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By Phillip N. Yasnowsky

This Bureau of Mines report examines the percentage depletion allowance rate structure in relation to several criteria that are indicative of U.S. mineral import dependence. These criteria are the minerals considered as strategic and critical for stockpiling purposes, the ratio of reserves to forecast cumulative demand (1976-2000) for selected minerals, and the U.S. net import reliance as a percentage of apparent consumption (1978), also for selected minerals in general, it was Found that there does exist a direct, although not perfect, relationship between the percentage depletion allowance rates and the degree of import dependence as indicated by these three criteria. The higher percentage rates tend to he associated with those minerals for which the United States is, or will likely he, heavily dependent on foreign sources. In addition, a basic discussion of the mineral depletion allowance is provided, including numerical examples illustrating the computation of the allowance under several assumptions. Also, the percentage depletion allowance rates for individual minerals are tabulated.

Jan 1, 1980

By Harold M. Smith

The data in this report were prepared to show how Bureau of Mines routine crude oil analyses could be used to evaluate crude oils in terms of common commercial products . The use of Bureau of Mines routine analyses to determine hydrocarbon - type relationships for the gasoline and gas - oil fractions is demonstrated . For this purpose the correlation index , the aromatic profile and the naphthene profile are used to establish reasonably acceptable values for hydrocarbontype relationships . The derivation and meaning of these indications are discussed . These analytical interpretations are applied to a group of high - sulfur crude oils from the Near East , the Permian basin of West Texas , Venezuela , Colombia , California , and other locations , and the resultant data for gasoline , gas oils , lubricating oils , and asphalt are compared by appropriate tables and graphs . Because the Near East crude oils contain higher quantities of paraffins in the gasoline and gas oil ranges , they will yield good , lowsolvency solvents and good kerosine , jet fuel , and diesel fuels , but straightrun gasoline of inferior quality compared to similar products from either West Texas or Venezuelan high - sulfur oils . The Near East oils also should be good sources of lubricating stock . However , when used as stock for catalytic cracking or reforming , the Near East oils suffer by comparison because they are deficient in naphthenes .

Jan 1, 1964

By J. W. Davis

The storage stability characteristics of a diesel type fuel were determined to evaluate the effect of the polar compounds in the fuel. These compounds, comprising most of the nitrogen and oxygen containing compounds and many sulfur containing compounds, were separated from the fuel with a chromatographic column. This fraction was further separated into three polar extracts by graded elution through the column. Each extract was characterized. A storage program using the depolarized fuel, the fuel as received, and blends of the extracts with both fuels, was conducted. Results showed that the removal of the more polar components stabilized the fuel. Blending the polar extracts with the original fuel and with the depolarized fuel in the same ratio as they existed originally and at two and three times the original ratio increased the amount of gum present before storage, but had little effect on the formation of additional gum during storage. Distillate fuels produced by commercial refining of petroleum contain traces of organic nitrogen, sulfur, and oxygen compounds that are more polar4 than the remainder of the fuel. Recent laboratory studies by the Federal Bureau of Mines (1),6 in which these compounds were removed from a fuel, have shown that they influence its storage stability. The objective of this work was to determine the amount of these compounds present in a fuel and their effect upon its stability in storage. To evaluate the role of these polar compounds, it is necessary to remove them from the distillate fuel. Many can be removed by chemical treatment (2), but such treatment precludes reblending the polar components to approximate the original fuel composition. Solvent extraction is free of some of the criticism of chemical treatment, but it is more difficult because of the complex mixture from which compounds must be removed.

Jan 1, 1961

By J. E. Tress

The Bureau of Mines has developed a process to utilize waste heat from electric arc steelmaking furnace gases to preheat the ferrous material charged to the furnace. Four heat exchangers were designed, tested, and operated successfully on 1-ton electric arc furnaces. Briquets and pellets were charged continuously, both countercurrent to the hot furnace offgasses and at ambient temperatures. A comparison of the electrical energy consumed in each situation showed that preheating can lower energy requirements as much as 15.6 percent.

