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By Donald S. Colby

This Bureau of Mines report is essentially a handbook, or manual, for making the type of mineral resource valuation commonly required for such public policy problems as mineral leasing. The principle of resource valuation through the capitalization of cash flow is well established. A mathematical procedure, based on a simplified accounting system, is detailed for calculating cash flow from revenue, plant costs, and operating expense. Variations of procedure cover cost depletion, percentage depletion, and depletion limited to 50 percent of net income. The influence of the depletion provisions of the tax regulations on the value of a resource to an owner and to an operator is analyzed. The relationship of royalty, bonus payments, and sales price to resource value is also described, and methods for approximating resource values using these payments as input data are developed.

Jan 1, 1969

By Will H. Coghill, F. D. DeVaney

"Many of the iron ore deposits on the western end of the Mesabi Range Minnesota consist of the so-called ''wash ores."" Because of their high silica content these ores must be washed or concentrated to make them merchantable. Washing plants have been in operation for 20 years, during this period large quantities of tailings have accumulated in tailings ponds. These tailings contain the aggregate millions of tons of iron oxides which, if recovered, would greatly to the available tonnages and to the revenues of the mining companies. It the purpose of this paper to outline give results of concentration tests on tailings.In order that the reader may understand more clearly the type of material under consideration, a short description of the characteristics of the wash ores of the Western Mesabi Range and a brief resume a washing methods that have been are now being employed will be given. Appleby and Newton4 In their description of the district and of the ores say:The Western Mesabi district embraces the territory west of the town of Nashwauk in Itasca County. The territory to the east of this dividing line is known as the Central and Eastern Mesabi district. This subdivision is rot wholly arbitrary. While the ore bodies in the two districts resemble each other in. shape, size, and general structure, there is a marked and very important difference in the character of the respective ores. For purposes of comparison, the western deposits have been called washable ore bodies, and the central and eastern, standard ore bodies. The latter ores are the result of natural concentration processes which have teen carried far enough to produce a large proportion of high-grade ore Wet can be marketed direct; the Western Mesabi ores present a lesser degree of natural concentration and are as a rule of too low grade to admit of marketing without preliminary treatment. In many cases the grade can be improved by washing, hence the material is called washable ore. Exceptions to thin general rule may be noted in both districts. Many of the Western Mesabi ore bodies contain quite a proportion of merchantable ore. There are also portions of central and eastern Mesabi ore deposits which are of low grade and which can be improved by washing."

Nov 1, 1930

By McClelland. John J.

This Bureau of Mines report discusses recent applications of water in-fusion technology to control dust in U.S coal mines and presents recommended guidelines for determining coal seam infusibility. The techniques required to use water infusion are presented in detail. A Bureau case study indicated that water infusion reduced dust levels by 68 pct along a longwall plow face, bringing this section into compliance with the Z.0-mg/m3 Federal dust standard. Similar studies conducted by Occidental Research Corp. under a Bureau contract show water infusion at two longwall double-drum shearer operations produced dust reductions ranging from 38 to 50 pct. Water infusion was found to be cost effective, aver-aging 5 cents per ton.

Jan 1, 1987

By Earl T. Hayes

For several years the Northwest Electrodevelopment Laboratory of the Bureau of Mines, in cooperation with the Air Materiel Command, U. S. Air Force, has been studying zirconium alloys. A preliminary survey of these alloys has been completed and reported as a Bureau of Mines Report of Investigations. 4/ Originally the purpose was to determine the suitability of zirconium alloys in medium-temperature applications. However, data also were obtained on other properties of these alloys, and later the scope was broadened to include amore detailed investigation of a selected group. The zirconium-titanium system was one of those chosen. The Bureau of Mines has been instrumental in the commercial development of both of these metals and has constructed pilot plants for the production of titanium at Boulder City, Nev., and for zirconium at Albany, Oreg. Both elements are in subgroup A, fourth series of the periodic table, and therefore have many properties in common. Since both have similar atomic structures and lattice dimensions the possibility of extended mutual solubility seemed likely. Inc transition-point diagram of Fast indicated that the two metals are completely miscible in all proportions in both the alpha and beta forms.

