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This is what I term ... the graveyard end of any Conference. It's almost over. Those of you remaining are either all talked out or past the information overload stage. And some of the sensible? ones have left for more exciting field trips, or gone back to their work-site where they earn their daily crust, or headed off South to another Conference of interest to the Energy sector that is being held currently in Christchurch. But that's OK. I have a thick skin! And neither am I particularly Politically Correct! I am not a miner: I am not involved in the mining industry in a hands on way at all. I am not even an academic. I am not even too sure why I am here ... apart from the fact that I agreed to come! At various times in my life I have been a D istrict Councillor, Chairman of a Regional Council and even an MP. I am a supporter of responsible mining.  All of what I have to say is my own point of view rather than that of either the Coal Producers' Federation or the mining industry. That is not to say that we are often in agreement, but I thought I would clear that point right at the outset. And some of what I will talk about will not strictly be to the topic - it's hardly mind-bending riveting stuff. Well, is it? But obviously because you are still here you have some interest in the topic.

Jan 1, 1997

By S. H. Lorain

Mechanized dirt-moving equipment has greatly increased the scope of prospect trenching by lowering the costs and increasing the speed of such work. Where the soil covering was more than 3 or 4 feet deep, operators were quickly discouraged and abandoned surface exploration in favor of shaft sinking, drifting, or diamond drilling; wildcat trenching was seldom undertaken, even where the soil covering was thin. Although power shovels, trench diggers, and draglines are useful under special conditions, caterpillar-mounted angledozers will usually do the same type of work and have a far wider range of adaptability. They are therefore incomparably the most generally useful equipment for the purpose. Since 199 the Bureau of Mines has been engaged in a widespread search for minerals useful to the war program; this work required a great deal of pioneer exploration in areas where known outcrops were marginal or subcommercial by pre-war standards. Engineers in charge of field operations were quick to perceive the applicability of mechanized trenching on a fairly large scale, particularly in the Northwestern States, where completely exposed vein-outcrops are rare. Probably no other organization to date has done a comparable amount of angledozer prospect trenching under such a wide range of conditions. The following comments and accompanying cost tables are based on work performed chiefly in Idaho, under a variety of physical and climatic conditions. The most important applications of the angledozer for such work may be described under three heads:

Jan 1, 1944

By Vic Sterner

As cities and towns continue to grow, the need to install sewer, water, gas and other utilities becomes a necessity and the blasting of trenches for these service lines probably constitutes one of the most important forms of blasting in built-up areas. There f o re, understanding how explosives can be safely used in the most efficient manner is of prime importance. The need for protection against flyrock must be emphasized. The first consideration is that all explosive c h a rges should be located well down in the blastholes. The golden rule is to ensure that the depth of top stemming is never less than the burden on the hole. In the case of shallow holes, the minimum depth of stemming should not be less than 18 times the charge diameter, if airblast and flyrock are to be controlled. If there is a doubt, then additional cover and/or blasting mats should be used. Putting too much burden on blastholes is another possible cause of flyrock and raising ground vibration levels. Overburdening of explosive charges will also result in the blastholes not breaking to grade. This in t u rn re q u i res additional drilling of shallow holes down in the trench to achieve grade, thus further increasing the h a z a rd of flyrock .

Jan 1, 2004

By N van Aarde, B A. Moore, S van der Merwe

Frequently materials handling operations are compromised by transfer chute problems ranging from high wear rates, blockages and ineffective loading of the downstream conveyor. This paper will present the design flow implemented to overcome problems in two case studies utilising discrete element modelling incorporating material characterisation.Material testing is relevant in achieving a valid discrete element method (DEM) simulation model and subsequently a valuable design tool for transfer chute assessment and design. It is well recognised that in the current growth and demand for mineral resources, leading to ever increasing conveyor capacities associated with export terminals and mineral processing facilities that transfer chutes are a key focus point. The successful performance of the transfer chute is also dependent on operating with a ærobust rangeÆ of material flowability and handling characteristics. This requirement is crucial in accommodating mineral ores from developing resources, which are often more friable and stickier than in past decades.This paper will include details of chute installations associated with iron ore and coking coal, from the DEM simulations through to the performance of the installed and commissioned plant.CITATION:Moore, B A, van der Merwe, S and van Aarde, N, 2013. Implementation of advanced transfer chute designs, in Proceedings Iron Ore 2013 , pp 445-450 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By P. M. Wiltcher

