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By Richard M. Foose

FIVE miles southwest of Mt. Holly Springs, Cumberland County, Pennsylvania, the Philadelphia Clay Co. has been mining and milling a white clay since 1896; for use in white cement, as a filler in rubber, pigment and paper, in the manufacture of insecticides, and for other minor purposes. Until late in 1942, when the mine was abandoned because of labor shortage, combined underground mining and surface stripping produced approximately 30,000 tons of clay a year, of which 10,000 tons were refined in the mill. GEOLOGY Lower Cambrian Antietam quartzite and the Montalto quartzite, stratigraphically older, trend N.55°E. and make a sharp 1600-ft. anticlinal ridge of the South Mountains. The Tomstown dolomite overlies the Antietam quartzite on the southeast flank of the anticline, which is displaced near its crest by a steeply dipping oblique fault. Erosion of the less resistant Tomstown formation has resulted in a narrow valley at an elevation of 700 ft. Directly on top of the Antietam quartzite and at the base of the Tomstown formation is a zone of sandy white clay, lenticular along the strike of the formations, ranging in thickness from 10 to 300 ft. within a mile. All of the formations dip steeply to the southeast, from 65° to vertical. The clay crops out at an elevation of about 1000 feet. ORIGIN AND CHARACTER The uppermost part of the Antietam formation is sericitic and schistose at many places, and at all these places weathering is in an advanced stage. The clay is the residual product of weathering of this sericitic quartzite or sandy schist. The crude clay has the physical aspect of a sandy kaolin, but there are large areas in the clay formation that are low in free silica, and commonly the 30 ft. adjacent to the Antietam quartzite is notably free of silica. The overlying Tomstown dolomite has been weathered almost completely to a mixed yellow and brown clay, which carries a zone of nodular and chunky limonite and manganese ore, 4 to 12 ft. thick, about l00 ft. from the contact with the white clay. In mining, this zone is an important "marker," indicating where the white clay may be expected in an advancing tunnel. The contact of the white clay formation with the yellow and brown clay of the Tomstown formation is relatively sharp, although the line of contact is irregular and therefore responsible for the lenticular character of the white clay formation. Following is an analysis of the refined clay containing less than one per cent of moisture when dried at 212°F.: Si02, 67.05 per cent; A1203, 22.27; Fe203, 0.40; CaO, 0.00; Ti02, 1.05; MgO, 0.52; Na20, 0.04; K20, 0.88; ignition loss, 7.65; total, 99.86.

Jan 1, 1944

By E. H. Rose

THE question is often pondered whether the flotation process is still an art or has become a science. The fact is that flotation is a science in so many variables that only art can blend them. It is demonstrable that no less than one hundred variables are involved in any flotation operation, most of them immeasurable on a routine basis. The behavior of every one of them is always governed by orderly and unchanging law, as no man can doubt. There is nothing truly indefinite about that behavior; the only indefiniteness is in our knowledge of it, either in general or from hour to hour in the circuit. In dealing with a simultaneous equation in, say, one hundred variables, all not only affecting the outcome to some degree but many influencing each other as well, it is small wonder that the mineral-dressing profession presents a case history of debate and controversial opinion. The statement of the subject of this symposium-a symposium on flotation machines-seems to delimit and define the matters to be considered and at least the general nature of the conclusions sought. Nevertheless, in such a meeting it is not possible to meditate upon all the variables that do in one way or another affect performance of flotation machines. To attempt it would be much like trying to operate a hundred-ring circus. Perverse variables being what they are, one could expect the elephant in ring 36 to squirt a trunkful of water at the tightrope performer in ring 37 to ruin that artist's act, just as our learning to depress pyrite in the early 1920's ruined the act of the formerly faithful old Callows. HONEST DISAGREEMENTS Selective flotation dates from 1922 or 1923, when several plants established their regular flotation operations on a selective basis. Since then, two decades of efforr have gone into the development of better and better flotation machines. Many have come and gone. The competition has simmered down to perhaps a dozen machines, each one of which is staunchly defended by some operators as being the best for their particular jobs, and as scornfully dismissed by at least a few others elsewhere as being positively the poorest for theirs. These disagreements are honest disagreements, honestly arrived at after plenty of sweat. In many a flotation plant, one machine has been tried out against another under conditions as fair as they could possibly be made. Sometimes the results are on a par but more often one machine shows a consistent and unmistakable margin of superiority over the other. In equally honest and enlightened tests, machine A may win over machine B in one place, and machine B over machine A by as great a margin in another. This paper purposes to identify some of the more prominent reasons why this is so,

