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By P. H. Bohart

THe answer to the title question will be found by considering the ultimate influence of the petroleum engineers on industry and by considering the tools with which petroleum engineers must be equipped. Some 2000 to 3000 petroleum engineers are being absorbed by the industry yearly, indicating the magnitude of influence which they may exert on the industry. The petroleum industry is a highly technical one and it is inevitable that management be entrusted more and more to executives with technical training. The industry, therefore, expects the petroleum engineering schools to provide a broad basic training and a social and economic orientation which goes beyond merely supplying the minimum technical qualifications necessary to discharge responsibilities for a particular job. Because of the many branches of industry, emphasis must be placed on the Student's being trained in fundamentals, as well as grounded in other engineering branches, such as mechanical, civil and electrical engineering. The petroleum engineering graduate must know how to outline and organize the material for an engineering report and should be thoroughly grounded in English, both written and spoken. Even to the end that a five-year course may be required, they should receive instructions in auxiliary cultural and social science courses, industrial relations, and public speaking. Training in the method of approach to an engineering problem is something in which industry is deeply interested. A standard of ethics, a desire to arrive at the truth, and leadership training should be stressed. Introduction The basis of an an to any ques- tion concerning the petroleum engineering schools' responsibility to the industry will be found by considering the ultimate influence of the petroleum engineers on the industry and by considering also the tools with which petroleum engineers must be equipped in order to achieve success and happiness in the role in which their training, individual talents and choice of a profession ultimately will cast them. The problem must always be considered as it relates to a large group and not as it relates to a particular individual possessing strong natural talents and destined, by virtue of them, to pursue a certain course. The question implies that petroleum engineering schools have a responsibility, and indeed they do, not only to the industry but also to the students and even to the public. Because the responsibility is concentrated in a relatively few schools whose graduates are absorbed largely by the one industry, the responsibility is more apparent and the effect of failure to discharge the responsibility fully is more serious than the effect of similar failure on the part of schools supplying a smaller portion of the industry's intake of engineering graduates. This fact is especially true with respect to an industry such as the petroleum industry whose ratio of technical to nontechnical employees is relatively high and is increasing.

Jan 1, 1948

By John D. Meahin

THE use of digital methods for generating crystallo-graphic data is well-established and many programs are now available. Transmission electron microscopy usually requires a knowledge of the electron diffraction pattern which is obtained by plotting a planar section through reciprocal space. With cubic symmetry these sections are very easily produced, but with hexagonal and lower symmetry systems considerably more labor is involved. Johari and Buchanan1 have written a Fortran program for generating standard projections and along similar lines we have produced a short but completely general program for generating any section through reciprocal space. The required inputs are the lattice parameters and angles for the real crystal. The Miller indices of the direction [U, V, W] parallel to the electron beam are then specified and the program will generate the Miller indices of the plane normals perpendicular to [U, V,, W] up to some specified integer. A subroutine can be inserted to test for forbidden reflections if desired. We have used such routines for fct and hcp crystals. As each permitted index is generated it is printed or punched out and no storage arrays are utilized in the computer. The normal diffraction pattern corresponds to the zero-order Laue zone, but with thin crystals or crystals of large lattice parameters the higher-order Laue zones may contribute to the diffraction pattern. Accordingly the program will generate successive Laue zones and project them onto the zero-order zone. The output of the program first lists the zone axis [C, V, W] and the Laue zone, and then gives a list of permitted reflections and the corresponding XP and YP coordinates of the reciprocal lattice point in angstroms-'. In addition, ZP, the perpendicular distance of the reciprocal lattice point from the (U, V, Ur) plane in reciprocal space is given, as is the reciprocal interplanar spacing. In the case of the zero-order Laue zone ZP is zero. A diffraction spot from the higher-order Laue zones will be very slightly displaced from the computed coordinates as its position in an actual pattern is given by projection along the diffracted beam2 and not along [u, V, w]. For any given electron wavelength this correction could be readily incorporated into the program, but as it only amounts to -1 pct it was decided to leave the program in its most general form, i.e ., a computation of points

Jan 1, 1970

By ERNEST W. ELLIS

MORE or less contradictory findings as to the most satisfactory feed for concentration tables of the Wilfley type is shown by the diversity of opinion among experimenters. Prof. R. H. Richards,l as a result of his work, favors classification. On the other hand the work of Messrs. Cox, Gibbins, and Porter,' of McGill University, points in general to the desirability of screen-sized feed The ore used was obtained from the West mill of the Bunker Hill and Sullivan Mining and Concentrating Co., Kellogg, Idaho, and consisted of argentiferous galena in a gangue of quartzite and siderite. The natural feed was taken from the launder supplying the Fahrenwald classifier. Classified feed was collected from each of the ten spigots of this same classifier. From the natural feed the screen-sized feed was pre- pared in the laboratory. All three types of table feed were therefore derived from the actual mill circuit of a large plant.

