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By J. D. Davis

THIS REPORT gives results of an investi¬gation of the carbonizing properties of coals from Pittsburgh bed, Jamison No. 9 mine, Marion County, W. Va., and from Upper Freeport bed, Bull Run No. 1 mine, Preston County, W. Va. The study included Bureau of Mines-American Gas Association tests at 800° and 900° C. and various chemical and physical tests designed to evaluate the plastic, expanding, and agglutinating properties of coal. A blend of each coal was carbonized in the 500-pound slot oven. The carbonization sample of Pittsburgh coal contained 2.7 percent moisture, 35.8 percent volatile matter, 54.4 percent fixed carbon, 7.1 percent ash, and 0.9 percent sulfur. It contained 60.9 percent fixed carbon on the dry, mineral-matter-free basis and had a heating value of 14,780 B. t. u. per pound on the moist, mineral-matter-free basis. It therefore ranks as high-volatile A bituminous and was blended with low-volatile Pocahontas No. 3 coal. Upper Freeport coal contained 2.8 percent moisture, 27.7 percent volatile matter, 60.9 percent fixed carbon, 8.6 percent ash, and 1.0 percent sulfur, as carbonized. It contained 69.5 percent fixed carbon on the dry, mineral-matter-free basis and therefore ranks as medium-volatile bituminous. It was blended with high-volatile A Pittsburgh coal from Allegheny County Pa.

Jan 1, 1952

By Thomas M. Barczak

Wood cribs are used extensively by the mining industry to stabilize mine openings. While the cost per crib is relatively low, their extensive use can result in annual mine costs of over $1 million. In an effort to improve the utilization of these supports and to reduce ground control hazards, the U.S. Bureau of Mines has developed engineering methods to assist mine operators in wood-crib design and employment. Design and employment criteria are established based on the strength, stiffness, and stability of the crib structure in relation to the load conditions imposed by the mine environment. Models have been developed based on full-scale tests in the USBM's Mine Roof Simulator that compute the capacity of wood cribs of various configurations and material constructions as a function of displacement of the crib structure due to roof-and-floor convergence. These models permit the comparison of the loading characteristics and costs of employment of different crib designs, and in conjunction with roof behavior models, provide a means to determine the optimum design and employment strategy.

Jan 1, 1993

By J. B. Rosenbaum

This report presents new findings and consolidates previously published data to provide a single reference containing a concise and comprehensive description of the Bureau's work on electrolytic chromium. Two separate systems for electrolytic-chromium recovery were developed, one designated as the oxidized system the other as the reduced system. The electrowinning of chromium metal follows the dissolution of chromium from the ore or from ferrochrome and its separation from gangue and metallic impurities. Chromite was first solubilized by pressure digestion at slightly elevated temperatures in an oxidized acid solution using Na2Cr2O7 as an oxidizing agent. Later it was found that a sodium-free electrolyte was preferable, using return-cell anolyte containing H2SO4 and Cr03 as the oxidizing agent. Gangue materials were separated from the soluble metallics by filtration; and, after the Cr+3 had been stabilized, the metallic impurities were separated as crystalline ammonium salts by vacuum crystallization.

Jan 1, 1957

By R. J. Tocher

Uniaxial testing was performed on coal specimens to determine the time-dependent response. The testing was carried out on coal from six mine sites throughout the Western United States and Pennsylvania. Testing configurations were varied to allow analysis of moisture dependency, stress level and specimen orientation. Several theories were presented for the behavior of coal due to moisture diffusion. Experimental results showed the correlation between the theories and the actual material response. Coal deformation was found to be highly dependent on the moisture level of the testing environment. Moisture migration causes drying and shrinkage which lead to progressive degradation of the material. The coal tested experienced a rebound if saturated after a period of drying. This type of time-dependent behavior overshadows the dependence on the applied stress level, which, however, still produces a noticeable creep behavior. Analysis of one series of creep test results was performed. A relationship was developed on the basis of a simplified rheological model to describe the coal response to uniaxial stress. Previous empirical formulations in the form of power laws were compared and their deficiencies pointed out.

