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By D. Bienstock

As part of the development of the hot-carbonate scrubbing process by the Bureau of Mines, the corrosion rates of steel in boiling solutions of potassium carbonate saturated with carbon dioxide and hydrogen sulfide were determined, and the effectiveness of various inhibitors was evaluated by Bureau researchers. The highly corrosive solution of carbonate saturated with carbon dioxide can be inhibited with a 0.2-percent concentration of either potassium chromate or sodium metavanadate. Solutions of carbonate saturated with carbon dioxide and hydrogen sulfide are mildly corrosive, 0.01 inch per year. Complete absence of corrosion is obtained with 0.2 percent sodium metavanadate or 0.15 percent vanadium pentoxide. Oxidizing inhibitors such as potassium chromate are destroyed in the alkaline sulfide mixture, N-alkyl trimethylene diamines, at a concentration of 0.1 percent, lower the corrosion rate to about 0.005. Sodium metasilicate, at a concentration of 0.6 percent, completely inhibits the corrosion but may deposit free silica in the system. Commercial cladding materials such as the epoxy coatings also prevent corrosion.

Jan 1, 1962

By L. B. Pankratz

Heat contents were measured for Na2CaSi04 and Na2Ca2S02 between 298° and 1,300° K, for Na2Ca2Si309 between 298° and 1,500° K, and for Na4CaSi3O9 between 298° and 1,350° K. Copper-block drop calorimetry was employed. Reversible, first-order transitions were found for Na2CaSi04 and Na2Ca2Si309. The transition for Na2CaSi04 is at 830° K with a heat absorption of 160 cal/mole; that for Na2CagSi309 occurs at 750° K with a heat absorption of 1,550 cal/mole. Results for the other two silicates showed no irregularities. A table of heat content and entropy increments above 298.15° K and heat con-tent equations are included for use in thermodynamic calculations.

Jan 1, 1968

By J. R. Thoenen

This circular is part 6 of the third paper (entitled "Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes; part 2, power scrapers, slackline cableway excavators, and hydraulic monitors; part 3, hydraulic, clamshall, ladder, and diaper dredges; part 4, haulage equipment, particularly industrial cars with locomotive or hoist as the motive power; part 5, conveyor belt, motor truck, pump and pipe line, towboat and barges, and aerial-trams haulage. This circular discusses the application of these various types of equipment to the different types of sand and gravel deposits and contains a reference bibliography. It completes the discussion of excavating problems.

Jan 1, 1936

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 R. V. Higgins

A computer program is presented to calculate the shape factors and volumes of cells from a potentiometric model, using coordinates of the inter-sections of the stream lines and equal potentials and a few additional coordinates. Shape factors are used in flow computations when the geometry is complicated. The program also includes computer instructions to divide the channels into cells of equal volume and to obtain the shape factor for each of these equal volume cells. An illustrated example using the potentiometric model for the waterflood of a seven-spot well-spacing pattern is presented. The information contained in the report is of value not only to those allied to the subject but also to others, because many of the techniques can be conveniently used in formulating other computer programs.

Jan 1, 1966

By D. E. Wolfson

This report describes the carbonizing properties of the principal coal beds of Allegheny County, Pa., which rank low in the high-volatile A bituminous classification. Seven coal samples from 3 coal beds were selected for study, as follows: 2 each from the Redstone and Pittsburgh beds and 3 from the Upper Freeport bed. Selection was based on estimated reserves. The samples of Upper Freeport and Pittsburgh coals were satisfactory chemically for producing metallurgical coke. The ash contents of the samples of Redstone coal were moderately high. One of the samples of Redstone coal was high in sulfur content, and it would be difficult to upgrade to meet present metallurgical standards.

Jan 1, 1959

By H. H. Stoek

It would permit coal mines to operate continuously instead of intermittently . Intermittent operation increases the cost per ton for mining , and makes the yearly return to labor low . These conditions contribute to serious instability and unrest in one of the fundamental industries of the country and this can be changed only by coal buyers doing their part to insure steady work . The railroads are now required to transport the maximum amount of coal during the winter months when traffic is most interfered with by bad weather and when the maximum amount of coal is used by the railroads to handle other coal . The railroads now use nearly 30 per cent of the total output of coal . About one- third of their freight traffic is hauling coal , so that economy of fuel used by the railroads will produce a considerable gross saving .