Jan 1, 1926

By S. B. Flagg

Advancement in the art of burning fuels for steam generation has been so marked and so rapid in the last 10 or 15 years that one may well hesitate to classify as unsuitable for stationary steam boiler firing any material having a fuel value. This statement should not be interpreted to mean that any existing boiler plant can successfully utilize any fuel with which it might be supplied. It does mean, however, that almost without exception it is possible to design and construct stationary boiler plants so that they can be operated with whatever coal is the economic supply therefor. In considering the subject of the use classification of coals, it must be recognized, first, that the suitability or unsuitability of a coal for certain uses or conditions may be largely a matter of opinion and, second, that as advancement in the art of burning fuels continues, fuels that may have been considered unsuitable may later be regarded as entirely suitable. This is well illustrated in the creation of a market for slack bituminous coal and for the finer sizes of anthracite that resulted from the development of mechanical stokers adapted thereto. Coke breeze is another fuel of which large tonnages were formerly wasted, that has now been found suitable for use in properly designed furnaces. Again, results that would have been thought quite impossible a generation ago are being obtained in steam boiler plants today with lignites of high moisture content and with coals of excessive ash content. It must, however, be admitted that oftentimes an existing boiler plant can be successfully operated with only a limited number of the coals that are available as possible supplies. We may briefly consider some of the more important factors that may affect the suitability of coals for such a plant. Insufficient or barely sufficient draft to meet peak steam demands is often a limiting factor, and the permissible frequency of fire-cleaning periods is another. In some cases, the action of the molten coal ash on refractory furnace linings prohibits or makes inadvisable the use of certain coals. Again, clinker conditions in the fuel bed or slag conditions on the boiler-heating surface may be much worse with some coals than with

Jan 1, 1930

By C. Max Bauer

THE most important development in the petroleum industry in Montana, during 1924, was the bringing in of the Hepp well on May 12, by the Midwest Refining Co. This followed three years of active prospecting and drilling in the state by this company. The well is located 35 miles west of Billings, in Stillwater County, and makes a high-grade paraffin oil from the Dakota sand at a. depth of 3825 ft. After flowing for several months at the rate of 150 bbl. per day, the well has been shut in for lack of storage, awaiting further development in the field. TABLE 1. Production Cat Creek and Kevin-Sunburst Fields Month Kevin-Sunburst Pipe- Estimated Cat Creek Pipeline Estimated line Runs Fuel Oil Used Runs Fuel Used January 3,214 0 133,400 140 February 3,250 0 134,248 490 March 11,989 595 163,129 910 April 116,897 1,155 125,918 980 May 179,726 2,310 152,179 770 June 126,131 2,697 122,270 910 July 132,173 2,170 118,034 770 August 202,001 2,695 142,313 1,120 September 187,201 2,135 110,012 350 October 162,589 1,995 121,683 350 November 130,392 2,520 139,900 350 December 107,465 1,780 124,169 0 Total 1,363,028 20,052 1,581,255 .7,140 There are two producing oilfields in the state-the Cat Creek and the Kevin-Sunburst, which produced a total of 2,971,475 bbl. in 1924. The only other field of proved value is Soap Creek, which contains a heavy black oil and is shut in for lack of marketing facilities. Gas is produced for local use at Havre, Chinook, and Baker, and a carbon-black plant is located at Baker.

Jan 3, 1925

The income of the Institute is derived from dues, subscriptions to Mining and Metallurgy and sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for especial purposes. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes, It is allocated by the Board of Directors upon recommendation of standing committees in each case. An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization and at a minimum of expense. J. V. W. Reynders is chairman of the Endowment Committee. Seeley W. Mudd Memorial Fund THE Seeley W. Mudd Memorial Fund, consisting of $100,000, was given the Institute in 1929 by the family of Colonel Mudd who had served the Institute as Director, Vice-president and on many important committees. His long career of distinguished professional and public service is fittingly commemorated by this fund. The income is available for support of research and other special purposes. In view of Colonel Mudd's life work with the nonferrous metals and his keen interest in the younger men of the profession it is purposed to apply the fund particularly to the benefit of these two. Control of income is exercised by the Board of Directors on recommendation of a Committee consisting of the President and Secretary, ex officiis, together with three others selected by the Board. The Committee consists at present of the following members: W. H. Bassett, President; H. Foster Bain, Secretary; Harvey S. Mudd serving until October, 1931; Edgar Rickard serving till October, 1932; George Otis Smith serving until October, 1933. On recommendation of this Committee the Board has authorized as a first project the preparation of a series of small books designed especially to be helpful to the Junior Members. These are now being written and it is hoped will be available for distribution in 1931. The list includes: A Brief History of American Mining, by T. A. Rickard; Mining Costs, Why and What, by Arthur Notman; Introduction to Mineral Economics, by H. Foster Bain and T. T. Read; Choice of Methods—A Record of Experience in Making Decisions, with chapters by W. H. Bassett, F. W. Bradley, E. DeGolyer, Howard N. Eavenson, A. B. Parsons, J. V. W. Reynders, L. D. Ricketts, Robert E. Tally, Pope Yeatman and others. One other book is projected but final selection has not been made. The purpose of these books is to afford the younger men who now come into a highly specialized profession some substitute for the broad