Jan 1, 1951

By M. M. Fine

A laboratory mineral-dressing investigation of manganese ore from the Martin mine, Independence County, Ark., succeeded in recovering ferrograde manganese products. Sintered flotation concentrates analyzing 40.7 and 41.4 percent manganese at overall recoveries of 54.6 and 47.7 percent, respectively, were produced from preconcentrated feed, Preconcentration of the ore for flotation included treatment by magnetic separation and by a combination of magnetic separation and heavy-medium processing. The mineral-dressing study of the Martin mine rhodochrosite ore was part of a general program of the Bureau of Mines to develop domestic sources of strategic minerals, including manganese. Several such potential sources of manganese exist in the Batesville, Ark., district, one of which is represented by the Martin mine. Although the Martin mine area has not been delimited with respect to total reserve tonnage, it is considered to be one of the more important occurrences of manganese in the district. It is estimated that several 100,000 tons of manganese carbonate ore are present in this and similar properties.

Jan 1, 1954

By Michael J. Sapko, Kenneth L. Cashdollar

In This Chapter [Methane ignition as initiation source for much larger secondary coal dust explosions Rock dusting requirements to prevent coal dust explosions Dangers of hybrid mixtures of methane and coal dust] Although methane explosions are dangerous, those that involve coal dust are even more so. If exploding methane disperses and ignites the coal dust that has accumulated on the mine ribs and floor, the burning coal dust immeasurably increases the strength of the explosion. Such methane-dust explosions are prevented by inerting the coal dust in a way that prevents the exploding methane from igniting it. This chapter discusses the dust hazard and how it is pre-vented in U.S. coal mines. METHANE IGNITION AS INITIATION SOURCE FOR MUCH LARGER SECONDARY COAL DUST EXPLOSIONS The typical scenario for coal mine explosions starts with the ignition of a flammable methane-air atmosphere near the face. The turbulent winds from the primary methane explosion then disperse the coal dust. If there is insufficient rock dust (usually limestone), a secondary coal dust explosion then propagates throughout large sections of the mine. These scenarios have been studied extensively at the Bruceton Experimental Mine (BEM) and the Lake Lynn Experimental Mine (LLEM) of the NIOSH Pittsburgh Research Laboratory. The minimum quantity of methane required to initiate a coal dust explosion was studied in 1930 in the BEM [Rice et al. 1933; Nagy 1981] and then later in the LLEM, whose cross-sectional area (130 ft2) is over twice that of the BEM [Sapko et al. 1987a]. Studies conducted in the BEM closely simulated conditions that existed in operating mines in the early 20th century. The later tests in the 20-ft-wide entries of the LLEM simulated the geometries of modern mines with advanced roof support technology. The data from the BEM tests show that 13 ft3 was the minimum quantity of methane at the face that, when ignited, would disperse and ignite coal dust. In the BEM, this amount of methane was mixed with air to form a total flammable volume of about 140 ft3 of a 9% methane-in-air mix-ture. In the wider entries of the LLEM, about 37 ft3 of methane was required to disperse pure coal dust and start a self-sustained coal dust explosion. This amount of methane was mixed with

