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By A. D. Hahn

This report describes reconnaissance by the Bureau of Mines of titanium-bearing beach sands on Ship Island in the Gulf of Mexico off the south coast of Harrison County, Miss. The purpose was to determine the ilmenite, rutile, and associated heavy-mineral content of black-sand-bearing beach sands. The investigation was part of a survey of titanium resources of the United States. Ilmenite (FeTi03), an iron-titanium oxide, is the major titanium-bearing mineral consumed in the titanium pigment industry. Rutile (TiO2), titanium dioxide, is used mainly as a constituent in welding-rod coatings and in producing titanium metal. The major fieldwork was conducted during the first half of February 1961. Nine holes, totaling 220 feet of bore, from which 110 samples Her taken, were drilled at widely spaced intervals on the island.

Jan 1, 1962

By F. H. Gibson

In recent years physico-chemical techniques have been applied for rapid analysis of coal and coke ash as replacements for classical wet-chemical methods. Although the classical methods are accurate, they are time consuming because many chemical separations are necessary to complete an analysis, and they require skilled analysts for accurate work (12).4 For the past several years the Bureau of Mines has applied some of the newer physico-chemical techniques in its continued search for new and improved methods at analysis. The methods of analyzing coal and coke ash evolved from this work include spectrophotometric methods far SiO2, A120, , Fe203 , TiO2, and P2O5; chelatometric titration for CaO and MgO; and flame photometry for Na20 and K2O. The methods are rapid and direct, are suitable for analyzing a group of samples at the same time in production work, and dire results with almost the same accuracy as classical procedures. With the new methods, complete analyses in duplicate can be obtained at a rate of 2 to 3 times that of conventional methods.

Jan 1, 1962

By H. N. Smith

IN 1944 the Congress passed the Synthetic Liquid Fuels Act that authorized the Secretary of the Interior, acting through the Federal Bureau of Mines, to conduct basic research and construct and operate demonstration plants to produce synthetic liquid fuels from coal, oil shale, and other substances. As a basis for the oil shale investigations to be undertaken in this country, the progress of foreign countries in developing and using oil shale as a source of liquid fuels was studied by the technical missions of the Federal Bureau of Mines. Oil shale mines, retorting plants, and refineries were visited; geological information on the nature and occurrence of the foreign oil shales was obtained; and samples of the oil shales were collected where possible. Samples collected by these missions or acquired by other means came from Australia, Brazil, Canada, France, Manchuria (China) , New Zealand, Scot-land, Spain, Sweden, Thailand, and Union of South Africa. These countries represent a large part of the locations where oil shale developments have taken place. The major omissions are the Estonian, German, and Russian developments.

Jan 1, 1959

By John Ward Smith

The Bureau of Mines drilled Wyoming Corehole No. 1 in Sweetwater County, Wyo., to sample Green River Formation oil shale. Core obtained was assayed for oil yield to determine richness and stratigraphic distribution of oil shale in the deposit. Oil shale in place at Wyoming No. 1 site represents over 200 million barrels of oil per square mile. Additional data useful in evaluating the deposit, including generalized stratigraphy and mineralogy, detailed lithologic descriptions of the core, rock specific gravity, and bore-hole logs, are presented with the oil-yield data. The sampled Wyoming oil shale resembles Mahogany-zone oil shale in rock properties and gross mineralogy. A statistically derived equation relating shale density to oil yield for the Wyoming deposit compares with a similar relationship valid for the better known Mahogany-zone oil shales in Colorado and Utah. A density log from Wyoming Corehole No. 1 is calibrated for direct oil-yield logging. The alternating rich and lean beds of shale at this site may permit creating the permeability necessary for direct production of shale oil from the shale in place.

Jan 1, 1968

By Robin B. McCulloch

No producing mines are in the study area. Sample results indicate the only resources in the study area are low grade phosphate deposits associated with Cuyama Phosphate Mine (fig. 1). Within the study area, are more than 21.4 million tons of inferred subeconomic phosphate rock resources which would be reserves at an 80 percent higher phosphoric acid price; weighted average grade is 4.84 percent phosphorous pentoxide (P205). About 17.6 million tons of similar grade are outside the area to the northwest. The South Cuyama Oil Field, adjacent to the study area (fig. 1), produces petroleum from the Vaqueros Formation which underlies parts of the study area. Oil and gas potential was evaluated by U.S. Geological Survey. INTRODUCTION Location, Size, and Geographic Setting The U.S. Bureau of Mines conducted a mineral survey of the Fox Mountain RARE II area (No. 5120) during the summer of 1981. The area was examined to determine the presence or absence of mineral resources and reserves, and to estimate tonnage and grade where possible.

