Search Documents

By James H. Russell

The Bureau of Mines used a statistical approach to evaluate the effects of temperature, current density, and composition of the electrolyte on the purity of boron prepared by electrolysis of a fused mixture of boric oxide in potassium fluoborate. The quadratic equation which best fits the data was calculated for a temperature of 650° to 850° C, a cathode current density of 40 to 1,150 amp/ft2,and a boric oxide content of 0.3 to 7.1 molal. The best products, better than 95 percent boron, were obtained when the current density was less than 2 amp/ft2 and the boric oxide content was less than 2 molal.

Jan 1, 1967

By Oliver Bowles

"Simple systematic accounting that adequately records all transactions has long been regarded as essential to the welfare of any business enterprise. Some of the defects that detract from the prosperity of the slate industry are attributable to a lack of effectiveness in cost keeping. This condition has prompted the United States Bureau of Mines to make a detailed study of accounting methods for the slate industry, and to present for consideration a system of accounts, which it is believed would enable the industry to attain more economical management and operation if accepted by a fair proportion of its important units.The method of accounting presented herein has been worked out with the assistance of leading slate producers and the recommendation are tentative and are submitted in this form as a means of developing constructive criticism. Believing that cooperative effort in this, as in many other problems, will bring the most enduring benefits to the industry as a whole, the writer urges that the most earnest consideration be given to this vital problem now facing the slate industry.Grateful acknowledgment is made of the helpful assistance rendered by R. E. Eckert of the accounting firm of Eckert, Degan, and Palmer of Easton, Pa., in compiling the charts and the explanatory text. He has brought to this work a wide knowledge of accountancy, supplemented by a background of direct contact with the slate industry, and his presence at the various conferences has been of great advantage in clearing up difficulties. The National Slate Association sponsored the cost study and chiefly through the efforts of President W. H. Smith and Secretary W. S. Hays, has aided greatly in conducting it. Acknowledgment is also made of assistance rendered by William F. Marsh of the United States Bureau of Mines."

Nov 1, 1929

By Eric L. Trist

The objective of this contract was to review the results of the Rushton Mining experiment in work organization and design, to explore the extension of knowledge gained from Rushton to other underground coal mines, and to conduct a search for a potential mine site for a demonstration project. The primary focus of the contract was on a search process to provide the research team with the opportunity to evaluate the different potential experimental sites, in order to select one or more with the highest potential for success. This search process also provides the various levels of union and company officials the opportunity to fully understand the context of the research before making a decision on whether to participate. While the search project failed in its attempt to locate a specific mine site, the research team believes that this is not a rejection of the actual project but rather extreme caution because of the uncertainty within the UMWA.

Jan 1, 1978

By Mark K. Larson

A constitutive model for rock interfaces based on the principles of static fatigue is proposed. The model is applicable to weak rock or joints with cohesion. Friction and dilation are decreased as plastic work increases. At equilibrium, the creep time increases by one time-step interval, and interface cohesion at each node decreases according to a power function. A constant-load, direct-shear simulation showed that the model is cap- able of mimicking constant-rate and tertiary creep and predicting failure. Tests on core from a coal mine showed constant-rate and, sometimes, tertiary creep, but also weak transitory creep. The cohesion deterioration function may need modification to simulate primary-phase creep. If model parameters are known for a site, the model can predict the onset of tertiary creep and failure. Such predictions can help engineers make better entry design and support decisions, which will reduce the likelihood of roof falls and increase safety for underground miners.

By R. L. Crosby

A part of the liquidus of the magnesium-zirconium system was determined by chemical analysis of suction samples taken from the melt in the approximate temperature range of 850° to 1,450° C. The melt was prepared in a furnace pressurized with an inert gas. The average zirconium value in weight-percent of the liquidus composition at each sampling temperature was 0.96 at 867° C, 1.40 at 1,062° C, 2.05 at 1,262° C, and 2.96 at 1,402° C. The equilibrium solid phase was zirconium.

