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By Rogers F. Davis

This publication has been prepared to supply manufacturers and industrial users a listing of mobile diesel-powered equipment and subassemblies approved and certified by the Bureau of Mines for use in noncoal mines. Testing of diesel-powered equipment is one phase of the Bureau's program of health and safety that concerns approval of electrical and diesel equipment designed to prevent explosions, fires, shocks, or toxic hazards in underground mines, when such equipment is used and maintained properly. Manufacturers submit machinery and component parts to the Bureau for study of their design, safety features, and use. Equipment must pass exacting tests and must meet strict requirements established through research and experience and listed in the Bureau's permissible schedules before the Bureau approves it as permissible for safe use in mines.

Jan 1, 1963

By V. M. Troughton

Large diameter bored piles with grouted bases have been adopted for the foundations of the majority of the buildings at Canary Wharf in London's Docklands, including a deep basement car park. The piles are founded in the Thanet Sand which forms part of London's aquifer where water levels are reported to be slowly rising. A special pile test has been carried out to determine the effects of both the basement excavation and a possible long term rise in the groundwater level on the performance of base grouted piles. These effects were simulated by injecting water around the pile toe and thus reducing the vertical effective stress. In this paper the test layout and procedures are described and the results are presented. The test results showed that the reduction in pile base resistance under increased water pressures was less than predicted by conventional design methods based on vertical effective stress. The end bearing resistance was found to be proportional to the mean effective stress.

Jan 1, 1989

By Alfred Bodenlos

El presente texto señala los depósitos de plomo, zinc encontrados en la mina Huallpac, Macón, Cerro Plumisa; los cateos del área de la laguna Shagallán, Uchco, cateo del cerro Cieren y la mina Buena Casma y Mangán, pertenecientes a la Cordillera Negra, ubicado en Ancash, Perú.

Jan 1, 1958

By John W. Fredland

Many accidents occur in the mining industry as a result of the instability of material during handling and processing operations. Accidents due to dump point instability at stockpiles, and at spoil or waste piles, for example, occur with alarming frequency. Miners must be trained to be better aware of these hazards. Information on safe working procedures at stockpiles and surge piles is provided. Mine operators must review their training and operating procedures regularly to ensure that hazardous conditions are avoided.

Jan 1, 1993

The coalmining industry in most countries has, at various times, suddenly been confronted with a decrease in demand for coal. Readjustments made to reduce productive capacity to match the reduced demand for coal have often resulted in hardship to mineworkers, loss of capital investment to mineowners and loss of coal reserves. The consequences of the methods of readjustment adopted in the past have contributed to the low esteem in which coalmining has come to be regarded by a large section of the gel).eral public in many countries.Four sections of the coalmining industry, representing different periods of time, different countries, and different methods of industrial organisation have been examined:Great Britain and the U.S.A. during the inter war years, the post war European Coal and Steel Community, and post war Great Britain under the National Coal Board. An assessment has been made of the methods adopted in each case to reduce productive capacity to match a reduced demand for coal. Finally the fundamentals of the problem-as it affects the coalmining industry of any country-are considered, and possible solutions put forward.During the 1950's, surplus productive capacity was a problem in many coalmining countries, including Australia and New Zealand. As a rule no techniques are developed beforehand to solve problems introduced by a sudden decrease in demand for coal. The situation is usually tackled by a series of short term decisions based on expediency, which often in the long run only aggravate the problem.

Jan 1, 1961

By William R. Yernberg

In October 1999, Liebherr-America, Liebherr Construction and Liebherr Mining Equipment held anopen house at its Newport News, VA, plant. The open house was held to celebrate the company’s50th anniversary and to demonstrate the new TI 272mining truck. Attending the open house members of the media, vendors and company representatives from all over the world. In his introductory comments, company president Peter Eller announced Liebherr’s dedication to expanding its presence in North America. Liebherr now has 30 dealers across the United States. As part of the open house, a brief history of Liebherr was presented, beginning with its creation in1949. Liebherr engineering and sales representatives were available to answer questions.

Jan 1, 2000

By Steve Colbum

LTl’s MapStar LPS (laser positioning system) utilize both tripod mounted and hand held reflectorless distance meters. These are eye safe, easy-to-use, and specifically designed to endure the harsh environment characteristic to the mining, quarry and explosives industries. Survey data collected by the systems is digitally stored in a ruggedized data collector and then processed with a specialized, interactive software program, which can be run on any standard PC. Win Prof, the Windows-based analytical software package is used to reduce the data for generating bench face profiles, surfaces, volumes, estimating true burdens and mining ratio calculations. In addition, the software has many other built-in routines to calculate powder factors, toe shear, to map structural contacts and to predict the flyrock potential based on the Burden to Energy ratios. An extensive, built-in library of explosive’s data facilitates these calculations. It will also conform automatically to user-specified minimum and/or maximum burden in relation to the explosive energy, hole diameter and bench geometry - for both vertical and inclined holes. Numerical data can be represented in 2D or 3D to emphasize the hole-burden-face relationships.In this workshop, the MapStar LPS instruments and Win Prof analytical software will be thoroughly demonstrated. Demonstrations include equipment configuration, typical field setups and several effective survey procedures, including processing of some sample data.

