening, and flotation to the concentrating process, pellet silica content has been reduced; the process reclaims and reuses all process waters; all tailings are stored in a zero discharge tailings basin; and all air emission standards are being met. Initial Beneficiation at Silver Bay Reserve's Peter Mitchell mine at Babbitt, MN, is on the eastern end of the Biwabik iron formation. The open-pit mine is approximately 16 km long, 0.8 km wide, and presently has a maximum depth of about 50 m. Principal constituents of the ore body are magnetite, quartz, and iron-magnesium silicates. The company's large commercial plant began operating at Silver Bay, 75 rail km from the mine, in 1955. Facilities have historically had the capacity to process 31.5 Mt/a of taconite, containing an average 24% magnetic iron, into 11 Mt/a of iron ore pellets. Reserve's initial beneficiation process-which existed up to early 1979-consisted of two crushing stages at the Babbitt mine site, two additional crushing and screening stages at Silver Bay, grinding in a conventional rod-ball¬regrind mill circuit, size classification with cyclones, and concentration with magnetic and hydraulic separators. Concentrate produced by that circuit assayed 65% iron and 8.5% silica, with a screen analysis of 94% -44 µm, and a surface area of 9300 cm2/cm3. Pellets produced from this concentrate assayed 62.5% iron and 9% silica (dry basis). Construction began in 1977 to modify Reserve's operation. Process modifications were designed from pilot scale operations that had been operated and researched by Reserve for more than 10 years. There were two design restraints imposed on the process: economic constraints that Reserve continue to use much of the existing processes and structures in the new operation; and a substantial number of government-imposed permit constraints. In effect, the tailings process was designed first and then a concentrating process was developed that would "fit" the tailings disposal system. Operation of the modified process began in June 1980. Crushing Remains Unchanged No changes in process flow were made at either the Babbitt mine and crushing plant or at the Silver Bay fine crusher. Gyratory crushers reduce run-of-mine taconite to -90 mm-diam at the mine. Taconite is then transported to Silver Bay by intra-plant railroad. There are 10 fine crushing lines. Each consists of a double deck screen, followed by a heavy duty short head crusher, a second double deck screen, and second short head crusher. All screen undersize material bypasses the crushing lines, resulting in an open circuit crushing process. Fine crusher product is approximately 98% - 20 mm, 80% -12 mm, and 50% -10 mm in diameter. Each fine crusher line processes about 400 t/h of crude taconite. Cobbing Provides Aggregate for Tailings Dams The first major process change was the addition of dry cobbing, a dry magnetic separation step between the fine crusher and concentrator. Dry cobbing serves two major purposes in the new process. Its principal function is to provide large volumes of dry coarse aggregate for use in construction of tailings dams. This process rejects about 20% of the fine crusher product as tailings with a size analysis of 98% -20 mm and 50% - 10 mm. These tailings are free draining and have high frictional shear strengths-two key requirements for dam building aggregates. Fine crusher product is conveyed to a new dry cobbing building. Here crushed ore is discharged into one of two 30-minute capacity surge bins. Crushed ore is withdrawn by 12 constant speed conveyor belts; each discharges 500 t of crushed taconite into a dry cobbing machine. Each machine consists of a 3-m-long riffle splitter and two vari-

