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By C. R. Hopkins

"The petroleum refiners of the United States made rapid strides in fuel economy in 1928, when the calculated number of B. t. u. required to refine a barrel of crude petroleum was 637,000 as compared with 698,000 in 1927, a decline of 9 per cent. The major portion of this indicated increase in fuel efficiency was undoubtedly due to the gain in use of the pipe-still and the continuous process of refining as contrasted with the old batch method of distillation.,Almost without exception the new refineries are equipped with one or more pipe-stills, and many of the older plants are changing over to this type of equipment. The refineries of the Appalachian area are among the oldest and most conservative of the country, yet a number of them dismantled their old shell and cheese-box stills and installed pipe-stills in 1928.The more extensive use of the pipe-still was not the only way in which the refiners lowered their fuel requirements in 1928. The use of heat-exchangers, in which the heat from hot vapors to be condensed is used to heat the incoming cold oil, also increased in 1928, and in addition the refiners have kept abreast of the times in saving fuel through better insulation and improved burners.For the year 1928 the refiners burned as fuel the following: 46,400,000 barrels of-fuel oil; 3.362,000 short tons of coal; 114,950,000,000 cubic feet of natural gas; 77,313, 000,000 cubic feet of refinery or still gases; and 470,000 short tons of coke, in addition to a little electricity. This fuel was calculated to have produced a grand total of 582,156 billions of B. t. u., as compared with 578,784 billions B. t. u. in 1927.The total of 46,400,000 barrels of fuel oil burned represents an increase over 1927 of about 5,000,000 barrels, which made it about equal to the 1926 figure. Practically all of the refinery districts used more oil as fuel in 1928. The most important increase - over 2,000,000 barrels - occurred in the East Coast district, where greatly expanded throughput of foreign crude was instrumental in increasing fuel-oil production.The use of coal for fuel at refineries again registered a material decline, the total for 1928 of 3,362,000 short tons being 33 per cent below that of the previous year. The outstanding decrease in the use of coal in 1928 occurred in the East Coast district, where coal was probably replaced by oil. The use of coal for fuel at refineries in the States of Ohio, Pennsylvania, and West Virginia declined materially in 1928; the substitute used in the majority of cases was oil burned in pipe-stills."

Nov 1, 1929

By Russell J. Foster

This Bureau of Mines review focuses on the extent to which technologically and economically feasible programs in substitution, improved processing practices, including recycling, and design can achieve conservation of cobalt, chromium, manganese, and platinum-group metals, and thus reduce U.S. vulnerability to interruptions of supply. In addition, supply-side options--domestic and foreign resources, ocean minerals, and stockpiles--are identified. The report consolidates four major studies on these strategic and critical minerals sponsored entirely or partially by the Bureau in the last few years. These studies have been updated with further information from the recent literature.

Jan 1, 1985

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 Haiti 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 .

Sep 1, 1930

The dust exposure of the longwall shearer operator is usually determined by his position relative to the cutting drums. The dust generated during cutting may travel up-wind, against the primary airflow, and be carried out into the walkway where it can contaminate the intake air for as much as 10 feet outby the shearer operator's controls. Thus, both head and tail drum operators are exposed to un-acceptably high levels of air-borne respirable dust. One Solution The latest generation of long-wall shearers has features that make the use of radio remote or umbilical (hard wire) remote control relatively easy to implement. Remote control can enable shearer operators to control machines from positions that are less dusty than normal control stations. With either type, the head-drum operator can now control the shearer from a position up to 20 feet on the intake-air side of the shearer, while the tail-drum operator's station is now located across from the head drum.

Jan 1, 1984

By G. D. Jermain

Exploration of the Antimony Peak district by the Bureau of Mines was conducted under the authority of the Strategic Minerals Act of 1939. Antimony was one of the seven metals designated at that time as strategic by the Secretaries of War, Navy, and Interior upon advice of the Army and Navy Munitions Board. As a result of many field examinations, the Antimony Peak property was chosen as one of the most attractive for the possible development of emergency antimony reserves. Exploration by the Bureau of Mines began in November 1940 and was concluded in May 1941.