The construction of a deep structural slurry wall in a restricted city centre location is always a challenging prospect. However, when the city is London and the site is bounded on two sides by high level canals and a main traffic highway on the third, the challenges are greater than usual. The paper discusses the design considerations required by the principal contractor to accommodate a single high level lateral support, value-engineered, bottom-up construction technique and the impact this had on the design detailing and construction of the slurry wall panels. This paper discusses the logistical challenges successfully overcome during the construction of 65,000sq ft of 40inch thick, 80ft deep structural slurry wall in the City of London. The paper reviews the benefits gained from using the state-of-the-art hydraulic grab and rotator system. Technological advances in computer instrumentation and real time monitoring were utilised to assist the grab operators in consistently delivering deviational control during excavation better than 1:200. With working space always at a premium on construction sites, the need for high quality, pre-fabricated reinforcement cages has never been greater. This paper reviews the argument for off-site fabrication of reinforcement members.

Jan 1, 2006

By W. G. Pariseau

Introduction Caverns of 50 m in linear dimension at depths below 2300 m with a life of more than 25 years are proposed for the next generation of water-filled neutrino detectors. Little precedent exists for excavations in such an extreme environment, although some guidance is available from mining experience at great depths, for example, in South Africa, in Canada and at the former Homestake Mine in the U.S.A. Unlike mining for ore, there are choices available in the construction of such caverns that may mean the difference between success and failure. These choices should be informed by rock engineering principles. Recently proposed guidelines for orientation of brick-shaped caverns where the long dimension is a small multiple of the short dimension indicate that the most favorable orientation is with the long and short dimensions parallel to major and minor preexcavation principal stresses (Pariseau, 2005). Numerical analyses at reduced strength indicate some yielding at cavern walls should be expected but that an equilibrium state is quite possible and is aided by arching the back into a spherical dome when the cavern is an empty cylinder (Tesarik and others, 2002). The same indications of stability occur with brick-shaped caverns. However, the most dangerous situation occurs during the excavation sequence to final cavern dimensions. There are any number of excavation sequences that lead to the same final cavern shape, so there is an opportunity to partially optimize the sequence with construction guidelines that minimize peak stress concentrations during construction. This contribution discusses three practical excavation sequences that lead to the same brick-shaped cavern in the strong, massive Yates formation at the Homestake Mine where considerable rock mechanics data has accumulated through the years(e.g., Pariseau, 1985, Pariseau and others, 1995) and where actual mining on the 8000 Level indicates a strong possibility of successful investment in the next generation of large, deep neutrino detectors. The main results are: (1) a favorable brick-shape is one with dimensions in the same proportion as the preexcavation principal stresses (compressionpositive), and (2) favorable orientation of the most extreme but temporary shape of excavation is also best for the construction sequence. Analysis results from a mix of Homestake Mine data and possible excavation geometry illustrate the advantages of these guidelines.

Jan 1, 2006

This Bureau of Mines report contains the proceedings of a symposium cosponsored by the Bureau of Mines and the University of North Dakota concerning utilization and technology of Western coals and lignites. The symposium, the sixth in a series, comprised 12 papers.

Jan 1, 1972

By R. C. Diehl

Coal, fly ash, and flue gas samples were analyzed for mercury (Hg) by double gold amalgamation-flameless atomic absorption spectrophotometry. The purpose of the study was to elucidate the fate of the trace mercury in the coal when the coal is burned. Samples were collected from a bench-scale 100-g/hr combustor, a 500-lb/hr combustor, and three coal-burning powerplants. In all cases mercury was found in the fly ash. The amounts ranged from about 9 to about 70 percent of the mercury in the coal that was burned.