Jan 12, 1980

By Leslie C. Richards

The competitive position of producers of industrial minerals depends upon the delivered price of their product. Freight charges are a major factor in the sales to consumers. A comparison of freight rates on movements of limestone and silica rock in the Pacific Northwest shows a wide variance in mills per ton mile for like hauls, thereby favoring some localities over others. Introduction: Sooner or later the potential miner of industrial minerals reaches the conclusion that of the various factors he must consider, the marketing of his product is. the most important. The sooner he realizes this the better, as successful industrial mineral producers .will confirm. Herein lies a difference between i.ndustria1 mineral mining and metal mining. Often in the latter, technical problems of mining or concentrating are equal to or even surpass those of marketing. This is not meant to imply that there are no problems in mining and beneficiation of industrial minerals, but these usually are outweighed by the problem of marketing. Recentlv. an official of a nationally known corporation :i the elecl.ro-metallurgical industry made an industrial mineral survey in the Pacific Northwest. In the course of his investigation he interviewed producers and potential producers of the various industrial minerals scheduled for use in the plant now being constructed in this area. He stated that he was interested in only three factors: namely, (1) Can your product meet our specifications? (2) Are you able to supply our tonnage requirements? and (3) What will be the delivered price? If there are several sources of supply of sufficient grade and tonnage, as is often the case in the Northwest, then the third factor becomes the important and deciding one. While industrial minerals are usually sold f.0.b. cars with the freight being paid by the buyer, it is the delivered and riot the f.0.b. price that determines the competitive position of the producer and his industrial mineral product. Unfortunately for both the consumers and producers of industrial minerals in the Northwest, the sources are generally a considerable distance from the markets. This necessitates long rail hauls, for which transportation charges make up the largest share of the delivered cost and the delivered price of the product. Is it any wonder then, that rail rates play such an important part in the marketing of industrial minerals? In order to sell his product, the producer must be able to deliver to the market at a competitive price. It must be remembered that his largest cost factor is rail transportation, and that he is limited to markets that he can reach competitively. Since the cost of rail transportation is so important, let us compare various freight rates in the Northwest and attempt to determine their influence on marketing. A study of all rates on all industrial minerals transported in this area, is beyond the scope of this paper. For the purposes of comparison, let us consider limestone (broken, crushed, or ground), and silica rock. These are widely used industrial minerals, and are carried by several different rail routes from.the sources of supply to the centers of consumption in the Pacific Northwest. Markets and Sources of Supply: Limestone has a number of uses in western Oregon and Washington. Among them are agricultural lime for the soils of the Willamette Valley and southwestern Washington; paper rock for the mills in such cities as West Linn, Oregon City, Newberg, St. Helens, and Salem, Oregon, and Camas and Everett, Wash.; chemical and metallurgical-grade limestone for the metallurgical plants centering around Portland, and the Tacoma-Seattle areas'; and sugar rock for the sugar refineries at Toppenish, Wash., and Nyssa, Oregon. Since limestone for cement manufacture is generally processed near the quarry, transportation

Jan 1, 1951

By Fengyu Ren, Ruslan Puscasu, Kunpeng Yu, Gideon Chitombo, Liangliang Kang

Weak rock mass and poor flow of material can cause excessive ore loss and dilution in sublevel caving. This paper proposes a method to establish design parameters for an inclined deposit within a weak rock mass and evaluates its effectiveness through a case study. In order to solve the problem of low production capacity and poor safety conditions of sublevel caving mining at the Yingfangzi silver mine in China and to ensure a smooth production from the refractory ore body, it is necessary to select appropriate stope structure parameters. Based on random medium theory of gravity flow and the improved equation of ore discharge in random medium, an end wall drawing experiment is carried out to determine the optimum design and flow parameters. It was observed from the experiment that, due to the influence of the randomness of particle movement, there is a mismatch in the flow parameter measurement. The flow characteristics and distribution of the marker particles are different from that of the tested particles resulting in large drawbody shape distortion. The study finds that the flow parameters obtained by the new method are more practical and account for drawpoint width and recommends that the new method for determining the sublevel stope height is used when the drawbody is a non-standard ellipsoid. The outcomes have shown a significant reduction in the dilution and improvement in the recovery rates, and the safety and efficiency of mining have been greatly improved.

By Don W. Deere

Faults under high rock cover represent some of the most severe ground conditions a Tunneler can encounter. High ground water pressures and flows are usually associated with mountain faults. Ground behavior can range from blocky ground to flowing sands and squeezing clays. Sticking a IBM within a fault zone for many weeks, with the disastrous financial consequences, is still a common occurrence. Interpreting the geology and detecting the location of a fault prior to penetrating it is a fundamental step to successful tunneling. Ground water control through predraining or pre-grouting is the second fundamental step. This paper discusses techniques applied for detecting and crossing mountainous fault zones through the use of case histories across the globe.

