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By Sarkis G. Ampian

The Bureau of Mines has developed a method for identifying fine particles of beryl in mineral samples by preferentially staining the beryl grains. The sample is first subjected to a heated sodium hydroxide solution to etch the beryl particles, which are subsequently stained an intense blue color in a boiling alkaline solution of quinalizarin. Positive identification of beryl grains permits quantitative analyses by microscopic techniques. INTRODUCTION Beryl, a beryllium aluminum Silicate, is the principal ore mineral of beryllium. The only known commercial concentrations of this mineral are found in pegmatite dikes of granitic composition. Normally beryl is associated with muscovite mica, quartz, and the sodium-and potassium-bearing feldspars (orthoclase, microcline, and albite). Other beryllium-bearing minerals which are found occasionally in minor amounts with beryl are phenacite, a beryllium silicate, and chrysoberyl, a beryllium aluminate.

Jan 1, 1962

By D. D. Bolstad

This report describes the construction and use of a direct-reading azimuth protractor (DRAP) by the Bureau of Mines for measuring fracture orientations in mines, tunnels, or other excavations having a magnetic environment. The DRAP allows a rapid and simultaneous measurement of dip and azimuth of dip of a fracture plane. The instrument is rugged, lightweight, and easily constructible from standard hardware items. The DRAP can measure dip to within ±0.5° and azimuth of dip to within ±5° of corresponding values obtained with a Brunton compass.

Jan 1, 1974

By Rose L. Ballard

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are the tables that show the principal nonfuel mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is ordinarily termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1982

By Rose L. Ballard

This chapter summarizes data on crude nonfuel mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are tables that show the principal nonfuel mineral commodities exported from and imported into the United States, and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume II of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output." It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the output from auxiliary processing at or near the mines.

Jan 1, 1982

By L. C. IlsLey, E. J. Gleim

It is the firm belief of the Bureau's engineers that the introduction of electrical mining machines has done much to increase safety in mining as a whole . There can be no doubt but that the substitution of machine mining together with permissible powder for the method of " shooting from the solid " has been the means of saving the lives of many shot- firers . Machine mining also leaves the roof in a better condition as lighter charges of powder are required to bring down the coal . Thus the danger from falls of roof are lessened . It is recognized that every effort should be made to prevent all accidents due to the use of electrical machinery but it is felt that any action tending to limit the use of such machinery would be a backward rather than a forward step in the safety measures laid out to decrease the hazards in coal mining .

May 1, 1920

By Edward W. Parsons

The explosive-expansion center-hole anchor was designed and developed for the specific purpose of use as a component of an instrument system that measures differential ground movement within a small drill hole in rock. Such anchors should have an unobstructed center hole, should be installed without a twisting action which could tangle connecting wires, and should be capable of being installed at depths in excess of 100 feet. The anchor has a thick-walled center tube and a thin-walled outer tube. Low-energy detonating cord, wrapped around the center tube and detonated with a mild end primer, expands the outer tube to produce anchorage. The explosive-expansion center-hole anchor can be installed easily in drill holes of any inclination but cannot be installed under water. Centering of the anchor is critical with regard to its subsequent holding power. The anchor is safe to make and handle.

Jan 1, 1965

By Stephen Gerard Sawyer

The Bureau of Mines developed a method for analyzing elastically certain types of protective cabs and canopies used on underground electric face equipment. The method is based on plane frame theory, and to be amenable to analysis by this method, cabs and canopies must contain symmetry about one plane. Additionally, protective structures with one or more top members in the long direction that do not frame into the columns should be approximately twice as long as they are wide and have two or more internal top members in the short direction. The assumptions and limitations of the plane frame method as regards analysis of three-dimensional cabs and canopies are discussed. A step-by-step procedure for application of the plane frame method is given, and three example canopies are analyzed following this procedure. Elastic strengths calculated for the three example canopies compare within 10 percent of those computed by the more complicated space frame analysis. Formulas employed in plane frame analysis of cabs and canopies are given in the appendixes.

