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By G. Andrews

This case study details the process that was used for project planning and permitting for the Greens Creek Mine, located near Juneau Alaska, as seen through the eyes of one of the primary environmental consultants. This case shows how a Company could involve the public and the agencies in the early 1980's and develop a project sensitive to concerns expressed with a high level of environmental protection. Comparisons are made to the current environmental permitting situation. Initial baseline studies performed during the exploration phase provided helpful information for more detailed environmental work in 1980-1981 as planning and permitting formally got underway. Since the mine was in a National Monument and abuts up to a designated wilderness, the Monument Manager administered the project for the lead agency, the USDA Forest Service. Planning and permitting progressed smoothly to a Final Environmental Impact Statement (FEIS) in 1983. Metal prices were depressed when the FEIS was completed and the project permitting proceeded slowly. Ownership changed several times in the mid-1980's. New owners re-evaluated the project and suggested five changes that required a supplemental EA prior to development. The project was fully permitted and started construction in 1988. Operation began in 1989. Today the environmental process in southeast Alaska is now much more complex, detailed, expensive, and time consuming than in the early 1980's. Significant issues discussed that may impede development and operation include overlapping agency jurisdictions, personal agendas of agency staff, conflicts between agencies that impede project progress, changing regulations, and a well organized environmental opposition.

Jan 1, 1993

By Robert E. Wood

[The temperature dependency of the low-density thermal conductivity coefficients, ?°T, of nitrogen, 100° to 1,200° K, is correlated with the Keyes' equation, ?T ½ -1 -12/T) WT = aT+ bT 10 The equation ?T,P = ?°T +a[ ]ß represented 509 experimental higher V pressure thermal conductivities in the temperature range 131.2° to 973.15° K for pressures to 500 atmospheres, with a mean absolute deviation of 2.35 percent. This equation was used to compute thermal conductivities of gaseous nitrogen for 47 pressures, 1 to 240 atmospheres, and 110 temperatures, 133° to 740° K, which are common to conditions encountered in Bureau of Mines helium purification processes. Isobaric heat capacities, CP, and viscosities, ?T,P, from previous work were combined with the present thermal conductivities, ?T,P, to compute Prandl1 numbers, C?T P / ?T ,P, of nitrogen. Tabular values of Prandtl num¬bers are presented for 49 pressures, 1 to 240 atmospheres, and 75 temperatures, 133° to 740° K. Estimated uncertainties are ±5 percent in the tabulated thermal conductivities and ±15 percent for the computed Prandtl numbers. However, the uncertainty may rise to ±10 percent for thermal conductivities and to ±30 percent for Prandtl numbers as the critical conditions of nitrogen are approached.]

Jan 1, 1971

By I. L. Feld

This Bureau of Mines report describes the development of a simple method of producing low-phosphorus hematite concentrates from certain submarginal southeastern iron ores. The investigation was undertaken to obtain additional information on the Clinton iron ore outcrops at the southwestern extremity of the Birmingham district of Alabama and to assist in the development of operating techniques that would make it profitable to use the marginal ores of this area for blast-furnace feed. Batch and continuous pilot-plant tests demonstrated that a relatively simple wet scrubbing treatment) followed by a desliming operation to reject argillaceous (clayey) gangue, consistently yielded a marketable granular hematite product. Iron losses were relatively high but could be tolerated in view of the low treatment cost.

