Search Documents

By Paul D. Merica, O. B. J. Fraser

PROBABLY the first metallic objects used by man were nickel alloys. In search for flints suitable for the fashioning of their rude tools, our paleolithic ancestors, some 25,000 years ago, quite likely may have come upon some of those heavy, metallic fragments that we now know as meteorites, which consist of an alloy of nickel and iron containing usually from 5 to 15 pct of nickel. Whether paleolithic man ever did discover and use meteoritic fragments, his sketchy records do not actually disclose. We do know, however, that such fragments have been found and used by peoples, particularly the North American Eskimos, for weapons and implements in just the same manner as stones, and prior to any knowledge by those peoples of the reduction of metals from ores. Meteoritic showers were recorded frequently in earliest times and the meteorites often were found and fashioned into useful objects. The ancient Arabic and other myths of "invincible swords fallen from heaven" seem thus to have had a very definite basis in fact, and such weapons, of meteoritic material, have actually been re- covered from archeological excavations. It thus seems probable that meteoric nickel-iron was found and used long before iron was recovered by smelting iron ores (perhaps about 1200 B.C.) and probably even before there was knowledge and use of bronze and gold. Although many centuries were to pass before nickel was first isolated, in 1751, from Swedish ores and recognized as an elemental

Jan 1, 1953

By Donald H. McLaughlin, John H. Moses

IN the latitude of Lima, the broad uplifted block that forms the Andes is made up of a complex sequence of folded and faulted sediments and volcanics, broken by large and small bodies of granitic rocks and porphyries with which the principal mineral deposits are closely associated in both time and space. The intrusives are a final episode in the geologic history as revealed by the consolidated rocks, for after their emplacement and after the formation of the primary ore deposits in and about them the record is simply one of long continued erosion and uplift.

Jan 1, 1945

By H. R. Wheeler

CREATION of a "committee on promotion of student interest in coal mining" has an encouraging implication for the coal industry. It is indicative that mining men, both in the field and in the educational centers, realize that the problems of the industry require the best talent available. Young men are being invited into coal on the premise that it needs them, that it offers opportunity for creative work and the realization of their objectives. In initiating a movement which purports to meet the objectives of any young man who spends four or five years of his life in college, the industry does so with a full realization of its obligations.

Jan 1, 1940

NEW MEMBERS The following list comprises the names of those-persons who became members during the month of January, 1914. Members ADIASSEWICH, ALEXANDER, Dept. of Commerce & Industry, 11, Nadejdinskaia, St. Petersburg, Russia. BEARD, JOHN W., Mine Supt., Lane-Rincon Mines, Inca, Temascaltepec, Mex., Mexico; BORCHERDT, WALTER 0., Supt The Bertha Mineral Co., Austinville, Va BREWSTER, BURT B., Sales Engr., Sullivan Machinery Co., 1127 Central National Bank Bldg., St. Louis, Mo: CHASE, ROGER E., JR., Assayer 3906 No. Baltimore St., Tacoma, Wash. CULBERT, J. VICTOR 7S4 Wellington St., London, Ont., Canada; DICKINSON, ALBERT W., Supt. Of Mines Bevier, MO. DODSON, T. M Mores, Colliery, Schuylkill Co., Pa FORREST, CHARLES N., Chem. Engr Maurer, N. J.

Jan 2, 1914

By J. R. Linney

THE Eastern Magnetite Industry produced approximately 7,850,000 long tons of crude ore in 1945 from which was obtained approximately 3,650,000 long tons of shipping product or a ratio of 2.10 to 1. Lack of skilled or experienced miners was the greatest handicap. Veterans returning to work improved the underground labor shortage in some localities but as a whole the labor shortage was keenly felt throughout the industry. One cannot now predict what may be accomplished in 1946 but barring major steel strikes a worthwhile improvement can be expected. At the Richard mine of the Richard Ore Co., the shipping product for the year amounted to approximately 124,650 long tons of concentrate and lump ore. Crude-ore production was 160,600 long tons. The average analysis for lump ore was 63 per cent iron and for concentrates 66.05 per cent. The Warren Foundry and Pipe Corp. at their Mt. Hope mine produced 73,000 long tons of lump ore averaging 59.5 per cent and 57,000 long tons of concentrate averaging 67 per cent. The total mine hoist was approximately 209,000 long tons. Operations were commenced through the new Leonard shaft on Jan. 18; the Brown shaft through which operations had been conducted since 1912 caved beyond repair on Sept. 26. No one was injured but pumping facilities were somewhat disrupted. In order to reach designed capacity a total of 400 men will be required with 300 underground. Due to shortage of labor all operations in 1945 were concentrated on the 1700 level. As fast as men can be hired and trained development of the 2100 and 2500 levels will commence. Mt. Hope has a consider-

