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By W. L. Falke

This Bureau of Mines report illustrates critical path planning and scheduling techniques as applied to typical mining operations. Detailed examples of arrow diagramming and computer oriented applications of critical path methods are given. Program Evaluation and Review Technique (PERT) is discussed briefly in comparison to the Critical Path Method (CPM).

Jan 1, 1966

By G. L. Neumann

Owing to the need for additional sources of supply of both zinc and lead following World War II, the Bureau of Mines investigated many abandoned lead-zinc mines in the eastern United States. A series of shallow veins in south-western St. Lawrence County has long been a subject of speculation. These veins, which average about 4 feet in width and cut across the bedding of the country rock at right angles, are filled with calcite-carrying galena and sphalerite. The deposits have been worked sporadically during the last 115 years. From 1837 to 1852 the Coal Hill, the North, and the Victoria mines near the village of Rossie were at their peak of activity. Other calcite veins were prospected and a small production was realized. The Bureau of Mines began diamond drilling May 1, 1950, under the general supervision of McHenry Mosier, chief, Mining Branch, Bureau of Mines, Region VIII, and under the immediate supervision of the author) who was project engineer, following the preliminary examination by Robert S. Sanford. A total of 3,870.2 feet was drilled in 18 holes on four of the numerous deposits scattered over Macomb and Rossie townships. Drilling was completed September 21, 1950.

Jan 1, 1952

By Douglas F. Scott

This case study provides an example of how social marketing was applied to meet the needs of business customers. Federal regulations require that all companies develop a written program to track hazardous chemicals at their sites. The HazCom Writer, created by the National Institute for Occupational Safety and Health (NIOSH), is a software tool designed to help companies prepare their required Hazard Communications (HazCom) written plan and list all hazardous chemicals at the company's worksite. The social marketing goal was to provide a product for small- to medium-sized companies to use for federal HazCom rule compliance. The HazCom Wm'ter is a direct NIOSH response to customer and stakeholder needs (including the Mine Safety and Health Administration, the mining community, and Occupational Safety and Health Administration- regulated companies).

Jan 1, 2009

By B. W. Gandrud

This is the first report published by the Bureau of Mines on washability characteristics of coal from beds in Tennessee. It is based principally upon screen-sizing and float-and-sink tests of raw coal from a bed on the Cumberland Plateau. Stripping operations were undertaken recently on this bed by the Cumberland Collieries, Inc., near Chalybeate,Van Buren County, Tenn. The bed has not been definitely correlated, but it may be an extension of the Sewanee bed, which has been mined extensively in the Tracy City district to the south-vest and at points near Dunlap and Pikeville to the southeast and east. It was spoken of by officials of the Cumberland Collieries as the Sewanee bed at the time of sampling for this study. In a letter dated October 16, 1948, W. D. Hardeman, geologist of the Department of Conservation, Nashville, Tenn., states: "The stripping operations of the Cumberland Collieries near the old postoffice at Chalybeate are, I am fairly certain, in the upper part of the Whitwell shale, which carries the Sewanee coal. This coal may be a stray seam, but it probably can be correlated with the Sewanee coal, which is mined farther east. "There are no detailed geologic maps or reports covering the area, and this opinion is based on what was observed in visiting the strip mines in that general vicinity." The laboratory work upon which this report is based was done at the Southern Experiment Station of the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama and the Cumberland Collieries, Inc.

Jan 1, 1949

The Bureau of Mines is establishing design criteria for effective roof support systems and is developing technology to improve mine planning and design. Geologic studies, surface and underground mine monitoring, and laboratory evaluations were conducted. The seven papers in this proceedings Information Circular present results of several investigations. Addressed are problems existing in both longwall and multiple-seam mines. Discussions include the effect of dewatering at a longwall mine site in the Pittsburgh coal seam and the effect of chain pillars on subsidence. Other results are measurement and characterization of longwall rock mass movement and an integrated design for stability in multiple-seam mining.

Jan 1, 1987

By Jon C. Volkwein

The Bureau of Mines and many member companies of the Industrial Sand Association have been working in several areas to reduce personal exposure to respirable dust. Areas investigated include ventilation, modification of hardware, moisture addition to the product, and improved housekeeping practices. Ventilation systems have been devised and shown to contain 100 pct of a tracer gas released within the hood. An industrial clean air island has been developed and shown to reduce dust levels 90 pct at the opera- tor's position, Modification of hardware on a bag filling machine has been demonstrated to reduce dust 83 pct at the machine operator's lapel. This particular development has been termed a significant advancement in the state-of-the-art of bag filling by industry representatives. Addition of moisture to dried product materials has been tested with results showing dust reductions of 90 pct are possible!, Control of the moisture addition method still needs refinement and costs may be prohibitive. Dust sampling results clearly show the benefits of housekeeping practices such as building cleaning and vacuum sweeping. Rotation of work schedules is also effective for reducing personal exposure.

