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By H. E. Powell, T. E. Hill, W. A. Calhoun

The object of this investigation was to determine the effectiveness of certain cationic flotation collectors , Ethomeens , in recovering fine particles of lead minerals from mill tailings at a grade equal , at least , to that of the mill feed ( 1.7 percent lead ) . The Ethomeens , derived from tertiary amines having one fatty alkyl group and two polyoxyethylene groups attached to the nitrogen , were evaluated by bench- scale flotation tests . The 14 Ethomeens tested consisted of four groups : Coco amine , soybean amine , tallow amine , and stearyl amine . The best results were obtained with coco amine C / 12 , soybean amine S/ 15 , tallow amine T / 12 , and stearyl amine 18/20 . From a feed containing 0.23 percent lead , rougher concentrate grades of 2.12 to 3.89 percent lead were obtained , with recoveries of 17.3 to 27.5 percent of the total lead . Some of the lead mineral particles recovered had diameters of less than 1 micron . In comparative tests , the Ethomeens , or polyethoxylated amine types of cationic surface active agents , were more selective than conventional xanthate collectors for flotation of slimed lead minerals .

Jan 1, 1964

By C. H. Schack, K. C. Dean

An investigation was made to devise and evaluate a flexible flotation method for beneficiating typical tactite types of calcareous scheelite - bearing ores ; these scheelite - bearing ores are available in large tonnages in deposits containing 0.2 to 0.3 pct tungsten trioxide . The objective was to achieve a high recovery of the tungsten in concentrates , containing a minimum of 10 pct WO3 , that would be suitable for chemical processing into high- quality synthetic scheelite . The principal problems encountered and resolved by bench- scale flotation tests on ore samples from five different deposits were to define the conditions and reagent combinations essential for ( 1 ) achieving selective flotation of a small amount of scheelite from a large amount of calcite and ( 2 ) controlling the effect of small amounts of calcium , magnesium , and iron salts in the ores and water used . The flotation process was evolved from batch tests and continuous runs in a pilot - scale mill with a capacity of 100 lb per hour . The flotation process comprised ( 1 ) removal of sulfide minerals , ( 2 ) conditioning the residual ore pulp with sodium carbonate , quebracho , and trisodium phosphate , and ( 3 ) rougher flotation and single - stage cleaning of a scheelite concentrate . In a pilot plant run , over 91 pct of the tungsten was recovered from ore containing 0.27 pct WO3 , in a concentrate containing 11.2 pct WO3 .

Jan 1, 1964

By Richard W. Lewis, Lloyd Carpenter

The objective of the investigation was to determine spectrochemically 19 elements in the general range of 0.5 to 1,000 ppm in high - purity hafnium and its compounds . Samples were converted thermally to hafnium dioxide , mixed with buffer - carrier - internal standards , and excited by a dc arc . Spectra were recorded on photographic plates . Transmittance values were recorded densitometrically and converted to relative - intensity ratios . Four groups of standards were used to establish analytical curves from which the concentrations of impurities were obtained . Average precision of the method was 14.2 percent relative standard deviation , and relative error was 4.2 percent .

Jan 1, 1964

By R. T. DeWoody, J. W. Chester, W. C. Miller

The work was done to develop a relatively efficient muffler for quieting the exhaust of a rock drill . The exhaust of a pneumatic rock drill is the source of the major part of the noise generated by the drill . The exhaust noise can be reduced in a number of different ways , but this study involved only reactive mufflers . The reactive muffler can be simulated by an electrical circuit . Information obtained from analogous electrical circuits was used to design an efficient exhaust muffler for pneumatic rock drills . Electrical analogies proved to be a valuable tool in the design of mufflers .

Jan 1, 1964

By BUREAU OF MINES

This report is submitted in accordance with the provisions or une Synthetic Liquid Fuels Act of April 5, 1944 (30 U.S.C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1951 has been divided into two separate publications. Each has been published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: Oil from Coal. R. I. 4865, Part I - R. I. 4866, Part II - Oil from Oil Shale. Identical in each report, the introduction summarizes research progress made in 1951 under the entire Synthetic Liquid Fuels program. A free copy of these publications may be obtained by a written request to the Bureau of Mines, Publications Distribution Section, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Jul 1, 1952

By L. C. George, J. W. Jensen

A new system for precisely counterbalancing and measuring vapor pressure operates by servomechanical principles . It was developed with the objective of determining the vapor - pressure equations of metal halides . The system is isolated from the vapor - pressure bulb by a diaphragm transducer that signals a pressure regulator to null any pressure difference that is detected . Pressure measurement and readout are continuously performed by a servomanometer , accurate to ±0.003 cm Hg for the range of 0.1 to 200 cm Hg . High response rate and sensitivity are obtained . Methods of use are described , and results for CdC1 and PbC1 , in agreement with data of other investigators , are given as examples .

