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By J. D. Vincent, Pierre R. Hines

INTRODUCTION OF FROTH FLOTATION INTO THE UNITED STATES "The introduction and development of the flotation process have proved to be of such momentous importance to the mining industry of the United States that they deserve to be considered historically ." T. A. Rickard l James M. Hyde installed the first froth flotation process in the U. S., about Aug. 1, 1911, at the Basin Reduction Co. plant, Basin, Mont., which was then under lease to the Butte and Superior Copper Co.2 Two months later, the Minerals Separation Ltd.. filed suit in the U. S. District Court of Montana against Mr. Hyde char& him with infringement of their Patent 835, 120/1906. The U. S. District Court decided in favor of Minerals Separation Ltd. on July 28, 1913. This decision was reversed by the Ninth Court of Appeals in San Francisco on May 4, 1914. Then the U. S. Supreme Court, on Dec. 11, 1916, upheld the patent on three counts only but restricted it to 'the use of less than one percent of oil.” The Miami Copper Co. was sued by Minerals Separation on Oct. 10, 1914, for infringement of Patents 835,120 and 962,678, and 1,099,699. The Miami Copper Co. was operating under John M. Callow's froth flotation process Patent 1,104,755/~uly 23, 1914. Miami lost this suit in the District Court of Wilmington, Del., and appealed to the Court of Appeals, Third Circuit, Philadelphia. The Third Court of Appeals decided against Miami, May 24, 1917. The case was referred to a Master and hearings to determine profit and damages were not settled until 1923. Nevada Consolidated Copper Co. was sued Sept. 9, 1919, and Magma Copper Co. was sued Jan. 10, 1920. Thus, the first ten years of froth flotation in the U. S. were beset by patent litigation. This litigation suppressed the free circulation of new discoveries or useful information that might be cited in a patent suit against the originator; it accounts for many of the blank spaces in the historical record. T. A. Rickard3 has reviewed the history of flotation and has given the chain of discoveries, patents, and processes that resulted in froth flotation. He has re- ported also on the patent litigation beginning in 1911 and ending in November 1923, when Minerals Separation's Patent 835,120 expired. He comments on

Jan 1, 1962

By Basil B. Zavoico

The World War I1 spread to Russia on June 22, 1941, when the German Armies began their invasion. The Soviet industries, which were already engaged in a tremendous armament program, further accelerated the flow of munitions, and equipment and supplies for all purposes not directly military were either entirely eliminated or reduced to an absolute minimum. With the occupation by German armies of the Dniepr and Kharkov industrial regions, this trend was necessarily further accentuated. The oil industry of Russia, in consequence, was left to rely more and more upon itself, its own very limited manufacturing facilities, extensive repair shops and probably much used equipment out of order stacked in the warehouses. All evidence available to date points to the fact that the new situation not only did not affect the production either quantitatively or qualitatively, but, on the contrary, caused a larger flow of much needed fuels to the country's war machine, primarily by renaissance of both management and labor. The oil industry of the Soviet Union, left to depend entirely upon itself for equip ment and supplies, and even for new workers and technicians to replace those called into the services, did and is still doing a good and effective job. Since it could not hope for new equipment and parts and could not blame any other industry for the delays in delivery, it dragged out old machines from storage and repaired them in its own machine shops. Often such stored and used equipment was but slightly defective, waiting for some small part from factories in Central Russia, plants that now were either in German hands or entirely converted to the manufacture of munitions. More particularly, instead of the pipe that could not be taken to the Caucasus from Central Russia, casing reclaimed from abandoned or submarginal wells was used, or pipe from the abandoned or but slightly used pipe lines; and this practice is being continued even now on a large scale, to create an ample reserve for the duration of the conflict. Indirectly such a development was even an improvement on pre-war days, when many wells about to be completed had to wait for weeks, even months, for the arrival of new pipe, all blame then being placed outside of the industry on the factories in Central Russia. For the purpose of reclaiming equipment and pipe still usable, special crews were organized. The war also caused much quicker adaptation of certain American practices and introduction of many emergency measures, such as: removal of derricks upon completion of wells and the use of drilling equipment mounted on skids for rapid transfer from location to location—both of these practices, while standard in the U.S.A., being new in Russia; installation of simplified surface pumping units; substitution of wooden bearings in the surface pump equipment; completion of wells in the Ural-Volga district, where formations are hard and tight throughout the sedimentary column, without either casing or

