Search Documents

By Herbert H. Einstein

The thrust of research reported in Part I was to collect in-situ data from exploration programs and the published literature, and to empirically establish distributional patterns for these variables. Since discontinui¬ties in a rock mass govern to a large extent its engineering properties and thus the performance of any slope in the mass, work has been devoted to determining the appropriate distributional forms for attitude spacing and length of discontinuities and to distributional properties of resis¬tance and deformability parameters. The conclusion from these analyses is that trace lengths are logNormally distributed and that joint spacing is Exponentially distributed, regardless of orientation of the sampling line, and regardless of whether each joint set is considered separately or not. Joint orientation (attitude) data representing 22 individual joint sets from eight sites (a total or approximately 20,000 joints), do nor strongly support any of the commonly used distributions as broadly applicable in practice. The autocorrelation )f geometric joint properties is also examined. However, no significant spatial correlation could be found even after extensive data manipulation. The investigation of resistance and deformability parameters starts with a review of mechanisms and models that are used to represent them. Review and statistical evaluation of approxi¬mately 2,000 discontinuity shear tests has shown that good statistical estimates for use in reliability analyses can be obtained for friction angles.

Jan 1, 1979

By R. Ward Stahl

This publication is a revision of Report of Investigations 5363 updated to reflect the improvement in fire protection at selected coal mines and contains suggestions on what may be considered good fire protective equipment, suggested methods of organizing the attack on fires at various locations underground, and helpful hints on testing and evaluating firefighting facilities.

Jan 1, 1968

By Hanns J. Billmayer

Optimized Operator Compartment layouts based on previous Bureau of Mines activities in standardization and optimization of controls were designed and installed in three operating vehicles. Two National Mine Service 48A-36 TorKars were modified in production prior to delivery to the Quarto Mining Company. An Elkhorn AR-4 scoop owned by Adanac Coal Company was modified in a local rebuild shop. The modified vehicles were then evaluated underground under normal production conditions for a 60 day period. Vehicle operators and management appear well satisfied with the compartment modifications.

Jan 1, 1976

By J. Cseff

A variety of shaft and hoist equipment exists in the United States. Nearly all hoist systems are electrically driven. Machine elements which comprise the hoists and ancilliary equipment include bearings, shafting, drums, gear reducers, couplings, brakes, clutches, sheaves and electrical motors. Volume I, Systems Description, describes the various components encountered in most mine hoist and shaft installations, and brief descriptions of functions and constructions. Hoist ropes and balance ropes are specifically excluded from this report. Associated with the hoisting system is the headgear, shaft and equipment, loading/dumping facilities and the actual conveyances and their rope attachments. Volume II, Inspection and Maintenance Procedures, discusses scheduled Inspection and preventative maintenance in general terms. Preventive scheduled inspection and maintenance procedures assist in the smooth operation of mine hoisting plant, by the prevention of unscheduled or catastrophic equipment failure and its attendant downtime. Schedules and overall maintenance planning is required at the management level. Records and equipment logs must record inspection and maintenance, and unusual operations or incidents. A cross reference between MSHA regulations and various equipment components is included as part of the report. A discussion of the various non-destructive testing methods which may be applied to hoisting equipment is also included.

Jan 1, 1981

A mineral survey of the Rough Hills WSA (Wilderness Study Area) in northeastern Nevada was done by the U.S. Bureau of Mines in 1985 at the request of the Bureau of Land Management. The WSA is comprised of 6,685 acres of mountainous, desert lands within the Elko District of the Bureau of Land Management. The survey entailed investigations of prospects or mineral occurrences to provide information on possible resources within the WSA. No mineral resources were identified in the WSA. The only historical mining activity was for placer gold at the Prunty prospect at the confluence of Copper Creek and the Bruneau River. Total gravel at the prospect is about 6,500 cubic yards; however, the survey showed significant gold values (greater than $0.10 gold per cubic yard) only in the southwestern portion. There, however, the gravel averaged less than $1.00 gold per cubic yard, and only about 3,000 cubic yards are present, a grade and yardage insufficient to be of commercial interest. The occurrence, however, may have value for recreational mining by hobbyists.

