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By Andrew B. Cecala

The U.S. Bureau of Mines has designed and evaluated total mill ventilation systems at two different mineral processing operations. Both systems have proven very effective at reducing respirable dust levels throughout the mill in a cost-effective manner. A 25,500-cfm system installed at a clay processing mill provided approximately 10 air changes per hour. This system reduced respirable dust concentrations by approximately 40 pct throughout the mill building. The second evaluation was performed at a silica sand operation. Tests were performed with 50,000 and 100,000 cfm of ventilation to the mill building, corresponding to 17 and 34 air changes per hour. Average mill-wide respirable dust reductions were 36 and 64 pct, respectively. Not only did these systems reduce respirable dust concentrations and increase visibility throughout the mills, they were also easy to install and required minimal maintenance. A total mill ventilation system provides a general purging of the mill air; the system should be viewed as a supplemental technique to assist other dust control systems in operation.

Jan 1, 2010

By W. L. Dare

This information circular is one of a series published by the Federal Bureau of Mines in which the methods and costs of producing uranium ore on the Colorado Plateau are discussed. This report describes the three largest company-operated uranium mines of Climax Uranium Co. - the G-1, the Mineral Joe, and the Frank No. 1. Climax Uranium Co., a subsidiary of American Metal Climax, Inc., was [corporated] May 11, 1950, just 2 years after establishment of the domestic uranium program by the Atomic Energy Commission. Twenty-five years earlier Arthur H. Bunker, now chairman of the board, American Metal Climax, Inc., organized and operated the U. S. Vanadium Co. at Rifle, Colo.3/ Soon after Climax Uranium Co. was organized, it entered into a contract with the Federal Government to build a uranium-vanadium processing mill in Grand Junction, Colo. Under the contract Climax leased from the Federal Government certain uranium-bearing lands that had been withdrawn from public entry in 1948. From Minerals, Engineering Co. on June 12, 1950, Climax acquired other uranium-vanadium properties on Calamity, Outlaw, and Monogram Mesas in Colorado and on Polar Mesa and in the Yellow Cat area of Utah. To house the milling equipment, Climax leased the old Grand Junction sugarmill building of the Holly Sugar Co. Milling facilities, based on a then new process developed for treating both uranium and vanadium, were completed, and the plant went into production in 1951.

Jan 1, 1959

By Thomas W. Camm

In this U.S. Bureau of Mines report, mine and mill cost models are presented to make quick estimates of the cost to develop mineral deposits in the desert region of the Southwest United States. Regression analysis was used to generate capital and operating cost equations for each model in the form Y = AXB, where Y is the cost estimated and X is the assumed daily capacity in short tons. A and B are constants determined by the regression analysis. Each is broken down into 11 subcategories to facilitate escalation of costs for inflation and to increase their versatility in economic evaluation work. This report contains 2 open pit models, 6 underground mine models, 11 mill models, and cost equations for access roads, powerlines, and tailings ponds. In addition, adjustment factors for variation in haulage distances are provided for open pit models and variation in mining depths for underground models.

Jan 1, 1991

By D. R. Mathews

The solubility of carbon in electrorefined vanadium was determined to be approximately 0.27 wt pct at the eutectic temperature 1,650° C and 0.03 wt pct at 700° C. The tensile strength and hardness of vanadium increased with car-bon content to the solubility limit, but this effect was small, probably because of the narrow solubility range. Between the solubility limit and 0.3 weight-percent carbon, the second phase had essentially no strengthening effect in vanadium. The second phase, observed metallographically at the grain boundaries and within the grains, was shown by autoradiography to contain high-carbon concentrations. This second phase was identified as VgC by X-ray analysis. The VgC in the grain boundaries contributed largely to the poor cold-and-hot workability of vanadium-carbon alloys. Increased concentrations of V2C occurred at the grain boundaries of the high-carbon alloy ingots as a result of homogenization at 1,600° C for 1 hour. Alloy ingots containing more than 0.36 wt pet carbon (a calculated 2.9 wt pct VaC) following homogenization, cracked severely and failed by intergranular fracture upon swaging at 900° C.

Jan 1, 1965

By William J. Campbell

One of the principal objectives of the Bureau of Mines program for developing super refractory materials is to obtain fundamental data on the physical properties of refractory oxides. This particular investigation obtained accurate thermal expansion coefficients for alpha alumina and evaluated, critically, those coefficients with other published values. High-temperature X-ray diffractometer measurements, by the Bureau, showed that alpha alumina expands anisotropically with expansion parallel to the c axis approximately 10 percent greater than parallel to the a axis. Thermal expansion characteristics of four different alumina samples were determined up to 1,200° C.; the results are presented in both tabular and graphical form. The combined random and systematic errors in the measurements are considered less than 3 percent above 500° C, and approximately 2 percent at 1,000° C. No differences in expansion were observed between the samples or between the heating or cooling cycles.

