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By Richard L. Rains

In 1984 and 1985, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied part of the 162,887-acre Mormon Mountains Wilderness Study Area (NV-050-161) in order to evaluate its identified mineral resources. The study area is located in Lincoln County, NV, about 60 miles northeast of Las Vegas. The study area had no mines or mining claims in 1985, and no mineral resources were identified within the study area, or at the Whitmore mine or Iron Blossom prospect near the study area. The alluvial fans around the southern boundary are staked with about 450 placer claims. Chemical analyses of samples indicate that some limestone in the study area is suitable for manufacturing cement or for agricultural purposes but the limestone is distant from markets and therefore not economic in the foreseeable future. The study area is blanketed with oil and gas leases, but no known productive horizons were identified.

Jan 1, 1986

By A. Wahab Khair, S. Jung

"This paper deals with the fracturing process of laterally confined blocks of coal subjected to impact indentation. During the test, blocks of coal with approximate dimensions of 10 in. x 10 in. x 6 in. were laterally confined to predetermined equivalent in-situ stresses and then subjected to an impact indentation by dropping coal cutting bits (various shapes) attached to a known weight from a known height. During the test a number of parameters, namely surface strains (using strain gages), penetration depth (using L.V.D.T.) and acoustic emission characteristics were measured. After the test, the fractured surfaces were photographed with the aid of a camera attached to a microscope. The fracture, its intensity and extended zone within the coal blocks were mapped using sonic techniques. By correlating measured parameters, fractured zones under a given set of test parameters were identified and characterized.INTRODUCTION To improve the understanding of basic failure mechanisms in coal cutting, a better knowledge of fracture and crack regions caused by the indentation in coal is needed. This study reports the detailed experimental procedure used in fracture analysis of indentation experiments on coal specimens using the Acoustic Emission (A.E. hereafter) and sonic techniques. The relationship between microcracking and the inelastic deformation of rock was confirmed by a series of experiments in which the A. E. generated by the cracking in the rock specimen were recorded and the number of events were compared to the strain measurement. (Scholz, 1967).According to fracture mechanism theory, crack initiation in brittle materials such as rocks begins from ""flaws"" either pre-existing or induced by the indentation process itself. Rocks are pervaded by natural cracks and pores, from which numerous possibilities for crack initiation arise (Lindquist, Lai and Alm, 1984)."

Jan 1, 1989

By Margaret R. Egan

The Bureau of Mines experimentally burned Pittsburgh Seam coal and other combustible materials found in mines in order to obtain a better knowledge of their emission products. These experiments were conducted in the Bureau's intermediate-scale fire tunnel, which simulates environ-mental conditions in underground mines. Smoke characteristics, gas concentrations, mass loss, and ventilation were measured. From these values, heat-release rates, particle sizes, obscuration rates, combustion yields, and production constants were calculated. This information was sought as part of a comprehensive study of combustible materials that will ultimately advance the design of more efficient fire detection and suppression systems. The coal combustion measurements presented in this report, together with previous analyses of wood and transformer fluid fires form a data base by which future studies of other mine combustibles can be compared.

Jan 1, 1987

By R. W. Stahl

A survey of firefighting facilities and practices in coal mines conducted by the Bureau of Mines3/ showed such variations in equipment and apparent attitude toward fire protection that a comparison with other industry seemed advisable. Although other industry is confined generally to surface operations and the hazards probably are not as great, the same general methods of extinguishment are employed, so that the cost and protection at least should be comparable. An investigation of industry other than mines revealed a generally greater emphasis placed on fire-combating equipment, fire-brigade training, fire-fighting facility inspection, and fire-hazard elimination, as well as a greater average expenditure for fire protection.

Jan 1, 1959

By Barry L. Warner

This program involves testing to determine whether a fire hazard exists when the exposed wood surface area of timber in a mine passageway equals 40 percent of the surrounding strata surface, excluding the sill. Twelve full scale fire tests were conducted in a simulated mine passageways, using kerosene pan fires as the ignition source. The tests included three timber sizes, plus one test with roof lagging, two wood types, plus one test with treated timbers, and two ventilation air velocities. The results show air velocity to be an important factor in the occurrence of flame propagation, and that the 40 percent surface area ratio of wood to surrounding strata appears to b0. a valid criteria for fire safety at 150 fpm, but not at 350 fpm.

