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By D. Randolph Berry

The United States Bureau of Mines (USBM) awarded a contract to Foster-Miller, Inc. to develop guidelines for the storage and use of Self-Contained Self-Rescuers (SCSRs) in underground non-coal mines. An SCSR is a device capable of supplying, in an emergency, one hour of self-contained oxygen (no breathing of mine air). The information and recommendations in this report were developed primarily from three sources: discussions with mine representatives (including management, labor, and government), site visits in underground mines I and a detailed analysis of every reported non-coal accident which produced d hazardous atmosphere during the 5-year period 1976-1980 -plus ten other major incidents from prior years. Volume IV has three major sections: Recommendations and Discussion (Section 2), Analysis of Mine Accidents (Appendix A), and a Summary of Discussions with Mine Representatives (Appendix B).

Jan 1, 1983

By Joseph Daniels

[Adequate supplies of suitable coal and coke are prime requisites in many industries, particularly those dealing with the utilization of mineral resources, recently interest has been focused on the possibilities of using electricity produced at Bonneville and Grand Coulee, Wash., in many electrochemical and electrometallurgical processes, in which core or some form of carbon is necessary in addition, discussion has been revived on the possibility of making iron and steel by the conventional methods employed in blast and open-hearth furnaces. The subject also is important at this time because of its relationship to industrial preparedness for national defense. A supply of coke from local sources on the Pacific coast is necessary in any program of production for strategic sufficiency of certain materials. An anal trio involving tae establishment of such industries should include detailed data on available supplies of coal, the quality and properties of the coke produced, and the technologic and economic factors involved in manufacture of echo and disposal of byproducts.]

Jan 1, 1941

By Robert E. Wood

The temperature dependency of the low-density viscosity coefficients, ?°T, of helium and of nitrogen, 100° to 1,000° K, is correlated with empirical equations, and the temperature and composition dependencies of the low-density viscosity coefficients, ?°T, of helium-nitrogen mixtures are correlated with the Chapman-Enskog expressions by using the Lennard-Jones (6:12) potential function. The residual viscosity, ?T,P - ?°T (the difference between the viscosity of a compressed gas and the dilute gas at a given temperature), was found to be a function of the thermal pressure coefficient, (?P/?T)V, and two parameters, a and 1, which are characteristic of gas composition. The equation ?T, P = ?°T + a [(?P/?T)V]ß represented 1,340 higher pressure experimental viscosity values with a mean absolute deviation of 0.86 percent, and this equation was used to compute viscosities of the gaseous helium-nitrogen system for a range of temperatures and pressures including those encountered in Bureau of Mines helium purification processes and in a crude-helium conservation gas reservoir. Tabular viscosities for helium, nitrogen, and 13 helium-nitrogen mixtures are presented for 110 temperatures, 133° to 740' K, and 49 pressures in the range 1 to 240 atmospheres. The accuracy of the tabulated viscosities varies because correlation parameters were obtained from experimental data of unequal reliability. It is estimated that uncertainties in the computed viscosity values are ±5 percent for the region 325° to 740° K, ±2 percent for the region 183° to 325° K, and ±5 percent for temperatures below 183° K. The latter uncertainty may rise to y10 percent as critical conditions are approached.

Jan 1, 1970

By M. L. Glenn

The Bureau of Mines is conducting research on Fe-based alloys using Si and Al additions to reduce the Cr required for heat-resisting appli-cations. Part of this research is being done to evaluate alloys containing (8-10)Cr-(10-14)Ni-(0-8.5)Si-(0-4) Al to determine which of these alloys have austenitic structures, as well as fabrication properties and oxidation resistance sufficient to substitute for type 304 stainless steel. Based on initial results, an Fe-lOCr-11Ni-5Si alloy and an Fe-8Cr-13Ni-5Si alloy were selected for evaluation of oxidati.on, stress rupture, and tensile properties. Both alloys have oxidation resistance at 7000 and 8000 C that is better than that of type 304 stainless steel. The stress rupture strengths are less than that of type 304 stainless steel but significantly better than that of commercial heat-resisting steels with similar Cr contents. Yield strengths of the alloys were equivalent to that of type 304. Both alloys had high tensile strengths comparable to those of stainless steels that transform to martensite during straining (e.g., type 301). These alloys have weld-hot-cracking resistance comparable to that of type 304 stainless steel. This initial study shows that Si has potential as a substitute for Cr in stainless steels for heat-resisting applications.

