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By W. L. Cooley

A significantly different method of evaluating mine ground system safety is investigated. The method measures touch and step potentials around ground beds and grounded equipment resulting from a series of extremely small simulated faults. The values are then scaled for a full-scale fault. The method should be particularly useful for large ground beds and under conditions where the ground bed cannot be isolated from the rest of the ground system in order to make traditional ground bed resistance measurements. Instrumentation for making the alternative measurements is evaluated under rigorous field conditions. A step-by-step procedure is proposed for evaluating a surface mine ground system. This procedure was subject to several field tests at eastern metal/non-metal mines. The final evaluation procedure is written as a stand-alone document for use by MSHA inspectors and mine operating personnel, and is included as an appendix to the report. The authors conclude that the procedure is effective in evaluating ground system safety and recommend that it be further evaluated in the field.

Jan 1, 1985

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski County, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations beginning with No. 4251, of which this is the eighth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is no followed by a description of each deposit developed in that half township. The 14 half township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project, except the deep holes drilled to test the geophysical anomalies. The locations at those holes show on figure 13 in volume I. The descriptions of the deposits developed are followed by complete detailed logs at the drill holes. Many at the widely spaced exploratory holes did not discover bauxite of minable thickness and gra.de. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each halt township is given with the discussion covering that area.

Jan 1, 1948

By Edwin S. Secor

The Federal Bureau of Mines conducted a field survey of 153 bituminous coal strip and auger mines to estimate coal recovery from surface mines in the Eastern United States. Recovery was calculated from field data by measuring coal losses resulting from mining coal and leaving barriers. Mean total recovery for strip mining in States east of the Mississippi River was 83.0 percent and ranged from 72.3 percent for Tennessee to 91.3 percent for Maryland. Mining losses and barrier losses were 10.1 and 7.7 percent, with standard deviations of 4.8 and 10.4 percent, respectively, indicating that barrier losses, although less than mining losses, were more variable. Mean total coal recovery varied only slightly for the two regions studied; 82.7 percent for Appalachia and 84.3 for the Midwest. Total recovery grouped by mining method--contour, area, and mountaintop removal--was 79.8,84.7, and 85.3 percent, respectively. Mean auger recovery was 35.9 percent; of the total average loss of 64.1 percent, over one-half resulted from design limitations while the remainder was attributed to operating losses. The wide recovery range at individual mines indicates the variability of the eastern surface coal mining industry. Because of this, care should be exercised in applying the results of this report to reserve estimates other than those of a general nature.

Jan 1, 1977

By Grant Buma

Groundwater restoration is an uranium leaching. Information on the technology, costs, and the current permitting regulations is of vital operators and to firms considering in important aspect of in situ effectiveness of the current state and federal government importance to in situ leach situ leaching. This study, funded by the U. S. Bureau of Mines, describes: (1) all recent restoration attempts at commercial in situ leach operations, (2) restoration costs reported by the industry, (3) empirical equations that predict the amount of groundwater flushing required to meet the current restoration criteria, and (4) in situ uranium permit requirements for the states of Texas, Wyoming, New Mexico, Utah, Montana, Colorado and South Dakota, and Federal requirements.

Jan 1, 1981

By R. C. Diehl

Coal, fly ash, and flue gas samples were analyzed for mercury (Hg) by double gold amalgamation-flameless atomic absorption spectrophotometry. The purpose of the study was to elucidate the fate of the trace mercury in the coal when the coal is burned. Samples were collected from a bench-scale 100-g/hr combustor, a 500-lb/hr combustor, and three coal-burning powerplants. In all cases mercury was found in the fly ash. The amounts ranged from about 9 to about 70 percent of the mercury in the coal that was burned.

Jan 1, 1972

By R. E. Head

[This paper embodies the data obtained by a detailed statistical, microscopic analysis of the composite mill feed concentrate, and tailing from the Magne and Arthur mills of the Utah Conger Co. for 1 month in 1929. It is one of a series of papers by the same authors5 dealing with the mineralogical characteristics of the ore and concentration products from various well-known plants. The work was done in the cooperateive microscopic service laboratory at Salt Lake and represents the results of cooperation between the United States Bureau u of Mines, the Utah Copper Co. and the University of Utah.]

Jan 1, 1935

By R. E. Head

This paper embodies the data obtained by a detailed statistical, microscopic analysis of the composite mill feed concentrate, and tailing, from the Magne and Arthur mills of the Utah Conger Co. for 1 month in 1929. It is one of a series of papers by the same authors dealing with the mineralogical characteristics of the ore and concentration products from various well-known plants. The work was done in the cooperative microscopic service laboratory at Salt Lake and represents the results of cooperation between the United States Bureau of Mines, the Utah Copper Co., and the University of Utah.

