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By Horace C. Porter, F. K. OVITZ

Much has been written of the changes undergone by coal in storage and the deterioration of coal through exposure to the weather. In order to obtain definite information for the benefit of the Government departments and of all who store coal in large quantitieS', a series . of tests was begun in the fall of 1909 under the supervision of tT. A. Holmes, then chief technologist of the United States Geological Survey, and was continued by the Bureau of Mines after its establishment in 1910. The tests were confined to determinations of the loss in heating value of the coals and did not include a study of other deterioration; for exaIp.ple, in coking quality or the yield of by-products in coking. The Bureau of Yards and Docks of the Navy Department cooperated in tests of New R~ver (W. Va.) coal, a variety largely used by the Navy. A preliminary report presenting a brief account of the early results of these tests has been published by the Bureau of Mines as Technical Paper 16.a The detailed report is presented in this bulletin, which gives a fu11 account of the tests and the analytical data covering a period of five years' storage. Data of somewhat similar experiments for shorter periods with gas coal from the Pittsburgh bed, with Pocahontas coal on the Isthmus of Panama, and with Sheridan, Wyo., subbituminous coal, which is used for railroad and other purposes in the West, are included. The tests of New River coal, in cooperation with the Navy Department, were undertaken to determine the advantage to be gained by storing coal under water, and particularly under salt water. Small lots were used in order to make the tests of maximum severity, and parallel experiments were made with run-of-mine and crushed coal under one-fourth inch size. All of the small lots tested under the different conditions (except those tested near Key West, Fla.) were taken as representative portions from one large original lot. The tests of Pocahontas coal, which, like the New River, is semibituminous, were undertaken chiefly to determine th.e effect of the tropical conditions in Panama. They were made on an outdoor pile of 100 tons of run-of-mine coal. Pittsburgh gas coal, a high-volatile, bituminous type used at gas and by-product coke works, was exposed for test at Ann Arbor, Mich., in cooperation with the University of Michigan. The university agreed to make tests at successive intervals of storage to determine, in its illuminating-gas experiment station, the yields of gas and byproducts from the coal. The coal, screened lump, was stored in about 4-ton lots out of doors in open bins. Subbituminous coal, which is mined in Colorado, Wyoming, and other States, and is known also as "black lignite," is commonly supposed to deteriorate rapidly in storage, especially by "slacking" or crumbling of the lumps. The tests herein described were undertaken at Sheridan, Wyo., in cooperation with the Chicago, Burlington & Quincy Railroad Co., in order to determine the extent of this slacking and the accompanying loss of heat value. The tests were in open bins holding 4 to 12 tons.

Jan 1, 1917

By G. S. Scott

[The Duretiu of Kinen, as :) pr<r"Yof its :;encr:rL propan clealini: with the causes, behavior, n.ncl tor-trol of o1:t1?;.?cite-mine fires, hns investic:&apos;lte3 I varionr. Te:.nr, for Je tec tin:: iccj.r)ic:~ t he;, tint; :,:.zqdergro-.:rid and of <~e termining the trend of the hen tir..: once -I i&apos;i re j 7 knnm tr, he nrcsc~t.]

Jan 1, 1938

By G. S. Scott

[The Duretiu of Kinen, as :) pr<r"Yof its :;encr:rL propan clealini: with the causes, behavior, n.ncl tor-trol of o1:t1?;.?cite-mine fires, hns investic:&apos;lte3 I varionr. Te:.nr, for Je tec tin:: iccj.r)ic:~ t he;, tint; :,:.zqdergro-.:rid and of <~e termining the trend of the hen tir..: once -I i&apos;i re j 7 knnm tr, he nrcsc~t.]

Jan 1, 1938

By J. G. Stuart, A. W. Cipkins, R. H. Thompson

Preliminary safe distances for blasting wiring from typical electromagnetic sources are presented. The distances are for underground coal mines and electromagnetic sources in the frequency range below 10 MHz. The distances are based on measurements performed at 3 locations in each of 3 coal mines. The measurement apparatus, measurement procedure, measurement results and the rationale used in the calculation of the safe distances are all described. The safe distances presented are dependent on the measurement results and their interpretation. More measurements are clearly necessary to establish the validity of the suggested distances.

