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By Frederick C. Trutt, Jeffery L. Kohler, Joseph Sottile

Twenty-five years ago, the former U.S. Bureau of Mines funded a research project aimed at developing the enabling technology for incipient failure prediction in electric power system components as a means of reducing the injuries and fatalities that sometimes occur when equipment malfunctions. Over the ensuing years, interest in this has waxed and waned, but recently interest has been growing for both civilian and military applications. This paper addresses the level of turn-to-turn insulation deterioration that can be resolved using an on-line monitoring technique. The detection of turn-to-turn defects is especially important because they are believed to represent the beginning stage of most motor winding failures.

By Dorsey A. Lyon, Robert M. Keeney

In the inquiries and investigations that the Bureau of Mines is making with a view to increasing safety, efficiency, and economic development in the metallurgical industries, the application of elec- tricity to various processes, and especially to those in the manu- facture of iron and steel, is being given attention. Some results of the work already done are presented in this bulletin, which gives a historical review of the development of electric furnaces for making iron and steel, and discusses the problems that remain to be solved in the use of electric furnaces for the smelting of iron ores and the production of pig iron at a profit on a commercial scale.

Jan 1, 1916

By Van H. Manning

Of all the war work by the Bureau of Mines none ultimately covered such a variety of processes and equipment, employed as many men, or called for as large an outlay as that started in con- nection with the solution of problems relating to the use of noxious gases in warfare. Beginning with an investigation to develop the best type of gas mask, the scope of the work extended until it included researches relating to a wide range of devices, such as different types of poisonous and irritating gases and smokes, smoke screens, gas shells and gas bombs, flame throwers, trench projectors for firing gas bombs, signal lights, and incendiary bombs. The Bureau of Mines in starting this work selected the necessary personnel, pro- cured the early equipment, and for some months, from the begin- ning to June 30, 1917, paid the cost of the work from its own funds. The Bureau of Mines built up a research staff of more than 700 chemists, including many of the most prominent chemists in the country, and obtained the cooperation of many of the universities and chemical companies. When the results obtained through this research were to be applied by the War Department, the Director of the Bureau of Mines cooperated in the selection of men to have charge of manufacture or further development, recommending chemiste who subsequently received commissions in the Army. The personal cooperation with the War Department was thus very close. The bureau can fairly claim that because it started this work on gas warfare and received the hearty support of the Department of War, the Navy Department, the National Research Council, and State, educational, and private institutions, the country was in July, 1918, months ahead of where it would otherwise have been in the production of gas masks and other devices. The production of toxic gases then far exceeded the supply of shells. In addition the later work in gas-mask manufacture by the Surgeon General's Office of the Army, which resulted in the development of the best mask produced anywhere; in gas manufacture and gas proving-ground tests by the Bureau of Ordnance, and in the chemical warfare pro- gram of the Navy, including the use of smoke screens, shells and toxic gases, were the direct results of the bureau's experimental work. The American charcoal and soda lime, developed through the research work, are the best used by any nation. The Bureau of Mines was instrumental in developing satisfactory methods of manu- facturing chlorpicrin, phosgene, mustard gas, brombenzylcyanide, cyanogen chloride, and other noxious substances on a large scale. The bureau also developed a smoke funnel for the Navy which no doubt saved many ships from submarine attacks, and devised smoke barrages, signal lights, incendiary darts, etc., for the Army. The Ordnance Department of the Army asked for incendiary bombs and were furnished with bombs better than any made previously. Perhaps the greatest single result of the research work has been the demonstration of the value of the services that the chemist and chemical engineer can render in time of need and the recogni- tion of chemical investigations as a necessary function of the Gov- ernment.

