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By A. V. Bradshaw, R. I. L. Guthrie

The behavior of large bubbles in the size range 4 to 25 cm3, rising through molten silver, has been studied. It was found that rising velocities were equivalent to those in aqueous systems of low viscosity. Mass transfer coefficients for oxygen bubbles dissolving in silver were found to be 0.036 ± 0.007 cm sec-1, being close to those predicted for transfer through the front surface of the spherical cap bubble only. It is suggested that the surface active nature of oxygen in silver could account for the relatively low coefficients obtained. MANY metallurgical processes involve interactions between gas bubbles and liquids. Examples include the removal of carbon monoxide in Open Hearth Steelmak-ing, the removal of sulfur by blowing air through copper matte during converting, and the removal of hydrogen from steel during vacuum degassing or inert gas flushing. The steps involved in such refining processes include; transport of the dissolved species to the bubble interface, adsorption and chemical reaction of the species at the interface, desorption of product molecules from the interface, and transport of product gas into the bulk gas phase of the bubble. It has been concluded1 that all the interfacial steps involved proceed so rapidly at steelmaking temperatures that transport of the solutes, present in the metal, become the important rate controlling factors provided nucleation phenomena are not restrictive. The O-Ag system was chosen for the investigation into gas bubble-molten metal interactions due to the relatively high solubility of oxygen that enables rates of oxygen transfer to be measured from changes in bubble volume. Other advantages of this system include the absence of a stable oxide phase at an oxygen pressure of 1 atm and the relatively low melting point of the metal which permits the use of a metallic container, providing that it is resistant to oxidation. In those metallurgical processes where bubbles have an important influence, bubble volumes are usually greater than 5 cm3. For this reason the present study relates specifically to single large bubbles of oxygen rising in silver. These bubbles adopt the characteristic spherical cap shape similar to that shown in Fig. 1 for a 30 cc bubble rising in water. After an initial investigation to determine the velocities of inert (nitrogen) bubbles rising in molten silver, experiments were carried out with oxygen and the rates of mass transfer between the oxygen bubbles and the silver were measured. EXPERIMENTAL Apparatus. The apparatus, Fig. 2, for containing molten silver, was constructed from "Nimonic 75" Alloy (75 pet Ni, 20 pet Cr, 5 pet Fe, Mn) and provided for the release of single bubbles from an hemispherical cup, situated at the bottom of the column. The cup was turned by translating the rotation of the drive shaft through 90 deg. This was accomplished by the use of a bevelled gear system, and a smooth drive was provided by the lubricating action of the silver on the gears. Since reliable high temperature seals at 1000°C were found to be impracticable, the filling and drive shaft tubes were extended outside the 3.5 kw resistance wire tube furnace, where connections were made using easily accessible O-ring seals. The apparatus remained gas tight to the atmosphere at pressure differentials far in excess of those used. The filling tube was connected via a small bore tube to the differential pressure transducer. Gas could be bubbled into the inverted cup from two i-in. tubes which passed down the inside of the column to preheat the gas. The temperature of the silver was maintained at 1020°C during all experiments. Measurement of Bubble Volume. In order to calculate mass transfer rates, it was necessary to obtain a continuous record of the bubble's volume during its passage through the column of molten silver. The method adopted for measuring the bubble volume involved closing off the top gas space to the atmosphere prior to each experiment, and recording the variation in gage pressure of this space during the formation and rise of the bubble. Since any change in bubble volume results in an equal change in top space volume, Boyles Gas Law may be applied (for isothermal con-

