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By H. J. Kelly

[This investigation of the refractory properties of seven Pacific Northwest chrome ores and concentrates has shown that five of the ores and one of the concentrates are suitable for making refractories and that all may be used in combination with high-grade chromite. The specific objectives of the investigation were to determine the inherent physic al and chemical characteristics, to shapes using each of the chrome ores and concentrates, to compare the refractory qualities of the laboratory-prepared with commercial chrome refractories. As far as possible, standard tests were used as criteria.]

Jan 1, 1952

By Ulrich Neumann

Mining coal by employing a method called longwall mining is gaining more and more popularity in the United states since it offers many advantages over the conventional deep mining methods. Those advantages are a higher productivity, an almost total extraction of the mineral since no pillars must be left behind for support, and an increase in safety since the personnel are protected by the shield supports and rarely have to work near unsupported, exposed root. However, on some longwalls, the dust levels liberated by various equipment such as belt conveyors, chain conveyors, crushers, longwall shearers, and moving shield supports can exceed the maximum permissible limits and therefore have an adverse effect on productivity. Many attempts have been made over the past years to reduce the dust liberation by changing designs, installing various types of sprays or scrubbers, treating the mine water with wetting agents, or even using foam to catch dust before it becomes airborne. In the year 1984, the Bureau of Mines awarded Eickhoff Corporation a contract to demonstrate a water-jet-assisted cutting system for the multiple purposes of reducing dust levels, improving bit consumption, and increasing material size. During the previous phases of this contract, various trials were conducted aimed to design, build, and test d shearer loader to meet the objective of the contract. In the early stages of the research program, it was expected to see a reduction in the overall power consumption of the machine due to the fact that the high-pressure water jet would pre-cut the mineral in front of the bit. This, in turn, would then reduce the bit wear. Since there is less cutting action performed by the bit, a reduction of the dust liberation and a reduction of product fines was sought.

Jan 1, 1991

By GLADYS G. HEFFNER, William H. Waggaman, Edwin A. Gee

Thallium is one of the rare and relatively neglected elements that has recently assumed conspicuous importance. This element is widely distributed in nature but occurs in such minute quantities in most rocks and minerals that its recovery at present is only commercially feasible as a byproduct of other industries. World War II, with its unprecedented demand for products having special or unusual properties, led to a study of a number of the rarer elements that previously had been given comparatively little attention for one or more of the following reasons: 1. 2. Limited knowledge of properties. Small quantitios present in available raw materials. 3. High cost of concentration and recovery. Some of those rare elements, either alone or in the form of compounds, have already proved of such value for certain military and industrial purposes that their extraction from ores and waste products, oven at high cost, is fully justified. On the othor hand, further investigation of their character- istics, discovery of more adequato sources, and improvement in methods of con- centration and recovery would greatly broaden their field of usefulness and establish new and expanded industries. The current market for some of these elements exceeds the available supply. One of the functions of the Bureau of Mines is to study the properties of such elements in greater detail, locate the most promising raw materials from which they can be derived, and work out methods of extraction that will render the recovery of such elements more economical. The purpose of a serios of information circulars on the raror elements is to present in condensed form the facts and data so far available. This information may serve as a basis in planning more complete investigations loading to a full utilization of such elements.

Mar 1, 1950

By W. D. Dietzman

This Bureau of Mines report presents a profitability analysis of producing crude oil by waterflooding. Included are the estimated costs of installation of water injection and producing equipment for waterfloods at 2,000 and 4,000 feet and the estimated annual operational expenses for each in west Texas. Using these cost estimates as a base for selecting a range of costs that are indicative of producing crude oil by waterflooding, a simulation technique was derived for determining the profitability under various conditions. Because of the large number of combinations of variables used in this study, a high-speed digital computer was utilized for the calculations. The variables include operational expenses, capitalized costs, price of the oil, annual production, and leasehold acquisition cost. The results obtained from the simulations are presented Fn the appendix. In addition, a nomographical approach was chosen for presentation of the profitability. Five nomographs are presented that can be used for fast estimation of the discounted cash flow (DCF) rate of return that might be expected from a prospective or active operation under various sets of assumed conditions.

