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By Seth C. Schaefer

[As part of the Bureau of Mines effort to provide thermodynamic data for advancement of mineral resources technology, the standard Gibbs energies of formation (?G°f) of MnS (manganese sulfide) and Fe0.9 S (pyrrhotite) were investigated with a high-temperature galvanic cell employing stabilized Zr02 (zirconia) as the electrolyte. Potential measurements were obtained for the cell Pt, MnS, MnO, S02 (g, 1 atm)//Zr02//02(g, 0.0114 atm), Pt with the overall cell reaction MnS (s) + 1.5 02 (g, 0.0114 atm) = MnO (s) + S02 (g) . (1) These results give the standard Gibbs energy of formation of MnS for the reaction Mn (s) + 0.552 (g) = MnS (s) (2) ?G°f = -66.487 + 15.19 x 10-3T±0.207 kcal/mole (896.4 - 1,208.1 K) (3) where temperature (T) is expressed in kelvins. Similar measurements were obtained for the cell Pt, FeO .9S, Fe304 , S02 (g, 1 atm) //Zr02//02 (g, 0.0114 atm) , Pt with the overall cell reaction 10/3 FeO .9 S (s) + 16/3 02 (g, 0.0114 atm) = Fe.,04 (s) +10/3 S02 (g). (4) These results yield the standard Gibbs energy of formation for the reaction 0.9 Fe (s) + 0.5 S2 (g) = Fe0.9 S (s) (5) ?G°f = -35.229 + 12.67 x 1073T+-0.104 kcal/mole (839.5 - 1,086.6 K). (6) A third-law analysis of MnS data yields a standard enthalpy of formation (AH°f) for the reaction Mn (s) + S (rh) = MnS (s) (7) ?H°f298 = -51.16±0.21 kcal/mole (8) A similar third-law analysis for Fe0.9S data yields a ?29°f298 for the reaction 0.9 Fe(s) + S(rh) = FeO .9S(s) (9) ?HO\°f298 = -24.01±_0.15 kcal/mole. (10) ]

Jan 1, 1980

By M. J. Ferrante

The preparation and subsequent reduction of vanadium trichloride was investigated as a process for the production of high-purity vanadium metal. Chlorine was reacted with vanadium oxide in the presence of carbon to vanadium tetrachloride. The contaminant vanadium oxytrichloride was also formed and later converted to tetrachloride by reaction with chlorine in the presence of activated charcoal. Vanadium tetrachloride was stirred continuously during thermal dissociation to vanadium trichloride powder from which volatile contaminants were removed by distillation. The vanadium trichloride powder was reduced to vanadium sponge by controlled feeding of the trichloride into molten magnesium. Excess reductant and byproduct salt were removed from the vanadium sponge by high-vacuum distillation. Batches as large as 6.5 kilograms of sponge metal were prepared at an average reaction efficiency of 98 percent. Vanadium sponge after consolidation by arc-melting contained 820 to 11330 ppm of interstitial impurities and had a hardness between Rockwell B 40 and 70, This metal exhibited excellent workability at room temperature. The purification of impure vanadium metal by electron-beam melting resulted in lowering interstitial impurities from 1,890 to 504 ppm and hardness from Rockwell B 87 to 28.

Jan 1, 1968

By Margaret R. Egan

The U.S. Bureau of Mines conducted experiments in the intermediate-scale fire tunnel to assess the influence of air velocity on the gas production and smoke characteristics during smoldering and flaming combustion of Pittsburgh seam coal and its impact on the detection of the combustion products. On-line determinations of mass and number of smoke particles, light transmission, and various gas concentrations were made. From these experimental values, generation rates, heat-release rates, production constants, particle sizes, obscuration rates, and optical densities were calculated. Ventilation has a direct effect on fire detection and development. The results indicate that, in general, increased air velocity lengthened the onset of smoke and flaming ignition, increased the fire intensity, but decreased the gas and smoke concentrations. Increased air velocity also lengthened the response times of all the fire sensors tested. Rapid and reliable detector response at this most crucial stage of fire development can increase the possibility that appropriate miner response (fire suppression tactics or evacuation) can be completed before toxic smoke spreads throughout the mine.