Jan 6, 2006

By D. I. Bleiwas

Bureau of Mines personnel evaluated the potential availability of nickel from 151 deposits in 18 market economy countries and selected 126 for detailed analyses. An evaluation was made of tonnage-cost relationships indicating the quantity of nickel available at various total costs of production expressed in dollars per pound nickel, including a 15-pct rate of return on the invested capital. The 126 deposits studied contain approximately 73 million metric tons (t) of nickel. An estimated 52 million t is available from laterite deposits, of which less than 2 pct could be produced at $3.50/lb Ni, about equal to the average published price of nickel in 1981. Approximately 21 million t of nickel is available from sulfide deposits, of which about 10.0 million t can be produced at $3.50/lb. Sensitivity studies performed for both laterite deposits and sulfide deposits indicate that the total cost of nickel from laterites is most sensitive to increases in energy costs, and that sulfides are most sensitive to increases in labor costs; sulfides are also sensitive to changes in byproduct revenues. In 1983 the Nickel Mountain mine in Oregon was the only U.S. producer, though development continued on the Gasquet property in California. Of the total 5.1 million t of recoverable nickel in the United States, about 20 pct is available at or below $3.50/lb.

Jan 1, 1984

By J. P. Dunford

This U.S. Bureau of Mines report describes the development of a yielding steel post for underground mine support. The report covers concept development, laboratory tests, modifications, and field evaluations. The objective of this work was to develop a stiff support member capable both of supporting high loads and yielding when excessive amounts of mine entry closure were present. The 6-to 7-ft steel post was designed to yield nearly 2 ft while maintaining a 45-ton (force) load. The post is a three-piece unit consisting of top and bottom telescoping legs and a separate foot bracket. It develops its load-carrying characteristics when the lower pipe, with an attached interference ring, is forced into the larger top pipe. Laboratory tests were used to determine critical loads and post performance for various post lengths. Field tests showed that the posts could perform in actual mining conditions. The post has the ability to provide support in highly yielding ground and also, because of its slender profile, enhance ventilation and provide more area for travelways and escapeways. The design is simple enough to allow for fabrication at most mine shop facilities.

Jan 1, 1989

By H. William Zeller

The Bureau of Mines is conducting research to determine whether the use of chemical surfactants improves respirable coal dust control and is evaluating laboratory test criteria for selecting effective surfactants. This publication presents the results from wetting effectiveness tests with emphasis on the capillary rise test. The test variables investigated included coal particle size, type of surfactant, surfactant concentration, test duration, and mineral con-tent of the water. In addition to the rise test, measurements of con-tact angle, zeta potential, and sink time for various coal and surfactant combinations were conducted. No significant correlations among the four wetting tests were observed, a surprising result which implies that each test type measures specific aspects of the wetting phenomenon and also that each test type should only be used to select surfactants for specific applications. For example, the rise test shows solution penetration into porous materials, and the sink test discriminates among surfactants for dispersing finely ground materials into suspension. Another important conclusion is that combinations of agents retain their individual wetting properties, allowing mixtures to be for-mulated to perform well in both rise and sink tests.

Jan 1, 1983

By O. C. Blade

This survey report, the first for this type of fuel, is issued to provide information on the characteristics of the burner-fuel oils now manufactured for sale. Reports of surveys of diesel fuel, conducted under a cooperative agreement between the American Petroleum Institute and the Bureau of Mines, United States Deportment of the Interior, have been published annually since 1950.2/ This survey of burner-fuel oils is similar to the diesel-fuel surveys In pattern and has been conducted under an extension of the same agreement at the request of the Oil-Heat Institute of America and the petroleum industry. It is not intended to conflict with the diesel-fuel survey but rather to supplement it. Burner-fuel oils, also specifically referred to as heating oil, range oil, furnace oil, "Bunker C," and fuel oil, are sold in increasing volumes for use in this country and for export. Sales of all grades of fuel oil in the United States have increased from 340 million barrels in 1926Y to over a billion barrels per year. 4/ Distillate fuel oil sales, in proportion to total fuel-oil volume sold, increased from 42 percent in 1950 to 50 percent in 1954. Sales of distillate and the heavier residual oils during recent years are shown: [ ] It must be realized that the data given are not accurate indications of the use of these materials as burner fuels. Some burner fuel, used as range oil, is kerosine, which is not included above. A large volume of fuel oil--approximately 30 percent of the distillate type and some residual fuel oil--is sold as diesel fuel. Smaller

