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By John C. Machisak

This publication, for the calendar year 1959, contains statistical data on injuries and employment pertinent to metal mines, ore-dressing plants, and primary nonferrous smelters, refineries, and reduction plants. The Bureau of ,Mines is authorized to request data on injuries and employment in the metal-mining industry, and the information, voluntarily submitted by the operators, contributes immeasurably to the promotion of safety in the metal- mining industry. Every effort has been made to make the annual canvass as complete as possible. The data presented are classified according to the hind of ore mined and includes information on copper, iron, lead-zinc, gold-silver lode, placer, uranium- vanadium, and miscellaneous metals. A breakdown of miscellaneous metals by commodity is shown in tables 17 and 18.

Jan 1, 1963

By L. G. Marshall

This report is one of a series published by the Federal Bureau of Mines, describing mining methods and performance at individual mining operations throughout the United States. The objective of these papers is to promote development and conservation of our mineral resources by disseminating reliable technological information on mining methods, practices, and performance. Limestone deposits in Iowa are extensive and reserves are large. Most of the past production came from the eastern third of the state, although over half of the counties in the state have produced, or are now producing limestone. The stone is used as aggregate, road metal, agricultural lime, riprap, fluxing stone, railroad ballast, and in the manufacture of cement and lime.

Jan 1, 1962

By Thomas Novak, Jeffrey L. Kohler, Joseph Sottile, Steve J. Gnapragasam

Modern underground coal mines can be very large, having a total connected load in excess of l5 000 hp. These mines generally have many miles of high-power conveyor belts and 15 or more miles of high-voltage power cables at distribution voltages of 12.47, 13.2, 13.8, or 14.4 kV. The shielded cables used in mine power distribution systems have a significant level of capacitance, on the order of 110 pF/ft. This level of capacitance, in an extensive power distribution system at today's voltage levels, can cause significant charging currents during a ground fault. This paper addresses the potential detrimental effects of capacitance charging currents during line-to-ground faults in mine power distribution systems. A representative mine power system is modeled, and simulations with faults at various locations are conducted to evaluate the effects of this capacitance on the level of fault current and relay selectivity. This paper also includes results of capacitance measurements made on mine power feeder cables used to validate the simulation model.

By J. L. Schwendeman

This is the final report of work done under contract H0210060 for the U. S. Department of the Interior, Bureau of Mines. This program was to show the feasibility of using plastic liners containing sand and other fillers as a means of roof support in coal and other mines. This laboratory study was conducted in two phases, namely: Phase I, directed toward determining which state-of-the-art resin systems might have utility as a means of roof support in a coal mine, consisted of a canvass of resin manufacturers to learn which resins were available commercially that might have utility for this application. The resins submitted by the manufacturers were evaluated in a number of simple tests to define which of them would be most suitable for roof support use.

Jan 1, 1972

By F. Sillers, R. T. C. Rasmussen

"INTRODUCTION This is the fourth report of investigations dealing with the cooperative tests between the Bureau of Mines and industry on the use of electrolytic manganese in steelmaking. The first report dealt with the use of electrolytic manganese in the manufacture of stainless steel 3/ the second with its use in acid electric steel practice, 4/ and the third with its use in low-carbon basic open-hearth steelmaking. 2/ A résumé of those investigations E7 appeared in the magazine STEEL. 5/ The present report deals with the use of electrolytic manganese in the manufacture of four types of stainless steel and the new Timken 16-25-6 alloy. The Bureau of Mines supplied The Timken Roller Bearing Co. with 62,000 pounds of electrolytic manganese for use in the tests.The electrolytic manganese was produced at the Bureau of Mines pilot plant, Boulder City, Nev., by the process developed by the Bureau and described in Bulletin 463, Operation of Electrolytic Manganese Pilot Plant, Boulder City, Nev., by J. H. Jacobs. J. W. Hunter, W. H. Yarroll, P. E. Churchward, R. G. Knickerbocker, R. W. Lewis, H.A. Heller, and J. H. Linck. The workcarried out under the direction of R. S. Dean, formerly assistant director, Bureau of Mines, and R. G. Knickerbocker, formerly chief, metallurgical branch, as part of a long-range program involving the development, manufacture, and use of manganese from domestic ores. Preliminary arrangements for the plant tests were made by the late A. A. Dow. 7/"

