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By Elmer W., Pehrson

NOT much serious consideration was liven to the military aspects of raw materials before World War 1. Following the outbreak of war in Europe in 1914, however. this situation was promptly changed. Disruption of allied shipping and German submarine warfare soon cut off a substantial part of the material the United Staten was accustomed to receiving from overseas. At the same time, raw material requirements rose rapidly as the tempo of industrial preparedness was stepped up in anticipation of war. By April 1917, when we entered the war, serious shortages threatened and consideralde attention was being given to our "deficcient" raw materials. The term "war mineral," began to appear after we became active combatants. But there is no evidence that "strategics" and "critical." as now used, had entered the lexicon of our raw materials experts during the last war nor were there apparently any officially recog¬nized list or definitions of what con¬stituted war materials. According to G. A. Roush in his book, `'Strategic Mineral Supplies," C. K. Leith, while serving as mineral advisor to the War Industries Board. compiled the first unofficial list of deficient minerals in 1917.

Jan 1, 1944

By B. Alexander, G. Derge W. Peifer

This is part of a research project in the Metals Research Laboratory of Carnegie Institute of Technology, sponsored by the Carnegie-Illinois Steel Corporation. In organizing our program it became apparent that the problem of analyzing molten steel for hydrogen must be divided into two parts: (I) the correct analysis of a given sample, and (2) the correct sampling of the bath. Emphasis has been placed upon these divisions in the order named because methods of sampling cannot be evaluated until a satisfactory method of analysis is available. Vacuum fusion was selected from the list of possible analytical methods because it seemed to us to offer the best possibilities for giving rapid, accurate results on solid steel samples. A number of objections have been raised against this method as usually practiced. We have sought to meet some of these by proper design of the apparatus. Experiments will be described which show that others are not valid. In the conventional apparatus the sample is held under high vacuum for a period of several hours before it is actually analyzed and one might expect considerable hydrogen to escape during this period. We have provided a means of introducing the sample to the vacuum just before analysis. Another difficulty has been that the entire apparatus has been designed primarily for the purpose of analyzing for oxygen, which constitutes upward of go per cent of the total gases evolved from the sample The volume and pressure measurements have therefore been insensitive to the relatively small amounts of hydrogen present. This difficulty obviously can be taken into account in any apparatus designed especially for the amounts of hydrogen expected. Analysis in Vacuum-fusion Apparatus A number of experiments were carried out to determine the importance of several factors that have been stated as possible sources of error or uncertainty in vacuum-fusion analysis for hydrogen; namely, that hot graphite will absorb some of the gases, that metal vapor will cause discrepancies, and that low results may be obtained as a result of the water vapor (produced by the oxidation of the hydrogen) dissolving in the butyl phthalate of the manometer, or that the blanks obtained from the apparatus are so great as to make the method inaccurate. The experiments also checked on the accuracy and feasibility of using differential freezing as a method of gas analysis in a vacuum-fusion apparatus.

Jan 1, 1945

By D. Y. F. Lai, R. J. Borg

Tracer diffusion of Fe59 has been measured in the a-stabilized Fe-1.8 at. pet V alloy from 700° to 1500°C. The activation energies are obtained in both the presence and absence of magnetic order. Furthermore, it is established that diffusion in the alloy is identical to that in pure iron and consequently the values of Do and Q accurately represent the temperature dependence for self-diffusion. The purpose of this investigation is to obtain an accurate estimate of the temperature dependence for self-diffusion in bee iron in both the presence and absence of magnetic order, and, in so doing, to establish the temperature range of the magnetic effect.&apos;" As the temperature interval suitable for diffusion measurements is severely limited in both bee phases of pure iron because of the intervening fee ? phase, the experiments were performed on an a-stabilized alloy containing 1.8 at. pet V. This alloy is bee over the entire range from room temperature to the melting point. Although there have been several independent investigations of self-diffusion of iron in a, iron,1, 3-6 there still exists considerable disagreement regarding the values of Do and Q for the paramagnetic region. The two systematic studies of diffusion in 6 iron6, 7 previously reported are also only in fair agreement; but in view of the extremely small temperature range available for diffusion studies, i.e., 1390o to 1535oC, this is not surprising. It is comparatively easy to obtain accurate values of Do and Q for the a-stabilized alloy inasmuch as measurements can be made over the entire temperature range -700o to 1500°C. However, in order to assume that these same values apply to pure iron requires careful comparison of the data in the a, and 6 regions in both the alloy and pure iron. We have made several measurements in the appropriate temperature ranges and are unable to establish any systematic difference between the diffusion coefficients of iron in pure iron and in the alloy. We therefore conclude that the values obtained for the alloy are truly applicable to pure iron; the complete evidence favoring this conclusion will be discussed later in this paper. EXPERIMENTAL The experimental methods will be given here only in barest detail since they have been thoroughly de- scribed elsewhere.l, 7 The alloy was prepared by induction melting and chill casting under argon. Diffusion samples were machined from the ingot and annealed in hydrogen for several days at 900°C to give an average grain diameter of 1 to 2 mm. The penetration profiles of the tracer were established by a sectioning technique, the residual activity being counted after the removal of each section. The tracer used is Fe59 which emits two high-energy ? rays of 1.098 and 1.289 Mev, respectively; these were detected by a ? scintillation counter equipped with a pulse-height analyzer. For the measurements in the temperature range -700o to 1130°C the samples were vapor-plated with Fe59, encapsulated in quartz under vacuo, and annealed in resistance-heated furnaces which are controlled to ±1°C. The specimens diffused at higher temperatures are prepared as edge-welded couples, the two halves being separated by a thin washer of the alloy to prevent sintering. The diffusion anneal is then carried out by inductive heating under a dynamic vacuum. The temperature is monitored pyrometrically. RESULTS The diffusion coefficients are obtained from the penetration profiles in the usual way using the error-function complement relationship. The results over the entire temperature range are shown in Fig. 1. In the linear region, 900o < t > 1500°C the least mean squares (lms) values of the diffusion coefficients are given by D = 1.39 exp[-(56.5 ± 1) x 103/Rt] cm2/sec [l] The average departure of the measured diffusion coefficients from the values given by Eq. [1]In order to determine whether or not the slope is truly constant over the entire range from 900" to 1500°C, the data are arbitrarily divided into two groups, the first containing values between -900" and 1133°C and the second between -1133o and 1500°C. The lms values for the two groups are given by Eqs. [2] and [3]: D = 0.519 exp[-55.7 x 103 /RT](900° to 1133°C) cm2/sec [2] D = 1.45 exp[-56.7x103/RT] (1133° to 1500=C) cm2/sec [3] Thus, there is no significant difference between the high- and low-temperature segments of the linear region. This not only assures us of the consistency of the values obtained by induction heating as compared to those obtained from the resistance-heated

