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By P. A. Cox

Guidelines are provided for the design of explosion-proof electrical enclosures that will meet MSHA certification requirements according to Part 18, Title 30, of the Code of Federal Regulations, and fulfill their intended service underground. The guide covers only those aspects of design which affect enclosure strength, ruggedness, endurance and flame path, i. e., the enclosure ability to properly contain an internal explosion. Internal static and explosion pressures, external impact and thermal heating load are treated as well as the proper selection of materials and welding procedures.

Jan 1, 1985

By Ivor Hawkes

This report describes how longitudinal and bending stress waves in' percussive drill rods generate noise. It is shown that in practical drills the largest noise source is the bending waves, which are mainly generated because of imperfections in the piston, chuck, and drill rod alignment. Equations are presented which enable the noise spectra generated by the bending and longitudinal waves to be precisely predicted. Means for reducing the amplitude of the bending waves are discussed.

Jan 1, 1977

By Michael Rieber

Among the principal gathering/distribution systems for coal is over-the-road trucking. Where alternative trunk line modes such as barge or rail links are weak or nonexistent, trucks may, particularly for relatively short line hauls, act as substitutes. Their major application, however, appears to be in connection with smaller mines or coal users particularly where terrain problems are significant. Truck use has increased as rail lines have been abandoned or suffered neglect. For example, in 1956 about 38 percent of the coal transported in eastern Kentucky and about 8 percent of the coal moved in western Kentucky went by truck. By 1975, the percentages were almost 77 percent and 26 percent, respectively [4,U-11]. While rail route .limitations and deterioration played a part in the change, increased emphasis on road building, particularly during the 1950's and 1960's, and improved truck load capacity and efficiency were also important.

Jan 1, 1977

By A. J. Kraemer

This paper on the physical and chemical properties of crude oils from California fields is one of a series of reports on the on the districts of the United States. The paper includes a short discussion of results, tabular data, and individual analyses of eight. California crudes. Analyses of other crude oils from California have been published it Reports of Investigations 2595, 2608, and 2846. The samples were obtained by members of the San Francisco office of the Bureau of Mines. The collecting 65 samples was facilitated by the courtesy of representatives of oil companies in California. The methods used in testing and analyzing the samples are described in detail in Bureau of Mines Bulletin 207. A discussion of the interpretation of crude-oil analyses, as made by the Bureau of Mines, is given in Bureau of Mines Report of Investigations 2806.

Jan 1, 1931

By H. G. Miller

The success of any project in which gas is injected into oil-producing sands to increase the current rate or the economic ultimate production of oil or in which surplus gas from oil-producing operations is stored temporarily in reservoir sands that have been wholly or partly depleted of their producible oil depends mainly upon an understanding of the underground movements of oil, water, and injected gas and the ability to control their speed and direction of migration through the reservoir sends. Many operators believe that injected gas always travels up the structure and drives oil to wells structurally higher than the injection wells, because the specific gravity of the injected gas is less than that of the fluid substances in the formation. Consequently, many injection wells are located on the flanks of oil-bearing structures with the idea of utilizing the energy of the injected gas to drive the oil to producing wells higher on the structure. It is true, under certain conditions of pressure and fluid depletion of the reservoir sands that injected gas will move in an up-structure direction, but the theory that injected gas always moves up the structure is based on an erroneous conception of the laws that pertain to the expansion of gases. By definition, "a gas is distinguished by its property of infinite expansion and is limited in volume only by the walls of the vessel which contains it." The expansion of gas that is injected into reservoir sands also is limited by "walls" that surround the space influenced by the injected gas. The walls of the majority of undrilled or virgin oil-bearing reservoirs in California are the impervious shales overlying and underlying the productive strata and the "dams" or effective barriers of edge water around the rims of the reservoirs. When gas is injected into the sands of a producing reservoir, regardless of the location of the injection well on the structure or the degree of depletion of oil from the sands, one of the walls which confine the gas in the structure about the injection well is fluid. This wall will be edge water in a nearly depleted reservoir, where the drainage cones or regions of reduced pressure about injection and producing wells intersect; and, where there is no interference of drainage cones and the injection well is structurally above the edge water, the wall will be oil. In some producing reservoirs bottom water may be the lower wall of the space that confines the gas about injection wells, but the effect of bottom water on limiting the expansion of gas is the same as if the water was not present and impervious formation separated the producing from the underlying nonproducing strata. Therefore, since compressed gas always seeks regions of reduced pressure and its final volume is limited only by formation and fluid barriers and since the force exerted by the gas under pressure is equal in all directions, the course of migration of injected gas in reservoir sands in California and the effect of the gas pressure on fluid movement does not depend necessarily upon the up-structure location of low-pressure regions.

