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By A. R. Taylor

Using solution calorimetry, the following heats of reaction were determined: (1) NaCN(c) + 1/Cu20(c) + 129H20(l) ? CuCN(c) + NaOH?128.5H2O ?H = -13.44±0.10 kcal/mole, (2) HCN(2) + NaOH?128.5H20 ? NaCN(c) + 129.5H20(l) ? = -2.52±0.02 kcal/mole. From these reactions, the heats of formation for CuCN(c) and HCN(2) were calculated to be 22.7±0.4 kcal/mole and 24.9±0.4 kcal/mole, respectively. Reaction 2 was made to check the consistency of literature values for heats of formation of HCN and NaCN. Adiabatic calorimetric measurements between 10° and 400° K showed the entropy and heat capacity of CuCN(c) to be 21.51±0.06 eu and 14.58±0.04 cal/mole deg, respectively, at 298° K. A broad anomaly in the heat capacity was found in the temperature range 285°-320° K. The heat of transition associated with this anomaly was less than 1 cal/mole, the sensitivity of the measurements.

Jan 1, 1971

Volumetric measures [ ]

Jan 1, 1962

By W. P. Yant, G. W. Jones

During the testing of porcelain insulators with a " 60 - cycle flash - over apparatus " , gases are liberated having an odor greatly resembling that of ozone . Since the two main constituents of normal air are nitrogen and oxygen , and high voltages (approximately 90,000 volts ) are used during the tests , the conditions are favorable for the production of ozone or oxides of nitrogen , and perhaps both simultaneously . The presence of these gases is only noticeable during the testing period . They soon disappear after the test is over . No fatalities have ever resulted from these gases at the plant visited nor are there any records of any of the men who worked on the tests being confined to their homes from this cause . New employees sometimes complain of a depressed feeling and shortness of breath , which is most noticeable after leaving work and getting into fresh air , but they som become accustomed to it and no ill effects are noticed . In view of previous work*** which the Bureau of Mines has done on oxides of nitrogen in connection with mine gases and problems in gas analysis , tests were made at the plant of the Westinghouse High Voltage Insulator Company at Derry , Pa . to determine the kind and amount of gases liberated .

Jun 1, 1923

The largest producing coal field in Alabama, the Warrior Coal Field, was discovered in 1821'. Since then, coal has become Alabama's leading industrial mineral, both in production and income. Alabama has traditionally been one of the nation's major coal-producing states. This level of production is expected to continue due to Alabama's high-quality, low-sulfur coal. Alabama produces both bituminous and lignite coal. The bituminous coal is mined by underground and surface methods from four major coal fields in 24 counties. Alabama's lignite deposits, which are located in the southern part of the state, are not presently being mined. However, Alabama lignite is high-grade, and deposits are very shallow and easily surface-mined. Alabama gained primacy when its regulatory program was conditionally approved May 20, 1982. The program was fully approved July 5,1984. Alabama's Abandoned Mine Lands program was approved May 20,1982, and its emergency program was approved January 23, 1991. Although a Federal Lands Cooperative Agreement between Alabama and OSM became effective August 30,1985, no coal mining is currently taking place on federal lands in the state.9

Jan 1, 1992

By R. V. Ramani, P. M. T. White, D. Sutton

1.1 General The examination and evaluation of a mineral deposit to determine whether or not it can be profitably exploited entails many factors unrelated to the physical nature and intrinsic worth of that deposit. Nevertheless, geology and geologically related factors have great bearing on the economic potential of the deposit. This is only natural because the deposit owes its existence to these factors. This is even more so in underground mines where the whole system is a geologically enclosed one. Geology plays a major role in at least four phases of a mineral venture. Firstly, it acts as an indicator of the existence of parti¬cular minerals. For example, it is inconceivable that a sedimentary coal deposit would exist in a granitic batholith or stock, or that a sandstone would host primary copper or nickel sulphides. Further, the positional relationship of different rock types may be significant in locating deposits such as replacement zinc and copper sulphides in limestones which have been intruded by igneous rocks. Thus, geology is important in the exploration phase of a mineral deposit. Secondly, once potentially valuable minerals have been discovered, knowledge of geology plays a significant role in determining the dis¬tribution, grade and extent of the mineralization. Controls on mineralization include one or all of those related to structure, rock type, sedimentary features, post-depositional redistribution, etc. Con¬sequently, in order to effectively evaluate a deposit in terms of