Jan 1, 1964

By R. R. Sayers

Mine operators and managers for a number of years have known that the maintenance of health among the workers has an appreciable financial value, In order to maintain the health, it has been found ne cessery to imow; 1. The health hazards existing in the industry as a whole and the specific hazard in the individual mine. 2. The physical condition of applicants for employment as well as that of the old employees. This can be determined only by systematic physical examination of all applicants and of regular employees at intervals of at least once a year thereafter. 3. All cases of sickness that occur among the workers. No operator or manager, or personnel, medical, or safety organization can control or prevent sickness without knowing where, when, and under what conditions the sickness actually occurs. In order to obtain information as to the hazards of industry, investigations have been and are being made of the effects of the condi- tions both in the field under usual working practices and in the laboratory. In the field several factors are generally present which affect the health. The effect of these factors may be determined by studying each of them separately in the laboratory. However, both the field and the laboratory studies are limited in value in that such studies usually have been made over a comparatively short period. While we have some information as to their immediate effect, we do not know to what extent extreme heat, humidity, the presence of dust or other health hazards are the cause of disability. Mortality statistics are probably the most easily available indices as to the hazards of industry. As an example, a study of such statistics among coal miners of Indiana shows a marked increase in the death rate in 1918.

Mar 1, 1923

By R. B. Stroud

This report, part 3 of a series, describes and gives results of field. investigations by the Bureau of Mines on manganese resources of the Batesville district, Arkansas, from July 1956 through June 1961. The purpose of the Bureau's work was to evaluate the manganese potential of the district in fur- therance of the Government's program with respect to domestic resources of critical and strategic minerals. The work comprised areal reconnaissance, mapping, churn and core drilling, and sampling. In more recent years, the investigations were confined to manganiferous limestone, which constitutes a significant potential resource of manganiferous material. The resources of manganiferous material in the district are inferred to be on the order of 198 million long dry tons averaging between 4 and 5 percent manganese.

Jan 1, 1964

By M. H. Rinkenbach, C. A. Taylor

The detonating compound cyanuric triazide was discovered*** and patented**** by Erwin Ott, and on account of his claims, the Bureau of Ordnance, U. S. Navy, desired more complete data, so an investigation was made. The results obtained were such that the Bureau of Crdnance recommended publication thereof for the benefit of the explosives industry. Some of the patent claims regarding cyanuric triazide are as follows: 1. It is not poisonous in contradistinction to fulminating mercury and lead azide. 2. In contradistinction to the hitherto employed priming agents it is fusible, and its fusion point (94°C) is so low that the product melted by a single heating in water or steam bath, can be poured without danger in the capsule shell. It solidifies therein after cooling, and shows the density of 1.5. 3. It has been determined that the cyanuric triazide, in spite of its very much higher priming actions, is much less brisent then ful- minating mercury and lead nitride. 4. The chemically pure cyanuric triazide (C3M2) constitutes colorless crystals melting at 94°0., and is not volatile. It is not affected by cold water, and only slowly saponified by hot water. It is relatively insensitive to friction and not too strong concussion, but explodes by impact or when hea ted to 170°C., or when heated suddenly. It is not more sensitive to friction and shocks then fulminating mercury. 5. The preparation of the triazide is preferably carried out by acting with an excess of sodium azide in an aqueous solution; in the cold, on cyamric chloride gradually suspended in the said solution.

Aug 1, 1923

By A. B. Hooker, L. C. IlsLey

Several ignitions or mine pa, which might have led to explosions, and at least ona mine fire attributed to heated leg wires of electric detonators, have occm.rred. at rn1::.es in which outside shot firing is practiced. Photographs taken at one mine ind.la.ted. that the wires became red hot during firing. These results having been --i·-led. to the .Lttention of the electrical section of the Bureau of the Mines, ignitions the tests and to reportd aid in herein preventing were made future to trouble determine of if this possible kind, the cause of The investigation, which 1• considered preliminary, included tests to determine the conditions tha.t cause gas ignitions from heated. leg wires of electric and. of detonators, copper leg possible wires, remedies The tor samples such of heating, wire used. and in the the relative test were behavior the of reg\llar ironDa. Pont iron and copper leg wires (No, 22 A,W,G.) C\1t from Du. Pont electric detonators.