Jan 1, 1965

By R. W. Fenn, H. A. Lepper, W. R. Hibbard

THIS paper reports the results of static tension and torsion tests made on single crystals of alpha brass for the purpose of determining its elastic coefficients. 70-30 alpha brass was chosen because it has been used extensively in the study of the plastic deformation and because it has the following desirable characteristics: (1) face-centered cubic structure, (2) marked elastic anistropy, (3) low elastic modulus. In 1928 Masima and Sachs&apos; using static methods reported the following values for the elastic coefficients of 72-28 pct alpha brass: S11 = 19.4 X 10-13&apos; cm2 per dyne S12 = —8.35 X 10"&apos; cm2 per dyne S44 = 13.9 X 10-13= cm2 per dyne These values were obtained from the measurements shown in fig. 1. The experimental points for both tension and torsion lie consistently below the lines drawn to represent them. Fig. 2 shows the stress-strain curves for their specimens. Only a few points in the elastic range of these curves were available to obtain their values for Young&apos;s modulus. Therefore, it was considered that a re-evaluation of these data was desirable. In addition a variation of from 1.13 to 1.485 kg per mm2 was found in the values of the critical resolved shear stress for 70-30 alpha brass reported by Burghoff,² Treuting and Brick: Martin,4 Maddin, Mathewson and Hibbard5,6 and von Goler and Sachs.&apos; Therefore, it was desired to evaluate the conclusion of Boas and Schmid8 that a constant resolved shear stress and not a constant elastic shear initiates plastic deformation. Theoretical Considerations*: The elastic deformation of cubic crystals may be defined by three elastic coefficients (S11, S12, S44,) or three elastic parameters (C,,, C,, C,,). These coefficients or parameters are sufficient to define the stress and strain relations for cubic crystals in the generalized form of Hooke&apos;s law referred to Cartesian coordinates. Elastic parameters and coefficients in the cubic system are related by the expressions: C11 —S11+S12/(S11-S12)(S11+2 S12) C12=-S12/(S11-S12)(S11+ 2 S12) (S11 — S12) (S11 + 2 S12) [2] C44 =1/S44 PI It is possible to determine all the elastic coefficients for a cubic metal by measuring two of the three elastic constants: Young&apos;s modulus (E), torsion modulus (G), or compressibility (S). The following relations exist between crystallographic orientation and E, G and S for cylindrical crystals of the cubic system: 1/E = S11 — 2 [(S11 - S12) — Su] (?1² ?2² + ?2²?83 + ?3² ?1²) [4]

Jan 1, 1951

Dr. Oldshue has provided a useful summary of a voluminous subject and my task will be to select and direct attention to those areas of mixing theory and practice which are germane to mineral processing in general, and to fine particle treatment in particular. Pulp mixing in impeller actuated reactors occurs in mineral processing in several different applications: (1) emulsification of reagents; (2) mixing pulp with &apos;reagents as in conditioning for subsequent operations (such as flotation, flocculation or agglomeration) ; (3) high intensity agitation, as in (a) disintegrating and dispersing aggregates, and (b) aggregating particles as in shear flocculation or in selective agglomeration; (4) hydrometallurgy; (5) hydrometallurgy with gas phase (e.g., Arbiter process); . (6) flotation in sub-aeration machines. Attention is invited to 3 above in which two opposite effects can be induced by proper choice of chemical treatment and hydrodynamic conditions. Successful processes for treating mineral fines require excellent aggregate dispersion in order to fully accomplish the liberation stage. Some processes depend further upon selective aggregation following dispersion. The term “dispersion” is often used in different senses which for present purposes will be clarified at the bottom of the next page.

