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By M. Haase

[ ] How important is a robust communications system for your mine site in order to meet operational and safety requirements? Do you currently have VSAT in place and need a low cost, high quality multi-line VoIP phone system at the site? By adding a single, compact piece of hardware, you can utilize your existing satellite internet connection and have as many as twenty-four separate phones lines from a single unit. The platform is scalable for any size of operation and can be implemented above or below ground.

Jan 1, 2012

By Gerald Edmunds

In a paper1 before this Institute in 1940, the writer reported that the surface orientation texture of zinc and cadmium differed from the texture existing within the casting, in that basal planes were parallel to the surface. He was unable to rationalize the , origin of this surface texture. It is conceivable that the surface orientation texture is influenced by the atomic force fields, which are different at the surface and within the body of metal. It was considered that a radical changc in the surface against which the metal is cast might alter the surface texture. In trial of this, zinc has been cast against a surface of molten lead, but the same result has been obtained—i.e., (001) parallel, ± 2oo, to the surface—as was obtained when it was cast against air, Transite or iron.' Into the bottom of an open cast-iron tray, 7 by 14 in. by 2 in. deep, preheated to about 275°C., about 1/4 in. of lead, then 1/2 in. of zinc was poured, and the whole was covered with an electric heater to enforce freezing from the bottom upward. After a lapse of time sufficient for the zinc but not the lead to solidify, the zinc slab was raised free of the molten lead. The bottom surface of the zinc casting was coated with a thin layer of lead. A specimen of the slab 136 in. square was metallographically polished to flatten it and remove the slight film of lead, and the orientation was determined by the method used before,' with the result stated above. Some determinations have also been made on other metals, as follows: Surface orientation determinations were made on the 3/8-in. diameter grip section of two 1/4-in. diameter aluminum-alloy die-cast tensile bars and on a 1/8 by 1/2-in. flat aluminum-alloy die-cast tensile bar. None of these three aluminum die castings exhibited any preferred orientation at the surface. A brass die casting (nominal composition: 60 Cu, 37.75 Zn, 1.00 Sn, 1.00 Pb, 0.10 Al, 0.15 Si) furnished by C. S. Smith was also examined. The surface showed a random orientation of alpha and beta. Summary A zinc casting solidified against a molten lead surface was found to have the same surface orientation texture, (001) parallel to the surface, as other zinc and cadmium castings. Aluminum and alpha-beta brass die castings were found to have random grain orientation textures at the surface. Acknowledgment The X-ray determinations were conducted by M. L. Fuller.

Jan 1, 1945

By T. M. Barczak, Zach Agioutantis

The Support Technology Optimization Program (STOP) has been developed by the National Institute of Occupational Safety and Health (NIOSH) to provide a comprehensive tool for evaluating the performance of available secondary roof support systems and designs based on support strength, convergence, cost, installation time and material handling considerations. This program uses engineering models developed from full-scale testing of numerous supports under controlled loading conditions in the unique NIOSH Mine Roof Simulator load frame to determine the support load-displacement performance as a function of the various sup- port design parameters. Both standing supports, such as wood cribs installed within the entry, and intrinsic supports such as cable bolts, can be evaluated. Support systems can be designed and compared for use in a new mining section or to evaluate potential replacements for an existing design. The support design requirements are defined from 1) estimating the failure height in the immediate roof, 2) in-mine measure- ments of support and strata interaction or development of ground reaction curves from numerical modeling, 3) the performance of an existing support system, or 4) from any arbitrary load and convergence criteria. All settings can be saved to permit resuming an evaluation in progress at a later time. This paper presents the updated MS Windows version of this tool, which can be easily installed and run on a personal computer. This Windows implementation will feature a project and application scenario setup where multiple scenarios can be assigned to one project. Scenarios can then be compared on support parameters and cost. Cost parameters can be provided either as individual cost items or using a price grouping feature. Additional support performance curves and/or additional ground reaction curves will be distributed with program updates as new information is developed. Users can also provide their own support and/or ground reaction curves.

