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By John J. McClelland

The U.S. Bureau of Mines formed a team in 1991 to begin developing a long-range research plan for computer-assisted mining that would benefit the metal-nonmetal mining industry. This report details the team's accomplishments, specifically, the development of a model that identifies metal-nonmetal mining research needs that could be addressed by the application of automation technology. The report also provides a summary of automation needs and applications based on visits with mining company representatives. The status and future direction of this work is also presented.

Jan 1, 1994

Founded in 1994 through a joint effort between Underwriters Laboratories Inc. (UL), the U.S. Consumer Product Safety Commission (CPSC) and the National Electrical Manufacturers Association (NEMA), the Electrical Safety Foundation International (ESFI) is North America?s only non-profit organization dedicated exclusively to promoting electrical safety in the home, school and workplace. ESFI is a 501(c)(3) organization funded by electrical manufacturers and distributors, independent testing laboratories, utilities, safety and consumer groups, and trade and labor associations. ESFI sponsors National Electrical Safety Month each May, and engages in public education campaigns and proactive media relations to help reduce property damage, personal injury and death due to electrical accidents. The Foundation does not engage in code or standard writing or lobbying and does not solicit individuals.

Jan 1, 2004

By B. R. Mohal, F. F. Aplan, S. Chander

"The wetting behavior of coal has been determined in the presence of nonyl and octyl series of nonionic surfactants containing polyethoxy groups of different sizes. The wetting behavior was determined by a modified Walker technique and contact angle measurements. The results show that the wetting rate of coal varies with coal rank, structure of the hydrocarbon chain and number of ethoxy groups in the hydrophilic group of the surfactant. A close relationship has been observed between the wetting rates and the short-time advancing contact angles.INTRODUCTIONNonionic surfactants are used in many applications to improve wettability of solids. They can be used as dispersing agents [ 1 ] or dust suppressants [ 2-5] and to control the flotation, flocculation, filtration and, flowability of particulates. This study was undertaken to study the effect of a series of nonionic surfactants on the wetting behavior of coal. Two series of surfactants, namely, ethoxylated nonyl and octyl phenols were used. The nonyl phenol series con tains a linear hydrocarbon chain containing nine carbon atoms (CH3 ( CH2 )8-C6H4- ( OC2H4 ) n, where n is the number of ethoxy groups) . The octyl phenol series contains a branched hydrocarbon chain containing eight' carbon atoms ( ( CH3 ) 3CCH2C ( CH3) 2-C6H4- ( OC2H4 ) n ).Initial wetting rates — modified Walker techniqueWalker et al. [ 6 ] developed a sink test to determine the wettability of coal particles. In this technique, coal particles are dropped individually onto the surface of surfactant solutions of different concentrations, and the most dilute concentration in which coal would sink ""instantaneously"" is determine& This technique is a variation of a procedure initially developed by Draves and Clarkson [ 7 ] to determine the effect of surfactants on wettability of cotton fibers."

Jan 1, 1989

By Frederick C. Trutt

A guide to the development and utilization of an interactive mine-power-system fault program (Z-bus by algorithm) is presented. Theoretical foundations, as well as implementation considerations are discussed with respect to the mine-power system. Alternative Kron reduction techniques are presented along with a triangular-storage method for storage conservation. Program capabilities include the analysis of balanced and unbalanced (line-to-line, line-to-ground, and line-to-line-to-ground) fault situations using symmetrical component theory. To account for phase shifting in delta-wye transformers and zero-sequence network constructions, transformer and load configurations are specified by the user. The positive-and zero-sequence connections needed for network conformity are automatically constructed with the required impedances.