Jan 1, 1979

By N. LILIENBERGS

DURING the past few years, the requirements for steel have been raised so high that soundness is more important than ever before. The old practice was to mike steel ingots of sufficiently large sections to permit a considerable reduction of area in rolling and hammering to a given size, relying on the fact that by such rolling and hammering all cavities will be squeezed together and practically eliminated. The finished sizes, if found by inspection of the surface to be faultless, were therefore pronounced to be sound. But when such steel is ?worked up,? the manufacturer is surprised and disappointed to find that it splits, or that streaks and seams make the product unmarketable. Large sections, such as rails, beams or heavy forgings, may, within certain limits, be sufficiently strong, even if the sides of the cavities are only squeezed, and not welded together. But it is well known that, in the interior of heavy articles, under certain conditions, forging may develop small streaks into large cavities. Small sections, steel for ordnance and tubes, and numberless articles in the tool-trade, always show up the defects. It may be doubted whether cavities in steel ingots can ever be completely welded. The old theory, is, that the silver-clear blow-holes, without the blue oxide, can be welded by sufficient working. They are, however, not empty, but are filled with carbonic oxide. It is admitted that the "blue" cavities, resulting from air mechanically drawn down into the mold during the casting, can never be welded, because the oxide does not melt, and there would be no escape for it if it did. The only way in which steel can be made satisfactory for the above-named particular purposes is by having it ?dead molten." But then the trouble of piping is encountered. As is well known, a pipe is the result of the contraction of

May 1, 1906

By W. McA. Johnson

The work of J. E. Johnson, Jr., on the effect of small amounts of oxygen in cast iron in increasing its strength and resistance to shock, is of interest from the technical and scientific standpoints. The following exposition of the theory carries Mr. Johnson&apos;s explanation further and, in my opinion, will disclose certain related phenomena and perhaps shed further light on the subject. Some facts, so novel in character as to excite incredulity, have been accepted finally by many metallurgical authorities. One of these is that oxygen to the amount of 0.060 per cent. in cast iron gives it a breaking strength of 3,500 Ib. per square inch, compared with a breaking strength of 2,500 lb. per square inch in cast iron of the same composition with respect to elements other than oxygen, but having only 0.010 per cent, oxygen. The "oxygenated" cast iron, even if made in a coke furnace, has properties equivalent to the best charcoal pig iron. Mr. Johnson has also established the fact that the variations in combined carbon cannot account for the results. By microphotographic evidence he has shown that in oxygenated cast iron the graphite particles are dense and spherical, while in well-deoxidized cast iron the graphite particles are flaky and leaf-like. It is just a matter of common sense that iron of the latter structure is much weaker than the former. The analytical and microscopical work has been done with care and there is no doubt in my mind about the accuracy of the experimental results. In this paper then, we shall consider it as accepted that small amounts (0.060 per cent.) of oxygen increase the strength of cast iron by producing a structure in which the round and solid particles of graphite are surrounded firmly by a principal matrix of ferrite. The purpose of this paper is to show that the reason why the graphite particles are round is founded on the fact that the particles of any precipitate are made denser and harder by the presence of a reagent having a solvent action on the precipitate. This can be stated as a law, although I have never seen it so given in any textbook. Let us then, for purposes of illustration, give a concrete example and develop the theory of such mechanical and chemical actions as occur: It is well known that, by a soluble sulphate, a barium salt in solution is precipitated in a dense and easily filtered body when the solution is

Jan 1, 1916

By K. Adam

Grinding in steel mills adversely affects the flotation of pyrrhotite. The electrochemical nature of inter action between pyrrhotite and active metals was investigated by contacting pyrrhotite with platinum at different applied potentials. Flotation tests, scanning electron microscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy were wed to examine the surface properties of pyrrhotite. The formation of hydroxide or oxide and sulfate species of iron through the oxygen reduction reaction at the cathodically polarized surface of pyrrhotite was shown to be the mechanism responsible for the reduced floatability of pyrrhotite.

Jan 1, 1985

By Thomas MacFarlane

IN smelting copper, lead, and silver ores, it is scarcely possible in every case to make analyses of the various parcels of ore, with the view of combining these and the fluxes so accurately as to yield, in the furnace, slags of exactly the most favorable composition. This is even more difficult with ores which require previous calcination, or with mattes which have been roasted in heaps. Even in cases where the greatest pains have been taken and the most elaborate calculations made beforehand, it frequently happens that variations in the working of the furnace interfere with the result so much desired. Generally, the practical metallurgist must be content with ascertaining the average composition of his ores and fluxes, making a calculation once for all as to the most advantageous mixture, and leaving slight changes in its composition to be taken care of as it is passing through the furnace. The various products then afford him the best material whereon to base his judgment as to the manner in which his smelting mixture is working. Of course the character of the slag is one of his chief guides, but it is not always possible from its outward characters alone to form a correct judgment as to its composition. Neither would it be possible or practicable to apply chemical analysis for this purpose, as it would be impossible to wait for its results while working a furnace. Abich was, I believe, the first to point out the relation existing between the composition of volcanic rocks and their densities, and to show that, the latter being ascertained, very correct conclusions