Jan 1, 1961

By James C. Cawley

A summary is presented of existing leaky feeder communications systems currently in operation in North America. Background information pertaining to previous use of leaky feeder technology is discussed along with the survey methodology. A review of some pertinent facts concerning propagation in tunnels and specific reference to mine tunnel propagation is presented. A summary of the characteristics of each mine visited is presented in tabular form, and methods of procurement and maintenance are discussed. The role of user training in efficient system use is presented. Seven sites representing eight mines are included in the survey. Economic and technical topics are considered.

By Charles Vaught, Richard S. Fowkes, Ronald S. Conti, Barbara Fotta, William J. Wiehagen

The purpose of this study was to determine mine workers' state of fire-fighting preparedness and the technology being used to detect and respond to underground coal mine fires. To investigate this problem, 214 underground coal miners were interviewed by U.S. Bureau of Mines researchers. Frequency distributions of workers ' responses are presented in this report, along with segments of narrative accounts, to profile miners' fire-fighting capabilities. The data indicated that much variability exists from mine to mine and that there are several important changes operators may undertake in order to make miners better prepared to deal with fire underground: select appropriate sensors, establish and test a warning and communication protocol, construct a system capable of delivering hundreds of gallons of water per minute for sustained periods, institute formal fire preparedness audits, develop case studies of events that occur at an operation to use as teaching and assessment tools, and provide structured practice that can be incorporated into fire drills.

Jan 1, 1995

By Robert N. Roby

The Hornsilver lead-zinc property was examined by the Bureau in 1942 and again in 1944. A project was started on the property in April 1946 and completed in January 1947. Silver was first discovered in this district in 1883, and while complete production records are not available, it is known that a substantial tonnage of high-grade silver ore was shipped before 1887. All of the ore was mined from surface or near-surface workings. When the high-grade oxidized ore was exhausted, the district became inactive and remained so until the 1920's. In 1928 and 1929 some activity was shown in the district, but the Hornsilver mine was not reopened until November 1937. Between 1939 and 1946, the mine produced about 16,000 tons of ore of 531 ounces of gold, 283 ounces of silver, over a million pounds of load, and nerdy 2 million pounds of zinc. The property is now controlled by the Era Mining & Development Co., which has acquired the Last Chance and Ella groups of claims, in addition to the Hornsilver mine.

Jan 1, 1948

A spectrochemical procedure applicable to the determination of iron, manganese, and magnesium in titanium metal and to the determination of alloying constituents in three types of titanium alloys is presented. Acid solutions of samples and standards are excited with a spark-type discharge and porous-cup electrode arrangement. The method is particularly applicable for analyzing samples for which a self-electrode method cannot be used. Calibrations are accomplished with synthetic standard solutions, resulting in a primary method that makes calibrations based upon results of other analytical methods unnecessary. Replicate determinations are reproduced to within 5 percent, and the average percentage deviations from reliable chemical values are less than 6 percent. The method can be extended readily to determine additional elements that are similarly soluble and have similar spectral sensitivities. It also can be used as a starting point to establish standards for a direct sparking procedure for analyzing titanium alloys. In view of the absence of established reliable analytical methods in the titanium industry, the spectrochemical method described here should prove to be a timely contribution.

Jan 1, 1956

By F. G. Miller

[Petroleum technoloF;istz and 1 rot-re s s ive OT e:?ztors. con stantl;, are striving to increase the percentage of oil that y to recovered from reservoir rocks throe::;:: wells. The exhaustive studies that have been made of the function of natural r:; as in t h-_ T r odI action of oil, for cx<n.mTnle, have aidedd of.erators greatly in incroasin,&apos; the q-:Arrntity of oil recovered from reservoirs. i.rtural gas dissolv3d in ar--d otinerwwisa &apos;1s&apos;.,ocintjd under rre3suro with oil in roscrvoir roci.s, howover, i:; not the only source of energy available for moving oil through sa&apos;:&apos;l to wells. l becoming "reservoir-energy conscious&apos;t engineers hr-vo -d o^.rued t}:-Lt in many petroleum reservoirs the edgewater flanking t -,e oil accum.-,lation conetitutos a potential source of onergy capable, tL-ou;_h rro? gr control, oil&apos; increasing oil-recovery efficiencies materially. i o ]enter is ti-.-,, on-cronchinunt of water into the oil- and gas--fillod ?art of the reservoir considered as an evil to be combatted by devious mot&apos;:r:ci :i,.t r,ttL er a natural conseque::c4, incident to the withdrawal of oil nna gas from the wells, that nay be T.usod advantrt eou ;ly in lonr`t}toning tr e r&apos;lowin g lift of wells a.nd, i norcas in:; the economic recovery of oil and Little is known about the by which water off: oratos in driving nil throe:gh reservoir roc:-.:,, nd i:. a scorcity of rubli:;Lad informs-¬t .on nn rates of :)Ov.:m.,:- t of : r.tcr ..at v:1:11 res,-_lt in ^r i-nu oil recoveries. Bureau of :fines engine_:? ; - reciate. the r,aucity of scientific knowledge or. the &apos;test methods of a,r.lying the natural water arive to in¬crease oil-recovery efficiencies ant ,i.;?l __-itir?,~ ting irties that will, they hope, Contribute to t.1&apos;.e T ros?Jr.t. small _ %nd of information now av tilable on tt:e cubjoct. This r».crt a oyno-.::is or brief comrilnt.ion of r,ublished data and thought accuinulnt.~d so far, to la)or;~.tory ox-:erimnntrr¬tiorn and, further rosoarch on the z_rrinciplos unri;rlyir..g the natr.rr+1 eater drive no it nffocts oil recovery. :Lie writer:: Lore that t.i.c cx-nositiorn of a?rzilable inforr-at ion i rcs?r.toi in the rernrt r .-II .i ,.1rtt cor_jt_-i:ctive tho.-_.I_t and efforts loadir,-z to -:ard more con.r .ote extraction n;&apos; o tl from reservoirs.]

