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By Tobias W. Goodman, Joseph Cervik

This Bureau of Mines report investigates the horizontal trajectory of boreholes drilled in coalbeds using the rotary drilling technique. Test holes drilled in coalbeds showed that the path of a borehole in the horizontal plane depends on drilling assembly configuration, drill bit rotation, and coalbed geologic features. An assembly that contained an 18-ft (5.53) long drill collar and two centralizers had the best horizontal stability evidenced by trajectories that deviated less than 16 ft (4.9 m) from a target at 1,000 ft (305 m). Removal of one of the centralizers resulted in a loss of control of hole trajectory in the horizontal plane. Generally, holes tended to turn to the right, presumably because of right-hand rotation of the bit. Deviations from the original bearing line were as much as 200 ft (61 m) or more at a depth of 1,000 ft (305 m).

Jan 1, 1988

By Thomas J. Peters

This report is part of the U.S. Bureau of Mines Idaho Land Assesment Program to study the mineral resources of priority roadless areas in Idaho. The results of these mineral inventories provide minerals information needed to make wise decisions regarding future land management practices, and to ensure a dependable supply of minerals at a reasonable cost. The 16,300-acre Lionhead area, studied in 1991, lies along the Montana border north of Henrys lake, 10 mi west of West Yellowstone, Montana. The study area includes much of the rugged Henrys Lake Mountains, and is largely covered with conifer forest. Several peaks are over 10,000 ft in elevation. The Lionhead area has been proposed for Wilderness. No mineral resources were identified within or near the Lionhead study area. Five prospects occur in, or within 1 mi of the area: these include 1) an intermittently used road gravel pit, 2) the Thimbleberry lateritic iron prospect, of geologic and historic interest only, 3) the Tick Heaven talc prospect, 4) the Dry Fork garnet prospect, and 5) the lynx prospect, which appears to be of historic interest only. Talc is seen only as float at the Tick Heaven prospect, but the geology is permissive of talc resources at depth. The garnet prospect, and nearby similar alluvial terrane, mainly outside the study area, appears to be the most likely setting to contain mineable resources. Examined workings include four trenches and pits in rock and one gravel pit.

Jan 1, 1992

By P. L. Swanson, S. Billington, F. M. Boler, L. H. Estey

Stabiity analyses of fractured and faulted rock masses require delineation of the position, extent, and orientation of geologic discontinuities. The size of the smallest active discontinuity that may potentially be resolved using the spatial distribution of microseismic event locations is limited by the accuracy and precision of the location methods. At a hard-rock mine in the Coeur D'Alene mining district of northern Idaho, two data sets consisting of calibration blast signals from a known source site and origin time and microseismic event signals were recorded using a stope-wide accelerometer array. These seismic signals are used to quantify various sources of error in event location. Five factors influencing source location errors are examined in this US. Bureau of Mines study: (1) biases of the numerical source location techniques, (2) receiver array geometries, (3) uncertainties in receiver positions, (4) errors in picking arrival times, and (5) uncertainties in seismic velocity structure, including the effect of mine openings. In addition, synthetic data (accelerometer positions, travel-time picks and wave velocity) are used to determine the effect of known systematic and random errors on source location calculations. It is shown that the commonly accepted association of minimum travel-time residuals with the best location solution does not necessarily hold true when there is a systematic error in seismic velocity. Recommendations are made for increasing the accuracy and precision of locations of microseismic events detected under similar field conditions.

Jan 1, 1992

By John L. Ellenberger

The Bureau of Mines investigated the occurrence of slickensides in mine roof in the Pittsburgh coalbed in a portion of the Valley Camp No.3 mine in southwestern Pennsylvania to improve the potential for prediction of slicken-sided zones and determine the orientations of the most prominent slickensided planes. Two distinct types of slickensides were identified; those which were associated with clay veins observed in the coalbed (genetic), and those which were unrelated to any visible structure (nongenetic). The study draws three conclusions: (1) Nongenetic slickensides are not the result of tectonic forces, (2) both genetic and nongenetic slickensides tend to dip at an angle of 30°, and (3) genetic slickensides tend to be alined parallel to the trend of the clay vein and usually dip toward the center of the clay vein. A schematic roof bolting plan is presented that may provide improved roof support where slickensides are present. Roof stability could be improved by supplemental bolting in the direction normal to the plane of slickensides.

