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By Oliver Bowles

The National Granite Commission at its annual meeting in Norfolk, Va., in January, 1930, passed a resolution requesting the Bureau of Mines to conduct an economic study of the granite industry. In with this request a preliminary review has been made of trends in the production and uses of block granite.. Some unfavorable conditions were thus brought to light, and certain suggestions regarding a more orderly and consistent growth in the industry are herein discussed. The results of the study are, presented in this report for the earnest consideration of. the industry, and comments are invited, not only on this report but as to future work that might be accomplished by the Bureau of Mines. The authors desire to acknowledge many helpful suggestions and comments from Paul M. Tyler of the Bureau of Mines and from Harris F. Sherman, secretary of the National Building Granite Quarries Association. Miss A. T. Coons of the Bureau of Mines rendered valuable assistance through her wide knowledge of granite statistics. The block granite industry has shown little expansion during recent years. While the value of the annual production has grown from about $14,000,000 in 1904 to nearly $25,000,000 in 1928, the increment in value is caused mainly by mounting prices rather than by increased production. Even granite for memorials shows a very small advance in production volume, although the value has increased from about $3,500,060 in 1904 to more than $11,000,000 in 1928, which is the most consistent growth of any branch of the industry. The value of building granite has fallen for a number of years much below the figure for 1904, and in 1928 was very little in advance of the value attained 24 years previously. The use of granite paving blocks and rubble has shown a gradual decline.

Jan 1, 1931

By Fred N. Kissell

This handbook describes effective methods for the control of mineral dusts in mines and tunnels. It assumes the reader is familiar with mining. The first chapter deals solely with dust control methods, regardless of the application. It is a brief tutorial on mining dust control and will be of help to the reader whose dust control problem does not conveniently fit any of the mining equipment niches described in later chapters. The subsequent chapters describe dust control methods for different kinds of mines and mining equipment. This includes underground coal and hard-rock mines, as well as surface mines, stone mines, and hard-rock tunnels. Because dust sampling has so many pitfalls, a chapter on methods used to sample dust is included. For those occasions when there is no practical engineering control, a chapter on respirators is also included. Except for those listed as ?future possibilities? in the longwall chapter, the dust control methods described are practical and cost-effective for most mine operators. If controlling dust were a simple matter, dust problems in tunnels and mines would have been eradicated years ago. Unfortunately, most underground dust control methods yield only 25% to 50% reductions in respirable-sized dust. Often, 25% to 50% reductions are not enough to achieve compliance with dust standards. Thus, mine operators must use several methods simultaneously, usually without knowing for sure how well any individual method is working. In fact, given a 25% error in dust sampling and day-to-day variations in dust generation of 50% or more, certainty about which control methods are most effective can be wanting. Nevertheless, over the years, some consensus has emerged on the best dust control practices. This handbook summarizes those practices.

Jan 1, 2003

By Wils L. Cooley

The report covers several aspects of mine safety ground systems, primarily for underground coal mines. The design of a combined ground fault-ground check monitoring system is presented. An analysis is made of grounding systems for dc shuttle cars. Complete resistance data and results of physical inspections of self-salting ground rods are presented. A detailed resistance and economic analysis is presented for the use of composite materials for building inexpensive and effective ground beds in high-resistivity areas. The desireability of penetrating the coal seam with a borehole safety ground is investigated. A report is made of a Mine Substation Grounding and Bonding Workshop.

Jan 1, 1980

By Sheridan J. Rodgers

Improved methods of dust control in the metal and nonmetal mining industries were studied. Preliminary dust surveys were made at selected mines and three mines were chosen for additional studies. Dust control effectiveness was evaluated using full shift gravimetric sampling and GCA Dust Monitor readings. Analyses for free silica content and particle size distribution were conducted. A belt washing system which was used to control dust at a transfer point was evaluated. The average reduction of respirable dust was 48% and the average reduction of total dust was 78%. The belt washing system not only maintained the work place within compliance but reduced maintenance problems along the beltway by 90%. Exhaust ventilation at a crusher was evaluated for control effectiveness. Ventilation along with operation of the crusher control room under slight positive pressure, maintained the work place within compliance. An exhaust ventilation system was designed for use at an underground rotary dump. Although the system was not installed or evaluated, details on the design are given. High expansion foam was used at an ore chute in an attempt to control dust at the draw point and loading point. Results indicated that foam did not effectively control dust.

