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By M. H. Stanczyk, I. L. Feld

Dewatering of typical Florida phosphate rock slime by electro - osmotic techniques was investigated to determine if a compacted , plastic solid product could be obtained with simultaneous recovery of the water for re - use . Tests with porous cathodes and rod - type anodes imbedded in dilute slime charges of up to 4 tons in weight showed that the slime could be dewatered to about 35 percent solids . The dewatered products had the consistency of modeling clay . In the large - scale tests using 2.5 - foot electrode spacings , about 21 kilowatthours of power were consumed per ton of water removed in thickening the slime from 17 to 25 percent solids , but the rate of water removal was so slow that the process was not considered commercially feasible . Other tests made with electrode spacings of from 2.5 to 8 feet showed that more rapid dewatering could be obtained but that the power required was excessive . However , for special uses such as stabilizing slime pond dikes where the cost of dewatering might not be a prime requisite , high voltages could be used to rapidly remove the water . Tests of 400 - pound slime charges using a combination of electroosmosis and vacuum filtration showed that the rate of dewatering could be expedited . The average power required to thicken a ton of slime from 15 to 35 percent solids was 5 and 50 kilowatt - hours when operating the electroosmotic filtration cell at potentials of 20 and 100 volts , respectively . calculated filtration area of about 10 square feet per ton of slime treated per day was required to thicken the slime from 15 to 35 percent solids .

Jan 1, 1964

By Joseph A. Hrabik

The Bureau of Mines compared the feasibility of mining deep phosphate deposits by a borehole mining system with mining by proven conventional techniques. An economic comparison of the borehole mining system with conventional dragline and bucket wheel excavator mining systems was completed at various mining depths and production rates. Hypothetical phosphate deposits, with various overburden thicknesses and reserve tonnages, were defined. Geologic conditions necessary for the application of the borehole system were identified. Discounted cash flow analyses based on derived capital and operating costs were used to generate rates of return and product prices. Borehole mining was found to be more economical where overburden thickness was 150 ft or greater; however, at 50- and 100-ft thicknesses, conventional surface mining was more economical. Overburden thickness has a great effect on the economic feasiblity of the conventional mining systems but less effect on the economics of borehole mining. Economies of scale are only realized in conventional mining, since larger equipment is employed to achieve greater production, whereas increased production from borehole mining is achieved using additional equipment units. A comparison of the environmental effects of borehole and conventional surface mining systems showed that borehole mining is environmentally more desirable.

Jan 1, 1983

By William H. King

The Fannie Ryan deposit is situated about 9 miles northwest of Boulder City, Clark County, Nev. at an altitude of about 2,000 feet on the north side of the River Mountains. The deposit is covered by several unpatented claims owned by Fannie B. Gulick of Las Vegas, Nev. The Boulder City deposit is within the Hoover Dan National Recreational Area. It is situated about 3 miles southeast of Boulder City in sec. 23,T. 23 S., R. 64 E., Clark County, Nev. The Deposit was covered by several unpatented mining claims owned by S. R. Whitehead of Las Vegas. The deposits occur in sedimentary beds of the Muddy Creek formation that overlie older volcanic extrusive. The manganese minerals occur as soft oxides of the wad type. The exploration was conducted by the Bureau of Nines in cooperation with the Federal Geological Survey and comprised a study of the geology, mapping of the areas, and development by shaft sinking; diamond drilling, and sampling. On the Fannie Ryan Gulick property the work consisted of cleaning and sampling seven old trenches on the outcrop and diamond drilling seven holes totaling 1,482 foot. At the Boulder City deposit 188 feet of drilling was done in two holes. A 4- by 6-foot shaft was sunk to a depth of 44.5 feet, and the north and south sides of the shaft were sampled.