Jan 1, 1986

By Jr. Frost

Helium used as a tracer gas in petroleum reservoirs continues to show great promise as a new tool for the oil and gas industry, according to tests conducted jointly by the Bureau of Nines and The Pure Oil Co. in-the Cabin Creek field, Boone and Kanawha Counties, W. Va. Helium, when used as a, tracer gas, is mixed with natural gas being injected into a reservoir for secondary recovery of oil, recycling, pressure-maintenance, or other purposes. Three separate experimental helium tracer-gas tests were run in the Cabin Creek, W. Va., field, wherein helium was added as a tracer to the natural gas that was being injected into the oil-bearing Berea sandstone. The results obtained in each test permitted determining the direction and rate of travel of the injected gas, calculating the volume of injected gas in the gas produced at the various wells, and determining the nature of the transition from natural gas to injected gas during a gas-injection program. Data were obtained on the effects obtained from waves of injected gab containing 1 percent and containing 5 percent helium and from a wave of essentially pure helium injected into the formation.

Jan 1, 1950

By Paul J. Remington

The field data gathered as part of the measurements described in Volumes I and II were re-analyzed in the low frequency regime (.1 Hz to 1 Hz) where motion sickness normally occurs. These data were compared co the international standard ?ISO 2631 Addendum 2: Evaluation of exposure to whole body z-axis vertical vibration in the frequency range 0.1 to 1.0 Hz." For both underground mining machines and surface mining machines the results showed that one would not expect motion sickness to .be a severe problem. New field data were gathered on the vibration reduction performance of various seat designs found on surface coal mining machines. The vibration during normal operation was measured on the seat using the standard seat pad accelerometer package described in the previous two volumes and simultaneously on the floor of the machine at the base of the seat. Preliminary indications are that the so-called high performance seats used for operator vibration reduction do not offer significant improvement over conventional seats.

Jan 1, 1984

By Donald W. Ross

"INTRODUCTION Sponge iron has been made commercially since 1912 at a Swedish ceramic plant; and the product, known as Swedish disk—type sagger sponge iron, has an excellent reputation as a superior furnace feed wherever high—grade steels are made. The general procedure for making brickyard sponge iron was described frequently in Swedish technical journals prior to 1932 and at that time consisted in filling clay refractory containers, called saggers, with a super-concentrate of Gellivare magnetite plus the necessary amount of solid reducing agent and desulfurizer and then firing in a Hoffmann ring furnace, as used in the ceramic industry.The early Swedish publications describe two types of brickyard sponge iron: (1) An inferior high-sulfur product obtained by mixing the ore and reducing agent, and (2) a high-grade low-sulfur product in the form of coherent disks 7 to 9 inches in diameter and 1 to 1-1/2 inches thick made by the saggers with alternate layers of solid-fuel reducr and of uniaxed ore."

Sep 1, 1945

By Francis Church Lincoln

"INTRODUCTION During the period from September 18 to November 27, 1944, the Bureau of Mines conducted an investigation and exploratory churn-drilling program in an area immediately north of the Crow Branch Diggings, a district lying approximately 2 1/2 miles southwest of the town of Livingston in Grant County, Wisconsin.The work was undertaken as part of a general Bureau of Mines investigation of the zinc-producing area of southwestern Wisconsin at a time when all effort was being made to increase the production of metals important to the Nation's war prrgram.Although no mining has been done in the district in recent years the Crow Branch Diggings were an important source of galena and may be found today in the dumps remaining from old surface-mining operations.The Bureau of Mines undertook an exploratory churn-drilling program on the northwestern projection of the general strike of the digging in a zone where subsurface,lead and zinc mineralization had been reported from drilling done in the early 1900's."

