Search Documents

By John M. Kelly

New Mexico produced 31,913,816 bbl. of oil in 1942, the lowest annual production since 1936, and dropped one place to rank eighth among oil-producing states. This production decreased 7,838,052 bbl., or 19.71 per cent, from the 1941 figure is the result of transportation difficulties caused by the dislocation of tanker sailings to east coast ports. The average per-well allowable in New Mexico on Jan. I, 1942, was 43 bbl. and at the end of the year was 38 bbl. Allocations as set by the New Mexico Oil Conservation Commission followed the recommendations of the Petroleum Administrator for War. After setting the daily outlet, however, the average daily pipe-line runs were 87,545 bbl.—11.06 per cent short of these allocations. Production for Lea County was 26,812,949 bbl., Eddy County 4,624,578 bbl., northwestern New Mexico 473,609 bbl., Chaves County 2,680 barrels. Drilling activity for New Mexico in 1942 was approximately 84 per cent of that in 1941 with 339 completions. Of these completions 254 were oil wells, II gas wells, and 74 dry holes. Proven fields accounted for 55 of the dry holes and 19 were wildcats. Three new oil fields and one new gas field were discovered as the result of wildcat drilling. Extensions were made to one oil field and one gas field. By the close of the year, the New Mexico Oil Conservation Commission had designated 59 areas as proven for oil and/or gas. Southeastern New Mexico Lea County Monument was again the largest producing field in the state, with 5,729,336 bbl.; Eunice was next, with 5,217,965; Vacuum produced 3,295,624 and Hobbs 2,973,488. The Hobbs field has the largest accumulated production, which at the close of 1942 totaled 100,381,417 bbl. The 100-million-barrel mark for Hobbs focused attention on the fact that this is the first field in the state to attain this figure, and also that, as Hobbs has been under continuous proration since July 1930, or approximately the entire life of the field, this 100-million-barrel recovery was obtained with 86 per cent of the wells in the pool still flowing and having a drop in bottom-hole pressure of only 3.5 Ib. per million barrels recovered. Hobbs stands out as perhaps the best regulated major oil field in the world. Two new oil fields were discovered in Lca County, the most inlportant being the area designated as East Lusk, consisting of the south 4 tiers of Sections in T. 19 S., R. 32 E. The discovery well was drilled in the SW. SW. 1/4 of sec. 21, T. 19 S., R. 32 E., by Culbertson and Irwin, Inc., and others. It was completed at a total depth of 2751 ft. in the Seven Rivers formation of Permian age. The initial potential of the well was 237 bbl. per day on pump. The oil produced has a gravity of 24.10 A.P.I., with sulphur content of 0.9 per cent. This oil has an asphaltic base and because

Jan 1, 1943

By John M. Kelly

New Mexico produced 31,913,816 bbl. of oil in 1942, the lowest annual production since 1936, and dropped one place to rank eighth among oil-producing states. This production decreased 7,838,052 bbl., or 19.71 per cent, from the 1941 figure is the result of transportation difficulties caused by the dislocation of tanker sailings to east coast ports. The average per-well allowable in New Mexico on Jan. I, 1942, was 43 bbl. and at the end of the year was 38 bbl. Allocations as set by the New Mexico Oil Conservation Commission followed the recommendations of the Petroleum Administrator for War. After setting the daily outlet, however, the average daily pipe-line runs were 87,545 bbl.—11.06 per cent short of these allocations. Production for Lea County was 26,812,949 bbl., Eddy County 4,624,578 bbl., northwestern New Mexico 473,609 bbl., Chaves County 2,680 barrels. Drilling activity for New Mexico in 1942 was approximately 84 per cent of that in 1941 with 339 completions. Of these completions 254 were oil wells, II gas wells, and 74 dry holes. Proven fields accounted for 55 of the dry holes and 19 were wildcats. Three new oil fields and one new gas field were discovered as the result of wildcat drilling. Extensions were made to one oil field and one gas field. By the close of the year, the New Mexico Oil Conservation Commission had designated 59 areas as proven for oil and/or gas. Southeastern New Mexico Lea County Monument was again the largest producing field in the state, with 5,729,336 bbl.; Eunice was next, with 5,217,965; Vacuum produced 3,295,624 and Hobbs 2,973,488. The Hobbs field has the largest accumulated production, which at the close of 1942 totaled 100,381,417 bbl. The 100-million-barrel mark for Hobbs focused attention on the fact that this is the first field in the state to attain this figure, and also that, as Hobbs has been under continuous proration since July 1930, or approximately the entire life of the field, this 100-million-barrel recovery was obtained with 86 per cent of the wells in the pool still flowing and having a drop in bottom-hole pressure of only 3.5 Ib. per million barrels recovered. Hobbs stands out as perhaps the best regulated major oil field in the world. Two new oil fields were discovered in Lca County, the most inlportant being the area designated as East Lusk, consisting of the south 4 tiers of Sections in T. 19 S., R. 32 E. The discovery well was drilled in the SW. SW. 1/4 of sec. 21, T. 19 S., R. 32 E., by Culbertson and Irwin, Inc., and others. It was completed at a total depth of 2751 ft. in the Seven Rivers formation of Permian age. The initial potential of the well was 237 bbl. per day on pump. The oil produced has a gravity of 24.10 A.P.I., with sulphur content of 0.9 per cent. This oil has an asphaltic base and because