Apr 1, 1920

By M. Kanda

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in and above an operating coal mine, McElroy Mine, located near Moundsville, West Virginia. The electromagnetic environment created by 300 volt dc and 480 volt ac machinery was measured. In one technique noise was measured over the entire electromagnetic spectrum of interest for brief time periods. The noise was recorded using broadband analog magnetic tape. The noise data was later transformed to give spectral plots. In the other technique, noise amplitudes were recorded at several discrete frequencies for a sufficient length of time to provide amplitude probability distributions. The specific, measured results are given in a number of spectral plots and amplitude probability distribution plots.

Jan 1, 1974

By E. C. Lane

Although motor gasoline marketed in the United States in January of this year was, on the average, slightly more volatile than that sold in January 1925, the improvement in quality is too small to be of importance. In other words, there is no evidence that any radical change in the quality of gasoline is being made at the present time. During the past six years the Bureau of Mines has made semi-annual surveys of the gasoline marketed in the United States, the survey just completed being the thirteenth in the series. The cities in which samples have been collected have been chosen as representative of the more important marketing territories as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country.

Jan 1, 1926

By H. B. Humphrey

[EXPLOSION of gas and dust in coal mines, have caused death t lid injure to mines, and destruction of workings in all countries where coal is mined underground. In the United Stales the first reported explosion wits in Min; explosions have continued to the present. The danger to film ill it mine When an explosion occurs in not always measured by the violence created or by their nevi lies, to the area through which flame and Violence extend. As many, perhaps more, risen have died from gases and lade of oxygen (known as "after-damp") than have been killed by the blast and hart. Me explosions often are caused by it combination of factors, including concentration of methane in air, formation of clouds of dust, and the presence of a flame or spark. These explosion factors have varied with changes ill milting method and practises over the years, but the basis causes have always been the salve. Understanding of the causes and to acceptance of ways to guard against explosions and their effects have been slow to spread from investigates to officials and Own to bosses and miners. To a considerable extent there hats lawn a belief that explosions were a joining risk but might hr, put oil hut could not be presented. Such belief is based on the human failure to maintain and observe necessary precautions. These failures, caused by inertia to change, carelessness, or reliance on continuance, of past explosion-free years, are being reduced in number and effect by education of miners and supervisors and acceptance of higher prevention standards.]

Jan 1, 1959

By H. E. Peterson

Rhenium occurs in very small quantities (12).4 In order for the Federal Bureau of Mines to conduct an investigation of rhenium sources and methods of extraction, it was necessary to devise improved techniques for detecting and measuring minute quantities of the metal. A modification of the procedure of Malouf and White (46) was developed which can be used to detect rhenium in concentrations as small as 0.1 part per million and can be used to measure quantities of 1.0 part per million. It can be used for the analysis of siliceous and calcareous ores, of molybdenite concentrates, of fumes, of flue dusts, and of other metallurgical products. Development of the method involved devising an amine extraction procedure for separating rhenium from all interfering elements except tungsten and a selective distillation procedure for separating rhenium from tungsten. Adoption of these separation procedures permits use of large samples and precise determination of rhenium by colorimetric analysis of the thiocyanate complex of rhenium by means of a spectrophotometer.

Jan 1, 1961

By Timothy M. Barton

The U.S. Bureau of Mines is conducting research to assess the effectiveness of different chain pillar designs in maintaining gate entry stability. A particular concern is ground control for deep-cover 1ongwalls located at depths in excess of 1,000 ft. The study described in this report was performed in two experimental sections in one longwall headgate section which contained three different pillar designs. Two of the designs used conventional abutment pillars, while the third was a total-yielding pillar system. Both of the test areas were located under 1,800 ft of cover. The purpose of this study was to evaluate the effectiveness of these three pillar designs for gate road stability. As the longwall mined passed the test areas, Bureau engineers monitored entry convergence, roof sag, and changes in roof quality. The study indicated that the all-yield system performed nearly as well as the better of the two abutment pillar systems; but all of the three designs would have failed to provide acceptable stability for second panel mining without considerable artificial support.