Jan 1, 1932

This paper on. the physical and chemical properties of crude oils from California fields is one of a series of reports on the oil-producing districts of the United States., The paper includes a short discussion of results, tabular data, and individual analyses of eight California crudes. Analyses of other crude oils from California have been published in Reports, of Investigations 2595,3/ 2608,4/ and 28465/. The samples were obtained by members of the San Francisco office of the Bureau of Mines. The collecting samples was facilitated by the courtesy of representatives of oil companies in California.

Jan 1, 1931

By R. H. Jefferson

This Bureau of Mines report describes a series of rapid wet chemical methods for the analysis of blast furnace slags. A "complete" analysis for total iron, manganese, silica, lime (calcium oxide), magnesia (magnesium oxide), sulfur, and mixed oxides (R203) can be routinely performed in less than 3 hours. These methods were employed as the analytical control procedures for the Bureau's experimental blast furnace operations and have been satisfactorily applied to the analysis of other slags and calcareous materials.

Jan 1, 1974

By Foster Fraas

A comparison has been made between cubes and spheres in the matrix of the high-intensity wet magnetic separator. For two inclined plane surfaces, such as may occur with cubes, the maximum force value, H [dH-dx] is at the point of nearest approach and is much higher than the force resulting from adjacent spheres. Although the maximum force value for cubes is higher, it decreases more rapidly at increasing distances. The maximum force for spheres is at an appreciable distance from the point of nearest approach. At field intensities for magnetic saturation of the iron spheres, the force extends to further distances with greater uniformity approximating that of the constant force or isodynamic field. The force is also independent of the sphere diameter, which permits the scaling of the sphere diameter to provide changes in particle migration distances without changes in force gradient.

Jan 1, 1972

By Robert Lee Stahl

Comprehensive field tests were made by the Bureau of Mines at the Schwartzwalder mine near Golden, Colo., to determine whether surface geophysical techniques could be used to detect and delineate faults in uranium deposits. The tests included seismic refraction, magnetometer, electrical resistivity, airborne infrared thermal scanning, and airborne photography. Of the several geophysical techniques tested in the field, horizontal resistivity profiling with electrode spacings in the range of 10 to 15 feet was most diagnostic of faults. The method is quick, inexpensive, and accurate and can be easily used by mining company personnel to detect and delineate faults.

Jan 1, 1974

[This is the eighth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the interior. The fir t report gave data on motor gasolines sold during the winter of 1935-36.3/ The present report, covering 1,679 simples, represents the products of US companies plus those from the Pacific coast, witch were averaged by the Pacific Coast Technical Group before being submitted and arc published exactly as they were submitted. The three groups of data on samples of regular, premium, and third-grade gasolines are averred separately. the, number of samples and brands representing each grade are as follows: Regular price, 869 samples, 76 brands; premium price, 452 sample, 45 brands; third-grade 358 samples, 52 brands. In this report the same marketing districts are retained as were used in the preceding report, and as for as possible the actual sampling points in each area are indicated on table 1.]

Jan 1, 1940

By H. Stuart Auvil

Twelve samples of run-of-oven coke were taken at coke plants in the United States and Canada. Sampling procedure was directed toward obtaining the highest possible degree of uniformity in the gross samples, so that variations in results caused by sampling variations were at a practical minimum. Under these conditions the standard deviation of the screen analysis test on 500-pound samples is found to range from 1.2 percent for the 1-inch screen to 4.5 percent for the 5-inch screen. At present, the A.S.T.H. standard method of test requires that results be reported to the nearest 0.1 percent. This implies a higher than actual degree of precision, and revision of the report required by the method is suggested. Much larger Samples than are generally tested are required to reduce normal testing errors to a point where they are not appreciable fractions of the total variations found in a smoothly operating plant. For example, it is deduced that over 100,000 pounds of coke must be screened to determine if ordinary day-to-day variations in screen analysis have appreciable effects on the performance of a blast furnace.

