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By C. J. Walker, Ray V. Huff

The feasibility of inert - gas cushions in underground gas storages was studied by the Bureau of Mines in accordance with a continuing program of cooperative research between the natural gas industry -- through the American Gas Association . As mixing of the inert - gas cushion with the stored natural gas is undesirable , the various mechanisms tending to bring about such mixing were the subjects of both theoretical and experimental studies . These studies indicated the practicability of such cushions is dependent upon both reservoir and operating conditions . Equations and tables of illustrative data relating the various reservoir and operating conditions to the expected time required for undesired mixing to occur in ideal reservoirs are presented . This information permits estimating the relationship of such factors in actual storage operations .

Jan 1, 1964

By H. R. Wells

The Blackbird district, Lemhi County, Idaho, has long been recognized as a potential source of cobalt and copper. However, the comparatively low grade and small size of the known ore bodies, the small demand for cobalt, and. the lack of adequate roads throughout the region precluded extensive exploration of the early discoveries in the area. Recent advances in alloy metallurgy, accentuated by wartime activities, greatly increased the demand for sources of domestic cobalt. Beginning In 1941, engineers of the Bureau of Mines conducted an examination and exploration program in the Blackbird district. This work was supplemented by an exploration program by engineers of the Howe Sound Mining Co., 730 Fifth Ave., New York 19, N.Y.

Jan 1, 1948

By William S. Miska

The study is an economic evaluation of historical, current, and projected refractory uses in the iron and steel industry of the United States. The first part of the report presents a refractories classification and identifies principal trends in the refractories industry; such as, value and volume of shipments, prices of finished refractory products, the number of manufacturers and plants for refractories production and marketing. The main part of the report treats refractory use patterns and technologic developments affecting refractories usage in the iron and steel industry. Changes in use patterns in each furnace type, refractory, and installation costs and the future outlook for refractories in ironrnaking and steelmaking are covered. The last part of the report identifies the principal raw materials used in refractories production and treats trends in refractory raw material consumption. An appendix to the report contains historical time series graphs of shipments of refractory types used primarily by the iron and steel industry and principal refractory raw materials sold or used by producers. An equation of the line of best fit was calculated from the earliest to the latest year in each time series, usually 1950 to 1965; these were extrapolated in order to derive volume estimates for the year 1975.

Jan 1, 1968

By S. C. Schaefer

The Bureau of Mines investigated tIle standard Gibbs energies of formation, 8Gfo, for MllF2 (manganese difluoride) and CoF2 (cobalt difluo-ride). High-temperature galvanic cells employing CaF2 (calcium diflu-oride) as the solid electrolyte were used to measure the open-circuit potentials for the cell reactions ?

Jan 1, 1985

By G. L. Oldright

By means of a technique developed in cooperation with the Eagle-Picher Mining & Smelting Co. and outlined in the first report of this series (R. I. 4333 ), it was possible to take many thermocouple readings with base-metal couples at temperatures over 2300° F with unsupported protection tubes for over half the lengths of the Henryetta retorts. -This technique made it possible to avoid the use of the usual optical pyrometer, which gives temperatures dependent upon the luminosity of the flames, and which is not conveniently usable to read temperatures for the lengths of the retorts from the front of the furnace. The temperatures of the retorts themselves were necessary in order to set upper limits for safe operation; the lower limits of operating temperatures are set by the zinc content of the retort residues. The zinc content left in the retort residues for various sections of length also varies with retort temperatures rather than with flame temperatures. The variations in temperature along the retort can then be used as guides to distill more zinc from the residues, to avoid fluctuations in the rates ,of flow of zinc vapor into the condenser and to employ lower temperatures if such rates become high enough to cause losses of uncondensed zinc.

