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By GORDON H. FISHER

During the year 1945, the drilling pace in West Texas increased above that in the year 1944, and represented the highest number of well completions since 2941. The 1680 new wells drilled 8,287,958 ft. of hole for a per well average of 4933 ft. This depth is approximately 30o. ft. deeper than the average for the year 1944. Although the deepest well drilled in West Texas (Phillips Petroleum Company's Ada Price No. 1, in Pecos County) was completed during the year. 1944 to a depth of 15,279 ft. and tested the Ellen-burger horizon, the producing depth record for West Texas was set during the year 1945 with the completion of Amerada Petroleum Corporation's Jones No. I-A, in the Jones Ranch field, Gaines County, which now is producing at 11,422 ft. from the Devonian formation.

Jan 1, 1946

By Jorge Ganoza

Los procesos de carbón en pulpa (CIP), carbón en lixiviación y en columna son los más comunes para el tratamiento de soluciones de cianuro que contienen oro, aunque presenten limitaciones como la regeneración del carbón. En ese sentido, el presente texto describe las ventajas de la resina de intercambio iónico puesto que son más versátiles que el carbón activado porque el grupo funcional específico puede ser fijado en la matriz de la resina durante la síntesis. En consecuencia, el carbón activado puede requerir de altas temperaturas para la elución, así como una reactivación térmica.

Aug 1, 2013

By E. A. Pelczarski

Initially, the objective of this contract was to develop a PWSCSR that could meet proposed criteria (that were different from 30 CFR 11(Title 30 of the Code of Federal Regulation part II) and that would be less than twice the size and weight of a filter self rescuer. This objective was met. Consequently, the original contract was extended to develop a PWSCSR that would meet existing CFR-30 criteria within the same size and weight constraints. This resulted in the development of a PWSCSR (the SR-100) that received NIOSH/MSHA approval (TC-239). This report presents a historical discussion of the design and development of the SR-100 as developed by CSE Corporation under Bureau of Mines contract number H0368013. The technical parameters and the test results of NIOSH/MSHA 30 CFR 11 certification are also presented.

Jan 1, 1990

By C. J. Bise, M. F. Sindelar

Regulations, such as the MINER Act of 2006, require the installation of redundant and secondary communication systems to assure that contact can be established with coal miners who may become trapped underground as a result of an event such as a fire, explosion or inundation. For half a century, the orientation towards underground communications has been that more complex systems better serve the coal miner. However, if a goal is to provide for an alternative means of establishing communication between the surface and trapped miners underground, then some of the technology employed should be simple, reliable and cost-effective. Coal mines spend hundreds of thousands of dollars on exploratory drillholes to characterize reserves, sometimes decades ahead of mine development. During the pre-mine planning phases, certain exploratory drillholes could be located and then outfitted with a simple communication link that would remain compatible with the continuing evolution of communication systems. Inexpensive links, whose locations would be accurately recorded, would be exposed by continuous miners during mine entry development, thereby allowing an underground phone to be connected to a surface station in the event of an emergency. A latent network of these communication links could be installed for less than $500 each, minimally affecting drilling and grouting operations, and could be designed to be compatible with many communication devices. This research examines methods and materials for incorporating an embedded communication link during pre-mine exploration drilling, addresses significant factors affecting its implementation, and presents a recommended design. Since mine plans are known to change, the objective is to minimize cost so that, if not used, the investment is minimal for a potential secondary means of communication between the surface and underground workings.

Jan 1, 2014

By Sara Silva Ferreira de Dafé

Os aços com um alto teor de Mn (15-30%) e os elementos de liga, Si e Al, apresentam plasticidade excepcional devido à geração de maclas de deformação (efeito TWIP) ou múltiplas transformações martensíticas (efeito TRIP). Este trabalho avaliou a evolução microestrutural, a formação da textura e sua influência sobre o comportamento mecânico de um aço contendo 17%Mn-0,06%C laminado a frio com reduções de 45% e 90%, e recozimentos a 700°C durante tempos diferentes. A microestrutura foi analisada por microscopia óptica e eletrônica de varredura, EBSD e difração de raios X. A redução um frio favorece a formação da martensita a'. No aço recozido estão presentes as fases martensita a? e e e austenita. O limite de escoamento e de resistência à tração alcançaram 750 e 950 MPa, respectivamente, com o alongamento total de 45%, confirmando sua alta capacidade de encruamento. A reversão da martensita para austenita ocorre simultaneamente com a recristalização desta.