Jan 1, 1946

By Ralph E. Esarey, George V. Cohee

In Indiana, 349 wells were drilled for oil and gas in the year 1942. Of this number, 125 oil wells and 21 gas wells were successfully completed and 203 were dry holes. Drilling activity declined 37 per cent as compared with that of the year 1941. This reduction was brought about largely by Federal Conservation Order M-68, restricting drilling to one well on 40 acres, in order to save steel. This Order was later supplemented to permit closer spacing of wells drilled to sandstone formations in southwestern Indiana. Most of the drilling in 1942 was in the southwestern part of the state. Posey County ranked first, with 94 completions and 44 producers; Gibson County, second, with 77 completions and 38 producing oil wells and 2 gas wells. There were 58 drilling operations in the state at the end of the year. During 1942 a total of 589,734 ft. of hole was drilled, of which 231,702 ft. was wildcat footage. The total initial production of the oil wells completed was 9974 bbl. and of the gas wells, 11,148,000 cu. ft. (Table 2). Of the 349 wells completed, 122 were wildcat wells (Table 3); 26 were completed as oil wells; 17 were extensions to proven fields and 9 discovered new pools. Posey County was foremost in wildcat drilling, with 37 wells completed (Table 6). Thirty-five per cent of the wells drilled in 1942 were wildcat, as compared with 25.5 per cent in 1941. It is anticipated that the percentage of wildcat wells drilled in 1943 will be greater, although the total number ol ,wells drilled in the state will probably be less. The new discoveries in Indiana in I942 were, for the most part, one-well pools in the southwestern part—in Posey, Gibson and Spencer Counties (Table 4). Most of the development in pools took place in the . Hazelton and Kirksville pools in Gibson County, Mr. Vernon pool in Posey County and the Vernon Heights pool in Vander-burgh County. Deeper production was obtained from the Osage limestone in the Hazelton pool at a depth of 2402 ft., 650 ft. below the productive McClosky limestone. The well had an initial production of 140 barrels. Extensions to 17 pools in the southwestern part of the state were successfully completed (Table 5). An interesting development during 1942 was new production from the Devonian limestone in the Dodds Bridge pool, Sullivan County. The Ohio Oil Co. deepened one of its wells, which had been producing from a shallow sand, to the,Devonian, and it was completed for an initial production of 77 bbl. Five other Devonian producing wells were completed in that area. Crude-oil production in Indiana in 1942 was 6,609,000 bbl. (Table I). The Griffin field, Gibson and Posey Counties, which produced approximately 3,550,000 bbl., accounted for more than half of the state's production. The Mt, Vernon and New Harmony fields were next in importance of production, with 684,000 and 523,000 bbl., respectively. The price of crude oil was $1.22 a barrel for the old