Jan 1, 1972

By I. Liebman

Two triggered barrier systems and several extinguishing agents were tested against coal dust explosion propagating in the main entry of the Bureau of Mines Experimental Mine at Bruceton, Pa. One system used a high-pressure cylinder to propel the extinguishant; the second system used pressurized nitro-gas or Halon 1301 (CF3Br) in a low-pressure system to power the disperser. The relative efficiencies of the extinguishants were determined by compar¬ing calculated concentrations of the extinguishant clouds present in the mine during suppressing of the explosions. Results showed the following trend of increasing effectiveness: Purple-K (KHC03)<water<hybrids consisting of foam or water combined with Halon 1301<Halon alone. On a weight basis, water was two to three times as efficient as Purple-K, whereas the hybrids and Halon alone were only marginally superior to water. Maximum efficiency of an extinguishant is attained by high rates of discharge from the barrier and by minimizing the time interval between onset of discharge and flame arrival to that necessary for discharge. Both the high- and low-pressure barrier systems were demonstrated to be capable of suppressing coal dust explosions; however, because of the potential hazard of the former, the low-pressure system is considered to be the most attractive prototype.

Jan 1, 1979

By Raymond W. Henn, Kent A. Pease, Glen J. Rorison

The paper focuses on construction of a 2.55-km (8,365-ft) long, 2.4-m (8-ft)diameter storm drain tunnel in Evansville, Indiana. The tunnel was driven through saturated soft ground varying from clay to fine sand. The paper presents: an overview of design and design rational including specific EPB machine requirements; the contractor’s proposed and accepted alternative construction methods and TBM design; and construction issues and performance. Some of the key points discussed are the use of the TBM in different operational modes for alternative ground conditions, the effectiveness of dewatering systems, production rates, and issues such as surface settlements and gas.

Jan 1, 2001

By J. B. Gwiazda

S. Budirsky J.B. Gwiazda&apos;s article deals with an interesting problem that has not been studied thoroughly up to now. Gwiazda has proposed a technical solution that eliminates horizontal load imposed by the supports on the roof. That load is due to a discrepancy between the trajectories of the canopy and the overlying strata. It is true that the improved lemniscate guidance system proposed by Gwiazda could eliminate the horizontal load but, on the other hand, it would represent a higher cost of the supports, and it would complicate the already complicated mechanism of powered supports. That is why we must be convinced that the proposed improvement is actually needed. From that point of view, the following questions should be elucidated. As shown in Fig. 1, the point 0 travels along the curve a, which produces horizontal load on the roof in the direction of the coal face. As stated by Gwiazda, "such a high load is capable of destroying the roof above the support, causing rock debris to be scattered around the face." The results of our measurements carried out in coal mines of the Czechoslovak part of the Upper Silesian Coal Basin show that the convergence in the modern type of powered supports does not exceed several millimeters (not more than 10) per hour. Similar conclusions were drawn from field measurements performed in the Polish part of the Upper Silesian Coal Basin (see S. Romanowicz and H. Szopka in Proceedings, Scientific and Technical Symposium Simmex&apos;85, Katowice, Poland, pp. 73-83). The small vertical closure of the supports also induces a small horizontal displacement of the canopy. In addition to this, the transmission of forces between the roof and the canopy is influenced by the layer of debris on it, i.e., the canopy slides without imposing a greater horizontal load on the roof. This was deduced from field measurements of Voest-Alpine F 4/4500 powered supports equipped with rams instead of the common front lemniscate links (denoted as 1 in Fig. 5). In these supports, the pressurizing of the space of piston rod (1a in Fig. 5) causes the rams to close, which induces horizontal load on the roof in a direction toward the coal face. After the setting of a support unit, the pressure in the piston rod space was found to drop, frequently to zero, because the small horizontal sliding between the canopy and the debris or inside the debris caused the horizontal reaction from the roof to fall to zero, although the debris were pressurized by vertical setting load. As a consequence, there was no horizontal load imposed by the canopy on the roof. A rise of the horizontal load was recorded only after the passage of the shearer and during lowering of the adjacent units. Thorough information on the results of the aforementioned field measurement is given in the paper, "Analysis of the performance of shield powered supports installed in a thick seam," published in Mechanizacja i automatyzacja gornictwa, 1982, No. 12, pp. 38-46. An English translation of the paper is available from the author. We have deduced from our observations that horizontal load imposed by the canopy on the roof in the direction toward the coal face is useful for roof control because it limits the displacement of the immediate roof toward the gob particularly during the rise working. We came to the conclusion that horizontal load on the roof toward the coal face should be induced on purpose. Could Mr. Gwiazda prove with the results of field measurements his contrary opinion? Has the small horizontal displacement of the canopy toward the face actually had an adverse effect on the roof? As shown in Fig. 2, during the setting of a support unit, the canopy imposes a horizontal load on the roof in the direction of the gob. In this case, I share Gwiazda&apos;s opinion that the horizontal load could have an adverse effect on the roof. Nevertheless, two important circumstances were neglected - the horizontal compliance of the supports and the interaction of adjacent units. The question of the compliance was analyzed precisely by I. Krumnacker in Gluckauf-Forschungshefte, 1984, No. 5, pp. 219-223. He found that due to the clearance between the hinge pins and the eyes of the sheild and due to the elasticity of the steel structure,

