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By Charles D. Wood

"Selected Topics,? in reviewing the control of emissions from diesel engine powered equipment used in underground mining, explores these fields of interest: hydrogen as fuel; lubricating oil as a source of particulates; applicability of stationary source scrubbers; worldwide diesel exhaust scrubbers; instrumentation technology for measurement of N02; control of emissions through application of sensors and microprocessors; use of fuel additives; technology transfer of marine diesel practice; technology required to use 4-stroke, aftercooled, turbocharged, direct injection engines; oxidation and reduction catalysts for diesel engine exhausts. "Selected Topics? makes recommendations for research and provides a bibliography and lists of references.

Jan 1, 1979

By Henry P. Chandler

THE year 1950 was one of increased activity in almost all branches of the abrasives industry, with nearly all abrasive materials showing a marked increase in tonnage and value. New records were made In the production of tripoli, ground sand and sandstone, pumice and pumicite, and garnet. Total production of crude artificial abrasives in the United States and Canada increased 17 percent in tonnage and 30 percent in value. Imports of industrial diamonds increased 100 percent in total value and 72 percent by weight, the 1950 importation being the largest since 1944. Imports of corundum increased 76 percent in tonnage and 4 percent in value.

Jan 1, 1953

Industrial Minerals production in New Zealand is limited in both quantity and range, but imported in quantities that make New Zealand the world's biggest consumer per head of population. The use of industrial minerals is assured as both population and standard of living increase regularly. But to develop these minerals in the New Zealand environment requires the mineral, or its market (both local and export), to have characteristics that negate the remote geographical location. Volume and/or uniqueness can achieve this.

Jan 1, 1997

By F. G. Horino

This report presents the theory and design of a stiff loading machine used by the Bureau of Mines. The machine incorporates three high-strength steel columns as the restraining member in parallel with the specimen. The theory presented gives the basis of design and the dimensions of component parts of the machine. Laboratory verification of the theoretical stiffness is described using three different setups involving a hydraulic jack and spacers and confirms the stiffness calculations to within 1 percent. Experimental techniques, testing procedures, and special equipment designed for determining the complete stress-strain behavior of NX cores of both hard and soft rock are described. Typical test data are presented as force-displacement curves for two rock types, a marble and a granite.

Jan 1, 1972

By M. T. Baquera

A comparison of microstructures associated with W single-crystal ([001], [011], [111]) rods prior to deformation (as grown), and after quasi-static compression (at a strain rate of ~1/s) by transmission electron microscopy (TEM) shows several orders of magnitude difference in dislocation density. Dislocation substructures were not significantly different amongst the deformed sample orientations. In contrast, [001] W rods penetrated into steel targets, at impact velocities of ~1.3 km/s, exhibited heavy dislocation densities and dynamic recrystallization as very distinct microstructural regimes accommodating the penetration process. Twinning on {112} also occurred as a precursor to, or remnant of, these microstructures near the projectile head. These results suggest that deformation accommodating the extreme strains and strain rates associated with the penetration of a single-crystal rod into a metal target is not adequately represented by conventional deformation

Jan 1, 2006

The Functional Performance Equation for ball milling circuits provides plant staff with a new means to improve circuit performance. However, successful execution of a plant project, with verifiable circuit processing performance improvements, requires a significant number of accompanying steps beyond the equation alone. In order to identify and articulate all these steps, a study with plant staff from two milling operations and a grinding media supplier was undertaken. ?Task analysis? of improving plant grinding performance was carried out. This analysis called for the development of a number of system components, and ultimately yielded a ?Plant Grinding Circuit Processing Performance Management/Improvement System.?