Jan 1, 1943

By George V. Cohee, Ralph E. Esarey

In Indiana, 349 wells were drilled for oil and gas in the year 1942. Of this number, 125 oil wells and 21 gas wells were successfully completed and 203 were dry holes. Drilling activity declined 37 per cent as compared with that of the year 1941. This reduction was brought about largely by Federal Conservation Order M-68, restricting drilling to one well on 40 acres, in order to save steel. This Order was later supplemented to permit closer spacing of wells drilled to sandstone formations in southwestern Indiana. Most of the drilling in 1942 was in the southwestern part of the state. Posey County ranked first, with 94 completions and 44 producers; Gibson County, second, with 77 completions and 38 producing oil wells and 2 gas wells. There were 58 drilling operations in the state at the end of the year. During 1942 a total of 589,734 ft. of hole was drilled, of which 231,702 ft. was wildcat footage. The total initial production of the oil wells completed was 9974 bbl. and of the gas wells, 11,148,000 cu. ft. (Table 2). Of the 349 wells completed, 122 were wildcat wells (Table 3); 26 were completed as oil wells; 17 were extensions to proven fields and 9 discovered new pools. Posey County was foremost in wildcat drilling, with 37 wells completed (Table 6). Thirty-five per cent of the wells drilled in 1942 were wildcat, as compared with 25.5 per cent in 1941. It is anticipated that the percentage of wildcat wells drilled in 1943 will be greater, although the total number ol ,wells drilled in the state will probably be less. The new discoveries in Indiana in I942 were, for the most part, one-well pools in the southwestern part—in Posey, Gibson and Spencer Counties (Table 4). Most of the development in pools took place in the . Hazelton and Kirksville pools in Gibson County, Mr. Vernon pool in Posey County and the Vernon Heights pool in Vander-burgh County. Deeper production was obtained from the Osage limestone in the Hazelton pool at a depth of 2402 ft., 650 ft. below the productive McClosky limestone. The well had an initial production of 140 barrels. Extensions to 17 pools in the southwestern part of the state were successfully completed (Table 5). An interesting development during 1942 was new production from the Devonian limestone in the Dodds Bridge pool, Sullivan County. The Ohio Oil Co. deepened one of its wells, which had been producing from a shallow sand, to the,Devonian, and it was completed for an initial production of 77 bbl. Five other Devonian producing wells were completed in that area. Crude-oil production in Indiana in 1942 was 6,609,000 bbl. (Table I). The Griffin field, Gibson and Posey Counties, which produced approximately 3,550,000 bbl., accounted for more than half of the state's production. The Mt, Vernon and New Harmony fields were next in importance of production, with 684,000 and 523,000 bbl., respectively. The price of crude oil was $1.22 a barrel for the old

Jan 1, 1943

By E. A. Breitenbach

A computer program has been developed to afford rapid and complete quantitative log analysis for exploration and production decisions. The computation consists of automatic selection of tops and bottoms of porous intervals from the digitized data, and then point-by-point calculations within each selected interval. Nearly all log types can be analyzed. This paper presents the calculation techniques found to be appticable to machine evaluation and gives examples of their use. INTRODUCTION As the quantitative interpretation of well logs entails repetitive use of charts and equations, it is natural that digital computer programs would be written. A Universal Log Interpretation Computer Program (ULICP) has been developed to afiord rapid and complete analysis for exploration and production decisions. Application of this program enables the log analyst to: (I) apply rapid quantitative log analysis for exploration and production decisions on either a field, a well or on a single zone basis; (2) apply concepts of interpretation requiring detailed numerical analysis; (3) analyze all porous intervals on each log, rather than a few selected zones, and complete the analysis in less time than previously required. Computations are reported for every digitized point in each zone; (4) use empirical techniques applicable to a given area as an integral part of the computation; (5) experiment with the empirical coefficients and exponents in the interpretation equations to find the best possible solution; and (6) automatically plot both the original and computed data to scales analogous to the field prints. The primary utility of a log interpretation program stems from its ability to do an overwhelming amount of work with very little man-power. If a calculation procedure or thought process can be formalized to the extent that step-by-step logic can be written, a computer program can be developed that follows this logic. The major question is one of economics. A feasibility study of the costs for such a program indicates that digital processing is economical primarily as a means of increasing the productivity of the log analyst. In effect, the probability of missing productive intervals in any well, because of a lack of time to do detailed calculations, is greatly reduced. The nucleus of ULICP is programmed to compute large sections of a suite of logs by selecting zones automatically and then performing all pertinent computations on a data point by data point basis within each zone.'.' An entire suite of logs can be processed in this manner with very little manual intervention. Sufficient programming logic is available so that each log analyst can request computations pertinent to his area. These requests are made by simple additions or deletions of information on the input header cards. Hence, the log analyst is always in complete control of the computation process. The evaluation of a suite of logs requires pre-editing, digitization, computation, presentation of results and interpretation. Work by the log analyst is reqilired only in pre-editing and interpretation. Thus, he is allowed more time for comprehensive interpretation, rather than calculation. For continuity, the discussion of ULICP is organized sequentially: pre-editing, digitization, computation and presentation of results. DISCUSSION PRE-EDITING The extent of pre-editing prior to computation is dependent on the format of the original data. For analog prints, it requires inspection, correlation and editing of the logs, plus the entering of required data an special forms. For digitized data such as magnetic tape field recordings, only the special forms are necessary. The process for analog prints will be given here. The inspection and correlation process involves the selection of sections for digitization and the correlation of the traces to a common depth. To decrease the cost of digitization, traces that exhibit large variations in shale formations can be redrawn to a non-zero baseline. The next step is to enter all pertinent data on the input header cards. The header cards presently used for ULICP are presented as Figs. 1 through 6. Cards 1, 2, 3 and 4 (Fig. 1) are defined as the Main Header Cards. They describe the particular well for output identification and give basic information. Cards 5 through 15 (Figs. 2 through 6) are defined as the Block Header Cards. As such, they define the log types and the interpretation parameters for the block of data immediately following. Cards 1 through 10 are required for every computer run. Cards 11 through 14 pertain only to nuclear logs. Card 11 is required if any nuclear log is supplied, and cards 12 through 14 are required only when gamma-ray, density or neutron log data, respectively, are supplied. Card 15 (Fig. 6) must be supplied when cross-plot calculations are required. Either two- or three-component