Feb 1, 1947

By P. M. Ambrose, A. C. Fieldner

This , the 11th annual report of research and technologic work conducted by the Bureau of Mines on coal and coal products , is issued following the closing of the Bureau's war work on fuels and contains references to most of the published articles containing results of war investigations . The few remaining papers will be discussed in next year's report . The trend in coal research in the Bureau of Mines was discussed in Mechaniza- tion . This publication , covering the period from the close of armed con- flict to resumption of normal coal -research activities , includes a section never previously presented . There is included for the first time a discussion of the Bureau's activities in the Liquid Fuels and Lubricants and the Solid Fuels Subcommittees of the Technical Industrial Intelligence Committee . This report does not replace the more comprehensive ones prepared by individual authors and listed as footnote references in this publication . purpose is to bring to the reader a résume of the work for the fiscal year ended June 30 , 1946. The material presented herein is based largely upon publications , but the results of some research and testing, which would not otherwise be published in the near future, are presented in detail .

Jul 1, 1947

By George H. Holmes

The water situation in Nevada mineral and related industries is described in this report. It contains information on the sources and adequacy of supply to current operators, requirements and uses, quality and costs, geography, hydrography, precipitation and evaporation characteristics, and Nevada water laws. Also, information is given on the water requirements of one public utility powerplant, and the source and consumption of water in four major cities. Water distribution at 24 operations is shown on schematic waterflow diagrams. The mineral industries of Nevada in 1962 used 8.6 billion gallons of new' water and reused 3.8 billion gallons for a total usage of 12.4 billion gallons. The copper industry was the major water user. The 1962 value of all mineral production in Nevada was $85.5 million. The large amount of water required to maintain thin high production is obtained principally from ground-water sources in alluvial valleys and the permeable rock formations of some mountain ranges. Some water is also obtained from perennial streams and springs. Sources of water utilized by existing industry ire near most mineral industry operations; however, seven companies are forced to pipe water distances ranging from 2 to 8 miles. Although water supplies of presently operating companies are adequate at most operations, several companies resort to large-scale reuse of water as a matter of conservation and economics. Acquisition of water by new operators is possible but takes considerable negotiation. Water rights, surface and underground, are controlled by the State. The quality of the water is satisfactory for most purposes. Analyses of 19 samples, listed in the appendix, show the range in water quality at various plants throughout the State. Costs of delivering new water to current operations range from 2 to 26 cents per 1,000 gallons with an average of 10 cents per 1,000 gallons for power and maintenance. No firm costs for recirculating water were available; estimated costs range from 1.5 to 2.5 cents per 1,000 gallons. The mineral-product value of the entire Nevada mineral industry in 1962 was equivalent to $10 per 1,000 gallons of new water and $26 per 1,000 gallons consumed. Projection of the 1962 water requirements of the Nevada mineral industry indicates that the demand For new water will increase from 8.6 billion gallons in 1962 to 11.9 billion gallons in 1980, a 43-percent increase. Water requirements in the year 2000 are estimated as 14.8 billion gallons, an increase over 1962 water demand of 78-percent.

Jan 1, 1966

By Michael G. Zabetakis

Vaporization of a solvent into an airstream at temperatures above the flash point of the solvent is hazardous if vapor is liberated at a rate that is sufficient to produce a flammable mixture. In may operations, the formation of such a mixture is prevented by rapid diluton of the vapors with air. The minimum air requirements for the dilution process are determined by the composition of the lower limit mixture at the temperature and pressure of interest. Because limits of flammability cannot always be calculated with sufficient accuracy for a proposed operation, they .rust often be determined experimentally. The present Bureau of Mines investigation was prompted by an application in which the lower limits of flammability of a number of solvent mixtures were required over a range of temperatures at atmospheric pressure. These limits were to be used along with available solvent-vaporization-rate data to establish minimum airflow rates needed to prevent the formation of flammable mixtures in an industrial process. Lower limits of flammability were determined for a number of mixtures containing methyl ethyl ketone, tetrahydrofuran, toluene, ethyl alcohol, and ethyl acetate in dry air-at atmospheric pressure and temperatures between 16° and 200° C. The experimental values were found to be in good agreement at with those predicted by Le Chatelier's law; variations with temperature were in fair agreement with those predicted by a modified Burgess-Wheeler law.