Jan 1, 1960

SMCRA contains five principal regulatory provisions that form the basis for its implementation: Performance Standards Performance standard safe intended to ensure that all surface mining is conducted in a way that protects the environment and the public and ensures that the mined land is restored to productive use following mining. Permits Before developing a surface or underground coal mine, an operator must have a permit issued under SMCRA. An application for a permit to conduct a surface coal mining operation is a detailed document that consists of text and numeric data describing the proposed mining and reclamation. Information must be furnished on pre-mining environmental conditions, existing land use, proposed mining and reclamation, how the performance standards will be met, and the post-mining land use. This provides the regulatory authority with the information necessary to determine that the operation can be conducted in accordance with the regulations. Performance Bonds Before a permit can be granted, an operator must post a performance bond sufficient to cover the cost of reclaiming the site in the event the operator fails to complete reclamation. The bond is not fully released until all performance standards have been met and reclamation of the site has been determined to be successful after five years in the East and Midwest, and after 10 years in the arid West. However, the bond can be partially released as various phases of reclamation are completed. Inspection and Enforcement If a violation of SMCRA or of a state surface mining and reclamation law is observed, an inspector issues a notice of violation to the operator. The violation must be corrected within a specific time, and the operator may also have to pay a fine based on the severity of the violation. If the violation is not corrected, acessation order is issued to immediately stop active coal mining, and the operator must pay a fine. If a violation is especially serious (for example, creates an Following reclamation, the land was immediately put back into agricultural production. Today, grain and corn crop yields have continually exceeded targets. 2 imminent danger to public health or safety or causes significant damage to land, air, or water resources) the inspector immediately issues a cessation order. An operator must correct all violations in order to obtain permits for new mines. Lands Unsuitable For Mining Congress recognized that certain coal deposits cannot be mined without permanent damage to unique cultural or natural resources. As a result, SMCRA protects these resources in two ways: It prohibits mining within the boundaries of national parks, forests, wildlife refuges, trails, wild and scenic rivers, wilderness and recreation areas; in areas which will adversely affect sites listed on the National Register of Historic Places; and within a restricted distance of occupied dwellings, public roads, buildings, parks, schools, churches, and cemeteries; and Provides a process that allows anyone whose interests may be adversely affected by proposed mining to petition to have specific lands designated unsuitable for mining.

Jan 1, 1992

By R. W. Stahl

Gas accumulation and dust suspension are the major safety hazards in coal stockpiling and reclaiming operations. This report presents a schedule of safety precautions and plant design features devised by the Bureau of Mines to reduce danger from these and other sources.

Jan 1, 1965

By Paul M. Tyler

Graphite is chemically identical with diamond, both being crystallized allotropic forms of carbon. Graphite obviously differs greatly from diamond in physical properties and is easily recognized by its blackness, its softness (1 to 2 on Mohs' scale), and its slick feel when rubbed between the fingers. Strictly speaking, all graphite is crystalline, but grades in which the individual grains cannot be distinguished with the naked eye are commercially classed as amorphous. Natural mixtures of the two varieties occur in all proportions, and the classification of a given sample as "amorphous" or "crystalline" graphite is based largely upon trade practice. Until recently different varieties of vegetable or animal charcoal, lamp black, soot, gas carbon, and coal ware considered strictly amorphous, but modern examination by X-ray methods indicates that even these materials possess the same internal crystalline structure as graphite, differences in physical properties being perhaps explained by porosity or presence of combined hydrogen or other impurities.

Jan 1, 1941

By Robert W. Ageton

Optimal planning for mining the deep, lead-zinc-silver deposits of the Coeur d'Alene mining district, Shoshone County, Idaho, could be facilitated by a knowledge of the magnitude and direction of the pressure acting in the virgin rock. The distribution of primary stresses should be considered in order to prevent possibly destructive mining-induced stress concentrations. This particular investigation was concerned with determining stress in a zone 4,000 feet below the surface and known to be ender stress concentrations due to mining operations. Disking of the stress-relief cores obtained in a vertical down hole permitted qualitative evaluation from visual observations; the results indicate that a high lateral stress existed at the time the measurements were made. Stress-ellipsoid determinations gave a compressive principal stress of -13,000 psi oriented about N 45° W and nearly horizontal, a compressive principal stress of -11,000 psi oriented about S 45° W and abut 60° off the vertical pointing away from the vein, and a compressive principal stress -5 -7,000 psi oriented N 45° E and about 60° off the vertical, pointing toward the vein. Subsequent to the overcoring stress-relief drilling, a rock burst occurred about 100 feet northwest of the test site.

