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By R. Wiebe

During a recent investigation the authors were interested in determining: (1) How many points were necessary to locate the deviation curve for copper-constantan thermocouples within an accuracy of about 0.05° C., used in connection with the, "standard" thermocouple of L. H. Adams (2) Whether copper-constantan thermocouples showing considerable deviations from the "standard" were consistent throughout their calibration. (3) How reliable the extrapolated portion is - that is, the interval between -183 and -220° C. of the "standard" thermocouple.

Jan 1, 1931

By Martin J. Gavin

[The theory of fractional "eduction" of oil from oil shale has been used by several inventors as the basis for the design of retorts for the production of oil f roan the oil shales of the United States. The term fractional "eduction" gives expression to the rather common belief that when an oil shale is he-test et produces light, low-boiling oils at to temperatures, and increasingly heavier, higher-boiling oils as the temperature of retorting rites. The theory evidently had its is origin in the fact that crude petroleum may be fractionally distilled, yielding light oils at low distillation temperatures, and heavier oils as the distillation temperature increases. Thus, gasoline is produced from petroleum at relatively log: temperatures, kerosene at a higher temperature, and heavier products such as gas-oil and lubricating distillates at still higher temepratures, The writers have examined several oil-shale retorts designed to take advantage of the belief that crude, and en some cases refined, gasoline can be recovered from the shale at low temperatures; kerosene at higher temperatures, and so on. Such retorts are usually designed to operate continuously, and. have several vapor-pipes lending from them at differing intervals and passing to separate condensers. Designers of such retorts expect that the distillate from the low-temperature parts of the retort will be gasoline, and that as the shale basses to zones of increasingly higher temperatures, the vapor lines leading from these zones will remove increasingly heavier products such as kerosene, gas-oil, etc.]

Jan 1, 1924

By Laurance L. Oden

Titanium-enriched smelter slag produced commercially by Quebec Iron and Titanium Corp., Sorel, Quebec, was evaluated as feed material for a process developed by the Bureau of Mines to prepare rutile. Glass-forming agents including P205, B203, and two binary mixtures were added individually to the as-received and preoxidized smelter slag, and the nonferrous tramp oxides were effectively partitioned into the resulting noncrystalline phase. Iron in the ferrous oxidation state was moderately soluble in the glass of reduced specimens but less soluble under oxidizing conditions. The solubility of iron oxide in phosphate glass exceeded the solubility of iron oxide in borate glass. Effective conversion of titanium oxide to rutile was not achieved in the high-iron commercial smelter slag, and 20 to 30 pct of the titanium remained as pseudobrookite, a mixed iron-titanium oxide.

Jan 1, 1973

By R. Wiebe

During a recent investigation the authors were interested in determining: (1.) How many points were necessary to locate the deviation curve for copper-constantan thermocouples within an accuracy of about 0.05° C., used in connection with the "standard" thermocouple of L. H. Adams. (2.) Whether copper-constantan thermocouples showing considerable deviations from the "standard' were consistent throughout their calibration. (3.) How reliable the extrapolated portion is - that is, the interval between -183 and -220° C. of the "standard" thermocouple. It seems that a calibration between 0 and -193° C. can be made within the stated accuracy by determining experimentally the e.m.f. of the particular couple at -78.50°, the normal sublimation point of carbon dioxide, and at -182.97°, the normal boiling point of oxygen. Substituting the values found for the two fixed points in the simple quadratic. Equation