Jan 1, 1965

This report describes the redesign, development and field demonstration of a remote shotcrete lining system, capable of operating in shafts and mines from 8 to 16 feet in diameter at depths up to 1000 feet. The original contractural scope of work outlining problems and remedial measures associated with a previous unit proved inadequate. Significant additional effort was necessary in order to fulfill the project objectives of producing a functionally reliable remote shotcrete lining system. Included with the engineering and technical description of the system, is a comprehensive technology package. Included with this material is ancillary equipment, materials selection procedures, mix-design data, quality control and assurance program, selection and training of personnel and the organizational aspects required to operate the entire system. The report concludes with details of a successfully completed borehole lining operation at the Nevada Test Site. An irregular 104 inch diameter borehole was lined at a rate of 4.8 feet per hour and 20 feet per hour respectively for 8-9 inch and a 2 to 3 inch shotcrete thickness.

Jan 1, 1983

By Sidney Katell

This report, covering the period January 1965 through December 1965, is a continuation of a series that began with the publication of Information Circular 7516 in October 1949. It is the seventh in a series of reports prepared in cooperation with the American Association of Cost Engineers. The abstracted articles are concerned with all phases of cost engineering in the field of chemical and petroleum plants and related subjects. They are From the following sources:

Jan 1, 1966

By A. J. Farstad

Electromagnetic location tests were conducted by Westinghouse Georesearch Laboratory under the sponsorship of the U. S. Bureau of Mines at the Galena Mine in Northwest Idaho. The objectives of these tests were to evaluate the performance in deep hardrock mines of an electromagnetic location system previously developed for the U. S. Bureau of Mines for use in coal mines. Tests were performed using long wire transmitting antennas as well as horizontal and vertical transmitting loops at depths from 3000 feet to 4300 feet (995 metres to 1311 metres). Surface measurements were made of magnetic field strengths, field strength patterns, and background noise, These measurements were compared with theoretical predictions for a homogeneous ground conductivity consistent with this particular geologic region. The results of the Galena Mine tests show conclusively that light-weight portable electromagnetic transmitters can be effectively utilized to provide uplink communications and location information in deep hardrock mines. Typical metal mines such as Galena utilize deep vertical shafts for mine access and haulage and these shafts produce signal enhancement at the surface from underground electromagnetic transmitters by as much as 30 dB. The results also show that horizontal wire configuration can serve as an effective alternative to the magnetic dipole antenna as a rescue transmitting antennaa and can be used when the required area is not available for deployment of a loop antenna. In spite of the electromagnetic coupling effects observed in the vicinity of the shafts, the location accuracy obtained still provided useful information on the general location of the transmitting sources involved. The horizontal wire location accuracy was within 46 metres, while the vertical magnetic dipole and the horizontal magnetic dipole accuracies were within 152 metres and 110 metres respectively at a 915 metre depth.

Jan 1, 1973

By A. F. Robertson

"INTRODUCTION This report is supplemental to R.I. 4178 and deals with the work accomplished between June 15, 1945, and September 7, 1945, on the Mitchell-Hodge mine, Grady mine, Albea and York property, and Cuzzort property.ACKNOWLEDGMENTSIn its program or exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigcal Branch, O. C. Ralston, chief, analyzes samples and performs benefication tests.Acknowledgment is due Mitchell H. Kline, chief, Raleigh Division, Mining Branch; Abraham L. Fox, acting chief, Raleigh Division, Metallurgical Branch; and Rowe McCrae, district engineers, U.S. Bureau of Mines, Gainesville,"

Jan 1, 1946

By H. A. Watson

Laboratory tests on three commercial methane detectors, two combustion-type detectors and one interferometer-type detector, were made by the Bureau of Mines to determine their response to certain single and multiple flammable gases mixed with normal and abnormal air atmospheres. Although both types of detectors responded accurately to methane-normal air mixtures, they did not show correct concentrations for other single flammable gases in air. Uniquely, the response of the interferometer-type detector to hydrogen was in a negative direction. The effects of individual gases in multiple flammable gas mixtures were approximately additive. In oxygen-deficient atmospheres the methane response of the interferometer-type detector erred on the high side, but only in very low oxygen concentrations were the combustion-type detectors affected-showing low, erratic methane readings.