Jan 1, 1944

By B. Paul, C. C. Fu

Experiments indicate that the fatigue limit of various drill steels becomes vanishingly small in the presence of water and other corrosive liquids. Therefore one must generally expect fatigue failures of drill steels in a great many field operations. However, it is theoretically possible to so choose the hammer impact speed of a percussion drill in order to maximize the total length of hole drilled before failure occurs. In this paper the existence of an optimum speed is demonstrated and it is shown to be comparable to presently used piston speeds. The influence on drilling speed and hole length of a number of other pertinent design features, such as bit geometry, hammer geometry and steel properties is also established. Although machinery should be designed to obtain optimum performance, it is not always clear just what performance characteristic is to be optimized. For example in a rock drill it would be desirable to optimize all of the following characteristics: drilling speed, bit life, steel life, total length of hole drilled before failure, and efficiency of energy conversion. The word failure could signify excessive bit wear, bit fracture, steel fracture, or some other type of component failure. It is not possible in general to optimize all performance criteria simultaneously. For example, one could achieve fantastically large drilling rates at the expense of bit or steel life, energy requirements and physical size of system. It therefore becomes necessary to compromise requirements in order to achieve a well-balanced albeit non-optimum design. It is, however, extremely useful to explore the interrelationships between the different performance characteristics. Such a procedure would help to establish theoretical limits of performance within the framework of existing knowledge and also serve as a practical design procedure for special applications where a particular performance characteristic is of greatest concern to the user (e.g., steel breakage might be especially undesirable in certain locations). It is the purpose of this paper to examine the problem of how one may drill the deepest possible hole before breakage of the drill steel occurs. Of course the problem is almost trivial if a well defined fatigue limit (endurance limit) exists for the drill steel. In such cases one merely keeps the piston impact speed sufficiently low to insure that the stresses in the steel never exceed the fatigue limit, thereby achieving an infinite life. If, however, no definite fatigue limit exists, as seems to be the case in the presence of even mildly corrosive agents such as water (see later discussion), then a finite life is inescapable and one can at best hope to maximize the useful life of the system. Indeed it will be shown that the system life is related to drilling speed in the manner shown schematically in Fig. 1-a. Even if a definite fatigue

Jan 1, 1965

By R. W. Brown, J. L. Loper

The process of sand erosion has been harnessed to perform a useful function—the directed perforating of oilfield tubular goods and formation rock. In this process the sand is carried by a liquid medium and the resrrlting slurry is forced through a nozzle at an extren~ely high velocity. Upon impingement against casing or formation, the fast-moving sand particles erode a perforalion in the casing followed by cavity formation in the medium behind the casing. The many factors influencing the rate and extent of this penetration are inherently difficult to establish experimentally. Equations describing submerged jet behavior have been applied to these conditions. The following paper develops the equations for predicting the performance of the perforating jet. INTRODUCTION The cutting power of high-velocity sand has been well known in the petroleum industry for many years. Sand carried by a high-velocity gas stream causes severe erosion. This effect has been the cause of numerous production problems in certain areas. It was logical to expect that this phenomenon would one day be adapted to useful industrial applications. Development of mobile, high-pressure, high-horsepower pumping equipment in the last decade has made this possible. The sand erosion process involves pumping a fluid containing abrasive solids through a set of nozzles at a high differential pressure (2,000 to 4,000 psi). The pressure conversion into kinetic energy imparts high velocity to the sand particles which, upon impact with the formation face or casing wall, erode the material in an organized pattern. This paper attempts to establish the effects of the various parameters and to predict the performance and limitations of the process. The following factors will be considered: nozzle differential pressure, perforation size, sand concentration, nozzle stand-off distance and backpressure. In general, this discussion is presented along theoretical lines and is substantiated by field results and data where reliable field data exists. POWER EQUATIONS The penetration rate of a high-velocity hydraulic jet is proportional to the power or energy of the jet at the point in quesion. The power of the submerged jet will decrease with distance (or penetration) into the cavity created by the jet. As the cavity is extended into the formation, the power of the jet diminishes to a value equal to the threshold cutting power of the particular formation which is defiined as the lowest power level at which the formation will be abraded by the jet. Obviously, when this point is reached, no further cutting of the formation can occur. It is assumed that this power level for a particular formation is a function of the hardness of that formation. The following equation can be written for the hydraulic process of formation abrasion.

By Lester C. Uren

Tars paper reviews the industrial trends and changes in educational concepts that have led to the development of the modern petroleum engineering curriculum. A trend toward emphasis on engineering fundamentals is noted. While most universities are committed to the traditional four-year engineering program, it is agreed that more than four years is necessary for academic preparation of the petroleum engineer in all phases of his profession. The author proposes a coordinated program of undergraduate and graduate training that will permit of adherence to the general pattern of the present four-year engineering course, with provision for extension of the program into specialized graduate courses of professional character. In the latter, emphasis may vary with the interests and objectives of the individual student. A specific undergraduate curriculum is proposed in which upward of 80 per cent of the available time is devoted to engineering fundamentals. A broad survey of the professional field is afforded in courses grouped in the third and fourth undergraduate years, but detailed treatment of the professional aspects of petroleum engineering is reserved for the graduate program. INTRODUCTION Of necessity, engineering curricula must ever be changing to reflect the new techniques, the changing concepts that are presented as the engineering industries develop and unfold. Particularly is this true of the younger engineering curricula representing comparatively new and rapidly changing industries such as the petroleum industry. Institutions that planned their petroleum engineering curricula a decade or two ago now find that the petroleum industry has become vastly more technical in its requirements. En¬tirely new methods and techniques have come into vogue and must be given place in the curriculum, and some of these are of a character that demands changing emphasis in the fundamental preparatory subjects. College and university faculties cannot complacently assume that curricula in this field that were considered appropriate 10 or 20 years ago still reflect the needs of the industry that they are designed to serve. If they do, their graduates will be poorly equipped to meet the requirements imposed upon them by a rapidly changing industry. Perhaps it is not too much to expect academic authorities to anticipate the trends of industry and equip their graduates with what they will need to attain leadership 10 or 20 years after graduation. Whether or not this desirable objective is possible, there is no excuse for allowing curricula to fall behind the current needs of industry. DURATION OF CURRICULUM The majority of our engineering schools and colleges still adhere to the four-year curricula and there appears to be a definite sentiment among many engineers engaged in industry that work should be so planned that the engineering student may secure the essential academic preparation for his profession in a terminal four-year program. Yet, in recent years, it has become increasingly apparent that four years of

