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By Richard V. Ageton

Compressed- air blowers are frequently used both in large and small metal ines , not only as an aid to ventilation , but in some mines as a substitute for an dequate ventilation system . As a temporary fixture , blowers have their uses , but hey should never be used in lieu of a permanent ventilation system. A number Probably the most common error made in placing dependence on compressed- air lowers as an aid to underground ventilation is the tendency to over- rate their cooling efficiency . It is a very common but natural error to assume that compressed air which issues freely from a blower is of the same temperature as the compressed air which issues freely from the exhaust port of a rock-drilling machine . of readings were taken in different mines of the temperature of the rock- drill exhaust , of the compressed air flowing from the blowers , and of the surrounding air In both cases . In general , the temperature of the rock- drill exhaust was from 10 to 30 degrees below that of the surrounding air , in many instances being slightly below freezing , 32° F . The average temperature for a number of compressed-air lowers and for the mine air surrounding them is shown in Table I.

Jan 1, 1922

By Richard A. Andre, R. Larry Grayson, Thomas Simonyi

"INTRODCICTIONThe search for the cause(s) of coal workers' Pneunoconiosis continues despite the vast amount of research that has been undertaken over the past forty to fifty years. Good correlation between the mass of dust inhaled over workers' lifetimes and the incidence of the disease has led to the development of effective environmental standards and implementation of good procedures for the control of dust generation and dispersion in the working place. Research has only begun, however, to uncover the biochemical mechanisms involved in initiating the disease.Correlation between the rank of the coal seam in which miners worked and disease incidence and severity is acknowledged worldwide, but the agents in the higher rank coal seams which cause CWP arc still not defined. The basic components of the coal seams, i.e., the elements and minerals, are generally known, but the way in which they interact with human pulmonary cells is largely still a mystery.The process of disease development is a biochemical one which depends on the characteristics of the pulmonary cells within their immediate biochemical environment and the characteristics of invading respirable coal mine dust particles, probably both chemical and physical ones. The cell-particle relationship, therefore, must be defined, and both cells and particles must be characterized according to properties which potentially are involved in the disease process.Following such characterization, specific respirable dusts from different coal seams, which appear to have different effects on coal workers, must be obtained or constructed and then used in experiments designed to determine dust toxicity or the response of animals exposed to the dusts.The results presented here focus on characterizing properties of respirable coal mine dust particles collected from operating longwalls in West Virginia and Virginia Longwall panels were selected for analysis because the respirable dust in the coal face areas is largely uncontaminated by rock dust and analysis of the dust yields results unconfounded by rock dust."

Jan 1, 1990

By L. C. IlsLey

In the normal operation of mines, the aggregate effect of many seemingly minor op rations may be very important as respects economy and safety. Anion: these operations is the method employed in coupling and uncoupling mine cars. For economic reasons the equipment in mines has not been protected as well as railroad equipment. It is pertinent that haulage accidents rank second in severity among mine accidents, and that manual coupling of cars has been one of the most frequent causes of such accidents. One study4/ revealed that coupling was responsible for about 20 percent of haulage accidents underground. A review of early conditions on steam railroads, which were responsible for the introduction of safer methods of coupling cars, indicates how conditions in might be improved. THE STORY OF RAILROAD COUPLING As any considerable improvement in mine-car coupling probably will follow lines somewhat similar to those that brought order out of chaos for the railroads, it seems appropriate to review briefly the steps taken to improve railroad coupling from the days of link and pin couplings of various types to the adoption of the standard ?M.C.E? automatic coupler.