Jan 1, 1978

By G. E. McElroy

This report discusses the construction and use of an all-pressure psychrometric chart in which the requirements of simplicity of appearance and absolute accuracy have been waived, to a certain extent, to provide for the rapid determination of psychrometric data and for the rapid solution of air-conditioning problems of major interest to the mining industry. Many mines in which air-conditioning problems are important are situated at elevations far above sea level and embrace great differences in elevation - in excess of 8,000 feet in certain mines - throughout their airflow circuits. Under these conditions, the effects of variations in the pressure of the atmosphere upon the physical properties of the mixture of air and water vapor of which it is composed are considerable and should be taken into account in the solution of problems. The simple types of psychrometric charts in common use, such as the Carrier, Bulkeley, Hill, and Goff (American Society of Heating and Ventilating Engineers Guide), are not generally suitable, in that they are drawn for a single barometric pressure - 29.92 inches mercury.

Dec 1, 1947

By G. T. Lineberry, W. J. Wiehagen

A Paradigm Shift As market economists, mine managers are interested in "staying in business" and even "prospering." Bottom-line results are the "order of the day." Concern for bottom-line results invokes questions such as: How much was produced? At what cost? And, was anyone injured? While these questions will always carry everyday emphasis at the mine, they are fundamentally lacking in that they often appear, especially to lower levels of management and to the production worker, as preeminent concerns. Driven by market economics, many organizations have decentralized, outsourced, downsized, restructured, and formed new coalitions. Investments in new technology and concentration on productivity have been part and parcel with these changes, contributing to improvements in both safety and efficiency. A reason for (and, perhaps a result of) these improvements has been the development of a highly experienced and flexible work force. These changes in mining present an interesting opportunity to modify a few paradigms about work life in general, and perhaps a few paradigms about how we invest in the miner, in particular. Studying these issues now might offer some interesting opportunities for the future, as the foundations for the next generation of mine workers are laid. With the average "experienced" U.S. miner five to fifteen years from retirement, perhaps a key determinant of future success in the world market might be how well we make the transition from today's work force to the work force of tomorrow. We can ill afford to wait a few more years to tap into the special knowledge residing within a veteran mining work force. The WCPM work Crew Performance Model, see pp. ) is one approach to defining, capturing, and transferring this expertise.

By Avery H. Reed

RECORD production of crude petroleum, lime, crushed marble, and talc highlighted the mineral industry of Alabama in 1963. Among the States, Alabama ranked second in the production of bauxite, third in the production of scrap mica and native asphalt, and fifth in iron ore. The mineral industry of Alabama was dominated by mining and processing coal and stone, the manufacture of cement, and the production of crude petroleum, which together comprised 86 percent of the total value of production, compared with 82 percent in 1962. The iron-ore industry continued to decline; in 1959 the value of iron ore produced was 12 percent of the total State production value; in 1960, 11 percent; in 1961, 10 percent; in 1962t 8 percent; and in 1963, 5 percent.

Jan 1, 1964

By E. R. Maize

[In report of Investigations 3452,5/ baling with roof movement in the Crucible mine, reference was made do to the fact tart timber decay was being studied at the time of writing. This roper, written after completion of that study, describes s the work and summarizes the data obtained. When the study of roof movement as begun at Crucible two ideas were advanced on decay Of timber by some of the officials: (1) That timber decay vas unusually rapid in the Crucible mine, and (2) that timber coated with rock dust decayed more rapidly than those teat were not so coated. There yore no records by which these ideas could be tested, and it appeared wise to make a limited; investigation particularly of the effect of rock dusting on decay, as rock dusting is an important means of preventing coal-dust explosions.]

Jan 1, 1940

By R. G. Gürtunca, J. A. Breslin

This paper briefly describes the progress in mine safety in the United States, with emphasis on recent events that have followed since the explosion at the Sago Mine in January 2006. Legislation following the mine accidents last year and areas of work carried out by the National Institute for Occupational Safety and Health (NIOSH) related to the accidents are discussed. American coal production in 2006 was 1,150 million short tons. Most of this coal is consumed domestically, with annual exports of coal about 50 million tons. One third of annual production is produced at surface mines and the rest from underground. This coal is produced by about 82,000 miners working at 1,400 coal mines. Major improvements in coal mine safety have been made in the US since the Federal Mine Safety and Health Act of 1977. The fatal injury rate in underground coal mines between 1977 and 2004 was reduced by 47.8% to 0.036. The annual number of fatalities dropped from 112 to 14 during that period. Likewise, the non-fatal days-lost injury rate was reduced by 42.6% from 10.87 to 6.24. The improvements in mine safety during this period can be seen in the graph of underground coal mine explosion fatalities and injuries from 1980 to present, which is shown in Figure 1. Between 1984 and 1993 (9 year period) there were 5 explosions and one major mine fire, for a total of 55 fatalities. Over the seven year period from 1993 to 1999 there were no fatalities from coal mine fires and explosions. However, in the six years since 2000 there have been 5 explosions and one fire, which have caused 37 fatalities. [ ]

By P. M. Daling

This report, sponsored by the U.S. Bureau of Mines, presents the results of an examination of the safety of the impactor shaft sinking system in comparison to conventional shaft sinking technology. Detailed study of the impactor system was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the impactor machine and its support systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates measures of both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the impactor shaft sinking system was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that the impactor shaft sinking system is safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by an average of over 35 percent with use of the impactor shaft sinking system. Design change recommendations to further improve the safety of the impactor system include a revised fire suppression system, improved access to and from the operator cabs, reliable noise attenuation measures, and improved communication systems. An operational safety manual was also developed for the impactor shaft sinking system.