Jan 1, 1967

Lower the respirable dust expo-sure of longwall mine workers by reducing the amount of air-borne respirable dust generated during coal extraction. Approach Increase the moisture content of the coal seam through water infusion before the coal is mined. How Water Infusion Works Increasing the moisture content in coal tends to prevent respirable dust from becoming air-borne during mining and transport. The moisture content of the coal seam can be increased by infusing water into the seam. Water under pressure is forced into the cracks (cleats) of the coal seam through sealed bore-holes. The effectiveness of water infusion is a function of the amount of water the coal seam accepts (its infusibility), which depends on the cleat density (cleat spacing) and cleat size (crack diameter). Thus the effect of water infusion on dust control depends mainly on coal seam characteristics. Water infusion techniques are generally used to restrict the flow of methane gas to the working face; however, the technique provides an alternative dust control method in mines with severe dust problems which limit production.

Jan 1, 1987

By Thomas A. Phillips

An economic evaluation of the Bureau of Mines process for the separation of raw urban refuse into its metal, mineral, and energy components is presented. The process recovers ferrous metal, mixed nonferrous metals, aluminum, mixed-color glass cullet, and refuse-derived fuel products from raw refuse. Data for this evaluation were obtained from selected runs at the Bureau's pilot plant in Edmonston, Md. A cost estimate was prepared for a plant capable of processing 1,000 tons per day of raw urban refuse operating two shifts, 6 days per week. The fixed capital cost, based on second quarter 1976 equipment costs, is approximately $14.5 million excluding land and shipping containers. The estimated operating cost is approximately $8 per ton of refuse processed. This does not include credit for the products, transportation of the products, a tipping fee, or a dumping fee for wastes produced. No finance charges or taxes are included in the operating costs.

Jan 1, 1977

By J. R. Nettle

The electrodeposition characteristics of seven binary alloys of titanium have been investigated. The object of the electrorefining experiments with an alloy was to determine the efficiency of titanium separation from individual alloying elements under established conditions. Reported results are only indicative. It is conceivable that numerous duplications of tests might give average maximums that would vary from those noted in this report; however, in the few tests that were repeated, the magnitude of transfer of the alloying elements was of the same order. The results detailed herein are for a given set of conditions. Many combinations of operating variables are possible, and the results achieved under different conditions probably would differ from those reported.

Jan 1, 1958

"A coordinated, integrated research effort aimed at studying the scientific, engineering and medical aspects of the respirable dust problem is underway in the areas of dust generation, dust dispersion and dilution, dust characterization, interaction of dust and lungs, and relationship of seam characteristics to dust generation and mobility. (FIGURE 24) The Center's research program explores these concerns with the objective of refining existing strategies and developing new respirable dust control techniques that are consistent with the dust-lung interaction processes that lead to mine worker disability. The fundamental aspects of this work are applicable to the control of respirable dust problems in both hard rock mines and coal mines and to other dusts such as diesel-generated.Research projects in the Generic Mineral Technology Center for Respirable Dust have effected several improved methods for the preparation and characterization of the dusts needed by these projects. Superior procedures for generating ""standard"" dust samples have been developed and are in regular use in the laboratory. Questions raised during the course of some projects regarding ""stale"" versus ""fresh"" dust have led to the development of sampling techniques where the dust is directly collected in a surfactant. MSHA and CANMET have requested and received information on Center generated software. An equipment manufacturer, TSI, Inc., requesting input on modifying the inlet of an aerosol sampler has been assisted as a result of research that was conducted at the University of Minnesota.The objectives, scope and progress of all the research projects in the Center, in the form of abstracts and reports, have been detailed in Volume 1 of this series. Research papers written by the principle investigators and resulting from the findings of projects (FIGURE 25) and which are funded by U.S. Bureau of Mines grant number G1135142 have been published in Volumes 3 through 6 and Volume 8 of this series. Volume 2 relates the cooperation and interaction of the U.S. Bureau of Mines and the Generic Mineral Technology Center for Respirable Dust in research on the problem of respirable dust in the mineral industries."

Aug 31, 1989

By R. J. Seibel

A statistical comparison of the dust exposures of coal miners with identical occupations in Pittsburgh, Pocahontas, Freeport, and Kittanning seams was conducted. Results indicated that, in some cases, identical occupations have different dust exposures in different seams. For example, the continuous miner operator in the Pittsburgh and Pocahontas seams is exposed to more dust than the same man in the Kittanning seam, but the Kittanning seam has more dust along the haulage roads than the other seams. Also, average dust exposures for similar occupations in continuous and conventional mining operations are similar.

