Search Documents

By A. M. Gaudin, R. T. Hukki

Previous work on the principles of comminution has shown: (I) that the surface produced is proportional to work input (Rittinger law,1a-3); (2) that there is regularity to the weight distribution of the fragments according to size.4-10 In this paper it is brought out that the surface on the fragments is distributed in definite and simple relation to size. The experimental work has involved: I. Construction of an apparatus capable of measuring the surface of mineral fragments independently of the chemical composition of the fragments and independently of the site of the surface; 2. Refining the methods available for measurement of particle size; 3. Designing and building a crusher capable of operating on very small quantities of mineral, if necessary on single crystals, and in such fashion as to minimize handling losses of material. Complete experiments have been carried out with massive quartz and individual quartz crystals. partial experiments, lacking surface measurements, have been made with glass spheres, galena, sphalerite, fluo-rite, salt and coal. Introduction The existence of regularity in weight distribution with size was noted many years ago, especially by A. 0. Gates;' the subject was also studied in detail by one of us.6 In the latter paper it was shown that rocks can be divided into two classes: homogeneous rocks, which show no preferential breaking, and heterogeneous rocks, which show preferential breaking at the grain size of the rock. It was shown, furthermore, that the fragments obtained by rupturing a homogeneous rock occur (in the fine range) in such abundance as to permit the writing of a relatively simple equation to relate the weight retained on a screen to the screen opening. With screens of which the openings are in constant ratio, the weight retained, w, is related to the screen size x by the equation w = Cxm [I] In this equation C and m are experimental constants. A plot of weight retained against particle size is a straight line of slope m if the scales for x and w are both logarithmic. In the fine range, the slopes of the size-distribution graphs plotted according to the method described above vary within a limited range. An inspection of a number of size-distribution data by various experimenters indicates that the slope very seldom exceeds 1.0, but is usually greater than 0.7. More recently, schuhmann8 proposed a method of charting that has so many advantages of its own that it has been used primarily in this work. For fine particles Schuhmann has found that the data are represented by the equation (x)m k [2]

Jan 1, 1947

By Carl A. Zapffe, M. Eleanor Haslem

The present investigation has three principal purposes: 1. To develop a method for measuring hydrogen embrittlement that avoids cer, tain errors complicating previously used methods. 2. To explore in a preliminary way some of the fundamental factors controlling embrittlement. 3. To apply the measurements specifically to stainless grades of steel, whose sensitivity or insensitivity to hydrogen embrittlement has never been clearly defined. Selecting a Test Method Hydrogen embrittlement is a condition of low ductility resulting from excessive absorption of hydrogen by the steel at some period in its history, and may be revealed by almost any test involving cold deformation. Tensile tests, impact tests, and bend tests are commonly used for detecting hydrogen embrittlement; although numerous other tests, such as cold-upsetting or extrusion, could be used. The simplicity of using a wire specimen for cathodic and acid pickling tests, and the especial adaptability of the bend test to wire specimens, led to selection of the bend test for the present research. Bend tests usually have been of three general types: (I) fatigue, (2) reversed bend, and (3) single bend. The first two types, though widely used, are inaccurate because their measurements are counteracted by an aging effect; and the third type has not been developed to its fullest utility. The effect of cold-working in removing hydrogen is well known. During a bend test hydrogen can be observed escaping from the convex side simply by coating the specimen with oil; and any technique employing flexing or reverse bending may therefore have its measurements masked because the mechanical action reduces the embrittlement during the test. This factor is so important that even elastic flexing of a hydrogen-charged wire specimen should be avoided before testing if accurate measurements are desired. Developing a Machine for Measuring Hydrogen Embrittlement As for the single-bend test, its theory is good, and recovery caused by mechanical work is kept to a minimum. With a given degree of hydrogen embrittlement, a specimen will break at a given angle if the bending is applied unidirectionally and uniformly. The radius of the bend must be kept constant; and the rate of bending should be a constant, slow enough to allow reading of the breaking angle, and yet rapid enough to prevent significant recovery from the escape of hydrogen during bending. A simple apparatus (Fig. I) was constructed using a type H Foxboro drive unit A, which is a synchronous motor with a gear-reduction ratio of 600 to I. A cord, fixed at one end to a wooden pulley B on the drive shaft of the motor, follows the pe-

