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By Henry M. Harris, Hal J. Kelly

Electrical dewatering tests are described in which the laboratory cells were designed for continuous operation using an endless metal belt as the anode . The test slurries were dilute , containing from 2.5 to 14.4 percent solids (specific gravity of 1.02 to 1.10 ) that were all minus 8 microns in size . Recovery of the solids of low water content was the practical objective of the investigation . Process variables evaluated and reported are : The effect of feed rate , amount of electrolyte , samples from different sources , and the use of two cells in series . These variables are evaluated on the basis of yield of clay per kilowatt - hour , recovery , and the amount of solids in the deposited clay . Recovery , yield , and solid content of the belt anode product are interdependent , and changes that will improve one of these characteristics often are accomplished at the expense of the others . Tests in which recoveries range from 50 to 60 percent usually result in yields of 8 to 9 kilograms (kg ) of dry clay per kilowatt- hour (kwhr ) . Under these conditions , the solid content of the deposited clay approximates 50 percent . One test sample , composed of kaolinite , showed very high yield , 13 to 16 kg per kwhr ; high recovery , 53 to 58 percent ; and 52 to 54 percent solids in the cake .

Jan 1, 1964

By George W. Heim

Before and during World War II, the Bureau of Mines investigated a large number of ore deposits in the United States and Alaska in a search for domestic sources of strategic minerals. Deposits chosen for development included those expected to contain metals of importance in the successful prosecution of the war. This report describes the work performed and results obtained in developing the Daggett Chief manganese deposit near Manila, Daggett County, Utah (fig. 1), during 1941. The work comprised mapping and a study of the geology by the Federal Geological Survey, and bulldozer and hand trenching, sinking of two shafts, and sampling by the Bureau of Mines. Work was started April 17, 1941, and was completed June 28, 1941. Two bulk samples for metallurgical testing were taken.

Jan 1, 1950

By J. D. Marchant

Solid-state electrotransport of impurities in cerium, lanthanum, and praseodymium, using a pulsed current, was investigated. The results were compared with those of using a steady current. Impurities that showed appreciable movement with the pulsed current, but not with the steady current, were as follows: Molybdenum and oxygen in cerium, aluminum, iron, and molybdenum in lanthanum. The use of a pulsed current enhances the practical application of solid-state electrotransport to remove a wider variety of impurities from the host metals.

Jan 1, 1971

By E. C. Lane

The motor gasoline that is being marketed in the United States this summer is slightly more volatile than that sold a year ago. The increase in volatility is shown by a lowering of the distillation temperatures, ranging from 2°F. at the average initial boiling point to 4°F. at the average end point. During the past nine years the Bureau of Mines has made semiannual surveys of the gasoline marketed in the United States, the survey just completed being the eighteenth in the series. The cities in which samples were collected have been chosen as representative of the more important marketing territories, as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country. Samples were collected in Omaha as well as in the 11 cities where samples were taken last winter. It was believed advisable to include samples from Omaha in order to give a better balance to the survey for the country as a whole.

Jan 1, 1928

By C. Ortuglio

The Bureau of Mines developed equations to determine the relationship of yields and products obtained from BM-AGA carbonization in 13-and l8-inch-diameter retorts. The developed equations indicate that results of carbonization in l8-inch-diameter retorts can be predicted from results obtained with l3-inch-diameter retorts.

Jan 1, 1966

By Barry L. Warner

This program involves testing to determine whether a fire hazard exists when the exposed wood surface area of timber in a mine passageway equals 40 percent of the surrounding strata surface, excluding the sill. Twelve full scale fire tests were conducted in a simulated mine passageways, using kerosene pan fires as the ignition source. The tests included three timber sizes, plus one test with roof lagging, two wood types, plus one test with treated timbers, and two ventilation air velocities. The results show air velocity to be an important factor in the occurrence of flame propagation, and that the 40 percent surface area ratio of wood to surrounding strata appears to b0. a valid criteria for fire safety at 150 fpm, but not at 350 fpm.

