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By F. G. Schwartz

This circular presents the results of a survey of research on jet fuel thermal stability jointly sponsored by the National Petroleum Refiners Association (NPRA), Tulsa, Okla., and the Bureau of Mines. The development of supersonic planes has led to many problems that did not exist in the operation of subsonic aircraft. One of the most important of these is rapid deterioration of the fuel at the high temperatures to which it is subjected. At higher speeds, aerodynamic heating of the airframe imposes severe thermal problems, and conventional techniques of rejecting the heat to the atmosphere become impractical. The fuel is the only material present in sufficient bulk to be used as a heat sink. Thus, the fuel is subjected to aerodynamic heating and also is used to dissipate heat from lubricating oil, hydraulic fluid, electronic equipment, wheel wells, and cabin air. Consequently, the fuels may have to withstand both moderate temperatures for sustained periods in the fuel tanks and higher temperatures for brief periods during transfer from the tanks to the combustion chamber. Because of high temperatures, insoluble residue or gum may form in the fuel and contribute to heat exchanger fouling and to clogging of the fuel manifolds, nozzles, control systems, and other components of the fuel system.

Jan 1, 1962

By Paul M. Tyler

Graphite is an essential war mineral and for that reason has received much attention from the standpoint of national defense. During the World War the situation with respect to graphite supplies, though it never became acute, caused considerable concern. Even in peace time, however, graphite has aroused more interest than the actual size of the industry seems to warrant. Despite this wide interest the facts of the industry do not seem to be generally known. Often there has been an almost total disregard of the essential' economic and technical problems involved. Long ago Bastin3 made the following statement; in a Government' report: "To-day there are more abandoned mines and mills in the United States than the number in operation * * *. In the number of times' some of these properties have changed hands in the course of a few years, there is a record of misrepresentation and disappointment that can hardly be equaled in any other branch of mining; and many properties have been notoriously associated with stock manipulation of doubtful character." According to one authority fully 600 graphite mines have failed in the United States, and the record shows that of all these properties scarcely a score have ever succeeded in operating for as much as a year or two. More than 40 mines have been worked at various times in the State of New York alone and at least that many in Alabama. Throughout the country, in fact, there are scarcely a dozen States in which efforts have not been made at some time to exploit graphite deposits. At the present time the list of mines that can be classed as at all active is reduced to less than ten. Failures inevitably occur in all lands of mining, but the disheartening feature of the record of graphite mining in this country is that so few ventures have even paid back the money put into them and. that none has been a conspicuous success.

Jan 1, 1929

By Rustu S. Kalyoncu

A major goal of the Bureau of Mines is to conserve the Nation's mineral resources by developing improved performance materials. In support of this mission, a survey of the state of the art of chemically bonded refractories has been made, covering the scientific literature, government reports, and patents. This review includes research and development results for phosphate, silicate, oxychloride, oxysulfate, and other bonding agents used in refractories manufacture. A significant finding of the review was that references on bonding mechanisms, bond formation kinetics, and other important process parameters and conditions were few and universally vague. As a result, recommendations are made to expand research efforts to investigate the kinetics and mechanisms of reactions in chemically bonded refractories.

Jan 1, 1982

By Lloyd A. Morley

A concept is presented to improve underground coal mine electrical system safety and availability. This proposed technique is based upon the ability to predict incipient failures in the mine power system. Prediction is made possible by a new method, developed during this research, which uses a minicomputer to implement pattern recognition algorithms. The theoretical basis of the prediction system is discussed, along with synthesis of the hardware and software sections. The deterioration modes which could be detected are examined, and an evaluation of the system's ability to predict incipient failure is presented. Typical results of the system's performance during laboratory simulation of power system deterioration are given.

