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USBM Contract H0133045 consists of the design, build and test of 50 waveform generators. The waveform generator is a small ULF transmitter operating in the 1 to 3 KHz frequency range for the purpose of locating trapped miners during a mine disaster. This contract provided for the design, test, and building of 50 waveform generators using a discrete component construction with an option of using hybrid construction techniques within 105 days after the effective date of the contract. Because of large quantity economic considerations, this option was not initiated. Two engineering models were designed, constructed and tested and 50 final production units were fabricated using discrete construction. Complete documentation is supplied under a separate package which includes final schematics, parts list, layout information, equipment specification, production test procedures and qualification test procedures. Ten units have been delivered to the USBM. The remaining 40 units are being retained for packaging under contract H0242010 Transmitter Package and Receivers. A great deal of experience has been gained as a result of this contract. A final discrete potted printed circuit configuration has been arrived at that is now ready for field testing. After field testing, any desired changes should be incorporated into a final design. However, as a result of the current experience gained building and testing the production units, this printed circuit package together with potting procedure could be improved to reduce future costs. For example, the printed circuit board could be increased in size by 0.125 to 0.2 inches and all components could be mounted directly to the board eliminating costly hand stacking of components. The new printed

By Thomas A. Phillips

This publication is an economic evaluation of the Bureau of Mines electrolytic process for recovering lead from scrap lead-acid batteries. In this process, scrap batteries are crushed and separated into metal and sludge fractions. The metal fraction is cast as anodes and electro- refined. Lead in the sludge fraction is converted to lead carbonate by reaction with an ammonium carbonate-ammonium bisulfite solution. The lead carbonate is then dissolved in a fluosilicic acid electrolyte from which pure lead metal is electrowon. A cost estimate is presented for a plant capable of processing 10,000 scrap batteries per day. The fixed capital cost for this plant is estimated to he $14 million on a fourth quarter 1984 basis. Operating costs are estimated to be $0.15/lb Pb recovered. Assuming a lead selling price of $0.17/lb, the interest rate of return on investment after taxes is 11 pct. A lead selling price of about $0.21/lb is needed to obtain a 20-pct-interest rate of return.

Jan 1, 1986

By E. H. Denny

"Reduction of mine accidents appears to depend upon essentially the same fundamentals, whether considered from the viewpoint of the mine operator, miner, State mine inspector, or safety engineer. Conditions of mine operation with respect to safety are governed in most States by a mining law, usually somewhat general in its provisions but more specific than laws dealing with other industries, Methods of mining development and practice evolved through experience have been handed down from generation to generation; many of these are intended to avoid injury to men and also loss of property. To carry out the intent of these bases of law and experience relating to safety supplemental measures and conditions are necessary. Among these may be: (1) Planned safety rules adapted to the mine and compliance by both officials and Miners with such of these rules as pertain to their work; (2) a supervisory force adequate and competent to ¬administer the mining laws and safety rules; (3) discipline adequate to secure compliance with safety measures; (4) safeguards against mechanical, electrical, falling, and other hazards; (5) mining operations planned with respect to safety of workers; (6) an active safety organization of officials and employees; (7) education of officials and employees in safety practices; and (8) an active sustained interest in safety by management and employees.This paper presents the viewpoint of the safety engineer, though a safety engineer connected with a specific mine or group of mines would be in a better position than the writer to present the industrial engineer's thought. The application of the mine safety fundamentals just outlined will be given consideration from observations of methods used by safety engineers and supervisors.The term ""safety engineer"" includes men of various duties, various degrees of experience, and various authority. Depending upon the size of the operation or the interest of the management in safety, the safety engineer may have accident prevention as his sole duty; he may be the head of a sizable safety organization; or he may be in part a claim agent; a statistician compiling figures for the enlightenment of the company, the public, or a mining institute meeting; a surveyor who must convince the miner that his scale of 10/10 equals 1 foot does not defraud the miner of 6 inches to every yard measured; or he may be by heaven¬ly gift an orator capable of assuring the employees that ""all's right with the world""; he may be a young engineer gaining, experience while checking the observance of company rules and investigating accidents; or he may have the physical ills frequently resulting from several decades of mining experience and instead of a pension, the position of safety engineer has fallen to his lot. He may have mine-operating authority to correct immediately a dangerous condition or practice or he may have his recommendations officially disregarded at the monthly meeting or when the bottom of the desk basket is reached. He is likely to find that his viewpoint on accident reduction is considered unsound today because of youth and inexperience and unsound later because of old age and senility. He is likely to find the easiest course to be that of attributing to Providence and the carelessness of the worker the mishaps that result in the removal of a man to the hospital or the morgue."

