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By R. J. Leary

The natural gas-air burner described in this report was designed and constructed to meet the thermal requirements of a convective process for heating steel scrap. This process involved downward combustion of natural gas with air, blending the combustion products with diluent air, and then passing this tempered stream of gases downward through a porous bed of steel scrap contained in the furnace chamber. The scrap would be heated to a temperature limited by the adiabatic flame temperature of the gas stream in a period that depended on the rate at which heat was supplied per unit of bed cross section. The temperature of the gas stream would be limited to that beyond which an objectionable degree of oxidation would occur; for carbon steel this limit had been found to vary from 1,900° to 2,100° F. with the superficial velocity of the gas stream. The productivity of the process was dependent on the rate of heat input per unit of furnace cross section; for the 3-foot-diameter experimental furnace an input of 680,000 B.t.u. per hour was desired. The burner described was designed to meet these conditions of temperature and heat input. It provided for three streams of entering gases: (1) A primary air-fuel mixture too rich to be combustible, that is, above the upper flammable limit; (2) secondary air for combustion of the primary mixture; and (3) tertiary air, principally for cooling the combustion products to the temperatures desired for process operation. Downward combustion of the primary and secondary streams occurred in a flame stabilized on an annular port, while tertiary air flowed in an annular path surrounding the port and also through an axial channel whose wall formed the inner ring of the annular port. This burner performed beyond the designed heat-input rates while producing stable flames, which were adjusted readily to the temperatures desired. Gas-stream temperatures were easily controlled to within 15° F. of the desired value by simple manual adjustment of the flow valves.

Jan 1, 1959

By M. B. Cooke

An analytical method for the determination of the gum-forming material in gasoline has been developed by the Bureau of Mines, during a study nor in progress to determine the best rays for elimination of such constituents from gasoline. This method is similar in principle to that previously described by Smith end Cooke,2 which involved evaporation of e sample of gasoline in a small glass dish. The evaporation was started on an actively boiling steam bath and completed in an air oven at 105°C. In the improved method described below, the stem bath has been replaced by a steam heated oven in which an inert atmosphere is maintained. Air is excluded from the oven, consequently the precision of the determination is increased. Furthermore, evaporating dishes different from those previously described may be used.

Jan 1, 1925

By McHenry Mosier

This is the fourth progress report in the series on the use of detachable rock-drill bits in the metal mines of the United States. It contains comparative statistics and costs or drilling at eight mines not reviewed in previous reports, comparison of the use of detachable bits at small mines and large mines, a discussion on the life of drill rods, and general conclusions derived from an analysis of the rock-drilling practice at all the mines investigated on this survey. This paper completes the descriptions of operating practice in rock drilling at individual mines. Data on drilling practices at 28 mines are given in appendices I and II and drilling costs are shown in appendix III. Research in the fundamentals of rock drilling, including the use of detachable bits, has been undertaken by the Bureau of Mines in its testing adit at Mount Weather, Va. Reports on the progress off this investigation will be issued when results warrant their publication.

Jan 1, 1937

By F. L. Wideman

This paper lists resources of sulfur in Wyoming, Colorado, Utah, New Mexico, and Arizons, an area comprising approximately 522,600 square miles, Sources of sulfur occuring within the region are sulfur are, pyrite and pyritic ores, and natural gases and petroleum. Data concerning these sources are presented on a statewide basis. Some of the known deposits of sulfur ore are surficial and of fumerole origin; other deposits have resulted from oxidation of pyrite or sulfide ores of copper, lead, and zinc. The deposits are small and the sulfur is distributed erratically in them. There is a small production from some of the deposits, and the material produced is used as soil conditioner.

Jan 1, 1957

By John Nagy

Results of initial research by the Bureau of Mines are given on the dust explosion hazard of float coal and on the related factors of occurrence, rate of production, sampling techniques, transport, and deposition of float coal. Tentatively, it is suggested that where float coal deposits prevail, a mini-mum of 80 percent incombustible be maintained in the top 1/8-inch layer to neutralize the explosion hazard of the surficial coal deposit.

