Search Documents

By Andrew Corry

GEOPHYSICAL investigations based on radioactivity have been applied to the earth's crust for the purpose of discovering bodies rich in radioactive substances, or for the location of solutions with high emanation or radioactive-salt content, or for the detection of oil, which, in virtue of colloidal properties, has strong powers of radioactive absorption. RADIOACTIVE SUBSTANCES Radioactive substances are distributed in all rocks, waters, and gases in the earth's crust in small quantities. Granites and similar acidic rocks are richest in uranium and thorium, two chief radioactive substances; yet the quantities present in such rocks are of the order 10-12g., this concentration being expressed in grams per gram of the whole substance per cubic centimeter. In granites the uranium yields, according to Haddock, 3 X 10-12 g. of radium per gram of rock. In basalts the uranium yields 1.19 X 10-12 g. per gram per cubic centimeter. Of thorium the granites yield -2 X 10-5 g. per gram of rock; the basalts, 0.77 X 10-5 g. per gram. Certain series of alkalis of low atomic weight, like potassium and rubidium, show weak radioactivity; this property has no significance so far for geological research. The uranium is esti-mated indirectly from the electrical properties of one of its derivatives as a -gas (emanation) into which it is transformed. The thorium is expressed directly, though it is measured as a derivative, thorium emana-tion. There is a measure for the gaseous radium emanation, the curie, which is that quantity of radium emanation, or radon, which stands in equilibrium with 1 g. of radium. The concentration of the emanation is the Mache unit corresponding to 3.64 X 10-10 curie per liter. When gases become permeated by alpha, beta, and gamma rays, plus and minus ions are produced in them by the decomposition of neutral gas molecules, and under the influence of an electrical field these ions are given opposite motions. The measurement of the alpha rays and the bisection thicknesses of the beta and gamma rays is a means of analyzing unknown radioactive substances. These rays accompany the disintegration of radioactive substances and arise from "spontaneous internal changes

Jan 1, 1929

By A. H. Grobe, F. N. Rhines

AT elevated temperatures the oxide of silver is unstable in the air at atmospheric pressure, consequently no external oxide scale forms upon pure silver under conditions of high-temperature annealing When small quantities of certain alloying elements are present in the silver, the formation of a thin external scale is possible' and in addition there may form a subscale composed of the oxide of the solute element precipitated within the body of the silver Norbury2 and Leroux and Raub3 have reported internal oxidation (subscale formation) in alloys of silver with 2, 7 5, and 30 per cent of copper The presence of the subscale is believed to be responsible, at least in part, for the objectionable "fire mark" in Sterling silver' Several other alloys of silver, after oxidizing heat-treatments, are known to exhibit undesirable polishing characteristics that may be the result of internal oxidation Except for the absence of an external scale of silver oxide, it is to be anticipated that silver alloys will prove to be very similar in their oxidation behavior to the alloys of copper, the oxidation characteristics of which have been studied in some detail 5,6 The present research confirms this anticipation The oxidation of a series of 20 dilute alloys of silver has been studied metallographically, some types of subscale not encountered among the copper alloys have been found Instances of internal oxidation in alloys of most of the metals of the I-b and VIII groups of the periodic system are on record, but evidence of this type of oxidation in alloys of the metals of the intermediate groups is lacking A number of the metals of the intermediate group, among them cadmium, lead, tin, and zinc, appear to provide the conditions essential to subscale formation, i e , they form oxides with a relatively low negative free energy of formation, they dissolve other metals that form more stable oxides, and, presumably, oxygen will diffuse through them In a study of 4o alloys of these white metals only a few cases of internal oxidation have been found The probable reasons for this difference in behavior will be discussed presently EXPERIMENTAL PROCEDURE Silver -The silver alloys employed in the oxidation studies were prepared in heats of 30 grams each from high-purity silver (99 993 per cent Ag)* and the purest avail-

