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By W. P. Yant, R. R. Sayers

The rather sudden increase in the use of methanol as an antifreeze for automobile radiators has caused considerable comment , with some anxiety to persons interested in industrial and public health , regarding the possible health hazard in dispensing and using the product . In view of this , the chemical industry interested in the manufacture and marketing of methanol requested the Bureau of Mines to make an impartial and extensive investigation of the hazard involved . With the assistance of the industry this investigation is now in progress and will extend throughout the present winter . When these observations are finished a complete report will be made . At present , however , the acute interest in the problem and the many inquiries that have been received from manufacturers of methanol , garage owners , the automotive industry , public health officials , and private persons demands a brief statement relative to the reasons for the recent availability of methanol for antifreeze purposes , the plan of the bureau's investigation , and the trend of the results of the investigation obtained to date .

Dec 1, 1930

By G. W. Jones, F. E. Scott, R. E. Kennedy

Methylene chloride , dichloromethane CH2C12 , a low - boiling and highly volatile organic chlorinated compound, is used extensively as a refrigerant in air conditioning installations , as an intermediate in organic synthesis , and as a solvent for cellulose acetate and other materials . As its vapors are not inflammable in air at ordinary temperatures , it can be used to advantage where it would be highly dangerous to use ordinarily inflammable solvents . The question has been raised as to its inflammable range in pure oxygen and in air enriched with oxygen . To find the answer to this question, tests were carried out with various mixtures of methylene chloride , oxygen, and nitrogen mixtures . It was found that methylene chloride has wide limits of inflammability in pure oxygen . Additional tests were then made to establish the complete range of inflammability of these gases . The methylene chloride employed in the tests was cbtained from the Eastman Kodak Co. It had a reported boiling range of 40.5 ° to 42.0 ° C. and a density of 1.322 at 20 ° C.

Oct 1, 1943

By Joan Weinberg

Real gross national product (GNP) grew at a seasonally adjusted annual rate of 2.2% in the third quarter, down from a revised 3.0% in the second quarter, according to preliminary data from the U.S. Department of Commerce (table 1). The slowdown in the rate of growth was attributed to the summer drought, a larger trade deficit, and a decline in Federal spending for defense. Exports slowed from the second quarter, as the dollar, compared with other industrial country currencies, edged up. Imports of both consumer goods and capital goods rose sharply, with consumers buying more foreign cars, computers, and electrical machinery. Although net exports of goods and services deteriorated slightly from the second quarter, the U.S. trade position continues to be much improved from 1987 and first quarter, 1988. Business spending for new plant and equipment rose at a 4.6% pace, well below that recorded earlier in the year. The 3.5% increase in consumer expenditure was accounted for mainly by nondurable goods and services; expenditure for durable goods--those products lasting more than 3 years--rose only 0.4%. Inflation, as measured by the fixed-weighted GNP price index, rose at an annual rate of 4.9% in the third quarter. Prices rose slightly less than they had in the second quarter, when inflation reached a 6-year high. In September, 1988, the President signed a U.S.-Canada free trade agreement (FTA) which will eliminate all tariffs and most nontariff barriers between the two countries by 1999, thereby creating the world's largest open market. In 1987, U.S.-Canadian bilateral trade totaled $161 billion. The expansion of trade is expected to generate 5% higher growth for Canada and up to 1 % higher growth for the United States by the end of the century. The higher growth for the United States translates into an estimated 750,000 jobs, and $2.4 billion in exports. Canadian parliamentary approval of the agreement is still required before the treaty can take effect. The debate in Parliament is continuing, and the issue is not expected to be resolved until after the November 21 election.