Jan 1, 1950

By John J. Sammarco

This U.S. Bureau of Mines report describes the research effort and results for a computer-assisted appendage control system of a Joy 14CM continuous mining machine. The cutter head (shear), gathering head, conveyor, and stabilizer jack are the appendages. Positional control of each appendage is accomplished by specifying the desired position to the appendage control computer, which uses appendage position sensor data. Appendage movement is actuated until the desired position is attained as determined by control algorithms. A description of the sensors, mechanical and electrical interfaces, data acquisition and control (DAC) system, experimental method to determine appendage response characteristics (range of motion, start and stop delay times, and movement rates), and their application to the position control loop algorithms are presented. Also, the test results for the shear in an unloaded (free space) and loaded (cutting) condition of the shear are presented.

Jan 1, 1991

By Laurence G. Trudell

A geologic framework for interpreting stratigraphic and geographic variations of the Green River Formation in the Piceance Creek Basin is developed from lithologic data accumulated by the Bureau of Mines from oil-shale coreholes. From detailed Bureau of Mines descriptions of samples from nine coreholes and supplementary lithologic data from seven additional sampled sections, three cross sections were constructed along lines transecting the basin. Plotted as lithologic columns with corresponding oil yields and resistivity logs, the sampled sections are correlated on a time-stratigraphic basis. Distribution and correlation of nahcolite and halite zones are shown, and the approximate base of leaching of these saline minerals is indicated. General lithologic characteristics of members and zones are discussed and interpreted. Large-scale lithologic logs illustrate the nine Bureau of Mines core descriptions, and the complete description of Bureau of Mines-Atomic Energy Commission Colorado Corehole No. 1 is included in an appendix. The time-correlated cross sections provide a necessary framework for understanding the depositional history of the Green River Formation and will facilitate evaluation of oil shale and other mineral resources in the Piceance Creek Basin.

Jan 1, 1970

By Martin J. Gavin

In an earlier paper (Karrick, Lewis, C. A convenient and reliable retort for assaying oil-shales for oil yield: Bureau of Mines, Reports of Investigations, Loral No. 2229, March, 1921. Reprinted in Eng. and Min. Jour, April 30, 1921, also in Mining & Met., May, 1921) which describes the apparatus and method used in the laboratories of the Bureau of times for assaying oil-shales, no mention is made of the quality of oil obtained when the apparatus is operated under conditions determined to be most suitable for producing highest yields of oils. So many inquiries regarding the nature of the oil have been received, that it seems advisable to present a short report on the subject. Experimental work indicates that it is possible to vary the quantity and quality of the oil obtainable with the assay retort from a given shale by varying the conditions of retorting. As an example, some figures that are averages for several closely agreeing tests are shown below.

Jan 1, 1921

By Ray J. Holmquist

"INTRODUCTION The Elk Mountain mica deposit was examined in June 1943 by the Bureau of Mines. An exploratory project and an access road for the property were recommended, provided the zinc was put in operation under competent management. K. Garard obtained a lease on the properly and started operations in June 1944; this was followed immediately by the Bureau's exploratory work. Road construction was begun by the Forest Service in July the same year.The lessee mined mica from the richest exposure with a crew of three men for 2-1/2 months. His operation terminated late in September, but the Bureau of Mines project and the Forest Service road construction continued until snow forced suspension of activity during the first week of November.The Bureau of Mines work consisted of trenching with a bulldozer, hand excavating on undeveloped outcrops, extending an existing adit, and starting a new adit below the older workings."

Jul 1, 1946

Since its creation in 1910, the Department of the Interior's Bureau of Mines has pioneered in the development of mineral technology, through research. From the very beginning, research on mine health and safety has been a dominating concern, and a responsibility that expanded markedly as a result of the Coal Mine Health and Safety Act of 1969. Until the mid-1970's research on fuel technology and coal production also was an important part of the Bureau's work. But in the four years following the 1973 oil crisis, Congress established a reorganized Federal energy research apparatus in which all fossil fuel research-encompassing extraction, use, and conservation-was centralized. Today, the Department of Energy houses Federal research on coal mine production technology, while research on coal and noncoal mine health and safety and environmental technology, and on noncoal mine production technology, remains in the Interior Department as a continuing responsibility of the Bureau of Mines. In carrying out its authorized research programs, the Bureau conducts both short- and long-term re-

