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By D. B. Gawthrop

"One of the properties of an explosive, of interest to the user, is its ability to transfer detonation across an air gap to another explosive charge. This Property is of particular importance with permissible explosives used in coal mines, since they are relatively insensitive to detonation when compared to many of the commercial dynamites used in metal mining.An essential characteristic of an explosive is that it shall always be sufficiently sensitive to propagate detonation completely. An insensitive explosive constitutes a hazard because of (1) the danger of drilling into unexploded portions of charges of explosives which have partially misfired, and (2) the likelihood of a low order of detonation, or the burning, of all or part of the charge in a hole prepared for blasting. The latter condition not only usually produces large volumes of poisonous gases, but it is particularly hazardous in gassy or dusty coal mines where explosions may result.The Bureau of Mines and manufacturers of explosives determine the sensitivity of explosives to detonation over an air gap by means of a [(halved-cartridge gap test,"" for which the ends of the cartridges of explosive exposed to one another, are cut off. Since in blasting, the crimped ends remain on the cartridges used, this investigation has been made to ascertain the effect of the crimped paper ends on the distance detonation is propagated over an air gap as compared with the propagation distances obtained when the crimped-paper ends are removed."

Nov 1, 1932

By F. P. Haver

The purpose of this investigation was to determine the effect of common impurities, that is, oxygen, nitrogen, carbon, and iron, on the Brinell hardness of electrolytic titanium. On a weight basis, nitrogen had the greatest hardening effect, followed by oxygen, carbon, and iron in order. The hardening effects of oxygen and carbon were almost identical up to a concentration of approximately 0.1 percent by weight. Above this concentration, the relative hardening effect of carbon decreased rapidly, possibly because of its limited solid solubility in a-titanium. Hardness vs. composition curves for both oxygen and nitrogen were essentially straight lines over the range of Brinell hardness numbers (B.h.n.) covered in the investigation. The hardness of titanium was also determined as a function of the percentage of impurity atoms. On this basis, iron in concentrations up to 0.17 atomic percent had a greater hardening effect than either oxygen or carbon. INTRODUCTION Determination of the as-cast hardness of arc-melted titanium is a method of quality control widely used in industry. Numerous studies4/ have been made of the effect of impurities on the hardness obtained by this method. However, most of them have been based on the use of either iodide titanium or commercially pure Kroll sponge (B.h.n. >90), as a starting material.

Jan 1, 1959

By H. L. Riley

This report describes the methods and equipment used by the Watauga Stone Co. to drill und blast limestone in a two-level quarry, and to crush, screen, blend, and load this stone. Power requirements per ton of stone produced are reported. The personnel requirements for individual phases of the operation are tabulated in man-hours per ton of stone produced.

Jan 1, 1963

By E. B. Swanson

Atlantic seaboard refining and marketing companies , dependent largely upon other producing and refining areas for the crude and refined petroleum needed to meet the demand for petroleum products within the Atlantic Coast States , reported an increase in 1929 receipts of 2,542,000 barrels of crude petroleum and 13,479,000 barrels of gasoline over the quantities received during the preceding year . The relatively large expansion in gasoline receipts undoubtedly resulted from the unexpected increase in gasoline consumption which characterized the petroleum industry during 1929. Gasoline receipts from California increased 6,354,000 barrels and shipments from foreign countries were 5,381,000 barrels in excess of the 1928 figures , while receipts from Gulf Coast ports , the major source of outside supply, declined 811,000 barrels . Shipments of domestic crude oil by tanker from Gulf Coast ports during 1929 continued the average annual increase of approximately 7,000,000 barrels which has been recorded during the five years of this annual survey . These shipments have increased from 72,556,000 barrels during 1925 to 99,828,000 barrels during 1929. Shioments of Mid- Continent crude by pipe- line to Atlantic Coast refineries have , on the other hand , dropped from 11,903,000 barrels in 1925 to 1,409,000 barrels during 1929. Receipts of foreign crude oil declined 1,461,000 barrels from the preceding year . : Gasoline demand within the Atlantic Coast area reached a total of 123,345,000 barrels , an increase of 15.7 per cent over 1928. Gasoline production increased 4,157,000 barrels , while tanker receipts were nearly 11,000,000 barrels larger than in 1928. Indicated shioments from Appalachian refineries were somewhat larger than in the preceding year . Gasoline production showed an average of 33.5 per cent of the crude throughout , as compared with 31.5 per cent in 1928 and 32.7 per cent in 1927. Cracking operations accounted for 44.6 per cent of the gasoline produced , as compared with 40.6 per cent in 1928 and 35.3 per cent in 1927. Gas oil and fuel oil production averaged 52.8 per cent of the crude throughput , as compared with 55.1 per cent in 1928 and 49.5 per cent in 1927 , the decline reflecting the smaller quantities of foreign crude refined during the year .