Jan 1, 1931

By Wilbur A. Haley

The demand on the nation's reserves of high-quality coals suitable for metallurgical purposes is resulting in the rapid depletion of some of the thicker coal beds. These beds are thick enough to permit the use of modern mechanized mining equipment. Many of the thin beds are not being mined at present. In limited areas where the coal is less than 36 inches thick some beds are mined by various conveyor methods. Usually, the room-and-pillar system or some modification of it is used, and often no attempt is made to extract pillars. Consequently, an appreciable quantity of a valuable resource is lost. Many steel companies and coal operators consider reserves of low-and medium-volatile coking coals to be critical, especially in areas where the thin beds are not being mined by modern mining methods. To improve recovery and to promote more-extensive mining in thin beds, methods and devices that are new to American coal mining but applicable to the mining of thin coal beds should be tried. As one of the functions of the Bituminous Coal Mining Section of the Bureau of Mines is to promote improved mining practices and efficiency in the interest of conservation, research in that line is necessary. In 1945 coal planers were observed in operation in Germany by a Bureau engineer member of Solid Fuels Mission to Germany. Planer designs and history of early developments and operations were published. In 1949 an improved planer was again studied by Bureau engineers, and its adaptability to certain conditions in the United States, especially thin beds of friable coal, was considered practicable. After the war the planer was improved, in design and for several years has been operating successfully in the Ruhr. Because of the conviction that the device would be successful, both from the standpoint of conservation and operational prodl1ctivity, under certain conditions in the United States, the Bureau of Mines, through the Bituminous Coal Mining Section, entered into a cooperative agreement with the Coal Division of Eastern Gas & Fuel Associates and Mining Progress, Inc. The purpose of the agreement was to conduct an experiment in modified longwall mining, using a new-type German-built coal plow or planer, known as the Loebbe Habel, supplied by Mining Progress, Inc. The experiment was made to determine if this type of mining equipment operated on a longwall face could be adapted to some of the thinner American coal beds. Such an experiment also would afford many opportunities to study the possibilities and principles of this type of equipment as well as the many factors involved in the mechanical mining of a longwall face.

Jan 1, 1952

By Nan C. Jensen, Oliver Bowles

"INTRODUCTION Limestone (which consists essentially of calcium carbonate) and dolomite (calcium magnesium carbonate) occur widely in the United States. Their presence is of vast economic importance, because they are used much more extensively than any other form of rock. In 1945, limestone (which, broadly, includes dolomite) was quarried in every State except Delaware, New Hampshire, North Dakota, and Rhode Island, and also in Hawaii and Puerto Rico. Total production (including that used in cement and lime manufacture) exceeded 151,700,000 tons, or 79 percent of the quantity of all kinds of stone sold or used during that year.Important well-known uses of limestone are as concrete aggregate, road material, railroad ballast, for liming the land, for cement manufacture, as riprap for shore protection, harbor work, and spillways at dams, and as building stone.. None of these uses, however, are considered herein. The purpose of this paper is to discuss the industrial and chemical uses that are less widely known and yet are of tremendous importance in a great variety of processing industries. Important examples are dolomite as a refractory furnace lining and limestone as a fluxing agent in blast furnaces, and as a raw material employed in sugar, paper, glass, and alkali manufacture.PRIOR REPORTIn May 1941, the Bureau issued a report 4/ that described these uses in some detail. As new and important developments have taken place during the ensuing years, a revision and representation of the salient features of these uses seem desirable. Asphalt filler and mineral wool uses included in the earlier report are omitted from this paper because they are identified more closely with the highway and building industries, respectively, than with the industrial applications."

May 1, 1947

By Robert Howard

With the rapid depletion of the Peerless Coal Co.'s mine in Spring Canyon, it was necessary, if the company was to remain in the coal-producing business, to look to the development of a new property or to acquire a mine already developed. After careful investigation of several operating properties it was decided by the officials of the company to take over the lease on an undeveloped acreage held by a private party in Price Canyon, about 3 miles north of Castle Gate, Utah.