Jan 1, 1943

By Oliver Bowles

"On January 15, 1920, a man was killed by falling rock in a limestone quarry in Utah. The quarry was visited by a representative of the Industrial Commission of Utah, and the cause of the accident was carefully determined. The facts concerning this accident, and the Bureau's recommendations are given in some detail in the hope that quarrymen may take steps to avoid dangerous conditions, and thus reduce the liability to accident.The quarry rock face is about 180 feet high, and the ledge is covered with an overburden of 10 to 20 feet of a mixture of soil and boulder. The rock face is not vertical, but slants at an angle of about 45° to 50°, while the stripping face stands at an angle of 70° to 80°, and is flush with the rock face. The conditions are shown in the accompanying figure.The man who was killed was employed in breaking rock at the foot of the quarry wall. The sun had been shining on the stripping face, and probably thawed the ground, thus permitting a boulder weighing about 20 pounds to roll down the slanting face, striking, and almost instantly killing the workman who was working with his back toward the quarry wall."

Feb 1, 1920

By McHenry Mosier

Diamond -drilling blast holes at Eastern Magnetite Mine C is proving economical in boundary shrinks , in removing pillars not readily accessible for percussion drilling , and in driving scraper drifts . The cost per foot drilled is greater than for percussion drilling , but savings in associated factors outweigh this handicap . The rocks drilled include trap rock and magnetite ore . The mining method is the panel , block- caving system utilizing scraper sublevel drifts instead of branch raises to convey the ore to the haulage level . Diamond -drilling blast holes was begun early in 1945. Three rigs equipped with noncoring bits are now in active operation two shifts per day . They are owned by the company , and the drill operators are paid by the day . In shrinkage stopes the drill is mounted on a horizontal bar set against opposite walls of the stope . Stoping holes are horizontal , which gives better results in blasting and requires fewer set ups . In scraper drifts the drill is mounted on a horizontal bar clamped to two columns about feet apart . Trim holes around the periphery of the drift and reliever holes are drilled 50 to 80 feet in length . A 10 - foot wedge cut drilled with a stoper is blasted in conjunction with a corresponding length of the trim holes to effect a 10 -foot advance of the full- sized drift . Recent drilling averages 97 feet per machine shift , excluding time utilized in setting up and moving the machine , hand mucking , and barring down . The feet drilled per bit at present is 417. These data represent the average for drilling in both rock (waste) and ore . Percussion drilling utilizes three types of wet drills . Detachable bits are standard . Gage changes for new bits is 1/8 inch and for reconditioned bits 1/16 inch . The life of a bit is five uses . Resharpening is on contract . A drill carriage is used in haulage headings .

Feb 1, 1948

By D. J. Parker

The oft-repeated expression that the taproot of safety lies in the attitude of the management toward accident-prevention work is indisputable and has become almost an axiom. Trite and somewhat timeworn though the statement may be, it is nevertheless true that the supervisory force must earnestly support a policy of safety and maintain at all times a con¬ siderate regard for the welfare of the employee if that high degree of cooperation of the employee, so vital to the successful prosecution of any safety program, is to be expected. The responsibility for preventing accidents rests upon the management, and in the case of the Spring Canyon Coal Co. such responsibility is recognized and accepted with little or no reservation. This company, aside from the humanitarian aspects involved, believes that safety is good business and not a matter to be treated passively or in a perfunctory manner. The problems with respect to safety that have been met and wholly or partly solved can best be appreciated when some of the natural conditions, adverse and otherwise, existing at this operation are taken into consideration. Mine 1 is about 1 mile north of the town of Spring Canyon, Carbon County, Utah, and is served by both the Denver & Rio Grande Western and Utah Coal Route railways. During the year 1931 the mine produced 312,397 tons, approximately 10 per cent being derived from pillar workings. The normal daily output during the summer months is about 2,000 tons, and during the peak of production in the winter season the daily production varies from 2,500 to 3,000 tons. The number of miners varies from 87 in summer to 220 in winter, and the day men vary in number from 66 in the winter to 45 in the summer; 12 company men are employed the year around. The officers of the company are J. B. Smith, president, San Francisco, California; T. R. Stockett, general manager, Salt Lake City; and G. A. Murphy, superintendent, David Brown, assistant superintendent, and John Sullivan, mine foreman, all of Spring Canyon, Utah.

