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By J. W. Pugh, J. D. Nisbet

THIS study of the ternary has been made as one phase of a metallurgical investigation which began nearly four years ago in the General Electric Company's Research Laboratory in Schenectady, N. Y. The objective of this program is the discovery of new metallurgical information which will lead to the development of better high-temperature materials. Combinations of the four pure base elements—iron, chromium, nickel, and cobalt—are being studied at the present time. It is essential in an investigation such as this to know as much as possible about the constitutional diagrams involved. The study of the iron-chromium-nickel system has been made to this end. Preliminary Explanation of Experimental Procedure: In all, fifty-five alloys at steps of 10 at. pct were made for the investigation of this ternary. Several ternary alloys in the chromium rich corner had to be omitted because their extreme brittleness made testing impractical. All alloys were vacuum melted with hydrogen reduction and centrifugally cast. The apparatus and technique of this process has been described in detail by Nisbet.1,2 The purity of the alloys prepared in this way is considered to be quite good. Impurities are listed as follows: Pct Carbon.............................0.02 Oxygen................................0.02 Nitrogen.........................0.005 Magnesium..................0.03-0.05 Sulphur...........................trace Hydrogen....................trace Phosphorous..................trace Silicon........................ trace After casting, all samples were given a homo-genization treatment which consisted of holding them for 15 hr at 1150°C (2100°F) and water quenching. Testing was begun with the samples in this condition. The tests employed in the study of this system were (1) dilatometer, (2) hardness versus aging temperature, (3) tensile strength and elongation versus temperature, (4) microstructure analysis, and (5) electrical resistance versus temperature. Dilatometer tests were made at the rather rapid heating rate of 1093°C (2000°F) in one hour on a Bristol-Rockwell type instrument. Hardness data were taken on specimens cooled from 204", 427", 649°, 760°, 871°, 982°, and 1093°C under conditions which are thought sufficient to bring the specimens to equilibrium in all but the cases of the very sluggish transformations. Electrical resistance data for several specimens were taken for both heating and cooling conditions in a vacuum furnace especially designed for this work by D. W. Bainbridge, formerly of this laboratory. Provisions were made for heating and cooling standard specimens at a constant rate, while autographic records of resistance and temperature were made simultaneously. Micrographs of all the alloys were made in the quenched condition. Some question may exist as to how such physical values as hardness, tensile strength, and elongation were interpreted to indicate a change in phase. Original data were recorded on physical property versus temperature graphs, each of which was made from the data of a single alloy (fig. la). From these, another series of graphs were plotted with the physical property as a function of composition for constant temperatures (fig. 1b). Sharp deviations in the slope of these composition versus hardness curves often indicate a change in phase. The example of fig. 1 will serve to describe this experimental technique. The plotting of a single point from graph "a" to graph "b," and finally to the phase diagram "c," is illustrated. The location of the point on graph "b" is indicated as point (1). If all the alloys of the A-B binary system were solid solutions at temperature X, the hardness in this curve would be expected to rise at a fairly even rate as A is diluted with B to a maximum at some intermediate value between A and B, as

Jan 1, 1951

By Dubois Eastman

BEHIND the contrasting liquid-fuel technologies of Germany and the United States lie the basic differences of scarcity and abundance. The chemists and engineers of each nation have developed processes that accommodate available raw materials. In the United States, processing is based on an abundant supply of petroleum, which is refined into a variety of fuels and lubricants. Germany has little indigenous petroleum but has a readily available supply of coal that can be converted into liquid fuels and lubricants. As a result, in Germany several basic processes have been developed for the conversion of coal into synthesis gas (carbon monoxide and hydrogen). In turn, this gas is processed into products. As a normal function of its researches into petroleum processing, the petroleum industry in the United States has made careful studies of various conversion and synthesis techniques. A number of oil companies are carrying out independent development programs with the aim of synthesizing hydro- carbon products that can be marketed at a price that will compete with the price of refined petroleum products. American oil companies hope to perfect synthesis processes that will directly benefit the consumer. A good example of progress in these terms is the synthesis plant at Brownsville, Texas, which is based on the conversion of natural gas to synthetic fuels and other valuable products. When this plant is operated at near capacity, it is expected that the products will be able to compete favorably for the consumer dollar. The complete gasification of coal is a technique well rooted in history. As a controlled process on a small scale, it goes back centuries. As a practical technique on a commercial scale, it dates back to 1839, when "producer gas" appeared in Germany for limited industrial use. By 1873, "water gas," or "city gas" as it is sometimes called, was being manufactured commercially in the United States for use in heaters and stoves. The water-gas process was the cornerstone for modern synthesis. To older methods that were concerned only with carbon and oxygen reactions, it added hydrogen by means of steam. Thus far the goal of conversion was to produce gas for heating, lighting, industrial use, and cooking. The long step forward to synthesis was made in 1927, when Germany started to make gasoline from coal by means of the revolutionary Bergius hydrogenation process. A year earIier, Franz Fischer and Hans Tropsch had announced their process, which finally reached the

