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By W. E. Lamont

The Federal Bureau of Mines, in cooperation with phosphate companies in the Florida land-pebble area, made a comprehensive study of the waste clays, or "phosphate slimes," produced in the mining of phosphate rock in Florida. These slimes represent a significant ecological problem and a major deterrent to effective land recovery in the phosphate-mining areas. Physical, chemical, and mineralogical studies were made of slime samples submitted by 15 of the 16 plants in Florida in an effort to identify factors that prevent successful consolidation of the slimes and subsequent recovery of the mined lands. Results of these studies indicated that the clay mineral attapulgite, a hydrated magnesium silicate, was primarily responsible for the very poor settling characteristics of the slimes, and that the quantity of attapulgite in the slimes effectively controlled the settling rate, pulp density of terminal solids, viscosity, percent solids of filter cake, and flocculant requirements.

Jan 1, 1975

By E. J. Gleim

[THE ORGANIC act under which Federal Bureau of Mines was established provided for the investigation of the safe use of electricity in mines. Each Congress appropriates funds for conducting this investigation. As part of this investigation, electrical apparatus used in mines is studied to determine if its operation and use might introduce a hazard. From this study, certain safety standards have been developed. These standards, established with the aid of both the manufacturer and user of such apparatus, are published in schedules, and apparatus that complies with the requirements set forth these schedules is classified as "permissible." This term is defined to designate apparatus as "completely assembled and conforming in every respect with the design formally approved by the Bureau of Mines." In the judgment of the Bureau, the manufacturers of such apparatus have adhered to certain minimum standards of safety in supplying a product that when properly used and maintained is safe for operation in mines where flammable gas or coal dust may accumulate. This work of the Bureau of Mines for increasing safety does not make it obligatory for manufacturers of mine equipment to produce only that of permissible classification. Before the effective date of the Federal Mine Safety Code,5 the Bureau sought to promote safety by recommending that mine operators install permissible equipment in gassy mines as a preventive measure against gas and dust explosions initiated by electrical equipment. For some years, the mining laws of several States have prescribed the conditions under which permissible equipment must be used. The Federal Mine Safety Code requires that ?all new electric face equipment and replacements of equipment purchased for mines where nonpermissible equipment is now being used shall be of a permissible type approved by the United States Bureau of Mines,]

Jan 1, 1955

By W. E. Robinson

Samples of raw oil shale and kerogen concentrates were oxidized by alkaline potassium permanganate, air, nitric acid, oxygen, and ozone to obtain information about the chemical structure of organic kerogen in oil shale. In one test, oil shale and oil-shale products were oxidized exhaustively with alkaline potassium permanganate, and the distribution of the organic carbon in the final oxidation products was determined. Comparing results of this oxidation with those obtained from other carbonaceous materials and known compounds gave information about the structure of kerogen. Alkaline potassium permanganate oxidation also was used partly to degrade kerogen into soluble products for characterization purposes. Structures present in these degradation products were indicative of type structures originally present in the kerogen. Nitric acid, oxygen, and ozone were used also for partly degrading kerogen to soluble oxidation products. Carbon-balance oxidation tests using alkaline potassium permanganate showed that Colorado oil-shale kerogen differs from many other carbonaceous materials such as coal and kerogens from other areas. Composition of the degradation products indicated that Colorado oil-shale kerogen is predominantly cycloparaffinic and saturated heterocyclic structures with some long-chain paraffinic and aromatic structures present. The ring systems may be connected through short carbon chains or bridges containing oxygen, nitrogen, and sulfur.

Jan 1, 1963

By H. E. Powell

The magnetic susceptibilities of 34 manganese-bearing minerals were determined. The source of each sample and petrographic, spectrographic, and chemical analyses are given. Included are values for ismorphous series showing wide ranges of composition and for a few high-purity synthetic minerals.