Jan 1, 1943

By B. E. Sundquist

The various methods based on solution models for obtaining free energies of mixing from miscibility-gap data have been applied to a number of binary-alloy systems. For nine of these systems there exist experimental thermodynamic data that permit a comparison of the results to experiment. It was found that the method of van der Toorn and Tiedema almost invariably leads to results that are physically unacceptable and that vary drastically with small changes in the miscibility-gap parameters. The subregular solution model is found in all cases, except the Al-Zn, Fe-Cr, and Cu-Pb systems, to exaggerate the free energy of mixing by 30 pct or more. The model developed by Lumsden is found to give results that are often in excellent agreement with experiment and which exaggerate the free energy of mixing by no more than 30 pct. These results and others give evidence that the Lumsden treatment of the effect of unequal atomic sizes and of imperfect configurational randomness due to deviations of AB bond energies from the mean of AA and BB bond energies is adequate for most systems. ANALYTIC expressions are frequently proposed for the dependence on composition of the activities of the components of a solution. Because the development of solution theory is incomplete, these expressions contain parameters which must be determined by experiment. The measurement of activities is often difficult and consequently such measurements are less readily available than are measurements of phase equilibria which, under certain conditions, can also be used to evaluate these parameters. For example, suppose it is known that two structurally dissimilar phases, each of known composition, in an n-com-ponent system are at equilibrium at a given temperature and pressure. n equations can be set up in terms of these parameters expressing the equality of the chemical potential of each component in the two phases. In addition, one can write the Gibbs-Duhem equation for each phase that also contains these parameters. Thus, if these n + 2 equations contain n + 2 parameters, these parameters can be determined (at the temperature in question) from the phase diagram alone. If the average number of parameters in each expression for the activity of a given component in a given phase is V then there will be 2nV parameters involved. Equating 2nV to n + 2 shows that, for n + 2, V = 1. If the temperature dependence of each parameter were to be expressed in some explicit form one could use equilibrium conditions at a number of temperatures to increase V. The situation is much improved when the two phases in equilibrium are structurally similar. It can then be assumed that, stably or metastably, two phases will become one at higher temperatures. Thus the number of parameters involved becomes nV instead of 2nV. Hence, V = 2 for n = 2 using only one temperature. (It is implied here that the activity expressions used are valid over the entire composition range.) In this investigation only the equilibrium of two structurally similar, two-component phases (miscibility-gap systems) will be considered. The various proposed solution models will be applied to a number of these systems and the results compared with available experimental results. All of the analytic expressions that have been proposed for the free energy of mixing of a two-component system are of the form where ?Gmix is the free energy of mixing per mole of solution, N1 and N2 are the mole fractions of components 1 and 2, respectively, and f(Ni, T) is some function of composition and temperature. In the "ideal" solution model f = 0. In the "regular" solution model f = a constant. Since these two models permit only a symmetric equilibrium diagram they will not be considered further here. The simplest model that permits a nonsymmetric miscibility envelope is the so-called "subregular" solution model proposed by Hardy.1 This model gives where the Ci(T) are functions of temperature only. The same expression for f is obtained from the "linear a function" model proposed by Darken and Gurry2 and applied to miscibility-gap systems by Wriedt.3 This model requires that the a function defined by be a linear function of composition (yi is the activity coefficient of component i). This model is not purely hypothetical for it has been found2 to hold true for a number of systems. It is readily shown3 that the f(Nl, T) obtained from this model is of the form given in Eq. [2]. It will be noted that the subregular solution model contains only two parameters and hence both of them can be determined at any desired temperature below the critical temperature, Tc, for a miscibility-gap systems in the manner described previously. At T, the two constants can be determined by equating the second and third derivatives of ?Cmix with composition to zero. Another two-parameter model was proposed by Lumsden4 who set