Aug 1, 1922

By Harold M. Smith

The data in this report were prepared to show how Bureau of Mines routine crude oil analyses could be used to evaluate crude oils in terms of common commercial products . The use of Bureau of Mines routine analyses to determine hydrocarbon - type relationships for the gasoline and gas - oil fractions is demonstrated . For this purpose the correlation index , the aromatic profile and the naphthene profile are used to establish reasonably acceptable values for hydrocarbontype relationships . The derivation and meaning of these indications are discussed . These analytical interpretations are applied to a group of high - sulfur crude oils from the Near East , the Permian basin of West Texas , Venezuela , Colombia , California , and other locations , and the resultant data for gasoline , gas oils , lubricating oils , and asphalt are compared by appropriate tables and graphs . Because the Near East crude oils contain higher quantities of paraffins in the gasoline and gas oil ranges , they will yield good , lowsolvency solvents and good kerosine , jet fuel , and diesel fuels , but straightrun gasoline of inferior quality compared to similar products from either West Texas or Venezuelan high - sulfur oils . The Near East oils also should be good sources of lubricating stock . However , when used as stock for catalytic cracking or reforming , the Near East oils suffer by comparison because they are deficient in naphthenes .

Jan 1, 1964

By Wilbert J. Huff

For the past 9 years , the technical studies conducted by the Explosives Division of this Bureau have been summarized in a series of reports issued annually . The following account presents investigations undertaken from July 1 , 1943 , to June 30 , 1944. The work is detailed under a number of main headings corresponding to the organizational structure of the Division , the various activities being under the immediate direction of unit chiefs , who report directly to the author . Specific credit , however , is due to the individual unit leader and his assistants .

Jan 1, 1945

By William R. Wayment, David E. Nicholson

A modified percolation - rate test is proposed for use in determining flow rates through hydraulic backfill ; in contrast to the conventional test , a percolation- rate versus void - ratio relationship is established . requirements and a detailed test procedure are described . Equipment Results of a conventional test are compared with those of the proposed modified test . The proposed modified test method yields more accurate , realistic , and usable percolation- rate ( permeability ) data . The significance of obtaining accurate percolation rates for use in analyzing waterflow through hydraulic backfill is discussed .

Jan 1, 1964

By L. C. IlsLey

A n'Ulllber or operators have installed f'lBJ!le-proot or so-called exploaion­ proot electrical outfits, under the impression that such equipments met· all of the reqiirements of the Bureau of Mines as regards safety, There a.re todq in gaseous mines a large nwnber of euipments that have not been approved by the Bureau ot Mines, and unless mod1f'iecl could not receive sucl1 approval.. These e qu.ipments represent in pa.rt the product of manufacturers whil ha.ve never submitted. equipments for insri?ction or tests. and iri pat types developed. previous to the safety work or the bureau. Sometiu.es saleimen advocate the use of unapproved. types in gaseous mines in place of Bureau of Mines approved outfits, the purchase price beini slightly less than approved types,

Sep 1, 1922

By Carl Rampacek, W. A. McKinney

The feasibility of leaching calcareous and siliceous oxidized copper ores by downward percolation with dilute acid was investigated in the laboratory and in a small continuous plant operated by the Federal Bureau of Mines . The crushed ore was leached in deep columns with solutions containing 1 or 5 percent sulfuric acid to dissolve the oxidized copper . Bench - scale laboratory tests on two calcareous ores from the same deposit indicated that a maximum copper extraction , about 72 percent , could be expected from heap leaching a feed as coarse as 1 inch . Laboratory tests on a siliceous ore showed that almost 70 percent of the copper could be extracted by leaching a 1 / 4 - inch feed . The bench - scale tests were supplemented by larger continuous runs wherein the copper was recovered from the leach liquors by precipitation on detinned scrap iron . Leaching the calcareous ore for approximately 10 days recovered 62 percent of the total copper . The sulfuric acid consumption was 9.6 pounds per pound of copper recovered . Treatment of the siliceous ore recovered 62.5 percent of the total copper in a 2.5 - day leach and the acid consumption was 3.7 pounds per pound of copper recovered . Cement copper products that assayed over 71 percent copper were obtained from the leach solutions by precipitation on scrap iron . The bench - scale and continuous tests demonstrated that downward percolation leaching of the calcareous ores was technically feasible but not economically practicable because of high acid consumption by the gangue . Leaching of the siliceous ore was rapid and the acid and water requirements were nominal . The downward percolation leach procedure is simple and requires a minimum of plant equipment .