Jan 1, 1930

By William M. Thornton

[Owing to the comparatively high freezing point of nitroglycerin (14, 15, 16, 17, 18, 23, 37, 38)3/ - 1.9° C. and 13.0° C. for the labile and stabile modifications, respectively, as determined by Hibbert (16) - manufacturers of dynamites have incorporated into the liquid portion of these composite explosives various substances capable of participating in an explosion, to depress the above-mentioned freezing point. Aromatic nitro-compounds, chiefly nitrobenzenes, nitrotoluenes, and nitronaphthalenes, have been used to a considerable extent (11), but such nitrosubstitution products have not proved altogether satisfactory, as has been shown clearly by Naoúm. (14). Consequently there has been a strong tendency in recent years to replace them with one or more of several nitric esters, among which the following (29, 35) have been prominent: Dinitrochlorhydrin (monochlorhydrin dinitrate); nitrosugars, for example, sucrose octanitrate (19); tetranitrodiglycerin (diglycerin tetranitrate); nitroglycol (ethyleneglycol dinitrate); and diethyleneglycol dinitrate (13, 46, 47). Of these, nitroglycol (33, 4l, 45, 48, 49, 65) is outstanding in importance. As the Bureau of fines is naturally interested in the analytical chemistry of the "explosive oils," it seemed desirable to bring together in this report the widely scattered experimental work covering the problem of differentiation that has appeared in various chemical and physicochemical publications.]

Jan 1, 1941

By Donald F. Reed

In the latter half of 1948 the Bureau of Mines investigated the Magnet Cove Rutile Co.'s prerty in northern Hot Spring County, Ark. This work was supplemental to the work done by the Bureau on the same property in 1945.2/ It was undertaken for the purpose of investigating the extent of the ore body toward the south and west and at depth and to obtain representative samples of the ore for metallurgical tests. For the latter purpose, the samples were so taken as to minimize alteration of the physical characteristics of the ore, these characteristics being determining factors in working out processes of bencficiation. During the investigation, 27 holes were drilled, 10 with a diamond-coro drill end 17 with churn-drill rigs using a Baker standard cable-tool core barrel. Drilling developed an extension of the ore deposit westward from the previously mined area but did not disclose the full depth of mineralization. Metallurgical tests to determine methods of beneficiating the ore and utilizing the resultant products are now in progress.

Dec 1, 1949

By S. M. Shelton, A. L. Engel

The carnotite deposits of western Colorado and adjacent sections of Utah and Arizona were formerly an important source of radium and uranium until displaced by the exploitation of foreign deposits in the Congo and northern Canada . Recently interest has been renewed in domestic carnotite ores as a source of vanadium . Carnotite is a canary - yellow, crystalline , pulverulent mineral occurring in sandstones in the Colorado - Utah district as an incrustation on the faces of joints and fractures and deposited around and between individual sand grains , often strongly adhering to the surface of the grains . Chemically, it is a variable combination of potassium, uranium , and vanadium oxides with water of crystallization . It is soft and friable , and occurs in fine - grained or earthy form . In spite of a specific gravity of 4.1 , gravity concentration has not proved practical as a means of beneficiation because of the earthy texture of the mineral . Vanadiferous sandstones occur with minerals ranging from roscoelite (vanadium mica) , containing little uranium , to high- uranium and low -vanadium carnotite . There is considerable local variation in the texture of the ores . The treatment of carnotite ores has been described previously , with attention directed to the elimination of waste in mining and the extraction of radium . The suggested methods included those suitable for the recovery of vanadium , since both radium and vanadium occur in the same minerals . Moore and Kithil suggested crushing from 40- to 80 - mesh with rolls , accompanied by a rubbing action to loosen the carnotite adhering to the sand grains . Fine grinding was to be avoided because it diluted the final product too much . The crushed and rubbed material was to be washed and

May 1, 1942

By C. Golumbic

Most early research on solvent extraction of coal has been concerned with the molecular structure of coal. Although rush work is continuing, practical aspects of the subject also are being emphasized. For example, development of the Pott-Broche extraction process resulted from the discovery of very efficient solvents for the pressure-extraction of coal. Recently, Orchin and Storch reported the use of even more efficient solvents under similar conditions. In addition to the discovery of more effective solvents, the possibility of efficient extraction at atmospheric pressure is obviously of practical interest. H. J. Rose observed that phenanthrene at its atmospheric boiling point readily dispersed 80 percent or more of Pittsburgh-bed bituminous coal. This fact served as the starting point of the present investigation, ill which determination of the chemical specificity of this solvent and the chemical nature of the resulting extracts was undertaken. This paper represents a progress report of the results obtained to date.