Jan 1, 1989

By H. L. Burmeister

This is one of a series of publications by the Bureau of Mines dealing with mining methods and costs at representative operations in the United States. The report describes all phases of the mining methods for the open-pit operation and milling practices employed at the Vermont Asbestos Mines in Lamoille and Orleans counties, Vermont. A brief history of discovery and development of these asbestos deposits is given, and the ore deposits are described. Methods employed in exploration, sampling, and estimation of tonnage and grade are outlined. A breakdown of available cost figures is summarized in the last section. All asbestos ore produced in this area has been won by the use of surface-mining methods. Two quarries, the Lowell and the "C" Area, are in operation. The quarries combined are producing and the mill is processing approximately 3,500 tons of ore per 3-shift day The average 40,000 tons of crysotile asbestos fiber produced at this plant annually accounted for 96 to 98 percent of the total fiber produced in the United States in 1958. The mine is located (fig. 1) approximately 4 miles north of Eden Mills village on the southeastern flank of Belvidere Mountain (fig. 2).

Jan 1, 1962

By H. H. Schrenk

"One phase of the Bureau of Mines' work in the field of health and safety is the promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To promote the development of such devices the Bureau has established schedules of minimum requirements for oxygen breathing apparatus3/ gas masks/, supplied-air respirators5/ (hose masks, airline respirators, and abrasive blasting helmets, hoods, or masks), and mechanical-filter respirators6/.Manufacturers of respiratory protective devices may submit their equipment to the Bureau for approval under the requirements of these schedules.As a prerequisite to such submittal, the Bureau requires a statement that the device is completely developed and of the design and material the manufacturer believes suitable for a finished marketable device; that the device has been subjected to inspections and tests such as described in the schedules, and that it met those requirements when tested by the manufacturer or his testing agency; and a. statement regarding the nature, adequacy, and continuity of control of the quality of the respirator. If the manufacturer can satisfy these requirements, and if the device, when tested by the Bureau, meets its requirements, a certificate of approval is granted by the Bureau of Mines. The approved devices bear distinguishing marks that indicate that they have been approved, the purpose for which they are approved, and the limitations of their use. If it is found at any time that approved devices purchased in the oven market and tested do not meet the requirements of the schedule, the Bureau may rescind that approval. Lists7/ of approved devices are published periodically for the convenient information of the public.Respiratory equipment may be divided into two main groups: (1). Those that afford protection by removing atmospheric contaminants and (2) those by which a respirable atmosphere from an uncontaminated source is supplied to the wearer.The devices that protect by the removal of contaminants may be divided into two subgroups: (1) Those that protect against gaseous contaminants and (2) those that protect against particulate matter. There may, of course, be combinations of these two.The devices by which a respirable atmosphere is furnished to the wearer also may be divided into two subgroups: (1) The self-contained type, by which the supply of oxygen, or material from which the oxygen can be generated is carried by the wearer, and (2) the hose type, by which air is supplied to the wearer through a hose or tube."

Sep 1, 1939

By John B. Bennett

This Bureau of Mines report presents a method of standardizing forecasts of mineral consumption that attempts to resolve the problems caused by the use of different data bases, different definitions of minerals consumption, and different base years for making projections. Using this method, forecasts of U.S. and world mineral consumption, in the year 2000, for nine commodities (aluminum, chromium, cobalt, copper, manganese, nickel, tin, tungsten, and zinc) are standardized and compared. Also selected forecasts or associated growth rates are used to generate implied values of consumption for 1980-83, which are then compared to actual values of consumption for 1980-83. The economic growth predictions underlying the forecasts are examined, and some general conclusions are drawn. A description of each methodology used to generate these forecasts is given in an appendix.

Jan 1, 1986

By G. R. Hopkins

[A new record in fuel efficiency at petroleum refineries was established in 1939, when a the average B.t.u. requirements per barrel of crude oil processed declined to a new low of 557,000 B.t.u. (see fig. 1). The average fuel requirement per barrel of crude oil refined has remained virtually stationary for the past 3 years. Thus in 1937 the average was 562,000 B.t.u., in is it rose to 567,000 B.t.u., and in 1939 it declined to 557,000 B.t.u. she largest gains in fuel economy cane a decade or so ago on the widespread introduction of heat exchanges and pipe stills. In recent years many successful innovations in heat saving have been adopted, but the combined effect of those is completely masked by the degree to which the capacity is utilized. Some heat requirements are relatively inelastic, so the average consumption per barrel of crude oil refined tends s to increase when the operating ratio (crude runs divided by capacity) declines and vice versa. In 1939 crude runs to stills increased 6 percent (from 1,165,015,000 barrels in 1938 to 1,237,840,000 in 1939) compared with a decline of about 2 percent in 1938. The operating ratio in 1939 was 82 percent compared it's 78 percent in 1938.]