Jan 1, 1942

By Basil B. Zavoico

The World War I1 spread to Russia on June 22, 1941, when the German Armies began their invasion. The Soviet industries, which were already engaged in a tremendous armament program, further accelerated the flow of munitions, and equipment and supplies for all purposes not directly military were either entirely eliminated or reduced to an absolute minimum. With the occupation by German armies of the Dniepr and Kharkov industrial regions, this trend was necessarily further accentuated. The oil industry of Russia, in consequence, was left to rely more and more upon itself, its own very limited manufacturing facilities, extensive repair shops and probably much used equipment out of order stacked in the warehouses. All evidence available to date points to the fact that the new situation not only did not affect the production either quantitatively or qualitatively, but, on the contrary, caused a larger flow of much needed fuels to the country's war machine, primarily by renaissance of both management and labor. The oil industry of the Soviet Union, left to depend entirely upon itself for equip ment and supplies, and even for new workers and technicians to replace those called into the services, did and is still doing a good and effective job. Since it could not hope for new equipment and parts and could not blame any other industry for the delays in delivery, it dragged out old machines from storage and repaired them in its own machine shops. Often such stored and used equipment was but slightly defective, waiting for some small part from factories in Central Russia, plants that now were either in German hands or entirely converted to the manufacture of munitions. More particularly, instead of the pipe that could not be taken to the Caucasus from Central Russia, casing reclaimed from abandoned or submarginal wells was used, or pipe from the abandoned or but slightly used pipe lines; and this practice is being continued even now on a large scale, to create an ample reserve for the duration of the conflict. Indirectly such a development was even an improvement on pre-war days, when many wells about to be completed had to wait for weeks, even months, for the arrival of new pipe, all blame then being placed outside of the industry on the factories in Central Russia. For the purpose of reclaiming equipment and pipe still usable, special crews were organized. The war also caused much quicker adaptation of certain American practices and introduction of many emergency measures, such as: removal of derricks upon completion of wells and the use of drilling equipment mounted on skids for rapid transfer from location to location—both of these practices, while standard in the U.S.A., being new in Russia; installation of simplified surface pumping units; substitution of wooden bearings in the surface pump equipment; completion of wells in the Ural-Volga district, where formations are hard and tight throughout the sedimentary column, without either casing or

Jan 1, 1942

By N. R. Pillai, T. R. Anantharaman

THE striking alterations in the constitution and structure of cast A1-Si alloys brought about by addition of small quantities of some elements, particularly sodium, have been extensively investigated. Many theories' have also been propounded to explain this so-called lLmodification" process, but their main concern has been more to throw light on the action of sodium than to arrive at general criteria underlying this interesting as well as intriguing phenomenon. Such theories have generally dealt with one or more, but not all, factors that seem to have a direct or indirect influence on the cast structure of A1-Si alloys, e.g.., formation of ternary eutectic, removal of oxides, hydroxides, and so forth, by fluxing, morphological changes in silicon, and inhibition of growth of silicon grains through colloidal action, compound formation, preferential adsorption, or reduction of surface tension. Kim and Heine2 were the first to study the modification of A1-Si alloys in a systematic as well as comprehensive manner and to list the important characteristics of a satisfactory modifier. According to them, an important property of the modifying element is its capacity to form a stable compound with silicon in the appropriate temperature range. Other subsidiary requirements are that the element should get adequately dispersed in the melt at the inoculating temperature and also must not form stable compounds with aluminum. The alkali elements, with the exception of lithium, fulfill these requirements most satisfactorily and have been shown to be successful modifiers by these workers. Sodium is the most effective of these and seems to be in a class by itself for various reasons noted by earlier investigators.37 None of the other elements tried by Kim and Heine, viz., Mg, Ca, Cd, Zn, In, Pb, P, As, Bi, S, and Se, showed any significant modifying action. We wish to report here briefly on substantial modifications in cast eutectic A1-Si alloys brought about by some V group elements, which do not comply with the Kim-Heine requirements. Aluminum and silicon used in the present work were indigenous and had purities of 99.8 and 99.5 pct, re-