Jan 1, 1975

By Bertha R. Klahold

"In response to numerous inquiries regarding tests and analyses of minerals and related inorganic materials; Bureau of Mines Information Circular 6999, ""Laboratories That Make Fire Assays, Analyses, and Tests on Ores, Minerals, Metals and Other Inorganic Substances,"" by C. W. Davis and M. W. von Bernewitz, was published .in 1938 and revised in 1939 (I. C. 6999R). In this paper on analytical and testing laboratories, the original text has been rewritten and expanded, and a table has been added, in which are listed laboratories prepared to offer a number of special testing services in addition to ordinary assays and chemical analyses. The arrangement of laboratories on, a geographical basis has been maintained.This circular is compiled as a public service, and none of the laboratories listed herein is recommended over any other,These lists were compiled from questionnaires sent to organizations whose work is connected with mineral and metallurgical testing. The response in general was very satisfactory, and the author takes this opportunity to express her appreciation to the officers of the listed laboratories for their cooperation.Acknowledgment is also made of the valuable assistance of the members of the technical staff particularly Morris Slaving/ of the Eastern Experiment Station of the Bureau of Mines at College Park, Md., in the preparation of the questionnaire and technical descriptions.Many mineral samples are sent to government agencies in the National Capital with the request that they be assayed or chemically analyzed. It should be emphasized that there is no place in Washington D. C. where assays and quantitative analyses are made for the public b the Federal Government.Virtually all of the States maintain a bureau of mines, a geological survey, or some similar organization, frequently at the State University, where minerals found by residents of the State will be identified free of charge. Usually, a charge is made for assays. Specific tests, as on clays, are made by some of these offices.The Federal Bureau of Mines, although it attempts to avoid duplication of services rendered by State Bureaus, is always glad to give advice as to prospective markets. It does not compete with private assayers and chemists, but with respect to samples sent to its field laboratories, it does offer to identify them as far as this can be done by inspection and simple optical and chemical tests. This examination is usually sufficient to indicate whether the material has commercial value, or at least if the expense of an assay would be warranted. Except in connection with its own technical investigations, no assays or other special tests are made by the Bureau of Mines.The Federal Geological Survey and the National Museum also make simple tests of specimens as a public service. Neither of these bureaus nor the Bureau of Mines, however, can afford to render such services on long suites of specimens submitted by mineral dealers, well drillers, or others, when such work can be done regularly by commercial concerns."

Oct 1, 1949

By J. A. McAllister

In the course of a study of domestic Manganese resources, 2-ton representative samples of ore were taken by Bureau of Mines' engineers from the Payday claim, Weber County, and the Newcomb-claims, Rich County, Utah. The Payday No. 1 deposit is situated 13 miles northeast of Huntsville, Weber County, Utah. The manganese ore is a. replacement deposit in limestone and consists of manganese oxides imbedded 'in clay and also as the cementing agent consolidating small pebbles and pieces of quartz and limestone.

Jan 1, 1949

The National Personal Protective Technology Laboratory (NPPTL) of the National Institute for Occupational Safety and Health (NIOSH) has undertaken a collaborative study with the Mine Safety and Health Administration (MSHA) to determine how well self-contained self-rescuers (SCSRs), deployed in accordance with Federal regulations (30 CFR 75.1714), withstand the underground coal mining environment with regard to both physical damage and aging. Apparatus tested included the CSE SR-100, the Draeger OXY-K Plus, the MSA Life-Saver 60, and the Ocenco EBA 6.5 and M-20. This report presents findings regarding laboratory-tested SCSRs in the tenth phase of testing, from July 2004 to March 2006. The SCSRs were tested on a breathing and metabolic simulator and on a human subject walking on a treadmill. The tests performed in this study are not the tests used for certification (Title 42 of the Code of Federal Regulations, Part 84). The tests performed in this study continue until the apparatus are empty to enable comparison of new versus deployed apparatus. The method for obtaining deployed SCSRs for this evaluation was not a random selection from the deployed population of SCSRs. We sought older apparatus with visible environmental impact rather than newer apparatus, and we attempted to sample a wide range of deployment modes. Although the results of these tests are useful for observing performance of the tested SCSRs, they are not representative of all deployed SCSRs. This report is the last of 10 report phases begun in 1982. Previous reports describe phases 1 through 9 [Kyriazi et al. 1986; Kyriazi and Shubilla 1992, 1994, 1996, 2000, 2002, 2004, 2006] A new evaluation protocol, with revised sampling strategies, test methods, and reporting procedures, is currently being designed to enhance the applicability of the results. The results of these studies suggest that the large majority of SCSRs that pass their inspection criteria can be relied upon to provide a safe level of life support for mine escape purposes. However, the storage and handling in the mining environment seems to have caused performance degradation in some of the apparatus. In this phase, phase 10, we found some CSE SR-100s (93 tested) that exhibited high CO2 levels, stuck-together breathing hoses, starter-O2 failure, breathing hose punctures and tears, high breathing pressures, and loose particulates in the breathing hose. The loose particulates caused coughing in human-subject tests. One MSA Life-Saver 60 (20 tested) in this phase had a stuck-open relief valve. One Ocenco EBA 6.5 (50 tested) had an unattached O2 supply hose. An unexplained phenomenon occurred with two Ocenco M-20s (20 tested): low O2 flow rates preventing their successful use. Almost all of the failures noted involved units that failed their inspection criteria.