Jan 1, 1982

By H. R. Appell

The Bureau of Mines is experimentally converting cellulose, the chief constituent of organic solid waste, to a low-sulfur oil, All types of cellulosic wastes, including urban refuse, agricultural wastes, sewage sludge, wood, lignin, and bovine manure, have been converted to oil by reaction with carbon monoxide and water at temperatures of 350° to 400° C and pressures near 4,000 psig, and in the presence of various catalysts and solvents, Cellulose conversions of 90 percent and better (corresponding to oil yields of 40 to 50 percent) have been obtained. A continuous reactor for use at maximum conditions up to 500° C and 5,000 psig has been operated successfully, Using sucrose as a feedstock, operation in this system has permitted a simplified and preliminary chemical study of the conversion process. Oil yields of over 30 percent have been obtained with this unit.

Jan 1, 1971

By Phillip R. Moyle

A cobalt/manganese occurrence in Clark County, Nevada was the subject of a site-specific mineral investigation by the U.S. Bureau of Mines in 1988-90. The study site is in the northern part of the Million Hills (wilderness) study area which is administered by the Bureau of Land Management. Field work during a period of one week consisted of geological mapping and sampling of workings and outcrops, and geochemical and geophysical surveys conducted on four transects totalling 7,600 ft. Although the concentrations of cobalt (0.1 to 0.5 percent) detected in samples from the fissure zones are within the range of grades associated with world-class economic deposits, the volume of material enriched in cobalt at the study site is insufficient to warrant consideration as a potential resource. Concentrations of manganese, nickel, copper, lead, zinc, barium, and thallium, although anomalous, are too low for economic consideration. At the study site, workings consist of three trenches and nine pits. The exploration history is unknown, and no production is reported.

Jan 1, 1990

By G. F. Kuncir

The analysis summarized herein evaluates the Bureau of Mines Program for Advancing Mining Technology Oil Shale in terms of the economic benefits which may be derived for the Nation as a result of its successful research and development efforts. On the basis of postulated oil shale production scenarios, benefit-cost ratio indicators are computed for the program elements as they apply to surface, underground, and modified in situ oil shale mining systems. Eight value indicators are used to measure the Program's beneficial impact on the future oil shale industry in relation to planned research and development costs. These are: capital cost savings, operating cost savings, labor savings, environmental quality maintenance cost reduction, reduction in production costs, byproduct production benefits, total production benefits, and additions to recoverable reserves. Program costs are aggregated from 1974 through 1987 and major benefits are accrued from 1982 through 2040. Both cost and benefit streams are discounted to mid-1975 present value.

Jan 1, 1977

By Llewellyn A. Rubin

Under Bureau of Mines Contract H0122007, Telcom, Inc., with the assistance of Fenix & Scisson, Inc., conducted a 17-month research and development project aimed at provid¬ing a field-test model of a guidance system for use with the Bureau of Mines Probe Drill. The Probe Drill is a part of the Bureau's Mine Rescue System developed under Contract H0101262. Volume I of this report is subdivided into seven sections. Volume II consists of a number of supporting appendices. In addition, there were delivered under the Contract, a number of other documents which are referenced in the text. Section 1 deals with essential contract information, Program Background, and a general system description. Section 2 covers the project chronology in brief. Section 3 is a digest of design considerations and implementation related to the requirements of the Contract. Section 4 is a description of the System, including illustrations of the hardware, and software. Section 5 is devoted to Operation and Maintenance. Para. 5.1 describes step-by-step field assembly and disassembly of the downhole unit. Para. 5.2 covers Operation. Para. 5.3 covers various aspects of maintenance from the lowest field echelon possible. Higher level maintenance must be accomplished in the laboratory, for the present field-test model. Para. 5.4 covers system calibration. Para. 5.5 covers detailed step-by-step operational sequences. Section 6 covers the results of the field testing, post-test evaluation, and recommendations. Essentially, we conclude that the present hardware (field-test model) has proven every aspect of system performance, but failed to provide reliable assurance of an operationally ready system. Telcom, therefore, recommends a three-phase continuing effort devised to provide the operationally-ready model of the system.