Jan 1, 1980

"Guideline Augered Cast-In-Place (ACIP) Pile Specification and Commentary11.0 GENERAL1.1 SCOPEThe Pile Contractor shall furnish all labor, materials, tools and equipment necessary for furnishing, installing and testing Augered Cast-in-Place (ACIP) piles as shown on the Contract Drawings and as specified herein.ACIP piles are commonly referred to by several other names. Some of them are trademarks or service marks owned by Foundation Contractors and some are names that try to describe the installation process. The term “cast-inplace” is sometimes replaced with “cast-in-situ,” especially in Europe. Some common names are Auger Cast Piles, Intruded Mortar Piles, Augerpress Piles, Augered Pressure Grouted Piles, AugerPile Foundations, Continuous Flight Auger (CFA) Piles, Grouted Bored Piles, Augered Grout-Injected Piles, Drilled or Augered Uncased Piles, and Uncased Cast-in-Place Concrete Piles. To avoid confusion, ACIP pile will be used exclusively herein.1.2 PILE CONTRACTOR QUALIFICATIONSThe ACIP piles shall be installed by an experienced Pile Contractor who upon request of the Engineer shall submit evidence of successful ACIP pile installation under similar job and subsurface conditions, including a job supervisor who shall have a minimum of five years of method specific experience.The proper installation of the ACIP piles is dependent upon the procedures used by the Pile Contractor’s field representatives and equipment provided. The Pile Contractor’s personnel responsible for the installation should have relevant experience with the auguring and pumping equipment, experience placing piles under similar site conditions (including restricted headroom if appropriate), in similar subsurface conditions, as well as experience handling the special grout mixes, admixtures, etc."

Jan 1, 2016

By T. L. McCall

AUTHENTIC records show that coal mining in Cape Breton dates from the year 1720, when the French military authorities obtained coal from what is now known as the Blockhouse seam, in the Morien district, for use at Louisburg, where the fortress, now of such historic interest, was being built. Thereafter, coal was mined more or less continuously, and although, for many years, in a very haphazard way, there was, on the whole, a steady growth towards a better regulation of the industry, culminating in the year 1825 with the arrival of the General Mining Association in Nova Scotia. This Company, more generally known as the G.M.A., had acquired extensive tracts in Brazil and Colombia and had also purchased the mining rights for the whole of Nova Scotia-excepting such areas as had been previously leased-the attraction being the rich veins of copper currently reported as occurring in the Province. These fabulous copper veins, upon examination, failed to materialize, but the engineer sent out to report on them returned with such good accounts of the coalfields he had seen that steps were taken immediately to investigate them. From that rime onward, the history of coal mining in Nova Scotia is one of progress and achievement. One of the first acts of the G.M.A. was to acquire the areas already leased to other concerns and develop these in a masterly fashion, employing the best machinery and talent available at that time. Such dominant control over the minerals of the Province, although it led to orderly development in the several coalfields, also, later on, resulted in restricting operations in the various coal centres to such an extent that a determined effort was put forward by the people of Nova Scotia to end such a state of affairs. Consequently, in 1857, the original lease of the G.M.A. was abrogated, the Company, however, being allowed to retain certain areas in the districts it had already developed. This opened the way for the formation of other coal-mining companies, and numbers of these immediately sprang into existence in the various coal-mining centres. In 1893, the Dominion Coal Company, Limited, was formed by the amalgamation of seven companies operating in the neighbourhood of Glace Bay, in Cape Breton. Later, in 1910, the Dominion Iron & Steel Company, Limited, obtained control of the Cumberland Railway & Coal Company, which had been formed in 1884 to acquire the rights of the two companies working in the Cumberland County coalfield.

Jan 1, 1936

By C. O. Brawner

Approximately 7 billion tons of soil, rock and ore are currently being excavated in open pit mines and quarries on the North American continent at the present time. As the depth of excavation increases and the grade of ore being mined reduces, the safety and economy of the stability of the pit slopes becomes increasingly important. The magnitude of the potential influence on economics can be appreciated from the results of recent full scale field studies by Kennecott Copper Corporation at the Kimbley pit near Ely Nevada (Merrill, 1968). This pit was originally excavated with an average wall slope of 45°. Based on detailed studies it appeared that a slope of 610 would be stable. Subsequent excavation to this slope proved the original pit could have been steepened by 16° during production.

Jan 1, 1968

By Howard B. Hamilton

A switching system for high fault current 300 and 600 volt DC trolley and haulage systems, as used in the mining industry is presented. The system consists of paralleled main and auxiliary contactor circuits with a liquid metal current limiting device (CLD) in series with the auxiliary contact-or. Upon detection of a fault, the current is commutated into the CLD circuit. The liquid-metal vaporizes, increasing the CLD resistance and Considerably decreasing the actual current to be interrupted. This system will materially reduce the wear and tear on contactors because of the reduced interrupting requirement. the CLD is pressurized; when the current is interrupted, liquid metal flows back into the bore. Thus, it is resetting. Electrical and mechanical design principles are presented as well as materials for use, as found satisfactory in field tests on the device.