Jan 1, 1987

By Robert B. Parsons

"Exploration and development of mineral resources in developing countries by Canadian-based multinational mining companies is becoming increasingly common. One problem being encountered is that the objectives of the governments of developing countries can differ from those of developed countries. These objectives are not always consistent with maximizing returns from the projects, which can create conflicts between the mining company&apos;s responsibility to its shareholders and the desire to be a good corporate citizen. This article discusses how a mining tax regime can be designed to make the social goals of a government consistent with the economic goals of the company.IntroductionAt the recent International Seminar on Mining Taxation organized by CIM and the United Nations there was considerable discussion about the role of international mining companies operating in developing countries. Not surprisingly, given the diversity of backgrounds of individuals attending the Seminar, there were different opinions about what this role should be.Government PositionRepresentatives of governments pointed out the strong desires of their countries for technology, high-level technical training of their workforce, increased employment, and development of social infrastructure. They pointed out that, to a large extent, these objectives could be more efficiently met by mining companies operating in the country than by the governments themselves. For example, a multinational mining company (""MMC"") would have extensive knowledge of the various technologies available, and would have performed a detailed evaluation of the mineral resources before choosing the most cost-efficient technology for that project. They would, therefore be in an ideal position to assist the country in importing and developing such technology. Similarly, the company could provide opportunities for hands-on training, both at the technical and managerial levels, which would otherwise be unavailable to the government."