Jan 1, 1968

By F. W. Wessel

Manganiferous carbonate slates of the Cuyuna range, which are part of the unoxidized thin-budded iron formation, represent a large potential source of manganese. This report details recent bench-scale research by the Federal Bureau of Mines in applying mineral-dressing techniques to these materials in order to investigate their potential uses. Work outlined in the report was directed toward the production of concentrates usable as iron-blast furnace feed, but an equally important objective might have been to furnish an enriched feed for extractive processes for recovering manganese. Flotation concentrates were prepared that contained 11.1 percent manganese, 27.8 percent iron, and 12.2 percent silica, with recoveries of 73 percent of the manganese and 48 percent of the iron. Calculated analysis for a simulated sinter suggests a product containing 16.0 percent manganese, 40.2 percent iron, and 17.6 percent silica, with 31 percent recovery of the dry weight of the ore. The silica in the flotation concentrates was due to quartz and iron silicates. Substantial quantities of the iron silicates (stilpnomelane and smaller amounts of minnesotaite) were present in the slate, and the need to reject these minerals limited the recovery of iron. The sintered flotation concentrate would be usable as ferruginous manganese ore for iron blast-furnace feed because of its favorable manganese silica ratio. The unsintered flotation concentrates, representing 45 percent of the feed weight and containing manganese enriched in the ratio of 1.6 : 1, also could be used as feed to processes for extracting manganese.

Jan 1, 1961

By Edwin M. Murphy

Methods are described for filling underground cavities remotely with dry material pneumatically injected through a borehole to seal openings, prevent air movement, and reduce subsidence; this often brings underground fires under control by limiting the access of air. Large-scale tests were made in the Bureau of Mines Experimental Coal Mine, Bruceton, Pa., in an operating mine, and in an abandoned Pennsylvania mine. Supplemental trials were made aboveground in galleries and in the laboratory. The parameters studied include horizontal and inclined passageways, obstructions in the entry, water leakage into the borehole, dry material, and grout and slurry mixes. The materials studied were fly ash, crushed and pulverized limestone, and sand. Best results were obtained with dry fly ash, though satisfactory seals were obtained with the other materials. When a borehole is dry and ends at an open void, casing is not necessary. If more than 5 gpm of water flows in the borehole, if the void contains loose debris, or if coarse material is injected, a material feedpipe should be inserted through the borehole. Fly ash was most suitable for remote filling because of its low angle of repose (8°) and its good flow characteristics. The depth of borehole through which the fly ash is injected has no appreciable effect on the filling operation.

Jan 1, 1968

By Homer J. Ballinger

The Alma, Degraff and other mines controlled by the Mon-Ark Mining Co. comprise one of the more important groups of zinc-lead mines in Christian County, Mo. The mines were first operated in .1857 and produced more than 5 million pounds of lead from rich, shallow ore deposits. Recent exploration and development led to the discovery of zinc sulfide ore at a depth of 165 to 214 feet in the northern part of the Alma mine. After examination of these mines in September 1942 by Bureau of Mines engineers, investigation of the extension -of the Alma mine and of the depth of mineralization at the other mines appeared justified in order to encourage the production of additional zinc and lead for war purposes. Twenty-nine churn-drill holes totaling 6.463 feet of bore were completed by the. Bureau from September 1943 to January 1944.

Jan 1, 1948

By D. N. Nilsen

A mathematical modeling method was developed by the Bureau of Mines for the prediction of the principal equilibrium species in the solvent extraction of copper. The use of models for predicting the amount of metal extracted can reduce the amount of experimental work required to characterize a system for purposes such as optimization studies. Models were developed for the extraction of copper from ammoniacal sulfate and carbonate solutions with commercially available extract ants commonly used by industry. Results from laboratory shakeout tests compared well with predictions of the equilibrium concentrations of copper and pH values. For example, the loading of copper onto the solvent was predicted for most cases within ±S pct of the measured values, and the pH to with-in ±O.l pH unit in sulfate systems and ±O.2 pH unit in carbonate systems. Both mechanistic and empirical extraction equations were developed from laboratory data for copper and ammonia. The empirical-based models were slightly more accurate than were the mechanistic-based mod-els. Industrial level concentrations of the aqueous and organic constituents were used in this work. Independent variables included copper concentration, ionic strength, and initial pH of the aqueous phase; extractants, diluents, and their concentration in the organic phase; and temperature.