Jan 1, 2010

By C. E. Munroe

In order to meet the emergencies of the world wr, tne quantities of explosivea produced in the Unitecl States, and the number of explosives plants were onti:.1.1.:l,lly ncreased so that when the armistice was declared the Government had on hand larg ..mounts oi militazy explosives in excess of existing military needs. Tle stor3.gs of these explosives entailed a liirge expense and their protection neessitatei the employment of m'3.l'lY men who could be better employed otherwise in the military estlish.11ent. Moreover, mar.y ex.ploives, like QJ.l other material, deteriorate on prolonged storage, They lose tht precise definiteness of properties and behavior on which reliance· is placed in military operations, The continued expen3e and d3.nger ttending storage of theae explosives might be diminished by dcst1et1on of the surplus beyond immediate needs, but such·deetniction is danger• ou5 qnd coetly. Hence, the evident solution o! the problem was the salvage d prompt ut111zation of the ru.rplua •

Aug 1, 1922

By Steven J. Page

The Bureau of Mines used fiber-laden air to test two identical fibrous aerosol monitors (FAM) in order to establish the FAM-optical count correlation. The FAM is a unique instrument developed by GCA Corp. (GCA) to measure real-time fibrous aerosol concentrations. It will also respond to particulates that have sufficient shape irregularities to possess fiber characteristics such as the 3:1 length: diameter (L:D) aspect ratio. Results of the Bureau's laboratory tests showed that the FAM response is linearly correlated to concentration data obtained using the optical membrane filter count technique approved by the National Institute for Occupational Safety and Health (NIOSH), U.S. Department of Health, Education, and Welfare. A plot of the FAM-optical count correlation showed that FAM concentration readings are generally well within ±25 pct of the optical membrane filter count. Initial tests to estimate the best ratio control setting of the FAM for 5-µm fiber-length discrimination were performed using one instrument only (the ratio control setting determines the minimum threshold fiber length that will be detected by the FAM). The estimated setting was then used to correlate both FAM units. The result was a 65 pct difference in correlation between the two units. It appears that the major factor responsible for this difference was the internal adjustment of the photomultiplier detector sensitivity for each of the two FAM units.

Jan 1, 1980

By W. J. Kroll

This report on the bibliography of zirconium has been confined to those publications and patents that appear to be useful in the commercial development of the metal, both the malleable and the nonmalleable. The methods of production have been stressed and special attention has been given to the alloys. Compounds of importance, like the oxide and chloride, for the manufacture of the metal or of the alloys have been considered. The use of the oxide in refractories anal in the glass and porcelain industries has been omitted. The present survey is critical; that is to say, an attempt has been made to evaluate the effectiveness of suggestions made in the literature. The exhaustive work of Marden and Richy, Bureau of Mines Bulletin 186, published in 1921, has been taken as a base to start from with the intention of bringing the subject up to date with material published in the last 24 years. During this time there was considerable 'advance in the preparation of the metal and Its alloys, and in the development of new uses. On the other hand, there was little progress in the methods of decomposing the ores, so that the chapter on this latter phase is necessarily short.

Jan 1, 1946

By Hamid N. Maleki

Cooperative efforts by the Bureau of Mines and Agapito & Associates, Inc., Grand Junction, CO, achieved the research objective of showing that data from measurements of the rate and change in rate of mine roof movement can be effective in detecting roof instability. Several instruments and techniques have been used to monitor roof movement and to detect imminent roof caves during pillar robbing. Early detection of unstable conditions can provide time either to withdraw personnel and equipment or to allocate supplemental support to prevent injury or down-time. Critical convergence rates were determined both manually and electronically. The detection of critical rate of movement has been shown to be an effective tool in ground control efforts.

Jan 1, 1988

By Holmes, George H. Jr.