Jan 1, 1985

By Walter K. Utt

The vibration levels of the heavy machines used in surface mining are much greater than for vehicles used on highways. In order to assure the proper functioning of electronic equipment placed on the surface mining vehicles, the U.S. Bureau of Mines has conducted a program of field measurements to define their vibration environment. The information in this report is for a class of vehicle that has a blade for scraping and wheels with rubber tires. The statistical information derived from these measurements can be used as a basis for laboratory testing to qualify equipment for a surface mining vehicle of this class. The envelope that would encompass 99 pct of the vibrations encountered in normal operations is presented for each location on the vehicle. The five locations for which data were recorded are the floor of the cab, the engine, the frame, the drive train (gear, differential, and torque converter), and the axle. Tabulated data are provided for those who wish to use a different probability level. The appropriate test profile for the laboratory testing can be determined from the information presented in this report.

Jan 1, 1993

By R. W. Watson

At the request of the Mine Safety and Health Administration (MSHA) the Bureau of Mines evaluated the potential hazards of three compressed oxygen self-contained self-rescuers (SCSR&apos;s) designed for use in under-ground coal mines. The evaluation followed the lines used in a similar investigation of chemical self-rescuers and involved laboratory experiments as well as field trials designed to simulate a mining environment. They included bullet impact, bonfire, feeder-breaker impact and feed-through, and mining machine runover tests. The work showed that the units were not inherently unsafe but that under certain conditions of extreme abuse they can present a potential ignition or explosion hazard. This, coupled with a survey of reported damage on SCSR&apos;s currently deployed in underground mines, which indicated a relatively high frequency of incidents leading to the destruc-tion of the units, led to new recommendations on the deployment of SCSR&apos;s. The recommendations formulated by MSHA state that the units should be either properly worn by the miner, stored in heavy containers, or otherwise protected from situations in which they might be accidentally ruptured or destroyed, such as runover by mobile mining equipment.

Jan 1, 1984

By Stanton L. Tainter

"As an adjunct to its minerals-investigation program, the Bureau of Mines has developed a number of operating devices and techniques worthy of note. This paper, prepared under the supervision of J. H. Hedges, chief, Tucson Branch Mining Division, and under the general supervision of Lowell B. Moon, chief, Mining Division, reports upon certain methods devised to overcome difficulties encountered in cementing of diamond-drill holes at a Bureau of Mines project at Christmas, Gila County, Ariz.Pressure grouting was employed to recondition a caved hole it was desired to reopen and deepen. The hole, which had boon stopped 7 months previously at a depth of 488 feet, was caved below 449 feet in a contact zone of claylike, altered diorite and crumbly metamorphosed limestone. As other means of obtaining moderate pressure were not available, carbon dioxide gas, drawn from tank of liquid carbon dioxide through a pressure reducing and regulating valve, was used. The hole was reopened successfully with 12 grouting jobs.Another hole, where cawing from several water-bearing fractures between 202 and 232 feet gave trouble, was successfully cemented by the use of a grouting plug. An attempt to cement through the rods had failed, owing probably to agitation caused by water currents. Pressure grouting through the caning set above the cave could not be need, because water was forced up outside the casing when pressure was applied. The problem was solved by using a wooden plug 1-13/16 inches in diameter, which, when soaked in water, expanded to a tight fit in an AX hole. A hole was drilled through the plug, and a rubber flap valve was nailed to the lower end. In the upper end of the plug the hole was enlarged to fit loosely over an EX rod coupling finished smooth. The plug was lowered on the end of the drill rods to a point about 10 feet above the cave, where it was allowed to expand tightly to the hole. Cement grout was then pumped through the rods, and the rods were removed from the hole. After allowing time for the cement to set, the wooden plug was chopped out and drilling van resumed.Over 300 tests were made to determine the type of cement most suitable for use on the Christmas job, and the effect of cement-water ratio, temperature, and various admixtures on workability, setting time, and strength. The results of these tests, described in detail in the body of this report, indicate the desirability of thoroughly testing available cements when it is necessary to drill holes under difficult conditions that may cause failure.When it became desirable to reopen and deepen a caved drill hole, it was considered easiest to recondition the hole by pressure grouting, As other mans for obtaining moderate pressure were not available, a method utilizing carbon dioxide gas was employed. The hole was reconditioned successfully with 12 grouting jobs."