Jan 1, 1982

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 Leslie H. Sharp, Martin J. Gavin

Those of the oil-shale operators in this country who are sincerely attempting to make a real industry out of oil-shale developments, are anxious to obtain fundamental data on the retorting of oil-shale; particularly as regards the effect of certain variable factors in the process of retorting on the quantity and quality of products yielded from oil shales when they are subjected to destructive distillation. From careful examination of a con siderable number of suggested processes for treating oil shales and the con flicting ideas on which they are designed, it seems probable that accurate information of a fundamental nature is highly essential to the successful establishment of an oil-shale industry in this country. . Accordingly, the United States Bureau of Mines, in cooperation with the State of Colorado, is undertaking to furnish some definite and impartial information of this type through investigations now under way at the University of Colorado, Boulder, Colo. A retort for the distillation of oil from oil shale has been designed and installed, together with the necessary auxiliary equipment for controlling and determining variable factors of distillation, and for recovering and de termining the quantity and quality of the products yielded from the shales. The retort is of such a nature that conditions of retorting can be accurately . and completely controlled, and varied at will. It is not designed as a com mercial retort, but only for research purposes. A testing laboratory with equipment necessary for the examination of the shales, physically and chemic ally, and the products yielded by them, has also been fitted up . The material used in the investigations is oil shale obtained from the DeBeque, Colorado, shale field. It yields on distillation in the Bureau of Mines testing apparatus, about 42 gallons of oil to the ton, and is there fore a fairly representative sample of the shales that probably will be first worked in Colorado. The shale used will be as uniform as possible in character and oil yield and will all be obtained from the same seam at the same point, in order to avoid the introduction of unnecessary variable factors in the tests and to render results strictly comparable •

Jul 1, 1920

By J. J. Sammarco

Light emitting diodes (LEDs) are emerging as viable replacements for incandescent-based cap lamps used in mining. The photometric and energy characteristics of these light sources differ in important ways. The present paper describes the performance of LED and incandescent sources in cap lamps in terms of correlated color temperature, color rendering, light output, electric power, ambient temperature and airflow, and light source aging. Importantly, these characteristics can influence a miner?s ability to spot mining hazards thus impacting safety. Secondly, some of these characteristics interact with the operating life of the cap lamp?s battery power, such that differences between LED and incandescent sources can be magnified toward the end of a 10­hour battery discharge cycle. Empirically, we have determined that after 8 hours at an ambient temperature of 25 °C, the average light output of an incandescent cap lamp can decrease to about 69% of its initial value when powered by a lead-acid battery and it can decrease to about 65% of its initial value when powered by a nickel-hydride battery. An LED-based cap lamp using a constant current drive circuit can maintain about 96% of its initial value when powered by a nickel-hydride battery. Real-world tests addressing the effects of ambient temperature and airflow on the light output of an LED and incandescent cap lamp were conducted in the NIOSH Safety Research Coal Mine (SRCM). The LED cap lamp yielded a vertical average illuminance improvement of approximately 9.5% and the INC cap lamp yielded a vertical average illuminance degradation o f approximately 4%. The differences between LED and incandescent cap lamps were further quantified by the calculation of ?mesopic luminance? data that indicated for the same photopic luminance (i.e., as measured using a conventional light meter) the LED cap lamp could be up to 38 % more efficient than the incandescent cap lamp with a lead-acid battery at the end of the 10-hour driving cycle. Lastly, accelerated life tests were used to empirically determine light output depreciation as the incandescent light source age approached its useful life. There was about a 35% decrease in light output. This is quite considerable, especially given that the light output will decrease an additional 30% to 45% over the period of a 10-hour shift. The implications of the differences between LED and incandescent sources are discussed. This information is crucial in determining how visual performance could be affected for real-world conditions where batteries discharge during the work shift and as the light source ages. To date, only idealized conditions have been used for LED and incandescent cap lamp visual performance research.

Jan 1, 2008

By H. E. Perlee

Autoignition temperatures and limits of flammability of nine halogenated hydrocarbons in atmospheres of air, oxygen, and nitrogen tetroxide were measured in a modified standard autoignition apparatus and limit-of-flammability apparatus previously developed at the Bureau of Nines. Of the nine halogenated hydrocarbons investigates--bromochloromethane, bromotrifluoromethane, bromochlorodifluoromethane, 1,1,2-trichlorotrifluoroethane, 1-bromo-l-chloro-2,2,2-trifluoroethane, dibromodifluoromethane, l,2-dibromo-1,1,2,2-tetrafluoro-ethane, 1,1,1,3,3-pentachlorotrifluoropropane, and l-bromo-2,4-dichloro-1,1,2, 3,3,4-hexafluorobutane--two formed flammable mixtures with nitrogen tetroxide and six with oxygen; none formed flammable mixtures with air. Three of the halogenated hydrocarbons formed no flammable zones with any of the three oxidizing atmospheres. For those halogenated hydrocarbons that supported combustion in oxygen atmospheres, explosion pressures developed during constant-volume burning of mixtures near the middle of the flammable zone were observed to range from about 6 psig for dibromodifluoromethane to 158 psig for 1-bromo-1-chloro-2,2,2-trifluoroethane. In all cases, the calculated burning velocities of these mixtures were less than 8 in/sec.