Jan 1, 1969

By Bernard York, John J. Reed

W. 0. Philbrook (Carnegie Institute of Technology, Phila.)—Mr. DeVaney's paper is a valuable addition to the growing technology of the magnetic roasting of lean iron ores. His furnace is ingeniously designed to permit close control of the process and to achieve high thermal efficiency by counter-current heat exchange and the withdrawal of both solid and gaseous products at relatively low temperatures. The principle of using a lean reducing gas to avoid over-reduction of the ore even at high operating temperatures (for rapid reaction rate) is thoroughly sound. The gas analyses and flow rates reported, however, are internally incon- sistent and render suspect any details of a heat balance based upon them. While it is entirely proper to consider the entrant gas as a reagent and to account only for the heat evolved by consuming a portion of the gas, many operators are accustomed to a heat balance using the total calorific value of the reagent supplied; and comparison of heat balances made with different bases of calculation can be quite misleading. Since Mr. DeVaney's paper is likely to be cited frequently in future discussions of magnetic roasting processes, it seems worth while to point out the internal discrepancies and to give alternate values of heat requirements for different bases of calculation.

Jan 1, 1954

By Mourad Aissa

From our previous work (Gardner, Aissa, and Verghese, 1982) on determining the residence time distribution of ball mi 11s from radiotracer data taken in closed-circuit operation without interruption of the process, it occurred to us that the data taken for this purpose also contained information on the breakage rates of all the sizes present. It is the purpose of the present work to evaluate methods to obtain breakage rates from this data. A numerical solution for the impulse injection and subsequent detection of radiotracer in a closed-circuit linear comminution process is developed and used with typical breakage parameters, residence time distribution, and classifier functions to study and evaluate these methods.

Jan 1, 1984

By Reich G. Gaertner

Almost every mining engineer who has had charge of extensive underground workings will have observed how often directions as to course and levels, deduced from careful theodolite measurements, have been slighted or disregarded by mine-foremen and shift-bosses, and how often these tedious measurements had to be repeated, even for minor works, such as ventilation-drifts or winzes, in order to carry them on with the required or desirable regularity. Besides the time and care absorbed by theodolite surveys, there is still another inconvenience, namely, the interruption of transportation during the time of observation, and, in heavily producing mines, the loss consequent upon such interruption. In proposing a subsidiary instrument to the theodolite, it is my purpose not to present a new one, but simply to recommend to the consideration of American mining engineers one which has been in use in nearly all the prominent mines of Europe for many decades, and has there fulfilled its purpose admirably. I refer to the mining or hanging compass (Fig. 1). At my urgent request, the firm of Keuffel & Esser, of New York, have lately constructed this instrument in a form which adapts it better to use in this country. By the addition of the trigonometer, the banging compass becomes at once an instrument which will prove of value even in the hands of foremen and practical miners, who have little or no knowledge of trigonometrical calculations. Probably many will say that me have no use for needle-instruments ; that our modern theodolites are of such perfect description, and leave so little to be desired, that the introduction of a compass would look like a step backwards compared to the fine results obtained by angle-instruments. I concede all that, and do not pre-