Jan 1, 1947

By Carl A. Zapffe, M. Eleanor Haslem

The present investigation has three principal purposes: 1. To develop a method for measuring hydrogen embrittlement that avoids cer, tain errors complicating previously used methods. 2. To explore in a preliminary way some of the fundamental factors controlling embrittlement. 3. To apply the measurements specifically to stainless grades of steel, whose sensitivity or insensitivity to hydrogen embrittlement has never been clearly defined. Selecting a Test Method Hydrogen embrittlement is a condition of low ductility resulting from excessive absorption of hydrogen by the steel at some period in its history, and may be revealed by almost any test involving cold deformation. Tensile tests, impact tests, and bend tests are commonly used for detecting hydrogen embrittlement; although numerous other tests, such as cold-upsetting or extrusion, could be used. The simplicity of using a wire specimen for cathodic and acid pickling tests, and the especial adaptability of the bend test to wire specimens, led to selection of the bend test for the present research. Bend tests usually have been of three general types: (I) fatigue, (2) reversed bend, and (3) single bend. The first two types, though widely used, are inaccurate because their measurements are counteracted by an aging effect; and the third type has not been developed to its fullest utility. The effect of cold-working in removing hydrogen is well known. During a bend test hydrogen can be observed escaping from the convex side simply by coating the specimen with oil; and any technique employing flexing or reverse bending may therefore have its measurements masked because the mechanical action reduces the embrittlement during the test. This factor is so important that even elastic flexing of a hydrogen-charged wire specimen should be avoided before testing if accurate measurements are desired. Developing a Machine for Measuring Hydrogen Embrittlement As for the single-bend test, its theory is good, and recovery caused by mechanical work is kept to a minimum. With a given degree of hydrogen embrittlement, a specimen will break at a given angle if the bending is applied unidirectionally and uniformly. The radius of the bend must be kept constant; and the rate of bending should be a constant, slow enough to allow reading of the breaking angle, and yet rapid enough to prevent significant recovery from the escape of hydrogen during bending. A simple apparatus (Fig. I) was constructed using a type H Foxboro drive unit A, which is a synchronous motor with a gear-reduction ratio of 600 to I. A cord, fixed at one end to a wooden pulley B on the drive shaft of the motor, follows the pe-

Jan 1, 1947

By Robert H. Richards

The extent to which sizing by sieves should be carried, as a preliminary to the separation, by jigging, of minerals of different specific gravities, has been a matter of controversy for many years. The subject has been investigated by several authorities, yet the ground does not seem to have been completely covered, nor are the questions involved entirely settled. For my present purpose I shall refer to but three investigators—Rittinger, Munroe, and Hoppe. In seeking additional light, I have gone over part of the old ground which has been considered satisfactorily settled; and since these preliminary tests have thrown light on some points, they have been included in this paper. In the investigations here described, I have confined myself, for several reasons, wholly to small sizes—grains of 0.1 inch in diameter and less. Rittinger's work was mainly done upon larger sizes, and there is much need among millmen of information concerning the smaller sizes. Moreover, these sizes brought the investigation within the means at my disposal. The laws that have been claimed as the laws of jigging by the several authorities are: 1. The law of equal-settling particles. 2. The lam of interstitial currents. 3. The law of acceleration. 4. The law of suction. The first of these has been considered by investigators, generally, to be the most important of all, and the larger part of the work of jigging is thought to be governed by it. But that it does not cover the whole of jigging is clear to all; and to account for the increased efficiency which we may call the extra jigging-catch, the other three laws have been advanced. The investigation described in this paper was undertaken to determine, as far as possible, to what extent each of the four laws con-

Jan 1, 1895

By R. H. Sweetser

AT the Buffalo meeting in October, 1898 (Trans., xxviii., 865), our Secretary, Dr. Raymond, in speaking of the obstacles he had encountered in securing contributions to the Transactions from members in practice, said: "It is the disinclination of many members to communicate incomplete or partial or preliminary results. They are going to write, ' some day,' a thorough and monumental paper; and meanwhile they prefer to communicate nothing. . . . It is the difficulty to which I have just referred that I have encountered in a wide correspondence with members, undertaken for the purpose of securing contributions of fact and opinion concerning the special subject of this discussion. . . . Almost none of them seem to recognize the value of preliminary, incomplete and indecisive reports of practice, as laying the foundation for a thorough inquiry." This remark was made in immediate reference to a discussion concerning blast-furnace tuyeres ; but, notwithstanding this appeal from the Secretary, little has been recorded regarding the distribution, the penetration, and the pressure of the blast at the tuyeres and inside the iron blast-furnace. I am therefore encouraged to contribute the following incomplete and crude observations of the blast-pressure inside the hearth. At the suggestion of J. H. Frantz, the General Manager of the Columbus Iron & Steel Co., a test was made at the East furnace of the company to determine whether there was any difference in blast-pressure at the different tuyeres. The apparatus used for this test was not sensitive enough to give accurate results. It consisted of a small pressure-gauge mounted on a 3/8-in. gas-pipe. A hollow plug, fitting into the peep-hole of the tuyere-cap, prevented the blast from blowing-out during the test. The test-pipe was held in place by means of the handle on the outer end.

