Search Documents

By S. H. Ash

Safety records in the mineral industry for 1954 will do well to hold their own as compared with 1953, because of the poorer rate in the coalmining branches, even without the recent mine explosion at the No. 9 mine of the Jamison Coal & Coke Co., Farmington, W. Va., that killed 16 persons. .The cause of that disaster has not yet been ascertained. The metal-mining branch appears to have improved its record over the last year, however. Health Diesel equipment continues to be favored in non-coal mines. Equipment includes locomotives, trucks, tractors, and muckers. Of major concern and interest is the establishment of a new threshold limit for oxides of nitrogen-5 ppm as compared with 25 ppm. This gas is the most harmful component of diesel-engine exhaust gas

Jan 3, 1955

By D. C. Livingston

The Pilares de Nacozari mine is located ill Sonora, 75 miles south of Douglas, Ariz. The town of Douglas is on the International Boundary and is the place at which the ores from the Bisbee mines are smelted. The Moctezuma Copper Co. owns the mines at Nacozari, and the copper-concentrates shipped to the Copper Queen smelter, at Douglas, make a good smelting-mixture with the Bisbee ores. The Moctezuma Copper Co. and the Copper Queen smelter at Douglas, as well as the railroad from Douglas to Nacozari, are owned by the Phelps, Dodge & Co. The ore-deposit occurs in the form of a large ellipse with a major axis of approximately 2,000 ft. and a minor axis of about 600 ft., the major axis bearing about 9" W. of N. The

Jan 1, 1913

W: 0. HOTCHKISS, Madison, Wis. (written discussion*).-Mr. George's paper on. "The Wisconsin Zinc District" is a very complete and clear description, which it is a pleasure to read. His discussion of the origin of the ores is the least satisfactory part, and Mr. George correctly states present knowledge when he begins his paragraph on a origin with the words "the general supposition is, etc." There is still much to be learned regarding the details of the processes by which the ores have reached their present situation. In this the Wisconsin district differs not at all from other mining districts. It is my hope that Mr. George and others, equally clear-thinking, who are in close touch with these operations will be able at an early date to give us more information on this subject.

Jan 3, 1918

By A. B. Parsons

When the Seeley W. Mudd Memorial Fund was established in. 1929 the donors mentioned certain types of projects to which preference might be given in selecting those to he financed by the income from the Fund. One suggestion. was that the projects "be of particular benefit to young engineers." This modest little book meets this specification most aptly. It seeks to guide the engineer-particularly the young one-with the least loss of time and effort to the most convenient source of authentic information regarding any topic in which he may at the moment be interested. Knowing the best place to find the literature on a subject is almost as valuable-and far more practicable-than maintaining a library of one's own large enough to provide the information.

Jan 1, 1933

As a representative of the Institute in the Joseph A. Holmes Safety Association, which comprises some twenty-three different National Societies, it is proper that I make some report of the progress of the Association to the Institute. The societies represented in the organization are as follows: Association- Representatives, 1916 American Association for the Advancement of Science L. 0. Howard American Chemical Society Charles Baskerville American Electro-Chemical Society F. G. Cottrell American Federation of Labor : A. E. Helder American Forestry Association P. S. Ridsdale American Institute of Electrical Engineers John H. Finney American Institute of Mining Engineers Hennen Jennings American Mining Congress David T. Day American Red Cross Society Maj. Robert U. Patterson American Society for Testing Materials A. W. Gibbs American Society of Mechanical Engineers..... John A. Brashear

Jan 4, 1917

Albin, B. R Billings, Mont. Amster, Nathan L 25 Broad St., New York, N. Y. Bache, Jules S 42 Broadway, New York, N. Y. Barrett, C. P6338 Harper Ave., Chicago, Ill. Baum, Frank G Hobart Bldg., San Francisco, Cal. Bayless, Hon. William S Russ Bldg., San Francisco, Cal. Bean, Louis H., V.P., Dwight P. Robinson & Co., Inc 125 E. 46th St., New York, N. Y. Beatty, Ross J 1106 First National Bank Bldg., Chicago, Ill. Benwell, Oswald F 205 Colorado National Bank, Denver, Colo. Beymer, Albert S., V.P., Keystone National Bank Pittsburgh, Pa. Bingham, Charles W 1542 Hanna Bldg., Cleveland, Ohio. Blumenthal, Hugo 44 Pine St., New York, N. Y. Boettcher, Charles Ideal Cement Bldg., Denver, Colo. Bowlus, Thomas H Iola, Kans. Bragg, E. B Carmel, Cal.

