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By H. E. Sadler, Prof. Silliman

The research here recorded was undertaken early in the present year, and has been prosecuted steadily for about eight months. While the work has been under my constant supervision and advice, the labor has all been performed by Mr. Sadler, to whom is chiefly due the development of the successive steps which have led to the final result. The process is better than I dared to hope, and we are able to place at the command of chemists and engineers interested in the matter an apparatus of continuous and uninterrupted action, and methods of analysis by which the daily averages of the two variable and inconstant factors of illuminating gas, ammonia and sulphur, may be determined with all needful accuracy, even by those little skilled in chemical manipulation, and with very little loss of time. This research has been carried out in the laboratory of the New Haven Gaslight Company.

By Paul E. Blackburn, Joan B. Berkowitz-Mattuck, Edward J. Felten

The oxidation behavior of MOSi2 has been studied between 450° and 650°C, the temperature region where "pesling" occurs. Disintegration ("pest-ing") of MoSi2 is shown to occur in the presence of oxygen, but not nitrogen, carbon dioxide, carbon monoxide. or argon. The rate of disintegration is extremely sensitive to oxygen pressure. The crack density of polycrystalline MoSi2 increases ivith lime at temperature. All kinds of cracks are observed: THE excellent oxidation resistance of MoSi, at temperatures of 1000 to 1700°C promises to have important technological benefits. However. the ap- Ihose which are confined within a single grain, those that ci'oss grain boundaries transversely, and those that follow grain boundaries. Laue photographs verify the existence of Iranscryslalline cleavage. Single crystals of MOSi2 do not "pest". Tlrcd solrlbility of oxygen in MoSi2 is extremely low, no lattice changes being observed as a result of exposure of MoSi2 to oxygen in the "pest" temperature range. plicability of MoSi2 is somewhat restricted by the occurrence of a completely destructive oxidation of the intermetallic phase at intermediate temperatures (300" to 6003C). This phenomena was ternled to be the "MoSi2 pest" by Fitzer who first observed it.' Molybdenum disilicide is a metallic material in both physical appearance and electrical properties.

Jan 1, 1965

By B. L. Seegmiller

Horizontally stratified lithologies of certain open pit or strip mines create unique stability problems for mine operations. Such problems may result when specific lithologies, such as sandstone and shale, exist in final or long-term slopes. Slope instabilities may occur when a sandstone unit directly overlies a shale unit and ground water drains into the mine along the lithologic contact. In essence, the ground water erodes the underlying shales and undercuts the sandstone. Large sandstone blocks fail in a toppling mode and cause safety and cleanup problems. Use of rock reinforcement including chain link fencing, roof bolt mats, rock bolts, rock anchors, and shotcrete offers a possible solution to the problem.

Jan 1, 1985

By H. H. Haung, J. D. Miller, E. F. Pereira

The chemistry of copper extraction from ammoniacal solutions by hydroxyoxime extractants was studied Equilibrium measurements were made by shakeout experiments with subsequent analyasis of the aqueous and/or organic phases The kinetic experiments were carried out in a single drop reaction cell in order to establish the details of the intrinsic reaction kinetics for this system. Equilibrium measurements Indicated that the extraction involves complete displacement of ammonia ligands from the coordination sphere of the cupric ion by the extractant molecules The extraction reaction has the following stoichiometry

Jan 1, 1981

By W. A. Hooker

This portion of Mexico is quite beyond the ordinary routes .of travel, and is seldom visited. Its mines have not the record of enormous wealth which has recently attracted foreign capital to other parts of the republic; but for many centuries it has been a mining country, and at some periods evidently a productive one. In 1881 the writer visited the State and spent some time in the inspection of the mines. The absence of published information regarding its mining industry is his apology for presenting to the Institute these notes on the subject. Oaxaca is, with one exception (Chiapas), the most southerly of the Mexican States. It extends from latitude 18o 20' to 15' 45' N.— about 180 miles, by some 300 miles, in an east and west direction, and embraces a large part of the Isthmus of Tehuantepec. The coast-line is wholly on the Pacific. The State has an area of 27,470 square miles, nearly that of the State of Maine, and a population estimated at one million, or thirty-six to the square mile. The great continental Cordillera which farther north and west expands into broad table-lands, is here converged into narrower limits and occupies the greater portion of the country; the main