Jan 1, 1979

By Oliver A. Dibble

This paper it one of a series being prepared for and published by the United States Bureau of Mines, describing mining methods and costs at clay pits throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. The open-pit recovery of clay for cement plants is a comparatively simple operation in comparison with underground mining of clays; nevertheless, it represents an appreciable factor in the cost of cement manufacture. The following report deals specifically with the methods employed by the Aetna Portland Cement Co., which operates cement mills at Fenton and Bay City, Mich., in recovering clay from their pit at Corunna, Mich., on the Grand Trunk Western Railway.

Jan 1, 1932

By J. G. Linn, H. H. Schrenk, W. P. Yant, R. R. Sayers, John Chornyak, F. A. Patty, S. J. Pearce

"This report is the first of a series dealing with the results of a comprehensive investigation of methanol poisoning, conducted jointly by the Federal Bureau of Mines, Carbide & Carbon Chemicals Corporation, du Pont Ammonia Corporation, and the Commercial solvents Corporation.The study dealt mainly with physiological effects produced by inhalation of methanol vapor, and concentration studied ranged from approximately 500 to 15,000 p.p.m., and periods of exposure from 4 hours daily to continuous. The range of concentrations and periods of exposure were such as to produce acute effects, with and without fatalities, by a singel exposure and chronic poisoning, with and without fatalities, as well as little or no response after repeated daily exposures. In addition to the inhalation experiments, skin absorption was studied, and field surveys were made to ascertain the hazards associated with the manufacture and, use of methanol."

Feb 1, 1942

By Ralph L. Windrow

This paper is one of a series being prepared for and published by the United States Bureau of Mines describing methods and costs of mining and preparing sand and gravel for market at various plants throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. The Clowdy plant, with which this paper deals, is located 7 miles west of Dallas, Tex., and has a rail connection with the Texas and Pacific Railway. In addition to the rail outlet there is a paved road over which materials produced at this plant can be moved into Dallas by truck.

Jan 1, 1932

By George S. Rice, O. P. Hood

The need of protecting mines from the danger of inflow of natural gas from neighboring wells has become more apparent each year since it was found that oil and gas underlie the productive coal measures of Pennsylvania, West Virginia, Ohio, Indiana, Illinois, Kansas, Oklahoma, Colorado, and Wyoming, and, to some extent, the coal measures of other States. The proximity of the known gas and oil areas in the United States to the coal fields and the manner in which the fields overlap in certain States are shown in the map comprising the frontispiece (Pl. I). As the result of many requests received from various sources a conference to consider the protective measures necessary to insure the safety of mining operations in gas and oil fields was called by the Director of the Bureau of Mines to assemble in Pittsburgh, Pa., Feb- ruary 7 and 8, 1913. To this conference were invited a considerable number of gas-well, oil-well, and coal-mine operators within conven- ient distance from Pittsburgh, as well as State geologists and State mine inspectors from a distance. Gas and oil wells are also found near other kinds of mines, such as shale and limestone mines in western Pennsylvania, but these cases are so few that for this and other reasons it was deemed best to con- fine the present inquiry to the consideration of the questions involved in connection with coal mines. It was also not thought advisable to consider the protection of mines from other kinds of bore holes than those for gas and oil, such as coal-prospecting holes, drilled either with churn or diamond drills, or salt wells and artesian wells, because little trouble has been ex- perienced in mining operations from these classes of wells. There- fore the following papers and discussions concern almost entirely the following relations between coal mines and gas and oil wells: (1) Protection of coal mines froin gas and oil wells penetrating -through: (a) Open workings; (b) inaccessible spaces or goaves; (c) pillars, or coal which may be left as pillars. (2) The manner of drilling gas and oil wells passing through workable coal beds so as to provide protection for future mining. The preliminary inquiries of the engineers of the bureau had dis- closed that there was no uniformity in the methods of protecting mines against the leakage of gas from wells, that thousands of wells in coal fields are abandoned yearly without adequate plugging, and without surveys or records being kept to show the location of the holes, from which the casings are generally pulled. According to the State geologist of Pennsylvania, as many as 3,000 wells are being drilled annually in Pennsylvania, 2,000 of these holes being aban- doned within a single year. It is such unplugged, uncharted wells that are the greatest menace in mining. The quantity of gas that the wells produce, although not sufficient to be commercially avail-