Jan 1, 1967

By Robert F. Mehl

THE mechanical behavior of metals and alloys is presumably conditioned by two factors; namely, the crystalline symmetry and the interatomic forces. Considerable attention has been given to the first of these factors through the recent advances in X-ray technique. It is the purpose of the present paper to call attention to the importance of the second of these factors, to point out promising methods of investigation, and to present some pertinent data. Plastic deformation takes place by slip along atomic planes.1 This slip may be inhibited in a number of ways: by the interatomic forces of cohesion which bind the atoms rigidly in a lattice structure, which in pure metals is usually of high symmetry; by lattice distortion caused by solid solution formation or by mechanical strain; by the intercrystalline boundaries where slip is restrained, probably by the non-registration of the atom planes in adjacent crystallites;2 and by the presence of small hard particles which serve to "key" the slip along the atom planes.3 In pure metals, and perhaps also in solid solutions, the atom planes of easiest slip are those exhibiting the greatest density of atomic population and the greatest interplanar distance4 and apparently can now be predicted from the analysis of the lattices. Concerning the interatomic forces, which resist this slip by holding the atoms firmly together, little is known. Most textbooks on physical metallurgy, following the work of Bottone,5 correlate the hardness of the pure metals with the atomic volume,

Jan 1, 1928

By H. C. Fowler, G. B. Shea

MODERN industry's incessant demands for increased operating efficiency and lower costs require that hazards attending all occupations be reduced to a minimum. Reduction of the inevitable losses that result from accidents and injury to the worker is one of the important economic problems confronting industry today and is the basis for the widespread safety movement. Dr. Charles E. Munroe, chief explosive chemist of the U. S. Bureau of Mines, is father of the statement, "The existence of a nuisance is evidence of an economic waste." This pointed expression of the internationally recognized scholar and explosives engineer has a direct relation to the prevention of accidents. Every injury and death in industry is a waste in human endeavor and a lessening of productive gain. Dr. Munroe has aptly paraphrased his previous summation with reference to wastes as follows: "A lost-time accident is evidence of an economic waste." That the economic waste entailed by occupational accidents is chargeable to industry is well substantiated by the fact that all but four states (Mississippi, South Carolina, Florida and Arkansas) now have workingmen's liability and compensation laws.

Jan 1, 1933

PROF RICHARD ÅKERMAN Stockholm, Sweden ANDREW CARNEGIR New York, N.Y. DR. JAMES DOUGLAS New York, N.Y. PROF HATON DE LA GOUPILLIERE Paris, France R.A. HADFIELD Sheffield England PROF HANS HOEFER Leoben, Austria PROF HENRI LOUIS LE CHATELIER Paris France M FLORIS OSMOND Paris, France JOHN E. STEAD Middlesborugh, England PROF DIMITRY CONSTANTIN TSCHERNOFF St Petersburg, Russia CHARLES D WALCOT Washingtion D.C. PROF DR HERMANN WEDDING Berlin, Germany

Jan 1, 1910

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during the period Oct. to Nov. 10, 1915: Lester S. Thompson, New York, N. Y. Arthur L. Sweetser, Boston, Mass. William Reed, El Oro, Mexico. Dorsey A. Lyon, Salt Lake City, Utah Heinrich Ries, Ithaca, N. Y. D. W. Blaylock has resigned his position with the St. Joseph Lead Co., Bonne Terre, Mo., and has accepted the position of division engineer for the Big Creek Coal Co., of Chicago, at Harrisburg, Ill. R. B. Lamb announces the removal of his office to Room 1809, 43 Exchange Place, New York, N. Y. C. C. Sanders has taken a bond and lease on the Red Mountain group of 34 mining claims (copper), Patagonia, Ariz., and has commenced extensive development.