Jan 1, 1984

By Thomas M. Barczak

This U.S. Bureau of Mines report is intended to assist coal mine operators in the selection of longwall supports by providing advanced guidelines for performance testing and standardized test documentation to facilitate support comparisons. These advanced guidelines culminate in a series of proposed tests to evaluate (1) support resistance characteristics, (2) stiffness characteristics, (3) leg mechanics, (4) stability, (5) load transfer mechanics, and (6) structural integrity. The Bureau has conducted extensive studies on shield mechanics to identify boundary conditions that induce loading in support components, which is often not included in current testing techniques. This report discusses influential parameters that affect support behavior and provides insight into how components are loaded and what conditions produce the most severe loading. Testing philosophies and techniques in both active and static frames are discussed. Proper methods for determining support resistance are described and instrumentation requirements for advanced performance testing are provided.

Jan 1, 1989

By WM. H. RINKENBACH, C. A. Taylor

No complete work on explosives, their constitution and analysis, has hitherto been published. Several books that contain chapte.r;s on analysis do not cover the matter thoroughly. Methods tha;t, manu~ facturers, testing stations, and other . agencies have developed to meet their own requirements have not been made public. The Bureau of Mines has issued four publications 1 - cov:eri:ng special phases of the subject. This bulletin. is not inte.nded to replace those reports, but rather to cover present methods employed 'in the , industry and to include all classes of explosives and the materials used in their manufacture. No sharp distinctions can be drawn between classes of explosives. . Surplus military explosives, for example, may be used for blasting, just as blasting explosives, under some conditions, may be employed for military purposes. Moreover, one class gradually merges into another because of similarity in composition. Explosives are here grouped as dynamites, black powders, propellants, detonators, and primers. Some materials are used in practically all these groups ; others in only one. To discuss all the materials that have been or that may be used and the methods for their identification and quantitative determination is not feasible, but the methods described will probably suggest ways of examining new mixtures.

Jan 1, 1923

By Robert C. Steckley

A study of joints in Marathon County, Wis., was made to determine the orientation of regional paleotectonic stresses and to develop a method of using optical diffraction analysis (ODA) in studying joint orientations and spacings. Standard geologic and petrofabric techniques employing the use of a geologic compass and a Schmidt net were used in gathering, describing, and reducing joint orientation data. Analysis of selected outcrops with ODA indicates that ODA can be applied to study both joint orientations and spacings. ODA is shown to be a rapid method that can be used to complement standard petrofabric techniques, especially in the study of joint spacings.

Jan 1, 1972

By C. Daniel Kealy

Finite-element,, mathematical models that solve LaPlace's and Richard's equations numerically were used to locate the phreatic surface within tailings pond embankments and to define the subsurface flow of water from the pond. Both must be known to design structurally and environmentally safe tailings dams. The permeability distribution within and beneath the embankment, the fluid potential values upgradient and downgradient from the embankment, and the geometry and elevation of an approximately impermeable layer at some depth beneath the embankment were used as computer inputs in analyzing over a dozen finite-element models of tailings dams varying structurally from simple to complex. Results predicted with the finite-element model were confirmed with measurements in a laboratory model of a tailings pond and in the field. Of particular importance to the design of safe slopes, all data indicated that the phreatic surface within a tailings dam is concave upward, a configuration opposite that in most earth dams. The close correlation between predicted and experimental values confirmed the practicability of using the finite-element technique to design safe tailings dams.

Jan 1, 1971

By J. J. Wallace

This report describes the initial phase of Bureau of Mines research in the hydraulic mining of bituminous coal. The mining site and equipment are described, and the test procedures and results obtained with a bar-mounted monitor are given. Tests showed that hard Pittsburgh-bed coal can be mined hydraulically from a solid face at water pressures of 4,000 pounds per square inch.4 Coal was penetrated to a depth of 4 feet in 20 seconds with 225 gallons of water per minute coming from a 3/8-inch nozzle at 4,000 pounds per square inch pressure. Some difficulty was encountered in cutting the binders occurring in the coal; it was not possible Lu penetrate directly the overlying draw slate.

Jan 1, 1961

By John C. MacCartney

In the Pennsylvania anthracite region, the principal source of U.S. anthracite, refuse disposal problems are common since cities and towns are located over the anthracite measures. The Bureau of Mines surveyed refuse banks in the area, determining that 863 banks containing aver 910 million cubic yards of material occupy a total area of about 19 square miles. The vast bulk of the refuse is located within 2 miles of the traffic centers of incorporated c unities which have a total population of 625,000. Twenty-seven banks are burning, causing considerable distress in a number of communities.