Jan 1, 1919

By J. W. Thompson

The Sullman, Picard & Ballot patent, No. 835120, is a process of concentrating ore which consists in mixing the powdered ore with water, adding a small proportion, a fraction of 1 per cent on the ore, of an oily liquid having a preferential affinity for metal- liferous matter, agitating the mixture until the oil-coated mineral matter forms into a froth and separating the froth from the remain- der by flotation. The process is known as an air-flotation process which consists in the use of a frothing agent in conjunction with such agitation of the ore pulp as will distribute the metallic particles of the ore throughout the mixture and produce bubbles of air and bring them in contact in the mixture with the metallic particles so dis- tributed. The bubbles will become attached to such metallic par- ticles, carrying them separately from the particles of gangue up through the surface of the mixture where they can be readily collected by skimming, by overflow, or by the use of other well-known devices. The air-flotation process was a patentable invention in the discov- ery made in March, 1905, and was not anticipated and is valid. Prior to that time there had been no suggestion in the arts that a propor- tion of 0.1 per cent of oil to ore or of any other fraction of 1 per cent of oil to ore would or might result in successful concentration. While the ascertainment that such a minute proportion of oil would affect a successful concentration of ore through a flotation process was a discovery, it was nevertheless of such a character, viewed with respect to the circumstances under which it was made, as to involve inven- tion and confer patentability. Claims 1 and 12 of the Sullman, Picard & Ballot patent, No. 835120, for a process of concentrating ore, known as the air-flotation process, are valid; but claim 9 is so indefinite as to render the claim void. The object of the Sullman, Greenway & Higgins patent, No. 962678, dated June 28, 1910, for improvements in ore concentration, is to separate metalliferous matter, graphite, and the like from gangue by means of oil, fatty acid, or other substances which have a prefer- ential affinity for metalliferous matter over gangue, and it is valid. The Greenway patent, No. 1099699, dated June 9, 1914, for improve- ments in the concentration of ores is invalid, as in view of the prior art the omission to use acid in the process can not confer patenta- bility.

Jan 1, 1917

By GEORGE S. POPE

The purchase of coal by the Government under specifications depending on the heating value of the coal, its content of ash and of moisture, and other considerations, rather than upon the reputation or trade name of the coal, was based on the fuel investigations begun by the Technologic Branch of the United States Geological Survey in 1904. The plan was first adopted by the Treasury Department in 1906. Since then the plan, variously modified in form but the same in principle, has been gradually adopted by other departments until at present of the coal used by the Government, the total value of which approximates $8,000,000 annually, more than half is purchased under specifications. The Government publications dealing with the adoption by the Government of the specification plan, the number of contracts awarded on that basis, and the quality of the coal delivered under such contracts in the several fiscal years covered by the reports are given in publications listed at the end of this bulletin. Under the authority of acts of Congress making appropriations for analyzing and testing fuels belonging to or for the use of the United States Government, a laboratory is maintained at the headquarters of the Bureau of Mines, Washington, D. C., where samples represent- ing deliveries of coal purchased under specifications for Government use are analyzed and tested. At this laboratory more than 1,200 samples have been analyzed and tested in one month. With the complete equipment and the efficient force employed, the analytical work has been so perfected that the analyses and heating-value tests of the samples received are as accurate as may be reasonably expected in laboratory work of this nature. One of the serious drawbacks to the general adoption of the speci- fication method for the purchase of coal is the difficulty of obtaining at reasonable cost samples of coal that can be considered fairly repre- sentative of the commercial product delivered in wagons, railroad

Jan 1, 1913

By W. P. Yast, R. R. Slyers, J. H. Hildebrand

 The Bureau of Mines, in conducting investigations of atmospheres in mines and tunnels for the purposes of determining and combating hazards to the health and safety of workers, has from time to time closely cooperated with municipal, State and Federal agencies in safety work in engineering and ventilating probleme. Recently the writers have conducted experiments with animals and men breathing helium-oxygen mixtures under pressure. The object of this work was to determine whether helium-oxygen atmospheres can be utilized to advantage in place of normal air for caisson and diving work. In such work the permissible pressures and times of compression and decompression are limited by the physiological effects on man. The major effect is that the nitrogen, (which is the inert con- stituent of normal air and is absorbed by the body tissues and fluids in abnormal amounts when under pressure,) tends to form bubbles in the tissues on too rapid discompression from high pressures. The Bureau of Mines is interested in this problem on account of the pos- sibilities of mitigating caisson illness in tunnel construction and other engine eering operations requiring men to work in compressed air. In addition, the Navy Department is interested on account of the possibilities for extending the range of salvaging and marine engineering operations. The results of the experiments conducted by the writers lead to the following conclusions: Helium is without odor or taste and has physical properties which promise to be of interest physiologically and which have been found to have possibilities of creat practical use, especially in making a synthetic atmosphere that will re- duce the hazard of caisson disease. The substitution of helium for the nitrogen ordinarily present in the air we breathe has been found to result in an atmosphere which it as respirable as that provided by nature. The results obtained indicate that helium not only has the advantage of being less soluble than nitrogen, but