Jan 12, 1915

By John McDonald

THIS report is a continuation of an earlier one with a similar title,1 to which the reader is referred for such details of procedure as do not appear here. A brief summary will be given of the objects and methods of the research at this time. It was pointed out in the previous paper that properties of magnesium alloys, as re-ported by different workers, often differ. This was thought to be due to differences in the preparation of the specimens tested. The ideal way to compare alloys would be to prepare each of them in so many ways that reasonable assurance would exist that the best properties of each alloy had been developed. The alloys would then be com-pared on the basis of these properties. The treatment actually given the alloys of these studies is necessarily a compromise with completeness. Nevertheless, enough treatments have been given so that a con-siderable degree of assurance exists that the properties obtained are representative of the alloy as such, and not merely of the manner in which it was worked and heat-treated.

Jan 1, 1940

By J. J. Rutledge

I. DESCRIPTION OF THE CLINTON ORES AND ASSOCIATED POCKS. THE Clinton rocks in Stone Valley comprise (1) thick layers of deep-red shale, (2) layers of reddish-gray shale interspersed with beds of sandstone and thin beds of extremely fossiliferous limestone, and (3) yellowish-gray shales alternating with thin layers of olive-colored shales. These layers of shale are all very thin and are at no point massive.1 A bed of gray-white sandstone varying in thickness from 12 to 30 ft. occurs in the tipper portions of the Clinton shales. This is called the ore sandstone, a name given to it by Rogers and adopted also by the Second Pennsylvania Geological Survey. It is the surest guide to the presence of the iron-ore bed, which lies below its lower edges at distances varying from 10 to 20 ft. This ore sandstone, in the valley, lies generally at very low inclinations, but often is locally subjected to considerable changes in dip. At its outcrop this ore sandstone weathers very easily and yields a rather sparse crop of stone, Composed of dirty, iron-stained boulders. Upon the roads these boulders are quite well rounded, and bear fragments of crinoid stems and other fossil forms. The ore sandstone exhibits at many points evidences of former movements in this very great thickness of the shales, and as it is the only stratum in this series competent to transmit and record stresses due to structural movements, its evidence is of considerable importance in determining the occurrence of movements in times past.

Nov 1, 1908

(Members, are urged -to send in for this column any notes of interest concerning themselves or their fellow-members,). Members and guests R: ho called at Institute headquarters during the period Dec: 10, 1916 to Jan. 10, 1917: F. L. Antisell, Perth Amboy, N. J. William Kelly, Vulcan, Mich. F. J Brulé, Toronto, Ont., Canada. W. H. Lanagan, San Francisco, Cal. Zar T. Crittenden, The. Pas, Mau, Canada. S. Lefevre, Forest Glen, N Y Thomas F. Donnelly, Tucson, Ariz. ' D. A. Lyle, St..David's, Pa. - John Davenport, Brighton, 14 lass. -Domingo Nugués, Buenos Aires, Argon-. E. E. Ellis, Birmingham, Ala. tine. N. H. Emmons, 3d, Copperhill, Tenn. - H. L. Scaife, Clinton, S. C. W.. E. Erdofy, New York, N. Y. Mortimer A. Sears, Washington, D. C. C. L. French, New York, N. Y. E. Spurny, New York, N. Y.' , M. H. Gannon, Butte,. Mont. R. K. Stockwell, Santiago, Chile. R. E. Hoffman, Hannibal, Mo. Benjamin F. Tibby, Salt Lake City, Utah. C. Vey Holman, Rockland, Me. Arthur P. Watt, St. Francois, Mo. Arthur P. Allen has left the employ of the Calumet &- Hecla Mine and is now with the Highland Min. Co., Ashcroft, B. C., Canada. H: C. Bellinger has been appointed. general manager of the Chuqui- - c mata mine-of the Chile Exploration Co. -