Jan 1, 1941

By Horace W. Hindry

This paper presents the ingredients composing a type of oil-base mud that has been successfully used in drilling oil horizons in California, the effect of ingredient concentrations on physical properties, methods of handling at the well and possible advantages of a waterless drilling fluid with excellent plastering properties. INTRODUCTION AN oil-base mud is a rotary drilling fluid in which oil has been substituted for water as the principal liquid ingredient. In recent years such a mud has been developed and used successfully for drilling the oil horizons of wells in various California fields. There are several types of oil-base mud, but only the type that is currently used to any appreciable extent will be considered at this time. The oil-base drilling-mud compositions used by Shell Oil Company, Incorporated have been covered by several patent applications on which patents are expected to issue at an early date. The purpose of this paper is to present data on the fundamental design of the mud; the ingredients used and their specifications; the effect of ingredient concentration on physical properties; the selection of the proper mud; the facilities needed for handling the mud; and a general discussion [oil] drilling with oil-base mud. In view of the early stage of development of oil-base mud, the great number of variables, and the almost unlimited possible combinations of these variables, which in turn require extensive laboratory study, there are certain irregularities and omissions in the data presented here. However, it is believed that sufficient data are at hand to permit a fairly complete analysis of the characteristics of oil-base muds. In view of the excellent plastering properties of oil-base mud when properly proportioned, its use should: (I) minimize the possibility of impairing the natural flow potentialities of the producing horizon such as that resulting from infiltration of water from water-base muds; (2) permit smaller clearances for setting liners, since the mud sheath has no appreciable thickness; (3) eliminate the possibility of clogging the perforations of the liner with thick mud sheath; (4) facilitate the removal of the mud sheath from the walls of the hole, for its mud sheath has no appreciable strength; (5) assist in drilling through formations, such as "heaving shale," where water wetting appears to be a source of difficulty. (6) permit cores to be obtained without contamination from drilling water. FUNDAMENTAL DESIGN OF AN OIL-BASE MUD In the design of any rotary drilling mud it is necessary to select materials that will fulfill the following requirements: (I) act as the liquid medium and regulate the viscosity; (2) impart initial and final plastering properties; (3) give gel strength and structure in order to prevent settling; (4) serve as a weighting material. The

Jan 1, 1941

By G. G. Gunther, C. L. Boeke

DISCUSSION I. M. Symonds, (Cia. Minera de Penoles, Monterrey, N. L., Mexico)—Messrs. Boeke and Gunther have written most interesting papers describing their zinc de-leading operations. Mr. Gunther was kind enough to show me his operation last fall. Aside from the excellent results, I was most impressed by the ease of control. I had expected a difficult operation requiring careful control and supervision, but found one requiring little attention. The only disappointing fact of the separation is the poor copper recovery in the concentrate of the delead-ing float. The final zinc concentrate still has about 3 pct chalcopyrite, assuming the copper is chalcopyrite, and adversely affects the zinc grade. If the copper mineral is free, the poor recovery is probably due to the high cyanide concentration. Fortunately, about 75 pct of the copper is recovered before the pulp goes to the zinc circuit. Mr. Gunther's remarks about proper cyanide to zinc sulphate ratios cannot be overemphasized. Although our experience has been confined mostly to the conventional lead-zinc separation, we have found these ratios most important, and more important in the mill than in the laboratory. The laboratory appears to give optimum results over a wider range of reagent control than the mill, especially in regard to the effect of cyanide. In handling relatively high grade ores in the mill we usually find that ratios of cyanide to zinc sulphate of 1 to 10 or 20 or higher work best. Where there is a substantial amount of chalcopyrite present it has been noted that cyanide in the range of 0.02 to 0.10 lb per ton of ore is often beneficial in zinc rejection and possibly in copper recovery in the lead concentrate, while larger amounts, say 0.20 to 0.25 lb per ton, will float more zinc and cause a serious rejection of chalcopyrite. On an ore with 15 to 20 pct zinc content we have had to use 0.8 to 1.2 pounds of zinc sulphate per ton of ore with the above cyanide to obtain optimum results. Some time ago we made a laboratory study following Parral and Santa Barbara practice on an ore which had never a very satisfactory rejection of zinc in the lead concentrate. The results were not encouraging and a mill test was not run. Since then the study has been reopened using in the laboratory fresh zinc concentrate from the mill instead of one made in the laboratory. A reasonably clean lead float from the zinc concentrate was obtained. It has been checked several times and each time the zinc concentrate made in the mill responds and the one made in the labora-