Jan 1, 1975

By Liane L. M. Kacinuck

This U.S. Bureau of Mines publication is intended to provide mining industry representatives and regulatory authorities with a reference package dealing with studies on hydrology and underground mine subsidence. An annotated bibliography and a list of additional sources are given and represent references published prior to June 1993. Ninety-two references ware identified and 72 obtained for assessment. Annotating the references included evaluating the study methodology and summarizing the basic results. The references are also compiled based on geographic location to aid the user in identifying articles of particular interest.

Jan 1, 1994

By Allen D. Look, Alan A. Sharp

"INTRODUCTION The bottoming of the United Verde sulfide pipe has shortened the expected life of the United Verde mine to a matter of a few years. First located in 1876, this Arizona mine has had a long period of activity, having reached a peak production in 1929 of over 71,000 trans of copper. Through these many years of successful operation, a safety program has evolved in keeping with the proficiency developed in mining the ore body. It is the purpose of this paper to record the safety practices in effect at this mine so that others may have the benefit of lessons ,learned through experience 'and years of work toward an improved accident record.ACKNOWLEDGEMENTSAcknowledgment 'is 'made to ,the Phelps Dodge Corp. for its cooperation in making available data contained in this paper, and to C. E. Mills, general superintendent; W. W. Little, mine superintendent; John Riordan, employment agent; and G. S. Leisk, safety engineer, for their helpful suggestions and information furnished.GENERAL INFORMATIONThe United Verde copper mine is situated just west of Jerome, Ariz., at an altitude of approximately 5,500 feet. Purchased by the Phelps Dodge Corp. in 1935, the mine employs approximately 500 men - 385 underground and 115 on the surface."

May 1, 1949

By E. G. Baglin

The Bureau of Mines devised a procedure for selectively extracting platinum-group metals (PGM) and gold from Stillwater Complex flotation concentrate. The Stillwater Complex is the only major U.S. PGM resource. Development of a suitable extraction technique will contribute to its exploitation. The concentrate was roasted at 1,050° C to convert host base-metal sulfides to oxides and the PGM from sulfide minerals to their elemental states. The roasted concentrate was preleached with dilute sulfuric acid to remove easily soluble gangue minerals. After pre-leaching, the concentrate was slurried with 6M HCI and leached at ambient temperature and pressure with a strong-oxidizing agent. Hydrogen peroxide, chlorine, sodium hypochlorite, nitric acid, and a persulfate salt were the oxidants investigated. The two-stage leaching scheme ex-tracted up to 97 pct of the platinum, 92 pct of the palladium, and 99 pct of the gold from the roasted concentrate. The base metals were not solubilized and reported to the residue. No attempt was made to devise a procedure to recover the copper and nickel because they comprise less than 5 pct of the value of the concentrate. Viable techniques for recovering the precious metals from the pregnant solution were sulfide precipitation, cementation with nickel, or adsorption on activated carbon.

Jan 1, 1985

By D. D. Fischer

Recovery and separation of molybdenum and rhenium from a process solution was accomplished by a technique developed by the Federal Bureau of Mines involving a combined solvent extraction and activated carbon adsorption procedure. The processing sequence required treatment of the solution with S02 to reduce the chlorate ion and adjust the pR prior to solvent extraction of molybdenum and rhenium with a tertiary amine. Molybdenum and rhenium were stripped from the organic phase with an NH40H solution, and the strip solution was then passed through activated carbon to preferentially adsorb the rhenium. After washing entrained molybdenum from the column with a brine solution, rhenium was eluted with an MeOH-H20 mixture. The activated carbon was regenerated with water. Molybdenum was recovered as (NH4)6Mo7024 by evaporating the column effluent. Rhenium in the column eluate was reextracted with a tertiary amine, stripped from the organic phase with dilute NH40H, and recovered as NH4Re04 by evaporating the strip solution. The final (NR4)Re04 product contained < 80 ppm impurities. Sodium sulfate was crystallized from the first solvent-extraction raffinate by lowering the solution temperature to 0° C. Precious metals contained in the original process solution were adsorbed onto the activated carbon.