Jan 1, 1929

The Engineering Council met on October 11 in the rooms of the American Society of Mechanical Engineers, Engineering Societies Building, New York. The Rules Committee submitted a draft of rules for the admission of other societies to the Council and progress was made in their consideration. The Committee on Public Affairs reported on a number of requests that the Council support pending or proposed legislation. Remedial laws intended to promote hydro-electric development were favored and Council voted to offer its cooperation to the United States Chamber of Commerce which is interesting itself in this matter. A movement to coordinate, unify and strengthen the work of various engineering committees cooperating with the federal authorities at Washington was favorably considered. Messrs. H. W. Buck and Charles. Whiting Baker were appointed Council conferees. CALVERT TOWNLEY, Secretary.

Jan 12, 1917

By William Kranz

Discussion of the paper of WILLIAM G. KRANZ, presented at the San Francisco meeting, September, 1915, and at the New York meeting, February, 1916, and printed in Bulletin No. 101, May, 1915, pp. 927 to 930. J. W. RICHARDS, So. Bethlehem, Pa.-At the present time I believe there are 35 electric steel furnaces under construction in the United States, and many more in operation. The United States Steel Corporation, for example, is putting up for one firm a plant of eight electric furnaces. The principal increase in use of the electric furnace at the present time is based on its superiority for making steel for shrapnel and for munitions of war. I understand that electric steel has been found far more reliable and suitable than ordinary steel for these purposes in Europe.

Jan 5, 1916

The following list contains the names of members of whose deaths notices have been printed in MINING AND METALLURGY during the year ending April 1, 1937. Biographical sketches published in MINING AND METALLURGY are indicated in the last two columns. YEAR OF ELECTION - NAME - DATE OF DEATH - ISSUE CONTAINING BIOGRAPHY - PAGE I892 ALLDERDICE, TAYLOR May 20, I934 1919 ALTMEYER, MAURICE E June 9, I936 1917 ANDERSON, JAMES P Jan. I4, I937 I936 ANDERSON, O RAN M Jan. 12,1937 I908 AUSTIN, E. A I935 1914 BACON, MAURICE W Jan. 4, I936 Apr. I936 22I 1914 BARTHOLOMEW, WILLIAM F Oct. 7, I936 Dec. I936 602 I930 BERRY, HAROLD R July 1, I936 1915 Betts, Robert M Jan. 9, I937 HON

Jan 1, 1937

By David LeCount Evans

Not only E. B. Mayo but also W. C. Lacy, who apparently urged the preparation of this analysis, is to be commended. Regional thinking of this type is needed to assure future success in the never-ending search for new mineralized and petroliferous districts. As is usually the case, here is a regional study that will be read by the mining geologist alone. It is ironic that several of the trends established in this study have suggested themselves in northern mid-continent, detailed, and regional studies. These, where established, have offered new keys to petroleum exploration and have provided a possible basis for unraveling a number of broad generalities. The oil geologists, active in Colorado, Kansas, and Oklahoma, would find much food for thought in Mr. Mayo's projections.

Jan 6, 1959

By Ross W. Smith, M. E. Wadsworth, T. James Smolik, A. S. Peck

Ross W. Smith (Acting Instructor, Department of Mineral Engineering, Stanford University, Stanford, Calif.) and T. James Smolik (Kennecott Copper Corp., Salt Lake City, Utah) - Professors Peck and Wads-worth have made an interesting contribution to the study of fluoride activation of beryl. We have a few comments to make regarding the paper and a question to ask of the authors. We note that glass containers were used in the study. Hydrofluoric acid should react with glass to produce SiFg2 in quantity which could adsorb onto the beryl surface (onto either beryllium or aluminum sites). The authors propose that individual F- ions actually go into the mineral surface lattice rather than onto the surface by adsorption of siFi2 ions. Based on infrared reverse bands with an untreated