Jan 1, 1966

By C. R. Sponsler, O. C. Blade

"INTRODUCTION This report on the properties of motor fuels sold through service stations in the United States is a continuation of a series of reports made in accordance with a cooperative agreement between the Coordinating Research (CFR) Committee of the Coordinating Research Coouncil (CRC) 4/ and the Bureau of Mines of the United States Department of the Interior. The first of these reports presented data on motor gasolines sold during the winter of 1935-36. 5/ Further reports were issued describing motor gasolines sold during the succeeding summers and winters to and including the summer of 1941. 5/ reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed. 5/The present report presents analytical data for samples, representing the products of approximately 100 companies. Most of the samples represented in this report were obtained during December 1)55 and January 194o. As in previous surveys, the companies covered by the survey include both large and small suppliers. Conforming to former reports, the data cover three groups of samples - regular-price, premium-price, and third-grade gasolines.As the number of analyses submitted for samples of third-grade gasoline are not considered adequate to represent this type of motor fuel, data for the analyses have not been averaged, but the individual items are tabulated. The number of samples, items, and brands comprising each group is as follows:Regular-price, 1,958 samples, 317 items, and 96 brands; premium-price, 1, samples, 292 items, and 85 brands; third-grade, 58 samples, 22 items, and 14 brands. The meanings of these terms as used in the surveys are as follows;"

Jul 1, 1946

By Richard Lusignea

A single boom roof bolting machine was outfitted with measurement and recording systems for detecting changes in machine parameters while drilling. The purpose of this instrumented bolter or "smart drill" is to detect changes in roof conditions from the machine parameters of penetration rate, thrust, rotation rate, torque, rejected light from rock cuttings, and vibration of the roof during drilling. The system was demonstrated underground in coal mine conditions and showed correlation between rock type and drilling parameters.

Jan 1, 1982

By Cliff McCartney, Michael A. Trevits

The National Institute for Occupational Safety and Health (NIOSH) is conducting a program of research to evaluate and improve remote mine seal construction technology for mine fire control and suppression. The main focus of this work is to develop reliable technology that will remotely seal a mine opening from floor-to-roof and rib-to-rib. NIOSH, in partnership with Strata Mine Services Inc.1, is evaluating the capability of a two-component phenolic foam-based product, called Rocsil®1, that is intended for cavity filling, air and gas sealing, and consolidation of highly fractured strata. Rocsil® can be rapidly applied, has a quick cure time, a high expansion rate, good compressive resistance and excellent anti-static properties. When the resin and catalyst are mixed, an immediate foaming reaction occurs followed by rapid expansion up to 30 times the original volume. By virtue of its fire-resistance properties, Rocsil® foam has application for sealing underground mine areas undergoing heating from spontaneous combustion and it could be useful for remote mine seal construction to aid in mine fire control and suppression. This paper presents an overview of remote mine sealing technology, introduces the use of Rocsil® foam for remote mine seal installations, offers a case study of the use of this rigid foam material to remotely construct a temporary in-mine seal and discusses technology improvements. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of NIOSH.

By H. D. Hunt

This paper which describes the milling practice of the Miami Copper Co. is one of a series being prepared by the United States Bureau of Mines. LOCATION The mine, concentrator, and other surface plants of the Miami Copper Co. are located near the town of Miami in the Globe-Miami mining district of Gila County, Ariz.

