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By W. L. Falke

Procedures in which manganese compounds are reduced and the metal is volatilized and selectively condensed, a hitherto neglected area, were investigated. More than 95 percent of the manganese was recovered from high-melting-point ores whether vacuum volatilization or atmospheric pressure volatilization was used, but neither process is economically attractive under present price-cost conditions.

Jan 1, 1966

By Ann G. Kim

Gas samples containing 02, N2, H2, He, CO2, CO, CH4, and trace amounts of C 2 to C6 hydrocarbons are analyzed by a gas chromatographic method that utilizes both thermal conductivity and flame ionization detectors. A porous polymer support and molecular sieve columns are used with argon as the carrier gas. A column selector valve makes it possible to perform a complete analysis either on one 1-ml sample in 40 minutes or on two samples in 20 minutes, one sample for each detector. Samples are introduced either by on-column injection or through a gas sampling valve. By varying operational parameters, the speed, sensitivity, and accuracy of analysis may be modified to suit a particular situation.

Jan 1, 1974

By W. T. Millar

Graphite in the Suffern deposits near Hillburn, N. Y., consists of flakes ranging in size from fines to one-half inch in diameter. The Bureau of Mines investigated the Suffern deposits in the spring of 1943. Gneiss outcrops were examined, and five trenches excavated and sampled. The graphite is not confined to any definite zone but occurs in small, local pockets. Eleven samples were collected and combined for laboratory tests. Tests by the Bureau of Mines indicate that the graphite ore can be beneficiated by stage crushing, "skin flotation" of coarse flakes, and wet flotation of minus 10-mesh flakes. Over 90, percent of the graphite was recovered.

Jan 1, 1949

By Jacqueline A. McClaskey

The U.S. Bureau of Mines Information and Analysis Directorate collects worldwide data on virtually every commercially important non fuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. The Bureau's data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), which placed the collection of mineral statistics on an annual basis. The most recent authority for the U.S. Bureau of Mines survey activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress). This act strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1993

By A. A. Berk

In the course of a study of the formation of external deposits on tubes in water-tube boilers it became desirable to determine the sulfur dioxide (SO2) and sulfur trioxide (SO3) in the Due gases. Determinations made by the A.S.M.E. method for SO2 and SO3 in gaseous products of combustion did not give accurate results. It was found that minute quantities of copper, present in the flue gases from the coal in use, caused oxidation of sulfite in the absorption bottle and that the carbon dioxide (CO2) in the flue gases caused high values for SO2. The A.S.M.E. test procedure was revised to prevent oxidation of sulfite in the absorption bottle and to allow for the effect of CO2; subsequent analyses of flue gases produced reliable results. The revised procedure is described.

Jan 1, 1950

By A. R. T. Dennues

"INTRODUCTION There are presented in this report the results of limited studies by the Bureau of Mines of the firedamp safety of some powder-powered tools proposed for use underground in coal mines. This study was made to obtain general information and specific technical data for a cable splicer and some rail punches now commercially available, the aim being to keep abreast of developments and to anticipate hazards.ACKNOWLEDGMENTSAcknowledgments are made to the Mine Safety Appliances Co., Pittsburgh, Pa., for supplying equipment for these tests, and to the Pittsburgh Coal Co. for making possible observations of the use of these tools in coal mines.The assistance of other members of the Explosives Division is acknowledged: J. E. Crawshaw, for examination of ammunition and, propellant powders; H. L. Wilson, for analyses of the natural gas used in the gallery and Jerome C. P. Weinheimer and Martin Bashel, for conducting the gallery tests.GENERALDescriptions of the DevicesPowder-powered tools of the type tested utilize the energy of charge of,propellant powder accomplish tasks. They are essentially small guns adapted to special work. Of the family of such tools now commercially available from one manufacturer, two have been proposed for use underground in coal mines, namely a cable splicer known as model TI and two models of rail punch known as R40 and R60. These tools employ blank-cartridge ammunition and special projectiles to accomplish the work indicated by these descriptive names."

Jul 1, 1947

By Liming Yuan

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Jan 1, 2009

By L. W. Kelly

The purpose of this circular is to show that, under the conditions prevailing in the Stony Point mine, wooden bolts were just as satisfactory as steel bolts or conventional timbering, with a reduction of approximately 80 percent in cost of material. This one fact alone is enough to justify an experiment with wood. This circular will show that production records have remained constant with both wooden and steel roof bolts. INTRODUCTION The successful use of steel roof bolts is now an accomplished fact in the coal industry, but the use of wooden bolts in place of steel is a rarity. The first experiment with wooden roof bolts was mane in 1949 in the Rio Verde mine, Norton Coal Corp., Nortonville, Ky.2/ This experiment was successful; the company obtained excellent results, but operations in the mine were suspended before enough time had elapsed to prove the value of wooden roof bolts conclusively. It is obvious that, if wooden roof bolts could be used in place of steel bolts or conventional timbering-methods, every mine operator would use word, as the cost is only a fraction of the other two methods. The Stony Point experience has proved conclusively that, under certain conditions and with a certain type of roof, wooden roof bolts can be used successfully.

