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"The major thrust of this research is directed towards a better undstanding of the behavior of airborne dust particles in underground mine airways. Figure 61 shows a schematic of dust flow in mine airway. The work included development of a mathematical model of dust behavior in mine airways, experimental study of the behavior of dust clouds and comparison of computer model output and experimental results. Re-entraiment is a secondary source of dust in mine airways and factors affecting re-entrainment are being identified.Investigations have encompassed both experimental and theoretical research into the behavior of dust in mine airways. Experiments were performed in mine airways under both controlled and normal operating conditions (Figure 62). The controlled experiments included the documentation of the concentration and desposition patterns for two types of dust under three different velocities. Real-time dust concentration data were obtained using real-time aerosol monitors (RAM-1) (Figure 63).On the theoretical front, a convection-diffusion model of the dust flow phenomenon in mine airways was developed considering dominant mechanisms affecting dust transport and deposition in mine airways. Mechanisms modeled include turbulent and gravitational deposition, coagulation, and dispersion. Comparative analyses of results of the controlled experiments with the predictions of the mathematical model were carried out. In addition to the overall validity, the adequacy of the individual components of the model, such as deposition in the total and respirable range, and dispersion were examined in light of the experimental observations."

Nov 1, 1988

By G. K. Derby

The Bureau of Mines studied the problems caused by airborne contaminants from welding exhaust in surface mining operations and investigated equipment designed to reduce existing hazards. Four commercially available welding-fume exhaust units were tested to determine their effectiveness. Results indicated that the four units had the capability of controlling airborne particulate concentrations and bringing them to within allowable exposure limits.

Jan 1, 1981

By R. V. Thurston, Edmund S. Leaver

"During the development of the sulphur dioxide leaching process for the treatment of ""mixed"" copper ores at the Southwest experiment station of the Bureau of Mines*** the pulp from treatment of roasted cupriferous pyrite with sulphur dioxide gases and water showed an unexpected amount of sulphuric acid. After following out several false premises it was found that this was due to iron in the solution, and also that this iron tended to oxidize to the ferric state if the concentration of sulphur dioxide in the roaster gases used did not rise above a certain figure. While the percentage of iron present was email it was enough to cause an entirely different set of conditions from those of the original sulphur dioxide leaching process and to promise a much wider application of the general idea. Sulphurous acid dissolves only certain copper minerals, sulphuric acid solutions certain additional minerals and ferric sulphate solutions certain further additional copper minerals, so this observation was of importance in connection with possibilities in the hydrometallurgy of the so-called ""mixed"" or partly oxidized copper ores.The work has been carried along by a number of experimenters. L. R. Eckman, junior chemist of the Southwest station, contributed largely to the early developments. L. Roberts, W. D. Bonner and C. G. Maier each in turn physical chemists at the Pacific Experiment station, (Berkeley, Calif.) have studied the reactions involved. A complete report of all the work on this process will be prepared later under the direction of O. C. Rolston. The purpose of the present paper is to place a summary of the more practical phases of this seemingly important piece of work before those interested."

Dec 1, 1923

Graduate education is an integral part of the Center's research program. The scope of. work and the duration of each research project is calculated, in part, by taking into consideration the needs of the graduate research program and graduate training. Full development of student involvement, as demonstrated by the research practicum which is offered to qualified senior undergraduates at Penn State University and is designed to acquaint them with research methods and techniques and inform them of the opportunities available in this field. and the fulfillment of graduate program requirements are of the utmost concern. The Pennsylvania State University and West Virginia University have accredited mining engineering curricula and rank among the schools with the largest enrollment in this area in the nation. The number of undergraduate students enrolled in mining engineering at Penn State and West Virginia University account for nearly 20%, of the total undergraduate enrollment in this discipline in schools across the United States. The Pennsylvania State University. West Virginia University, Massachusetts Institute of Technology, University of Minnesota, and Michigan Technological University, have granted a total of thirty-five (35) doctorate and masters degrees which can be directly attributed to research conducted in the Center.' Of these graduates, fifteen(15) have found employment in the mineral sector of the economy, i.e., in private industry, with government agencies, and at various universities, worldwide. In addition, a number of those graduating with masters degrees are currently pursuing a doctorate degree.

Aug 31, 1989

By F. E. Armstrong

The Bureau of Mines has conducted a research program to systematize the art of locating uncharted and lost oil and gas wells that penetrate coal seams; this publication presents a preliminary summary of its findings. Although no method or combination of methods will guarantee finding all uncharted and abandoned wells in a particular area, at least 75 percent of such wells can be located by compiling and applying all available information and using modern metal detectors.