Jan 1, 1935

By WM. H. RINKENBACH, C. A. Taylor

No complete work on explosives, their constitution and analysis, has hitherto been published. Several books that contain chapte.r;s on analysis do not cover the matter thoroughly. Methods tha;t, manu~ facturers, testing stations, and other . agencies have developed to meet their own requirements have not been made public. The Bureau of Mines has issued four publications 1 - cov:eri:ng special phases of the subject. This bulletin. is not inte.nded to replace those reports, but rather to cover present methods employed 'in the , industry and to include all classes of explosives and the materials used in their manufacture. No sharp distinctions can be drawn between classes of explosives. . Surplus military explosives, for example, may be used for blasting, just as blasting explosives, under some conditions, may be employed for military purposes. Moreover, one class gradually merges into another because of similarity in composition. Explosives are here grouped as dynamites, black powders, propellants, detonators, and primers. Some materials are used in practically all these groups ; others in only one. To discuss all the materials that have been or that may be used and the methods for their identification and quantitative determination is not feasible, but the methods described will probably suggest ways of examining new mixtures.

Jan 1, 1923

By L. L. Oden

The Bureau of Mines analyzed vapor-aluminum-diffused stainless steels prior to conducting corrosion measurements in severely sulfidizing environments. These studies were conducted in response to the national need to better control the environmental and economic costs of corrosion. Specimens of a ferritic alloy and austenitic alloys types 316 and 310 were treated by a proprietary vapor-aluminum diffusion process and a dual vapor-aluminum diffusion process. Weights and dimensions were recorded before and after treatment, and comprehensive metallographic, X-ray, and electron micro-probe analyses were conducted for both single-and dual-vapor-aluminum-diffused specimens. Surface aluminum concentrations ranged from 26 to 34 wt-pct for all alloys. Dual treatment increased the quantity of aluminum per unit area by a factor of 2 and increased the depth of penetration by a factor of 3. The aluminum-diffused region of the ferritic alloy was single-phase aFe solid solution that was ordered on the surface, whereas two distinct diffusion layers were ob-served on the austenitic alloys. The outer layer comprised aFe solid solution that was ordered on the surface, and the inner layer was a two-phase mixture of aFe solid solution and the interrnetallic compound AINi.

Jan 1, 1982

By R. H. Schutz

This publication lists the respiratory protective devices approved by the Bureau of Mines as of December 31, 1968, and the names and addresses of their manufacturers. The purpose of this publication is to inform the public about approved equipment for safe use in mines and mineral and allied industries.

Jan 1, 1969

By D. Harrington

The greatly extended use of the underground trolley-locomotive system for hauling coal without doubt was one of the most important factors in the rapid progress of coal mining and the increased production of coal in American coal mines during the period 1910-20. Much of the superior efficiency of production of our underground coal and metal lines should also be credited to the trolley locomotive system. The trend to mechanization of mines during the past 15 years, mere particularly the past 5 years, with higher production per man employed and greatly accelerated advancement of working places, has required increased use of trolley locomotives, necessitating larger equipment, higher speeds, and more 'frequent turn over of pit cars. This is re¬flected in increased size of locomotives and the use of larger mine ears (some with a capacity up to or over 10 tons); moreover, heavier rails and larger-size trolley wires have boon or ought to have boon installed. Trolley-locomotive haulage has proved to be rapid; economical, efficient, and productive; nevertheless; in spite of these advantages, so-many hazardous features and, unsafe conditions are involved and the price paid in life and property is so high as to justify the statement that the system should be scrapped if it cannot be operated under reasonably safe conditions. Since bare trolloy wires were introduced into underground mines, they have boon responsible for the death of hundreds of diners, property damage totaling millions of dollars, an indeterminate loss of tonnage through the abandonment of mines or parts of mines, and loss of time after disasters caused by fires or explosions originated by the trolley haulage system.

Jan 1, 1945

By John D. Foulkes

An investigation is made into whether commercially available equipment can be used to engineer effective emergency warning systems for underground coal mines. Discussions with members of the Bureau and the Mining Enforcement and Safety Administration established that the preferred system should operate over the existing Pager Phone twisted pair, and broadcast an audio alarm. Applicable equipments such as voice band tone signaling equipment, alarm sounding equipment, mine telephones and complete alarm systems from over thirty manufacturers are listed. Factors affecting the range over which an alarm could be detected in representative mine situations were studied. These included (a) the subjective masking effects of typical background noise found in mines, such as that due to continuous miners (b) the attenuation of sound in mines (using both a theoretical and experimental results) and (c) the attention-getting qualities of different sound for miners. Audio alarm systems meeting the requirements can be installed and representative systems are described.

Jan 1, 1977

By Harold J. Bennett

This study was performed by the Bureau of Mines to evaluate the potential supply of primary copper from domestic resources. A tonnage-price relationship was developed indicating the quantity of copper that could be produced economically from known deposits at various copper prices and at various rates of return on the required capital investment. Costs of production are based on estimated capital and operating costs for mining, concentrating, smelting, and refining the copper. Total known recoverable copper resources are 189 million short tons of which 83 million tons could be economically recovered assuming a price of $0.50 per pound of copper, credit for the recovery of byproducts, and a 12-percent rate of return on capital investment. The quantities of recoverable byproducts associated with the 83 million tons of recoverable copper are molybdenum, 1.8 million tons, gold, 43 million troy ounces, and silver, 740 million troy ounces.