Nov 1, 1930

By T. J. Ballard

The Conrad Hill mine vas first opened as a gold mine about 182 and has been operated at various times since then. The Bureau of Mines, as part of the strategic minerals program, mapped and sampled the accessible mine workings. The work failed to reveal appreciable copper values or evidence of additional ore deposits.

Jan 1, 1948

By W. I. Nelson

This paper describing the mining practices at the Engels mine is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The Engels Copper Mining Co. operates two mines about 3 miles apart in Plumas County. Calif. Both mines send ore to the same mill, and the methods of the larger, or Engels mine, are described in this paper. Between 800 and 1,000 tons of 1-3/4 to 2-1/2 per cent copper ore are mined daily from this mine by a shrinkage method. Connection is made with the Western Pacific Railroad at Paxton by the Indian Valley Railroad, which is 22 miles long and operates a daily mixed train to the mine.

Jan 1, 1930

By William D. Monaghan

The U.S. Bureau of Mines evaluated a teleoperated continuous mining machine for deep mining in thin-seam applications as low as 1 m. Teleoperation increases the safety of mining machine operators because it removes the operator from the face, an area of immediate hazards to safer outby locations. By using teleoperation, the miner can avoid many including unexpected roof falls that can maim or kill miners instantly, methane and coal dust explosions that can be ignited with just a small spark or flame, adverse health effects from miners breathing coal and silica dust, adverse long-term inner ear damage from loud noise pollution, and other hazards related to heavy mining equipment moving about in confined underground roadways. This report presents the surface evaluation results of a teleoperated control system.

Jan 1, 1994

By Henry J. Kellner, Michael J. Brnich

This U.S. Bureau of Mines report addresses issues involved in using a limited number of training apparatus to give hands-on self-contained self-rescuer (SCSR) training to a succession of miners, and provides guidance regarding methods for minimizing the spread of infectious diseases. Procedures used for preventing the spread of infectious organisms in dentistry, cardiopulmonary resuscitation (CPR) training, and scuba training are examined. The sanitizing methods of three organizations that require individuals to insert the mouthpiece as part of the SCSR donning sequence are discussed. It was found that each of these organizations was able to render their mouthpiece assemblies microbe free simply and inexpensively.

Jan 1, 1989

By W. H. Tomlinson

Although the thoughts and efforts of the great majority of people in many parts of the world are today directed toward killing each other, the purpose of this paper is to discuss means of conserving human life. In a world of turmoil and strife, we find time to discuss and make plans to achieve our objective -prevention of the "sacrifice" of life through avoidable accidents. The word" sacrifice" is used here advisedly, as one meaning of the word given in the 1942 edition of Funk and Wagnalls New Dictionary of the English Language is "the act of giving up some desired or valued object for the sake of *** future good." As everyone agrees that life is man's most priceless possession, one wonders if past sacrifices have been in vain. It appears that life is cheap in America; it is cheap because some of the industrialists are too much concerned with making a profit to devote much time and thought to conserving human life; it is cheap because some labor leaders apparently are interested solely in personal power and prestige; it is cheap because a great many workmen fail or refuse to cooperate energetically with the various organizations interested ill; their safety and welfare; it is of little value because, individually and collectively, we are indifferent to our responsibilities toward our fellow men.

Jan 1, 1944

By John B. Bennett

In this report estimates are presented of the impact of the passage of five recently proposed "acid rain" bills on electric utility costs for coal-burning utilities servicing the domestic aluminum smelting industry, and on the costs of production for affected aluminum smelters. As aluminum smelting is an energy-intensive industry, domestic increases in electricity prices could affect the industry's competitiveness. Energy costs in U.S. aluminum smelting are compared to aluminum smelting energy costs in the rest-of-the-world. Governmental policies affecting these energy costs are discussed.

Jan 1, 1988

By D. Harrington

We Americans fondly believe that ours is the greatest , most progressive and most civilized country in the world , but the cold statistical facts reveal that we apparently have little appreciation for the lives of those whose efforts of various kinds give us whatever greatness we have . The latest available statistics indicate that the annual death rate per 100,000 persons , from accidents is nearly 80 , or far higher than that of any other country in the world ; it is more than double the rate in Denmark , Belgium, Netherlands , France , Sweden , Italy , Ireland , Germany , Norway, and Austria; it is practically double the rate in England and Wales and in Japan , and is from 25 to 60 per cent higher than the corresponding rate in Scotland , New Zealand , Australia, Switzerland , and Canada . And added to this is the fact that of the main industries of the United States mining has by far the worst accident record , viewed from either the frequency or the severity basis . The National Safety Council's latest figures for 27 of the country's main industries give mining the highest or worst accident frequency rate, 74.43 in 1929 ; meat packing comes next with 55.94 , and construction third with 50.41 . In accident severity in 1929 mining also was the worst offender , with a rate of 9.99 ; quarrying is second with 6.11 , and construction third with 4.62 . Metal mining's frequency rate in 1929 was 52.16 , as against 69.25 for bituminous coal mining ,99.68 for anthracite mining, and 74.43 for the entire mining industry ; accident severity for metal mining in 1929 was 5.99 , as against 11.69 for bituminous coal mining , 10.87 for anthracite mining , and 9.99 for the mining industry as a whole . Although this figure indicated that metal mining is on a much safer plane than either bituminous or anthracite coal mining, the frequency rate of 52.16 for metal mining was higher in 1929 than the frequency rate of all but one of the other 26 industries about which data are available ; the metal mining severity rate of 5.99 , while much better