Jan 2, 1917

By N. E. Rogen, N. J. Grant

AGE-hardening in nickel-chromium-titanium-aluminum alloys in the composition range characterized by the Nimonic alloys, is dependent upon the precipitation of the Ni3(AI,Ti) (y') phase.1 This phase is found to precipitate at about 700°C.1 Ni,Al is a face-centered-cubic ordered structure with a lattice parameter of 3.560 A. The atomic configuration is such that the aluminum atoms occupy the cube corners and nickel occupies the cube faces with titanium substituting for the aluminum preferentially. A maximum of three out of every five aluminum atoms can be replaced by titanium atoms in the -y 'phase.' When the solubility of the y'-phase is exceeded for titanium the T(Ni,Ti) phase is formed. The T-phase is an ordered close-packed hexagonal intermetallic structure which shows little solubility for the other elements in these alloys. The lattice parameter for T-phase is a - 2.5454 kr and c = 8.2900 kx units."

Jan 1, 1959

By D. W. Fuerstenau, D. A. Sullevan

In the experimental work for this comparison of wet and dry grinding, it was found that the size distributions for wet grinding operations are characterized by a constant value of the distribution modulus, (a; whereas, for dry grinding the distribution modulus decreases slightly with increased size reduction. Wet grindability seems independent of the weight of material in the mill while dry grindability depends on weight. Experimental data and eqmtions for each process are presented for noncleavable isotropic material, for cleavable or material in which there is some form of internal stress, and for energy consumption. The equation ED/EW=BK-? (where ED and Ew are, respectively, energy for wet and dry grinding, k is the size modulus, and B and ? are constants) was found to give the ratio of energy. Dry grinding is generally considered to require more energy than wet grinding. Taggart' states that power consumption in wet grinding ranges from 60 to 90 pct of that required for dry grinding. Bond' states that dry grinding requires one third more power than wet grinding. It is interesting that Rose and Sullivan' note this same difference in power required for wet and dry grinding, but they state that on purely mechanical grounds it is difficult to see any great difference in fundamental principles between wet and dry milling, since dry milling may be regarded as wet milling with a fluid of low viscosity (i.e., air vs water). Yet it must be the viscosity of the fluid that is responsible for the differences between wet and dry grinding. Probably the most comprehensive investigation comparing wet and dry grinding has been that made by Coghill and Devaney. They compared the grind-ability of both chert and dolomite in a 19x36-in. batch ball mill under both wet and dry conditions. In these tests the weight of ore in the mill was varied from 35 to 200 lb and each grinding test was carried out for such period of time that the amount of -200-mesh material in the product was essentially the same for each test with a given material. Cog-hill and DeVaney's data for the grindability of dolomite, which are reproduced in Fig. 1, show that a comparison between wet and dry grinding is com- plex. The comminution of a material by a wet grinding method is characterized by a constant grindability over a wide range of mill loadings. Since grindability is the weight of material comminuted per unit of energy expended, it is equivalent to (w)/ (p)(t), where W is the weight of material being ground, P is the power, and t is the grinding time. In the case of wet grinding, the grindability of dolomite in the Coghill and DeVaney experiments was 0.546 * 0.009 ton per hp-hr when the load of dolomite in the mill ranged from 50 to 200 lb. On the other hand, for dry grinding no such simple relationship was found to exist between power, time, and weight of material in the mill. Dry grinding efficiency appears to depend greatly upon the amount of material within the mill. When the mill contained