Jan 1, 1942

By Henry A. Stiff

The classification and correlation of water analysis data presents many problems which can be solved by graphic methocis. The pattern system, a new type of graphic procedure described in this communication, is believed to have several advantages over older methods. Examples of the application, of the pattern system to the solution of problems encountered in petroleum production are given. INTRODUCTION Several graphic methods for presenting analytical water data have been developed and are now in use.1,2,3,4 It is believed, however, that a recently developed type of graph called the "pattern" offers several advantages over other methods. This system presents a better picture of the total salt concentration than is usual in such graphs. The effect of dilution or concentration has been reduced to a minimum, and at the same time distinction between various types of water has been improved. The system is extremely versatile, yet so simple it can be plotted on ordinary graph paper and adapted to almost any type of filing system. DISCUSSION The essential feature of the pattern system is the graph shown in Fig. 1. Horizontal lines extending right and left from a vertical line at zero form the graph. Positive ions are plotted to the left while negative ions are plotted to the right. The figure immediately beneath each ion gives the scale. Most oil field waters can be plotted on a scale where 100 milli-equivalents of sodium and chloride and 10 milliequivalents of each of the other ions are represented by one scale unit. For highly concentrated brines, 1,000 milliequivalents of sodium and chloride and 100 milliequivalents of each of the

Jan 1, 1951

By Henry A. Stiff

The classification and correlation of water analysis data presents many problems which can be solved by graphic methocis. The pattern system, a new type of graphic procedure described in this communication, is believed to have several advantages over older methods. Examples of the application, of the pattern system to the solution of problems encountered in petroleum production are given. INTRODUCTION Several graphic methods for presenting analytical water data have been developed and are now in use.1,2,3,4 It is believed, however, that a recently developed type of graph called the "pattern" offers several advantages over other methods. This system presents a better picture of the total salt concentration than is usual in such graphs. The effect of dilution or concentration has been reduced to a minimum, and at the same time distinction between various types of water has been improved. The system is extremely versatile, yet so simple it can be plotted on ordinary graph paper and adapted to almost any type of filing system. DISCUSSION The essential feature of the pattern system is the graph shown in Fig. 1. Horizontal lines extending right and left from a vertical line at zero form the graph. Positive ions are plotted to the left while negative ions are plotted to the right. The figure immediately beneath each ion gives the scale. Most oil field waters can be plotted on a scale where 100 milli-equivalents of sodium and chloride and 10 milliequivalents of each of the other ions are represented by one scale unit. For highly concentrated brines, 1,000 milliequivalents of sodium and chloride and 100 milliequivalents of each of the

Jan 1, 1951

By James Norman

SEPARATION of minerals by froth flotation is rightly called an art. It can truthfully be said that no two ores separate in the same way. The difference in results obtained when natural and synthetic mixtures of minerals are separated is so great that such tests frequently have been worthless in attempting to select conditions in which a natural mixture will separate. With a few rare exceptions, the natural mixture is much more difficult to treat than a synthetic mixture, and a much poorer separation is obtained. Perhaps several experimenters have wondered why 10 or 20 per cent of a mineral being floated from an ore does not float and is different from the 90 or 80 per cent that is recovered. In experimental tests on pure sphalerite, observers1 have noted that varying amounts of sphalerite may be froth-floated with pine oil alone, the amount recovered in the froth depending apparently upon the source of the sulphide. The only explanation of results such as these, barring insufficiency of frother or time of flotation, is that the surface of the mineral floated is different from that of the mineral depressed. This difference often has been found to be caused by natural contamination of mineral surfaces, apparently brought about by weathering and exposure to natural solu-tions. There is virtually no rock that is absolutely unweathered. One of the writers had an exceedingly instructive experience in 1931 while working with United Verde copper-zinc iron sulphide ore in Arizona. Nonselective flotation of chalcopyrite and sphalerite away from some of the pyrite was all that could be accomplished. All known depressants produced only slight effect. Sodium cyanide showed some effect, but so much had to be used that only a small amount of chalcopyrite could be

Jan 1, 1939

By Arthur S. Coffinberry, Ralph Hultgren

We have studied the gold-aluminum system by X-ray diffraction and by the microscope over the entire range of composition for temperatures between 300° and 500° C. Results obtained are shown in Fig. 1, combined with the work of Heycock and Neville1 at higher temperatures. The diagram differs in important details from that given by Hansen2 in his critical compilation of the literature of binary alloy systems. This work was undertaken both because of the intrinsic value of a knowledge of the phase diagram of this system and because of the need of theoretical metallurgy for precise and accurate data, particularly X-ray diffraction data. Systematic studies of equilibrium diagrams, particularly by Hume-Rothery,3 have shown regularities that yield a certain insight into the nature of alloying forces. It has been shown, for example, that solid solubility depends on the concentration of free electrons in the alloy, on the relative radii of solvent and solute atoms, on the forces of attraction between atoms, and on the relative stability of intermediate phases. The well-known Hume-Rothery rule states that the crystal structures and compositions of many intermediate phases depend on the electron-to-atom ratio. This has been confirmed and extended by wave mechanical calculations.4 A knowledge of the forces between atoms in alloys, even an imperfectly developed empirical one, should be a valuable guide in the preparation of technological alloys of desirable properties. Furthermore, such information is basic in such problems as rate of diffusion, age-hardening, phase transformations, and others. The most valuable data for this purpose are furnished by X-ray diffraction studies. Unfortunately, work has been

