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By Robert T. Beckman

The results of a preliminary investigation of compressive strength versus length-diameter (L/D) ratios of potash specimens and the statistical treatment of the data are summarized in this report. The purpose of the study was to evaluate a laboratory method for obtaining estimates of the strength of potash pillars during robbing operations. The specific objectives of this preliminary investigation were to test the method and the reliability (confidence limits) of the data, and to determine the number of additional specimens necessary for given confidence limits. The specimens were taken from three sites at two mines in New Mexico. The statistical analyses included the determination of the confidence limits for the data and the number of additional specimens necessary to obtain confidence limits of ±500 and 100 psi. The testing method was found acceptable, and estimates of the comprehensive strength, within 1500 psi, could be obtained by testing about 110 additional specimens from the three sites. The compressive strength of the specimens tested fits an empirical equation of the type

Dec 1, 1963

By J. C. Edwards

The Bureau of Mines developed a mathematical model for analysis of the impact of scrubber bed length, porosity, and gas flow rate on the absorption of C02 in a breathing apparatus. The model accounts for the decrease in available absorbent through chemical conversion. The pre-dicted efflux of C02 from a canister containing LiOR compared favorably with measured values reported elsewhere. It was determined from a com-putational study that the time for breakthrough of C02 at a prescribed level is nearly directly proportional to bed length and inversely pro-portional to gas flow and porosity.

Jan 1, 1987

By Richard B. Moore

This bulletin presents a summary of available information regarding the sources of uranium, radium, and vanadium, the methods used in treating the ores, and the uses of the finished products. In particular the paper describes the ores found in the United States, giving especial attention to those characteristics of the ores and the conditions of their occurrence that affect mining and treatment. ACKNOWLEDGMENTS. In the preparation of this bulletin a number of persons rendered assistance by furnishing information and by making it possible for us to visit the carnotite deposits in western Colorado and eastern Utah at a time of the year when without this assistance it would have been difficult to obtain satisfactory results. We desire to express our thanks to the following persons: Henry Hall, W. L. Cummings, T. V. Curran, K. D. Hequembourg, David Taylor, H. C. Brown, Forbes Rickard, George W. Alsdorf, Dr. Herman Fleck, Orr J. Adams, C. S. Cherrington, Newt. Stewart, O. B. Willmarth, Angus Cameron, George A. Head, and Lorimer Bros.

Jan 1, 1913

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

As part of remote sensing research on an abandoned mine lands (AML) site in the Colorado Springs, Colorado area, a geographic information system (GIS) database was generated. This GIS database contains information on the locations and extents of abandoned underground coal mines, the geology of the area, subsidence features and degrees of subsidence risk, topography, drill hole locations, and lineaments (linear features) related to subsurface geologic structures. A GIS database allows the reproducible and accurate comparison and analysis of any data sets which geographically overlap and are within the same coordinate system. The database has been released to the public domain so that government agencies, researchers, educators, and the general public can access this coherent database for the purposes of better understanding the study area and GIS technology. Data files and maps are available in formats that are compatible with the GIS software used in the research project and with most CAD systems so that as many people as possible can make use of the majority of the database. This document serves as the data dictionary for the database by providing descriptions and origins of the data files.

Jan 1, 1992

By R. Karl Zipf

A fatal explosion in a sealed area at the Sago Mine in 2006 prompted researchers and regulators in the United States to re-examine the requirements for explosion-resistant mine seals. Seals are used in underground coal mines to isolate abandoned mining areas from active workings. Prior to the Sago disaster, mining regulations required seals to withstand a 140 kPa explosion pressure. Recent research at the National Institute for Occupational Safety and Health (NIOSH)Pittsburgh Research Laboratory showed that pressures from explosions can far exceed this pressure. U.S. mining regulations now require much stronger seals. Current research focuses on understanding the science, engineering and management of sealed areas of coal mines. Scientific efforts seek understanding of how explosive methane-air mixtures accumulate using measurements and models of the sealed area atmosphere. Additional scientific efforts aim to understand the explosion pressures that can develop using a combination of numerical modeling and experiments. Engineering efforts aim to produce design guidelines for seals that can resist the new higher pressure design criteria. NIOSH researchers are also developing guidance for monitoring of sealed area atmospheres and inertization of potentially explosive gas mixtures within sealed areas. This paper seeks to encourage scientific discussion among international peers since preventing explosions within sealed areas is of interest to underground coal operators and regulators.