Jan 1, 1974

The Aluminum Co. of America raised its 99.5 percent unalloyed aluminum ingot selling price in March by 34 to 514 per pound. Other producers, including Kaiser Aluminum and Chemical Corp. , Anaconda Aluminum Co. , and Reynolds Metals Co., followed Alcoa's lead, raising their quotes to 51$. In late March, domestic merchants quoted ingot at levels ranging between 49.56 and 50.50 per pound. BISMUTH: Several domes tic dealers lowered their bismuth prices in recent weeks by 50t-606 to within a range of $5.60-$5.75 per pound; producers continue to hold published prices at $7.50.

Jan 1, 1977

By T. L. Turner, Daniel T. Rogers

As part of a program to investigate technology for the extraction of studied HNO3 alumina from abundant domestic ores , the Bureau of Mines leaching of calcined Georgia kaolinitic clay . In this investigation , iron impurities were removed from the aluminum nitrate pregnant leach liquor by solvent extraction , and the purified liquor was evaporated to prepare a suitably concentrated crystallizer feed liquor . Aluminum nitrate nonahydrate was crystallized from the liquor to separate the aluminum from undesirable trace elements and excess water . Continuous crystallization at 40 ° C in a pilot plant vacuum evaporative unit was performed for 5 days to observe the effects of impurity buildup under minimum bleed- stream conditions . Liquor feed rate was 26 lb/h and AAll (( NNOO33 )) 33..99HH22O0 ((AANNNN)) crystal production rate was 17 lb/h . Fe 203 and Cr203 were not effectively separated from the crystals , and P205 , MgO , and K20 impurities must be removed by recrystallization . Other impurities did not excessively contaminate the crystals . Washing the crystals with water or aqueous HNO3 gave an equivalent increase in crystal purity levels by displacing mother liquor . Theoretical equations , applicable to any continuous evaporative crystallization of developed to produce material balances for engineering ANN , were applications .

Jan 1, 1965

By J. P. Hansen

Wustite beds were reduced with carbon monoxide and mixtures of hydrogen and nitrogen in the temperature range 900° to 1,300° C to determine the effect of temperature, gas flow, and surface area on the rate of reduction to iron. The composition of the gas stream as it passed through the wustite bed was continuously measured with infrared absorption cells and heated-wire methods. The change in composition was used to calculate the reaction rates. Arrhenius plots of the data give heats of activation of 34 kcal for particles using CO, 27 kcal for particles using H2, 24 kcal for pellets using C8, and 6 kcal for pellets using H2. The velocity of reduction is dependent on the area of reacting interface and the driving potential of the gas (reducing gas concentration minus equilibrium concentration) as well as the exponential temperature effect. The reaction rate was independent of the gas velocity over the range of conditions studied.

Jan 1, 1965

Commodities statistics and otter information are available through the following t et systems: Internet Access: To acccess the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, enviromental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature of ash, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions~ issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor and, if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1956

By K. Shimamoto

This study has been prompted by the anticipated demand for rhenium by the petroleum industry and the concern for an adequate supply of rhenium to meet the demand. The present and projected outlook for rhenium relative to its distribution and occurrences, the recovery factors involved in ore beneficiation, capital and operating costs, changing technology, and the projected uses and market growth of rhenium are presented in this report as part of the Bureau of Mines program to determine the availability of recoverable rhenium in a developing market.

Jan 1, 1973

By W. H. Young

THE DOMEST[C bituminous coal and lignite industry remained fairly steady in 1959 compared with 1958. Although mechanization continued to expand and production increased slightly, consumption, average value, exports, and employment decreased. The percentage of underground production mechanically loaded, the percentage of total production mined by stripping, and tonnage per man per day were at their highest levels. Production.-The output of bituminous coal and lignite in 1959-412 million tons-was 0.4 percent greater than the 410.4 million tons produced in 1958. Production was retarded in 1959, largely owing to the steel strike and reduced exports.