Jan 1, 1938

By Arthur S. Coffinberry, Ralph Hultgren

We have studied the gold-aluminum system by X-ray diffraction and by the microscope over the entire range of composition for temperatures between 300° and 500° C. Results obtained are shown in Fig. 1, combined with the work of Heycock and Neville1 at higher temperatures. The diagram differs in important details from that given by Hansen2 in his critical compilation of the literature of binary alloy systems. This work was undertaken both because of the intrinsic value of a knowledge of the phase diagram of this system and because of the need of theoretical metallurgy for precise and accurate data, particularly X-ray diffraction data. Systematic studies of equilibrium diagrams, particularly by Hume-Rothery,3 have shown regularities that yield a certain insight into the nature of alloying forces. It has been shown, for example, that solid solubility depends on the concentration of free electrons in the alloy, on the relative radii of solvent and solute atoms, on the forces of attraction between atoms, and on the relative stability of intermediate phases. The well-known Hume-Rothery rule states that the crystal structures and compositions of many intermediate phases depend on the electron-to-atom ratio. This has been confirmed and extended by wave mechanical calculations.4 A knowledge of the forces between atoms in alloys, even an imperfectly developed empirical one, should be a valuable guide in the preparation of technological alloys of desirable properties. Furthermore, such information is basic in such problems as rate of diffusion, age-hardening, phase transformations, and others. The most valuable data for this purpose are furnished by X-ray diffraction studies. Unfortunately, work has been

Jan 1, 1938

By G. G. Gunther, C. L. Boeke

THE zinc deleading processes at the Parral and Santa Barbara mills are described separately to provide a basis for comparison. Although the two procedures are fundamentally alike, there are some differences in application to meet specific conditions. The Asarco mill at Parral in the State of Chihuahua is a flotation plant treating 1450 metric tons per day of complex sulphide copper-lead-zinc ores. In general, the procedure used for selective separation of the minerals into a copper, a lead, and a zinc concentrate follows the usual practice. First, a bulk copper-lead concentrate is floated and then separated into a final copper and a final lead concentrate by the sulphurous acid process. A small tonnage of high grade gravity lead concentrate is tabled from the bulk copper-lead cleaner tailing before it is reground so as to avoid undesirable over-grinding and sliming of this portion of the lead mineral. Next, a zinc concentrate is floated from the lead rougher tailing and, as described later, is separated into a final lead product and a final zinc concentrate. Finally, the zinc rougher tailing receives a strong scavenger float to remove all recoverable middling values for regrinding and return to the flotation circuits. The slime is separated from the scavenger flotation product, and only the sand portion goes to the regrind section. The minerals in the separated slime are extremely resistant to all methods of selective separation and pose one of the major problems awaiting solution. Nevertheless, the slime shows a profit when mixed with either the lead or the zinc concentrate, except when metal prices are very low, so it is accepted as a final product for lack of a more profitable method of handling it. In contrast, the minerals in the reground sands of the

