Search Documents

By Arthur Gray

THE thermal analysis of a metal or alloy is ordinarily made with the aid of heating and cooling curves, in which transitions are indicated by the rapid changes in curvature that accompany .changes in the rate of heat absorption or evolution. Analysis by the method that depends on the change in thermal expansivity is not customary, partly, at least, because of the difficulties involved in making the necessary measurements. However, under certain circumstances, the dilatometric method of analysis may possess advantages over the thermometric method that will justify the additional trouble required. The addition of 1 per cent. of zinc to an alloy has been found to produce, upon the volume changes that take place during transition, effects that suggest the possibility of using the dilatometric method of thermal analysis as a rather sensitive means of obtaining chemical information. Although the illustrations presented in this paper are drawn from data obtained during an investigation of dental amalgams, similar phenomena can doubtless be observed with other alloys. Some of the results found during an investigation made in 19171 have been confirmed by data on the thermal expansivity of amalgams published by Souder and Peters of the Bureau of Standards in reporting tests of dental materials.2 Although the Bureau of. Standards made experiments for the purpose of discovering effects of including zinc as one of the constituents of a dental alloy-a matter much discussed in dental literature but without the presentation of reliable experimental evidence to support the views of ;either side-the reports of the test made by the Bureau give the impression that certain striking phenomena associated with the presence of zinc were not noticed. Among such phenomena are those connected with the conditions that determine whether or not a specimen of amalgam becomes covered with droplets from which crystals develop.

Jan 9, 1920

By Edmund Kirby

THE results to come from the application of cheap oxygen to industry in general will be so great that it is not possible to enumerate them beforehand and still less to estimate them. We naturally think first of the fuel to be saved; yet this is only a minor item. The main results will be changes in methods of manufacture or of operation. The speed of operation will be greatly increased, with consequent savings in labor and fixed charges, and also, in most cases, in the cost of fuel. High temperature will be brought within the reach of every manufacturer, whereas it is now available only to those operating expensive electric furnaces located within reach of large water power. New speeds and new temperatures mean improvements and processes not thought of at present. Incidentally the changes in methods will probably change the location of important world industries, the tendency being to concentrate at the fuel centers. The whole subject is so new that most of the data which an engineer requires for definite estimates do not exist. All that is possible now is to obtain a general view of the subject with rough and fragmentary estimates for some of the industries with which we are specially concerned. Most of the figures presented deal with fuel saving merely because there are available no data from which to estimate the effect on speed of operation. When working out the practical problems involved in substituting oxygen for air, in most cases the change will be made step by step; by trying out air enriched with increasing percentages of oxygen. Such partial applications of oxygen will be temporary expedients during the transition and there will be no stopping place short of the complete substitution of air by oxygen. This final stage is therefore the one discussed in this paper.1

Jan 11, 1924

By L. W. McKeehan

IT is no longer necessary, if it ever was, for your annual lecturer to apologize for including in his remarks frequent references to the arrange-ment of metal atoms in crystals and for basing his arguments that metals behave as they do upon their crystal structure. Neither will any objec-tion be raised because the large metallic crystals of which we will speak are hard to prepare and of negligible commercial interest. The particular set of physical properties we propose to discuss-ferromagnetic proper-ties-may require more justification. Very few in this audience are primarily, or even remotely, interested in the ferromagnetic behavior of the metals they handle. By no means all of you ever deal, by choice or by necessity, with metals which display any ferromagnetism at all, and even those who study or control ferrous metallurgy must usually depend upon electrical engineers for assistance in ferromagnetic applications. My excuse for talking about such an obvious specialty is, like all Gaul, divided into three parts. In the first place, the members of the com-mittee who select the annual lecturer must wish the speaker to confine himself to matters he has at least thought about before he prepares his speech. In the second place, the study of ferromagnetism in crystals has, as you will soon realize, suffered in the not-too-distant past from inade-quate metallurgy. Further progress probably depends upon proper use being made of the skill and knowledge of some members of the Institute of Metals Division who have not, before today, been asked to think about the problems presented here. Finally, there is at least a sporting chance that the ferromagnetic properties of a few metal crystals will give some insight into the more generally interesting properties which they share with nonferromagnetic metal crystals.