Mar 1, 1909

By C. W. Davis, L. R. Messer

THE name fuller's earth, which was derived from its early use in "fulling" or removing grease from woolen goods, is a term that is generally considered to designate mineral matter, containing hydrous aluminum silicates of the clay group, which has a high capacity for removing colors from oils, whether of animal, vegetable, or mineral origin. Fuller's earths are usually dried and may be "tempered" by heating or may be treated with water or reagents to improve their efficiency. For our purpose the term "acid-treated earths" will include those products from the partial decomposition of mineral water by acid which are equal to or more efficient than an untreated fuller's earth from Quincy, Fla., when used in bleaching mineral oil by the "contact" process. In general, the contact process for treating oils consists of heating and agitating a mixture of oil and finely divided adsorbent, the latter being subsequently removed by filtration. The term "adsorbent" is used because, although there has been a great deal of controversy over the mechanism of removal of impurities from oils by mineral matter, there is no doubt that adsorption, which involves the surface of the solid, plays a major part.' The properties that make fuller's earth useful in the treatment of petroleum products by "percolation1' and in the purification of edible oils by the contact process have long been studied, but the comparatively recent adaptation of the contact process to the bleaching of petroleum products has made desirable the further investigation of fuller's earth and other adsorbent earths.

Jan 1, 1929

The following is am incomplete list of members and guests who called at Institute headquarters during the period May 10, 1918 to June 10, 1918. Arthur K. Adams, Potrerillos, Chile. J. M. Mahoney, Wilkinsburg, Pa. John Carter Anderson, Tucson, Ariz. Benjamin L. Miller, South Bethlehem, Pa. George S. Blair, Camp Cordon, Ga. Wilbur A. Nelson, Nashville, Tenn. W. A. Deane, Summitville, N. Y. Miles G. Nixon, Chicago, Ill. Charles H. Fulton, Cleveland, Ohio. Walter G. Perkins, San Francisco, Cal. Rudolf Gahl, Inspiration, Ariz. G. M. Ponton, Ottawa, Canada. C. C. Griggs, Eureka, Utah. D. A. Powell, Columbus, Ohio. J. F. Hanst, Potrerillos, Chile. H. W. Reed, Salt Lake City, Utah. Stanley C. Herold, Pittsburgh, Pa. J. C. L. J. Seelig, Padong, East. Indies. Floyd D. James, Boston, Mass. Oberlin Smith, Bridgeton, N. J. Charles Janin, San Francisco, Cal. Harrison Souder, Cornwall, Pa. E. Horton Jones, Copper Cliff, Ont. Stanley A. Spellmeyer, Camp Meade, Md. William Kelly, Vulcan, Mich. Roger S. Sperry, Waterbury, Conn. Ichiro Kitsunezaki, Tokyo, Japan. D. R. Thomas, Toronto, Canada. P. K. Lucke, San Antonio, Tex. Thor Warner, Phoenix, Ariz. E. Francis McCrossin, Birmingham, Ala. L. Douglass Anderson, formerly superintendent of the United States Smelting Co., Midvale, Utah, is now manager of smelters, Intermountain District, United States Smelting, Refining & Mining Co., Salt Lake City, Utah.

