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By E. M. SEELEY, F. S. LOTT

The total capacity of the natural-gasoline industry to produce light hydrocarbon products increased to 21,322,000 gallons ( 507,670 barrels ) daily on January 1 , 1948 , from 17,928,000 gallons ( 426,860 barrels ) daily on January 1 , 1946. Expansion of the industry in the first two post -war years , 1946 end 1947 , thus averaged 9 percent annually , compared with 6 percent annually in the last two war years , 1944 and 1945 . The number of cycle plants increased only from 37 to 39 in the years 1946 and 1947 , and total capacity of these plants gained 21 percent to 5,857,000 gallons de ily on January 1 , 1948 , represent ing 27.5 percent of the total capacity of the industry , compared with 27.0 percent on January 1 , 1946. All other plants decreased in number in the two-year period from 589 to 510 on January 1 , 1948 , but their total daily capacity increased 18 percent to 15,465,000 gallons . The daily capacity of the average plant in the industry was enlarged from 28,600 gallons on January 1 , 1946 , to 38,800 gallons on January 1 , 1948 , continuing the long -established trend to producing units of greater size and efficiency . The average cycle plant capacity increased from 131,000 gallons daily to 150,200 gallons daily on the same dates as the average capacity of all other natural -gasoline plants increased from 22,200 gallons to 30,300 gallons . Owing to the elimination of small , obsolescent plants in Illinois , Oklahoma , and Pennsylvania , these States experienced the greatest reductions in numbers of plants in 1946 and 1947. In Oklahoma and Texas , several consolidations of two or more plants into a single operating unit were reported . Louisiana and Mississippi were the only States in which the number of plants increased , but daily capacity to produce light products was larger in eleven States on January 1 , 1948, than two years earlier . Added facilities in California and Texas accounted for 41 and 36 percent , respectively, of the national gain in capacity .

Sep 1, 1948

Exposure to airborne respirable crystalline silica dust can lead to silicosis, a debilitating lung disease. On surface coal mining and construction sites, blast hole drills are notorious sources of airborne respirable dust that may contain significant amounts of silica. The drill operator and drill helper usually receive the greatest silica exposure compared with other occupations. As a result, many drilling operations have been, and still are, on more stringent dust standards. Drilling through various rock formations naturally presents a strong potential for silica dust generation for several reasons. First, drilling is a pulverizing process that generates large amounts of very small dust particles. Second, the bailing air used to flush cuttings from the hole leaves the hole at a very high velocity and can be difficult to contain. Third, many fixed shrouds used to enclose the area beneath the drill deck have a significant amount of leakage due to 1) gaps between the shroud and ground created by raising/leveling the drill, 2) gaps in the corner seams, and 3) tom deck shrouds. CONTROLS A dry dust collection system is typically connected to the drill deck to collect dust as the bailing airflow transports the cuttings (and significant amounts of airborne respirable dust) out of the drill hole. Deck shrouds are installed in an attempt to enclose the volume around the drill steel and prevent dust escaping. However, most deck shrouds are rectangular and constructed of four separate pieces of rubber belting attached to the deck. Because of this design, there is usually a significant amount of dust escaping from the open seams as well as the open area between the shroud and the ground. This dust can be a significant source of silica exposure to drill operators as well as other personnel downwind of the drill.

By H. M. Thorne

Oil shale, a potential source of products presently obtained from petroleum, is found in many countries. The most extensive known deposits from the standpoint of potential shale oil in place are those in Brazil and the United States of America. Mining methods used for oil shale range from open-pit operations for shallow deposits to room-and-pillar and longwall techniques for deposits with thick overburdens. Oil shales from different sources vary greatly in the amounts and types of organic and inorganic constituents. By retorting, the organic material is converted to oil, gas, and coke. The largest percentages of oil are obtained from materials having the highest hydrogen content. Over 2,000 retorting systems have been patented, but only a few have been used industrially, and no single process seems best for all types of shales or economic conditions. Shale oils have different characteristics, depending on the source rock and method of retorting. They contain large quantities of olefinic hydrocarbons and more oxygen, nitrogen, and sulfur derivatives of hydrocarbons than most petroleums. Consequently, petroleum refining methods usually must be modified for shale oil. This is particularly true in catalytic processing. Hydrogenation, even under mild conditions, improves shale-oil refinability. Several byproducts may be obtained from both the retorting and refining steps,

Jan 1, 1964

By Arnold P. Pipilen

In a study of the principal factors affecting the transport of coal-water mixtures through a centrifugal pump and a pipeline, the interrelation between solids concentration, velocity, and pressure drop was established for a bituminous lump coal (minus 2 inch) in concentrations up to 48 weight-percent. An optimum concentration was found to exist for maximum capacity of a given pipe-line, and for minimum energy requirements per ton of coal. Coal size degradation by particle fracture took place in the pump; abrasion and attrition to form fines took place in both pump and line. A novel system of studying flow of solid-liquid mixtures in pipelines by the determination of relative sound intensities was developed.