Jan 1, 1930

By G. Derge, R. E. Grace

Diffusivity of bismuth in liquid Pb-Bi alloys has been measured by the capillary reservoir method as a function of temperature and composition. Fair agreement between theory and experiment is found for the measured diffusion coefficients and activation energies of diffusivity and viscosity in dilute lead alloys. The measured diffusion coefficients in the high bismuth alloys describe mass transport in special concentration gradients. THE study of diffusion in liquid metals has been restricted largely to the amalgams over small ranges of temperature and composition. In contrast to this, diffusion and transport of ions and molecules in aqueous and organic solvents have been studied extensively for the past 50 years. The general difficulty of measuring diffusion coefficients in both gases and liquids at high temperatures has been that of eliminating convection currents. Measuring techniques based on freezing and sectioning after the diffusion period1 are not particularly satisfactory because of the volume changes and segregation which occur during freezing. The most promising technique which is currently being developed for liquid metals is the capillary reservoir method. This eliminates convection currents from the diffusion zone and requires measurements only of the length and initial and final compositions of the alloy within the capillary. Anderson and Saddington' have measured the diffusion coefficient of tungstate anions in aqueous Na,W04; Wane4' and Hoffman- ave studied structure and self-diffusion in water and self-diffusion in mercury, respectively, by similar techniques. Selection of the Pb-Bi system for initial study was made for several reasons: I—It afforded a low temperature system for development of techniques which would be suitable for high temperature measurements in liquid iron. This research on diffusion in liquid iron is now in progress as a part of a general program on the rates and mechanisms of slag-metal reactions. 2—Activity data on liquid Pb-Bi alloys of all compositions are available from the emf meas- urements of Strickler and Seltz.9 3—Some data are available on the diffusion of bismuth into solid lead. The measurements on solid alloys were made by von Hevesy and Seith7 for the concentration range of 0 to 2 pct Bi. An appropriate solution to Fick's law (unsteady state) for the capillary reservoir has been found by considering the mass flow which passes through a unit area of surface on a slab of infinite thickness as a function of time. This is the first application of this solution to diffusion measurements, although a similar solution is available for identical boundary conditions.' By analogy with heat conduction, the problem reduces to a perfectly insulated infinite slab at temperature C,, one surface of which is quenched to C, for all times, t. Heat is permitted to flow from quenched surface of the slab to an infinite supply of coolant at C.' (see Appendix). For the corresponding solution for diffusion in liquids, these terms become Where Cu is the initial concentration of component A" in entire capillary at t - 0, C, is the final con- In this case. component A is bismuth, and C, = 0. centration of component A in entire capillary at t = t, C, is the concentration of component A in bath for all t, 1 is the length of the capillary in centimeters, t is the time of diffusion period in seconds, and D is the diffusion coefficient in square centimeters per second. By comparison with solutions to Fick's law used in the solid state, this solution for liquids is similar to the Grube solution for solids, where the change in D with chemical composition is not taken into consideration. Difficulty is to be expected if large concentration gradients are employed and if the concentration gradients extend over an appreciable length of the capillary.