Jan 1, 1887

By Martin J. Conway

DURING the past year, the intense interest shown by the metallurgical industry in the use of relatively pure oxygen has been evidenced by the number of papers dealing with its application and production. The reason for this interest is apparent when it is realized that, weight for weight, oxygen enters into the formation of steel equally with iron. In the manufacture of steel, approximately one ton of oxygen is required to produce one ton of ingots. Until the recent development of plants capable of producing oxygen at far lower costs than had ever previously been considered possible, the oxygen required for steel manufacture was used as it occurs in air, where it is associated with approximately four times its volume of nitrogen. Because of the diluent nitrogen more than 4 tons of total gaseous material per ton of steel must be handled rather than only approximately one ton required when pure oxygen is used. In addition, provision must be made to handle the large quantity of waste, gases resulting from the process. There are cases where the reduction in gas volume alone can justify the installation of an oxygen plant.

Jan 1, 1947

By Nicholas M. Short

Many a geologist or driller has wished he could somehow climb into a borehole to see for himself what fractures looked like. Or why recovery was poor. Or how the bit was actually lost. Now it is possible to do the next best thing to climbing into the hole. TV cameras are being used for a close-up look at borehole conditions. Ever since television was invented, geologists and others interested in subsurface conditions have wanted a TV camera that could be used in the narrow confines of a borehole. But development of such a camera was slow, mainly because of the need for compact size. Not until the late 1950's did the technology of electronic miniaturization develop to a point where a camera satisfactory for the purpose could be put together.

Jan 1, 1963

By V. V. Strishkov, Zane E. Murphy, George Markon

Soviet industrial expansion depends on coal as a source of power and raw materials for the USSR's metallurgical and chemical industries. Knowledge of the Soviet Union's coal resources and production outlook is essential for a critical evaluation of the Soviet industrial potential. Although there is considerable literature on the Soviet coal industry, no single source provides an authoritative study of how the coal industry functions and how well it per- formed its job. Soviet reports are singularly lacking in the precise data in terms that are comprehensible to a westerner. It is essential, therefore, to clarify the terms in Soviet parlance. These terms are not comparable to those in common use in the West and are the cause of most inaccurate results. Official Soviet data on labor productivity refer to a limited group of "production workers" while in the West all wage earners are counted. Statistics are based on unprepared or run-of-mine coal, whereas it is customary elsewhere to measure productivity in terms of marketable coal. Thus, many western publications, while diligently and accurately reporting published Soviet data, overstate the case, presenting an exaggerated picture of Soviet progress in coal production and technology. (In terms of Western criteria, there is a three-fold exaggeration of labor productivity.)

Jan 5, 1973

By R. P. King

The two-phase distributed-parameter kinetic model for flotation has been wed as the basis for a digital simulation of flotation plants of arbitrary configuration. Ores that contain any number of minerals can be handled. The effects of incomplete liberation and particle-size distribution are specifically allowed for. The simulator allows the investigation of variations in throughput and in the slurry density of the feed, and of variations in stage volumes and aeration rates. It can handle cell behavior even under conditions of hindered flotation. The requirements for data preparation are completely documented so that the computer program is suitable for general-purpose use. The program is written in Fortran. The output from the simulator consists of the complete material flows in the plant, as well as the grade, recovery, and particle-size distribution in each stream.