Jul 1, 1960

By John H. Soule

Appreciable quantities of sine and lead orus have been produced from the West. Pinos Altos district of Grant County, N. sex. This area was visited many times by engineers of the Bureau of ines. D. H. Johnson and 4. R. Storms visited the district in haren 1943 in connection with an acrenu road to toe wines. M. H. Storma again visited the area in July 1943 in connection with a hetals Feserve Corporation loan on the Routen-Thomas

Apr 1, 1948

By Henry M. Harris, John E. Kelley, Thomas D. Roberts

A penetrometer apparatus for measuring viscosity of glass at temperatures up to 1,450 ° C was developed for use in establishing the viscosity coefficients required for high- temperature forming of ceramic materials . The major advantage of the method is that it can be used with samples of almost any shape or size without the necessity of forming or measuring shapes to close dimensional tolerances . Also , it has proved accurate in the range of 106 to 109 poises , a gap between the normal limits of other methods . The device , which operates on a single penetrometer principle , was used to determine the absolute viscosity coefficient of substances in centimeter - gram- second units of poises instead of relative penetration - rate units as with other penetrometers . Penetration of the viscous sample was sensed with a linear , variable differential transformer . The output of this transformer was recorded versus time , and the penetration rate was used in calculating the viscosity coefficient . The general equation relating penetration rate and viscosity coefficient was found to be 11 = F ( ln L/a 0.72 ) 2 π UL · where is the viscosity coefficient in poises , F is the penetrator load in dynes , L is the penetration depth in centimeters, a is the penetrator radius in centimeters and U is the penetration rate in centimeters per second . The penetrometer was tested using a standard viscosity sample of sodalime - silica glass obtained from the National Bureau of Standards ( NBS ) . Values obtained at several temperatures all agreed within 10 percent with comparable data calculated from the Fulcher equation derived by NBS for this glass . Equivalent accuracy was obtained with other glasses used to evaluate the apparatus .

Jan 1, 1964

By H. H. Stoek

It would permit coal mines to operate continuously instead of intermittently . Intermittent operation increases the cost per ton for mining , and makes the yearly return to labor low . These conditions contribute to serious instability and unrest in one of the fundamental industries of the country and this can be changed only by coal buyers doing their part to insure steady work . The railroads are now required to transport the maximum amount of coal during the winter months when traffic is most interfered with by bad weather and when the maximum amount of coal is used by the railroads to handle other coal . The railroads now use nearly 30 per cent of the total output of coal . About one- third of their freight traffic is hauling coal , so that economy of fuel used by the railroads will produce a considerable gross saving .

Apr 1, 1920

By D. S. Harper, C. O. Carman

A German coal planer was put in operation in the Keystone mine of the Eastern Associated Coal Corp. , Keystone , W. Va . , in August 1960 . At present , the planer is mining in the fourth panel . The blocks of coal mined were 340 by 1,900 feet in panel 1 , 340 by 1,660 feet in panel 2 , 590 by 1,900 feet in panel 3 , and panel 4 , currently being mined , is 590 by 1,900 feet . Almost one- half million tons of coal have been mined from these four panels . An 11 - man crew handles the complete planer operation and produces an average of 500 tons of clean coal per shift . Self - advancing hydraulic props are used to support the roof over the entire face . Roof control and action on all of the panels has been highly satisfactory . During periods of extreme pressure , some additional support is required in the tail entry where evidence of weight from the retreating longwall extends about 200 feet outby the face . The time lost from production by moving equipment between panels has been reduced steadily . The move from panel 3 to panel 4 required 5 days , but it is believed that even that time could be reduced .

Jan 1, 1963

By A. E. Schwaneke

Plans and specifications are given for constructing a quartz composite oscillator designed to measure internal friction in metals and alloys . The characteristics of the system are listed , and detailed procedures for its operation are explained . Typical measurements on manganese - copper alloy , on single - crystal magnesium , and on polycrystalline magnesium are shown to illustrate applications of the system .

Jan 1, 1964