Jan 1, 1953

By S. D. Thompson

An AIME transaction by P.L. Allsman (1960), "Analysis of Explosive Action in Breaking Rock," contains many useful concepts applicable to blast design. Of special interest was the derivation of a heave blasting burden formula, which is important in establishing the maximum burden. Unfortunately, its derivation contains a fundamental error and then a compensating one. This formula was: [bImpulse _P d At max =nwuwu where: bmax = maximum burden in m (ft). P= average detonation pressure in N/m2 (lb per ft2). A= duration of the average detonation pressure in sec. n= 3.1416. w= specific weight of rock in N/m3 (lb per ft3). u= minimum velocity that must be imparted to the rock in m/sec (ft per sec). d= borehole diameter in m (ft).] The derivation used the impulse-momentum principle, with a 0.3 m thick (1 ft thick) radius of rock mass being acted on by an explosive impulse. However, the rock weight was not converted to mass by dividing by the gravitational constant. This mistake can be verified by checking the units in the formula, which resolve into m1/2-sec instead of meters. Adding the gravitational constant corrects this: [P d Atbmax =gu g = gravitational constant equal to 9.81 m/sect (32.2 ft per sec2).] If the minimum velocity is now taken as 0.3 m/sec (1 ft per sec), as was recommended, excessively large burdens result. Any appropriate rock velocity should be capable of throwing the rock mass a minimum distance so that the swell needed for breakage can occur. Unless the burden is extremely small and the bench height is very high, it is unlikely that a velocity of only 0.3 m/sec (1 ft per sec) will be sufficient. A review of the literature indicates that average rock velocities observed by camera studies typically range from 15 to 30 m/sec (50 to 100 ft per sec) (duPont deNemours and Co., 1977; Tansey, 1979). On this basis, a minimum rock velocity of about 15 m/sec (49 ft per sec) would be expected and not 0.3 m/sec (1 ft per see). When a velocity of 15 m/sec (49 ft per sec) is inserted into the corrected formula, the results approximate those of the original formula with a velocity of 0.3 m/sec (1 ft per sec). The errors were approximately self-compensating [(9 = 1.24)]. ? References Allsman, P.L., 1960, "Analysis of Explosive Action in Breaking Rock," Transactions, AIME, Vol. 217, pp. 475-476. E. I. duPont deNemours and Co., 1977, Blasters' Handbook, 175th Anniversary Edition, Dupont, Wilmington, DE, pp. 233. Tansey, D.O., 1979, "The DuPont Sequential Blasting System," CIM Bulletin, Vol. 72, July, p. 80. Thompson, S.D., 1981, "Critical Review and Revision of Surface Blasting Practice," MS thesis, West Virginia University, pp. 308-316.

Jan 1, 1986

By P. W. Bridgman

IT is characteristic of most scientific investigators that they are not satisfied with the discovery of new facts, no matter how curious or unex-pected, but that along with the factual discovery there is a constant effort to understand. It appears that one's interest in, and satisfaction with, the discovery of an array of new experimental facts is enormously increased if one has at the same time a theory or hypothesis guiding one's expectation of what sort of new experimental discovery may lie around the corner. Conversely, as a theoretical physicist one's satisfaction with his theory is greatly enhanced if along with the development of the theory can go the discovery of new experimental facts, confirming or perhaps modifying the theory as it grows. Of course, there have been long arid stretches in the history of physics in which new data of unquestioned ultimate importance have piled up, without much inspiration or illumina-tion in the way of understanding. For 50 years spectroscopy had such an arid history, but how irksome this was felt to be is plainly shown by the almost audible relief that greeted the first success by Bohr in injecting understanding into the situation, and by the fresh rush of experimenters into this field when the prospect of understanding had once been offered. The investigations in the field of high pressure, which have occupied me for a long time,1 until the last few years have been in very much the same sort of situation as spectroscopy before the advent of Bohr. A great many kinds of data were collected for a great many solid and liquid sub-stances, and there could be no question of the importance of these data, because the uniform change of dimensions produced by hydrostatic pressure is perhaps the simplest conceivable type of alteration to which a body can be subjected. But except for a few isolated flashes, there was no theoretical illumination, so that it had to be to a large extent the enthu-siasm of the collector that kept me going. However, within the last few years the wave-mechanics theory of solids has progressed so rapidly that

Jan 1, 1938

By James A. Crookston, William D. Fitzpatrick

Committee C-8 of the American Society for Testing and Materials defines "Refractories" as "Material, usually nonmetallic, used to withstand high temperature," and it defines the term "Refractoriness" thus, "In refractories the capability of maintaining the desired degree of chemical and physical identity at high temperatures and in the environment and conditions of use." The ability to withstand high temperatures is critical to classifying a material as a "refractory." However, as the foregoing definition of "refractoriness" implies, the refractory material may be subjected to and is expected to resist not only high temperatures but a variety of other destructive forces incident to its use. These include abrasion, impact, thermal shock, chemical attack, and high level loads at high temperatures. The various industrial applications of refractories represent an infinite variety of combinations and degrees of severity of these destructive forces, including high temperatures. Naturally, such a variety of application conditions leads to a need for a wide variety of refractory products to satisfy those conditions. The number of refractory products available is great enough that some form of classification is necessary to a discussion of refractories. Refractories may be classified in several ways, but the most suitable one is based on their general compositions and to lesser degrees on their physical condition and distinctive properties. The primary types of brick include aluminosilicate brick (fire clay and alumina), basic brick (magnesia and chrome ore, alone and in various combinations), silica brick, insulating brick, and special refractories (carbon, Sic, ZrO,, zircon, borides, and nitrides). Brick are, of course, preformed and are usually heat treated at high temperatures before use, but are in some instances unburned and/or chemically bonded, including the relatively new class of tar-bonded magnesia and/or dolomite brick. In addition to preformed refractories, another broad category includes the so-called specialty refractories, which are usually made in the same types as itemized for brick-bonding mortars and high temperature cements, hydraulic setting castables or refractory concrete, plastic firebrick, and ramming mixes. Refractory grains, such as fire clay and high alumina calcines, dead-burned magnesite and periclase, and dead-burned dolomite are also considered refractory products. Brick are also classified on the basis of physical dimensions, as standard sizes and special shapes. The standard sizes are those which are of definite shape and design and are designated as 9 x 4 ½ x 2 ½ in. and 9 x 4 ½ x 3 in. straights and series. All other brick of non- standard sizes are referred to as special shapes. These come about as a result of a particular need for a given furnace or for a particular application.