Jan 1, 1979

By Paul R. Thimas, Edward H. Boyle

"The Bureau of Mines evaluated the long-term cost and availability of primary gold production from 135 mines and deposits worldwide. Collectively, the evaluated countries represent 93 pct of world gold production. Total recoverable gold available (as of January 1984) from a subset of 111 significant producing mines and developing deposits in 13 market economy countries (MEC's) is estimated at 810 million tr oz. The Republic of South Africa is estimated to account for 87 pct of total recoverable gold. The United States and Canada account for 4 and 4.5 pct of the total, respectively. Eighty-three percent of total recoverable gold is available at a constant 1984 break-even price of $400/tr oz, and 70 pct is available at $300/tr oz. South Africa accounts for 90 pct of the gold available at $400/tr oz or less.Major conclusions are that (1) South Africa should remain the largest world producer through the year 2000, (2) annual MEC output in 2000 should not be significantly different than current output given constant 1984 gold prices of more than $300/tr oz, and (3) there may be a significant decline in production after 2010 in the absence of major new discoveries and continued development of new mines to offset the depletion of the South African mines. INTRODUCTIONSince the late 1970's the world gold mining industry has been characterized by dynamic growth in production and volatility in price. World production in 1983 was almost 15 pct greater than in 1980, and the short-term trend continues upward. Annual dollar-based price changes since the early 1970's have been unprecedented in both magnitude and volatility. This commodity, which sold for $35/tr oz3 for over a third of a century, reached an annual average $612/tr oz in 1980. Until 1980, the future price of gold seemed set on an upward trend. Since that year, however, world gold prices have fallen by over 50 pct to slightly over $300/tr oz at the end of 1984.Against this background, this study was undertaken to determine (1) the level of world demonstrated gold resources, (2) total and annual availability of gold mine production, (3) long-run production costs per operation and by national aggregates, (4) the economic and technical factors that impact upon cost and availability, and (5) probable future mine production and cost trends."

Jan 1, 1985

By E. Wittenau

This paper describing the concentrator practice of the Copper Queen Branch of the Phelps Dodge Corporation at Bisbee, Ariz., is one of a series of papers on milling methods and costs being prepared by the United States Bureau of Mines. The Copper Queen Concentrator treats 4,000 tons of copper ore daily by preferential flotation, whereby the copper sulphides are floated and considerable iron pyrite is depressed. During 1929 the heads to the concentrator averaged 2.15 per pent of copper, the recovery was 91.32 per cent of the total copper, and the concentrates produced contained 12.92 per cent of copper.

Jan 1, 1931

By Laird Crocker

This report describes a study of beryllium recovery from sulfate leach liquor by di-2-ethylhexyl phosphate (EHPA) solvent extraction in conjunction with caustic stripping. The work was one phase of Bureau of Mines research on process development for Spor Mountain, Utah, ores. Solution for the solvent extraction studies was prepared by sulfuric acid leaching of ore containing 0.6 pet BeO, Before solvent extraction of beryllium, the leach liquor was treated to prevent coextraetion of iron by either (1) removal of ferric iron by amine solvent extraction or (2) reduction of ferric iron to nonextractable ferrous iron by treatment with sulfur dioxide. Beryllim was extracted from the aqueous leach liquor by countercurrent multistage contacting with a kerosine solution of EHPA. The loaded organic solution was stripped with sodim hydroxide solution. Subsequently, beryllium hydroxide was precipitated by boiling the sodium beryllate strip solution and converted to beryllium oxide of 98 pct BeO-grade by calcining. Material of this grade can be directly processed into beryllium-copper alloy or be used as starting material for further refining to produce high-purity, nuclear-grade beryllium. Over 90 pct of the beryllium contained in the leach liquor was recovered as beryllia.

Jan 1, 1963

By John H. Soulé

"INTRODUCTION The property of the Silver Spot Mines Co. is in the Boston Hill area within and adjacent to the southwest corner of Silver City, N. Mex. The area was visited by Bureau of Mines engineers 3/ in 1941 and 1942 during the investigation of possible sources of manganese. The area was visited again in November 1944 4/ to study the possibilities of geophysical exploration of the manganiferous-iron deposits. This geophysical work was performed in 1945 5/, confirmed the existence of known deposits of manganiferous-iron ores, and indicated the probable extent and situation of others.The Silver Spot property was churn-drilled from 1926 to 1929 during exploration for manganiferous-iron ores. The sludges from a number of the holes indicated low-grade lead-zinc mineralization. Lead and zinc minerals also were found on the dumps of some of the old shafts when the property was visited by D. H. Mullen, an engineer of the Bureau of Mines late in 1946. A diamond-drilling project was proposed. It was started in April 1947 with the intention of investigating the best of the known ore indications as shown by the old churn-drill holes and thus gathering new data upon which to base future work. Only one hole was drilled before the project was terminated because of lack of funds and time."

Mar 1, 1948

By H. -F. Krausse

Roof failures in underground coal mines are related to the lithology and geologic structure of the roof. There are two distinct suites of roof rock above the Herrin (No. 6) Coal in Illinois, and each has distinctive patterns of structure and roof failure. In black shale-limestone roof areas, roof instability is correlated with thinning of limestone beds and presence of faults and clay dikes. In gray shale roof regions, the prime roof hazards are posed by rolls, shear bodies, and presence of coal or carbonaceous partings in the roof. Most structural features examined are believed to have formed during early stages of sediment diagenesis and compaction. Structural trends and lithologic patterns are strongly interdependent for this reason. In many cases geologic patterns are so complex and locally variable that prediction of roof stability far in advance of mining is difficult. The need for greater flexibility in roof control planning is apparent.