Jan 1, 1953

APPROXIMATELY 26 percent of the total ore production to date from the largest single deposit of copper-bearing material in the world was mined during the war years, 1942 to 1945, at Chile Exporation Company's great open-pit mine at Chuquicamata, Chile. About 18 percent of the total waste removed during the life of the mine was handled in the same period. The total of ore and waste represents approximately 24 percent of the total material that has been excavated from the pit. This is more than was removed in the first fourteen years of operation from 1914 through 1927. The pit at Chuquicamata is 17/8 miles long, 1/2 mile wide, and has a present vertical extent of 817 ft between the top of the highest bench and the lowest bench being worked. However, when

Jan 1, 1948

By Stanislaus Skowronski

OVERPOLED copper, as commonly defined, is copper which has been excessively reduced during the poling period of the refining process. Owing to its porosity, such copper is unfit for commercial purposes. The cause of this phenomenon is undoubtedly the lack of oxides in the copper, yet this does not completely explain it. Refined copper of the same "pitch" and "set" varies considerably in oxygen contents, and analyses of overpoled bars also show similar wide differences; moreover, it is possible to melt copper in crucibles so as to obtain bars that are practically free from oxygen although they show a "tough pitch" and "level set" surface. Frederick Johnson advances the following theory: The regulation of the quantity of oxygen in copper is the keynote of all copper refining. It is the presence of a Well defined proportion of oxygen in the form of cuprous oxide, forming a copper-cuprous oxide eutectic, Which enables copper to be cast free from blowholes. It seems that When oxygen is present, other gases are less soluble in molten copper; When oxygen is absent, or is present in insufficient quantity, the copper dissolves other gases, such as hydrogen and carbon monoxide, Which are insoluble in the copper when solid, and, being rejected during the process of solidification, causes internal porosity and external ridges and excrescences.1 The "level set" of Wire bars, etc., is entirely the result of a compromise between the occluded gases and cuprous oxide. With excess of the former the metal would be "overpitch" and spongy, While an excess of the latter would result in the metal being "underpitch" and brittle.2 The result of the absorption and subsequent expulsion of reducing gases, carbon monoxide and hydrogen, and the effect of this action. on the overpoling of copper are in dispute; the literature on the subject is full of contradictory statements and will continue to be so until better analytical methods have been developed. Sulphur, however, is tangible. The refiner can see it in his button sample and consequently attributes to it any trouble that may happen during the melting of the copper.