Dec 1, 1936

By L. C. IlsLey

The United States Bureau of clines has been conducting Investigations of electrical equipment during a period of more than 25 years in an endeavor to encourage the development of safer electrical equipment for coal mines. In order to conduct these investigations in an orderly manner they are carried out under a published schedule of tests known as Schedule 2C, which specifies detailed requirements for motors, controllers, etc., and fees covering the various inspections and tests made as part of a routine investigation.

Jan 1, 1937

By P. L. Weston

The Bureau of Mines used high-temperature reduction roasting, magnetic separation, acid-leaching, and autoclave precipitation processes to recover iron and manganese from brown Cuyana range ores of Minnesota. Wet magnetic separation concentrated over 90 percent of the iron in 3 of 4 ores as high grade products analyzing 74 to 85 percent iron, 2.5 to 6 percent manganese, and 3 to 10 percent SiO2. The nonmagnetic fractions were leached with dilute sulfuric acid extracting 83 to 93 percent of the contained manganese and small amounts of iron. The leach solutions contained Mn-to-Fe and Mn-to-SiO2 ratios favorable enough for possible consumption in metallurgical mane operations. Exceptionally pure Mn solutions were achieved by pressure precipitation of the remaining iron in an autoclave followed by lime precipitation of silica and alumina.

Jan 1, 1966

By Arthur V. Petty

The Bureau of Mines has researched the utilization of mining and pro-cessing wastes as raw materials for the production of glass-ceramic pipe. Characterization of various wastes as to occurrence and chemical composition is reported. A computer program was developed and used to identify waste materials and mixes that would result in glass melts from which glass-ceramics could be produced after cooling and subsequent heat treatments. The production of abrasion-resistant pipe from inexpensive and readily available domestic resources could offer an economical substitute for high-alloy steels containing the critical and strategic materials cobalt and chromium.

Jan 1, 1984

By P. M. Sullivan

A physical beneficiation flowsheet was designed by the Bureau of Mines for reclaiming and recycling metal and mineral values contained in municipal incinerator residues, and a continuous processing plant was installed. Residue samples collected from incinerators located in various parts of the country were processed at a rate of 1/2 ton per hour. Continuous screening, shredding, grinding, magnetic separation, and gravity concentration techniques were applied to produce metallic iron concentrates, clean nonferrous metal composites, clean fine glass fractions, and tine carbonaceous ash tailings. Research to develop systems for refining and upgrading the reclaimed metals and glass into marketable products is also underway. From the engineering data developed in the continuous processing plant, evaluations of the capital and operating costs for plants with capacities of 250, 400, 670, and 1,000 tons of dry incinerator residues per day were made. Research on a parallel system to separate and recover the metals, minerals, glass, paper, and plastics from raw, unburned refuse it currently underway, as are studies on the use of air classification to separate the refuse into organic and inorganic fractions.