Jan 1, 1988

By Clarence Hall, Spencer P. Howell

The tests and studies begun by the United States Geological Survey in the fall of 1908 with a view to lessening the accidents attending the use of explosives in coal mining are being continued by the Bureau of Mines at the Pittsburgh experiment station and in the field. One hundred and six applications for the testing of 209 different explo- sives had been received at the Pittsburgh station prior to March 1, 1913, and on that date 97 explosives that had passed the required tests were on the "permissible" list issued by the bureau. This bul- letin gives the results of tests of all permissible explosives tested between May 15, 1909, and March 1, 1913. Bulletin 15 entitled "Investigations of Explosives used in Coal Mines" contains the results of tests of 17 permissible explosives tested prior to May 15, 1909. A copy of the test requirements and the names of explosives on the per- missible list dated March 1, 1913, are appended to this bulletin. An explosive is considered permissible for use in coal mines when it is similar in all respects to the sample that passed the tests required by the bureau, and when it is used in accordance with the conditions prescribed. The physical tests reported in this bulletin were conducted by Messrs. H. F. Braddock, A. J. Strane, J. W. Koster, A. S. Crossfield, A. J. Hazlewood, A. B. Coates, and J. E. Tiffany at the Pittsburgh experiment station of the bureau. The act of Congress making appropriations for sundry civil ex- penses of the Government for the fiscal year ending June 30, 1912, authorized the Secretary of the Interior to charge a fee covering the actual necessary expenses involved in making such tests by the Bureau of Mines as might be approved by him. After careful consideration had been given to the actual necessary expenses involved in the test- ing of explosives to determine their permissibility for use in coal mines, the sum of $150 was approved by the Secretary of the Interior as a reasonable charge for each complete official test. During the first year this law was in effect the fees collected amounted to more than $6,000.

Jan 1, 1913

By Henry Kreisinger, F. K. Ovrız

Some of the investigations conducted by the Bureau of Mines have for their object the collecting and disseminating of information regard- ing methods by which the fuels of the country may be most effi- ciently used. As the analysis of flue gases tends to develop better methods of firing, which in turn reduces waste of fuel, the Bureau of Mines in this bulletin presents for the benefit of those in charge of boiler plants and all other persons interested detailed information on methods of sampling and analyzing flue gases, and on the utilization of the analyses in promoting boiler-room economy. This bulletin is intended to be a companion to Technical Paper 80," and is written in plain and nontechnical language, as far as pos- sible, so that it may be readily understood by persons who have not had the advantage of a technical education. Whenever possible, illustrations of apparatus and methods of handling have been used rather than elaborate descriptions. The material presented in this report is arranged in two parts. The first part contains the description of the apparatus and the methods used in sampling and analyzing flue gases. The second part gives experimental results obtained with the different methods of sampling and collecting flue gas that are recommended in the first part of the report. Only simple apparatus and methods are considered, as they are accurate enough to show the large heat losses due to the use of too much air, and are also accurate enough to indicate any incomplete combustion losses of economic importance. Without doubt the loss due to large excess of air is the greatest one in the boiler room, and can usually be greatly reduced by making proper use of gas analysis. Before engineers in the isolated industrial plants can be induced to analyze for small traces of combustible gases, they must be first taught how to analyze for carbon dioxide (CO), and they must learn to appre- ciate the great possibilities of reducing loss from large excess of air. Furthermore, in the face of the great difficulty of obtaining a fair

Jan 1, 1915

By D. T. Randall

In carrying out a general plan of ascertaining more efficient and more economical methods of utilizing the fuel resources of the United States, in order to prevent unnecessary waste and thus conserve the available supply, the United States Geological Survey made a series of experiments on the combustion of fuel in house- heating boilers. As it was realized that steam boilers of the ordinary types used for heating private houses are often installed and operated under conditions unfavorable to fuel economy and smoke prevention, these experiments were made with briquets, raw coal, and washed coal, so as to determine what is to be expected of these fuels in a representative house-heating plant, properly installed and operated. Briquetted coal had been frequently tested in the hand-fired furnaces under the Heine boilers in the Survey fuel-testing plant at St. Louis. The results were so satisfactory as regards economy and smokelessness that it was decided to conduct a series of tests to determine the value of this fuel for domestic heating purposes. Beginning in October, 1906, a number of evaporation tests were made on the house-heating boiler installed to heat the buildings occupied by the structural-materials laboratory, both briquets and coal being used. After these tests were well under way, it was thought advis- able to conduct some additional tests under conditions more constant than could be maintained at this plant. A carload of briquets was shipped to the University of Illinois engineering experiment station at Urbana, Ill., where two house-heating boilers of a size commonly used in residences were available. This equipment permitted more uniform conditions of pressure and capacity, making the results more valuable for comparison. Tests were made with this fuel at Urbana in June and July, 1907. The present paper is an account of both series of tests, and includes also details of tests made at Urbana on three standard fuels in the spring of 1908. Perhaps the most important result obtained is that showing the relative value of different fuels for domestic purposes. From Table 16. on page 39, it is possible by comparison to arrive at the probable value of any fuel in any part of the country. The figures in the table

