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By K. J. Liles

Research was undertaken by the Bureau of Mines to determine the technical feasibility of producing lightweight aggregate from the waste glass fraction of municipal incinerator residues. Tests were conducted to determine the amount and optimum size of glass, the amount of sodium silicate, and the method used to form the material to be expanded. The most suitable mixture, 78 percent glass, 20 percent clay, and 2 percent sodium silicate, was pelletized and then expanded by exposure to a temperature of 1,550° F for 15 minutes The resulting lightweight material had a bulk density of 38 lb/cu ft and exhibited excellent pore structure. Concrete test cylinders made from the light weight aggregate had a unit weight of 104 lb/cu ft and a compressive strength of 2,550 lb/sq in after a 28-day steam cure.

Jan 1, 1976

By W. H. Strickland, R. H. King

Ultrasonic ranging sensors are inexpensive, have no moving parts, have no lenses to clean, are normally small and unobtrusive, and can measure distances through moderate amounts of dust, smoke, and humidity, so they are well suited to underground mines. In the work reported here, conducted by the U.S. Bureau of Mines, researchers tested ultrasonic ranging sensors for their abiity to define rib line features for computer-aided navigation of underground mine mobile equipment. The investigation began with laboratory tests of field of view, angle of incidence, intersensor variation, and ranging accuracy of the individual rangers in a ring array produced by Denning Robotics of Wilmington, MA. The results showed that the sensors have good accuracy and low variability. Additional experiments at AMAX's Henderson Mine showed the sensors could accurately and reliably measure the distance to mine features, including convex and concave corners and rib intersections. The results showed that when used properly, the ranger data are accurate enough for reliable mine vehicle navigation When used incorrectly, ultrasonic rangers do not provide the anticipated data. Therefore, this report explains the principles of ultrasonic range measurement, describes the ranger's strengths and weaknesses, and explains proper ranger use and data analysis.

Jan 1, 1993

By E. D. Palmes

A new type of personal sampler for quantitative estimation of atmospheric concentrations of contaminant gases was first reported from this laboratory in 1972. The sampler requires no pumps or flow regulators and employs instead the motion of the gas molecules them-selves to furnish the power for sampling. Under this grant, work was completed on development of a kit for the field determination of both NO2 and NO. Detailed instructions for the preparation of the samplers and the use of the kit was supplied to the Technical Project Officer. Attempts were made to adapt the same type of sampler to the measurement of SO2 and CO. Both gas chromatographic and turbidimetric procedures for the final estimation of the S02 proved to be unsatisfactory. For CO no reagent was found which would react sufficiently rapidly with this gas to utilize the essential feature of the diffusion sampler, the maintenance of a diffusion gradient which is at least approximately numerically equal to the ambient concentration. A number of publications on use of the NO2 sampler, both at occupational and community air pollution levels, have resulted from this work.

Jan 1, 1979

By William G. Pariseau

The research reported here concerns ground control in multi-seam mining and relates mainly to the analysis of stress about multi-seam room and pillar mines. The two variables of most concern are distance between seams and alignment of pillars between seams. The first year results of the two year investigation apply to the development phase of mining when the extraction is typically less than 50 percent. The second year effort is concentrated on retreat mining and barrier pillar safety when the extraction is typically greater than 50%. The procedures in both cases are readily applicable to more than two seams. Although two seam mines are the most frequent type of multi-seam operations, because of the potential for three seam operations in the Western United States, a number of three seam development analyses are also presented. The results enable one to make a rapid assessment of stability of rooms and pillars during production and barrier pillar size during extraction of adjacent panels. In the event of low safety factors, more site-specific analyses can be undertaken.

Jan 1, 1983

By Rudolf E. Grauer

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Jan 1, 1981

By F. A. Patty

[Health and safety hazards from contamination of the atmosphere in places frequented by persons depend to a considerable extent on whether the contaminating agent possesses sense-perceptive properties which will give warning of its presence before it '.an create harmful conditions. If a distinct and easily recognized warning is given in advance of harmful conditions, hazards ace mitigated, but if warning properties are inadequate or absent, the hazards are augmented. When evaluating the hazard presented by a potentially harmful substance used under conditions of possible escape into the air of places frequented by persons, it is therefore necessary to consider the warning properties of the substance along with ether pertinent information such as toxicity, inflammability, physical properties, and mode of use. If the contaminating agent inherently lacks warning; properties it may be possible to impart them by adding to the hazardous substance a small quantity of a relatively harmless substance which has a high warning intensity.]

