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By Richard W. Lewis, Lloyd Carpenter

The objective of the investigation was to determine spectrochemically 19 elements in the general range of 0.5 to 1,000 ppm in high - purity hafnium and its compounds . Samples were converted thermally to hafnium dioxide , mixed with buffer - carrier - internal standards , and excited by a dc arc . Spectra were recorded on photographic plates . Transmittance values were recorded densitometrically and converted to relative - intensity ratios . Four groups of standards were used to establish analytical curves from which the concentrations of impurities were obtained . Average precision of the method was 14.2 percent relative standard deviation , and relative error was 4.2 percent .

Jan 1, 1964

By Frank B. Fulkerson

A study was made of the economic factors governing silver production in the Coeur d'Alene mining region, Shoshone County, Idaho. Production and other stat is tics were analyzed. It was concluded that if the rapid rise in the open market price that began late in 1961 continues, greater production of the metal should result from the mines of the Coeur d?Alene mining region. However, the output gain would be limited, because costs per ton of ore mined would rise as production was increased beyond optimum capacity. Advances in the price of silver would increase the size of ore reserves by making some marginal ore profitable to mine and by providing greater funds for exploration projects that might result in discoveries adding to the reserves. Output of byproduct silver from lead-zinc mining probably will not exceed 4.3 million ounces, judging from the trend from 1946 to 1961.

Jan 1, 1964

INTERNATIONAL conferences on safety in mines originated in 1912 when, in response to an invitation issued by the United States, representatives of Austria-Hungary, Belgium, France, and Germany participated in a conference held in Pittsburgh, Pa The record shows that a permanent organization was proposed to be developed through. diplomatic channels. However, the advent of war 2 years later prevented this proposal from coming to fruition. No further cooperation between the Bureau of Mines and a group having: similar interests in a foreign country took place until 1924, when formal cooperation with the Safety in Mines Research Board of Great Britain was established. Interchange of personnel and results of research under that arrangement have resulted in a number of publications in both countries and more rapid advance in knowledge than could have been obtained through the same efforts exerted independently.

Jan 1, 1950

By David C. Grant

In situ uranium mining offers the advantages of minimal environmental disturbance, low capital and operating costs, and reduced mining development time. It is becoming an increasingly attractive mining method for the recovery of uranium from secondary ore deposits. In order to better understand the process, a laboratory technique was developed and used to study and simulate both the chemical and physical phenomena occurring in ore bodies during in situ leaching. The laboratory simulation technique has been used to determine effects of leaching variables on permeability uranium recovery, and post-leach aquifer restoration. This report describes the simulation system and testing procedure in sufficient detail to allow the construction of the system, and to perform the desired leaching tests. With construction of such a system, in situ leaching of a given ore using various leach conditions can be evaluated relatively rapidly in the laboratory. Not only could optimum leach conditions be selected for existing ore bodies, but also exploitation of new ore bodies could be accelerated.

Jan 1, 1985

By R. E. Brewer

A critical review of the numerous test methods that have been devised for measuring the "plastic" and "swelling" properties of bituminous coking coals and the practical evaluation of the data obtained has long been needed. The author appreciates fully, first, the arduous problem of doing justice to the merits and limitations of the many original test methods and their manifold modifications and, second, the more difficult task of interpreting the test data obtained in their practical applications to the important problems involved in the coking process. It has been the constant aim of the author to point out the broader significance of the test principles employed in the different classes of test methods and the usefulness of the test data obtained in relation to the problem of coking bituminous coals, rather than to stimulate unduly a controversial criticism of the merits and limitations of any particular class of test methods or of individual test methods devised by different workers. The task has been quite difficult because of the almost total lack of accepted test standards and specifications.

Jan 1, 1942

By S. Ralph Austin

This Bureau of Mines investigation determined the effects of so-called annealing at high temperatures on radon-222 emanation from domestic uranium ores. Concurrently, a method was developed for closely estimating the emanation coefficients of hot samples from measurements of their gamma activity after cooling. Emanation coefficients of 102 samples from 14 domestic areas of past, present, and possible future uranium production were investigated using modifications of the closed-can, gamma-only assay method at and after cooling from 100° to 1,000° C. True annealing probably does not occur below 500° C. In limited investigations at 500° C and above, effects of annealing are masked by the effects of other parameters. Emanation is commonly less at one or more of the steps investigated in the 100° to 500° C range than before heating. This decrease is tentatively attributed to water loss at temperatures dependent upon the minerals present. The average sample emanates least at 300° C; emanation increases with higher temperatures to at least 900° C. Emanation decreases sharply on cooling, but it is partially restored by prolonged exposure to the atmosphere at room temperature. Higher than average emanation of coffinite ores at 500° C and above may be related to destruction of the coffinite crystal structure.