Jan 7, 1918

By C. G. Dunn

Nuclei that are formed during the recrystallization of a grain following plastic deformation generally have orientations that differ from the original. This aspect of recrystallization may be described in terms of orientation changes. It was shown previously, in an investigation on recrystallization in silicon ferrite,&apos; that the observed orientation changes were highly improbable on a chance basis, and that some mechanism must be involved. Analysis showed that the data could be satisfactorily classified into the smaller of two subclasses† of the 36 third-order twin transformations. No attempt was made at that time to classify the data within the special class of 12 third-order twin transformations, although results did indicate a greater probability for some of them to occur. A classification of this type would be more valuable, of course, with more data on orientation changes per old deformed grain. The present work fulfills this condition to some degree and also extends the scope of the investigation to include the effects of original orientation and the amount of plastic deformation. The effect of original orientation is of considerable interest because of the known effects of orientation on plastic deformation, particularly with regard to degree of fragmentation and the formation of deformation bands, and because the orientations produced by deformation should influence the orientations obtained through recrystallization. Barrett and Levenson2 reported that single crystals of iron deformed in the range 82 to 97 per cent could be put into three general classes; namely, crystals in class I maintained a reasonably sharp single orientation, those in class 2 transformed into two distinct orientations, and those in class 3 changed into a large number of major and minor orientations. Something similar would be expected for silicon ferrite crystals, and verification of this for a few cases of types class I and class 2 deformation has been reported elsewhere3 for single crystals of silicon ferrite cold-rolled in the range 10 to 20 per cent. As an example of class 2 deformation, it was shown that a crystal of silicon ferrite cold-rolled in a (110) plane in a <100> direction developed two layers, or deformation bands differing in orientation. When this happens it is possible to etch away one band and leave a single structure for use in studying the orientation changes that occur during recrystallization. when preferred crystal orientations are obtained in recrystallization, it is not particularly necessary to evaluate groups of common orientation, as was done previously (ref. I, Table 6); but an

Jan 1, 1947

By C. G. Dunn

Nuclei that are formed during the recrystallization of a grain following plastic deformation generally have orientations that differ from the original. This aspect of recrystallization may be described in terms of orientation changes. It was shown previously, in an investigation on recrystallization in silicon ferrite,&apos; that the observed orientation changes were highly improbable on a chance basis, and that some mechanism must be involved. Analysis showed that the data could be satisfactorily classified into the smaller of two subclasses† of the 36 third-order twin transformations. No attempt was made at that time to classify the data within the special class of 12 third-order twin transformations, although results did indicate a greater probability for some of them to occur. A classification of this type would be more valuable, of course, with more data on orientation changes per old deformed grain. The present work fulfills this condition to some degree and also extends the scope of the investigation to include the effects of original orientation and the amount of plastic deformation. The effect of original orientation is of considerable interest because of the known effects of orientation on plastic deformation, particularly with regard to degree of fragmentation and the formation of deformation bands, and because the orientations produced by deformation should influence the orientations obtained through recrystallization. Barrett and Levenson2 reported that single crystals of iron deformed in the range 82 to 97 per cent could be put into three general classes; namely, crystals in class I maintained a reasonably sharp single orientation, those in class 2 transformed into two distinct orientations, and those in class 3 changed into a large number of major and minor orientations. Something similar would be expected for silicon ferrite crystals, and verification of this for a few cases of types class I and class 2 deformation has been reported elsewhere3 for single crystals of silicon ferrite cold-rolled in the range 10 to 20 per cent. As an example of class 2 deformation, it was shown that a crystal of silicon ferrite cold-rolled in a (110) plane in a <100> direction developed two layers, or deformation bands differing in orientation. When this happens it is possible to etch away one band and leave a single structure for use in studying the orientation changes that occur during recrystallization. when preferred crystal orientations are obtained in recrystallization, it is not particularly necessary to evaluate groups of common orientation, as was done previously (ref. I, Table 6); but an

Jan 1, 1947

By Paul W. Chase

Centralized process control has received increasing emphasis in recent years. Its application at U. S. Steel&apos;s Minntac facility for production of taconite pellets is discussed in this paper. A brief description of the flowsheet will provide background for discussion of the process instrumentation and digital system.