Jan 1, 1965

By W. C. Phalen

"Tho the term “magnesite” is generally applied to the iron-bearing carbonate of magnesium, such as is found in Austria and Hungary, by some Austrian magnesite is referred to as bruennerite. The mineral bruennerite has become of commercial importance only in Austria. The important deposits are found in Styria, lower Austria and northern Hungary. It is of interest to know that the world's largest deposit of spathic iron ores or iron carbonate (FeCO3), occurs at Eisenerz, Styria, while the world's largest deposit of spathic bruennerite is found at Veitsch in the same province.The Styrian and lower Austrian deposits are located much nearer the Adriatic sea than are the deposits of northern Hungary; and it is from the former that most of the exported magnesite has come. They are located south-west of Vienna, and extend west from Semmering thru the Murz Valley to Tyrol. The chief deposits reckoning from east to west are those of Semmering, Veitsch, Breitenau, Trieben, Radenthein, and Dienten.The largest and most important deposit is that at Veitsch located near Mitterdorf, on the South Austrian railroad in the Murz Valley, Styria. Here the magnesite, which occurs in the form of a lens is quarried on the slope of a hill in a series of terraces about 50 feet apart. The entire work extends thru a vertical distance of 500 feet. The huge magnesite lens is nearly 4 of a mile long and over 1,000 feet in width, and probably extends to a considerable depth.The formation containing the magnesite extends eastward beyond Vienna into Northern Hungary where magnesite is quarried beyond Jolsva and Nyustya in the Gomor district. In spite of the remote location of these deposits as compared with those in Styria, magnesite was shipped from them before the war a distance of 360 miles to the port of Fiume for overseas shipments to other parts of Europe and to America.The average analysis showing the composition of the Austria-Hungary mineral is as follows:The magnesite occurs as lenticular masses in a belt of Carboniferous rocks consisting mainly of metamorphosed Shales, sandstones, conglomerates,,and limestone, It is grayish in color when fresh, and contains sufficient ferrous carbonate to blacken it when calcined. It turns brown owing to the oxide ion of the ferrous carbonate when exposed to the air. The quantity of carbonate of iron is ariable and different analyses show that it ranges up to 13 or 14%For the most part, only the sintered article has been imported into The United States. This material has achieved an enviable reputation for its uniformity both as to chemical and physical characteristics. The homogeneity of the sintered Austrian magnesite is doubtless due in part to the averaging effect of the different operations, such as crushing, dressing, sintering, And mixing, n effect which is not obtainable in mere hand samples.There is comparatively little variability in the sintered magnesite as marketed, and five analyses of this sintered magnesite as quoted by Cornu* are gas follows:"

Aug 1, 1919

By Paul Wellman

A computer program is presented that may be used to calculate the bare equipment cost of the major processing units for any hot potassium carbonate gas purification system. The program is designed such that, with only minor modifications, it could be used with a variety of computer systems.

Jan 1, 1968

By Francis Church Linxoln

"This property was explored as part of a general investigation of zinc-prodccing areas of southwestern Wisconsin at a time when an effort was being made to increase the production metals important to the Nation's war program. This report describes the work that was done and presents the data obtained.ACKNOWLEDGEMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the and that they make the greatest possible contribution to national security and economy. It is the policy of the bureau to publish the facts developed by each exploratory protect as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, P., G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director. Special acknowledgment is due Professor G. H. Pett, of the Wisconsin Institute of Technology at Platteville, Wis., Jack Tracy, manager of the Mifflin Mining Co., and J. M VanMatre, representative of the Defense Property, for their assistance in the work. Acknowledgment is also due to A. F. Agnew and A. V. Heyl, geologists of the Federal Geological Survey, for furnishing geologic interpretations and lithologic studies of the drill-hole sections. All drilling was done under the immediate supervision of Francis C. Lincoln and M. Howard Berliner, project engineers, Edward P. Barrett, district engineer, Minneapolis, and E. D. Gardner, regional engineer, of the Bureau of Mines."