Jan 1, 1911

By Oliver Bowles, J. E. Crawshow

A line of cordeau detonating fuse was placed in hole No. 2, no electric detonators being used in the hole. After 12 or 13 cases of 40 per cent nitro starch powder had been poured into the hole in loose form, it was found that a space of only 17 ft. remained for stemming. It was decided that space for an additional case of powder might be obtained by tamping the charge. The tamping was done with a heavy plunger, about 3 or 3 inches in diameter and 10 inches long, made of lead with an iron core with an iron eye in the top to which a 3/4 inch rope was attached, and weighing between 30 and 40 pounds. This weight was intended for use in sinking explosive in wet holes, and not for tamping. It is estimated that the tamping had continued at least 10 The quarry superintendent had gone a considerable distance for a box of powder, returned, and reached a point about 10 feet from the hole, minutes.

May 1, 1920

By Kenneth M. Earl

In its investigation of deposits of strategic minerals, the Bureau of Mines lid some development drilling at the Milan deposit in an endeavor to find an additional source of supply of copper. The deposit, which is in Coos County, northern New Hampshire, is about 8 miles northwest of Berlin. It was discovered in the seventies and was worked steadily until 1886, yielding a monthly production of 2,600 tons of ore. Lessees opened the mine again in 1695 and mined 1,500 tons. The Milan Mining & Milling Co. acquired the property in 1907 and made regular shipments of ore and concentrates until 1910. From 1911 until 1938, the tract was held by a local resident for timber land, Ventures, Limited, a mining concern with headquarters at 25 King Street, West, Toronto, Canada, acquired the property in 1938. No production has been recorded since 1910. To cut the vein below the old mine workings and to search for extensions to the northeast and southwest, the Bureau of Mines diamond-drilled eight holes for an aggregate of 3,596.2 feet.

Jan 1, 1950

By Edward E. Johnson

The U.S. economy boomed in 1965, completing its fifth consecutive year of expansion. Although the advance was somewhat irregular, previous records for production, sales, employment, and income were topped. During the first few months of 1965, as the economy recovered from the depressing effects of the automobile strikes of late 1964, increases were unusually large. The gains moderated in early spring, but were stimulated at midyear by sharply rising capital outlays, excise tax cuts, in? creased Social Security payments, and accelerated Viet-Nam defense expenditures. Gross national product (GNP) in cur-rent dollars rose $49.5 billion or 7.8 percent, to a total of S681.2 billion. In constant dollars (effects of price changes eliminated), GNP increased 5.9 percent, a rate considerably higher than the historical postwar annual average growth of 3.5 per-cent. Demand increased in most final markets and was especially strong for business fixed investment and consumption expenditures. With the exception of construction, most of the increases in GNP were real, since prices increased less than 2 percent.

Jan 1, 1966

By Launa Mallett, Charles Vaught, Michael J. Brinich

The lack of good communication is a very real problem in mine emergencies. Sometimes critical information is not communicated to those who need it to make decisions. At other times, those on the receiving end of a warning do not think to ask the right questions. What happens in underground coal mine fires is a case in point. The authors interviewed 48 workers who escaped three serious fires in western Pennsylvania. In each case the location of the fire was known but did not get communicated to many of those who had to evacuate. Sometimes, even the nature of the problem was not clearly communicated. Some workers began their evacuation knowing nothing about what was happening. In an effort to improve emergency communication National Institute for Occupational Safety and Health (NIOSH) researchers worked with safety professionals to determine what sorts of information are critical in a mine emergency. An extensive list was generated, which proved too long to be remembered by individuals. The list was therefore collapsed into six categories. A communication protocol was derived from these categories.

Federal lands often contain extensive mineral resources and decisions affecting access to those lands are made with knowledge of the possible minerals-related consequences. Information is provided to the Bureau of Land Management (BLM) in this report for use in preparing environmental impact statements on the Western Mojave Management Area (WMMA) and the Desert Tortoise Priority Habitat (DTPH). To augment U.S. Bureau of Mines (USBM) efforts such as the Mineral Assessment of the Planned Foil Irwin Expansion, Modified Silurian Valley Alternative, San Bernardino County, California which is in progress, and the Economic Analysis of the Minerals Potential of the East Mojave National Scenic Area; California, the USBM studied mineral deposits and estimated the potential impacts of mining in a segment of the California desert; the 8.7-million-acre WMMA, an area which includes the 1.2-million-acre Desert Tortoise Priority Habitat (DTPH). In addition, this information is intended to assist administrators, legislators, and the concerned public in understanding the economic importance of mineral resources in the California desert, especially that portion designated as the WMMA. See figure 1.