Jan 1, 2009

By J. J. Hoeppner

Lignite samples were collected so as to be widely representative of the extensive deposits in the western north-central area. These were carbonized at temperatures ranging from 450° to 550° C., according, to a standardized procedure. In general, product yields varied; extremes obtained on selected samples show char recoveries on the moisture- and ash-free basis as 56.7 percent for slack lignite or "leonardite" to 80.8 percent for a concentrate of the fusain component from a typical face sample; normal lignite samples averaged approximately 70 percent. Tar-plus-light-oil yields ranged from 3.3 percent for the fusain concentrate to 11.0 percent for a normal sample, averaging approximately 8 percent; gas recoveries varied more widely both in yield and in composition, ranging, from 10.0 percent to 27.7 percent, the latter being from leonardite and quite high in carbon dioxide. Sampling was conducted with the view of representing, as nearly as possible, all beds delineated by Brant (2);4/ many are necessarily missing since collection was confined largely to worked deposits. Data presented in this report indicate a general uniformity of North-Central lignite in respect to low-temperature carbonization, with a few possible exceptions of a local nature. When processed according to the indicated conditions, maximum tar yield may be realized with minimum loss of recoverable heating value of the original coal. Natural weathering of lignite, however, does affect tar yield adversely and should be held to a practical minimum in any commercial operation.

Jan 1, 1956

By Larry G. Stolarczyk

This report deals with the creation of an efficient method to determine if command, control, communication and monitoring (3cm) equipment in coal, metal and non-metal mines is susceptible to Radio Frequency Interference (RFI) from the Medium Frequency (MF) radio communications system. A qualitative and quantitative RFI test plan was developed for in-mine and laboratory evaluation of the equipment. The laboratory testing was accomplished using the TEM Test Chamber. Detailed information on the Test Plan and the TEM Test Chamber is included. During in-mine testing of the MF System some underground equipment malfunctioned when the transmitter's radiating antenna was in close proximity. Electromagnetic Compatibility (EMC) testing was done on three levels; Component (circuit or box), subsystems and system. Nine tables are included which show the results of testing various equipment for RFI.

Jan 1, 1986

By Ernest A. Curth

A 3-month study in 1971 of the Essen Roof Support and Rock Mechanics Research Center's program of roof and support evaluation included 25 mine trips. German miners must adopt mining methods and environmental control measures involving methane drainage and water infusion to improve productivity under severe natural conditions. Pressing problems in ground control must be solved such as cavities in front and above the supports at longwall faces and excessive convergence in gate roads. The Center developed automatic data processing methods to quantify the results of roof and support surveys and to establish criteria. Another approach to ground control is the study of mine models. The Center's laboratory has the facilities to test elements of powered roof support and whole assembled units. Face automation and roof control by powered shields are novel developments that are under close scrutiny in the field as well as in the laboratory. Though the Essen Center's roof and support evaluation techniques are tailored to the needs of the coal mining industry of the Federal Republic of Germany under conditions vastly different from those in the United States, some application may be found here, for instance, monitoring faces and roadways and preventive maintenance of hydraulic systems.