Jan 1, 1974

By Irving Hartman

The results of the first experimental study by the Bureau of Mines on the explosive properties of metal powders were published in 1945. Since that time the explosibility of numerous other industrial dusts and powders has been investigated. Part of this information has been published, but most of the data has not been released to date. This paper summarizes the results of experiments on 22 samples of titanium, zirconium, thorium, uranium, and hydrides of these metals. The major part of the investigation was made under cooperative agreement with the Atomic Energy Commission.

Jan 1, 1951

By G. R. Hopkins

A fifth successive record in fuel efficiency was established by the petroleum-refining industry in 1937, when the average heat requirement per barrel of crude oil run to stills was 554,000 3. t. u. compared with 597,000 3. t. u. in 1936. These amounts represent roughly the heat ob¬tainable from a tenth of a barrel of fuel oil (see fig. 1). Innumerable factors can influence heat consumption at rep aeries, but only a few are important enough to be subject to statistical measurement. Foremost of these is the ratio of runs to capacity, it being generally recognized that because the fuel demands for other than stills are comparatively inelastic, total heat requirements do not increase in direct proportion to crude runs. Thus, in 1937, crude runs of 1,183,440,000 barrels wore 11 percent higher than in 1930; the average operating ratio was 93 percent compared with 79 percent in 1936; but the total heat requirement increased only 4 percent, or from 639,149 billion 3. t. u. in 1936 to 663,966 billion 3. t. u. in 1937.

Jan 1, 1938

By J. S. Kennedy, M. M. Fine

"INTRODUCTION Barite is one of the major industrial minerals whose production has increased considerably in the last 10 years. In 1935 domestic production of barite was 218,075 tons and. had increased by 1944 to 515,136 tons. 3/ Most of the primary uses for barite and barite products were developed before 1935, so the increase in barite production reflects the growth of industry in general rather than any recent developments in barite technology.The principal uses for ground and crushed barrite are as a weighting agent in heavy drilling fluids, as a filler in rubber and other materials, as a pigment and extender in paints, and as a flux in glass melt. In addition, a considerable' quantity of barite serves as the raw material for the manufacture of lithopone and barium chemicals.Specifications for barrite vary widely and depend primarily on the use to which the material is put. The primary requisites for barite used in heavy drilling muds -are that it have a minimum specific gravity of 4.2 and be very,low in soluble salts. A minimun barium sulfate content of 92 percent may be specified; but this is less important than the gravity. 4/ In addition before consumption the material must be ground to '92 percent minus 325-mesh. 5/ Lithopone and chemical manufacturers require a minimum of 94 Percent barium sulfate, a maximum of 1.0 percent iron oxide, and not more than a trace of fluorine. 6/ Barite used as fillers in light-colored products should be of fairly high grade, but the filler used in dark products may be considerably lower grade.Glass barite should contain a minimum of 96 percent barium sulfate, not more than 3 percent moisture, a maxium of 0.2 to 0.4 percent iron oxide, and not more than a trace of titanium oxide. Particle size is a matter of some importance in glass barite, also. 7/"

May 1, 1948

By G. Dale Coe, Will H. Coghill

The " periodic pincer " herein described fills a need for a device to control the rate of flow of a wet ore pulp through an orifice . Two uses of the periodic pincer to be discussed are on classifiers and on a wet ore feeder . Although the immediate necessity that brought about this device was for better operation of a miniature hydraulic classifier , in connection with an investigation of iron- ore concentration being conducted by the Federal · Bureau of Mines , with the cooperation of the University of Alabama , the device has promise of a wider field of application . In the iron - ore work , the need became so acute for a nonchoking , uniform - delivery classifier spigot that development of a suitable device was imperative .