Jan 1, 1969

By W. D. Robertson, J. -P. Briant, M. Gell

The distribulion of dislocatiorls genevnted during the propagalion of hydrogen-induced cracks in Fe-Si cryslcrls was studied as a funclion of temperature f-110o lo 243°C) and silicorz conlenl (3.1 and 4.2 pct). It zoas found that the clislocntiotl densily and the size of the plctslic zone increased with increasing tempevalnre and decreasing silicon conlent. Furtheruvzove, there was a correlcrtion in the dislocalion patterns formed around cracks that propagated at different tempevattrt-es in cvyslals of diffevent silicon contents such that a 1 pcl itlcverise in silicon content was equivalent to a lemperaluore redziclion of approximately 120°C. The experimenlal YeSnllS were compaved with the results of an elastic-plastic wodel that relates the size of the pluslic .zone to the cvack length, internal pressure, and yield stress. it was found that the clzunges in the dislocctlion cryrays with lemperature and combosition can be e-kplaincd by the lemperatrnre and composilion dependence of the yield stress. An wmtsual feature of this study was the observation of low -temperature noncrystrrllogruphic cracks. PLASTIC relaxation can occur at the edge of a moving crack by the operation of pre-existing dislocation sources or by the creation of new sources in a region of perfect 1attice.l'2 The amount of relaxation in a given crystal depends on the crack velocity and the temperature, and can determine whether a crack propagates in a brittle or a ductile manner.1-3 Tetelman and Robertson4 observed microcracks m Fe-3 pct Si single crystals that formed on (100) planes by the precipitation of hydrogen gas during electrolytic charging at 23°C. The plastic deformation accompanying crack propagation was observed in the form of dislocation etch pits and an extensive analysis has been made of the size, shape, and crystallography of the dislocation arrays5-7 This paper describes the effect of temperature on the plastic deformation generated around hydrogen-induced cracks in Fe-3.1 pct Si and Fe-4.2 pct Si single crystals. The observations are compared with the results of an elastic-plastic model for yielding around a crack containing an internal pressure. 1) EXPERIMENTAL PROCEDURES The composition of the materials used in this study are given in Table I. Single crystals of alloy A and the 4.2 pct Si alloy were grown by the strain-anneal method; crystals of alloy B and the 5.1 pct Si alloy were cut from an ingot grown from the liquid. he ~ingle-cr~stal metallographic specimens had a Cross section of 0.100 by 0.050 in. with a length of at least 3/8 in. Specimens were annealed for 3 hr at

Jan 1, 1968

By H. S. Thomsen, W. C. Duesterhoeft, R. E. Hartline

The attenuation and phase shift which formations produce in the electromagnetic field of an induction-type electrical well-logging instrument are great enough to substantially affect the response of the tool to formation conductivity under normal logging conditions. The application of the general equations for the propagation of an electromagnetic field in a conductive medium to the transmitter-receiver coil pair of an induction-logging-tool coil system gives an expression for the response which properly takes the propagation effects into account. A comparison of a calculation of this type with the response computed from the commonly used geometric factor concept, which does not include the propagation effect, leads to a factor Go representing the ratio of the responses computed by the two methods. The value of Go decreases not only with increasing formation conductivity, but also with increasing transmitter-to-detector coil spacing. For a single coil pair with a 40-in. spacing, the value of Go is 0.972 in a 20-millimho/m formation. The value is reduced to 0.915 and 0.812 for conductivities of 200 and 1,000 millimhos/m. As a result, the basic signal generated by the induction-logging coil system is not linearly related to formation conductivity as expected from the geometric factor concept. A uniform conductivity scale can be obtained only by adding a suitable nonlinear element to the recording system. The addition of auxiliary coils, having spacings less than the main-coil span, to achieve focusing results in an even greater departure of the basic signal from linearity with conductivity. The solution of the field equations near the interface between two formations of different conductivity gives the curve shape on an induction logging tool in crossing the interface. The addition of auxiliary coils to achieve focusing can add anomalous character to the curve shape in crossing the interface, which might be mistaken for lithological detail. Preliminary calculations which include the propagation effects in the determination of the conductivity correction for thin beds lead to correction factors which are substantially smaller than those obtained from geometric factor considerations. It is apparent that thin-bed corrections derived from geometric factor calculations are of doubtful validity. INTRODUCTION Although the electromagnetic induction type of electrical well log has been used for a number of years and has gained general acceptance in quantitative well-log interpretation, no technically complete investigation of the mechanism and of its operation has been published. The studies which have been presented are based upon the premise that neither the shape nor the intensity of the induction field of the logging tool is in any way affected by the electrical characteristics of the formation. From the inception of induction logging it has been recognized that under some formation conditions the performance of the instrument could be expected to be substantially different from that predicted by the simplified analysis. This anomalous performance has been called "skin effect" since it is the result of the same phenomenon which causes high-frequency alternating currents to flow only near the surface of metallic conductors. In the range of conductivities encountered in the sediments, the formation actually does not exhibit the sharply defined conducting "skin" shown by metals. The gradual modification of the distribution of the currents in the formation, produced by the induction field of the logging tool, is the direct result of phenomena associated with the propagation of the electromagnetic field through the formation. Therefore, it can be much more appropriately described as the "propagation effect". One purpose of this paper is to review the results of a solution of the equations for the performance of a single transmitter-receiver coil pair induction-logging system which takes into account the propagation effect, showing the manner in which the tool performance established by this analysis differs from that derived from the less comprehensive analyses currently in use. PRINCIPLE OF OPERATION OF THE INDUCTION LOGGING INSTRUMENT The high-frequency alternating current which is maintained at a constant value in the transmitter coil