Jun 1, 1947

By B. J. Moore

This publication contains analyses and related source data for 269 natural gas samples from wells and pipelines in 18 States. All of the samples were obtained and analyzed during, calendar year 1979 as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the general public. Twenty-one previous publications have presented tine results of 11,883 gas analyses made prior to 1979. The first three, Bulletins 486,4 576,5 and 617,6 contain analyses and related source

Jan 1, 1980

By Anil Mahyera

Towards the goal of achieving uniform-high-tensions in roofbolts to provide superior roof support[1-7] for extended periods, Terra Tek installed mechanical-anchor bolts in a mine in eight different ways -- under torque/thrust control with and without hardened washers, belleville washers and tension equalization; in a conventional manner with and without a hardened washer. The various bolt groups were analyzed in terms of their tension uniformity and mean tension levels. Installing the bolts accurately with ? a hardened washer under the bolthead, and ? proper torque/thrust control resulted in the mast uniformly tensioned bolts -- with a coefficient of variation of only 14%, an improvement of 3 times over a conventional installation. Also, these bolts maintained a high tension level -- 80% of the installation tension, compared to 50% achieved conventionally.

Jan 1, 1982

By Bill York-Feirn

The Colorado Mine Safety & Training Program (MSTP), in late 2005, completed and began distributing two new training tools; one geared to underground coal mine foremen and the other to surface aggregate employees. Through strong partnerships with MSHA, Colorado Coal Mine Board of Examiners, Colorado Mining Association and the Colorado Rock Products Association, the MSTP continues to create innovative and interactive training tools for not only Colorado, but for the national mining community. "Although we shoot and produce these materials in Colorado, it's important to us to make sure they are useful nationally," said Bill York-Feirn, MS TP Manager. The interactive DVD program "Underground Mine Foreman Certification Study Guide (Coal)," was completed in October 2005. It won the 2005 Grand Prize at the MSHA National Training Materials Competition in Beaver, West Virginia. [ ] This program is fully based upon the requirements of Title 30 Code of Federal Regulations (30 CFR) Parts 48, 50, 70 and 75 for underground coal mine foremen. It contains eight modules plus immediate access to relevant laws in the appendix. Topics covered include: Federal Law, Practical Math Skills, Mine Gases, Ventilation Maps, and scenarios addressing a variety of practical mining concerns. The DVD is designed for self-¬paced study and practice.

Jan 1, 2006

By C. A. Rhoades

The spillage that accumulates under conveyor belt lines presents a possible fire and explosion hazard fomiinqjetsoruiel, especially to those who must clean up the spillage. The U.S. Bureau of Mines conducted research to reduce this hazard by identifying and investigating the parameters affecting the efficiency of conveyor belt cleaning. The amount of material carried back under the conveyor and the wear rates of metal cleaning blades decreased with increasing blade-to-belt pressure to a limiting value, after which the carryback and wear rates remained essentially constant. The optimum blade-to-belt pressure was found to be 11 to 14 psi for the research conveyor system. Greater pressures increased the blade-belt friction without improving either cleaning or blade life. The modes of blade wear were three-body abrasion and slurry erosion caused by the sand-lime test mixture. Wear rates were reduced by increasing the metal hardness, opti-mizing the pressure, and removing conveyor belt imperfections. Corrosion was not observed to affect the wear of various steels in tests of less than 34 h. The results of this study should allow mine operators to run their conveyors under conditions that will maximize cleaning and minimize equipment wear.

Jan 1, 1989

By A. R. T. Denues, A. P. Rowles

"INTRODUCTION Summarized data developed by J. E. Crawshaw and E.J. Murphy, 4/of the Explosives Division of the Bureau of Mines, suggesting marked variations in oxygen condition in three permissible explosives, have been reported 5/. Such variation is of interest in other work, it having been shown, for example, that the oxygen condition may have marked effect upon the products 3/ and the propulsive strength 7/ of explosives. It seemed that a more detailed presentation and more usual statistical analysis of these data might be of considerable general interest and not complemented in the literature.This report presents both the original data developed by Crawshaw and Murphy and the results of a simplified but seemingly acceptable statistical analysis of these data. The logical ground for this analysis might seem somewhat questionable because of the lack of systematic information concerning the extent of errors in the analytical procedure but the data show that there are several cogent and seemingly unequivocal indications of real heterogeneity in the explosives."