Jan 1, 1973

By E. D. Gardner

The Bureau of nines, in cooperation with the mining companies of the Southwest, is conducting an investigating to ascertain the safest and most economical explosives to use in metal mines, and to ascertain the best methods of blasting under various conditions. A part of this investigation has been a study of drilling and blasting drift rounds in metal mines. This paper covers one phase of work on drift rounds and discusses the methods of loading the individual holes of the rounds. The blasting tests, on which this paper is based, were made at the Copper queen Branch of the Phelps Dodge Corporation at Bisbee, Arizona.

Jan 1, 1927

By William C. Larson

A study was conducted by the Bureau of Mines to provide quarry operators with information regarding (1) the effects of jointing and bedding on rock fragmentation when bench blasting in two small-scale (2.5-ft) limestone benches, and (2) the successful use of inexpensive equipment and field techniques to determine the orientation and spacing of joints and bedding separations within the quarry. Using inexpensive equipment, such as a pocket transit and steel and paper tapes, joint and bedding separations were mapped and their frequencies measured. Results from two small-scale bench blasts in the Stewartville member of the Galena limestone formation showed that when the row of vertical blast-holes was oblique to the vertical joint orientations, the backface expression was outlined by two relatively large triangular protrusions (joint surfaces). In this blast, part of the rock burden was unbroken. When the line of vertical blastholes paralleled a predominant joint set, all of the rock burden was broken and displaced. The thickness of fragments that had been displaced by a blast correlated with the observed bedding thickness in the bench.

Jan 1, 1974

By Ludwig Schmidt

[The use of vapor-tight tanks has proved so effective in reducing the evaporation losses of petroleum that today practically all operators are using this typo of equipment. It has boon shown, however, that vapor-tight tanks should be supplemented with additional measures which will further reduce evaporation. Probably the most effective use of the supplemental measures are found on the small producing leases where the breathing losses from vapor-tight stock tanks materially affect the volume and gravity of the stored oil. The breathing loss from a vapor-tight stock tank that is filled and emptied daily is a negligible quantity. Also, the filling loss, which on the average varies between 0.1 and 0.2 per cent, usually is not of a sufficient quantity to affect materially the value of the crude. However, the combined breathing and filling losses from a vapor-tight tank requiring several days to fill are of sufficient importance to warrant the use of measures in addition to the vapor-tight tanks. The breathing losses are caused by atmospheric variations. Probably the greatest are the changes in atmospheric temperature which cause changes in temperature of the vapors in the tank. During the day, as the temperature increases, the gasoline-saturated vapors in the tank expand and are forced out into the atmosphere. At night the vapors are cooled and contract, drawing into the tank fresh air, which becomes saturated with gasoline vapor and is forced out of the tank during the following day. In Addition to the maximum and minimums temperature variations there are many smaller variations throughout a twenty-four period caused by showers, clouds, winds, and other atmospheric conditions which likewise cause the tank to breathe. The two mist common measures used by lease operators for reducing breathing losses in vapor-tight tanks are, first, operating; lease tanks under pressure, and second, the use of light colored paints anti tank houses. In this report these two methods are discussed together with their adaptability to lease operation. Results of experimental observations are given which show the reduction of evaporation looses where these supplemental measures have been used.]