The Cherry Creek tungsten district was explored by the Bureau of Mines from April 16 to August 13, 1942. This district is in north-central White Pine County, Nev., 50 miles north of Ely. Principal work was done on the property of the Cherry Creek Tungsten Mining Co. and at the adjacent Chance mine, although the entire district was examined and mapped. The exploratory work was done in cooperation with the Federal Geological Survey and comprised surveying, trenching, sampling, long-hole and core drilling, rehabilitation of mine workings, road building, drifting, and shaft sinking. The more important tungsten occurrences were explored by trenching and diamond drilling. Sixteen holes, having a total length of 2,515 feet, were drilled. The project resulted in partial development of three new tungsten deposits and small increases in the reserve tonnage of two scheelite-bearing lenses that were being mined by the company. The following pages summarize the history of the district, outline the ownership of the properties explored, and describe the physical features and mineral deposits. Mining and milling practices at the Cherry Creek tungsten mine are outlined, and the plan and results of project work are presented in detail together with surface maps, assay maps, and drill-hole logs.

Jan 1, 1950

By Jr. Koch

As a part of a larger study of the distribution of metals within ore deposits, the geometry of distribution of gold, silver, lead, copper, and zinc in five veins of the Fresnillo mine, Zacatecas, Mexico, was established. The purpose was to obtain basic data necessary for evaluation of geological theories about processes of vein formation and useful for practical mining applications in ore estimation and prediction of ore beyond present workings. The Bureau of Mines investigation comprised statistical analysis of 64,000 assay values from some 16,000 mine samples. The samples were taken at 2-meter intervals in drifts exposing the veins through a vertical range of some 750 meters. Within individual veins, the metals are distributed in dome¬like patterns with highest metal contents tending Lo occur in oreshoots at the centers of the developed parts of the veins. However, in the block of ground containing all five veins, base metals define mathematical domes with highest contents near the center; precious metals define mathematical basins or troughs with low contents near the center. The ratio of silver assay values to lead assay values corresponds to two geographically distinct types of mineralization: one in which silver is closely related to lead, and another in which silver is independent of lead. Other metal ratios also vary regularly from one place to another. The statistical methods employed in this study would be useful for other geologists or engineers who need to analyze large amounts of assay or similar numerical data.

Jan 1, 1967

By N. A. C. Smith, D. D. Stark

"Sulphur is apparently a normal Constituent of crude petroleum, but in most crudes is present in percentages of less than one-half of one per cent. Some crudes, however, contain more, and occurrences have been reported of heavy asphaltic oils with as much as five per cent of sulphur.Occurrences of Sulpher-bearing CrudesIn North America, the fields rest of the Mississippi River are almost entirely free from sulphur oils, the time oil from Northern Ohio and Indiana, and the Potrolia crude in Ontario, being practically the only ones which contain sulohur in amounts over 0.5. per cent. In the Mid-Continent district the production of high sulphur crude in general is small and unim¬portant. The two main excentions are the Healdton field in Oklahoma and the El Dorado field in Arkansas, both of which produce oils with considerable sulphur content. In the Wyoming field, one sand, the Ember Sandstone, pro¬duces a crude of high sulphur content, and it is probable that this crude rill be of considerable importance as production increases. At present, however, very little crude is produced from this formation. In the Gulf Coast conditions are irregular, some crudes being low in sulphur and others comparatively high. The same is largely true of California. The crudes of Mexico contain notable amounts of sulphur, and as they have been of great commercial importance in this country, a typical sample of light Mexican crude was selected for the present study. It is probable that the results obtained poly also (but to a lesser degree) to other sulphur-bearing oils. An analysis of this crude will be found in Table 3, also analyses of other typical sulphur-bearing crudes from different sections of the United States."

Mar 1, 1924

By Clyde L. Brown

Recent developments in portable communication equipment for use in emergency recovery work following mine fires and explosions have wade possible a convenient and dependable means of directing rescue teams working under hazardous conditions. INTRODUCTION Mine rescue and recovery operations following; fires and explosions are frequently conducted under adverse conditions that require the use of oxygen breathing apparatus by members of a 5- or 6-man team. Conventional apparatus used for this purpose for many years was equipped with an oxygen supply adequate for at least 2 hours. The design of the apparatus is such that the nose passages are closed with a clamp, and breathing is accomplished through a mouthpiece connected to the apparatus by tubes and arranged to prevent inhaling air or gases from outside sources. The use of the mouthpiece has presented difficulties in the development of telephone communication because of the wearer's inability to speak while wearing the mouthpiece. The method of conducting operations of rescue teams requires a person to direct operations at a fresh-air base as close to the rescue team as possible. At least one standby rescue team and 2 or 3 other persons assigned to various tasks are stationed at the fresh-air base. An efficient and reliable means of communication between the director of operations and the rescue team is necessary for reasonably safe and efficient work in hazardous areas.

