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By J. A. Cavallaro

The heats of formation of anhydrous barium carbonate (witherite), strontium carbonate (strontianite), and lead carbonate (cerussite) were determined by solution calorimetry. The solution mediums were hydrochloric acid for barium and strontium carbonates and perchloric acid for lead carbonate. The heats of formation at 298.15° K are as follows: BaCO3 -297.5 ± 0.8 kcal/mole; SrCO3 -294.6 ± 0.5 kcal/mole; and PbCO3 -168.0 ± 0.3 kcal/mole.

Jan 1, 1966

By X. B. Starnes

"INTRODUCTION The Eva Tanguay property is in Crittenden County, Kentucky, about 1 mile south or the village of Mexico, and can be reached from Marion, the County seat, by travellng south on State Highway 91 for 6.8 miles and then turning southwest on State Highway 70 and traveling 2 miles farther.Although the property lies between the Huffaw and Pigmy properties, which together have produced 200,000 tons of fluorspar ore, production from the Eva Tanguay has been estimed at only 1,000 tons. Geological factors on the property indicated the likelihood of an ore occurrence, and the author examined the property in April 1944. Shortly thereafter, the U.S. Geological Survey wrote a report on the property, which was not published. A drilling program was initiated by the Bureau of Mines November 1, 1944, and continued until eight holes totaling 3,137.5 feet were drilled.The holes showed that the Tubb fault system on the Eva Tanguay property is composed of three members, all of which contained commercial ore. The line dividing the Haffaw and Tanguay properties crosses the vein outcrops, causing a part of the ore indicated to be on each property.The mineral rights, which are leased by Robert Frazer of Marion, are owned by Mrs. O. S. Denny and W. C. Bohn, both of Marion."

May 1, 1947

By Harold B. Ewoldt

The Appalachian Ores Co., Sweetsprings, W. Va. was a small but persistent producer of manganese ore for several years prior to 1942. Most of the ore mined was hard, nodular psilomelane, with some pyrolusite and, wad, occurring in clay. The Bureau of Mines started an investigation of the area in January 1942 and completed the work in May 1942. Twenty-four churn-drill holes were bored, aggregating 2,084 feet. A total of 420 feet of test pits was sunk on selected drill holes to check the churn-drill sampling. Twelve drifts and crosscuts aggregating 139 feet were driven from the bottom of test pits to investigate concentrations of manganese nodules. Three hundred sixty-six churn-drill samples and 102 other samples were sent to Bureau laboratories for analyses. Beneficiation tests were conducted in the Burp.au of Mines laboratory in Rolla, Mo. Results of testing 10 samples indicated that approximately 80 percent of the material in crude ore could be discarded by log washing. Gravity tests indicated 'that 55 percent of the total manganese in the crude ore was recoverable as a gravity concentrate averaging 34.6 percent manganese.

Jan 1, 1949

By D. R. Brooks

The Bureau of Mines has tested a dewatering technique for phosphatic clay waste. The technique utilizes a flocculant, polyethylene oxide (PEO), that forms strong, stable flocs that can be dewatered on a static screen followed by further dewatering on a rotary screen or trommel. In field tests conducted in central Florida, clay wastes containing approximately 4 pct solids have been consolidated to greater than 20 pct solids. The rate at which PEO-treated material continues to dewater in a mine cut also was monitored. Preliminary results indicate that PEO-treated material will dewater to 30 pct solids in 80 days. Pretreatment of phosphatic clay waste with lime lowers the PEO dosage required for dewatering.

