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By C. E. Munroe

In order to meet the emergencies of the world wr, tne quantities of explosivea produced in the Unitecl States, and the number of explosives plants were onti:.1.1.:l,lly ncreased so that when the armistice was declared the Government had on hand larg ..mounts oi militazy explosives in excess of existing military needs. Tle stor3.gs of these explosives entailed a liirge expense and their protection neessitatei the employment of m'3.l'lY men who could be better employed otherwise in the military estlish.11ent. Moreover, mar.y ex.ploives, like QJ.l other material, deteriorate on prolonged storage, They lose tht precise definiteness of properties and behavior on which reliance· is placed in military operations, The continued expen3e and d3.nger ttending storage of theae explosives might be diminished by dcst1et1on of the surplus beyond immediate needs, but such·deetniction is danger• ou5 qnd coetly. Hence, the evident solution o! the problem was the salvage d prompt ut111zation of the ru.rplua •

Aug 1, 1922

By Miles B. Royer

The experimental blast furnace has attracted increasing interest during the past decade as a practical means for investigating a broad range of blast-furnace smelting problems. Under experimental-furnace conditions, information can be obtained with less expenditure of time and raw materials and, therefore, at lower cost than comparable information could be obtained under industrial operating conditions. Furthermore, the experimental furnace may be operated beyond the range of smooth operation, even to failure, to delineate the limits of operability. Such deviation from normal operating practice would be economically intolerable in industrial operations where production and operating stability might be disrupted. The Federal Bureau of Mines experimental blast furnace at Bruceton, Pa., near Pittsburgh, has been operated and under development since 1951. However, the usefulness of this experimental data to industrial practice was somewhat nebulous in early experiments, and the correlation of the experimental blast furnace with the industrial blast furnace was not known.

Jan 1, 1961

By C. T. Sheeran

The Bureau of Mines investigated a microprocessor-based real-time control and monitoring system for uranium mining applications. The system is capable of controlling and monitoring up to 768 stations within 3 km of the central processor on a common four-wire cable. It can be used in conjunction with detectors to continuously monitor and display radiation working levels at points throughout the mine. Surface alarms are sounded for critical situations such as rapid radiation buildup, loss of power to monitors or fans, and changes in air door position. Permanent records of all changes are automatically printed out with their time of occurrence. Printouts can also be obtained for shift reports or trend logs. The system can be used to remotely control fan startup and shut-down, and also can alert miners of underground conditions by blowing horns or turning on lights. Battery backup keeps the system operative for up to 4 h in case of a mine power outage. A special software feature permits automatic, time-delayed, sequential restart of fans.

Jan 1, 1984

By H. H. Storch

"INTRODUCTION The first paper of this series contained data concerning the behavior of polyhalite (K2S04.MgS04.2CaS04.2H20) upon calcination and subsequent leaching with water at 100° C. It was found that upon heating polyhalite to temperatures between 298 and 500° C. the water of crystallization is driven off, leaving, an amorphous mixture of K2S04, MgS04, and CaS04. Two transition points were located; one at 298° C. which coincides with the vigorous evolution of steam; and one at 551° C. which results in the formation of a hard mass of crystals. The latter probably consist of a solid solution If the compounds langbeinite (K2504, 2MgS04), potassium dicalcium sulphate (K2304. 2CaS04), and anhydrite (CaS04). The heat of decomposition of polyhalite at 298° C. was measured and found to be 66,000 ± 5,000 calories per mol. The optimum temperature of calcination with regard to subsequent extrac¬tion with two parts of water (at "" 0° C.) is 430 to 450° C. for 65 to 100 mesh material, if one half hour at the calcination temperature is allowed. The maximum concentration of K2S04 obtainable in the extraction of calcined polyhalite is 11.4 grams per 100 grams of water. This concentration of K2304 is considerably above the equilibrium value (3.6 g. per 100 L. of H20 at 83° C.) with respect to the solid phases polyhalite, potassium calcium pentasulphate, ¬and anhydrite. The figure 11.4 K. of K2804 per 100 g. of H20 is also somewhat than the equilibrium value (9,65 g. per 100 g, H20) with respect to the solid phases potassium calcium pentasulphate and syngenite."