Jan 1, 1949

By D. J. Parker

Since the introduction of electricity into the mines of the United States , the hazards incident to the industry have increased materially in both coal and metal mines . For economic reasons the tendency at present , particularly in coal mining , is decidedly toward the adoption of electrical mine machinery , including alternating current machinery , on a more extensive scale than ever before . Obviously, the growing use of such equipment will result in an ever -increasing number of underground transformer stations . The principal electrical hazards in mines are threefold ; fire , explosion, and contact . Of these , fire is the greatest hazard involved in the use of electricity underground , and several fires have originated in underground transformer and motor generator set stations . The fire hazard due to improperly installed and poorly maintained underground transformer stations is an ever-present one , and failure to take the necessariman remedial action is likely to result , sooner or later, in the destruction of life and property . Upon suggesting the necessary corrective measures with respect to such installations , one is often confronted with the statement to the effect that even though this particular hazard has existed over a period of years , there have been no unfavorable results therefrom thus far . Frequently , the desirability for action is not apparent to the mine management until it is too late . Because a mine has a record free from fires , explosions , etc. , over a number of years of operation during which these hazards existed , such good fortune should not be taken as a guarantee that this or any other mine is immune from these common dangers . When the elements of an existing hazard are properly balanced or in the right proportion, the unfortunate combination must of necessity culminate in misfortune of one kind or another. The fire hazard due to underground transformer installations can be very definitely minimized by proper installation and maintenance . In coal mines the transformer banks , connected to 2,300 and occasionally to 4,400 volt circuits , are often found located in open- ended crosscuts , mounted on concrete or timber foundations , and in nonfireproof surroundings .

Jul 1, 1930

By Wesley A. Grosh

The Sutherland copper prospect is situated in Floyd County, Va. The immediate area was prospected around 1850, and one of the adits possibly dates from that time. Little or no ore has been mined from the deposit. The deposit is a mineralized sulfide zone occurring in mica schist and consisting mostly of pyrrhotite with minor amount of copper. A magnetometer survey of the deposit by the American Metal Co. in 1939 showed an anomaly that was thought to indicate a zone: of secondary enrichment. The Bureau of Mines diamond-drilled 14 holes, totaling 913 feet, and opened an adit during February and March 1943. No appreciable copper values or indications of secondary enrichment were found.

Jan 1, 1948

By E. P. Youngman

The law now in effect (January 30, 1931) in the Netherlands with respect to the prospecting for and the developing of minerals is regulated by , or based upon , the French Act of April 21 , 1810 , "Concernant les mines , les minières et les carrières ( Bulletin des Lois No. 285) . " A second edition of a compilation ( by Drs . Ccuvee and Ritter ) of the mining legislation of Holland , including this act with other legal requirements , was published in 1928 under the title of "De Nederlandsche Mijnwetgeving , " by H. T. Tjeenk Willink & Zoon , Haarlem. In this abstract reference is made to the Act of 1810 , the Royal Decree of September 18, 1818 , the Mining Act of 1903 , and the Act of June 20 , 1924 .

Aug 1, 1931

By Paul T. Allsman

Iron-ore deposits in southwestern Utah, as the major source of iron ore for western steel plants, were investigated by the Bureau of Mines in 1942-45 in cooperation with property owners and operators and with the assistance of the United States Geological Survey with a view to determining and extending the known reserves. The factual data resulting from that project were presented in a previous report and in a report on the geophysical surveys now in course of publication. The present report has been prepared in response to expressed public interest in the ore reserves of Iron County. Mining began in the district in 1871} but. did not become important until 41 1923. From 1923 to 1946, inclusive) production totaled 10,139,500 long tons. In 1945 the district yielded 1,931,749 long tons containing 52.84 percent iron; in 1946 the corresponding figures were 1,317,671 and 53.75. The deposits lie .in a narrow, 23-mile long belt extending northeasterly from Washington 'County into Iron County along a line of mountains, chief of which are Iron Mountain, Granite Mountain, 'and Three Peaks in Iron. County. The deposits are hematite-magnetite bodies, chiefly in limestone near its contact with the monzonite of the mountain masses, but with a few important veinlike bodies in the monzonite or at the contact. They range in size from small pods to several millions of tons, and in depth from surface or near-surface to a known maximum of 1,300 feet:

Jan 1, 1948

By Hylton R. Brown

This publication, an abstract of a progress report covering an investigation of hazards in thermal coal-drying plants has been prepared according to the suggestions and recommendations of a committee6/ appointed by J. J. Forbes, Director of the Bureau of Mines, when the original report was reviewed at a meeting of representatives of the mining industry, operators of coal-drying plants, coal-mine workers, and the Bureau in Washington on May 6, 1955. The investigation on which the report is based was made in accordance with action taken at a previous conference in Washington on May 19, 1954, called by Director Forbes to consider what should be done to prevent explosions and fires in coal-drying plants. Scope of Investigation The investigation was planned to obtain information considered essential for properly appraising fire and explosion hazards in different types of coal driers. A questionnaire sent to Bureau personnel provided preliminary information on coal-drying facilities at more than 270 preparation plants. Information on methods used in operating different types of driers, with their furnaces, fans, cyclones, and other auxiliary equipment, was obtained by personal visits or conferences with the operators at 13 plants. Factual data on operating temperatures, composition of the drying gases, air flow, dust loading of the air or gas currents, use of water sprays, auxiliary air controls, and other factors were obtained by conducting full-scale tests at six different plants and making laboratory investigations with samples of dust and gas collected during the tests.

Jan 1, 1956

By C. E. Augustine, P. Nicholls

"INTRODUCTION A layer of soot on the heating surface of a boiler decreases efficiency because it increases resistance to the flow of heat, with the result that the heat transfer to the water is lower and the temperature of the flue higher than they would be if the surface remained clean. The percentage of reduction in heat transfer depends on the position and area of the sooted. The percentage of reduction in heat transfer depends on the position and area of the sooted surfaces, the thickness of the most, until the percentage of the total heat absorbed by those surfaces when clean; thus it will vary with the type of boiler and in particular with the ratio of the area of the convection heating surface to the total area. Medium-size and large boilers usually are equipped with soot blowers, and tests have been published giving the increase in efficiency resulting from removal of the soot. Fuel savings up to,8 percent have been reported, but 4 to 5 percent is probably more conservatives. However, these savings may not be due wholly to a reduction the thermal resistance of the surfaces but may be due partly to improvement in the combustion because of better draft or more uniform flow of the gases. In addition, the deposits on the surface of boilers include as a clinker, and as the size of the boiler and the rate of burning increase very little or none will be soot.There are no corresponding test data on small boilers operated at low rates of burning. In stall boilers, deposits are much thicker, and it might be expected that the reduction in efficiency would be greater; in fact, statements have appeared suggesting that the decrease may be as high as 50 percent. This investigation was undertaken because the Bureau frequently receives requests for authoritative information on the effect of soot in small and other heating boilers."

Feb 1, 1935

Reduce the hazards to which mine personnel are exposed by providing safer procedures for removing dragline wire rope terminations. Background The termination points of wire ropes used on draglines consist of a wedge and socket that lock the rope in place through friction. These components must be separated when the wire rope is changed. At present, the cannon method is the most common procedure used to accomplish this. However this method, using a small cannon and primer (detonator) cord to propel a steel projectile that will knock the wedge out of the socket, has the potential of causing injuries to mine personnel and damage to equipment. The Bureau of Mines, has devised safer, and equally efficient methods of removing wire rope terminations. The Bureau began by studying the cannon method, its merits and draw-backs. Safety guidelines were then developed for the cannon method, and two alternative methods-the pendulum ram and hydraulic pusher-were devised and tested. The Cannon Method The steel projectile used to separate the wedge and socket in the cannon method was found to be very effective. However, the method poses the inherent hazards of any explosive de-vice-hazards that could be increased by lax work procedures. There is no strict uniformity in the manufacture of the cannon or in the work procedures used in the mines employing it. Hazards could be reduced, or even eliminated, with adaption of certain manufacturing and work-procedure guidelines, such as 1) making the cannon and projectile de-signs, as well the work procedures used, uniform, 2) ensuring separate loading of the charge and detonator with insertion of the detonator through a separate port, 3) connecting electrical firing circuits only after the charge and projectile are loaded and the cannon is placed in its final firing position, 4) using approved detonating devices, 5) anchoring the cannon before firing and, 6) placing armor netting over the cannon before detonation.