Jan 1, 1986

By R. K. Koch

The Bureau of Mines developed a zircon sand molding process for static casting of small titanium or zirconium shapes. Castings with unfinished weights up to 3.5 kg (7.7 lb) were produced in an inductoslag furnace and castings up to 7 kg (15.4 lb) were poured in a consumable electrode skull-casting furnace. Molds and cores were made by ram-molding, foundry-grade zircon sand (AFS gfn 93 to 95) bonded by grade D waterglass and tempered with water. Molds and cores were cured either at 250° C (482° F) or 900° C (1,652° F). Castings from the higher temperature molds broke cleanly from the sand while the lower temperature molds produced castings that had to be cleaned by sand-blasting. However, low-temperature cured molds and cores have a number of advantages as follows: (1) A faster, less energy-consuming curing cycle is used; (2) expended cores are water soluble which greatly facilitates core removal; and (3) enough of the binder in crushed expended molds is reactivated by temper water so that the molding mix can be reused five times without any fresh binder additions and up to twenty times without exceeding a total cumulative binder addition of 52 ml/kg dry sand. Crushed used molds that had been cured at 900° C had no detectable binding strength when mixed only with temper water. A large number of oxide and silicate mold washes were studied for improved casting integrity. The most effective wash found for zirconium or titanium casting was monoclinic zirconia (325 mesh).

Jan 1, 1977

By G. W. Jones

An important activity of the Bureau of Mines is the promotion of safety in mining and industry. As a part of this program, the Bureau determines the explosion hazards of combustible gases, vapors, and solids and investigates means of controlling and preventing explosions. The limits of inflammability (explosive limits) of combustibles are not only of theoretical but also of practical importance, because many industries at one time or another contend with explosive mixtures of combustible gases or vapors in their manufacturing processes. At present many new organic compounds are being manufactured, transported, and used in huge quantities which a few years a ago were only laboratory curiosities.

Jan 1, 1941

By Lloyd Carpenter

Eighteen elements were determined spectrochemically in vanadium metal and its compounds in the general range of 1 to 1,000 ppm by means of spark-ignited unidirectional arc excitation. The samples were converted to vanadium pentoxide and combined with a mixture of graphite, lithium carbonate, and gallium oxide. For the molybdenum determination, the oxidized samples were mixed with sodium chloride and packed in copper electrodes. Average precision of the method was 15.6 percent relative standard deviation and relative error was 4.4 percent.

Jan 1, 1963

By K. Robert Dorman

Spray-applied polyurethane foam was used to insulate the walls of heated rooms excavated in permafrost. The experiment was designed to determine whether polyurethane foam can be sprayed successfully on frozen ground under freezing conditions and to measure the effectiveness of the insulation in maintaining--at elevated temperatures for an extended period--a room excavated in frozen ground. Two manufacturers' foams were investigated in the laboratory. Subsequently, one of the foams was employed to insulate two small rooms, one in frozen gravel and one in frozen silt, in an experimental tunnel belonging to the U.S. Army Cold Regions Research and Engineering Laboratory (USACRREL) near Fairbanks, Alaska. Following insulation, heat was introduced into the two rooms. Heat migration across the insulating barrier into the walls, in addition to wall closures, was monitored over an 8-month period. The results show that polyurethane foam can be successfully sprayed on frozen ground in below-freezing temperatures. Given this type of insulation, together with winter cold to supercool the surrounding ground, it should be possible to maintain a shaft or heated room in permafrost for several years.