Jan 3, 1918

By A. A. Toprac

The recurring problem of joint failures in ofjshore structures, coupled with the catastrophic collapse of many of these structures during Hurricane Hilda (1964), hay forced reconsideration of techniques presently used to design sfuctural joints. This paper presents results of studies conducted for this reconsiderat?on. Only right-angled T-joint,s and cross-joints where a brace was welded directly to the undisturbed surface of another tube (the chord) were considered. Tests were performed on seven T-joint and 12 oross-joint specimens of two types which were designed to give a broad but practicd range to the geometrical parameters believed to be of significance to the problem. These paramefers were expressed in dimensionless form. Each specimen of the T-joints was instrumented wirh both electrical resistance strain gauges and deflection dials. After the elastic tests were concluded, each specimen was loaded to failure by applying an axial tensile load to the brace. The cross-joints were tested to failure without measuring elastic strains. Theoretical solutions for the stresses in a cylindrical shell due to a distributed radial load over portions of its surface were numerically evaluated. The experimental results are compared with calculated values obtained using Bijlaard's and Dundrova's theoretical analyses. INTRODUCTION During the last IS years a large number of structures were built for the offshore exploration of oil both in the Gulf of Mexico and dong the Pacific Coast.' In all these offshore platforms, the tubular shape was extensively used since this shape provides outstanding strength in proportion to its weight, compared to other shapes, when all directions (x, y, z) are considered. Past use of tubes was hampered because of connection details. But with the advent of welding, it became no more difficult to connect tubular shapes than to connect rolled shapes. However, some problems have been encountered in actual construction in making welded joints that are adequate and yet economical. In trying to connect tubular members, designers have used a varied number of methods; consequently, some of the joints seem to be very expensive in detail while others appear weak and underdesigned. An inspection of offshore platforms owned by different companies indicates the use of a large number of joint arrangements and configurations. Such a variety of joint types in current service indicates the wide divergence of opinion that exists on how such joints should be designed, stiffened and strengthened. Fig. 1 shows the various types of connections that have been used in practice. This paper reviews the present state of art on tubular joints of the T and cross type, and presents results of experimental and analytical work being conducted at The U. of Texas and elsewhere. It is believed that such information will be of great help to designers for the formulation of proper design procedures for joints. CONNECTION PROBLEM Recently, cracks have been observed in several welded connections in offshore structures. Fortunately, until about 1 1/2 years ago, these failures have been localized and have not resulted in the collapse of structures or loss of life. For example, one platform installed in Louisiana during 1955 in about 60 ft of water had been subjected to four tropical hurricanes. This platform successfully withstood these forces and was later removed because operations at this location had been completed. Many joint failures were observed during the removal.

By K. A. ACKLEY

The petroleum industry experienced a year of satisfactory accomplishment in Oklahoma during 1945. Crude oil production was increased, a new record for recent years was established in well completions, and refinery operations were maintained at a maximum level. Daily average crude oil production increased to 382,000 bbl., reflecting a 13.5 per cent gain compared with production during the previous pear. Total wells drilled during 1945 amounted to 2556, a gain of 28.7 per cent over 1944 Refinery throughout averaged 187,500 bbl. daily, an increase of approximately 4 percent over the preceding year.

Jan 1, 1946

By Augustus Locke

MY conclusions apply to the engineer in California ore hunting; and, because the product has been overwhelmingly gold, that means gold-ore hunting. But, I wish to think of ore hunting, not as employment for engineers, but as engineering. I wish, moreover, to think of it as productive of ore in significant quantity. The small mine, even if good, means little. Only new districts, or large extensions of old districts can engage our attention here. The conclusions are summarized as follows: (1) The bright color of California mining history comes from the suddenness and intensity of its outburst of gold. Had the mining been averaged from the start, it would soon have become dimmed among greater industries. For fifty years, California has proceeded as an agricultural, timber and oil, but not a mining region. 1