Jan 1, 1952

By Alla D. Mah

Combustion energies of barium and strontium were measured by means of the combustion bomb calorimeter. The heats of formation obtained for the oxides were ?H298.15 = -139,060 ± 700 cal/mole of barium oxide (BaO) and ?H298.15 = -144,440 ± 400 cal/mole of strontium oxide (SrO). Tables containing heats and free energies of formation from 298.15° to 2,000° K were prepared.

Jan 1, 1963

By Fred C. Turin, Lisa J. Steiner, Kim M. Cornelius

Like many experienced workers, remote control continuous miner operators perform their everyday jobs making choices and decisions that they may not consciously think about. While performing tasks, they are continuously processing feedback and cues which guide them for the next move. Initial training teaches the operators the tasks necessary to operate the equipment and perform the job. However, with experience they are better able to deal with hazardous conditions and non routine situations. To better understand what potential cues and feedback help to guide the operators, a questionnaire was developed to learn what factors affect decisions. Operator responses address issues related to specific tasks, equipment operation, visibility, lighting, and communication issues. The information collected is useful to understand what cues experienced operators use to make task performance decisions. Results will be used to develop interventions and training for safe and effective operator performance.

By Ray J. Holmquist

"INTRODUCTION The Copper King or Red River copper mine was examined on December 13, 1942, by the Bureau of Mines at the request of Richard Kelly of Santa Fe, N. Mex. The examination was made to determine whether the expenditure of funds for rehabilitation work necessary to make the workings accessible for examination would be warranted.As a favorable report was made, the workings of the Copper King mine were opened and sampled under the direction of the author. The portal of the Copper King adit was opened first. Considerable rehabilitation was necessary in the first 50 feet of the workings, but the remainder of the drifts and crosscuts were sufficiently open to permit surveying and sampling.An attempt was made to open the Waterbury atilt, which was reported to be about 30 feet east of the Copper King portal, and to crosscut the ore body nearly to its southern border. However, slide rock and mine dumps had completely obscured the portal of this adit, and no opening into it could be found or made.Work on the project was started on September 27 and vas completed on November 6, 1943."

Apr 1, 1947

By K. C. Strebig

The effect of some organic additives in diamond drilling of quartzite was investigated in the laboratory with a drill instrumented to measure the rate of penetration, the thrust, and the torque and to record each as a function of the distance drilled. A statistical plan was followed throughout the investigation, and an equation representing the bit performance was derived from the mathematical theory of reliability. The coefficient of friction in drilling increased with the use of additives, although the wear coefficient decreased. The decrease in wear associated with an increase in energy per unit volume consumed and the increase in penetration rate resulted in a net decrease in the cost per foot of drilling. A hypothesis explaining the effects achieved with the additives is given.

Jan 1, 1971

By F. J. Smith, W. A. Gallagher, C. A. Herbert

"INTRODUCTION A fire started about 10 a.m., November 10, 1947, at the Kings mine, Princeton Mining Co., Princeton, Ind., about 1,800 feet inby the main shaft bottom on the main west haulage road at a point estimated to be 2 miles from the faces of the main west entries. No lives were lost, as 27 men escaped from the mine after a series of explosions, which necessitated sealing the mine on the surface. This information circular shows"" how adverse conditions might be overcome, when reopening a sealed mine, by expert planning and close cooperation on the part of various organizations. Conditions found in the mine after it was reopened were comparable to the worst that had been anticipated, yet the mine was recovered with comparatively little difficulty and a minimum of risk. The open workings in the mine covered a vast area, but most of the mine resumed production of coal after being sealed for only 37 days.The information contained herein also points to the desirability of adhering as closely as possible to a predetermined schedule of operations."

Feb 1, 1949

By Merle L. Bowser

The Bureau of Mines has constructed a miniature oxygen deficiency alarm system using an electrochemical cell as the sensor. Distinct audible signals are produced at either of two preselectable oxygen levels which can be varied from approximately 10 to 20.9 percent oxygen. The high or cautionary range produces a 500-cycle-per-second tone pulsed at about a 1-cycle-per-second rate, whereas the lower or more dangerous oxygen level produces a continuous 500-cycle-per-second tone.

Jan 1, 1968

By M. M. Fine

This report describes a Bureau of Mines technical feasibility study of simultaneous reduction and induration of pelletized iron ore to make a product with superior qualities as blast-furnace feed. Highly reduced, physically competent pellets can be made from magnetite and specularite concentrates that contain small additions of bentonite as binder. In batch tests, pellets were dried, surrounded with solid fuel in crucibles, and heated to the reducing temperature. Total iron content of the best products was higher than 80 percent and crushing strength of 1/2-inch metallized pellets ranged up to 600 pounds or more. Comparative tests of several commercial oxide pellets showed a wide range in crushing strengths, but most values were less than 350 pounds. Continuous tests in a rotary kiln resulted in the same degree of reduction, but the pellets had lower crushing strengths because of the limitations in the maximum operating temperature of the small kiln.