Jan 1, 1886

By E. S. Bumps, H. D. Kessler, M. Hansen

The titanium-rich end of the Ti-AI phase diagram has been determined to the compound TiAI3 (62.7 pct Al), thus joining the aluminum-rich portion previously investigated by others and completing the diagram. Micrographic analysis and X-ray diffraction were the chief methods used to determine the phase relationships. THE Ti-Al phase diagram has been investigated as part of a program on titanium phase diagrams for the Wright Air Development Center. Included in the available information concerning the phase relationships in titanium-rich Ti-A1 alloys is a brief statement by Brown' that: "aluminum raises the transformation temperature to 1000°C (183Z°F)." This observation is interesting in that it is the first example of a metallic alloying component raising the transformation temperature of titanium, and consequently widening the field of the a solid solution. Busch and Freyer' presented resistivity data which indicated the formation of titanium-rich solid solutions of 1 and 3 pct A1 alloys prepared by powder metallurgy methods. Duweza found that there is only one other intermediate phase other than the known compound TiA1, (62.7 pct Al). This phase, designated as y, is of variable composition; its crystal structure is of the AuCu type and is therefore based on the composition TiAl (36.02 pct Al). Earlier work on the constitution of the aluminum-rich alloys has been reviewed by Hansen, and need not be discussed here. The tetragonal crystal lattice of TiAl,, as found by Fink, Van Horn, and Budge," was confirmed by Brauer." Recently, Schubert7 has reported that TiA1, is homogeneous within a limited composition range; however, the solubility limits were not given. The Ti-A1 phase diagram as presented in. this paper was determined by micrographic analysis of alloys containing from 1 to 62 pct Al, annealed at and quenched from temperatures between 700" and 1400°C. The phases and phase ranges investigated extend to the compound TiA1, (62.7 pct Al) to join the aluminum-rich end of the system determined by other investigators, thus completing the diagram. Methods of Investigation Preparation of Alloys: Iodide titanium, 99.9+ pct pure, obtained from the New Jersey Zinc Co., and high-purity (99.99+ pct) aluminum sheet from the Aluminum Co. of America were used to make up alloy ingots weighing 10 to 20 g. Detailed descriptions of melting techniques have been presented previously for work on the Ti-Mo and Ti-Cb> nd Ti-Si" phase diagrams. Briefly, the melting practice consisted of arc melting an accurately weighed charge in a copper block crucible insert in a non-consumable tungsten electrode furnace, under helium at atmospheric pressure. All ingots were carefully weighed after melting to detect possible losses. Comparison of weight before and after melting showed no appreciable weight changes. Also, chemical analyses were in close agreement with nominal compositions, Table I. The diagram as presented is, therefore, based on nominal compositions. Alloys were prepared having the following nominal aluminum contents: 1 ... 36 (1 pct increments), 38, 40, 41, 42.5, 44, 45, 46, 47.5, 49 . . . 64 (1 pct increments), 67, 70, 80, and 90. Ingots with up to 14 pct A1 were cold-pressed various amounts in order to increase the rate of attaining equilibrium structures on heat treatment. The amount of cold deformation that could be applied decreased with increasing aluminum content, until alloys containing 12 pct A1 or more cracked after only a few percent deformation. Annealing Treatments: Samples annealed at temperatures of 700" to 1000°C were sealed in

Jan 1, 1953

The Library of the above-named Societies is open from 9, A.M. to 10 P.M. on all week-days, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special, attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that, the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library y forwarding copies of mining reports, maps privately issued, and similar material, which will be classified; indexed, and made availableto other members. Suggestions for additions to the Library, either y purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 8, 1914

The Library of the above-named Societies is open from 9 A.M. to 10 P.M. on all week-days, except holidays, from September 1, to June 30, and from 9 A.M. to 6.P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. T o these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be What is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 7, 1914

By M. J. Humenick, K. Garwacka

A laboratory experimental research project was conducted to evaluate the use of chlorine for the oxidative destruction of residual ammonia that may remain in ground water after in-situ uranium solution mining operations. The work tested the idea of injecting high strength calcium hypochlorite solution into the mining zone to convert ammonia to nitrogen gas as a final cleanup process for ammonia removal from the ground water system. This paper details ammonia removal efficiency as a function of chlorine dose, reactant, and product material balances, and how the concept may be used as a final ground water restoration process.