Jan 1, 1988

By E. V. Cilento, R. C. Laotz, K. A. DiGregorio

"PULMONARY ALVEOLAR macrophages (PAM) protect the lungs by providing a first line of defense against inhaled foreign debris and bacteria. In this role PAM phagocytize foreign matter, secrete enzymes that augment microbial killing and digestion, and produce reactive oxygen me-tabolites (2, 3, 18, 19, 22, 26). However, in addition to this antibacterial function, PAM participate in a diversity of functions, such as tissue repair, lipoprotein metabolism, and immunoregulatory activities (11, 22).Studies have suggested the existence of a heterogeneous population of PAM with respect to immunologic function, enzyme release, phagocytosis, morphological characteristics, expression of membrane receptors, ad-herence, and superoxide (O2•) release (4-7, 10, 16, 21, 23, 28). This heterogeneity has been observed by analyz¬ing subfractions of PAM separated by cell density frac-tionation. For example, using guinea pig PAM, Dauber et al. (7) showed heterogeneity in cell density and size, morphological characteristics, and cytochemical properties, whereas Holian and co-workers (16) reported variations in migration, chemotaxis, O2• release, and pinocytosis among subfractions collected. Similarly, O'Neill et al. (21) observed functional heterogeneity in rat PAM with regard to phagocytosis, O2 • release, and lysosomal enzyme activity.Several investigations have reported a correlation between PAM activity and cell volume. Most studies have shown that O2 release from PAM increased with decreasing cell size (15, 21, 25), although Bielefeldt Ohmann and Babiuk (4) reported a decreasing trend. However, Gallin (13) has suggested that significant variability may even exist within density-defined or cell-volume subfractions that could lead to misinterpretation of results concerning PAM heterogeneity.A better understanding of the heterogeneity in O2 production may be obtained by using single cell meas-urements to evaluate whether functionally distinct sub-populations actually do exist. As such, the present study was designed to examine heterogeneity in O2 • release from single PAM using a recently developed electrooptical technique (8). The initial oxygen metabolite, O2•, produced by NADPH oxidase at the surface of the plasma membrane, was measured by quantifying the reduction of nitro blue tetrazolium (NBT I to a diformazan precipitate. Measurements were made from video recordings of individual cells stimulated by their adherence to the bottom of a culture dish. The cell volume and degree of spreading also were determined directly from the same video recordings, and the data were correlated with the initial rate and maximum amount of diformazan produced by the same cell."

Mar 1, 1992

By W. C. Holliman

This second of a series of reports on the characteristics of commercial aviation gasolines presents inspection test data furni8hed on their products by 15 manufacturers of commercial grades of aviation gasoline and special data obtained in Bureau of Mines laboratories on samples of these gasolines. Data on 18 grade-80, 20 grade-91/98, 20 grade-100/130, and 9 grade-115/145 aviation fuels are presented. These gasolines represent July 1947 production.

Jan 1, 1948

By R. C. Hickman

"INTRODUCTION Marl, consisting of a bed of coarse shell conglomerate from 1 to 5 feet thick, occurs on the Chesapeake Corporation tract and Philbates properties in New Kent County, Va.Nine holes were drilled on these properties in February 1946. ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts prelimi¬nary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.The project was under the immediate supervision of Mitchell H. Kline, chief, Raleigh Division, Mining Branch.LOCATIONThe Chesapeake Corp. deposit is reached from West Point, Va., by driving west on State Route 33 to the junction of State Route 634, approximately 5 miles. Proceed southeast along State Route 634 about three-quarters of a mile, at which point an old longing road turns north along a ridge and leads to the marl outcrops about one-half mile distant. The Philbates property lies three-quarters of a mile farther west along State Route 33 from the junction with State Route 634. The property lies north of State Route 33 and east of State Route 623 (fig. 1). The marl deposits are on the north end of the farm. The Chesapeake Corp. tract comprises 174 acres and the Philbato property 58 acres."

Aug 1, 1947

By Thomas A. Davidson

The Bureau of Mines Helium Field Operations has developed a simple and accurate method for calculating the viscosity of gas mixtures. Only the composition of the mixture and the molecular weights and viscosities of the pure components in the mixture are required. The momentum fraction of a mixture is calculated from the composition. The fluidity is calculated as a quadratic function of the momentum fractions. The efficiency factor for transfer of momentum in collisions between bodies of different masses is derived and used with one empirical constant. The viscosity is the reciprocal of the fluidity. Results of the method are compared with 752 reported viscosities for 40 dilute binary systems at temperatures from -78 to 276.9°C. Using this method the average absolute deviation is 1.29%, the root-mean-square deviation is 1.99%, and the average deviation is -0.84%.