Jan 1, 1934

By H. F. Silliman, Daniel R. Hull, John R. Freeman

IN the normal operation of a brass-rolling mill, sheet and strip has, for the most part, been finished in comparatively thin gauges, involving a substantial amount of coldwork and a considerable number of anneals. This condition has been disturbed by the prep0nderance of cartridge brass, which is not rolled to thin gauges, and particularly by brass for artillery cartridge cases, on which the mill may finish its work at a thickness between 0.400 and 0.900 in. Obviously, the amount of rolling and the number of anneals to which such a product can be subjected are small compared with strip that is carried to a thickness of a few hundredths of an inch. As a result, critical examination into the internal condition of metal has been made on an extensive scale at a stage of manufacture that would not, in normal times, have been chosen for complete inspection. Under these conditions, a type of defect has been recognized that is not seen at thinner gauges. It might be more accurate to call it the appearance of a defect, since it refers to an apparently laminated, discontinuous structure, which, in fact, does not exist as such, and disappears after suitable treatment. For this reason it has been called a phantom lamination, which the authors consider an appropriate term. It is the purpose of this paper to describe the phenomenon and the conditions of its occurrence and, at least tentatively, to discuss its nature and cause. Great numbers of phantoms may be found in 2: 1 brass, either hot-rolled or cold-rolled. They are also found in 70-30 brass, sometimes when hot-rolled and generally when cold-rolled. It is not believed that phantoms are confined to these alloys but this paper is limited to them for the purpose of description. HOT-ROLLED 2:I BRASS For illustration, therefore, a typical cake of hot-rolled 2: 1 brass has been chosen. This was rolled to a slab 7/8 in. thick, from a casting 5 in. thick by 24 in. wide by 18 in. high, which was believed to have been sound. After hot-rolling and cooling, the slab was sheared and a portion of such a shear cut is shown in Fig. 1. It would be difficult to convince anyone viewing this specimen that the metal was not unsound. The impression would be confirmed by the appearance of a tensile break, as shown in Fig. 2. This is an ordinary tensile-test piece from metal just described. Although there was nothing in its tensile strength or elongation that suggested unsoundness, it appeared run through with pipes and laminations. To question the reality of such a condition would imply questioning the obvious. But, considering the history of the metal, it w0uld be difficult to believe that it could be so bad as it appeared. It seemed reasonable, though, that if the defects were what they appeared to be, they could be traced back from the sheared or broken face.

Jan 1, 1945

Discussion of the paper of MANUEL EISSLER, presented at the New York meeting, February, 1915, and printed in Bulletin. No. 9.5, November, 1914, pp. 3661 to 2703. J. W. RICHARDS, So. Bethlehem, Pa.-I do not see in the paper a description of the Mabuki hearth as used for ore smelting. I noticed it described for concentrating matte, but I believe the older Japanese process was to use it for-smelting directly, by a pyritic smelting and Bessemerizing all in one operation, in the same simple hearth apparatus. There is a monograph published in German, on Copper-Ore Smelting in the Mabuki Hearth. At Ashio the practice of injecting bituminous coal at the, tuyères is noteworthy. It is very interesting to see two men load little cartridges on the end. of an iron rod with bituminous coal, and push them into the furnace tuyères, and with a piston inject 2 or 3 lb.. of bituminous

Jan 5, 1915

The data about production in this county are exceedingly meager, and there are few reliable data about shipments. It is probable that consid¬erable amounts of coal from here moved north to Erie by both the Beaver and Erie. Canal and the Erie and Pittsburgh Railroad, and if so, they are included with Mercer County. The data in the early state reports are very inaccurate and are always much too low. Much of this coal was used in local furnaces and iron plants and not handled by railroads. There was some production in this county on the line of the Pittsburgh, Fort Wayne and Chicago Railroad, of which no record can be found. The estimated production is based on the number of mines reported as operating in the county at various dates and their probable output, as suggested occasionally in county histories. It is believed that these figures are below, rather than above, the actual figures, which can now never be obtained.