Jan 1, 1973

By Virginia E. Gleason

In this report, recommendations are made for programs to develop workable techniques to stop or prevent acid mine drainage formation in those underground coal mines where acid production could take place. These recommendations include development of mine closure technology, development of surface water infiltration control procedures, study of the effect of roof collapse on mine water characteristics, evaluation of the long-term effects of flooding underground mines above drainage, investigation of the effectiveness of section sealing in active mines, development of a simple model for predicting mine water quality and quantity, preparation of a manual on mine drainage abatement procedures, and development of a program to disseminate information on mine drainage abatement to the coal industry. These recommendations are based on an in-depth evaluation of information acquired over years of research on acid mine drainage formation, on numerous laboratory and field studies of methods of preventing or minimizing acid mine drainage formation, and on review of the geological, hydrological, and mineralogical factors involved. There are 772 references.

Jan 1, 1978

By Charles C. Boley

Using bench-and pilot-scale coking facilities, the Bureau of Mines produced experimental coke from blends of char with Sunnyside coal (high-volatile A bituminous) from Carbon County, Utah. At bench scale, additions of char made from lignite improved resultant cokes when concentrations of up to 60 pct were used in the blends. At pilot scale (500-pound movable-wall oven), four chars made by entrained-bed carbonization techniques from the parent Sunnyside coal and from a North Dakota lignite were used in two-component blends with the Sunnsyide coal. Chars from Sunnyside coal had volatile matter contents of 5.8, 9.8, and 16.0 pct, moisture-free basis; the char from the lignite had 16.6 pct. In twenty-five 500-pound tests, improvement in coke quality was observed from all blends at char concentrations to 17.5 pct. The best coke, produced from a concentration of 12.5 to 15 pct of S.8-pct volatile char, exhibited physical properties approaching those of an industrial coke produced from Sunnyside coal blended with three higher rank blending coals. Studies were also made of the effects on coke quality of char source, of particle size, of comparative use of char and of a blending coal, and of prolonged coal storage.

Jan 1, 1973

By B. J. Dalton

The Bureau of Mines Helium Activity has developed a computer program for use in the reduction of pressure-volume-temperature (PVT) data obtained with a Burnett compressibility apparatus. This program includes important modifications and extensions of some of the methods currently used for treating these types of data and yields statistical information that cannot be obtained from any other published work. The methods of calculation make use of a general nonlinear least-squares technique developed at the Helium Research Center. Because of a need to investigate different functional forms for representing the compressibility factor isotherm, 2, the computer program has been written in such a way that the only additional coding required is the so-called compressibility function subroutine. This subroutine defines the analytical form of Z and certain of its partial derivatives. The program described herein is believed to be the most advantageous for use in treating isothermal Burnett compressibility data.

Jan 1, 1970

By F. G. Horino

This report presents the theory and design of a stiff loading machine used by the Bureau of Mines. The machine incorporates three high-strength steel columns as the restraining member in parallel with the specimen. The theory presented gives the basis of design and the dimensions of component parts of the machine. Laboratory verification of the theoretical stiffness is described using three different setups involving a hydraulic jack and spacers and confirms the stiffness calculations to within 1 percent. Experimental techniques, testing procedures, and special equipment designed for determining the complete stress-strain behavior of NX cores of both hard and soft rock are described. Typical test data are presented as force-displacement curves for two rock types, a marble and a granite.

Jan 1, 1972

By Robert L. Davidoff

Growing domestic and global demands for mineral resources have established an imperative need for developing comprehensive, versatile mineral supply analysis evaluation tools. The Minerals Availability System (MAS) of the Bureau of Mines is meeting this need with its computerized Supply Analysis Model (SAM). This paper describes the SAM system and the quantitative methods used by the MAS for mineral supply analyses. The MAS evaluating process consists of deposit identification, tonnage and grade determinations, engineering and cost evaluations, financial analyses, and supply curve generation. MAS has developed this computerized system primarily to facilitate the maintenance of data information for the constructing of commodity supply curves. The SAM system presently has the analytical capabilities of simultaneously (I) evaluating many mineral deposits, (2) updating mineral supply information to reflect inflationary changes in costs and prices, and (3) conducting sensitivity analysis to determine impacts on mineral supply under various conditions. Many potential users in both government and industry will find the SAM system a valuable tool for policy analysis, forecasting, and planning. The SAM system has been constructed so that any types of information that are similar to the data elements in the MAS data base may be used to perform supply studies. The storage space needed for the SAM system?s programs, files, and output data is approximately 14 million characters.

Jan 1, 1980

This report describes the work performed by Mine Research Company in developing a prototype mobile roof shield during 1971-1972 for the U. S. Bureau of Mines, along with background information leading to the design decisions adopted for the project. In addition, the report evaluates the choice of design and analysis and the results of the project in terms of future possibilities of mobile roof support systems. The report begins with the discussion of the problems of designing, building, and using mechanical and hydraulic roof support in coal mines. It then gives a historical summary of past work with discussions of the design choices made for previous roof support systems.

Jan 1, 1973