Jan 1, 1977

By Alice V. Peter

The rare-earth group are among the least familiar of the 92 known elements. Moreover, the relatively few people who have even heard of the rare earths ordinarily regard them merely as very rare elements having unusual names but doubtful commercial application. This typical attitude can be attributed partly to the fact that no commercial uses have been developed for most of the members of the group and partly to the fact that those which do enter into useful articles do so anonymously. Most people speak with a degree of familiarity of the "chromium" plating on their automobiles or household appliances; "antimony" ash trays and cigarette boxes are on sale in many department stores; and "tungsten" lamps and even "molybdenum" steels are advertised in popular magazines. However, the average user of a pocket cigarette lighter is not conscious that the important sparking element is a "flint" made from ferrocerium, and if he does chap on to inquire about the composition he is likely to be told that it is "sparking alloy", "misch metal", or 'pyrophoric alloy." Similarly, the wearer of spectacles made of "Crookes" or other tinted glass probably is not aware that the light softening effects are due to the presence of rare-earth oxides, or that the arc light on his street may owe its brilliance to cerium fluoride in the carbon electrode. Despite a variety of practical applications, however, most of the rare-earth metals still must be listed as scientific curiosities. In fact, little is known as to the properties which may make them useful products at some future date. Meanwhile it is important to note that Nature has been relatively generous in her distribution of the rare earths and that adequate supplies of most of them will be forthcoming when these elements have proved their worth as commercial products.

Jan 1, 1935

By R. D. Groves

Laboratory research has demonstrated that high - grade copper powders can be produced under controlled conditions from cement copper products . The technique should enable small producers to prepare a directly marketable product by means other than smelting and electrolytic purification . A continuous drum- type precipitator was the preferred unit for producing fine - sized particles of cement copper that were further processed by chemical digestion in a copper sulfate solution , by reduction and sintering in a hydrogen atmosphere , and by grinding to a powder . The effects of variables related to all stages of the process were investigated . Treatment of leach solutions from three different sources resulted in copper powders containing 99.2 to 99.8 pct Cu , apparent densities of 1.97 to 2.25 grams per cu cm , good powder flow rates , and a size distribution of 54.9 to 60.1 pct minus 325 - mesh material .

Jan 1, 1964

By John M. Devine

Hydrogen sulphide associated with natural gas was noted as early as 1892, at Point Albino, Canada.4 The presence of this impurity was recognized also in other of the earlier oil and gas fields, although the occurrence urea by no means common. However, in recent years, with the development of the producing zones of west Texas and the Texas Panhandle, the production of "sour" crude has increased greatly and hydrogen sulphide has proved a generally troublesome factor--frequently a major problem--in the drilling and operation of many wells in those areas. The problems arising from the drilling and producing of oil or gas wells in hydrogen-sulphide areas, fall under two general divisions: safety problems and corrosion problems. Mention is mane of a third division which is closely related to the other two, that of treating--or the development of processes for the removal of hydrogen sulphide. From the standpoint of safety end health hazards, hydrogen sulphide in the petroleum industry has been discussed in a number of publications. 5 Likewise, the problem of hydrogen-sulphide

Jan 1, 1931

The XVIth International Conference on Coal Mine Safety Research was divided into eight half-day technical sessions. In accord with the established practice of these conferences, at each session, presentation of the papers was followed by a discussion period. Questions and comments submitted in writing to the session chairman were answered or discussed by the authors of the relevant papers or by their representatives. These discussions were tape-recorded in the original language of the speaker and subsequently translated into English when necessary. Questions to which no answer was available at the time and a few comments that exceeded the scope of the session have been omitted.

Jan 1, 1975

By James Paone

This report shows the feasibility of predicting drillability, analytically, by using regression analysis techniques. The approach is new in diamond-drilling research. Further, the study shows that this technique may be of value to drill manufacturers and others in mathematically delineating performance characteristics of new drills in specific rock types. Another application might be the prediction of penetration speeds in extraterrestrial material based on the physical properties of the materials as samples become available. Prediction equations for penetration rates are presented for 9 rocks drilled in the laboratory and for 20 rocks drilled under field conditions. The prediction equations are based on drill operating parameters and on characteristics of the rock penetrated. No single physical property appeared consistently in the best predictor equations, and all the physical properties were found to be highly correlated with each other.