Jan 1, 1971

By D. Harrington

The prevention of accidents to children from blasting cans is of vital importance not only to everyone using commercial explosives but to the country at large. The manufacturers of explosives have realized this danger for years and have attempted to publicize the hazards of allowing blasting caps to fall into the hands of children. Unfortunately, many of tie users of explosives have failed to realize the danger or have ignored their responsibilities in the matter. Investigations of accidents to children from blasting caps (and scores of them occur annually) reveal that most of them are caused by blasting caps picked up or made easily accessible to the victims. The children who are blinded, maimed for life, or killed are in large part the innocent victims of the carelessness, thoughtlessness, or negligence of their elders, by whom blasting caps are left lying about, carried in the pockets, dropped or lost around blasting operations, stored away and forgotten, or left in places where trey can be found or are accessible to children. Many such accidents occur to children under 12 years of age, when they are still curious or inquisitive. One of the first reactions of a child upon finding a blasting cap is to investigate and "see" how it is made or how it "works." A blasting cap in itself, with one end open, invites a child to poke it with a nail, piece of wire, or some other object to see what is inside; or he may attempt to break it open with a rock or hammer. A lighted match could be thrust into the open end, and there are numerous other approaches, may of which can result in serious accidents.

Jan 1, 1944

By J. F. Barkley

To aid in winning the recent world war, the Bureau of Mines conducted a National Fuel Efficiency Program, directed to commercial plants throughout the Nation, to save greatly needed fuel, a basic resource vital to industrial production. In planning this program it was realized that to accomplish a satisfactory reduction in fuel consumption in any plant, it would be necessary to reach, enthuse, and usually educate to some extent the actual operators of the various types of plant equipment. A major part of the programs consisted, therefore, of visits to plants and work with the operators, including a review with them of their operating conditions and of educational and guiding literature pertinent to the operating problems involved. Through a Nation-wide organization, local volunteer engineers served in making visits to local plants. Each cooperating plant appointed an employee as the "waste chaser," who headed the work of saving fuel in that plant. The educational literature was designed to interest the operator, as well as serve as a guide in eliminating waste of fuel. Volumes have been written on many subjects relating to the saving of fuel. Writings of the treatise type contain considerable good information but do not have wide appeal and probably will be read only by a few studious operators. The problem is not one of getting clown on paper everything that the experts know and would like to have the operator know, but rather to write something that will actually interest the operator and stimulate him to action. Past experience led to the adoption, therefore, of the "quiz-sheet" type of writing, using a quiz sheet of not more than two pages for any principal item. The results obtained during the National Fuel Efficiency Program in many types of plants further demonstrated that the short quiz sheet is satisfactorily appropriate and does accomplish results. Each sheet was prepared and checked by many engineers expert in the particular subject matter of the sheet. Committees of men with much experience in the manufacture and operation of equipment and in the

Jan 1, 1947

By David K. Ingram

Research performed by the U.S. insurance industry has determined that mine subsidence is uninsurable. Consequently, the insurance industry has decided not to voluntarily offer mine subsidence insurance. The U.S. Department of the Interior has long been investigating the effects of mine subsidence. These investigations have resulted in Federal regulations and controls of mine subsidence. This U.S. Bureau of Mines report generally describes mine subsidence, the development of mine subsidence insurance programs, and the eight current mine subsidence insurance programs in the United States. The States that have these subsidence programs include Colorado, Illinois, Indiana, Kentucky, Ohio, Pennsylvania, West Virginia, and Wyoming. Major aspects of the programs include history, administrative and operational procedures, insurable structures, recognition of mine subsidence, major exclusions, claims, insurance premiums, and the economic health of each program. Addresses of agencies involved with mine subsidence insurance are also given. Information within this report can be useful for residential and commercial property owners and mine operators. States that are considering starting or have an existing mine subsidence insurance program can also use this report as a model for initiating or modifying their programs.