Jan 1, 1970

By Gerhard Derge, Arthur H. Grobe, Harold Markus

The high corrosion resistance possessed by tin under most circumstances, combined with its generally satisfactory appearance and useful physical properties, has led to many and varied uses for the metal. These uses have been partly limited by the fact that tin is an expensive metal, therefore many applications have been developed in which tin has been employed in combination with lead, either by coating, as in tin-lined collapsible tubes, or by the formation of alloys containing various proportions of tin-rich and lead-rich phases, as tcrne plate. A detailed knowledge of the corrosion characteristics of the tin-lead couple therefore is of general interest and has become specially important at the present time, when every effort is being made to conserve tin as much as possible. The present study has been limited to carbonate solutions with a pH range from 8.4 to 11.2 so that the results may be related to earlier work on the corrosion of tin and its alloys. 1-3,6 In these papers, the effects of a number of anion and cation additions to these solutions have been observed. Apparatus and Method The electrodes for the corrosion cell were cut from rolled sheet about 1/16 in. thick. The length of all specimens was held constant at 7 in., while the width was varied from M to 2 in. These electrodes were fastened to brass electrode supports, which were attached to rubber stoppers fitting into tall-type one-liter Pyrex beakers that contained the electrolyte. The lead electrodes were prepared from Omaha pig* and the tin was rolled from a slab of Chempur.† After cutting to size, the sheets were polished with No. I emery paper and cleaned with carbon tetrachloride. The edges, back and upper parts of the specimen were coated with a synthetic lacquer, which was supplemented with beeswax for the lead electrodes. The binding posts were coated with beeswax after the electrodes had been clamped. The pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicarbonate. Approximately 600 ml. of electrolyte was used in each beaker. The entire assembly was placed in an oil bath thermostatically adjusted to operate at 30°C. + 0.1". Potentials were measured against a saturated calomel electrode connected to the cell by an agar-agar salt bridge. The carbonate solution used in the salt bridge was the same as that used in the corrosion cell. Currents were measured with a milliam-

Jan 1, 1942

By Harold Markus, Arthur H. Grobe, Gerhard Derge

The high corrosion resistance possessed by tin under most circumstances, combined with its generally satisfactory appearance and useful physical properties, has led to many and varied uses for the metal. These uses have been partly limited by the fact that tin is an expensive metal, therefore many applications have been developed in which tin has been employed in combination with lead, either by coating, as in tin-lined collapsible tubes, or by the formation of alloys containing various proportions of tin-rich and lead-rich phases, as tcrne plate. A detailed knowledge of the corrosion characteristics of the tin-lead couple therefore is of general interest and has become specially important at the present time, when every effort is being made to conserve tin as much as possible. The present study has been limited to carbonate solutions with a pH range from 8.4 to 11.2 so that the results may be related to earlier work on the corrosion of tin and its alloys. 1-3,6 In these papers, the effects of a number of anion and cation additions to these solutions have been observed. Apparatus and Method The electrodes for the corrosion cell were cut from rolled sheet about 1/16 in. thick. The length of all specimens was held constant at 7 in., while the width was varied from M to 2 in. These electrodes were fastened to brass electrode supports, which were attached to rubber stoppers fitting into tall-type one-liter Pyrex beakers that contained the electrolyte. The lead electrodes were prepared from Omaha pig* and the tin was rolled from a slab of Chempur.† After cutting to size, the sheets were polished with No. I emery paper and cleaned with carbon tetrachloride. The edges, back and upper parts of the specimen were coated with a synthetic lacquer, which was supplemented with beeswax for the lead electrodes. The binding posts were coated with beeswax after the electrodes had been clamped. The pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicarbonate. Approximately 600 ml. of electrolyte was used in each beaker. The entire assembly was placed in an oil bath thermostatically adjusted to operate at 30°C. + 0.1". Potentials were measured against a saturated calomel electrode connected to the cell by an agar-agar salt bridge. The carbonate solution used in the salt bridge was the same as that used in the corrosion cell. Currents were measured with a milliam-

Jan 1, 1942

By A. L. Engel

STRICTLY speaking, ore-dressing does not commence until after the ore is in the mill bins, but where complex ores are treated and their minerals separated to make the best commercial concentrate with the lowest economical tailing, ore-dressing problems begin and often center in the mine itself. This does not refer to the grade of the ore, but rather to the frequent condition in which metallurgical results radically different from customary are obtained because of changes in the character of the ore treated. Different varieties of ore can usually be identified as coming from well-defined depths or zones in the mine, or from known sections of the orebody. Varying degrees of alteration of the ore, inclusions of harmful gangue material, or variations in the quantities of component metallic minerals are often causes of temporarily bad metallurgical results in otherwise successfully operated plants, especially those employing differential flotation to. recover several valuable minerals contained in the ore.