Jan 1, 1969

By C. G. Dunn

NUCLEI that are formed during the recrystallization of a grain following plastic deformation generally have orientations that differ from the original. This aspect of recrystallization may be described in terms of orientation changes. It was shown previously, in an investigation on recrystallization in silicon ferrite,1 that the observed orientation changes were highly improbable on a chance basis, and that some mechanism must be involved. Analysis showed that the data could be satisfactorily classified into the smaller of two subclassesf of the 36 third- order twin transformations. No attempt was made at that time to classify the data within the special class of 12 third-order twin transformations, although results did indicate a greater probability for some of them to occur. A classification of this type would be more valuable, of course, with more data on orientation changes per old deformed grain. The present work fulfills this condition to some degree and also extends the scope of the investigation to include the effects of original orientation and the amount of plastic deformation. The effect of original orientation is of considerable interest because of the known effects of orientation on plastic deformation, particularly with regard to degree of fragmentation and the formation of de- formation bands, and because the orientations produced by deformation should influence the orientations obtained through recrystallization. Barrett and Levenson2 reported that single crystals of iron deformed in the range 82 to 97 per cent could be put into three general classes; namely, crystals in class I maintained a reasonably sharp single orientation, those in class 2 transformed into two distinct orientations, and those in class 3 changed into a large number of major and minor orientations. Something similar would be expected for silicon ferrite crystals, and verification of this for a few cases of types class I and class 2 deformation has been reported elsewhere3 for single crystals of silicon ferrite cold-rolled in the range 10 to 20 per cent. As an example of class 2 deformation, it was shown that a crystal of silicon ferrite cold-rolled in a {110} plane in a < 100> direction developed two layers, or deformation bands differing in orientation. When this happens it is possible to etch away one band and leave a single structure for use in studying the orientation changes that occur during recrystallization. when preferred crystal orientations are obtained in recrystallization, it is notparticularly necessary to evaluate groups of common orientation, as was done previously (ref. I, Table 6); but an

Jan 1, 1946

By Henry W. Edwards

Concrete is not a new, nor even a modern substance. Important structures built by the old Romans before the commencement of the Christian Era are to-day sound and solid— for example, the dome of the Pantheon in Rome, 142 ft. in diameter. I do not propose, therefore, to discuss the durability of the material, as in the mining and metallurgical business, structures, as a rule, are not calculated to endure for two thousand years. I do wish to urge, however, that much of the stone masonry around mines and smelters would have given better results if concrete had been used in place of stone. Concrete looks better; is stronger, cheaper, more durable, more quickly built, and above all requires no skilled labor, except that of the carpenter, who, like the poor, is always with us. Well proportioned concrete, that is to say, having well proportioned ingredients, may be safely relied upon to withstand a compressive or crushing strength of 50 tons per square foot. In most American cities, however, the building laws limit it to the absurdly low figure of 16 tons. This restriction is probably due to the political influence of the building-trades unions, which object strongly to its too free use, undoubtedly owing to its not requiring the services of skilled workmen. I hope to show that quite important construction work may be&apos; undertaken without the aid of the gentleman with the trowel. In some of the isolated districts of the West and Southwest this is no mean advantage. The weight of good concrete, dry, is from 130 to 160 lb. per cubic foot. Ingredients of Concrete. Concrete is composed of four ingredients; viz., 1. Crushed Stone; 2. Sand; 3. Cement; and 4. Water.

Jan 1, 1905

By H. R. Spedden

As part of its broad program of educational assistance-including grants, fellowships, and scholarships -Kennecott Copper Corp. offers summer employment opportunities for college students at each of its operations. Originally, summer job programs were intended primarily to help students defray their educational expenses. But as the nation&apos;s economy expanded with increased production and a growing demand for well-trained engineers, summer employment became an important means to help qualify future professionals and fill industry&apos;s need for them. Both the employer and the student thus derive benefits from such training.

Jan 6, 1967

By H. L. Hazen

The uranium mill at Gunnison, Colorado, started crushing ore Dec. 31,1957, and has now been operating four months. The acid leached ore is washed by counter-current decantation through a system of four classifiers and four thickeners and most of the dissolved uranium reports in the overflow from the first washing thickener. This uranium is extracted from the aqueous pregnant solution by solvent extraction using di-2-ethyl hexyl phosphoric acid and tri-butyl phosphate dissolved in a high-flash-point kerosene as the extracting organic. The pregnant organic is then stripped with soda ash solution. The uranium bearing soda ash solution is filtered to remove insoluble carbonates and any sediment reaching that part of the circuit. The clarified carbonate pregnant solution is then acidified to 3 pH, heated to 180°F to drive off the last traces of CO2, and the uranium finally precipitated as yellow cake with MgO.

Jan 11, 1958

By Thos Egleston

The sands of Snake River, Idaho, have long been known to contain gold. They were worked by some of the first prospectors who came to Idaho, and on the banks still stand the ruins of camps abandoned for years. There are almost always prospectors searching for gold during the season of low water, and it is not an infrequent thing to find a miner of the old type actually panning the sand, or the prospect-hole which he has just left. There is more or less mystery about these miners and their methods of finding the spots where they work. They are always subjects of much speculation to the ordinary traveller. The rich discoveries are, for the best of reasons, concealed until the claims can be taken up. It is difficult to find a place where there are no prospects, but the " colors " are so very fine that they do not offer much inducement to enterprise. The California miner usually values a color at from 5 to 10 cents, often the latter; while on Snake River it would take 100 colors, or even more, to make that amount.