Jan 1, 1967

By Richard H. Bube

Photoelectronic radiation detectors may be conveniently classified as homogeneous intrinsic, homogeneom extrinsic, or junction type. Highly photosensitive homogeneous intrinsic photodetectors may be prepared from a number of different II-VI, III-V, or IV materials. Such materials require the presence of specific imperfections that can act as sensitizing centers to provide long majority carrier lifetime. Homogeneous extrinsic photodetectors are of interest primarity for infrared detection, and consist principully of germaniuim and silicon with suitable inpurities. A vaviety of junction photodetectors exist, with silicon us the most common material for them all. The following extrema in performance are found: 1) highest photoconductivity gain in homogeneous intrinsic photodetectors; 2) smallest response time (highest frequency response) in p-i-n junctions; 3) largest gain-bandwidth product in avalanche diodes. ALTHOUGH the total number of materials exhibiting photoconductivity effects is very large, only a relatively few of these have appropriate properties for a practical photoelectronic radiation detector. In fact if one surveys the commercial detectors currently available, one finds that the field is dominated by some ten or fewer materials. These are summarized in Table 1 in terms of the other important variable in detector fabrication, the structure of the material, i.e., whether the material is used as a single crystal or in polycrystalline form, and whether the material is used as a homogeneous detector or whether the detector depends upon the existence of a junction or barrier in the material. The principal wavelength range for each type of material is also shown, together with an indication of the utilization of intrinsic or extrinsic excitation. For the purposes of the present comparison of various detectors, it will be convenient to discuss two main topics: homogeneous photodetectors and junction photodetectors. The performance of a photoelectronic radiation detector is measured in terms of two parameters: the photoconductivity gain, and the response time of the detector. A convenient figure-of-merit is given by the ratio of gain to response time, often called the gain-bandwidth product. The photoconductivity gain is a device parameter since it varies in many cases with the applied voltage and the detector geometry, and should be distinguished from the actual photosensitivity of the material involved. This photosensitivity can be conveniently given as the product of free carrier lifetime and mobility in the material. The photoconductivity gain is defined as the number of charge carriers which pass between the electrodes per second for each photon absorbed per second, where G is the photoconductivity gain, is the pho-tocurrent in amperes, e is the electronic charge in coulombs, and F is the total number of electron-hole pairs created in the photo conductor per second by the absorption of light. The gain may also be expressed as the ratio of the lifetime of a free carrier to the transit time for that carrier, i.e., the time required for the carrier to move between the electrodes. For a material in which one-carrier conductivity dominates, where T is the lifetime of a free carrier, ttr is the transit time for this carrier, p is the carrier mobil-ity, V is the applied voltage, and L is the electrode spacing. From Eq. [2] it follows that the photoconductivity gain is proportional to the photosensitivity of the material (tP), the proportionality constant being The photosensitivity of a material, and hence the photoconductivity gain of a device utilizing the material, depends on the lifetime of the free carriers as a critical parameter. In a homogeneous material this lifetime is determined by the nature of imperfections in the material, and in an inhomogeneous material the lifetime is determined by the specific junction structure. The speed of response, the other basic photodetec-tor parameter, is determined by factors quite similar to those important for photoconductivity gain. Imperfections are of primary importance in homogeneous materials, and the structure of the junction is a determining factor in junction devices. For infrared detectors it has become common to define another quantity designed to indicate directly how effective the detector is in distinguishing between a small photoconductivity signal and random noise due to the detector and its environment. The detectivity D* is given by