Jan 1, 1962

By J. S. Stachulak, G. H. Schnakenberg

The objective of the Diesel Emissions Evaluation Program (DEEP)-sponsored project at Inco's Stobie mine was to conduct a long term field evaluation of diesel particulate filter (DPF) systems available to the underground mining industry. Some of the major issues studied were criteria for selecting the filter media, means of DPF regeneration, efficiency of DPF systems and the occurrence of unwanted secondary emissions, and reliability and durability of DPF systems. Nine state-of-the-art diesel particulate matter (DPM) filtration systems have been retrofitted to heavy-duty and light-duty vehicles and have been subjected to extensive long-term in-mine evaluation. Periodic efficiency tests were conducted at various stages of the study (2001, 2002 and 2004) to establish in-use efficiencies and durability of the tested DPF systems. The results were used to assess the effects of the filter systems on the concentrations of particulate matter, nitric oxide, nitrogen dioxide and carbon monoxide in the vehicle exhaust. The variety of filtration systems and regeneration concepts used in this study offered the opportunity to investigate their advantages and disadvantages. This paper also offers a review of selected experiences with the installation and operation of the DPF systems on underground mining vehicles at the Inco Stobie Mine.

By Wesley Holmes

Concentrating, nodulizing, and smelting studies were conducted at the Albany Metallurgy Research Center of the Bureau of Mines to determine whether (1) western iron ores of the type found in the Carter Greek deposit near Dillon, Mont., could be utilized; (2) concentrates of acceptable grade with good iron recovery could be attained by wet-magnetic beneficiation; (3) nodulized concentrates could be smelted with reductants readily available in Montana; (4) iron concentrates could be smelted without prior agglomeration; and (5) high-purity iron could be produced directly from high-grade concentrates, Three small samples and two tonnage samples from the Carter Creek deposit were uniform in chemical composition, and their iron content averaged about 31 percent. They were found to be banded gneisses, and magnetite was the principal iron-bearing mineral.

Jan 1, 1962

By C. H. Herty

As the problem of inclusions in steel has become increasingly important, more and more attention has been paid to the source of the oxide inclusions in steel. In killed steels the oxide inclusions are traceable to the reaction of deoxidizers with the iron oxide dissolved in the steel during the refining period of the open-hearth heat. In a large class of steel known as "rimming steel" the action of the steel during solidification depends entirely on the gas evolved, and this evolution in turn is controlled by the amount of iron oxide in the liquid steel in the mold. It is therefore of great importance to be able to determine the amount of iron oxide dissolved in steel and to devise methods for the control of iron oxide in any class of steel. The object of the present investigation was to obtain a true value of the oxygen content of liquid steel. If the steel has not been deoxidized, the greater percentage of the oxygen is present as iron oxide in solution.

Jan 1, 1932

By G. L. Oldright

In the first paper of this series (R. 1. 4333) on the cooperative work with the Eagle-Pitcher Mining & Smelting Co., changes in the nature of the sinter feed were measured by corresponding changes in the retorting temperatures necessary to distill zinc at the best rates; the firing schedules summarized such changes. In this paper, third of the series, are noted same of the changes in practice that were brought about by the need to treat more fused, glassy, and "hard" sinter, as the operators qualify it. Losses of uncondensed zinc were increased by adding zinc-bearing materials from which? the zinc was readily distillable to hard sinter requiring higher-temperatures for zinc distillation. The rates of zinc distillation were increased by grinding the fuel finer; there were few benefits and loss of dust on grinding the sinter finer, unless the fine ?coal and fine sinter were brought into contact by pelletizing, and the pellets made but little dust.

Jan 1, 1948

By James C. Barker

Unverified reports of rare earth element (REE) concentrations in gold placers and radioactive mineral prospects in the Zane Hills were investigated by the U.S. Bureau of Mines as part of the Alaska critical minerals program. REE is reported to occur in dredge concentrates at the Hogatza mine and up to 1.2 pct REE was previously analyzed in alkalic syenite (bostonite) dikes marginal to the pluton. In addition, numerous thorium-rich veins, explored for their uranium content but unevaluated for REE, occur on the western margin of the Zane Hills. The Bureau mapped and sampled all of the reported or suspected REE occurrences. Dredge concentrates contain abundant uranothorianite, a mineral species which incorporates cerium subgroup REE. Bostonite dikes occur in conjunction with a multi-phased zoned alkalic intrusion, however, no significant REE concentrations were found. Thorium-rich veins contain nil to 0.5 pct Y but resource potential is limited by this relatively low grade, the ultimate low tonnage potential, and the lack of uranium as a major economic element. The Zane Hills exhibit attractive exploration targets for uranium deposits, primarily in a sedimentary form. Gold may be found peripheral to the pluton in both placer and lode deposits. Resource potential of REE, however, appears limited to a placer by-product of REE-Zr-Ti that is recoverable only during large scale gold placer mining. Placer exploration of the lower Wheeler and Dakli Creeks is suggested.