Jan 1, 1985

By H. E. Cline, T. H. Alden

A study zvas made of rate-sensitive plastic deformation and superplasticity in alloys of lead and tin. These alloys (lead, PO-19 pct Sn, Sn-38 pct Pb, Sn-2 pct Pb, tin) were extruded, aged at room temperature, or melted and resolidified to produce a variety of ~nicrostrnctures. Flow stress us strain rate data were obtained frorn tension tests for strain rates between 10-6 and 1 min-1. The curve log o .us log £ was S-shaped jor fine-grained materials and approxinzately linear for coarse-grained nzaterials. At constant grain size, the behavior was relatively insensitive to conposition. High rate sensitivity (d log o/d log k) and superplasticity occurred at intermediate strain rates in fine-grained materials and are believed to be associated with a transition with strain rate in the mode of plastic flow. This transition was shifted to higher strain rates with increasing temperataire or decrensing grain size. The high rate rneclzanisrn is presunzed to be slip, while rnetallographic evidence sug-gests that the low rate lnechanism is pain boundary sliding. PEARSON' discovered that extruded eutectic alloys of Pb-Sn and Bi-Sn could be elongated as much as 2000 pct in tension. The ability for stretching decreased with aging time or annealing to increase the grain size. At high strain rates, or if the material was in the cast condition, normal ductility was observed. Following deformation of the extruded Pb-Sn eutectic at low rates, Pearson observed an equiaxed granular structure on an initially flat surface, while rapid straining produced elongated grains. He attributed the large deformation in the extruded alloys to the persistence of extremely small grains to a temperature sufficiently high for inter granular flow. Avery and backofen2 measured the strain rate sensitivity of the flow stress, m = d In old In 6, in the Pb-Sn eutectic and established a correlation between m and the tensile elongation. In the extruded eutectic alloy the strain rate sensitivity was 0.1 to 0.2 at rapid rates and the elongation was small, while at low rates m increased to 0.4 to 0.6 and superplastic elongation was observed. They also noted a grain size effect. In the case of the cast Pb-Sn eutectic the strain rate sensitivity remained at 0.1 over the range of strain rates of their experiment (3 x 10"3 to 2 min-I). These authors suggested that diffusional (Nabarro-Herring) creep was the mechanism by which deformation occurred at low strain rates, while climb-controlled creep occurred at high rates. Two predictions of this model are that, at low strain rates, the strain rate sensitivity approaches 1, i.e., Newtonian viscosity, and that the strain rate at constant stress varies as D/L2, where D is the coefficient of self-diffusion and L the grain size. More recently, a mechanical and microstructural investigation of the dilute superplastic alloy, Sn-5 pct Bi, has been done.3 The results show that the high strain rate sensitivity is associated with a transition with strain rate of the mechanism of plastic flow. At low strain rates, grain boundary sliding and its associated accommodation processes were evident, while at high strain rates quasi-uniform slip was concluded to be the dominant deformation process. The following experiments were performed to extend our knowledge of the phenomena of superplasticity to a larger range of strain rates, compositions, temperatures, and microstructures in the Pb-Sn alloy system. The question of why a cast structure does not exhibit viscous behavior although it appears to have a fine microstructure2 was investigated.

Jan 1, 1968

By Vernon Read, John K. Hayes

Generally speaking, drilling equipment and techniques presently in use are not capable of meeting the complex technical-and economic-requirements of deep core drilling. Drilling to great depths involves increasing risk, time, and money. And it is especially true that costs increase with depth when conventional core drilling methods are used. Introduction of wire-line drilling techniques has been a great boon to deep core drilling, and is rapidly gaining general acceptance. But, in spite of recent progress, there remains a great need to improve productive drilling time and penetration rates, and still maintain high core recoveries.

Jan 1, 1959

By V. Patarini, M. Salkind

BECAUSE of its high strength and stiffness coupled with low density, continuous boron filament is showing great promise as a potential reinforcement for both metals and nonmetals. Of primary consideration for structural applications is the fatigue behavior of boron fiber composites. Composite fatigue behavior is dependent upon three factors: 1) fiber fatigue behavior, 2) matrix fatigue behavior, and 3) the effect of the interface and fiber ends. The purpose of this note is to describe the behavior of boron filament in rotating beam fatigue. The filament, described by Talley' and Galasso, Salkind, Kuehl, and Patarini,' was made by the hydrogen reduction of boron trichloride on a hot tungsten filament. Testing was performed using a commercial rotating beam wire fatigue tester* described by Votta.~ One end of the test sample is held in a chuck in a synchronous motor. The sample is bent around in a "U" shape, and the other end inserted into a carbide bushing. The maximum strain occurs at the bottom of the "U" where the radius of curvature is a minimum. The strain is adjusted by adjusting the length of the specimen and the location of the bushing. Samples were rotated at 3600 rpm and an automatic shutoff device used to determine the number of cycles to failure. The measurements were accurate to the nearest 360 cycles. The fatigue behavior is summarized in Fig. 1 for fifty-one samples of 4.8 x 10"3 in. diam fibers and ten samples of 3.2 X 10"3 in. diam fiber. The two sample groups represent two different filament production runs and two different nominal size groups. Both groups exhibited nominal tensile strengths of 400,000 psi. No significant difference in the fatigue behavior of the two sample groups is apparent. The scatter in the data is not unexpected for a brittle filament which exhibits a tensile strength distribution with a standard deviation of 10 to 15 pct. Because the test procedure provides a known outer fiber strain in the sample, the maximum stress was calculated assuming a Young's modulus of 58 x 10' psi. This value was selected as being representative of several nominal fiber sizes.2 All of the samples which failed exhibited sudden, catastrophic fracture, and no permanent deformation. One sample was stopped after 1.66 x lo8 cycles at *200,000 psi. The fiber exhibited no apparent damage or deformation. It is apparent that the fatigue resistance of boron filament is quite good. It can therefore be speculated that the fatigue behavior of boron fiber composites would be controlled by the "weaker links", namely matrix fatigue resistance and interface behavior. In fact, preliminary investigations have revealed that this is true for boron-reinforced aluminum? It should be noted that the data presented herein may not necessarily reflect the tensile fatigue behavior of boron filament. It is well-known that boron filament has a radial residual stress pattern with the outer surface in ~om~ression.~ Because of this fact, tensile failure is normally nucleated in the interior of the filament.5 Since the data presented herein is for a rotating beam test in which only the outer surface of the fiber is stressed to the maximum value, it would be incorrect to assume that the failure mechanism and fatigue behavior would be the same if the fiber were tested in tensile fatigue. The fact that many of the data are well above the nominal 400,000 psi tensile strength would tend to support this argument. The authors would like to express their appreciation to the United Aircraft Research Laboratories for supporting this investigation and for permission to publish the results. A portion of this effort was supported by the Air Force Materials Laboratory under contract AF33(615)-2125.