Jun 1, 1942

By James H. Prout

Roof warning signals were studied in 18 mines covering 5 coal seams. The results of this study confirmed that roof talk must be interpreted for each individual mine after all other conditions are present that indicate danger of roof fall. Characteristics of roof talk pulses were studied to ascertain features used in interpretation. Roof talk pulse decay time was found to be typically 0.1 to 0.5 seconds depending on the dimensions of the entires. Time between roof talk pulses was found to correlate inversely with the degree of danger under certain conditions. Roof talk and machinery noise recordings obtained during this study were used for subjective tests of ear protectors in a simulated coal mine noise environment. These tests required a detailed interpretation of roof talk and yielded results with high statistical power. Results of these tests showed that the use of personal ear protectors in high noise levels does not degrade a miner's ability to discriminate speech and roof talk. A training course was developed to encourage coal miners to pro-tect their hearing by proper use of personal hearing protectors.

Jan 1, 1973

This appendix is composed of five sections, each of which is tabbed for ease of access. The sections are as follows: ? Fire incident report forms for underground mine fires. There is one form for each incident listed in Table II-1a. They are ordered chronologically with incident numbers corresponding to those in Table II-la. ? Fire incident report forms for surface mine fires. There is one form for each incident listed in Table II-lb. They are ordered chronologically with incident numbers corresponding to those in Table II-lb. ? Journal article report forms. There is one form for each article reviewed. They provide supplemental information to that contained in the fire incident report forms for selected fires. Index 11-14 keys the journal article report forms to the appropriate fire incident report forms. ? Non-reportable incident descriptions for underground mine fires. This is a listing of underground fires for which MSHA regulations do not require formal reports. ? Non-reportable incident descriptions for surface mines. This is a listing of surface fires for which MSHA regulations do not require formal reports. This appendix is intended to be used in conjunction with the tables and indexes contained in Volume II of this report and, as such, should be considered an integral part of Volume II. The indexes in the body of Volume II provide a means of ready reference to the underground and surface mine incident report forms. For those readers with interests other than those indexed, Tables II-la and II-1b can be used to locate specific incidents of interest. Complete incident information can then be obtained from the corresponding report forms in the first two sections of this appendix.

Jan 1, 1980

By W. W. Roepke

The Bureau of Mines has developed an interactive computer program that enables mine operators and others to identify the effect of cut-ting system changes on relative dustiness at the face. The program, which simultaneously evaluates machine parameters, coal seam parame-ters, and operator-controllable parameters, was developed for use on any microcomputer using BASIC programming language. The program allows the user to change one or more of the cutting system parameters at a time to see how these changes affect relative dustiness. A complete program listing and flowchart are included along with operating in-structions and sample outputs. An example showing how to use the program is also included.

Jan 1, 1985

By Christopher Mark, Gregory M. Molinda, Timothy M. Barton

The Coal Mine Roof Rating (CMRR) was first presented at this Conference nine years ago. Since its introduction, the CMRR has been incorporated into many aspects of mine planning, including longwall pillar design, roof support selection, feasibility studies, and extended cut evaluation. It has also become truly international, with involvement in mine designs and funded research projects in South Africa, Canada, and Australia. The purpose of this paper is to bring the mining community up to date with recent improvements and applications of the CMRR. The most important new development is a streamlined process for determining the CMRR from exploratory drill core. Just three types of information are now required: •Fracture spacing (or RQD) •Uniaxial compressive strength (or axial Point Load Testing) •Diametral Point Load Testing The moisture sensitivity adjustment has also been changed, and new research has related the immersion test to slake durability. Most recently, the CMRR has been implemented in a computer program, which can be obtained from NIOSH free of charge. The program facilitates calculation of the CMRR from either underground or drill core data. Values from many locations can be saved in a single file, and an interface with Autocad allows CMRR contour plots to be integrated into mine planning.

By Mark P. Meyer

A mineral investigation of the Chugach National Forest, Alaska was conducted jointly by the U.S. Geological Survey and the U.S. Bureau of Mines from 1979 to 1983 as part of the RARE II program. The U. S. Geological Survey remapped the geology and distribution of mineral resources. The Bureau investigated mines, prospects, and mineral occurrences. Previously unreported mineralization in three areas, Long Bay, Wells Bay, and Miners River were discovered in the western portion of the SOUND study area. Copper, lead, zinc, gold, silver, nickel, cobalt, fluorite, and arsenic were found in north-northeast to north-northwest trending shear zones, veins, felsic dikes, and granitic intrusives in Tertiary Orca Group metasedimentary rocks.