Jan 6, 2008

By R. L. Crosby

The Bureau of Mines investigated alloys of copper with 2, 3, and 4 vol pct alumina and with 2 vol pct yttria. Alloys were prepared by a coprecipitation process and were fabricated by pressing and sintering of powders, extrusion, and swaging. Tensile properties at room and elevated temperatures, stress-rupture strength, electrical conductivity, and density were measured. The superiority in elevated temperature strength of dispersion-strengthened copper to OFHC copper was confirmed. Increasing the oxide content from 2 to 4 vol pct produced only a small improvement in strength properties and decreased the electrical conductivity. The 3 vol pet alumina alloy had the best overall combination of properties.

Jan 1, 1969

By M. P. Youker

USE OF LOW-PRESSURE GAS BURNERS IN OIL- FIELD BOILERS

Feb 1, 1922

By Robert E. Barieau

This report gives the principles of the method used by the Helium Research Center of the Bureau of Mines when solving nonlinear-regression problems and contains the mathematical equations necessary to accomplish the following objectives: the evaluation of the parameters in such a way that the sum of the weighted squares of the residuals of an experimental observable is a true minimum, regardless of the functional relationship between the variables and these parameters; and the evaluation of all variances and covariances of the parameters by means of the usual approximation of the law for the propagation of errors.

Jan 1, 1967

By Henry E. Blake

The Bureau of Mines has been engaged in a continuing research effort to develop processes for increasing the recovery and utilization of fluorine from low-grade resources. This current research has shown that over 98 percent of the fluorine in phosphate rock is extracted when the ore is treated with excess phosphoric acid in the presence of water vapor at 150° to 180° C. More than 80 percent of the fluorine can be recovered as fluosilicic acid, which can then be converted to commercially useful hydrogen fluoride or fluorspar by previously developed Bureau processes. Extraction of P205 from the ore was about 98 percent in batch tests and 90 percent in semicyclic tests.

Jan 1, 1974

By Ronald P. Hollenbeck

This study reviews and discusses the fluorspar industry in the Eastern United States, with emphasis on factors controlling the industry such as production, consumption, uses, and transportation. The greatest potential for increased consumption of fluorspar in the immediate future was found to be in the manufacture of fluorine chemicals and steel. Important factors affecting the future domestic industry include imports and the maintenance of adequate domestic fluorspar reserves. Exploration, commercial deposits, mining and milling, reserves, and new developments in the industry are covered.

Jan 1, 1967

By G. E. Johnson

A bench-scale study was made of removing hydrogen sulfide from synthesis gas at elevated pressure by iron oxide impregnated on wood chips. The gas contained 0.02 to 0.06 percent oxygen. The removal of hydrogen sulfide by iron oxide impregnated on wood chips is more efficient at elevated pressure. At constant space velocity, longer periods of operation at 400 p.s.i.g. are possible before the exit gas reaches a given maximum concentration of hydrogen sulfide, compared with 200 p.s.i.g. or atmospheric pressure. In tests at room temperature, 60° C., and 100° C., the most effective removal of hydrogen sulfide was obtained at room temperature and the least effective at 100° C. Dry impregnated wood chips removed only about half as much hydrogen sulfide as chips wetted to a water content of 50 percent.