Jan 1, 1968

By W. A. Koehler, M. E. Hinkle

INTRODUCTION THE oxidation of pyrites and marcasite in coal-mine strata to produce discolored acid mine drainage has long been explained by chemical reactions occurring in three stages: I. The iron sulphide minerals are oxidized by air in the presence of water to produce a nearly colorless solution of fer¬rous (iron) sulphate and some sulphuric acid. 2. The ferrous sulphate and part of the sulphuric acid combine with additional oxygen to form ferric (iron) sulphate. 3. The ferric sulphate hydrolyzes to form a reddish-brown precipitate and additional sulphuric acid. Nevertheless, chemical data alone are not sufficient to explain all observed facts. The first stage seems to proceed more slowly in the chemical laboratory than in nature. The second and third stages nor¬mally occur to a marked extent within a few days with raw mine water. However, the visible discoloration that characterizes these latter stages will not develop for months if the mine water is sterilized. By means of bacteriological techniques, two organisms have been isolated from acid coal-mine drainage. These are believed to have a part in promoting the chemical reactions summarized above. One organism is considered to be Thio¬bacillus thiooxidans, which is known to be able to convert elementary sulphur or sodium thiosulphate to sulphuric acid. Its relation to the formation of acid mine drainage has not yet been established. Apparently it does not promote the oxida¬tion of ferrous iron compounds in mine, drainage to the ferric state. The second organism has not been identi¬fied by name but is described as "Gram negative, non-spore-forming rods approxi¬mately 0.4 micron wide by o.8 to 1.0 micron long." A pure culture of this when added to sterile mine water will cause the latter to become amber and develop the typical rusty precipitate. However, it has not been found to convert sulphur com¬pounds to sulphuric acid. Further research is planned to determine whether or not these microorganisms play a significant part in the first stage of oxidation whereby pyrites and marcasite minerals go into solution. Some of the conditions found in abandoned sections of coal mines, such as a reduced percentage of oxygen and increased percentage of carbon dioxide in the air, as well as the existing temperature and acidity ranges, will be tolerated by and may even be favorable to these organisms. ACID COAL MINE DRAINAGE Acid coal mine drainage has been the concern of coal mine operators, industrial¬ists, sportsmen and public officials for many years. The amount of acid flowing into our streams in the coal-producing areas varies considerably from mine to mine and from