Jan 1, 1880

By Thomas MacFarlane

In smelting copper, lead, and silver ores, it is scarcely possible in every case to make analyses of the various parcels of ore, with the view of combining these and the fluxes so accurately as to yield, in the furnace, slags of exactly the most favorable composition. This is even more difficult with ores which require previous calcination, or with mattes which have been roasted in heaps. Even in cases where the greatest pains have been taken and the most elaborate calculations made beforehand, it frequently happens that variations in the working of the furnace interfere with the result so much desired. Generally, the practical metallurgist must be content with ascertaining the average composition of his ores and fluxes, making a calculation once for all as to the most advantageous mixture, and leaving slight changes in its composition to be taken care of as it is passing through the furnace. The various products then afford him the best material whereon to base his judgment as to the manner in which his smelting mixture is working. Of course the character of the slag is one of his chief guides, but it is not always possible from its outward characters alone to form a correct judgment as to its composition. Neither would it be possible or practicable to apply chemical analysis for this purpose, as it would be impossible to wait for its results while working a furnace. Abich was, I believe, the first to point out the relation existing between the composition of volcanic rocks and their densities, and to show that, the latter being ascertained, very correct conclusions

Jan 1, 1880

By Howard Drullard

To OBTAIN the best results from hammer drills, close attention must be paid to two factors in drill maintenance, which are of equal importance; one is lubrication, the other is the shank. With the exception of stoping drills, most modern rock drills require both oil and grease. The oil ports are in the lubricator, on or behind the hammer cylinder; the grease port for the lubrication of the &apos;chuck sleeve and rotating mechanism is on the chuck end. Ordinary machine oil is not, adapted to rock drills; a heavier more gelatinous oil such as castor machine oil or liquid-grease should be used. The lubricators should be filled-once for every 12 or 14 ft. (3.5 to 4m.), of hole drilled. Grease-guns should be used to fill the port in the chuck end once a shift; a medium ( No. 3) grease is well adapted to this purpose. Hard grease must not be put into- the lubricators, as it will not flow through that part. Contrary to the popular belief, oiling a machine once or twice a shift does not provide sufficient lubrication; the drills should be oiled once for every 12 or 14 ft. of, hole drilled. The rotating handle of a stoping drill -is an oil reservoir and is provided with a port for oiling. The rotating handle is packed with wicking, or similar material, which causes the oil to feed slowly from the handle to the other parts of the machine. Stoping drills require oil at. least twice a shift; lighter oils than castor, such as Arctic Ammonia may be used.

Jan 8, 1920

Discussion of the paper of J. V. EMMONS, presented at the Pittsburgh meeting, October, 1914. and printed in Bulletin No. 93, September, 1914, pp. 2233 to 2248. ALBERT SAUVEUR, Cambridge, Mass.-Mr. Emmons is to be congratulated for having placed before us in so forcible and satisfactory a manner a question of much importance-that of the surface decarbonization of steel. Of course, both manufacturers and consumers have known for many years that during the heat treatment of high-carbon steel, surface deca.rbonization is always likely to occur to a greater or less degree, but the subject does not seem to have been investigated with the method and thoroughness it deserves. I am in substantial agreement with Mr. Emmons&apos;s conclusions, and I have but little to add to what he has so well said. His statement that carbon dioxide is just as effective an oxidizing agent as pure oxygen is likely to cause surprise and some will wonder whether his investigation has been carried far enough to warrant so unexpected a conclusion. The reaction C + 0 = CO, expressing the oxidation of carbon by pure oxygen, is decidedly exothermic, whereas the reaction C + C02 = 2C0, expressing the oxidation of carbon by carbon dioxide, is endothermic. Decarburization by pure oxygen, therefore, should take place much more readily than by carbon dioxide. One cannot help regretting that the author does not mention&apos; the best way of preventing in a practical manner surface decarbonization while treating tool steel and other high-carbon steels.

Jan 4, 1915

By E. A. Nesbitt

The important permanent-magnet alloys 15 years ago contained carbon and depended upon it for their permanent-magnet properties. In recent years great advances have been made in a number of new alloys substantially free of carbon. These include Remalloy,&apos; an alloy of iron, cobalt, and molybdenum, the various iron-nickel-aluminum alloys of the Mishima2 type, and the more recent Alnico V3 in which the best properties are developed by heat-treating in a magnetic field. The Mishima and the Alnico types of alloys are very brittle and after casting must be ground to size. This article describes a permanent-magnet material4 that can be machined as cast, and when handled with some care can be rolled to thin sheet and drawn to fine wire. Optimum magnetic properties are developed by a simple heat-treatment, and at this time the ductility of the alloy disappears. If the cast alloy is heat-treated without cold-working the mag netic energy product is about 1.0 X 106. This material is called Vicalloy I (pronounced vicalloy, V for vanadium, I for iron, and C for cobalt). When the alloy is first hot-worked and then considerably reduced in area by cold-swaging, drawing or grooved rolling, it is found that after heat-treatment the magnetic energy product measured in the direction of previous extension can be increased to 2.0 to 3.5 X 106. These higher values have been obtained only after reductions in area of 75 to 95 per cent, and since the material hardens considerably during working, the reduction ordinarily can be accomplished only in fine wires, although larger sizes can be reduced by the use of powerful machinery. When the material has been cold-worked in such a manner as to improve its energy product substantially, it is called Vicalloy 11. Commercial use of Vicalloy has been made in the recording of speech. Tape 0.002 by 0.050 in. has been found superior in quality to all others tried, and is now used in the Western Electric Mirrorphone 5 In a variety of forms Vicalloy I or I1 is useful in many laboratory instruments, and in experiments in which the sizes and shapes required cannot be obtained with the other more brittle permanent-magnet materials. In 1936, during a study of other age-hardening magnetic systems, it occurred to the author that some of the iron-cobalt-vanadium alloys might be suitable for permanent magnets. The proportions of iron, cobalt, and vanadium were varied and a range of alloys of particular interest was found, as shown by the indicated area in Fig. I. The limits of this range of composition are 30 to 52 per cent iron, 36 to 62 per cent cobalt, and 4 to 16 per cent vanadium. The compositions indicated by points outside this area were also tested. Preparation and Properties OF Vicalloy I The alloys were usually cast in graphite molds into bars 3/4 in. in diameter and