Jan 1, 1931

By T. S. Washburn

THE grades of commercial steel produced in large quantities can be divided into two general types from the standpoint of ingot structure-killed and rimmed. Killed steel covers a wide variety with carbon contents throughout the range of the steel portion of the iron-carbon diagram, and is the kind usually used in the production of alloy steels. Rimmed steel is normally associated with carbon ranges under 0.30 per cent, and is not yet used to a large extent in alloy practice, except for copper-bearing steels. The fundamental differences in the ingots made from these two types of steel can be seen most easily in Figs. 1 to 7. In the rimmed ingot shown in Figs. 5 to 7 there are two lines of blowholes approximately parallel to the sides and coming together at the top and at the bottom of the ingot. In the killed ingots shown in Figs. 1 to 4 these blowholes are not present. Also, the rimmed ingot has no well defined pipe, as com-pared to the deep pipe on the killed ingots, and there are numerous pri-mary blowholes in the lower portion of the rimmed ingot perpendicular to the surface and close to it, while on the killed ingot there are no blowholes of this type in the ingot shown in Fig. 1 and very small ones close to the surface in the lower part of the ingot shown in Figs. 2 to 4. With respect to the presence of pipe and the primary blowholes, the structure may vary considerably in both rimmed and killed ingots, therefore these cannot be considered as fundamental structural characteristics differ-entiating the two types of steel. The primary blowholes in rimmed ingots may be much less pronounced than those in the ingot shown in Figs. 5 to 7-as, for example, in "ingot iron," which is entirely free from them. An example of a cross section of an ingot-iron ingot is shown on page 16 of "Research and Methods of Analysis of Iron and Steel," published by the American Rolling Mill Co. (1920). A certain amount of pipe may also occur in rimmed ingots, though it is normally porous and not as well defined or deep as in the killed ingot of Fig. 1. In killed ingots, pri-mary blowholes may occur near the surface, as in Figs. 2 to 4, and

Jan 1, 1937

By J. R. Kyte, L. A. Rapoport

The material balance equation for partiai or complete 1:trter-drivc reser1,oir.s been re-arranged to include a pressure irrferferencr ternr. This pressure interfernce term was ohtained from the theory established hy Morinda. A .successful progranl deissed to solve the resrclritlg c,qrration in a few hours on a nleelitr .sizeti, digital compuier. No prior knowdelge of the properties of the eqrrifer is required in the solution. 7' ri~rl calculations areatle using various assumed con!binuiions of value of the constant expretsing the qquifer properties correspoinds to the best fit ohtained between observed and calculated field history. Details of the method of calculaion are illus trated by an example. INTKCDUCTICN A method 01' calculating the material balance equation for a partial water-drive reservoir completed in an aquifer has been described in the literature." Pressure interference i'rc,m other pools iocated in the same nquiucr is not taken into account in this solution. When present, the pres- sure interference effect must be included in order to make a complete performance analysis. A correction for this effect has been developed using the theory cstahlished by Mor-tada.' Manual calculation of the material balance for water-drive reservoirs is a formidable task. Such manual ca1culation when interference eflects are includcd would be impossible to completc in any reasonable time period. However, a medium-sized stored program, digltal conlputer can he used satisfactorily. The method is described in the following sections. THECKETICAL CONSIDEKATIOhS The material balance equation for a reservoir producing by partial or total water drive, as proposed by Van Everdingen, This relationship is linear for Z/a from which thc slopc, Z, and the intercept, N, can be obtained by the least-squares method from the data points. It is not necessary lo know the aquifer properties to uktain oplimum values tor 2nd IV. Various assumptions are made tor At,,: where 11 is production time, seconds (oilfield between the equal successive time intervals into which the history is divided. t,, h It, times the number of equal time periods from i.e.. the total dimen-sionless time interval from It is noted that the dinlensionless time interval, At,,, involves all the relevant aquifer properties. Accordingly, any assunlption of is an assumption of the combined aquifer properties which pertain to the solution of the equation. Deviations of the data points from a straight line arc calculated for each assumption of and the value of A, correspond ing to the minimunl deviation is chosen as the optimum solution. This method is described in Ref. 1 and 2. Thc material balance solution is usually made with an initial assumption that the reservoir being studied is located in an infinite aquifer from which there are no other withdrawals. Deviation of the points by amounts greater than can be attributed to inaccuracies in field data may be the result of: (1) boundary effects of a limited aquifer, (2) pressure interference from othcr pools completed in the .sarne aquifer, and (3) a combination of these effects. Differentiation of these effects can be made only on the basis of geologic data. Pressure interference from other fields will result in a pressure drop at the original oil-water boundary having an interference component, The measured instantaneous pressure drops at the oil-water

By AIME AIME

AMONG the European nations Germany is the center of interest economically as well as politically, and of prime importance for Europe as a whole is Germany's capacity to produce mineral products for armament and for export in exchange for the import of the essential supplies to maintain its industries. So far as minerals are concerned, Germany is worse off than any other great power except Italy, and deficiencies are being met by attempts to increase output from local deposits and by greater use of substitutes derived from domestic raw materials to replace imported metals, petroleum products, and other minerals.