Jan 1, 1966

By G. W. Jones

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

Jan 1, 1954

By J. Burlin Johnson

In small-scale blasting experiments conducted in the Bureau of Mines laboratory, small charges were used to produce craters in blocks of concrete mortar. The results are compared with larger scale experiments of other research workers, and the comparison demonstrates the similarity of the results obtained and indicates that small-scale blasting should be a useful tool for predicting large-scale blasting effects. INTRODUCTION The purpose at this investigation was to conduct blasting experiments in mortar in the laboratory and then, by comparing the results with those from larger scale field blasts in rock to determine to what extent, if any, the laboratory results resemble those in the field. The work described herein was the initial phase of a project aimed at evaluating small-scale blasting as a tool for use in improving blasting techniques. It is evident from the stand-point of control and cost that small-scale blasting would be valuable in the study of rock fragmentation by blasting in mines and quarries, if the extrapolation is valid.

Jan 1, 1962

By Robert C. Steckley

The Bureau of Mines performed a fragmentation experiment in cooperation with Duval Corporation in a porphyry copper-molybdenum deposit near the Sierrita pit south of Tucson, Ariz. This experiment evaluated the fragmentation created in a 10-hole test blast having blasthole spacings of 25, 20, and 15 feet. The 10 blastholes were 9 inches in diameter and contained a total of 17,400 pounds of aluminized slurry blasting agent in 50-foot columns with 60 feet of stemming. Diamond drill core examination was the primary method used to determine the condition of the rock before and after blasting. These core examinations included study of length recovery, rock quality designation (RQD), weight recovery, and size distribution. Topographic surveys were used to measure the rock swell produced by the blast and a fragment size distribution was obtained for the broken material on the surface. Fragmentation to depths of 110 feet was excellent from the 15-to 20-foot blasthole spacing patterns. Good breakage was also produced by the 25-foot pattern although the effects of the blast were not so obvious. In situ leaching tests were not conducted. However, based only on size consideration, all three blasting patterns produced adequate breakage for successful leaching.

Jan 1, 1975

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 Thomas H. Dubaniewicz

Fiber optic systems are being deployed in locations where explosive gas atmospheres are normally present or are present under fault conditions. The National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory (NIOSH, PRL) conducted a study of laser safety in potentially flammable environments. Researchers conducted experiments to estimate the mean and standard deviation of laser powers needed to ignite 6% methane-air atmospheres using single mode optical fiber tips covered by two types of iron oxide (Fe304 and (FeMn)203) mixed with a ceramic adhesive. The iron oxides, heated by a 1064 nm continuous wave laser, ignited the methane-air mixtures ,at similar powers. The minimum igniting power and maximum non-igniting power (10 tests) were 407 and 350 mW, respectively, using a 62.5 pm fiber. Laser beams guided by 125 and 80 pm diameter cladding single mode fibers produced similar methane-air igniting powers. Ignition was not observed using coal particles at powers that produced ignition with the iron oxides. Threshold ignition delays using the single mode fiber were approxinlately proportional to the inverse square of the igniting power. Ignition delays were significantly longer than the reported activation time for a comnlercial fiber optic power limiter. Comparisons are made with the results of other researchers. Published by Elsevier Ltd.