Aug 8, 2018

By Sabri Ergun

This report gives the result of investigations of coals of different rank, coal com¬ponents, chemically and thermally treated and irradiated coals, and sedimented organic matter. In most studies the arbitrary parameters obtained from the usual quantitative profile analyses are not given largely because they lack physical meaning. Instead comp interpretations are offered. X-ray patterns of high-volatile bituminous and lower rank coals are not self¬-sufficient for structural interpretation by the methods of analysis developed to date. The patterns of hydrogenated and dehydrogenated coals indicate that the basic change in the structure of bituminous coals with increase in rank is the conversion of alicyclic structures into aromatic layers. In low-rank anthracites the aromatic layers are about 10 A in size. The increase in rank is the result of coalescence of layers. High-rank anthracites have layer sizes of 25 to 40 A and exhibit the development of three-dimensional (hkl) reflections of graphite, indicating ordering of adjacent layers. In meta-anthracites the layers are > 1000 A and the basic structure is that of defective crystalline graphite. The well-known petrographic components in low-rank coals have different structures; the differences dissappear in low-volatile bituminous and higher rank coals. The patterns of sedimented organic matter, except impsonites, differ from those of coal hydrogen contents are high, and their X-ray patterns are consistent with those of structures. In contrast to normal coals, the patterns of uranium-bearing coals show increased diffuseness with decrease in hydrogen content. The diffuseness is accompanied by increase in the uranium content of the coal. It is very likely that high uranium-bearing coals have predominantly tetrahedral structures.

Jan 1, 1968

By Robert F. Pettit

This paper on methods and costs of mining and milling iron ore at the Iron Mountain mine of Ozark Ore Co., St, Francois County, Mo., is one of a series of Bureau of Mines reports on methods, practices, and costs of mining and milling throughout the United States. The Iron Mountain operation is notable for its successful transition from open-pit to underground mining, for use underground of large earth-moving equipment, and for development of a multilevel room-and-pillar mining method. Milling methods also have undergone transitions - from hand sorting and log washing in the early days to gravity concentration. Milling ultimately may include flotation to recover additional iron from products now discarded as tailing,

Jan 1, 1957

By Ludwig Hermann

"Phosphorus is required by every cell of living organisms and essential for plant growth. It is a non-renewable resource that must be mined from natural deposits, going gradually into depletion. Abundant secondary resources are available in sewage sludge and meat and bone meal, with the highest exploitable P concentrations in ashes that remain from their widely used combustion with energy recovery. ASH DEC has successfully removed heavy metals and transformed sewage sludge ash into a marketable P fertilizer by application of a thermo-chemical treatment process. Pilot scale investigations in which ash was treated proved that generally heavy metal limits required by fertilizer legislation can be attained. To achieve a high P availability for crops – an essential fertilizer quality feature – was a more challenging R&D task. Our presentation demonstrates the scientific approach and R&D results that lead from assessment of market requirements to licensed products.IntroductionPhosphorus (P) is required by every cell of living organisms. It is one of the major elements for plant nutrition and therefore essential for crop production. P supply in plant nutrition depends entirely on external inputs into soils [1]. This is achieved by P-fertilizers deriving from rock phosphate deposits that are gradually going into depletion. Serious prognoses anticipate that rock phosphate will be the first low running resource in the world [2]. In the EU, last year 2.530 kt of phosphorus (P2O5 in fertilizers) was consumed and only 313 kt (P2O5 in rock phosphate) was mined. Since 2007, rock phosphate prices have increased by 500% because of a tight supply situation [3].For these reasons, P recycling is becoming an increasingly important issue. Suitable secondary raw materials with regard to their high P-content and abundance are sewage sludge and meat and bone meal. In the EU 989 kt P2O5 are accumulated annually in theses materials, of which 632 kt P2O5 are permanently lost to landfills and other forms of disposal. The main reasons for their limited recycling are concerns on heavy metal contents and organic pollutants that may incite health hazards. As an additional shortcoming, the availability of P from these materials to plants is poor and storage and transportation are problematic issues [4, 5]."