Jan 1, 1939

By T. S. West

Completion and production data presented for three wells in the Oakville area of Live Oak County, Texas, which were completed near the gas-oil or water-oil contact, indicate that coning may not be as prevalent a cause of failure in such cases as is commonly assumed. Failure in the cases discussed is indicated to be due instead to: (I) erosion of the formation, (2) flowing out of mud filter cake, or (3) failure of the cement. An open-hole gravel-pack type of completion procedure is proposed for preventing failures of this kind by preventing movement of all solid material in the space in which completion is made. Various combinations of layers of gravel, sand, and cement are utilized for this purpose. Experimental results and theoretical discussion as to the applicability of gravel pack completion are included. Introduction This paper is primarily a study of the reasons for failure of oil-well completions near the gas-oil or oil-water contact, and suggests a procedure for increasing the efficiency of this type of completion. The value of improvement in completion effectiveness near the gas or water zone is not confined, however, to wells of relatively thin oil columns. Thick oil columns become thin as depletion progresses. It would seem to follow that the minimum distance from the gas or water zone at which completion can be made in a new well indicates the limit to which depletion may be carried in a well having an oil column of any initial magnitude. Only four ways can be postulated in which high gas-oil or water-oil ratio can initially occur if the zone exposed for production is within the oil column: 1. Failure of the cementing material. 2. Vertical coning. 3. Failure along the boundary between the cement and the wall of the well. 4. Failure of the formation comprising the wall of the well. Cementing materials such as portland cement and plastics have reached a high stage of development. Failures of this type are probably due almost always to extraneous causes such as mud contamination rather than to faulty cementing material. Vertical coning can and obviously does occur. However, the usual occurrence of thin impermeable streaks in sand sections and the success with which open-hole drill-stem tests can be made near the gas-oil contact suggest that over-all effective vertical permeability, and in turn vertical coning, is less prevalent than frequently is assumed. Much has been written on failure by flowing out of the mud filter cake between cementing material and the formation. A filter cake is always present if, prior to cementing, mud has come in contact with a permeable formation at pressures exceeding the pressure head of the fluid it contains. Mechanical methods are in use for removing filter cake during the cementing operation? which undoubtedly are of

Jan 1, 1947

By T. S. West

Completion and production data presented for three wells in the Oakville area of Live Oak County, Texas, which were completed near the gas-oil or water-oil contact, indicate that coning may not be as prevalent a cause of failure in such cases as is commonly assumed. Failure in the cases discussed is indicated to be due instead to: (I) erosion of the formation, (2) flowing out of mud filter cake, or (3) failure of the cement. An open-hole gravel-pack type of completion procedure is proposed for preventing failures of this kind by preventing movement of all solid material in the space in which completion is made. Various combinations of layers of gravel, sand, and cement are utilized for this purpose. Experimental results and theoretical discussion as to the applicability of gravel pack completion are included. Introduction This paper is primarily a study of the reasons for failure of oil-well completions near the gas-oil or oil-water contact, and suggests a procedure for increasing the efficiency of this type of completion. The value of improvement in completion effectiveness near the gas or water zone is not confined, however, to wells of relatively thin oil columns. Thick oil columns become thin as depletion progresses. It would seem to follow that the minimum distance from the gas or water zone at which completion can be made in a new well indicates the limit to which depletion may be carried in a well having an oil column of any initial magnitude. Only four ways can be postulated in which high gas-oil or water-oil ratio can initially occur if the zone exposed for production is within the oil column: 1. Failure of the cementing material. 2. Vertical coning. 3. Failure along the boundary between the cement and the wall of the well. 4. Failure of the formation comprising the wall of the well. Cementing materials such as portland cement and plastics have reached a high stage of development. Failures of this type are probably due almost always to extraneous causes such as mud contamination rather than to faulty cementing material. Vertical coning can and obviously does occur. However, the usual occurrence of thin impermeable streaks in sand sections and the success with which open-hole drill-stem tests can be made near the gas-oil contact suggest that over-all effective vertical permeability, and in turn vertical coning, is less prevalent than frequently is assumed. Much has been written on failure by flowing out of the mud filter cake between cementing material and the formation. A filter cake is always present if, prior to cementing, mud has come in contact with a permeable formation at pressures exceeding the pressure head of the fluid it contains. Mechanical methods are in use for removing filter cake during the cementing operation? which undoubtedly are of