Jan 1, 1976

By Richard E. McElvain, I. Cave

The selection of centrifugal pumps for mill discharge duty should be based on the total circuit concept. The practice of operating the mill circuit based on limitation of the pump can result in losses in one day which would offset the pump cost. Operating data from 25 grinding circuits have been reviewed and comparative results on added mill capacity have established advantages far beyond the less significant maintenance costs with increased circulating load and better cyclone operation. Mill discharge pumps should be selected on the following basis: i) Best available design for wear performance ii) Size to provide best economic life iii) Liner material best suited to circuit conditions Pump efficiency is a secondary consideration because power consumed by pumps is small compared to mill power input. Energy dissipated in mill pumps is contributing to comminution of ore.

Jan 1, 1982

By Paul Weir

Bleaching clays have been used extensively in the oil-refining industries for a number of years. Their use in water purification is relatively recent and less extensive. They are frequently classified as (1) those naturally active and (2) those active after artificial activation with acid. Fuller's earths fall within the general group of bleaching clays and gradually the commercial term "fuller's earth" has been applied to natural clays originating, for the most part, in the southeastern section of the United States. Bentonitic clays are usually classed as activable and are prevalent in the southwestern section of the United States.l Bleaching clays vary considerably in chemical and physical properties throughout the country, or even in different parts of one deposit (Table 1). The fuller's earth type of clay is characterized by a lack of plasticity, relatively adsorbent, foliated structure, and does not swell to form a

Jan 1, 1942

By H. J. Ward

RUM Jungle uranium field lies in the subtropical portion of the Northern Territory on the Finniss River, East Branch. It takes its name from a railway siding about 2 ½ miles to the southwest and 52 miles from Darwin. The field can be reached from Darwin by a bituminized road. Monsoonal rains of the wet season, October to April, provide an annual rainfall of about 60 in. Vegetation is of the open forest type with denser tree growth along the watercourses and scattered throughout the area are isolated dense patches of jungle growth which are always found on ironstone cappings overlying limestones. The name, Rum Jungle, is thought to have been derived from this unusual occurrence of jungle growth. The wet season prevents the movement of motor vehicles and personnel. It is not until March, when the grass which ranges up to 15 ft in height is burned and the alluvial flats dry out, that field work can be undertaken.

Jan 12, 1954

By Harrison R. Cooper

Measurement of process material composition with on-line instrumentation has commanded attention of metallurgical plant management as a logical extension of the sampling operation, making possible immediate determination of essential data needed to maintain efficiencies at the highest possible level. The current status of methods employed for online composition analysis of slurries and solid materials is reviewed.

Jan 1, 1984

By Edmund Newton

THE steel industry of the United States has depended in the past almost wholly upon imports for its supplies of manganese. Many of the important domestic sources yield ores leaner in their natural condition than the foreign ores the steel industry has been accustomed to use. To make them available, therefore, either' the ores must be concentrated or the practice of the steel industry modified. Roughly 25,000 T. annually of high-grade manganese ores are used for dry batteries, for chemical purposes, and in other ways; while approximately 750,000 T. are required for making steel. By present practice, every ton of steel takes an average of about 14 lb. (1.8 kg.) of metallic manganese. This is generally added to the steel in the form of an alloy, the standard alloys being the 80-per cent. ferro-manganese and the 20-per cent. spiegeleisen. During the year 1917 286,000 T. of ferromanganese and 193,291 T. of spiegeleisen were made in this country, the former largely from imported ores; and 45,381 T.

Jan 2, 1919

By S. H. Cathcart

Price, production and drilling operations exceeded any year since 1930. A top price for crude of $2.55 was maintained from May 1 to November 6 and increased activity about coincides with that period. The average crude price for the year was: Bradford, $2.46; Kane-Butler, $2.34; Southwest Pennsylvania, $2.13. Production for the year exceeded 15 million barrels, an increase of about 2 million barrels over 1933. That this increase was more than justified by market demand is indicated by a reduction of 892,000 bbl. in stocks for the year. Two classes of data appear on Table 1, which are differentiated by footnote references. Where possible the .figures were obtained from individuals and companies that, from long acquaintance and varied contacts, are most capable of supplying an estimate where an estimate is necessary. The remaining data represent a rather careful compilation from all available published records (see p. 378). Drilling operations and production as summarized by the Oil City Derrick are as shown on Table 2.