Jan 1, 1969

By Alfred Wild

The Kraftile Co. plant, Fremont, Alameda County, Calif.--the largest producer of glazed, structural wall units west of the Rocky Mountains-- maintains modern processing facilities to evaluate and blend a wide variety of clays from several sources to produce quality products. The report desribes the prospecting, exploration, and test methods used to locate raw material sources and covers processing methods, cost factors, and trends. Also, the geologic and ceramic factors are considered in a general discussion of the economics, potentials, and requirements of clays as raw materials for ceramic tile manufacturing.

Jan 1, 1963

By J. E. Tress

The Bureau of Mines prepared submicron tungsten powder by reducing tungsten hexachloride with hydrogen. The particle diameters of the resulting tungsten powders ranged from 0.015 to 0.046 micron. Within the limits of the variables investigated, no clear-cut correlation was found between process conditions and final size of the powder. Oxygen was the major contaminant in the product; being present both as an adsorbed gas and as suboxides of tungsten. Studies showed that the powder yielded compacts of approximately 45 per-cent of theoretical density when compacted mechanically. Low-temperature sintering produced more rapid densification in these compacts than in compacts prepared from conventional powders. Adding up to 20 percent ultrafine powder to conventional tungsten powder caused an increase in density upon compaction with maximum densification occurring at approximately 12 percent ultrafine powder.

Jan 1, 1966

By P. M. Ambrose

This report describes an accident, which took place in the Chemical Corrosion Laboratory at the College Park, Md., Station of the Federal Bureau of Mines. The accident occurred while Walter L. Acherman, chemist, was performing a routine manipulation during a corrosion experiment involving commercially pure titanium and red-fuming nitric acid. There was a sudden and very violent reaction, and a large quantity of acid was thrown in the face and over the body of Acherman, causing serious injury. L. B. Golden, chief of the Chemical Corrosion Section, was exposed to nitric acid fumes during the ensuing rescue and first-aid operations and died on January 25, 1954. According to the medical report, the direct cause of Mr. Golden's death was pulmonary edema and confluent bronchopneumonia; the contributary cause, was inhalation of fumes from red fuming nitric acid. The following employees of the College Park Station contributed to this report by supplying information on the accident and assisted in the rescue operation: L. B. Golden, chief, Chemical Corrosion Section; T. E. Green, chemist; Robert Warf field, chemist; L. A. DeVivo, laboratory mechanic; D. W. Chalkley, laboratory mechanic; E. H. Neagle, laboratory welder; and R. L. Heath, laboratory general mechanic.

Jan 1, 1955

By Alfred Wild

The Kraftile Co. plant, Fremont, Alameda County, Calif.--the largest producer of glazed, structural wall units west of the Rocky Mountains--maintains modern processing facilities to evaluate and blend a wide variety of clays from several sources to produce quality products. The report desribes the prospecting, exploration, and test methods used to locate raw material sources and covers processing methods, cost factors, and trends. Also, the geologic and ceramic factors are considered in a general discussion of the economics, potentials, and requirements of clays as raw materials for ceramic tile manufacturing.

Jan 1, 1963

By Ruth F. Brinkley

This circular describes the activities and publications of the Bureau of Mines, Explosives Research Laboratory4 for the fiscal year 1960 (July 1, 1959 -June 30, 1960). Part 1 describes briefly the principal projects that were active during the report period, and presents some data not scheduled for publication elsewhere in the near future. Certain of the results are only preliminary and should be regarded as tentative, pending the findings of the completed investigation. Publications that appeared during the report period are listed and described briefly in part 2. In general, the research activities reported in these publications antedate fiscal year 1960. The published material relating to activities that are still current is indicated by references in part 1.

Jan 1, 1962

This publication summarizes the research (in-house and contract projects) programmed by the Bureau of Mines for fiscal year 1984 (October 1, 1983-September 30, 1984) under its Health and Safety Technology Program. The objective of these projects is to provide an ordered and sequenced advance toward the Bureau's overall goal of providing the systems technology required to create a more healthful and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1983