Jan 1, 2011

By Richard F. Link

The objective of this report is to explain a statistical method for the summarization, organization, and classification of multivariate assay and other data from the mineral industry. Multivariate data are those characterized by several measurements at each data point, such as assay data from a mixed metal mine, or blast furnace data. A specific method of linear discriminant analysis, the Mahalanobis d2 procedure, is explained, starting from elementary principles; the d2 procedure enables many measurements at many data points to be studied by investigating the interrelationships among the data. The relation of linear discriminant analysis to other statistical methods for treating multivariate data, in particular the eigenvalue technique of factor analysis, is also explained. Example analyses are made on data from the Frisco mine, San Francisco del Oro, Chihuahua, Mexico. The data comprise assay values for silver, lead, copper, and zinc taken at some 19,000 sample points distributed into 91 groups.

Jan 1, 1967

By John L. Thames

The benefits of water harvesting as an alternative to conventional reclamation were demonstrated on the Peabody Coal mines in Northeast Arizona. The project produced food crops for four years, and demonstrated that a catchment/crop area ratio of about 2.5:1 was sufficient to obtain sufficient water from the 11 inch annual precipitation to produce garden and fruit varieties in quantities equal to or exceeding national production averages. The economic returns exceeded those of the conventional practice of returning the mine area to rangeland by at least ten fold. Subsidence of the regraded spoil was the only major problem in maintaining the system. Although, water harvesting systems have the potential of providing high economic returns and greater social benefits, as demonstrated by this project they are presently at variance with the strip mining regulation.

Jan 1, 1984

This report presents the results of studies of Kennecott Copper Corporation's tailings embankment at Magna, Utah. The stability studies described were performed on only one cross section of the embankment, utilizing; data obtained from drilling, sampling, and testing, which was limited in nature. The main objective of the data collection was to provide background information to support the overall research effort. Because of this limited scope, it is not possible to evaluate the degree of safety or adequacy of the embankment or disposal system, and the information and data contained in the body of this report must be judged in that light. The first part of this report contains discussion of site geology and seismicity, pertinent information on the refuge disposal system, a discussion of the tailings materials characteristics, a summary of the engineering analyses, and A bibliography. The second tart (appendices) contains basic geologic and engineering data supporting the discussions in the first part of the report.

Jan 1, 1974

The Full Scale Model Roof Bolt Test System described herein was designed, fabricated, erected, and installed by MSA Advanced Systems Division for the U. S. Department of Interior, Bureau of Mines, Spokane Research Center. It was furnished under USBM Contract No. 50271014 and Modifications. The test system is intended for use by the Bureau of Mines to run comparison tests on roof bolt systems. The mine entry cross section is made from special concrete pillars and roof slabs. They are constructed within a steel beam frame with hydraulic operated cylinders to apply loads that simulate the action of mining overburden. The frame is designed so it can be disassembled for replacing the concrete in subsequent tests. A computer and data acquisition system is furnished to control the load application and measure and gather data.

Jan 1, 1979

By J. R. Thoenen, J. L. Vallely, M. C. Malamphy

"SUMMARYMagnetic and gravimetric surveys wore conducted over an area of ap¬proximately 1,400 square miles in the bauxite district of central Arkansas. The primary purpose of these surveys was to discover any possible buried and hitherto unknown syenite masses favorable for the occurrence of bauxite and to determine the approximate position of the buried flanks of the known syenite masses which might offer conditions favorable for the discovery of new ore bodies.Those surveys indicated that the various syenite outcrops were domes or bosses on a large batholith and that ether similar domes occurred on the batholith but did net outcrop.Drilling on the local geophysical anomalies proved the presence of 10 buried domes, but only 2 of them were found to project above the upper surface of the Midway clays, a requisite of conditions favorable for the occurrence of bauxite ore bodies. The geophysical data indicated the approximate configuration of the buried flanks of the known syenite coutcrops, and the portions of these flanks that project above the Midway have now been outlined more accurately by drilling.The geophysical surveys have produced evidence permitting the elimi¬nation of a large area as unfavorable for the occurrence of bauxite.Magnetic surveys extending along the Midway-Wilcox contact from Gurdon, in Clark County, on the southwest to Searcy, in White County, on the northwest have proved the improbability of the existence of other syenite masses similar to those found in Pulaski and Saline Counties. A detailed magnetic survey of the Magnet Cove area in Hot Spring County has proved that the syenite mass exposed in that locality is an isolated intrusion and entirely unrelated to those of Pulaski and Saline Counties. This syenite mass does not occur under conditions believed to be favorable for the occurrence of bauxite."

Feb 1, 1945