Jan 1, 1982

By Dennis R. Dolinar

The National Institute for Occupational Safety and Health?s Pittsburgh Research Laboratory conducted a full-scale test of a composite polyurethane-aggregate seal in a hydrostatic chamber at the Lake Lynn Experimental Mine. This composite seal consisted of a polyurethane and limestone aggregate core that was formed between two concrete block walls. In the hydro-static chamber test, water is used to pressurize the seal. During the test, the maximum average water pressure the seal was able to withstand was 18.9 psi. Further, the seal began to yield at an average water pressure of only 17 psi. At the time of the test, the minimum seal design requirement was 20 psi under 30 CFR4 75.335 (2005). Therefore, based on this test, the seal did not meet the regulatory minimum design requirement. Uniaxial compressive tests conducted on samples from the polyurethane-aggregate core revealed that both the compressive strength and the elastic modulus of the material were much less than that for polyurethane only with a density of 10.0?12.0 lb/ft3. The significant reduction in the strength and stiffness of the polyurethane-aggregate mixture results from the formation of a soft polyurethane foam around each piece of aggregate. The formation of the soft foam seems to be caused by residual moisture from the aggregate. The moisture also caused the density of the polyurethane in the polyurethane-aggregate mixture to be less than the design requirements. The lower density of the polyurethane in the mixture, along with the formation of zones of pure polyurethane only, resulted in the overall seal density being less than the design requirements. During seal construction, steps were taken to control the moisture, but were not successful. An analysis of the seal failure showed that the calculated shear stresses at failure and the estimated shear strength of the polyurethane-aggregate mixture are fairly close. This suggests that the strength properties of the polyurethane-aggregate mixture along with a weak zone of poorly bonded aggregate controlled the maximum pressure the seal could withstand. At the time of the seal testing, the minimum design requirement was 20 psi, as specified at 30 CFR 75.335 (2005). New emergency temporary standards for seal designs were promulgated on May 22, 2007, with a minimum requirement of 50 psi under specified conditions. However, it will be shown that the evaluation of the polyurethane seal performance as designed to meet the older 20-psi criterion can be relevant to the design requirements under the new standards.

Jan 1, 2008

By John W. Frey

Although there are certain general uniform provisions in the laws ... of the several Provinces of Canada the differences are so great that it is considered advisable to present digests of separate mining laws rather than a digest of Canadian mining law as an entity . This analysis , accordingly , has been divided as follows : Nova Scotia , New Brunswick , Quebec , Ontario , British Columbia , and a group of Provinces under Dominion Law .

Sep 1, 1930

By A. G. Starliper, H. Kenworthy

A procedure was developed for the separation of lead and sulfur in industrial concentrates of galena by a combination of chlorination and fused - salt electrolysis . Galena could not be satisfactorily electrolyzed in the various media tried ; however , when it was treated with chlorine the resulting lead chloride could be effectively separated electrically into lead and chlorine . An apparatus was designed and constructed to chlorinate galena and to volatilize simultaneously most of the chloridized impurities . By electrolyzing the chlorinated concentrate , a high percentage of lead was recovered . Anodic chlorine was drawn from the cell and was used to chlorinate new feed . In many runs , the recovered metal analyzed from 99.8 to 99.9 percent lead . Lead was also distributed as a chloride in the bath , and a small portion was in the volatile fraction produced during the chlorination step . During a tinuous operation , only 0.1 percent of the total lead was discarded ; 99.9 percent was accounted for in the metal , electrolytic bath , and washed or leached chlorination condensate which was essentially lead chloride . About 95 percent of the sulfur from the galena was recovered as a byproduct of over 90 - percent grade .

Jan 1, 1964

By E. P. Youngman

Tantalum is a rare element ; estimates indicate that there is less tantalum than gold in the earth's crust . After remaining a laboratory curiosity for many years , it was used to a limited extent and for relatively few years (1903- 1911) for incandescent electric-light -bulb filaments . Another wave of interest in tantalum appeared when its electrolytic-valve action was taken advantage of in charging storage batteries , especially for radio work . Tantalum chargers were eventually displaced by other types of chargers , but for a time they were manufac tured in sufficiently large numbers to create a demand for the metal and to bring about its production on a commercial scale in the United States . As tantalum became available in larger quantities and at substantially lower prices , and as high prices for platinum encouraged the employment of tantalum as a substitute , the metal was put to many new uses . Ferrotantalum was made and sold before the World War , and patents have been taken out for a number of special alloys for industrial purposes , but probably the largest use for the metal to-day is in vacuum tubes .