Jan 1, 1975

By C. G. Dunn

Nuclei that are formed during the recrystallization of a grain following plastic deformation generally have orientations that differ from the original. This aspect of recrystallization may be described in terms of orientation changes. It was shown previously, in an investigation on recrystallization in silicon ferrite,&apos; that the observed orientation changes were highly improbable on a chance basis, and that some mechanism must be involved. Analysis showed that the data could be satisfactorily classified into the smaller of two subclasses† of the 36 third-order twin transformations. No attempt was made at that time to classify the data within the special class of 12 third-order twin transformations, although results did indicate a greater probability for some of them to occur. A classification of this type would be more valuable, of course, with more data on orientation changes per old deformed grain. The present work fulfills this condition to some degree and also extends the scope of the investigation to include the effects of original orientation and the amount of plastic deformation. The effect of original orientation is of considerable interest because of the known effects of orientation on plastic deformation, particularly with regard to degree of fragmentation and the formation of deformation bands, and because the orientations produced by deformation should influence the orientations obtained through recrystallization. Barrett and Levenson2 reported that single crystals of iron deformed in the range 82 to 97 per cent could be put into three general classes; namely, crystals in class I maintained a reasonably sharp single orientation, those in class 2 transformed into two distinct orientations, and those in class 3 changed into a large number of major and minor orientations. Something similar would be expected for silicon ferrite crystals, and verification of this for a few cases of types class I and class 2 deformation has been reported elsewhere3 for single crystals of silicon ferrite cold-rolled in the range 10 to 20 per cent. As an example of class 2 deformation, it was shown that a crystal of silicon ferrite cold-rolled in a (110) plane in a <100> direction developed two layers, or deformation bands differing in orientation. When this happens it is possible to etch away one band and leave a single structure for use in studying the orientation changes that occur during recrystallization. when preferred crystal orientations are obtained in recrystallization, it is not particularly necessary to evaluate groups of common orientation, as was done previously (ref. I, Table 6); but an

Jan 1, 1947

By C. G. Dunn

Nuclei that are formed during the recrystallization of a grain following plastic deformation generally have orientations that differ from the original. This aspect of recrystallization may be described in terms of orientation changes. It was shown previously, in an investigation on recrystallization in silicon ferrite,&apos; that the observed orientation changes were highly improbable on a chance basis, and that some mechanism must be involved. Analysis showed that the data could be satisfactorily classified into the smaller of two subclasses† of the 36 third-order twin transformations. No attempt was made at that time to classify the data within the special class of 12 third-order twin transformations, although results did indicate a greater probability for some of them to occur. A classification of this type would be more valuable, of course, with more data on orientation changes per old deformed grain. The present work fulfills this condition to some degree and also extends the scope of the investigation to include the effects of original orientation and the amount of plastic deformation. The effect of original orientation is of considerable interest because of the known effects of orientation on plastic deformation, particularly with regard to degree of fragmentation and the formation of deformation bands, and because the orientations produced by deformation should influence the orientations obtained through recrystallization. Barrett and Levenson2 reported that single crystals of iron deformed in the range 82 to 97 per cent could be put into three general classes; namely, crystals in class I maintained a reasonably sharp single orientation, those in class 2 transformed into two distinct orientations, and those in class 3 changed into a large number of major and minor orientations. Something similar would be expected for silicon ferrite crystals, and verification of this for a few cases of types class I and class 2 deformation has been reported elsewhere3 for single crystals of silicon ferrite cold-rolled in the range 10 to 20 per cent. As an example of class 2 deformation, it was shown that a crystal of silicon ferrite cold-rolled in a (110) plane in a <100> direction developed two layers, or deformation bands differing in orientation. When this happens it is possible to etch away one band and leave a single structure for use in studying the orientation changes that occur during recrystallization. when preferred crystal orientations are obtained in recrystallization, it is not particularly necessary to evaluate groups of common orientation, as was done previously (ref. I, Table 6); but an

