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By M. S. Oudenhoven

The Bureau of Mines conducted an investigation to determine the theoretical stress distribution in the vicinity of explosively expanded rock bolt anchors independent of their bolts. Plane-strain solutions applicable to this problem were obtained by combining the field pressure with the uniform pressure that would be produced by vertically placed anchors having 2-, 3-, and 4-foot spacings. High rock stress which would be produced by an anchor was localized, as would be expected from St. Venant's effect, and increased as the field pressure decreased.

Jan 1, 1967

By Victor Kalcevic

A gas-flow retort for thermal processing of oil shale to recover shale oil was developed by the Bureau of Mines at its Oil-Shale Demonstration Plant, Rifle, Colo., from 1948 to 1952. The retort is a crossflow gas-to-broken-solids heat exchanger. The heating medium is the gas produced in the shale retorting process. The gas is heated in specially designed stoves outside the retort and recycled to the retort. Oil shale from the Mahogany ledge section of the Green River formation in northwestern Colorado was the material processed. Indicated maximum oil recoveries for 20-to 25-gallon-per-ton shale in a l2-inch-thick shale bed and a 20-inch bed are 96 and 91 weight-percent of Fischer assay, respectively. Heat requirements for maximum recovery are 600 to 750 B.t.u. per pound of shale. Properties of the recovered shale oil are affected slightly by shale-bed thickness and extent of retorting. Oil recovery from oil shales assaying over 30 gallons per ton is lower than that from leaner shales.

Jan 1, 1959

By C. H. Elder

Two degasification test boreholes were drilled to depths of 1,238 and 1,212 feet on Bureau of Mines property at Bruceton, Pa., as part of the Bureau's long-range coal degasification program. The holes provided detailed geologic information and geologic sections, which were correlated with regional stratigraphic cross sections prepared by the Pennsylvania Geological Survey. Gas content determinations and coal analyses were made on the Upper Freeport, Middle Kittanning, Clarion, Brookville, and Mercer coalbeds; gas content of the coalbeds ranged from 53 to 165 cubic feet per ton. Formation pressure and gas flow tests were conducted on selected coalbed intervals in borehole 1; formation pressures ranged from 292 to 473 psig. The middle Kittanning coalbed was hydraulically stimulated using very heavy gelled water, but gas production remained low because gel residue and formation water inhibited the flow of gas. Gas contents in the Clarion, Upper Brookville, and Mercer coalbeds were anomalously low owing to the proximity of porous sand-stones which act as reservoirs for gas migrating from coalbeds.

Jan 1, 1977

By Paul M. Tyler, Amy B. CLINTON

The four elements fluorine (F), chlorine (C1), bromine (Br), and iodine (I) form the most intimate family in the entire system of elements and are grouped under the name "halogens" or salt formers (by derivation from the Greek). The first member of this family, fluorine, is the most chemically active element known; and fluorspar, and to a less extent cryolite, the chief sources of fluorine, are important commercial minerals. Fluorine occurs in nature chiefly in combination with sodium as common salt, but it also appears in other natural compounds in sea water, salt-well brines, and bedded deposits. In addition to common salt, various compounds containing chlorine (chlorides) have long been consumed by industry on a large scale, and within the last two decades that element itself has come rapidly into prominence as one of the leading industrial chemicals. Bromine and iodine, the two retaining members of the family, are less abundant in nature and less readily isolated and in consequence of their relatively high price have found few industrial uses, being consumed chiefly in medicine and in photography. Bromine, however, is now entering the industrial field to a considerable extent, due to the rapidly growing use of ethylene dibromide in anti-knock compounds for gasoline. The present paper is devoted to bromine and iodine, but in order to compre- hend the physical and chemical characteristics of these two elements (and hence their potential economic significance) it is convenient to consider them as members of the family series to which they belong. The family relationship of the halogens is illustrated by the following:4 (1) The similarity in the chemical and physical properties of the elements and their corresponding compounds is such that the prop- erties of any one member of the family can be said to summarize or rather to typify the properties of all the other members, although fluorine diverges a little in some of its properties. (2) The gradual transition of chemical and physical properties is such that if the elementa are arranged in order F, Cl, Br, I the variation in any particular property in passing from fluorine to iodine nearly always proceeds in the same order, and that is the order of their atomic weight. Taxing almost any property and comparing its magnitude in passing from the element fluorine to iodine, or from the fluorides to the iodides, a similar graiation will be observed. Thus, take the melting point of the cadmium, calcium, barium, sodium, or potassium salts, in degrees.