Jan 1, 2012

By L. E. Schultze

[The Bureau of Mines conducted bench-scale studies to develop techniques for stripping tetravalent cerium from tri-n-butyl phosphate solutions. Experiments were conducted in a constant-temperature bath using beakers and mechanical stirring. Ninety-five pct of the cerium was stripped from a 50-pct tri-n-butyl phosphate 50-pct kerosene solution containing 0.18 M cerium in 15 minutes at 50° C using 0.11 M aqueous formaldehyde.]

Jan 1, 1974

By P. L. Woolf

Two blast furnaces, one a. commercial furnace and the other the Bureau of Mines experimental furnace, were successfully operated with extremely low slag volumes. The lowest slag rate obtained on the industrial furnace was 335 pounds per ton of metal. Using the same burden materials a 245-pound slag volume was achieved on the furnace. The coke rate saving and increase in productivity resulting from lowered slag rates are discussed as well as the factors limiting a low slag practice.

Jan 1, 1965

By Frank E. Federspiel

In 1986 and 1987, at the request of the U.S. Forest Service, the U.S. Bureau of Mines examined the 47,000-acre Electric Peak study area (part of the formerly-designated RARE II Non-wilderness Recommended Area no. 1609) to evaluate its' identified mineral resources. The study area is in Powell and Jefferson Counties, YT, about 30 mi southwest of Helena and 30 mi north of Butte. Three lode localities within the study area contain an estimated 159,000 tons of identified subeconomic resources containing gold, silver, and accessory lead, copper, and zinc. Resources at those localities range from 10,000 to 134,000 tons with grades ranging from 0.04 to 0.32 oz/ton gold, 0.92 to 16.42 oz/ton silver, 0.14 to 79.65 percent lead, and as much as 0.41 percent copper and 0.68 percent zinc. One property also contains 0.15 percent antimony. Gold, silver, and base-metal content in samples of poorly exposed mineralized structures indicate that further exploration may identify resources on seven additional study area localities.

Jan 1, 1988

By J. W. Miller

Depletion of coals most suitable for metallurgical fuel has nude necessary a general survey of coking-coal reserves in the United States. These investigations were begun in 1948 at the joint request of the Munitions Board, Department of Defense, and a number of coal companies. This report, which is one of a series, by counties, describes the preparation characteristics of the coals of Letcher County, Icy. From these data it is possible to determine: (a) Which coals either as mined or after beneficiation by conventional preparation are suitable under present standards for producing metallurgical coke, (b) which coals require special and more intensive treatment in preparation than is now practiced, and, (c) which coals cannot be upgraded by known commercial preparation methods to metallurgical fuel standards now accepted.

Jan 1, 1955

By John K. Alley, Robert C. Johnson

The primary objective of the research was to grow aluminum borate whiskers or fibers and to determine their properties . Molten salt bath and vapor deposition methods were used for synthesis . Whiskers exceeding 25 mm in length were grown . The best results were obtained by vapor deposition and most of the data presented were determined on whiskers produced by this method of synthesis . Three different aluminum borate compositions ( 4.8A1203 B₂03 , 3.8A1203 B203 , and 2.5A120, B203 ) were identified by X- ray and chemical analyses . The aluminum borates 4.8A1203 B20, X- ray diffraction pattern was indexed . Optical data were obtained on the three aluminum borates . In addition the following whisker properties and growth factors were determined : ideal atmospheric dewpoint for vapor deposition method , near 65 ° F ; temperature range of whisker formation , 1,000 ° to 1,400 ° C for the molten bath method of synthesis , > 1,000 ° to < 1,400 ° C for the vapor deposition method ; whisker growth rates by the vapor deposition method , maximum 12 mm per hour ; raw material vaporization , 50 to 60 percent of the fluoride lost in 1 hour ; tensile strength , maximum obtained 174,162 psi ; melting points , ranged from 1,675 ° to 1,795 ° C.