Jan 1, 1970

By Heine Kenworthy

"INTRODUCTION In 1930 the Shenandoah-Dives Mining Co. near Silverton, Colo., put into operation a newly erected, 300-ton selective flotation plant to mill complex ores from its nearby mine. The operation was a steady producer and was enlarged to treat 600 to 800 tons a day. In 1942 the company opened and started milling an area in the mine containing semioxidized ore. The valuable mineral content of this ore was considerably higher than in, the straight sulfide ore previously handled alone. The mixture of clean sulfide and semi-oxidized ore was difficult to treat; consequently, tailing losses, especially with respect to lead, were high. A few years later, in order to study the possibilities of obtaining higher recoveries by a modification of the mill flow sheet, a 1,200-pound sample of mill, feed, taken over a period of several days by the company, was submitted to the Mississippi Valley Experiment Sta¬tion for testing-. Although this sample proved to contain more than twice as much lead as the average yearly mill feed, the same problem of recovering the oxidized values was present.A résumé of the ore-dressing treatment used in the Shenandoah-Dives mill follows. After crushing, the ore passes through a ball mill, the minus 5-mesh discharge of which is distributed to three tables. A finished lead concentrate is made on the tables, and the table tailing goes to the classifier which is in closed circuit with the ball mill. The classifier overflow is treated -by flotation to obtain a bulk sulfide concentrate at a relatively coarse size. The bulk concentrate is thickened and reground to about 95 percent minus 325-mesh before flotation treatment to separate a lead-copper and a zinc concentrate. A typical monthly average showed that the table concentrate contained about 45 percent lead, 1 percent copper, 4 percent zinc, 12 ounces of gold, and 40 ounces of silver; that the lead flotation concentrate contained '35 percent load, 6 percent copper, 7 percent zinc, 3.5 ounces of gold, and 50 ounces of silver; and that the zinc flotation concentrate contained 2 percent lead, 0.5 percent copper, 60 percent zinc, 0.15 ounces of gold, and 4 ounces of silver. Recoveries in salable products were roughly b5 percent of the lead, 70 percent of the copper, 45 percent of the zinc, 85 percent of the gold, and b5 percent of the silver."

May 1, 1948

By M. J. Lempel

A theoretical study of the heat-transfer characteristics of a dilute gas-solids mixture in an externally heated tube is reported. Detailed equations are developed describing the system, and a numerical method is presented to solve the equations using a digital computer. The methods are applied to a system containing fine coal particles entrained in hydrogen, flowing through a hot tube. Heat-transfer coefficients and several other physical constants are evaluated in detail.

Jan 1, 1967

By Welby Courtney

Because of the inherent safety problem associated with the deposition of airborne respirable dust onto the floor and other airway surfaces, the Bureau of Mines investigated the rate of reduction of airborne respirable dust in an airway due to deposition of the particles onto the surfaces of the airway. The effects of relative humidity and air velocity on the deposition rate were examined. It was found that the deposition rate was comparable in magnitude with the Stokes sedimentation rate and that it was independent of relative humidity. However, near the dust source the deposition rate depended significantly upon the air velocity, with such dependence decreasing with increasing distance from the dust source. In addition, the size distribution of the airborne particles was approximately constant along the first 300 ft of the airway, indicating that it was not merely the larger (heavier) particles that were being deposited. These results suggest that deposition, though comparable with the Stokes sedimentation rate in magnitude, does not follow a simple Stokes-type process, and that the process of deposition remains to be explained.

Jan 1, 1986

By G. W. Jones

An important activity of the Bureau of Mines is the promotion of safety in mining and industry. As a part of this program, the Bureau determines the explosion hazards of combustible gases, vapors, and solids and investigates means of controlling and preventing explosions. The limits of inflammability (explosive limits) of combustibles are not only of theoretical but also of practical importance, because many industries at one time or another contend with explosive mixtures of combustible gases or vapors in their manufacturing processes. At present many new organic compounds are being manufactured, transported, and used in huge quantities which a few years ago were only laboratory curiosities.

Jan 1, 1941

By Robert E. Meredith, Thomas T. Campbell

An investigation was undertaken to examine the feasibility of employing low- temperature nonaqueous baths for electrodepositing some of the refractory metals of the ferroalloy group . To date , such metals as tungsten , molybdenum , and vanadium have been produced only by high - temperature processes that are technically difficult and sometimes cumbersome in operation . Deposition studies were performed in a wide variety of organic solvents , including amides , ammonia derivatives , ketones , polyhydroxy alcohols , and ethers . Compounds prepared and used as solutes included the chloride and bromide salts of vanadium , tungsten , and molybdenum . Studies were conducted over a temperature range of 20 ° to 200 ° C under inert atmosphere . Conductivity and current potential data were obtained for all baths that contained reasonable solute concentrations . Qualitative solubility data were obtained for compounds of ferroalloy metals in a variety of solvents . In general , all solutes showed low solubility in ethers and ketones but reasonable solubility ( in excess of 20 grams per liter ) in alcohols , amides , and ammonia derivatives . No successful metallic deposits that would encourage further study were obtained with any of the systems that were examined .