Jan 1, 1986

By G. R. Hopkins

"A new record in fuel efficiency at petroleum refineries was achieved in 1935, when an average of only 615,000 B. t. u. was needed to refine a barrel of crude oil, compared with an average of 638,000 B. t. u. in 1934 and 829,000 B. t. u. In 1925. (See fig. 1.)Refiners have made almost uninterrupted progress in firing efficiency during the last decade although much of this gain was brought about by improved technique and greater use of heat exchangers and pipe stills, the determining factor was the trend in crude runs to stills. Most plants can increase their crude throughput materially with but small increase in fuel consumption. Consequently, in years in which crude runs have increased substantially, average requirements have declined; but in years in which crude runs have decreased, the average has tended upward. This conclusion is confirmed by figure 1, which shows that there has been but one minor exception to this rule in the last 10 years.Technical progress in fuel efficiency may be illustrated by comparing crude runs and total B. t, u. consumed. Between 1925 and 1935 crude runs to stills increased 31 percent, but the total quantity of heat required did not increase; in fact, it declined slightly.The trend of modern still construction is from shell stills, in which a large body of oil is heated, to tube stills, in which the heat comes into much closer contact with the oil. In 1935 the total capacity of operating pipe stills increased about 4 percent; this increase, though small, probably was related to the gain in average efficiency.The Increased use of heat exchangers and their role as fuel savers have been discussed in previous reports of this series. It is sufficient to say that refiners with insufficient exchange capacity added as much in 1935 as their budgets would permit."

Jan 1, 1937

By Kevin Connor

The mineral industry in Burundi was a minor contributor to the country's gross domestic product (GDP), which was estimated at just $1 billion for 19812. Coffee and tea continued as the Nation's major export commodities. Mineral exports consisted of small tonnages of wolframite, cassiterite, and baetnasite. Burundi's trade balance of payments situation worsened in 1981, with import payments more than double export revenues. Petroleum imports alone equaled 46% of the export revenue total. By year-end, the only indigenous fossil fuel source to have been found in Burundi was peat, which the Government had been attempting to develop to alleviate some of the petroleum import requirements. In June 1981 the Irish Peat Development Authority, Bord na Mona, signed a 4-year contract with the Burundian Government to supply technical staff for the ongoing peat project work there. Funding for the project was provided by the VS. Agency for International Development and the Government of Ireland. The new contract, which was an extension of ongoing peat research there, represented Burundi's increased awareness of the value of its large peat reserves for both energy and agricultural uses. At yearend, Burundi's Ministry of Public Works and Mines was does to selecting a contractor to study the feasibility of developing Burundi's phosphate deposits. The study would determine the potential for establishing fertilizer production facilities based on the country's phosphate reserves at Matongo-Bandaga, The study's specific objectives are to prove mineral reserve tonnage and grade, draw up mining and processing facility designs, estimate capital and production costs, and conduct a regional market and distribution survey. The cost of the study was estimated at slightly over $1 million, and it should take approximately 16 months to complete. The proposed project will mark the Burundian Government's first step in its plan to exploit on a large scale its natural mineral resources for advancing its agriculture-based economy. Burundi was dependent on imports, which are expensive to transport inland from coastal ports, to supply its domestic requirements for fertilizer. It was planned that part of the fertilizer production from the

Jan 1, 1983

By L. C. IlsLey

Briefly, a permissible schedule of the Bureau of Mines establishes certain minimum standards for safety; it gives details of test methods adopted to determine whether these standards have been met, and a list of charges for such tests. Any manufacturer has the privilege of submitting his product for test in accordance with the conditions outlined in the schedules. His action is wholly voluntary, for the Federal Government has no jurisdiction as to what equipment shall be used in mines, this authority being left to the various States. When the product of a manufacturer has met the schedule requirements, he is permit¬ted to advertise this fact and to attach an approval plate with the bureau's seal to each machine he makes that is identical in every way with the equipment tested, inspected, and approved by the bureau. This work of approval has grown by the addition of new schedules until at present a great many mines are using one or more classes of permissible equipment, and there is still a demand for other approved apparatus in the ever-widening field of electrically operated machinery. The safety of electrical equipment of this type depends on four fundamentals, namely, (1) correct principles of design; (2) proper assembly of parts at the factory; (3) proper assembly and installation of equipment at the mine; (4) and proper operation and maintenance after installation. The first two factors are within the province of the manufacturer. The bureau either inspects and tests several models of one product, such as electric cap lamps, or one model, such as an electric motor. If this series of tests proves satisfactory, the manufacturer is given the privilege of making other appliances, and assembling them in the same way; the approval plate he attaches is his guaranty that the equipment is identical with the one tested and inspected by the bureau. The third and fourth factors concern those who use such permissible equipment, and it is to them that this paper is mainly addressed, in an effort