Jan 1, 1955

By Marvin L. Whisman

This report describes the preparation of tritium-labeled organic compounds to be used by the Federal Bureau of Mines in studying the role of certain gasoline constituents in gum-forming mechanisms. The gasoline constituents that have been investigated boil within a range of approximately 90 to 230° C. and can be classified as paraffins. naphthenes, olefins, diolefins, monocyclic aromatics, polycyclic aromatics, and organic sulfur, nitrogen,: and oxygen compounds. The technique of Wilzbach has been applied to more than 50 samples. Purification techniques have been developed that accomplish rapid and effective purification as well as removal of labile tritium in a one-step operation. Data are presented to show the rate of exchange between tritium and hydrogen that can be expected for a variety of compounds common to a full-boiling-range gasoline. These values should be useful to other investigators using tracer programs involving tritium labeled compounds.

Jan 1, 1961

By M. L. Wouden

In the late 1970's, the Bureau of Mines began to examine the criteria for reestablishing vegetative cover on coal strip mine spoils near Glenrock, WY. A 9-acre plot, consisting of (1) spoils covered with topsoil, (2) spoils without topsoil, and (3) spoils treated with sewage sludge, was constructed. These plots were seeded with Tegmar intermediate wheatgrass (Agropyron intermedium), Fairway crested wheatgrass (A. cristatum), and Critana thickspike wheatgrass (A. dasystachyum). After 5 yr, the topsoil had about 70 pct plant coverage. Revegetated spoils, without topsoil addition, averaged approximately 30 pct plant coverage, and sewage sludge-treated spoils had about 45 pct plant coverage. Comparison of grass types showed the intermediate wheatgrass produced greater surface coverage.

Jan 1, 1986

By X. Shi, K. S. Kaspnak

"The generation of free radicals from reactions of nickel (Il)-thiol complexes with molecular oxygen and model lipid hydroperoxides was investigated by electron spin resonance (ESR) utilizing 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap. Incubation of nickel (II) [Ni(II)) with cysteine in an aerobic environment generated hydroxyl (·OH) radical, which then reacted with cysteine to generate a carbon-centered alkyl ( · R) radical. Radical generation was inhibited under a nitrogen atmosphere. Model lipid hydroperoxides, cumene hydroperoxide, and I-butyl hydroperoxide enhanced the yield of these radicals and also generated an alkoxyl (·OR) radical. Radical yield decreased by approximately half under a nitrogen atmosphere. Although histidine did not cause radical formation in the reaction between Ni(II) and cumene hydroperoxide under aerobic conditions, the addition of histidine to a mixture containing Ni(ll), cysteine, and cumene hydroperoxide under the same experimental conditions increased the yield of · R radical but lowered the yield of ·OR and ·OH radical adducts. It thus appears that histidine caused the ·OH attack to be more site-specific. Similar results were obtained utilizing 1-butyl hydroperoxide. Penicillamine or N-acetylcysteine yielded similar results except that under aerobic conditions, reaction between Ni(ll) and N-acetylcysteine without hydroperoxide did not generate a significant concentration of free radicals. Under the same experimental conditions, cystine did not generate any detectable free radicals, suggesting an important role of the -SH group in Ni(II)-mediated free radical generation. The results indicate that free radical generation from the reaction of Ni(Il)-thiol complexes and molecular oxygen, and/or lipid hydroperoxides, may play an important role in the mechanism(s) of Ni(II) toxicity and carcinogenesis. INTRODUCTIONWhile nickel is a well-recognized carcinogen [l, 2]. the underlying biochemical mechanisms remain unclear (3, 4). Recent studies suggest that these mechanisms may involve oxidative DNA damage through free radicals, especially the hydroxyl (•OH) radical [5-13]. The mechanisms of nickel carcinogenicity and toxicity may also involve lipid peroxidation [14-21]. Unlike ferrous ion [Fe(II)], the Ni(II) cation itself does not directly react with 02, H2O2, or lipid hydroperoxides to generate free radicals [12, 21]. However, it has been reported that Ni(II) complexes with certain synthetic oligopeptides, e.g., tetraglycine or glycylglycylhistidine, make Ni(II) reactive with 02. This reaction results in transitory formation of Ni(III) and degradation of the organic ligand via free radical reactions [22]. Such Ni(II)-peptide complexes are also capable of reacting with H2O2 to produce oxygen free radicals [11, 12]. Although the cellular environ¬ment may not contain these particular peptide ligands that are known to render Ni(II) redox active in vitro, it does contain a variety of oligopeptides that are capable of forming Ni(II) complexes at physiological pH, and thus may facilitate Ni(II) redox activity in vivo. These oligopeptides include glutathione (y-L glutamylycysteinylglycine), carnosine (homocarnosine (y aminobutyryl-L-histidine), and anserine ( B-alany1-3-methyl-L-histidine)."