Aug 1, 1930

By Alfred W. G. Wilson

In this paper is presented a review of the changes that have taken place in certain Canadian non-metallic mineral industries since 1909. The fifteen-year period 1909 to 1923, inclusive, has been selected for two reasons. In the first place, statistical treatment of the subject under review has been nearly uniform throughout the period. In the second place, this decade and a half is itself further subdivisible into three well marked quinquennial periods, the middle one covering the period of the great war when industrial conditions were greatly disturbed. It then becomes possible to institute certain comparisons between equal periods before and after the war disturbances. The items selected for inclusion in this review are certain of the more important members of that class of minerals usually grouped together under the heading of non-metallics. They are all minerals of which Canada is known to possess important resources, and which are indispensable to many of our greatest manufacturing industries.

Jan 1, 1925

By Walter J. Mead

By American tradition, if not by rational decision, publicly owned natural resources have been transferred to private industry for processing. The process of transfer requires specific determination of the price which the patentee, buyer, or lessee must pay to the government in exchange for the right to develop a resource, and selection of the patentee, buyer, or lessee from among several possible contestants. Pricing of natural resources owned by the government presents a set of problems quite different from ordinary commodity pricing. Natural resources in situ are not homogeneous commodities. Within any class of natural resources, specific leasable parcels will differ in value by reason of location and accessibility, as well as quality and quantity. Thus, there is no "going price;" every lease within a specific resource class will have a different value. To complicate further the pricing and buyer selection problems, competition may not be reliable. Natural-resource markets are characterized by oligopsony conditions. In a significant number of cases, as will be shown later, there has been only one bidder for a given lease, and in most lease sales the number of bidders is equal to or less than three. As a further complication, there is great uncertainty regarding the value of specific resources, even among the best-informed buyers, as well as within the leasing agency. In some instances, particularly with regard to oil and gas resources, there may be uncertainty about the presence of resources, as well as the quantity and quality of any resources contained in the tract offered for lease. In other cases, such as oil shale and some deep ocean minerals where new technologies are involved, the presence of the resource is clearly established. There may be a relatively high degree of knowledge about the quantity and quality of the resource, but there is great uncertainty concerning the cost of production. These problems in total make it difficult for the leasing agency to appraise accurately the resource to be leased, as well as for the potential bidder to calculate a bid price that will yield him a normal profit. The pricing goal of the federal government as the seller or lessee may be to capture the economic rent; that is, the price of a resource might equal its discounted present value. A required price substantially above this amount would either generate no bids, or, in the long run, would bankrupt the buyer. A price below this amount is a disguised subsidy to the lessee. A subsidy to mineral lessees, as to any other economic interest group, as a minimum should be justified by a clear showing of net external benefits from the economic activity. In the case of timber sales by the U.S. Forest Service, the Forest Service Handbook asserts that "the aim in national forest stumpage appraisal is to determine market value,"8 and "market value" is equated to "fair market value." Regarding minerals, there is no reference in legislation or regula-

Jan 1, 1976

The 1965 Lignite Symposium, the Louth in a series and the third sponsored by the University of North Dakota and the Bureau of Mines, was held at Bismarck, N. Dak., on April 29-30, 1963. These symposia provide a forum for those interested in the technology and utilization of solid fuels, especially lignitic coals. As part of the meeting, a 200-mile field trip was taken including; inspection of (1) the 200-megawatt, pulverized lignit-fired Leland Olds plant of Basin Electric Power Cooperative, under construction near Stanton, N. Dak.; (2) the site of the Glunharold mine of the Truax-Traer Coal Co., Division of Consolidation Coal Co., where a wheel excavator was being assembled; (3) the operating Beulah mine of Knife River Coal Mining Co., subsidiary of Montana-Dakota Utilities Co., near Beulah, N. Dak.; and (4) the 400-megawatt, hydroelectric Garrison Dam powerplant, near Garrison, N. Dak.