Jan 1, 1913

1. In 2003, a total of 734 nonmetal mining operations reported employment to the Mine Safety and Health Administration (MSHA). Examples of nonmetal mining operations include, but are not limited to, the mining of clay, shale, barite, potash, trona, phosphate rock, rock salt, gypsum, talc, gemstones, mica, perlite, and pumice. • Nonmetal mines comprised 5.1% of all mining operations. • Nonmetal mining operations are located in all states and territories except Alaska, Delaware, Maine, New Hampshire, Rhode Island, Puerto Rico, and the Virgin Islands. • Mines producing common clay comprised 28.6% (n = 210) of all nonmetal mining operations.

Feb 1, 2005

By J. E. Tiffany, Z. C. Gaugler

This supplement has been prepared to furnish information on amendments to the regulations that were approved by acting secretary of the Interior on June 24, 1946, while this report was in the press. Page 14, item 2, and page 20, item 4, have been amended by the addition of the following footnote: "Pending the development of a satisfactory multiple-shot permissible blasting unit, a blasting unit of Type II, Class A, covered by Federal Specification WB 411, December 31, 1941 (with or without Amendment 2, June 16, 1945), may be used until Decem- ber 31, 1947. Should a satisfactory multiple-shot permissible unit be made available prior to that date, this interim approval may be terminated." Page 14, footnote / has been amended to read as follows: "The use of charges over 1-1/2 pounds and not exceeding 3 pounds is approved pending further investigation. The approval, which may be withdrawn at any time, expires December 31, 1947, unless renewed. For charges over 1-1/2 pounds, the following additional requirements must be observed: (1) Shot holes must be 6 feet or greater in length. (2) Explosives must be charged in a continuous train with no cartridges deliberately deformed or crushed, with all car- tridges in contact with each other, and with the end cartridges touching the rear of the hole and the stemming, respectively. (3) The permissible explosive must be one showing toxic gas omission that will place it in either Class A or Class B."

Jan 1, 1947

By Dennis R. Dolinar

The danger to personnel, equipment, and pillar structure created by the spalling of a coal rib can be minimized by installing rib bolts. To assure that a configured support system will maintain a coal rib, the U.S. Bureau of Mines developed a rib bolt system based on a nonpreventable failure concept. A statistical equation quantitatively relates the amount of rib retained to the bolt spacing and the width of the spalled material. Laboratory test results show that the equation accurately predicts the amount of material retained and confirm the validity of the support concept. The examination of rib bolting at a coal mine experiencing rib sloughage provides evidence that the effectiveness of the support can be related to the failure pattern of the spalled material. An analysis of roof and roof support reaction to rib sloughage at the mine indicated that the rib sloughage had little effect on roof stability. Although supporting ribs might not affect roof stability, laboratory test results indicate that the material retained by the support can sustain a load up to 20 pct of the intact compressive strength of the material.

Jan 1, 2010

By M. J. Ankeny

All bituminous-coal mines, by the nature of their product and inherent gassy tendencies, are subject to explosions or mine fires. The evolution from large, hand-loading sections employing numerous men and containing open-type equipment, lights, and nonpermissible explosives to small, concentrated mechanical sections with but few well-supervised men utilizing modern preventive equipment has not altered this premise. Mine catastrophes such as Centralia and New Orient No. 2, as well as recent disasters of less magnitude, have refuted the trend of thinking that modern equipment, will prevent or localize explosions and prevent widespread or loss of life.