Nov 1, 1949

By Liane L. M. Kadnuck

This report summarizes the results of a hydrologic research study conducted by the U.S. Bureau of Mines (USBM) in cooperation with Energy West Mining Co. at the Deer Creek and Cottonwood Mines, near Orangeville, UT. The USBM evaluated hydrologic and overburden failure data to assess the response of local ground water to underground coal mining in single-and multiple-seam conditions. Fourteen springs located over the two mines were investigated in the study along with overburden failure response caused by longwall panel extraction. Spring discharge was compared to climatic variation and time of undermining to quantify response to undermining. Spring discharge had been reduced owing to below-normal precipitation during the period evaluated. The response of springs to mining in the vicinity was influenced in part by the thick overburden present at the study site the presence of hydrophilic clays and mudstones in the overburden stratigraphy, and elevation of the springs above mine level, which buffered the effects of undermining.

Jan 1, 1994

By R. M. Gooding

This paper presents a short history of the production of mineral-energy fuels and energy from waterpower in the United States, with brief discussions of the utilization of each of the fuels and hydropower, and a look at fuels competition and interchangeability. Basic data, in figures and tables, are brought together in this publication for the production of coal in the United States from 1800 to 1960, for crude petroleum, natural gas liquids, and natural gas from 1859 to 1960, and for hydropower since 1900. Production for each segment of the fuels complex in the principal producing States from 1946 to 1960 is shown. Data are not included for consumption as such or for imports and exports.

Jan 1, 1963

By R. M. Gooding

This paper presents a short history of the production of mineral-energy fuels and energy from waterpower in the United States, with brief discussions of the utilization of each of the fuels and hydropower, and a look at fuels competition and interchangeability. Basic data, in figures and tables, are brought together in this publication for the production of coal in the United States from 1800 to 1960, for crude petroleum, natural gas liquids, and natural gas from 1859 to 1960, and for hydropower since 1900. Production for each segment of the fuels complex in the principal producing States from 1946 to 1960 is shown. Data are not included for consumption as such or for imports and exports.

Jan 1, 1963

By G. W. Jones

The Bureau of Mines has advocated the use of stenches as warning agents in metal mines and in gas-distribution systems since 1920 A considerable amount of research has been conducted on ethyl mercaptan and other compounds to determine their effectiveness when used for this purpose.4/5/6/7/8/9/10/11/12/13/ Miners are warned of danger by a stench injected, in measured quantity, into a compressed-air line through which it is rapidly carried to the working faces, where it escapes from the compressed-air equipment and imparts a characteristic odor to the air. This method is not applicable to mines where only a limited number of com-pressed-air lines are used, as for example, many coal mines; the ventilation currents available in these mines may be too slow for warning purposes.14/

Jan 1, 1954

By Paul McIlroy

Costs of producing lead from various known resources in the United States are developed by the Bureau of Mines to define the future availability of domestic lead at various price levels. It is estimated that 60 million tons of primary lead (75 percent of the total resource) is available at $0.20 or less per pound; 72 million tons (90 percent of the total) is available at $0.50 or less per pound; and the 79 mil- lion ton total estimated resource can be obtained at a price or $1.82 or less per pound. The supply available at $0.20 per pound or less will meet demand for over 78 years at the 1970 annual consumption rate of 763,000 tons.