Jan 1, 1946

By E. A. Nesbitt

The important permanent-magnet alloys 15 years ago contained carbon and depended upon it for their permanent-magnet properties. In recent years great advances have been made in a number of new alloys substantially free of carbon. These include Remalloy,&apos; an alloy of iron, cobalt, and molybdenum, the various iron-nickel-aluminum alloys of the Mishima2 type, and the more recent Alnico V3 in which the best properties are developed by heat-treating in a magnetic field. The Mishima and the Alnico types of alloys are very brittle and after casting must be ground to size. This article describes a permanent-magnet material4 that can be machined as cast, and when handled with some care can be rolled to thin sheet and drawn to fine wire. Optimum magnetic properties are developed by a simple heat-treatment, and at this time the ductility of the alloy disappears. If the cast alloy is heat-treated without cold-working the mag netic energy product is about 1.0 X 106. This material is called Vicalloy I (pronounced vicalloy, V for vanadium, I for iron, and C for cobalt). When the alloy is first hot-worked and then considerably reduced in area by cold-swaging, drawing or grooved rolling, it is found that after heat-treatment the magnetic energy product measured in the direction of previous extension can be increased to 2.0 to 3.5 X 106. These higher values have been obtained only after reductions in area of 75 to 95 per cent, and since the material hardens considerably during working, the reduction ordinarily can be accomplished only in fine wires, although larger sizes can be reduced by the use of powerful machinery. When the material has been cold-worked in such a manner as to improve its energy product substantially, it is called Vicalloy 11. Commercial use of Vicalloy has been made in the recording of speech. Tape 0.002 by 0.050 in. has been found superior in quality to all others tried, and is now used in the Western Electric Mirrorphone 5 In a variety of forms Vicalloy I or I1 is useful in many laboratory instruments, and in experiments in which the sizes and shapes required cannot be obtained with the other more brittle permanent-magnet materials. In 1936, during a study of other age-hardening magnetic systems, it occurred to the author that some of the iron-cobalt-vanadium alloys might be suitable for permanent magnets. The proportions of iron, cobalt, and vanadium were varied and a range of alloys of particular interest was found, as shown by the indicated area in Fig. I. The limits of this range of composition are 30 to 52 per cent iron, 36 to 62 per cent cobalt, and 4 to 16 per cent vanadium. The compositions indicated by points outside this area were also tested. Preparation and Properties OF Vicalloy I The alloys were usually cast in graphite molds into bars 3/4 in. in diameter and

Jan 1, 1946

By L. W. Strock

Metallurgists handling lead and zinc ores have long been familiar with the spectrograph as a routine analytical tool, as its earliest regular use by American industry was in controlling impurities of zinc metal and its alloys. This application has been extended to other metal industries on an extensive scale, accompanied by refinements of procedure to such an extent that a large part of some metals produced, especially magnesium, aluminum and steel, are checked only by spectrographic methods for conformity to specifications. The spectrographic analysis of ores and other poorly conducting powdered solids presents difficulties not encountered with metallic samples, which can be arced or sparked as self-electrodes or can be readily dissolved, so that their solutions can be analyzed, as in the American Society for Testing Materials standard methods for zinc and zinc-base alloys. Spectra of powdered solid samples can be prepared by using carbon electrodes provided with a crater of suitable size, into which the sample is packed. Ore samples and many other powdered solid materials usually analyzed in the chemical and metallurgical laboratory are more complex and varied in composition than samples of metals produced in large tonnages. &apos;lore preliminary work therefore is usually necessary in devising a spectrographic method for analyzing a given type of powdered sample than for analyzing metal samples, in order to use that method with confidence. The howledge that the standard samples and unknowns produce equivalent line intensities at equal concentration is the fundamental basis of any quantitative spectrographic method. On the other hand, powdered samples have an advantage over metals in that any desired number of chemical compounds can be mixed dry in any desired ratio to produce a synthetic standard. Expcrience has shown, however, that spectra of elements in finely divided compounds introduced into a standard in preparing a synthetic ore sample do not always behave in the electric arc in a manner that produces spectral line intensities similar to those observed at the same concentration in a natural mineral. In ore samples minor elements frequently are contained in the crystal lattice of larger particles of an abundant ore mineral. Their dissociation and volatilization from the sample into the arc then proceeds differently in the standard and sample, with resultant differences in intensity. During the past 10 years I have devised and applied several quantitative spectrographic methods for determining various elements in rocks and minerals in connection with studies on their geochemistry,&apos; but the incentive has gradually changed since the summer 0. 1940 to the specific practical problem of searching for domestic sources of rare and stratcgic metals. The

