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By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

4. Preliminary Study - Remote Seal Checker 4.1 Introduction Determination of the completeness of each individual seal at the time of its emplacement is essential for an effective remote sealing system. A satisfactory seal checking technique should provide a signal which: (1) indicates percentage completion as the seal is emplaced (2) provides a definite indication of a complete seal (3) indicates the size of the unsealed area if a complete seal is not feasible This information is required to establish the need for additional seal material, the need for additional seals, and the risk likely involved in entering the mine., In many situations it is as important to know the quality of a seal as it is to build an effective one. It is likely that with repeated use the remote sealing technique developed by Foster-Miller Associates will be sufficiently reliable and predictable to preclude the seal checking requirement. It is recommended, however, that each seal be checked during construction to insure its completeness and increase the level of confidence so necessary in reopening the mine. 4.2 Description of General Problem Several characteristics of remote mine seals are important in considering techniques for evaluating the effectiveness of these seals. These include:

Jan 1, 1973

By Gordon H. Dechman

This report presents the concept, design, and testing of a sonic velocity monitoring system for the early detection of slope failure in open pit mines. The heart of the system is a device for producing reproducible sonic signals in rock. Because changes in the velocity of sound through rock near the top of the pit wall are a measure of extent and rate of fracturing of the rock, velocity histories obtained from periodic, automatic sonic velocity surveys provide positive information about developing slope instability.

Jan 1, 1976

By J. V. Batty

In the course of the investigation of manganese mineral occurrences in the United States, Bureau of Mines examining engineers collected several lots of ore from the Black Rock, Kramer, and. Morgan-Cromar properties, Tooele and Juab Counties, Utah. Extensive laboratory tests were made to determine the amenability of the ores to standard ore-dressing methods of concentration. The Black Rock claims 1 and 2 are 42 miles northwest of Jericho, Tooele County, Utah. A. J. Huber of Salt Lake City and Ross Rydalch of Tooele, Utah, are the owners. The deposit-is reported to be a definite manganese fissure vein in quartzite along which considerable shearing and cross fracturing have occurred. Laboratory work was conducted on a 2-ton sample of run-of-mine ore procured by a Bureau of Mines examining engineer and two smaller, higher-grade samples submitted by the owners as a result of later development. The Kramer deposit is described as a bed of manganese oxides in quartz. The property is being worked by L. E. Kramer, Tooele, Utah, and is 41 miles northwest of Jericho) Tooele County, Utah, approximately 1 mile north of the Tooele-Juab County line. A 1-ton run-of-mine sample was submitted for testing by the examining engineer.

Jan 1, 1952

By Ralph B. Adair

The Bureau of Mines conducted laboratory and continuous pilot plant flotation tests to determine the feasibility of recovering commercial-grade mica from an Alabama graphitic-mica schist. Preconcentration of the ground ore on a Humphrey's spiral was employed to reject the heavy minerals and part of the quartz in a product virtually free of mica. The acid-cationic mica flotation process recovered over 89 percent of the mica in a product containing 98.7 percent mica. Grinding of the mica concentrate in a fluid energy mill produced a product with a bulk density of 12 lb per cubic foot.

Jan 1, 1969

By Irving Hartmann

The Bureau of Minas has been charged by the Congress with the responsibility for administrating the provisions of the Federal Coal-Mine Safety Act. One of the important duties of bureau inspectors under this act is to determine whether proper measures are taken to prevent mine explosions, which in moat miner includes Judea adequate rock dusting The investigation made after the explosion in Orient No. 2 mine, December 21, 1951, showed that much information is lacking on the adequacy of current rock-dusting and duet-sampling practices in the United States. To obtain such information, an intensive sampling survey was conducted by the Bureau in an Indiana coal mine. This paper summarizes the more Important findings from this survey, describes special samplings at several Pennsylvania coal miners, and discusses related studies in the Bureau's Experimental coal mine.

Jan 1, 1954

By Richard D. Miller, Geraldine P. Norrell

This publication contains routine analyses and related source data for 295 natural gas samples from 18 States collected during calendar year 1963 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the Bureau of Mines since 1917. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4 Five previous publications have been made to present the results of 5,998 gas analyses made by the Bureau of Mines Helium Activity , prior to 1963. The first three , Bulletin 486,5 Bulletin 576,6 and Bulletin 617,7/ contain analyses and source data on 5,214 gas samples collected from 1917 to January 1 , 1961. The fourth and fifth publications , which are published as Information Circulars , supplement the three Bulletins and contain 784 analyses of samples collected during 1961 and 1962. The present Information Circular is the third annual publication supplementing the three Bulletins .