Jan 1, 1890

By J. D. Pennock

About a year and a half ago, Mr. Morris, an engineer of the Solvay Process Company, was sent to Belgium and France to study the manufacture of coke in the Semet-Solvay ovens, which were in operation at Havre. With complete plans of construction and a good understanding of the methods of running the ovens, he returned to Syracuse. Work on twelve Semet-Solvay ovens was immediately begun. These ovens, with plant for crushing and washing coal, and the necessary condensers, scrubbers, and concentrator for the recovery of the byproducts are nearly finished, and will soon be in operation. As the work approached completion it became necessary to determine what coal should be used. Accordingly, a chemical investigation of the various bituminous coals was made. I. Investigation of Coals. The samples of coal taken for analysis were: I. A sample of Reynoldsville coal that had been exposed to the weather for a year; 11. Reynoldsville coal taken from a car direct from the mine; 111. Morris Run lump coal; IV. Morris Run fine coal; V. Coal from the Fairmount Coal and Coke Company; VI. A special enginecoal from Pardee colliery, Phillipsburg, Pa.; VII. South Fork, Pa., coal; VIII. Coal from Laceyville, Ill.; IX. Pittsburgh bituminous coal from Ocean mines (gas-coal); X. Steubenville, Ohio, coal; XI. Evansville, Indiana, coal; XII. Coal from the Ohio Coal Company. Proximate Analysis. I. 11, 111. IV. V. VI. Water at 90° C.,* ..................................... Volatile,. .. 31.14 33.00 17.73 18.12 37.20 23.86 Fixed Carbon,. . 64.49 58.07 71.92 71.89 56.68 73.00 Ash,. .. 4.37 8.93 10.35 9.99 6.12 3.14 Coke,. .. 68.86 67.00 82.27 81.88 61.88 76.80

Jan 1, 1893

By J. P. Denny

The constitution of the Ga-In system was determined by thermal methods. An experimentally determined metastable equilibrium line (an extension of the indium-rich liquidus) was obtained. The various alloys were studied metallographically using polished samples obtained by a casting method. These low melting alloys required a special dry-ice assembly to maintain a suitable temperature. RECENT interest in alloys that are liquid at room temperature has led to rather extensive investigation of gallium-base alloys. Widely distributed over the earth, gallium could be produced in substantially larger quantities than at present, if a significant demand existed.&apos; One study&apos; has established its presence in 12 out of 14 zinc blends, in all of 15 aluminum ores, in 4 out of 12 manganese ores, in 35 out of 91 iron ores, and in all of 7 magnetite ores. It occurs as a rule in minute amounts, however, leading to high extraction costs. Recent quotations run from $2.50 to $7.50 per g. During the course of the present investigation, portions of the system Ga-In have been redeter-mined, and the results of this study are presented herein. Thermal and metallographic methods have been employed. Lecoq de Boisbaudran, the discoverer of gallium, conducted the first investigation" on Ga-In alloys in 1885. The temperatures of incipient melting, and of completion of melting, were determined at four alloy compositions. In 1936, Hansen&apos; constructed a eutec-tic-type phase diagram for the system Ga-In, based on . work. The existence of a Ga-In compound was regarded as improbable by Hansen, and subsequent investigations are in agreement. French, Saunders, and Ingle3 conducted a more complete study of the system in 1938, using thermal methods. Their phase diagram is a eutectic type, containing a unique concave-upward liquidus. The solid-solution range of gallium in indium was reported as 9.5 pct by weight, and that of indium as less than 1 pct, at the eutectic temperature. The eutectic composition, determined as being bracketed by the compositions showing a true horizontal at the eutectic temperature (16°C), was reported as 76 5-0.5 pct Ga and 24 i 0.5 pct In. Experimental Procedure The preparation of Ga-In alloys is simplified by the low melting points involved. Various compositions were prepared by melting in pyrex tubes, using a cover of distilled water or parafin to prevent the alloys from wetting the glass wall. In all cases, the melts were homogenized. by stirring. Where possible, both cooling and melting curves were determined. The extensive undercooling of gallium was found to prohibit a satisfactory cooling-curve analysis of gallium-rich alloys, however, and transition points on the gallium side of the eutectic could be determined only by melting curves. The inverse rate method of thermal analysis proved to be most satisfactory and was used to a great extent. Various heating and cooling rates were used, ranging from 0.2" to 5.0°C per min. Low temperature melting analyses were conducted within a constant temperature bath, maintained at about 70 °C. The alloys were solidified (under water or paraffin) within a pyrex tube, using dry ice; the tube was then sealed within a cold Dewar flask, the unit transferred into the constant temperature bath, and periodic temperature readings taken. The high temperature melting-curve determinations and all cooling-curve determinations were made in a vertical tube furnace. At near-eutectic compositions, the furnace was placed within a refrigerated room held at —20°C. Accordingly, the furnace on cooling approached —20°C asymptotically and permitted the determination of those phase transitions occurring below room temperatures. Temperatures were measured with a 30-gage iron-constantan thermocouple, immersed directly in the alloy. To prevent contamination of the melt, the leads and junction were coated with Lucite, applied by painting with a solution of Lucite in ethylene dichloride. Electromotive force measurements were made with a Leeds and Northrup precision potentiometer, type 8662. The couples were calibrated against the boiling point. of water and, at lower temperatures, against a calorimeter thermometer having a Bureau of Standards certificate. The melting points of gallium and indium used in the present investigation were determined as 29.-77° and 156.1°C, in good agreement with previously reported values of 29.78°C° and 156.4"C.&apos; The spec-