Jan 1, 2007

By H. Tomlinson

"INTR0DUCTIONThis publication is a third of a series devoted to falls of roof and coal in coal mines of the Western States. It gives the results of examinations of the mines of the Rock Springs coal District of Sweetwater County, Wyo., which represent the principal coal beds therein and approximately 75 percent of total production of the State.A study was made of safety conditions at all the producing mines of the district and suggestions were offered the operators regarding methods and practices which would, in the opinion of the writer, provide additional safeguards to prevent accidents from falls of roof and coal.In presenting the subject, consideration must be given to such features as character of the coal beds, depth of cover. methods of mining, timbering practice, roof testing and supervision, and for comparative purposes to certain statistical matter bearing upon relation of accidents to their causes, tonnage produced, men employed, days worked, and lost days due to accidents during the 3—year period covered by this study.ACKNOWLEDGMENTSThe writer acknowledges the cooperation of the officials of the various coal companies, without whose assistance this work could not have been completed.F0UR REPRESENTATIVE COAL OPERATIONSThis report relates to four representative coal operations in the Rook Springs district of Sweetwater County, Wyo., which are referred to as mines A, B, C, and D. This group employs yearly an average of 993 men, representing 37 percent of the men in coal mines of the county, and has an average annual production of 1,484,373 tons, representing approximately 44 percent of the coal produced in the county. Figure 1 is a map of the Rook Springs coal district."

May 1, 1933

By A. Fahimifar, H. Soroush

Abstract: In order to develop non-destructive methods in studying physical and mechanical properties of rock and replacing them with difficult and expensive static methods, several ultrasonic tests were carried out on cylindrical rock specimens in accordance with the ISRM suggested methods and velocity of P and S waves were determined. Also, density, porosity, water absorption, uniaxial compressive strength and indirect tensile strength were determined for each specimen in accordance with ISRM suggested methods. According to above tests static and dynamic elastic constants were calculated After statistical analysis of data obtained from tests, the relationships between velocity of elastic waves and physical or mechanical parameters were determined and some equations were obtained. Also similar analyses were performed on static and dynamic constants and some equations were extracted. Using these equations, the physical and mechanical parameters of rock and also static elastic constants can be estimated by conducting simple and quick tests (i.e. ultrasonic tests). Abriß: Um zu entwickeln, die zerstörungsfreien Methoden für Studieren die physischen und mechanischen Eigentümer von Steinen und auch ist für Ersetzen diese Methoden mit schwierigen teuren statischen Methoden, mehrere altrasonic Prüfungen auf zylindrischen Steinproben gemäß ISRM anregenden Methoden und den Geschwindigkeiten von S und P Wellen bestimmt worden sind durchgeführt worden. Außer der Dichtheit und der Porosität betonen Wasser Aufnahme und monoaxial Widerstand und dehnbaren indirekten Widerstand jeder Probe betreffend der erhaltenen Ergebnisse die atmosphärische Aufladung sind bestimmt worden und die dynamischen Faktoren der Steine sind kalkuliert worden. Nachdem statistische Analyse die Korrelation der Ergebnisse zwischen der Geschwindigkeit elastischer Wellen und mechanischer und physischer Eigentümer der Steine erhalten worden ist, und mehrere Verhältnisse sind vorgeschlagen worden. Eine ähnliche Analyse ist auf atmosphärischer Aufladung und dynamischen Faktoren durchgeführt worden und einige Verhältnisse sind erhalten worden. Mit Hilfe dieser Verhältnisse die physischen und mathematischen Eigentümer von Steinen und auch können die Statistik Faktoren durch einfachen und schnellen altrasonic Prüfungen erhalten werden. Resume: Puor le development des method non-destructive et evaluuation des propietes physical et mechanical des rock et superseding avec les methods dificzle et cher statique, c‘ est fait plusieur essayes ultrasonique sur les echantillons cylinrique et par a port le proposale TSRM et le vittesse des ondes P et S et densite et porosite et absorption des eaux le resistant de pression uniaxial et resistance de chaque echantillon est determinee. A la fin en base des resultat obtenue les constant statique et dynamique des roches sont calcule. Apres les analyses statistiquc sur les resultat obtenue du les essaybs, c‘ etait produit les relation entre les viptesse les ondes elastique et les proprietes physic et mechanicue des roches et c est propose quelque relations. Aussi le meme enterpretation sur les constant statique etdinamique. En possezon de ces relations, les spesificatio physique, aussi on peut trouver leur constant statique, avel les essayes sample et raptid a d ultrasonique.