Jan 1, 1974

By R. C. Wang, W. M. McKewan

The behaviour of wire ropes used in mine hoisting is not well understood. In an effort to improve this understanding, the structure of round-strand wire ropes was analysed. This report provides a generalised mathematical model that completely describes the geometry of the wires. It consists of two sets of vector equations and is valid for any round-strand wire rope. One set of equations is used to trace the paths of wires that have the form of a single helix. The other is used for the paths of double helical wires. The specific model for a 33-mm 6x1 9 Seale, IWRC, right regular lay wire rope was presented as an example. The paths and the geometric properties of the wires which include the path length per lay of strand, the curvature, and the torsion were determined from this model. In future work, the model could be used to conduct stress analysis for the wires in the deformed rope at a given rope strain and also to study the effect of wear and breaking of wires on strength loss for the various round-strand wire ropes used in mine hoisting.

In this U.S. Bureau of Mines report, proposed narrow-vein and longwall mining concepts using drill-split technology (described in part 1 of this series) and in situ liner concepts (described in part 2 of the series) are combined and applied conceptually to environmental problems. Proposed applications deal with (1) acid mine drainage (AMD), (2) solid waste disposal, (3) site remediation, and (4) pollution prevention through innovative industrial design. For control of AMD from abandoned hillside mine workings, it is proposed that source veins be re-mined, processed for residual values, then backfilled using an impermeable compound backfill mix. For solid waste disposal, "vertical landfills" are proposed, consisting of trash-backfilled underground rock quarries. Vertical landfill activities take place in in situ lined containments that geohydrologically isolate the mining-backfilling activities. Site remediation through the creation of in situ underliners, for the capture of toxic leachates, and pollution prevention through the underground storage of toxic, flammable, and explosive materials in in situ containments, are proposed.

Jan 1, 1995

By Russell C. Frith, David C. Oyler, Dolinar Dennis R., Christopher Mark

Unusual circumstances may require that a longwall retreat into or through a previously driven room. The operation can be completed successfully, but there have been a number of spectacular failures. To help determine what factors contribute to such failures, a comprehensive international database of 131 case histories has been compiled. The cases include six failures where major rock falls occurred in front of the shields, and seven even more serious failures involving major overburden weighting. The case studies suggest two types of room failure mechanism. The first is a roof fall type failure caused by loading of the immediate roof at the face as the fender or remnant longwall panel narrows. The second is an overburden weighting type failure caused by the inability of the roof to bridge the recovery room and face area, and affecting rockwell above the immediate roof. The data indicate that the roof fall type of failure is less likely when intensive roof reinforcement (bolts, cables and trusses) is employed together with higher-capacity shields. The overburden weighting failures, in contrast, occurred when the roof was weak and little standing support was used. Weighting failures were not greatly affected by the density of roof reinforcement. In one of the overburden weighting cases, in a Pittsburgh coal bed mine, stress cell, convergence, bolt load and extensometer data have been used to analyze the failure in detail. Key words: coal mining, ground control, longwall, recovery room.

By D. J. Bauer

Solvent extraction techniques were used to determine the extraction sequence of yttrium and the rare-earth elements in an amine solvent extraction system. Single-stage extraction with Primene 81-R resulted in separation factors of 3.8 between yttrium and dysprosium and 25 between yttrium and cerium. Yttrium was concentrated in the aqueous phase. EDTA and DTPA, as aqueous phase counterextractants, enhance separation factors in mine-rare-earth sulfate systems. Yttrium separation from heavy rare-earth elements exhibits marked sensitivity to the position of yttrium in the selectivity scale of the rare-earth elements with the sequestrants. Yttrium-ytterbium separation is more effective with EDTA, whereas yttrium-dysprosium separation is more effectively increased with DTPA.

Jan 1, 1963

By Donald A. Wilson

As part of a continuing effort to maximize metal recovery from domestic secondary resources, the Bureau of Mines investigated a process for recovering the metallic portion of scrap alkaline batteries. A pyrometallurgical method for recovering nickel and cadmium from Ni-Cd scrap batteries previously developed on a laboratory scale, was scaled up to 25-and 43-pound charges. The method employed reduction and/or decomposition in a retort using a minimum of 2.5 percent carbon as a reductant. Metallic cadmium was distilled at atmospheric pressure and a minimum of 900° C. Purity of the recovered cadmium was 99.8 percent minimum and the nickel-iron residue contained less than 0.02 percent cadmium.