Jan 1, 1927

By W. J. Pena, C. W. Owings

"Generally, the hazard of cool-dust explosions in tipples and cleaning plants is not given the consideration that is given it underground. This lack of consideration is probably due to failure to appreciate the potential hazard. An explosion in a tipple or cleaning plant is basically little or no different from an explosion underground. If bituminous-coal dust is raised into a cloud in the air and comes in contact with arcs from motor brushes, switches, or open flame, the dust is very likely to ignite, and flame will very probably propagate or extend through it if the quantity of dust per unit of air space is sufficient. The open space in a tipple or cleaning plant may reduce the violence of the explosion, but it is not likely to prevent ignition or propagation of flame.The movement of coal through a tipple or cleaning plant naturally puts into suspension a large amount of dust, which finally settles on exposed surfaces. Any disturbance that will put this dust into suspension in a sense enough cloud can result in the dust being ignited by an arc or open flame if one should be present. An explosion of bituminous-coal dust in a tipple or cleaning plant generally can be prevented either by keeping it thoroughly clean or by removing all sources of ignition, or both.The tests at the U.S. Bureau of Mines Experimental mine have shown that the explosibility of coal dust is proportional (other things being equal) to the ratio of the volatile matter to the volatile matter plus the fixed carbon, indicated thus:The volatile ratio for the Pittsburgh coal bed is calculated as follows:Therefore, as the volatile matter decreases the liklihood of ignition decreases; however, coal-dust explosibility depends on other factors also, such as fineness, dryness, and cloud density; and under some conditions other factors also intervene.Proof of the explosibility of coal dust in the absence of explosive gas has been shown in numerous cases in mines and mine plants and also by a series of tests. In these tests a dense cloud of dust is blown onto an open flame or an electric arc, almost invariably with resultant exploding of the dust. The Safety Division of the United States Bureau of Mines has made a number of demonstrations of the explosibility of Pittsburgh coal-bed dust, using a small gallery or box in which a cloud of coal dust is blown onto a lighted match; larger-scale tests have been made with an electric arc as the igniting agent. Bituminous-coal dust is readily ignited with a medium arc, but with low-volatile coals a larger arc is required. For test purposes, a 100-ampere arc has been used. Ignition has occurred readily under these conditions with Pocahontas No. 5 coal dust with ratios of volatile to total combustible of 0.232 to 0.253, and with Pocahontas No. 3 coal dust with a combustible ratio of 0.242. Lower Kittanning coal dust, with a ratio of 0.187, did not give definite ignitions, and Pocahontas No. 4 dust did not explode, although part of the coal-dust cloud ignited. It is probable that even the low-volatile coal dust will be found to be explosive with a higher-amperage electric arc as the initiating agent."

Jul 1, 1936

Preventive maintenance practices are listed in the manufacturers' instruction books. In general, equipment that requires frequent and extensive preventive maintenance is generally the most costly. The manpower spent on these frequent trips to remote areas is such that it is usually better to invest in a more costly system which requires little preventive maintenance. The best preventive maintenance for the system is a good installation. 7.2 Preventive Maintenance and Inspections With any system, periodic inspection is required because of the corrosive atmosphere and adverse conditions that exist in underground mines. These inspections can spot potential trouble in the system. Repair or replacement at that time averts the possibility of losing effectiveness of all or part of the system. 7.2.1 Cables Approximately once per month all cables in the communications system should be inspected for kinking, chafing, cracking, wear, stretching, or other signs of physical abuse. Particular attention should be paid to cable glands at the entry or exit points to the various units in the system, where the cable goes around sharp corners, in the vicinity of holding cleats which may be clamping the cable too tightly causing potential damage, and across the areas where the cable is exposed to physical damage from outside sources, such as equipment or falling objects. If a cable is damaged, it should be replaced as soon as possible. It is mandatory that the ground leads and connections to carrier current phones be thoroughly inspected and maintained in good condition, since considerable hazard may exist to the operator or equipment if a ground connection is broken. 7.2.2 Pager Phones The most readily available test set to determine if a pager telephone is operating correctly is the pager phone itself. The following physical check of the system can be performed at any phone station. 7.2.2a Listen Circuit Remove the handset from its cradle and listen to determine if the circuit is functional, as indicated by the presence of noise or conversation on the line. If no noise or voice signals are present at the handset receiver, take the following corrective action: 1. Operate the handset press-to-talk switch several times. Any corrosion on the contacts of this switch may cause a receiver to be temporarily inoperative. Repeated operation may clear the condition. 2. Open the cabinet and see if the battery cables are properly connected and are making firm contact. Check the handset cable and its connections in the cabinet of the pager phone, and see if there is any evidence of a break in the cable, corroded contacts, or poor connections. 3. Remove the handset receiver earpiece by unscrewing it counterclockwise (to the left), and remove the receiver from the socket. Examine the handset cavity; in some units, a patch of cotton batting or floss is used as a barrier to reduce acoustic feedback in the handset. If the cotton patch has absorbed moisture, remove it and replace with a crumpled ball of soft rubber, stuffed just far enough into the handset so it will not touch the receiver or switch terminals. 7.2.2b Page Circuit and Talk Circuit Push the page switch, squeeze the handset press-to-talk switch, and call any other phone. Release the page switch