Jan 1, 1975

By G. R. Fitterer, C. H. Herty

"INTRODUCTION Manufacturers and consumers of steel have come to realize during the past few years that cleanliness is of great importance in steels which must meet rigid specifications for various physical properties. Of equal importance is the consistent production of steel which is uniform in these properties. For maximum utility steels should be uniform not only from heat to heat, but also from ingot to ingot and within each ingot. In the manufacture of killed steels such as the higher carbon forging grades, uniformity as indicated by the usual chemical analysis in easy to obtain, provided that a normal top discard is taken, as is always the case in steels poured with hot—top practice. No such uniformity, however, holds true for the nonmetallic matter, which consists for the most part of the products of deoxidation of the steel.For a large tonnage of steels which go into articles manufactured by deep—drawing processes, killed steel has never been successfully applied because with the present deoxidation practice, low—carbon killed steel is almost invariably extremely dirty. To obtain the desired qualities for deep drawing, the steel is rimmed, — that is to say, deoxidized with manganese and perhaps a small amount of aluminum, — the resultant product being of high purity in the skin of the ingot, but very badly segregated at the center of the ingot, particularly in the upper—central section. This segregation necessitates a very heavy top discard, and one of the major segregates is carbon which renders the steel too hard to draw properly. If clean, low—carbon killed steel could be made successfully, much better ingot yields would be obtained than by the present rimming steel practice. Furthermore, banded structures and outside and inside seams, which are undoubtedly due in a large measure to blowholes in the ingot, are defects which are very difficult to control in rimmed steel. These defects would be minimized by clean killed steel."

Feb 1, 1931

By Robert H. Mattes

The Lake Lynn Laboratory is a multipurpose mining research laboratory operated by the Bureau of Mines and located in Fairchance, Pa, It consists of both surface and underground facilities. The initial focus of the facility, scheduled for full operation in fall 1982, will be on the problems of fires and explosions in mines. The initial experimental explosion was fired on March 3, 1982. The intent of this document is to provide the reader with detailed information on the physical capabilities of the Lake Lynn Laboratory. Subsequent publications will focus on the capabilities of Lake Lynn as compared with those of other similar facilities worldwide, and a comparison of initial explosion test results realized at Lake Lynn and comparable results from the Bruceton Experimental Mines.

Jan 1, 1983

By John C. Feeley

This paper is the result of a field study of prospect drilling in the Florida phosphate fields. The objective is to describe the drilling methods employed . . Since the general policies of the operating companies in the land - pebble area do not permit the dissemination of prospecting information and costs thereof , the writer has carefully avoided mentioning names and locations except by reference to existing publications ,

May 1, 1949

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 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 C. Q. Cupps

n view of increased interest in secondary recovery of oil in the Cut Bank field, Montana, a review has been made of unpublished data obtained during a 1943-44 study of reservoir oil characteristics in this field. Considerable uncertainty was attached to interpretations of subsurface oil sample analyses from six Cut Bank zone wells, one Lander sand well, and one Moulton sand well, because of adverse sampling conditions and wide range in the data. Much of this uncertainty has been removed by this review which has shown two of the Cut Bank zone samples and the Moulton sand sample to be representative of the reservoir oils. Estimates of original reservoir oil characteristics derived from differential-liberation analyses of these samples show that the oil in the Cut Bank zone was initially saturated at the gas-oil contact pres-sure, 750 psia, and the oil in the Moulton sand was undersaturated with a saturation pressure of only 380 psia. The rest of the samples were indicated to be nonrepresentative of the reservoir oils because of a disproportional vaporization of heavier components of the solution gas. The vaporization of these components is believed to be a cumulative effect of contact of the oil with bypassing, light-gravity gas which had been liberated at higher pressures from solution in oil farther back in the formation, or which had come from the gas cap, rather than from the singular effect of gas evolution caused by excessively low bottom-hole pressures. Change of oil composition caused by the latter was found to conform closely to that occurring during a differential liberation of gas in the laboratory.

