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By Steve Kral

Worker safety is an issue that transcends industries, whether it be mining, construction, manufacturing or even general office work. In the mining industry, safety and training are particularly important because mining is a dangerous occupation. Throughout the years, federal and state safety regulations have been written and revised to keep up with the changing technologies. And mine operators have installed their own safety and training programs. They have come to realize that a safe and healthy workforce has positive effects on productivity and profitability —not to mention avoiding the high costs of injury-related absenteeism.

Jan 1, 2003

By Alex Lázaro

El presente texto describe la utilzación de las herramientas de modelaje en la formación de los alumnos de la Escuela de Ingenieria de Minas. Entre los primeros cursos de formación de la especialidad de Minas está: Autocad, Topografía, etc. y entre algunas de las aplicaciones que el alumno desarrolla tenemos: la importación de puntos y líneas hacia los programas de modelamiento; la generación y análisis de taladros, a partir de los datos obtenidos en la exploración, la visualización e interpretación de la realidad, criterios de interpretación del cuerpo Geológico y el desarrollo del modelo de bloques y su análisis. Asimismo, los alumnos desarrollaron proyectos sobre modelamiento y planeamiento de operaciones mineras tales como: proyecto de modelamiento geológico y diseño de cono óptimo y el proyecto de modelamiento geológico y diseño de labores subterráneas.

Aug 25, 2002

By J. A. Theron

"This paper provides guidelines on performing mass and energy balance modelling involving coal and coal derivatives. Usually, the inputs to a pyrometallurgical process would be specified in terms of elements and compounds. Reliable thermochemical data is more widely available for species involving uniquely defined, relatively smaller molecules. However, in the case of coal, the molecules are extremely large and not uniquely defined. Consequently, modelling processes involving coal and its derivatives involve several potential pitfalls. These are outlined in the present paper.It was found that coal proximate analysis should not be regarded as absolute; it could vary with several parameters, including heating rate. For modelling, the use of ultimate analyses should be considered a preferable option to proximate analyses, where ‘fixed carbon’ and ‘volatiles’ are not defined in terms of chemical composition. Significant errors could be incurred if the larger molecules are neglected during calculation of the calorific value (CV) of coal gas (the gas liberated when coal is heated in the absence of oxygen).For elemental analysis determination, the oxygen content (which is calculated by balance) should be checked to ensure it is within the expected range. For representation of sulphur in coal, one should avoid doublecounting due to SO3 in the ash analysis.Potentially, oxygen in coal could be represented as O2, H2O, CO, or CO2.However, use of some of these species without considering the experimentally determined gross CV leads to significant errors in the energy balance. If coal enthalpy is calculated from elemental analyses without correction, representation of coal oxygen as H2O(l) gives reasonable accuracy. Coal volatiles could be represented by a complex mixture of compounds, even using different oxygen-containing species than these four, provided the enthalpy is corrected.It is recommended that an ‘enthalpy correction value’ be incorporated in energy balances involving combustion, devolatilization, or conversion of coal and coal derivatives, e.g. coke, char, or tar. That would imply that proximate analysis, elemental analysis, as well as the gross CV would be required for all solid or liquid coal-derived substances being modelled. No other correction due to carbon being present in a form other than graphite should be used, as that would imply double-counting some effects."

Jan 1, 2015

Analysis of Electrostatic Separation for Rutile Cleaning Duty Using a Plate Electrode Assisted High Tension Roll Separator A plate assisted electrostatic high tension roll separator has been used for the removal of impurity mineral grains from a rutile rich product stream. A laboratory study and a subsequent production study explored the effect of machine conditions with a view to the optimisation of the separation performance of the separator. The performance requirement was that the TiO2 grade in the non-conductor stream was to be less than ten per cent whilst at the same time the ZrO2 grade in the conductor stream had to be less than 0.5 per cent at mass recoveries of greater than 90 per cent to the conductor stream and less than 5 per cent to the non-conductor stream. Mineralogy data was utilized to determine the feasibility of achieving the production targets with the feed under study. Since the feed stream mineralogy was dominated by rutile, leucoxene and zircon, it was possible to use an approximation to the actual mineral assemblage as well as the raw X-ray fluorescence data to understand the separation duty of the Carrara machine. Since there were four conflicting criteria used for the performance requirement, an index was devised that incorporated all the requirements simultaneously. This new index was the sum of the squares of the difference between the achieved and desired values, weighted with respect to the variance of each variable. If the desired value for a particular criterion had been met its contribution to the sum was set to zero, no matter how well the criterion had been met. For the production machine the strict requirements were almost achieved. As expected, the achievement of the target performance was dependent of the feed conditions at the time of measurement. This paper reports the results of this study.