Jan 1, 1968

By R. E. Tate, L. J. Herman

We have had occasion to produce wire of Np-237 in small diameters for use in some chemical experiments. Since the mechanical metallurgy of neptunium has not been investigated extensively, it seems desirable to report our successful extrusion technique. Because of the neptunium activity and its attendant health hazard the experimental work was done in glove boxes and related equipment also used for Pu-239. At room temperature a phase neptunium' is a hard (Dph -355) orthorhombic metal of high density (p = 20.45 g per cu cm). a neptunium transforms2 to tetragonal ß neptunium at about 280°C and this in turn transforms to bcc y neptunium at about 577°C. The y phase melts at about 637°C. A temperature of 340° to 345°C was selected for the extrusion, this temperature being a compromise be- tween a possible advantage of working with the presumably more plastic cubic y phase above 577°C and the risk of having the neptunium react with the alloy steel die to form the low-melting Fe-Np eutectic. A 0.75-in.-long, 0.26-in.-diameter ingot of good-purity* Np-237 was extruded by the direct *C = 230 ppm, Pu = 200 ppm, thirty-five metallic elements below limit of detection by spectrographic methods. process through flat-face orifices to form several sizes of wire ranging from 0.010 to 0.030 in. in diameter. Molybdenum disulfide was used as the die lubricant. The extrusion was done in a vacuum of about 10-4 torr to reduce reaction of the neptunium with atmospheric gases. British workers3 at Harwell have extruded neptunium under similar conditions. The force required to extrude 0.010-in.-diameter wire at the rate of 4 in. per min was 6000 lb, as measured with an electrical load cell. Wire 0.020 in. in diameter was extruded with a force of 4700 lb at a rate of 2 in. per min, and wire 0.030 in. in diameter was extruded with a force of 4000 lb at a rate of 1.3 in. per min. An extrusion constant, c, can be computed from the measured forces, P, for the equation4 P = c log-A/a where A/a is the extrusion ratio or the ratio of the cross-sectional areas of the container and the

Jan 1, 1965

By M. S. NORTH

IT may be a far cry from the days of the old horse whim, and it is relatively a long way back to hand production in factories. Modern machinery has made possible deep shaft-sinking, newer methods have increased the recovery of mineral. Technically, excavating and ore dressing have advanced as has mass production and its many ramifications in the manufacture of commercial product. To those of the mining industry who would have us believe that mining and manufacturing are totally different enterprises, it can be said that certain differences do exist. These differences rather than being fundamental are the result of adhering to past practices which were possibly sound years ago but do not measure up today. Differences in managerial control, sales, and distribution, cost finding, etc., are often so pronounced that efforts to compare or contrast are almost futile.

Jan 1, 1930

By James R. Finlay

SOMETIMES the American Institute of Mining and Metallurgical Engineers appears to be a strictly technical society, and if so my paper should deal with the technical operations of finding and producing gold. But I have not been engaged in practical gold mining since 1910. What I have been doing mainly for the last 25 years is to try to figure out what the income of a mine-gold, or any other-would be worth to an investor. So I have been in contact with gold mining, in one way or another, for some 42 years. I say that with a purpose. In that time the industry has been through one of its cycles. The value of gold mines is very dif¬ferent at different points in one of these cycles. For this reason the cycle of gold mining is a highly practical study. The cycle of gold is a more or less rhythmical change in its value or purchasing power measured in the grand average of other commodities, which is the same thing as its price. Taking the price of gold in 1897 as a stand¬ard, a dollar at that time declined to 55c. in 1913, to 26.8c. in 1920, and since then it has risen to 47.4c. in 1930 and to about 64c. in 1932. It is worth about 21/ times as much now as it was in 1920, but less than two¬thirds as much as in 1897. When this change is applied to the value of a gold mine still greater differences are evident. The cost of producing gold is of course measured in labor and other commodities, and as that cost goes down the margin of profit measured in the gold itself increases. Thus a mine which might make only 10 per cent profit in 1920 on its gross output may easily make 25 per cent now. The stockholder gets 2 ½ times more gold that is worth 2 1/2 times as much in purchasing power, therefore the real value of his holding has risen by the one factor multiplied by the other, giving him 61/4 times as much goods or services as he had in 1920.