Jan 1, 1979

By George T. Krempasky

This report is one of a series of Bureau of Mines Information Circulars dealing with mining methods and costs throughout the United States. It describes drifting, crosscutting, and raising operations at several mines in the Coeur d'Alene mining district, Shoshone County, Idaho. Ore bodies in the Coeur d'Alene district are generally in steeply dipping tabular ore zones, are irregular in shape, erratic in occurrence, and have been extensively mined along the strike and down dip. Because of the extended attitude of the deposits a great deal of development work is required. Drifting, crosscutting, and raising methods are described in this report. Shaft sinking is the subject of another report in the same series.

Jan 1, 1960

By Richard A. Allwes

This U.S. Bureau of Mines report presents the results of structural analyses and full-scale physical tests conducted on a steel-set arch and tri-set. The purpose of the analyses and tests was to evaluate the suitability of these structures for use in roof-fall prone areas. The arch canopy test and design procedures previously developed by the Bureau were utilized in this evaluation. Theoretical resistance functions were established for the steel-set arch and tri-set and were representative of the experimental behavior of the structures. The resistance functions were used to determine the energy absorption capacity of the structures and to predict their dynamic response to impact loading. The dynamic tests demonstrated that the arch canopy design procedure is appropriate for tri-sets and yields conservative designs for both steel-set arches and tri-sets. As a result of this work, it is recommended that these two structures may be considered for use in roof-fall prone areas and for rehabilitation work, provided the arch canopy design procedure is utilized for each application and the principles underlying the design procedure are understood.

Jan 1, 2010

By Albert E. Schreck

[THE COMPOUNDS of strontium were confused with those of barium until 1790, when A. Crawford discovered that the mineral strontianite, long believed to be a barium mineral, was a compound of a new element. This discovery was confirmed 2 years later by I. C. Hope. The mineral was named strontianite because it was found near the town of Strontian in Argyllshire, Scotland. In 1808 Sir Humphrey Davy isolated strontium metal by the electrolysis of fused chlorides. Celestite (strontium sulfate) and strontianite (strontium carbonate) are the principal strontium minerals. Because of its more widespread occurrence, celestite is more important commercially.]

Jan 1, 1959

By Earl T. Hayes

For several years the Northwest Electrodevelopment Laboratory of the Bureau of Mines, in cooperation with the Air Materiel Command, U. S. Air Force, has been studying zirconium alloys. A preliminary survey of these alloys has been completed and reported as a Bureau of Mines Report of Investigations. 4/ Originally the purpose was to determine the suitability of zirconium alloys in medium-temperature applications. However, data also were obtained on other properties of these alloys, and later the scope was broadened to include amore detailed investigation of a selected group. The zirconium-titanium system was one of those chosen. The Bureau of Mines has been instrumental in the commercial development of both of these metals and has constructed pilot plants for the production of titanium at Boulder City, Nev., and for zirconium at Albany, Oreg. Both elements are in subgroup A, fourth series of the periodic table, and therefore have many properties in common. Since both have similar atomic structures and lattice dimensions the possibility of extended mutual solubility seemed likely. Inc transition-point diagram of Fast indicated that the two metals are completely miscible in all proportions in both the alpha and beta forms.

Jan 1, 1951

By G. R. Strimbeck

Experimental work is report on the gasification of 90-percent through 200-mesh, strongly coking Sewickley-bed coal with oxygen and with steam in three temperature ranges, namely, 2,700° to 3,400° F., 1,600° to 2,000° F., and 230° to 250° F. Thirty-one runs have been made, during which 56,000 pounds of coal have been charged to the generator at feed rates of 200 to 450 pounds of coal per hour. The average results, not the optimum results, are given in the following tabulation:

Jan 1, 1950

By D. S. Kingery

Experiments initiated by the Bureau of Mines on August 26. 1969, and recent work of others, have demonstrated the effectiveness of ventilation for controlling concentrations of respirable coal mine dust. Substantial reductions in dust concentrations have been attained by increasing the volume and rate of air movement across the face and by controlling the airflow pattern. Ventilation experiments conducted by the Bureau using high-pressure fans as auxiliary ventilation units showed that lace-generated dust could he effectively controlled in five mines employing continuous mining machines. Additional data was obtained on industry installations in two mines using similar ventilation systems. By maintaining an airflow approaching 100 fpm across the entry, the experimental system reduced the concentration of respirable dust by factors as great as 6.4. In all mines where the system was used the face-generated dust concentrations were reduced to below 3 mg/m3. Total respirable dust in two cases was above the 3 mg/m value because of the dust content of the intake air. In some mines. depending upon the type of coal being mined and other dust control factors in use, it was possible to Obtain concentrations of less than 2 mg/m Although the technology for the application of the dust control system investigated is readily available, it is evident that additional engineering studies should he made in each mine where the system is to be applied.