Jan 1, 1991

By E. Fernandez

HIGH SPEED RAILWAY NETWORK Spain is a very adequate country to develop the high speed railway network thank to its geographical feature which has a 600km long radius, from Madrid- the capital that covers mostly the whole country. Therefore, the railway is a major competitor of the airline. In Spain, the new access to the north and northwest is nowadays the most important railway project which will allow a significant saving of time in the near future to the central plateau and the northern territories. Time savings as well as strict environmental considerations have been the main objective of various studies during the last decade leading to Guadarrama and Pajares tunnels as ones of the optimum solutions. Cordoba-Malaga high speed railway, the extension of the present Madrid—Sevilleline, through the Abdalajis range and the rail project to cross oriental Pyrenees between Spain and France are another two samples of large tunnels currently underway. In these four projects, the ground already encountered and to be soon encountered is highly variable, from very hard granite and gneiss in Guadarrama and Pertus to very poor argillite in Abdalajis, shale in Pajares and schist in Pertus. A number of faults are also expected. Hence, double shield hard rock TBM has been chosen. Figure 1 shows a general scheme in four projects. These four projects represent a total of 2 × 68 km of which 87 km are under DRAGADOS contracts. PROJECTS UNDERTAKEN BY DRAGADOS Guadarrama Tunnels This project is the longest twin tunnel with 28.377km, in Spain and considered one of the longest in Europe. The operating speed will be 300 km/h. This tunnel will link Madrid and the north territories through Guadarrama range. (Figure 2). The south portal is placed at el. 997.8m above the sea level. The tunnel starts with an inclination of 3‰, increasing until 15‰. After 6,620m length, the tunnel passes under the Morcuera ridge with an overburden of 960m. After 13,400m length, the elevation is 1,024m which is the highest point, and then the tunnel declines with a slope of 9.5‰, 2‰ and 19‰ until the north portal in Segovia province. At the border of Madrid and Segovia that is Penalara peak, the maximum

Jan 1, 2005

Atlas Copco Wagner launched its ST1010 Scooptram load haul dumper. The ST1010 replaces the company’s Wagner ST-1000 Scooptram. The improvements to the Wagner ST1010 include increased reliability, ease of maintenance and driver comfort or ergonomics. The ST1010 has been redesigned and has added several new features and options not offered in the earlier model. These include anew boom design with side stops. Heavy reinforcements to the bogie offer better protection against the harsh working conditions in underground mining and tunneling. An auto lube system has also been added as has paint-on grip tread to reduce slips and falls during maintenance checks or repair work. Other features include a heavy-duty, auxiliary-fan motor, an isolated transverter, remote diagnostic pressure taps, a bolt-on battery box, raised air-intake, improved fuel-filter access for easier maintenance, larger wear-bars around the engine tub, and smaller, higher output batteries

Jan 1, 2000

By R. Al-Hent, M. Aissa, J. Asfahani

"This paper focuses on determining the favorable geological and hydrogeological conditions for forming uranium occurrences in the Froqlos-Jabal Abou Rabah region, Palmyrides, Syria. Eighty rock samples from this area were analyzed by spectrometric gamma-ray technique to determine the radioactive concentrations of eU and eTh, and of %K. Uranium concentrations in shallow and deep groundwaters were also determined. High uranium concentrations were registered owing to the presence of phosphatic outcrops in the study region. The uranium migration trends and its remobilization were analyzed through the analysis of the behavior of eU, eTh, and their ratio. A positive relationship between eU and eU/eTh, and a negative relationship between eTh and eU/eTh in geological formations of different ages supports the secondary remobilization of uranium. The role of groundwater movement in transportation and redeposition of uranium mineralization is discussed: deep waters are less oxidizing than near-surface waters, and do not appear to have significantly remobilized uranium. This indicates that the source of secondary uranium mineralization is surficial or near surficial, and is mainly related to the leaching of outcropping phosphatic layers.Integration of the results with established radioactive and geological sections reveals four radioactive anomalous zones: north Froqlos, Kherbet Hannora, northwestern flanks of Jabal Abou Rabah (Kherbet Al-Hajar), and the northwestern limit of the Ghuntor depression. The high uranium concentration in north Froqlos is because of its original presence in the phosphate beds and extensive fracturing, which allows groundwaters to penetrate and remobilize the uranium. High uranium concentrations in the other three locations are caused by the presence of evaporites and capillary action, which draws solutions upwards and causes redeposition as surface crusts (gypcrete)."