Jan 1, 1965

By M. J. Kovalik

Lower Sunnyside seam coal from Utah was blended with various proportions of char and high-temperature coke to improve the quality of the coke obtained from carbonizing this coal. The Hanson 5-pound carbonizer was used as a "screening test" for the larger scale Bureau of Mines-American Gas Association (BM-AGA) tests, which were correlated with industrial production. Eighteen carbonization tests were made in the BM-AGA 13-inch retort, with a coal charge of about 90 pounds; the cokes were evaluated by the standard ASTM tumbler test. Carbonization of blends containing char and coke breeze yielded less fissured and blockier cokes of significantly higher ASTM I-inch tumbler indices as compared with the value for the straight Sunnyside coal. It was found that the simultaneous addition of char and coke breeze yielded stronger cokes than that obtained by the addition of either one of these additives. Addition of a small proportion of Pocahontas No. 3 or Sewell coal to an optimum blend improved the resulting coke strength further.

Jan 1, 1969

By R. E. Perry

To develop new or improved flotation methods for beneficiating low-grade red iron ores, the Bureau made many bench scale and continuous anionic flotation tests on ferruginous sandstones and calcareous iron ores from the north-eastern part of the Birmingham, Ala., iron district. The ores contained about 21 to 36 percent iron, a to 11 percent lime, and 22 to 64 percent silica. Production of iron concentrates containing 48 to 52 percent iron was technically feasible in batch tests, and the iron recoveries ranged from 85 to 92 percent. In continuous tests 49 to 51 percent iron products were obtained with 80 to 90 percent recovery.

Jan 1, 1962

By J. A. Eisele

The Federal Bureau of Mines is engaged in a continuing program on the recovery of alumina from domestic source materials. Of the six processes being studied, current efforts focus on HCl leach of clays. A key step in the HCI process is the removal of iron from the aluminum chloride leach liquor. This was accomplished .by solvent extracting the iron with a tertiary amine in kerosine to which decanol was added as a phase modifier. In a mixer-settler operation, iron in the raffinate was reduced to <10 ppm in two extraction stages from a feed containing 1.4 gil Fe. Iron was stripped from the organic phase in three stages with dilute HCl.

Jan 1, 1976

By H. S. Caldwell

A magnesium-base incendiary alloy, containing about 20 percent cadmium, 4 percent aluminum, and 0.5 percent zinc, was investigated in a series of vacuum-distillation experiments to determine the feasibility of recovering magnesium and cadmium as refined metals. Alloys prepared in the laboratory and actual bomb-casing alloy were studied at temperatures of 550° to 750° C. and pressures of 100 to 150 microns. Simple distillation and fractional distillation methods were only partly effective in separating the cadmium and magnesium. They were separated satisfactorily, however, with a special vapor baffle designed to condense the metals selectively. Magnesium and cadmium products were 99 percent pure and together comprised 82 percent of the total condensate. About 17 percent of the condensate was intermediate-grade alloy that could be recycled with new charge and contained about 70 percent magnesium and 30 percent cadmium.

Jan 1, 1959

By B. Demoulin, J. Fontaine, R. Gabillard, P. Degauque

To realize a radiowave communication along mine galleries a few kilometers long without repeater, we show that it is possible to use a coaxial cable bearing an important surface transfer impedance like a transmission line with an inductive coupling to the transmitter and the receiver. We determine the electrical and geometrical constants of the cable and the optimal frequency.

Jan 1, 1973

By L. R. Willmott

An ethanolamine purification unit for removing carbon dioxide and hydrogen sulfide from Firscher-Tropsch synthesis gas was installed at the Bureau of Mines synthetic liquid fuels demonstration plant at Louisiana, Mo. The unit was a surplus Radford Girbotol unit from the Missouri Ordnance Works modified for a capacity of 90,000 std. cu. ft per hour of synthesis gas at 450 p.s.i.g., operating pressure. The hydrogen sulfide loading of the feed gas was specified at 500 grains per 100 cu. Ft. The unit was designed by the Girdler Corp. and installed by the Koppers Co. Initial operations were conducted far 11 days in May 1951. Thereafter 7 additional runs were made, varying lo duration from 8 to 54 days. The last run was terminated on May 29, 1953, the total time the Plant wars in operation being 219 days.