Jan 1, 1966

By Nan C. Jensen, Oliver Bowles

"INTRODUCTION Limestone (which consists essentially of calcium carbonate) and dolomite (calcium magnesium carbonate) occur widely in the United States. Their presence is of vast economic importance, because they are used much more extensively than any other form of rock. In 1945, limestone (which, broadly, includes dolomite) was quarried in every State except Delaware, New Hampshire, North Dakota, and Rhode Island, and also in Hawaii and Puerto Rico. Total production (including that used in cement and lime manufacture) exceeded 151,700,000 tons, or 79 percent of the quantity of all kinds of stone sold or used during that year.Important well-known uses of limestone are as concrete aggregate, road material, railroad ballast, for liming the land, for cement manufacture, as riprap for shore protection, harbor work, and spillways at dams, and as building stone.. None of these uses, however, are considered herein. The purpose of this paper is to discuss the industrial and chemical uses that are less widely known and yet are of tremendous importance in a great variety of processing industries. Important examples are dolomite as a refractory furnace lining and limestone as a fluxing agent in blast furnaces, and as a raw material employed in sugar, paper, glass, and alkali manufacture.PRIOR REPORTIn May 1941, the Bureau issued a report 4/ that described these uses in some detail. As new and important developments have taken place during the ensuing years, a revision and representation of the salient features of these uses seem desirable. Asphalt filler and mineral wool uses included in the earlier report are omitted from this paper because they are identified more closely with the highway and building industries, respectively, than with the industrial applications."

May 1, 1947

By Francis X. Cannaday

The purpose of this investigation was to find whether the moduli of elasticity obtained were the same for the following methods : ( 1 ) Deformation of a borehole in a prism subjected to uniaxial stress ; ( 2 ) deflection of a thin beam of uniform cross section uniformly loaded ; ( 3 ) sonic - pulse velocity measurements , and ( 4 ) strain measurements on a prism under uniaxial stress . The rock tested was chosen for its good elastic behavior and relatively good homogeneity and elastic isotropism . The same rock was used for all methods . Results indicate that for given environmental and stress conditions the moduli obtained by each of the four methods check one another within the limits of experimental error and that the differences introduced which are characteristic for each method are smaller than physical variations within the rock tested .

Jan 1, 1964

By A. E. Sands

This report deals with a portion of the research and development work in the field of synthesis gas purification, carried out by the Bureau of Mines at its Morgantown, W, Va., Station in cooperation with West Virginia University. The Bureau's work in connection with gas purification has been performed with the objective of finding effective, low-cost, processes for removing impurities from synthesis gas to protect the catalyst used in the Fischer-Tropsch process for production of liquid fuels. Synthesis gas used for the production of other chemicals, such as ammonia, alcohols, and methane, requires equally rigorous purification. Although present-day practice in the manufactured-gas industry does not require such a high degree of purification, there is increasing interest in the complete removal of sulfur compounds from city gas. Although the gas-purification work at Morgantown deals with several impurities, major effort has been devoted to organic sulfur compounds in gas; this paper represents a progress report on some of the more important studies in connection with those compounds. Because this is a progress report on the Bureau's experimental work, no attempt has been made to cover the work of others on the subject; references to the literature have been restricted to those bearing directly on the work described.

Jan 1, 1950

By Sara Jane Boles

The purpose of this Bureau of Mines investigation was primarily to isolate and examine the effect of liquid content upon the apparent porosity and bulk density of compacts pressed from high-purity, fused aluminum oxide, and, secondarily, to study the actual mechanism by which the liquid content affects the bulk density. No attempt was made to approach the theoretical maximum density of the oxide by introducing additives, particle packings, or similar variables; instead this study is an intercomparison of the bulk densities obtained as functions of the water contents of the compacting mixtures. Water content was varied from 7 percent to 25 percent, on a total-weight basis. The data gathered indicated a well-defined optimum water content for obtaining minimum apparent porosity and maximum bulk density, under the conditions of the experiment. During the course of this study, a number of additional variables in the forming process were discovered and are introduced in this report, although a thorough evaluation was found to be beyond the scope of this present investigation.

Jan 1, 1963

By H. A. Dierks

The work and costs involved in controlling three large fires in abandoned mines in the anthracite region of Pennsylvania are presented in detail. The work was done under authority of Public Law 89-4. Three basic control techniques were successfully employed by the Bureau of Mines: (1) forming underground fire-containing barriers by systematically flushing incombustible material into mine voids, (2) excavating an isolation trench around the fire area, and (3) complete excavation of hot and burning material in the fire area. When methods 2 and 3 were used, the excavations were subsequently back- filled with incombustible material. Preliminary location of fire perimeters by the standard use of patterned 6- and 8-inch-diameter boreholes is discussed. Investigations into air-borne infrared scanning, shallow subsurface thermal anomalies, and the use of helium to trace the movement of mine air currents are covered. Although they are costly and time consuming, boreholes have proven to be the most efficient means to date of obtaining necessary subsurface fire data. Infrared scanning was ineffective in delineating fires under more than 30 feet of cover. Helium-tracing was shown to have a good potential for determining possible hazards to adjacent residential areas from traveling mine fire gases.