Mar 1, 1932

By R. W. Huber

While conducting an investigation on electrolytic reduction of magnesium oxide in 1943, it became necessary to obtain accurate data on the conductivity and density of various mixtures of fused chlorides. AZ the required information was not available in the technical literature, or there were inconsistencies in the data from several investigators, an independent study was made at the Bureau of. Mines laboratory at Salt Lake City on the conductivity and density of the molten chlorides MgCl2, CaCl2, BaCl2, KCl, and NaCl and the binary mixtures of MgCl2 with the other four chlorides. Studies were also made on the binary system KCl-CaCl2 and on certain portions of several ternary systems. Measurements covered a temperature range from the melting point to 1,000° C. The results of this study were reported in an intra-Bureau report prepared early in 1944. Since then the Bureau of Mines has received several requests for data on fused chlorides; the results of the previous study, therefore, are being published to make the data available.

Jan 1, 1952

By Maria I. De Rosa

The U. S. Bureau of Mines performed experiments to determine if the primary gas toxicities evolved during the early (~300° C) and later (~400° C) combustion stages of chlorinated polyester-reinforced mine ventilation ducts could be predicted by a smoke particle characteristic, for the development of a test parameter. The experiments were conducted in an approximately 20-L furnace, at 14-min durations at set furnace temperatures of 2500 and 1,000° C, with an airflow through the furnace of 10 L/min. The variables studied, as a function of time, were the hydrogen chloride (HCI), carbon monoxide (CO), carbon dioxide (C02), and oxygen (02) concentrations, furnace temperatures, the sample mass weight loss, the average smoke particle diameter (dg and average number and concentration (no), and the product of the average smoke particle diameter and concentration (dgno). Results show that the inverse of the smoke particle diameter-concentration product [(l/dgn0)], correlates directly and significantly with the primary gas toxicities evolved during both early (HCI) and later (CO) stages of combustion.

Jan 1, 1989

By A. G. Galaitsis

The two volumes of this report summarize the noise control work performed by BBN on a rail personnel carrier operated in coal mines. Volume I of the report - submitted November 1977 - describes the aboveground work performed to identify the noise sources, design, fabricate, and install the treatments, and evaluate the treatments through noise and vibration tests. The current volume (II)-describes the underground work conducted by BBN to determine the deterioration, if any, of the treatments when the vehicle is operated normally in a mine. There were no significant changes in the acoustical performance or mechanical integrity of the treatments at the end of a three-month period.

Jan 1, 1980

By Louis A. Panek

The practice of roof bolting or rock bolting to stabilize rock surrounding underground excavations has increased tremendously within a few years. This widespread application has led to many questions concerning the mechanics of bolting and has pointed up the need for a quantitative method of designing bolting systems. To answer these questions a research program was initiated to determine the principles of roof bolting. The first problem chosen for investigation was the use of bolts to reinforce bedded roof, since the great majority of bolts are used under these conditions. The attack employed is a combination of theoretical and experimental stress analysis. Centrifugal testing of models was chosen as the experimental method because it is particularly suited to the study of stratified roof. This report describes the models, the experimental method, and the model-prototype relations. By using dimensional analysis, a general expression for a roof-bolting design formula in terms of the structural variables has been obtained. Certain model-prototype similarity requirements have been relaxed, thereby minimizing the number of variables to be studied and extending the applicability of quantitative test data to a large class of full size structures.