Jan 1, 1931

By Rizo-Pairón Alfonso, A. M. Gaudin

PREVIOUS studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector The results obtained indicate that a I I ratio of collector ion to activator ion gives optimum results, and that a 2 I ratio almost fails to achieve activation and flotation Yet, a 2 I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids, they confirm that an adsorbed coating is inescapable APPARATUS AND SUPPLIES The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz The flotation machine was built according to the design of D W McGlashan It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel stator, as in the Fagergren laboratory machine The air intake is controlled by a valve, and the cell consists of a beaker The quartz was obtained from vein quartz stored in large chunks It was first crushed to 20 mesh, then sized on a 28-mesh screen The 20 to 28-mesh size alone was retained for use This size was freed of coarse iron by passage through a Ball-Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used The barium was used as barium chloride, Baker's analyzed C P The oleate was used as sodium oleate It was prepared from sodium hydroxide, Baker's analyzed C P , and oleic acid purified by R R de Arellano3 in the laboratories at the Massachusetts Institute of Technology The purification procedure was elaborated from the recent researches of Brown and Shinowara 2 It consisted in (I) saponification of olive oil with potassium

Jan 1, 1942

By Webster Hodge

MALL generators and motors are required to Soperate, in some critical applications, at temperatures where cold-worked silver-bearing copper re-crystallizes. Copper containing up to 30 oz Ag per ton has been used for many years to build the highest grades of commutators and slip rings. With failure of commutators impending because silver-bearing copper cannot withstand the stresses imposed at these higher temperatures, Cr-Cu was tried as a substitute with varying degrees of success. Cr-Cu proved difficult to fabricate because a critical heat treatment was necessary to obtain sufficient ductility. Besides, its rupture strength was shown to be low at operating temperatures, its electrical conductivity lower than desired, and its cost high. Furthermore, it often contained hidden flaws. The Nippert Electric Products Co. set out to find a better material by undertaking a research project with the stated objective of providing a material suitable for commutators that would have 1) a softening temperature above 750°F (400°C), 2) a minimum electrical conductivity of 90 pct of that of pure copper, 3) a strength not less that that of cold-worked silver-bearing copper, and 4) a materials cost of not over 1.5 times the cost of copper containing 25 to 30 oz Ag per ton. No commercial alloy met these specifications. However, it was found that copper containing from 0.18 to 0.35 pct Zr could be produced quite easily in the laboratory, and promised to fulfill the major requirements noted above. Interest naturally centered in the lower part of this composition range, since such alloys gave somewhat better electrical conductivities, and were lower in

Jan 1, 1958

Albert SaUveur, Cambridge, Mass. (communication to the Secretary*):—On close examination I think it will be found that the evidence by which Mr. Corson claims to have shown the inaccuracy of a statement I made a few years ago, is far from convincing. This statement is: "Hot work as such has no influence upon the structure of the metal. Indirectly, however, by retarding crystallization until a lower temperature is reached, it may influence its structure most decidedly ; but the same results could be accomplished by heat treatment alone, i.e., by re-heating the unworked metal to the temperature from which the worked piece was allowed to cool undisturbedly." The Melallographist, vol. ii., p. 267 (under the head of "Changes of Structure Brought About by Work"). Of the two pieces of steel tested by Mr. Corson, one was worked and finished at a a cherry-red" and the other reheated to a cherry-red, and the assumption was made that in both cases the temperature was about 715' C., although no pyrometric device was used to record it. The possibility of considerable difference in temperature alone is so great as to invalidate Mr. Corson's inferences. The apparent temperature,

Jan 1, 1907

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) No. 488.-Mining engineer, member, technical graduate, married, age 38, desires position of superintendent or assistant superintendent. Has had 15 years' practical experience as miner, millman, machinist, surveyor, engineer, foreman, and superintendent in the West, Southwest, and Mexico. Speaks Spanish. Now employed as superintendent of copper property in Southwest. Can give the best of references. Minimum salary $250. Available after Sept. 1. No. 495.-Member, age 36, married, technical, 10 years'. all round

Jan 12, 1918

By C. M. Marquardt

Tramp iron and steel moving on a conveyor belt cause small currents to be generated in a coil situated in a strong magnetic field, which are converted to an alternating current and are amplified. The output voltage from the amplifier fires a thyratron with a relay in its anode circuit, which actuates a howler and simultaneously drops a spot of marker material on the belt.