Jan 1, 2009

A BRIEF DESCRIPTION OF TELPHER HANDLING AND BLAST FURNACE EQUIPMENT.The various sections will be described in the following order:(a) Telpher Handling and Storage Bins.(b) Blast Furnaces.(c) Slag Disposal.(d) Bullion Handling to Drossing Kettles.(e) Copper Drossing.(f) Copper Matte Furnace.(g) Bullion Delivery to Refinery.(h) Fume Handling.(a) TELPHER HANDLING.The telpher installation is an all-steel structure designed to carry out the work of assembly and delivery of charge materials to the blast furnaces.To simplify description, the primary telpher installation will be divided into three (3) sections:-No. 1 Section. 395 ft. long, running north and south, parallel to the water front, and so located that coke, which...

Jan 1, 1937

By D. Bernabe

The mine scheduling process defines a mining sequence across the life of the mine and stipulates the amount of ore, waste, and specific blocks to be mined each year so that the highest economic return can be obtained under a number of constraints. There are a number of mine scheduling software packages available. Each claims to be the best scheduler by maximizing Net Present Value (NPV) or by minimizing overall mining costs. These mine scheduling programs follow different procedures and scheduling philosophies based on either mathematical or heuristic principles. There was no study in which the mine production scheduling procedures applied by these packages were discussed and compared. This paper evaluates four open pit mine scheduling programs recently developed and compares them in order to determine if significant differences exist among them. The same input data, which consist of a 3-D block model, an economic set of parameters, and the initial surface topography for a operating copper mine in Southern Peru, was used to test each technique. The following programs were investigated with respect to their ability to optimize the NPV for the case study. 1) M821V1 Scheduler by Mintec; 2) NPV Scheduler by Earthworks; 3) Milawa Scheduler by Whittle Programming; and, 4) Fundamental Tree Scheduling Method (FTSM) developed at the Colorado School of Mines. The results from this case study demonstrate that the scheduling software packages, Mintec, Earthworks, and Whittle obtained similar NPV’s, while FTSM scheduler gave a six percent higher NPV than the other schedulers.

Jan 1, 2002

By R. S. Dean

In addition to the normal work and that pertaining to strategic minerals, the Metallurgical Division has been made responsible for carrying on major investigations in the development of processes&apos; for the treatment of low-grade domestic manganese ores that heretofore have failed to yield products suitable for the preparation of ferromanganese, an alloy essential to every ton of steel produced. These investigations are particularly important at this time because of their part in tucking this country self-sufficient with regard to manganese when the stock-piled ore becomes e exhausted and as foreign shipments of ferro-grade ore are cut off. The results indicate that there is a good probability of accomplishing this objective, while at the same time conservation may be promoted through the use of normally useless material from the large, low-grade ore deposits.

Jan 1, 1941

By B. P. Faulkner, M. Weinecke

Svedala started a development program in 1997 to develop a process to convert waste tires into valuable commodities. A review of numerous approaches revealed short-comings in the various approaches either process, mechanical, combination of factors, or trying to emphasis the production of low value products. A market study revealed that a process that could produce a good grade of carbon black would be economically feasible. This paper discusses the laboratory and pilot plant development and commercial plant design.

Jan 1, 2001

By A. R. Miller, G. Desrivières, T. MacKinnon, H. Bursey, M. C. Bétournay, B. Replogle, D. L. Barnes, P. Laliberté

"A mine production locomotive, the world’s first applied industrial fuel cell vehicle, has been designed and tested in the context of a number of proof-of-concept projects supported by the Fuelcell Propulsion Institute, an international consortium of stakeholders dedicated to facilitate the commercialization of fuel cell vehicles.The locomotive’s simple electric-powered motor and controller system was ideal to study a number of requirements related to fuel cell power application: hydrogen power plant operation, underground hydrogen use, risk and regulatory requirements, production performance versus the conventional battery- powered locomotive version under measured duty cycles and production requirements, power plant design improvements for other fuel cell vehicles, and cost benefit aspects.This article will focus on the design and testing aspects of this project which has led to successful performance demonstrations of the vehicle under surface and underground conditions at two mines. It will also present information on the creation of a safe, reliable, and efficient power plant that fulfilled its design objectives, including longer productivity time for a given vehicle fill-up."

Jan 1, 2004