Jan 1, 1929

By J. M. Gomes

Bench-scale flotation tests were conducted on two western tactite ores to study the recovery of tungsten and zinc minerals. The investigation, which is part of the Bureau of Mines ongoing program to develop methods for beneficiating minerals and metals from domestic low-grade ores, demonstrated the feasibility of producing scheelite, sphalerite, and their bulk concentrates. Sphalerite concentrates containing 51 to 53 pet Zn and less than 0.11 pct W03 were selectively recovered prior to scheelite flotation. Zinc recovery ranged from 85 to 91 pct. Scheelite concentrates containing 17 to 25 pct W03 were then recovered from the ore; tungsten recoveries ranged from 88 to 94 pct. Bulk flotation concentrates containing 84 to 91 pct of the W03 and 87 to 95 pct of the zinc also were prepared. More than 98 pct of the W03 in a bulk concentrate containing 9 pct W03 was extracted by autoclave leaching with a soda solution. The zinc remained in the leached residue.

Jan 1, 1982

By E. A. Mihok

A pilot plant for treating mine drainage by neutralization with limestone was designed, fabricated, and operated by the Bureau of Mines. The process consists of (1) producing a very fine (minus 400-mesh) limestone slurry, (2) mixing the slurry with the mine water, (3) aerating the resulting mixture to remove carbon dioxide and precipitate iron, and (4) separating the solids from the liquid by sedimentation. A mine discharge of pH 2.8, containing 1,700 ppm total acidity, 36 ppm ferrous iron, and 360 ppm total iron, was treated at rates from 300 to 400 gpm. The treated water ultimately reached a pH of 7.4 and contained no detectable iron. The resulting sludge compacted to approximately one-third the volume of sludge from mine water neutralized with lime. The advantages of the limestone process, compared with the conventional lime process are as follows: Widespread distribution and lower cost of run-of-mine, indigenous limestone; simplicity of plant design; reduced hazards and plant operating and maintenance costs accruing from the use of a less reactive chemical agent; higher solids concentration of the precipitated sludge; and no deleterious effect caused by accidental overtreatment. While total process costs could not be determined, it is conservatively estimated that the cost of treating mine water by the limestone process is one-third to one-half the cost of the lime process, depending on the characteristics of the water to be treated and the availability and quality of limestone used.

Jan 1, 1968

By J. W. Thompson

ESTATE IN MINERALS. Minerals beneath the surface may be made the subject of separate ownership either by a grant of the minerals by the owner of the land or by a grant of the land excepting the minerals, and thereby an estate in fee simple is created in the minerals, as corporeal things real. Colby, In re, Iowa, 169 Northwestern 443, p. 444. DEEDS EXCHANGING DIFFERENT MINERALS-RIGHTS OF PARTIES. The lands of two adjoining owners were underlaid with cement rock and clay at a depth of about 100 feet from the surface and with coal veins some 600 feet below the surface. By an exchange of deeds one of the land owners conveyed to the other the cement rock and clay with the right to mine and remove the same without entering upon the surface, but the deed contained no covenant not to injure the surface. The other deed conveyed the coal seam and so much of the rock and other minerals just above and below the coal as might be required in connection with the mining and removing of the coal, together with the right to mine and remove the same, and the adja- cent rock, clay, and other minerals, without entering upon or injuring the surface, with one immaterial exception. The deeds do not define the word "surface" and neither expressly nor by implication did they secure to the coal owner the right to subside the overlying cement rock; but the implication is to the contrary, as the deed gives the right to mine and remove coal without entering upon or injuring the surface. The provision that the coal owner should not enter upon or injure the surface amounts to a clause that the coal mine. shall not be worked so as to let down the surface and this does not create any inconsistency with the provision giving the right to mine and carry away the coal.