Jan 1, 2008

By Dennis Nottingham

"Increased interest in seismic soil liquefaction and preventative soil stabilization sets the stage for improved deep compaction methods using pile driving techniques. In 1971, L.B. Foster Company personnel patented a method of deep compaction using a vibratory pile hammer and pile probe. The technique had some success, but did not produce consistent results and thus found its way to obscurity. Other patents attempted to modify the technique by various probe modifications, but again without measurable improvement from a practical point of view. Solutions to economical deep compaction up to 100-foot depths particularly in saturated granular soils would have a great impact on the construction industry and new bulkhead structures being developed, thus PND was prompted into related research and development. The advent of higher horsepower vibratory hammers, coupled with PND engineers’ experiments, observations and measurements, led to an “H” pile probe design which has produced measured soil density improvements up to 250% using SPT “N60” values as a measure. Case histories of two projects involving extensive SPT soil sampling comparative measurements will be discussed along with findings that led to the compaction success. Applications to numerous modern “Open Cell” bulkhead projects will be presented and discussed.INTRODUCTIONNecessity often is the basis for innovation and such was the case for needed cost-effective deep soil fill compaction in Open Cell bulkheads where granular fill below water levels was often placed.Open Cell bulkheads were developed by PND Incorporated starting in 1980, for the express purpose of meeting client demands for an economical, easily constructed, extremely strong structure. Earth-filled structures historically have had a long history of problems with stability, scour and settlement.Open Cells are flexible steel sheet pile membranes supported by soil contact with embedded tail anchor walls.This concept creates an integral reinforced soil system. The result is a structure that can withstand large settlement and support a variety of very large loads. In effect, viewed from above the structure becomes a series of U-shaped horizontal membranes that require no toe embedment for stability. The Open Cell bulkhead is constructed of only three components: flat sheet piles, fabricated connector wyes and anchor piles. Compared to alternative structures, several cost savings are realized from this land based construction such as, reduced sheet pile area, greater construction tolerance, minimal pile penetration, and simplified backfilling procedures. In seismic regions or weak soils, the tail walls can be extended as required to guarantee fill mass stability."

Jan 1, 2005

By R. L. Handy

The objective of this research was to devise and test an apparatus to rapidly evaluate the cohesive and frictional strength of coal in situ, in order to increase the safety and percentage of coal recovery from underground coal mines. During the first year device was designed utilizing the bore-hole shear test principle from soil shear strength testing: Two opposing corrugated plates are forced outward to exert a controlled contact pressure against the sides of a previously bared hole, and then the plates are very slowly pulled along the axis of the hole to cause shearing of coal in contact with the plates. Results with the device are expressed in terms of a friction angle[_] and a cohesion c. The [ ] angles obtained from an Iowa coal arc in close agreement with and fall between results from triaxial and direct shear laboratory tests on the same coal. The measured cohesion was found to be much less than from the comparable laboratory tests. It may be increased by pre-stressing and other techniques to embed the shear plate teeth for the first shear test point.

Jan 1, 1973

By C. T. O’Connor

Since the first IMPC took place in London in 1952 there have been many developments in our understanding of flotation, both in terms of chemical and physical factors influencing the process. Many of these developments have been captured in the proceedings of thirty congresses that have taken place since that first event, as well as in numerous journal papers and special volumes dedicated to flotation. This paper attempts to highlight the individual contributions which many eminent researchers and engineers have made over the past 70 years towards extending our understanding of, especially, the effects of chemical factors on flotation. Although the focus is mainly on more fundamental aspects, it seems that the ‘pull’ of practice has often preceded the ‘push’ from laboratory-based research. As the fundamental understanding of the role of chemical factors on flotation continues to be developed, the major challenge remains to transfer this knowledge effectively into the domain of operations of this profoundly complex process.

Jan 1, 2020

By R. E. Heithecker

The Zwolle oil field of Sabine Parish, La., is different from most oil producing areas of the State in that the oil is obtained from marl and chalkrock formations. The thickness of the reservoir rocks averages 500 feet; but production is not continuous throughout this thickness, as the oil apparently is localized in vertical and nearly vertical solution cavities and channelways or in porous zones of limited horizontal extent. The nature of the oil accumulation has caused two outstanding peculiarities of the field: (1) About 60 percent of the tests drilled were dry holes and (2) there were many instances of well interference. Commercial production was discovered in November 1928, after 17 years of prospecting in and around the present limits of the area now developed which has a length of about 22 miles and a maximum width of 4 miles. The field had produced 10,266,896 barrels of oil to January 1, 1934. The oil ranges in gravity from 400 to 420 A.P.I.