Jan 1, 2010

By R. J. Leary

Significant improvements in surface conditions or mechanical properties of steels have been attributed by several investigators to ladle additions of small quantities of rare-earth metals or their oxides. To investigate systematically these effects in wrought and in cast plain carbon and alloy mechanical steels containing approximately 0.35 percent carbon, heats of four representative compositions were melted by the Bureau of Mines in a 4-ton open-hearth furnace. Each heat was cast into three sets of ingots to exemplify respectively, treatments with (1) rare-earth metals, (2) rare-earth metal oxides, and (3) an untreated set as a control. The development of melting, casting and rolling practices is described and discussed. Lance injection of oxygen shortly after melt raised the temperature of the metal immediately as much as 500° F., principally because mechanical agitation exposed the high-carbon metal to the flame and furnace root. An exceptional degree of superheat in the metal at the termination of the refining period was attributed to oxygen injection during the refining period. Bath temperatures higher than industrial practice were permitted by the all-basic furnace lining. Rates of carbon elimination as high as 0.036 percent carbon per minute were achieved by oxygen injections.

Jan 1, 1961

The object of this program was to design and build a self-contained system for remote monitoring of the atmosphere in mines. The system developed uses the mine pager phone line as the primary communication channel and also has the capability of using 208 Hz in the ELF band for wireless transmission through the earth. The depth for through-the-earth transmission is expected to be about 80 to 90 meters in high conductivity soil and is limited by the noise level in the ELF band-pass filters. The underground components of the TEM System are energized by mine power through a battery charger - storage battery power supply. In the event of mine power failure the battery capacity is more than sufficient for one week's operation with interrogations every four hours.

Jan 1, 1980

By Agnes Y. Lee

The Bureau of Mines has developed an effective hydrometallurgical method to recover high-purity Pb metal and elemental S from concentrates. This low-temperature process eliminates S gases and Pb emissions, in contrast to the current high-temperature smelting technology. The method consists of (1) oxidative leaching with H202, Pb02, and waste fluosilicic acid at 95° C to produce a solution of PbSiF6 and a residue containing elemental S, (2) electrowinning the PbSiF6 solution at 35° C to produce 99.99 pct Pb metal and H2SiF6, and (3) solvent extraction to recover S, leaving a residue containing Cu, Ag, and other metal values. Spent electrolyte was recycled repeatedly, with impurity buildup controlled by controlling the leach parameters.

Jan 1, 1986

By Foster Fraas

Under a very high vacuum of 10-8 torr the transfer of terrestrial mineral beneficiation methods to the vacuum ambient of extraterrestrial locations such as the lunar surface was investigated. In the size range for the electro-static and magnetic separation of ores (minus 35 plus 150 mesh) there is no adhesion of particles produced by crushing and grinding due to the limited contact area, and for repeated contacts area size has a frequency of occurrence in accordance to the normal law. The photoelectric effect which is successful in separating a few minerals in an air ambient has a wider application in a vacuum, while the lack of air viscosity and sound transmission provides for high feed velocities and the adaptation of particle vibration to dispersion and grinding. Contact electrification is reversible upon return to atmosphere.

Jan 1, 1970

By J. M. Stuve

Low-temperature heat capacities and the enthalpy of formation were deter-mined calorimetrically by the Bureau of Mines for CuO?CuS04. The derived standard entropy (S°298.15) was 40.36±0.04 cal/deg-mole, and the enthalpy of formation (?H°f) was -219.l±0.3 kcal/g-mole. A large thermal anomaly was observed in the heat capacity of CuO?CuS04 at 20±0.1 K. Gibbs energy of formation data are tabulated up to 1,200 K. Construction details of a precision low-temperature adiabatic calorimeter capable of determining heat capacities of solids in the temperature range 5 to 320 K are given. A calibrated miniature germanium resistance thermometer was incorporated into the calorimeter to extend the range of accurate measurements below 15 K. High-resistance dc heater windings were used throughout the cryostat to reduce heat conduction of inner connecting wires.