Jan 1, 1947

By J. R. Long, T. R. Graham, R. S. Dean

ALTHOUGH considerable information has been published concerning manganese additions to the aluminum bronzes, these data refer principally to the two-phase alloys containing 8 to 11 pct aluminum, with some incidental information on the single-phase alpha solid solution alloys. Strauss1 gives an excellent review of the literature on aluminum bronzes up to 1927 and a bulletin2 of the Copper Development Association brings the bibliography up to 1938. The most extensive work on manganese addition is that of Rosenhain and Lantsberry,3 who investigated alloys ranging up to 10 pct aluminum and up to 10 pct manganese, and presented data on the physical properties of sand-cast, chill-cast, and several wrought alloys. The greater portion of the work, however, concerns alloys ranging from 7 to 10 pct aluminum in the cast condition and sheds little light on the properties of wrought single-phase alloys. Corson4 notes that alloys containing 10 pct manganese and 4 pct aluminum are not hardenable by heat-treatment, while one with 15 pct manganese and 5 pct aluminum can be hardened, but he gives no tensile data on it. In fact, no systematic study of the properties of single-phase wrought alloys containing substantial amounts of manganese has been reported. It should also be noted that most of the investigators worked with alloys containing significant amounts of iron and silicon, and that these impurities, whether intentionally added or accrued from the raw materials used in the preparation of the alloys, may be expected to have a direct bearing on the resultant properties. In the work on alloys made with electrolytic manganese, the Bureau of Mines has undertaken an investigation of the copper-manganese-aluminum system for the purpose of establishing the constitution and properties of high-purity alloys. In a recent paper5 the authors reported a metallographic investigation of the alpha solid solution area and the adjoining fields of the copper-manganese-aluminum system up to 50 pct manganese. This study established the alpha-phase boundaries at 50° temperature levels from 400° to 850°C. It was found that the addition of manganese to copper-aluminum alloys decreases the solubility of aluminum in the alpha phase (Fig I), curving the boundary toward the copper-manganese base line. The greatest change occurs in the first 20 to 25 pct manganese, which decreases the solubility of aluminum to approximately 4 pct. With larger amounts of manganese the alpha boundary tends to parallel the copper-manganese binary. At 1300°F and higher,

Jan 1, 1947

By F. M. Perkins, R. H. Jamison

Publications concerning scaling laws for laboratory flow models of oil reservoirs indicate that the relative permeability and capillary pressure relations must be the same functions of saturation in the model and its prototype. In this paper, the relative permeabilities and saturations are redefined in a way which permits one to have diflerent relative permeability and capillary pressure relations in the model and prototype. The development of the new scaling criteria is demonstrated by deriving scaling laws for one simple flow problem. INTRODUCTION The successful application of information gathered through bench-scale model studies to the prediction of multi-phase fluid flow behavior in petroleum reservoirs requires careful consideration of the scaling criteria. The requirements which must be met for a small-scale model to duplicate the behavior of a much larger reservoir prototype have been discussed by Leverett, et al,&apos; Rapoport,2 and Geertsma, et al.3 According to these authors, the relative permeabilities to water, oil and gas and the dimensionless capillary pressures must be the must have the same values in the model and prototype. Furthermore, they point out that the viscosity ratios must have the same values in the model and prototype. In addition to these requirements, other scaling criteria are given which, when considered, usually dictate a much higher permeability in the model than exists in the reservoir. Since the more permeable model sands may have connate-water and residual oil saturations quite different from those in the prototype, the scaling requirements pertaining to the dependence of relative permeabilities and dimension l ess capillary pressures on saturation usually are not met. Also, if the model fluids are selected to give equal viscosity ratios in the model and prototype, one may find greatly different mobility ratios* in the two cases and, therefore, may expect grossly different flow patterns. For this reason, Craig, et al,&apos; correlated the results of their model studies with mo- bility ratio rather than with viscosity ratio. As yet, however, no satisfactory method has been advanced which permits use of anything other than the scaling requirements outlined in the previously mentioned papers. The purpose of this paper is to present a method of developing a set of scaling criteria which permits different relationships between saturation and relative permeability or capillary pressure in the model and prototype. Rather than attempt to report scaling criteria for a variety of practical situations, this paper demonstrates by use of one simple example how the modified scaling criteria are derived.

By Edwin Hopkins

THE year 1923 started a few days after the Venezuelan Oil Concessions, Ltd., discovered a 140,000-bbl. well at. La Rosa and a well of between 2500 and 5000 bbl. at La Paz, on the opposite side of Lake Maracaibo. These nearly simultaneous events changed, overnight, the general aspect of oil affairs in Venezuela. Up to that time, big things had been expected by the companies then in the district, but many major companies had shown little interest in the country. Within a few weeks the Pure Oil. Co. and the Gulf Oil Corpn. entered the field and acquired large properties. The Texas Co. purchased several concessions and the Standard of California, Atlantic Refining Co., and Mexican Petroleum Co. established offices. Representatives of many other companies visited the district during the first few months of the year. The sudden influx of buyers naturally caused a great rise in prices and this, together with overproduction in the United States, doubtless caused the slowing up of concession transfers in the latter part of the year. The following property transfers occurred: (1) The Gulf Oil Corpn. contract with the Maracaibo Oil Exploration Corpn., whereby the Gulf acquired the right to select 100,000 acres from the Maracaibo&apos;s zones. (2) The Gulf Co. purchase of one-quarter interest in seven concessions of the New England Oil Corpn., Ltd. (3) The Gulf Oil Corpn. purchase of several concessions of Kunhardt and others in the Perija district. (4) The Gulf Oil Corpn. purchase of certain portions of the one-kilometer Lake zone that were not covered by parcels or Government reserves (namely the "sobrantes"). (5) Pure Oil Co. purchase of all Government reserves turned back by Maracaibo Oil Exploration Corpn. in the districts of Mara and Miranda. (6) Standard Oil Co.: of New Jersey deal with the British Controlled Oilfields, Ltd., for control of approxi-mately the eastern third of the .district of Buchivacoa, state of Falcon. (7) Royal Dutch deal with the British Controlled Oilfields, Ltd., for the control of the central third of the district of Buchivacoa, Falcon. (8) The Texas Co. purchase of several concessions in Perija and one west of Mene Grande on the east side of Lake Maracaibo. (9) Purchase by the British Equatorial Oil Co., Ltd., of Goverment reserves corresponding to certain Creole Syndicate parcels under the margin of Lake Maracaibo near La Paz. (10) The Lago Petroleum Co. acquired a concession on all of Lake Maracaibo except a 1-Km. strip along the shore.