Jan 1, 1956

By M. Garfinkle

LITERATURE data1'3 have suggested that the resolved shear stress necessary to initiate slip in a particular slip system in tungsten single crystals is strongly dependent on the tensile orientation of the crystals. This orientation dependence is contrary to the critical resolved shear stress criterion. Because the Schmid factors for slip on particular {110}( I l l), {112}(Ill), or {123}(111) slip systems in a (100) oriented tungsten crystal are virtually identical to the respective Schmid factors for a (110) oriented crystal, slip should initiate on the same system in both orientations, independent of the values of the critical resolved shear stresses. Thus, it would be expected that, for a critical resolved shear stress model to hold, the proportional-limit stress for these two orientations must be similar. The expectation of similar proportional -limit stresses has not been borne out by reported experimental observations. Rose et nl.' reported that the proportional-limit stress for crystals near the (110) orientation was 92,000 psi, approximately three times that of (100) oriented crystals (31,000 psi). Garlick and probst2 reported greater than a fourfold difference. Most recently, Beardmore and ~ull~ examined tungsten crystals with orientations along the edge of the standard stereographic triangle and showed a gradual increase in proportional-limit stress from 28,000 psi for the (100) orientation to 93,000 psi for the (110) orientation. Again, the difference was more than threefold. As has been emphasized by these investigators, the apparent gross variation of proportional-limit stress with orientation precludes any meaningful analysis of slip mechanics using a simple critical resolved shear stress relation. The purpose of the present communication is to report that, by use of refined strain-measuring techniques, the proportional-limit stresses for the (100) and (110) orientations are quite similar. Obviously, to determine accurately the value of the proportional-limit stress, which is by definition the stress at which nonlinear stress-strain behavior first occurs, the method of measuring strain must be capable of high accuracy. The investigators cited used as the measured elongation the crosshead displacement of the tensile machine. This method, however, introduces extraneous strain contributions from the load train. Because these extraneous contributions are considerable in the initial portions of loading (as has been well-documented in the literature) the proportional-limit stress measurement, dependent on the deviation of a line from linearity, can be significantly affected. During the course of a recent study, room-temperature strain was measured directly on several (100)-and (110)-oriented tensile specimens axially oriented within 5 deg of the desired direction. Each specimen was fitted with two foil strain gages mounted on opposite sides of the 0.08-in.-diam reduced section. The tensile specimens were loaded at a crosshead speed of 0.01 in. per min on an Instron Universal Testing Machine. Strain was monitored through an external bridge circuit in which the specimen strain gages comprised two arms. The bridge output was recorded against the applied load. A strain of 2 x 10"" could be readily detected by this method. Some specimens were subjected to conventional loading while the load for others was cycled between zero and continually increasing values until the first deviation from linearity was observed. The results of these methods were similar, and the stress at which nonlinear behavior occurred was considered the proportional-limit stress. The proportional-limit stresses measured in this study are approximately 5000 and 6500 psi for the ( 100) - and ( 110) -oriented crystals, respectively, a range of values almost a magnitude less than those reported previously. Representative curves are presented in Fig. 1. Because of the nature of the measurements made, the point of departure of a line from linearity is often debatable. While the load-strain curve for the (100) -oriented crystals made a relatively abrupt deviation from linearity, the curve for the (110) -oriented crystal was more gradual, so that the actual point of tangency may be at a lower load than reported. Thus, the difference in values for the proportional-