Jan 1, 1975

By J. H. Soulé

"The Copper King copper-gold-silver deposit was discovered about 1880. Various individuals and companies have been interested in the deposit and considerable work has been done, although production, if any, has been small. The deposit is located in the western part of Laramie County Wyo., and is favorably nituated with respect to rail and truck transportation and high-tension power facilities.Mild summers and cold winters characterize the climate. Precipitation averages between 16 and 17 inches annually, with considerable snowfall in the winter. Permanent streams are small and most available water in being stored for use by Cheyenne, Wyo. Range grasses comprise the bulk of the vegetation, with small treed and shrubs common in the most rugged areas.The deposits lie upon land owned by Wyoming, now leased by a group of Wyoming and Colorado businessman constituting the Copper King Mining Co.Primary copper-gold mineralization seems largely confined to an equigranular, relatively fine grained gneiss that is part of a pre-Cambrian complex of metamorphic rocks ranging from schists to pegmatites. The copper minerals are oxidized to a depth of from 100 to 150 feet, with the occasional occurrence of secondary minerals at greater depths. The copper minerals chalcopyrite, malachite, chalcocite, bornite, cuprite(?), and some native copper were observed in Le deposit.In addition to the 4,030 feet of diamond-core drilling in 11 holes done on the deposit by private companies, the Bureau of Mines drilled 3 holes for a total of 2,630 feet. The sample results of this drilling plus available data from previous drilling and sampling are appended to this report."

Jun 1, 1955

By J. D. Davis

The Bureau of Mines Coal Carbonization Laboratory has been interested for the past 20 years in the quality of coke in connection with the selection of coals for the manufacture of coke. The principal experimental. method of carbonization, whereby 100- to 200-pound charges are carbonized in sheet-steel cylindrical retorts with recovery and determination of the properties of coke, gas, and products, was developed in cooperation with the American Gas Association,4 5 and it is known as the BM-AGA method. Results of the investigations of 90 coals included in the BM-AGA Survey of the Carbonizing Prop¬erties of American Coals have been published; 6 and, in addition to these, about 200 coals have been carbonized over limited temperature ranges. Because coke from cylindrical retorts differs in shape from that made in rectangular ovens, the BM-AGA method has been criticized, although those who developed it have always believed that it served well as a means of measuring the relative strengths of cokes from different coals. It is recognized that no laboratory-method carbonization, even on a large twit, can yield results that exactly duplicate those obtained in commercial ovens and retorts. However, with the completion and satisfactory performance of an experimental vertical slot oven of 500-pound capacity at the University of Illinois Geological Survey Laboratory,' the opportunity to directly compare BM-AGA coke with coke made by two-sided heating became available and the necessary test apparatus was installed. The Bureau of Mines slot oven, which is similar to that designed by the University of Illinois Geological Survey, has been used to carbonize 11 coals (or blends) tested by the BM-AGA method. This report compares the results obtained by the two methods.

Jan 1, 1950

By Milford L. Skow

Utilization of domestic ores in the winning of metallurgical alumina requires a convenj.ent method of treating siliceous bauxites and other aluminous materials. In the United states there are only small reserves of high-grade bauxite but considerably larger tonnages of low-grade material. In addition, there are large deposits of high-alumina clays. If these high-silica bauxites or high-alumina clays could be beneficiated, either by are dressing or by chemical dissolution to remove a large proportion of the silica, then the potential reserves of aluminum ores would be increased materially. Faced with a similar situation, the German industry, chiefly dependent on high-grade French bauxites prior to World War II, was compelled during the war to Use lower-grade ores. For desilicating the lower-grade bauxites before the Bayer treatment, a method was developed in which the bauxite was calcined and then given a dilute caustic leach preliminary to the pressure digestion. It was planned to regenerate the caustic by treatment of the desilication liquor with lime. As European bauxites are mineralogically different from those found in this country, preliminary work was undertaken to determine whether this process might be applied to domestic materials. The results of this work, along with a review of the German process, are presented in this report.

Jan 1, 1950