Jan 1, 1932

By V. H. Gottschalk, John Grodd, R. S. Dean

"Elemantary ConsiderationsAlthough magnetiem was first discovered in and derives its name from an oxide of iron found in magnesia and called lodestone its pracical uses date from the discoveries of Faraday concerning its relation to the electric current. We may therefore start our discussion of magnetic properties with Faraday's law for relation between induced electromotive force and the change in a magnetic where e is the electromotive force induced in an electric circuit by a unit rate of change of magnetic flux N, H is the intensity of the magnetic field, S is the area enclosed by the circuit, and i an angle between H and the normal to dS. In the simplest case we could use this law to measure the strength of a magnetic field by passing it at a measured rate through a coil of copper wire and determining the,electromotive force. As a matter of practical convenience, it will be simpler to nee the total quantity of electricity produced by a change of magnetic field. For this purpose we may let i denote the strength of the electric current induced by the change of magnetic field in time in a circuit of area a and resistance R. Then the total electric quantity. Q is given. by"

Mar 1, 1934

The objective of this study was two-fold: 1. To perform a world literature search pertinent to the analysis, selection and design of hoisting systems and their components and to codify the search into a literature compendium. The search resulted in a technical data file of over 1500 hard copy items. The compendium index was also suitable for establishing a comprehensive computer-loaded data base on the subject. 2. To develop a comprehensive system of guidelines to cover salient aspects of analysis, selection and design of electrical, mechanical and structural components of a hoisting system with a view to establish parameters for maximum safety and efficiency of operation, installation and revision of the system. 3. Major mechanical components in the hoist and mechanical drive train are considered. Design and specification criteria based on American standards and practices are developed as they apply to typical mine hoist arrangements.

Jan 1, 1988

By C. A. Geffen-Fowler

This report, sponsored by the Bureau of Mines, presents the results of an examination of the safety of the Blind Shaft Borer (BSB) shaft sinking system and an alternative modified BSB design concept in comparison to conventional shaft sinking technology. Detailed study of the two systems was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the BSB systems with conventional shaft sinking was made an the basis of relative risk levels. Risk incorporates both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the two BSB systems was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that both BSB systems are safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by over 30%, on the average, with the use of the original BSB system, and by an average of about 10% with the modified BSB. Design change recommendations to further improve the safety of these systems include a better fire suppression system, improved man haulage systems and more compact hydraulics. An operational safety manual was also developed for the modified BSB system.

Jan 1, 1981

By J. H. Bilbrey

A recording thermobalance ,vas used to determine the rates of oxidation of mol-ten tin over the temperature range 550°-900° C. Oxidation rates were found to vary widely for a given temperature, as previously reported by other investigators. 1 X-ray diffraction data indicated that the probable cause of these variations was the development of preferred orientations in the crystals forming the oxide film. No reasons for the differences in degree of preferred orientation were discovered. For relating the weight of the oxide formed (w) to the time of oxidation (t) an equation of the form wn = kt was found to best represent the experimental data. INTRODUCTION In the course of conducting investigations on the feasibility of using selective oxidation techniques for the purification of various metals in the molten state it was soon discovered that data on the oxidation of molten metals and alloys were very scarce. In contrast to the many hundreds of publications on the oxidation of metals in the solid state there are relatively few articles on the rates of molten-metal oxidation. In view of this scarcity of data, it was decided to institute a series of investigations into the oxidation processes of molten nonferrous metals and alloys with the expectation that the information derived could be put to practical use in developing and improving refining processes based on selective oxidation. This report is the first of a series in which oxidation data for molten nonferrous metals and alloys are presented.

Jan 1, 1955

By B. J. Moore

This publication contains routine analyses and related source data for 528 natural gas samples from 21 States collected during calendar year 1965 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the' Bureau of Mines since 1917. The analysis published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4

Jan 1, 1966

By B. J. Moore

This publication contains routine analyses and related source data for 528 natural gas samples from 21 States collected during calendar year 1965 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the Bureau of Mines since 1917. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4

Jan 1, 1966