Jan 1, 1993

By S. J. Aresco

The Bureau of Mines has been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions4 issued by the Bureau of Mines; the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. Analyses of the delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1966

By L. H. ADAMS, C. N. HASKINS, J. K. CLEMENT

In the course of its investigations of the fuel resources in the United States and of the methods by which these resources could be utilized with greatest efficiency, the United States Geological Survey tested a great variety of coals and lignites as gas-producer fuel. Early in these testa it was found that many factors controlling the formation of gas in the generating chamber of the producer and, consequently, having a direct bearing on the management of producer-gas plants, were not as well understood as they should be. The Geological Survey therefore took up a detailed investigation of the chemical and physical processes that take place in the producer, keeping in view not only the possibility of increasing the efficiency of the producer as a source of energy, and the ensuing benefits to the public of cheaper power and greater utilization of low-grade fuels, but also the application of the results to the problems of boiler-furnace operations. - The Bureau of Mines, to which the testing and analyzing of fuels as carried on by the United States Geological Survey has been transferred, is continuing producer-gas investigations at the testing station at Pittsburg, Pa. Results of the gas-producer tests a made at the coal-testing plant erected at St. Louis, Mo., and of a study of some of the problems° that came up in the tests have been published by the Geological Survey. Results of the tests made at Norfolk, Va., and Pittsburg, Pa., and of further studies of particular problems, will be published by the Bureau of Mines. In the gas producer solid fuel is transformed into more readily combustible gaseous fuel. The transformation is relatively slow and consists of several processes: 1. The distillation of the volatile hydrocarbons from the freshly fired fuel at relatively low temperatures. 2. The combustion of the fuel by its combining with the oxygen of the air forming carbon dioxide (COO. 3. The formation of carbon monoxide (CO) and hydrogen (11 3), the essential constituents of producer gas, in accordance with the equations:

Jan 1, 1911

By Joseph J. Wallace

1. From the standpoint of known recoverable reserves, the following is the order of importance of the beds: Upper Kittaoning, Lower Kittanning, Upper Freeport, Lower Freeport, Middle Kittaning, Clarion, Pittsburgh, and Redstone. 2. mown measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and on 1,800 tons per acre-foot of coal in place, me estimated at 1,859 million short tons as of January 1, 1952. Of this, 1,351 million short tons me in beds 28 inches and more thick. Areas in each bed were omitted from the estimates because available data relative to the bed characteristics are too meager to make an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1953

By John E. Miller

Supercompressibility factors, Fpv, were derived from experimental compressibility data for five helium-nitrogen mixtures containing from 50 to 100 pct helium. These Fpv values are required as volumetric correction factors for or if ice meter measurement of "crude helium" (helium-nitrogen) purchased by the Government in a program of helium conservation. Although compressibility measurements were made by the Burnett method (2)3 - for pressures from 100 to 3,400 psia and temperatures from 40° to 100° F, Fpv values were needed only for pressures from 400 to 2,000 psia. Consequently, values at increments of 2° F, 2 pct helium, and 10 psia were tabulated only for the required pressure range. Values for pressures outside this range can be calculated from information shown in the tables. Values for the second, third, and fourth coefficients in the equation Z = 1 + BP + CP2 + DP3 are also included.

Jan 1, 1963

By T. H. Miller

An attempt has been mace in this publication to present annotated references to all articles pertaining, to ore dressing that were published during 1931 and 1932; in a few instances reference is made to articles published prior to 1931 where the articles have not been included in previous bibliography appended to the annual statistical discussions of ore concentration published by the Bureau of Mines. Articles have been taken from more than 75 periodicals, journals, serials, etc., and 423 articles are abstracted herewith. A number of these abstracts, particularly those appearing in foreign publications, have been taken from Chemical Abstracts (published by the American Chemical Society, Easton, Pa.), the general use of which the authors wish to acknowledge. Other annotations were taken directly from the original publications. The entire field of ore dressing has been included in the bibliography and articles dealing with crushing, grinding classification, concentration, thickening, and filtration have been included, as well as on amalgamation, cyanidation, leaching, magnetic concentration, washing, etc., and on theory and laboratory operation. The articles are arranged in alphabetical order by authors. Lack of printing funds prohibited the inclusion of a subject index.