Jan 1, 1981

By James M. Spear

The U.S. Bureau of Mines and the U.S. Geological Survey conducted a mineral survey of the Black Butte RARE (I area during the summer of 1981. The study area encompasses 17,800 acres [27.8 sq mi (7,233 ha)] along the course of the Black Butte River, 13 mi (22 km) southeast of Covello, California. No mineral deposits were identified by the U.S. Bureau of Mines during this survey. Assay results of samples taken in this area indicate only trace amounts of manganese, chromium, and nickel. No radioactive or fluorescent minerals were detected. No oil and gas, coal, or geothermal leases have been recorded for the study area.

Jan 1, 1982

By A. B. Hooker

Nineteen of the installations were on rental contracts 1.L."'1der whtch the lamps belong to the lamp company and are rented by t.½em to the mine operatj.nt; company. · The other nine installations had been upon an O\Vnership-rental basis, by which the lamps had become the property of the renter at the end of 5 years. Five of t.11e rentec installations were en a special contract calling for a guaranteed light output. These contr2.cts were based upon certified . initial performance, with the provision that the lamps be replaced whenever periodic tests of fully charged lamps, taken at random from t..h.e charge racks, showed a light output of less than 80 percent of the certified performance.

Jan 1, 1942

By H. H. Schrenk

"One phase of the Bureau of Mines' work in the field of health and safety is the promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To promote the development of such devices the Bureau has established schedules of minimum requirements for oxygen breathing apparatus3/ gas masks/, supplied-air respirators5/ (hose masks, airline respirators, and abrasive blasting helmets, hoods, or masks), and mechanical-filter respirators6/.Manufacturers of respiratory protective devices may submit their equipment to the Bureau for approval under the requirements of these schedules.As a prerequisite to such submittal, the Bureau requires a statement that the device is completely developed and of the design and material the manufacturer believes suitable for a finished marketable device; that the device has been subjected to inspections and tests such as described in the schedules, and that it met those requirements when tested by the manufacturer or his testing agency; and a. statement regarding the nature, adequacy, and continuity of control of the quality of the respirator. If the manufacturer can satisfy these requirements, and if the device, when tested by the Bureau, meets its requirements, a certificate of approval is granted by the Bureau of Mines. The approved devices bear distinguishing marks that indicate that they have been approved, the purpose for which they are approved, and the limitations of their use. If it is found at any time that approved devices purchased in the oven market and tested do not meet the requirements of the schedule, the Bureau may rescind that approval. Lists7/ of approved devices are published periodically for the convenient information of the public.Respiratory equipment may be divided into two main groups: (1). Those that afford protection by removing atmospheric contaminants and (2) those by which a respirable atmosphere from an uncontaminated source is supplied to the wearer.The devices that protect by the removal of contaminants may be divided into two subgroups: (1) Those that protect against gaseous contaminants and (2) those that protect against particulate matter. There may, of course, be combinations of these two.The devices by which a respirable atmosphere is furnished to the wearer also may be divided into two subgroups: (1) The self-contained type, by which the supply of oxygen, or material from which the oxygen can be generated is carried by the wearer, and (2) the hose type, by which air is supplied to the wearer through a hose or tube."

Sep 1, 1939

By E. P. Youngman

The law of June 5, 1911, suplements and amends the Laws of April 21, 1810 (the basic law) and May 2, 1837. The Royal Decree of September 15, 1919, coordinates the provisions of the Law of June 5, 1911, with those of the Laws of April 21, 1810, of May 2, 1837, and of July 8, 1865, that have remained in force, as well as with certain articles of the Law of September 1, 1913, which revisad the system of taxation. The revised code has been brought together in one volume.3 All citations in this abstract refer to the coordinating Royal Decree of September 15, 1919, unless it is otherwise specifically indicated.

May 1, 1930

Design a model health and safety program which, when implemented, can improve mine safety by reducing occupational injuries and accidents. Approach The Bureau of Mines developed a model program which identifies the elements essential to the effectiveness of health and safety programs designed for mining operations, and is readily adaptable to all types of sizes of mines. The model program primarily provides training on loss control and accident investigation and technical assistance with health and safety problems. In order to assess the effectiveness of the program, it was tested at both a coal and gold mining operation. Monthly statistics were generated to reflect the number of occupational injuries and accidents, and the severity of injuries (as measured by the number of work days lost during recovery). Observations were made of employees performing a large number of randomly selected jobs in order to estimate. the proportion of the workforce that was working in the presence of one or more of three types of safety deficiencies: Type A-individual job performance deficiencies which could be corrected by the employee alone I e.g., an employee is seen not wearing a seatbelt.