Jan 1, 1952

By Gary P. Sames

This report discusses some practical applications of a geotechnical investigation conducted by the U.S. Bureau of Mines that can help mine operators meet revised Federal regulations in their roof control plans. The investigation, designed to characterize roof conditions near the coalbed outcrop in drift coal mines in eastern Kentucky, revealed that weathered stress-relief joints near outcrop are crucial ground control factors in the region. The joints' origin and character were determined through underground mapping of many joints in coal mine roof and detailed observations and measurement of joint trends and physical characteristics in widely separated strip mine highwalls and roadcuts. This resulted in an understanding of stress-relief-joint patterns and the effect of various rock types on the intensity of weathering in the joints. That information is used in this report to show how stress-relief joints contribute to roof failure and how, through improved roof support and mine planning, safer roof support plans can be developed.

Jan 1, 1992

By N. A. Caspero, W. E. Eckard, W. T. Wertman

A thermal oil-recovery experiment was conducted in the Venango First sand, Goodwill Hill oilfield, Warren County, Pa., about 10 miles northeast of Titusville. The Quaker State Oil Refining Corp., Bradford, Pa., performed the experiment with assistance from Sinclair Research, Inc., Tulsa, Okla., and the Federal Bureau of Mines. The Goodwill Hill field was discovered in 1885. Primary-production oper- ations continued until 1930 when an air-gas injection project, which is still in operation, was started. At the location of the combustion experiment, the reservoir is 400 feet deep and 30 feet thick, with wide permeability and porosity variations. The crude oil is typical Pennsylvania Grade paraffin- base oil with a gravity of 43.9° API and a viscosity of 4.55 cp at 60° F. The well pattern for the experiment consisted of 5 producing wells, enclosing an area of 1.28 acres, and a central ignition-injection well. An air-natural gas mixture was ignited in the ignition well on July 29, 1961. Ignition was followed by injection of air and natural gas at various rates. The experiment was suspended January 5, 1962, when it became evident that economic oil production could not be achieved. There was no conclusive evidence that self-sustained combustion was achieved or that combustion increased oil and water production. A slight increase in liquid production was attributed to stripping action caused by the air-injection rates, which were higher than those normally used during air-gas injection.

Dec 1, 1963

By J. N. Geyer

In coal mining it is essential to maintain the roof over working places and roadways in the safest condition possible. To this end every effort should be made to win the coal with the least injury to the immediate roof strata, as broken strata certainly present a greater hazard than a sound roof. The chief causes of injury to the roof in mining are inherent in the method of development and recovery and the blasting practices followed. The first, which may produce severe stresses in the roof, weakening it over comparatively large areas has been discussed in previous papers3 and will not be treated here. The second cause is local in effect, but with the same general method of blasting being employed throughout a mine having uniform roof conditions, similar effects on the roof may be expected. In the Bureau's investigation of accidents caused by falls of roof and coal it has been necessary to make a careful study of blasting practices and their effect on the immediate roof. The purpose of this paper is to show the effect of the observed methods of blasting on different types of roof and to point out methods that have been proved to be least harmful to the roof strata. The data used in preparing this paper have been compiled from reports made by Bureau engineers engaged in the study of falls of roof and coal, and embrace mines opened in the Pittsburgh coal in Ohio and Pennsylvania and the Pittsburgh and Sewickley coals in West Virginia.

Jan 1, 1933

By H. H. Schrenk

One phase of the Bureau of Minest work in the field of health and safety is the promotion of safe, satisfactory, and reliable respir atory protective devices. To insure that such devices will be available, the Bureau has established schedules of what it considers the minimum re- quirements for oxygen breathing-apparatus,3 gas masks, hose masks,5/ and mechanical filter-respirators (a schedule of requirements for hose- type supplied-air respirators is being prepared). Approval of oxygen breathing-apparatus is given by the Safety Division; approval of other types of respiratory equipment is given by the Health Division, both divisions being in the Health and Safety Branch, Manufacturers of respiratory protective devices may submit their equipment to the Bureau for approval under the requirements of these schedules. As a prerequisite to submitting a device for approval, the Bureau requires a statement that the device is completely developed and of the design and material that the manufacturer believes suitable for a finished marketable device; that the device has been