Jun 25, 2024

By Gerald Edmunds

IN a paper1 before this Institute in 1940, the writer reported that the surface orientation texture of zinc and cadmium differed from the texture existing within the casting, in that basal planes were parallel to the surface. He was unable to rationalize the origin of this surface texture. It is conceivable that the surface orientation texture is influenced by the atomic force fields, which are different at the surface and within the body of metal. It was considered that a radical change in the surface against which the metal is cast might alter the surface texture. In trial of this, zinc has been cast against a surface of molten lead, but the same result has been obtained-i.e., (001) parallel, ±20°, to the surface-as was obtained when it was cast against air, Transite or iron.1 Into the bottom of an open cast-iron tray, 7 by 14 in. by 2 in. deep, preheated to about 275°C., about ¼ in. of lead, then) ½ in. of zinc was poured, and the whole was covered with an electric heater to enforce freezing from the bottom upward. After a lapse of time sufficient for the zinc but not the lead to solidify, the zinc slab was raised free of the molten lead. The bottom surface of the zinc casting was coated with a thin layer of lead. A specimen of the slab 1 ½ in. square was metallographically polished to flatten it and remove the slight film of lead, and the orientation was determined by the method used before,1 with the result stated above. Some determinations have also been made on other metals, as follows: Surface orientation determinations were made on the 3/8-in. diameter grip section of two ¼ -in, diameter aluminum-alloy die-cast tensile bars and on a 1/8 by ½ -in. flat aluminum-alloy die-cast tensile bar. None of these three aluminum die castings exhibited any preferred orientation at-the surface. A brass die casting (nominal composition: 60 Cu, 37.75 Zn, 1.00 Sn, 1.00 Pb, 0.10 Al, 0.15 Si) furnished by C. S. Smith was also examined. The surface showed a random orientation of alpha and beta. SUMMARY A zinc casting solidified against a molten lead surface was found to have the same surface orientation texture, (001) parallel to the surface, as other zinc and cadmium castings. Aluminum and alpha-beta brass die castings were found to have random grain orientation textures at the surface. ACKNOWLEDGMENT The X-ray determinations were conduced by M. L. Fuller.

Jan 1, 1945

By W. M. McKewan

The U.S. Bureau of Mines has established a wire rope research laboratory to examine the factors that affect the life of wire rope. A 2-in-diameter 6x25 fiber core rope was degraded on a bending fatigue machine. This was the first in a series of tests on rope of this construction and size. Baseline testing at the laboratory was reported in an earlier publication. Tensile and nondestructive tests were performed on samples of the rope to determine the relationship between rope deterioration and rope breaking strength. The tests indicated that as a wire rope nears the end of its useful life, deterioration and the consequent loss of rope strength increase at an accelerated rate.

Jan 1, 2010

By J. F. Archibald

This paper reviews the formation of the Canadian Mining Education Council (CMEC) and its terms of reference. CMEC considers that Canada?s mining schools represent a distinct competitive advantage to the Canadian Mining Industry. The core objective of CMEC is to reinforce the links between the constituent schools and their individual Industry Advisory Committees. The latter traditionally provide the schools with a great deal of guidance on a range of planning issues, including recruitment, curriculum, research and infrastructure. Beyond those bounds CMEC intends to improve its ability to network with the industry and government. It is concerned overall with the objective to raise the quality and level of its educational and research contributions to meet the needs of industry and society.

May 1, 2002

By Bruce Vandenberg, R F. Chiappetta

"The High Speed 2D Analysis program allows the user to bring in data from several different sources. Of course, keyboard entry is included as a source. Other data is inputted through the serial port (X-2321 of the PC. Two types of data are transferred via the serial port. The first is the tablet digitizer data. The three types supported presently are the GTCO, tablet digitizers. and the Calcomp 2500 and 9100 series To transfer digitized data turn on the selected digitizer and place the cursor on the tablet. Enter the High Speed pmg.ram and select from the Input Program menu the Digitize Inputs(20) option and follow the instructions. TO exit the session, either a keyboard entry or a cursor button is pressed. The second type of serial port input Is from the collectors of the listed survey systems. Typically a file transfer program will be used to send the data from the collector to the PC. This topic will not be addressed at this time."

Jan 1, 1989

By Y. Rao, Y. Huang, G. Wang, W. Liu

The properties and deterioration in strength of cemented tailings backfill (CTB )in the underground acidic environment under oxidizing conditions were studied. X-ray diffraction analysis and scanning electron microscopy of the surface of the CTB was carried out, and the sulphuric acid corrosion mechanism elucidated. The properties tested included compressive strength, elastic modulus, cohesion, internal friction angle, variation in the hydrogen ion concentration, and stress-strain relationship in different corrosion periods. The damage model of the CTB was established considering the effects of parameters such as corrosion time and strain on the damage evolution. It was found that the compressive strength, elastic modulus, cohesion (binder effect), and internal friction angle increased at first and then decreased with exposure time. In the long term, the peak stress decreased with corrosion time while the peak strain increased; elastic modulus, and deformation modulus also decreased. The damage caused by corrosion and by load were related by means of a mathematical model, which revealed the relationships between sulphuric attack, load, and damage to backfill in complex underground environments. During corrosion, the expansion of gypsum and ettringite caused microfractures in the CTB. With increasing corrosion time, micro-cracks developed and proliferated. The mechanism of corrosion damage was found to be the dissolution of hydrogen ions and a sulphate ion reaction that produces an expansive substance, resulting in deterioration of the strength of CTB.