Jan 1, 2000

By Floyd Smith

Based on underground observations made in .the coal mines of the Dominion Coal Company Ltd., this paper deals with the stress phenomena in the approach roads and headways and in the gob areas associated with the longwall method of total extraction. The deformation of roadways during development and the deformation of roadways during the total extraction period is delineated and presented in graphical form .. Conclusions are made as to the feasibility of the introduction of the retreat method of longwall extraction in one of the colhenes. The importance of future studies are enumerated, especially. those pertaining to the determination .of the opti.m.um sizes of protective pillars and to increasing the efficiency of the current methods of artificial roadway support.

Jan 1, 1967

By M. J. Scoble, L. M. Daneshmend, C. Hendricks

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993. An attempt is made to relate emerging technologies to education and training requirements by examining the nature of the Canadian mining industry's human resources. Particular attention is given to the trends evident in mine automation and their likely impact on instructional needs. The characteristics of "computer-aided instruction" systems are reviewed and related to the implementation and support of mine-wide monitoring and communication networks, which are seen as fundamental to the eventual automation of underground hardrock mines

Apr 1, 1994

By S. Yadav, T. G. Murthy, C. Saldana

"An experimental study has been carried out in order to study the deformation of porous brittle materials under plane strain indentation. Gypsum, which is well known model system for understanding the behaviour of soft rocks, is used in this study. The effect of wedge angle is investigated in this research through this series of experiments, using wedges of 3 different apical angles. High-speed, high-resolution images are captured using a CMOS camera during the experiment. The images obtained are analyzed using a Particle Image Velocimetry (PIV) algorithm in order to obtain the evolving velocity, strain-rate and strain fields.INTRODUCTIONThe problem of indentation, which is usually referred to in the context of hardness testing is ubiquitous as a material characterization technique for a large class of solids. Mechanical properties of materials such as yield stress, flow stress, fracture toughness, elastic moduli etc. can be related to the hardness of a given solid. The indentation problem involves a given material or solid (whose properties are to be determined) indented by a relatively harder material (indenter) allowing the solid to undergo plastic deformation, which is then related to the yield stress of the material. The problem of indentation and its variants see many applications ranging from mining and petroleum industry, infrastructure industry, manufacturing, and biomedical sectors. Indentation has been extensively studied in metals, with accurate measurement of deformation parameters, stresses and comparison with analytical solutions. On the other hand, understanding of indentation in other class of solids such as cellular solids, porous solids, rocks, and soft solids is still nascent. In case of rocks, a comprehensive understanding of the indentation problem is very crucial because of the obvious applications in mining, petroleum and infrastructure sectors. The inherent porosity, the brittle nature of the rocks, adds to the complexity of indentation in these porous brittle solids. Various theoretical models with degrees of simplifying assumptions have been proposed to study the indentation in rocks. The most common model used in the study of indentation in rocks is a cavity expansion model, wherein a blunt indenter indenting into a rock is approximated with the expansion of cylindrical or spherical cavity in an elastic-plastic material. Complementary studies in understanding fracture initiation and propagation due to indentation has been largely based on the studies of traditional brittle materials such as glass."

Jan 1, 2015

By Cintia Braga

O processo de retificação é empregado na fabricação de componentes que requerem excelente qualidade dimensional com elevado acabamento superficial. O desempenho deste processo depende muito das condições de lubri-refrigeração produzidas pelos fluidos de corte, que são utilizados para amenizar os problemas que afetam a integridade superficial das peças, como queima e danos microestruturais, e também proporcionar melhor desempenho do processo e aumento da vida útil do rebolo. Entretanto, os fluidos de corte são uma das fontes mais problemáticas na manufatura, pois são produtos nocivos ao meio ambiente e a saúde humana, e aparecem como elemento determinante para a otimização do processo de fabricação. Desta maneira, este projeto visa analisar o comportamento do fluido de corte integral comercial em comparação com formulações biodegradáveis (óleos de soja e milho) no processo de retificação cilíndrica externa de mergulho no aço ABNT 4340 temperado e revenido com dureza média de 52 HRc. A avaliação do desempenho dos fluidos consistiu na análise da integridade superficial (rugosidade, microestrutura e microdureza) e no desgaste do rebolo. Os resultados comprovaram a eficiência dos óleos vegetais e viabilidade do uso no processo de retificação, proporcionando melhoria na eficiência do processo e contribuindo para uma manufatura ecologicamente correta.