Jan 1, 1941

By D. B. Gawthrop, A. Taylor, G. St. J. Ferrott

"This paper presents data obtained as part of an investigation of the explosive properties of ammonium nitrate. During the course of the work: it was found desirable to investigate the sensitizing action of nitrostarch in mixtures of ammonium nitrate containing low percentages of this material. Data were derived as to the sensitivity to decomposition by heat and the completeness of detonation and,of detonation of straight ammonium nitrate, as compared with ammonium nitrate-nitrostrarch mixtures containing 1 to 10 per cent of nitrostarch.The ammonium nitrate was a sample of coated material obtained from the salvage of amatol shells. Its analysis was as follows:"

Feb 1, 1930

By M. J. Ferrante

New data on zirconium tetraiodide (ZrI4) have resulted from high-temperature enthalpy and X-ray powder diffraction studies conducted by the Bureau of Mines. These studies were undertaken as part of the Bureau's efforts to provide important thermodynamic data essential to the advancement of mineral resources technologies that can be employed with minimal energy requirements and minimal environmental degradation. Enthalpies were measured with a copper-block drop calorimeter. No transitions or other anomalies were found. Tabulated values are given from 298.15 to 772 K for relative enthalpy, heat capacity, entropy, and Gibbs energy function. Enthalpies are expressed in equation form and combined with data from the literature to calculate values of the standard enthalpy of formation and the Gibbs energy of formation. X-ray powder diffraction data indicate that ZrI4 is primitive cubic with a lattice parameter of 11.79 A and is isostructural with stannic iodide (SnI4).

Jan 1, 1980

The following methods should be used to protect miners from the adverse health effects of exposure to respirable coal mine dust and respirable crystalline silica: ? Informing workers about hazards ? Establishing written emergency procedures ? Using engineering controls, work practices, and personal protective equipment (including respiratory protection when dust control equipment is being installed, maintained, or repaired) ? Monitoring exposures ? Conducting medical screening and surveillance ? Encouraging smoking cessation ? Maintaining medical records

Jan 1, 1997

By F. J. Bailey

"In the fall of 1919, the U.S. Bureau of Mines began an inquiry as to the possibility of utilizing airplanes in conjunction with its rescue work, for quickly transporting engineers and oxygen rescue-apparatus to mine disasters.It was realised that this proposed use of airplanes has serious limitations, and if it were feasible, that the Bureau would have to rely on the cooperation of the established aviation fields of the U. S. Air Service for furnishing airplane service. Therefore Van. H. Manning, Director of the Bureau of Mines, under date of October 28, 1919, wrote the Director of Air Service outlining the rescue and first aid organization of the Bureau, the location of headquarters of district engineers, the distribution of safety cars and stations, and other essential details, and asking whether the Air Service could cooperate with the Bureau in the event of serious mine disasters. Major-General Charles T. Menoher, Director of Air Service, responded that the Air Service would be glad to cooperate insofar as possible, and designated those Air Service stations nearest the district engineers' headquarters, which might be best able to assist.The Bureau of Mines has ten mine rescue cars and eight mine safety stations distributed throughout the mining regions of the United States. The cars are each equipped with sets of oxygen mine-rescue breathing-apparatus and first-aid supplies. The car personnel consists of a mining engineer, surgeon, foreman, first-aid miner, clerk and cook. A foreman miner is in charge of each station and at five of the eight stations are mine safety trucks. The work of the cars and stations is two-fold; (1) Assisting in rescue and recovery work at mine disasters, and (2) training miners in mine rescue and first-aid methods, and in investigations looking to prevention of mine accidents. The country is divided into nine safety districts, with nine district engineers in charge."

Apr 1, 1920