Jan 1, 1950

By Boyd Guthrie

Methods of distilling topped crude oils and distillates under vacuum, accompanied by good fractionation, have taken a place of major importance in the refining industry. In the refining of petroleum products it is generally desirable to produce a distillate of good quality, and this objective is attained by fractionation of a high degree. The laboratory and commercial practice have proved that by varying the amount of fractionation the quality of the distillate can be changed, and refiners are cognizant of the advantages of good fractionation. Distillation under high vacuum, however, is a relatively new practice in petroleum refining, and only during the last few years has there been an indication that this method may become a general practice in the industry. Vacuum distillation offers many advantages over older methods of distilling petroleum products. Vacuum combined with steam distillation, for example, is replacing straight-steam distillation because the quality of the products of vacuum and steam distillation surpasses that of those produced by straight-steam distillation. Although the injection of varying amounts of steam in a vacuum unit is common practice, the amount of steam used is becoming loss as the vacuum within the unit is increased. This report describes the construction of a visible-action laboratory batch still and fractionating column and gives certain data pertaining to the operation of the apparatus under vacuum for the production of lubricating distillates. The apparatus was designed and built to produce lubricating distillates under as nearly ideal conditions as possible, in order that a subsequent study of the characteristics of the distillates could be made. For example, a study could be made of the distillates obtained up to the point of cracking of the charge if a topped crude were charged to the still; if the still was used as a rerun unit for lubricating distillates a study of nearly the entire charge could be made. Only topped crude has been charged to the still so far, and therefore this paper is limited to the results obtained from the distillation of such a charge. The results so far obtained indicate that such an apparatus is valuable in a study of different crude petroleums as sources of lubricating distillates.

Jan 1, 1932

By O. C. Blade

This report on the properties of motor fuels sold through service stations-in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Deparment of the Interior. It presents analytical data for 4,397 samples, representing the products of 130 companies. The samples were collected during December 1952 and January and February 1953. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers. The data were obtained by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation. A list of the National Motor-Gasoline Survey reports published during the past ten years is given on page 5.

Jan 1, 1953

By John R. Reeves

The data presented in this paper form the chief part of a general survey of the oil-shale resources of Indiana. Other papers* have already been published which contain data an various aspects of this resource. In combination, these papers present data with reference to the following points; (1) distribution of the New Albany shale; (2) amount of shale available; (3) homogeneity and thickness of the formation; (4) amount and quality of the oil obtained from the shale; (5) nitrogen content of the shale; (6) extractibility of the shale and its amenity to breaking; (7) some economic factors bearing upon the utilization of the shale; and (3) other miscellaneous factors and data. In the future, technical work on other phases of the general problem is expected to be done with the object of making a complete survey of this resource which is of much potential importance to the state and nation.

Jan 1, 1923

By H. C. Miller

The success of any project in which gas is injected into oil-producing sands to increase the current rate or the economic ultimate production of oil or in which surplus gas from oil producing operations is stored temporarily in reservoir sands that have been wholly or partly depleted of their producible oil depends mainly upon an understanding of the underground movements of oil, water, and injected gas and the ability to control their speed and direction of migration through the reservoir sands. Many operators believe that injected gas always travels up the structure and drives oil to wells structurally higher than the injection wells, because the specific gravity of the injected gas is less than that of the fluid substances in the formation. Consequently, many injection wells are located on the flanks of oil-bearing structures with the idea of utilizing the energy of the injected gas to drive the oil to producing wells higher on the structure. It is true, under certain conditions of pressure and fluid depletion of the reservoir sands, that injected gas will move in an up-structure direction, but the theory that injected gas always moves up the structure is based on an erroneous conception of the laws that pertain to the expansion of gases. By definition, "a gas is distinguished by its property of infinite expansion and is limited in volume only by the walls of the vessel which contains it."3 The expansion of gas that is injected into reservoir sands also is limited by "walls" that surround the space influenced by the injected gas. The walls of the majority of undrilled or virgin oil-bearing reservoirs in California are the impervious shales overlying and underlying the productive strata and the "dams" or effective barriers of edge water around the rims of the reservoirs. When gas is injected into the sands of a producing reservoir, regardless of the location of the injection well on the structure or the degree of depletion of oil from the sands, one of the walls which confine the gas in the structure about the injection well is fluid. This wall will be edge water in a nearly depleted reservoir, where the drainage cones or regions of reduced pressure about injection and producing wells intersect; and, where there is no interference of drainage cones and the injection well is structurally above the edge water, the wall will be oil. In some producing reservoirs bottom water may be the lower wall of the space that confines the gas about injection wells, but the effect of bottom water on limiting the expansion of gas is the same as if the water was not present and impervious formation separated the producing from the underlying nonproducing strata. Therefore, since compressed gas always seeks regions of reduced pressure and its final volume is limited only by formation and fluid barriers and since the force exerted by the gas under pressure is equal in all directions, the course of migration of injected gas in reservoir sands in California and the