Jan 1, 1979

By I. Iwasaki

In recent years the rapid depletion of high-grade iron ores and the demand by blast furnace operators for increasingly low-silica ores have stimulated interest in flotation studies of low-grade iron ores, such as wash-ore tailings and oxidized taconites. Four processes have been reported for the flotation separation of these iron ores--anionic and cationic collection of the iron oxides, cationic collection of siliceous gangue, and anionic collection of activated siliceous gangue (5).5/ The effectiveness of any one method, however, depends largely on the mineralogical composition and on the physical structure of the sample; hence, a comprehensive study of the floatability of the individual minerals occurring in these materials is essential. A review of the literature shows that the floatability of hematite and magnetite has been frequently investigated, whereas very little corresponding information is available for goethite, or for its more earthy form, limonite, both of which are abundant in the Mesabi and Cuyuna ores (19). The purpose of this investigation was to formulate general information on the floatability of goethite. Vacuum flotation, contact angle measurement, and simplified flotation tests using a modified Hallimond tube were used. The experimental results were correlated with the electrokinetic properties of goethite as determined by streaming potential measurement. The results were used to interpret the batch flotation tests made on an artificial mixture of quartz and goethite.

Jan 1, 1960

By Sidney Katell

The reaction of coal, oil, or natural gas with air and oxygen and/or steam yields a gas containing varying amounts of impurities. Depending on the raw material and the end use of the product, these impurities include solids, such as dust or slag, and gases, such as hydrogen sulfide, carbon dioxide, and nitrogen. Considerable effort has been expended in developing and operating purification systems, and the literature is replete with equipment data and operating results. The research problems, the design, and the operation of the various systems have been the subjects of patent applications, journal articles, and textbooks.

Jan 1, 1959

By D. Harrington

An explosive may be defined as a substance (usually a mixture) that has the property of yielding, readily to combustion or oxidation upon application of flame or shock, the combustion or oxidation process being rapid and accompanied by formation of such relatively large quantities of gases that much violence and pressure are produced; these, in turn, react against their surroundings and cause what is termed an explosion. By their very nature their action is destructive and disruptive of adjunct materials; hence, all explosives axe potentially hazardous and every type of explosive, irrespective of its relative safety, should be handled, .stored, and used with utmost care at all times and under all conditions. It should always be remembered that any explosive can be rude safe only in certain of its features and under certain conditions and circumstance. If these facts (and they certainly are facts) are always kept in mind, most of the modern types of explosives can be utilized advantageously in our industrial life and with a considerable degree of safety. That commercial explosives can be handled. safely is borne out in part by the fact that in the past 15 years at least 3,000,000,000 pounds of the commercial explosive dynamite have been transported by railroads in the United State, without injury to any person, insofar as available records indicate.

Jan 1, 1939

By Ann G. Kim

The Bureau of Mines estimated the methane content of a coal, which depends primarily upon rank and pressure, from the adsorption equation V =kpn, where k and n are constants related to rank. By incorporating corrections for moisture, ash, and temperature, and estimating pressure and temperature as a function of depth, the methane content of coal in place can be estimated from the following equation: [ ] Values calculated with this equation generally are in reasonable agreement with direct determinations. By assuming a standard moisture and ash content, and using the hydrostatic head to estimate pressure, a graph of rank and depth versus gas content was constructed. Although estimated values were consistently high for several high-volatile bituminous coals from an area where the pressure is known to be less than hydrostatic, the estimated methane content for most coals shows reasonable agreement with values determined by the direct method.

Jan 1, 1977

Study to develop a new and more cost effective equipment system, incorporating a winch-pulled dozer blade, for leveling spoil and performing reclamation of area strip mines.

Jan 1, 1975

By Sarkis G. Ampian

Published optical microscopic and X- ray diffraction characteristics of the following compounds are critically evaluated and compared with Bureau of Mines data : Tricalcium aluminate , calcium monoa luminate , dodecacalcium heptaluminate , dicalcium silicate , tricalcium silicate , and sodium aluminate . A recommended set of definitive optical and X- ray diffraction characteristics is presented . These values are used to identify products of the lime soda sinter process for production of alumina . Polymorphism of gamma- , beta- , and alpha prime - dicalcium silicate is reexamined , and new data are presented on polymorphism of tricalcium silicate and sodium aluminate by high- temperature X- ray diffractometry . Polymorphism is not observed for tricalcium aluminate , calcium monoaluminate , and dodecacalcium heptaluminate . Bureau of Mines data indicating a stoichiometry of 12Ca0.7A10 for the phase 5Ca0.3A1 0₂ are discussed . A critical review of the literature concerning calcium dia luminate and sodium undecaluminate ( 8 -A10 ) is also included .