Jan 1, 1963

By A. D. Bauer

For several years the Bureau of Mines has conducted surveys to determine the changes in motor gasoline being sold throughout the United States. The present survey shows that far the districts in which samples were collected, the average gasoline is becoming more volatile instead of less so, as is sometimes supposed. This year's gasoline is much more volatile than that sold two years ago, and it has a somewhat better distillation range than last summer's samples. A comparison of the average figures for several years, shows that motor gasoline is also becoming more uniform in character. The large seasonal change is disappearing, but ?winter gasoline', still has a lower initial boiling point than "scanner gasoline". This difference in volatility is made intentionally to facilitate starting the motor in cold weather. The end point shown in the present survey is slightly lower either than that of last winter or of the summer of 1921.

Jan 1, 1922

By C. C. Popoff

The development of glass-making industries in the Pacific Northwest as well as other industries that use pure silica has been retarded by lack of local supplies of low-cost raw material. Several quartz deposits along the Skagit River constitute the only known source of relatively pure silica within the range of cheap transportation to the Seattle industrial area. Although some silica has been mined from these deposits, very little information regarding their size, grade, and other physical characteristics has been available to the general public. As a part of its program of investigation of the mineral resources of the Pacific Northwest, the Bureau of Mines assigned the writer to examine the Skagit River silica deposits in October 1946. This report presents the factual data obtained from an examination of the so-called Stoner, Bacon Creek, and Pressentin deposits. These deposits are the largest and most easily accessible known to exist in the area. The deposits are near Marblemount, which is on State Highway 17A. They are within 1 mile to 1-1/2 miles of the Skagit. River Railway, which provides transportation to Seattle, a distance of 130 miles. None of the deposits has been developed thoroughly. The Stoner deposit, however, has been developed by a quarry about, 5,0 feet square and has been exposed by hydraulic removal of the overburden throughout a distance of 180 feet along the hanging wall of the vein

Jan 1, 1949

By Robert Roby

The Mouat copper-nickel deposit in Stillwater County, south-central Montana, was examined by Paul T. Allsman, an engineer of the Bureau of Mines, in 1939. Because of the strategic importance of nickel, a project was executed by John East, Jr., J. J. Naughton, and E. W. Newman, engineers of the Bureau, to further delimit some of the copper-nickel sulfide-bearing bodies that had been discovered by the Anaconda Copper Mining. Co. in 1937 and to investigate the central part of the deposit, which had not been drilled previously. This report is based largely upon the results of the. Bureau of Mines investigation and the results of exploration by the Anaconda Copper Mining Co. In addition, a brief description is given of some other copper-nickel sulfide-bearing deposits along tho Stillwater Complex.

Jan 1, 1949

By D. W. Butner

As a part of the Bureau of Mines program for the discovery and development of critical and essential mineral deposits, the Darwin district, Inyo County, Calif., was chosen for investigation as a possible source of, tungsten ore. Two properties were active in the district at the time. One was producing tungsten concentrate and the other was preparing to produce tungsten concentrate as a byproduct in the milling of lead-zinc ore. The objective of the project set up by the Bureau was to investigate promising areas and to sample, thoroughly those which preliminary inspection indicated contained tungsten ore. Work was begun November 17) 1941, and completed January 19, 1942. In the course of the project, 18 localities were inspected and 9 were sampled. The following pages brief the history, note the location, and outline the physical features and geology of the district. The work performed by the Bureau of Mines is described and supplemented with assay maps.