Jan 1, 1993

By D. R. Tesarik

An instrumentation and numeric modeling study was conducted by the Bureau of Mines at the Magmont Mine in Bixby, MO. An isolated section of this room-and-pillar mine was monitored with borehole and closure extensometers during a pillar recovery program to determine stress redistribution. In situ stress measurements were taken in the rib before pillar extraction began. Sample cores from the boreholes were taken for analysis of the properties of the host rock in the laboratory. The extensometers recorded no measurable displacements during most of the operation. Two-dimensional, finite-element; three-dimensional, finite-element; and three-dimensional displace-ment discontinuity codes were used to model the area of study. The finite-element models were run with two initial stress conditions, i.e., stress due to gravity only and stress obtained by in situ measurements. Horizontal stresses in the models reduced the calculated factor-of-safety in the mine back by up to a factor of 10, but did not have a significant effect on calculated pillar stability.

Jan 1, 1989

As longwall shields are lowered in preparation for advance, dust from the canopy falls directly into the air stream with the potential of becoming entrained. Historical dust sampling data from the early 1980s shows that shield advance contributed an average of 12 percent to the airborne respirable dust levels found on longwalls in the United States. Data from the 1990s indicates that shield dust liberation had increased to an average of 23 percent. Increased longwall production levels over this time resulted in the need to move a larger number of shields during each shift, while an increase in air velocities on the face was also occurring. These factors combine to suggest that greater quantities of shield dust are being entrained into the face air. A series of controlled laboratory tests were conducted in a test stand simulating shield dust entrainment to evaluate changes in airborne respirable dust levels at different air velocities. Significant differences in respirable dust entrainment were observed. The test facility, test methodology, and dust sampling results will be reviewed and discussed

By W. A. Haley

The purpose of this investigation was to develop and improve mining methods for mining thin coal beds, to increase productivity, and to increase the recovery of coal. German coal planers and a modified longwall system of mining were introduced into American mines and are bringing about increased productivity and better recovery as compared with the conventional methods displaced. Since the first installation, 4 additional planers have been purchased by coal companies and over 1-1/2 mil¬lion tons of coal has been mined by them, using the modified longwall mining method. INTRODUCTION Except from 1932 to 1934, the growth of mechanical loading in underground bituminous-coal and lignite mines in the United States has increased steadily. The amount of coal loaded mechanically in underground mines has increased from 0.3 percent in 1923 to 79.6 percent of the total underground production in 1953.3/ The use of new and improved mining machines and auxiliary equipment, together with new techniques in mining methods, usually has resulted in increased productivity.

Jan 1, 1957

By Charles Zahn

Gas chromatography is a method of separating mixtures of gases and volatile materials by entraining their vapors in a gas stream, which passes over an appropriate stationary phase. Two techniques are in common use: Gas-Liquid Chromatography, in which the stationary phase is a liquid supported on an inert solid, and Gas-Solid Chromatography, where the stationary phase is a solid adsorbent, such as charcoal or alumina. In both techniques components emerge from the column after a characteristic residence time. Gas chromatography is applicable as a qualitative or quantitative tool in a wide variety of problems in chemical research and processing. It may also be employed for purification and separation. A running bibliography on gas chromatography has been maintained at the Bureau of Mines synthetic liquid fuels laboratories, Bruceton, Pa., for several years for the benefit of research workers, who use chromatography as an analytical tool. Since the number of references grew and interest in the technique became more wide-spread, the Bureau is publishing this list rather than maintain it as a purely internal source.