Jan 1, 1965

By Raymond L. Carpenter

The thermal conductivity, electrical resistivity, and Seebeck coefficient for nine compounds, based on the formula for enargite Cu3AsS3, were measured in a search for efficient materials to be used in thermoelectric generators or refrigerators. Results indicate that one of these compounds, Cu3SbSe4, has thermoelectric properties approaching those of bismuth telluride. An investigation of the effect of adding small quantities of tellurium to Cu3SbSe4 and Cu3SbS4 in order to improve their properties also was made. A figure of merit of 2.1 x 10-4 °C-1 was obtained for Cu3SbSe4 + 0.1 percent tellurium.

Jan 1, 1963

By K. E. Soroka

More than 500 fires are now burning in abandoned coal waste banks and coal deposits in the United States. Once established, such fires can burn for decades, and extinguishing them by conventional methods such as surface sealing to exclude air, excavation to remove fuel, or flushing to cool the fire zone is usually difficult and always expensive. Burnout Control, a technique developed by the Bureau of Mines for the control of abandoned coal fires, involves the accelerated combustion of coal in place with total management of the heat and fumes produced. A burning waste bank or mine is placed under negative pressure relative to the atmosphere, and heat and combustion products are drawn from the combustion zone through an exhaust ventilation system. Heat produced appears as sensible heat in the exhaust, at temperatures as high as 1,0000 C (1,832° F), and could be recovered for the production of steam, hot water, process heat, or electricity. The Bureau&apos;s first held field demonstration of Burnout Control was at Calamity Hollow in Allegheny County, PA (near Pittsburgh). Calamity Hollow was the site of an underground mine in the 1900&apos;s and was surface mined in the 1940&apos;s. In the winter of 1961-62, a fire of undetermined origin was discovered in the exposed coal. In 1963, the Bureau constructed a trench barrier around the fire and a surface seal over the affected area. The fire was isolated but not completely extinguished. In 1979, when the Bureau began work on the Calamity Hollow Mine Fire Project to demonstrate controlled burnout, the fire was still smoldering on the hot side of the trench barrier. The project, which was begun in December 1979 and ended in July 1982, consisted of the design, construction, operation, and subsequent dismantling of a Burnout Control ventilation system. This report is the fifth in a five-part series that describes the Calamity Hollow Mine Fire Project. The first report, part 1, describes the design and construction of the field installation. Part 2 will present the results of a continuous 4-month burnout operation. (Because part 2 involves the analysis of a substantial body of data, it will not be published until after publication of parts 1, 3, 4, and 5.) Part 3 describes the instrumentation used to control and monitor the progress of the burnout operation. Parts 4 and 5 deal with the closeout phase of the field demonstration. Part 4 describes the procedure used to quench the fire, and this part (part 5) describes the final excavation and backfilling of the heated zones. The reports in this series document the Calamity Hollow controlled burnout demonstration which showed that (1) controlled in situ combustion is a feasible method for controlling underground fires in abandoned mines, (2) the resultant thermal exhaust output is sufficient for energy utilization, and (3) water injection-fume exhaustion is a potentially effective method for cooling large underground fire zones. Further investigations of both Burnout Control and the water-injection-fume exhaustion quenching procedure are planned.

Jan 1, 1986

By B. E. Blair

The physical properties and related geological and petrographic data for 81 rock types obtained from operating mines or selected test sites are presented in this report. Most of these rock data were obtained to supplement structural studies in underground mines; however, the data may be equally applicable to other problems where the physical properties of rock are an important factor. Stress-strain curves are presented, where available, and free medium velocities from laboratory and field measurements are compared for several rock types. Rock-type, geographical, and geo-logical indexes are included for reference relative to physical property data in this and previously published Bureau of Mines physical property reports. INTRODUCTION This report presents the physical properties of 81 rock types from 16 different projects (sections 53-68). Three previous physical property reports2 3 4/ (herein after referred to as parts I, II, and III) presented data on 244 rock types from 52 project areas. (Part I included sections 1-25, part II sections 26-36, and part III sections 37-52).