Oct 1, 1930

By Jr. Reistle

The tests reported in this paper were made in the East Texas field in the summer and fall of 1932 as a part of the Bureau of Mines study of the operation of flowing wells and reservoir performance; and to determine, if possible, the minimum reservoir pressure necessary to produce the wells in this field by natural flow through different sizes of flow strings. The minimum reservoir pressure that would be required to Maintain natural flow through 2 1/2-inch tubing was determined experimentally for the existing energy conditions in the East Texas field. With the present available data, however, it is impossible to predict accurately or to determine by calculation the necessary energy requirements for maintaining the vertical flow of oil and gas mixtures under all conditions. Although some valuable data were obtained which seem to have application to the solution of problems involving vertical flow, this important research of the petroleum industry is so involved that more study of the complicating factors influencing the flow of oil-gas mixtures through vertical pipes is required.

Jan 1, 1933

By J. B. Littlefield

The Greenburg-Smith impinger was developed at the Bureau of Mines in cooperation with the United States Public Health Service in 1922 in the course of an investigation of dust-sampling instruments available at that time. Although it is not used extensively outside of the United States, it is now soused in this country to collect samples for the determination of any dustiness, and most of the information correlating degree of dustiness with physiological effect has been obtained by the impinger method. The chief disadvantages in the use of the regular impinger, especially in mines and other places accessible with difficulty, are its bulk, weight, and power requirements. It requires a source either of electricity or of compressed air, which necessitates connections and extension of existing supply lines to each sampling point; the only alternative is the use of a relatively large pump hand-operated with considerable effort.

Jan 1, 1937

By S. K. Ash

In arriving at economic losses in coal mining due to accidents, a statistician is confronted with many difficulties on account of the lack of information relative to nonfatal accidents. For comparative purposes the ex¬ perience of those countries, States, or companies that keep complete records can be drawn upon and an extimate can be arrived at whereby one State can be compared with another, or one mine compared with another in the same district. Such a comparison for the United States has been compiled by the United States Bureau of Mines. It will be observed in Table 1 that the cost per ton for accidents in the State of Washington for the year 1927 is higher than for any other State, with the exception of Georgia and North Carolina, with a small combined tonnage of 130,089 tons. (The figures for coal production in Table 1 are taken from Bulletin 319, 1930, of the United States Bureau of Mines.) The reasons why the cost of accidents in Washington might be higher than the average are on account of physical conditions such as steep pitches, faults, igneous intrusions, highly explosive coal-dust, extremely friable coals, presence of gravel and water, very gassy coal beds, rugged topographic conditions, inherently bad roof and floor, thick beds, and heavy cover. The nature of the coal beds requires the use of preparation machinery. The mines are often deep, and topographic conditions are such that long and fast haul¬ age becomes necessary. All of these factors not only tend to cause high cost of production, which is manifested largely in a. lower than average daily pro¬ duction, per man, but..they.also affect to some degree a tendency toward a higher than average cost for accidents.

Nov 1, 1931

By H. W. Busch

In the course of examinations by representatives of the Bureau of Mines of several compressed-air systems in which explosions had occurred, samples were obtained of the carbon deposits that are formed normally in various parts of the systems by decomposition of the compressor lubricating oil. Experimentation with these carbon deposits has demonstrated that they contain a "carbon-oxygen complex" similar to that formed on coal and on other carbonaceous materials and generally recognized as being the cause of spontaneous heating of coal. The exothermic properties exhibited by such a complex are considered significant in relation to the possible initiation of combustion reactions that may lead to explosions or formation of carbon monoxide in compressed-air systems. This report discusses the occurrence of explosions and formation of carbon monoxide in the use of compressed air and presents results of experimentation conducted with carbon deposits from air compressors.