Jan 1, 1985

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network. and 2)development at a set pit digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the models and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated fur their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

As part of its regular program to provide timely information on domestic mineral commodities, the Bureau of Mines conducted an engineering appraisal of more than 1,300 lode and placer gold deposits in the United States to deter-mine their gold production potential. While these deposits were estimated to contain over 400 million ounces of gold, only 9 million ounces, or slightly more than 2 percent, was found to be producible at $35 per ounce under prevailing mining and metallurgical technologies. The study revealed that any significant increase in available gold in the United States is most likely to come from the discovery of new sources, intensive exploration and development of the more promising known mineralized areas, and development of new or improved mining and metallurgical techniques.

Jan 1, 1967

By Kenneth J. Miller

The Bureau of Mines two-stage coal-pyrite flotation process was modified to provide a more concentrated final clean coal slurry underflow which could be dewatered economically by filtration or centrifugation. This was accomplished by doing the first-stage coal flotation step in the conventional manner with a slurry of about 8 percent solids, but running the second-stage pyrite Flotation step with undiluted coal froth concentrate containing about 25 percent solids. The final clean coal underflow produced by the new technique contained between 26 and 30 percent solids; this pulp was sufficiently concentrated to be filtered industrially without further thickening. Sulfur removal was equal to that obtained using dilute second-stage pulp,

Jan 1, 1975

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1981 was $312.7 million, a decrease of $15.7 million from that of 1980. Output of most non fuel minerals declined; cement, crushed stone, lime, clays, and sand and gravel were the major commodities produced in the State. Alabama led the Nation in the production of crushed marble; was second in bauxite; third in native asphalt, kaolin, and oyster shell; fourth in bentonite, dimension marble, and fire clay; fifth in masonry cement; and sixth in common clay, ferroalloys, and lime.

Jan 1, 1983

By Charles F. Jackson

Gold mining is a subject that not only appeals to the popular imagination but has vital importance to the world's economic structure. However, a discussion of the use of gold as a medium of exchange, and a basis for credit between nations and for monetary systems is not within the scope of this paper. The importance of gold in carrying on the commerce of the world, the present supply and rate of production, the probable trend of future production, the probable future requirements, and related subjects have recently received much attention from bankers and economists, and many articles on these subjects have been published. During slack periods of base-metal production due to falling prices, accompanied by scaling down of base-metal mining operations and often by the closing down of at least some mines, there usually result revival of interest in gold mining, search for previously undiscovered deposits, and reopening of some old gold mines.

Jan 1, 1932

By I. AITKENS

The basic mining law of Cuba is contained in the basic Spanish mining decree having the effect of law December 29 , 1868. This legislation has remained substantially unchanged , with the exception of a few minor administrative changes made by the present Government . These changes provide for the register of mines , oil wells , and operations of such nature , and also provide for the keeping of records showing the value of minerals taken out . By Royal decree of April 17 , 1883 , the law of mines enacted for the Peninsula ( Spain ) on July 6 , 1859 , and the General Bases of December 29 , 1868 , were declared in force in Cuba . In order to encourage the mining of iron org , in 1883 the Crow of Spain issued a royal decree to the following effect.

Jul 1, 1931

By C. M. Harrer

The location, features, qualities, and extent of iron occurrences and the associated resources--limestone and dolomite, bentonite, coal-lignite, petroleum and natural gas, power, and water--are evaluated. The results of pioneer beneficiation tests on South Dakota taconite are discussed. In addition, pertinent features of taconite development, cost factors, the Western and Central United States trade area and markets are reported. The State's production of iron ores until 1963 has been small and for purposes other than the manufacture of iron. This investigation disclosed the probability of large resources of taconite in Pennington and Lawrence Counties. The average iron content is 29 percent, and a 65-percent or better iron concentrate might be produced. Ample resources are available for mining and processing taconite. An investment of at least $26 million would be required for a plant capable of turning out 1 million tons of agglomerated iron concentrate per year. The feasibility of such an enterprise is indicated, but intensive investigation and research must be completed to justify such an investment.

Jan 1, 1966

By S. M. Dar

The U.S. Bureau of Mines constructed a full-scale model of a 15-ft-wide coal mine entry to use in combination with finite-element analyses to investigate roof support systems and various types of roof bolts. The objective was to enhance understanding of the fundamental mechanics of the interaction between rock and supports and the relative integrity of bolted mine roof as a function of roof bolt type, length, spacing, and tension, and the basic characteristics of the roof strata. The laboratory test results, when correlated with computer simulations using fmite-element analysis and underground verification tests, should provide a basis for desigillng safer, more cost-effective roof control systems and help to establish guidelines for employing fully grouted resin and mechanically anchored bolting systems. The background for this research, the research approach, the methods and equipment employed, and the results are described in this report.