Nov 1, 1930

By M. E. Tyrrell

Mixtures of zirconium diboride and iron, cobalt, and nickel were resistance sintered to high-density compacts using modified electric welding equipment. To evaluate the use of iron, cobalt, or nickel as binders for zirconium diboride, the sintered compacts were examined in polished section and tested for crushing strength, hardness, microhardness, oxidation rate, and resistance to mechanical shock. Each of the zirconium diboride-metal mixtures produced brittle cermets, but the hardness was generally satisfactory. The iron- and cobalt-bonded cermets exhibited rather poor oxidation resistance. Cobalt provided the least brittle bond, and nickel, the hardest and most resistant to oxidation. Iron tended to form chalky compacts with low resistance to mechanical shock.

Jan 1, 1963

By Donald W. Mitchell

Certification tests for urethane-foam systems and techniques for apply-ing foam safely in mines are described. Fire hazard from foam exists if flame propagates beyond the ignition source or penetrates the foam. Foam that passes the certification tests can be applied on stoppings, continuous sections of ribs of relatively wide passageways (with no foam on the roof), short sections of roof such as overcasts, roof cavities, and intersections (with no foam on the ribs), and between buntons on one wall of a shaft. Foam on the ribs and adjoining roof presents a fire hazard. Stoppings covered with foam passing the certification tests are resistant to penetration of heat, flame, and smoke than similar stopping without foam. Flame propagation can be arrested by water sprays. Spontaneous ignition of foam can be prevented.

Jan 1, 1966

By W. M. Myers

Water has been commonly used as a collecting medium in many instruments employed in the sampling of dusty atmospheres in mines** add industrial plants, and for this purpose has much to recommend it, particularly the following factors:1.,Water is a very efficient dust collector.2.,Distilled water of great purity may be readily obtained at slight expense. The analytical error introduced by the extremely small amount of foreign matter in carefully distilled water is very small,3.,Water is a very convenient medium with which to work as all the analytical operations of diluting, aliquoting, and filtering are readily and speedily carried out. Water has therefore been used extensively in such instruments as the Palmer apparatus, the Greenburg-Smith impinger, and the dust collector recently described by Drinker, Thompson, and Fitchet. The Bureau of Mines has conducted investigations in many metal-mining districts of the country, determining of dust the nature and amount of dust present in working places, its effect the health of workers, and what precautions may be taken to decrease the hazard of exposure to dangerous dusts. The Bureau is therefore interested in any factor that affects the accuracy of dust sampling.