Jan 1, 1934

By Craig J. Nelsen, J. Leroy Schutz

The Carache Canyon Prospect consists of a hypabyssal breccia pipe which intrudes a gently dipping sequence of Cretaceous Mancos Formation and Mesa Verde Group shales and sandstones. This sedimentary sequence is intruded by a number of Oligocene (34-30 Ma) calc- alkaline sills. The formation of the breccia pipe and its subsequent gold mineralization is related to the emplacement of an alkaline intrusive complex dated between 30-26 Ma. An exceptionally large block within the pipe provides compelling evidence that brecciated sills and sedimentary rocks form a relict stratigraphy that collapsed 400-800 ft (120-240 m) below their counterparts outside the pipe without substantial changes in stratigraphic position. Native gold and sulfide mineralization within and around the pipe occurs in fractures that are primarily controlled by competency differences between sills and sedimentary rocks and secondarily controlled by ductility contrasts between the relatively brittle Mancos Formation hornfels and the more ductile Menefee Group shales. The resulting pattern of gold mineralization is a series of stacked, tabular, mineralized sills and sandstone separated by barren shale in an annular region along the southwest margin of the pipe. A series of near-vertical, subparallel, sill and sandstone breccias separated by barren or weakly mineralized shale breccia occur within shallow levels of the pipe.

Jan 1, 1990

By William H. Schiffbauer, Ph. D. Mowrey

Proximity warning devices can improve workplace safety by alerting workers when they are in a hazardous area near moving equipment. Industrial work sites often present extreme challenges to safety-based proximity warning devices. Many commercially available types of proximity warning sensors and systems can be rendered useless when covered with mud, ice, snow, ore, rock, and other material. The list includes radar, ultrasonic, capacitive, and visual types of sensors and systems. Addressing these shortcomings, NIOSH personnel have developed a patented active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) which employs lowfrequency, low-power magnetic fields which are quite impervious to severe environmental conditions. A shapeable wire loop antenna which provides the marker of dangerous work areas, has been mounted on a continuous mining machine and was mounted inside 1.3-cm thick angle iron. This loop antenna was exposed to more than six months of active underground coal production, which included being covered by and scraped over with tons of rock, sprayed by a continuous stream of water, and immersed in thick mud. After six months the loop antenna showed signs of wear, but was still capable of performing its intended function. The HASARD system is now being applied to other industrial applications and is showing much promise, especially in harsh environments. This paper details the system, describes the tests that have been done, and mentions other areas where it can benefit the safety of industrial workers.

By Wallace W. Roepke

The Bureau of Mines tested new designs of drag bit cutters with sintered diamond inserts instead of standard tungsten carbide tips. The bits were tested for orthogonal cutting forces, primary dust generation, and incendivity, with a standard plumb-bob type conical cutter (600 included tip angle) as the reference. Preliminary wear and impact-failure testing were also done. The results were mixed. Two new designs had forces similar to those of the reference bit, but one new design had about twice the normal force. This same design had almost twice the specific energy during shallow cutting but generated an equal or slightly lower amount of primary dust than did the reference bit. Incendivity was eliminated for two radial designs. One conical design had ignition only after more than 15 impacts, but the other conical design was incendive. Impact failure occurred, but not so quickly as anticipated. Over 7,500 impacts on a sandstone face, with a total cutting distance of more than 1,981.2 m, only scuffed the leading edge of the sintered diamond cutting face but put hairline cracks in the substrate mounting pad. Additional design and testing are needed to develop an optimum cutter, but prospects look good for this material.

Jan 1, 1983

Founded in 1994 through a joint effort between Underwriters Laboratories Inc. (UL), the U.S. Consumer Product Safety Commission (CPSC) and the National Electrical Manufacturers Association (NEMA), the Electrical Safety Foundation International (ESFI) is North America?s only non-profit organization dedicated exclusively to promoting electrical safety in the home, school and workplace. ESFI is a 501(c)(3) organization funded by electrical manufacturers and distributors, independent testing laboratories, utilities, safety and consumer groups, and trade and labor associations. ESFI sponsors National Electrical Safety Month each May, and engages in public education campaigns and proactive media relations to help reduce property damage, personal injury and death due to electrical accidents. The Foundation does not engage in code or standard writing or lobbying and does not solicit individuals.

Jan 1, 2004

By Robert M. Becker

Part 5, the last of this series, deals with the theoretical confirmation and application of results developed in parts 1 and 2. The bulk-sampling variances of Hassialis and Kassel and Guy are compared with those in part 2, both as to formulation and as applied to ores and coal. The results provide confirmation for much of the development in part 2. Examples are presented for determining the reliability of bulk samples with respect to various measurable characteristics. These characteristics include, for example, assays for elements or compounds and particle surface area. The bulk samples considered consist either of a given weight, a given volume, or a given number of particles. In addition to problems of sample reliability, some of these examples may also be applicable to quality control. Several possible applications of results developed in parts 1 and 2 are outlined. These include tests for random data, degree-of-mixing indices, and particle-fineness indices.