Jan 1, 1950

By Alfonso Rizo-Patrón, A.M. Gaudin

Previous studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector. The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest. In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector. The results obtained indicate that a I: I ratio of collector ion to activator ion gives optimum results, and that a 2:1 ratio almost fails to achieve activation and flotation. Yet, a 2:I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion. To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful. The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids; they confirm that an adsorbed coating is inescapable. Apparatus and Supplies The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz. The flotation machine was built according to the design of D. W. McGlashan.* It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel sta-tor, as in the Fagergren laboratory machine. The air intake is controlled by a valve, and the cell consists of a beaker. The quartz was obtained from vein quartz stored in large chunks. It was first crushed to 20 mesh, then sized on a 28-mesh screen. The 20 to 28-mesh size alone was retained for use. This size was freed of coarse iron by passage through a Ball-Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used. The barium was used as barium chloride, Baker's analyzed C. P. The oleate was used as sodium oleate. It was prepared from sodium hydroxide, Baker's analyzed C. P., and oleic acid purified by R. R. de Arellano3 in the laboratories at the Massachusetts Institute of Technology. The purification procedure was elaborated from the recent $researches of Brown and Shinowara.2 It consisted in: (I) saponification of olive oil with potassium

Jan 1, 1943

By Alfonso Rizo-Patrón, A. M. Gaudin

Previous studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector. The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest. In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector. The results obtained indicate that a I: I ratio of collector ion to activator ion gives optimum results, and that a 2:1 ratio almost fails to achieve activation and flotation. Yet, a 2:I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion. To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful. The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids; they confirm that an adsorbed coating is inescapable. Apparatus and Supplies The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz. The flotation machine was built according to the design of D. W. McGlashan.* It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel sta-tor, as in the Fagergren laboratory machine. The air intake is controlled by a valve, and the cell consists of a beaker. The quartz was obtained from vein quartz stored in large chunks. It was first crushed to 20 mesh, then sized on a 28-mesh screen. The 20 to 28-mesh size alone was retained for use. This size was freed of coarse iron by passage through a Ball-Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used. The barium was used as barium chloride, Baker's analyzed C. P. The oleate was used as sodium oleate. It was prepared from sodium hydroxide, Baker's analyzed C. P., and oleic acid purified by R. R. de Arellano3 in the laboratories at the Massachusetts Institute of Technology. The purification procedure was elaborated from the recent $researches of Brown and Shinowara.2 It consisted in: (I) saponification of olive oil with potassium

Jan 1, 1943

By Harold Markus, Gerhard Derge, Arthur Grobe

THE high corrosion resistance possessed by tin under most circumstances, combined with its generally satisfactory appearance and useful physical properties, has led to many and varied uses for the metal. These uses have been partly limited by the fact that tin is an expensive metal, therefore many applications have been developed in which tin has been employed in combination with lead, either by coating, as in tin-lined collapsible tubes, or by the formation of alloys containing various proportions of tin-rich and lead-rich phases, as terne plate. A detailed knowledge of the corrosion characteristics of the tin-lead couple therefore is of general interest and has become specially important at the present time, when every effort is being made to conserve tin as much as possible. The present study has been limited to carbonate solutions with a pH range from 8.4 to 11.2 so that the results may be related to earlier work on the corrosion of tin and its alloys.1-3,6 In these papers, the effects of a number of anion and cation additions to these solutions have been observed. APPARATUS AND METHOD The electrodes for the corrosion cell were cut from rolled sheet about 1/16 in. thick. The length of all specimens was held constant at 7 in., while the width was varied from ½ to 2 in. These electrodes were fastened to brass electrode supports, which were attached to rubber stoppers fitting into tall-type one-liter Pyrex beakers that contained the electrolyte. The lead electrodes were prepared from Omaha pig* and the tin was rolled from a slab of Chempur.† After cutting to size, the sheets were polished with No. I emery paper and cleaned with carbon tetrachloride. The edges, back and upper parts of the specimen were coated with a synthetic lacquer, which was supplemented with beeswax for the lead electrodes. The binding posts were coated with beeswax after the electrodes had been clamped. The pH of the electrolyte was controlled by adjusting the ratio of carbonate to bicarbonate. Approximately 600 ml. of electrolyte was used in each beaker. The entire assembly was placed in an oil bath thermostatically adjusted to operate at 30°C. ± 0.1°. Potentials were measured against a saturated calomel electrode connected to the cell by an agar-agar salt bridge. The carbonate solution used in the salt bridge was the same as that used in the corrosion cell. Currents were measured with a milliam-