Jan 1, 1953

By G. G. Gunther, C. L. Boeke

THE zinc deleading processes at the Parral and Santa Barbara mills are described separately to provide a basis for comparison. Although the two procedures are fundamentally alike, there are some differences in application to meet specific conditions. The Asarco mill at Parral in the State of Chihuahua is a flotation plant treating 1450 metric tons per day of complex sulphide copper-lead-zinc ores. In general, the procedure used for selective separation of the minerals into a copper, a lead, and a zinc concentrate follows the usual practice. First, a bulk copper-lead concentrate is floated and then separated into a final copper and a final lead concentrate by the sulphurous acid process. A small tonnage of high grade gravity lead concentrate is tabled from the bulk copper-lead cleaner tailing before it is reground so as to avoid undesirable over-grinding and sliming of this portion of the lead mineral. Next, a zinc concentrate is floated from the lead rougher tailing and, as described later, is separated into a final lead product and a final zinc concentrate. Finally, the zinc rougher tailing receives a strong scavenger float to remove all recoverable middling values for regrinding and return to the flotation circuits. The slime is separated from the scavenger flotation product, and only the sand portion goes to the regrind section. The minerals in the separated slime are extremely resistant to all methods of selective separation and pose one of the major problems awaiting solution. Nevertheless, the slime shows a profit when mixed with either the lead or the zinc concentrate, except when metal prices are very low, so it is accepted as a final product for lack of a more profitable method of handling it. In contrast, the minerals in the reground sands of the

Jan 1, 1953

By G. G. Gunther, C. L. Boeke

THE zinc deleading processes at the Parral and Santa Barbara mills are described separately to provide a basis for comparison. Although the two procedures are fundamentally alike, there are some differences in application to meet specific conditions. The Asarco mill at Parral in the State of Chihuahua is a flotation plant treating 1450 metric tons- per day of complex sulphide copper-lead-zinc ores. In general, the procedure used for selective separation of the minerals into a copper, a lead, and a zinc concentrate follows the usual practice. First, a bulk copper-lead concentrate is floated and then separated into a final copper and a final lead concentrate by the sulphurous acid process. A small tonnage of high grade gravity lead concentrate is tabled from the bulk copper-lead cleaner tailing before it is reground so as to avoid undesirable over-grinding and sliming of this portion of the lead, mineral. Next, a zinc concentrate is floated from the lead rougher tailing and, as described later, is separated into a final lead product and a final zinc concentrate. Finally, the zinc rougher tailing receives a strong scavenger float to remove all recoverable middling values for regrinding, and return to the flotation circuits. The slime is separated from the scavenger flotation product, and only the sand portion goes to the regrind section. The minerals in the separated slime are extremely resistant to all methods of selective separation and pose one of the major problems awaiting solution. Nevertheless, the slime shows a profit when mixed with either the lead or the zinc concentrate, except when metal prices are very low, so it is accepted as a final product for lack of a more profitable method of handling it. In contrast, the minerals in the reground sands of the

Jan 1, 1952

By G. G. Gunther, C. L. Boeke

THE zinc deleading processes at the Parral and Santa Barbara mills are described separately to provide a basis for comparison. Although the two procedures are fundamentally alike, there are some differences in application to meet specific conditions. The Asarco mill at Parral in the State of Chihuahua is a flotation plant treating 1450 metric tons per day of complex sulphide copper-lead-zinc ores. In general, the procedure used for selective separation of the minerals into a copper, a lead, and a zinc concentrate follows the usual practice. First, a bulk copper-lead concentrate is floated and then separated into a final copper and a final lead concentrate by the sulphurous acid process. A small tonnage of high grade gravity lead concentrate is tabled from the bulk copper-lead cleaner tailing before it is reground so as to avoid undesirable over-grinding and sliming of this portion of the lead mineral. Next, a zinc concentrate is floated from the lead rougher tailing and, as described later, is separated into a final lead product and a final zinc concentrate. Finally, the zinc rougher tailing receives a strong scavenger float to remove all recoverable middling values for regrinding and return to the flotation circuits. The slime is separated from the scavenger flotation product, and only the sand portion goes to the regrind section. The minerals in the separated slime are extremely resistant to all methods of selective separation and pose one of the major problems awaiting solution. Nevertheless, the slime shows a profit when mixed with either the lead or the zinc concentrate, except when metal prices are very low, so it is accepted as a final product for lack of a more profitable method of handling it. In contrast, the minerals in the reground sands of the