Jan 1, 1934

By M. P. Ahola

This U.S. Bureau of Mines report presents an overview of the use of three unique numerical modeling methods to analyze cutter roof problems in underground coal mines. Cutter roof failures are common in coal mines where the immediate roof is comprised of thin laminae exposed to highly biaxial tectonic stress fields. The predominant mechanism for failure is assumed to be excessive shear stress at the entry corners exceeding the shear strength of the rock. Early work in this area utilized the finite-element method and then the boundary-element method to analyze several cutter roof control measures. Various stress control measures were simulated to estimate their respective effects on reducing the high levels of shear stress at the entry corners. More recent studies made use of the discrete-element method. This method was used to take the analyses beyond the elastic continuum limits to simulate the propagation of a shear fracture and subsequent redistribution of stress within the mine roof. A simple roof bolt model was implemented to show the benefits of bolting to increase the resistance to shearing and separation along horizontal bedding planes and maintain roof stability.

Jan 1, 1991

By Oliver Bowles

Calcareous rocks, of which the principal varieties are marble and lime¬stone, are used extensively for building and ornamental purposes. Onyx and travertine, subdivisions of these groups, are sufficiently distinctive in origin and use to merit separate classification. The purpose of this paper is to define the terms "onyx" and "travertine" and to describe the occurrences and uses of the materials bearing these names. ORIGIN AND CHARACTER Confusion exists in the use of the word "onyx." True onyx is a banded chalcedony, a form of silicon dioxide related to jasper, agate, and flint. Calcium carbonate is commonly deposited from solution in successive layers of varying color closely resembling onyx, and for this reason such calcareous rock is also called "onyx." To distinguish the calcareous from the siliceous

Jan 1, 1940

By R. R. Lowery

An analysis of three 1-1/4-diam manufactured wire ropes of 6x19 classification was done to identify and describe reference conditions of new rope. Reference condition is of value when examining tested or retired ropes. Measurements of strand and rope pitch and of wire and rope diameter confirmed adherence of all ropes to those construction specifications. Mechanical properties of strength and ductility were determined by accepted methods for the ropes and wires from the ropes. Individual wires from one rope failed to meet minimum wire ductility values. Wire chemical composition varied in average carbon levels, from 0.70 to 0.78 wt pct, and in manganese content, from 0.45 to 0.80 wt pct. One manufacturer's product contained 1 to 3 wt pct Ni and Cr. Heavily wrought pearlitic steel microstructures were porous and contained inclusions. Cold work variations were evidenced by wrought grain width. Recorded anomalies reflected the condition of the manu-factured products. The report provides data that compare the three wire ropes studied, but cannot verify the effects that these conditions or anomalies have on rope service life.

Jan 1, 1983

By Xavier B. Starnes

The Dike and Eaton veins in Crittenden County, Ky. (fig. 1), are along northwesterly trending relief fractures that lie between two northeastward striking major faults - the Moore Hill and- the Levias, in Crittenden County, Ky. The veins contain small, narrow, irregular ore bodies of fluorspar with subordinate quantities of sphalerite and galena. Gravel fluorspar was found on the surface in the Eaton vein, and open-cut mining was in progress on the W. M. Conyer property about 1900. Discovery of fluorspar in the Dike vein came much later, about 1933, on the W. H. LaRue tract, but the principal production on the Dike vein started after the discovery of gravel spar in 1938 on the land of the P. J. Gilless estate. Production from the Eaton vein was estimated at 9,400 tons and that from the Dike vein at 15,700 tons, a total of 25,100 tons. A large part of this production was gravel fluorspar from within 50 foot of the surface. Beneath the gravel spar the veins are very narrow, averaging 2 to 2.5 feet in width, and the ore shoots are small. The deepest mine level was 140 feet below the surface, and the deepest shaft 150 foot. Orb was concentrated by log washer or sent unwashed to custom mills at Marion, Ky. about 6 miles distant.