Jan 1, 1973

By Douglas C. Peters, Valois R. Shea-Albin, Dennis R. Dolinar

An accurate assessment of the vertical stress on a coal seam at depth is important for mine design. Vertical stress calculation techniques presently available either are not sufficiently accurate or cannot handle complex surface topography. Therefore, the U.S. Bureau of Mines developed a computerized method to calculate vertical stress exerted on surfaces at depth that includes the effect of topography. Two input data sets are required: a digital elevation model containing topographic elevations and a coal seam file defining coal seam elevations at depth. Boussinesq's equation then quantifies the vertical stress resulting from topography. The computerized method was tested on a coal seam overlain by a complex topography where a vertical stress map encompassing several square miles was produced. Results show that depth mitigates the affects of surface topography, while the coal seam topography has a direct effect on the vertical stress. In comparison to the computerized method, the direct stress method overestimates stress under hills and underestimates stress under valleys. The largest difference between the two methods occurs under the steepest topographic relief. A limitation of the computerized method is that stresses cannot be accurately determined near an outcrop.

Jan 1, 1992

By A. F. Jolly

As a part of ongoing research into the sulfidation partitioning of selected complex minerals, the U.S. Bureau of Mines conducted research designed to selectively recover Cu from sulfidized chalcopyrite (CuFeS2). Ferric chloride (FeCI3) solutions leached >90 pct of the Cu and <20 pct (sometimes < 10 pct) of the Fe in the sulfidized concentrates. Cupric chloride (CuCI2) leaches were even more selective, solubilizing essentially 100 pct of the Cu and < 5 pct of the Fe. In contrast, leaching non-sulfidized CuFeS2 with either FeCl3 or CuCl2 showed that somewhat more Fe than Cu dissolved. These studies demonstrate that Cu is substantially more leachable from sulfidized CuFeS2 than from nonsulfidized CuFeS2? The Cu-and Fe-bearing constituents generated as sulfidation products, CuS (covellite) and FeS2 (pyrite), respectively, are differentially dissolved. The solubility of Fe from pyrite in sulfidized CuFeS2 is much lower than the solubility of Fe from complex nonsulfidized sulfide where Fe and Cu are bound in the same crystal lattice. Thus, the Cu dissolves selectively, producing a high-Cu filtrate from which Cu can be recovered by cementation or by electrolysis. Flotation of CuS-FeS2 mixtures indicates partitioned phases can be physically separated if effective liberation can be achieved. Magnetic separation tests yielded less promising results.

Jan 1, 1991

By Oliver Bowles

It is noteworthy that 80 to 95 per cent of the gross production of all slate quarries in the United States is discarded as waste . In view of the loss involved in handling so much waste , and the consequent added cost of the finished product , the Bureau of Mines has undertaken a study of the slate industry for the purpose of devising the best means of reducing the proportion of waste , and of utilizing the unavoidable waste . The utilization of waste has received special attention , and the cooperation of many prospective purchasers of waste slate has been enlisted in testing its adaptability for various uses .

Mar 1, 1921

By Kenneth L. Rubow, Virgil A. Marple, Bruce K. Cantrell

"In a cooperative study by the University of Minnesota and the U.S. Bureau of Mines, diesel exhaust and mineral dust concentrations have been measured for aerosols generated in the laboratory and in five underground coal mines. Three mines utilized diesel-powered haulage equipment and two used all-electric equipment. Two source apportionment techniques have been applied to differentiate between the mineral dust and diesel exhaust aerosol concentrations measured. The first technique, using a micro-orifice, uniform deposit impactor (MOUDI) for size selective sampling, is based on modeling aerosol size and the premise that the diesel exhaust portion of the aerosol is predominantly submicron and the mineral dust portion is mostly greater that one micrometer in size. The second technique, Chemical Mass Balance (CMB) modeling, was used to referee the analysis of diesel exhaust and mineral dust aerosol concentrations from the size selective sampling results.The MOUDI size distribution data were modeled to obtain parameters describing the fine and course fractions of the sampled aerosol and to estimate the contributions to each mode from both mineral dust and diesel exhaust aerosol sources. The results showed the size distribution of the mixed aerosols exhibited two definite modes with the minimum between the modes occurring at 0.8 µm. Less than 5 pct of the coal mine diesel aerosol was found in the coarse size fraction. CMB analysis confirms the original premise for using aerosol size to separate diesel exhaust and mineral dust aerosol during sampling.Based on the results from the size selective sampling, a personal diesel aerosol sampler has been developed for measuring diesel aerosol mass concentrations. Th.is sampler uses an inertial impactor to size separate the respirable aerosol at 0.8 µm. All material less than 0.8 µm is collected on an after filter for subsequent gravimetric analysis."