Jan 1, 1949

By L. H. Banning

In the fall of 1953 the Philippine Bureau of Mines, under a Foreign Operations Administration Technical Assistance (FOA-TA) program, began a systematic investigation of the nickel content of the well-known Surigao laterite areas, on the island of Nonoc northeast of Mindanao, to determine the occurrence, distribution, and grade of nickel contained in the laterite and in the subjacent serpentine. At the same time, a technical review of the possibility of producing commercial ferronickel from the nickeliferous materials in the Philippine Islands was made, and a smelting process was suggested. The proposed process would be similar to that developed by the Federal Bureau of Mines for the reduction of the nickeliferous serpentine occurring in the Nickel Mountain ?deposit at Riddle, Oreg. The potential avail-ability of electric power from the Maria Cristina facilities at 3 mils per kw.-hr. would enhance the economic possibility of this program. Development of an economically feasible process for recovering nickel from the nickeliferous serpentines and laterites should lead to the establishment of a new industry in the Philippines, to the development of a source of nickel in the Far East, of which at present there is none, and to partial solution of the problem of supplying the free world with nickel. Enough preliminary reconnaissance had been completed by early 1954 to permit sampling of the deposit for metallurgical investigations. The FOA then requested the Federal Bureau of Mines Northwest Electrodevelopment Laboratory, Albany, Oreg., to conduct preliminary electric smelting studies on nickeliferous serpentine and laterite samples.

Jan 1, 1955

By E. G. Erspamer

Laboratory investigations were made by the Bureau of Mines on ore containing the sulfides of both mercury and antimony to develop a method or methods for the economic recovery of mercury metal and the concurrent recovery of antimony as metal or salts,. If standard mercury-recovery techniques are applied to such ores, the antimony content interferes with the effective production of mercury metal; further-more, the antimony is lost. This report presents the results of tests on a sample of cinnabar-stibnite ore from the Red Devil mine near Sleitmute, Alaska. Red Devil ore was chosen for the investigation because it is purported to be typical of ores of the Kuskokwim River area, which, in their aggregate, constitute large potential reserves of mercury and antimony. Studies included petrographic, spectrographic, and chemical analyses, gravity-separation tests, bulk flotation of mercury and antimony sulfides, differential flotation, leaching, and furnacing of crude ore and of flotation concentrate.

Jan 1, 1956

By V. F. Parry, J. B. Goodman, W. S. Landers

"This investigation was conducted: under the direction of A.C. Fieldner, chief, Fuel and Explosives Branch, Bureau of Mines, Washington, D. C. The following members of a Technical .advisory Committee were helpful in advancing the investigation: L. C. Harrington, dean, College of Engineering, University of North Dakota; D. F. Pane, president, Sheridan-Wyoming Coal Co.; Carson W. Smith, president, Consolidated goal & Coke Co.; Durbin van Law, consulting, engineer, Denver & Rio Grande Western Railroad; and C. B. Carpenter, professor of metallurgy, Colorado School of Mines. Coal samples from the Northern Colorado field used in the stoker during 3 years of service were supplied through the cooperation of N. C. Brooks, secretary, Northern Colorado Coals, Inc.This report describes the development and practical tests made on a small stoker-fired system for heating service water automatically. The system was designed to take advantage of the favorable reactivity of low-rank fuels, and the objective was to devise a combination of stoker, heat-receiving, and hot-water storage system Which would be automatic for at least 30 days without attention, while heating service water at minimum cost. The system was developed to a point where coal consumption was less than 10 pounds (or less than 100,000 B.t.u.) per day. The total operating cost of hot water for an average-family-was about $1.00 per month, with coal retailing at $6.00 per ton and electric power at 4 cents a kilowatt-hour. The heating system was designed for the utilization of low-rank fuels, but the general features of the double-tank system can be 'employed fuels, either gas or liquid fuels.The Subbituminous Coal and Lignite Section of the Bureau of Mines began investigations on the utilization of low-rank fuels in domestic appliances during 1939. Tests were made on various devices to find out if they were suitable for the low-rank fuels. Most of the available appliances for burning coal have been designed for the higher-rank fuels, and they are not well-suited for burning the lower-rank coals at maximum efficiency, because subbituminous coals and lignite have high bed moisture ranging between 20 and 40 percent by weight, which lowers heating value to the range of 10,000 to 6,500 B.t.u. per pound. They are noncoking, and the ash content ranges between 4 and 6 percent, with a fusion temperature of about 2,0000 F."

Jun 1, 1946