Jan 1, 1948

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1976

By M. Hayashi

The Bureau of Mines conducted laboratory studies on Idaho mudstones to examine techniques for extracting vanadium. Recovery of vanadium from low-grade sources could contribute to future vanadium production and reduce reliance on imports. An Idaho mudstone surface sample containing 0.30 pct V205 and an underground sample containing 0.21 pct V205 were used in the extraction tests. Leaching of the surface sample for 18 h at 800 C with the addition of up to 1,000 lb/ton H2S04 recovered 70 pct of the vanadium. How-ever, leaching of the underground sample under the same conditions re-covered only 47 pct. By adding 15 wt pct NaCl and roasting the samples at 7500 C for 2 h, followed by leaching with 800 lb/ton H2S04, vanadium extractions were increased to 78 pct from the surface sample and 83 pct from the underground sample. Water leaching of samples roasted at 7500 C for 4 h with a 25-wt-pct NaCI addition yielded about 60 pct of the vanadium from both surface and underground samples. Autoclave leaching at 2000 C for 3 h with 1,000 Ib/ton H2S04 extracted 97 pct of the vanadium from the surface sample and 86 pct from the underground sample. An exploratory solvent extraction investigation to purify and concentrate vanadium in the leach solution using several organic reagents was also conducted.

Jan 1, 1985

By David T. Couillard

Task training is increasingly important in mining operations because of the ever-accelerating pace of technological innovations and the concomitant increasing complexity of mining equipment. This Bureau of Mines report describes two successful task training program In use in two open-pit taconite operations in northeastern Minnesota. The programs are different in approach, but both have improved safety and in- creased productivity while lowering costs. Methods of training both before and after passage of the 1977 Mine Safety and Health Act are described, and the impact of this act on task training at each operation is discussed. The report identifies four common principles that have contributed to the success of the two training programs and presents plans each operation has for improving future training through new technology.

Jan 1, 1984

By W. A. Stickney, J. W. Town

Studies on continuous - circuit leach - aluminum precipitation and leachelectrodeposition of mercury were made by the Bureau of Mines to determine optimum conditions and cost estimates for recovering mercury from mercury sulfide flotation concentrates . With 150 grams of sodium sulfide and 50 grams of sodium hydroxide per liter , from 98 to 99.8 percent of the mercury was extracted from flotation concentrates , with about 0.5 pound of sodium hydroxide used per pound of mercury produced . Precipitation of mercury from the caustic - sulfide solution with minus 8 - mesh aluminum shot required about 0.2 pound of aluminum per pound of mercury produced at a cost of $ 0.05 per pound of mercury . Electrodeposition cost with 7 mill power , based on 50 percent current efficiency , was below 2 mills per pound of metal deposited . Feed solutions ranged from 10 to 130 grams of mercury per liter , and current densities , from 2 to 70 amperes per square foot . The cost of open- pit mining 250 tons per day was estimated at $ 1.75 per ton , and flotation - leachingelectrodeposition of the ore , at $ 3.54 , resulting in a cutoff grade of about 0.1 percent mercury . The cost of underground mining 50 tons per day was estimated at $ 20.00 per ton , and the cost of milling the ore was estimated at $ 13.33 , which resulted in a cutoff grade of 0.6 percent mercury .

Jan 1, 1964

By D. Harrington

"In at least three out of every four working faces in metal mines there is no attempt made to cause air circulation other than by use of compressed air, and in at least nine cases out of ten the compressed air is released merely by opening, or partly opening, the valve and allowing the compressed air to escape through open air hose used to convey the compressed air to the drilling machines. Usually no blowers are in use during periods of drilling, as the exhaust from the drill provides cool, comparatively fresh air for the driller; however, in some instances, the compressed-air line is provided with a tea connection, which permits taking air for the drill from one side of the tee, and air for ventilation through a separate hose used as a blower, simultaneously with drilling.Table 1 contains temperature and humidity data as to compressed-air blowers from open end of air hose at 36 working places in eleven metal mines of four States, embracing the mining of gold, silver, copper, lead and zinc ores, and at horizons ranging from 500 feet below the surface to as low as 4900 feet.It is noticed that the ordinary air surrounding the worker at the face gives an average wet bulb temperature of 81.7° F. for the 36 working faces, with 84.7° F. dry bulb and 87.2 per cent relative humidity. The average wet bulb tem¬perature of 36 readings at these working faces of compressed air at the end of the,hose as the air issues from the hose was 67.4° F., or 14.3 degrees lower than the average wet bulb readings of the air of the working places; however, the average dry bulb temperature of the 36 readings of compressed air as it issued from the end of the hose was 79.7° F., or only 5 degrees less than that of the general air (84.7°); the relative humidity was 51.1 per cent as against 87.2 per cent for the surrounding air. Readings were taken in five raises, seven crosscuts, ten drifts and 14 stopes.It will be noted that the velocity or movement of the general atmosphere at each of the entire 36 working faces, was found to be practically imperceptible; this might readily be inferred since compressed air is rarely used on blowers if there is adequate circulation of the general air of the place. Where rook temperatures could be obtained readily, they are shown; it is noticeable that the dry bulb temperature of the air of the working place varies little from the rock temperature, and that the dry bulb temperature of the compressed air as it issues from end of air hose varies only a few degrees from the temperature of the surrounding rock; in some instances the dry bulb temperature of the compressed air as it issued from the end of the air hose was higher than the rock temperature or the dry bulb temperature of the surrounding air."