Jan 1, 1967

By C. E. Sims, F. W. Boulger, H. A. Saller

Most of the data on equilibrium constant and the deoxidations potentialities of those elements, considered to be stronger deoxidizers for steel than is silicon, have been calculated from thermodynamic data. The reason for this is, primarily, the obvious difficulty of obtaining direct experimental evidence of equivalent accuracy. This is an excellent use of the principles of thermodynamics and has given valuable data not otherwise available. Such results, of course, can be no more accurate than the physical constants used in the calculations, and one can never be sure that the basic data are either complete or accurate. In fact, as in the case with silicon,1 there are not only discrepancies among the calculated theoretical values of the equilibrium constant for deoxidation of steel but also between the theoretical and experimental values. It is highly desirable, therefore, to obtain experimental values for checks on calculated results whenever possible. If they disagree, both cannot be right, but if there is good agreement, their value is enhanced. The present work was done in an effort to obtain experimental evidence in regard to some of the common alloying additions but more particularly the so-called "strong" deoxidizers for steel. The method used was to determine the minimum concentration of the deoxidizer that would effect a certain definite degree of deoxidation in steel. The criterion of deoxidation was the change from the large globular Type I sulphide to the eutectic Type II as described by Sims and Dahle.2 This change is sharp and definite, and inasmuch as it can be produced with equal facility by aluminum, zirconium, and titanium, it is considered a manifestation of a certain degree of deoxidation and not an alloying effect. Ostensibly such a procedure could give only a comparison of deoxidizing powers and no absolute values. Nevertheless, repeated observations have shown that, when increasing increments of aluminum are added to a steel, the residual aluminum content begins to increase simultaneously with the appearance of Type II inclusions. Thus it seems warranted to postulate that the Type II inclusions appear coincident with the virtual elimination of FeO as an active constituent of the steel. Experimental Procedure The data obtained were primarily from the microexamination of polished and unetched specimens and from chemical analysis. Experimental heats weighing 200 to 250 lb were made in a basic-lined high-frequency induction furnace. The base composition was nominally that of a medium-carbon casting steel to which the appropriate additions were made. Specimens were poured into sand-cast ingots 3 in. in diam as shown in Fig 1. Sand-cast ingots were used to prevent chilling and to allow sufficient time in freezing for normal inclusions to form of a size large enough to be studied readily. In the first few heats, the tapered wall ingot was used, but in the majority, the extra large riser was used to prevent piping in heavily deoxidized steels. Specimens for microexamination were taken from the location shown in Fig 1, and drillings for chemical analysis were taken from a similar location. The procedure was to melt the base composition and deoxidize with the usual manganese and silicon additions and then to pour an ingot. The furnace was then tilted back, and the first increment of strong deoxidizer or special alloy was added and allowed to disseminate through the melt, with enough power on to hold the temperature constant, for 45 sec. Then a second ingot was poured. After this, another increment was added, and after the same holding time another ingot was poured. In this way from 9 to 12 ingots were poured from each heat, each successive ingot having progressively larger total additions of alloy. Eighteen heats were made altogether, and the range of alloys used and additions made are outlined in Table 1. The three principal types of sulphide inclusions found are illustrated in Fig 2. The globular Type I sulphides are characteristic of silicon-killed steels, the eutectic Type II are characteristic of steels deoxidized with a small amount of aluminum, while the larger, angular Type III are usually found in steels with a residual aluminum content above about 0.02 pct. In all specimens studied, the transition from Type I to II either did not occur at all or was very abrupt and clear cut. There never was any doubt as to just which increment produced the change, although the individual additions were small, in the order of 0.01 pct. The change from Type II to Type III was considerably less sharp, and, in some cases, both types were found together. Inasmuch as the formation of Type III sulphides is apparently not a deoxidation phenomenon, they will not be discussed here.

Jan 1, 1950

By F. H. Spedding

From thermal, metallographic, X-ray, dilatometric, and electrical resistance data a Phase diagram is proposed for the La-C system. TWO compounds are formed, body-centered-cubic Laz C, having a large range of solid solubility, and body -centered-tetrago-nal Lac2 . The former melts incongruently at 1415°C, and at 25OC it has an electrical resistivity about two and one-half times that of bure lanthanum. The latter melts congruently at 2356°C and at room temperature has an electrical resistivity about equal to that of bure lanthanum. The addition of carbon to La lowers the melting Point of La about 115' C, raises the higher (B-Y) transfomzation about 10" C and appears to have no effect on the lower ( a-0) transformation. The addition of carbon appears to lower the oxygen content in the metal and improve the machinability; however, the tendency to oxidize is increased. Two eutectics are formed in the system. The first occurs at 2.2 pct C and melts at 806" C, while the second occurs between Lac2 and C with a melting point of2271"C. PETTERSSON,~ in 1895, was the first to prepare lanthanum dicarbide by heating the oxide with carbon in an electric furnace. He showed that this yellow, crystalline but brittle carbide had a formula corresponding to LaCz and that it reacted with water with the evolution of hydrogen and hydrocarbons and the formation of the hydrated oxide. Von Stackelberg's investigation of the crystal structure of the MCz carbides showed that the lanthanum dicarbide is of the tetragonal calcium dicarbide-type structure. He found the lattice parameters were a = 3.92 and c = 6.56.* Bredig,' using X-ray methods, showed that the room-temperature form of lanthanum dicarbide is stable up to 1750 °C and that above this temperature it transformsoto a face-centered-cubic structure, a = 6.0 ± O.lA, probably of the pyrite, FeSzstruc- typ? The reported discovery of two new cerium carbides, suggested that a corresponding face-centered-cubic lanthanum monocarbide and a body-centered-cubic lanthanum sesquicarbide might exist. This paper describes work on the lanthanum-carbon system which is part of a study of the rare earth metals and their alloys now in progress in this laboratory. EXPERIMENTAL PROCEDURE Source of Materials—The lanthanum metal was prepared at the Ames Laboratory by metal1o;hermic reduction of the fluoride with calcium metal. The results of spectrographic and chemical analysis indicated the presence of 0.01 pct Y, Al, Cu, Fe, and Si; 0.02 pct Ca and Mg; 230 ppm C; and 115 ppm N. The carbon used was of two types: 1) "National Special Graphite Spectroscopic Electrodes," and