By William A. Beck

"The Old Cline mine, also known as the Old Cruse mine, was first worked for gold in1895. The property was opened by several shafts and trenches; and some stoping has been done, producing several cars of copper-gold ore in the early nineteen hundreds. Chalcopyrite is visible in selected samples; and, with the aid of a mineralite, several samples showing a considerable amount of scheelite were found on the old waste dumps.The mine is in Township 6, Cabarrus County, N. C., 5 miles north of the village of Mount Pleasant, 10 miles northeast of Concord, and about one-half mile south of Watts Crossroads. It is one-fourth mile east of the county road.When examined, the property was owned by H. F. Tompkinson, Concord, N. C., and was leased, with option to buy, by L. Nash. Titles of record were not investigated.As stated above, the Cline mine was first worked in 1895. The property was Purchased in 1902 by J. A. Clark and A. A. Smith of Atlanta, Ga., and worked for gold and copper. No record is available of the quantity of ore removed during these operations.A Bureau of Mines mining engineer3/ examined the mine as, a copper prospect on October 13, 1944.The Cline mine is in an area characterized by flat to rolling topography, dissected by many streams and rivers. It lies in the Piedmont Plateau and Varies in elevation from 700 feet to 800 feet. The surrounding country is partly wooded and partly cleared farm land.A quartz vein occurs in country rock of quartzite and greenstone.4./ The ore occurs in a series of quartz lenses, having a width of 1 to 3 feet and dipping about 750 NE, and striking N. 300 W. All these lenses have fairly sharp boundaries and in some cases are entirely separated from each other, while at other times they are connected by thin stringers of quartz. They can be traced for 1,000 to 1,200 feet by a series of shafts and test pits."

Apr 1, 1946

By Jack E. Fraley

The Bureau of Mines has successfully developed and tested a machine for spraying sealant onto coal mine roof and ribs. Dry material is transported pneumatically to a water-adding nozzle designed to provide dust-free spraying while being nonplugging and self-cleaning. The machine is self-cleaning, 35 inches in height, and capable of applying l/2-inch-thick coatings at over 1,000 ft2/hr.

Jan 1, 1978

By R. L. Hopkins, H. T. Rall

A continuous method has been developed for preparing thiolacetic acid . Acetic anhydride and hydrogen sulfide are passed concurrently over an amine ion- exchange resin , under 20 - psi pressure . The thiolacetic acid , a product of the reaction , is flashed continuously from the crude reaction mixture and is purified by fractional distillation . The yield of thiolacetic acid is in excess of 80 percent based on the acetic anhydride charged . INTRODUCTION In the synthesis of reference compounds needed in the identification of sulfur compounds in petroleum , thiolacetic acid has become an important reagent because of its use in the synthesis of thiols by addition to appropriate olefins : R - CH = CH₂ + CH3 - COSH R- CH2 - CH2 - S - COCH R - CH2 - CH₂ - SH + CH3COONa NaOH (1 ) The commonly used procedures for its preparation , as described by Clark and Hartman (1 )4 and by Ellingboe (2 ) , are based on the batchwise reaction of acetic anhydride with hydrogen sulfide :

Jan 1, 1964

By G. Richards Gwinn

Vermiculites are secondary minerals formed by the: alteration of biotite and philogopite mica and are associated with basic rocks such as dunites, serpentines, and pyroxenites. Vermiculite was first described by T. H. Webb in 1824. It remained a mineralogical curiosity until 1913, when the first commercial deposit was discovered in the Turrett mining district of Colorado. Expanded or exfoliated vermiculite was first marketed in 1915 from a deposit in this district 5 miles southeast of Hecla, Colo. This activity was brief, but successful and continuous commercial development began in 1921 in Montana. 'Deposits in other States have been found and developed, but Montana is by far the largest producer. Vermiculite has also been found in South Africa, Western

Jan 1, 1944

By J. P. Bennett

The Bureau of Mines investigated the dimensional changes of ceramic materials exposed to acid environments to evaluate construction materials for emerging technology in chemical and metallurgical processes. Six commercial ceramic materials (two red shale, two fireclay, one silica, and one silicon carbide (SiC» were exposed to H20, 20 and 30 wt pct HCl, 40 and 60 wt pct HN03, and 10 and 50 wt pct H2S04 at temperatures from 50° to 90° C for 300 days. Linear expansions ranged from a low of -0.02 pct for the silica to a high of 0.45 pct for the red shale. A general ranking of the volume expansion of the materials tested, (from high to low), is as follows: high-porosity red shale A and fireclay B » low-porosity red shale B and fireclay A > silicon carbide and silica. A general ranking (largest to smallest) of the effect of exposure environments is HCl > H2S04, HN03 > H20. An autoclave test method was evaluated. Data obtained from 8-to 24-h exposures were compared with data obtained from the 300-day exposures. The relative expansion trends were similar, indicating that this method could be used as an accelerated test.

Jan 1, 1988

By Jos. R. Guiteras

This paper is one of a series describing; mining and milling methods and costs being published by the Bureau of Mines. It deals with the mineral resources of western South Dakota and describes the mining and milling of tantalite and associated amblygonite by the Black Hills Tin Co. and the Fansteel Mining Corporation. ACKNOWLEDMENTS Acknowledgment is made to Earl C. Schultz and Arthur I. Johnson, respectively superintendent and engineer for both the Black Hills Tin Co. and the Fansteel Mining Corporation, who contributed the information on mining and milling operations.

Jan 1, 1939