Sep 1, 1946

By D. H. Baker

THIS REPORT presents the technique and equipment used in determining the hardness of titanium sponge. Detailed descriptions are given of the methods used in preparing test samples for chemical analysis and hardness testing, the method of melting and surfacing test ingots, and the technique of reading Brinell-hardness impressions. The arc-melting furnace described, for which engineering drawings are included, will produce from 70 to 90 double-melted buttons each 8 hours of operation. Experimental data are also presented depicting the effect on hardness of the methods of surfacing specimens, temperature of test specimens, and the effect of time at test load. These data show that surfacing of the specimen involves no critical machining operations but that the test surface must be paralleled by a relatively flat surface for contact with the anvil of the Brinell tester. The heating of a specimen to 150° C. during surfacing does not materially affect the results if the ingot is cooled to room temperature before the hardness impressions are made. The optimum time at load appears to be approximately 30 seconds, but load times of as much as 1/ ½ minutes will not cause major errors.

Jan 1, 1959

By Frank E. Cash

The data in this circular were compiled so that individual phosphate companies might have the benefit of the experience of other phosphate companies, and that industries in general might compare experiences (taking into consideration relative hazards), thereby promoting accident preven¬tion. ACKNOWLEDGMENTS The descriptive matter is taken in part from a. paper by Cash and von Bernewitz.4/ Production figures ore from Mineral Resources of the United States;5/ accident data were furnished by each of the operating companies in the pebble-phosphate district, and their assistance in making this report possible is gratefully acknowledged.

Jan 1, 1936

By D. K. Dysinger

In this U.S. Bureau of Mines study, neodymium metal of 99.8 pct purity was prepared by electrolysis of Nd203 salts dissolved in a molten fluoride electrolyte. The metal was electrowon in a molten state at current efficiencies of 50 to 60 pct. Oxygen and carbon were the major impurities detected in the product. During operation of the small-scale laboratory cell, a number of technical problems including anode effect, low oxide solubility in the electrolyte, high neodymium metal solubility, reactivity of the metal with the cell materials, and back reaction of the metal with the anode gases were encountered. Approaches to improve cell operation and prospects for commercial adoption of the electrolytic production of neodymium metal are discussed.

Jan 1, 2010

By R. J. Matetic

The objective of this U.S. Bureau of Mines hydrologic-subsidence investigation was to evaluate the effects of longwall mining on the local ground water regime through field monitoring and numerical modeling. Field data were obtained from multiple-position borehole extensometers (MPBX's) that were used to measure subsurface displacements. Survey monuments were installed to measure mining-induced surface deformations. Numerous drawdown and recovery tests were performed to characterize hydrologic properties of the overburden strata. Coreholes were drilled above the study area to determine lithologic and strength characteristics of the overburden strata using the rock samples collected. Electronic recorders were installed on all monitoring wells to continuously monitor ground water levels in coordination with mining of the longwall panels. A combined finite element model of the deformation of overlying strata, and it's influence on ground water flow was used to define the change in local and regional water budgets. The predicted effects of the postmining ground water system determined by the model correlated well with field data collected from the fieldsite. Without an infiltration rate added to the model, a static decrease of 3.0 m (10 ft) in water level would occur due to mining of both longwall panels and if an infiltration rate was inputted in the model, no predicted long-term effects would occur to the ground water system.