By S. B. Christy

This report on the electrodeposition of gold and silver from cyanide solutions represents work that has occupied my time at intervals during the past 20 years. The investigation has been carried on simultaneously with my duties as professor of mining and metallurgy of the University of California. During shis long investigation I have been assisted in the details of the work by, a number of my former students, acting in turn as assistants. Particular mention in this connection is due W. H. Hilton, who graduated in 1900; C. T. Dozier, 1902; N. C. Stines, 1905; H. N. Herrick, 1907, and L. C. Uren, 1911. It is impossible to publish full details of the many thousands of experiments performed. Effort has been made to present only the essential data. Wherever possible, the results of the experiments have been expressed in diagrammatic form by curves showing the relation between the simultaneous variables of the experiments. It is necessary to show, as nearly as may be, the state of the art. This is difficult because of the meager literature on electrodeposition in the cyanide process; hence resort must be had to the specifications and claims of patents, most of which seem never to have been applied on a working scale. Such information consequently can not be taken at its face value. Expressing the essential ideas evolved in such specifications is no easy task. Clearly, in quoting from patent records it is not ·feasible to enumerate all of the specifications or the claims allowed the inventors. A statement of the chief contributions to the art in the patent cited must suffice. Legal details, of course, must be obtained from the original patent. In the study of patent literature, when one compares the ardent hopes of the inventors with the results realized from their efforts, it becomes clear that in the development of an art no one man contributes everything. Each subsequent inventor stands on the shoulders of the one who has gone before. It is only through the summation of the contributions of many inventors that the art as a whole prospers. On October 19, 1887, a British patent was granted to McArthur and Forrest for the use of dilute cyanide solutions for treating gold and silver ores. The rapid extension of this process, in various forms, all over the world, has almost revolutionized the treatment of ores containing precious metals. It is a remarkable fact, however, that long before this patent was granted there was issued, on February 5, 1867, to J. H. Rae, U. S. patent 61866, for an electrocyanide process. Thus a method of electrodeposition from cyanide solutions used for treating ores was invented 20 years before the McArthur and Forrest patent .was granted, although the process did not come into general use. On May 24, 1889, U. S. patent 403202 was granted to McArthur and Forrest for the use of zinc shavings for removing gold and silver from cyanide solutions. The use of finely divided zinc is still the standard method for recovering 'gold and silver from cyanide solutions. Since this patent was granted, many attempts have been made to replace the precipitation upon the zinc by methods of electrodeposition. It is the purpose of this report to give an outline of some of these methods, as well as to show the relative advantages and disadvantages of the zinc and the electrical methods of recovering gold and silver from cyanide solutions.

Jan 1, 1919

The purpose of the contract was to develop an improved coal mine dust sampler whose electrical-to-mechanical energy conversion efficiency would be superior to that of the presently available equipment. The electrical to (pressure) X (volume) conversion efficiency directly affects the size and weight of the air samplers. At least half of the mass of present equipment is composed of the rechargeable batteries. Any increase in efficiency will allow this mass to be reduced or the flow rote to be increased.

Jan 1, 1974

By James Westfield

Bureau of Mines activities for safety and health in the mineral industries were reorganized during the fiscal year to provide direct supervision by the Assistant Director -Health and Safety. On December 19, 1954, the field offices conducting these activities were designated as district health and safety offices reporting to the Assistant Director. The functions of determining the causes of accidents and injuries in the mineral industries and recommending measures to eliminate them were continued, with satisfactory results in improved safety records. The inspection of coal mines and enforcement of the Federal Coal Mine Safety Act of 1952 were conducted as directed by the Congress, and safety conditions in the mines were notably improved. One coal-mine explosion classed as a major disaster occurred during the year. The causes of that explosion and means for preventing a recurrence were still under investigation because of the extreme difficulty in recovering several portions of the mine. Basic research on the nature of certain hazards and ways of eliminating them is continued. Training of individual workmen and supervisors in this knowledge is a major part of the work.

Jan 1, 1956

By B. W. Jong

The Bureau of Mines studied reinforcement of sulfur concretes using glass, polyester, and aramid fibers. The objective of this research was to determine the feasibility of fiber-reinforcing the sulfur concrete to enhance the flexural properties. Optimum fiber sulfur concrete compositions were formulated with a cement-to-fiber ratio of 9.0:1 for glass-fiber and polyester-fiber sulfur concretes and 12.1:1 for aramid-fiber sulfur concretes. Test samples were prepared using techniques developed by the Bureau of Mines. Flexural strength values of up to 50 pct of compressive strength values were achieved with fiber additions. With non-fiber-reinforced sulfur concrete, the values ranged up to 20 pct. The impact strength and fracture toughness of sulfur concretes were increased sig-nificantly by reinforcement with glass or with aramid fiber and were adversely affected by use of polyester fiber. Strain tolerance was doubled and failure mode was shifted from catastrophic to noncatastrophic type by adding glass fiber. The glass-fiber and aramid-fiber sulfur concretes are resistant to acid corrosion and have proved durable in freeze-thaw cycles. This laboratory and field evaluation has shown that fiber reinforcement of sulfur concrete is feasible and that it enhances the flexural properties.

Jan 1, 1985