Jan 1, 1974

By R. V. Ramani, J. Qin

"In this paper, the results of a research study on airborne dust transport in a full scale simulated longwall face are presented. The simulated longwall face was set up in the Lake Lynn Laboratory mine of the U.S. Bureau of Mines to conduct experiments under controlled conditions. The controlled parameters in the experiments were the dust dispersion rate, dust size distribution, density of the dust, air velocity, and the rate of travel of the dust generating source. The analyses of the experimental results on mass concentrations, particle size distributions, and real-time respirable dust concentrations are discussed. There are definite spatio-temporal trends between the location of the shearer, the concentration at any location in the face, and the dust generation rates. The size-consist and density characteristics of the source dust, the air velocity in the face, and the air leakage into the gobs all affect the concentration. INTRODUCTIONA detailed experimental study on the characteristics of longwall dust cloud in operating longwall faces has been reported by Ramani, Qin, and Jankowski (1991). The study indicated that there are several important factors whose effects on dust transport in longwall faces need to be further investigated. In an operating longwall face, the effect of these parameters could not be easily isolated as control over the affecting parameters is not readily possible. In a simulated longwall face, however, these parameters can be controlled. Therefore, as a follow-up to the field study, a series of controlled experiments were conducted in a full scale simulated longwall face in the Lake Lynn Laboratory mine of the U.S. Bureau of Mines [Qin, 1992]. Specific aspects which were addressed during the experimental design phase included determining the types of samples to be collected, selecting proper instruments to collect these samples, and developing detailed sampling and time-study plans to correlate the dust concentrations with face activities. Two types of dust--anthracite and bituminous--were used. Dust dispersion rate into the air as well as the source dust particle size distribution were documented. Control was exercised over both air velocity at the face and air leakage along the longwall face. During experiments, the dust source was moved to simulate the shearer movement at operating longwall faces. Detailed descriptions of the design of experiments, experimental results, and data analyses follow in the subsequent sections."

Dec 1, 1996

By H. B. Hill

The Salt Flat field, formerly called the Toe -Bruner field, is located northeast of the town of Luling in Caldwell County, Tex. This field, which is a fault structure, approximately parallels and is about 5 miles east of the Old Luling field. The proved area is approximately 1,280 acres, on which 332 producing wells (September, 1930) have been drilled. The majority of the wells are producing from the Edwards limestone at an average total depth of 2,700 feet. A few wells are producing from the Austin chalk or from other formations above the Edwards limestone. The Wilcox formation is exposed, and the fault trace in places is scarcely evident. The strike of the structure is approximately 111. 20 to 45° E. The displacement of the fault is probably 200 to 500 feet. The discovery well was completed in the Austin chalk by the Lutex Oil Co. during April, 1928. In October, 1928, the Sun Oil Co. completed the discovery well in the Edwards pay. This well was an important discovery, as it indicated the potential oil possibilities of the Edwards limestone in echelon fault structures. The discovery led to the development of the third fault field in the Edwards limestone and opened up a large area for future prospecting. The total oil production for the Salt Flat field to and including September, 1930, was 19,833,215 barrels. The most reliable figures available of water production were compiled for a number of leases and wells in the south half of the field. These data show that the water percentage for the average well in this part of the field increased steadily from 30 per cent for January, 1929, to 81 per cent for December, 1929. The estimated daily water production of the entire field for December, 1929, was about 82,000 barrels as compared with a daily oil production of 29,725 barrels; or approximately 2.7 barrels of water were produced with each barrel of oil 14 months after the discovery well was completed in the Edwards pay. Estimates of water production in the (Old) Luling field, which is near the Salt Flat field, place the daily water production at about 150,000 barrels (July, 1929) as compared with a daily oil production of 11,000 barrels. These figures indicate that in the Luling field approximately 14 barrels of water must be lifted for each barrel of oil produced. The Luling field was discovered in August, 1922, and a peak annual production of 10,210,000 barrels was reached during 1924. The production during 1928 was 5,057,000 barrels of oil from an average of 567 producing wells for the year. Although water appeared early in the life of the Luling field, the oil production has been well sustained. Another feature of outstanding interest is the comparatively few producing wells that have been abandoned on account of water during the soven years of operation of this field. Comparison of data between the Luling and Salt Flat fields is of importance because of the nearness of the two fields. The Luling field is a narrow strip or "shoestring" approximately 8 miles long, with a maximum width of 3,400 feet. Production is obtained in the Edwards limestone at an average depth of 2,200 feet on the upthrow side of a fault. Similar conditions of accumulation are found in the Salt Flat field at greater depth to Salt Flat field as outlined (April, 1930) is about 7 miles long? with a maximum width of 2,000 feet. At the time the field work was begun (July, 1929) in the Salt Flat field, drilling operations had been almost completed in the south half of the field, while the north half was still under development. Cross sections and a structure contour map interpret the subsurface conditions in the south half of the field, where the water conditions first became serious.