Jan 1, 1953

By A.S. Richardson

AIR conditioning, or air cooling, for the improvement of ventilation in the Butte mines has come into increasing use during the past 10 years. In part, the methods practiced have been described in previous publications of the Institute, but some improvements on earlier methods have been made and a number of new features have been developed. This paper is presented as a record of progress made, and for the sake of completeness describes all general features of the work. The need for air conditioning in the ventilation of mines in the district arises from the fact that the temperature of the ground and mine water has shown a very great increase with increase in mining depth, and has now reached a maximum of slightly over 130°F. The most difficult part of the ventilation problem is the maintenance of temperature and humidity of a satisfactory standard in the working places, especially on the lower levels. Although ordinary ventilation is adequate to maintain good conditions in most of the working places it is subject to a number of limitations at great depth. Most important among these limitations is that with increase in depth the air becomes heated before it reaches the working places, both by compression from increase in atmospheric Pressure and by heat transferred to it from rock at high temPerature, so that its capacity for lowering temperatures is greatly reduced before it reaches the operating zone. Increasing depth of mining also increases the distance traveled by the air in its passage through the mine, and this causes a corresponding increase in resistance to air flow, so that there is greater difficulty in maintaining even the same volume in circulation. Thus, in the face of a demand that the ventilating system have a very much greater capacity to remove heat from the mine, the tendency is for that capacity to diminish. The only evident alternatives were (I) the opening of additional air shafts to increase the volume of air in circulation, (2) an extension of the existing system that would be subject to the same limitations, or (3) the adoption of an entirely different method such as air cooling. Fortunately for an economic solution of the problem, the mean annual temperature of the surface atmosphere at Butte is about 40°F., with very low relative humidity in summer, so that there is unlimited natural cooling power at a temperature range adaptable to air-conditioning methods. Methods Two similar methods of air conditioning are used, as necessitated by service requirements and dependent upon the equipment available. In one, which is the more important and has the greater cooling capacity, water is circulated in a closed circuit, and, alternately, first absorbs heat from warm mine air and then dissipates it in the surface atmosphere by cooling at a cooling tower. The second

Jan 1, 1943

By A. S. Richardson

AIR conditioning, or air cooling, for the improvement of ventilation in the Butte mines has come into increasing use during the past 10 years. In part, the methods practiced have been described in previous publications of the Institute, but some improvements on earlier methods have been made and a number of new features have been developed. This paper is presented as a record of progress made, and for the sake of completeness describes all general features of the work. The need for air conditioning in the ventilation of mines in the district arises from the fact that the temperature of the ground and mine water has shown a very great increase with increase in mining depth, and has now reached a maximum of slightly over 130°F. The most difficult part of the ventilation problem is the maintenance of temperature and humidity of a satisfactory standard in the working places, especially on the lower levels. Although ordinary ventilation is adequate to maintain good conditions in most of the working places it is subject to a number of limitations at great depth. Most important among these limitations is that with increase in depth the air becomes heated before it reaches the working places, both by compression from increase in atmospheric Pressure and by heat transferred to it from rock at high temPerature, so that its capacity for lowering temperatures is greatly reduced before it reaches the operating zone. Increasing depth of mining also increases the distance traveled by the air in its passage through the mine, and this causes a corresponding increase in resistance to air flow, so that there is greater difficulty in maintaining even the same volume in circulation. Thus, in the face of a demand that the ventilating system have a very much greater capacity to remove heat from the mine, the tendency is for that capacity to diminish. The only evident alternatives were (I) the opening of additional air shafts to increase the volume of air in circulation, (2) an extension of the existing system that would be subject to the same limitations, or (3) the adoption of an entirely different method such as air cooling. Fortunately for an economic solution of the problem, the mean annual temperature of the surface atmosphere at Butte is about 40°F., with very low relative humidity in summer, so that there is unlimited natural cooling power at a temperature range adaptable to air-conditioning methods. Methods Two similar methods of air conditioning are used, as necessitated by service requirements and dependent upon the equipment available. In one, which is the more important and has the greater cooling capacity, water is circulated in a closed circuit, and, alternately, first absorbs heat from warm mine air and then dissipates it in the surface atmosphere by cooling at a cooling tower. The second