May 1, 1921

By Cloyd M. Smith

Progressive mine management is placing increased emphasis on improved ventilation as a contribution to better safety , health , and productivity of miners . Management is on the alert for means of bettering the working environment by increasing the flow of air and distributing it more effectively to the working places , having in mind the necessity of avoiding exorbitant ventilation costs . A basic need in planning betterments of this kind is knowledge of existing rates of flow and air pressures , infCoorrmmaattiicon that is supplied through ventilation surveys . Some companies make partial surveys from time to time , but few make complete surveys on a routine basis . This report describes the practice of a large British anthracite -mining company , which operates 24 collieries in South Wales , in carrying out a routine program of ventilation surveying . Ventilation characteristics and climatic conditions in the working places of its collieries are determined at frequent intervals with a view to increasing the effectiveness of ventilation and protecting the health of workers . It is thought that many of the points of the procedure used in making the surveys and in compiling and reporting the results will be applicable to American practice and that a discussion of the program may be helpful to colliery managers who are planning similar work .

Oct 1, 1949

By G. L. Neumann

"INTRODUCTION Mining in this area is inactive. The entire region is now comprised of small farms. Because approximately 1,500,000 tons of magnetite ore had been shipped from this area between 1855 and 1915, it was deemed probable that geophysical surveying and core drilling might indicate other ore bodies or sizable extensions of the previously mined ore bodies.ACKNOWLEDGEMENTSIn its program of investigation of mineral deposits, the Bureau of Mines has, as its primary objective, the most effective utilization of our mineral resources, thus fortifying our national security and economy. It is the policy of the Bureau to publish the facts developed by each project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiatien tests.The chemical analyses and beneficiation tests included in this report were performed at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under the general supervision of J. B. Zadra, chief, College Park Division, Metallurgical Branch, and the immediate direction of Dr. Alton Gabriel, head of the laboratory service unit.The Mineral exploration Was under the general supervision successively of G. D. Jermain, district engineer, C. B. White, district engineer, and McHenry Mosier, chief, College Park Division, Mining Branch.The geophysical section of the exploration was performed by G. B. Botsford, engineer of the Bureau of Mines. Assistance was given by the Division of Geophysical Exploration of the Bureau of Mines, Dr. F. W. Leo, chief."

Dec 1, 1947

By John W. Cole

As part of a general preliminary investigation of lead-zinc deposits in Stevens County, Wash., the Electric Point and Gladstone mines on Gladstone Mountain, in the Northport Mining District, were examined by R. M. Gammell, an engineer of the Bureau of Mines, in June 1946. A trenching and sampling program was executed later the same year under' the supervision of Miro Mihelich and the author. This report presents the factual data obtained from the trenching and sampling operations.

Jan 1, 1949

By James P. Bennett

The Bureau of Mines investigated the role of imported natural flake graphite in dolomite-carbon refractories used in steelmaking processes. Fundamental engineering data were obtained to enable the evaluation of substitute materials. Changes in oxidation resistance (2,000° F), hot strength (2,750° F), and deformation under load (2,7500 F) caused by 10-wt-pct additions of five different kinds of natural flake graphite and increasing quantities (0 to 30 pct) of a 90-pct-carbon natural flake graphite were studied. Results indicated that carbon purity of 10-wt-pct-graphite additions did not influence hot strength or deformation under load. When the quantity of 90-pct-carbon graphite addition varied between 0 and 30 wt pct in a dolomite-carbon brick, hot strength was highest and de-formation under load lowest with 10-wt-pct additions. As hot strength test temperature was increased from 5000 to 2,750° F, the strength difference observed between 0-and 30-wt-pct additions of a 90-pct-carbon graphite became smaller. Additions of a boron-treated graphite caused significantly higher strength and lower deformation under load at high temperatures, while an addition of ball clay significantly reduced strength and increased deformation.