Jan 1, 1967

By R. R. Backer

The Bureau of Mines, in cooperation with Washington Irrigation and Development Co. (WIDCO), evaluated the dewatering of fine coal-refuse slurry using chemicals and various types and combinations of drains in natural earth impoundments. About 40 lb of lime and 2 lb of polymer per ton of dry solids were mixed with the underflow from the preparation-plant thickener. Clear, free water was immediately liberated from the slurry. The percent solids by weight of the slurry increased from about 17 to 30 immediately, and after 5 days increased to 45 wt-pct. This indicates a threefold reduction in total volume after 5 days from 172 cu ft/ton solids originally to 56 cu ft/ton solids.

Jan 1, 1981

By James R. McVey

Tests during pillar robbing, longwall operations, and other mining activities indicate that roof-floor convergence rates can be used as an indicator of imminent roof failure. A large number of electrical-mechanical devices have been built to measure convergence as well as convergence rates, but most obstruct mine traffic and are costly and time consuming to install. The Bureau of Mines has designed and is evaluating three types of small ultrasonic units to make these measurements. The new instruments provide nonobstructing measurements up to 35 ft away. The ultrasonic transducers can be attached to a roof bolt, placed in an unsupported area (by means of a toss basket), or handheld. Total distance to the target and rate of closure are displayed digitally to 0.001 ft and 0.01 ft/min, respectively.

Jan 1, 1984

By E. D. Gardner

"In recent years efficient safety organizations have been considered essential at all well-managed metal mines. Statistics from numerous mines throughout the country show that the expense of operation of these safety departments is repaid many times by the saving due to fewer accidents. Men trained in first aid, mine rescue and fire-fighting are important parts of the safety organization at most mines. It is more desirable, however, to lay stress ma accident prevention and fire precautions rather than on first aid and fire fighting. Both of these phases of safety work have been well developed in the Globe Miami district. The co-operative mine rescue organization* in this district under Orr Woodburn, is one of the best in the country. Mine rescue teams are kept trained at all the mines and the oxygen breathing apparatus is constantly maintained in good condition. Miners are also trained in first aid, and are offered incentives to make themselves proficient both in mine rescue and first-aid work.The Old Dominion Company is among the leaders in the safety movement in the Globe-Miami district. The safety department at this mine was established January 1, 1914, and has been developed to a high degree of efficiency. W. G. McBride, general manager of the company, takes an active part in the safety work and has given Albert Talon the safety inspector, his active support in developing the organization. The success of the department is dos largely to the ability, tact, and personality of the men directing the work.The following description of the establishment and operation of the safety organization at this mine was prepared from information supplied by Mr. Tallon."

Jun 1, 1921

By Hillary W. St. Clair

This report describes a mathematical procedure for analyzing size distribution data by the method of moments. The method was applied to Andreasen&apos;s data on a variety of grinding mill products. It was found that the observed size distributions could be represented by gamma and beta distribution functions over a wide range of sizes. A computer program, written in BASIC, is described for calculating moments, distribution parameters, and the weight fraction in any size range.

Jan 1, 1969

By A. W. Decora

Gas-liquid chromatography has been applied to separating basic nitrogen compounds, such as pyridines and amines. Close-boiling compounds have been separated by exploiting structural and polarity differences, using selective liquid substrates dispersed on specially prepared solid supports. Development of these special supports was necessary in order to obtain symmetric peaks for basic nitrogen compounds; solution of this problem was important in applying gas-liquid chromatography to the analysis of basic nitrogen compounds found in shale oil. Attempts to analyze shale-oil tar bases by conventional gas-liquid chromatographic techniques, using Chromosorb4/ or Celite 545 as the support for a nonpolar liquid substrate, resulted in asymmetric peaks. These asymmetries were caused by adsorption of sample vapors on the solid support. Symmetric peaks were obtained when strongly polar liquid substrates were used on either Chromosorb or Celite. However, a solid support giving symmetric peaks only with strong polar substrates restricts the choice of substrate, and frequently, desired separations cannot be achieved.

Jan 1, 1961