Jan 1, 1966

By A. W. Fahrenwald

"About two years ago the Bureau of Mines, Department of the Interior, and the University of Idaho undertook an investigation of classification in its relation to table concentration of Idaho ores. The cooperation of the management of the Bunker Hill & Sullivan Co. in placing at our disposal their West Mill and facilities as desired, offered an unusual opportunity for studying the field of hindered classification in its practical and economic relation to table concentration.It has been shorn theoretically, and demonstrated experimentally, that ore products are more easily and economically concentrated on tables if the natural feed, consisting of various minerals and of all sizes of particles of each mineral, be classified or grouped into a series of products in which the mineral particles of greatest density are small in diameter relative to the diameter of the mineral particles of lesser density. Products in which the maximum difference in diameter of light and heavy minerals occurs are to be obtained only by true hindered settling classification. To our knowledge there has never been a really good hindered settling classifier used in practice and the present tendency seems to be to by-pass any attempt at such classification.After a careful study of the nature of hindered classification and of the requirements for hindered settling in practice, a classifier has been developed that takes fullest practical advantage of the widely known, but generally only meagerly understood, condition of hindered settling so well analyzed a number of years ago by Dr. Richards.The present paper presents briefly some of the more important practical results accruing through the investigation."

Jun 1, 1924

By Peter H. Toepfer

This report presents the factual data obtained by the Bureau of Mines during diamond-drilling investigation of the Sunset copper deposit in the Index mining district, Snohomish County, Wash. The Sunset mine, first produced copper ore in 1902, but its main period of activity was from 1923 through 1930, The mine has produced 263,500 tons of ore, from which 1,500 ounces of gold, 156,000 ounces of silver, and 12,912,000 bounds of copper-were recovered. The mine has, been idle since 1946

Jan 1, 1953

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

By G. H. Keith

A vanadium-base alloy consisting of the following elements in weight-percent--molybdenum, 20; titanium, 10; carbon, 0.1; silicon, 0.5; and yttrium, 0.5--had exceptionally high strength at temperatures up to 1,200° C. This alloy was capable of fabrication to sheet of ~ 1 mm thickness by a combination of hot swaging and hot and warm rolling. In the warm-rolled condition at ambient temperature, its ultimate tensile strength was 1,205 MN/m2. The strength at 1,200° C was 150 MN/m2. Within the temperature range of 25° to 1,200° C, the ductility of the alloy as measured by elongation increased from 4 to >90 percent. Strengthening was achieved by both solid-solution and dispersed-phase mechanisms. Alloys of 20 percent molybdenum and 10 percent titanium were stronger than the other molybdenum-titanium alloy compositions tested. Strength was increased 15 percent in the temperature range of 25° to 800° C, with no accompanying loss in ductility, by the addition of 0.5 percent silicon. Workability was improved by additions of 0.25 and 0.5 percent yttrium.

Jan 1, 1970

By F. J. Palumbo

An electronic color-sorting machine was tested for recovering colorless glass concentrates from mixed glass products. The tests were made using glass recovered from unincinerated (raw) urban refuse and residues resulting from the incineration of refuse. The results of the study revealed that concentrates analyzing about 86 percent colorless glass could be recovered from mixed unincinerated glass containing 54 percent colorless glass material. Recovery of the colorless glass was about 62 percent. Color sorting the incinerated glass was somewhat more difficult. Multiple-stage processing was required to recover 59 percent of the colorless glass material in a product analyzing 89 percent colorless glass. The feed material analyzed 41 percent colorless glass.

Jan 1, 1971

By J. Mutmansky, C. Lee

"The size distribution of coal mine dust is one of its most important characteristics because the particle size is known to govern the region of deposition of dust within the human respiratory tract. In addition, dust characteristics, particle settling rate, transportability of the dust and the efficiency of dust control measures are all affected by the particle size. As a result, particle size distribution of the airborne dust in a coal mine is a fundamental property that impacts on the health of underground workers.This paper deals with some basic findings on the size distribution of cool mine dust based upon the results of data collection in six underground coal mines using continuous miners. All airborne dust sampling was performed on development sections using eight stage cascade impactors and permissible 2. O l / min pumps. Samplers locations were fixed in the sections with respect to the continuous miner and roofbolter or with respect to the intake and return airways • Sampling times varied from 45 minutes to 6 hours , depending upon the dust concentration. The first topic of analysis was the test to determine whether the commonly used lognonnal distribution is valid when applied to airborne coal mine dust. Secondly, the conventional method of representing the· distribution using two parameters, the geometric mean and the geometric standard deviation, is questioned. Since almost all size data were found to show some degree of bimodality, the two parameter lognonnal distribution may not represent the total airborne coal mine dust size , quite adequately. Bimodal lognonnal distribution was tested to be a good approximation in the case with two modes in the size distribution.The final topic discussed in this paper is the 'locational variation of the airborne dust size distributions within the continuous mining section. The size distributions varied considerably at the different sampling locations with the continuous miner and roofbolter producing the coarser distributions. Fine size modes in the range of 2 to 4µ m including mostly respirable dust particles were present in almost all samples • Second dust generating sources such as the shuttle car movement were found to be major causes of high respirable dust concentrations in some cases ."