Feb 23, 2014

By M. Javier

Defining the concept of sustainability is an important step for industry and society. It is necessary in order to clarify what it means when debunking the many misinterpretations pervasive in different levels of anthropogenic activities. Essentially, the extractive industry has a harvest of differences. Mining involves the extraction of natural resources which are finite, exhaustible, non-renewable, unsustainable, and pay only once. It is remarkable that the definition of sustainability that we will shortly arrive at has totally different characteristics from the definition accepted throughout society. We categorize nature as having its own destiny which is controlled by its own rules and principles and its own society, and is part of nature; therefore, society depends on nature and not vice versa as the initial focus. To society there are no conditions to humanize nature but only respect nature?s rules. It was a challenge to find simplicity for this task not only for the definition but also for the explanation of this concept specifically, to answer the question, ?what is the true meaning of sustainability?? Finally, we are also able through this definition to provide fuel for wide discussions and stimulate critical thinking to improve such a concept. As a result, we present this definition as the tool for society today and for future generations.

Jan 1, 2012

By Thomas A. Giordano

Portable communications equipment is becoming increasingly important in underground mining. Proper selection of microphones and hearing devices to be part of these communication systems is essential if the messages are to be transmitted intelligibly. In this program a thorough study of the requirements for these transducers was made with respect to intelligibility, mechanical configuration, human factors and safety. A computer analysis was made to predict how several combinations of transducers would perform at typical mining noise levels. A survey has been made of those microphones and hearing devices on the market today that might be applicable to the miner communication system. Several systems are proposed and evaluated.

Jan 1, 1976

By Dipak C. Talapatra

This report describes the development of guidelines for design, inspection and maintenance of automatic couplers. In order to devise the guidelines, performance requirements for automatic couplers were carefully established. This was clone through a comprehensive survey of coupler manufacturers and extensive observation of automatic couplers in service in a broad spectrum of mines. The capability of the couplers to withstand the demands of the mining environment in terms of strength characteristics, gathering range, curve negotiability, and other factors were all carefully evaluated. An analysis of coupler related accidents for the years 1972-1976 was carried out to provide information on the safety and reliability of existing automatic couplers. This formed an important input to the development of the guidelines. It is expected that these guidelines will he useful to coupler manufacturers for establishing designs for improved automatic couplers, and to mine operators for maintaining their couplers in a safe and good operating condition throughout their expected lifetimes. This report is in two volumes: Volume l - Technical Report Volume 2 - Design, Inspection, and Maintenance Manual

Jan 1, 1977

By John L. Thames

The benefits of water harvesting as an alternative to conventional reclamation were demonstrated on the Peabody Coal mines in Northeast Arizona. The project produced food crops for four years, and demonstrated that a catchment/crop area ratio of about 2.5:1 was sufficient to obtain sufficient water from the 11 inch annual precipitation to produce garden and fruit varieties in quantities equal to or exceeding national production averages. The economic returns exceeded those of the conventional practice of returning the mine area to rangeland by at least ten fold. Subsidence of the regraded spoil was the only major problem in maintaining the system. Although, water harvesting systems have the potential of providing high economic returns and greater social benefits, as demonstrated by this project they are presently at variance with the strip mining regulation.

Jan 1, 1984

By Les Gutzwiller

Fan applications in the mining industry have changed during the last 70 years. In 1922, J.R. Robinson authored a technical volume entitled Practical Mine Ventilation. At that time, atmospheric control had only recently shifted from natural to mechanical. The large, mechanical draft fans that were used then were centrifugal. The fans ran at low speeds, about300 rpm. Most were steam-engine driven. In the late 1920s and early 1930s, mines became larger, increasing the pressure and volume requirements of the fan equipment. Axial fans were designed to run at much higher speeds (710 to 880 rpm) and were driven by electric motors. They were also smaller and less expensive to install than the cumbersome centrifugal units. However, changes in mining have resulted in progressively higher static-pressure requirements. So centrifugal fans are once again proving to be a good choice.