By Forbes Rickard

Gilpin County, the cradle of mining in Colorado and the Cornwall of North America, is too well known to need much introduction; get, for the benefit of those not familiar with the district, it may be well to premise that it comprises a tract of country of about 122 square miles, lying between the counties of Jefferson, Boulder and Clear Creek, and hounded on the west by the main range of the Colorado Rockies. It is located centrally in the State, 40 miles west from the city of Denver. During the 38 years since the first gold-discovery, Gilpin county has contributed about eighty million dollars in gold and silver to the world's supply of these metals. Many mining districts have had their rise and decline in half this time; but, very far from being exhausted, this mining district is still in the ascendant; its output is increasing (it was $3,600,000 for the year just closed), and it was never more prosperous nor productive than to-day. Taken generally, there does not exist anywhere in the world so great a number of permanent veins within so small an area as in this district. Gilpin is practically a " poor man's camp." Its veins, with few exceptions, outcrop at the surface. In the oarlier---days of the camp these outcrops were worked in many instances by sluice-mining; particularly is this the case with regard to the veins of the Russell gulch. Discoveries are still made in the heart of this district, and the productive area is every year extending its limits. The districts of Yankee Hill, Hawkeye and Pine Creek, which used to be isolated, are now part and portion of the one gold-field of Gilpin county. Within the last year sensationally rich gold-discoveries have

Jan 1, 1899

By Reno Sales

INTRODUCTION. THE geology of Butte possesses especial interest on account of the magnitude of the ore deposits, their extraordinary richness and persistence in depth. Since its discovery in the early 60's the district .has yielded, in round numbers, 6,000,000,000 lb. of copper, 260,000,000 oz. of silver, 1,250,000 oz. of gold, and a large but not definitely known number of pounds of zinc. This enormous metal production has been derived from an ore tonnage estimated roughly at 65,000,000 tons. At the present day, most of the important mine shafts have reached a depth of. 2,400 ft., while several are more than 3,000 ft., deep. At these-great depths rich bodies of copper ore are being exploited, showing no diminution in metal content as compared with the ores of the higher levels. The present (1913) daily rate of production is approximately 14,000 tons, of which 13,250 tons may be regarded as copper ore, although a small percentage of this is minable only because of the presence of

Jan 8, 1913

By Arthur Bell

(San Francisco Meeting, September, 1915) . PRIOR to 1908 the oil production in the State of California, had been almost entirely a heavy fuel, oil, with a high flash point, hut changed within a-short period to a large percentage of refining oil with a low flash, by reason of the coming in of the Santa Maria field, the Midway field, and the increased production of the Fullerton field. This is clearly shown in the following tabulation of California's production: Year Barrels . Below -20° Be, Above 20° Be,, Per Cent_ Per Cent. 1905 48,307,000 90 10 1910 77,698,000 SO 20 1912 90,075,000 6o 31 1914 10:3,600,000 47 53 The bringing in of these high percentage's of light oil with their dangerous low flash and the increasing demand for the refined products necessitated the devising of some cheap and efficient means of quickly separating the lighter elements either in the field or at the main distributing points; also it became necessary to remove the excessive percentage of water which many of the light oils carried in emulsion.