Jan 1, 1942

By Alfonso Rizo-Patrón, A. M. Gaudin

PREVIOUS studies of activation in flotation have directed attention to the action of the activator on the mineral to be floated rather than to the relationship of the activator to the collector. The latter phase of the problem, however, seems to have definite scientific, if not also practical, interest. In the investigation reported in this paper, experiments were carried out, largely with quartz as subject, barium as activator, and oleate as collector. The results obtained indicate that a I : I ratio of collector ion to activator ion gives optimum results, and that a 2:I ratio almost fails to achieve activation and flotation. Yet, a 2:I ratio would have been expected on stoichiometric grounds, had the coating been a normal salt of the activator ion with the collector ion, since barium is a divalent cation and oleate a monovalent anion. To interpret and rationalize the observations, considerations of the crystal chemistry of quartz are helpful. The point of view to which these considerations lead may be of general applicability to systems involving suspensions of solids in liquids; they confirm that an adsorbed coating is inescapable. APPARATUS AND SUPPLIES The experimental work consisted in barium-ion abstraction tests, hydrogen-ion and hydroxyl-ion abstraction tests, flotation tests, and determinations of the surface of the crushed quartz. The flotation machine was built according to the design of D. W. McGlashan.* It consists of a drill press in which the bit has been replaced by a stainless-steel impellor surrounding a stainless-steel stator, as in the Fagergren laboratory machine. The air intake is controlled by a valve, and the cell consists of a beaker. The quartz was obtained from vein quartz stored in large chunks. It was first crushed to 20 mesh, then sized on a 28-mesh screen. The 20 to 28-mesh size alone was retained for use. This size was freed of coarse iron by passage through a Ball Norton magnetic separator, bleached with boiling hydrochloric acid to remove residual abraded iron, washed with distilled water until the washings were thoroughly free of ferrous, ferric, and excess hydrogen ion, and stored in covered Pyrex beakers under water until used. The barium was used as barium chloride, Baker's analyzed C. P. The oleate was used as sodium oleate. It was prepared from sodium hydroxide, Baker's analyzed C. P., and oleic acid purified by R. R. de Arellano3 in the laboratories at the Massachusetts Institute of Technology. The purification procedure was elaborated from the recent researches of Brown and Shinowara.2 It consisted in: (I) saponification of olive oil with potassium

Jan 1, 1942

By A. F. Frederickson

A MINERAL can best be defined as a phase,' where the term "phase" is described as a homogeneous,* physically distinct, and mechanically sep- arable portion of a system. If one phase develops from another, certain nuclei must first be available.2.394 The manner in which new material is added to these nuclei, and the subsequent structural and other characteristics of the phase, is often markedly influenced by factors other than its temperature, pressure, and gross compositional environment. Rates of growth, presence of impurities, the availability or lack of oxygen, the pH of the system, and percentage of completion of the often determine which modification will develop. Many transitional phases develop when a relatively insoluble precipitate is formed from solution. Different modifications are formed, depending on the speed and percentage of reacting solution added. Some of these "forms" are stable and do not "age" or transform into the so-called stable modifications. These modifications are difficult to treat in terms of equilibrium diagrams for the simple reason that these minerals do not represent an equilibrium situation described by only two (temperature and composition) or three terms (when pressure is considered). Many crystals exist as stable or meta- stable phases in nature in environments much different from those indicated by certain equilibrium diagrams. Cristobalite octahedra grow on zeolite needles in vugs, diaspore develops from a medium that does not appear to have been subjected to high pressures and temperatures, authigenic feld-