Jan 1, 1966

By Gerald H. Luttrell, Seyed Hassan Amini, Aaron Noble

One of the most important processing engineering tools for designing mineral processing facilities is linear circuit analysis. This technique, originally conceived and developed by Meloy, Williams, and Fuerstenau nearly four decades ago, provides fundamental insights regarding how unit operations interact and respond when arranged in multi-stage processing circuits. Researchers have successfully utilized this tool to improve the operating performance of industrial processing circuits incorporating coal spirals, magnetic separators, mineral spirals, and eddy current separators. More recently, advanced versions of this tool have also been developed to provide a standardized framework for circuit mass balance calculations, to output exact analytical solutions to mass yield and value-based efficiency expressions, and to estimate uncertainty propagation in separation circuits. This article reviews the historical development of linear circuit analysis, describes how the technique has evolved to address more complex circuit design problems, and presents industrial case studies that highlight the importance of this process engineering tool.

By D. Mas Ivars, K. Suzuki, J. A. Vallejos

"A comprehensive geotechnical characterization has been undertaken at the El Teniente mine to describe and determine the rock mass behaviour strength properties of the primary copper ore. The Synthetic Rock Mass (SRM) modelling approach is used to simulate the mechanical behaviour of this heavily and unfractured rock mass. The micro-parameters of the model have been calibrated against mechanical properties and scaling laws for intact rock and veins, in order to represent virtual samples of four different geotechnical units. Results can be used to predict the rock mass scale effects, anisotropy, and brittleness properties that cannot be obtained using empirical methods.INTRODUCTIONThe primary copper ore at the El Teniente mine is described as very competent and massive, given that it exhibits a brittle behaviour (Rojas, Cavieres, Dunlop, & Gaete, 2000). This description is coherent with the geological description of the rock mass, which does not have discontinuities match as the definition provided by International Society of Rock Mechanics (ISRM, 1981). Only faults can be classified as discontinuities, but they are widely spaced. The primary copper ore has a high frequency of veins, where the cooper mineralization is hosted, these vein network structures are known as stockwork. Soft veins containing weak minerals as infill (chalcopyrite and anhydrite) control the disassembling of the rock mass during caving (Brzovic & Villaescusa, 2007).Presently, there are mainly two traditional methods used to estimate the strength of the rock mass: 1) determination of the strength envelope of the rock mass using scaling parameters from laboratory tests and 2) using numerical modelling based on back analysis of previous experiences of failure observed and measured in mining or civil excavations. The primary copper ore of El Teniente mine has no fractures; therefore, it is difficult to determine a rating that would enable to scale laboratory data, such as, RMR (Laubscher, 1977) or GSI (Hoek, 1994). This is the reason why the first option is not valid unless the entry data is manipulated or adjusted in order to obtain reasonable results. The second option requires, in general, a good characterization of a previous failure event in the rock mass, which is not always available. In recent years, new techniques of numerical modeling have been developed (PFC3D, ELFEN, Abaqus). Those methodologies are the third way to estimate the strength of the rock mass, but they are still in development. Particularly, the concept of SRM developed by Itasca is implemented in this study (Pierce, Mas Ivars, Cundall, & Potyondy, 2007; Mas Ivars et al., 2011), aiming to capture the real behaviour of the rock mass."

Jan 1, 2015

By Gary Cavanough

The spontaneous exothermic reaction of ammonium nitrate explosives with sulphide-containing rocks, commonly referred to as reactive ground, is a site-specific condition that can lead to spontaneous detonations. Mine sites typically carry out regular assessment of ground for reactivity. In Australia, reactive ground testing is conducted according to the Australasian Explosives Industry Safety Group (AEISG) Code of Practice. This paper presents a new method to assess reactive ground. The new method can be completed on the mine site or in the laboratory. The new method allows samples to be tested in hours not weeks, as required when using the method prescribed in the AEISG Code of Practice. The new method also provides an explanation of why ground is reactive or not reactive, Whereas the AEISG Code of Practice provides a reactive, not reactive or marginal results with no understanding of reason for these results. Case studies on the use of weathering agents, pH, sulphide content and carbonate content will be reported. These case studies identify instances where the testing as per the AEISG Code of Practice provides false positive and false negative results. A false positive result will require the use of inhibited products when they are not actually required which increases costs and reduces productivity due to the need to used multiple explosive products. A false negative result increases the risk of an unplanned initiation of a blast hole.

Feb 6, 2023