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By Rossiter Raymond

JOHN BIRKINBINE was born Nov. 16, 1844, at Reading, Pa., the eldest son of H. P. M. Birkinbine, widely known as a hydraulic engineer. The family removed subsequently to Philadelphia, where, as a young man he established with his father the office now continued by his sons, after more than 60 years. His education was received at public schools, the Friends' High School in Philadelphia, the Hill School at Pottstown, Pa., and the Polytechnic College of Pennsylvania, where his studies were interrupted in 1863-4 by service in the Union Army, which included participation in the battles at and around Gettysburg. Later, he devoted two years to work in a machine shop; and subsequently he became associated with the late P. L. Weimer, under the firm. name of Weimer & Birkinbine, operating the Weimer Machine Works at Lebanon, Pa. Much of his work was in mining, metallurgy, and blast-furnace construction. As manager for the South Mountain Mining & Iron Co. he carried on experiments with various fuels for iron-ore smelting while maintaining the furnace in constant operation. The carefully recorded results obtained were widely published, and are referred to in text-books by other metallurgists as most complete. From his Philadelphia office he was sent to nearly every State, and to Canada and Mexico, for examinations, reports, constructions or improvements in iron-ore mines, blast furnaces, iron works, water supplies, hydraulic development, irrigation projects, etc., and his engineering knowledge was requisitioned by several European corporations. A number of business trips were made to Mexico, beginning with a visit to the Cerro de Mercado at Durango, before railroads were established in that portion of Mexico, to make a critical examination and report on this "Iron Mountain." Later visits covered other localities and engineering problems, familiarizing him with the major part of the iron industry in Mexico. The late disturbed political conditions in that Republic have retarded the probable enlargement, modernization, and improvement of much of the iron and steel industry of Mexico, upon which he investigated and reported for various capitalists on both continents. One interesting subject included in these reports was a proposed electric furnace, to be operated by energy from water power.

Jan 7, 1915

ALTHOUGH the open-hearth charge contributes CO, C02, H2, A and water vapor to the combustion gases and absorbs oxygen from them, in the main the thermal effects in the melting charge and molten bath can be considered independently of those in fuel combustion; the latter then is regarded simply as the source of the net heat required to finish a heat of steel. First of all, it should be remembered that a large percentage of the heat supplied to the bath is furnished by oxidation of the various elements in the charge itself. If this charge consisted of 80 to 100 per cent of hot metal and the oxidation were accomplished by blowing in air or oxygen, as in the bessemer converter, the net heat absorption would be negative; that is, the bath would contribute part of the heat required to keep the melting chamber hot, in addition to that contained in the finished steel and slag. In actual open-hearth practices, probably the nearest approach to this is in the duplex furnace, charged with bessemer-blown metal and some hot metal, where very little heat is required to complete the refining and nearly all the heat energy from fuel combustion is used to keep the roof and walls of the melting chamber up to around 2900 to 3000 F (1600 to 1650 C), so that the bath will not cool off during the refining. The other extreme is with all-cold charges containing around 80 per cent steel scrap and 20 per cent cast iron or cold pig iron, in which case a very large proportion of the heat in the bath at tap is supplied from the fuel combustion. THERMAL EFFECTS IN MELTING In a typical heat, the fuel furnishes about four million British thermal units per ton of steel produced. The heat required, for the metallurgical processes is not easily defined in useful manner but it ranges downward from about one million Btu, depending not only on the charge but on the manner of calculation. In, any event, this requirement appears. small in comparison with the