Jan 1, 1960

By L. J. Prosser

The Bureau of Mines has completed an underground degasification project in which an underground piping system was used to transport methane from the coalbed to the surface. In a la-month period four horizontal holes were drilled to an average depth of 1,450 feet. All four holes were surveyed vertically and azimuthally. In 991 days of degasification, 255 MMcf of gas was drained from the coalbed. The underground piping system proved to be a safe and effective means of transporting methane from the coalbed to the surface.

Jan 1, 1981

By W. Beckering

In characterizing tars obtained by the low-temperature carbonization of North Dakota lignite, infrared spectra have been an invaluable aid in both qualitative and quantitative examination. Quite, early in the tar-research program of the Federal Bureau of Mines it became evident that the small number of published spectra available for hydroxy-aromatics would be inadequate for comparative purposes when dealing with the wide range of compounds present in coal tar; therefore, compiling a catalog of spectra was begun as a continuing part of the tar program. Because these spectra should be valuable to other investigators in this and related fields, they are being presented in these reports. This supplement to the original publications presents the spectra (figs, I to 32), representing 32 compounds, largely phenolic materials. The major problem of this project has been the availability of materials for examination. Most of the compounds included in this supplement were synthesized at the Bureau of Mines Lignite Research Laboratory. Some were obtained from commercial sources, whereas the compound 2'-hydroxy-l-phenylnaphthalene was synthesized at the Bureau of Mines laboratory in Bruceton, Pa. The spectrum of 2-ethyl-4-methylphenol, figure 32, is a correction of the spectrum presented as figure 26 in the original reports

Jan 1, 1961

By Edward L. McHugh

Twelve properties in the Riverside Mountains have moderate to high potential, for silver, gold, copper, and molybdenum. Six properties in the Big Maria Mountains have moderate potential for zinc, lead, copper, silver, iron ore, and limestone. The Big Maria Mountains also have occurrences of building stone. Four properties in or near the study area have low-grade gold-silver-copper resources totalling more than 300 thousand tons (270,000 t). An estimated 29 million tons (26 million t) of limestone and dolomite, and 620,000 long tons (630,000 t) of iron ore are in the Big Maria Mountains section of the study area. INTRODUCTION The Big Maria Mountains Wilderness Study Area covers about 50,538 acres (20,453 ha) near the Colorado River in eastern Riverside County, California (fig. 1). The study includes portions of both the Big Maria and Riverside Mountains. It lies north of Blythe, California and south of California Highway 62 in the Mojave Desert province of the California Desert Conservation Area. The study area consists of two mountain ranges surrounded mostly by broad alluvial slopes or bajadas. It extends for 25 mi (40 km) from the Riverside Mountains on the north, to the south end of the elongate Big Maria Mountains.

Jan 1, 1982

By P. C. McWilliams

The Bureau of Mines investigated ground support problems in four major block-cave mines to assess the current "state-of-the-art" and to delineate areas for future research. The most significant problem is the inability of present support systems to hold moving ground. Further, as mining progresses to greater depth, this problem becomes more serious. Providing adequate temporary support capable of withstanding primary and secondary blasting is the next most significant problem. A detailed analysis of the effect of mining methods on support problems is also recommended for future research.

Jan 1, 1975

By W. W. Adams

Three hundred and twenty-eight mines and quarries, representing 36 States, took part in the twelfth yearly accident-prevention contest conducted by the United States Bureau of Mines and known as the National Safety Competition. Four underground mines and one open-cut mine (which represents the quarry and open-cut mine group), each the leader in its group, were awarded the ?Sentinels of Safety? trophy. Relative standing in the contest" was determined by the number of days lost from accidents in proportion to the total number of man-hours worked. Since 1925, when the National Safety Competition was inaugurated, an increasing interest has been taken in it by mining and quarrying companies as a means of stimulating mine and quarry safety by competition among similar plants. Each participating plant can, on a basis of its standing and record in the contest, determine to what extent its safety program is succeeding or to what extent it needs strengthening. With this information, each company that has a low standing in the contest can intensify its safety-promotion efforts the following year to obtain a lower rate and possibly win the trophy or achieve honorable mention in the competition. Except for 1929, the National Safety Competition of 1936 represented more man-hours of employment than any other year since the yearly contests began.