Jan 1, 1961

By Eugene McAuliffe

The mining press, as well as certain federal and state bulletins, refer from time to time to the relative hazards that attach to loading bituminous coal by hand when compared with the so-called "mechanical loading" process. Much of the coal coming under the head of hand-loaded coal is won in part by the use of machinery; the coal-cutting machine is in general use, the electric power drill employed to a lesser extent. Therefore it may be said that the principal difference in the process employed, mechanical loading versus hand loading, lies in the fact that some type of loading machine is employed in the mechanical loading process to lift the coal from the face of the room, place or entry, after it is mined, placing it in the pit cars for transport to the tipple. It is a common practice to compute accident records on the basis of tons mined per fatal and per nonfatal accident, disregarding the fact that it is possible to produce by the aid of coal-loading machines the same daily, monthly and annual tonnage with a much smaller force than is required where the coal is all shoveled by hand. Inasmuch as the men who are released by the substitution of machinery for hand labor must find employment elsewhere, suffering some measure of hazard in their new occupation, we are of the opinion that the true relative hazard that attaches to the processes of mechanical loading and hand loading can be determined only by using as the basis of comparison "man shifts worked" or "hours of exposure" experienced per accident. The Union Pacific Coal-Co., beginning with the year 1929, undertook to maintain a true record of man shifts worked per compensable accident, giving equal weight to fatal and nonfatal accidents. Accidents lacking sufficient severity to come under the compensable terms of the Workmen's Compensation Act were not included in the compilation, the Act providing that "no compensation, except the expense of medical attention, shall be allowed for the first seven (7) days of disability, unless the incapacity runs beyond the period of twenty-one (21) days, in which case the compensation shall run from the time of the injury." With the further thought that all accidents suffered by employees engaged in any service, in or about the place where the loading process

Jan 1, 1931

By Milnor Roberts

CORNWALL, a Mecca for metal miners the world over, is easily reached from the southern coast of England. Passengers who land at Plymouth or Southampton can connect with a fast train from London called the "Riviera express," which traverses the beautiful counties bordering the English Channel. In Cornwall the traveler soon notices the pits and stock-piles of white china clay, and the metal mines, both placer and hard rock. The deposits are associated with granite batholiths, of which there are four principal ones, each a few miles in diameter. Tin mines are especially worked in the granite near its borders and also in the immediately surrounding Paleozoic slates. Copper and lead are no longer of importance here but tin is being produced steadily from several mines, with arsenic and tungsten as by-products. At the close of the war the man-power available. for these mines had been reduced to one-third of normal, and only now is it again reaching full strength. As mining in Cornwall antedates the Christian era, even a Nevada prospector would have to admit that "she's a permanent camp." SUB-TROPICAL CORNWALL Redruth and Camborne are industrial centers of the tin mining industry, but more tourist hotels are found in neighboring resorts such as St. Ives, a quaint fish-ing town on the Atlantic-side of the peninsula of Corn-wall, where the numerous cats descended from those mentioned in the ancient riddle-rhyme about St. Ives now occupy every doorstep and wall. Another charm-ing resort. Penzance on the shore of the English Channel, is known by name to the public through the opera "The Pirates of Penzance," but is of especial in-terest to students of nature for its palm trees and other subtropical plants, which thrive owing to the nearness of the gulf stream, although the latitude is that of northern Newfoundland, Winnipeg, and the northern end of Vancouver Island. Among the industrial plants at Camborne are those of Holman Brothers, Ltd., where drills and other forms of mining equipment are manufactured. At the Corn-wall School of Mines, which specializes on the district, the staff has assembled excellent collections of local ores, which repay study by a visitor.

Jan 1, 1928

By AIME AIME

ON Thursday a most interesting symposium on "Gases in Metals" was held, with both morning and afternoon sessions. The morning was devoted principally to the considerations of the steel maker, the nonferrous field being taken up in the afternoon period. Dr. John Johnston, as chairman, introduced the subject with "A Short Analysis of the Gas-metal Problem and Its Practical Importance." He then introduced P. H. Brace who explained in considerable detail the various vacuum fusion and other methods in use at present, both here and abroad, in the study of "gases" in metals. He was fol¬lowed immediately by H. W. Graham on "The Effect of Oxygen in Steel." The papers elicited considerable discussion, the point being particularly noted by both Dr. Rawdon and Dr. Sauveur that a knowledge of "total oxygen" alone is not sufficient information for the metallurgist, distribution of oxygen being probably the more important. Dr. Johnston, in commenting on the lack of agreement among many of the methods now in use, such as the Ledebur and vacuum fusion, spoke of the contemplated plan of the Iron and Steel Division to have a number of standard samples analyzed by many laboratories by the various methods, the Bureau of Standards acting as a clearing house, so that more definite information may be obtained on the comparative accuracy of the method.