Jan 1, 1943

By Horace R. Graham

CHEMICAL nitrogen and the "nitrates" of commercial significance are derived mainly from three basic sources: (1) the natural deposits in the form of nitrate-bearing earth and clay, which, being largely water-soluble, can exist only in the most arid portions of the earth; (2) coal, which yields not only nitrogen but also the additional by-product hydrogen required for the synthesis of ammonia and its compounds; (3) the atmospheric air, which contains 75.5 pct by weight of pure nitrogen gas. NATURAL NITRATE DEPOSITS Occurrence Although natural nitrate deposits consisting principally of the salts of sodium and potassium have been reported in Egypt, South Africa, Mexico, Argentina, Colombia, Peru and the USA, the only known natural nitrate resources of commercial importance are the vast deposits found in the Atacama, Tarapaca and Antofagasta regions of northern Chile, lying in a narrow strip 10 to 50 miles wide and roughly 450 miles long, between latitudes [19O] and [26OS]. In addition to yielding nitrates of sodium and potassium, these deposits are the source of the major portion of the world's supply of iodine. The nitrate-bearing ores known in Chile as caliche are variable in composition and may contain from 5 to 30 pct each of nitrate, chloride and sulphate. While the deposits are present chiefly in the form of the sodium salt, potassium, magnesium and calcium also occur in percent- ages from 0.1 to 5; usually as double salts with sulphate, which are but slightly soluble in nitrate leach solutions. These double salts are bloedite(Na2S04.MgS04.4H,0), glauberite (Na2S04.CaS04), polyhalite (K2SO4.- MgS04.2CaS04.2H20). Some deposits contain up to30 pct of their ni-

Jan 1, 1949

By Orson Cutler Shepard

The term "electrocapillary amalgamation" is used in this paper to designate amalgamation processes that depend upon electrocapillary phenomenon; i.e., the action of an electric current upon the surface tension of mercury at the contact with aqueous solutions. Electro-capillary amalgamation is selected as a name for these processes because the electrocapillary phenomenon has been found to be the effective agent in the use of sodium amalgam, as well as in the various processes using an electric current from a source outside of the amalgam. Amalgamation processes that depend upon supplying an electric current to the amalgam from an outside source, such as batteries and generators, have previously been called electrical amalgamation processes. There has been a tremendous amount of experimental work done on amalgamation processes involving the use of an electric current, as shown by the large number of patents issued on these processes: the earliest in 1885 and the latest in 1934l. Regardless of all the experimental work, the fundamental principles causing the operation of electrocapillary amalgamation processes have not been described. The explanation usually given is that an electric current keeps the amalgam bright and clean. Patent No. 328532 states: It is well known that when amalgam plates are used for collecting gold and silver from their ores the surfaces of these plates are liable to become tarnished or sickened by certain substances contained in the ores or in the current of water which is employed to carry the ore over the plates, and that in this condition they are unfitted for amalgamating the particles of gold and silver. To prevent this and to keep the surfaces of the amalgamation plates always bright and in a better condition for catching and amalgamating the particles of gold and silver I employ electricity in the following manner: . . . A similar explanation is given 49 years later, in patent No. 1953364: The sodium (Na) ions lose their charge at the cathode becoming sodium atoms, which do not react with the electrolyte, but follow the grounded electrical current through the mercury body producing in their passage sodium amalgam and liberate themselves in the amalgamation compartment when brought in contact with the fed

Jan 1, 1939

By Orson Cutler Shepard

The term "electrocapillary amalgamation" is used in this paper to designate amalgamation processes that depend upon electrocapillary phenomenon; i.e., the action of an electric current upon the surface tension of mercury at the contact with aqueous solutions. Electro-capillary amalgamation is selected as a name for these processes because the electrocapillary phenomenon has been found to be the effective agent in the use of sodium amalgam, as well as in the various processes using an electric current from a source outside of the amalgam. Amalgamation processes that depend upon supplying an electric current to the amalgam from an outside source, such as batteries and generators, have previously been called electrical amalgamation processes. There has been a tremendous amount of experimental work done on amalgamation processes involving the use of an electric current, as shown by the large number of patents issued on these processes: the earliest in 1885 and the latest in 1934l. Regardless of all the experimental work, the fundamental principles causing the operation of electrocapillary amalgamation processes have not been described. The explanation usually given is that an electric current keeps the amalgam bright and clean. Patent No. 328532 states: It is well known that when amalgam plates are used for collecting gold and silver from their ores the surfaces of these plates are liable to become tarnished or sickened by certain substances contained in the ores or in the current of water which is employed to carry the ore over the plates, and that in this condition they are unfitted for amalgamating the particles of gold and silver. To prevent this and to keep the surfaces of the amalgamation plates always bright and in a better condition for catching and amalgamating the particles of gold and silver I employ electricity in the following manner: . . . A similar explanation is given 49 years later, in patent No. 1953364: The sodium (Na) ions lose their charge at the cathode becoming sodium atoms, which do not react with the electrolyte, but follow the grounded electrical current through the mercury body producing in their passage sodium amalgam and liberate themselves in the amalgamation compartment when brought in contact with the fed