Jan 1, 1975

By E. J. Matson

The Bureau of Mines has been investigating deposits of critical and essential minerals in the United States since 1939. The Rush Creek lead-zinc deposit, Mono County, Calif. (fig. 1), was examined by W. T. Benson in July 1944 and again in September 1945 by D. W. Butner, engineers of the Bureau of Mines. From the results of these preliminary examinations, a core-drilling program (fig. 2) was started in August 1946 and continued until November 1946, when work was stopped on account of inclement weather. Field work was again started in May 1947 and completed in June 1947. The drilling program was laid out to develop the horizontal .and vertical extensions of showings exposed in surface pits.

Jan 1, 1949

By Carl F. Wingquist

In support of Bureau of Mines studies of thermal fragmentation of rock, the elastic moduli of four types of rock were measured at temperatures ranging from room temperature up to 1,500° F (1,089° K). The sonic method was employed to determine the resonant frequencies of the rock specimens and from these frequencies, the elastic moduli were calculated. Data for Young's modulus, shear modulus, and Poisson's ratio are given as a function of temperature for Dresser basalt, Reserve taconite, Jasper quartzite, and Charcoal granite. Young's modulus and the shear modulus decreased with increasing temperature up to about 1,200° F and then became relatively insensitive to temperatures from 1,200° to 1,500° F.

Jan 1, 1969

By M. A. Mahtab

This report presents a new procedure for analyzing the orientations of rock fractures in an engineering site. This procedure, coded in a computer program, identifies clusters or groupings among the fracture orientations and calculates (1) the mean orientation of the fractures within each cluster and (2) the dispersion or scatter among these fracture orientations. Data points are represented by intersections of joint normals with the upper hemisphere, which is divided into 100 equal-area quadrilateral patches. The points in adjacent patches where the Poisson distribution test shows significant concentrations are assigned to a single cluster. For a cluster whose fracture orientations follow Arnold's hemispherical normal distribution, a confidence interval for the fracture orientation mean is calculated by applying Fisher's estimates. The technique is applied to the treatment of three examples.

Jan 1, 1972

By B. J. Scheiner

Extraction of molybdenum from molybdenite ore by an electrolytic oxidation procedure was investigated by the Bureau o f Mines. Various parameters affecting molybdenum extraction, such as salt concentration, temperature, treatment rate, current density, and particle size, were studied. Molybdenum extraction of 95.2 percent was achieved on a laboratory scale from an ore containing 0.35 percent molybdenite. Corresponding power consumption was 24 kwhr per pound of molybdenum extracted with a base consumption of 4.5 pounds of sodium carbonate. Laboratory and pilot plant experiments are in progress on low-grade molybdenum concentrates containing rhenium and copper. Preliminary results indicate that molybdenum extractions in the 90- to 99-percent range and rhenium extractions of 93 to 99 percent can he obtained without appreciable oxidation of associated copper minerals.

Jan 1, 1972

By J. W. Paul

This circular is one of a series of papers4 on coal-mining methods and costs which are being prepared through the sponsorship of the U. S. Bureau of Mines for the purpose of presenting information on present mining methods and certain features which govern costs, safety, and conservation. The methods employed are influenced by natural local conditions with respect to the thickness, character, and dip of the coal bed, the nature of the roof and thickness of the overbearing strata, and the means employed for roof support and its control.

Jan 1, 1929

By J. Baicker

A two-inch diameter probe containing an intrinsic germanium detector, a canister-type solid cryogen cooling system, cooled FET preamplifier, linear amplifier, high voltage supply, analog-digital converter, microprocessor, buffer memory, bidirectional cable link, and all power supplies has been designed, assembled and tested. A surface support vehicle was designed, built and outfitted. A mini-computer system was constructed and preliminary software developed and tested. A special handling system for a Cf-252 neutron source was designed and has been ordered. The entire system (less the neutron source) is ready for its first field tests. Lab description of the system is presented.