Jan 1, 1938

By C. P. Mangelsdorf

When the finely bedded shale frequently encountered over coal seams experiences a separation, the material below the separation must behave like a beam or plate in that it must resist both bending and shear. Be-cause of the weakness in interlaminar shear inherent in such strata, shear deflections that are usually ignored in isotropic beam theory may account for a significant part of the total roof sag. Similarly, when a roof truss is installed in such a roof the upward displacement reducing the sag will have components due to shear as well as bending. Questions asked by mine operators about the installation of roof trusses frequently deal with optimum position, slope, and initial tension of the inclined chords. This Bureau of Mines report examines the effects of those chord parameters on the strain energy of both shear and bending and offers optimum values that will minimize the total strain energy of the immediate roof. Design charts are provided, several design examples are included, and the results are compared with current practice. The effects of in situ stresses are investigated and are shown to be equivalent to an additional load on the beam.

Jan 1, 1988

By James A. Browning

Conventional flame channelling operates continuously at over 120 db --flame-drill channelling at a maximum of 95 db. The latter process was developed under this program. Individual drill holes are spaced to leave narrow rock webs. Sound and dust passing from the hole are effectively treated by a muffler and water injection.

Jan 1, 1980

By Kenneth M. Earl

This report describes the results of a field study conducted by the Bureau of Mines during 1956 and 1957 on manganese-and iron-bearing mineral deposits in the southern district of Aroostook County, Maine. The work was undertaken to determine the extent of deposits largely concealed under glacial drift and to obtain subsurface samples for manganese mineral identification and research in ore dressing and extractive metallurgy. The investigation was confined to the Westford Hill-Daggett Hill area in Hodgdon Township and to the Stewart prospects and vicinity in Linneus Township. Over 50 magnetic anomalies were mapped by magnetometric surveys in the Westford Hill-Daggett Hill area, Hodgdon Township. The largest anomaly, as outlined by the 1,000-gamma contour, indicates a deposit 3,200 feet long with a maximum width of 350 feet. The smallest anomaly measures about 10 feet wide by 25 feet long.

Jan 1, 1962

By Herman W. Sheffer

This report describes and discusses present-day leaching technology employed to recover copper from low-grade mine and dump materials derived from the exploitation of copper ore deposits in the Western United States. Illustrations of the integral parts of the leaching, precipitation, and recovery operations at several copper-producing companies are presented. Schematic drawings are included to present typical flowsheets of leaching and precipitation operations. Operational problems common to most copper leaching and precipitation plants are discussed. Areas of present and future research to improve leaching techniques are cited.

Jan 1, 1968

By Walter R. Storms

"INTRODUCTION Geological examination of the Iron Mountain beryllium deposits was begun by a field part 3/ of the Federal Geological Survey in May 1942. Later in that month the occurrence was examined by the author and C. H. Johnson, of the Bureau of Mines, and a preliminary exploratory program was outlined. Trenching and sampling began about June 15 and were completed in July 1942. A large tonnage of beryllium-bearing material was indicate by this preliminary survey, so that additional funds wore allotted for further trenching and sampling, underground exploratory work, and diamond drilling. This later program was initiated in July 1942 and was completed in May 1943. 4/ACKNOWLEDGEMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilisation 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 preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R.G, Knickerbocker, chief, analyzes samples and performs beneficiation tests."

