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By Joan Weinberg

Seasonally adjusted new factory orders for primary metals declined in January, February, and March, especially in the steel industry. The decline was part of an apparent slowdown for the entire manufacturing sector. Orders for all durable goods, including not only primary metals, but also clay, glass, and stone products, fabricated metal products, machinery, and transportation equipment, fell in January and February. In March, orders rose a slight 0.8%. According to the U.S. Department of Commerce, the downturns in durable goods orders in January and February were the first back-to-back declines in 3 years. They were largely attributed to a drop in orders for transportation equipment, mainly auto-mobiles and aircraft, while the small gain in March was due to a surge in aircraft orders. Higher interest rates may be partly responsible for the slowdown in durable goods orders over the past 3 months. The higher rates have also hit the construction industry--another major end-user of minerals. Construction of new homes and apartments fell by a seasonally adjusted annual rate of 5.4% in March, following a 12% decline in February.

Jan 1, 1989

By Welby G. Courtney

The Bureau of Mines conducted a field test program in the Pittsburgh coal seam to investigate the effect of water sprays in the suppression of respirable dust being formed while cutting with a continuous-mining machine. Emphasis was given to the location of spray nozzles on the top and bottom of the cutting boom. Results showed that (1) sumping caused about 60 percent of the dust escaping the face area, and shearing and loading caused the other 40 percent; (2) during sumping, top and bottom sprays were equally effective in dust suppression and reduced dust ~13 percent; (3) during shearing and loading, bottom sprays reduced dust 61 percent and were about 50 percent more effective than top sprays; (4) the combination of top and bottom sprays was slightly more effective than the separate systems, but water consumption increased 60 percent; and (5) inclusion of throat sprays decreased dust reduction by removing some of the water from top and bottom sprays where it was more effective.

Jan 1, 1978

By R. Blickensderfer

Several thin film absorber stacks with spectrally selective characteristics were developed by the Bureau of Mines. The stacks consisted of a silicon thick film or a zirconium compound thin film on a reflective thin film of silver. The zirconium absorber films, with the general formula ZrCxOyNz, were prepared by reactively sputtering zirconium or zirconium carbide in argon with small amounts of oxygen, nitrogen, or both, or by oxidizing zirconium films in air. A few similar types of films were prepared from titanium. The short-wave absorptance over the solar spectrum, a(s), and thermal emittance at 600 K, e(600 K), of the solar absorber stacks were calculated from room-temperature reflectance data. The values of a(s) ranged from 0.47 to 0.93, e(600 K) from 0.49 to 0.034, and the ratio a(s)/e(600 K) from 1.7 to 34. The specimen with the best combination of properties, a ZrNx-Ag stack, had a solar absorptance a(s) of 0.85 and a ratio, a(s)/e(600 K), of 24. The effect of film thickness and composition on spectral selectivity was determined. An emissometer for measuring normal total emittance up to 800 K and a method for determining a (s), e(T) (hemispherical), and a(s)/e(T) using simulated solar radiation are described. A calorimetric method for measuring a(s) and e(T) (hemispherical) at elevated temperature is also described. Measurements made on several specimens agreed favorably with calculated values.

Jan 1, 1976

By Russell R. Trengove

Bureau of Mines exploration at the property of the Tulare County Tungsten Mines was by core drilling from the surface from May 16, 1950, to July 13, 1950. The property is in the western foothills of the Sierra Nevada Range, 18 miles northeast of Lindsay, Calif. It has been in almost continuous production since 1942 and has produced 40,831 units of tungsten trioxide (W03) with a grade of approximately 67 percent. The work performed comprised a study of the geology, mapping the area, sampling the outcrops, and diamond drilling the area adjacent to the mine workings. Ten holes were drilled for a total of 1,824 feet. Ore reserves were found to be confined to tactite zones in a surface area approximately 250 by 400 feet and extending downward about 350 feet.

Jan 1, 1956

By R. P. Vinson

The Bureau of Mines examined the effects of high humidity and water droplets on the GCA Corp. real-time aerosol monitor (RAM--l). which uses a lO4mm cyclone preseparator. Tests were conducted both in a laboratory and in a full-scale model mine entry. The laboratory tests were conducted in a test chamber saturated with moisture and water droplets. Under these extreme conditions. the RAM-I responded by indicating dust concentrations of 1-1/2 to 2 mg/m3? although the air was dust free. Within the first 2 h of each test. water accumulated in the cyclone and affected the cyclone particle separation characteristics. resulting in readings of 3 to 4 mg/m3. In addition. condensation formed inside the RAM-I case and affected the liquid crystal display (LCD). However. the full-scale mine entry tests revealed that the RAM-I can function ac-ceptably in an atmosphere of water vapor and water droplets similar to the most severe conditions found in an underground mine.