Jan 3, 1924

By P. W. Bridgman

THE thesis of this article is that the age of Newton is now coming to a close, and that recent scientific discoveries have in store an even greater revolution in our entire outlook than the revolution effected by the discovery of universal gravitation by Newton. The revolution that now confronts us, arises from the recent discovery of new facts, the only interpretation of which is that our conviction that nature is understandable and subject to law arose from the narrowness of our horizons, and that if we sufficiently extend our range we shall find that nature is intrinsically and in its elements neither understandable nor subject to law. The new experimental facts are in the realm of quantum phenomena. Comparatively little has been written for popular consumption about this new realm which has opened in the last fifteen years. The man in the street has been much more interested in relativity, which to him has seemed extremely interesting and revolutionary. Occasionally, however, there has filtered down to him the news that nearly all the theoretical physicists are occupied with a new order of phenomena which they find very much more exciting and revolutionary than any in the realm of relativity. For after all is said and done, the practical effects of relativity, measured in ,dollars and&apos; cents or in centimeters and grams, are exceedingly small, and require specially de- signed experiments executed by men of the highest skill to show their existence at all. The phenomena with which quantum theory deals, on the other hand, are of the greatest practical importance and involve the simplest aspects of everyday life. For example, before the advent of the quantum theory no one could explain why a tea kettle of water boiling on the stove should not give out enough light in virtue of its temperature to be visible in the dark; the accepted theories of optics demanded that it should be visible, but every burned child knew that it was not.

Jan 1, 1929

Edgar Hall, Silverspur, Queensland, Australia (communication to the Secretary*):—Dr. Douglas has written on this subject before, and his influence has had a powerful effect on the eide of freedom among the&apos; younger generation of engineers. Moreover, it is not the first time that he has attributed the decline of the copper-smelting industry in Swansea to the secrecy maintained by the firms there engaged in smelting-operations. In this latter statement I think his conclusions are open to criticism. Whether the firms mentioned have suffered by their secrecy is their own business—I hold no brief for them ; but that the decline of the copper-industry at Swansea was inevitable seems to me to he proved conclusively by Dr. Douglas&apos;s own writings. In his paper on The Copper Situation,&apos; Dr. Douglas says : "In comparing iron and copper mining,...it must be remembered that 2 tons of average iron ore from the most prolific source now available ... will make 1 ton of metal; whereas from 33 to 75 tons (say an average of 50 tons) of copper ore must be mined to produce 1 ton of copper." And further: "Last year&apos;s production of iron was made from approximately 50,000,000 tons of ore. Our copper mines, to yield a production of 900,000,000 pounds, must have handled approximately 22,000,000 tons of ore, or nearly half the quantity raised from our iron mines." Is not this the key to the whole situation ? In transporting the 50,000,000 tons of iron-ore, 25,000,000 tons of the metal iron were carried so much nearer to the market, but the transportation of 22,000,000 tons of copper-orc would have carried only 450,000 tons of the metal copper nearer to its ultimate destination. The small percentage of copper available in its ores makes

Jan 1, 1909

By G. G. Gunther, C. L. Boeke

(Any discussion resulting from presentation at the Los Angeles Extractive Metallurgy Division Meeting will appear in the November 1953 issue.) I. M. Symonds (Cia Minera de Penoles, Monterrey, N. L., Mexico)—This is a most interesting paper describing zinc deleading operations. Mr. Gunther was kind enough to show me his operation last fall. Outside of the excellent results, I was most impressed by the ease of control. I had expected a difficult operation requiring careful control and supervision, but found one requiring little attention. The only disappointing fact of the separation is the poor copper recovery in the concentrate of the deleading float. The final zinc concentrate still has about 3 pct chalcopyrite (assuming the copper is chalcopy-rite) which adversely affects the zinc grade. If the copper mineral is free, the poor recovery is probably due to the high cyanide concentration. Fortunately, about 75 pct of the copper is recovered before the pulp goes to the zinc circuit. Mr. Gunther&apos;s remarks about proper cyanide to zinc sulphate ratios cannot be overemphasized. Although our experience has been mostly confined to the conventional Pb-Zn separation, we have found these ratios most important, and more important in the mill than in the laboratory. The laboratory appears to give optimum results over a wider range of reagent control than the mill, especially in regard to the effect of cyanide. In the mill in handling relatively high grade ores, we usually find that ratios of cyanide to zinc sulphate of 1 to 10 or 20 or higher work best. Where there is a substantial amount of chalcopyrite present, it has been noted that cyanide in the range of 0.02 to 0.10 lb per ton of ore is often beneficial in zinc rejection and possibly in copper recovery in the lead concentrate, while larger amounts, say 0.20 to 0.25 lb per ton, will float more zinc and cause a serious rejection of chalcopyrite. On an ore with 15 to 20 pct Zn content, we have had to use 0.8 to 1.2 lb of zinc sulphate per ton of ore with the above cyanide to obtain optimum results. Sometime ago we made a laboratory study following Parral and Santa Barbara practice on an ore which never had a very satisfactory rejection of zinc in the lead concentrate. The results were not encouraging and a mill test was not run. Since then the study has been reopened using fresh zinc concentrate from the mill in the laboratory instead of one made in the laboratory. A reasonably clean lead float from the zinc concentrate was obtained. It has been checked several times and each time the zinc concentrate made in the mill responds and the one made in the laboratory does not. Although undoubtedly some reasonable explanations can be given, it is presented here only