Jan 1, 1962

By H. Netuka, J. V. Horak, A. W. Khair

"A general review of major problems concerning mathematical modelling of roof bolting problem is given. A mathematical model (MM) of interactive set Bolt - Resin - Rock and its discretization based on the Finite Element Method (FEM) is developed to calculate numerically course of displacement, stress and strain fields in this set. This new MM enables to get also course of the normal and tangential components of contact stress vector, normal displacement and then mutual tangential slip at the bolt - resin and resin - rock interfaces, respectively.Behavior of system on all interfaces is modelled in the MM as a ""unilateral contact"" governed by so called non-classical boundary condition of Signorini's type including Coulomb's law of friction between resin and rock, and ""a given friction"" law between bolt and resin (see Duvaut, Lions (1972) for mathematical formulation).Numerical example and some values of resulting stresses are shown and remarks on necessary and sufficient conditions for solvability of the problem are also given.IntroductionAs is well known roof bolting has become the primary support system in almost all underground coal mines. But the ""theoretical"" design criteria for roof bolt patterns are rather problematic because: "" ... real mechanisms by which the roof bolts reinforce the immediate roof of underground coal mine entry are still relatively unknown"", see Peng (1986).The aim of this contribution is to present brief description of fundamentals of mathematical theory (see Hlavacek et al., 1988) which could be, according to our opinion and knowledge, very helpful for numerical modelling of a such type of problems. For the sake of brevity we restrict ourselves here to just one of the simplest possible problem: analysis of the behavior of interactive set composed by only single full - length - grouted bolt, resin (or cement) and suitable part of domain of a ""immediate"" neighborhood of bolt which should represent physical action of real rock material."

Dec 1, 1995

By Michael J. Magyar

The Federal Bureau of Mines has developed a hydrametallurgical method to recover aluminum, aluminum oxide, and fluxing salts from aluminum salt slags. The slag is leached with water at room temperature to produce a saturated brine slurry. Screening of the slurry yields an aluminum-rich fraction that can be returned to the dross furnace. The remaining slurry is vacuum filtered, yielding a clear brine solution and an aluminum oxide filter cake. Evaporation of the clear filtrate produces a high-purity fluxing salt for reuse in the dross furnace. Over 80 pct of the metallic aluminum is recovered in the aluminum-rich oversize fraction, while essentially all the fluxing salts are recovered by evaporation. This report contains the final results of an investigation on a process research unit scale, an economic evaluation of the method, and recommendations to further improve the process.

Jan 1, 1979

By Larry A. Haas

The Bureau of Mines constructed a torsion effusion apparatus to measure the equilibrium vapor pressure of pure metals, alloys, and compounds at temperatures up to 1,500° K. The reliability of the apparatus was established by determining the vapor pressure of silver. The data obtained on solid and liquid silver in the temperature range 1,200° to 1,500° K can be expressed by the following equations:

Jan 1, 1965

By George Saliba

This report disucsses the formulation of a mathematical model for the steering of a conveyor belt by a flat return idler and a troughed idler under various loading conditions. Significant parameters associated with belt training are identified. The generation of a skewed flat return idler model in terms of a steering force and self-aligning torque is presented. Development of the mathematical model for the flat return steering idler is illustrated for the case of no circumferential slip occurring and for the assumption of a bidirectional slip mechanism. Experimental results supporting the theoretical analysis is presented.

Jan 1, 1977

By J. A. Rowland

Magnesium alloys containing nickel, nickel and manganese, lithium, lithium and manganese, and lithium and aluminum were investigated. Melting, casting, and mechanical working techniques and the heat treatment of various compositions were studied. Amenability to cold and hot working was shown for many compositions. The magnesium-nickel and magnesium-nickel-manganese alloys failed to develop superior mechanical properties and were very low in resistance to corrosion. The magnesium-lithium series, although entirely plastic, had low strength properties. The addition of small amounts of aluminum to the Mg-Li base did not affect greatly either the ductility or the strength; further additions developed increased strength, but only at room temperature, and the alloys became brittle with age. Continued study, concentrating on the ductile lithium-rich beta phase as a base composition for ternary and quaternary systems, is recommended.

Jan 1, 1956