Jan 1, 1939

By Stephen Taber

JOHN C. BRANNER, Stanford University, Cal. (communication to the Secretary *).-Wideawake teachers of geology are constantly on the lookout for good illustrations of veins, especially where the processes of formation are either clearly shown or suggested. And I long ago found out that one who would learn nature's laws must despise nothing. It thus happened that in 1910, Dr. George J. Peirce of the depart-ment of botany at Stanford University called to my attention a cracked and broken yellow earthenware dish, 8 ½ in. across the top and 2 ½ in. deep, that, to the ordinary observer, seemed to be of no further use, and quite ready for the waste can. The striking thing about this dish was that the thin glaze over much of the outside surface and over the upper margin of the inside surface had been lifted in small scales, varying in. diameter from ½ cm. to 1 cm., and thrust outward and held there by some sort of white fibrous mineral. The process looked very much like one we are familiar with in the Southern States where. we often see in the winter pebbles and soil thrust out from a clay bank or lifted from a clay soil and held there supported by what is popularly known as needle-ice. Upon inquiry I learned the following facts in regard to the history of this particular dish: In the summer of 1910, it had been partly filled with a concentrated salt solution taken from one of the salterns of the Stauffer Chemical Co. at Redwood City, Cal. A qualitative analysis of the original brine showed: Present: iron, magnesium, sodium, potassium, chlorides, sulphates, nitrates (trace), bromides, carbonates, borates (trace), and considerable amounts of organic matter. Absent: calcium, lithium and iodides.

Jan 3, 1917

By L. G. E. Bignell

Surveying what was done in 1929 in meeting problems of oil-field equipment corrosion, one is struck by the fact that fewer meetings were held for discussion of these problems and fewer papers written than in any year since the subject engaged the attention of petroleum engineers. This does not mean that progress has not been made, for a great deal actually has been accomplished. Recommendations that accompanied field reports have been put into actual trial and some results obtained are gratifying. The type of papers prepared also has undergone a change, for they now deal with things accomplished rather than recite damages and suggest possible remedies. Some of the most notable work pointing the way for future solution of many pipe line problems is that done for the U. S. Bureau of Standards by Dr. K. H. Logan and Dr. Gordon N. Scott, dealing with tests of pipe coatings and reports on soil conditions. Many facts of great importance have been isolated and defined by these two men, not only indicating what may be done in some instances to retard corrosion, but showing that things formerly considered of importance have little bearing apparently upon the practical results. All-aluminum Storage Tanks In April, 1928, an all-aluminum 500-bbl. field storage tank was put into actual field use in Crane County, Texas, together with another tank of the same capacity but made with steel bottom and lower section of side sheets and aluminum upper ring of side sheets and deck. In April, 1929, after a little over one year's use these tanks were opened and examined by a group of engineers and chemists. The results of the test were enlightening. Other tanks made entirely of steel and used in the same battery with the two test tanks had some of their side and bottom sheets destroyed by corrosion in six to nine months, but the all-aluminum tank was in actual use for 18 months before holes were found corroded through the bottom, when the tank was examined for a second time in September, 1929. This field test of the aluminum tank confirmed the already known