Jan 1, 1956

By J. M. Mutmansky

"The objective of this study was to produce coal dusts for laboratory research that are similar to mine airborne dusts in chemical, mineral, and physical characteristics. In this investigation, dusts produced in laboratory comminution equipment were compared with continuous miner- generated dust for similarity in physical characteristics. Mining-generated dust (MGD) and bulk coal samples were first collected from an underground mining operation. The bulk samples were then processed in the laboratory for size reduction in various comminution devices. These laboratory- generated dust (LGD) samples were subjected to size and microscopic analyses. Physical properties of the dust particles were studied on a scanning electron microscope (SEM ). A numerical shape coordinate system (SCS) was also developed and applied to 300 particles from each sample. Statistical analysis was then performed on the collected data and characteristics of the MGD and LGD samples were compared. IntroductionIn many biomedical studies, researchers routinely introduce a dust mass into an experimental environment to assess the response of a biological entity, usually lung macrophages in vitro or a live laboratory animal, to the dust mass. To provide data of maximum usefulness, it is highly desirable to use dust with characteristics of actual mine airborne dust. The primary objective of this research was to produce dusts in the laboratory similar in chemical, mineralogical, and physical characteristics to mine airborne dusts. This paper outlines the evaluation of the physical characteristics of the lab-generated dusts.Particle shape analysis is perhaps the least-developed area in mineral-related particle science and technology. There are still no standard methods or instruments to scientifically quantify particle shapes. To date, many attempts have been made to characterize particle shapes. These procedures can be roughly classified into three categories:"

Dec 1, 1995

By Martin Hertzberg

The concept of limit burning velocities is used to formulate a quantitative theory of flammability limits. Competing processes dissipate power from a combustion wave and quench propagation at some characteristically low limit velocity. There are four competing processes and one complication: (a) Free, buoyant convection, (b) conductive-convective wall losses, (c) radiation, (d) selective, diffusional demixing (the complication), and (e) flow gradient effects (flame stretch). These complexities are unraveled by creating an idealization that is initially freed from these competing processes. The ideal serves as a standard, and its burning velocity (Su), ideal is a unique function of the initial thermodynamic variables of state. By adding each process individually, it is possible to evaluate their significance, quantitatively, in terms of a limit velocity (Su)a , b , c , or e , and to explore the nature of their cooperative interactions. The larger the limit velocity, the more significant the process. The apparently diverse observations of flammability behavior are readily unified within this simple, conceptual framework.

Jan 1, 1976

By Earl T. Hayes, W. M. Sternberg, F. P. Williams

"INTRODUCTION The limited domestic demands for lithium salts and metal before the war were met readily by the use of minerals particularly lepidolite (lithium mica) and amblygonite (a lithium phosphate), from which lithium can be recovered relatively easily. New wartime uses, however, created such a demand that it became necessary to turn to spodumene (a lithium feldspar) as the principal source of supply. Although very large deposits of spodumene occur in South Dakota and in North Carolina, it much more difficult to extract lithium from spodumene than from lepidolite or amblygonite.During the spring and summer of 1942 a study was made in Salt Lake City laboratory of the Bureau of Mines on the recovery of lithium from spodumede. Preliminary tests were made on two processes - roasting with potassium sulfate 4/ 5/ and roasting with calcium chloride and calcium carbonate 6/ -,which appeared to be the most promising of the various processes that had been proposed. By roasting spodumene with approximately its own weight of potassium sulfate at 1,050º C. and leaching the product with water, about 70 percent of the lithium could be extracted. Consumption of the relatively expensive potassium sulfate, however, was high; much of the potassium was found in the insoluble leach residue, end large amounts were lost by volatilization and dusting. By roasting the spodumene with calcium chloride and calcium carbonate, nearly 90 percent of the lithium was chloridized temperatures of 850° to 1,050° C. Much of the lithium could be extracted from the calcine by leaching with water after roasting at the lower temperatures, but volatilization of lithium chloride was appreciable, amounting to 20 to 25 percent in a direct gas-fired furnace at temperatures of 800° to 850° C. At 1,000° to 1,050° C., volatilization was far from complete. Thus, it would be necessary to use both fume collection and leaching of the calcine, unless the roasting temperatures were sufficiently high to volatilize all the lithium chloride. Because of the well-known difficulties of collecting chloride fumes, it was decided to search for a better process."

Mar 1, 1946

By C. M. McCulloch

A geologic study of Mines 32 and 33 in Cambria County, Pa., was conducted as part of a methane control research program. Areas of high methane emission and roof instability are encountered which are related to the structural and stratigraphic features that characterize the geologic setting of these mines. Locally the folds trend N 20° E ±2°, the direction of the butt cleat in the Lower Kittanning coal. The face cleat strikes at N 69° W ±2° and the systematic rock joint in the surface bedrock strikes N 67° W ±2°. This suggests that a directional stress oriented N 70° W produced the folds and influenced the directions of coal cleat and systematic joint sets. Analysis of SLAR indicates three directions of prominent regional lineation: N 39° E, N 31° W, and N 70° W. Little gas was encountered during development mining; large volumes of gas are encountered when roof falls. Most of the gas comes from strata above the mined coal; therefore, to control methane, roof instability must be controlled. Roof falls and high rates of methane emission are most likely where less than 30 feet of many thin layers of limestone, shale, and sandstone occurs between the Lower Kittanning coal and the next coal and in zones along the margins of a sandstone channel.