Jan 1, 1942

THERE are three chief production zones of tungsten ore in China. In the Province of Kiangsi mines are located at Kanchow, East River, and West River. Their combined production is understood to amount to 300 to 350 tons of ore per month, and their original exportation is made through the port of Kiukiang, largely to Shanghai. The second zone is in Kwangtung Province, the mines there being at Tayulin. Produc-tion reaches about 200 tons per month and cargo is gen-erally exported through the port of Hong Kong. In the Province of Hunan approximately 25 tons of ore are produced monthly in the mines at Ton-on. Tungsten ore from Kiangsi and Kwangtung Prov-inces is generally about 70 per cent WO, (tungstic acid), while that from Hunan is of lower quality, run-ning about 65 per cent WO3. Kiangsi ore is received from the mines in 100-1b. and Hunan in 224-lb. gunny sacks. No repacking is done except as it is made neces-sary by the condition of the sacks. Kiangsi Province contains the Chinese districts pro-ducing the largest amount of salable wolframite or tungsten. Many districts west and south of Kiangsi have been found to have wolframite deposits.-Com-merce Reports.

Jan 1, 1928

By P. Martignan

UNTIL quite recently, Alsace was the only district in France where petroleum could be found in somewhat industrial quantities. The Pechelbronn fields produce, however, only about 80,000 tons a year, which represent approximately one-eighth of the domestic consumption. Much research work has been done in Alsace to find the prolongation of the Pechelbronn fields, but instead of oil the drillings revealed the existence of large deposits of potash. This can be easily explained when one remembers that the Pechelbronn oil is of the Oligocene period, and that in the Alsatian stratification the Oligocene lies immediately on the Keuper, i. e., on the strata that originate from a period during which the largest salt and potash deposits were constituted. Before the war, and mostly at the end of the last century, some wells were drilled in. various districts of France where some analogies could be found with the Alsatian geology, the borings being mainly made in the Triassic and Tertiary beds. They led to negative results. After the war, the growing importance of oil urged the necessity of resuming the explorations. But it. is our belief that this was greatly facilitated by the enacting of new legislation, which is embodied in the Mine Act of May 16, 1922.

Jan 3, 1925

Very few data are available about production in this county. The amount mined was used locally, or shipped by river, until 1839 when the canal was completed to Dunnsburg. Only partial records for four years remain of canal shipments. Considerable coal was used locally by the iron works at Farrandsville for some years. Rail shipments started in 1861 and those shown are the estimated shipments of these mines as compared with the mines in other counties served by the Philadelphia and Erie Railroad, the total tonnages being given in the annual reports to the Auditor General. It is not likely that any coal used by the railroad is included in these figures. (Table 40.)

Jan 1, 1942

By Manuel Eissler

INTRODUCTION THE history of copper metallurgy in Japan goes back into remote ages, of this there is abundant proof, and that the working of this metal is closely connected with the artistic development of this nation is evidenced by some of the glorious monuments which have been produced by these ancient metal workers. The traveler sees to-clay in a perfect state of preservation bronze statues 150 ft. high, and over, 300 ft. in width, and 170 ft. in depth, delicately chased and beautifully marked, and when one reflects that some of them date back to the eighth century A. D., the question naturally suggests itself, how did these ancient metallurgists with their crude and primitive appliances accomplish this stupendous task? The bodies of these images are formed of bronze castings 10 to 12 in. thick, which were gradually built up and soldered together, but other pieces of magnitude, like the heads and other portions of the body are single castings. In many cases another method of construction must have been adopted. The walls of the molds were gradually built up and as the lower portion of the castings cooled, the walls were raised higher and higher and fresh metal must have been added, instead of constructing the whole mold first and then making the casting in one piece. There are still traces of substantial gilding visible on these statues, and how the pious Buddhist priests who were the constructors of them got the precious metal, is preserved in legendary tales.