Feb 1, 1925

By C. W. Lee

"Introduction of diesel engines in underground mines may generate severe health hazards associated with exhaust contaminants. One of the most important parameter in determining the optimal air quantity for hazard reduction is the exhaust dispersion. Through analyzing the exact solution of the diffusion equation and its approximation by finite difference method(FDM) , this paper aims at doing a fundamental research to find an efficient dispersion model suitable to the domestic mines. Diffusion coefficients are likely to be small in the underground airways with high ventilation resistance. This makes concentration profiles similar to the convection-based step functions. It is the case for fixed as well as moving engines. Concentration estimation by exact solution is almost impossible in the case of either a single engine moving at a variable speed or the existence of multiple engines. Application of FDM to the diffusion equation including turbulent dispersion results in the various problems; unstable concentration profiles depending on the engine location, nuctuating concentrations near the engine, and overestimation of the dispersion region of which error grows with waning diffusion coefficient.Convection-based dispersion model is found to fit well for dynamic simulation of exhaust dispersion from multiple diesel engines in the airways showing low diffusion coefficients. Its suitability is more likely in the regions with frequent equipment passage. Published"

Nov 1, 1995

By N. S. Dalal, B. Jafari, V. Vallyathan

Electron spin resonance measurements have now been completed on the decay kinetics of the organic free radicals formed on crushing or grinding of a well characterized anthracite coal. The free radicals exhibit a complex decay pattern for the first few hours after the grinding, and a smooth decay thereafter. Parallel hemolysis studies indicate. a half-life of the decrease in the cytotoxicity of the fresh· dust to be about half-a-day. The cytotoxicity of the freshly-made dust decreases on addition of superoxide dismutase, catalase and sodium benzoate. The hemolysis rate is lower for the dust stored in buffers as compared to air. A chemical model will be presented to accomodate the cytotoxicity and spectroscopic data, and ~heir implicati6ns to pneumoconiosis.

Jan 1, 1988

By W. A. Heitbrink, M. Schmitz, J. A. Organiscak, A. B. Cecala, E. Ahrenholtz

Operator cabs on a front-end loader and a rotary rock drill were retrofitted with ceiling mounted heating1AC units and air filtration systems. Subsequently surface coal mine field studies were conducted to evaluate the respirable dust protection these retrofitted cab systems offer to the equipment operator. A significant 10: 1 respirable dust protection factor (ratio of outside to inside cab dust levels) was measured for the front-end loader cab with positive pressurization of the cab interior. Whereas an insignificant 3: 1 respirable dust protection factor was measured for the drill cab without positive pressurization of the cab interior. These results indicate that achieving positive interior cab pressurization with retrofitted cab filtration systems is a key element to their dust control effectiveness.

By P. A. Wasson, M. M. Fine

Roasting research involving small , batch experiments was conducted to explore the use of solid reductants for converting nonmagnetic iron ore to a magnetic type . Three typical Minnesota ores were tested with one or more of the following reductants : Lignite , lignite chars , anthracite , bituminous coal , petroleum coke , peat , and pyrite . Reductive roasting was accomplished in a 3- by 4- inch externally heated rotating drum . Ore and reductant were placed in the drum and heated to a desired temperature , which was maintained for a predetermined period . Recoveries of over 90 percent of the iron in magnetic concentrates were achieved at 650 ° C , using lignite , some lignite chars , a high- volatile bituminous coal , peat , and pyrite . Pyrite is a novel reductant , which is superior to carbonaceous materials other than lignite and some chars .