Jan 1, 1953

By J. G. Tilton

While most of the Pittsburgh coal horizon is dependably regular, there are areas where it is dis-turbed by sandstone cutouts which can seriously hamper mining operations. Because these channel sandstones often cut out the coal abruptly, they are difficult to detect by core drilling; and mine operators, for want of a better way to discover them, have largely trusted to luck to avoid them. This paper, based on a study the author is presently conducting, is an attempt to point out some sources of information and signposts which might aid the operator in determining the presence of a cutout before he begins to mine. The presence of sandstone cutouts in the Pittsburgh coal has been known for many years. Some of these irregularities were observed at outcrops and others were discovered by drilling, but the majority were and are found during mining operations. These sandstone cutouts are commonly called "faults" and have been a bane to mining companies wherever they have been encountered. Profiles of some typical deposits appear in Fig. 1. The cutouts disrupt the normal system of mining, replace valuable coal reserves, create ventilation problems by emitting large quantities of gas and sometimes oil, limit the number of entries that can be economically driven, affect the quality of the coal, disrupt the normal structure of the coal, and create roof control problems. It might be expected that such severe disturbances in the structural regularity of the coal would instigate determined and extensive searches for possible cutouts prior to mining operations, but this apparently has not been so except in isolated cases. Two reasons may be cited to explain this lack of exploratory work. The first and probably the strongest reason is the over-all regularity of the Pittsburgh coal. No coal seam in the country exhibits the horizontal continuity and relative regularity of the Pittsburgh coal. It lies in an almost unbroken sheet across southwestern Pennsylvania, eastern Ohio and northern West Virginia, and has been recognized as far east as the Potomac Basin of western Maryland. Over 5729 square miles are underlain by this coal, of which 2077 square miles are in Pennsylvania, 2214 square miles in West Virginia, 1410 square miles in Ohio, and 28 square miles in Maryland. The area covered by this study is outlined by the map in Fig. 2. Over most of this territory the coal has the following characteristic structure as illustrated in Fig. 3: roof coal, draw slate, breast coal, parting, bearing in coal, parting, brick coal, parting, and bottom coal. With such regularity of thickness and structure, mines were opened and laid out with confidence that the coal would be present. Extensive drill testing was considered unwarranted and it was also quite expensive because the coal dipped to the west away from the Monongahela River. Consequently, drill holes were widely spaced and rarely encountered ad-

Jan 1, 1968

• In 1949 the United States imported 7,400,000 tons of iron ore; Chile, Sweden and Canada, in that order of importance, supplied over 80 pct of this amount. U. S. imports have increased from 3 pct of the total supply in 1940 to 8 pct in 1949. • Mica has been successfully synthesized by scientists of the National Bureau of Standards. quartz, magnesite and bauxite, plus a fluorosilicate compound to act as a crystallizing agent, are heated to 2500°F in a platinum-lined crucible and as the furnace cools mica crystals grow. The key to parallel growth to make sheets is in precision control of temperature. • Inland Steel Co. of Chicago has taken an option to lease from Steep Rock Iron Mines, Ltd., of Canada -- a large undeveloped acreage in the vicinity of Steed Rock Lake, Ontario -- for the purpose of exploring and developing a new iron ore mine. The exploration program is expected to begin at an early date. •A 20-yr test conducted by the U. S. Bureau of Mines with the cooperation of Cleveland-Cliffs indicated that chemically treated timbers last from 2 to 3-1/2 times as long as untreated ones set in the same passageway. Of the three reagents used, zinc chloride gave the best result -- 13.3 yr as compared to 3.8 yr for untreated timber. •Senator Pat McCarran charged that President Truman used a "shotgun approach" to the taxation problem when he accused the mining industry of enjoying excessive depletion exemptions when actually mining taxes should be lowered. He introduced to the Senate a report of the National Advisory Council -recommending a decrease * The country&apos;s first graduate program of research and instruction in conservation of natural resources will begin at Yale in September. The Conservation Foundation is supplying $20,000 a year to finance the program. •Felix E. Wormser urged that adequate tariff protection should be provided to offset effects of devaluation on the domestic mining industry in an address before the Colorado Mining Association. He advocates tariffs rather than subsidy legislation, such as S. 2105, for the protection of the lead-zinc miners because the latter would promote inefficiency and "impair our priceless free market." •"It may be startling to realize that for the world&apos;s white population the per capita requirements for minerals have multiplied 30 times in 30 yr, or that more minerals have been mined in the last 40 yr than in all prior history." -- Evan Just, in "Mineral Depletion and Metal Supply." •The National City Bank in its monthly letter states that both management and the unions concede that there are too many miners trying to make a living out of the industry for its present market. •On Feb. 3 it was reported that 6000 Anaconda employes in Chile quit jobs in sympathy with striking telephone and electric workers. The government has ordered them back to work on penalty of discharge. It appears that the walkout will not be prolonged in view of the government stand.

Jan 3, 1950