Jan 1, 1999

By J Lea, P Hatherly, J L. Edwards

Coal exploration has traditionally involved the acquisition of data to enable a resource to be quantified and qualified to the extent that its economic potential can be determined. This process commonly relied on: drilling to determine the depth and thickness of coal seams, broad characterisation of the overburden and interburden, and to provide cores for coal quality analyses; basic wireline logging to cross-check the depth and thickness of coal seams and provide some indication of rock mass strength; and basic surface geophysics and remote sensing to identify major geological structures. In recent years, the adoption of the JORC Code as a basis for the reporting of resources and reserves has placed a greater emphasis on the need for detailed, reproducible data sets that not only satisfy the traditional requirements of mine planners, but also satisfy the governance requirements of corporate and financial institutions. Similarly, the development of sophisticated numerical modelling techniques for use in both open cut and underground mine design, has seen a greater demand for precise geotechnical data, in situ stress characterisation and hydrological information as routine input to the design process. These requirements, coupled with the prevailing trend toward high capital, relatively inflexible mining techniques less tolerant of geological surprises, and the need for consideration of environmental issues such as groundwater impacts and surface subsidence, requires that modern exploration programs be multifaceted, and designed to commence capturing data relevant to ædownstream issuesÆ even during the initial phases of exploration planning.

Jan 1, 2009

By William G. Pariseau

The research reported here concerns a four year study of the rock mechanics aspects of two underground hardrock mine study stopes. The first study was conducted at Anaconda Minerals Company's Carr Fork Mine near Tooele, Utah. The second study was conducted at the Homestake Mining Company's Homestake Mine In Lead, South Dakota. Both case studies were cooperative efforts of mining company personnel, the Spokane Research Center of the Bureau of Mines and the Department of Mining Engineering, University of Utah. Large diameter (6 1/2 In.) blastholes were an integral part of the stoplng method at each mine. A true vertical crater retreat (VCR) method was used at the Homestake Mine, while a vertical bench mining method (VBM) was used at the Carr Fork Mine. VCR and VBM methods were developed In the 1970's; they offer significant productivity gain and are now used throughout the world. The new technology, however, brings with It a requirement for more sophisticated engineering design and control. Since there are no personnel in a VCR or VBM stope, all ground control Including dimensioning of stopes and pillars and the layout of cable bolt assays or other artificial support must be done in advance of production blasting. Accordingly, the objective of the research study was the establishment of a procedure for optimizing stops and pillar sizes. The approach taken was In each case a combination of mine measurements of the study stope response to mining, laboratory testing for rock properties and In situ stress measurements of the premining stress field, and theoretical calculations of the study stope response to mining. All calculations were done with the UTAH-II finite element computer program. Simulation of the blasting sequence gave a correlation of 0.88 between measured and calculated extensometer readings (Incremental relative displacements) at the Carr Fork Mine where other 30 Instrumentation boreholes were used to monitor the test stope response. A correlation of 0.84 was obtained at the Homestake Mine where 19 instrumented boreholes were used for monitoring purposes. These high correlations validated the computer mode and calibrated It for rock mass properties. The calibrated model was then used In parametric studies of alternative design layouts.

Jan 1, 1985

By Robert C. Rabeler

Soil and Materials Engineers, Inc. (SME) has utilized drilled cast-in-place (D-CIP) piles on a number of projects in the midwest. These foundation systems have typically consisted of drilling an 8 to 9-inch diameter borehole with a rotary type drill rig or driving a casing with a small hammer. A structural steel member is installed in the center of the excavated space, and the borehole or casing is grouted to complete the installation of the D-CIP pile. This type of piling system has also been called: mini-pile, micro-pile, or drilled-in pier. The capacity of these piles varies depending upon subsurface conditions, as well as the structural capacity of the pile. The structural capacity can be modified based on the size and yield strength of the structural steel member. SME has used the D-CIP piles for underpinning of lightly-loaded structures for a number of years. Steel brackets can be welded to the structural steel member in the center of these piles, and the bracket extended underneath existing foundations to provide proper foundation support. D-CIP piles have also been used for new construction where access was limited. Recently, SME had the opportunity of providing design as well as construction monitoring services for a unique project where these piles were used, but at much higher capacity. The project involved adding seven additional floors on top of a five-story building (total of 12 stories). New columns were extended through the existing building to support the new floors. Access to construct foundations was available to one level of underground parking beneath the structure, as well as to a basement area. Access required equipment to travel through a 3-foot wide hallway. A special duplex drilling machine was used to access the foundation locations and to install the piles in a limited headroom condition. Eight-inch diameter D-CIP piles were extended to a depth of approximately 40 to 50 feet below grade and socketed into a dense clay till or sandstone, and No. 18 or No. 20 threaded bars were installed in the center of these piles. The design pile capacity was as high as 190 kips and were verified by a compression load test. The load test was performed with limited access and headroom. These piles were installed by Spencer White and Prentis Foundation Corporation (SWP). For conditions where rock or hard soils are encountered at reasonable depths, D-CIP piles can provide working load capacities comparable to larger driven steel piles. The ability of the equipment to access very restricted areas, combined with the high capacities results in a very attractive solution to a number of difficult foundation problems.