Jan 1, 1963

By David Ingram

The results from the sound level measurements, the dosimeter recordings and the time-activity studies on four different air-rotary rigs indicate a wide variation of operator noise exposure during hole development. These variations appear to be dependent on the cab design and the operator?s drilling behavior. Studies have documented that exposure to high sound levels for long periods of time can cause hearing loss. The results of this study help identify the loudest parts of the drilling cycle. Sound level measurements on the four rigs show that all the rigs generate sound levels that are 90 A-weighted decibels (dB(A)) and above within 6 feet around the rigs during drilling. It is easy to conclude that some type of noise protection, such as a cab, is needed to protect the operator from overexposure to noise for an eight-hour shift of uninterrupted drilling. However, even when rigs are outfitted with cabs, operators observed in this study are being exposed to sound levels above 90 dB(A) during some activities required to complete a drilling cycle. An evaluation and comparison of the four dosimeter recordings and time-activity studies during one drilling cycle may explain why variations in operator exposure occur. Table 1 summarizes the time-weighted average (TWA) and accumulated dose percentages for each of the four operators during the time needed to complete one typical hole cycle.

Jan 1, 2008

By Alex C. Smith, Thomas P. Mucho, John B. Walsh, Alden Ozment, Michael R. Thibou, Michael A. Trevits

The National Institute for Occupational Safety and Health (NIOSH), with US Foam Technologies, Inc. and On Site Gas Systems, Inc., conducted research on the remote application of extinguishing agents with the intent of improving deployment strategies to limit miner exposure and to help ensure the best possible outcome during a mine fire. Full-scale in-mine were conducted at the NIOSH Lake Lynn Experimental Mine to determine the flow characteristics, stability and fire-suppression capability of gas-enhanced foam. The in-mine experimental work was designed to evaluate movement of gas-enhanced foam through mine workings closely simulating an underground coal mine environment and how long gas-enhanced foam would remain stable. This paper presents results of the experiments and provides valuable insight into mine fire deployment strategies for gas-enhanced foam technology.

By Van H. Manning

PETROLEUM INVESTIGATIONS. The work of the petroleum division of the Bureau of Mines during the period of the war was under the supervision of Chester Naramore, chief petroleum technologist. In its petroleum investigations the bureau cooperated freely with other Government bureaus and acted as a source of information on petroleum matters. COOPERATIVE WORK ON INTERALLIED PETROLEUM COMMISSION. On July 15, 1918, Mr. Naramore and W. E. Perdew, chemical en- gineer of the bureau, left for London to act as representatives of the United States Fuel Administration and the United States Shipping Board on the Inter-allied Petroleum Commission. Numerous con- ferences were held with representatives from France, England, and Italy on specifications and requirements of the various allied Govern- ments for petroleum products, and for this purpose meetings were held in London, Paris, and Rome. EXAMINATION OF PETROLEUM FACILITIES IN FRANCE. The storage facilities and the transportation system in France were studied, and recommendations based on the information gained were made to the director of the oil division of the Fuel Administra- tion and to the chairman of the Shipping Board. Refinery plants in France were inspected, as well as filling stations and shipping facilities from ports in France and Italy to the various fronts and the petroleum base of the American Expeditionary Force at Romorantin. France. At the request of Ambassador Sharp, a re- port was prepared on the advisability of developing the petroleum resources in France.

Jun 1, 1919

By Sean Gallagher, Christopher A. Hamrick, Arnold C. Love

Twelve subjects participated in an investigation of the biomechanical stresses of asymmetric lifting in stooped and kneeling postures. Three factors were manipulated in this study: Posture (stooped or kneeling), height of lift (35 or 70 cm), and weight of lift (15, 20, or 25 kg). Subjects were required to lift or lower a box every 10 seconds for a period of 2 minutes. Electromyography (PIG) of eight trunk muscles was collected during a lift in this period. The PIG data, normalized to maximum extension and flexion exertions in each posture, were input to a biomechanical model and used to predict compression and shear forces at the L, level of the lumbar spine. Results from the EMG-driven biomechanical model indicated that compression was greater when lifting to a higher shelf (p < 0.001), and indicated a significant interaction between posture and the weight of the lifting box (p < 0.01). Peak lateral shear was not significantly affected by any main effects or interactions (p < 0.05). Anterior shear was increased with increasing height of lift (p < 0.001), and also by the posture x weight interaction (p c 0.01). A multivariate analysis of variance (MANOVA) indicated a complex relationship for recruitment of the eight trunk muscles, with the triple interaction being significant (p < 0.001). The results of this investigation will be used to evaluate safe loads for lifting in these restricted postures.