Jan 1, 1962

By Charles D. Litton

Laboratory experiments were conducted to determine the responses of a prototype smoke detector and a commercially available photoelectric smoke detector to smoke particles generated from various combustion sources. The prototype smoke detector combines optical scattering measurements with ionization chamber measurements in order to reduce/eliminate nuisance alarms due to the presence of airborne dusts or diesel exhaust particles. The commercially available smoke detector is designed for use in harsh environments where airborne dust represents a major problem due to both nuisance alarms and detector contamination. In the experiments, the responses of the two detectors were measured when exposed to smoke particles from the exhaust of a diesel engine and from a variety of fire sources, including wood, coal, styrene butadiene rubber, and No. 2 diesel fuel. For the solid fuels, data were obtained for both smoldering and flaming combustions. This report describes the experiments, their results, and the use of these results as they apply to early-warning fire sensors capable of the rapid and reliable detection of fires in atmospheres that may or may not be contaminated by either airborne dust or the products produced from diesel engines.

Jan 1, 2008

By Oliver Bowles

"Properties and Uses.Iceland spar is a name given to a pure crystallized form of calcite (CaCo3) which is sufficiently transparent and free of defects to be used in the manufacture of optical instruments. While the actual requirements are small, the degree of purity and physical perfection demanded renders it somewhat difficult to obtain suitable material.The properties of value in Iceland spar are its transparency combined with double refraction. It is used in the manufacture of polarizing microscopes, saccharimeters, colorimeters and photometers. Its most important use is in the manufacture of Nicol prisms, which constitute an essential part of every polarizing microscope. The principle governing the construction of the Nicol prism is as follows:Ordinary light in passing through a crystal of calcite is resolved into two rays of plane polarized light vibrating in planes at right angles to each other and having different indices of refraction. Thus the two rays follow different paths through the crystal. The prism of Iceland spar is cut diagonally and cemented together again with a transparent cement having an index of refraction intermediate between the two rays passing through the prism. Canada balsam is employed for this purpose. The prism is cut at such an angle that the ray having the greatest index of refraction meets the surface of the balsam at an angle greater than the angle of total reflection, and it is thus deflected to the side of the prism, while the second ray passes through. Thus one of the rays is eliminated and polarized light vibrating in a single plane is obtained."

Apr 1, 1920

By J. M. Gomes

The Bureau of Mines has investigated the occurrence and recovery of by-product heavy minerals from sand and gravel operations as a means of assessing the Nation's resources. Sand samples from 63 locations in central and southern California were treated to yield heavy-mineral concentrates. The mineral compositions of the concentrates were characterized by chemical and mineralogical examinations. Additional large quantities of concentrates were prepared from selected deposits that contained significant quantities. Beneficiation studies were performed on these concentrates to recover individual mineral products. Gold was recovered by amalgamation; platinum-group metals and radioactive minerals by flotation; magnetite, ilmenite, and chromite by magnetic and high-tension separation techniques.

Jan 1, 1980

By D. R. Mathews

The Bureau of Mines investigated the effects of tungsten and chromium, separately and combined, on improving the mechanical properties and oxidation resistance of vanadium. Binary and ternary vanadium-base alloys were prepared and tested for oxidation resistance and tensile strength. Softening occurred with less than 1 weight-percent of either tungsten or chromium, followed by strengthening with higher alloying contents. Vanadium alloys containing up to 9.8 weight-percent chromium or 14.1 weight-percent tungsten were more resistant to oxidation in air at 600° C than unalloyed vanadium. For the alloys with 12.20 weight-percent chromium or 14.56 weight-percent: tungsten, the maximum concentrations used, the lower yield strengths were about twice that of 38,600 psi for the unalloyed vanadium. Recrystallization temperatures for these alloys were 100 and 150° C higher, respectively. Alloys containing both chromium and tungsten had properties similar to those of the vanadium-tungsten alloys.

Jan 1, 1967

By Charles L. Harness

Fifty years ago, the belief that "fillers" were added to paints for the sole purpose of diluting and cheapening the pigment may have been justified; but paint technology has made tremendous progress since that time, and today both the manufacturer and the consumer know that the judicious use of fillers may add desirable properties to a paint that cannot be introduced in any other way. A growing respect for these accessory materials has led to the use of the more euphemistic term "extender." The names "extender" and "filler" are to a considerable degree synonymous. The newer term, "extender," is adopted in this paper, though it is actually no more descriptive than the older name. Stewart's3/ definition of extender is: "A cheap pigment, usually of an inert type, used to extend or increase the bulk of a paint, thus reducing its unit cost. Extenders are also used to adjust the consistency of a paint and to let down colored pigments of great tinting strength. The use of an extender in a paint does not necessarily mean the resultant product will be inferior. In fact, extenders sometimes, improve -certain characteristics of a film." All extenders are not cheap, as, for example, wet-ground mica and diatomite. Research in the, use of extenders (also sometimes called "inerts") has been one of the host active branches of study in the paint field; and many thousands of dollars have been spent in establishing the physical and chemical characteristics required of various natural mineral extenders for numerous paint formulas

Jan 1, 1943