Jan 1, 1999

By C. W. Davis, M. W. Von Bernewitz, S. C. Lind

During the past few years our possible domestic resources of platinum have attracted much attention . On account of the extensive use of platinum during the World War , and the practical elimination of the Russian supply , the price of this metal rose to new high levels , as shown in Table 1 ; and though it since receded to some extent , the price is now nearly six times that of gold .

Jun 1, 1923

By J. Bakken, M. Th. Jonsson, G. Sævarsdottir

A typical three-phase submerged-arc furnace for production of silicon metal and ferrosilicon has arc currents ~100 kA, phase voltages ~100 V and total furnace power ~10 - 60 MW. The arcs burn in gas filled cavities or "craters", where the main atomic components of the plasma mixture are silicon, oxygen and carbon. Two quite different simulation models for high-current AC arcs have been developed: the simple Channel Arc Model (CAM), and the more sophisticated Magneto-Fluid-Dynamic Model (MFD). These models have been described extensively and results reported at INFACON-8 and INFACON-9, respectively. The coupling between the arcs and the AC power source is described by a complete three-phase Electric Circuit Model. Recent numerical modelling studies of industrial AC arcs show that the boundary conditions at the cathode and anode are critical for the simulation results. A novel Cathode/Anode Sub-Model for high-current AC arcs that treats both cathode and anode indicates a completely different cathode behaviour than previously assumed. A cathode spot which serves a high-current electric arc is shown to be dominated by the energy impact from the arc. This leads to lower cathode fall voltage than obtained from previously developed models. The anode fall voltage is negative, as the main function of the potential barrier is to repel plasma electrons. The cathode spot is diffuse in the sense that the arc in fact contracts away from the cathode. Simulation results are compared to measurements on both industrial furnaces and smaller scale pilot furnaces. An important conclusion, supported by our arc studies, is that the arc length in silicon metal and ferrosilicon furnaces does not exceed 15 cm and the arc may burn anywhere on the electrode, not necessarily beneath the electrode tip.

Jan 1, 2004

By J. T. McLendon

As part of its research project in developing improved refractory materials for metallurgical applications, the Federal Bureau of Mines obtained hot modulus of rupture data at 1,500°,1,550°, and 1,600° C on samples of 13 refractory periclase materials produced from seawater, lake brines, and natural magnesite. The periclase samples also were characterized to establish chemical and mineralogical composition and microstructure. The results indicated that a high MgO content does not necessarily assure good hot strength and that an optimum and varying CaO-Si02 ratio exists for each individual periclase sample.

Jan 1, 1979

By Roy L. Wilfong

The thermal decomposition of the ammonium sulfate, carbonate, nitrate, oxalate, and sulfate salts of praseodymium, neodymium, and samarium was investigated thermogravimetrically in the temperature range 25° to 1,500° C. Each salt was decomposed at a heating rate of 2.5° C, per minute. The pyrolytic sequences have been identified and the temperatures of formation of inter-mediates, the minimum oxide formation temperatures, and values for loss on ignition have been determined. The nonstoichiometric ranges between Pr6011 and Pr203 and the extent of these ranges have been determined for oxides derived from the carbonate, nitrate, and oxalate salts of praseodymium. The alum and sulfate salts of praseodymium produced the sesquioxide without forming the intermediate non-stoichiometric oxides. The temperature limits of formation and regions of stability for the alums and sulfates were better defined than were those for the carbonates, nitrates, and oxalates. The minimum oxide formation temperature increased in the order of samarium, neodymium, and praseodymium irrespective of the anion.