Jan 1, 1960

By C. J. Osborn

The temperature dependence of the free energies of formation of metallurgically important oxides, sulphides, chlorides, carbonates and sulphates is presented graphically, whereby the task of deriving practical metallurgical information is greatly simplified. The diagrams have been revised according to the latest available thermodynamic data. WHILE it is true that much careful investiga-tional work remains to be done, there are already available in the literature sufficient thermo-dynamic data to enable the metallurgist to predict with reasonable confidence the equilibrium conditions to be expected in most important, and potentially important, metallurgical reactions. In this connection, the careful, critical compilations of K. K. Kelley and his collaborators in numerous U. S. Bureau of Mines Bulletins are particularly valuable. However, the translation of reliable thermo-dynamic data into metallurgical language unfortunately involves lengthy manipulations of the cumbersome formulas which can be set up from heat of formation, entropy, and heat capacity data. Many years ago, Kelley20 predicted that thermo-dynamic calculations would be made in the future "with the aid of free energy, heat content, and entropy tables, rather than by means of the algebraic methods employed at present", and where such tables are available they greatly simplify the task of deriving practical metallurgical information. However, in addition to these tables, there are also available one or two reliable graphical presentations, particularly of free energy data, which may be used in the same way as the tables, but which have the added advantages that interpolation is never necessary, and that the behavior of different metals or compounds may be compared at a glance. Some years ago Professor Robert Lepsoe, Head of the Department of Metallurgy at Norways Institute of Technology (N.T.H.), began a compilation of curves showing the temperature dependence of the heat contents of the elements, and the heat contents and heats and free energies of formation of the common metallurgical compounds. With such a compilation, the thermal and free energy requirements of a reaction may be read from curves in a matter of seconds; and this statement applies not only to the formation of compounds from their elements, and to the reverse dissociation, but to any reaction involving substances whose thermodynamic properties are available. This follows from the fact that heats and free energies of formation are completely additive. For example, the free energy change associated with the chlorination of a metallic oxide at any temperature, T, is given by the free energy of formation of the chloride at temperature T minus that of the oxide also at T; both of these quantities may be read directly from curves of the type suggested above. Since this early, unpublished work of Lepsoe, both Ellingham7 and Richardson and Jeffes46 have

Jan 1, 1951

By Frank R. Corwin, Selden S. Rodgers

PAGE I. Introduction,........... 383 11. Brief History of Present MacDoUgall Plant,.... 384 III. First Experimental Work on Increasing Capacity of Furnaces, 385 IV. Effect On MacDouRall Plant of IncreaBed Draft from New Smelter Stack,,.......... V. Increasing the Capacity of the MacDouGall FurnaceS,.. 391 (A). Test of Arthur Crowfoot on Increasing Capacity,.... (a). Description of Test,........ (6). Discussion of Results Obtained from Test,... 393 (B). Investigation Carried Out by John A. Church, Jr.,... 395 (a). Advantages of High Speed,......398 (C). Effect on Regular Operation of Department by Applying Results Obtained from Experimental Work ..... 399 (D). Fundamental Principles Involved in Increasing the Tonnage, . 400 VI. Treatment of an INcreased Amount of Ore Screenings,.. 401 VII. Maximum Percentage oF Ore Screenings in a MacDoUGall Feed, 403 VIII. Tests to Further Increase Capacity of Furnaces,... 406 IX. Tests to Decrease PercentaGe of Flue Dust made by MacDouGall Furnaces,............. (A). Repath-Marcy Furnace......... 408 (B). Modified Hepath-Marcy Furnace,....... (C). Crouse Furnace Designed for Dust Prevention,.... 413 (a). Tests on Crouse Furnace,....... X. Concrete Hearths,.......... 419 XI. Conclusion,............ I. Introduction. Since the first installation of MacDougall roasters at the Great Falls smelter of the Anaconda Copper Mining Co., the capacity of the furnaces.has been more than doubled. During the first nine or ten years of the operation of the MacDougall department the tonnage treated by the furnaces remained practically unchanged. Experimental work carried out in 1906, however, showed that increasing the draft of the furnaces would bring about an increase in capacity. In 1909 the MacDougall department was connected to the new smelter stack and

Jan 1, 1914

Said Plutarch a long time ago, ?To appreciate a man's work at the full, it is well to know the man himself, his circumstances and the incidents of his career." He might as truly have said "gift" instead of "work." Ambrose Swasey, engineer, collaborater with scientists, promoter of engineering research, patron of Engineering Foundation, advancer of the good of mankind, modest gentleman and generous giver, is, happily, well known to a great many engineers, who will therefore more fully appreciate his recent additional gift, for the use of the Engineering Foundation, which; purpose is "the furtherance of research in science and engineering, and the advancement of the profession of engineering and the good of mankind." But full appreciation of a gift of money necessitates more than acquaintance with -the giver and knowledge of the amount. Its timeliness; its inspiration; the character and continuity of its benefits, all must be comprehended. But whose imagination, though far-visioned as the great telescopes Mr. Swasey has built, can see the limits of benefit of such gifts as he has made to the Engineering Foundation, attracting-as they will-other gifts and evidences of, devotion to a great cause-? Every such gift lays responsibilities upon the recipients. Will American engineers grasp not merely, their pecuniary value but also emulate the spirit of fraternity and desire for harmony which have accompanied them? Shall we not work together and with Ambrose Swasey to advance still further the good of mankind, thus to demonstrate an acceptance of our obligations to humanity which is a counterpart in a democracy of the noblesse oblige of aristocratic tradition?