Jan 1, 1988

By E. J. Matson

From February until July 1943 the Bureau of Mines conducted an exploration project at the Majuba Hill mine to determine tonnage aria grade of the copper and tin ore and to search for extension of the mineralization. The work comprised sampling, long-hole drilling, underground excavation, and ore-dressing test.

Jan 1, 1948

By Arthur B. Johnson

The Bureau of Mines investigated the concentration characteristics of high-clay sylvinite ores from four potash companies operating in the Permian Basin near Carlsbad, N. Mex. These ores, containing 13 to 22 percent K20 and 3 to 7 percent clay slimes, cannot be effectively processed by current commercial flotation methods because of their high slime content. A solution to this problem was shown to be the use of two-stage moderate scrubbing conditions and washing of the ore as opposed to strenuous attritioning. Bench-scale physical beneficiation techniques for recovering potash minerals and the development of ore-dressing systems by flotation resulted in obtaining acceptable product grades and recoveries. By using a coarse grind, emphasis was placed on production of premium granular and coarse products. Flotation results showed that concentrates of 58.7 to 60.4 percent K20 with recoveries of 71.0 to 83.4 percent 0f the K20 values can be obtained.

Jan 1, 1971

By T. A. Sullivan

The use of sulfur combined with either sand or waste copper tailings was investigated by the Bureau of Mines as a substitute for a good graded aggregate in asphalt paving materials. The research was part of a utilization program to develop meaningful uses for a projected oversupply of sulfur. Many sections of the country lack good aggregate for paving but do have available sources of sands and sulfur. The development of paving mixtures of desert sands or tailings with sulfur and asphalt was accomplished in the laboratory and tested by laying small paving test sections. Three types of material were studied for use with the sulfur and asphalt. They were (1) a concrete sand similar in gradation to river or beach sands, (2) desert blow sand, and (3) waste copper tailings. Desert blow sand and waste copper tailings are much finer than concrete sand. Mix designs were established for the three types of materials, sulfur, and asphalt used in the paving materials. The best mix designs were as follows, in weight-percent: 80.5 concrete sand, 13.5 sulfur, and 6 asphalt; and 77 either blow sand or tailings, 17 sulfur, and 6 asphalt. Small-scale testing showed that these mixtures were suitable paving materials but would require specialized equipment for transporting and laying. The chemical modification of sulfur to obtain properties that would allow placement of these materials with normal asphalt paving equipment was studied. Results indicate that reacting sulfur with dicyclopentadiene before adding it to the paving mixture was effective in modifying the sand-sulfur-asphalt paving so it could be placed and rolled with conventional equipment.

Jan 1, 1975

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 E. B. Kester

A study of the composition of the corresponding fractions of a primary and a high-temperature tar was undertaken to throw light on the net results of the pyrolysis of the primary products of coal decomposition in high-temperature coking practice, with reference both to total quantities of the chemically similar constituents and to their distribution throughout the boiling range. No exactly parallel investigations are on-record. The distribution of substances in high-temperature tars, however, is fairly well understood. Such tars are more or less similar, for they consist of the more stable phenols, aromatic and olefinic compounds resulting from the pyrolytic decomposition of a wide variety of primary tar constituents. For example, from a typical distillation curve for high-temperature tar phenols it may be seen that the greatest portion of the phenols distills between 180° and 220° C., a fairly narrow range. Low-temperature tars, on the other hand, are more complex, and hence exhibit dissimilarities from one to the next. Edwards, who has made a study of the acids, bases, and neutral oil of four low-temperature tar distillates, shows that the bases and neutral oil are evenly distributed among the fractions but that the concentration of the acids is greatest in the 200° to 230° fraction. Morgan and Soule find that in tar from the "Carbocoal" process, the 237° to 281° fraction has the highest acid content, whereas Davis and Parry find the 200° to 225° fraction of Freeport tar richest in phenols. Previous investigators have noted the following differences between primary and high-temperature tar: In the latter, naphthalene and anthracene occur in large quantities, the paraffins and naphthenes are negligible, the percentage of higher phenols is much lower than in primary tar, and the lower and more stable aromatic hydrocarbons have increased. In an endeavor to reconcile the change undergone when a primary is converted into a secondary tar, the writers have been unable to find references dealing with the extent of change which any one of the constituents of primary tar may undergo when subjected to secondary heating effects in the presence of other components, and the amount of the more stable compounds that may be expected from a given starting material.