Jan 1, 1989

By W. G. Freeman

This study provides recommendations for improved safety in underground blasting procedures based on in-mine observations of blasting practices in 30 underground metal, non-metal, and coal mines, and the analysis of blasting accidents since 1970 and existing state and federal regulations pertaining to the storage and use of explosives. Results of these analyses and observations indicate that 1) blasting accidents have declined but are an important contributor to the hazards of underground mining; 2) existing regulations are essentially adequate; 3) greater emphases should be placed on human errors and unsafe practices and the enforcement of existing regulations; and 4) future revisions of these regulations and standards should be organized, and their intent coordinated to eliminate ambiguities.

Jan 1, 1980

By T. A. Henrie

The Federal Bureau of Mines has investigated methods of sodium reduction of titanium chlorides to produce high purity titanium metal (14).4/ This investigation was made to obtain a better understanding of the reactions involved in sodium reduction of titanium chlorides and was part of the Bureau's activities toward improving the technology of titanium. Theoretical and experimental evidence show that sodium reduction of titanium tetrachloride occurs by stepwise reactions. The first stage reduction between sodium vapor and vapors of titanium chlorides produces titanium di-and trichlorides which subsequently condense with sodium chloride to form a salt mixture. The second stage reduction takes place in the condensed salt mixture between sodium and titanium subchlorides. Final reduction is a heterogeneous reaction between two separate phases, the a phase which consisted of sodium dissolved in sodium chloride and the ß phase titanium subchlorides dissolved in sodium chloride. The mechanism of the heterogeneous reaction between these phases is electrochemical in nature. The model proposed is a galvanic reaction at the interfacial region.

Jan 1, 1960

By Edmund S. Leaver

The selection of a process for treating a gold ore is governed primarily by the characteristics of the ore under consideration. The form in which the gold occurs, its mode of association with other minerals, and the size and surface condition of the gold particles are important factors which influence materially the choice of procedure for recovering gold. A knowledge of these characteristics may be obtained by microscopic and chemical methods combined with experimental testing. Cyanidation and amalgamation, either alone or in conjunction with flotation and gravity methods, are peculiarly adapted to the treatment of gold ores, especially those of relatively low grade. Gold alloys readily with mercury provided both present clean surfaces. The presence of oils and grease, antimony and arsenic minerals, or soluble sulphides have a harmful effect. Very small, flaky particles of gold frequently are lost in amalgamation because of noncontact with the mercury. Fine gold in pyrite, or gold having rusty or contaminated surfaces, is often lost for the same reason. Grinding or some form of abrasion sometimes removes surface films of iron oxide or substances of a similar nature, and alkalies or other chemicals are used to remove grease. Gold is readily soluble in cyanide solution, and this method of treatment is particularly effective in the recovery of gold from the tailings resulting from other types of concen¬tration procedure. Cyanide solutions must contact the gold to insure recovery, and the porosity of the ore treated and the fineness of grinding required are important governing factors. The use of lime in cyanidation is necessary to protect the cyanide, to precipitate undesirable substances, and to settle slimes. Certain substances in ores are harmful in cyanidation; chief among them are those that combine with cyanide, forming cyanides, and carbon which precipitates gold from solution. Arsenic and antimony are also harmful if present in sufficient quantity. These and other difficulties encountered in cyaniding certain ores often are overcome by roasting prior to leaching. Zinc dust is used almost universally for precipitating precious metals from cyanide solutions. The refining and melting of the product may be accomplished by oxidizing the zinc before melting it in graphite pots with fluxes, although sulphuric acid is now used largely to remove the zinc before melting. Straight cyanidaticn practice is being replaced by flotation as a major process, followed by cyanide leaching of the tailings, but amalgamation is still needed as a primary process for the recovery of coarse gold before either flotation or cyanidation.