Jan 1, 1984

By Ben E. Argyle

"The tungsten area in southern Mecklenburg County, Virginia, was studied by the Bureau of Mines during the period August 1944 to March 1945. The explorations were an expansion of the work done by the Bureau in 1943 in the tungsten area of Vance County, North Carolina, which joins Mecklenburg County on the south.3/Outcrops of quartz veins in the area were searched for and examined, and the only Promising showing found (a vein on the Gladys N. Taylor tract) was explored by trenching, test pitting, and diamond drilling (fig. 1).Mecklenburg County, Virginia, is in the southeastern part of the State, bordering on North Carolina,U. S. Highways 1, 15, and 58 traverse the County, and State and County roads provide ready access to most parts of the area.In 1942, Joseph and Richard Hamme discovered tungsten-bearing quartz veins in Vance County, Forth Carolina, and started mining and milling the ore. The first concentrates were shipped in July 1943. In August 1943, the Hamme holdings were acquired by Haile Mines, Inc., who continued the mining operations.The Bureau of Mines began exploratory work in North Carolina in June 1943. Reconnaissance work showed that the mineralized belt extends north-ward into Virginia. The Kimball tract, which joins the Taylor property on the north, was explored in 1943 by trenching and drilling by the R. G. Lassiter interests of Raleigh, Y. C., with disappointing results.The topography of the district is mature and characterized by wide, shallow valleys and low, rounded ridges. The main ridges trend northeast. Most of the area ranges from 300 feet to 400 feet above sea level.The relief apparently is controlled by resistant quartz lenses and the associated hard, silicified zones. The enclosing schists and granites are usually deeply weathered. Consequently, most of the quartz veins are found on the ridges."

Apr 1, 1946

By R. R. Sayers

Carbon monoxide poisoning is one of the most widely distributed and most frequent causes of industrial accidents . Carbon monoxide gas is a product of incomplete combustion , and since it is without color , odor , or taste , its presence is frequently unsuspected in many places where it exists . It is an ever present danger about blast and coke furnaces , smelters , and foundries . It may be found in buildings having a leaky furnace or chimney , and in buildings where a gas stove is used without a proper flue connection , such as is often found in tenements , tailor shops , and boarding houses . Hospitals receive annually a great number of victims of poisoning , either by accident or in an attempt at suicide , from artificial illuminating gas . People may be affected by leaks wherever water gas is formed or used . The exhaust gases from gasoline motors under average running conditions usually contain 5 to 7 per cent carbon monoxide , and sometimes as much as 13 per cent ; deaths from running an automobile engine in a closed garage are not infrequent . A similar danger may arise in operating gasoline engines in launches without sufficient ventilation . The gas is formed also in stoker rooms , in gun turrets on battleships , in petroleum refineries , and by the Lablanc soda process in cement and brick plants . In underground mines carbon monoxide may appear as the result of shot firing , mine explosions , or mine fires , and in tunnels where automobiles , coal or oil - burning locomotives are operated . In spite of the common occurrence of carbon monoxide poisoning there appears to be no uniformly recognized treatment for a person overcome by carbon monoxide . In the rescue work of the United States Bureau of Mines , however , a method has been developed which has been supported by laboratory investigation , and has proved successful in practical experience , over a period of years . As outlined in this article , the method is useful in the hands of first -aid men as well as physicians .

Dec 1, 1921

By F. D. Osgood, A. C. Fieldner, W. A. Selvig

In connection with investigations being conducted by the Bureau of Mines regarding pulmonary disease which is prevalent among metal miners in certain districts , a large number of rock- dust samples have been collected , and have been examined in the Bureau's laboratories . The earlier work has been described in Bureau of Mines Technical Paper 105 , " Pulmonary disease among miners in the Joplin district , Missouri , and its relation to rock dust in mines " by A. J. Lanza and Edwin Higgins , 1915 , and in Bureau of Mines Bulletin 132 , " Siliceous dust in relation to pulmonary disease among miners in the Joplin district , Missouri , " by Edwin Higgins , A.J. Lanza , F.B.Laney , and Geo . S. Rice , 1919. The methods of collecting and examining dust samples have been greatly improved during the investigation , much valuable information having been made available by similar investigations conducted by the Miners ! Phthisis Prevention Committee , Union of South Africa . The latter are described in the " General report of the Miners ' Phthisis Prevention Committee , Johannesburg, Union of South Africa , 1916 " , and " Final report of the Miners ' Phthisis Prevention Committee , Johannesburg, Union of South Africa , 1919. " The investigations by the Bureau of Mines and the South African committee show that by prolonged inhalation of air containing minute particles of sharp and insoluble rock dust , the lungs retain sufficient dust particles to cause decided injury to the lung tissue , the injured lung becoming very susceptible to the development of tuberculosis .

May 1, 1920

By Paul W. Jeran

Subsidence was monitored by the U.S. Bureau of Mines over the ends of longwall panels operating in the Pittsburgh, Kittanning, and No. 2 Gas Coalbeds of the northern Appalachian Coal Basin. The final subsidence over the finishing ends of three panels in the Pittsburgh Coalbed are compared with the subsidence measured over the rib at these panels. The characteristics of subsidence are different. At Mine A, data over the start of a longwall panel shows similar characteristics to the subsidence measured over the rib. Subsidence over the fmishing ends of panels in the Kittanning and No.2 Gas Coalbeds are also different from the subsidence over the rib. The use of a subsidence prediction model based on data gathered over the rib of a panel will not yield accurate results if it is applied to the finishing end of a longwall panel. Acceptable results may be obtained along the centerline over the starting end of a panel.