Jan 1, 1919

By H. W. Gillett

This bulletin is issued by the Bureau of Mines as a contribution to the increase of safety and efficiency in the preparation and utilization of the mineral resources in the United States. Notable among the drains on these resources are the demands made by the nonferrousmetal industries, and in these the losses occasioned in melting brass and bronze are worthy of particular attention. This statement will be better appreciated by a consideration of the size of the brass industry. MAGNITUDE OF THE BRASS INDUSTRY. According to the Thirteenth Census, in 1909 there were in the United States 1,021 fu-ms that dealt mainly in brass and bronze. This total included jobbing foundries, manufacturing plants that both cast and machine a brass or bronze product, and rolling mills, but did not include iron foundries having nonferrous departments nor the numerous large brass-foundry departments of manufacturing plants that produce the castings used in the manufacture of electrical apparatus, cash registers, pumps, and the thousands of machines that require brass castings for their construction. Penton's Foundry List for 1910 gives about 1,150 exclusively nonferrous foundries and about 2,300 iron or steel foundries that also melt brass. If the rolling mills and. jobbing foundries in manufacturing plants be included, and if due credit be given to the rapid growth of the industry in the last few years, largely through the stimulation of the automobile busi¬ness, it is probable that not less than 3,600 plants are to-day melting brass or bronze.

Jan 1, 1916

Reports by researchers in government, industry, and universities of the United States are given for various projects on basic coal research concerning, the metamorphism, physical and chemical properties, and reactions of coal, and how many of these studies can lead to better utilization of coal.

Jan 1, 1968

By Francis E. Federspiel

Bureau of Mines personnel examined mines, prospects, and mineralized areas to determine the mineral resource potential of the Log Cabin Saddlebag, Hall Natural Area, Horse Meadow, and Tioga Lake RARE II areas in Mono County, California. These areas, along the east slope of the Sierra Nevada, are underlain by Paleozoic metasedimentary and metavolcanic rocks of the Log Cabin Mine and Saddlebag Lake roof pendants. The roof pendants are in Cretaceous granitic rocks. Pleistocene volcanic flows cap some of the older rocks, and glacial till and outwash locally cover the bedrock. The region was eroded by alpine glaciers. Four parts of the Log Cabin Saddlebag area have moderate gold and silver resource potential. Moderate potential for gold and silver resources was identified in one part of the Hall Natural Area and low potential for tungsten and molybdenum in two other parts (fig. 1).

Jan 1, 1982

By D. S. Burgess

About 100 tests of flammability were carried out with H2, CH4, and CO in mixtures with air using the Federal Bureau of Mines 12-ft-diameter spherical pressure vessel as an explosion test chamber. The LeChatelier approximation gave slightly conservative estimates of the limits of downward flame propagation (onset of significant pressure rise) using the following measured values for the individual gases, in percent: H2, 8.5; CH4, 5.25; CO, 13.0. No justification could be offered for using the LeChatelier law for upward flame propagation limits and indeed reported data suggest that calculated values would not be conservative. The observed upward limit for methane-air mixtures (4.85 pct) was less than the widely accepted lean limit for this fuel; those for lean hydrogen-air mixtures and carbon monoxide-air mixtures did not differ from the lowest accepted values. Diffusional effects on the propagation of single, binary, and ternary fuel mixtures are discussed.

Jan 1, 1982

By J. P. Capp

The Bureau of Mines conducted field-scale experiments in underground gasification of coal with oxygen-enriched air. A path about 140 feet long was linked at the rate of LO feet per day through a coalbed hydraulically fractured with a mixture of starch gel and sand. During the best gasification period, which extended for 2-1/2 days, 785,000 std. c.f. per day of 124-B.t.u. gas was produced. In other periods the heating value at times was almost 300 B.t.u. per std, c.f,, but sustained production of such gas was not achieved. During gasification, a total of 50 tons of coal was gasified and 114 tons of coal was carbonized. Approximately 12 million B, t .u. per foot of nominal path was recovered at the surface.

Jan 1, 1962

By B. J. Moore

This publication contains analyses and related source data for 675 natural gas samples from wells and pipelines in 24 States and 5 foreign countries. The samples obtained and analyzed during calendar year 1980 are included in tables 1-4. Those samples included in tables 5-7 were collected during the years 1960 through 1979. However, permission to publish the analyses of those samples was not given until the past year when the operators were again contacted to seek release of the information. All of these samples were collected as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576. The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the general public. Twenty-two previous publications have presented the results of 12,152 gas analyses made prior to 1980. The first three, Bulletins 486,' 576,5 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1980. The other

Jan 1, 1981

A mobile vacuum sweeper to remove loose coal and coal dust from underground coal mine workings was designed, built, tested, and evaluated. The design was based on an extensive test program. Pick up and conveying rates vs. air volumes, velocities, and nozzle shapes were determined for coal rubble in a laboratory pneumatic handling system. A gas/solids separation system was developed and tested in the laboratory capable of separating the solids loading from the vacuum system air stream to the very high degree required to preclude degradation of the ambient (mine) air. Two designs were made, one for belt conveyor and one for general district cleanup. The belt cleanup machine was chosen for test and demonstrated in an underground coal mine performing cleanup work in belt haulageways and on ribs.