Dec 1, 1932

By G. M. Kintz, E. H. Denny

Although some engineering colleges recognize the importance of instructing young engineers in industrial safety , the different institutions handle this instruction in various ways . It is believed that a recent industrial safety course , conducted at the Colorado School of Mines through the cooperation of this school and the Bureau of Mines , U. S. Department of Commerce , presents some unusual features that are of interest to other schools and to the mining public .

Sep 1, 1930

By John P. Harmon

Vehicles traveling on untreated dirt and gravel roads at open-pit mines disseminate high concentrations of dust (fig. 1). Excessive dust creates safety hazards by reducing visibility and may endanger the health of the men who breathe it. If the dust contains free silica, it can cause silicosis. In addition, maintenance costs of mechanical equipment are increased if equipment is operated in extremely dusty places. Dust on haulage roads in hot, arid country can be controlled if the surface of the road is sprinkled frequently and adequately with water. Often, when roads are sprinkled with water to control the dust, hazards are caused through reduced traction and skidding because of the mud that is formed on the surface of the road. Reducing the amount of water used will help to reduce the hazard of skidding.

Jan 1, 1957

By L. Y. Sadler

The Bureau of Mines conducted a study Lo determine the loss in weight of silica (Si02) volatilization from low-alumina (A1203) refractories used as hot face liner materials in such process equipment as coal gasifiers, synthesis gas transfer lines, and ammonia plant secondary re-formers. Small specimens of 80-and 40-pct-A1203 brick and 95-pct-SiO2 brick were exposed to steam in high-pressure furnaces at pressures of up to 1,000 psig and temperatures up to 1,400° C for periods ranging up to 120 h. Weight losses from the 40-pct-A1203 brick after 40 h of exposure were highest, 2.75 pet at 1,400° C and 1,000 psig. The rate of weight loss had dropped to near zero after 80 h of exposure at all temperatures. No relationship between total silica content of the specimen and weight loss could be established nor did scanning electron microscopic examination of the specimens before and after exposure identify specific regions (e.g., surface) suffering a disproportionate share of the silica loss. It was concluded that minor silica volatilization is likely to occur, if at all, at temperatures of less than 1,000° C and pressures below 1,000 psig, and that low-alumina refractories should be used as dry-ash coal gasifier hot face linings.

Jan 1, 1986

By C. P. Lazzara, Y. Miron, A. C. Smith

This report presents a U.S. Bureau of Mines study to identify the causes of self-heating events beneath the floor of a deep underground coal mine. Mine samples from both heated and unheated areas were examined by various techniques, including visual, microscopic, thermal, chemical, and instrumental tests. The combined results led to the conclusion that pyrite (FeS2) oxidation was the prime cause of the beatings. However, adiabatic oven tests of selected samples did not indicate the effect of the pyrite on the self-heating process, probably because of the experimental conditions. A fast, simple procedure to assess the concentration of pyrite in the mine samples was developed, utilizing the reactivity of the sample with an aqueous solution of hydrogen peroxide (H2O2)

Jan 1, 1992

By L. C. IlsLey

So many subjects are covered in State mine-safety regulations that any attempt to compare different State laws in their entirety would be futile. On the other hand, if one selects a single phase or branch of safety work, such a comparison may prove profitable. The subject selected for study in this paper is limited to legislation or regulations dealing specifically with safeguarding (electric) motored equipment used in gassy mines. T When one reads glowing accounts of the safety activities being carried on here and there it is easy to believe that everything which is right and proper is being done to safeguard the mine.workers; but, when one takes time to look into the weakness of many State regulations, it is evident that there is still room for improvement. Undoubtedly it would have been much better for the safety of mines if electrical equipment had been introduced into mines 50 years earlier. If electricity had been in general use when the first mine regulations were pre- pared, those formulating the rules would have covered this hazard along with other hazards, but as electricity came in at a later period, safe mine legisla- tion regarding it has been woefully neglected. Today the United States in general is far behind most other coal-producing nations in the provision of adequate safety rules or laws for the installation and maintenance of electrical equipment and wiring. Returning to the subject of our study, approximately 30 of the 48 States mine coal. More than 20 of these States' produce coal in large quantities. How- ever, of the 30 States only four, 3 Pennsylvania, Utah, Washington, and West Virginia, have laws which specially call for the use of explosion-proof types

