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By A. F. Roberts

The subject of mine fires is a very wide one. To give reasonable coherency, the paper concentrates on the behaviour of fires in the ventilated airways of mines; spontaneous combustions are not considered. The following topics are considered in some detail: 1) Material selection: Performance requirements for mining materials in terms of flammability and smoke/fume production; methods of test and need for relevance to mining conditions. 2) Fire growth: The influence of material properties and method of use on the rate of growth of fire in a mine roadway; the influence of ventilation, slope, material orientation, proximity of walls and roof on fire behaviour. 3) The fire in the ventilation network: The influence of fire on the ventilation distribution; the circulation of fire products in the network. The influences of these topics in determining fire control strategy are then considered but topics such as fire detection and fire extinction methods are not reviewed in detail. An extensive Bibliography on papers relating to mine fires is included.

Jan 1, 1989

By Steven W. Hunt, Glen R. Frank

Assessment of abrasivity and cutter life are necessary to properly manage risks when tunneling in mixed face ground which includes ground with cobbles and boulders. Maximizing cutter life requires: (1) abrasivity and strength parameters for soil matrix and rock clasts, (2) methods of combining both, (3) proper selection of cutters and (4) modified TBM operation including use of boulder detection methods from the TBM to help make operation decisions. This paper presents approaches for addressing these factors sufficiently to improve tunneling success in mixed-face and cobbly-bouldery ground. Current laboratory abrasivity testing will be assessed along with equivalent quartz content correlations to soil matrix and rock clast abrasivity. New approaches to combining abrasivity testing of both the soil matrix and rock clasts for various cobble and boulder volume ratios will be suggested to estimate cutter life and intervention intervals. Methods for detecting boulders and using detection data to modify TBM operations to minimize boulder impacts are provided.

Jun 13, 2021

By Gordon E. Green

This report addresses remote monitoring of coal waste impoundments for stability. Existing automated geotechnical monitoring systems are described and reviewed along with details of instruments suitable for such systems. An impoundment in West Virginia which was in the construction stage was instrumented and monitored between July 1979 and may 1981. Sensors which measure surface and subsurface parameters including settlement, horizontal deflection, surface tilt, pore water pressure, seepage, pond level, and meteorological parameters were installed. Data from the 37 sensors were collected by on-site logger and transmitted by telephone to a central processing station in Seattle for recording and interpretation. Difficulties were encountered with telephone and powerline outages and malfunction of electronic units. Detailed descriptions of the design and performance of the system are provided along with evaluation and comparison with other systems. Recommendations for improving and expanding the capabilities of the monitoring system are given.

Jan 1, 1982

By D. Harrington

For many years the Federal Bureau of Mines-in cooperation with other agencies-has been making investigations and compiling and publishing reports and statistics on accidents in the various branches of the mineral industry.4 Its assistance has been enlisted also in health, safety, and ventilation problems' incident to the driving of many large tunnels in the United States in recent years. As part of this work the Bureau has compiled considerable statistical and other information on accident experience in the tunneling branch of the heavy-construction industry. It has always been difficult to obtain up-to-date information on tunneling methods and tunnel accidents. Published accounts of tun¬nel construction furnish much interesting material of engineering, historical, or fiscal value, but usually little or no attempt is made to discuss and critically analyze the means taken to preserve the health and life of employees.

Jan 1, 1941

By Gordon T. Austin

The combined value of production of natural abrasives, which includes tripoli, special silica stone, garnet, staurolite, and emery, increased about 9% in 1988. In the case of emery, the increase was due to an increase in unit value of the material produced. The increase in the value of garnet and staurolite production was simply the result of an increase in the quantity of materials produced. However, special silica stone experienced both an increase in unit value and quantity produced. The nonmetallic manufactured abrasives industry, which includes only silicon carbide and fused aluminum oxide in the reported statistics, enjoyed the best production year since 1981 in terms of total quantity produced. Production increased 22% in quantity and 16% in value com-pared with those of 1987.