Jan 1, 1931

By Louis A. Panek

Determining the change of stress in rock based on measurements of the deformation of a drill hole is a procedure that is increasing in popularity. A closely related procedure involves the applicat10n of this principle to determine the existing stresses in a rock medium, by cutting free (core drilling) an annulus containing the drill hole. In this Bureau of Mines report, expressions are derived from which one can calculate the stress ellipsoid--the three-dimensional change of stress, or the existing three-dimensional stress field, as the case may be. Study of these equations shows that the stress components in three dimensions can be determined by measurements in only two drill holes, and yields general principles that are useful in planning an efficient program of drilling and measurement. Procedures are given for calculating the least squares estimates of the stress components and their standard errors, and for evaluating or comparing calculated values by means of standard statistical inferences.

Jan 1, 1966

By Gordon L. Kinney

The only economically important mineral currently produced in Bangladesh was natural gas. Bangladesh was not a world? ranked producer of any mineral commodity, but the possibility of producing and exporting commercial amounts of liquefied natural gas (LNG) was being examined. Proved reserves of natural gas were sufficient to supply most of the country's industrial and domestic heating and electric needs and still support an export-oriented LNG plant. Other mineral production was of virtually no significance to the economy, although there were a few prospects for nonmetallic mineral development. Bangladesh continued to make economic progress during 1978 and into early 1979. Gross domestic product (GDP) at current prices rose from $6.6 billion in 1976-772 to $8.2 billion in 1977?78 and $9.3 billion in 1978.79.2 In fiscal 1979, the economic conditions were favorable until a severe drought hit most of the country. It W88 reported that conditions were the worst in 40 years, and 88 of July 1979, substantial crop losses were predicted. The agricultural sector accounts for over 53% of the GDP and about 75% of all employment. The poor weather will cause economic problems in the form of slower growth, larger trade deficits, and a higher rate of inflation. The 1978.79 statistics showed that real GDP increased just 4%.

Jan 1, 1981

By Theodore L. Turner, Joseph H. Swift

A study on a small laboratory scale was made of the use of ammoniacalammonium carbonate for batch leaching Mn from low- grade manganiferous materials ( 6 to 16 pct Mn) obtained from deposits in the southern district of Aroostook County , Maine . These materials were partially reduced at 500 ° to 700 ° C with H₂ or CO and then leached with solutions of NH and CO₂ dissolved in water . Extraction of 80 to 90 pct of the Mn was obtained from some sample materials , but 10 to 34 pct of the iron was also extracted . Material from the Littleton Ridge deposit contained manganese intimately associated with Fe , a condition which contributed to difficulties in obtaining a commercially acceptable product . Extensive investigations of the leach and reduction processes with various mixtures of H₂ and water vapor , and CO and CO₂ , failed to disclose a set of conditions for selectively leaching the manganese . Finely divided metallic Fe was probably produced during the reduction steps so that Fe was leached with the Mn in the subsequent extractions .

Jan 1, 1964

By K. C. Dean

A semiquantitative test for the presence and identification of cesium and rubidium in rocks, clays, and mineral waters has been developed by the Bureau of Mines. The test can be used in the field, as a guide for the prospector, geologist, or mining engineer engaged in location or development [w]ork. It comprises two simple spot tests of a solution prepared from the [m]ineral sample. Phosphomolybdic acid, added to a drop of the test solution, [d]etects cesium, rubidium, and potassium in quantities as low as 60 parts per [m]illion. Silicomolybdic acid, added to a second drop of test solution, enables the operator to distinguish between cesium and/or rubidium and potassium. Test procedures, equipment requirements, and limitations of the method are described in this report. Cesium and rubidium were discovered in 1860 and 1861 by Bunsen and Kirchhoff with a spectroscope. The elements usually occur together, particularly in granite and granitic pegmatites. Rubidium does not occur as an essential constituent of any known mineral, yet it is found as a minor element in so many minerals that rubidium is 16th in abundance in the earth's crust. Cesium, which ranks as the 37th most abundant element, is the principal component of pollucite and a minor element in a wide variety of minerals.

Jan 1, 1960

By Oliver Bowles

In 1943 the Bureau of Mines began a review of trends in consumption and prices of the more important nonmetallic minerals. The first report covering building materials4/ appeared in December of that year. The present paper, which deals with chemical raw materials and fertilizers, is the second of the series. The 34 years from 1910 to 1943, for which statistics are presented herein, comprise periods of uneventful peace, unparalleled prosperity, industrial depression almost to the point of stagnation, and two wars of world proportions.