Jan 1, 1964

By Howard Eavenson

THE mines of the United States Coal & Coke Co. are located in the Pocahontas coal field, in McDowell County, West Virginia. Twelve plants have been opened and equipped, of which, by reason of the present business depression, only nine are now in operation. These twelve plants serve eighteen mines; some of the plants having several openings, in either the same seam or in different seams, tributary to the same tipple. Only nine of these mines are now being worked at the plants in operation. Construction work was begun in 1902, and coal from the first three plants started was shipped in December of that year. An additional plant was opened in 1903, two in 1904, two in 1905, two in 1907 and the last two in 1908. On Jan. 1, 1915, the plants have been in operation an average period of 8.8 years. The rules of the company, which have been in operation since work was first begun, are similar to those in use by the H. C. Frick Coke Co. at its mines in Pennsylvania, in which "Safety First" was incorporated as early as 1907; and it has always been the policy of both companies to look carefully after the safety of their employees. Although the field is an extension of the old Pocahontas field, the mines, located upon a new branch railroad, are away by themselves, and, as is usual in such cases, the class of labor attracted at first was temporary in character. The rapid development of the mines required the employment of many new men and officials each year; and, while the accident record from 1904 to 1909 was as good as the average of the field, it was felt to be not as good as it could be made, and a determined campaign was inaugurated for preventing accidents of all kinds. Fig. .1 shows the tonnage of coal produced per fatality, both total and for inside accidents only, at our mines; the tonnage per fatality of all West Virginia mines, and of those in the Pocahontas field.

Jan 2, 1915

ALTHOUGH the open-hearth charge contributes CO, C02, H2, and water vapor to the combustion gases and absorbs oxygen from them, in the main the thermal effects in the melting charge and molten bath can be considered independently of those in fuel combustion; the latter then is regarded simply as the source of the net heat required to finish a heat of steel. First of all, it should be remembered that a large percentage of the heat supplied to the bath is furnished by oxidation of the various elements in the charge itself. If this charge consisted of 80 to 100 per cent of hot metal and the oxidation were accomplished by blowing in air or oxygen, as in the bessemer converter, the net heat absorption would be negative; that is, the bath would contribute part of the heat required to keep the melting chamber hot, in addition to that contained in the finished steel and slag. - In actual open-hearth practices, probably the nearest approach to this is in the duplex furnace, charged with bessemer-blown metal and some hot metal, where very little heat is required to complete the refining and nearly all the heat energy from fuel combustion is used to keep the roof and walls of the melting chamber up to around 2900 to 3000 F (1600 to 1650 C), so that the bath will not cool off during the refining. The other extreme is with all-cold charges containing around 80 per cent steel scrap and 20 per cent cast iron or cold pig iron, in which case a very large proportion of the heat in the bath at tap is supplied from the fuel combustion. THERMAL EFFECTS IN MELTING In a typical heat, the fuel furnishes about four million British thermal units per ton of steel produced. The heat required for the metallurgical processes is not easily defined in useful manner but it ranges downward from about one million Btu, depending not only on the charge but on the manner of calculation. In any event, this requirement appears small in comparison with the

Jan 1, 1951

Discussion of the paper of W. R. SHIMER, presented at the New York meeting, February, 1915, and printed in Bulletin No. 99, March, 1915, pp. 557 to. 585. WILLIAM R. WEBSTER, Philadelphia, Pa.-I would like to ask Mr. Shimer how the finishing temperature of the H-beams and other beams rolled on the Gray mill at Bethlehem compare with the rolling temperatures of the rails referred to in this paper. Also, how the reductions in the rolling of the beams compare with the reductions in the rolling of the rails. I would also like to know if any drop tests were' made on the rails referred to as having been allowed to cool and then annealed; in other words, what results, if any, were obtained from tests on rails after the internal strains of rolling had been removed; and in the matter of the rail blooms, I would like to ask if they are not often heated to a higher temperature than is desirable on account of the thin flanges in order to carry the heat through to the finishing pass. The tensile strength of the steel in these rails is given as 125,000 lb. per square inch, which is almost as high as tire steel. If some of these blooms were rolled into rounds of about the same section as the head of the rail, would you not get better results from tension tests than those from the head of the rail? In other words, in rolling rounds, whether you would not be able to control the rolling and finishing temperatures better than is possible in the rail, owing to thin section of the rail flanges. Some years ago I had experience with the rolling temperatures of tire steel, running from about 127,000 to 133,000 tensile strength. These tires had the tensile strength and the deflection specified. One of the manufacturers had no trouble whatever, after a little experimenting, in meeting the conditions of the specification. Another manufacturer who made some of these tires came to the office and stated that he had tried tires from three heats of steel and could not meet the specifications and

Jan 5, 1915

By Thomas R. Cunningham, A. B. Kinzel

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By A. B. Kinzel, Thomas R. Cunningham