Jun 1, 2021

By E. Shelobolina, S. M. Pickering, J. E. Kogel

A long history of weathering and bacterial alteration processes have transformed Georgia’s Coastal Plain kaolins from dark organic muds to recrystallized white pigment-grade industrial clays. A sequence of six stages in development of these valuable mineral deposits is outlined over their Late Cretaceous and Tertiary deposition and alteration history. Anaerobic and aerobic iron oxidizing and iron-reducing bacteria are present in the Georgia kaolins. These bacteria may have had a major role in iron and organic matter removal during several of the alteration stages that occurred over the past 60+ million years. Iron was likely solubilized by both iron-reducing and iron-oxidizing bacteria, depending on availability of Fe(II), Fe(III), and NO3. Thus, over long periods bacterial activity slowly led to nearly complete groundwater removal of iron from the kaolin deposits. Further bacterial iron removal on an industrial process scale may eventually prove feasible. “Without the multitude of living reactions as channels for energy and electrons and without the enormous capability of life to transfer with and against chemical gradients, there would be practically no or at least a very reduced geochemical rock cycle on this planet.” (Krumbein and Dyer, 1985, p. 157)

Jan 1, 2002

"Requests are frequently received by the Information Service of the Bureau of Mines for published information on the coals of different foreign countries, as compared with coals mined in the United States. The analyses of various coals from several countries on the Pacific, which were submitted to the Fuels Division for certain tests between the years 1913 and 1916, may be of interest, and are shown below: Results of Analyses of Various Coals from China, New Zealand, Japan and Australia."

Sep 1, 1925

By D. J. Parker

On Thursday, March 18, 1937, the country was shocked by news of a terrific explosion at the New London, Tex., school, which caused the death of 280 pupils avid 14 teachers. The explosion occurred at about 3:05 p.m. in the largest of the 11 school buildings on the campus. Fire 1 shows this building, marked "Main high school building", with respect to other buildings, pipe lines, oil wells, and gas lines or the property.

Jan 1, 1937

By M. Yavuz

Equipment selection in mining operations is an important issue, and also difficult to solve in multiple criteria environments. The paper in question has aimed to develop computer software for solving equipment selection problems in mining. In their paper, Basçetin et al. have analysed two case study problems related to open pit and underground mining method selection. By using Yager?s method1, the authors have selected 18 different criteria in the first case study and 21 criteria in the second case study. However, as emphasized by Ozdemir2, in pair wise comparison matrices the appropriate number of criteria should be seven as the maximum, from the point view of validation, consistency and redundancy. In cases where there are more than seven criteria to be handled, it is suggested that the criteria should be clustered and then the maximum number of clusters and subcriteria of every cluster should be limited to seven4.

Jan 1, 2007

By A. J. Kraemer

Few important improvements other than the development of cracking processes were made in technical petroleum refining from 1914 to 1919. Refiners were concerned mainly with enlarging their plants and erecting new plants to meet the growing demand for petroleum products. Shell stills operated as a unit or arranged in series for progressive or continuous distillation were the prevailing distillation equipment. Some improvement was made in condensers, but in most refineries of the period coils of pipe immersed in tanks of water were used to condense vapors and cool liquid products of the stills. Heat exchangers to conserve heat and reduce costs were more highly developed at California topping plants than at other plants. In this connection Wadsworth3/states: It is regretted that information concerning the operation of topping plants with eastern and Middle West oils is not available. The writer carefully canvassed the Middle West, but did not find a plant where operation had progressed beyond the early experimental stages and reliable figures could be furnished.

Jan 1, 1941

By Alan D. Akerman

This paper describes the significant advantages and improvements in operational availability, reduced breakdowns, and overall cost reductions that can be achieved through the application of a Reliability Centred Maintenance (RCM) program, including Condition Based Maintenance (CBM) and Equipment Health Monitoring (EHM), in a mine environment. It uses a case study to illustrate the essential elements that constitute the basic requirements to establish such programs. This CBM case study analyzed the Load-Haul- Dump (LHD) vehicle sub-systems and their dominant failure modes, as a precursor to the development of condition indicators. The case study describes a disciplined process to enable condition indicator development and qualification in support of a CBM program. The identified condition indicators vary from readily applicable off-the-shelf monitoring systems and techniques, through to "leading edge" technologies that require further research and development. The paper also explores the developments that have been made in the combination of expert system software associated with modern computer based control systems, and the availability of "intelligent? sensor technology that complement the control system capability.