Jan 1, 1952

By G. Abowitz, R. B. Gordon

The velocity of sound, mass density, and thermal expansion coefficient were measured in dilute lead, tin, zinc, bismuth, cadmium, indium, and potassium amalgams as a function of composition. Measurements in the Hg-TI system extended ovev the wider range of composition, 0 to 40 at. pct TI. The sonic velocity was measured as a function of temperature. The calculuted adiabatic compressibility in all cases was found to decrease much more rapidly than would be expected on the basis of a linear variation with composition. An interpretation of the results is given in terms of changes in the Debye characteris -tic temperature of mercury on alloying and a possible change in the bonding of mercury itself. If a liquid is considered as an isotropic elastic medium, the phase velocity of a longitudinal elastic wave traveling in the liquid is given by where K is the bulk modulus, G the shear modulus, and d the mass density. G can be neglected for liquids of ordinary viscosity, i.e., approximately 1CT2 poise, because the shear stress component is relaxed essentially at once. That is, for liquids of ordinary viscosity and at frequencies of the applied stress up to several hundred megacycles, the relaxation time of the shearing process is much shorter than the period of the applied stress. Eq. [I] then reduces to The adiabatic rather than the isothermal compressibility is measured at the megacycle frequencies used in ordinary ultrasonic velocity measurements. The sonic velocity and compressibility have been determined for many organic liquids and aqueous eletroltes,' and the results have been interpreted in terms of existing theories for these fluids. The velocity of sound and compressibility are important parameters in theories of the liquid state. For example, equations of state have been proposed relating the free volume of liquids to the acoustic velocity.3 Comparatively very little work has been done on the acoustic properties of liquid metals and alloys. leppa,' orddon, and several other investigators

Jan 1, 1963

By Wallace W. Wilson

The Cook Ranch Field produces from a very permeable lens of Cook Sand of lower Permian or upper Pennsylvanian age, occurring at an average depth of 1.300 ft. The field was discovered in 1926, and has been operated with low pressure gas injection since July, 1927, one of the first such projects in Texas. Cumulative recovery to Dec. 31. 1950, was 14,701,131 bbl of crude oil, an average of 1,013 bbl per acre-ft of oil rection. and 72.5 per cent of the oil originally in place. Analysis of the reservoir performance indicates that grav-ity drainage has been an important factor in the producing mechanism. The high permeability and uniformity of the reservoir were extremely Favorable tor this type of operation. INTRODUCTION The Cook Ranch Field is the largest of a number of relatively small, shallow producing areas near .Albany, in Shackelford County, Texas. This field is one of the first to be operated by gas injection in Texas, and probably is the most successful low pressure gas injection project ever attempted. The field is owned entirely by Koeser and Pendleton, Inc., and Continental Oil Co., and has been operated by Roeser and Pendleton, Inc., since it was discovered. This study has been made possible through the cooperation of Roeser and Pendleton, Inc.. in making availahle a remarkably complete set of records covering all phases of their operations. The purpose of this paper is to present a summary of the history of the operations through Dec. 31, 1950, and to analyze some of the factors which appear to be responsible for the success of the project. Information concerning the physical plant and the early gas injection history has been presented in an earlier paper.' RESERVOIR CHARACTERISTICS production in the Cook Ranch Field is from a large lens of Cook Sand. of lower Permian or upper Pennsylvanian age, occurring at an average depth of 1.300 ft. The average dip of the sand body, as shown in Fig. 1. is only about 50 ft per mile to the northwest. The reservoir has an area of 930 acres and contains 15,512 acre-ft of Sand, consisting of about 14.512 acre-ft of produc-tive oil zone. and an estimated 1.000 acre-ft of primary gas-cap. The iso-pachous map (Fig. 2) was prepared from drillers' logs. Recent coring in the field has proven these logs to be quite accurate. The productive limits of the field are defined by shale on all sides but the southwest where a small zone of edgewater was encountered. This water does not appear to have encroached into the reservoir, and water production has been small. A smaller producing area to the south of the Cook Ranch Field also produces from the Cook Sand. but is separated from the reservoir under consideration by a band of shale. The sand consists of well sorted, coarse grained. rounded and subangu-lar quartz fragments. very poorly cemented. The analysis of 46 chip-core samples from two recently completed test wells indicates a range of porosity values between 12.5 and 28.2 per cent. wit11 an arithmetic average of 24.0 per cent. Air permeability values range between 50 and 2,300 md, with an arithmetic average of 1.200 md. The reservoir where cored is a Solid sand body. with no discernible major shale breaks or impermeable streaks. Vertical permeability appears to be of the same magnitude as the horizontal permeability. A core of the Cook Sand was cut ill the smaller field to the south, using lubricating oil as drilling fluid. The connate water content of the sand in this core was found to average about ten per cent, and the porosity and permeability were comparable with the values reported above. No analysis was made of subsurface or recombined hydrocarbon samples,