Jan 12, 1918

By Edmund Leaver

IT is generally recognized that the .addition of limited small amounts of various lead salts may aid the extracting power of the mill cyanide solution in the dissolution of silver from ores and in some cases may aid in the treatment of gold ores. Excess soluble lead compounds retard the dissolution of precious metals by the usual mill cyanide solution. Another phase of cyanidation is the use of the zinc-lead couple as an aid to better precipitation of gold and silver from solution containing a low percentage of cyanide. The chemistry of the use of lead salts in cyanidation has been dis-cussed by Clennell;1 the addition of lead salts in various cyanide mills is recorded by von Bernewitz;2 and the reasons for the use of lead salts in cyanidation have been explained by Clevenger.3 This paper deals with the adaptation of cyanidation to a different condition, in which the presence of lead minerals in a gold ore that is refractory to direct cyanidation complicates the treatment. If free gold is roasted in the presence of sulfur and lead salts, or if pyritic gold ores containing even a small percentage of lead minerals are roasted to free the gold from the pyrite, lead compounds coat the gold particles enough to make them almost insoluble in the usual mill cyanide solution contain-ing lime for protective alkalinity. Also, the lead compounds remaining in the calcine are slightly soluble in the mill solutions and such dissolved lead may retard the dissolution of the gold by the removal of oxygen or

Jan 1, 1933

By C. A. Stetefeldt

In May and June, 1885, I was engaged in examining the goldores of Las Minas, in the State of Vera Cruz, Mexico, with a view of finding a cheap and efficient method for extracting the gold. The following minerals could be plainly seen in the ore : magnetite, pyrites of iron, pyrites of' copper, quartz, and garnet. Neither galena nor zinc-hlende mere visible, but the ore contained a trace of lead, and in some samples of ore from the Muertos mine, 1.19 per cent. of zinc mas found. Antimony and arsenic were not present. Native gold could scarcely be seen in specimens of' the ore, and it only appeared—mainly in extremely fine particles—after pulverizing and washing. Magnetite was in every instance the most prominent mineral, its quantity varying between 43 and 67 per cent. Determinations of copper and sulphur showed that from 3.5 to 7 per cent. pyrites of copper, and from 3 to 22 per cent. pyrites of iron were present. The gold-value of the ore varied between 0.3 oz. and 0.8 oz. per ton. I do not speak of specimens, but of average samples of large quantities of ore put through the battery. In ore that had been crushed through a No. 40 screen, the gold appeared, in part, as free gold, the rest being thoroughly mixed with the magnetite and pyrites, both minerals containing about the same percentage of gold. If this free gold was brought in contact with pure quicksilver it (lid not amalgamate readily, even if the quicksilver was charged with sodium amalgam.