Sep 13, 2010

By Heithecker R. E.

In June 1933 the Bureau of Mines, in cooperation with the State of Oklahoma and the Oklahoma City Chamber of Commerce,, published a report of the gas reserves in the Oklahoma City oil field3/ based upon data as of October 1932, at which time there were 43 classified gas wells in the field, The estimates were obtained by the ?porosity-area" method. There are two general methods of estimating natural-gas reserves. The porosity-area method, as used by Hill and Rawlins, is used when a gas field is comparatively new but after enough drilling has been done to determine the average thickness, porosity, and areal extent of the producing horizon. The "pressure-volume? method of estimating gas reserves, the method used in this report, may be used after a sufficient volume of gas has bean withdrawn from the reservoir to cause an appreciable decline in reservoir pressure.

Jan 1, 1937

By R. E. Heithecker

In June 1933 the Bureau of Mines, in cooperation with the State of Oklahoma and the Oklahoma City Chamber of Commerce, published a report of the gas at reserves in the Oklahoma City oil field3/ based upon data as of October 1932, at which time there were 43 classified gas wells in the field, The estimates were obtained by the ?porosity-area" method. There are two general methods of estimating natural-gas reserves. The porosity-area method, as used by Hill and Rawlins, is used when a gas field is comparatively new but after enough drilling has been done to determine the average thickness, porosity, and areal extent of the producing horizon. The "pressure-volume? method of estimating gas reserves, the method used in this report, nay be used after a sufficient volume of gas has bean withdrawn from the reservoir to cause an appreciable decline in reservoir pressure.

Jan 1, 1937

By Carlos Soria

El presente texto describe los Sistemas de Gerencia de la Información y su aplicación en la industria minera con el objetivo de optimizar la gestión total de la empresa. Dichos sistemas manejan información del proceso y sus valores de producción, cálculos, consumos de energia, emisiones de plantas, tiempos de funcionamiento de equipos, eventos, alarmas, mediciones de laboratorio y control estadístico, etc. De forma que dicha información pueda ser reunida y consolidada, convirtiéndose en materia de significado y relevancia disponible en base a análisis, reportes, listas, tendencias y gráficos para que el usuario final de una planta o en sus oficina pueda tomar mejores decisiones.

Jul 17, 2000

In the minerals industry allocating capital for setting up a new project or for upgrading an existing facility usually requires that a compromise be found between the initial cost of equipment, its operating performance and on-going operating costs. To maximise the return on the investment usually requires that various possible combinations and layouts of equipment be assessed. This task is both difficult and time consuming. Computer simulation can be used as a means of determining the expected operating performance of a range of alternate equipment configurations. Simulation is a particularly important technique for analysis as it is one of the few approaches that allows the analyst to take into account the variability inherent in a mining process. While computer simulation is a well established technique its use, until recent years, has been limited to large organisations with access to substantial computing facilities. However, with the current availability of low cost computing platforms combined with easily understood animated displays, simulation is now becoming more widely used across the industry.

Jan 1, 1990

By David L. Shearer

INTRODUCTON James Howden first secured an order for two Service Tunnel Boring machines in November 1986. These Tunnel Boring machines were 5.7 and 5.4 metres in diameter and the full length including back up was 215 metres. Manufacture commenced in December 1986 at the Glasgow factories of James Howden & Company with the deliveries to site of the machines in September 1987 and March 1988 respectively. In December 1987 two further orders were secured for the land running tunnels at 8.7 metres diameter. This paper presents some of the challenges in building tunnel boring machines for the Eurotunnel project between Britain and France. The general specifications of the Tunnel Boring machines and length of drives are shown in Appendix 1. DESIGN PARAMETERS The specification given by the Consortium TML on behalf of their client Eurotunnel cleary indicated that cutting of the face should be concurrent with the building of the precast concrete lining rings. In order to do this a telescopic machine was thought to be the best solution. Ground conditions were described as chalk marls of homogeneous nature with the possibility of friable areas and some revelling. A shielded type TBM with open cutter head was chosen together with a telescopic section and a rear