Jan 1, 1922

By Joseph V. Mather, E. H. McCleary

"INTRODUCTION Workmen are transported in shafts in various types of cages or skips, most of which were designed primarily for hoisting cars and materials. Therefore, in general the cages or skips are not completely enclosed, adequate and gates are not always provided, and at many mines signaling devices and telephones are re¬stricted to those at the various landings in the shafts.Shaft accidents are usually severe - frequently fatal - and as a rule such an accident is caused by failure to comply with company rules or by ignoring them.Sixty men were killed and 555 men were injured in shafts of the anthracite and bituminous coal mines of the United States during the 5-year period 1938-42. 4/ Many of these accidents could have been prevented by having properly enclosed cages and adequate locking devices on doors to prevent workmen from falling into the shafts.The officials of the Heidelberg Coal Co. contemplated utilizing an old coal-hoisting shaft as a man-hoisting shaft; however, it was their desire to avoid the use of the conventional cage and to try to provide a safer means of transporting men in the shaft. Investigations and studies made by the officials revealed that an elevator similar to those used in large buildings would be more economical in first cost, maintenance, and operating costs would be less, and it would be safer and more convenient for the workmen. Effective safety devices for such elevators have been developed to such a high degree that those properly installed seldom fail. The elevator or man cage finally chosen cannot be pulled above the top landing through mechanical or man failure; it stops automatically at each landing and cannot be moved while a door is open; when the cage leaves the landing the doors opening to the shaft are automatically locked by mechanical and electrically operated locks; electric lights, telephone communication, and push-bottom controls are available on the cage, and adequate safety switches and overspeed controls are provided."

Jun 1, 1947

By B. W. Gandrud

[The meaning of the term "bauxite' has always been somewhat vague and indefinite, and the term has been used in various applications to denote sometimes a rock, sometimes a mineral, but more frequently an ore. It seems logical to think of bauxite as an ore, however, because a very large part (probably at least 85 per cent) of the entire world's production of bauxite is at present being used as a source of aluminum and aluminum chemicals. In the United States there are two districts that, produce bauxite - the Arkansas district and the Alabama-Georgia-Tennessee-Mississippi district. The deposits in Mississippi have been discovered recently and are riot as yet productive but it seems reasonable to consider them as apart of the-district hat includes the deposits of Alabama, Georgia, and Tennessee. The, two districts are often referred to as the Arkansas field and the Appalachian field. Of these two the Arkansas field has been by far the largest producer, and at present over 90 per cent of the bauxite production of they United States comes from the Arkansas field. The bauxite industry in the Appalachian field had its beginning in 1889, and since that time the total production of the states of Alabama, Georgia, and Tennessee has been, nearly a million tons. The production of bauxite in this field has languished in the last five, or six, years, and In 1927 its production was only about 14,000 tons, according to Harder4. The recent decrease in production is due mainly to the fact that many .of the known deposits of commercial-grade ore have become exhausted. There are, however, considerable quantities of low-grade bauxite in the Appalachian field, but these have not been available because there has been no satisfactory way of concentrating low-grade bauxite. The quantity, of low-grade material in the Appalachian field is probably, fully as large as the tonnage of commercial ore which the field has already produced.]