Jan 1, 1990

By Wallace W. Key

This report concerns types, quantities, specifications, and uses of non-metallic minerals as a basis for improving their supply, conservation, and utilization. Supply-demand details concerning mineral fillers, roofing granules, and roofing rock used in asphalt are incorporated in this report, along with highlights on production and sales of roofing, floor tile, and other related asphalt products of California. Comparable data for the United States are included. Although large quantities of commercially prepared mineral fillers are used in asphalt for paving and related applications in other States, addition of commercial fillers for these uses rarely is required in California because of the natural fines available. On the other hand, California manufacturers of asphalt products other than paving utilize about 300,000 tons of asbestos, diatomite, limestone, mica, soapstone, slate, and other nonmetallic minerals as filler, mainly for roofing and flooring. Also, about 500,000 tons of roofing granules is produced in California, most of which goes into roofing manufacture in California. In addition, a significantly large and growing tonnage of relatively coarse mineral aggregates are used on low-angle, built-up, asphalt roofs to produce an attractive surface and offer protection against the elements. Nearly all minerals used in asphalt products manufactured in California come from local sources, except asbestos and mica--and there are indications that local deposits of these commodities could be utilized in some use categories.

Jan 1, 1966

By James R. Evans

Orange County, adjacent to the populous and industrialized Los Angeles area, is the fastest growing county in California and is second only to Los Angeles County in total population (figure 1). In addition to an equable climate and a burgeoning economy, there is room in Orange County for growth and expansion. Growth over the past decade has resulted in rapid development of industrial tracts, housing areas, and shopping and commercial centers, mostly in former agricultural areas. The value of new building in 1972 was a record amount-over I billion dollars (figure 2). Problems relating to the proper direction of growth are the concern of both government and the private sector. The intelligent and efficient use of areas to be developed requires planning for the conservation and protection of the County's natural beauty and for the orderly development of natural resources. The availability of sand and gravel, which is used in many phases of construction, will be a major controlling factor in the future of the County.

Jan 1, 1974

By E. H. Burroughs

This bulletin is the fifth in the series of petroleum bibliographies publis:\:l.ed by the Bure.au of Mines, Bulletins 149, 165, 180, and 189 being compilations for the years 1915, 1916, 1917, and 1918, respectively. In this bulletin the same general plan has been followed in arranging the references, but a few changes and additions have been made in the classification.

Jan 1, 1923

By Richard E. Thill

The Bureau of Mines' Oil Shale Data Bank (OSDB) was created in 1976 to serve as a centralized source for the storage, retrieval, and dissemination of technical literature, patents, and information on research projects in oil shale. Thousands of bibliographic references, patents, and research projects relating to the mining of oil shale have been identified, abstracted, and indexed according to selected keyword topics. The resulting data bank listings are contained in three sections, each with a separate keyword breakdown for use in rapidly identifying references pertaining to a specific subject. All references cited in the OSDB were published prior to an established cut-off date of May 1, 1981, when a redirection of Bureau of Mines programs resulted in the loss of project funds and the subsequent phasing-out of data bank operations. ACKNOWLEDGMENTS The oil shale data bank listings are the result of a team effort of the project staff. The contributions of Jimaleen Jansma for keypunching, information acquisition, and data entry, and John Brandenburg and Sandra Brake for keywording and information acquisition are gratefully acknowledged. Appreciation is expressed to the staff members of the Smithsonian Science Information Exchange, Washington D.C. for their cooperation in supplying data on recent research projects in oil shale for inclusion in the OSDB listings. Appreciation is extended also to the staff of the Gallegos Research Group for assisting with computer services to obtain the final printouts and transfer of files onto magnetic tape.

Jan 1, 1982

By Arthur E. Morris

Fifty years ago when Professor Yazawa began his career, the field of process simulation and modeling was in its infancy. Since then, tremendous progress has been made in our ability to model metal production flowsheets from mine to refined metal. This progress has come about by parallel developments in basic understanding of process chemistry and in computational techniques. This paper will review the progress made in process understanding and modeling in lead, zinc, and copper metallurgy from its inception to the present, and the role of Professor Yazawa's work in furthering this progress. Specific examples wi1\ be given for the sintering of lead concentrates, slag fuming, zinc concentrate roasting, flash smelting of copper, and pyro-extraction of zinc. Factors limiting further progress will be described.

Jan 1, 2003

The request for proposal from the U.S. Bureau of Mines outlined the purpose of this study in the following terms. "High grade near surface deposits are largely a matter of history. Most of the current mineral production in the united States is from large low grade ore deposits mined by large scale methods. It appears likely that exhaustion of near surface deposits and public resistance to open pit mining will tend to reverse the present trend toward open pit mining and lead to increased reliance on large scale underground mining. In view of the long lead time needed to improve basic technology, an in-depth study of the major underground mining methods is needed. "This study is intended to provide a systematic review and analysis of large scale non-coal underground mining technology with particular emphasis on current practices and problems, needed technological improvements, existing or potential environmental conflicts, and possible modifications or innovations that will assist in the satisfaction of projected national mineral supply requirements."