Jan 1, 1989

By S. L. Crouch

An important class of mining problems involves excavations in planar seam or vein-type deposits. In many instances it can be assumed that the seam is at 'infinite' depth in a homogeneous, isotropic or transversely isotropic, linearly elastic rock mss, and that the normal to the plane of the seam is a principal stress direction. Rational planning of excavations in such deposits requires a knowledge; of the stresses and displacements induced by complicated, irregular excavation geometries in the plane of the seam. This problem previously has been solved either numerically or by means of an electrical resistance network analog. Both of these methods effectively simulate the mined portions of the seam as a dislocation in an otherwise continuous mass, and determine the complete solution in terms of the stresses and displacements at the seam. In both cases, the plane of the seam is divided into a number - say, M x N - of squares, and the solution to the problem is determined in terms of the solution to an M x N system of equations. The numerical approach requires that these equations be solved explicitly, while the analog; solves them instantaneously with current analogous to stress and voltage to displacement. A purely numerical solution of practical problems can require a substantial amount of computer time, particularly in situations that demand some sort of sequential analysis, either due to successive mining or to nonlinear behavior of the seam material. This report describes a combined analog-digital computer system for solving problems that are impractical when either device is used separately. The digital computer and the analog are interfaced so that the digital computer can receive information from the analog via a switching matrix and an analog to digital converter, and can activate points of the analog via another switching matrix and a set of digital to analog converters. The resulting hybrid system can be used to simulate arbitrary "stress-strain" characteristics for any portion of the seam by an iterative procedure similar to the initial strain method used in nonlinear finite element analysis. Thus, the hybrid system combines the speed of analog computation with the decision-making capability of the digital computer: the analog instantaneously solves the set of equations, and the digital computer decides how the initial strains must be altered for the solution to be compatible with the prescribed "stress-strain" characteristics for the seam material. The hybrid computer system has many implications for rational planning of underground excavations, since it allows practically any type of inelastic seam behavior or artificial support characteristics to be simulated. Inelastic seam behavior, for example, might be due to either rock failure or to time-dependent deformation.

Jan 1, 1974

By David L. Bickel

The following instructions and descriptions are presented in two parts to assist an individual to make the borehole deformation gage transducer, and to assemble and test the three-component borehole deformation gage. This Bureau 8 of Mines three-component borehole deformation gage (4, 8, 11)2 fits in a 1-1/2-in-diameter borehole that is drilled in rock and then overcored to determine rock stress.

Jan 1, 1978

By Driver R. C, Moelle K. H R

This paper is dedicated to the memory of our friend Peter McKenzie who contributed much to the knowledge of the New South Wales Coalfields.ABSTRACTA fossil river system was recently mapped over parts of the Southern Coalfield, N.S.W. This river system occurs in the roof strata of the Bulli Seam. Sandstone of a fluvial nature was deposited in its course. The sandstone exhibits strong sedimentary vectorial properties and has a marked influence on strata-control in colliery workings.The sedimentary features analysed indicate an approximate S200W flow direction. Petrological studies reveal a clastic, well-cemented sedimentologically and structurally anistropic rock type. Washouts have been found and isopach maps of both sandstone and underlying roof-strata have been compiled. Relevant measurements were carried out in existing colliery workings and on bore cores.Optical determinations of feldspars revealed the presence of plagiocIase feldspars with few exceptions. Most of the feldspars are altered to clay minerals. It was found that a geographical trend exists in the distribution of feldspars, with more basic plagioclase in the northern part of the field.The source area of the fluvial sandstone lies to the north of the Southern Coalfield.Petrofabric analyses were done on several specimens of the fluvial sandstone. In the vicinity of major disturbances, penetrative fabrics were discovered.Calcites (e, 0112), micas (001), and quartz (crystalIo graphic c) show preferred orientations.