Jan 1, 1987

By Thomas C. Atchison

The experimental work described in this report is part of a continuing study by the Federal Bureau of Mines of the fundamental physical processes involved in breaking rock with explosives. Six explosives were tested for their strain-producing abilities in a dolomitic marble. The explosives selected for testing had a tenfold variation in detonation pressure and a fivefold variation in characteristic impedance (product of loading density and rate of detonation). Strain pulses produced by the detonation of small charges of the explosives were recorded at distances of 5 to 130 feet. Peak strain, ?, was found to decrease with distance, R, in accordance with an exponential propagation law previously determined for other rock types, namely ? = (K/R)e ?aR The absorption constant, a, did not vary significantly with the explosive and was of the same order of magnitude as that for other rock types. The different explosives produced a fivefold variation in the value of the intercept constant, K.

Jan 1, 1961

By Robert W. Metcalf

Since the spread of the European war virtually cut off imports from Denmark, Belgium, and France, the Bureau of Mines has had numerous inquiries as to domestic sources of grinding pebbles and silex or other types of ball mill liners. USES Flint pebbles and tube-rill liners are used by grinders of certain ceramic materials to prevent contamination of the finished product by iron abraded from steal baler and liners. The feldspar industry is one of the largest users of flint grinding mediums; they are employed also by curtain grinders of talc and soapstone, ground sand and sandstone, quartz, and chalk. Some paint materials, such as lithopone, have been ground in pebble Flint pebbles have been used more or less in the past, especially by cement manufacturers, and, for fine grinding of gold, copper, or other ores in which iron contamination is not especially deleterious.

Jan 1, 1940

By R. J. Kuczynski

The U.S. Bureau of Mines operated a 2,000-g (4.4-lb) batch process development unit for recovering platinum-group metals (PGM) from automobile catalysts. Virgin monolith, used pellet, and used monolith catalyst samples were tested. Leaching twice with 1-pct sodium cyanide (NaCN) solution at 1600 C for 1 h dissolved more than 95 pct of the PGM from virgin catalysts and more than 90 pct from used pellet catalysts. More than 85 pct of the PGM was dissolved from used monolith catalysts when a third autoclave step was added. Solid PGM concentrates containing more than 99.8 pct of the dissolved PGM and analyzing greater than 70 pct PGM were recovered by heating the pregnant leach solutions from virgin catalysts to 2500 C and used catalyst to 2750 C for 1 h. The solution after heating contained less than 0.2 ppm. total cyanide. The virgin residues passed the EPA Extraction Procedure Toxicity Test (EP Tox Test), the EPA Toxicity Characteristic Leaching Procedure (TCLP), and the California Waste Extraction Test (WET) for all elements except Ba. Adding sodium sulfate (Na2S04) to the virgin leach residues reduced the amount of Ba dissolved to an acceptable level. The used leach residues passed the EP Tox Test for all elements but failed the WET and TCLP for Pb.