Jan 9, 1915

By W. H. Bassett, C. H. Davis

The late J. P. Sparrow, chief operating engineer of the New York Edison CO., carried out a series of practical tests on condenser tubes of several copper alloys and reported on the results to the Association of Edison Illuminating Companies at its meeting in September, 1913. In the preparation of these tubes the senior author had the pleasure of cooperating. Copper-zinc alloys in the proportions of 60-40,70-30,80-20, 90-10, and Admiralty metal, which is in effect 70-30 with 1 per cent. of tin, were tried. Monel metal and several copper-nickel alloys, and 8, 5, and 3 per cent. aluminum bronze were also tried. At the time of this report, the aluminum bronze had been in service for 4 1/2 years and seemed to be giving especially good results but later it began to fail and showed no substantial improvement over Admiralty metal. Monel metal was unsatisfactory and the nickel alloys apparently did not give better service than the Admiralty alloy. Previous to the publication of the report, and after considerable discussion, it was agreed that a test where tubes of different kinds could be under laboratory observation would be advisable, so the apparatus described here was set up in The American Brass Co.'s Waterbury Laboratory. This was fitted with tubes of copper, brass, bronze, nickel silver, cupro-nickel and other alloys, and the test started on Oct. 11, 1912. Salt water from East River, New York harbor, was barrelled and transported to the laboratory for the test. A fresh supply, completely replacing the water in service, was obtained at the end of each six months period. Plan of Procedure In general, the procedure was to inspect the tubes at short intervals and to remove those that had begun to leak. The tubes removed were carefully examined and a photographic and microscopic record of the

Jan 1, 1925

(There are 82 Local Sections in the United States, 10 Foreign) ADIRONDACK Established June 18, 1952 Official year begins in January Meets next to last Saturday monthly April through October Local Section Dues AIME Mbrs $2 Affiliate Mbrs $3 Severn P Brown, Chairman George E Erdman, Vice-Chairman Patrick F Farrell, Secretary-Treasurer Republic Steel Corp Mineville, N Y