Jan 1, 1933

By S. H. Moll, R. E. Ogilvie

The investigation of solid-state diffusion phenomena may lead to much information concerning binary alloys. In particular, a study of the concentration gradients present in multiphase diffusion couples can lead to the determination of the solubility limits of the single-phase fields in the phase diagram. The specific concentration gradient which results from the heat treatment of a diffusion couple depends not only upon the time and temperature of diffusion, but also upon the number of phases existing in equilibrium at the diffusion temperature. Such concentration gradients possess sharp discontinuities whose terminal points correspond to the solubilities existing at the limits of the two-phase field in the phase diagram at the diffusion temperature. In general, there will be a discontinuity in the concentration curve for each two-phase field which exists in the phase diagram between the concentration limits of the couple. A number of investigators have analyzed the gradients present in multiphase diffusion couples. 1-8 The iron-titanium phase diagram exhibits a y loop in the temperature range from 900" to 1400°C, and the limit of the a + y field lies at some composition which is less than 1 wt pct Ti for any temperature. It was felt that a diffusion study could yield values not only for the diffusion coefficients involved, but also for the chemical solubilities in the phase diagram. The concentration gradients were analyzed by an X-ray absorption technique developed by Ogilvie.6 The absorption of a monochromatic X-ray beam is measured in steps parallel to the diffusion direction and the resulting intensity gradients are transformed into concentration gradients by applying the laws of X-ray absorption in a binary system. This technique has been applied by ogilvie6 to the systems Ni-Au, Cu-Au, Fe-Cr, and Ni-Cr; by Gelles7 to the systems Be-Fe, and Be-Ni and by Hilliarde to the system Al-Zn. Linear X-Ray Absorption Analysis—The use of X-ray absorption analysis as a tool for determining concentration gradients arises from the fact that the beam is absorbed according to the quantity and species of elements present in the sample and not according to their state of aggregation. This method is more advantageous than the chemical analysis of machined layers since it is less time consuming and less expensive and can analyze a very small area. IF a homogeneous binary alloy (A + B) is analyzed with two different monochromatic X-ray beams I0(2) and lo(2) the following relation between the transmitted intensities, the intrinsic absorption coefficients of A and B for the two different radiations and the weight fraction of each element may be derived.' In (I/Io) (a+b) xa(u/p)a(2) + xb(u/p)8(2) Eq. [1] is independent of specimen thickness and density, but requires that either element A or B possess an absorption edge between the wavelength limits of the two monochromatic beams. I, is evaluated for each radiation by measuring the transmitted intensity through a varying number of foils of a suitable absorber. A plot of the natural logarithm of the transmitted intensity as a function of the number of foils, when extrapolated to zero foils, yields the value of I,. If a plot of the ratio in Eq. [ I] is calculated as a function of xA, then a master curve results. From