Jan 1, 1990

By Hillary W. St. Clair

The effective coefficient for rate of reduction of a sample of granular iron ore may be determined by passing the reducing gas through a bed of the are at constant flow rate and periodically analyzing the effluent gas, The method of analyzing the data is based on a mathematical model that takes into account the variation in composition of the gas and solids with time and position in the bed. A method is described for determining the value of the rate coefficient that gives best agreement between the observed and calculated analyses of the effluent gas.

Jan 1, 1967

Reduce the costs associated with conventional treatment of acid mine water. Approach Conventional treatment of acid mine drainage consists of plants requiring large mixing and aeration tanks, mechanical aerators and large, shallow settling ponds. Such plants are usually very costly to construct, maintain and operate. The Bureau of Mines has developed a simple, low-maintenance, highly efficient system to treat acid mine drainage which mixes, aerates, and neutralizes mine water Simultaneously in the existing discharge pipeline by using the pressure generated by the deep mine discharge pumps. The mixing and aeration action of the in-line system significantly increases oxidation rates of ferrous iron. Iron and manganese are removed, even at near neutral pH levels, due to the high efficiency of this system. How It Works The In-line Aeration and Treatment System (ILS) consists of two commercially available components, a jet pump (ejector) and a static mixer. The jet pump is simply a nozzle that converts water, already under pressure, into a high-velocity stream that entrains air by Venturi action. If neutralization is required, sodium hydroxide or lime is added along with the air at the Venturi opening. The aerated and neutralized water then enters the static mixer, which is a length of internally spiralled pipe that mixes air and water together. The two components, which are both about 8 feet in length, replace the last section of discharge pipe at a point before the mine water is emptied into a pond. Along with the settling pond, these components treat the water so that it meets discharge criteria. The system has been used at surface drainage treatment facilities as well, but in such use a pump is required to provide the necessary pressure drop across the Venturi opening.

Jan 1, 1985

By D. B. Dow

"In the natural-gas Gasoline industry, the methods used in determining the amount of gasoline in natural gas are many and varied; they include the specific-gravity test, laboratory tests involving absorption, charge in volume of the gas or in the absorption medium, absorption in charcoal with subsequent distillation, compression of the gas which results in the condensation of the gasoline, and the absorption of the gasoline vapors in an absorption oil, from which the gasoline is distilled and measured. Each of these various tests has advantages, and disadvantages. It is however, conceded in the industry that the tests in which the gasoline is obtained and measured as such are the more reliable.This paper deals with certain factors which should be considered in making absorption tests using ""mineral seal oil"" as an absorbent; this method of testing is widely used not only in the field, but in control work in absorption gasoline plants where the gasoline content of the intake and discharge gas is determined daily. In control work it is frequently found that the plant produces more gasoline than the tests show, which gives the plant the appearance of making more gasoline than is actually present in the gas treated, or in other words operating at more than one hundred per cent efficiency. Obviously then, the tests as made in these cases are in error, and in hope of correcting some of these variances, the following factors have been studied at the U. S. Bureau of Mines petroleum station at Bartlesville, Oklahoma."

Aug 1, 1920

By S. J. Pearce

The Bureau of Mines has prepared, as circumstances have dictated, a series of schedules setting forth the minimum requirements that various types of equipment should meet to be considered safe and satisfactory for use under certain hazardous or unhealthful conditions. These schedules cover a wide variety of devices ranging from explosives to electrically operated mine locomotives. This paper discusses the functions and operations of schedules under which respiratory protective devices are tested and approved. It emphasizes that the aim of the Bureau respirator-approval system is to make available to the public respirators that meet definite performance requirements. The responsibility of the respirator manufacturer in pre-testing the device and in maintaining its quality after it is approved are explained. Aid is provided for the user in selecting the proper device for specific application, and a plea is made for better education of all concerned in the proper use of the devices. DISCUSSION Provisions have been made for testing and approving the following types of respiratory protective devices: Self-contained breathing apparatus,2/ supplied-air respirators,3/ gas masks,4/ dispersoid respirators,5/ and chemical-cartridge respirators.6/ These devices are tested at the Central Experiment Station of the Bureau of Mines in Pittsburgh, Pa. Self-contained breathing apparatus is tested by personnel of Health and Safety District B; other types of respirators are tested by the Branch of Health Research.