Jan 1, 1949

By H. M. Morse

This report on oil and gas development in Mississippi covers the period from Jan. I, 1944, to Dec. 31, 1944: Salt Domes During the year six salt domes were drilled for sulphur, but no commercial sulphur deposits were found. One salt dome, the Bruinsburg, in Claiborne County, has produced gas- at 935 to 940 ft&apos; in Moody&apos;s Branch marl. The Stringer salt dome in Smith County and the Ruth salt dome in Lincoln County both had a slight showing of heavy oil. Other salt domes have been dry. In addition to the Bruinsburg dome, the Allen salt dome, in Copiah County, and the Richton salt dome, in Perry County, were discovered in 1944; also the Sumrall dome, in Covington County. New Oil Fields Baxtemille Oil Field.—The Baxterville oil field was discoveredby the Gulf Refining Co, in sec. 7, T. I N., R. 16 W., Lamar County. At the end of the year this field had one oil well, with two active operations. Production for 1944 was 1047 bbl. of oil. GwinvilLe Field.—Gwinville field was discovered by S. W. Richardson, in sec. 24, T. 9 N., R. 19 W., Jefferson Davis County. This discovery well was a gas-distillate well, the oil being crystal clear. At the end of 1944 there were two gas wells and one oil well in the field. The oil well is approximately 2 1/2-miles from the gas- distillate wells. Gas production was 55,801 M cu. ft. and the distillate production was 2644 barrels. Heidelberg Oil Field.— The Gulf Refining Co. discovered the Heidelberg field in sec. 30, T. I N., R. 13 E., Jasper County, in January 1944. This field has by far exceeded the other 1943 and 1944 discoveries, having approximately 56 oil wells, 7 dry holes, and 10 active wells at the end of the year. Production to Jan. I, 1945 was 1,441,192 bbl. of oil. Mallalieu Oil Field.—The california Company discovered the Mallalieu oil field in set. 10, T. 7 N., R. 8 E,, Licoln. County. At the end of the year there was one well in the field with three active operations. Production was 32,303 bbl. of oil. Old Oil Fields Brookhaven Oil Field, in Lincoln County, has one oil well, which produced 2590 bbl. of oil during 1944. CarY Oil Field, Sharkey County1 has only one producing well, which produced 11,818 bbl- of oil during the Year- In Cranfield Oil Field, dams County, II oil wells and two gas-distillate wells were drilled in 1944 and there were five active wells on Dee. 31, 1944- The total production for the Year was 5251422 bbl-of oil. The gravity of the oil is 40" to 54.9&apos;- In Eucutta Oil Field1 Wayne County1 34 oil wells were completed during 1944. There were five dry holes and six active wells at the end of the year.. The field produced 454,332 bbl. of all d the average gravity is 25" Flora Oil Field, Madison County, pro-