Jan 1, 1950

By Harold M. Smith

[Important discoveries of new oil fields were made in 1937 in the State of Illinois. Oil production, which was virtually constant during 1934, 1935, and 1936 at about 4,400,000 barrels a year, a increased to 7,499,000, barrels during 1937, and in 1938 this production was trebled. In 1939, 94,302,0003/ barrels were produced (almost foot times the 1938 quantity), making Illinois one of the cost important oil-producing areas in the United States. The Bureau of Mines has analyzed 35 samples of petroleum from these new Illinois fields and presents the analyses herein. Included with them in this report are analyses of seven samples from fields developed before 1936.]

Jan 1, 1940

By Harold M. Smith

Important discoveries of new oil fields were made in 1937 in the State of Illinois. Oil production, which was virtually constant during 1934, 1935, and 1936 at about 4,400,000 barrels a year, a increased to 7,499,000, barrels during 1937, and in 1938 this production was trebled. In 1939, 94,302,0003/ barrels were produced (almost four times the 1938 quantity), making Illinois one of the cost important oil-producing areas in the United States. The Bureau of Mines has analyzed 35 samples of petroleum from these new Illinois fields and presents the analyses herein. Included with them in this report are analyses of seven samples from fields developed before 1936.

Jan 1, 1940

By H. J. Hager, B. W. Gandrud, G. D. Coe

"INTRODUCTION The reduction of washery losses of marketable coal is a phase of coal preparation important to many of the Alabama coal producers. The problem has wide scope, and this report deals with but one of its several aspects. The investigation on which this report is based was made by the Southern Experiment Station of the Bureau of Mines with the cooperation of the Alabama By-products Corporation and the University of Alabama. The Alabama Byproducts Corporation provided samples of table middlings from its Colta washery on the Mary Lee bed at Flat Creek, Ala.PRACTICE AT THE COLTA WASHYAt Colta run-of-mine coal is crushed in a hammer mill in closed circuit with 5/16-inch square-mesh vibrating screens and tabled without classification on eight rectangular-deck wet tables. The coal is more friable than the bone normally present, and hence the bone is concentrated in the coarser sizes. An unclassified feed of this character can not be tabled with high efficiency to low ash content because of the sizing action of a concentrating table, which is such that when the tables are adjusted to exclude the coarse bone from the washed coal, a large amount of fine coal is lost in the middlings. At the time this investigation was undertaken there was no market outlet for middlings, with the result that middling products had to be discarded with the refuse."

May 1, 1939

By Wallace W. Roepke

The Bureau of Mines determined coal-cutting forces and primary dust generation of four styles of radial gage bits as used on end rings of continuous mining machines. Direct comparisons for reference were made with two widely used conical plumb-bob types having 60' and 90' (nominal) included tip angles. The cutting forces for all of the gage bits were similar to those of the 60°-tip plumb-bob bit. All bits except the RAD-3 gage bit generated similar amounts of primary total dust at shallow cutting, but during deeper cutting, the amounts varied and the gage bits produced as much as 2-1/2 times the dust produced by the 60° bit. This seems atypical since past experience has always shown differences in dust generation at shallow cutting. The specific energy was more like that found previously with other bits, since the values were spread at shallow cutting but became nearly similar at deeper cuts. The 90° bit and the RAD-3 gage bit are not recommended for use except in extremely difficult cutting conditions where dust and forces are of secondary importance. The choice among the remaining four bits can be made on the basis of dust, energy, forces, or cost, as circumstances dictate.