Jan 11, 1914

By Donald D. Smythe

Tars paper describes briefly the topography and geology of the region where the mica-bearing pegmatites are found and discusses prospecting, the quality of the mica, its preparation, and evaluation of the deposits. Muscovite mica occurs in a number of widely separated localities in Brazil, but production has come largely from deposits in the southeastern and eastern part of the State of Minas Gerais (Fig. I). There the deposits form a discontinuous zone, which starts at a point 90 km. north of the city of Rio de Janeiro and extends north for some 500 km., roughly parallel to the coast. A maximum width of 180 km. is reached along the Rio Doce. To the west in Minas Gerais, and extending east into the states of Espirito Santo and Rio de Janeiro, the mica zone proper is fringed by areas in which there are scattered occurrences of mica-bearing pegmatites. A few of these outlying deposits have produced commercial mica, but most of them are unimportant. To the southwest, in the State of São Paulo, there are a number of mines, which at one time produced a very considerable amount of sheet mica, largely as a by-product of kaolin mining. These deposits, and, a few others lying between them and the main productive areas to the northeast, appear to be the southwestern continuation of the strong Minas Gerais mica zone. In the vicinity of Conquista, just north of the Minas Gerais boundary in the State of Bahia, and still farther north, near Jacobina, there are several known mica deposits. Their location indicates that they may be the northern continuation of the main mica zone. The major part of Brazilian mica production has come from four areas within the mica zone proper; from north to south, Governador Valadares, Raul Soares, Espera Feliz, and Muriaé. The first is 190 km. from north to south and reaches a maximum width of 180 km. The Raul Soares area extends 135 km. from northeast to southwest, and in places is 80 km. wide. The Espera Feliz area is 100 km. from north to south, and reaches a width of 35 km. The Muriaé area extends 150 km. from northeast to southwest and its width reaches 40 kilometers. Between the known productive areas, and in the areas directly to the southwest and to the north of them, little mica has been produced. These gaps, as well as certain irregularities in the outline of the mica zone itself, are to be ascribed either to lack of prospecting or to conditions preventing the discovery of mica, rather than to its nonexistence. Elsewhere in Brazil mica has been reported from eastern Goiaz, Ceará, Pernambuco, Rio Grande do Sul, Matto

Jan 1, 1946

During the last 15 years, the bucket wheel has become increasingly popular as a mining tool. Being a large-capacity continuous mining excavator, the machine offers low actual operating costs and low unit costs. Of German origin, the bucket wheel has now appeared on the American mining scene as well as in such other places as Australia, Northern Rhodesia, South Africa, Congo, Indonesia, and India. Patented in 1913, the first practical application waited until 1920 when a bucket wheel excavator was placed in operation at an open pit lignite mine in central Germany. This initial experiment met with little success due to difficulties in solving the technical problems of the machine's construction rather than to the design of the wheel itself.

Jan 9, 1960

By Frank Wartman

RECENTLY Horace Freeman1 obtained a patent on a successful method of conducting a roasting procedure described as to general features by Carl Schnabel2 almost forty years ago. Essentially, the Freeman process of roasting consists in introducing the finely powdered sulfide mineral, suspended in air or any other suitable gaseous medium, into the upper portion of a heated chamber. The stream of suspended particles is directed vertically downward. A counter-current stream of gas introduced at the bottom of the chamber flows upward. The mineral particles are oxidized as they fall through the heated atmosphere of the chamber. All air required for the oxidation may be admitted either at the top or the bottom of the chamber, or may be divided between the top and bottom inlets in any desired proportion. Heat may be recovered by passing the gases leaving the furnace through a waste-heat boiler or other form of interchanger. In speaking of the results obtained in roasting pyrite, Freeman says:3 Steam yield from the boiler exceeds 1 pound of steam per pound of pyrite con-sumed, which pays the cost of operation of the burner. The oxide produced is in the form of fused particles or hollow shells of magnetite, containing about 65 per cent of iron. It contains the gangue material ordinarily produced in flotation concentrate, of course, but it is being found that most of this can be eliminated by magnetic separa-tion, and that the sulfur content, as consistently produced, is below 0.2 percent. This material is especially interesting as a high-grade iron ore, free from phosphorus and low in sulfur. It may be sintered or briquetted. It is even more interesting as a raw material for sponge-iron production, to be directly smelted in electric furnaces without the usual cooling of the iron powder and magnetic separation between the reducing kiln and the electric furnace.