Jan 1, 1947

By Edward Sampson

Despite the many industrial uses, the world market for silver as a commodity is far from free, being dominated by the U.S. Government both through acts of Congress and by policy of the Treasury Department. This discussion will consider aspects of supply, demand, and price with a view to the future. Changes in Sources of Supply: The world's peak production of silver, 278 million oz, was in 1937. In the 1850's world production was about 30 million oz, having risen from a yearly average of 11 million oz for the first half of the century. From 1860 to 1940 there was a steady rise, broken only by World War I and the depression of the early 1930's.

Jan 7, 1960

By J. J. Carrigan

IN all mining operations a considerable portion of the work performed, especially underground; is accomplished under artificial light, yeti this subject is often not given proper attention. Poor illumination decreases mining efficiency, impairs the sorting or grading of ores, and increases the risk of accidents. In the beginning, and for several years afterward in the metal-mining industry of Butte, Montana, candles placed in candlesticks were carried by the men. Sconces or holders for candles were also provided at stations and curves in drifts to furnish better light for men engaged in. hand tramming. It was also common practice to place clusters of candles on the ground, with no provision for guarding against an underground fire other than the exercise of sufficient care by the men themselves. An accumulation of candle grease from this source was the direct result of the first serious fire in the Anaconda mine, in 1889.

Jan 1, 1936

By Michael J. Messel

OF the various minerals that occur in fibrous form known as asbestos, chryso-tile is the variety most in demand for commercial uses, and, last year, over 683,000 tons of the various grades were produced in Canada and United States, exclusive of African and Russian production, which figures are uncertain. Production has not been able to keep up with the increased demand, and an acute shortage exists. Canada, Russia, and Africa are still the most important producers. However, Russia consumes most of its production at home and exports very little. The United States consumes over 60 pct of the total production and produces only about 4 pct of the total from deposits in Vermont and small quantities from Arizona. This paper will review mainly, some of the more recent developments concerned with the extraction and processing of this fibrous mineral for various industrial uses, such as textiles, insulation, building materials and brake linings. Four of the more important factors that have influenced recent developments are: 1. The lack of discovering and developing new deposits of any important size to supply the increased demand. 2. Rapid postwar expansion of industrial uses, especially in asbestos cement products, together with in-rreased manufacturing facilities. Euro-peal) countries are again back on the market with their demand. 3. The ability of manufacturers to develop their technique of blending fibers and obtaining more utility value out of each ton of fiber, together with the utilization of shorter grades of fiber to obtain equally as good products. In the past, many manufacturers were wasteful in their use of fibers. 4. The struggle for reduced operating costs, in face of increased wages and prices of supplies, together with the necessity, at some mines, to change the method of mining from open quarry to underground. Most of the recent capital invested in the asbestos mining industry has gone into more efficient extraction of the fibers from the existing ore, especially in the recovery of the shorter grades. There has been very little new plant expansion. Progress in the utilization of shorter fibers has been so far reaching that some of the mining companies are retreating present tailings as they leave the mill, and others are considering retreating of the old tailing dumps for recovery of fibers that, until recently, were not saleable and were discarded as part of the tailing. Many of these dumps contain much valuable fiber from days when milling was very inefficient. It might be appropriate to mention here that the present known asbestos reserves of proved commercial value (excluding Russia) are being depleted at an alarmingly rapid rate, about 10,000,000 tons of ore is being mined annually. No new deposits have come into production during the last 15 years, with the exception of certain deposits in Africa, which are the most promising, and minor developments in Canada, Venezuela, Cyprus, Australia, and Brazil. The African deposits are the only ones that hold promise of developing large reserves. Unless new deposits are developed, in twenty years or maybe sooner, the supply picture will not be a very bright one. Stimulated by the acute shortage, increasing fiber prices and technical developments, many new areas are being prospected in Canada, United States, New Zealand, Newfoundland, South America, Europe, Africa, and China. From information now available, it appears that no real progress has been made in duplicating this rare development of nature by producing synthetic asbestos. The most promising experiments were carried out at the University of Leipzig, but they seem far from practical. There has been marked progress in fiber glass manufacture, but so far, it has replaced asbestos only in very few instances for minor uses. Asbestos ore and the fiber it yields are different in some respect at each mine and vary usually in the following: 1. Percentage of fiber content by weight to the gangue. 2. Variations in proportions of long and short fibers, some deposits being predominantly long fiber and others short fiber. 3. The hardness of the rock in which the fiber occurs. 4. The nature of the fiber, as to