Jan 1, 1975

By R. V. Ramani

One area of study in the Coal Mine Injury Analysis project was to illustrate and enhance the ability o mine safety management personnel to apply analytical techniques to Injury experience data and to justify requests for funds for safety enhancement actions on a cost/benefit and other quantitative basis. Four volumes of this final project report detail (1) the objectives and scope of the mine safety management research, (2) the results of literature review, and case studies, and (3) models developed for mine safety management. The four volumes are titled as Volume III: Mine Safety Management, Volume IV: Analytical Techniques for Mine Safety Management; Volume V: Mine Safety Management Case Studies and Volume IX: Training Cost Model. In this volume, the application of the quantitative procedures to mine-specific accident/injury experience data is discussed in detail in the form of case studies. The accident data from three mines are analyzed, and recommendations for training are proposed for each of the mines on the basis of this analysis. The procedures to apply cost-benefit analyses are described along with the cost benefit ratios for the training program/policies for the mines.

Jan 1, 1993

By Charles Findlay

As one of its projects for degasification of major panels of coal prior to mining within them, the Bureau of Mines conducted methane emission studies during development of a set of three headings 1,800 feet in a major coal panel (2,700 by 3,500 feet) which had been completely isolated by sets of main headings for 12 months in the Federal No. 2 mine (Pittsburgh coalbed) in northern West Virginia. Similar emission studies were conducted in the development of two sets of main headings in virgin coal areas nearby. Comparing the two sets of data indicated that the isolated coal panel had been degasified by approximately 70 percent.

Jan 1, 1973

By G. L. Oldright

"The various districts in the United States where complex lead-zinc ores occur are too well known to require description, there being hardly a mining State with any large amount of ores of either metal that is free from this problem. This paper briefly presents developments in the volatilization process, as applied to the treatment of such ores, since the data in Bureau of Mines Bulletin 211** were published. In that bulletin, among the many types of ore treated, examples are given of the treatment of lead-zinc ores by the chloride volatilization process for the separation of lead. An outline of the general process, with views of the rotary kiln, ore feeder, firing system (these three features resemble closely those of cement-kiln practice), dust chambers, and a Cottrell precipitator to remove the fume from the gas, are also shown in that bulletin, to which the reader is referred for the results obtained, and for practical details of operation. The small initial cost of a volatilization plant, and its adaptability for use in isolated districts were emphasized.In general, it was found that when an intensely oxidizing atmosphere was maintained in the furnace, a good lead-zinc separation could be made. Therefore, a heavy sulphide ore would have to be preroasted, and enough air would have to be admitted to obtain complete combustion of whatever fuel might be used.The work done by private companies and the bureau since the data for Bulletin 211 were obtained, indicates that the ores most immediately amenable to treatment by volatilization are of two types. The first is an oxidzed lead. silrer ore whose variable lime content makes it impractical to chloridize the ore for acidulated brine leaching, and whose base metal content makes treatment by cyanidattion unfeasible, The second type is the lead-zinc ore mentioned above, and is the one on which data are available for publication at present. This article Chows what ores of this latter type are amenable to treatment by volatilization, by giving briefly some of the more important physical and chemical properties an ore should preferably possess. Several examples are given from both laboratory experimental work, and from practice in the field, showing various phases of the volatilization process."

Nov 1, 1923

By Noel N. Moebs

The U.S. Bureau of Mines is conducting research on many topics relating to the mineral resources of the United States. This is done to ensure an adequate supply of minerals essential to a viable domestic industry and a sound economy. The United States is almost totally dependent on foreign supplies for a number of minerals such as chromium, niobium, tantalum, and manganese for which there is no available substitute, while many other minerals such as titanium are abundantly distributed throughout the earth but seldom occur in adequate concentrations or useful forms. This report describes an example of a small but high-grade occurrence of titanium are in Nelson County, VA. This occurrence could be exploited under favorable economic conditions with new mining technology such as borehole slurry mining. The report demonstrates that the dikes at titanium ore, a mixture of ilmenite and apatite locally termed nelsonite, can be detected and traced along strike using magnetometer traverses. This information will aid in the selection of appropriate slurry borehole mining test sites in the area.

Jan 1, 1993