Aug 7, 2018

By D. Whittles, S. Kingman, K. Jackson, S. Bradshaw, N. Miles

The influence of microwave energy at high electric field strength on ore strength has been investigated. Two ores of varying mineralogy were treated in both multimode and single mode microwave cavities. After treatment, any change in strength relative to untreated ore was established. It was shown that in the multimode cavity reduction in strength was related to the applied power level. Results of tests carried out in the single mode cavities showed that, for both ores, reductions in ore strength > 50% could be achieved in very short periods (<1 second). Thermal stress analysis showed that the mechanism of microwave induced failure was the development of tangential stresses at the grain boundaries. It was concluded that operation at 915 MHz with high power and short residence times gives feasible scale-up possibilities.

Jan 1, 2003

By Lawrence D. Hoy, Armand Savoie, Pierre Trudel, Ghislaln Tourigny, Robert Crépeau, Lao Kheang

"Recent fluid inclusion and stable isotopic studies in the Bousquet mining district have identified spatial and temporal trends in mineralization temperatures and isotopic compositions of vein forming fluids. These studies indicate that mineralizing temperatures were lower during sterile vein formation (T=200-300°C) than during auriferous vein formation (T = 300-400°C), and that 8 80 values of minerals in sterile veins are lower by 1-3 %o than in associated auriferous veins. In addition to these small differences in 8 80 within individual mineralized zones, a trend of increasing 8 80 values of vein minerals is identified from west to east across the district, with 8 80 of vein minerals increasing by4-6%o. Quantitative evaluation of potential causes of the observed oxygen isotopic shifts suggests that the best explanation for these trends is the derivation of the mineralizing fluids from an isotopically inhomogeneous terrain in which the fluid isotopic compositions are controlled by the isotopic compositions of the host lithologies due to high rock/water ratios in these source terrains. This inhomogeneous source terrain is interpreted as consisting of the Blake River Group volcanics (low 8 80 component) and the adjoining Kewagama and Cadillac Group sediments (high 8 80 component).The genesis of the hydrothermal fluids is attributed to crustal heating during metamorphism, with the fluids representing metamorphic dewatering products and/or fluids incorporated during deposition and burial of the host lithologies. Ductile deformation of the fluid source regions impeded fluid migration during metamorphism; the ultimate release of the mineralizing fluids is attributed to the penetration to depth of vertical structures (fault and shear zones) during brittle deformation of the crust under waning metamorphic conditions. Release of fluids caused by this puncturing of the closed hydrologic source regime produced a localized zone of lowered pressure, drawing fluids from adjacent lithologies toward the fault zones, feeding further hydrothermal fluid upwelling. Au mineralization resulted from chemical processes related to cooling of the hydrothermal fluids and/or interaction with lithologies encountered during fluid migration; the level of crust at which Au deposition occurred likely migrated upward with the thermal anomaly caused by hydrothermal fluid upwelling, eventually reaching the level of current exploitation. Cessation of fluid flow along the vertical structures is attributed to inadequate recharge of the hydrothermal systems as fluid contents were depleted in the lithologies proximal to the vertical structures and/or sealing of the structures by mineral deposition."

Jan 1, 1990

By M. Rebolledo, N. Mora, G. Zarate

For decades, the mining industry has been focussed to find an efficient and economically attractive process for the leaching of chalcopyrite. Jetti Resources has developed a novel hydrometallurgical alternative to extract metals of value from mineral ores that the mining industry has struggled to process. Jetti’s catalytic technology, whilst being especially advantaged for extracting copper from low-grade and highly refractory minerals, such as chalcopyrite, seamlessly integrates with existing heap leaching methods and downstream processing operations. The technology uses a catalyst which weakens the metal-sulfide bond in the crystalline structure of the chalcopyrite mineral and alters the structure of the passivation layer allowing the leaching process to continue. Metallurgical test work was conducted to examine the effect of ore variability, in terms of grade and copper deportment. The results presented in this study highlight the amenability of the technology and demonstrate that it is possible to enhance leaching performance of copper primary sulfides over a wide range of copper grades, from 0.1 to 2.2%. Further, it is concluded that despite the copper grade, the tests with increasing chalcopyrite content render copper recoveries up to 4 times higher compared to the tests under non-catalyzed conditions. Jetti’s catalytic technology is currently being evaluated at larger scales, namely a commercial dump leach operation and 50-tonne crib tests. The results obtained thus far are compared to the results from conventional sulfide heap leaching tests. INTRODUCTION For decades, the mining industry has been focussed to find an efficient and economically attractive process for the leaching of chalcopyrite. Chalcopyrite (CuFeS2) is the most abundant and recalcitrant of the copper sulfides (Singer, 2017). Owing to its abundance and economic importance, it is the most demandable natural source for copper worldwide. In fact, the projected demand for copper is further expected to rise much higher beyond the current demand by the year 2020 (Panda et al., 2015). Therefore, it becomes imperative to find low intensity hydrometallurgical technologies for the extraction of copper from chalcopyrite in ores of such low-grades that are un-economic to concentrate and to augment the supply by extracting copper from ores with complex mineralogy that cannot be concentrated (Watling, 2013).