Jan 1, 1966

By Boyd Wise

A jet pump injector was developed and successfully tested, thereby demonstrating the feasibility of a jet injector for introducing coarse coal into an operating slurry face haulage system: In Phase I a variety of injection concepts were evaluated, and the jet pump was identified as best, due to its simplicity, compactness and performance potential. In Phase IIA subscale jet pump injector tests were conducted, and a computer model of a jet pump injector was developed whose performance predictions correlated well with subscale test results. In Phase IIB various system configurations were defined for integrating a jet pump injector into a fully operational underground coarse slurry face haulage system, further highlighting the feasibility and practicality of such a system. In Phase III a full-scale mobile haulage vehicle embodying a jet pump injector and coal sizing equipment was detail designed into a practical vehicle with attractive performance characteristics. More importantly, fully operational full scale jet pump injector -and feeder/breaker subassemblies were tested and proven successful in their ability to down-size coal to 3" in all 3 dimensions and to consistantly provide slurry of 4217 weight concentration at 6.4 TPM throughput under a wide range of operating conditions including zero to maximum feed rate within 5 seconds.

Jan 1, 1985

By W. F. RITTMAN, E. W. Dean

This report presents the results of an investigation conducted by the Bureau of Mines for the purpose of assisting in the establishment of a satisfactory standard method for the analytical distillation of petroleum, a problem of great importance to the petroleum industry. Experiments were performed for the purpose of studying the charac- teristics of methods typical of those in use; comparative studies were made of the efficiencies of the principal types of fractionation ap- paratus available to the petroleum chemist; and the characteristics of a type of apparatus that the results of the experiments seemed to indicate was best adapted to the purpose were investigated in detail. Also, some experiments were made to determine the effect of cracking as a factor in the analytical distillation of petroleum in still heads.

Jan 1, 1916

By David E. Van Dillen

The computer program described in this user's guide provides for the static, three-dimensional, linear and nonlinear analysis of structural and geological systems by the finite element method. The guide describes the capabilities and general features of the program and shows how input is prepared. A number of recent advances in finite element theory and computer technology are incorporated in the program. Nonlinear material properties are provided for, including isotropic, anisotropic, and time-dependent material properties, gravity loading, simulation of a sequence of excavation or construction, and a slip or joint element. The finite elements include beam, rod, axisymmetric and plane quadrilateral, hexahedron, thick shell, axisymmetric and plane joint, and a three-dimensional joint. The program also has an automatic mesh generator to minimize user input preparation for continuum finite element meshes.

Jan 1, 1981

By Jesse A. Miller

ALTHOUGH the element titanium was discovered by William Gregor in 1790, over a hundred years passed before it was put to commercial use. The first commercial application of titanium was as an alloy additive to iron and steel, and the first ferroalloys were produced domestically in 1906. Titanium pigments were developed somewhat later and have been produced in the United States since 1918. The use of titaniferous material in welding-rod coatings first gained acceptance ill the mid-30's. The metal titanium has only had commercial importance since 1948; domestic production for that year was 10 tons. The relative importance of these major uses of titanium in various forms may he gaged by the consumption of titanium dioxide (Ti02) for these purposes in 1954. Of a total of 440,000 short tons of Ti02 consumed in 1954, 95 percent of the total was consumed for pigments; 2 percent for welding-rod coatings; 1 percent for non-titanium-base alloys and carbide; and 2 percent for miscellaneous uses. The titanium-metal industry is in its infancy, but it has more than doubled its output every year from 1948 to 1954, reaching 5,370 short tons in 1954.

Jan 1, 1957

By Lloyd A. Morley

This eight-chapter document is the second volume of a two-volume report that presents a comprehensive outline of coal-mine electrical power systems from theory to practice. Together, the two volumes contain the vital aspects that go into planning and designing a mine power system. Building upon Volume I, the subject of protective equipment and relaying starts Volume II, first as an introduction in Chapter 8, then by a treatment of device selection in Chapter 9. Chapter 10 continues system protection in terms of transients and overvoltages. Chapter 11 describes the design of major power equipment, including power centers, switchhouses, and substations. Solid-state applications in mining are given in Chapter 12, and batteries and battery charging are discussed in Chapter 13. Chapter 14 covers electrical-equipment in hazardous locations of mining operations. The report concludes with Chapter 15, a discussion of electrical maintenance as well as some specific mine electrical problems. Information on surface and underground use is included in all these chapters. An index finishes the documentation and is cross-referenced to both report volumes.

Jan 1, 1982