Jan 1, 1984

By R. G. Sandberg

The Bureau of Mines investigated a hydrometallurgical procedure to recover gold, silver, and byproduct lead from a complex lead-zinc sulfide ore. A ferric chloride (FeCI3) preleach, at 40° C in 6 h, extracted about 50 pct of the zinc and formed insoluble silver and lead chlorides. Subsequent acid thiourea leaching, for 1 to 3 h at 40° C, extracted about 85 pct of the gold and silver. Lead chloride was solubilized from the remaining residue with NaCI brine solution at 55° C in 1 h. Lead metal was recovered from the brine solution in an electrolytic cell with an anion perms elective membrane at a current efficiency of 95 pct and current density of 100 A/m2. Spent FeCl3 leach solution was reoxidized in the anode compartment at a current efficiency between 75 and 95 pct.

Jan 1, 1986

By M. I. Copeland

The investigation of the zirconium-gadolinium equilibrium diagram was part of a program to investigate rare:earth alloys for use as nuclear reactor control materials. Investigation of the zirconium-gadolinium equilibrium diagram revealed a eutectic system with limited terminal solubilities and one peritectoid reaction. The eutectic composition occurs at about 82 percent gadolinium, and the eutectic isotherm, which occurs at 1,220 ±5° C., extends from about 12 to 99+ percent gadolinium. A peritectoid isotherm occurs at 890 ±5° C. and extends from about 2 to 99+ percent gadolinium. The solubility of gadolinium in beta zirconium decreases from about 12 percent at 1,220 ±5° C. to about 2 percent at 890 ±5° C. The solubility of gadolinium in alpha zirconium decreases from approximately 5 percent at 890 ±5° C. to between 2 and 3 percent at 600° C. Vary little solubility of zirconium in gadolinium was indicated. An allotropic transformation of gadolinium was observed at 1,260 ±5° C. A change of the gadolinium transformation temperature on alloying with zirconium was not observed.

Jan 1, 1961

By F. A. Rutledge

"The W. E. Dunkle mine, sometimes called the Costello Creek coal mine, is 8 miles N. 20° W. of Colorado Station on the Alaska Railroad. The presence of coal in this area has been known since the district was extensively pros¬pected for gold between 1911 and 1915. At that time, coal from this deposit was used by miners for blacksmithing. The increased demand for coal resulting from government defense projects in Alaska led to exploitation of this deposit in 1941.The inability of Alaska coal mines to supply the quantity of coal required by public and private consumers and by the armed forces in Alaska was responsible for establishment by the Army of the Coal Procurement Section of its Alaska Department. It proposed to investigate the deposits and to expedite production from the Alaskan coal fields. The Bureau of Mines closely cooperated in this program.The quality of the Dunkle coal and the favorable location of the deposit caused it to be one of the properties chosen for investigation under a joint Army-Bureau of Mines-Geological Survey program.During July 1943, the coal area in the immediate vicinity of Costello Creek was geologically and topographically mapped. by Clyde Wahrhaftig and Jacob Freedman, geologists, U. S. Geological Survey. F. A. Rutledge, mining engineer of the Bureau of Mines examined the property July 18 to 22, 1943, and a project of trenching, diamond drilling, and sampling was initiated on August 4, 1943. During the project Clyde Wahrhaftig remained at the Dunkle mine to interprets drill cores and assist the author in planning the explora¬tory program. The project was completed October 7, 1943.Field investigations were under the general direction of R. S. Sanford, acting chief, Alaska Branch, Mining Division. Coal analyses were made by Maurice L. Sharp, coal analyst for the Alaska Railroad.Special mention is made of the cooperation and assistance received from Clyde Wahrhaftig, geologist, U. S. Geological Survey.The many courtesies received from the owner, W. E. Dunkle, and the members of the Army Coal Procurement Section, Alaska. Department, also are acknowledged.The W. E. Dunkle coal mine is in the Broad Pass region on the south slope of the Alaska Range at an altitude of 2,800 feet (fig. 1). It is situated within the Third Judicial Division, headquarters of which is Valdez, Alaska. The area is situated approximately at latitude 63° 15' N. and longitude 149° 30' W. and is connected with the Alaska Railroad at Colorado Station by an 11-mile gravel road that is passable throughout the year. This road is maintained by the Alaska Road Commission. A private telephone line to Colorado Station connects with the telephone and telegraph service of the Alaskan Railroad.The passenger rate from Anchorage, Alaska, to Colorado station is $12.10. Freight rates are $1.60 a hundred pounds for heavy machinery and $2.66 a hundred pounds for first-class freight.The Costello Creek coal basin is in an area of low relief and has been dissected by numerous creeks flowing down the south flank of the Alaska Range. The Dunkle coal mine is on Coal Creek, a small tributary of Camp Creek, 1,000 feet from their junction. About 700 feet below this junction, Camp Creek joins Costello Creek, which in turn empties into Bull River 1/2 mile above the latter's confluence with the West Fork of the Chulitna River. The location of the mine is shown on figure 1."