Jan 1, 1964

By A. G. Starliper

Research was conducted by the Bureau of Mines to determine feasible roasting methods for the removal and the recovery of germanium, cadmium, and lead as enriched fractions from sphalerite concentrates. The two types of roasting processes studied were: (1) Batch, with a stationary bed, and (2) continuous, with a suspended bed, Results indicated that either method gave satisfactory metallurgical recoveries} but the continuous process is recommended because of inherent advantages. Final products were enriched fractions that could be treated by conventional methods for production of metallic germanium, cadmium, and lead. In the batch process, the concentrates were placed in a large tube furnace and heated at 1,080° C, an average of 3 hours. During the heating period, inert, reducing} or sulfur-laden gases were passed over the stationary charge to convey the sublimed metal sulfides from the hot portion of the tube to a lower temperature condensing zone at the end of the tube, where the metal sulfides were collected on baffles and recovered. In the batch and fluidizing roasting processes alike, the gases passed over or through the charge and served only as carriers for the sublimates and as suspension media in fluidization roasting. Since both processes depended on the volatilization, at relatively high vapor pressures, of the sulfides of germanium, cadmium, and lead, it was imperative that very little oxygen come in contact with the charge to alter the sulfide minerals. Germanium has a high affinity for oxygen, but in this instance it was buffered by being in solid solution in zinc sulfide.

Jan 1, 1961

By William A. Beck

"The Old Cline mine, also known as the Old Cruse mine, was first worked for gold in1895. The property was opened by several shafts and trenches; and some stoping has been done, producing several cars of copper-gold ore in the early nineteen hundreds. Chalcopyrite is visible in selected samples; and, with the aid of a mineralite, several samples showing a considerable amount of scheelite were found on the old waste dumps.The mine is in Township 6, Cabarrus County, N. C., 5 miles north of the village of Mount Pleasant, 10 miles northeast of Concord, and about one-half mile south of Watts Crossroads. It is one-fourth mile east of the county road.When examined, the property was owned by H. F. Tompkinson, Concord, N. C., and was leased, with option to buy, by L. Nash. Titles of record were not investigated.As stated above, the Cline mine was first worked in 1895. The property was Purchased in 1902 by J. A. Clark and A. A. Smith of Atlanta, Ga., and worked for gold and copper. No record is available of the quantity of ore removed during these operations.A Bureau of Mines mining engineer3/ examined the mine as, a copper prospect on October 13, 1944.The Cline mine is in an area characterized by flat to rolling topography, dissected by many streams and rivers. It lies in the Piedmont Plateau and Varies in elevation from 700 feet to 800 feet. The surrounding country is partly wooded and partly cleared farm land.A quartz vein occurs in country rock of quartzite and greenstone.4./ The ore occurs in a series of quartz lenses, having a width of 1 to 3 feet and dipping about 750 NE, and striking N. 300 W. All these lenses have fairly sharp boundaries and in some cases are entirely separated from each other, while at other times they are connected by thin stringers of quartz. They can be traced for 1,000 to 1,200 feet by a series of shafts and test pits."

Apr 1, 1946

By W. P. Diamond, John C. LaScola, D. M. Hyman

In 1972, the Bureau of Mines developed a direct-method test for measuring the gas content of virgin coal core samples for coal mine health and safety considerations. Since that time, approximately 1,500 coal samples from more than 250 coalbeds in 17 States have been collected for gas content determination. The gas content data, when combined with geologic and engineering studies, can be used as a basis for a preliminary estimate of mine ventilation requirements, and to determine if methane drainage in advance of mining should be considered. The data are also critical in delineating coalbed methane resources and in utilization feasibility studies. This report makes the Bureau's extensive data base of gas content data more readily available to the coal and gas industries. The data are presented in tabular form, alphabetically by coalbed name and by State. The components of the total gas content (lost, desorbed, and residual gas) are given, Location (State and county), sample depth, coalbed or formation name, and coal rank are included for geographic and geologic identification.

Jan 1, 1986

By D. W. Dareing

Multiple branch wellbores and horizontal holes, when applied to deep lying ore bodies, have the potential of significantly reducing well costs by reducing total footage drilled per acre of well pattern. In addition, horizontal holes may increase sweep efficiency. Well completion is a major problem. They must be cased to contain leaching solutions within the underground portion of the production loop. Several drilling and completion concepts are given and evaluated in the report. Our evaluation shows that there is economic incentive to further develop these concepts for field application to ore bodies 1,500 feet. Multiple branch concepts are the most attractive. They can reduce well costs by as much as 30° when applied to 2,000 feet ore body depths (44%, at 5,000 feet) and can accommodate a lamer pump than conventional vertical wells. We recommend this concept be developed further to accommodate either dual or triple branches.