Jan 1, 1991

By John M. Gomes

In the repetitive electrowinning of tungsten from scheelite, the calcium impurity buildup in the molten electrolyte results in decreased metal purity, metal recovery, and current efficiency. Periodic addition of B2O3, which reacts with the lime liberated from the scheelite, more than tripled the life of the electrolyte in winning 99.9-percent-pure tungsten and also reduced the number of units of electrolyte required per unit of tungsten recovered from six to four.

Jan 1, 1966

By D. H. Baker

These investigations were conducted to determine the feasibility of molten salt electrorefining of zirconium scrap, offgrade sponge, and alloys under contract number AT(11-1)-475 between the Atomic Energy Commission and the Federal Bureau of Mines. Offgrade zirconium sponge having a Brinell hardness of 169 can be refined by this technique to produce metal having, consistently, a Brinell hardness of less than 90. Also, zirconium alloy scrap, approximating zircaloy-2 in composition, can be refined to recover zirconium metal with a Brinell hardness of less than 100 that is essentially free of the major alloying elements. Analysis showed that the quantities of these elements were decreased as follows: iron from 0.27 to 0.002, tin from 1.36 to 0.001, nickel from 0.02 to 0.001, and chromium from 0.12 to 0.002 percent.

Jan 1, 1961

By J. Whyatt

A variety of dynamic failure cases with regional impact were described at a bump symposium held in 1958. These types of events, while rare, are of particular interest because their ability to impact a large area has disaster potential. These cases can be grouped into two broad classes of events by mechanism. These are (1) slip along steeply dipping faults and (2) fracturing of strong strata above, or below, the coal seam. Both failure modes produce dynamic or ?shock? loads on the perimeter (roof, rib, floor) of mine openings. Special consideration should be given to these failure modes in planning of deep coal mines since their occurrence is not within the professional experience of many contemporary workers, and their potential is not evaluated by many of the analysis tools commonly used to evaluate hazards in coal mine plans.

Jan 1, 2009

By D. W. Frommer

Laboratory mineral-dressing investigations were conducted on talc-bearing samples from Arkansas and Texas under the Bureau of Mines program of examinations and surveys, which is concerned, in part, with the improvement of conservation and utilization of domestic mineral resources. Two of the soapstones in question were successfully upgraded by flotation, utilizing stage additions of a frother and an amine to promote their talc content. The process could enable the producers to meet more rigid specifications of higher priced talc commodities. INTRODUCTION Talc is an industrial mineral with distinctive properties, such as softness, smoothness, large surface area in relation to mass, chemical inertness, and good retention as a filler, that make it particularly valuable to a number of industries. Sales to 6 industries -ceramics, paint, insecticide, rubber, roofing, and paper -consumed 84 percent of the domestic production of talc, pyrophyllite, and ground soapstone in 1952. Mine production in that year totaled 600,908 tons. Sales of crude and ground material were 593,147 tons valued at $11,347,317.2/

Jan 1, 1956

By Oliver W. Keener

The operation described herein differs from the usual practice in the Tri-State district in two important respects: (1) the ore is loaded into cars which are tramped to the shaft and hoisted on self-dumping cages, and (2) about 30 per cent of the ore is loaded by power shovels. The four-month period covered by the cost data appended at the end of the paper immediately followed a period of about one year during which the mine was shut down, and the expense incident to the resumption of operations is reflected in the costs. The author acknowledges the assistance of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the preparation of this paper and the compilation of the data.

Jan 1, 1929

By Frank E. Cash

The iron-ore ranges in the Lake Superior district are the liarquette in Michigan, Menominee and Gogebic in Michigan end Wisconsin, and the Vermilion, Mesabi, and Cuvuna in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. Accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year but closely approximate each other over a period of years. During the 4-year period 1940 to 1943, inclusive, 323,667,599 long tons of iron ore was shipped from the Lake Superior district.4/ Michigan and Wisconsin shipped 65,386,608 tons, or 20.2 percent of the total, and employed approximately 15,000 men; Minnesota shipped 258,280,991 tons, or 79.8 percent of the total, and employed approximately 10,000 men. The tons produced per man employed is much, greater in Minnesota than in Michigan and Wisconsin owing to the large open-cut production in Minnesota.

Jan 1, 1945