Oct 1, 1948

By Steven J. Page, John A. Organiscak

Prolonged exposure to airborne respirable coal mine dust is responsible for coal workers' pneumoconi¬osis (CWP): Furthermore, miners who show evidence of higher radiographic categories of simple CWP are at increased risk of developing progressive massive fibro¬sis (PMF). As of 1990, there were nearly 130,000 coal miners in the United States. "' This excludes mines that produce less than 10,000 tons annually and the anthracite coal mines. Estimates indicate that at age 58, an average of 7/1000 U.S. workers and 89/1000 U.K workers will have developed PMF(2-1) Health research studies have iden¬tified that the risk of developing and the severity of CWP arc directly related to (1) the amount of respirable dust exposure and (2) the coal rank.,'- The rank of coal is its stage of formation in the series peat, lignite, sub-bituminous, bituminous, and anthra¬cite (in order of increasing rank). The rank of coal can also be represented by the com¬mercially important characteristics specified by its proximate analysis: fixed carbon, vol¬atile matter, mineral matter, and moisture content.

By H. A. Watson

Fluorine-containing polymers are comparatively new materials that exhibit very desirable characteristics not usually found in non-fluorine containing polymers. Among these characteristics are heat and flame resistance, desirable electrical properties, and chemical inertness. Polytetrafluoroethylene and polymonochlorotrifluoroethylene are examples of such polymers commercially available. In practical applications it is reasonable to expect thermal position of these materials if they are subject to high enough temperatures. The temperatures at which thermal decomposition takes place and the nature of the gaseous products of decomposition are considered pertinent data in intelligent use of these materials. The purpose of the tests discussed herein was to determine: (1) The temperatures at which gases were produced when small specimens of the two polymers were located and (2) determine the identity of the major constituents of gaseous products.

Jan 1, 1950

By E. C. Pattee

A mobile spectroscopic laboratory was completed by the Bureau of Mines in 195 to provide a rapid, inexpensive means of field testing samples for beryl¬lium and other associated metals of possible commercial importance. Spectro-copes have been used in laboratories for many years in various types of research and routine analyses, but this spectroscope is probably the first mobile unit. The laboratory provides for spectroscopic, radioactivity, fluorescent, and limited chemical tests of samples. The unit has been a valuable reconnaissance tool. It has been used to search for beryllium, cesium, columbium, tantalum, rubidium, and lithium in Idaho, Washington, and Montana. Several very low grade deposits of these elements were found, and occurrences of other important elements were identified; however, none are of economic importance. The spectroscope permits the detection of elements by analysis of visible light produced when elements in a small powdered sample are volatilized in an electric arc., A total of 70 elements can be detected; 29 can be detected at or below 0.01 percent, Electric power for the arc is supplied by a gasoline motor-driven generator, Equipment is housed in an aluminum van, mounted on a 4-wheel-drive vehicle for easy maneuverability on mountain roads, A trailer with crushing, pulverizing, and splitting equipment permits the reduction of samples to a small representative pulp.