Apr 1, 1944

By G. R. Hopkins

A fifth successive record in fuel efficiency was established by the petroleum-refining industry in 1937, when the average heat requirement per barrel of crude oil run to stills was 554,000 B. t. u. compared with 597,000 B. t. u. in 1936. These amounts represent roughly the heat obtainable from a tenth of a barrel of fuel oil (see fig. 1). Innumerable factors can influence heat consumption at refineries, but only a few are important enough to be subject to statistical measurement. Foremost of these is the ratio of runs to capacity, it being generally recognized that because the fuel demands for other than stills are comparatively inelastic, total heat requirements do not increase in direct proportion to crude runs. Thus, in 1937, crude runs of 1,183,440,000 barrels were 11 percent higher than in 1930; the average operating ratio was 83 percent compared with 79 percent in 1936; but the total heat requirement increased only 4 percent, or from 638,149 billion B. t. u. in 1936 to 663,966 billion B. t. u. in 1937.

Jan 1, 1938

By Manuel Gomez

Areal distributions for ash, total sulfur, and sulfur forms were developed for the top 12 inches, the middle section, the bottom 8 inches, and the total seam of Pittsburgh coal in southwestern Pennsylvania. The sulfur and ash exhibit an apparent high local variability. As a general rule, both the sulfur and ash show high concentrations in the top 12 inches and in the bottom 8 inches of the seam relative to the concentrations observed in the middle section of the seam. The high-low sulfur and ash concentrations in the top 12 inches of the seam are not coincident with the high-low sulfur and ash concentrations in either the middle section or the bottom 8 inches of the seam. With respect to sulfur and ash, it is suggested that the top and bottom sections of the Pittsburgh coal may reflect both a syngenetic and epigenetic origin. Present data support the belief that paleotopography controlled Pittsburgh seam deposition. Evidence is presented to show that channels were cut at various times into the semilithified sediments that buried the Pittsburgh seam. In this channeling process, portions of the Pittsburgh coal may have been eroded away. Following channel development, the lower part of the Pittsburgh sandstone filled the complex system of braided channels to produce the "want areas" encountered in present mining operations. In localized areas of the Pittsburgh seam, impingement of Pittsburgh sandstone may be responsible for the lateral displacement of the coal. Information of this type becomes important in the assessment of exploration data, in the development of a quality control system for mine output, and in mine life planning.

Jan 1, 1974

By Richard J. Mainiero, James H. Rowland III, Marcia L. Harris

This paper reviews the potential hazards posed by the toxic fumes produced by detonating explosives in surface mining and construction operations. Blasting operations produce both toxic and nontoxic gaseous products; the toxic being mainly carbon monoxide (CO) and the oxides of nitrogen (NOx). The quantity of toxic gases produced by an explosive is affected by formulation, confinement, age of the explosive, and contamination of the explosive with water or drill cuttings, among others. Techniques to protect workers and the public from the potential hazards of explosive-related toxic fumes are discussed. These include: • Minimizing the quantity of toxic fumes produced. • Determining where the fumes may go so workers and neighbors can be moved out of harm’s way. • Preventing the fumes from moving towards workers and neighbors. • Monitoring the air near workers and neighbors so they can be relocated if fumes appear. • Ventilating structures or confined spaces until CO falls below a hazardous concentration.

By J. A. Zimrner, R. J. Tirnko

The roles of main mine fans in underground mines are to induce airflow and continuously re- move hazardous gases and dust. While most larger mines use multiple fans to accomplish these tasks, many smaller mines employ only a single fan. This paper concentrates on those mines having only one fan to provide ventilation needs. If this fan should cease to function, it is likely that methane concentrations will in- crease in some areas of the mine. As a safety precaution, Federal Regulations require that personnel must be- gin evacuating the mine within fifteen minutes after fan stoppage. Powered haulage can be used to transport workers to the mine portal as long as travel is through areas where hazardous levels of methane are not expected. To determine where methane will accumulate along haulageways during a fan stoppage, air samples must be taken at specific areas and analyzed for hazardous gases. During this study, procedures were developed for measuring methane levels along the haulegeways that are used to exit a mine following stoppage of the main mine fan. Methane levels were measured in four different mines at selected underground locations during four planned fan stoppages. In these mines the measurements taken only at the specified locations showed that, if workers had used electrically powered haulage to exit the mine following a fan stoppage, the methane accumulated along haulageways during fan stoppages would not have significantly increased the risk of an ignition.