Jan 1, 1950

By Henry Kreisinger, WALTER T. RAY

This bulletin contains a statement of certain results that will be embodied in a report describing investigations of the combustion of fuel made by the United States Geological Survey and the Bureau of Mines in a specially constructed long furnace. The furnace forms part of the fuel-testing plant at Pittsburg, Pa., which was established and equipped by t.he Geological Survey, but passed under the control of the Bureau of Mines on July 1, 1910, when a t.ransfer of fuel-test.ing investjgations, authorized by act of Congress, became effective. The work discussed in this bulletin was done under the direction of the Geological Survey. The furnace was designed and built for an experimental study of the processes of combustiop, this study being part of a comprehensive plan for testing fuels to determine their heat value and the manner in which they can be used to best advantage. Although the main object of the researches made with the furnace by the Geological Survey was to examine critically the production of sensible heat by combustion along the path of the gases rising from the fuel, an interesting as well as important side problem developed in the study of the simultaneous dissipation of the heat through the walls and roof . of the furnace. Thus incidental data were collected on the temperature gradient through the walls at several places. These temperature data. (together with the heat conductivity of the material of the walls) formed the basis for calculating the heat dissipated through the walls. The object of this report is to present and discuss these temperature data. The discussion particularly concerns the air-space type of wall construction as compared with the solid brick wall or walls type, in which the air space is filled with some solid material of low heat conductivity. The conclusion of the authors, which perhaps will surprise some readers, is that, so far as loss of heat is concerned, a solid wall of brick or any ordinary material is preferable to a hollow wall of the same total thickness, especially if the air space in the hollow wall is near the furnace side. There is a general belief that l?ince air is a poor conductor of heat, air spaces built into the walls of a furnace will prevent or reduce heat dissipation through the wa.lls. Although there may be instances of furnace walls in which such construction reduces the rate of heat flow through them, yet as a rule the effect of the air space is just the opposite. While the heat does travel very slowly through the air by conduction, it leaps over the air space readily by radiation. Although this latter mode of heat propagation is common in nature, the laws governing it are not generall;y known and are seldom taken into consideration when furnace walls are being designed. It may be stated here that the quantity of heat passing through a. portion of a solid wall by conduction depends on the difference between the temperatures of the two planes limiting the portion of the wall. The quantity of heat that passes across the air space in the waH depends on the difference of the fourth powers of the absolute temperatUI: es of the surfaces inclosing Hie air space. It follows that, in case the heat. passes by conduction through the solid'portion of the wall, the loss remains approximately the same so long as the temperature of the two limiting planes remains constant, no matter what may be the temperature of the two planes. On the other hand, the heat passing across the air space by radiation increases rapidly with the temperatures of the inclosing surfaces, although the difference between these temperatures may remain constant. This feature will be shown by curves in the latter part of this paper and thoroughly discussed. The important point is that the air space, which is advantageous in the walls of a refrigerator because the temperatures are low, is objectionable in a furnace wall because the temperatures are high. It is customary to put air spaces in furnace walls between the firebrick linings and the common brick. Usually the fire-brick lining is only half a brick thick, which construction brings the air space too close to the furnace. The result is that the temperatures of the surfaces inclosing the air spaces are too high, and in consequence too much heat is radiated across the spaces. The heat passing through such walls would be much reduced if the air spaces were filled with brick, or, better, with some cheap nonconducting materials, such as ash, sand, mineral wool, etc. Even where the fire-brick lining is one brick thick (9 inches), the temperature in the furnace may be high enough to raise the temperatures of the air-space surfaces so much that the heat radiated across the space will amount to more than would the heat conducted through a filling, were the filling only common brick. This last statement is amply justified by the data here presented.

Jan 1, 1911