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By C. W. Washburne

Continued discussion of the paper Of ROSWELL H. JOHNSON, presented at the New York meeting, February, 1015, and printed in Bulletin No. 98, February; 1915, pp. 221 to 226. See also Bulletin No. 101, May, 1915, pp. 1157 to 1162, and No. 103, July, 1915, pp. 1449 to 1450. C. W. WASHBURNE, New York, N. Y. (communication to the Secretary*).-Mr. Johnson recognizes that connate waters must be driven, outward toward the earth's surface. He considers the ascent due to the settling and packing of the underlying sediments and to the formation of gas within the rocks, supplemented by abyssal pressures. The origin of the methane in the sedimentary strata probably is not simple. There are three possible modes of origin: (1) as marsh gas formed near the surface and entrapped in the sediments; (2) from abyssal sources; (3) by the decomposition of organic matter buried in the sediments. The abyssal source is generally negligible, and in all cases doubtful. The third origin is the most important in the gas fields. A fourth mode of origin, by the dissociation of liquid hydrocarbons, frequently has been suggested, but it is improbable, because crude oils are exothermic. Therefore they have no tendency, to split or decompose at low temperatures, as do endothermic substances, such as coal, which is geologically by the loss of methane, water, and carbon dioxide. This cannot happen to a hydrocarbon until its temperature of dissociation (" cracking point") is reached, which is over 250'.C. for the most easily cracked hydrocarbons and over 400° C. for others. Engler says that the dissociation of fats and waxes into oils is an endothermic process, thereby unconsciously nullifying his own theory of the dissociation of these substances at low temperatures. However, recently I have found reason to think that heat is liberated by the disruption of the molecules of fats and waxes, as it is in the molecular decomposition of the substances of wood, coal, etc. If this tentative opinion is correct, and Engler wrong, then it seems that the Engler-Höfer hypothesis of the origin of oil becomes not only possible, but even probable.

Jan 9, 1915

By N. B. Wittman

Among the objects of interest which the members of the Institute are invited to examine in connection with this meeting is the Brown segmental wire-gun, which will be seen in process of construction at the works of the Pennsylvania Diamond Drill and Manufacturing Company, at Birdsboro. This is a 5-inch breech-loading (highpower) rifle, 19 feet long, constructed upon the system of Mr. J. H. Brown, an inventor of recognized genius in many branches of mechanical industry, and under the engineering direction of Lieutenant G. N. Whistler, Fifth U. S. Artillery. The system consists essentially of the subdivision of the inner core or tube of the gun, which takes up the initial compression, into longitudinal segments of such size that a higher physical condition and degree of special elasticity may be set up therein than it is possible to produce in the larger masses of metal heretofore used for the tube of the modern high-power cannon. The process consists in winding layers of square steel wire, subjected to a constant tension of 130,000 pounds per square inch, around these segments, which, when so held together, form the tube of the gun. A lining-tube may or may not be used. The steel segments used in the gun now under construction are 18 feet 4 inches long, and 3 inches thick at the breech, from which they taper to 0.8 inches at the muzzle. The physical condition of the segments has been determined by test-pieces, cut from each end of each segment, which show the following characteristics: Tensile strength, 165,000 pounds per square inch. Elastic limit, 105,000 pounds per square inch. Elongation at rupture, 14 per cent. in 2 inches. They are of crucible chrome steel, made by the Carpenter Steel Works, at Reading, Pa. The wire which holds them together has 0.005 square inches sectional area and is wound under a constant tension of 650 pounds on each strand, equivalent to 130,000 pounds per square inch. The winding has been done by a machine designed