Jan 1, 1957

By C. W. Owings, F. E. Cash

"Transportation of explosives in mines is extremely hazardous, and where electric haulage is employed the danger is intensified. Insulated mine-car couplings have been adopted by at least five companies in Alabama and Pennsylvania - and undoubtedly in other States - to prevent an electric current passing from a mine locomotive to a car or between care joined by this coupling. The need for such protection is recognized in the report of an explosion.""Four hundred kegs of black blasting powder had been loaded into four mine cars at the railroad, to be hauled to the magazine, upgrade, by a trolley locomotive. On starting, the motorman put sand on the rail and a grounded circuit passed through the hitchings and so exploded the powder. No insulation was used between the locomotive and cars."" When used on man trips the insulated coupling further serves the purpose of guarding the men against shock. Four couplings are described so that a clearer understanding may be obtained of the details of construction.ConstructionThe general principles of construction are similar in all insulated couplings. The piece containing the hole for the coupling pin is made of steel and the steel parts are separated by an insulating material, such as fiber or wood. The coupling is either rigid or semirigid to prevent the bumpers of the mine cars from coming in contact and to keep the cars insulated from one another at all times."

Apr 1, 1928

By Larry G. Stolarczyk

An underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communications to any vehicle or roving miner in the underground mine. The system provides high quality radio coverage in work areas and along manways with existing "wireplant" conductors. The conductors include AC power cable, telephone cable, metal water and high pressure air pipes, etc. The measured communications range from the base station to mobile transceiver exceeded 12,500 ft without the use of repeaters. A cost/benefit analysis shows that the initial cost of the equipment can be returned 2-6 times in the first year. The mine productivity increases by approx. 13 percent.

By Ronald B. Hollenbeck

The value of mineral production in Alabama continued to increase and reached a new high of $260 million, 3 percent above the previous high established in 1967. Record high values were reported for bentonite, crushed marble, lime, miscellaneous clay, portland cement, salt, sand and gravel, and scrap mica. The value of coal, total cement, petroleum, and stone accounted for 87 percent of the State's total value of mineral production. Alabama ranked second among the States in the production of bauxite and scrap mica and third in kaolin, masonry cement, and native asphalt.

Jan 1, 1970

By H. M. Smith

Data from the Bureau of Mines routine method for the analysis of crude petroleum are used to characterize crude oils. Some data are used directly while other data are used to calculate the aromatic) naphthene) and paraffin contents of the distillation fractions and the correlation index of the paraffin-naphthene portion of the fractions. The calculated properties show significant differences in composition between crude oils. The methods of calculation and interpretation of data are explained and illustrated.

Jan 1, 1966

By Ralph H. Espach

In the spring of 1943, when it was evident that the Tensleep sandstone in the Elk Basin field, Wyoming and Montana, held a large reserve of petroleum, Bureau of Mines engineers obtained samples of oil from the bottom of nine wells and analyzed them for such physical characteristics as the volumes of gas in solution, saturation pressures or bubble points, shrinkage in volume caused by the release of gas from solution, expansion of the oil with decrease in pressure, and other related properties. The composition of the gas in solution in the oil was studied. The pressures and temperatures existing in the reservoir and the productivity characteristics of the oil wells were determined. The data obtained indicate that the oil in the Tensleep reservoir of the Elk Basin field has unusually varying physical characteristics, such as a saturation pressure of 1,250 pounds per square inch absolute and 490 cubic feet of gas in solution in a barrel of oil at the crest of the structure, and a saturation pressure of 530 pounds per square inch absolute and 134 cubic feet of gas in solution in a barrel of oil low on the flanks. The hydrogen sulfide content of the 6a r; in solution in the oil varies from 18 percent for oil on the crest to 5 percent for oil low on the flanks of the structure. Of even greater significance is the fact that these and other variable characteristics of the reservoir oil are related to the position of oil in the structure. Many geologists and petroleum engineers have considered all the oil in a petroleum reservoir to have uniform physical characteristics and that equilibrium conditions prevailed in all underground accumulations of oil and gas. That such is not always so is borne out by the results of the study made by the writers.