Jan 1, 1932

The principal activities of the Bureau of Mines Explosives Research Center (now Safety Research Center) during fiscal year 1968 (July 1, 1967, to June 30, 1968) are reviewed in part 1. Part 2 presents short abstracts of the publications issued during this period in the Bureau series and in other media. Part 3 describes a short study on the thermal decomposition of RDX and HMX not destined for publication elsewhere. ACKNOWLEDGMENTS The Bureau gratefully acknowledges the support received through cooperative agreement in fiscal year 1968 from The Manufacturing Chemists Association.

Jan 1, 1970

By O. C. Blade

The use of Diesel fuel as a source of power is continuing to increase in the United States. The latest available figures indicate that refineries are delivering in excess of 10,000,000 barrels of this type of fuel per month. Factors contributing to this increased consumption are conversions by a number of railroads from steam to Diesel locomotives and the growing use of Diesel engines in buses, trucks, tractors, earth-moving machinery, water craft, and stationary power plants. The increasing importance of Diesel fuel has led to a need for more information on its characteristics, particularly on the grades and qualities currently being marketed. To supply this information the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, under a cooperative agreement, are conducting annual surveys of Diesel fuels produced in refineries in this country. Samples of Diesel fuel were analyzed by the manufacturers in accordance with instructions from the Motor-Fuels Survey Panel of the Automotive Research Committee of the American Petroleum Institute. Results of the analyses were transmitted to the Bureau of Mines where the data were studied am compiled as shown in the tables of this report. The first survey was made in 1950 and was published as a Bureau of Mines report. The present report shows the results of a similar survey made during 1951.

Jan 1, 1951

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 M. M. Fine

The flotation work on samples from nine fluorspar properties in Crittenden and Livingston Counties, Ky., reported herewith was part of a wartime project that resulted in increasing the supply of metallurgical-grade fluorspar. The samples were tailings, dumps, and waste rock that had been rejected in previous milling operations. All were treated successfully by flotation to yield metallurgical-grade concentrates with recoveries ranging from 77.5 to 98.3 percent of the fluorite. After the laboratory testing, the results of which were available to the owners and operators of the properties, many of the tailing ponds and rock dumps were milled. The real value of this report, therefore, is to show the operators of gravity concentration plants the possibilities of re-treating waste products by flotation either at some future time or currently with the gravity

Jan 1, 1948

By E. V. Cilento, K. A. DiGregorio, R. C. Lantz

"DIGREGORIO, K. A., E. V. CILENTO, AND R. C. LANTZ. A kinetic model of superoxide production from single pulmonary alueolar macrophages. Am. J. Physiol. 256 (Cell Physiol. 25): C405-C412, 1989.-A kinetic model was developed to describe the production of superoxide (02) by single pulmonary alveolar macrophages (PAM). Model predictions were compared with experimental results obtained from single rat PAM. The 02 was quantified by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate (NBTH,) from video-recorded images of individual cells. The kinetic model considered three reactions: 1 ) the production of extracellular 02 from the reduction of oxygen by NADPH oxidase using intracellular NADPH as the substrate, 2) the subsequent dismutation of 02 to form H,O,, and 3) the reaction of 02 and NBT to form diformazan. NBT specificity for 02 was analyzed by comparing results in the presence and absence of superoxide dismutase (SOD) that catalyzes the dismutation of 02 to H,O,. Measured PAM heterogeneity was accounted for by varying the concentration of intracellular NADPH, its rate of depletion, and the concentration of intracellular NADPH oxidase in the kinetic model. Model predictions compared favorably with experimental results except when SOD was present. This discrepancy may be due to diffusional limitations because NBT is a relatively small molecule (818 mo! wt) compared with SOD (34,000 mol wt). In addition, the cell surface is both ruffled and negatively charged, which may introduce steric hindrances and/ or electrostatic effects, since SOD is also negatively charged, whereas NBT is positively charged.PULMONARY ALVEOLAR MACROPHAGES (PAM) protect the lungs by phagocytizing foreign debris and bacteria. This process is accompanied by the production of superoxide anion (02) at the surface of the plasma membrane (3, 31). Superoxide readily dismutates to form H20 2 and subsequently, other oxygen metabolites which have been shown to be both antibacterial and cytotoxic (21, 25, 35).Superoxide is produced from the reduction of extracellular O, at the surface of the cell membrane by NADPH oxidase by the following reaction (3, 4)"

Jan 1, 1989