Jan 1, 2003

By P. D?Elia

Following a study by NIOSH on the availability of teams in the U.S. as well as existing training sites and their capabilities, the Penn State University, leaders of the Pittsburgh Section of SME, providers of mine rescue equipment, and industry sponsors united to establish and make fully functional a student mine rescue team at Penn State University. With the growth of MERD and mine rescue competitive events at Missouri S&T, the Mine Training and Technology Center in PA, and at Colorado School of Mines Edgar Mine, a critical mass of effective training venues were made available to help student teams progress and develop mine rescue skills. The challenges to be met in creating and developing a student mine rescue team will be discussed. The rewards from this type of effort will be the quick capability of graduates from mining engineering programs to be involved in not only mining operations, but industry mine rescue teams and other leadership roles as well.

Jan 1, 2012

This technical note describes a problem with WANG82, a ventilation network analysis programme. The problem was highlighted by Renison Ltd when using the programme on large, complex networks. Under certain circumstances the programme produced incorrect results or failed to converge to a solution.

Jan 1, 1986

By T. Gupta, T. Ghosh

Rare earth elements (REEs) and their compounds are essential in a multitude of mundane and sophisticated applications such as renewable energy technologies, catalysts, medicine, and defense applications. The global supply deficit could be attributed to the destabilization of REE market that has, as a result, incentivized indigenous production of REEs. Cost-effective and environmentally benign opportunities are being explored for the production of REEs from non-conventional mineral sources including coal and coal by-products to stabilize the supply chain. Coal from Healy coal mine and Wishbone Hill deposits in Alaska have been quantified for REEs and were found to possess elevated total REE concentrations as compared to world average levels (60– 70 ppm). The objective of the study was to concentrate the REEs in the froth phase by froth-flotation of the fine size fraction (< 75 μm). A Box-Behnken design of experiment was employed to ascertain the main and interaction effects of operational parameters on response variable by analyzing 3D response surfaces. Experiments were carried out to maximize REE recovery and concentration by modeling and optimization of three operating variables (frother dosage, pulp density (% solids), and collector dosage). Based on the results, the optimum flotation conditions for maximum recovery at an elevated concentration of REEs in the froth fraction was obtained at 4.2% solids and 32.7 ppm of frother dosage for Healy sample and 10% solids and 37.9 ppm of frother dosage for Wishbone Hill coal sample. The quadratic relationship between the input and response variable was found to be independent of collector dosage suggesting good surface hydrophobicity and floatability of the two coal samples.

By Brandon Fryman, Josh Hoffman, Rhys Baker

A post-detonation debris collection project was led in conjunction with a large ammonium nitrate(AN) railcar detonation conducted by the Department of Homeland Security-Transportation Security Administration, Department of Defense-Combating Terrorism Technical Support Office, Sandia National Laboratories, and the U.S. Army Dugway Proving Grounds. This important work will aid in underpinning algorithms used in a Quantitative Risk Assessment (QRA) tool. The test also provided valuable data about the effects and consequences following an AN detonation. The test took place at the Utah Dugway Proving Grounds on April 27, 2018 and the debris collection was conducted the following two weeks with an average of 20 persons per day and an approximate total of 1,400 manhours. A paper was presented at the 2019 ISEE Conference on the collection efforts, challenges, and lessons learned. A complete data analysis effort was completed on the test data in 2019 that resulted in updates to the QRA Railcar Potential Explosion Site (PES)model and AN engine. The analysis included an assessment of the debris data resulting from the Derailed test. This paper is meant to serve as a summary of the analysis effort and findings and as an update to the previously presented lessons learned from the debris collection and analysis effort.