Jan 1, 1969

By Carl Belser

Approximately 30 million pounds of tungsten trioxide in the form of ferberite concentrates have been shipped from Boulder County. Since 1940, the production has varied considerably, being affected by the emergency needs of World War II and the Korean conflict. During World War II, attempts to stimulate production were made by the Metals Reserve Company by stabilizing the price for a specified period, the Reconstruction Finance Corporation by small mining development loans, and the Bureau of Mines and the Geological Survey, who cooperatively explored some of the district by surface and underground core drilling. During the Korean conflict and continuing through the first half of 1954) tungsten production was being stimulated by a Government-gauranteed price and by financial assistance loans under the Defense Production Act of 1950 to qualified operators of properties that have merited exploration. This combined program has increased production in Boulder County from about 1,900 pounds in 1949 to an estimated 383,000 pounds of tungsten trioxide in 1953. The 1953 production came from 67 properties. One of the problems confronting producers is the need for improved beneficiaton methods. Ores from the area have not been amenable to flotation concentration and gravity methods have resulted in poor recovery, often less than 70 percent.

Jan 1, 1955

By Robert W. Geehan

A preliminary examination of the Dayton iron deposit was made in 1941 and 1942 by Paul E. Pesonen and O. H. Metzger, engineers of the Bureau of Nines. Trenching and sampling were recommended, to be followed by core drilling if favorable results were obtained. The Bureau of Mines conducted a project at the property from June to December 1942. The deposit is in sec. 6, T. 17 N., R. 23 E.; sec. 31, T. 18 N., R. 23 E.; sec. 36, T. 18 N., R. 22 E.; and sec. 1, T. 17 N., R. 22 E., M. D. B. & M., about 15 miles west of Lahontan Reservoir in Lyon and Storey Counties, Nev. It lies at an altitude of about 4,500 feet north of the Carson Plains, in the foothill section of mountains that rise to about 7,000 feet to the north of the property. The deposit may be reached by driving 12.5 miles northeast of Dayton over U. S. Highway 50, thence northerly 2.7 miles over a dirt road to the property. The climate is hot and dry in summer, with occasional thunderstorms some of cloudburst variety, and frequent high winds. Winters are usually moderate, with light snowfall and some subfreezing temperature.

Jan 1, 1949

By Erich K. Bender

This report summarizes work performed under Phase I of USBM Contract No. H0366024, Noise Reduction of Jumbo Mounted Percussive Drills. Four drills -Gardner-Denver D93LAR and DH123 and Ingersoll-Rand 0475 and VL120 models were measured at the two manufacturers? test sites; data are given in terms of characteristic noise and vibration levels. A survey of percussive rock drill users is reported. The rationale for the choice of a demonstration drill, the Gardner-Denver DH123, is given and a desired noise reduction goal is established.

Jan 1, 1976

By C. R. Kuzell

This paper, describing the concentrator practice of the United Verde Copper Co., is one of a series being prepared by the Bureau of HISTORY The United Verde concentrator was constructed in accordance with recommendations based on certain novel reasons which were quite different from those usually justifying the expenditure of such an amount. Concentrator operations started in March, 1927, although the metallurgical staff had considered for several years the eventual addition of a concentrator department.

Jan 1, 1930

By Kathleen M. Kowalski

This research explores the emergence of leadership in a crisis situation. The study by the U.S. Bureau of Mines focuses on three underground mine fires and the resulting evacuations. The subjects for this study are 48 coal miners, who evacuated the mines as part of eight escape groups, The subjects described their escape during an open-ended interview. Data were coded according to: (a) evidence of leadership behavior, (b) evidence of lack of leadership behavior, and (c) characteristics of the individual in each group who led the subjects out of the mine. During analyses, attributes of the leaders, who facilitated the escapes, were noted and compared as were instances of lack of leadership. The structure of the group leadership before the crisis was compared with the reality of the leadership during the crisis. Some groups experienced an apparent breakdown of leadership during their escape, while others witnessed the emergence of leadership. Consensus characteristics of the leaders, who emerged during these crises, are discussed and generalizations drawn. Research into leadership during emergency escapes is needed to provide information for training in prevention, escape, and rescue. The authors suggest questions for further investigation and topics for further inquiry into the area of leadership evolvement during crisis.

Jan 1, 1994