Jan 1, 1971

By Lloyd Williams

1. This investigation shows that the Sewanee bed is the only coal bed being mined in Sequatchie County. Other coal beds are present, but as they do not contain known recoverable reserves, estimates of reserves were made only for the Sewanee bed. 2. Known measured and indicated reserves in the Sewanee bed, based on a minimum thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 76 million short tons as of January 1, 1953. Of this total 62 million short tons represent coal 28 inches and more thick. Areas in the bed were omitted from the estimate because available data relative to the bed characteristics were insufficient to permit making an estimate conforming with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves determined by this investigation.

Jan 1, 1955

By R. G. Nelson

The mechanical properties of low-hafnium, arc-melted, Kroll-process zirconium are presented. The effect of temperature on the ultimate strength, yield strength, proportional limit, elongation, hardness, Young's modulus, electrical resistivity, and impact strength are shown, The effects of cold work and annealing on the tensile properties, bend radius, and formability, as determined by cupping tests, are also given, Tensile properties are compared, in part, to those obtained on earlier graphite-melted zirconium and on crystal-bar zirconium. INTRODUCTION The commercial production of high-purity, low-hafnium bearing zirconium has been achieved, and this metal is becoming available for industrial use. However, there is little published information regarding the physical and mechanical properties of this product; and, since there have been many improvements in the production and arc-melting techniques of zirconium in the past 3 years, it was considered advisable to present the properties of the vastly improved zirconium representative of current production.

Jan 1, 1954

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

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

Jan 1, 1911

By R. G. Knickerbocker, C. T. Baroch, A. W. HACKWOOD

The difficulties inherent in the production of alumina by the formation of potassium alum and its subsequent thermal dehydration and decomposition have been overcome , to a large extent , in a process developed at the Boulder City Station of the Bureau of Mines . This process is applicable to the reserves of alunite known to occur in several Western States and , possibly , to certain clay and low-grade bauxite deposits known to exist in this country . The operations sequence of the process is shown in the flow sheet (fig . 1) . Only those steps included within the heavy line are considered in this report . Four different procedures for dehydration of alum were investigated ; ( 1 ) Spray drying , ( 2 ) rotary - kiln drying , ( 3 ) dry grinding in a thermal ball mill , and ( 4 ) dehydration in the vertical- column flash dehydrator . Based upon fuel requirements and other practical considerations , the vertical- column dehydrator , or some modification of its operating principle , offers the botter possibility for commercial use .

Feb 1, 1946

By John D. Bardill

This report covers the magnetic surveying done in the Plattsburg area , which was part of a general survey, of magnetite deposits in New York State . Other areas being surveyed are the Star Lake district , St. Lawrence County ; Brewster district , Putnam County; and the Sterling district , Orange County. Reconnaissance indicated an area about 3 miles long and 1,200 feet wide , but detailed surveys have been completed on only a portion of that area . In several districts , surveys of this type have served as a basis in the selection of areas for exploration by diamond drilling by the Bureau of Mines .

Jan 1, 1947

By Walter Kawa

Coals of various rank were reacted by the Bureau of Nines in plasma jets generated from argon and argon-hydrogen mixtures containing up to 33 volume-percent hydrogen. Average plasma temperatures ranged from about 3,400° to 12,000° C. Products were a solid residue and a gas containing hydrogen, methane, acetylene, diacetylene, and oxides of carbon. The highest yield of acetylene obtained with argon plasmas was 15 percent by weight of moisture- and ash-free coal. The data indicated that acetylene yields of 40 percent or higher can be obtained from the reaction of coal in argon-hydrogen plasmas, although results from these experiments could not be correlated with operating variables because of low recoveries plasma contained sufficient energy to heat the coal to temperatures as high 9,000 or 10,000° C, but complete devolatilization did not occur in any experiment.

Jan 1, 1966