Mar 1, 1947

By H. C. Hamontre

[The Bureau of Mines well-bore caliper was designed to provide an instrument that could be operated through 2-inch tubing, which &apos;a used particularly in many input wells on water-flooding projects of eastern, Kansas and northeastern Oklahoma. It should find wide application elsewhere under many other conditions where it has not been possible previously to make caliper logs with the larger probes used on other instruments. The caliper has three additional advantages over other instruments of this type: (1) It measures 4 radii (up to 18 inches) 90° apart with an accuracy of ± 1/4 inch; (2) the measuring arms can be opened and closed at will by remote control; and (3) it is run and operated on a single-conductor, armored electric cable (Amergraph, type 1-H-0). The caliper probe is 1-3/4 inches in diameter and approximately 6 feet in length. The electrical control and measuring circuits are encased in a stainless-steel tubular case. Measuring arms, made of 5/16-inch aluminum tubing, are attached near the lower end of the instrument. Distances the arms are extended are indicated t the surface by a meter calibrated to read directly in inches. Depths at which the radii measurements are taken are indicated by a wireline depth indicator on the cable-reeling. The instrument is not affected by pressure or temperature, it can be run open hole or under pressure through a lubricator. This paper describes and illustrates the instrument and outlines the operating procedures. A bibliography at the end of the report gives references to articles and patents on the development and use of other well-bore calipers.]

Jan 1, 1954

By J. W. Davis

The storage stability characteristics of a diesel type fuel were determined to evaluate the effect of the polar compounds in the fuel. These compounds, comprising most of the nitrogen and oxygen containing compounds and many sulfur containing compounds, were separated from the fuel with a chromatographic column. This fraction was further separated into three polar extracts by graded elution through the column. Each extract was characterized. A storage program using the depolarized fuel, the fuel as received, and blends of the extracts with both fuels, was conducted. Results showed that the removal of the more polar components stabilized the fuel. Blending the polar extracts with the original fuel and with the depolarized fuel in the same ratio as they existed originally and at two and three times the original ratio increased the amount of gum present before storage, but had little effect on the formation of additional gum during storage. Distillate fuels produced by commercial refining of petroleum contain traces of organic nitrogen, sulfur, and oxygen compounds that are more polar4 than the remainder of the fuel. Recent laboratory studies by the Federal Bureau of Mines (1),6 in which these compounds were removed from a fuel, have shown that they influence its storage stability. The objective of this work was to determine the amount of these compounds present in a fuel and their effect upon its stability in storage. To evaluate the role of these polar compounds, it is necessary to remove them from the distillate fuel. Many can be removed by chemical treatment (2), but such treatment precludes reblending the polar components to approximate the original fuel composition. Solvent extraction is free of some of the criticism of chemical treatment, but it is more difficult because of the complex mixture from which compounds must be removed.

Jan 1, 1961

By Theodore Kessler

The purpose of this Bureau of Mines investigation was to determine what new organic compounds or high concentrations of a particular organic species can be formed by exposure of coal derivatives to ultrasonic energy. Tetralin, l-methylnaphthalene, and pyridine were used as model compounds. Gaseous and solid reaction products resulting from the ultrasonic irradiation of these coal derivatives were determined using mass spectrometry. Products from the irradiation of tetralin were studied as a function of time, atmosphere, and sample size. The sonolysis (chemical reactions produced by ultrasonic energy) of tetralin and l-methylnaphthalene produced C2H2, HCN, CH4, H2, CO, and CO2, depending upon the experimental conditions. The ultrasonic irradiation of tetralin also produced diacetylene under certain experimental conditions. The cleavage of organic chemical bonds by ultrasonic cavitation in the absence of water was also observed in this study.

Jan 1, 1967

By Bertrand L. Johnson

As potash is more necessary to the agricultural economy of the United States now than ever before it is gratifying to find that the virtual stoppage of imports from Germany in late 1939 caused none of the anxious foreboding that gripped American farmers in 1914. For long decades this country, in common with tie rest of the world, depended upon German potash, but today our expanded needs can be mot from domestic sources. The present armed conflict in Europe, like that of 1914, disrupted a world monopoly, but the cartel that in recent years controlled 90 percent of the world output (see fig, 1) was an international syndicate comprising French, Polish, and Spanish as well as German producers and having reported sales agreements covering production in the U. S. S. R. and Palestine. The break-up of these commercial agreements has necessitated readjustments but generates no such alarm as the closing of a single source of supply. In striking contrast to the critical shortage that developed a quarter century ago, no increase in prices has occurred or is anticipated in the domestic market.

Jan 1, 1940

By H. H. Yancey

In this information circular is presented a summary of the more important articles that nave appeared in the literature pertaining to the experimental work and to the commercial operation of the froth-flotation and Trent processes as applied to the cleaning of fine coal.

Jan 1, 1933