Jan 1, 1951

By A. L. Engel

A representative sample of gold-silver ore from the Keystone Mine, Manhattan, Nye County, Nev., was submitted for these tests. The ore was an altered diorite rock with very small amounts of sulfide minerals of copper, lead, zinc, antimony, and arsenic disseminated in fine grains throughout. As indicated by test results, much of the silver content of the ore apparently was associated with these sulfide minerals. The gold probably occurred with iron oxides in the ore. Assays showed 0.16 ounce of gold and 2.8 ounces of silver per ton of ore. This investigation was made to study application of activated carbon in the cyanidation treatment of the ore. The treatment proposed for u.se at the mill is as follows: The ore is crushed to minus-10-mesh size and separated into plus -and minus-65-mesh portions. The minus-10, plus 65-mesh sands are cyanided by leaching and the minus -65-mesh slimes by agitating. After 48 hours of agitation the slime pulp is thickened to about 1:1 water:solid ratio, and part of the pregnant solution is recovered. The pulp is then diluted to a 2:1 ratio, and the remaining dissolved values are extracted with the activated carbon. The barren pulp then can be discarded. This procedure eliminates the necessity for further washing the slime pulp and also recovers most of the excess sodium cyanide required for extracting the optimum amount of silver from this portion of the ore.

Jan 1, 1951

? CAGER, CAGE RIDER, CAGE TENDER, SHAFT MEN All of the above job titles are variously associated with the handling of men and material at hoist stations. Generally, these classifications of personnel are involved with riding cages with personnel and in hoisting supplies into the mine. Job titles and activity description will be defined in the respective chapters. ? FLOW CHART SYMBOLS [Vertical Transportation Horizontal Transportation Storage Operation Delay ]

Jan 1, 1975

By G. W. Jones

As a part of it investigations pertaining to the promotion of safety, the Bureau of Mines is investigating various means, useful for the elimination or mitigation of the explosion hazards of combustible gases encountered in mining and industry. Information has been obtained and a procedure developed whereby the explocibility of many complex, gaseous, combustible atmospheres may be calculated in a simple manner without the necessity of performing laborious laboratory experiments. In a previous publication4/ data were given and a method described whereby the limits of inflammability of gaseous mixtures, including methane, hydrogen, carbon monoxide, nitrogen, carbon dioxide, and oxygen, could be determined by calculation. The information published in that report enables one to calculate the limits of inflammability of such gases as are liberated by mine fires, gases from explosives, automobile exhaust ran, uses present after mine explosions, blast-furnace gas, and other gases containing part of or all of the above-listed constituents.

Jan 1, 1938

By H. A. Doerner

For the past three or four years attention has been attracted to the deposits of lead vanadate in the Goodsprings , Nevada , district . Some ore running as high as 9 per cent 205 has been produced , but most of it runs from 0.5 to 3 per cent . Only a little ore , and that of the richer sort , has been shipped , since the low- grade ore will not stend the cost of shipment and no concentration mill has been available . Preliminary experiments indicate that chemical treatment of the low- grade ore without concentration is not feasible . Its treatment therefore involves two distinct problems ; first , mechanical concentration ; and second , a smelting or chemical treatment to obtain the lead and vanadium in marketable form . Upon this basis the work has been conducted . The writer wishes to acknowledge the excellent work done by J. T. Norton and Virgil Miller on table concentration and by J. E. Conley , who suggested and did preliminary work on the direct smelting method . Many helpful suggestions were received from Dr. S. C. Lind and John Gross of the Bureau of Mines . The ores were furnished by Mr. Frank Williams and Mr. James Ewing .

Jan 1, 1923