Jan 1, 1963

By R. E. Collom

The spontaneous explosion of charges of nitroglycerin placed in deep wells situated in parts of the Ranger and Caddo fields of North Texas has aroused considerable inquiry among operators end others as to the probable agency, or combination of conditions, which causes the explosion.The method now followed, under certain physical conditions of a well, of setting a charge of nitroglycerin and allowing it to explode spontaneously was discovered locally by accident. In certain deep wells where formations, overlying productive strata, cave upon withdrawal of casing, it has been the practice to fire the shot electrically. In some of these operations the electric wires are broken or the firing system is otherwise deranged by pulling casing or the caving of hole prior to the time for firing. Sucn accidents make it necessary for the driller carefully to clean cavings out of the hole to a depth close to the top of the charge, after which in the normal practice, an attempt is made to fire the charge by dropping a ""jack-squib"", fitted with a fuse and detonator, down the well. Mr. R. L, Fowler, production manager for the Pierce Oil Corporation, reports that a delayed shot was thus successfully tired through four feet of caved material lying on top of the nitroglycerin shells.When a shot destined to be fired electrically fails, because of the above mentioned accidental conditions to the electric firing system, much time is required for the driller to run casing into the hole and clean out caved material. It was during the time of such uncompleted operations that the spontaneous explosions first noted took place. Having noted these spontaneous explosions the well shooters now intentionally place a charge in deep holes, which because of probable caves would otherwise have to be tired electrically, and wait for the charge to go off. No detonators are placed with the charge.

May 1, 1920

By Richard A. Winters

In 1985 at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied 9,400 acres of the 10,005-acre Duncan Creek Wilderness Study Area (ID-111-78) in order to evaluate the mineral resources. The study area is located in Owyhee County, 10, about 36 miles southwest from Bruneau, ID. No mining districts are in the study area, nor were any mines or claims recorded or found. The southern half of the area was covered by oil and gas lease applications, all of which were cancelled prior to June, 1985. No economic concentrations of minerals were found in the study area. INTRODUCTION This report describes the USBM (U.S. Bureau of Mines) portion of a cooperative study with the USGS (U.S. Geological Survey) to evaluate mineral resources and potential of the Duncan Creek study area at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will be used to help determine the suitability of the study area for inclusion into the National Wilderness Preservation System. Although the immediate goal of this and other USBM mineral surveys is to provide data for the President, Congress, government agencies, and the public for land-use decisions, the long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the "fire door" type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they arc required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/Automatic Emergency Brakes" by G. E . Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By G. H. West, R. L. Sebastian, W. A. Darror

"This bibliography was compiled in the course of research work by the Bureau of Mines on the utilization of magnesites in the West. The results of the research will appear as a bulletin of the Bureau.1. ANALYTICAL METHODS. 11 Knight, X. and Wheeler, W.H. Proc. Iowa Acad. Sci., 13, 1907, 167 (C.A.1, 1370). Describes experience in analysing calcite and dolomite. Reports great excess of oxalate unnecessary and separation of sulphates by alcohol is best.2 Meyerhofer, J. Zeit, Angew. Chem., 21, 1908, 592. Direct determination of Mg as phosphate after removal of SiC2, by keeping R203 in solution with ammonium citrate.3 Merckschen Guano Phosphat Werke. Chem. Ztg., 33, 1909, 545 (C.A. 3, 2281). volumetric analytical methods.4 Popel, M. Zeit. Angew. Chem., 21, 1908. 2082 (C.A, 6, 412). Determination of CaO in presence of CaC03.5 Blasdale, W.C. Jour. Am. Chem. Soc., 31, 1909, 91? (C.A. 3, 2658). Studies of separation of Ca from Mg.6 Hundeshrgen, F. Zeit. Offent. Chem., 15, 1909, 85 (C.A. 3, 1853). Valua¬tion of caustic magnesia by analysis. Volumetric methods.7 Frerichs, H. and Krosberg, W. Apoth. Zeit., 24, 1909. 679 (C.A. 3, 2996). Tecting magnesia alba for Fe.8 Schoorl, N. Zeit. Anal, Chem., 48, 1009, 593 (C.A. 4, 5E9). Microchemical tests for Mg, Li, K. and Na.9 Heyer. Chew. 2Ag., 33, 1009, 1157 (C.A. 4, 1588). Determination of CaO in presence of CaCO3. CaCO3 in soluble in cold neutral solution of NH3 salts. Solubility Is diminished by free NH4OH."