Jan 1, 1960

By A. J. Shaler, J. Prieto Isaza, John Wulff

TANTALUM metal has a number of unique properties which give it widespread application in modern technology and in research. In electronic apparatus involving high temperatures in vacuo some of the refractory metals become brittle. Tantalum retains its ductility at elevated temperatures, and this property, together with its low vapor pressure and its ability to absorb gases, make it important in this field. Its chemical inertness in the presence of acids, halogens, and other corrosive media, makes it useful in chemical apparatus and in neuro and orthopedic surgical applications. As an addition to tungsten carbide in steel-cutting grades of cemented-carbide tools, the carbides of tantalum and of its sister element columbium have found considerable use. The present-day method1 of manufacturing tantalum is to sinter a powder compact of the metal in vacuo. Because tantalum- columbium alloys are difficult to work and since tantalum ores almost always contain columbium, the two metals must be separated chemically, the products of the separation being generally in the form of potassium tantalum fluoride and potassium columbium oxyfluoride. These salts are used in fused-salt electrolytic baths from which coarse metallic powder is deposited as a sponge at the cathode. Finer powder can be made from the coarse product or from tantalum scrap by first submitting it to an embrittling heat treatment in hydrogen and then crushing it. The fine hydrogen- containing powder may subsequently be degassed in vacuo at a high temperature. Prompted by the success of others2,3 in the magnesium reduction of titanium and zirconium halides, one of the authors under- took4 an investigation of the thermo- chemistry of the reaction between solid magnesium and gaseous tantalum penta-chloride, a subject which had not previously been studied. He found that the heat of formation of tantalum pentachloride is approximately 364,250 cal per mol at temperatures lower than the melting point of magnesium. A value of 83 units was found for the standard entropy at these temperatures. With these values, it was shown that magnesium and tantalum pentachloride are capable of reacting exothermically at temperatures less than the melting point of magnesium, and that no great violence is to be expected when these substances are heated together. The exothermic nature of the reaction indicated that the process should be efficient and should not require much externally applied energy. Tantalum pentachloride is not commonlv made commercially, and any process using it therefore involves the subsidiary problem of producing and handling this substance. A series of experiments was carried out in which dried chlorine saturated with carbon tetrachloride was passed over heated tantalum, either in the metallic state or combined

Jan 1, 1947

[FUQUA, H. B. and Thompson, B. E.: Oil and Gas Development and Production in North Texas for 1933, 107, 320; for 1934, 114, 417 Oil and Gas Development in West Texas 114, 438 FURMAN, W. F.: Heat and Corrosion-resisting Alloys. Printed in Oil & Gas Jnl., June 13, 1935 Furnace-bottom sand, uniformity, 73, 390 Furnace control, Isley apparatus, M27, 502 Furnaces (See also Holt-Dern; Blast Furnaces; Roasters; Wirebar, etc.): annealing: electric, 89, 424 gas-fired, 89, 425 gas vs. wood for nonferrous metals, 89, 422]

Jan 1, 1936

By B. W. Gonser

SOFT solders are used principally in the automotive, can-making, building construction and electrical industries, but their field of usefulness extends well beyond these principal users to a vast list of miscellaneous applications where metal joints are required. The most common soft solders and the only ones considered in this discussion are those com-posed of lead and tin, with or without various relatively small percentages of impurities or additions. A small amount of antimony is often pur-posely added. As an indication of the importance of these lead-tin solders, 8620 long tons were consumed in 1934 in the U.S., and during most of 1935 from 900 to 1000 long tons were used each month. A great many factors influence the properties of joints made with soft solders. Fluxes and the fluxing procedure used to prepare the surfaces to be joined in order to give a true metal-to-metal contact are among the most important of these factors. The temperatures used, cleanliness of the work and general soldering technique have their effect, but when results are unsatisfactory they are usually attributed to the metallic solder itself and the raw materials from which it is made. Some-times criticism of the solder is justified. The wrong composition may be chosen for a given job, impurities may be present that ruin certain desired qualities, or uniformity may be lacking. A solder may even be looked upon with suspicion because of its ancestry, regardless of its true composition and behavior. To clarify the effect of slight differences in composition as found in commercially refined solders, a comparison of properties of solders grouped according to their origin has been undertaken. This investigation seeks to give practical information on the proper-ties of tin-lead solders produced from virgin metals, from commercially

Jan 1, 1936

By Charles T. Holland, David A. Olsen

Considerable work has resulted in the development of a formula by which the strength of coal pillars for an L to T ratio of up to 12 may be estimated. One of the factors involved in this formula is the coefficient of friction between the coal pillar and the adjacent rock with which it is in contact. This paper presents the results of studies on sandstone, limestone, shale and coal and the coefficient of friction between coal and the other three under wet and dry conditions. With the coefficients of friction thus determined and the use of results obtained earlier by Meikle and Holland, it seems probable that coal pillar strength may be more closely estimated. Several investigators1-3 have found that the com-pressive strength of cubical coal specimens can be correlated by an equation such as

Jan 1, 1969