Jan 1, 1956

By W. F. Marshall

This report describes exhaust-emission data from 10 diesel engines: six 4-cycle, direct-injection, naturally aspirated engines; two 4-cycle, direct-injection, turbocharged engines; one 4-cycle, precombustion-chamber, turbo-charged engine; and one 2-cycle, direct-injection engine. These engines were tested over a 3-year period (1968-70). Lowest emissions were obtained with a precombustion-chamber engine. Emissions from the 2-cycle, direct-injection engine fell within the range of emission rates for the 4-cycle, naturally aspirated, direct-injection engines. Excluding the precombustion-chamber engine and excepting one of the 4-cycle, naturally aspirated engines, carbon monoxide emission rates were about the same for all engines tested. Test data on smoke, odor, and emissions of hydrocarbons, oxides of nitro-gen, carbon monoxide, and aldehydes are given.

Jan 1, 1971

By C. W. Smith

The U.S. Bureau of Mines; Tuscaloosa Research Center, in cooperation with the U.S. Army Corps of Engineers under interagency Agreement No. 14-09-0078-1510, conducted a comprehensive sampling program of 10 upland disposal sites along the Alabama, Black Warrior, and Tombigbee River systems in Alabama. Samples from each site were characterized according to particle size, chemical analysis, mineralogical content, and potential end use. Additionally, samples were subjected to the Toxic Characteristic Leachate Procedure to determine the presence of potentially harmful heavy metals. Based on the results of these studies, each sample was determined to have properties amenable for use as aggregate in general-purpose portland cement concretes and certain asphalt concrete applications.

Jan 1, 2010

By Thomas J. Peters

The Lime Creek study area lies 100 air km east of Boise, and 70 air km northeast of Mountain Home, Idaho. The eastern boundary of the 28,000-hectare, east-west-elongate study area lies 0.2 km west of the 3,077-m-high Smoky Dome. The area is mainly underlain by Cretaceous granitoid rocks of the Idaho batholith. No mineral resources were identified, but two mines and one prospect were found in the study area. At the President and the Last Chance mines, in the southwest corner of the study area, gold mineralization occurs along steeply dipping east-northeast-trending faults and associated quartz veins, and within adjacent Cretaceous granitic rock. The mineralized material is not rich enough to mine underground, and near surface, open-pit-mineable deposit areas could not be identified. The third prospect, the Ventura, is within altered pink granite of probable Tertiary age, but metal concentrations are very low. Geothermal activity was not observed within the study area, but hot springs do occur in the Vicinity. Bedrock observed is only suitable for the most basic high bulk and low end value applications, such as crushed aggregate. Numerous sources for crushed stone occur closer to markets. Alluvial concentrate (placer) samples did not contain free gold, and no substantial alluvial bars were seen; deposits were too small to contain resources.

Jan 1, 1993

By S. P. Howell

"Technical statistical study has been made of accidents in the anthracite region of Pennsylvania in which explosives were involved. The data have been taken from the accident reports in the files of the department of mines of Pennsylvania, supplemented by inquiries in the field.This study has disclosed a wealth of information regarding the nature and the cause of accidents that occurred where different means of firing shots of explosives were employed. In the anthracite region shots are fired with fuse, with squibs, and with electricity,Many of the salient features of this accident experience are illustrated in this report of investigations, and a number of recommendations are made to reduce the hazards of each of these three methods of shot firing.Experience seems to demonstrate that, under conditions in the anthracite region, electric firing of shots is substantially the safest method; that accidents wherein fuse is employed are more frequent than accidents in which electric firing is employed; and that the number of accidents when squibs are employed far exceeds those in which either fuse or electric firing is used."

Mar 1, 1930