Jan 1, 1933

By Charles Legrand

IN many iron, coal and copper mines where large tonnages are known before starting operation and proper provisions can be made, the problems of electric traction by trolley locomotives are not very different from those of surface plants. In such installations the gauge of the track, the radius of curves, and the clearances, both vertical and horizontal, can be made to suit the conditions of the traffic. It is more difficult to install electric traction in mines which were started with hand tramming and where no consideration was given to the possibility of mechanical traction being used. The writer having had some experience in the installation of electric traction in copper mines, the following remarks apply more particularly to these mines. With the gauge of track usually 18 or 20 in., the weight limit of locomotives obtainable from manufacturers in this country varies from 3 . to 6 tons. The full-load speed varies from 42 to 6 miles per hour. These locomotives, being made to run on very small radius curves, have a short wheel base and a long overhang from axle to coupling, which necessitates a coupling with a good deal of lateral motion to avoid derailing the cars on sharp curves, especially if couplings are of the standard railroad automatic type. Although, 3-ton locomotives will run on 12- or 16-.1b. rails, it has been found more satisfactory to use 25-lb. rails, as the track keeps in much better shape, it is easier to maintain the bonding in good order, and fewer derailments from dirt on the track occur with the larger rails. Where 6-ton locomotives are used the 25-1b. rails are satisfactory, but 40-lb: rails have proved cheaper where the traffic is heavy and the ground is soft, as the track maintenance is considerably lower with the heavy rails. The locomotives will run on 15-ft. radius curves, but on through runs it is advisable not to go below 40-ft. radius.

Jan 2, 1914

By D. F. Hewett

ALTHOUGH most persons will agree that an individual or a nation can profit from the experience of other individuals or nations, there is always room for debate over the degree of similarity of their past and present conditions and of their future problems. Noting the increasing interest that Americans are showing in our mineral problems, I have felt that we could profit from reviews of the experiences in mineral exploitation acquired by the industrial nations of Europe. Whether we can learn much from Europe's experience in exploiting such minerals as petroleum may be debatable, but certainly, with a record of metal production extending back nearly 3000 years, Europe should hold much of value for America. A trip to Europe in 1926 permitted me to visit 28 mining districts, of which about half are now or have been in times past outstanding sources of several metals. The districts range from England to Greece and from Spain to Poland. To summarize briefly my impressions of these mining districts, as well as such reactions to the thought and life of Europe as so short a visit permits, I shall only venture the opinion that Americans can review with great profit the ideas and actions of Europeans, with regard not only to the production of metals but to many expressions of life. I believe that America has made and is making new contributions to the art of living, as well as to the arts of mining and metallurgy, but in so far as Europe is and has been a laboratory of economic, social and political experiments, the results she has attained deserve the thoughtful attention of America. I have come to believe that many of the problems that harass Europe lie in our path not far ahead. I have therefore hoped that a review of metal production in Europe in the light of its geologic, economic and political background may -serve to clear our vision with regard to our own metal production.

Jan 1, 1929

By George J. Young

(Cleveland Meeting, October, 1912.) I. GENERAL. THE recurrence of mine-fires in Nevada during the past decade is not only a matter of interest, but also one of considerable concern to engineers and mine-managers. The more important fires may he enumerated as follows: Forman Shaft fire., Gold Hill, April 21, 1903 ; shaft-house, machinery, and shaft, destroyed; loss estimated at $50,000.; Cause Unknown. Union Shaft fire, Virginia City, July 14, 1904; shaft-house, machinery, and shaft in part destroyed; loss estimated it $100,000; cause of fire stated as the careless throwing of a match in the rope-house. Sutro Tunnel fire, Virginia City, Jan. 27, 1909 ; 700 ft. of tunnel-timbering destroyed, and direct damage of $10,000; cause ' probably electric wires." Belcher Shaft fire, Gold Hill, Aug. 9, 1910; shaft-house destroyed, machinery ruined, and upper part of shaft damaged; damage, $25,000; no cause given. Belmont Mine fire, Tonopah, Feb. 23, 1911; fire started in winze ; 17 men killed. Giroux Mine fire, Kimberly, Aug. 23, 1911 ; fire originated iii shaft-station from unknown cause; 7 men killed, and $34,¬521 damage caused. (NOTE 1.-On June 11, 1912, some time after the present paper was written, a fire broke out in the pump-room on the 2475 station of the Ward shaft, Virginia City. This fire was caused by the short-circuiting and exploding of the starting-switch on No. 5 pump. The oil in the switch was scattered about and set fire to the timbers and laming of the pump-room. The pump-roan in charge notified the surface, and the * Professor of Mining and Metallurgy, Mackay School of Mines.