Jan 1, 1932

By R. T. Sorensen

Bench-scale and continuous testing were performed to adapt the anionic process for flotation of calcium activated silica to the fine-grained hematitic-goethitic jaspers from the Marquette range, Michigan. These ores typically contain about 35 percent Fe and require grinding to about 80 to 100 percent minus 400 mesh to insure an adequate liberation of gangue from the iron oxides. A method for removal of troublesome slime fractions without excessive iron loss, by first dispersing the quartz and then selectively flocculating the iron oxides, was evolved in the laboratory and successfully accommodated to pilot plant practice. The efficiency of the flotation process was improved with respect to both reagent usage and concentrate grade and recovery by using the selective flocculation-desliming technique as a pretreatment. The benefits of the combined desliming-flotation procedure were most evident in pilot plant processing. The best tests on two ores yielded recoveries of about 84 percent in concentrates containing 65.1 percent Fe and 4.8 percent SiO2 and 66.2 percent Fe and 3.9 percent SiO2, respectively. These results are in comparison to recoveries about 10 percent lower than the above to concentrates containing 63.9 percent Fe and 6.6 percent SiO2 in the one instance, and 63.6 percent Fe and 7.2 percent SiO2 in the other, obtained by flotation without the prior desliming treatment.

Jan 1, 1967

By N. S. Dalal, X. Shi

While it is known that vanadate and related compounds of pentavalent vanadium ( V (V)) exert potent toxic effects on a wide variety of biological systems, the underlying biochemical mechanism is still not fully understood ( 1- 3). One of the pathways is thought to involve the oxidation of NAD ( P) H. Thus, considerable effort has been devoted to finding the mechanism of NAD ( P) H oxidation by Vcvi (1-15). Erdmann et al. (5) first noted that vanadate stimulated the oxidation of NADH by plasma membranes and attributed this effect to a membrane containing NAD(P)H-dependent V(V) reductase. Later studies by Liochev and Fridovich indicated that endogenous superoxide ( 02 ) plays a central role in this reaction ( 4, 12, 13) . They proposed that NAD ( P) H dehydrogenases or oxidases produce 02, which causes VCV ) to stimulate NAD ( P) H oxidation via the following free radical chain mechanism ( 4, 12, 13) :

Mar 1, 1992

By E. P. Youngman

A new mining law for the Recublic of Polend was promulgated by presiden- tial decree dated November 29, 1930, published in the Journal of Lews (Dzienni stex) No. E, text 654, December E, 1530, and wes to become effective January 1, 1932, in all Polend except Silesie. Its adoption in Silesia wes dependent pon the action of the Silesian Diet. As the new law is considered an im- provement over the old Austrian Mining Lew, which is operative in the Silesian districts of Bielsk and Cieszyn, and the Prussian Kining Law, which is opera- tive in Upper Silesia, no delay in its adoption for Silesin was looked for. This new law codifies the various juridical regulations pertaining to ines existing in different parts of the Polish Republic but does not include legislation with respect to the extraction of minerel oil, especially crude oil. Petroleum legislation was postponed to a later date in order to facili- tate codification in other fields. Koreover, as the oil industry exists in Galicia elone, deley will not be detrimental.

May 1, 1932

By M. J. Spendlove

A progress report is presented on a research program in which an attempt was made to develop a practical sulfide-volatilization process for recovering tin from low-grade Bolivian ores. Shaft-furnace designs and operating techniques were studied in a series of experiments in which the objective was to sulfidize cassiterite to stannous sulfide, remove the stannous sulfide by volatilization, reconvert the stannous sulfide to stannous oxide, and collect the resulting fume. A shaft furnace was developed and operated in a final test in which many of the previous difficulties were surmounted. Since the supporting funds were exhausted at this point, the project was discontinued; recommendations for further improvements in furnace design and operation were made on the basis of interpretation of experimental results obtained in shaft-furnace experiments and other related studies.

Jan 1, 1955

By J. L. Shultz

Mass spectrometric analyses were obtained for naphthalene and anthracene oils, heavy creosote, and three fractions of a pitch. The average molecular weight, aromaticity, and mean structural unit were determined for each fraction. The investigation of these fractions of coal tar has resulted in semiquantitative data for 38 structural types and carbon number distribution data for their alkyl derivatives. The molecular weights of 10 of these structural types indicate ring systems not previously reported in products from high-temperature carbonization of coal. Two of these structures are poly-nuclear aromatic hydrocarbons, two are oxygen-containing compounds, one contains sulfur, and five are nitrogen-containing compounds.

Jan 1, 1967