Jan 1, 1958

By Thomas H. Dubaniewicz, Gerald R. Cucci, Gregory M. Green, Kenneth L. Cashdollar

New types of industrial instruments use fiber-coupled law energy to power remote serum. Fiber-optic based instruments are useful in classified (hazardous) locations found in many industrial plants because the fiber provides a natural barrier against accidental electrical discharge into potentially explosive atmospheres. However, current safety standards do not cover the use of laser-powered fiber-optic instruments in potentially explosive environments such as found in coal mines. The U. S. Bureau of Mines began an investigation of laser-powered fiber-optic instruments in explosive atmospheres in support of the standards-making process. A commercial fiber-optic interface system, modified to sin relate several worst-case operating conditions, ignited explosive hydrogen-air mixtures. Worst-am simulations consisted of disabling a safety shutoff feature, operating the laser at significantly higher powers than intended for normal operations, and cleaving fiber-optic connections to direct laser energy onto selected absorptive materials. At the highest power level available, the fiber-optic interface system did not ignite selected methane-air mixtures. The obtained data should prove useful in establishing appropriate safety standards.

Although coal is found in several locations in Virginia, almost all recent mining has occurred in the southwestern part of the state. Potentially minable reserves are estimated at 2.6 billion tons, slightly less than one percent of the national total. Coal ranges from high- to low-volatile bituminous, and seams average three to four feet in thickness. Virginia produces coal with higher BTUs (British Thermal Units) and a lower sulfur content than the national average. Historically its high quality has made Virginia coal attractive for metallurgical coke production and for the export market. Coal production and related industries have a significant economic impact in southwestern Virginia. In the seven coal- producing counties, coal mining is the major industry. In the two largest coal-producing counties (Buchanan and Wise), over 40 percent of total earning is derived from the coal industry. Virginia's regulatory program was conditionally approved December 15,198 1, and received final approval May 8, 1984. Its Abandoned Mine Land Program was approved with the regulatory program December 15, 1981, with emergency program authority approved November 13,1987.

Jan 1, 1992

By J. P. Rider

Average production from longwall mining operations in the United States has risen from approximately 800 tons per shift in 1980 to over 4,600 metric tons per shift in 1999. Such a large increase in production has the potential to generate significantly more dust. Previous NIOSH research has shown that, on average, respirable dust levels generated by the shearer accounts for 50% of the airborne dust generated during longwall mining. Ventilating air and water are primary controls being used in an effort to reduce longwall dust levels. Longwall operators are applying more air and water than ever before and have expressed concern over reaching maximum practical limits for these controls. Full-scale laboratory tests are being conducted to evaluate the impact on shearer-generated dust levels for changes in face air velocity, water quantity at the shearer, water spray pressure, spray system design, mining height and cutting direction. Results of this research should identify the most appropriate control levels for various operating conditions. In addition, general recommended dust control practices for longwall mining will be discussed. KEYWORDS Longwall, coal dust

Apr 1, 1975

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

2, Survey of Representative Group of Metal and Non-mental Mines Before proceeding to develop and analyze Emergency Escape System Guidelines, it was necessary to obtain a broad range of information, including both fact and opinion. Although there were many areas to consider, the surveys had three primary goals 1. To determine the current state of underground escapeway planning and execution in American, metal and non-metal mines. 2. To determine, for a wide range of mining conditions, what difficulties can be encountered in complying with present and proposed escapeway regulatory standards. 3. To determine what improvements could be made and what equipment and technology was available to aid in implementing these improvements. To accomplish these goals, three major surveys were undertaken¬ 1. Survey of MESA and State Mining officials, discussed in Section 2. 1. 2. Survey of representative U S metal and non-metal mines, discussed in Section 2. 2. 3. Survey of manufacturers supplying equipment, primarily hoisting, suitable for use in escape systems, the product information which was obtained is discussed in Section 7.

Jan 1, 1976

By M. A. Trevits, S. W. Lambert

In this Bureau of Mines investigation, production was monitored for 1 year at over 30 coalbed gas-drainage boreholes located in Alabama, Pennsylvania, and West Virginia. Results indicate that the quality of data gathered from such wells can be improved greatly if potential problems are anticipated and prevented in the early stages of well production. Major water-monitoring problems include solids buildup, freezing, the presence of gas in surface waterlines, and improper pumping interval settings. Such problems may be avoided by incorporating in the original well design waterline filters, sand screens, separator tanks, and systems to automatically control pumping intervals. Problems related to measurement of coalbed gas flow include large quantities of water vapor contained in the gas, especially during winter months; freezing and subsequent obstruction of flow; sudden, uncontrolled release of gas pressure; and solids buildup in metering equipment. The installation of commercially available items, such as filters, separators, and insulation, and the thoughtful application of a basic knowledge of coalbed gas reservoir characteristics will prevent most production-monitoring problems.

Jan 1, 1978