Jan 1, 1967

By R. Pothina

The objective of this research was to develop a mathematical model for gyratory crushers to help in the prediction of energy consumption and to analyze dominant parameters that affect this energy consumption. The development of a gyratory crusher model was achieved in the following three main stages: mathematical representation and coding of the crushing process; building an amperage constant model to derive an energy-scaling formula; and modifying the amperage constant model to represent a full-scale model. Due to their significant influence on feed-size distributions, two blasting parameters, i.e., burden and spacing, were considered. The crusher parameters that affect energy consumption were also identified. A case study of an operating dolomite mine was performed. The results indicated that by changing the burden, spacing and crusher closed-side setting, the overall (blasting and crushing) costs could be reduced by 4.7% to 7.9% annually. It can also be concluded that burden and spacing values have a linear positive relationship with the crusher energy consumption, while closed-side setting values have an inverse linear relationship with the energy consumption.

Jan 1, 2007

By Tomohide Takeyama, Yuki Yoshida, Masaki Kitazume

"Abstract A series of centrifuge model tests was conducted to investigate the failure pattern and stability of cement treated clay ground having an unsupported vertical slope. The model ground was subjected to monotonically increasing centrifugal acceleration until it failed due to the enhanced self-weight. The test results were compared with the numerical analyses in which the treated soil was simulated by the Smoothed Particle Hydrodynamics (SPH) method. In the simulation, the Dracker- Prager model is employed as the constitutive model. In order to simulate the brittle behavior of the cement treated soil, it is assumed that the unconfined strength is gradually reduced to a certain value which corresponds to the residual strength due to accumulated plastic strain. It was found that the simulation by using SPH method can express the brittle failure observed in the centrifuge model tests.IntroductionBecause of economical and environmental concerns it has become more difficult in recent years to obtain enough soil to construct reclaimed land for airports, electric power plants, manufacture plants and so on. On the other hand, it has become difficult to find and construct disposal sites for waste subsoil or dredged soil. These circumstances have encourage geotechnical engineers at present to use these poor quality materials as filling materials more than they were used one or two decades ago. Several soil admixture methods have been developed to improve their properties and to manufacture high quality fill materials.The deformation and strength characteristics of cement treated soils have been investigated in Japan, which have revealed that the treated soil is characterized by a brittle behavior with quite high compressive strength and quite small strain at failure, and the treated soil with relatively high strength shows tensile failure instead of shear failure. Regarding to evaluate the stability of structures adjacent to or buried in the treated ground, Kitazume (1998) and Kitazume et al. (2003) investigated the earth pressure of cement treated ground by the centrifuge model tests. And they emphasized that the failure pattern of the cement treated ground was much different from that of ordinary ground. After the Hyogoken- Nambu earthquake in 1995, many design codes for the seismic stability were revised in Japan, so that seismic stability must be evaluated more precisely. The dynamic earth pressure of ordinary grounds is usually calculated by a pseudo-static limit equilibrium method based on the Mononobe- Okabe’s method (Okabe, 1924; Mononobe and Matsuo, 1929). This calculation method is also applied to the cement treated ground, although its applicability has not been thoroughly clarified."

Jan 1, 2014

By Lancucki C. J, Nickson N. M

X-ray diffraction and differential thermal methods were used to determine the mineralogy of some clays used by the heavy clay industry in the Adelaide area. A detailed analysis was made of the mineralogy and particle size distribution of eighteen samples from beds in two pits in the Recent sediments in the Adelaide plains, of six white clays developed from the weathering of the Adelaide series of sediments, and of four Recent alluvial clays from a pit in the Mount Lofty ranges south of Adelaide. Structural clay products in the Adelaide area are manufactured from mixtures of these clays, so the mineralogy and particle size distribution was determined of eighteen clay mixtures used to make red bricks, cream bricks, facing bricks, pipes and tiles.Knowledge of this mineralogy is important in understanding the ceramic behaviour of the clays.INTRODUCTIONIn this investigation an account is given of the clay mineralogy and particle size distribution of some ceramic clays from the Adelaide area. The clays are used in the manufacture of structura,l clay products and the results to 'be described are part of an overall 'plan of study covering the heavy industrial clays and shales of Australia. Previous work has been published (Cole and Carthew, 1953; Ferguson, 1954; Ferguson and Hosking, 1955; Cole and Nielsen, 1958/59).In this work no attempt has been made to examine clays from all pits engaged in supplying materials for the structural clay industry. However, in 1954 the senior author collected detailed samples from two pits working in Recent alluvial clays in the Allenby·Gardens and Beverley areas near...