Jan 1, 1948

By R. W. Fountain, M. Korchynsky

The precipitation phenomena occurring in cobalt-tantalum alloys have been investigated in the temperature range frm 500" to 1050°C by correlating the results of metallographic, X-ray, micro-and macrohardness, and electrical resistivity studies. The property andmacrohardness,changes were found to depend on 1) general precipitation, and 2) lamellar precipitation. Two new intermetallic phases have been identified: 1) a Co3Ta, a metastable ordered face-centered-cubic compound, and 2) a stable ß Co3Ta phase of hexagonal structure. In addition, the previously reported Co2Ta phase was found to exist in two allotropic modifications: the hexagonal MgZn,-type and the cubic MgCu2-type Laves phases. SINCE a large variety of structures can result as a consequence of the decomposition of a solid solution, predictions on the nature of property changes are difficult, if not impossible, to make. For any rational attempt to correlate properties and structures of a precipitation-hardenable alloy, a detailed understanding of the kinetics of decomposition and morphology of phase separation, as well as knowledge of phase relationships, appears to be prerequisite. Information of this type has been accumulated in the past for many alloy systems, both of theoretical and pastforpractical importance.1,2 Although the presence of intermetallic compounds has been reported in cobalt-base alloys,3 the amount of published information on precipitation-hardenable cobalt-base systems is very limited. A survey of the binary phase diagrams of cobalt indicates that cobalt-tantalum alloys might be of interest as typical of other cobalt-base systems in which Laves phases of the A,B type can be precipitated from solid solution. The present work has been undertaken, therefore, to study the kinetics and morphology of the precipitation reaction in this system and to establish a base for a correlation between the structural aspects and properties in this class of alloys. PREVIOUS WORK The only available phase diagram of the cobalt-tantalum system is based on the work of Koster and Mulfinger. According to these authors, the maximum solubility of tantalum in cobalt is about 13 pct (at 1275°C) and. less than 7 pct at room temperature. Tantalum additions lower the temperature of allotropic transformation of cobalt (about 420°C), and at 7 pct Ta, the high-temperature face-centered-cubic modification (ß cobalt) is retained at room temperature. The precipitating phase was originally designated as Co5Ta2 compound (55.2 pct Ta, about 1550°C melting point), but subsequent investigations by wallbaum5" identified this constituent as the A,B-type Laves phase. Wallbaum's data indicate that there are two modifications of this intermetallic compound: one richer in cobalt (Co2.2 Tao.8)of the hexagonal MgNi, type; and another of a higher tantalum content (Co2Ta) of the cubic MgCu, type. On the other hand, Elliott7 found that the cobalt-rich alloy (CO2.10,Tao.~l) was predominantly the cubic MgCu, type at 800°C and a mixture of both the MgCu2 and the hexagonal MgZn,-type Laves phases at 1000°C. At 1200°C, Elliott found only the MgZn, type while at 1400°C, he observed only the MgCu2 type. At the stoichiometric composition, Co2Ta, Elliott reported only the cubic MgCu2-type Laves phase in the temperature range of 600oto 1600°C. The precipitation of the cobalt-tantalum intermetallic compound is accompanied by a marked increase in hardness. According to Koster's4 data, the Brinell hardness of an 8 pct Ta-Co alloy increases from 230 to 340 upon short-time aging at 800°C. EXPERIMENTAL PROCEDURE The binary cobalt-tantalum alloys investigated contained 5, 10, and 15 pct Ta. The range of tantalum additions was thus slightly broader than the reported minimum and maximum solid solubility limits of tantalum in cobalt (7 and 13 pct, respectively)4 The alloys were vacuum-induction melted in a magnesia crucible using cobalt rondelles and technically pure tantalum sheet as raw materials. Deoxidation of the melt was accomplished with carbon, and the chemical analysis of the alloys is given in Table I. The effect of isothermal aging treatments on the progress of precipitation was studied on samples cut from cast ingots. These samples were solution treated for 2 hr at 1250°C and water-quenched. Aging was conducted in the temperature range from 500" to 1050°C for periods between 15 min and 1000 hr and followed by water-quenching. To prevent contamination from the atmosphere, all samples were sealed in evacuated Vycor or quartz tubes for heat-treatments. For solution treatment, argon at 0.2 atmospheric pressure was introduced prior to sealing of the capsule to prevent collapse at high temperature, and titanium sponge was placed at one end of the capsule to act as a getter. MACROHARDNESS The effect of aging on Vickers hardness (Dph) of

Jan 1, 1960

By D. R. Maneval

The Surface Mining Act of 1977 required a study by the National Academy of Sciences regarding the special mine reclamation requirements of Alaska. The status of mines operating and planned in Alaska will be presented. New mines opening in Alaska must establish a baseline inventory of plants and animals in the mine site area as well as determine pre-mining air and water quality. Current work in these areas will be summarized. Reclamation practices in Alaska and other Arctic countries as practiced currently will be described. A summary of current research in Alaska dealing with revegetation on surface mined lanais, re-establishment of animal populations, and water treatment processes necessary in this pristine environment will be discussed. Included will be future predictions of the direction of mine reclamation in Alaska as more mines enter the industry.