Jan 1, 1952

C. M. Bishop (Aircraft Div., A. V. Roe Cnnada Ltd., Toronto)—Reference is made to the coherency hardening of ß due to ß' and also to the hardening of ß due to a coherent precipitation of the a phase. What is meant by the term "ß'?" Would not the coherency hardening of ß during cooling be due to precipitation of a sub-microscopic dispersion of a, as is the case during reheating a ß-quenched alloy? I feel that these two phenomena are essentially the same mechanism, i.e., precipitation of a from unstable or supersaturated ß. From the text, it would appear that Tables III and IV are intended to show the effect of the martensite transformation on the properties of Ti-Mn alloys. Referring to Table 111, the ß-quenched alloys would contain a greater proportion of retained ß than would the equilibrated alloy. Could not the increase in properties be attributed to this, along with possible coherency hardening of the ß? In the same way, the structures referred to in Table IV contain ß from which they could derive their hardness. It would appear to be difficult, if not impossible, to assess the role of the martensite transformation from the data contained in these tables. F. C. Holden, H. R. Ogden, and R. I. Jaffee (authors' reply)—In reply to the first question raised by Mr. Bishop, the term "ß"' designates an apparent retained-p structure which is harder than it is after the most rapid cooling from the ß field. It is thought to be the result of a coherent precipitation of a. The mechanism by which hardening takes place is undoubtedly the same as that involved in the early stages of aging of a re-tained-p structure, and we are in agreement with Mr. Bishop on this point. The term "ß'" to designate the anomalously hard retained-ß structure was agreed upon at a symposium in 1953." The authors do not agree that the quantity of retained ß and/or ß' in the ß-quenched specimens of Table III is necessarily greater than that of the 600°C equilibrated specimens. The ß-quenched specimen has a structure which appears to be completely a' formed by the martensite reaction. It is recognized that there could be some retained ß (or ß') between the a plates if the M, temperature is below room temperature. This is unlikely for the 3.4 pct Mn alloy where the M, is known to be at about 640°C. Therefore, the increase in strength cannot be attributed to the presence of a greater quantity of coherency-hardened ß, but, rather, the increase in strength must be attributed to the transformation products formed, e.g., a' (martensiti-cally formed a). Concerning the data in Table IV, we agree that it is difficult to estimate the role of the martensite reaction, since the 6.4 pct Mn alloy was retained ß in the quenched condition.

Jan 1, 1955

By M. R. Geer, H. F. Yancey

Although the use of dense suspensions for coal cleaning was pioneered in the United States with the Chance sand flotation process, and during the past year a pilot plant using a magnetite suspension has started operation in this country, the more recent developments in this field of coal cleaning have occurred principally in the Netherlands. During the thirties the Dutch developed the Barvoys process, in which a medium of barite and clay is employed, the Tromp process, which utilizes a magnetite suspension, and the Loess process, in which is used the air-borne earth or soil known as loess.1-3 All these processes are finding increasing use in European coal-cleaning practice. Now a fourth process, the cyclone cleaner, is under development by the Netherlands State Mines. A cyclone thickener for reclaiming and thickening the dense suspension is a novel feature of the Loess process. Through accident, the discovery was made that the cyclone could be utilized as a cleaning device for fine coal. When the cyclone thickener at the Maurits mine plugged, the overflow was found filled with clean coal free of refuse, and from this observation developed the concept of the cyclone as a coal cleaner. In June 1945 the cyclone cleaner was observed by one of the authors,' and in September 1945 it was described by Dries-sen6 in a paper presented in London before the Institute of Fuel. As the cyclone seemed to offer unusual promise as a means of extending heavy-medium cleaning to the finer sizes of coal that cannot readily be treated in existing heavy-medium processes, the Bureau of Mines, following Driessen's, presentation, launched an investigation of the cyclone as a coal cleaner. Added impetus was given to this study by the present increased interest in heavy-medium cleaning in this country. Object and Scope of Investigation Driessen's report, although comprehensive in many respects, did not include a detailed description of the cyclone cleaner, and contained almost no information on the influence of the various operating variables of the cyclone. It was necessary, therefore, to investigate the influence of the cyclone adjustments on its performance before studying the application of the cyclone to various coal-washing problems. The present report is confined entirely to these preliminary tests, designed to demonstrate the operating characteristics of the cyclone. The investigation has been in progress