Jan 1, 1956

By W. C. Hudson

"The Miami-West Palm Beach belt of silica sand, which may be suitable for the manufacture of high-grade glass, extends 65 miles northward from the neighborhood of Miami to the vicinity of West Palm Beach, The sand presumably originated in the host rocks constituting the oceanward slope of the Appalachian Mountains and the Piedmont Plateau of Georgia and the Carolinas. The sand now lies in a long, narrow, and probably thin belt that forms a dune-capped terrace marking a previous stage of submergence. The highest dune crests appear to be no more than 30 feet above sea level, and the water table is about 10 or 15 feet below the general level of the terrace.The width of the belt in several places is known to be more than a mile, and the thickness of the clean glass sand sampled ranged from 4 to more than 7 feet. Visual inspection and the meager data indicate the existence of bodies of glass sand large enough to supply foreseeable markets.Analyses of three samples indicate that beneficiation would make the sand suitable for the better grades of ordinary and flint glass.The prospective grade and quantity of sand, an available market in Florida for glassware, and the expectation of postwar expansion of the new industry of glass producing justify more detailed exploratory work and beneficiation testing.U. S. Route No. 1, Old Dixie Highway, the Seaboard Railway, and the Florida East Coast Railway, all substantially parallel and usually within a width of a mile or two, run along parts of the belt or between it and the coast. In addition to many streets and unpaved roads, a paved road crosses the belt at right angles about every 5 miles. Numerous towns are situated within or near the belt. Any area selected for a mining, processing, and manufacturing plant would be near a railroad, a highway, and water and also accessible to public utilities.The subtropical climate, famous for its pleasantly warm winters, would preclude seasonal interruption of plant operations."

Apr 1, 1946

By J. M. Stuve

Standard heats of formation (AH°p) of YbCl3 (c) and TmCl3 (c) were measured by solution calorimetry. Heat of solution data are given for ytterbium and thulium metals and corresponding anhydrous trichlorides in 4.360 molal hydrochloric acid. The derived standard heats of formation of YbCl3 (c) and TmCl3 (c) were -229,370 ±720 and -235,820 ±400 cal/mole, respectively, at 298.15° K. The resulting heats of formation for YbC13 and TmCl3 are about 1 kcal and 6.3 kcal more negative than previously published values.

Jan 1, 1967

By E. J. HOFFMAN, J. c. W. FRAZER

The apparatus and methods described in the following pages were devised and used by the writers in connection with certain investiga- tions of the technologic branch of the United States Geological Sur- vey, especially those bearing on the improvement of furnace condi- tions and on efficiency in the use of fuel. The Bureau of Mines, which has charge of such analyses and tests of fuels as were formerly made by the technologic branch of the Sur- vey, is using the same apparatus and methods in connection with similar investigations that are being carried on at the testing plant of the bureau at Pittsburg, Pa. The furnace conditions prevailing both in small plants and in large industrial establishments in this country are frequently far from satisfactory. If such conditions are to be improved, they must be more thoroughly understood, and means must be found to insure complete combustion of the fuel, and yet to permit operation with such an excess of air as will result in the greatest efficiency. In this work the services of the chemist are indispensable. A very important problem is the determination of the small percentage of unburned combustible matter that escapes from the furnace in the flue gases. Under ordinary circumstances so little as 0.1 per cent of unburned combustible matter in a furnace gas is equivalent to about 1 per cent of the fuel used; and for the determination of such small percentages of gas more accurate and refined methods are required than have ordinarily been available heretofore. It is the purpose of this paper to describe some apparatus and methods which have proved satisfactory to those engaged in the chemical work of the investigations mentioned. While these methods and apparatus have been designed more particularly with regard to analysis of furnace gases, their use is by no means limited to that purpose. The reader will readily see their applicability to other uses in which the sampling and analysis of gases are involved.

Jan 1, 1911

By John H. Soulé

"INTRODUCTION Spodumene and lepidolite were shipped from the Harding pegmatite deposit, Taos County, N. Mex., in the period from 1930 to 1930. Tantalum minerals were noted as early as 1924 and described in 1931 3/ but no tantalum ore was shipped until 1942. The deposit was mapped and studied by geologists of the Federal Geological Survey and engineers of the Bureau of Mines late in 1942 and early in 1943, and a Bureau of Minus exploratory project was carried out in 1943. 4/ Thu following report presents the results of that project.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Minos has as its primary objective the more effective utilization of our mineral resources to the end that they make the greates possible contribution to national security and economy. It i the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lovell B. Moor, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallugiical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, Assistant Director."

Dec 1, 1946

By IRENE AITKENS

The Mining Law of 1910 , with amendments of 1914 and 1928 , is at present in force in the Dominican Republic . The first and basic mining law of the Republic was passed in 1876 , and although numerous changes and amendments have been made from time to time , the new laws and amendments thereto have not changed the original or basic law materially . However , these enactments have materially changed the legal methods governing the exploitation of the mineral resources of this country and have added new regulations and requirements to those concerning certain specific minerals , etc. The original or basic law still exists as it was first promulgated to protect the rights of the Dominican Republic itself , the rights of the landowner , and the rights of prospectors in general . The Mining Law of 1876 remained in force , without amendment , until it was superseded by the law of May 25 , 1904 , an enactment modeled after the Mexican mining law and designed especially to encourage the investment of

May 1, 1931