Jan 1, 1991

By D. Pennington

Ground-water levels and subsidence have been monitored over a longwall panel of a deep coal mining operation located in western Pennsylvania. The monitoring network includes eleven ground-water monitoring wells completed to measure water level changes in separate shallow and deep aquifer zone-, and 50-foot surveyed subsidence stations parallel and perpendicular to the panel centerline. Monthly monitoring data were collected during the premining, mining, and postmining tine periods. Aquifer testing and borehole geophysical logging were conducted during premining, and post-mining conditions to document any changes in aquifer properties and ground-water flow patterns. Results indicate ground-water declines were located with respect to the mining face and mined longwall panel. Dewatering of the deep aquifer zone caused a significant water level decline in deep wells; however, the shallow aquifer zone was isolated fro major impacts by an aquitardal layer during, the, one-year period. Transmissivity data were greatly impacted by fracturing, in the highly anisotropic aquifer system. Borehole geophysical logging indicated changes in ground-water flow patterns and zones of increased fracturing from subsidence.

Jan 1, 1984

By D. Harrington

"Coal—mine explosions are accidents that can and should be prevented. In former years hundreds of lives were lost each year in the United States as a result of such explosions, but after 1932 the numerous precautionary measures adopted had reduced their frequency and severity 75 percent or more until in 1940 several very disastrous explosions marred the good record. Unfortunately, both the number and severity of explosions seem to be tending to increase compared with the relatively good achievement from 1933 to 1940. The requisites for an explosion are ever present in all soft-coal and many hard-coal mines. A certain combination of circumstances, such as a flame or an arc in a cloud of dust or in a body of gas or both may start an explosion at any time. The fact that the frequency and severity of explosions were lowered for 6 or 7 years is no guarantee that such freedom from explosions will continue, as the bad record of 1940 has shown, and underground workers should feel honor bound to exercise the utmost care so that they will not help to bring about the circumstances that will cause an explosion.Although mine operators bear the main responsibility for preventing explosions, miners can do many things to help. As about 9 out of 10 explosions begin at a working face, it is largely within the power of workers to prevent them. All miners should do their part willingly and should not defend a fellow workman from punishment, even from discharge, for disobeying necessary rules, whose disregard may cause the death not only of the safety-rule breaker but also of many of his coworkers.When a miner is careless and is injured some other way than by an explosion he may be the only one to suffer, but if his carelessness causes an explosion he not only endangers his own life but also that of every other man in the mine and possibly the lives of persons outside the mine.Experiments have shown that ignition of as small a quantity as 150 cubic feet of an explosive mixture of methane and air under certain circumstances can start an explosion that will traverse an entire mine. Thus, ignition of an explosive mixture of gas 1 foot down from the roof and 13 feet back from the face of a 12-foot entry might cause a widespread explosion if the right quantity and kind of dust were present. Many persons have ignited much larger quantities of gas without being killed, but they survived only because dust, confinement, and other conditions were not exactly ""right."""

Nov 1, 1940

By Robert F. Pettit

This paper on methods and costs of mining and milling iron ore at the Iron Mountain mine of Ozark Ore Co., St, Francois County, Mo., is one of a series of Bureau of Mines reports on methods, practices, and costs of mining and milling throughout the United States. The Iron Mountain operation is notable for its successful transition from open-pit to underground mining, for use underground of large earth-moving equipment, and for development of a multilevel room-and-pillar mining method. Milling methods also have undergone transitions - from hand sorting and log washing in the early days to gravity concentration. Milling ultimately may include flotation to recover additional iron from products now discarded as tailing,

Jan 1, 1957