Jan 1, 1893

R. H. SWEETSER, Columbus, Ohio.-My experience with oxygen in the blast is limited to the use of one tank of oxygen in melting out a chilled anthracite furnace. The oxygen was introduced through the peephole of the tuyeres and opened them in a very short time. We could see that an intense heat was generated just as soon as the oxygen struck the fuel. I agree with the committee in respect to many. of the things that will probably happen in the iron blast furnace, particularly as to the speeding up of the operation. There will undoubtedly be changes in the shape of the blast furnace, and if I were designing one today I should hesitate about the form to give it. Mr. Kirby suggested that the proper shape might be rectangular. Some of the men of the American Rolling Mill Co. have reached the same conclusion, as a result of Royster and Joseph finding that the combustion zone in the front of the tuyeres extended into the furnace less than 40 in. If this is correct, we might build the furnace with an elongated rectangu-ular hearth having the shorter dimension a little over 80 in. and secure. a very intense temperature in the hearth. The committee's report said, "With more oxygen available in the blast, the smelting ability of the furnace will be increased beyond the' speed of the preparing zone in the shaft." This can be controlled by providing ample facilities for getting stock into the furnace, and this will be one of the biggest changes in blast-furnace construction. The question has been raised as to finding suitable refractories to withstand the increase of hearth temperature. If the furnace can be kept full, the descending column of cold material will probably take care of the increased heat from more rapid combustion of the coke. At the Cleveland meeting, in 1912, the iron blast-furnace men listened with great interest to a paper on copper slags; from Mr. Kirby's paper, it looks as though they might again have to go to the copper men, for many of the problems of the iron blast furnace of the. future that uses oxygen may be worked out on lines of the copper blast furnace.

Jan 11, 1924

By Rossier W. Raymond

John Birkinbine was born Nov. 16, 1844, at Reading, Pa., the eldest son of H. P. M. Birkinbine, widely known as a hydraulic engineer. The family removed subsequently to Philadelphia, where, as a young man he established with his father the office now, continued by his sons, after more than 60 years. His education was received at public schools, the Friends' High School in Philadelphia, the Hill School at Pottstown, Pa., and the Polytechnic College of Pennsylvania, where his studies were interrupted in 1863-4 by service in the Union Army, which included participation in the battles at and around Gettysburg. Later, he devoted two years to work in a machine shop; and subsequently he became associated with the late P. L. Weimer, under the firm name of Weimer & Birkinbine, operating the Weimer Machine Works at Lebanon, Pa. Much of his work was in mining, metallurgy, and blast-furnace construction. As manager for the South Mountain Mining & Iron Co. he carried on experiments with various fuels for iron-ore smelting while maintaining the furnace in constant operation. The carefully recorded results obtained were widely published, and are referred to in text-books by other metallurgists as most complete. From his Philidelphia office he was sent to nearly every State, and to Canada and Mexico, for examinations, reports, constructions or im-provements in iron-ore mines, blast furnaces, iron works, water supplies, hydraulic development, irrigation projects, etc., and his engineering knowledge was requisitioned by several Eukopean corporations. A number of business trips were made to Mexico, beginning with a visit to the Cerro de Mercado at Durango,,before railroads were established in that. portion of Mexico, to make a critical examination and report on this "Iron Mountain." Later visits covered other localities and engineering problems, familiarizing him with the major part of the iron industry in Mexico. The late disturbed political conditions in that Republic have retarded the probable enlargement, modernization, and improvement of much of the iron and steel industry of Mexico, upon which he investigated and . reported for various capitalists on both continents. One interesting subject included in these reports was a proposed electric furnace, to be operated by energy from water power.

Jan 1, 1916

By D. J. Salley, M. Burke, G. L. Simard

A PREVIOUS paper1 described experiments on the interaction of dithiophosphate with galena and suggested that the process had characteristics of both chemisorption and surface chemical reaction. In order to add to this knowledge, a study has been made of the competition of a second ion with the dithiophosphate for a galena surface. Use again was made of radiotracer methods. Since radiophosphate was readily available, it was chosen as the competing ion. It is a feature of the tracer method that, in spite of similarity in the chemical behavior of the ions, the measurement of one ion in the presence of another can be made as simply as if only one ion species were present. In order to study the competition effectively, it naturally was necessary to examine the interaction of phosphate with galena alone as well as in the presence of dithiophosphate; consequently, this report consists of two parts. The first is devoted to a study of the rates, the isotherms, the desorption, and the exchange in the phosphate-galena system in the same manner as was done for the dithio-phosphate-galena system. The second portion is concerned with the studies on the competition. Flotation experiments on the three-component sys- tem are also outlined and the relationships involved are discussed briefly. The experimental method was that of the previous paper. The preparation of the galena, the radioactive and the nonradioactive dithiophosphate, and the procedures for radioactive counting, for sorp-tion, and for flotation measurements were identical to those previously employed. The radiophosphate* was used in the form of disodium phosphate solution. In the competition experiments the effect of the phosphate ion in depressing dithiophosphate uptake was followed by holding the initial concentration of nonradioactive phosphate constant while varying the initial concentration of the radioactive dithiophosphate. Counterfashion, the depression of phosphate by dithiophosphate was obtained by keeping the initial nonradioactive dithiophosphate ion concentration constant and altering the initial concentration of the radioactive phosphate ion. All solutions were buffered at a pH of 7.8 a0.1 by 20x10-' mol per cc of sodium carbonate. Measurements with radiocarbonate indicated that little or no carbonate could be sorbed in the presence of