Nov 1, 1923

By Scott Turner

Within recent years , people have begun to realize the importance and significance of the mining and allied industries . The leading part the engineer plays in civilization is becoming recognized . However , accurate quantitative knowledge of the industrial importance of mining is still seldom possessed except by those close to this business . It is true that there are a few who go to the extreme and represent the whole progress of civilization as a reflection of man's gradual mastery of mineral utilization , but on the whole , the magnitude of the industry is underestimated . The uncertainties of mining , as evidenced by the variable results of prospecting on surface or underground , in an unknown new field or from the bottom levels of a mature mine , the ins and outs of tonnages and metal contents , the possibility of a widespread or even a sudden change between cost and realization-price , add to its picturesqueness and make mining attractive to some . To many , the fact that results are generally more uncertain and less predictable than in other industries lends added charm . The following pages may serve to call attention briefly to the importance of mining relative to other industries in the United States , in Canada , and in the world . Ordinarily , the annual primary mineral production of the United States amounts to about 5 billion dollars . The average for the last five years has been a little over 5 billion dollars . Last year , sadly enough , it was less than 34 billions . Just now , we are on the decline , and have been for the past two years . In Canada , the 5-year average was about 268 million dollars . Last year it was 227 million . Due in part to gold output ( in 1930 , for the first time , Canada's gold production exceeded that of the United States ) , the Canadian average is holding up better than ours . It has been estimated that the average world mineral production over the past five years has amounted to about 12 billion dollars , while in 1931 it was less than 8 billions . The mineral industries are as indispensable for the conduct of modern society as are those of agriculture , but , in the United States at least , they receive far less recognition from the Government . With us , agriculture is fostered by a great department that is maintained by enormous appropriations , while the mineral industries get but little financial support . In the United States , in the calendar year 1930 , the value of production by these two industries were as follows : to 1 . Agriculture ( inclusive of forestry ) 9.9 billion dollars ; mining 4.8 billions ; ratio 2 Direct appropriations by our Federal Government were 109 million dollars to agriculture and 2.8 million to mining , a ratio of 39 to 1. Obviously this is out of balance to the extent of 19 to 1 in favor of agriculture .

Jun 1, 1932

By James C. Barker

Alluvial cassiterite concentrations are widespread in river gravel and high level terraces within the Ray River watershed. The area lies in unglaciated terrain of Alaska's northern interior. Cassiterite originates from several calc-alkaline plutons of the Ruby batholith. Extensional stresses resulted in graben-like Tertiary basins that were flooded by a 200 ft thick section of mid-to late- Tertiary basalt flows. Basalt blocked local drainages, and 50- to 100-ft of terrace gravel was eventually deposited on top of the flows. Further downwarping and eventual fluvial downcutting of the flows resulted in cycles of accelerated sediment transport, deposition, and reconcentration. Repeated erosional cycles concentrated heavy minerals and resulted in development of tin placers. Preliminary resource estimates of contained tin in Recent alluvium range from 62 to as much as 172 million lbs-Sn in 300 million yd3. Grade of about 90% of the gravels is estimated to range between 0.2- to 0.5- lbs-Sn/yd3. Associated gold and rare earth elements (REE) in monazite and xenotime may be recoverable. Most of the tin is considered a subeconomic inferred resource, though, at least some of the gravels contain 2-to 6-lbs-sn/yd3. Estimates are projected on the basis of surface sampling and several auger drill holes and are provided for the purpose of land-use management planning.

Jan 1, 2011

By Robert L. Marovelli

The thermal conductivities of six rocks were measured by the transient line source method over the temperature range of -850 to 1,500° F. Close-fitting ceramic probes were used in 0.065-inch-diameter holes drilled through 5-to 6-inch-thick rock specimens. Taconite, granite, quartzite, and basalt were used in the tests. The method yields absolute data and is applicable to both laboratory and in situ measurements.

Jan 1, 1965

By Terry S. Cory

This report covers magnetic field strength measurements vs range and frequency in low-medium coal mines. Both quasi-conductor-free and conductor-proximity areas were investigated. The program covered 5 mines, 4 seams, 6 measurement sets, and 3 geographic areas. The results have been summarized in terms of maximum communication range expected per seam and noise condition. Scatter gain is further explored as a simple measure of energy coupled to conductors.

Jan 6, 1978

By H. S. Caldwell

The objective of this investigation by the Bureau of Mines was to develop and test for laboratory use a retort embodying many features required for practical commercial-scale applications of vacuum distillation of metals. A gas-fired vacuum retort was developed comprising a hollow, cylindrical graphite liner encased in a thin shell of stainless steel. The liner prevents the shell from collapsing under vacuum and protects it from corrosion by metal vapors and the molten metal charge. The vacuum-tight shell protects the liner from oxidation and flame erosion. The retort was used to distill zinc from dross and die-casting scrap. More than 99 percent of the zinc was recovered as a condensate containing 99.8 to 99.9 percent zinc. (Atmospheric distillation recovers 95 to 98 percent at a purity of 99.5 percent zinc.) Distillation rates of 50 pounds of zinc per hour were attained at a temperature of 65° C. with pressures ranging between 50 and 100 microns. Distillation at this low temperature is not practicable at atmospheric pressure. Also, the retort is suitable for distilling other volatile metals such as cadmium and magnesium.