Jan 1, 1980

By H. G. Iverson

An investigation was conducted on the conditions affecting the precipitation of aluminum by autoclaving synthetic solutions containing Na2SO4, Al2(SO4)3, H2SO4, and H2O. Virtually all of the alumina could be precipitated as natroalunite (NaAl3(SO4)2 (OH)6). This product could be readily filtered and dried. Results are reported in terms of alumina precipitated in this compound and not in terms of alumina itself. Solutions of ~ 0.30, ~ 0.60, and ~ 0.80 mole/liter A1203 and various concentrations of H2SO4 and Na2S04 were investigated. The optimum time and temperature for autoclaving were 20 to 30 minutes at 200° C. The highest yields of natroalunite were obtained from solutions containing little H2SO4 and ~ 2 moles Na2SO4 per mole A1202. Acid in quantities of 0.3 to 0.5 mole/mole of alumina in solution depressed the yield to 90 percent or less. In differential thermal analysis, at 1,000° C the natroalunite precipitate decomposed without melting to yield SO, and SO2 gases, a solid composed of Na2SO4, and gamma and alpha Al203. Continued heating to 1,200° C produced No SO, and alpha A1303. Water-leaching of this product removed the Na2S04 and left a final residue of alpha A1203.

Jan 1, 1968

By C. Stephan, E. Weiss, J. Trackemas, M. Sapko

The National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory (PRL), in collaboration with the Mine Safety and Health Administration (MSHA), the mining industry, and seal manufacturers recently conducted a series of full-scale experiments within the underground experimental mine at PRL’s Lake Lynn Laboratory. The purpose of the experiments was toe valuate the explosion-resistant characteristics of several new seal designs for rapid deployment during mine emergencies. These seals can be deployed in 6 to 10 hr and are capable of with standing explosion overpressures in excess of 140 kPa (20 psi). These novel seal designs use available mine materials, do not require conventional rib hitching, and, most importantly, can substantially reduce exposure time for coal miners during sealing and mine recovery operations.

By John Millhiser, Margaret Bonarek, Dennis McLaughlin

This report contains a description of the contract activities performed by ENSCO, Inc. under contract No. H0178069. The purpose of this project was to enhance the Bureau of Mine's Cableless Electronic Survey System use to aid in the drilling of long (approx. 2000 feet) boreholes in coal. This drilling is performed as part of the methane drainage program. The system that was ultimately developed was field tested and demonstrated in actual in-mine drilling activities. The significance of this system as compared to previous drill survey systems is the fact that it surveys without having to be inserted and removed for each survey point. It is so designed that it can withstand the shock and vibration experience by the drill string during drilling. This means an increased productivity is now possible in that drill operators can determine drill bit positioning in a near real-time environment.

By W. W. Adams

"The National Safety Competition of 1930, the seventh annual contest conducted by the United States Bureau of Mines to promote safety in the mines and quarries of the United States, has been concluded, and the five winners of the bronze trophies, The Sentinels of Safety,' which are provided by the Explosives Engineer magazine and awarded annually for the most excellent safety records, have been determined by the committee of award. One trophy was awarded to an anthracite mine in Pennsylvania, one to a bituminous coal mine in the same State, one to an iron-ore mine in Michigan one to a gypsum mine in Ohio, and one to an iron-ore opencut mine in Michigan.These trophies were awarded to the companies for having the smallest loss of time from accidents in proportion to the total number of man-hours worked by all employees at their mine or quarry. Honorable mention was awarded to each mine or quarry that ranked second, third, fourth, or fifth in its own ground and to all plants that were operated without a lost-time accident during the contest year. Eighty-four out of 337 plants that competed for the trophies were operated without an accident that disabled an employee beyond the day on which the accident occurred.Under the contest rules, all mines and quarries were divided into five groups, four of the groups representing different classes of underground mining operations (anthracite, bituminous coal, metallic ore, and nonmetallic mineral), and the fifth group repre-senting the quarrying or opencut mining of minerals whether metallic or nonmetallic. Twenty-seven mines were included in the anthracite group, 68 in the bituminous group, 52 in the metal group, 24 in the nonmetallic-mine group, and 166 in the quarry and opencut-mine group. The total of 337 mines and quarries was 26 more than the number of plants that completed the contest during the previous year.The committee of award which determined the winners of the contest was composed of seven members, all known throughout the mineral industry but not connected with the United States Bureau of Mines. The committee included W. H. Cameron, managing director of the National Safety Council; William Green, president of the American Federation of Labor; James F. Callbreath, Secretary of the American Mining Congress; T. T. Read, Vinton professor of mining of Columbia University and editor of Mining and Metallurgy; C. B. Huntress, executive secretary of the National Coal Association; A. J. Curtis, assistant to the general manager of the Portland Cement Association; A. T. Goldbeck, director of the bureau of engineering of the National Crushed Stone Association."

Jun 1, 1931