Jan 1, 1950

By C. R. Kuzell

Although furnaces constructed of refractory brick have been operated for many decades, there has always been an unfulfilled desire by the operators for a less arduous and more satisfactory method of patching weak spots and burned-out zones in order to postpone and to effectively extend the termination of a furnace campaign. Not only has this desire frequently arisen when small spots have approached incipient failure while the furnace structure as a whole was still in good condition, but also when larger areas showed signs of needing replacement. The available methods have been arduous, sometimes dangerous, inefficient with respect to the life of new refractory material used, and nearly always have necessitated interruption of the continuity of the furnace operations and therefore reduction in furnace production during the period of time required for the repair work. Most of these older methods have involved the replacement of masonry by refractory shapes in the weakened areas. Many attempts have been made to develop a method of patching the burned-out areas by spraying granular refractory material upon old surfaces. While some success has been attained in attempts to renew the grooved, corroded side walls and fettling, and the edges of hearths, there have been no known successful applications of the spraying method in patching the underside of arches of operating furnaces. The method developed recently at the Clarkdale smelter of the United Verde Branch of Phelps Dodge Corporation, at Clarkdale, Aria., and described in this paper, has been found to be not only convenient and successful with respect to patching vertical or inclined surfaces, but has met with a marked degree of success in patching the parts of furnace arches that are exposed to flame, the successful result being obtained without interruption or interference with the continuity of furnace operations. It may be described as a method of renewing the interior refractory surfaces of operating furnaces by pneumatic spraying of an aqueous suspension of finely divided. particles of refractory material. It has been used

Jan 1, 1944

By G. Chesneau

Two great discoveries of this century have diminished the dangers of fiery coal-mines,—the sifety-lamp, conceived in 1815 by Sir Humphrey Davy and successively improved by many engineers, such as Clanny, Marsaut, Mueseler, Fumat, etc., and safety-explosives, the appearance of which is comparatively recent, hut which, thanks to the persevering labors of several technical commissions (especially the French commission on explosives), and of the manufacturers and experimental users of these powders, appear likely to play, in the protection of the miner, a part as important as that of the safetylamp itself. Brit while it is true that by the use of a safety-lamp of approved form, and the exclusive employment, with all prescribed precautions, of these new explosives, complete security should be assured, even in highly fiery atmospheres, experience has shown that the imprudence of workmen, or the bad condition of a lamp, may nullify these protective means, so that it ought to be the constant care of the engineers of fiery mines to dilute the fire-damp by good ventilation so far as to maintain always and in all parts of a mine a proportion of this gas below the lower limit of explosiveness belonging to a mixture of air and methane. Good ventilation still remains the best preventive of explosions from fire-damp, and since, even with a rational and well-controlled mine-ventilation, the volumes of air traversing galleries and rooms are liable to vary within wide limits by reason of open doors, falls of rock, or other accidental causes, it follows that but a few thousandths of fire-damp should be left in the normal atmosphere of the mine-workings, so that a considerable