Jan 1, 1978

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 D. J. Parker, D. Harrington, L. H. Harrison

"INTRODUCTION The necessity for protection against the hazards of lightning manifests itself from time to time in the mining industry by reason of loss of life, damage to electrical equipment, fires in surface structures at mines, and accidents in the handling and use of explosives. This paper is intended to assemble, correlate, and present some of the salient points embodied in the available literature on the subject and at the same time give some factual data concerning instances of such loss of life and damage to property, with special application to the mining industry.The annual loss of life and destruction of property by lightning is considerable; the former may be prevented to a limited extent, though use of common sense as to exposure is required and not always followed; the latter can be prevented to a considerable degree. The manufacturers of electrical equipment, through improved types of lightning arresters, have done much toward the protection of electrical equipment, with consequent safeguarding of life and of property. Education based on unfortunate experiences has gone far to discourage the handling of explosives and blasting accessories during thunder storms, especially in open pits and quarries, and to a much smaller extent in underground workings. The lowly lightning rod plays an important role in the protection of certain types of buildings (especially isolated buildings), stacks, monuments, and other structures.LIGHTNING PHENOMENAIn 1751, Franklin proved that, lightning was simply a visible display of electricity - an extended spark; and until a generation ago little had been added to his exposition to define the various phases of the phenomenon. Matters pertaining to lightning are discussed in the following references:"

Apr 1, 1948

By R. V. Ramani, P. M. T. White, D. Sutton

This report was prepared by The Pennsylvania State University under USBM Contract No. G0111808. The contract was initiated under the Coal Mine Health and Safety Program. It was administered under the technical direction of DMSE, with Mr. G. R. Schottler acting as the technical project officer. Mr. J. A. Herickes was the contract administrator for the Bureau of Mines. This report is a summary of the work recently completed as part of this contract during the period June, 1971 to December, 1973. This report was submitted by the authors on March 31, 1974. The project personnel express their thanks to Dr. Jay Politzer, The Pennsylvania State University Computer Center for providing the subroutine POLITZ and function IFIND, to Dr. Ray Masters, Department of Architectural Engineering, for permission for the use of the GRID program and to Dr. Lother Weyher of Bethlehem Steel Corporation for providing coal data.

Jan 1, 1974

By N. E. Hanna

As part of a program for improving, the safety of permissible explosives, the Federal Bureau of Mines has undertaken an investigation to establish the ability of sodium chloride to reduce the incendivity of permissible explosives to firedamp atmospheres. A motivating influence for this investigation has been the comparatively extensive experience of British and other European investigators, who used sodium chloride as a component of their permitted explosives (1, 5, 6 7).5/ In the United States research and development work of this type has been less extensive, although sodium chloride has been added to permissible explosives as a cooling agent (9) for many years. The results of the first phase of this investigation were presented in a previous paper (8), which established that adding up to 10 percent sodium chloride to permissible explosives reduces the likelihood of ignition of firedamp in the gallery test; however, the results were somewhat inconsistent, and the conclusions were qualified. Accordingly, the investigation was continued with a study of the effect of added sodium chloride as a function of the quantity added and of the particle size of the salt.

Jan 1, 1960

By S. A. N. Sheya

Many gold-bearing ores in the Western United States also contain small amounts of mercury. The presence of mercury creates potential pollution and health hazards during several steps in gold processing. An investigation was undertaken by the Bureau of Mines to develop techniques for removing mercury from cyanide mill solutions by selective electrowinning to reduce the potential hazards. Sixty-five percent of the mercury was selectively electrowon from synthetic carbon strip solution at applied potentials of 1.00 to 1.50 V when using a mercury-coated platinum or copper plate cathode. Increasing the active surface area by using mercury-coated copper wool resulted in up to % pct of the mercury being electrowon from mill carbon strip solutions that contained 1.9 to 20 ppm Hg, 20 to 345 ppm Au, and 0.35 to 39.5 ppm Ag. About 98 pct of the silver was electrowon with the mercury onto the mercury cathode. Gold extraction ranged between 0 and 20 pet. Results of the investigation showed that choice of cathode material was critical to the success of the process. Selectivity was not achieved using uncoated steel wool cathodes.