Jan 1, 1974

By R. Barany

The heats of formation of seven substances were determined by solution calorimetry. At 298.15° K, the heat of formation of lithium sulfate from lithium, rhombic sulfur, and oxygen was -343.1 ± 0.7 kcal/mole, and the heat of formation of lithium sulfate monohydrate from lithium, rhombic sulfur, oxy-gen, and hydrogen was -414.3 ± 0.7 kcal/mo1e. For the silicates, the heats of formation at 298.15° K from the elements were kaliophilite, -503.8 ± 0.5 kcal/mole; leucite, -721.6 ± 0,8 kcal/mole; eucryptite, -505,2 ± 0.6 kcal/mole; alpha-spodumene, -727.9 ± 0.9 kcal/mole; and beta-spodumene, -721.1 ± 0.9 kcal/mole. The corresponding heats of formation at 298.15° K from the constituent oxides were kaliophilite, -42.7 ± 1.1 kca1/mole; leucite, -42.8 ± 1.1 kcal/mole; eucryptite, -16.1 ± 0.7 kcal/mole; alpha-spodumene, -21.0 ± 0.7 kcal/mo1e; and beta-spodumene, -14.3 ± 0.7 kcal/mo1e.

Jan 1, 1966

By Thomas A. Davidson

The Bureau of Mines Helium Field Operations has developed a method for determining the helium-3 CHe) content of natural gas and mixtures eontaining 0.5% to 100% helium. The helium is preconcentrated by passing samples through anhydrone, a liquid-nitrogen-cooled chareoal trap, and a titanium absorption trap. The mass spectrometer used to analyze the samples is tuned to 3He at mle ::=; 3.016. Hydrogen deuteride (HD+) interference is minimized by the titanium absorption trap and high instrument resolution. Sample measurements are compared with identically made measurements of a gravimetrically prepared primary standard. The method has a limit of detection of 0.15 ppb with a relative deviation of 13% below the 1~ppb level. The relative deviation is less than 7% for gases eontaining over 100 ppb 3He. The helium isotope ratios of natural gases from the Bureau&apos;s Tuck-Trigg Dome Red Cave, the Bush Dome Red Cave, and the Bush Dome Brown Dolomite Formations are distinguishable from one another and from the isotope ratio of crude helium produced from the Panhandle-Hugoton Gasfield.

Jan 1, 1990

By Joseph A. Conway

This paper is one of a series dealing with the mining and crushing methods and costs of the nonmetallic industries, prepared under the sponsorship of and in cooperation with the U. S. Bureau of Mines,. The quarrying methods described in this paper are those used at the Monocacy trap rock quarry which annually produces from 450,000 to 500,000 tons of crushed stone. This property is located 3 miles east of Birdsboro at Monacacy, Pa., and is one of the three quarries operated by the John T. Dyer Quarry Co. Throughout the paper an effort is made to explain the various methods used and the cost of operation.

Jan 1, 1931

By H. R. Babitzke, H. Kato, R. E. Siemens, G. Asai

The purpose of this investigation was to develop a wide variety of columbium and tantalum alloys and to determine their suitability for use at elevated temperatures . Sixty - nine columbium and tantalum alloys were investigated . For this study , columbium was alloyed with two or more of the following : nium, tungsten , vanadium , titanium, and zirconium . Tantalum was alloyed with vanadium or hafnium, or hafnium and carbon . The fabricability was determined by an arbitrary procedure . Hardness measurements , elevated - temperature tensile properties , and oxidation- resistance studies were made . Of the alloys studied , Cb - 15 Hf - 5W, Cb - 15Hf - 5W- 10Ti , Cb - 15Hf - 10W- 10Ti , Cb - 10V - 5W, Ta - 30V , and Ta - 20 to 33Hf exhibited excellent high - temperature properties . These alloys were not only easy to fabricate , but they also had good oxidation resistance and excellent high- temperature strength .

Jan 1, 1964

By O. C. Blade

Production of crude petroleum in the Middle East (southwestern Asia) and in South America has increased greatly during recent years and has become a significant factor in the world&apos;s production of crude oil. Crude oil from fields in the Middle East increased from 256,164,000 barrels in 1946 to 305,833,000 barrels in 1947 and 417,201,000 barrels in 1948. Production from South American fields increased from 446,417,000 barrels in 1946 to 518,652,000 barrels in 1947 and 574,837,000 barrels in 1948. Crude-oil production from Canadian fields increased from 7,726,876 barrels in 1947 to 12,370,875 barrels in 1948, most of the increase being attributable to two fields, Leduc and Redwater, both represented by analyses in this report. Present indications are that production of crude petroleum from all these regions will continue to increase.