Jan 1, 1894

By C. R. Kuzell

ALTHOUGH furnaces constructed of refractory brick have been oper-ated for many decades, there has always been an unfulfilled desire by the operators for a less arduous and more satisfactory method of patching weak spots and burned-out zones in order to postpone and to effectively extend the termination of a furnace campaign. Not only has this desire frequently arisen when small spots have approached incipient failure while the furnace structure as a whole was still in good condition, but also when larger areas showed signs of needing replacement. The availa-ble methods have been arduous, sometimes dangerous, inefficient with respect to the life of new refractory material used, and nearly always have necessitated interruption of the continuity of the furnace operations and therefore reduction in furnace production during the period of time required for the repair work. Most of these older methods have involved the replacement of masonry by refractory shapes in the weakened areas. Many attempts have been made to develop a method of patching the burned-out areas by spraying granular refractory material upon old surfaces. While some success has been attained in attempts to renew the grooved, corroded side walls and fettling, and the edges of hearths, there have been no known successful applications of the spraying method in patching the underside of arches of operating furnaces. The method developed recently at the Clarkdale smelter of the United Verde Branch of Phelps Dodge Corporation, at Clarkdale, Ariz., and described in this paper, has been found to be not only convenient and successful with respect to patching vertical or inclined surfaces, but has met with a marked degree of success in patching the parts of furnace arches that are exposed to flame, the successful result being obtained with-out interruption or interference with the continuity of furnace operations. ? It may be described as a method of renewing the interior refractory sur-faces of operating furnaces by pneumatic spraying of an aqueous suspen-sion of finely divided particles of refractory material. It has been used

Jan 1, 1939

By Charles Will Wright

DESPITE the war, the First Pan American Mining Congress, held in Santiago, Chile, Jan. 15-23, was attended by about 300 persons including the official delegates from sixteen of the American republics. The United States delegation consisted of Elmer Pehrson, of the U. S. Bureau of Mines; D. F. Hewett, of the U. S. Geological Survey; William H. Hobbs, of the Carnegie Foundation; and C. W. Wright, delegate of the Board of Economic Warfare and of the A.I.M.E. Mr. Wright was elected to head the delegation. Among the other members were Edward Steidle, of Pennsylvania State College and also an official A.I.M.E. delegate; John Huttl, of Engineering and Mining Journal; W. 0. Vanderburg, foreign mineral specialist from Lima, Peru; O. B. Hundley, of the American Cyanamid Co.; Horace Graham, of the Anglo-Chilean Nitrate Co.; and several officials and engineers from the Anaconda, Kennecott, and Bethlehem Steel companies' mines in Chile.

Jan 1, 1942

By Ralph Arnold

THE American oil 'industry has reached the critical stage where the demand exceeds the supply with no hope of permanently bettering the situation through the development of new fields in the United States. Remedies may be sought along three lines: 1. Securing a foreign source of supply. 2. Curtailment of the use of oil and its derivatives. 3. Improvement in methods of recovery (including the recovery of shale oil), refining, and utilization. The oil companies with proper government support will push the acquiring of foreign territory; the price of oil and oil products will enforce a curtailment in use; it remains for the producers and refiners to brings about improvements and economy in recovery, transportation and refining; the general public must be instructed in utilization. The solution of the problem, therefore, rests largely in the hands of the technologists of the industry -the drillers, engineers, geologists, chemists, etc. Only through an exchange of the ideas of the individuals who are conducting the industry will its technology be advanced. , Among the agencies at work to bring about this result are the United States Bureau of Mines, the American Petroleum Institute, and the A. I. M. E. The Bureau of Mines has a trained staff of experts, maintains experiment stations and a field force of technologists, and issues many technical papers helpful to the industry. The Petroleum Institute is a clearing house for useful statistics and is now. organizing a research division under the able direction of Doctor Manning, but its principal field of activities is in the realm of co¬ordinating ?the financial and commercial activities of the` oil' companies.' It remains for the American Institute of Mining and Metallurgical Engineers to organize the individual technologists of the industry and provide them with means of exchanging and disseminating ideas through meetings and publications. It is the aim of the Petroleum Committee of the American Institute of Mining and Metallurgical Engineers to foster this exchange of ideas among oil men by enlarging the membership of the Institute among the field and office technical forces of the oil companies and thus arouse their interest in the vital problems of the oil business.

Jan 1, 1920