Jan 1, 1952

By S. C. Carapella, E. A. Peretti

DURING a literature survey of the indium-zinc phase diagram, controversial reports on the composition of the eutectic point were encountered. The value reported in the investigation of Wilson and Perettil and in a later investigation by Valen-tiner' was 4.0 wt pct zinc. The most recent work recorded on this system consisted of an exhaustive survey of alloys by Rhines and Grobe8 in which they indicate a value of 2.8 wt pct zinc for the eutectic composition. To clarify this aspect of the diagram, a series of alloys were prepared by melting the respective constituents in a glass test tube under a covering of mineral oil and slowly cooling the melt in a furnace. The zinc used was Baker's C.P. and had the following analysis: insoluble in H2SO4—0.0l pct; pb—0.001 pct; Fe-—0.001 pct. The indium, which was supplied by the Indium Corporation of America, had a purity of 99.9'7 pet with the following impurities: Cu—0.002 pct; Pb—0.006 pct; Sn—0.01 pct; Zn—0.01 pct. The alloys were prepared for metal-lographic examination using a technique already reported' and a new value of 2.0 ± 0.1 wt pct zinc was observed. An alloy containing 2.00 wt pct zinc was also made by melting the constituents under a vacuum. In both of these methods of alloy preparation the losses can be kept extremely small. Again, the characteristic eutectic structure was obtained, assuring confidence in this value. The accompanying micrographs are presented in support of this point. Fig. la represents an alloy containing 4.00 wt pet zinc, and reveals excess zinc particles, which precludes the value of both Wilson and Peretti, and Valentiner. Fig. lb, gives the structure of an alloy containing 2.2 wt pct zinc, also showing the presence of excess zinc. Fig. lc is a micrograph of a typical structure of the eutectic observed in several sections of the 2.0 wt pct alloy. In the 1.8 pet zinc alloy, fig. id, the definite presence of the primary indium can be noted. From these re-

Jan 1, 1951

By A. B. Young

THE difficulties encountered in the preparation of. the lead smelter charge for the blast furnace and in the roasting and sintering of the ores, and the expert means taken for the preparation of these materials since the introduction of flotation concentrates into the lead smelter charge, have been described by W. H. Eardley1 and R. A. Wagstaff.2 FUNCTION OF ROASTERS AND BLAST FURNACES The lead smelter has first its roasters and its sintering devices, of which the primary object is the removal of sulfur from the ore or from the charge. The blast furnace follows; its function being the elimination of the gangue material left in the charge-the elimination of the insoluble, the iron, the zinc and the lime from the metallic lead. The secondary object is the separation of copper from the lead. A lead blast furnace is a sensitive apparatus. The materials composing the charge must be marshalled inn certain proportions before they will, make a fluid slag which will separate from the metallic lead. The silica, iron, lime and zinc must be put together in proportions that usually do not exist naturally in the ores, therefore fluxes are necessary. FUNCTION OF THE FLOTATION CELL The flotation cell-speaking from the standpoint of a lead concentrate-has taken over part of the work hitherto performed entirely by either gravity concentration or the lead blast furnace. It has eliminated gangue from the concentrate and separated waste products from the lead. In so far as it has done that, it has usurped some of the function of the lead blast furnace; and it is much cheaper to run a flotation cell than a lead blast furnace. The effect in Utah, and it will be similar to effects in other districts, has been to remove a great deal of the gangue by means of flotation, whereas in the old days it was eliminated by means of smelting. In this district, as in others, the insoluble content of the ores has been greatly out of proportion to the iron and lime content to make a proper slag