Aug 1, 1937

This study presents a reservoir modeling approach to investigate the relative effects of different coalbed parameters on the migration of methane into development entries. A base coalbed reservoir model of a three-entry development section, where grids were dynamically controlled to simulate the advance of mining at a constant section advance rate, was created and calibrated for a Pittsburgh Coalbed mine in the Southwestern Pennsylvania section of the Northern Appalachian Basin. The values of coalbed parameters were varied to evaluate their effects on predicted methane emissions for various development distances. The results of these parametric simulations were then used to derive linear expressions relating these parameters to methane emissions into the workings. These models were analyzed to assess their significance and adequacy for predictive purposes. This work shows that coupling reservoir simulations with linear modeling yield a technique that can be applicable to different coalbeds. The reservoir parameters used by the linear models (coalbed thickness, pressure, sorption time constant, Langmuir parameters, permeability) can be determined by running relatively simple laboratory tests, such as adsorption equilibrium and permeability determination, on coal samples obtained either from the mining operation or from the exploratory boreholes drilled ahead of mining.

Jan 1, 2008

By Philip W. Holland

This U.S. Bureau of Mines (USBM) report describes a chromatographic method that is used for rapid field determinations of carbon dioxide in natural gas streams at a USBM helium production facility. The method employs a commercially available portable gas chromatograph that is equipped with a 10-m fused-silica capillary column coated with a porous polymer. The instrument operating parameters permit determinations to be performed over a concentration range of 10 ppm to 10 pct with a frequency of 20 samples/h. The speed at which determinations can be performed is an important factor when evaluating efficiency or troubleshooting processes at the helium facility.

Jan 1, 1994

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

6. Computer Simulation of Mine Evacuation Analysis of mine evacuation involves manipulating a large number of interacting variables, such as mine passages, hoist movements, miner position etc. , which makes the problem very difficult to solve without use of a digital computer. Therefore, under this contract, a computer program is written to simulate evacuation of a mine under different configurations. The simulation input variables include characteristics of the mine, expressed in the form of a network of passages, properties of hoists and hoisting strategies, initial miner positions, ventilation and compressed air velocities, stench warning system and self-rescuer capabilities. The simulation can be carried out for cases in which there is no fire, i. e , fire drill simulation, or for cases in which there is a fire at any arbitrary location. The fire is assumed to generate gases which impede movement of miners in the gaseous region. However, the thermal effect of the fire on ventilation or on the miners is not considered. The simulation output includes the evacuation time for each miner, movement of the hoists, propagation of smoke through the mine passages and smoke exposure time of the miners. Details of the mine evacuation program are summarized in Appendices A and B Appendix A describes structure of the program and its capabilities. The flexibility of the program and its suggested uses are demostrated by a number of illustrative examples Appendix B is a user' s manual for the program which includes instructions for program use and explanation of the logic employed in the program. A computer listing and printout of a typical output are also included in the Appendix B The ten illustrative examples summarized in Section A 4 (Appendix A) provide proof of validity of the program and help make certain inferences about mine evacuation. The first example, which is simulation of an actual mine fire drill conducted in a mine, has predicted evacuation time within 5 percent of the actual evacuation time in the fire drill, demonstrating thereby, the ability of the program to make accurate predictions.

Jan 1, 1976

By E. H. Denny

The coal and metal mines of the United States furnish this country with a large part of the fuel and material necessary to support our industries and thus make possible the welfare and prosperity of our people and even the continuance of our present-day scale of civilization. Mining companies furnish material to industry with one general purpose in mind -- the making of a profit on their work. Efforts are being made successfully and continually to reduce operating costs, to increase production per man, and to perform work as far as possible mechanically and with more efficiency. These efforts are made primarily to reduce costs, to increase production, or to do both - in other words to make more profits or more certain profits. In the endeavor to reduce expense companies are considering more and more the factors which enter into costs of production, among them the factor of accidents and their cost. This paper endeavors to estimate the approximate cost of accidents to the mining industry in order to present the saving possible through accident reduction or elimination.

Jan 1, 1929