By C. B. Manula, R. L. Sanford, R. A. Rivell

A generalized flow diagram is presented in Figure 1, which shows the relationship of major model functions. This chart does not necessarily represent the anatomy of the computer program, but is designed to illustrate the informational interchange between major model functions. The related flow-charts-and computer program are listed in Parts I and II, Appendix A, respectively. Mine Car Stations The mine car stations are the activity centers for the model. The locomotive logic structure is designed to provide these stations with adequate cars and to clear them of car buildup. The model is designed to simulate a three stage haulage situation which suggests the need to differentiate station levels by type numbers. These are: a) TYPE 1 stations - mine cars are loaded here; b) TYPE 2 stations - intermediate stop and storage for mine cars; c) TYPE 3 stations - all mine cars that are stored here leave mine; and d) TYPE 4 stations - mine portal. TYPES 1, 2, and 3 have all loaded cars assigned to an ascending TYPE as their next destination. In input, if single stage haulage is designated, TYPES 1 and 3 do not exist, and if two stage haulage is called for, TYPES 2 and 3 are absent. A motor is not permitted to exchange cars between stations of the same type. Station Status Update. One major model function is to continuously evaluate the status of each mine car station. The major evaluations

Jan 1, 1974

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

3. Application of Proposed Revised Standards 57.11-50 to Mines Surveyed 3.1 Subparagraph (a) 1 "Each mine shall have at least two separate and properly maintained escapeways from each working place to the surface which are so positioned that physical or environmental damage to one will not lessen the effective¬ness of the other, and which meet the requirements of travelways and man hoisting standards These escape¬ways shall reach to within 1000 feet horizontally or 300 feet vertically of each working place " 3. 1. 1 Discussion This section will deal with the 1000 and 300 feet distance requirements, Section 3. 5 will deal with the "environmental damage" provisions. During the course of the mine surveys, it became obvious that one mine&apos;s 1000 foot distance was nowhere near equal to another&apos; s --not in the actual distance but in the time required to traverse that distance. This -Ls true for the 300-foot requirement as well. The most obvious example is that one could traverse down a 300-foot raise much faster than climbing up the same distance. The temptation is strong to recommend that the distance requirement be changed to travel times instead. However, this approach would unfortunately lead to a lot of subjective evaluations. Having a time requirement for an entire mine evacuation (Subparagraph 6) is one thing, time requirements and the requisite inspection proce¬dures for each working place are quite another.

Jan 1, 1976

By Charles L. Parsons

During the past year, in producing 500,000,000 tons of coal we wasted or left underground, in such condition that it probably will not be recovered in the future, 250,000,000 tons of coal; we turned loose into the atmosphere a quantity of natural gas larger than the total output of artificial gas during the same period in all the towns and cities of the United States; we also wasted or lost in the mining, preparation, and treatment of other important metalliferous and non- metalliferous minerals from 10 to 50 per cent of the year's produc- tion of such minerals. These losses serve to indicate the importance of inquiries and investigations by the Federal Government for the purpose of lessening the waste of essential resources-investigations on the same general lines as those looking to a reduction in the loss of life in the mining operations of the country and the far more exten- sive investigations looking to the more efficient production and use of agricultural products, both of which are being conducted by the Federal Government. In a consideration of the possible activities of the individual, the State, and the Federal Government in behalf of a less wasteful use of our mineral resources certain facts and principles should be kept clearly in mind, namely: That the present generation has the power, and it will exercise the right, to use as much of the country's resources as it actually needs; there can and there will be no such thing as stinting the present gen- eration by bottling up resources for the use of the future. That the Nation's needs are not likely to be curtailed; these needs will increase with the extent and diversity of the Nation's industries, and they will increase more rapidly than population increases, for the reason that the per capita consumption of mineral products is rapidly increasing; and That the men of this generation will not mine, extract, or use these resources at continuous financial loss to themselves in order that some- thing may be left for the use of future generations; there can be no such thing as a mineral industry without profits.