Nov 1, 1995

Prevention of coal-mine explosions depends largely upon thorough knowledge of the causes that initiate explosions. A review of coal-mine explosions in one geographical area when supplemented by nationwide data of similar nature, should serve as a guide for the adoption of measures for explosion prevention. Explosions in bituminous-coal mines of the United States during the 10 years ended December 31, 1932, ranked third in the causes of fatal accidents and constituted 16.1 percent of all fatal accidents in bituminous mines. Kentucky now ranks fourth in coal output in the coal-producing States of this country; a study of the coal-mine explosions in this state will be of definite interest locally among coal-mining people, as well as to those in the coal-mining industry who are concerned in preventing coal-mine explosions. This circular reviews gas and dust explosions in Kentucky coal mines to show their hazards, to point out the influence of certain factors in causing explosions, and to indicate the effectiveness of preventive measures.

Jan 1, 1934

By Charles T. Holland

ANALYSIS of 117 occurrences of bumps in coal mines shows that 67.6 percent are associated with pillar-line points.4 Slabbing and splitting pillars, development, and other unfavorable milling practices in abutment areas may be a contributory or the primary cause of bumps. The cure for pillar-line bumps is to recognize areas that can be expected to become highly stressed and to project the mining plan and operations to eliminate such areas insofar as possible. If such areas cannot be eliminated, then the mining plan and operations should be projected to avoid the necessity of disturbing these areas before the stresses have been dissipated.

Jan 1, 1954

By C. C. Popoff

The Dunkleberg district is in the Flint Creek Range of the northern Rocky Mountains, about 45 miles northwest of Butte, Mont. Silver - lead and zinc mineralization occurs over an area 4 miles long from north to south and 1 to 2 miles wide from west to east. Ore in appreciable quantity has been produced, mostly from the Forest Rose group of mines in the southern part of the district. The Forest Rose mine was the largest producer of lead and the Wasa mine, a mile farther south, the main producer of zinc. The total output of ore from these properties during World War II was 113,000 tons, or 98.2 percent of the total recorded production of the district. The Wasa mine was examined by a Bureau of Mines engineer2/ in 1944. Subsequent investigations during 1946, 1947, and 1948 included trenching and drilling Fn the Wasa area and examination of the Forest Rose and other mines.