Jan 1, 2010

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

C THRM 1 C CALCULATION OF MINE HEAD LOSSES FROM ALTIMETER SURVEY DATA TURN 2 C PENNSYLVANIA STATE UNIVERSITY - MINERAL ENGINEERING DEPARTMENT THRM 3 C THRM 4 C THRM 5 C THIS PROGRAM CALCULATES PRESSURE LOSSES USING THERMODYNAMIC RELATION- THRM 6 C SHIPS BASED ON POLYTROPIC FLOW BETWEEN STATIONS. FOR REFERENCE SEE THRM 7 C "A NEW TREATMENT OF MINE BAROMETER SURVEYS" BY M. J. MCPHERSON IN THRM 8 C 'THE MINING ENGINEER' NO. 109, VOL. 129, P 23. THRM 9 C THRM 10 C THRM 11 C THRM 12 C IDENTIFICATION OF ARRAYS THRM 13 C NOTE THE PROGRAM HAS BEEN DIMENTIONED FOR FOURTY (40) DATA POINTS THRM 14 C BASEC(6;2) BASE INSTRUMENT TEMPERATURE CORRECTIONS THRM 15 C TRAVC(6,2) TRAVERSE INSTRUMENT TEMPERATURE CORRECTIONS THRM 16 C BASER(I) BASE INSTRUMENT READING THRM 17 C TRAVR(I) TRAVERSE INSTRUMENT READING THRM 18 C TDRY(I) DRY BULB TEMPERATURE AT TRAVERSE STATION THRM 19 C TWET(I) WET BULB TEMPERATURE AT TRAVERSE STATION THRM 20 C ELEV(I) ELEVATION AT TRAVERSE STATION THRM 21 C VEL(I) AIR VELOCITY AT TRAVERSE STATION THRM 22 C TBDRY(I) DRY BULD TEMPERATURE AT BASE STATION THRM 23 C BASC(I) BASE READING CORRECTED FOR INSTRUMENT TEMPERATURE THRM 24 C TRAV(I) TRAVERSE READING CORRECTED FOR INSTRUMENT TEMPERATURE THRM 25 C BBASE(I) TEMPERATURE CORRECTED BASE READING IN BAROMETRIC THRM 26 C PRESSURE THRM 27 C BTRAV(I) TEMPERATURE CORRECTED TRAVERSE READING IN BAROMETRIC THRM 28 C PRESSURE THRM 29 C BTRAVS(I) BAROMETRIC TRAVERSE READING CORRECTED FOR ATMOSPHERIC THRM 30 C CHANGES THRM 31 C RELHUM(I) RELATIVE HUMIDITY THRM 32 C ASW(I) AIR SPECIFIC WEIGHT TURN 33 C R(I) GAS CONSTANT FOR MOIST AIR THRM 34 C STPRES(I) STATIC PRESSURE CHANCE BETWEEN STATIONS (I) AND (1-1) THRM 35 C TOPRES(I) TOTAL PRESSURE CHANCE BETWEEN STATIONS (I) AND (I-1) TURN 36

Jan 1, 1977

By Wing G. Agnew

The first six Reports of Investigations in this series , pertaining to the investigation of stemming at the Mount Weather Testing Adit, dealt with ( 1 ) the dust produced by blasting , ( 2) the effect of stemming upon gases generated by blasting , ( 3 ) the relative advantages and disadvantages of different types of stemming and no stemming when used with 60 - percent ammonia gelatin dynamite , (4) the length of stemming material through which a primer will fire and detonate a charge of dynamite , ( 5) comparison of dust and gases produced when blasting charges of dynamite in drill holes , bombs, and mud - cap shots , and ( 6 ) the relative advantages and disadvantages of different types of stemming and no stemming when used with 40 - percent ammonia gelatin dynamite .

Oct 1, 1943

By W. G. Pariseau

A U.S. Bureau of Mines case study of pillar recovery in high-grade ore near the Ross shaft at, the Homestake Mine, Lead, SD, has demonstrated the usefulness of the finite-clement method for the evaluation of shaft pillar mining plans and shaft stability. This report, one of three in a series describing the Ross shaft pillar case study, focuses on the premining stability analysis. The two-dimensional computer program UTAH2 was used in advance of pillar mining; results suggested that the shaft would remain stable. Subsequent reports describe parts 2 and 3 of the study. In part 2, borehole extensometers and other instruments were installed to provide data for model verification and shaft monitoring. Results of the recalibrated two-dimensional model confirmed the premining stability evaluation. However, after mining began, great concern developed because of the appearance of cracks and other signs of ground movement over considerable distances from the area of active pillar miping. In part 3, an intense three-dimensional modeling effort using UTAH3 was initiated. The results again showed that the shaft would remain safe. Three-dimensional analyses of alternative pillar mining scenarios indicated that more of the shaft pillar ore reserve could be recovered than previously thought.

Jan 1, 2010