May 1, 2002

These proceedings consist of papers presented at three Bureau of Mines Technology Transfer Seminars on ergonomics in the mining industry. These seminars were held in December 1981, and covered topics relating to ergonomics and mining in the areas of the man-machine interface, and design of the work environment. This area of research is directed toward reducing accidents traditionally associated with human error.

Jan 1, 1981

By Alan Jorgansen, Dave Hummer, Scott Scovira

Kennecott Energy's Colowyo Coal Mine is the largest open pit coal mine in Colorado and produces 5.5 MM tons per year. Colowyo uses the terrace mining method to recover up to seven seams of rolling coal ranging in thickness from 5 to 20 feet. Draglines are used to strip overburden ranging from 60 to 120 feet thick off two coal seams. These two seams are characterized by soft and fold fractured coal and in past practice cast blasting caused excessive coal damage. As a result, to ensure minimal coal damage and high coal recoveries, the overburden was excavated in two passes. The first pass removed the upper overburden to within 10 to 20 feet of the coal seam. The second pass removed the remaining overburden above the coal. Two-pass mining was effective in controlling coal damage, but also carried significant additional costs.

Jan 1, 2003

By Marion Loomis

Environmental regulation is an ever growing cost to the mining industry. Requirements for such items as air quality modeling, hazardous waste disposal, selenium concentration in water and sagebrush planting consume more of the mining industry’s resources each year. The mining industry is willing to make the necessary financial commitments to assure that the air, land and water resources are adequately protected and restored. However, it is sometimes difficult to explain to management and stockholders why money should be spent on a specific issue when science and common sense indicate it is being wasted. Common sense and sound science should dictate how mining is regulated.

Jan 1, 1994

By J. B. Carman

This paper, describing the mining practices and methods at the mine of the Molyb¬denum Corporation of America, is one of a series of similar papers on mining methods in the various mines of the United States being prepared by the Bureau of Mines. The mine of the Molybdenum Corporation of America is in the Red River mining dis¬trict, Taos County, northern New Mexico (fig. 1), The mill and camp are in the valley of Red River, about 7 miles east of the town of Questa; the mine is 1 ¼ miles away, in Sulphur Gulch, a tributary of Red River. The mine is about 600 feet higher than the mill, at an altitude of about 8,700 feet. The climate is cold in winter, but does not interfere serious¬ly with continuous operation. The mine normally produces about 40 tons of sulphide molybde¬num ore per day, which is concentrated at the local mill and chipped to the plant of the Molybdenum Corporation at Washington, Pa.; there it is made into either ferromelybdenum or "molyte" (calcium molybdate), for use in alloys. The ore is mined from narrow, irregular veins by the cut-and-fill method. About 65 men are normally employed underground and on the surface at the mine.

Jan 1, 1931

By David R. Gossett

For the 22nd year, the chance to exchange knowledge, experience and business cards drew hundreds of mining and phosphate professionals for a two-day regional Phosphate Conference in Lakeland, Florida Nearly 400 people participated in the October conference, which focused on the phosphate industry?s future success. There were 41 exhibitors, 13 program advertisers and 23 sponsors among those supporting the conference. It was chaired by David Gossett, 2006-2007 SME Florida Section Chairman. In the opening panel session that he chaired, John Garlanger (SME) of Ardaman and Associates posed the questions; ?How successful has the industry been? How do we measure it and what factors contributed to the industry?s success? How long will the ethanol boom last? Can the industry obtain the permits it needs to mine for the next 30 years? Can the industry attract and retain the quality of workers it needs??

Jan 1, 2008

By Thomas J. Weaver

Piles extending through soft soil near the ground surface will have a relatively low lateral stiffness. As a result, lateral serviceability limits may control the number of piles required for foundation support. Improving near surface soil properties may significantly increase lateral pile stiffness and thus reduce the number of piles required for the foundation. A series of analyses have been performed to assess the depth and lateral extent of soil improvement required to significantly increase lateral foundation stiffness. Analyses consisted of Winkler type beam on a spring foundation and three-dimensional, linear elastic finite element analyses. Results from the analyses show that lateral pile foundation stiffness can be doubled when soil properties are improved to a depth and lateral extent of 5 pile diameters. In order to achieve this increase in foundation stiffness, the modified/improved soil modulus of elasticity needed to be approximately 5 times greater than adjacent unimproved soil. This magnitude of soil improvement over such a limited lateral extent suggests that limited soil improvement can result in more economical foundation designs at soft soil sites.

Jan 1, 2006