Jan 1, 1986

By Harry R. Nicholls

As part of the pre- and post - shot mine examination at Project GNOME , acceleration data were recorded underground from a series of chemical explosive shots . The cube root of the charge weight was used to scale acceleration and distance because charge weight was not constant . Regression analysis of particle acceleration - distance data gave the following propagation equation : A W1 /3 = 5.10 x 105 ( R / W¹ / 3 ) −2 .43 The quantity A W1 /3 is scaled particle acceleration expressed in g's - lbs¹ / 3 , and R/W1 /3 is scaled distance expressed in ft / lbs¹ /3 Data obtained from the nuclear explosion were scaled and fall within one standard deviation of the calculated propagation law for the smaller shots . Cube root scaling laws were adequate to group acceleration data from explosive charges varying by a factor of more than 1 x 10 in charge weight and over shot - to - gage distances varying from 100 to 46,000 feet . Data obtained from a series of small tests provided sufficient data from which reliable predictions of acceleration could be made for the large nuclear explosion .

Jan 1, 1964

By M. J. Spendlove, P. P. Zapponi

"INTRODUCTION In carbothermic processes for the production of magnesium, magnesium oxide is reduced by carbon according to the following equation:(1) MgO + C = Mg(g) + CO.The reaction is virtually complete at temperatures above 2,000° C. but reverses rapidly at somewhat lower temperatures. To produce magnesium by this reaction, therefore, it is necessary to cool the gas very rapidly to a temperature at which the rate of the reverse reaction becomes negligible. Several media for quenching the gas have been proposed, among which are hydrogen, natural gas, liquid hydrocarbons, and molten metals of low melting point.The results of a preliminary investigation on the use of molten lead as the quenching medium are summarized in this report. The work was done in 1941, when the threat of war made it imperative to investigate every process that offered possibilities for rapid expansion of domestic production of magnesium. Although the results were encouraging, other processes appeared to offer better prospects for immediate wartime development, so the work was not continued. Shortly before the investigation was completed, several patents on the use of low-melting metals for absorption of magnesium vapors appeared, 4/"

Jun 1, 1947

By R. T. Stull, L. E. Geyer

"Previous Work:As outlined in previous papers* ond clays for graphite crucibles have been tested at the plants of the Detroit Lubricator Co., and the Detroit Copper and Brass Rolling Mills, Detroit, Mich.These tests indicated that there were two American clays (Missouri pot clay and Illinois kaolin) that tested better than the Klingenberg (German) clay. Dorset (English) ball clay was tenth in the list.Making the Crucibles:After it had been determined that American clays can be used successfully in graphite crucible manufacture and service, the next step in the investigation was to determine the value of American graphites as compared to the foreign, These final tests were carried out at the plant of the Detroit Lubricator Co., through the courtesy of Mr. G. B. Duffield. The crucibles, as previously. were made at the plant of the Vesuvius Crucible Co., Swissvale, Penna., from a formula compiled by the Bureau of Mines and under the supervision of Bureau engineers.The graphites to be tested were given an initial to indicate their source. The number of crucibles made and shipped are set forth in Table 1."

Nov 1, 1923

The U.S. Department of Labor?s Mine Safety and Health Administration (MSHA),through its winter alert program, warns U.S. mine operators and miners at underground coal mines of workplace hazards that can arise when the weather turns colder. MSHA records indicate that, historically, most explosions in underground coal mines occur during winter months. ?The changes in weather can increase the risk of fatal accidents,? says David G. Dye, Acting Assistant Secretary of Labor for Mine Safety and Health. ?Each miner and mine operator must take individual responsibility to eliminate the kinds of hazards that can cause fatal accidents in the workplace. Safety is not the other guy?s job?safety begins with you.? In fact, MSHA?s slogan for this year?s campaign is ?Winter Alert Starts Now and Safety Begins with YOU.? This message reminds miners and mine operators of the risks of colder weather and educates them about helping to reduce risks and hazards. ?Safety requires the joint effort of both management and labor,? Dye says. ?Everyone at the mine site must see safety as an individual value and act to ensure a safe working environment.?

Jan 1, 2006

By Murray Weintraub

The Bureau of Mines investigated the aerodynamic factors that control the functioning of the blowcase devices used in pneumatic processes for dispersing solids. Alumina powder of 8-micron mass-mean diameter was placed in 0.75- inch-diameter by 10-inch-long cylinders} and a blowcase technique was employed. It was determined that dimensions and gas rates for discharging the powder from the cylinder by a stream of gas may be calculated by assuming a fluidization mechanism and extrapolating residues to a desired finite quantity or to zero at the terminal velocity. The state of agglomeration of a powder at discharge may be determined from measurements of the velocity required for zero residue.

Jan 1, 1967