Jan 1, 1983

By B. C. Parks

This paper is a report on the relationships between petrographic composition, chemical composition, physical properties, and thermal behavior of banded bituminous coal. It describes the relationships between petrographic composition, behavior in various laboratory tests, and carbonizing properties of different petrographic types of coal that occur in relatively thick benches in a single bed of high-volatile A bituminous coal - the Hernshaw bed of Boone County, W. Va. Thin-section microscopic analysis and free-swelling index determinations of the thin-section samples were made of a standard column sample. A standard face sample, a representative channel sample, and representative samples of two prominent petrographic benches of bright and dull coal were subjected to chemical analyses and free-swelling-index, plasticity, dilation, agglutinating, low-temperature carbonization, and BM-AGA retort tests. A float-and-sink separation was also made of part of the standard face sample. The fractions from this gravity separation were subjected to petrographic and chemical analysis and free-swelling-index, plasticity, and dilatation tests.

Jan 1, 1959

By Susan M. Moore

The objective of this study was to evaluate the circumstances leading to fall from equipment injuries in the mining industry. Method: The 2006 and 2007 Mine Safety and Health Administration annual injury databases were utilized for this study whereby the injury narrative, nature of injury, body part injured, mine type, age at injury, and days lost were evaluated for each injury. Results: The majority of injuries occurred at surface mining facilities (~60%) with fractures and sprains/strains being the most common injuries occurring to the major joints of the body. Nearly 50% of injuries occurred during ingress/egress, predominately during egress, and approximately 25% of injuries occurred during maintenance tasks. The majority of injuries occurred in relation to large trucks, wheel loaders, dozers, and conveyors/belts. The severity of injury was independent of age and the median days lost was seven days; however, there was a large range in severity. Impact on industry: From the data obtained in this study, several different research areas have been identified for future work, which include balance and stability control when descending ladders and equipment design for maintenance tasks.

Jan 1, 2009

By R. Duncan Gardner

This paper describing the mining practice at the Harmony mine, Baker, daho, is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts in the United States. About 150 tons of copper ore containing 4 per cent copper, 0.001 ounce gold, and 0.1 ounce silver, is being produced daily from the Harmony mine by the shrinkage method of mining. The ore is taken by an aerial tramway 1/3 mile long to the mill, where it is concentrated. The concentrate is shipped 8 miles by truck to the railroad and thence by rail to Utah for smelting.

Jan 1, 1930

By D. Harrington

Insofar as prevention of mine explosions is concerned, it is apparent that the coal-mining industry has profited but little from experiences during the past 15 years. The fact that explosions can be prevented if well-known preventive measures are adopted and conscientiously carried out appears to warrant the conclusion that many coal-mining people are indifferent to the hazards that may result in explosions. Although the principal burden of preventing explosions is upon the management, and much of the evident carelessness in failing to place in effect and to enforce suitable precautions, is assessable directly against management, the worker also has a very definite responsibility, and numerous explosions have resulted because of his failure to carry out his part in accepted principles of safety. The record of fatalities from mine explosions during the past 5 fiscal years has been anything but encouraging or about which coal-mining people can take pride; more men were killed by explosions (673) than were killed from the same cause during the preceding eight years combined (577). During each of the fiscal years 1942 and 1943, 152 fatalities resulted from explosions, compared to 163 during the fiscal year 1941, 206 in 1940, and only 16 in 1939.

Jan 1, 1944

By Florence L. Feicht, Carlton E. Brown

"INTRODUCTION This report contains information on the approximate size of the smallest dust Particles revealed by or the limit of visibility of various microscopic systems. The information was obtained mainly for use in interpreting and evaluating results of number-contentration and particle-size, determinations on, samples of unhygienic particulate matter collected from industrial atmospheres and in developing better methods for determinations nations.Some speculation and even controversy have been published on the limit of visibility of the widely used microscopic system (16-mm., 0.25-or 0.3-N.A. objective, and axial light-field illumination) used in counting the dust in the liquid medium from impinger, 4/ 5/ filter-paper, 6/ and other samples, but little or no quantitative data have been published on the limits of visibility of this or other microscopic' system.ACKNOWLEDGMENTSThe interest, encouragement, and assistance received from H. H. Schrenk, chief of the Health Division are gratefully acknowledged, as is all other assistance received in this study."

Aug 1, 1945