Jan 1, 1974

By Wallace W. Key

This report concerns types, quantities, specifications, and uses of non-metallic minerals as a basis for improving their supply, conservation, and utilization. Supply-demand details concerning mineral fillers, rooting granules, and roofing rock used in asphalt are incorporated in this report, along with highlights on production and sales of rooting, floor tile, and other related asphalt products of California. Comparable data for the United States are included. Although large quantities of commercially prepared mineral fillers are used in asphalt for paving and related applications in other States, addition of commercial fillers for these uses rarely is required in California because of the natural tines available. On the other hand, California manufacturers of asphalt products other than having utilize about 300,000 tons of asbestos, diatomite, limestone, mica, soapstone, and other nonmetallic minerals as filler, mainly for reeling and flooring. Also about 500,000 tons of roofing, granules is produced in California, most of which goes into roofing manufacture in California. In addition. A significantly large and growing tonnage of relatively coarse mineral aggregates Ire used on low-angle, built-up, asphalt roofs to produce in attractive surface and offer protection against the clements. Clearly ill minerals used in asphalt products manufactured in California come from local sources, except asbestos and mica--and there are indications that local deposits of those commodities could be utilized in some use categories.

Jan 1, 1966

By Edmund J. Cardoza

WELCOME TO THE DEEP FOUNDATIONS INSTITUTE 26TH ANNUAL CONFERENCE AND WELCOME ESPECIALLY TO THIS SEMINAR ON NON-DESTRUCTIVE TESTING OF DRILLED SHAFTS, PRESENTED BY MEMBERS OF THE DFI DRILLED SHAFT COMMITTEE. MY NAME IS ED CARDOZA; I AM A VICE PRESIDENT WITH THE MILLGARD CORPORATION, A DRILLED SHAFT CONSTRUCTOR FOCUSING PRIMARLY IN THE EASTERN HALF OF THE UNITED STATES.

Jan 1, 2001

By William R. Hardwick

Present information indicates that a copper deposit can be safely fractured with a nuclear explosive and the copper successfully recovered by the in-situ leaching method. The process is not yet at the stage where it can be presented t ) the mining industry as a technique proven in all its aspects, but it is a method with high success potential. Unknown factors must be evaluated by a full-scale test before the economics or the extent of the use of the method by the mining industry can be predicted. Preliminary calculations indicate that the cost of fracturing a copper deposit nuclear explosives may range from l.8 to 55.2 cents per ton or in some case: less than a cent per pound of recoverable copper. Copper may be recovered at less cost than by conventional methods. Deposits with 4 pounds of recoverable copper may be economic and production from a deposit may begin in less than half the time required for conventional methods.

Jan 1, 1967

By Allen G. Gray

It's not news to you that the United States is highly vulnerable to potential problems in supply of critical and strategic metals, and that these metals - chromium, for example - are employed in important bearing alloys. It's also not news to you that there is a significant challenge to improve durability and life of bearing systems which contribute to conservation as well as productivity. The objectives of this workshop are to identify available technologies and opportunities for new technologies in conservation, substitution, and displacement of critical and strategic metals in bearing systems. These considerations are among the most viable options for reducing vulnerability to a cutoff of chromium and other critical metals and action should be taken to identify and develop those technologies now rather than after a crisis is upon us.

Jan 1, 1984

By Hazel J. Stratton

IN THE HALF-CENTURY that has passed since the Bureau of Mines was established in July 1910, the research and technologic investigations conducted by the Bureau's scientists, engineers, and other personnel have helped significantly in improving health and safety in the mineral industries and have contributed substantially in conserving the Nation's mineral resources through improved techniques in the mining, treatment, and use of mineral commodities. From Bureau laboratories have come new materials for industry and better methods of extracting and processing minerals and mineral fuels. Bureau safety investigations-complemented by equipment testing and by programs of mine inspection and education-have brought about safer and more healthful working conditions.