Jan 1, 1912

By Henry Kreisinger, F. K. Ovrız

Some of the investigations conducted by the Bureau of Mines have for their object the collecting and disseminating of information regard- ing methods by which the fuels of the country may be most effi- ciently used. As the analysis of flue gases tends to develop better methods of firing, which in turn reduces waste of fuel, the Bureau of Mines in this bulletin presents for the benefit of those in charge of boiler plants and all other persons interested detailed information on methods of sampling and analyzing flue gases, and on the utilization of the analyses in promoting boiler-room economy. This bulletin is intended to be a companion to Technical Paper 80," and is written in plain and nontechnical language, as far as pos- sible, so that it may be readily understood by persons who have not had the advantage of a technical education. Whenever possible, illustrations of apparatus and methods of handling have been used rather than elaborate descriptions. The material presented in this report is arranged in two parts. The first part contains the description of the apparatus and the methods used in sampling and analyzing flue gases. The second part gives experimental results obtained with the different methods of sampling and collecting flue gas that are recommended in the first part of the report. Only simple apparatus and methods are considered, as they are accurate enough to show the large heat losses due to the use of too much air, and are also accurate enough to indicate any incomplete combustion losses of economic importance. Without doubt the loss due to large excess of air is the greatest one in the boiler room, and can usually be greatly reduced by making proper use of gas analysis. Before engineers in the isolated industrial plants can be induced to analyze for small traces of combustible gases, they must be first taught how to analyze for carbon dioxide (CO), and they must learn to appre- ciate the great possibilities of reducing loss from large excess of air. Furthermore, in the face of the great difficulty of obtaining a fair

Jan 1, 1915

By D. T. Randall

In carrying out a general plan of ascertaining more efficient and more economical methods of utilizing the fuel resources of the United States, in order to prevent unnecessary waste and thus conserve the available supply, the United States Geological Survey made a series of experiments on the combustion of fuel in house- heating boilers. As it was realized that steam boilers of the ordinary types used for heating private houses are often installed and operated under conditions unfavorable to fuel economy and smoke prevention, these experiments were made with briquets, raw coal, and washed coal, so as to determine what is to be expected of these fuels in a representative house-heating plant, properly installed and operated. Briquetted coal had been frequently tested in the hand-fired furnaces under the Heine boilers in the Survey fuel-testing plant at St. Louis. The results were so satisfactory as regards economy and smokelessness that it was decided to conduct a series of tests to determine the value of this fuel for domestic heating purposes. Beginning in October, 1906, a number of evaporation tests were made on the house-heating boiler installed to heat the buildings occupied by the structural-materials laboratory, both briquets and coal being used. After these tests were well under way, it was thought advis- able to conduct some additional tests under conditions more constant than could be maintained at this plant. A carload of briquets was shipped to the University of Illinois engineering experiment station at Urbana, Ill., where two house-heating boilers of a size commonly used in residences were available. This equipment permitted more uniform conditions of pressure and capacity, making the results more valuable for comparison. Tests were made with this fuel at Urbana in June and July, 1907. The present paper is an account of both series of tests, and includes also details of tests made at Urbana on three standard fuels in the spring of 1908. Perhaps the most important result obtained is that showing the relative value of different fuels for domestic purposes. From Table 16. on page 39, it is possible by comparison to arrive at the probable value of any fuel in any part of the country. The figures in the table

Jan 1, 1911

The faculty, graduate students, and post-doctoral researchers are an integral part of the Generic Mineral Technology Center for Respirable Dust. More than fifty (50) scientists, engineers, and medical personnel are engaged in respirable dust research at five universities, The Pennsylvania State University, West Virginia University, Massachusetts Institute of Technology, University of Minnesota, and Michigan Technological University. The expertise, effort and contribution of these individuals has proven to be invaluable in the attack on respirable disease. Nationally and internationally recognized researchers in the areas of particle characterization, interaction of dust and lungs, dilution and dispersion, rock mechanics and continuing education lend their laboratory facilities, equipment and human resources to benefit the mining industry. The expertise and resources of the National Institute for Occupational Safety and Health--Division of Respirable Disease Studies is available through their relationship with West Virginia University.

Aug 31, 1989