Jan 1, 1949

By William Y. Mo

This Information Circular provides a detailed background documentation of how the Bureau of Mines projects U.S. mineral demand to the year 2000. These statistical projections serve as a quantitative basis for contingency forecasting of the low, high, and probable U.S. demand for nonfuel minerals by end-use categories and are published in the Bureau of Mines Mineral Commodity Profiles and Mineral Farts and Problems series. Aluminum is used as an example in this study.

Jan 1, 1980

By Patrick D. McMaster

"INTRODUCTION According to the Roane Iron Co. of Rockwood, Tenn., the Chamberlain. Barnardville iron deposit produced approximately three million tons of iron ore previous to 1928. The deposit is divided into two synclinal bodies termed the north and south synclines. Production has come from the northern extremities of both bodies.The need for developing additional iron-ore reserves during the war prompted the Bureau of Mines to initiate an exploratory program on the Chamberlain-Barnardville deposit in February 1944, which continued until December 1944.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical 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."

Oct 1, 1946

By John P. Capp

The feasibility of simultaneously burning several paths through a coalbed to develop a multiple path underground gasification system was investigated by the Bureau of Mines during two experiments, Boreholes were drilled through the overburden and into the coal and arranged in a circle approximately 50 feet from a central borehole. In the first experiment, in an area which had previously been hydraulically fractured,5 air was injected at the center borehole. The coal was ignited at the other boreholes and the fire fronts traveled toward the center, counter to the flow of air, to backward burn paths through the coalbed. Two paths were linked during the first 5 days of operation. The outlets of these two paths were throttled and air pressure was increased to maintain the flow of air, but no other linkages were made. Fourteen days after the two linkages these two paths were opened and gasification was carried on for 10 days, but with only moderate success. In an effort to overcome operating difficulties air was injected at the peripheral boreholes, and the gases were drawn off at the center borehole. Reversed flow operations continued for 12 days and two more paths linked. The heating value of the gas generally was higher than 100 British thermal units per standard cubic foot (B.t.u. per std. c.f.). Because only four of seven paths linked, however, the entire system could not be evaluated with respect to product-gas output and recovery of energy.

Jan 1, 1961

By R. D. Groves

Techniques were developed for preparing metallurgical-grade copper powder from industrially produced cement copper. Flotation was used for rejecting discrete gangue particles, acid leaching to remove residual iron and aluminum, hydrogen reduction to eliminate oxygen, sintering to consolidate the fine-sized copper, and grinding to obtain copper powder. Powders prepared from six different cement copper samples contained, in percent, 98.5 to 99.0 Cu, 0.10 to 0.05 Fe, 0.10 to 0.08 insoluble material and the remaining individual impurities less than 0.15 percent. The apparent density, flow characteristics, and other physical properties were suitable for powder metallurgy applications. An economic evaluation showed that this process was economically feasible. Processing costs appeared modest when considering that copper powder commands a price normally about 17.5 cents per pound over that of electrolytic copper.

Jan 1, 1971

By W. H. Herschel, E. W. Dean

"IntroductoryThe common practice of the petroleum industry is to measure viscosity by the use of instruments of the efflux or capillary tube type. The Saybolt universal viscosimeter has been tentatively adopted as a standard by the American Society for Testing Materials and is used extensively in the United States.Several instruments of foreign origin are also more or less familiar, such as the Redwood, the Engier, and the Baroey.Effina-type viscosimeters are well adapted to the ordinary needs of petroleum testing laberatories as they are simple and rugged in construction and away to manipulate, even in the hands of operators lacking scientific training. They have, however, certain limitations and for certain spacial types of work there are notable advantages incident to the use of the so-called torsion types of type of viacosimeter. The most satisfactory type of torsion viscosimeter now available in the market some to be that of MacMchael, which has been discussed in detail in a recent paper (Herschel, W. H., The MacMichael Torsional Viscosimeter. Jour. of Int. and Eng. Chem., vol. 12, 1920, pp. 282-286). The present paper indicates conditions under which this viscosimeter may be used to advantage in the petroleum laboratory, and outlines simple methods of operation and calibration."