Jan 1, 1928

By Huntington Adams

The arrangement of a flow of cyanide-pulp through Pachuca tanks in agitation, so as to permit a continuous process, instead of alternate filling, agitation, and emptying, has been proposed by various writers within the last two years, and more particularly by A. T. Grothe, agent for the Brown patents on Pachuca tanks in Mexico. It was first put into practice, I believe, by M. H. Kuryla at the Esperanza mine in El Oro, Mexico. The starting of agitation in Pachuca tanks after filling may offer no serious difficulties with ores which do not settle rapidly in such tall tanks; and the adaptation of the tanks to continuous agitation under such conditions may give simply a somewhat more convenient method of treatment and greater agitation-capacity for a given number of tanks, because of the saving of time lost in filling and discharging. But in the treatment of pulp which tends to settle rapidly, as in the cyaniding of concentrates or of the whole pulp of ores containing heavy sulphides, the packing of the slime at the bottom may cause much trouble. The use of the radial air-pipe attachments near the top of the cone and of the air-valve outside of the air-lift tube at the bottom may obviate the difficulty to some extent; but the action of the radial air-pipes on the cone-sides is that of a sand-blast, and their continuous use cuts through the tanks. Moreover, even when these pipes are used, some pulps will pack tightly below them in the cones. Under such conditions the use of Pachuca tanks with intermittent filling and discharging becomes a troublesome process. Time is lost in starting agitation; large quantities of compressed air are wasted; pulp is blown over the tank-tops; and not infrequently it may be necessary to dig out the bottoms of tanks by hand. This trouble is the only important one occurring in the use of Pachuca tanks; and, since it is caused by intermittent filling, the arrangement of a continuous flow of pulp from tank to tank,

Jan 1, 1912

By G. K. Manning, W. E. Few

WORK on the effect of vacuum heat treatment of 0.040 in. diam sintered and wrought molybdenum wires has been sponsored by the Office of Naval Research at Battelle for the past several years. An electrical resistance furnace' capable of maintaining a vacuum of less than 0.1 micron of mercury at temperatures as high as 4000 °F was used for heat treating the wires. Early in the work, it was found that the introduction of a few microns pressure of oxygen into the furnace resulted in a rapid increase in the oxygen content of the wire specimens and the appearance of a discrete oxide phase. Subsequent elimination of the oxygen atmosphere caused the disappearance of the oxide phase. This was used to determine the solid solubility of oxygen in molybdenum over the temperature range of 2000" to 3000°F.2 It was observed that, with the disappearance of the oxide phase, the wires regained some ductility. Single-phased wires possessed from 5 to as much as 40 pct elongation in 2 in. Later, attention became centered on determining the cause of this wide range in ductility. Wires containing less than 0.002 pct C, less than 0.0007 pct 0, less than 0.0005 pct N, and less than 0.00003 pct H exhibited the erratic ductility noted above. These percentages represent approximately the limit of accuracy of presently available methods of analysis and thus it became apparent that chemical analysis would be of little help in the study. A number of possible explanations for the wide range in ductility were suggested during the course of the work. It was first suspected that variations in the grain size of the recrystallized wire specimens might be responsible. Wire from several lots of material was available. One of these lots tended to develop very large grains when recrystallized, the others all developed an ASTM grain size of 3 to 4 when heated above 2700°F. No correlation between grain size and ductility could be found. It was thought that back diffusion of oil from the diffusion pump might cause contamination of the wire, principally with carbon, but when wires were treated without cooling the cold trap in the pumping system,

Jan 1, 1956

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 Nelson W. Taylor

With the extensive deposits of potash minerals which have been discovered in the southwestern states, and their rapid development, a permanent American supply of potassium compounds is now assured. The 325-year history of the potash industry in this country has been told by H. I. Smith1, of the U.S. Geological Survey, and the more recent activities of the Survey and of American potash companies were described last year by the same author2. In fact, it may be stated that so great is the productive capacity that two mines in New Mexico and one in California are able to supply more than half a million tons of crude and refined salts over and above that produced for agricultural purposes. The era of scarcity has given way to an era of superabundance. This situatiori makes it desirable for the potash producer to look for other applications for his product, and it is with this in mind that the writer presents some information pertaining to present and possible future uses for potassium compounds in the ceramic industry. Ceramic Products Ceramic products are essentially solid materials containing one or more oxides such as SiO2, Al2O3, CaO, MgO, FeO, K2O, Na2O, TiO2, which are the oxides of greatest abundance in the earth's crust. The typical ceramic process is that of firing or burning the batch, and the product may be glassy, crystalline or mixed. In the glassy or vitreous group come glass, porcelain enamel and glazes; in the crystalline group, refractory materials such as silica brick, or chromite or magnesia; and in the mixed group, porcelain, chinaware, stoneware, tile, brick, etc., which contain both a vitreous and a crystalline phase, in variable proportions. The ceramic industry of the United States is a billion dollar industry, and is important not only because of its magnitude but also because of the key position occupied by certain ceramic products in the whole manufacturing structure. From the standpoint of use of potash, the field of refractories is of no great interest, since K2O lowers the melting point of a refractory oxide and