Jan 1, 1945

By J. H. Jackson, P. D. Frost, C. H. Lorig, L. W. Eastwood, A. C. Loonam

It is well known that for equal weights of material, thin sections of the lighter structural alloys are more resistant to buckling under a compressive stress than thin sections of more dense material. Therefore, structural parts having the same resistance to buckling stresses are generally lightest when they are made of magnesium alloys. Consequently, there is considerable interest in the development of strong alloys having densities equal to or lower than that of magnesium and strength-weight ratios equivalent to those of the strongest aluminum alloys. The development of commercial magnesium-base alloys has been very successful, and their importance among materials in the structural field has been amply demonstrated. However, an even wider structural application of magnesium alloys might be effected if improvements could be made in the cold rollability and cold-forming characteristics. Such improvements, along with production of less directionality in properties. could be effected if the hexagonal close-packed lattice of present alloys could be replaced with a cubic lattice. In 1942, a project, having as its objective the improvement of some of the characteristics of commercial magnesium-base alloys, was initiated at Battelle Memorial Institute under the sponsorship of the Mathieson Chemical Corporation. At that time, one of the authors,* then Chief Metallurgist for the Mathieson Chemical Corporation, postulated that the addition of lithium to magnesium in sufficient quantities to change the crystal structure of the resultant alloy from a hexagonal to a body-centered cubic lattice should produce a magnesium-rich alloy which would have the desired improvements in cold-working characteristics with less directionality in properties. To test this view, a series of alloys was made and was found to have many of the attributes that were predicted. The view that magnesium-lithium alloys were of structural interest was also held by others. In 1943 and 1945, Dean and Andersonl,² obtained patents on magnesium-base alloys containing from about 1 to 10 pct lithium, from about 2 to about 10 pct manganese, and the balance substantially all magnesium; and on magnesium-base alloys containing from about 1 pct to about 10 pct lithium, from about 2 to about 10 pct manganese, from about 0.5 to 2 pct silver, and the balance substantially all magnesium. They noted that an alloy containing 83 pct magnesium, 10 pct manganese, 5 pct lithium, and 2 pct silver could be cold rolled by any of the usual methods and that this alloy was considerably harder and stronger than most other magnesium-base alloys heretofore available. In 1945, Hume-Rothery, et al.,3 predicted that magnesium-lithium base alloys should be soft and ductile and that such compositions, to which was added a third element for the purpose of producing a precipitation-hardening type of alloy, should be ductile, strong, and lighter than magnesium itself. Hume-Rothery investigated the binary magnesium-lithium and ternary magnesium-lithium-silver equilibrium relations and criticized the existing equilibrium diagrams. The binary magnesium-lithium equilibrium diagram has also been investigated by Grube, Von Zeppelin, and Bumm, Henry and Cordiano, Sal&apos;dau and Shamrai, Hof-mann,&apos; and Shamrai.8 The work of most investigators agreed with that of Grube, whose constitution diagram is shown in Fig 1. From the standpoint of development of structural alloys, the room-temperature equilibrium relations are of great interest. An examination of Fig 1 reveals that, from 0 to 5.7 pct lithium, the existing phase is alpha, which is a solution of lithium in hexagonal magnesium. The boundary between the alpha, and alpha plus beta regions, occurs at a Mg/Li of 16.5, corresponding to 5.7 pct lithium by weight. Between 5.7 pct and 10.3 pct lithium, there exists a mixture of the alpha phase (lithium dissolved in hexagonal magnesium) and the beta phase (magnesium dissolved in body-centered-cubic lithium). The boundary of the alpha plus beta and beta regions occurs at a Mg/Li of 8.7, corresponding to a lithium composition of 10.3 pct. Much of the work described here was directed toward obtaining an alloy made up of a large proportion, or entirely, of the body-centered-cubic beta structure. In his early work, Loonam found that specimens of lithium-bearing alloys were very malleable. Ingots of alloys prepared at that time were extruded to 3/8-in. diam bars, and the mechanical properties and the effects of heat treatment were then determined. These data are given in Table 1. The outstanding ductility of the alloys, combined with their moderately high strength, evoked considerable interest.

Jan 1, 1950

INSTITUTE MEDALS AND PRIZES ASIDE from the John Fritz Medal, in which the Institute participates through its representation on the John Fritz Medal Board, the Institute itself has four awards it may make annually, as fol¬lows. the Robert W. Hunt Medal and Prize, the J. E. Johnson, Jr., Award, the James Douglas Medal, and the William Lawrence Saun¬ders Medal. ROBERT W. HUNT MEDAL AND PRIZE The partners of Robert W. Hunt established a fund which was presented to the Institute at a fitting ceremony-on May 27, 1920, to establish an annual medal and a sum of money to be awarded under the following rules 1 The award shall consist of two prizes first of a gold medal, second of a sum of money, a certificate to accompany each prize The money prize shall not be awarded to a member over 40 years of age, but under unusual circumstances, both prizes may be allotted to one person provided that he is not over 40 years of age In general it will be understood that the Committee shall award the money prize to the younger men, rather than the medal 2 The awards shall be made not oftener than once a year to that person or persons contributing to the Institute the best original paper or papers on iron and steel The scope of the term "iron and steel" shall be determined by the sub-committee considering the awards In general, papers dealing with the practical side of the subject have preference over those dealing with the theoretical side in recognition of the fact that Captain Hunt&apos;s main contributions to the industry have been in the improvement of production and quality of material