Jan 1, 1929

By E. G. Valdez

Laboratory research demonstrated that ceramic wall and floor tile can be produced from electric furnace phosphorus slags composed of calcium silicates. Grinding the slag in a pebble mill, followed by magnetic removal of deleterious magnetite, produced a raw material that could be compounded and formed into wall tile by dry pressing, sintering, and glazing. The effects of process variables such as forming pressure and sintering temperature were investigated. Wall tile bodies produced by this method were comparable to commercial tile. The tiles were readily glazed to a smooth shiny finish and met ASTM Specifications C34-62 for structural clay load-bearing tile. The estimated cost of producing wall tile by this method compared favorably with the retail market value for similar wall tile. Addition of borax or other additives to the ground slag followed by dry pressing and firing likewise produced a commercial grade of floor tile.

Jan 1, 1974

By J. W. Holcomb

Many mines are opened into the coal beds by shafts; and, at some of these operations, the same cages or skips that are used for hoisting coal also are used for transporting men into and out of the mines. At some mines, separate man-and-material shafts are maintained, and the cages in these are utilized for transporting men and supplies only. In most instances, these cages are operated either singly or in pairs by a hoisting engine installed in a building near the shaft. Single ropes from the tops of the cages pass over bull wheels on the head frame to either electrically or steam-driven hoisting engines that require engineers to operate them. There are records of several instances where hoisting engineers have become incapacitated suddenly while hoisting men, and the passengers on the cages were killed or injured. Where the same cages are used for hoisting cars of coal and for lowering and hoisting men, especially where self-dumping cages or skips are used, safety pre¬cautions must be taken, such as providing steel bonnets for the cage deck, enclosed sides, adequate handholds, gates for closing the end openings, safety catches, and locking devices to prevent accidental dumping. Some of the newer hoisting installations are of the elevator type; where an operator rides in the cage in the same manner as an elevator operator in a building. These cages have single or multiple decks and are primarily for transporting men; but, in some instances, supplies also are transported. They are a great improvement over the installations where the same cages are used for hoisting cars of coal and transporting men.

Jan 1, 1952

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of El Salvador has been prepared from the best available information in Washington , but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State . Under the terms of the Code of Commerce ( arts . 12ff . ) , foreigners living in El Salvador can engage in business on the same terms as nationals . This involves ( = $434.00 ) - except for those with a working capital , of less than a thousand pesos inscription in the merchants ' register , which can be refused only in case of manifest disability of a permanent nature .

Sep 1, 1930

By D. S. Harper, C. O. Carman

A German coal planer was put in operation in the Keystone mine of the Eastern Associated Coal Corp. , Keystone , W. Va . , in August 1960 . At present , the planer is mining in the fourth panel . The blocks of coal mined were 340 by 1,900 feet in panel 1 , 340 by 1,660 feet in panel 2 , 590 by 1,900 feet in panel 3 , and panel 4 , currently being mined , is 590 by 1,900 feet . Almost one- half million tons of coal have been mined from these four panels . An 11 - man crew handles the complete planer operation and produces an average of 500 tons of clean coal per shift . Self - advancing hydraulic props are used to support the roof over the entire face . Roof control and action on all of the panels has been highly satisfactory . During periods of extreme pressure , some additional support is required in the tail entry where evidence of weight from the retreating longwall extends about 200 feet outby the face . The time lost from production by moving equipment between panels has been reduced steadily . The move from panel 3 to panel 4 required 5 days , but it is believed that even that time could be reduced .