Oct 1, 1912

By Charles Catlett

(San Francisco Meeting, October, 1911.) WHILE the occurrence of phosphorus in coking-coal has assumed less importance with the development of the open-hearth method of steel-making, it may not be without interest to note the form in which phosphorus exists in one particular coal-seam. In the examination of what is known as the Big seam, which outcrops a few miles west of Columbiana, Ala., my attention was called to the distribution through the coal, in the form of minute veins and particles, of a resinous-looking substance. A small amount of this was selected, and was provisionally identified as evansite (Al6, P2 014. 18 Aq). Subsequently, through the courtesy of Dr. Sharshall Grasty of the Geological Department of the University of Virginia, I was able to secure an additional amount of material, which was purified down to about 0.3 g. This was examined by Prof. John J. Porter of the University of Cincinnati, and gave the following partial analysis

Nov 1, 1911

By Thomas S. Carnahan

UNION MINIERE D HAUT-KATAIGA operates a group of mines and metallurgical works in the Katanga province of the Belgian Congo. It is especially prominent as a copper producer, but its output of accessory metals, such as cobalt, radium, silver, tin and gold have been considerable. The Belgian Congo covers 920,000 sq. mi. of central Africa, with a native population of about 8,500,000. In addition, Belgium controls by mandate the districts of Ruanda-Urundi (formerly a part of German East Africa) with an area of some 20,000 sq. mi. and a population of about 3,500,000 natives. Most of the native population of the Belgian Congo is found on the wide fertile plains of the great rivers, living under primitive conditions in a tropical climate, where it has survived throughout the centuries in spite of tropical diseases and intertribal wars. In more recent times, especially during the last two centuries, 'the natives have been subjected to frequent raids by the slave traders, which made their existence even more precarious, and if continued much longer would probably have resulted in their complete extermination.

Jan 1, 1932

By Werner Goldsmith

This discussion is confined to the first section of Professor Clark's paper entitled 'Elastic and Nonelastic Waves' and its application to wave propagation in rocks. Some published results by other investigators concerning measured decay of peak strain and variation of pulse duration with travel distance are cited, but the principal subject of this section is a detailed mathematical analysis of spherical (and, to a lesser extent, of plane) wave propagation in various homogeneous, isotropic media. The materials selected include an elastic substance, a Voigt and a 'modified' Voigt solid-the latter incorporating the assumption of a constant loss factor (defined here as the product of frequency and the ratio of the imaginary to the real part of the shear modulus)-and a solid friction model. While other possible representations of a solid continuum model are mentioned, corresponding solutions are not presented. The pulse inputs considered comprise exponential decay, a unit step, and steady- state sinusoidal excitation: the process of conversion from one solution to another in the operational plane is indicated. The basic problem relative to the analysis of wave propagation in rocks concerns the specification of the appropriate material behavior, since the equations of motion for a given geometry of the source and medium are well established. In principle, the required information can be deduced from two types of measurement: 1) field observations of underground explosions or seismic disturbances, and 2) laboratory tests on small samples of the pertinent rock. However, in practice both types of approaches are beset with difficulties and subject to valid criticism. Field observations must be carried out under relatively uncontrolled conditions, including, in general, a lack of knowledge of the precise arrangement of the medium, stratification, faulting. inhomogeneities, etc. Specimens investigated in the laboratory can not represent the environment found

Jan 1, 1967

By J. A. SINGMASTERN

THE New Jersey Zinc Co.'s vertical retort plants are believed to have been in continuous operation through the whole year. At Palmerton metal purer than that made from the same ore in the old plant has been produced and has been able to compete successfully with very pure electrolytic metal in die castings and other special uses where extreme purity is worth money. A new plant using this process was put in production by the Grasselli Chemical Co. at Meadowbrook, W. Va., early in the summer. It is said to be working very satisfactorily. It is understood that this plant will not produce high-grade metal. Two patents issued to Bunce and Mahler (Nos. 1,749,126 and 1,749,127) describe a method of operating the vertical retort so that practically lead-free metal can be obtained from ores containing consider- able lead. The zinc vapors and other gases leaving the reaction zone are filtered through a column of material maintained at a temperature high enough to prevent much zinc from condensing. The filtering medium is either periodically or continuously changed.

Jan 1, 1931