Jan 1, 1935

By T. F. Witherbee

That the single charging-bell, properly proportioned, is a good all-around device for distributing material in a blast-furnace can scarcely be questioned; yet it is equally true that, in some cases, it has not given perfect satisfaction; as has been demonstrated by the substitution of double bells, at furnaces under the beat management—generally in cases where anthracite, either alone, or with a portion of coke, was used as fuel. The defect of the single bell seems to be that it does not permit, beyond very narrow limits, such changes in charging as may be required by the temporary conditioil of the furnace. Modern furnaces using Connellsville or other good coke and Lake Superior ores seem to be well served with a single bell. At least, up to a certain size, somewhere about 18 by 85 ft. to 19 by 90 feet, these furnaces make low-silicon pig-iron with about 1,800 lb. of fuel, or in some cases very much less. The following instances occur to me, in which other forms of charging-apparatus have been employed with advantage: 1. A charcoal-furnace, 61 ft. high, 11 ft. in diameter at bosh, and 8 ft. 2 in. at stock-line, with a rectangular crucible, 42 by

Jan 1, 1905

By Ashbel Welch

Ashbel Welch, Lambertville, N. J.: Dr. Dudley has given the wear of steel rails under four different conditions. He arrives at the conclusion that the softer rails, or those that from their composition ought to be softer, wear better than the harder. But there is another condition which has an important bearing on the subject, and should not be overlooked,—the weight on a wheel. With the lighter weights of the past, the softer rails may have worn best; with the heavier weights of the future, the harder may wear best. Weights will probably be increased up to the capacity of steel to bear; then doubtless the harder steel will wear best. A leaden rail with ten pounds on a wheel might carry millions of tons, but with one hundred pounds on a wheel, it would be destfoyed by a few thousand tons. So in the days of iron rails, my experience was that the softer rails under light machinery stood better than some of the harder; but under heavy machinery the softer were much the most rapidly destroyed. It is doubtless the same with steel. The pounding motion of the wheels loosens or spreads the particles of a thin film of steel; the pull lengthwise on the rail de-

Jan 1, 1881

Jan 1, 1918

By Charles E. Nelson

In considering the types of scrap that are processed into secondary magnesium, it is important to point out that the greatest proportion of this material is fabrication, foundry and machine shop scrap that is generated during the conversion of magnesium products into the finished article. This material, then, is largely of the same composition and quality as the original ingot or heat of metal except as it may be mixed with other compositions or metals in the fabricating process. Insofar as such materials can be processed back into secondary ingots or final products which meet the composition and property standards required of the original virgin stocks, then it seems reasonable that such products are fully equivalent to the primary products. With these premises then, it is the intent of the present discussion to consider briefly some of the methods whereby scrap may be generated, segregated, shipped, and processed in such a manner that the final products will be equivalent to virgin materials. Some information on the effects of impurities will be given in order to aid in the evaluation of these products. SCRAP GENERATION The method by which scrap is generated serves in a rough way to classify the resulting materials in terms of how they may be handled and recovered. These methods will be dealt with briefly. Machining operations such as milling and turning undoubtedly provide the great-

Jan 1, 1943

By K. E. Merklin, F. D. DeVaney

Students of the modern blast furnace seem unanimously agreed that they are observing a major revolution in practice. Rather than changing construction and operation of the furnaces, most of the great advances now under way deal with the raw materials feed. Prepared burdens have gained increasing significance during recent years. Sizing, concentration, and agglomeration have all become bywords to greater production and reduced operating costs. The remarkable results with test furnaces in which self-fluxing sinter makes up part or all of the ore charge foretell even greater improvements. Other investigators have reported many of these advances, and it is enough to predict here that more and more operators will turn to the use of self-fluxing sinter.

Jan 3, 1960