Jan 1, 1961

By A. M. Gaudin

A study of the consumption of reagents used in flotation gives useful data as to the market which employment of the flotation process creates for the manufacturers of the necessary chemicals and oils, and furnishes a useful clue to the trends in flotation practice influencing the choice of reagents used and the' extent to which new reagents are displacing less suitable older reagents. In the present investigation an attempt has been made to cover both of these phases of the consumption of reagents in flotation. Unfortunately, however, the data collected in tie various districts have not been equally informative; some operators have reported very completely both the consumption of reagents and the metallurgical results obtained therewith, while others were apparently unable to supply these figures in sufficient detail to meet the requirements of this investigation. RESULTS OF INVESTIGATION Table 1 gives the tonnage of ore treated by flotation, as reported. This table shows that flotation has been most largely used in the concentration of copper ores, next in complex lead-zinc ores, followed by lead ores, zinc ores, miscellaneous ores, and copper-iron ores.

Jan 1, 1929

By Jack D. Ramsdell

The objective of this investigation was to make a preliminary evaluation of titanium-vanadium-zirconium, alloys using room-temperature tensile properties as criteria for selecting promising alloys for future critical studies. Arc-melted titanium-vanadium-zirconium alloys ranging in composition from 5 to 20 a/o (atomic-percent) vanadium and 5 to 30 a/o zirconium, were investigated to evaluate hardness, hot workability, and room-temperature tensile properties. Metallographic examination coupled with hardness measurements were used to follow structural changes and aging response. Room-temperature tensile properties were criteria for evaluating mechanical and engineering properties of the alloys.

Jan 1, 1960

By Alton B. Cook

The practice of using partly depleted oil reservoirs for gas-storage operations is proving successful. Moreover, this practice provides a method of secondary oil recovery when gas is cycled at full-storage reservoir pressure. Because of the relative newness of this operation, a study was undertaken to assist engineers in developing improved gas-injection and production procedures and in calculating the amount of gas needed for completely repressuring reservoirs. This paper is the third in a series reporting the progress of a study by the Federal Bureau of Mines of reservoir performance during complete gas repressuring and gas cycling. A procedure for estimating secondary oil recovery by this method is also under study. One report (7)3/ describes the laboratory equipment. The other report (8) gives (1) data on the New York City field, Clay County, Tex., which has been converted to gas-storage operations; (2) laboratory data from research with a model oil reservoir, in which primary production, complete gas repressuring, and gas cycling for the New York City field were simulated; and (3) theory to explain reservoir performance during gas repressuring.

Jan 1, 1961

By Ned H. Snyder

In recent years the Government and other large consumers of coal have appreciated more and more the desirability of definitely determining by chemical analysis and test the character and quality of the coal they purchase. Higher prices for coal point forcibly to the need of giving more study to engine room and boiler room efficiencies and economies; this implies an intimate knowledge of the character and quality of the fuel used. Analyses and tests of delivered coal furnish data whereby power plant results can be comprehensively studied and a continuous check maintained on the coal and on the conditions of plant operation. Under authority of acts of Congress making appropriations for technologic investigation of fuels and the analyzing and testing of fuels belonging to or for the use of the United States Government, a laboratory is maintained at the Pittsburgh station of the Bureau of Mines, where samples representing deliveries of coal purchased for Government use are analyzed and tested. The Bureau of Mines has been active in promoting the purchase of coal by the Government under specifications/ that is, by contracts that make definite requirements regarding the heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analysis. Under many of these specification contracts the bidders guarantee the quality of the coal offered, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled and analyzed to determine whether the coal is of the quality guaranteed by the contractor, and if it is not, the price to be paid is decreased in proportion; but if the coal is of higher quality, the price is proportionately increased. The known analyses of coals or the guaranteed analyses offered by the bidders may sometimes be used for determining the award of a contract, but if the coals offered differ widely in characteristics, it may be difficult to determine which would prove the cheapest fuel without data on their relative evaporative efficiencies. Hence, the making of evaporative tests under service conditions may be necessary in order to determine which coal is particularly adapted for successful and economical use in a certain plant. Once a particular coal is selected, however, regardless of the procedure of determining the award of a contract, then the greatest advantage of the specification method is realized, for it guarantees the purchaser receiving coal of uniform character and quality, thereby insuring the best results in the plant. The success of the specification method for the purchase of coal and the reliability of analysis now rests largely on sampling.3 Improper sampling leads to controversies, with resulting condemnation of the specification method in general and of the value of laboratory analyses and tests in particular.