Jan 1, 2010

By B. J. Arnold, F. F. Aplan

"The captive bubble and sessile drop contact angle techniques have been used to evaluate the hydrophobicity of petrographically identified coal macerals. The magnitude of the contact angle on vitrinite is shown to be a function of coal rank ( %C, %0 and % vitrinite reflectance), increasing with increasing rank to a maximum for low volatile bituminous rank coals then decreasing for anthracite. The least data scatter is found when vitrinite reflectance is used as a rank parameter. Contact angles measured or estimated for other discrete macerals, indicate a variation in hydrophobicity based on coal type. These data correlate well with known flotation results. Coal is a heterogeneous mixture of plant remains and associated minerals that have undergone chemical and physical changes by biological and geological processes. These plant remains form coal macerals, discrete organic entities in the coal which have characteristic chemical and physical properties. As the differing chemical nature of each maceral will affect its behaviour in processes such as carbonization the separation of macerals during coal preparation may provide an important asset in coal utilization.Separation of some of the macerals based on specific gravity has been achieved in the laboratory, and by Sun and Cohen , in a study of two Pennsylvania bituminous coal preparation plants. It was indicated that the lighter exinites report almost exclusively to the clean coal while the denser inertinites are concentrated in the higher gravity fractions. The Longwy-Burstlein process6 took advantage of the difference in hardness or friability of the macerals by using impact breakage followed by screening to remove the more friable vitrain,clarain and fusain. The remaining durain, often high in spore content, was then recrushed. The re-mixed fractions produced the optimum size for obtaining the best coke strength for a particular coal.Separation or concentration of rnacerals by froth flotation largely depends on differences in the hydrophobicity of the macerals. Sun and Cohen 5 . indicated an order of decreasing floatability as exinite, vitrinite and inertinite, while a Russian study (as cited by Brown 7 ) showed that vitrains floated more readily than the duller types. More recently, Hirt and Aplan8 showed that 'pseudovitrinite' floats somewhat faster than does vitrinite while fusinite floats very slowly. Olson and A plan found that vitrinite floated easily while substantial quantities of the non-floated coal contained fusinitic material. Burdon noted that vitrinite is more floatable than semifusinite, and Sarker et a/. 11 have shown that vitrinite is selectively concentrated by froth flotation and oil agglomeration. Sun indicated that flotation, based on his calculated floatability index, should decrease in the order clarain, vitrain, fusain and durain; while Horsley and Smith 13 indicated the decrease to be: vitrain, clarain, durain and fusain. These differences can be attributed to the specific coals used in each study and to the individual macerals composing each coal type within a given coal."

Jan 1, 1989

By James E. Hill

TECHNOLOGY is best nurtured by a sympathetic climate that is a composite of many factors. Necessity is a highly motivating factor as illustrated by the abnormal surge of technologic development curing wartime. Other factors include appropriate timing, economic pressures, available personnel, and in some instances, legislative action. Problems of recent concern to mining technology have been the quality and quantity of available technical personnel and the possibilities of restrictive legislation. The quality and quantity of technically trained personnel may be inadequate to meet the rapidly increasing complexity of modern technology coupled with the growing demand for qualified personnel. The question of appropriate training was a subject for debate.2 The curriculum and methods of teaching have changed. Questions have been raised on the relationship of scientist and engineer, interdisciplinary versus specialized curriculum, undergraduate versus graduate training, and the place of the smaller schools versus the large university-research complexes that have developed at some universities. Various aspects of the subject of engineering education for the mining industry were discussed at the meeting on Mining and Mineral Engineering Manpower at the Michigan College of Mining and Technology, November 18-19, 1963. Meanwhile, the trend toward interdisciplinary training gathers momentum as illustrated by the establishment of the School of Engineering Science at Johns Hopkins, the Schools of Engineering and Applied Science at Columbia, Princeton, and Yale, the Division of Engineering and Applied Physics at Harvard and, more recently, the School of Engineering Science at Florida State University which cuts across the conventional areas of civil, mechanical, electrical, and chemical engineering.

Jan 1, 1964

By O. T. Barrett, R. F. Aberethy, H. N. Cooper, Thomas Fraer, William L. Crentz

"INTRODUCTION The object of the techniques described in this report is to determine the possibilities of separating the components of a raw coal into such grades as may be necessary to recover some exceptionally clean functions for special purposes.To do this commercial gravity methods would require separation at very low specific gravities, entirely outside the range of conventional practice. Hence, a technique has been developed for breaking down cool ample, into very close fractions within the gravity range of the (-lean coal matter as well as for separating it from the refuse and particles.Such data on the fundamental specific-gravity consist of the clean-coal matter will serve to appraise the difficulty of the problem and to chow be accomplished if and when effective methods of making such separations commercially are developed."

May 1, 1945

By F. D. Wang

The Bureau of Mines has developed a computer program for evaluating pit slope stability by the finite element stress analysis and limiting equilibrium method. The program includes the finite element method of stress analysis using triangular elements, finite-element model mesh generation, plotting of the model mesh and stress contours, calculation of a factor of safety along a circular or a plane failure surface, and location of a critical circular failure surface. Instructions for preparation of input data, an example problem, and the program listing are presented.