Jan 1, 1933

By R. W. Smith, K. H. Lee

Bond type simulated closed-circuit grindability tests and batch grindability tests were run on six pure minerals plus a limestone and a taconite ore. The simulated closed-circuit tests were made at five different meshes of grind. The minerals tested varied widely in hardness and breakage pattern. For all simulated closed-circuit tests both Bond and Holmes work indices were calculated and compared. The Bond grindability testlm6 has been widely and quite successfully used for predictions of such items as ball mill power requirements and as an aid in plant comminution equipment selection. The test is interesting in that although run as a series of batch tests it is over-all a simulated closed-circuit test with a circulating load of 250%. The simulated closed-circuit feature is probably the primary reason for the notable success of the test. Perhaps the major criticism that can be brought against the test is that it is time consuming, since it normally takes a trained technician about an eight-hour shift to perform it.4 For many purposes this is an acceptable time requirement. However, if a grindability test is to be used for mill control purposes it should be performed in as short a time interval as possible, preferably under an hour. Sometimes in industry strictly batch tumbling mill tests are run and an attempt is made to correlate such batch tests with plant mill operation. Then an attempt is made to adjust operating tumbling mills based on data from the tests. The tests, however, frequently do not correlate well with operating data. The purpose of the present work was to explore some of the similarities and differences between a simulated closed-circui.t grindability test and a batch type test. Six different minerals plus a limestone and a taconite ore were tested in the experimentation. These materials varied widely in hardness, breakage characteristics, etc. Standard dry Bond grindability tests were mn on all materials at 48, 65, 100, 150 and 200 meshes of grind. Feed material was prepared by stage cmshing to -6 mesh. Initial feed volume was 700 cc. Care was taken to maintain the standard constant weight (about 20125 gm) and number of balls (283) during all the tests. Rotational speed was 70 rpm. Table I lists the materials studied along with pertinent data regarding the materials and Bond grindabilities obtained. In addition, dry batch tests were performed on all materials. These tests were made in the same mill as was used for the Bond tests. An identical ball charge and an identical feed volume were used. After rotating the mill for a predetermined number of revolutions at the same rotational speed as for the Bond test, the material was removed and separated from the ball charge. A screen analysis was performed on this product. Knowing the original size distribution of the feed and the size distribution of the product, it was possible to calculate the grindability or grams of a particular mesh produced per revolution of the mill. After the screen analysis of the product, the various fractions were recombined and placed back in the mill for further grinding. After grinding for additional revolutions of the mill the procedure was repeated. Thus, it was possible to obtain grindabilities for each material at a number of meshes of grind and for various revolutions of the mill. Grind-abilities obtained from batch tests are shown in Table 11. COMPARISON OF BOND AND BATCH GRINDABILITIES Figs. 1A through 1D show relationships between batch and Bond grindabilities. Figs. lA, lB, 1C and 1D show respectively graphs indicating the relationships for batch tests run for 100, 300, 500 and 700 revolutions of the mill. For a particular material on each graph, points are shown for 200, 150, 100, 65, and 48 meshes of grind except for several missing coarse meshes of grind for galena which did not fall conveniently on the figures. For each material and graph the point nearest the origin is for 200 mesh, the next for 150 mesh, the next for 100 mesh, etc. Considering Fig. lA, it is interesting to note that all relationships shown are essentially straight lines. There are, however, considerable differences

Jan 1, 1969

By L. R. MacLead

Delivery of tailing to any part of the area by gravity from the ridge was found practicable. Experiments with asbestos-cement pipe proved it possible to use level pipe across the dams if it is fed through an inclined section in which pressure could be developed. Use of pipe to transfer the tailing to the dams was not favored because of the possibility that choking might occur. Metal flume was not believed to have sufficient wear resistance on this material and wooden flume would not withstand damage by the weather so well- Flume -action made- of 26-in diameter asbestos-cement pipe, split before curing and molded to a specified cross section, were finally approved. The flume is connected to the 24-in. diameter tail in distribution pipe by heavy concrete lateral launders. Cascades of horizontal and vertical pipe sections are used at the top of the pressure leg where scouring by high-velocity flow of tailing might occur.