Jan 1, 1921

By C. W. Smith

The U.S. Bureau of Mines conducted research to determine the effect of ground water control on the dewatering of phosphatic clay wastes. Two storage impoundments were constructed. One impoundment was surrounded on three sides with a series of well points (shallow vertical wells) to lower the ambient water table and the second impoundment served as a control. Ground water was pumped from the area surrounding the test impoundment for a period of 490 days. A constant pumping rate of 60 gal/min resulted in a water table drawdown of 13 ft, approximating the bottom of the impoundment. At the end of the test period percent solids in the test impoundment was 35 pct, while in the control impoundment percent solids was only 26.8 pct. Percent solids of greater than 30 pct is required for capping and final reclamation using fertile overburden.

Jan 1, 1989

By Stephen C. Tadolini, Steve Bessinger, James Pile, Christopher Mark

The San Juan Coal Mine, located near Farmington, New Mexico, supplies the San Juan Generating Station with more than 6 million tons of coal annually. To replace dwindling surface mine production, San Juan installed a longwall in 2002. The roof rock in much of the underground reserve consists of interbedded coals, carbonaceous shales, and mudstones. Roof support consists of fully-grouted roof bolts, both tensioned and non-tensioned, supplemented by modified cable trusses. Short-encapsulation pull tests conducted by San Juan’s geotechnical engineering department showed that some of the immediate roof layers provided variable bolt anchorage. To ensure that the roof bolts were obtaining the necessary anchorage, additional tests were conducted in a variety of locations. The results have been used to determine the optimum support design for different areas of the mine. Another series of tests evaluated the performance of several bolt and hole diameter combinations. The experience at San Juan Mine shows that short-encapsulation pull tests can provide the information necessary to improve ground control in variable roof conditions. It also illustrates how a pro-active geotechnical engineering program can be an essential component of a state of the art underground coal mine.

By Robert M. Doerr

Isothermal oxidation kinetics were determined for three grades of Ni and for 99.99 percent Co in Ca and in air from 800° to 1,200° C. The oxidation reactions followed approximately the parabolic rate law. For 99.99 percent Ni in 02 at 1,200° C, the parabolic rate constant was 2 mg cm-2 hr-2. For 99.99 percent Co in dry air, the constant ranged from 1 mg cm-2 hr-2 at 800° C to 18 mg cm-2 hr-2 at 1,200° C; for 99.99 percent Co in 02 the constant was 2 mg cm -2 hr-2 at 800° C and 10 mg cm-2 hr-2 at 1,000° C. For 99 percent Ni in dry air, the constant ranged from 0.2 mg cm 2 hr-2 at 800° C to 3 mg cm 2 hr-2 at 1,200° C. By X-ray diffraction measurements, only divalent oxides were found in the scales. Volumetric and quartz-helix gravimetric methods were used. The volumetric apparatus was designed to permit less stringent restrictions on the corrosion specimens; it was also more convenient to use. The agreement between the weight gain determined gravimetrically and the 02 consumption determined volumetrically was not good enough for direct comparison of gravimetric and volumetric results.

Jan 1, 1963

By Michael S. Miller

In 1985 and 1986, at the request of the U.S. Forest Service, the U.S. Bureau of Mines studied the 17,000-acre Pyramid Peak planning area in order to evaluate its identified mineral resources. The planning area is located in Riverside County, CA, 15 miles south of Palm Springs. The planning area contains marginally economic resources of marble and mica, subeconomic resources of garnet and occurrences of gold and tungsten. The area is underlain by marble, quartzite, schist, migmatite, intrusive rock, and a wide zone of intensely sheared rock. Quaternary stream, landslide, talus, and colluvial material overlie the older rocks. Ten claims for marble in or overlapping the southwest and southeast parts of the planning area are current (1986). Many other current claims are outside the planning area, adjacent to or within 2 miles of the southwest and southeast corners. Hundreds of millions of tons of inferred, marginally economic marble in and near the planning area may be mined for cement or lime after other developed resources near markets are depleted or if large-scale construction or other markets develop nearby.