Jan 1, 1972

By Michael J. Gallagher

Diamond-bit performance data accumulated by the Bureau of Mines in core-drilling limestone and dolomite show that the physical characteristics of the diamonds and the sizes and types of bits used are economically significant. An analysis of the data establishes one trend of particular significance to those engaged in core drilling: Bits set with small, low-quality drill bort are the most economical. Detailed analysis of the factors that affect diamond-bit performance, such as size and quality of diamonds, sizes and types of bits, percentage of core recovered, and physical characteristics of bit matrices are assessed in the tables, bar charts, and discussion.

Jan 1, 1958

By Perry G. Cotter

As a portion of a general program for the synthesis of hard materials, a method was sought by which the hardness and density of tungsten carbide (WC)-cobalt compacts could be increased. It was demonstrated by Cotter that these improvements in quality could be made by employing an electric-resistance sintering process in which heat and pressure are applied simultaneously to presintered compacts composed of powdered tungsten carbide and cobalt. This conclusion was based on tests of material prepared by Cotter on welding equipment in use at the U. S. Naval Engineering Experiment Station, Annapolis, Md., and at Rensselaer Polytechnic Institute, Troy, N. Y. Rockwell-hardness tests made at Norris and core-drilling tests made at the Mount Weather Station of the Bureau of Mines indicated that, for some purposes, carbide material made by this process might be superior to the chemically analogous commercial products prepared by ordinary sintering methods. A program to develop optimum conditions for the electric-resistance sintering of tungsten carbide-cobalt compacts was initiated. The program was followed by a systematic evaluation of the hardness and density of compacts prepared by this method along with a series of carbide compacts furnished by various manufacturers. This paper presents a description of the electric-resistance sintering of tungsten carbide-cobalt compacts and the results of comparative physical tests.

Jan 1, 1955

By A. C. Fielder

It is with some diffidence that I venture to address the Montreal Section of the Society of Chemical industry on the subject of motor fuel from coal at a time when crude petroleum is produced in greater quantities than at any time in history, and at a time when the known reserves exceed all expectations, even the optimistic estimates of the Committee of Eleven of the American Petroleum Institute. Not only are new fields being discovered in America a -an embarrassing frequency but sources outside of the North American Continent show, unmistakable signs of adding materially to the world's sources of oil. Were it not for the tremendous scientific and technical importance of the work done in the past few years in transforming coal into liquid motor fuels, I should prefer to let this subject rest until a more propitious time, such as prevailed some years ago, when the gasoline consumption curve was rising rapidly and the production curve was slowing in its upward rise. That was the period which stimulated the researches which resulted in tetra ethyl lead and anti-knock gasolines on this side of the Atlantic and in methanol, synthetic gasoline and hydrogenation of coal on the other side. Some of you will recall a symposium on Motor Fuels and Oil Conservation held at the Chemists' Club n New York in September; 1925. Dr. R. L. Brown and I presented a paper at this meeting on "Complete Utilization of Coal and Motor, Fuel, in which we pointed out that coal was the most likely raw material source of gasoline substitutes if and when needed. We grouped the present and future, processes' for obtaining motor fuel from coal in three classes, namely:

Jan 1, 1928

By A. Visnapuu

The Bureau of Mines investigated carbonyl processing techniques for the recovery of the critical metals Ni, Co, Mn, and Cr from domestic primary and secondary sources. In most cases, the source materials require reductive precarbonylation treatment to metallize the contained Fe, Ni, and Co compounds to render them reactive with CO. The critical metals were recovered either by direct conversion to the respective carbonyls or as upgraded products by carbonyl removal of an undesirable metal. Best metal-to-metal carbonyl conversion was under CO pressure, from 80 atm upward, and at 1400 C. Carbonylation was accelerated by the addition of HzS in small quantities. CO pressure, temperature, promoter and pretreatment trends, and other factors enhancing metal carbonyl formation are presented.

Jan 1, 1987