Jan 1, 1963

By R. Q. Shotts

Factors of geological structure and occurrence of coalbeds, plus the resulting mining conditions, have required more care in preparing coals in Alabama than in most other districts almost since mining Alabama coals began. For this reason, literature on these coals may be interesting to those in areas where prime coals have been mined out, and thinner and less regular beds must now be exploited. This literature review has been arranged in order of subject matter. Some references have been listed more than once, but each separate review is limited to the material pertaining to the subject matter being discussed. For those seeking specific information, the authors have indicated which items repeat material and which items are most complete or specific. Geology, preparation, and carbonization of coal have been reviewed the most frequently.

Jan 1, 1963

"An active list of permissible explosives was published in July, 1930 as part of the United States Bureau of Mines Report of Investigations 3025, under the title of “Active List of Permissible Explosives and Blasting Devices Approved Proir to June 30, 1930”. Changes on that list were authorized in August, September, October and November, 1930, and January, March, April and June, 1931, as published in Reports of Investigations 3029, 3037, 3046, 3053, 3069, 3089, 3099, and 3123, respectively, By these changes the following explosives were added to the active permissible list:Big Red No. 9 Hercogel CBlack Diamond No. 5-A Liberty No 1Black Diamond No. 9 Liberty No. 2Burton 5, L. F. Liberty No. 3Burton 7, L. F. Liberty-Gel L.P.Duobel No. 4, L. F. Wesco Coal Powder No. 1Genigel No. 1and the permissible explosive EP-28 was transferred from the active to the in active list of permissible explosives.During June the following permissible explosives were added' to the active permissible list:Austin Red Diamond No. 9-B, L. F. BurtonAustin Red Diamond No. 9-C, L. F. Gelobel No. 4, L.F.Austin Red Diamond No. 10-A, L. F. Liberty No. 6Austin Red. Diamond No.12-A, L. F. Monobel 8 L.F.,- WR Austin Red-D-Gel"

Jul 1, 1931

By John C. Machisak

INJURY and employment figures for nonmetal mines and mills in 1959 are presented in this publication. Data for nomnetal mines are presented separately from those for nonmetal mills. The Bureau of Mines is authorized to send questionnaires to the nonmetal mining industry each year requesting their voluntary submission of injury experience and employment data. The voluntary response to these requests has contributed greatly toward the promotion of safety in the industry, and every effort has been made to make the information as complete as possible.

Jan 1, 1963

By Marc C. Bétournay

Over the last four years, an international initiative, championed by Vehicle Projects LLC, the Fuelcell Propulsion Institute and Natural Resources Canada, has been active in carrying out research projects to prove out the concept of applying fuelcell technology to underground mining vehicles. These have been carried out by a consortium consisting of mining companies, equipment manufacturers, technology developers, national laboratories and consultants, with the participation of Canadian and U.S. mine regulatory agencies. This clean technology, which produces only water and electricity, would allow several advantages to be obtained, in the health area (by eliminating diesel emissions and reducing noise generation), in lowering production costs (such as reducing ventilation required) and lowering green house gas emissions. This article outlines the results obtained in several key areas, such as the operation of fuelcells in underground conditions, risk issues related to underground and surface operation of hydrogen vehicles and hydrogen production and delivery systems, and the design and mining performance of the world?s first hydrogen mining vehicle, a mine production locomotive. The work to date on the fuelcell loader, designing the power plant and power transmission systems, operational requirements, and operating cost reductions, is also presented. There is also an evaluation of the overall mining applications and advantages this technology can bring to underground mining, including the facilitation of automation and tele-remote operation.

May 1, 2003

By William H. Hamilton

This report describes the results and conclusions of the development and evaluation of a unique concept for a lightweight air powered drill tool for probe drilling in anthracite mines. A concept model of the lightweight air powered tool was constructed and evaluation testing conducted at the Kocher Coal Company Porter Tunnel Mine. The unique anchoring method proved to be extremely satisfactory and the overall light-weight air powered drill tool concept proved feasible. Based on the results of the concept model testing, two prototype production units were designed and manufactured. These prototype units proved to meet all of their design requirements of lightweight, portability, drilling controllability, structural integrity and miner acceptance. The need for a better bit and drill steel system, however, became evident during the testing program and recommendations are made for further investigation and development of a bit and drill steel system suitable for this application.

Jan 1, 1979