Jan 1, 1923

By M. D. Arnold, P. B. Crawford, P. C. Hall

An experimental study has been made to determine the optimum flooding pressures for four different oils. The oil formation volume factors ranged from 1.08 to 2.13, and solution gas-oil ratios ranged from about 200 cu ft/bbl to 2,250 cu ft/bbl. Viscosities ranged from 0.38 to 0.95 cp at the respective bubble points of the fluids and from 0.7 to 20 cp at atmospheric pressure. Water floods were conducted at various pressure levels from run to run. The recovery as a function of flooding pressure was found to be different for each fluid, with optimum gas saturations ranging from 7 up to 35 per cent. The data indicate that substantially higher recoveries may be obtained if water floods are conducted at an optimum pressure and that this optimum pressure is a function of fluid properties. The same core was used for all tests, and the reproduction of saturations for various runs indicates that wettability in the predominantly water-wet core did not change. INTRODUCTION A paper was presented by Bass and Crawford&apos; which described an experimental study of the effects of flooding pressure and rate on oil recovery by water flooding. This work was conducted using high-pressure models operated in a manner similar to that of an actual reservoir, with gas saturations being obtained by a solution-gas-drive mechanism. They found that the greatest oil recovery was obtained for the system studied by flooding in the presence of a 5 to 7 per cent gas saturation. Another experimental study simulating field conditions was presented by Richardson and Perkins.&apos; They used an unconsolidated sand pack containing kerosene-natural gas fluid and interstitial water. They flooded at various pressures and flooding rates. For their system it was found that the recovery was independent of the pressure level at which the water flood was performed. Kyte, et al," found that oil recovery by water flooding was increased as the free gas saturation at waterflood initiation was increased. However, after the initial gas saturation was increased above 15 per cent, the increase in oil recovery tended to level off. All of their runs were made at the same pressure using a light oil saturated with helium. The desired gas saturation was obtained by injecting helium into the core. Dyes&apos; made calculations which showed that an optimum gas saturation of 12 to 14 per cent may result in an increase in oil recovery of 7 to 12 per cent over that obtained by flooding at the bubble-point pressure. Others have also found that the presence of a free gas saturation may increase the waterflood oil recovery. In each case shrinkage was small and changes in fluid properties with respect to pressure were small. A careful review of the literature reveals that at the present time there is a wide difference of opinion on the factors affecting waterflood recoveries. This diversity of opinion is probably due to the fact that very little research has been done which has taken into account the many variables existing in an actual field being water flooded. Since the literature contains little information on high-pressure waterflooding studies using various types of reservoir fluids, it was believed appropriate that such a study should be made. EQUIPMENT AND PROCEDURE All tests were made using the same consolidated sandstone core. Torpedo sandstone was used to turn a cylindrical core 13.5-in. long and with a 2.92-in. average diameter. The core had a porosity of 28 per cent and a permeability to brine of 146 md. This brine was made up by adding 20,000-ppm sodium chloride and 30,000-ppm sodium nitrite to distilled water. This was used as connate water and flooding water. No fresh water was ever brought in contact with the core, as tests showed the sandstone contained argillaceous material which swelled in the presence of fresh water and plugged the stone. The core was sealed in a section of 6-in. N-80 tubing with Woods metal filling the annulus. The core was mounted horizontally; an injection well was placed in the center of one end and a production well in the center of the other. Pressure control was maintained by placing a back-pressure regulator (upstream control) on the producing well. The "live" oil was stored in a separate bottle and water was injected into this bottle to displace the oil for saturating the core using a two-cylinder standard-proportioning pump. This same pump was used for water flooding the core at a constant rate. This system was enclosed in water jackets and the temperature was automatically main-

By Morris Muskat, James M. McDowell

A report is given of electrical analog experiments on the effect of casing perforation completions on well productivity for ideal uniform reservoirs under steady state homogeneous fluid flow conditions. Graphical results are presented for the effect of perforations of different densities and various degrees of penetration into the formation surrounding the casing or cement sheath. The latter range from perforations which terminate flush with the casing to those which extend into the formation a distance equal to the casing diameter. For the special case where the perforations terminate immediately beyond the casing with semi-spherical protrusions the electrical analog results correct and supersede previously reported theoretical calculations. It is found that the penetration of the perforations into the surrounding productive section may so increase the resultant productivity as to approach or even exceed that for open hole completions. INTRODUCTION A theoretical analysis of the effect of casing perforation on well completion, without additional penetration of the formation, was reported several years ago.&apos; In this treatment the perforations were represented by mathematical sinks and no explicit account was taken of the imperviousness to flow of the casing in which the perforations were made. This procedure was justified by consideration of the mutual interference between the sinks, which seemed to indicate that the analytical method automatically eliminated flow across the casing radius between the perforations. However, both further theoretical investigation and the electrical analog measurements described below showed that this assumption in the previously developed theory was not valid and that the calculated well capacities would considerably exceed the correct values. § Even if this simplifying assumption were retained the generalization of the theory to situations where the perforations extend into the producing formation would be extremely difficult. On the other hand, the electrolytic model analog of this type of steady-state homogenous fluid system is, in principle, so simple that it has not been worthwhile to attempt to develop the exact analysis even for the more limited case of strict casing perforation. The whole problem has therefore been studied anew by electrical models to cover the range from holes in the casing which terminate flush with the casing surface to such as extend into the surrounding rock to a depth equal to the casing diameter. It is to be expected that the productivity of a well completed with casing radius* rw, perforated with holes of radius Tp, and extending to depths d into the surrounding rock, would depend primarily on the dimensionless geometrical parameters Te Tw TP d of the system, such as —, —, — , and —, where re is the Tw, a a rw external boundary radius and a is the mean vertical separation between the perforations. It will also depend, of course, on the number of perforation lines or total perforation density. While such parameters automatically control analytical treatments, it would require a very extensive series of model experiments to fully disclose their functional effect on the well productivity. For practical purposes, however, a rather limited range of the variables suffices to give the effects of interest. Accordingly, in the experimental study reported here the casing diameter has been kept fixed? at six in., the perforation diameter has been taken as either one-fourth in. or one-half in., their density has been varied from one to eight per ft, and their penetration into the formation has ranged from zero to six in., with a primary scaling factor of one to six. EXPERIMENTAL METHOD AND RESEARCH Although electrolytic model experiments have been made for years, there still seems to be some question as to what set of conditions will give the best results. For this reason a number of electrode materials and electrolytes were tried. Those chosen for the final experiments were copper electrodes and a weak copper sulphate solution as the electrolyte. This &apos;Assuming that the casing has been cemented with a uniform and impermeable cement sheath, the effective casing radius is to be interpreted as the external radius of the cement annulus. It is also assumed here that the casing is set through the complete producing section that it is perforated throughout with a uniform density and that tie formation has a a and isotropic permeability. As noted later, however, a uniform scale change permits reinterpreting the primary measurements to correspond to a casing diameter of 12 in.

Jan 1, 1950