Jan 1, 1953

By Thomas J. Peters

The Lime Creek study area lies 100 air km east of Boise, and 70 air km northeast of Mountain Home, Idaho. The eastern boundary of the 28,000-hectare, east-west-elongate study area lies 0.2 km west of the 3,077-m-high Smoky Dome. The area is mainly underlain by Cretaceous granitoid rocks of the Idaho batholith. No mineral resources were identified, but two mines and one prospect were found in the study area. At the President and the Last Chance mines, in the southwest corner of the study area, gold mineralization occurs along steeply dipping east-northeast-trending faults and associated quartz veins, and within adjacent Cretaceous granitic rock. The mineralized material is not rich enough to mine underground, and near surface, open-pit-mineable deposit areas could not be identified. The third prospect, the Ventura, is within altered pink granite of probable Tertiary age, but metal concentrations are very low. Geothermal activity was not observed within the study area, but hot springs do occur in the Vicinity. Bedrock observed is only suitable for the most basic high bulk and low end value applications, such as crushed aggregate. Numerous sources for crushed stone occur closer to markets. Alluvial concentrate (placer) samples did not contain free gold, and no substantial alluvial bars were seen; deposits were too small to contain resources.

Jan 1, 1993

By Robert C. Johnson

Water-swelling fluormicas and fluormontmorillonoids were synthesized and described. They were found predominantly in the system Mg0 - MgF2 - Si02, with varying amounts of Li+ or Na+, Some water-swelling synthetic minerals were prepared with only strontium or lead in the twelvefold position, Water- swelling compounds containing either K+ or Ba+ were not found. The synthesized water-swelling products were shown by electron microscopy, X-ray diffraction, and chemical analysis to be typically two-silica-layer, platy compounds, Except for the complete substitution of fluoride for hydroxyl, the compounds were similar to the natural micas or montmorillonites. The stability and properties of the compounds were further established by electrodialysis, by differential thermal analysis, and by anion and cation exchange methods. Fluoride in the interlayer positions was nonexchangeable except through decomposition of the product. Exchanging the sodium or the lithium of the synthetic fluormicas or fluormontmorillonoids with potassium ion, particularly those derived from KOH provided a product from which a completely inorganic paper of extraordinary flexibility was fabricated. This paper had excellent mechanical and electrical properties except for water adsorption and a high power factor. Neither of these problems was solved during this investigation. However, papers with dielectric strength from 1,500 to 5,000 volts per mil were readily fabricated, particularly from the lithium containing fluormicas or fluormontmorill onoids.

Jan 1, 1963

By Ludwig Schmidt

This report, the second of a series, presents the results of laboratory corrosion studies which were made in connection with a one-year test on aluminum lease tanks conducted by the United States Bureau of Mines. Part 1 of the report contains the results of the field tests. The studies were made on an oil lease in a so-called "sour district," near Borger, Tex., where free hydrogen sulphide accompanied the production of oil, gas, and salt water. Steel tanks previously used on the lease had suffered severe corrosion, because steel is inherently susceptible to attack by hydrogen sulphide. Because of the high resistivity of aluminum to the action of hydrogen sulphide, it was believed that this metal had promising possibilities as a material for the construction of lease tanks in "sour districts." The results of the one-year field test proved that aluminum lease tanks will withstand corrosion by hydrosulphide, but it as found that aluminum was susceptible to attack by salt water, which was invariably present in certain portions of the tanks, and that hydrogen sulphide accelerated this salt-water corrosion in an indirect manner, as will be explained hereinafter. In order to study corrosion conditions encountered in the tanks during the test period, a laboratory was maintained at the site of the aluminum lease tanks.

Jan 1, 1931

By C. H. Johnson

The Big Jim mine of the United Eastern Mining Co. is at Oatman, Mohave County, Ariz. Oatman is in the foothills on the western side of the Black Mountains, at an elevation of about 3,000 feet. It is on a paved highway about 30 miles west of Kingman, the principal distributing; center for mining supplies in the district, and 25 miles from Topock, en the Colorado River. Both latter towns are stations on the Santa Fe Railroad; Oatman has no roil connection. Mining conditions are typical of western Arizona; water is scarce, no mine timber is available locally, and the winters arc mild and the summers hot. The supply of a killed labor is usually adequate, but in 1933-34 it w not more than sufficient for the restricted operations. Wages have been $4.00 to $4.50 for miners. Electric power was supplied from Kingman and cost about 2.6 cents per kilowatt-hour.

Jan 1, 1935