Jan 1, 1973

By A. F. Robertson

"INTRODUCTION This report is supplemental to R.I. 4178 and deals with the work accomplished between June 15, 1945, and September 7, 1945, on the Mitchell-Hodge mine, Grady mine, Albea and York property, and Cuzzort property.ACKNOWLEDGMENTSIn its program or exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigcal Branch, O. C. Ralston, chief, analyzes samples and performs benefication tests.Acknowledgment is due Mitchell H. Kline, chief, Raleigh Division, Mining Branch; Abraham L. Fox, acting chief, Raleigh Division, Metallurgical Branch; and Rowe McCrae, district engineers, U.S. Bureau of Mines, Gainesville,"

Jan 1, 1946

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but most of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority as collectors in the flotation and agglomerate tabling of micas, feldspars, guartz, clay, and other acidic minerals, but the separation of these minerals from each other necessitated of the study of the flotation of each mineral.]

Jan 1, 1941

By James E. Norman

[The flotation of mica is mentioned frequently in the literature, but must of the references have dealt with the recovery of mica by the old anionic collectors. The first use of the new cationic reagents indicated their superiority- as collectors in the flotation and a. agglomerate tabling of micas, feldspars, quartz, clay, and other acidic mineral, but the separation n of these minerals from each other necessitated study of the flotation of each mineral.]

Jan 1, 1941

By Terry J. Kreidler

In recent years, west-central Arizona and adjacent California have become the focus of geologic and exploration attention because of its excellent exposure of detachment-fault terrane. Detachment faults, normal faults with nearly horizontal fault planes, are the result of regional extension. Rocks on the lower plate consist of mylonitized intrusive, metasedimentary and crystalline rocks highly altered to chlorite; upper plate rocks comprise sedimentary, volcanic, metasedimentary, and metavolcanic rocks. The movement of the detachment fault causes the rocks on the upper plate to be severely fractured and brecciated thus making them Ideal conduits for mineralizing fluids. Mineralization favored the more reactive sedimentary and volcanic rocks of the upper plate. Three gold deposits, located in upper plate rocks, are currently being mined along the Colorado River corridor: the Picacho Mine near Yuma, Arizona, 70 mi south of the study area; the American Girl Mine In southeastern California, 60 mi southwest; and the Copperstone Mine near the southern end of this study area. Samples from the above three mines were used to create a geochemical model of detachment-related gold deposits. Antimony, arsenic, barium, copper, mercury, molybdenum, manganese, tungsten, and zinc all occur In the mine samples in concentrations at least three times greater than found elsewhere in similar rock types. Samples taken by the Bureau from the wilderness study areas contain similar anomalous concentrations of the same elements as well as elevated concentrations of several other elements Including: lead, fluorine, cerium, uranium, and samarium.

Jan 1, 1992

By Arnold C. Love

This report discusses current research by the U.S. Bureau of Mines on the effects of whole-body vibration (WBV) and shock on underground mobile equipment operators. The highlights of a comprehensive literature review of WBV, shock, and seating are presented. Factors discussed include health and physiological effects, comfort, performance, and fatigue. Vibration data were collected from shuttle cars and ramcars at several underground coal mines in Pennsylvania, Ohio, and Illinois. The data were formatted so that they could be used to drive the Bureau's motion platform, and to compare them with ANSI S3-1979, Guide for the Evaluation of Human Exposure to Whole-Body Vibration. Human subject testing in the Bureau's vibration research laboratory evaluated the effects of two different seat angles and of the presence or absence of vibration and of foam padding on heart rate, blood pressure, and subjective discomfort. Only vibration significantly increased heart rate and systolic and mean blood pressures. Vibration and a steel seat had a significant effect on subjective discomfort. The apparatus used for these tests and the experimental procedures are described in detail. Recommendations are made for additional research on the exposure of underground mining machine operators to WBV and shock.

Jan 1, 2010

By John D. Bardill

This report covers magnetic surveys in the Dannemora arca , which was part of a general survey of magnetite deposits in New York started in 1943 . The objective of these surveys was to afford a basis for the selection of exploration projects .

Jan 1, 1947

By R. S. Dean

[Methods s of preparing the manganese metal that has been used in chemical and metallurgical investigations have passed through a cycle. Most of the investigations made before the turn of the century, used Moissen's pyrophoric manganese.3/ This material was made by electrolysis into a mercury cathode and distillation in vacuo. The material was essentially pure, and investigations in which it was employed (with proper precautions against oxidation) led to accurate results on tie intrinsic behavior of metallic manganese.]

Jan 1, 1941