Jan 1, 1886

By R. S. Hoch, Roy A. Bobo

Maintenance of desirable plastic flow properties of weighted drilling muds may be greatly simplified by use of centrifugal classification to control the drilled solids content. The new application of a decanting type centrifuge to separate and reject the low density solids from the weighting material results in a drilling mud of greatly improved quality with lower values of yield and rigidity. Its practicality and economy has been proven in field operation. The degree of separation of light and heavy solids is not limited by the machine, but by the particle size distribution of the solids in the mud. Removal of the low density component of drilling mud that makes chemical treatment necessary permits a marked reduction in chemicals. The main uses of the centrifugal process are the treatment of muds while drilling, the reclaiming of discorded muds, cleaning up of workover muds, and the reduction in lime content of mud for completion. INTRODUCTION Drilling mud in any circulatory system is made viscous and difficult to pump by gradual accumulation of drilled solids which pass through the shale shaker and are continually reground. In a weighted mud containing a large proportion of barite by volume, the amount of drilled solids that may be tolerated is greatly reduced. Much effort has been expended to control by chemical treatment the effects of such solids. Though chemical treatment is quite effective, the time eventually comes at deeper depths after enough drilled solids have entered the system when a portion of the mud must be discarded and replaced with water and more weighting material. Once begun, this process is generally continued at frequent intervals with resultant high maintenance costs. At the termination of drilling, mud highly contaminated with light solids and spent chemicals is poorly suited for completion operations.' It is likewise limited in utility for other drilling operations. This investigation was conducted for the primary purpose of determining an acceptable mechanical means of removing the lightweight solids from weighted drilling muds in order to maintain viscosity at a minimum. A decanting type of centrifuge was selected from the various possible methods of mechanical separation. The centrifugal process has been employed in this country for this purpose in central mud reclamation systems in California in earlier years. It also was used for treatment of weighted muds on the Gulf Coast.' In more recent years only sporadic attempts have been made to employ it in the field on weighted muds. DISCUSSION OF PROCESS Selection of Apparatus Two factors favor mechanical procedure for the separation and removal of drilled solids or clays from the mud circulatory system. First, the greater specific gravity, 4.1 to 4.3, of the barite would promote more rapid settling than the clays whose specific gravity range is from 2.5 to 2.7. Second, the relative coarseness of the barite particles also facilitate faster settling of this phase. A decanting type of centrifuge was preferred for this process over other possible methods for these reasons: 1. Requires no costly additives or excess dilution. 2. Centrifugal force affords greatly accelerated separation as compared to gravity.

Jan 1, 1955

By Robert Longyear

IN, diamond-drill work, a true sample consists of all the material cut by the bit-both core and cuttings. As the recovery of this sample is the object of diamond drilling, the utmost care should be taken to secure it. Speed of drilling and low costs are of little value if an inaccurate sample is obtained. The engineer in charge must study his material and lay out the plan of sampling, and then see that the drill runner follows his instructions; for the runner may be more interested in obtaining a large footage than in developing accurate methods of sampling. FIG. 1.-CORE BOX. When the core has been removed from the core barrel, it should be placed in a core box in the exact order in which it is taken from the ground. This box, Fig. 1, is usually a shallow tray 4 or 5 ft. (1.2 or 1.5 m.) long, with partitions running lengthwise between which the core

Jan 12, 1921

By Robert W. Hunt

I have repeatedly said that the mechanical treatment of the metal forming a steel rail, during its manufacture, was comparatively of much greater importance than its chemical composition; and years of observation have confirmed and emphasized this fact. ' The comparison of the wear of the earlier steel rails with that of later ones, and to the great disadvantage of the latter, ia still being constantly made by railway oficials. And while some of us, with experience covering the whole history of the manufacture of steel rails, are aware of the great differences in the conditions governing their production at various periods, I do not think the engineering world generally appreciates the direct and imperative influence which these variations have had, and are having, upon the wearing-quality of the rails. In the earlier days, the steel was poured into ingots which would make but two 30-ft. rails not exceeding a weight of 60 lb. per yard—giving a mass weighing, say about 1,400 lb., and of a section of about 12 in. square. To-day the ingots are about 22 in. square, and weigh more than 4,000 lb. Of course, the interior of the larger ingots must remain hot and liquid longer than that of the smaller ones, and from this condition arises the steel-rail makers béte noire—segregation of the metalloids and piping of the steel. Ingots of the smallest section will pipe, but with the increase of the size, so will follow that of the interior cavity. This well-known tendency demands that special care should be exercised to avoid the evils arising from it.

Jan 1, 1905

By R. J. Robbins, D. L. Anderson

A tunnel boring machine has potential use in al- most any type of mining where the access shaft (or adit) is large enough or can be made large enough for its initial entry and where the orebody is of sufficient size to warrant its use. Some time will inevitably be lost in negotiating curves or making lateral moves and moving from level to level. Nevertheless, if the orebody is sufficiently large, advance scheduling can minimize the lost time encountered in such moves. Ideally, a mine will be planned for the use of these machines, thus eliminating access and transport problems. From the viewpoint of time involved, the rate of advance by boring as compared to conventional means is worthy of review. For instance, the Blanco Tunnel, one section of the Bureau of Reclamation's San Juan-Chama Project in southern Colorado, was bored in competent sedimentary rock with the following performance:

Jan 7, 1967

By C. P. Davenport, Garth Duell

What are the projected electrical power needs of the nation and of the Northwest during the next 15-20 years? No one who has researched the subject has reached a substantially different result than the following simple conclusion: electrical power requirements are doubling every decade. There are some who question the necessity of a power company's need to install capacity every ten years equal to what it has done during its entire previous history; there are even those who would argue that such growth should be arbitrarily curtailed. However, a power company must, by law, meet its responsibilities of providing the energy the public expects when the switch is thrown.

Jan 10, 1972