Jan 1, 1984

THE first session was held in the rooms of the American Philosophical Society, on Tuesday evening, February 26th. The President, Dr. T. Sterry Hunt, called the meeting to order, and after a few introductory remarks concerning the importance of theoretical and speculative science, which often involves principles of the highest economic value, and, more than all that, serves to enlarge our conceptions of the universe, and ennoble us, by the cultivation which it affords to our most exalted faculties, proceeded to discuss some points in the chemistry of the atmosphere. It is known that there is in the crust of the earth a great amount of oxidized carbon, not only in the shape of coal, but also in the graphite or plumbago of the crystalline rocks, in the various bituminous shales or pyroschists, which are found in all succeeding rock-formations, and also in the forms of bitumen and petroleum. All the analogies of nature lead us to conclude that these various carbonaceous substances have had an organic origin, and have been generated by the deoxidation of carbonic acid, a process effected by the growing plant, and attended with the liberation of oxygen. He showed that the carbon of a layer of coal covering the whole earth's surface to the thickness of one meter, would, in its production from carbonic dioxide, liberate an amount of oxygen equal to that now present in our atmosphere. But bituminous coal contains also a large amount of hydrogen, derived from the deoxidation of water, which implies the liberation of a farther portion of oxygen. The amount from this latter source would equal, for the various coals and asphalts, from one-eighth to one-fourth, and, for the petroleums, one-half of that set free in the deoxidation of the carbon which these hydrocarbonaceous bodies contain. From what we know of the composition of the stratified rocks, it is probable that they include an amount of deoxidized carbon and hydrogen many times greater than that contained in a layer of coal one meter in thickness, and, consequently, that the disengaged oxygen in past ages must have far exceeded that now present in our atmosphere. To this must be added

Jan 1, 1878

The first session was held in the rooms of the American Philosophical Society, on Tuesday evening, February 26th. The President, Dr. T. Sterry Hunt, called the meeting to order, and after a few introductory remarks concerning the importance of theoretical and speculative science, which often involves principles of the highest economic value, and, more than all that, serves to enlarge our conceptions of the universe, and ennoble us, by the cultivation which it affords to our most exalted faculties, proceeded to discuss some points in the chemistry of the atmosphere. It is known that there is in the crust of the earth a great amount of oxidized carbon, not only in the shape of coal, but also in the graphite or plunlbago of the crystalline rocks, in the various bituminous shales or pyroschists, which are found in all succeeding rock-formations, and also in the forms of bitumen and petroleum. All the analogies of nature lead us to conclude that these various carbonaceous substances have had an organic origin, and have been generated by the deoxidation of carbonic acid, a process effected by the growing plant, and attended with the liberation of oxygen. He showed that the carbon of a layer of coal covering the whole earth's surface to the thickness of one meter, would, in its production from carbonic dioxide, liberate an amount of oxygen equal to that now present in our atmosphere. But bituminous coal contains also a large amount of hydrogen, derived from the deoxidation of water, which implies the liberation of a farther portion of oxygen. The amount from this latter source would equal, for the various coals and asphalts, from one-eighth to one-fourth, and, for the petroleums, onehalf of that set free in the deoxidation of the carbon which these hydrocarbonaceous bodies contain. From what we know of the composition of the stratified rocks, it is probable that they include an amount of deoxidized carbon and hydrogen many times greater than that contained in a layer of coal one meter in thickness, and, consequently, that the disengaged oxygen in past ages must have far exceeded that now present in our atmosphere. To this must be added

Jan 1, 1879

This consolidated index covers all publications of the Institute for the years 1926 through 1935. The following list indicates subjects of volumes and gives numbers or abbreviations used to designate them. TRANSACTIONS VOLUME *G26. Petroleum Development and Technology in 1925 (Published in 1926). *G26. Petroleum Development and Technology in 1926. *E27. Institute of Metals Proceedings. 73. Nonferrous Metallurgy, Milling and Concentration, Nonmetallic Minerals, Institute of Metals and Iron and Steel. [ ]

Jan 1, 1936