Jan 1, 2019

Throughout history, many of the world&apos;s achievements, conflicts and problems can be traced to the demand for minerals. With the rapid expansion of our industrialised society in recent years the demand for minerals has grown to such an extent that uncertainties about availability and cost have arisen, especially in the case of energy minerals.Minerals have acquired a new dimension for governments as the availability of these resources is interwoven with the ability of governments to achieve their developmental goals on national and international levels. Accordingly, the supply of minerals will increasingly be affected by social and political factors.

Jan 1, 1986

Mining steeply dipping coal seams is a difficult task in the mining industry. Prior to 1996, fully mechanized longwall mining methods along the seam strike direction were tried in China and other countries. Due to its larger coal reserve in steep seams, China made more but still limited progresses on mining in such seams than the other major coal-mining countries. In the last two decades, accelerated research efforts have been made to improve the mining technology in steeply dipping coal seams. Based on these works, a dynamic model of ?R-S-F? system under asymmetrical constrains in mining steep seam is established and the theory of strata control and hazard prevention begin to be formed. The key technologies for mining steep coal seams include: global and regional strata control methods in longwall face, methods for the longwall face machines to sustain static and dynamic loads, and flexible protection technology. These theory and technologies have been successfully applied to mining of steep coal seams of varying thickness and hardness, with hard and soft roof and floor, and with high potential of spontaneous combustion in China. In the recent years, the technology has been introduced to Russia, India, Uzbekistan and other countries where steep coal seams are mined.

Jan 1, 2012

By John C. Machisak

Injury data and experience, with related employment statistics, at coal mines in the United States for 1960 are presented in this publication under the following general sections: A General injury experience: Tables 1 to 6: Current data on number of injuries, decree of injury, frequency and severity rates, average severity, and related employment and production data by work location. B Selected injury experience: Tables 7 to 38: Current data on principal agencies of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation?s coal mines.

Jan 1, 1962

By Bruce Haldeman

Timber has been used as pile support for structures for 6,000 years. Some means of preservation of wood go back almost that far. Timber piles support all types of structures ? some are buried below the water table; others raise a home for protection from animals or a chief&apos;s home for prestige. Millions of wood piles have been driven for bridge support. Earlier piles were driven by hand then by ingeniously raised weights. Charring, animal fats and oils have been used for preservation. Coal tar creosote and other preservative methods started only in the early 1800&apos;s and give effective protection.

Jan 1, 1984

By L. Rademeyer, P. Mazzoni, C. Kubank, F. Brown

The Corridor Sands deposits of heavy mineral sands represent the largest known economic resource of titanium dioxide minerals. The West Block of Deposit 1 alone contains Measured and Indicated Mineral Resources of 1.7 billion tonnes containing 4.14 per cent ilmenite, estimated in accordance with the JORC standard, sufficient for at least the first 20 years of mining. Total mineral resources are estimated to be approximately 17 billion tonnes at 5 per cent Total Heavy Minerals (THM). Test work was undertaken on the West Block of Deposit 1 over a period of two years in order to develop the process flow sheet to bankable standards. Geological, mineralogical and metallurgical test work was integrated from a pre-feasibility stage to the full bankable stage. The process flowsheet was developed with the central objective of the production of saleable products, of consistent quality and acceptable to the respective end-markets. The aim of this paper is to describe the way in which the various challenges for the project have been addressed by using integrated geological and mineralogical information, which has resulted in the development of a complete flow sheet. The process confirmed that material within customer specifications could be produced, once various metallurgical parameters were understood. This flow sheet development progressed from laboratory test work through to full field trials at pilot plant scale on large consignments of mineralized material. The flow sheet was developed to such a standard as to be used with confidence for both engineering design and cost estimates, and to determine the recovery factors to be used in financial evaluations. Keywords: Corridor sands, Flow sheet, Pilot plant Titanium dioxide

Jan 1, 2003

By Baxter J. L

Post-tertiary training programmes have been designed and produced for geologists at different levels of understanding and expertise in the relationship between gold mineralization and shear zones. A workshop format was used as it allowed both clients and facilitators to participate in the learning process. Evaluation by facilitators and participants refined the workshop programme as an effective skills oriented learning process. The general observation is that post-tertiary training in small, interactive, practical, learning oriented groups is far better than lecture oriented short courses for developing skills based learning. The evaluation indicates that the process in post-tertiary training must include aspects which are both useful and used.

Jan 1, 1989