Jan 1, 1922

This summary of State laws on explosives was compiled primarily to ascertain what subjects relating to their control have been acted upon by each State legislature and, in general, how they have been treated. It does not include any legislation passed after 1942, or any proclamations, regulations, or administrative orders. It does not purport or attempt to be authoritative. If any problem arises involving interpretation of the statutes of any particular State, the original source must be consulted for the exact words used by the legislature. This summary, however, will be useful in determining whether relevant statutes exist, and in locating them quickly with a minimum of effort. It will be of value also in comparing statutes in one State with similar statutes in other States to determine what construction has been placed upon them by the courts of these jurisdictions or to contrast the varying provisions of many States upon a similar subject. To make these comparisons easier, the statutory provisions for each State have been grouped under several major topics in outline form. Although this sometimes has resulted in disruption of the continuity of individual acts, the increased general clarity and availability of comparable sections have more than justified the procedure followed.

Jan 1, 1943

By G. L. Neumann

"INTRODUCTION Mining in this area is inactive. The entire region is now comprised of small farms. Because approximately 1,500,000 tons of magnetite ore had been shipped from this area between 1855 and 1915, it was deemed probable that geophysical surveying and core drilling might indicate other ore bodies or sizable extensions of the previously mined ore bodies.ACKNOWLEDGEMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has, as its primary objective, the most effective utilization of our mineral resources, thus fortifying our national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiatien tests.The chemical analyses and beneficiation tests included in this report were performed at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and the immediate direction of Dr. Alton Gabriel, head of the laboratory service unit.The Mineral exploration Was under the general supervision successively of G. D. Jermain, district engineer, C. B. White, district engineer, and McHenry Mosier, chief, College Park Division, Mining Branch.The geophysical section of the exploration was performed by G. B. Botsford, engineer of the Bureau of Mines. Assistance was given by the Division of Geophysical Exploration of the Bureau of Mines, Dr. F. W. Leo, chief."

Dec 1, 1947

By Robert J. Hundhausen, GEORGE M. GRISMER

This circular describes the methods and costs of deepening the Silver Summit three-compartment shaft in the Coeur d'Alene mining region of Idaho. A noteworthy rate of advance was achieved at this operation by the successful use of a mechanical shaft-mucking machine. The Silver Summit mine is 1 mile west from the town of Osburn, Idaho, via U. S. Highway 10. The adit-level portal of the mine is on the south slope of the Coeur d'Alene River Valley at an altitude of 2,700 feet. The Silver Summit shaft is 6,000 feet from the portal. In past years this shaft had been sunk from the adit level to a depth of 1,500 feet. During 1946 the Polaris Mining Co, deepened it to 3,095 feet. The work was done under a co- operative development agreement between the Silver Summit Mining Co. and the Polaris Mining Co.

Jan 1, 1948

In 2001, a total of 2,144 coal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Coal mines comprised 14.7% of all mining operations. • Bituminous mines comprised 92.0% (n=1,972) and anthracite mines 8.0% (n=172) of coal mining operations. • More than 71% of coal mines were located in three states: Kentucky (29.5%), West Virginia (21.3%), and Pennsylvania (20.6%).

Apr 1, 2003