Jan 1, 1953

By C. H. Lieb

ONE astounding fact in the production of petroleum is the comparatively recent realization by producers that flowing production is the cheapest crude produced. About 1910 or even later, operators actually endeavored to get a producing well to pumping as quickly as possible after completion. A well was not really considered to be completed until it was operating on the pump. Remarkable progress has been made since then. It was not until about 1920 that producers began to take a serious interest in pressures and to think a little about proper methods of handling oil wells. Pressure gauges were installed, and records of pressures maintained, which was quite an innovation. Desultory experiments were made with tubing of different sizes, as well as experiments with placing the bottom of the tubing string at different levels in the well. Probably the first important departure from customary procedure was about 1926, during the Seminole development, when gas lift

Jan 1, 1936

By Walther Mathesus

INTRODUCTION THE use of high blast heats on furnaces melting Mesaba ores is still the exception, the average blast temperatures carried on Mesaba stacks seldom reaching 1,100° F. Some 15 years ago, when the use of fine Mesaba ores in larger proportions to the total burden first came into practice, it was found difficult to employ even those blast heats which it had been possible to carry with the Old Range ores. The furnaces refused to "take" high heats, and would persistently labor with irregular stock movement, which impaired the practice and increased the coke consumption. By lowering the blast temperature, the working of the furnace became smoother, and experience taught that with the softer and more easily reduced Mesaba ores, satisfactory practice could be obtained with comparatively low blast heats. Therefore a large number of Mesaba furnaces have ever since been operated on very low blast temperatures, ranging between 800° and 1,000° F. In the face of these difficulties, furnace men were slow to recognize that furnaces could be so designed as to permit a free movement of the charges in combination with the use of higher heats. Since higher blast temperatures did not seem to offer great advantages in the smelting of Mesaba ores, investments in hot-blast stoves were not as attractive to the furnace man as labor-saving devices and means of obtaining greater tonnages. The effect of this preference is keenly felt at the present time. It has brought about the peculiar situation, that the majority of our furnace plants (among them some of the most progressive) lack modern and efficient stove equipment. The result is that, even where the proper furnace lines have been adopted and conditions are now favorable to the successful employment of higher blast temperatures, the heats required for the greatest fuel economy are not available.

Jan 3, 1915

P. Herasymenko (New York University, New York) —The authors&apos; experiments on equilibria between water vapor and liquid synthetic slags represent a valuable contribution to our knowledge of the nature of liquid slags. They can be regarded as a proof of ionic splitting of water molecules dissolved in slags. The assumption that water dissolved in slag was com- pletely ionized was made in my report on hydrogen equilibria in steelmaking as early as 194010. In that paper, the first systematic data were given on the content of ionized hydrogen in acid and basic open-hearth slags. The paper probably escaped the notice of the authors, although they mention the articles published later by other investigators who reported erratic and

Jan 1, 1958