Jan 1, 1987

By R. L. Hopkins, H. T. Rall, H. J. Coleman, C. J. Thompson

Two methods were tested for separating sulfur compounds in certain petroleum fractions into types . Such separation is preliminary to identifying the compounds . Each method involved extraction of sulfides from petroleum sulfur concentrates . In the first method , the sulfur concentrate was reacted with methyl - ptoluenesulfonate to form sulfonium compounds from which unreacted portions of the sample were removed by washing with solvent . The sulfides then were recovered by heating the sulfonium compounds with anhydrous triethanolamine . The second method consisted of passing anhydrous hydrogen iodide into a n-butane solution of the sample cooled in dry ice , whereupon the hydrogen iodide adducted with the sulfides to form sulfonium compounds . These adducts separated as crystalline solids or , more frequently , as glassy viscous liquids . The sulfide was regenerated by adding water to the filtered sulfonium compound and was recovered by steam distillation or by extraction with pentane . These methods have been evaluated , using individual pure sulfur compounds and blends of sulfur compounds . They also have been applied successfully to separating sulfides from sulfur concentrates derived from petroleum fractions .

Jan 1, 1964

By S. H. Ash

[On December 2, 1932, the Governor of California called upon the representatives of the mining industry of the State to attend a meeting at Sacramento to discuss ways and means of assisting is relieving some of its perplexing and extremely distressing problems, particularly the mounting cost of accidents which faces the industry with an industrial insurance rate for classification of $11.85 per $100 of pay roll, effective January 1, 1033. The significance of this fact is at once apparent when it is realized that the classification rates per $100 of pay roll for mining have steadily increased for some time, as follows: $3.91 in 1924, $5.54 in 1925 and 1926, $8.04 in 1927, $8.53 in 1928, $9.05 in 1929, $9.42 in 1930, $10.54 in 1931, $10.99 in 1952, and $11.85 in 1133. In other words, the cost rates have acre than doubled, wile statistics indicate that the accident rates nave shown an entirely different trend. At the meeting mentioned, one of the management officials sounded an effective keynote when he declared that a spade should be called: a spade. The perplexing problems of any industry can be approached best and remedies applied if that policy is kept to the front. It is appropriate to mention that high accident rates and a decrease in wages in recent years have unquestionably accounted in part for a unit cost rate, on a pay-roll basis; it also is well to explain that the policy years3 1926 to 1930, inclusive, are the years on which the accident-cost experience for 193: is based. That accident rates :lave not undergone the expected beneficial chance in California's experience is apparent in the words of a Bureau of Mines report:4]

Jan 1, 1933

By Clark F. Grain

These investigations were undertaken as part of the Bureau of Mines program for the development and evaluation of high temperature nonmetallic materials. This report consists of thermal expansion and phase inversion measurements by high-temperature X-ray diffractometry on the principal oxides of beryllium (BeO), calcium (CaO), titanium (TiO2 ), zirconium (ZrO2 ), hafnium (HfO2), and thorium (ThO2); all were high-purity commercially available oxides. Thermal expansion values were calculated from unit cell dimensions measured at selected temperatures. Expansion was determined parallel to each major crystallographic axis for the anisotropic oxides: BeO, TOi2, ZrC2, and HfO2. Combined random and systematic errors in the thermal expansion values are considered to be less than 3 percent of the total expansion at 500° C. and approximately 2 percent at 1,000° C. No hysteresis in the expansion curves was noted between heating and cooling cycles. The Bureau's values were compared with published expansion measurements obtained by X-ray diffraction, dilatometric, interferometric, and telemicroscopic techniques. For anisotropic oxides, average linear expansion values were calculated from the volume expansion.

Jan 1, 1962