Jan 1, 1930

By R. E. Ogilvie, N. L. Peterson

Diffi-lsion measurements were conducted at all compositims in the bcc solid solution of the U-Nb system employing incremental couples at composition intemals of 10 at. pct. Diffusion coefficients were determined by the Matano method from concentration gradients obtained with the electron-probe microanalyzer. The activation energy for inter-diffi-lsion as a function of compositim shows three distinct regions: 1) 80 to 100 pct U.6= 30 kcal per mole; 2) 20 to 80 pct U, $ - 70 kcal per mole; 3) Oto 20 pet U, Q = i40 kcal per mole. The frequency factor, fi0 and the activation energy $ were found to be roughly related by the following equation: log Do ^9.7 X IO-5Q -6,6. The Kirkendall marker movement indicates that DU is larger than DNb between 16 and 100 pct U and DNb is larger than DU from 0 to 4 pct U. FOR practical as well as fundamental reasons, the rates of diffusion in alloys are of considerable consequence. Most solid-state reactions are largely dependent upon the diffusion of atoms through the lattice structure and along grain boundaries. The high-temperature strength and reasonable nuclear properties of niobium have prompted its use as a reactor material in contact with uranium fuel. Hence, diffusion data for the U-Nb system are of considerable importance. In the previous diffusion study1 on the U-Nb system using pure element couples, reliable data were obtained only in the range of 0 to 10 at. pct Nb due to the large variance of the diffusion coefficient with composition. Also, a large Kirkendall effect and considerable porosity in the uranium-rich areas of the specimen were reported, which suggests that the true diffusion coefficients are somewhat larger. The purpose of the present study was to obtain reliable diffusion coefficients at all compositions using incremental diffusion couples with intervals of 10 at. pct. In view of the abnormal self-diffusion be- havior of y uranium2-4 and some other bcc transition elements,&apos;-&apos; it was felt that a comparison of the interdiffusion coefficients in the bcc U-Nb system with those of Reynolds et al.9 for the fcc gold-nickel system might shed some light on the diffusion mechanism involved. Both systems have similar phase diagrams, in that complete solid solubility exists above a miscibility gap. EXPERIMENTAL PROCEDURE The uranium used in this investigation was obtained through the courtesy of Argonne National Laboratory. An analysis of this material detected only Si-30, A1-7, C-6, N < 10 and 0-18 ppm. The niobium was electron-beam melted material obtained from Stauffer-Temescal. The gaseous impurities were less than 50 ppm, and the spec troc hemical analysis showed Ta-500 and W-200 ppm. U-Nb alloys were prepared at composition intervals of 10 at. pct by melting the appropriate amounts of the pure elements in an arc furnace. The buttons were inverted and remelted 6 times to assure complete mixing. The buttons were then wrapped in molybdenum foil, canned in Zircaloy-2 or stainless steel, and hot rolled 30 pct reduction in thickness at temperatures between 850" and 1100°C. Alloys with 10, 20, 30, 40, and 90 at. pct Nb rolled quite easily under these conditions, but the 50, 60, 70, and 80 pct alloys remained brittle. After melting and rolling (when possible), the alloys were annealed for 24 hr at a temperature within 100°C of their melting point in a dynamic vacuum of better than 4 x 10-8 mm Hg. These treatments produced alloys which were homogeneous on a 1 p scale within the detectability limits of the electron probe. During fabrication, the alloys picked up as much as 100 ppm Mo and 100 ppm Zr. Other elements checked for but not found were Co, Cr, Fe, Mn, Ni, and Ti. The grain size of the annealed samples ranged from 3 mm for the uranium-rich alloys to 0.3 mm for the niobium-rich alloys. This permitted measurements of the concentration gradients in the diffusion samples without crossing more than one or two grains, thereby eliminating any grain boundary effects. The specimens were bonded by theU&apos;picture frame" technique as reported by Kittel.10 Specimens of composition b)U + (100 - x)Nb were sandwiched between two specimens of composition (x + 10)U + (90 - x)Nb after they were ground flat and parallel

Jan 1, 1963

By Joseph F. Oesterele, Richard S. McCaffery

This investigation was undertaken to determine the quality of different iron blast-furnace slags as desulfurizing agents, and the possibility of using, in the blast furnace, materials of higher sulfur content than is now common. The solution of the problem would render possible the use of higher sulfur iron ores for pig iron and cokes containing more sulfur than now employed, and the economic manufacture of irons and steels of lower sulfur content. It is generally assumed that the sulfur that reaches the lower part of the iron blast furnace is removed from the pig iron by combining with lime to form calcium sulfide. Most of the sulfur introduced with the charge is in combination with iron or manganese or, perhaps in the coke, as a carbon compound.1 The iron and manganese sulfides are more soluble in the iron than is calcium sulfide, and as the latter is generally said to to be more soluble in the slag than the iron and manganese sulfides, this greater solubility of calcium sulfide in the slag tends to free the metal from sulfur. This greater solubility of the calcium sulfide is used not only to reduce the sulfur contents of the pig iron in the blast furnace, but by this means also low-sulfur steels are produced in the open-hearth and electric furnaces. The reaction2 FeS + CaO + CO = Fe + CaS + CO2 requires a high temperature and strongly reducing conditions in the presence of lime. The constitution of blast-furnace slags, first studied scientifically by Vogt13 indicated certain ranges of composition of the slag in which a

Jan 1, 1923