Jan 1, 1937

By J. V. Batty

Various ores from deposits in the Boulder Dam Recreational Area, Clark County, Nev., were submitted for ore-dressing tests as part of the Bureau of Mines studies of western manganese ores. The Virgin River manganese deposit is situated on the Virgin River arm of Lake Mead, 5 miles from Bonelli's Point, which was formerly the junction of the Virgin and Colorado Rivers. It is 20 miles from Overton, Nev., and 26 miles from Boulder City, Nev. The ore body, composed of wadlike manganese in a tuffaceous gangue, is a flat-lying bed overlain with beds of gypsum and basalt. Two ore samples were submitted by engineers of the Bureau for ore-dressing investigation. Low-grade sample 1 was a composite of channel samples cut from outcrops of the ore body; sample 2, of intermediate manganese grade, was taken from the dump-at the exploratory shaft sunk by the Bureau. The Boulder City manganese deposit is situated in the Boulder Dam Recreational Area -3 miles southwest of Boulder City. The ore body is a manganiferous gypsum bed 32 feet thick, slightly inclined from the horizontal. The ore sample submitted-by engineers of the Bureau for-testing was taken from channel cuts in the walls of the shaft, which cuts through the bed vertically.

Jan 1, 1948

By C. Babcock

When a flat-lying mineral deposit such as a coal seam is mined, some coal is left to separate the roof and floor so that miners and machines can safely mine the seam. The mineral left is in the form of mine pillars. If too much is taken, support problems and unsafe working conditions result. If too little is taken, the mining operation will be unable to compete economically with other mines. Therefore, one must select pillars of the optimal size to maximize mining recovery and minimize risk to miners and equipment. Later, if the pillar support is no longer needed and the surface can be allowed to subside the thickness of the coal seam, then the pillar support can be removed to increase mining recovery, and initial pillar size is not as critical. Only a small part of the information available on pillar design can be presented here. The purpose of this report is to summarize some of the work done by the U.S. Bureau of Mines and others on pillar design, which is reported in the literature from 1833 to the present, and present rock mechanics test results that aid in understanding mine pillar behavior. The variable names used are those of the authors cited. This results in multiple use of some variable names.

Jan 1, 1994

By R. J. Leary

A small electronic digital computer employing punched cards has been used to facilitate the solution of a variety of problems in Bureau of Mines pyrometallurgical research. In this work the computer has been found to be economical for solving both simple problems that occur repeatedly and those involving complex or iterative calculations. Each of these classes of problems and their respective solutions are described. These small computers can be used effectively by researchers when they work in consultation with a computer specialist. Close team work produces the required solutions in less time, and, oftentimes, in a more useful form. Participation in programming by researchers develops in them a skill for evaluating the suitability of problems for electronic computing.

Jan 1, 1960

By J. Douglas Causey

In 1986 and 1987, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied 73,010 acres of the 76,480-acre Lower Owyhee Canyon Wilderness Study Area (OR-003-110) in order to evaluate its identified mineral resources. The study area is in Malheur County, OR, about 8 miles north of Rome. There are approximately 7.7 million tons of subeconomic zeolite (heulandite and/or clinoptilolite) resources with ammonia ion exchange capacities as high as 1.75 milliequivalents per gram in the Chalk Basin-Lambert Rocks area. The bed is 25 ft thick with less than 100 feet of overburden. This resource probably will not be mined in the foreseeable future.

Jan 1, 1989