Jan 1, 1957

By Albert E. Long

By the USB of X-ray diffraction methods, scientists have learned how the atoms in a diamond crystal are arranged and how the atoms are tied together by chemical bonds. They have found that, even though the bonds between all atoms of the diamond have equal strength, they are so distributed that there are more bonds in certain layers or directions through the crystals than in others. The unequal distribution of the bonds in certain directions creates planes, within the diamond, of unequal strength and resistance to abrasion. The location and disposition of the directions that are relatively harder than the others were determined by Slawson and Kohn 3/ in 1950. By plotting these directions on stereographic projections they delineated the hard regions on the surface of the diamond, but only those trained in the methods of crystallography can readily interpret their diagrams. The principal purpose of this report is to present information that will help individuals without previous training in crystallography to learn to recognize the special features of the surfaces of diamond crystals that are definite guides to the location of the various hard directions of the stones. A crystallographer trained in using various precise laboratory instruments might consider such rudimentary criteria as rather unscientific, but these simple characteristics of diamond crystals are practical clues which anyone equipped with a magnifying lens can find and recognize. The use of the special faces, points, edges, and growth lines as a gui.de in orienting a diamond will allow it to be placed in a position reasonably close to the optimum. Preliminary results of experimental work conducted by the Bureau of Mines indicate that this is all that is necessary in setting diamond-bit crowns. This experimental work demonstrated that setting bits with the hard vectors of the diamond as cutting points greatly reduces the diamond loss and increases the efficiency of the bit.

Jan 1, 1952

By Gerald A. Munson, E. P. Barrett

Rapid and accurate estimation of the proportions of mineral in rock mix- tures is essential in mineral-dressing research and industrial operation. Estimation of the proportions of potash and soda feldspars in ground pegmatite material by casual observation is almost impossible and may be tedious or even difficult by petrographic examination. Chemical analysis may not be an accurate measure, as pegmatite rock may contain the following minerals:

Jul 1, 1947

This chapter summarizes data on crude mineral production for the United States, its island possessions, and the Commonwealth of Puerto Rico. Included also are tables that show the principal mineral commodities exported from and imported into the United States and that compare world and U.S. mineral production. The detailed data from which these tables were derived are contained in the individual commodity chapters of volume I and in the State chapters of volume n of this edition of the Minerals Yearbook. Although crude mineral production may be measured at any of several stages of extraction and processing, the stage of measurement used in this chapter is what is normally termed "mine output!&apos; It usually refers to minerals or ores in the form in which they are first extracted from the ground, but customarily includes the production of auxiliary processing at or near the mines.

Jan 1, 1979

By Oliver Bowels

Many inquiries are received by the United States Bureau of Mines for the names of elementary books on geology, mineralogy, methods of identifying minerals, prospecting, and similar subjects. In response to this demand the following brief bibliography has been prepared. As many of the inquiries are received from those who have limited technical knowledge of the subjects involved, the bibliography includes the simpler texts which present the subjects in nontechnical language. Other texts contain glossaries which define the technical terms used. A short note following the title indicates the character of each book, the number of pages, and the price. Thus, elementary mineralogists or geologists, prospectors, mineral collectors, nature students, or travellers may select the texts that best suit their requirements and their capabilities. To supply the needs of more advanced students, quite a number of the standard texts used in schools and colleges are included in a second group. A short list of books on economic geology and mineralogy has also been added.

Jan 1, 1929

By Earl C. Lane

The Bureau of Mines is making a survey of petroleum products manufactured on the Pacific Coast from California crude oils . California crude petroleum is known to differ in some characteristics from the crude oil produced in other parts of the United States , and the claim has been made that the present Federal specifications are unduly severe when applied to the products made from California crudes . The main purpose of the present survey is to determine whether these claims are justified . This report deals only with California gasolines . Other products , such as burning oil , fuel and lubricating oils , will be taken up later . The samples reported were furnished in most cases , by the four large refining companies located on the Pacific Coast , although a number of samples of motor gasoline were purchased in the open market . In Los Angeles , samples of motor gasoline were obtained from service stations representing as many different refineries as possible . Inasmuch as San Francisco is one of the cities covered by the regular semi -annual motor gasoline survey conducted by the Bureau of Mines , it was not considered essential that the set of samples obtained from this city be as comprehensive as would otherwise have been necessary . The gasoline consumed in the States of Washington and Oregon is furnished for the most part by California refineries , and no effort was made to procure samples from these States .

Apr 1, 1922