Jan 1, 1962

By Donald R. Clark

"Drilled shafts are being used as foundation support for parabolic solar troughs at the Genesis Solar Project being constructed near Blythe, California. Three types of drilled shaft foundations are required for the project. At project build-out, there will be a total of 23,008 drilled shafts installed at the site. Preliminary designs for the axial and lateral capacity of the drilled piers were based on conventional geotechnical engineering methodologies and soil-structure interaction. The drilled shafts and subsurface conditions were modeled through the use of the computer program LPILE v6.0.Conducting lateral load testing of drilled shafts was considered appropriate to confirm or modify the geotechnical parameters used in the preliminary design. The lateral load testing program was conducted to provide site-specific test data that would allow the design engineers (both geotechnical and structural) to predict the actual performance and adequacy of the proposed drilled shaft foundations and improve the efficiency and hopefully reduce project costs.The lateral load testing was conducted within two solar fields at the site. Three pairs of drilled shaft foundations were installed in each field, instrumented, and laterally loaded to determine load-deflection response. A value-engineered option, proposed by one of the drilled shaft contractors, was also load tested. The results of the load-deflection data obtained in the field was used to modify the soil modeling used in the original L-PILE analyses and adjust the production drilled shaft lengths.Based on the results of the lateral load testing, the in-situ moduli of the subsurface soils were significantly increased over that assumed in the preliminary analyses. Based on the final soil-structure interaction analyses, the preliminary drilled shaft lengths were reduced by 2 to 2-1/2 feet. This resulted in an overall reduction of 55,654 feet of drilled shaft construction on the entire project, a savings of approximately 16.5% over the preliminary"

Jan 1, 2017

By H. Lyn Bourne

This is the fourth annual tabulation that gives mineral royalty information. The table presents previous information plus about two dozen new entries. In addition to the royalty information, some entries show the cost of purchased reserves. Last year's tabulation appeared in two issues, to accommodate all of the information. This year the format has been changed slightly so the table can be printed in one issue. This year's table presents the commodities in the same sequence as last year. Sand and gravel information appears first, followed by: crushed stone for aggregate; other stone; industrial sand; other industrial minerals; energy minerals (coal, oil shale, uranium); and finally metals. As always, a caveat relates to factors that influence the reserve values. The data should serve only as a general reference. The table is not intended to present an absolute scale of reserve costs. Several factors influence the value of mineral commodities. These factors include: • location and transportation costs (especially significant for most industrial minerals); • market conditions for both the commodity and the company acquiring the right to mine it; • quality or grade of the deposit as it reflects the amount of processing and beneficiation necessary to produce the finished product; • and legislative restrictions and conditions for mining a given material at a given site. These and other factors will influence reserve costs of reserves. The table shows the range of royalties and the variations in the basis of computing the fees. In a few instances, it gives the cost of acquired reserves based on purchase price and quantitative estimates of the material in place. The table lists the commodity; the location (either by state, US geographic area, or Canadian province); the cost (R for royalty and P for purchased cost); and the year in which the lease or purchase agreement occurred. The last column offers either comments or gives a footnote number for more information. The cost column requires more explanation. The units may refer to cubic yards (/yd), cubic feet (/cuft), tons (/T) (2000 lbs) or acres (/A). 1 cu yd = 0.76m3 1 cu ft =0.28m3 1st = 0.9 t7 1 acre = 0.40 ha or m2 In several cases the royalty is a percentage of the finished products, sale price and is levied against either the amount produced or the amount sold. We thank those who contributed information for the table: J. Dunn, T. Eyde, K. Loda, L. Morgan, F. Nix, H. Sorenson, and L. Williams. Several people have said they would like this to be an annual tabulation. That can happen if new information comes to the writer. What appears in the table is only a very small fraction of the cost information relative to the various commodities and the geographic areas for which there is royalty information. If you find this column of interest and possess information write or call: H. L. Bourne, c/o Neyer, Tiseo & Hindo, Ltd., 38955 Hills Tech Dr., Farmington Hills, MI 48018, (313) 553-6300. Only with new information can this become an annual and current source of reserves costs.

Jan 8, 1986