Jan 1, 1973

By J. Sammarco

Proper illumination is critical to a miner?s ability to detect hazards in underground mines. Moving hazards are often located in the miner?s peripheral field-of-view, while slip/trip/ fall hazards are often located in the forward field-of-view. The objective of the research described in this paper was to determine if light-emitting diodes (LEDs) improve visual performance as compared to traditional incandescent (INC) cap lamps. The research presented focuses on comparative studies of a National Institute for Occupational Safety and Health (NIOSH) prototype LED, a commercial LED and an INC camp lamp. Thirty subjects participated in these studies, with ten subjects in each of the following age groups: 18 to 25 years, 40 to 50 years and 51+ years old. Visual per­formance was quantified by the subjects? speed and accuracy in detecting hazards, while visual performance for disability glare was quantified by the use of contrast sensitivity tests. Results suggest that LEDs with a visible spectrum containing a higher concentration of the shorter wavelengths can enable visual performance improvements with respect to disability glare, the detection of moving hazards in the peripheral field-of-view and the detection of floor hazards in the forward field-of-view. The NIOSH prototype LED cap lamp provided the best visual performance improvements for the older age groups in every test.

Jan 1, 2009

By Charles B. Kenahan

Vanadium is subject to only light corrosion in phosphoric acid at temperatures up to 60° C. and has a moderate corrosion rate in this acid at 100° C. It is relatively corrosion resistant in sulfuric and hydrochloric acids up to 60° C, but corrodes rapidly at 100° C. It corrodes rapidly in dilute nitric acid at 35° C. Vanadium is almost inert in 10-percent solutions of formic, acetic, lactic, tartaric, and citric acids; in 9-percent oxalic acid it corrodes slowly up to 60° C. and rapidly at 100° C. Vanadium is resistant to corrosion in substitute ocean water, tapwater, and in 3-percent sodium chloride and 10-percent sodium hydroxide solutions. It is readily attacked, however, by 20-percent ferric chloride, 20-percent cupric chloride and 5-percent mercuric chloride solutions. Vanadium is protected by contact with magnesium, aluminum, and steel SAE 4130 in substitute ocean water, by magnesium and aluminum in 3-percent sodium chloride solution, and by magnesium in tapwater. Vanadium protects copper in substitute ocean water. When vanadium and stainless steel are coupled in sulfuric acid solutions, both metals are usually unaffected by contact, whereas the corrosion rate of titanium in sulfuric acid is greatly reduced by contact with vanadium.

Jan 1, 1962

By W. D. Riley

The Bureau of Mines is conducting research on methods for the rapid identification and sorting of mixed scrap metals and alloys so that domestic scrap resources can be fully utilized. One method, spark testing, is the examination of the pattern of sparks that results when a metal or alloy is ground on an abrasive wheel. This technique requires experienced sorters. Bureau researchers have shown that spectrophotometric methods can be used in lieu of the highly skilled sorter. The spectra of a mild steel, an HSLA steel, several stainless steels, and four nickel-base alloys have been measured. Differences in the spectra that are sufficient for identification are apparent.

Jan 1, 1985

By J. K. Whyatt

During the past 2 years, U.S. Bureau of Mines (USBM) researchers reviewed an in situ stress investigation conducted in 1977 at a test site on the 4250 level of the Lucky Friday Mine, Mullan, ID. Although the field measurements of over core strain were found to be useful, significant deficiencies were found in the stress field estimation procedure. The stress field estimate was then updated to incorporate recent progress in statistical capabilities and new understanding of stress concentration factors for doorstopper cells, as well as to correct an error in the original stress solution procedure. Simple models were used to examine the possibility that systematic variations in material properties and stress fields existed at the site. These models succeeded in reducing the sum of squared error somewhat, but fell short of completely describing stress variations throughout the test site. This overcore measurement will be supplemented by two other measurements described in the second and third reports of this series. Other observations of stress field characteristics are discussed in the fourth report The final report will also characterize the natural in situ stress field in the vicinity of the Lucky Friday Mine. This work was undertaken to support USBM research on mining method design and rock-burst control for deep mines.

Jan 1, 2010