Jan 1, 1928

By Lloyd A. Morley, Alan M. Christman

General An important part of any mine power distribution system is its con¬nection to earth or ground. The grounding network serves to protect men and machinery from the hazards associated with electrical equipment which is operating improperly. Since the mine site is determined by the location of the rock or mineral to be extracted, the conditions required for the installation of an adequate grounding system are not always easily met. If annual rainfall is low or soil resistivity is high, an extensive array of buried metallic conductors may be necessary to assure a low-resistance connec¬tion to earth. Measurement of soil parameters can be made before the construction of a grounding grid is begun, and the configuration of a metallic network, which will yield the desired values of earth resistance and potential gradient, thereby ascertained. Proper design at the time the ground bed is installed will save much time and expense in later years. Ground conductors extend from the buried grid to each piece of mo¬bile and portable equipment via overhead lines or multi-conductor cables. In this fashion all machine frames are referenced to the same potential as the grounding medium. Protective circuitry must be installed to monitor\current flow in the ground conductors or the potential drop across the neutral grounding resistor, which is placed between the grounding grid and the neutral point on the distribution transformer secondary. When properly co-ordinated and used in conjunction with a low-resistance

Jan 1, 1976

By N. S. Dalal, V. Castranova, K. Van Dyke, V. Vallyathan

"IntroductionInhalation of crystalline silica is often associated with the development of pulmonary disease (Ziskind et al., 1976). Recently, it has been proposed that freshly sheared silica .may have surface properties that make it more reactive with lung tissue than aged silica, and that this unique reactivity ·of freshly crushed silica enhances its pathogenicity. A recent study in our laboratory strongly supports this theory (Vallyathan, et al., 1988a; 1988b). We found that grinding of silica cleaves bonds in a silica tetrahedral lattice generating reactive free radicals sites on the surface of the silica particles. The presence of surface radicals on freshly ground silica was monitored by electron spin resonance (ESR) spectroscopy. The ESR signal generated from fresh silica in air is characteristic of Si-0 and Si radicals. Evidence, i.e., the ESR signal after the addition of a spin trap (DMPO) and its sensitivity to ethanol, indicates that these silicon-based surface radicals can react with water to form hydroxyl radicals (OH). Results also indicate that these surface radicals make fresh silica more cytotoxic than aged silica; i.e., fresh silica causes more membrane damage as evidenced by hemolysis and lipid peroxidation. Therefore, the presence of reactive sites on the surface of freshly cleaved silica may play a significant role in its pathogenicity.If surface· free radicals are related to cytotoxicity, then screening dusts for the existence of such radicals may predict their relative pathogenicity. Since an ESR spectrometer is not available to many laboratories, the objective of this study was to develop a quick and simple technique to monitor the existence of reactive surface sites on dust. The technique chosen was the measurement of chemiluminescence using a liquid scintillation counter; i.e., an instrument which·would be accessible to most investigators."

Jan 1, 1989

The following additional studies are recommended: 1. Future development of the magnetic sludge process should involve optimization of the process variables; these include stirring rate, sludge heating time, aeration rate, method of preliminary sludge dewatering, and the effects of magnetic separation for final sludge processing. In addition, the matter of amenability of coal mine waters to treatment should be considered more thoroughly by means of a more comprehensive literature review as well as actual tests on mine drainage samples. 2. The technique of sludge freezing should be explored further. Emphasis should be given to conservation of energy in the process, and the filtration characteristics of the resulting sludges should be evaluated. 3. Further studies should be conducted on the feasibility of the CO2-addition approach to mine drainage sludge densification. The filtration characteristics of product sludges should be evaluated, and the possibility of recovering and recycling the residual alkalinity of the sludge, either directly as CaCO3 or as CaO plus CO2 after calcination, should also be explored further. 4. Efforts should be made to develop cost data for the conceptual processes involving magnetic sludge formation, sludge freezing, and C02 pretreatment, with the purpose of selecting at least one of these processes for further testing at a field site. 5. The use of inexpensive waste materials (e.g. fly ash, "red dog," slag) as sludge additives, possibly in conjunction with coagulant aids, should be considered further. Results of the present studies have indicated that such materials, employed in relatively large amounts, increase the density and enhance the filterability of sludges from lime neutralization of coal mine drainage. The use of pulverized blast furnace slag in this regard appears particularly promising, and studies should be made to ascertain its availability, relative cost, residual alkalinity, and behavior as an additive in conventional mine drainage treatment processes involving lime neutralization and aeration.

Jan 1, 1971