Jan 1, 1949

By Douglas Bunting

In the anthracite fields of Pennsylvania, mine fires occur with more or less regularity and their existence is an ever-present hazard in coal mining. In all probability 90 per cent. of the mine fires can be ascribed directly or indirectly to the ordinary miner's open lamp. Other causes may be smoking, electrical installations, gas explosions, gas feeders, and the communication of fire to the outcrops from ash dumps, culm banks, timber and brush fires. Fires in pump rooms, engine rooms, and barns have been largely eliminated as a result of the Act of Assembly, approved June 15, 1911, which provides that all inside buildings, including engine rooms, pump rooms, barns, etc., shall be constructed of incombustible materials. Smoking of pipes, cigars, and cigarettes should be prohibited in the mines and too much care cannot be exercised in preventing fires by enforcing all rules designed for that purpose. Mine fires that involve underground fighting are invariably dangerous, and all fires, irrespective of the method pursued in extinguishing them, involve property loss and expense. Each fire generally presents a more or less original problem, dependent on the particular conditions. Generally mine fires may be divided into two classes: Those occurring in inaccessible workings and those occurring in accessible workings. The methods pursued in extinguishing or controlling mine fires are as follows: (I) direct attack, (2) smothering by sealing, (3) flushing with silt or other solids, (4) flooding with water, (5) cutting off, (6) surrounding with incombustible materials, (7) digging out by stripping from the surface. Most fires arc extinguished in their incipiency by direct attack and failure to extinguish by this method is due to late discovery, lack of water, and facilities for fighting, or improper procedure in the initial attack. Should the method first pursued be unsuccessful, careful consideration should be given in determining next the method to be adopted; then the work should be carried on as rapidly as possible and under the supervision of the most competent persons. Materials and supplies should be furnished without delay and in sufficient quantities for the work to be accomplished.

Jan 1, 1922

A dinner was given to Ambrose Swasey by the United Engineering Society, at the Engineers' Club, on November 14. Those present -included -twenty-one presidents and past presidents of the Founder Societies. Charles F. Rand, President of United Engineering Society, presided. President Robert S. Woodward, of the Carnegie Institution of Washington, and Dr. Robert W. Hunt, of Chicago, made addresses to which Mr. Swasey responded. Dr. Michael I. Pupin, Chairman of Engineering Foundation, made the closing address. The evening was marked by the high character of the addresses, inspiration for grave duties lying before the engineering profession, and by the spirit of good fellowship. Among the seventy-two persons present were the following members of the Institute: E. E. Bartlett, William N. Best, J. Parke, Channing, C. R. Corning, F. C. Cottrell, J. V. Davies, J. V. N. Dorr, H. S. Drinker, Karl Eilers, H. M. Howe, A. C. Humphreys, Robert W. Hunt, Wm.. B. Jackson, D. S. Jacobus, J. H. Janeway, J. E. Johnson, Jr., John Johnston, George F. Kunz, Edwin Ludlow, Philip N. Moore, Fred'k. H. Newell; Wm. H. Nichols, H. Hobart Porter, Charles F. Rand, R. M. Raymond, .Jesse M. Smith, E. Gybbon Spilsbury, Bradley Stoughton, . Joseph Struthers, Benj. B. Thayer, Wm. H. Wiley, S. T. Wellman.

Jan 1, 1919