Jan 1, 1938

By W. O. Milligan, J. L. McAtee

THE constitution and structure of the hydrous forms of aluminum oxides and hydroxides have been studied in the laboratory of the Depart¬ment of Chemistry at Rice Institute for almost three decades. Progress reports have been made from time to time 13,17,18 summarizing and evaluating the existing state of knowledge concerning the complex inorganic system A12Oa-H2O. X-ray and electron diffraction analysis, together with dehydra¬tion isobars and isotherms, have been the most useful methods for increasing the understanding of the structure and interrelationships of the various forms of alumina and aluminum hydroxides. The purpose of this paper is to bring up to date the information now available, in the hope that a clearer understanding of the structures of these materials may prove useful in aiding mineralogists and geologists in studies of the genetic significance of the aluminum hydroxide minerals, and possibly of the closely related clay minerals. Early investigators found the system alumina-water to be confusing, since, prior to X-ray diffraction examination, it was not possible to clearly identify and characterize the various crystalline forms. One could not be certain as to whether or not different investigators were working with the same chemical individuals. In later studies, including some from the authors' laboratory, addi¬tional confusion resulted from difficulty in preparing pure samples of the various aluminum hydroxides and in obtaining relatively large crystals of dimensions above the colloidal range of particle size. Even at present, it is difficult to establish sets of interplanar spacings for the several forms of the aluminum hydroxides, as illustrated by the 29 different X-ray diffraction pat¬terns listed in a current publication. The nomenclature of the aluminum hydroxides is also extremely confus¬ing, inasmuch as two different systems are employed by large groups of in¬vestigators. Plans are being made to formulate a uniform system of nomen¬clature but in this report the designations employed will agree with previous papers from the same source.13,17,18 Four forms of crystalline aluminum hydroxides may be considered to be well defined and recognized, which, together with hydrous alumina "amor¬phous to X-rays," comprise an exceedingly complex inorganic system. Several

Jan 1, 1952

By Nelson W. Taylor

With the extensive deposits of potash minerals which have been discovered in the southwestern states, and their rapid development, a permanent American supply of potassium compounds is now assured. The 325-year history of the potash industry in this country has been told by H. I. Smith1, of the U.S. Geological Survey, and the more recent activities of the Survey and of American potash companies were described last year by the same author2. In fact, it may be stated that so great is the productive capacity that two mines in New Mexico and one in California are able to supply more than half a million tons of crude and refined salts over and above that produced for agricultural purposes. The era of scarcity has given way to an era of superabundance. This situatiori makes it desirable for the potash producer to look for other applications for his product, and it is with this in mind that the writer presents some information pertaining to present and possible future uses for potassium compounds in the ceramic industry. Ceramic Products Ceramic products are essentially solid materials containing one or more oxides such as SiO2, Al2O3, CaO, MgO, FeO, K2O, Na2O, TiO2, which are the oxides of greatest abundance in the earth's crust. The typical ceramic process is that of firing or burning the batch, and the product may be glassy, crystalline or mixed. In the glassy or vitreous group come glass, porcelain enamel and glazes; in the crystalline group, refractory materials such as silica brick, or chromite or magnesia; and in the mixed group, porcelain, chinaware, stoneware, tile, brick, etc., which contain both a vitreous and a crystalline phase, in variable proportions. The ceramic industry of the United States is a billion dollar industry, and is important not only because of its magnitude but also because of the key position occupied by certain ceramic products in the whole manufacturing structure. From the standpoint of use of potash, the field of refractories is of no great interest, since K2O lowers the melting point of a refractory oxide and

Jan 1, 1938