Jan 1, 1988

By W. A. Jacob, E. W. Dean

The Pittsburgh petroleum laboratory of the Bureau of lines has recently developed an improved method for the determination of water in pctroleum emulsions. It has been described in detail in an article entitled "A convenient method for the determination of water in petroloum and other organic emulsions" by E. W. Dean and D. D. Stark (Jour. Ind., and Enc. Chem. Vol. 12, ſay, 1920, page 436). It is essentially a modification of the familiar procedure of "distillation with an iniscible solvent", the improvement consisting in the use of apparatus that is rºck more convenient than any previously employed. The method has been used with marked success in the Bureau's laboratories for a period of about a year and has also been tried with equal satisfaction by a number of other laboratories. It has been most extensively employed for determining the water content of heavy fuel oils but has been applied also to several other types of emulsions, including shale oils, tars derived from coal, greases, and mixtures of powdered coal, oil and water. The Bureau has received a number of requests for information regarding commercial sources for the apparatus used, and having been assured of the value of the method, has taken steps to render it available for general use. - The equipment is, with the exception of two items, made of parts that are obtainable from the ordinary stock of chemical supply houses. The two exceptions are (1) the so-called "distilling tube receiver" and (2) the electric heater. The former is an essential part of the equipment; the latter is a convenient ac cessory but it can if necessary be roplaced by a gas burner. Efforts on the part of the Bureau staff to ronder these two items of apparatus available for purchase from supply houses, or for production by the user are hero described.

Sep 1, 1920

By A. G. Smelley

As part of research conducted in its mission to effect pollution abatement, the Bureau of Mines, U. S. Department of the Interior, is developing a dewatering technique that allows for disposal of phosphatic clay wastes, for reuse of water now lost with clays, and for reclamation of mined land. The technique utilizes a high-molecular-weightnonionic polyethylene oxide polymer (PEO) that has the ability to flocculate and dewater phosphatic clay wastes. A synergistic flocculation study was made to determine whether a portion of PEO could be replaced by other reagents. Several groups of reagents were tested: (1) those that increased the zeta potential of the phosphatic clay wastes; (2) those capable of hydrogen bonding; and (3) those which flocculated the phosphatic clay waste. Reduction in PEO consumption occurred only with addition of those reagents able to flocculate the slime. The use of natural guar gums resulted in a lower PEO requirement and also yielded a dewatered product of higher solids content, 43 to 45 percent, versus 33 to 35 percent obtained with PEO alone.

Jan 1, 1980

By Jerry G. Craig

The Bureau of Mines has developed a computerized oil and gas well data retrieval system from studies of the waterflood potential of a producing reservoir. This system stores pertinent information about each well completed in a reservoir and facilitates selection and manipulation of large volumes of data. Use of the system enables reservoir information to be supplied rapidly, accurately, and at less expense.

Jan 1, 1971

By J. W. Lyman

The U.S. Bureau of Mines investigated methods of separating valuable rare-earth materials from Fe in neodymium iron boron (NdFeB) magnet scrap. A selective oxidation treatment of the scrap oxidized the rare-earth portion while leaving elemental Fe. Magnetic and leaching procedures were tried for separating the metallic Fe and rare-earth oxides, but the extremely fine grain size of the oxidized scrap prevented recovery by either technique. The best separation of rare earths from bulk NdFeB magnet scrap was obtained by dissolution with H2S04 followed by precipitation of recyclable rare-earth salts. By precipitating neodymium-alkali sulfate double salts as an intermediate that can be converted to a variety of useful products, many materials-handling and economic disadvantages found with direct precipitation with fluoride or oxalate were avoided. Iron was removed from magnet leach solutions by precipitation as a jarosite, eliminating a major disposal problem. Research was also conducted with contaminated mixed SmCo5 and NdFeB swarf. Using a flotation-leaching technique allows the SmCo5 to concentrate in the froth, while the grinding-medium contaminant sinks and is removed as tailing. The NdFeB is dissolved by H2S04 during the process.

Jan 1, 2010

By ALICE V. Petar

Thallium is one of the rare metals that has come into commercial use within recent years . Its comparative scarcity , combined with a resemblance to the common metal lead , have retarded the development of uses for thallium . Although production is still measured in pounds rather than in tons , it is now finding application in a number of fields . Perhaps the earliest commercial use of thallium was as a constituent of optical glass of higher refractive power than similar glasses containing lead . One of the later applications to attract attention was the use of the oxysulphide in a sensitive electrical device similar to the selenium cell . The " Thalofide " cell , which was patented in 1919 , constituted for a time the most important outlet for thallium. During the next few years the limited use of thallium and its salts in other fields was insufficient to absorb an annual production of a few hundred pounds , and the price dropped from $ 16 or $18 per pound in 1922 to $ 5 per pound in 1924 . Beginning in 1925 several new uses were developed , especially as a poison for rodents and ants , and as a result the demand for thallium increased sufficiently to cause a recovery in price to the present level of from $12 to $15 per pound .

Jun 1, 1931