Oct 1, 1923

By James P. McGee

Use of nuclear reactors to furnish high-temperature heat is a field that has not received as much attention as propulsion and electric power production. Investigations are being conducted under a joint Atomic Energy Commission (AEC)--Bureau of Mines research program to determine the feasibility of using nuclear heat for chemical processing. A part of this process-heat-reactor program is the study of a system in [hich] helium transfers heat from 8 nuclear reactor to a chemical processing [essel]. This requires construction of (1) a nuclear reactor to operate with helium exit temperature of 2,500° F. and with pressures in the range of 250 to 500 p.s.i.g. and (2) a processing vessel (heat exchanger) to convert the enthalpy of the helium into chemical process reaction heat. Neither component exists at present, and development of each promises to be a formidable task. To aid in the study of such a system, the Bureau of Mines has designed and constructed a vessel heated by electrical induction to simulate a source of nuclear fission heat. This vessel is undergoing preliminary testing. Gasification of coal and reforming of hydrocarbons are promising uses for nuclear heat. It appears that a higher price per unit of nuclear heat can be tolerated for chemical processing than that allowable for power generation.

Jan 1, 1960

By J. W. Higgs

This paper, describing the operation of the Gifford Hill & Co. plant at Hoot Spur near Texarkana, is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of mining and preparing gravel and sand throughout the United States. These tapers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. Although the publication of total costs might not be advisable in some instances yet a knowledge of operating costs is essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulation shall ensue. The plant described combines some features of dredging and some of dry-pit operation, as material is excavated in a dry pit with a drag line, hauled to the plant in standard-gage cars, and then pumped. This operation should be of special interest to operators whose deposits contain a large quantity of clay.

Jan 1, 1936

By Gene Asai

Properties obtained for columbium carbide-carbon castings ranging in car-bon content from 12 to 17 weight-percent were compared with those of hot-pressed composites of similar composition. The properties were oxidation resistance in static air between 500° and 700° C, linear thermal expansion between 20° and 2,400° C, electrical resistivity between 20° and 1,500° C; microhardness between 20° and 1,500° C, and modulus of rupture between 1,300° and 1,800° C. CbC-C castings differed markedly from hot-pressed material with respect to microstructure, electrical resistivity, and modulus of rupture, but behaved quite similarly with respect to oxidation resistance, thermal expansion, and hot hardness. In oxidation resistance, thermal expansion, and hot hardness both materials were independent of carbon content. Both castings and hot-pressed composites oxidize rapidly in air above 600° C, have thermal expansion coefficients very similar to columbium metal, and the logarithm of the hardness decreases linearly with increasing temperature. The microstructures of hot-pressed composites contained varying amounts of graphite in a CbC matrix but did not contain significant amounts of a eutectic structure present in all castings, nor did they contain graphite needles which were present in the hypereutectic castings. The higher electrical resistivity of hypereutectic castings over hypereutectic hot pressings was attributed to the presence of highly oriented graphite needles in the castings. The modulus of rupture of castings was 1-1/2 to 2 times that of hot-pressed composites. Both materials displayed bend ductility above 1,800° C.

Jan 1, 1971

By G. D. Coe

Float-and-sink tests indicate what results are obtainable by gravity separation and rare therefore an invaluable adjunct to most coal-cleaning processes. However, it is difficult to make a direct interpretation of float-and-sink data on coal, and several systems for interpreting them have been proposed. Of these, that developed and used extensively by Bird3/, Yancey4/, and Gandrud5/ is considered by the author to be the most satisfactory. It makes use of four interrelated curves (hereafter referred to as be "washability curves"). These curves were explained by Bird in a paper6/ published in 1923, but his explanation has been regarded by some as not sufficiently

Jan 1, 1938

By D. J. Parker, J. B. Benson, J. H. Bird, F. E. Cash

"INTRODUCTION The organic act that became effective July 1, 1910, imposes two very definite primary obligations upon the Bureau of Mines: (1) The prevention of loss of life and limb and the protection of the health of workers in the mineral industries, and (2) the conservation and scientific utilization of the country's mineral resources.The subject of this publication falls within the scope of both of these responsibilities by reason of the fact that (1) certain safety precautions are involved in combating even surface fires and, (2) although peat is not now, so far as known, utilized commercially or otherwise in this country as a fuel, it is extremely valuable agriculturally in at least one of our States, The justification for the conservation of such low-grade fuel through fire prevention appears warranted because of its present value to agriculture and the possible advantages accruing to future generations as a source of heat and power.Although the Bureau of Mines has published information on the origin and uses of peat, this is the first attempt to give out data concerning the prevention and control of peat-bog fires. Although the information presented here is restricted to the Lake Superior District, California, and Florida, there may be similar conditions in other sections of the country that have not come to the attention of engineers of the Bureau of Nines."

Jul 1, 1947