Jan 1, 1945

By Robert A. Speirer, Richard G. Burdick

Methods of detecting geologic faults and other linear features by means of processed LANDSAT satellite images have gained prominence during the past several years . There have been numerous programs written to pick these " lineaments , " but they have been almost universally tailored to large computers . This Bureau of Mines report describes a detection method developed for use with a minicomputer . The method comprises a suite of programs that scans an image for all " potential " lineaments . From this partially analyzed data , the final lineaments are picked by another routine . The method was field tested in an area of south- central Wyoming , and results indicated good agreement between computer- picked lineaments and ground features . Most of the known geologic faults in the area were picked by the method . Such features as roads and trails were also picked but were easily distinguished from faults during field inspection . The method is relatively new but promises to be a viable reconnaissance technique for the mining industry in geologic structural analysis .

Jan 1, 1965

By A. T. Coumbe

The first survey 3/ covering sales of liquefied petroleum gases was made in 1930 by the Bureau of Mines, which at the time was under the United States Department of Commerce. This original canvass covered national totals for 1922 through 1929, and most of the supply came from natural gasoline plants. The 1930 report showed approximate totals for butane and propane and for butane-propane mixtures and pentane grouped together. No attempt was made to breakdown the national sales by various uses until 1931, when the quantities for domestic or household consumption, gas manufacturing, and industrial requirements, including miscellaneous uses were indicated. As the market for these liquid petroleum gases expanded and as new uses came into importance, their respective quantities were shown separately in the annual survey. Sales for internal-combustion engine fuel and for raw material for chemical plants were first taken out of the industrial total in 1936. During World War II liquefied petroleum gases became important as feed stock diverted to synthetic rubber plants, and consequently the survey was broadened to cover this particular demand, beginning in 1944. Pentane was dropped from the survey after 1943, as, being liquid at atmospheric pressure, it is not considered as one of the liquefied petroleum gases and furthermore, the quantity reported made up less than 1 percent of the total sales. Thirteen producing companies reported to the Bureau in the first survey made in 1930, and in the 1952 canvass about 130 producers--petroleum refiners and natural gasoline companies--and about 1,300 dealers cooperated by filing schedules showing a breakdown of their sales. Their 1952 deliveries of approximately 4.5 billion gallons of liquefied petroleum gases were equivalent to about 3.4 billion gallons of gasoline or 3.1 billion gallons of distillate fuel oil.

Jan 1, 1954

By F. X. Tartaron

Behavior of hard-burned quicklime was compared with that of soft-burned quicklime in an oxygen converter utilizing oxygen blowing in a rotating cylindrical vessel, set at a 30° to 60° angle to the horizontal and operated at a predetermined speed of rotation. Four pairs of tests were made) each comparing hard lime with soft lime. Three of the pairs differed from one another in the quantity of lime employed) and the fourth differed in blowing time, All four pairs showed an increase in yield when soft lime was used. Three of the pairs revealed that the ratio of the oxygen consumed with soft lime to the oxygen consumed with hard lime was the same as the ratio of metal yield with soft lime to the metal yield with hard lime. The fourth pair contained an error and could not be included. Finally, a close inverse relation was found between the combined iron in the slag and the combined lime in the slag, which can be expressed by the equation pct Fe = 52.67 -0,906 (pct CaO).

Jan 1, 1967

By N. E. Hanna

Originally developed for use in coal mines where on-shift blasting with explosives was prohibited, compressed-air blasting has been used for the past 15 years as a substitute for fixed explosives. With the current commercially available compressed-air systems -Airdox and Armstrong -coal is dislodged by a high-pressure discharge of air from a pressurized shell placed in the coal borehole. In the original systems stationary compressors were mounted on the surface or in the underground ventilated areas. These proved so successful that a mobile compressor unit was developed for use at the working face. Because of the possibility that such a unit might operate in a gassy atmosphere, the Bureau of Mines has investigated the hazards associated with operation under conditions where firedamp could accumulate in explosive concentrations. ACKNOWLEDGMENTS Grateful acknowledgment is made of cooperation of C. E. Carter, H. R. Hiller, R. E. Kennedy, H. Kohn, H. D. Metzinger, J. Mahoney, J. Nickovich, G. So Scott and I. Spolan in the experimental work.

Jan 1, 1956