Jan 1, 1935

By Edmund S. Leaver

The selection of a process for treating a gold ore is governed primarily by the characteristics of the ore under consideration. The form in which the gold occurs, its mode of association with other minerals, and the size and surface condition of the gold particles are important factors which influence materially the choice of procedure for recovering gold. A knowledge of these characteristics may be obtained by microscopic and chemical methods combined with experimental testing. Cyanidation and amalgamation, either alone or in conjunction with flotation and gravity methods, are peculiarly adapted to the treatment of gold ores, especially those of relatively low grade. Gold alloys readily with mercury provided both present clean surfaces. The presence of oils and grease, antimony and arsenic minerals, or soluble sulphides have a harmful effect. Very small, flaky particles of gold frequently are lost in amalgamation because of noncontact with the mercury. Fine gold in pyrite, or gold having rusty or contaminated surfaces, is often lost for the same reason. Grinding or some form of abrasion sometimes removes surface films of iron oxide or substances of a similar nature, and alkalies or other chemicals are used to remove grease. Gold is readily soluble in cyanide solution, and this method of treatment is particularly effective in the recovery of gold from the tailings resulting from other types of concentration procedure. Cyanide solutions must contact the gold to insure recovery, and the porosity of the ore treated and the fineness of grinding required are important governing factors. The use of lime in cyanidation is necessary to protect the cyanide, to precipitate undesirable substances, and to settle slimes. Certain substances in ores are harmful in cyanidation; chief among them are those that combine with cyanide, forming cyanides, and carbon which precipitates gold from solution. Arsenic and antimony are also harmful if present in sufficient quantity. These and other difficulties encountered in cyaniding certain ores often are overcome by roasting prior to leaching. Zinc dust is used almost universally for precipitating precious metals from cyanide solutions. The refining and melting of the product may be accomplished by oxidizing the zinc before melting it in graphite pots with fluxes, although sulphuric acid is now used largely to remove the zinc before melting. Straight cyanidation practice is being replaced by flotation as a major process, followed by cyanide leaching of the tailings, but amalgamation is still needed as a primary process for the recovery of coarse gold before either flotation or cyanidation.

Jan 1, 1935

By David B. Doan

This regional report covers 1993 mining and related activity in approximately 40 countries and territories of Canada, Latin America, and the Caribbean Basin. These countries of the Western Hemisphere, as with the United States, are endowed with a great variety of minerals, including metals, industrial minerals, and energy minerals. For most of these countries, such mineral production helps form foundations for their economies and earns export credits including hard currencies. Table 1 depicts an overall view of Latin America and Canada's production of its major mineral commodities in 1993; subsequent tables show the role of Latin America and Canada in world mineral production, trade, and import dependency on minerals from Latin America and Canada by the United States. Overall, the picture emerges of a rich mineral diversity throughout the hemisphere, attracting increasing interest and investment, and complementing the mineral resources of the United States.

Jan 1, 1995

By Janine Pierce, Robert Larson, Christine Raasch

The vibration and impact environment for crew members on locomotives has been investigated in a series of studies conducted by Exponent Failure Analysis Associates (Exponent) beginning in 1990. Locomotive cab vibration and impact levels were measured on a variety of locomotive models operating over many different track sections across the Union Pacific, Burlington Northern Santa Fe, CSX, Norfolk Southern, and CONRAIL systems. The comfort and health implications of exposure to the measured locomotive vibration levels were evaluated by comparison with the human vibration exposure boundaries given in the International Standards Organization (ISO) standard 2631-1:1997, the British Standard 6841:1987, European Union (EU) Directive 2002/44/EC, measurements made by Exponent on various commercial and recreational vehicles, and vibration exposure measurement data found in the literature. Methods Initially, vibration levels experienced by locomotive crews were measured and recorded at incremental speeds covering the range of normal train operation. In 2003, a method of measuring the vibration exposure continuously by means of a digital recorder was developed, allowing the vibration level over the entire run or crew shift to be analyzed. For each seating location measured, acceleration was recorded on the seat surface beneath the ischial tuberosities (pelvis) of the seated crew member and on the cab floor directly under the seat. At each of the locations, triaxial accelerometers were used to measure the vibration along the longitudinal, lateral, and vertical axes. Since the vibration environment varies throughout the route, and locomotive vibration levels have been found to be primarily speed dependent, a speed sensor was used to continuously measure the speed of the train. To evaluate the recorded vibrations levels, the data was divided into two-minute segments, which were each processed per the 1997 ISO standard for weighted RMS vibration levels and Vibration Dose Values (VDV). Additionally, PSDs and 1/3 Octave RMS values were calculated to determine the frequency content of the vibration. For each two-minute segment, the average speed of the locomotive was calculated to allow for correlation with the recorded vibration exposure values. The resulting exposure values for the entire run were calculated by combining the data from all of the two-minute segments. Since introducing the continuous method of recording acceleration, 23 seating locations have been recorded on 11 locomotives traveling 11 different routes across various parts of the United States. One of the routes was a shift of ‘yard work’, traveling back and forth in a rail yard coupling train cars together. Results A guide to interpreting weighted acceleration values with respect to health is given in Annex B of the 1997 ISO standard. A health guidance caution zone is defined to indicate the

Jan 6, 2006