Jan 1, 1960

By E. R. Gilbert

Klopp et al. have reported data on tensile and creep properties of are-melted and electron-beam-melted tungsten. We would like to point out some similarities between their creep results and ours on are-melted and powder-metallurgy tungstenand offer some alternate interpretations of the data which lead to different rate-controlling mechanisms. Klopp et al. observed extensive transient creep in the 2250" to 3500°F temperature range where the acthetivation energy is 106,400 ± 3300 cal mole-1. They suggest cross slip as the possible rate-controlling mechanism since "cross slip may occur only by the movement of screw dislocations, and not edge dislocations, thus allowing only partial recovery of the strain hardening and resulting in a continuously decreasing creep rate, characteristic of transient creep.'' Our tests on are-melted tungsten and powder-metallurgy tungsten displayed an extensive transient creep stage in the same temperature range but they also displayed a steady-state creep stage. The stress levels and strain rates of the two investigations, 1.4 to 7 kg mm-2 and 10-7 to 10-4 sec-1 for that of Klopp et al. and 4.5 to 10 kg mm-2 and 10-8 to 10-4 sec-1 for those of Gilbert et al., are overlapping. The activation energy for creep of our powder-metallurgy tungsten is 105,000 cal mole-1. This close agreement with the value found by Klopp et al. suggests that the same mechanism may be common to both types of materials. It may be possible to gain some additional insight into the rate-controlling mechanism by applying the analysis made by conrad22 in terms of the activation volume. The value for the activation volume depends upon the dislocation mechanism and may be used to help differentiate between various dislocation mechanisms. The activation volume for cross slip is 10 to 100 b3. Values determined from our data were 130 to 220 b3 which are in better agreement with the range of 102 to 104 b3 for nonconservative motion of jogs. Values determined from data of Klopp et al. are 240 to 1040 b3. We suggest that the rate-controlling mechanism for creep in this temperature range may be nonconservative motion of jogs assisted by enhanced diffusion along grain boundaries or dislocations. This model requires an activation energy lower than that for self-diffusion as is observed. If this is the controlling mechanism, a higher activation energy which is closer to that for self-diffusion might be expected for tests conducted on specimens with reduced grain boundary area, i.e., larger grain size. In support of this premise we have conducted tests on speci- mens having one to three grains per cross section for which a higher activation energy of 130,000 cal mole-1 was observed. Also, in agreement with results of Klopp et al., a faster creep rate resulted from the increased grain size and probable decreased dislocation density. Further argument against the cross slip mechanism is based on the constant activation energy we obsserved over the range of 5.0 to 10 kg mm-2,21 whereas the activation energy for cross slip displays a significant stress dependence.23 In addition to this, the powe on the stress term for the strain-rate dependence appears too high for cross slip. The values for tungsten fall in the range of 4.5 to 7 (Klopp et al. and Ref. 21) whereas values of approximately 2 are observed in creep by cross slip for hep metals.24 At temperatures from 3300° to 4000°F, Klopp et al. observed an activation energy of 141,000 ± 4000 cal mole-' which is less than that for self-diffusion, 153,000 cal mole-1, 25 and less than that reported for high-temperature creep of powder-metallurgy tungsten by Green:' 160,000 cal mole-1. Klopp et al. suggested that recovery of strain hardening by dislocation climb is the rate-controlling mechanism in this temperature region. Actually an activation energy larger than that for self-diffusion is predicted by this model if the temperature dependence of the elastic modulus27 is taken into consideration. Klopp et al. attributed this lack of correlation to the compositional differences between powder-metallurgy tungsten used by Green and their own arc- and EB-melted tungsten. It is our position that the value of 141,000 ± 4000 cal mole-' represents a transitional value between the higher and lower activation energies and does not represent a discrete mechanism of deformation. If the tests had been extended to higher temperatures the higher value of activation energy would have been observed as has been demonstrated by both our analy sis'' of isothermal test data by GE-NMPO28 and differential temperature tests28 on are-melted tungsten. The activation energies determined (170,000 and 160,000 cal mole-1) were greater than that for self-diffusion and are in better agreement with the value found by Green. The model of dislocation climb is associated with ; activation volume of 1 b3 according to Conrad.22 The activation volume calculated for the creep data of fou independent investigators in the temperature range where the activation energy for creep is near that for self-diffusion (Klopp et al. and Refs. 26, 28, and 30) is 110 to 2800 b3 and is in the range suggested for nonconservative motion of jogs. In the case of tungsten this mechanism may be preferred over that of dislocation climb. Sincere appreciation is expressed to Messrs. J. E. Flinn and F. L. Yaggee for the helpful discussions and suggestions in the preparation of this communication.

Jan 1, 1967

By T. D. Yensen

It is safe to say that of all the different materials that go to make up electrical machinery, iron is the most important. Upon its magnetic and electrical quality depends not only the efficiency of the machine but, to a very large extent, the cost. Aside from the mechanical strength, there are three characteristics of iron that are of importance in this connection, viz., magnetic hysteresis, electrical resistance, and magnetic permeability. In the homopolar machine, where the magnetic flux is unidirectional, permeability is the only important factor, but in all other machines the flux is reversed in one or more parts and causes losses due to hysteresis and eddy currents. The eddy-current loss depends largely upon the electrical resistance of the iron; the higher the resistance the lower the loss, under otherwise identical conditions. These hysteresis and eddy-current losses cause heating of the machine, and as they depend upon the magnetic density in the iron, this density must be regulated so that the heating shall not be excessive. If the hysteresis and eddy-current losses and the permeability of the magnetic circuit will permit an increase in the magnetic density, or, in other words, a decrease in the amount of iron, this in turn will mean a decrease in the amount of copper needed, with a consequent decrease in the copper loss. It is thus seen that, indirectly as well as directly, the above characteristics have an important bearing on both the efficiency and the cost of electrical machinery. In general, it may be said that iron for electrical machinery should have the following characteristics: (1) low hysteresis loss, (2) high electrical resistance, and (3) high permeability. These are the characteristics that investigators have been striving to attain since electrical machinery first came into use. Until the beginning of the present century, Swedish charcoal iron was regarded as the best grade of iron for magnetic purposes, and even now it ranks high among the various grades used. About that time Sir Robert Hadfield1 produced a number of iron alloys that revolution-

Jan 1, 1916