Jan 1, 1942

THE meeting was opened, Tuesday evening, May 25th, by an address from the President, R. W. Raymond. The following persons having been duly proposed for members and associates of the Institute, were recommended by the Council for election. They were unanimously elected MEMBERS. Florian Alexander, - Newark, N. J. Charles A. Ashburner, - Philadelphia, Pa. Phineas Barnes, - Pittsburgh, Pa. J. Y. Bergen, - Chicago, 111. Leopold C. Bierwirth, - Dover, N. J. Charles E. Billin, - Philadelphia, Pa. Jerome L. Boyer, - Temple, Berks County, Pa. William S. Cherry, - Streator, Ill. Thomas Couch, - Salt Lake City, Utah. W. S. De Camp, - Boonton, N. J. Thomas Donaldson, - Boise City, Idaho. H. Firmstone, - Longdale, Va. Franz Fohr, - New York City. Richard George, - Dover, N. J. John M. Hartman, - Philadelphia, Pa. C. W. Kempton, - Newburyport, Mass. James B. Lewis, - Dover, N. J. James F. Lewis, - Amenia, Dutchess County, N. Y. Arthur H. Meyer, - St. Louis, Mo. Edward H. Morrison, - Boonton, N. J. Charles J. Norwood, - Lexington, Ky. John R. Peters, - Dover, N. J. Charles I. Rader, - Vinton Furnace, Ohio. W. M. Rees, - Stockton, Luzerne County, Pa. George Richards, - Dover, N. J. Alexander H. Sherrerd, - Scranton, Pa. W. S. Sweeny, - Easton, Pa. W. J. Taylor, - Chester, N. J. Walter Tefft, - Mineville, Essex County, N. Y. J. Alexander Tyler, - New York City. J. D. Weeks, - Pittsburgh, Pa. William Wheatley, Jr., - New York City. Moses D. Wheeler, - Virginia, Nevada. Henry Woods, - Streator, III.

Jan 1, 1876

By G. F. Bolling

Single crystals of each metal were deformed at 77°K and heated at constant rates, variously in the range 0.125" to 4o°Kper min from 77" to -390oK, while being monitored in an X-ray diffractometer. Changes in diffraction-peak heights and line breadths were used to ascertain the temperature ranges of recrystalliza-tion. The results were subjected to the analysis of nicholas' in order to obtain the rate-controlling activation energies,Q. In this analysis no recourse to a separate and distinct nucleation stage is required and the results of studying recrystallization proved consistent with the hypothesis of a constant number of nuclei or equivalent hypotheses. The values Pb = 5.5 ± 0.5 keal per mole Zn ~ 7.5 Sn - 5 Bi - 9. 5 correspond for lead, zinc, and tin to activation energies obtained elsewhere for grain boundary migration, and for bismuth and lead to previous studies of re-crystallization by Barrett.6 This correlation allows the conclusions that interference from recovery was minimal and that the observed recrystallization rates in these pure metals are effectively governed by grain boundary migration. Good agreement was not found between the results of this kind of study in zone-refined aluminum and previous work; and supplementary isothermral experiments involving hardness tests and metallography did not resolve the discrepancy. Nevertheless, at least a range,Q = 11.5 ± 2 keal per mole, can be assigned to the activation energy for boundary migration in aluminum. An experimental study of one aspect of the recrystallization process is presented here for four metals of different crystal structure. The metals chosen for study were all zone-refined to reduce impurity effects, but the attendant high purity presented a difficulty. For any reasonably high driving force a "re-crystallization temperature", TR, is in the range of 0.25 T,, where T, is the absolute melting point, and study was therefore restricted to lower temperatures. An X-ray technique under constant heating-rate conditions adequate above 90°K was devised for the study; in consequence, a newer type of analysis following Nicholas1 had to be used to obtain quantitative information about activation energies. The standard methods of studying recrystallization have involved the comparable analyses of Johnson and Mehl2 and Avrami3 which are reviewed by Burke and Turnbull.* The general analysis4 which is applied only to isothermal studies using any of various investigative techniques states:

Jan 1, 1968

By A. C. Watts

FOR several years, a mine in Colorado experienced considerable trouble from small fires caused by the blasting of coal. Although a well-known make of permissible powder was used, it was first thought that the powder ignited gas that might be present and that this, in turn, set fire to line brattices or to the coal. Experiments were, therefore, conducted with another make of powder, but the results convinced the superintendent of the mine, Robt. Williams, Jr., that the fires were not caused by the powder but by the high-voltage electric current used for detonating the shots. The mine "makes" gas very freely, giving off from three-fourths to a million cubic feet of methane per 24 hours. The coal is a good grade bituminous of a very free burning quality. Electric shot-firing from the outside after all men and animals were outside had been practiced for a number of years. The shooting circuit was connected with the main power circuit at the mouth of each entry. Shooting circuit switches were mounted in boxes, which were kept locked with the handle of the switch, in open position, showing through the bottom of the box. The door of the box could not be shut and locked when the shooting switch was closed. At the entrance to each room, or working place, a small switch, called the miner's switch, was placed on the shooting line. It was the duty of the miner, when entering his place at the beginning of the shift, to see that this switch was open and that it was kept open until he left the place at the end of the shift to go out of the mine. Grounded return was used for main power lines. The current was 500 volts, direct current, with 100 to 300 amp. The nearest working face was 9600 ft. from the shot-firers' switch outside the mine and the most remote working face was 2 ½ miles. The various working faces were scattered over a wide area between these two points.

Jan 9, 1925

By Thomas Varley

IN THE congressional act establishing the Bureau of Mines one of the functions outlined was "to assist I the industry in the prevention of mineral waste." This had not only to do with the waste in mining but in milling and metallurgical practices, including smelting. The organization of the Bureau of 'Mines includes many divisions, each working in a particular field and charged with certain investigative work. The metallurgical division has the above duties under its immediate supervision, and the station located at Salt Lake City is directed by the chief of this division: There are ten experiment stations of the Bureau of Mines, located in various parts of the country, most of them being housed at state universities under cooperative agreements. Considerable care was exercised in locating the stations and in choosing the particular type of work to be investigated at each place. Inasmuch as the Bureau was designed to serve and cooperate with the industry it is only natural that the investigative work be of interest and importance to the territory immediately adjacent to the respective stations.

Jan 1, 1925

By Clyde E. Williams, JAMES L. GREGG

THIS review of the past year's progress in iron and steel metallurgy presents examples of only a few of the interesting or important accomplishments made in the United States. In the field of iron ore concentration increased attention was given to the study of the more difficultly separated wash ores and some progress was made in tabling. One difficulty with the table, in concentrating iron ore where the percentage of concentrate in the feed is large, has been the removal of fine silica from the thick layer .of concentrates in the cleaning zone. One company has -Made an important contribution toward the solution of this problem by an extension of the well-known plateau principle. By a special riffling of the plateau section of the table, the concentrates are crowded together. This action forces the fine silica to the top of the bed in the cleaning zone, whence the cross-flowing currents of water -can wash it into the middling product. Some work has been done on the application of froth flotation to the concentration of iron ores. Laboratory experiments were made at the Colorado School of Mines in which hematite was, successfully floated. Using oleic acid as a frothing and collecting agent and sodium carbonate as the conditioning agent, a high recovery of rich ,concentrate was obtained. A laboratory flotation unit is in use at Taconite, on the Mesabi range, and a commer-

Jan 1, 1932

By B. H. Sage

IN recent years there has been an increase of interest in the flow of gases at relatively high pressures. Hydrodynamic calculation of the energy losses in the flow of gases in conduits, as well as through the porous solid materials constituting natural petroleum reservoirs, requires a knowledge of the viscosity of the fluid at the pressure and temperature involved. Although there are numerous publications concerning the absolute viscosity? of hydrocarbon gases at atmospheric pressure, there appears to be little information available relating to the effect of pressure upon the viscosity of these gases. Vogel28 determined the viscosity of methane at 32° F. and atmospheric pressure. His measurements at 32° F. were later substantiated by the measurements of Rankine and Smith17 at 63° and 212° F. Ishida12 also reported values for the viscosity of methane at atmospheric pressure. Trautz and Kurz26 measured the viscosity of propane at atmospheric pressure, from 83° to 530° F., by the use of a short capillary tube. Rap-penecker18 determined the viscosity of gaseous isopentane at elevated temperatures. Day' made an accurate investigation of the effect of pressure upon the viscosity of n-pentane and isopentane at pressures from 2 lb. per sq. in. ? to the vapor pressure at 77° F. (approximately 9.8 and 13.3 lb. per sq. in., respectively). Earhart5 reported data upon the viscosity of several natural gases measured by the long capillary-tube method. The viscosity of air, at atmospheric pressure and 73.4° F., was measured by Harrington7 by the rotating-cylinder method. Kellstrom13 has recently made an elaborate investigation of the viscosity of air at atmospheric pressure. The latter work is perhaps the most accurate investigation of the viscosity of a gas that has been made. .

Jan 1, 1937