Jan 1, 1960

By Norman L. Wimmler

Active placer mining in Alaska began near Juneau in 1880, but the first gold rush did not start until 1896; then the discovery of the Klondike brought gold seekers from all parts of the world. A few of the newcomers were experienced miners, but the majority knew nothing whatever of placer mining. Even those who were placer miners of much experience found entirely new conditions, notably frozen ground, that presented many difficult problems. As a result, numerous methods of mining and of thawing frozen ground were tried. From these trials the practice described in this bulletin has been developed. All known placer fields in Alaska have been mined to some extent, and some have been virtually exhausted. In most districts, however, there remain large quantities of low-grade gravel and also some small isolated areas of comparatively rich gravels which could not be successfully mined because of adverse physical conditions. These districts are now the scene of most placer mining, including dredging, hydraulicking, drifting, mechanical methods of open-cut mining, and ground sluicing (or booming) followed by " shoveling-in."

Jan 1, 1927

By L. H. Duschak, C. N. Schuette

In the years 1850 to 1923, the United States produced 2,426,000 flasks- (73,600 metric tons) of quicksilver worth $120,500,000. California yielded 2,195,000 flasks of this total; the remainder came from Texas, Oregon, Nevada, and A.rizona. Most of this metal has been extracted from low-grade ores, those containing less than 0.5 per cent mercury or 10 pounds per ton. The finished product or " virgin metal" is made at the mine and shipped in flasks. Quicksilver is unique in being the only metal that is liquid at ordinary temperature. Because of this and other physical and chemical properties, it is perhaps more indispensable to industry than any other metal. On the other hand, the quicksilver industry of the world is of vanishing significance" when compared to the major mineral industries with respect to quantity and value of product, capital invested, or the number of men employed. The peculiar value of quicksilver is due to the fact that in some of its applications no substitute is available and in others the substitutes would be unsatisfactory or extremely expensive. Scarcely a branch of science or industry fails to make some use of mercury or its compounds. As a detonator for explosives, mercury fulminate holds first place and in safety and reliability could be replaced only by the highly expensive silver fulminate.t vThrough its use in detonators and in the metallurgy of the precious metals quicksilver is of special importance to mining. In medicine,in the manufacture of electrical apparatus, the production of pigments and antifouling paints, and the general field of experimental science quicksilver is equally indispensable.

Jan 1, 1925

Toward the goal of maximizing minerals and metals recovery from domestic resources, the Bureau of Mines, U.S. Department of the Interior, has conducted in situ corrosion studies at the Salton Sea Known Geothermal Resources Area (KGRA) in the Imperial Valley, Calif., to evaluate and characterize materials of construction for geothermal resources recovery plants. General-, pitting, and crevice-corrosion characteristics of 13 commercially available alloys were investigated for periods of 15 and 30 days in seven process environments expected to be found in typical geothermal resources plants. Stainless steel alloy 29.4, Inconel 625, and the Hastelloys G, S, and C-276 were the most resistant to general corrosion, did not pit, and exhibited little susceptibility to crevice corrosion. Stainless steel alloys 430, E-Brite 26-1, and 6X had low general corrosion rates, but pitted and were susceptible to crevice corrosion. Stainless steel alloy 316 L had a low corrosion rate, but corroded intergranularly, pitted, and was susceptible to crevice corrosion and to stress-corrosion cracking. Titanium-1.5 nickel and TiCode-12 had low corrosion rates, did not pit, and were not susceptible to crevice corrosion. Carbon and 4130 steels had high corrosion rates, pitted, and had high susceptibilities to crevice corrosion. The major scale-forming mineral on the corrosion samples in most of the process environments studied was galena mixed with lesser amounts of other minerals.

Jan 1, 1979

By W. J. Wiehagen

The Work Crew Performance Model (WCPM) seeks to define performance variability within similar tasks of an underground work crew and relate observed variability to a cost consequence. Performance variability is described using work site observations to determine the adherence to job elements con¬tained within a standard operating procedure. Key components of the WCPM include (1) job definition through task analyses and the ranking of job elements by perceived cost consequence, (2) observational techniques for establishing performance baselines by measuring adherence to safe and proficient job procedures, and (3) cost linkages between adherence to task procedures and measures of consequence for noncompliance. Data presented within this report were obtained through the study of shuttle car operation in an underground mine in Appalachia. Observed adherence to safe and proficient job procedures by opera¬tors matched well with the consensus profiles (measured through a nominal group technique) with min¬ing personnel. It was also found that experienced operators consistently outperformed less experienced, incidental operators. These findings imply potential use of the WCPM as a practical procedure for thinking systematically about the choices available to reduce performance variability. Field application of the model can offer useful data to evaluate training and financially support performance improvement strategies that can be tested for their ability to reduce human error.

Jan 1, 1994