Jan 1, 1950

By Robert A. Jankowski

"Following passage of the Coal Mine Health and Safety Act of 1969 (Public Law 911173), the Bureau of Mines initiated a research program aimed at controlling respirable dust exposures of coal mine workers. Respirable dust is the dust that gets into, and interacts with, the lungs of those who inhale it. It has long been recognized as a severe health hazard to mine workers. This program has been implemented by a team effort consisting of the Bureau's in-house capabilities, the Generic Center for Respirable Dust, and contractors, as necessary. Over the years, Bureau research has addressed principally three areas:o Compliance with the Federal 2.0 mg/m3 dust standard (1970-76).o Dust control for longwall mining (1976-1983).o More stringent respirable dust standards due to quartz dust (1983-1987).In addition, fundamental studies have been conducted by the Generic Center for Respirable Dust, with emphasis on penetration of dust into the lung. Accomplishments have been significant, but problems remain, as noted later.The Coal Mine Health and Safety Act of 1969, established a 2.0 mg/m3 dust standard for all coal mining operations, underground as well as surface. At the time of enactment of this legislation, the industry was averaging approximately 4.0 mg/m3. The Bureau of Mines respirable dust research program played a significant role in identifying and developing effective technology to allow better compliance with this new standard, thanks to industry implementation and Federal enforcement."

Nov 1, 1988

By Robert H. Merrill

This report summarizes the first phase of studies to determine the design and behavior of an unsupported roof in an experimental room in limestone. The selection of a roof horizon and the design of the room were results of an investigation of the geology of the formation, the physical properties of samples from the proposed roof, and calculations from the theory of gravity-loaded beams. The design of the opening, some physical properties of the roof in place, and the behavior of the roof were checked by tests in a full-scale experimental room. The room was instrumented to measure roof deflection, separations in the roof strata, and incipient failure. The dimensions of the room before instrumentation was installed were 10 by 100 feet; the room was widened in successive increments to 40 by 100 feet. Between widening operations periods up to 6 months were allowed to provide a time test of the roof spans. The results of the measurements of deflection and separations showed that the lowest 6-inch layer in the roof became detached as the room was widened. This layer was eventually removed after standing without failure for about 4 months at room dimensions of 40 by 100 feet.

Jan 1, 1957

By James J. Olson

The Bureau of Mines recorded and analyzed overpressure levels for three production blasts at the White Pine copper mine, Upper Michigan, to obtain representative data from single-heading blasts in a long, straight haulageway and to estimate the damage potential inherent in production blasts fired in close proximity to underground structures. Commercial pressure gages with a flat response to 1 kHz were used with an FM tape recorder to record the overpressures from one dynamite and two AN-FO (ammonium nitrate-fuel oil), 500-msec production blasts having zero-delay charge weights of about 75 lb (34 kg). The recorded waveforms from the underground blasts (1) were more complex than the typical free-air wave, (2) were of longer duration, and (3) had numerous secondary arrivals due to reflections from the ribs and roof. The waveforms showed that the zero-delay charges produced the only high overpressures. First pulse peak overpressures from the blasts ranged from 0.10 lb/in2 (6.9 X 102 N/m2) at a distance of 471.1 ft (144 m) to a maximum of 1.76 lb/in2 (121.3 X 102 N/m2) at 191,7 ft (58.4m) from the blasts. An analysis of variance of the first pulse overpressures from the three White Pine blasts showed that no statistically significant difference existed among the overpressure levels from the dynamite and AN-FO blasts and that a single equation P = 4.9 x 103 (D /W1 / 3) 2 .15, where P = overpressure in pounds/inch2, D = d-stance from the blast in feet, and W = zero-delay charge weight in pounds, could be used to describe the falloff of overpressure with distance.

Jan 1, 1971