Jan 1, 1963

By Scott Turner

We have gathered here in Pittsburgh, at the Nineteenth Annual Safety Congress, in order to advance the cause of safety. Although my personal inter- est in this movement alone would have been sufficient to insure my presence here, specific duties have brought me to this congress in an official capacity. My responsibilities as the head of the United States Bureau of Mines, which makes the promotion of safety in the mining and allied industries one of its major activities, necessitate my attendance. My obligations as president of the Joseph A. Holmes Safety Association, an organization closely allied to the bureau and which has for one of its objects the public recognition and reward of outstanding achievements in safety, require that I be present at this time. This morning, my job is to present the Holmes safety certificate to the Lehigh Portland Cement Co. First I will remind you of the nature of this safety association, named in honor of the first director of the Bureau of Mines. After Mr. Holmes' death, in 1915, a number of influential organizations banded together to commemorate the name of this leader in the conservation of human life. In order that you may appreciate the significance of an award by the Joseph A. Holmes Safety Association, I shall read you the list of 24 national organizations which comprise its membership:

Nov 1, 1930

By P. S. Lewis

Shortage of natural gas is reviving interest in low-Btu fuel gas made by gasifying coal in fixed-bed producers. The Bureau of Mines gasified strongly caking Pittsburgh bed coal over test periods lasting four days in an experimental gas producer located at Morgantown, W. Va, Mechanical stirring throughout the fuel bed was effective for keeping the fuel moving and this stirring made the operation successful; hence, the gas producer was named the stirred-bed producer. Nuclear density gages were applied as control instruments to indicate coal flow and fuel level, and to record the frequency and location of void spaces in the bed, The gas, of nominal 140 to 165 Btu/scf calorific value, could be burned in a boiler for generating steam.

Jan 1, 1972

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

B 2 Program Use Instructions necessary to execute the program, after the card deck has been prepared, are summarized in the following. B 2. 1 Input Data Format Input data is supplied to the program in two ways a. By data cards that are read in after program compilation. b. By data specifications that are included within the program.

Jan 1, 1976

By Raymond W. Hiteshue, Henry H. Ginsberg, Paul S. Lewis

Coal was gasified in the presence of up to 3.57 million roentgens of gamma rays by the Bureau of Mines to determine whether the irradiation increased the gasification rate or yields of methane and hydrogen . High volatile A bituminous coal was gasified with steam at 500 and 1,500 psig and temperatures of 1,400 ° and 1,800 ° F ; five other coals ranging in rank from lignite to anthracite were gasified at 500 psig and 1,800 ° F. The average results of replicate experiments with and without radiation were compared for possible effects of radiation from 40,000 curies of radioactive cobalt . The irradiation had no gross effect on the gasification rate or on the yield and distribution of methane and hydrogen . It was concluded that gammaray irradiation produced no improvement in the technology or economics of coal gasification .

Jan 1, 1964

By Oliver Bowles

Since 1922 when the Bureau of Mines issued a report2 covering the slate industry in detail, changes in technology have taken place which have an important bearing on the industry. The present paper comprises a record of these changes. Though the value of slate, for roofing, structural, blackboard, sanitary, and electrical uses is generally recognized, it has many competitors. To meet this constantly increasing competition producers are promoting economies in manufacture, and improving processes, thereby lessening costs of production, and are placing on the market products of the highest possible quality, thus creating satisfaction and confidence on the part of the user. This endeavor to place the industry on a better basis, both as regards processes and products, is shown in the recent developments in technology which are presented herein. Valuable assistance in obtaining data for this paper was given by W. S. Hays, secretary of the National Slate Association, N. M. Male, president of the National Slate Association, and Robert Notvest, consulting engineer, Cleveland, O.

Jan 1, 1926