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By F. F. Aplan

Mineral processing engineers have recorded an- other year of active research and development work. Most gratifying was the broadly based attendance at the Mineral Processing Fundamental (formerly Basic Science) Committee sessions at the 1968 Annual Meeting of the AIME. Because of the availability of good papers, the active discussion and the growing attendance, sessions have grown from one to three at the annual meeting. Prof. M. C. Fuerstenau of the University of Utah will chair the Mineral Processing Fundamentals Committee for the next two years and we may thus be assured of continued active leadership. The name change from "Basic Science Committee" to the more descriptive "Mineral Processing Fundamentals Committee" approved by the MBD executive council is a welcome improvement. Our profession continues to attract the interest and cooperation of those in other professional groups. The 1968 Engineering Foundation Particulate Matter Conference, under the chairmanship of John Karpinski of Bethlehem Steel, was devoted exclusively to comminution this year. It attracted conferees from five continents and served as a particularly stimulating source of interchange of knowledge from many technical fields. Next year's conference will be under the chairmanship of Professor L,. G. Austin of The Pennsylvania State University. This conference plus the Symposium on Wettability and Flotation to be held at the annual American Chemical Society meeting in Minneapolis in April indicates the success achieved in the inter-disciplinary approach to problems. Other evidence of this spirit of professional cooperation is the forth- coming book on Size Reduction edited by D. W. Fuerstenau. This is the outgrowth of an AIChE symposium on size reduction held in 1965.

Jan 2, 1969

By B. VISWANATH

T HE Mysore iron works, at Bhadravati, about 2000 ft. above sea level in the Shimoga district of Mysore, British India, is served by a meter gage branch line of the Mysore State Railways. The works which were designed and erected by Perin & Marshall, who still act as consulting engineers, are surrounded by a thickly wooded country which sup- plies about 400 tons per day of wood for fuel. The ore deposits lie 20 miles to the south, and limestone quarries are close by the works. The Bhadra river sup- plies the works and the town with the necessary quantity of water. Dwelling houses for the employees

Jan 1, 1930

By F. Keller, E. H. Dix, L. A. Willey

The consideration of alloying elements for aluminum has led to a series of investigations of the equilibrium relations between aluminum and those alloying elements. Therefore, the aluminum end of the aluminum-antimony diagram has been studied. The general form of the aluminum-antimony equilibrium diagram has been worked out by Campbell and Mathewsi and by Tammann.2 Canlpbell and mathews described principally the beginning of solidification. They found the curve of beginning of solidification rising gradually from the melting point of pure alunlinum to a maximum at about 67 per cent. aluminum. After a slight lowering of the curve at a little greater antimony concentration the curve again rises to a maximum at 18.4 per cent. aluminum, which corresponds to the compound AISb. The curve then drops to the melting point of pure antimony. Tamrriarln explained the maximum occurring at about 67 per cent. aluminum as the result of the slow formation of the single compound AISb. The space lattice of the compound AISb, according to Owen and Preaton,³ is face-centered cubic, the antimony atoms being intermeshed with an identical aluminum lattice. Very little, if any, work has been done on aluminum alloys containing small amounts of antimony. The Present Investigation It has been the purpose of this investigation to determine the solid solubility of antimony in aluminum and also to investigate the eutectic temperature and concentration. The experimental work has been carried out in a manner similar to that described in a previous paper4 from this laboratory.

Jan 1, 1931

By D. H. Thompson, A. W. Tracy

Season-cracking is a type of failure of brass that results from the simultaneous effect of stress and certain corrodants. The object of this paper is to present data that will aid in a more complete understanding of the mechanism of season-cracking and related phenomena. Results presented show that certain high copper alloys are susceptible to season-cracking or stress-corrosion cracking, and possible explanations are discussed. Starting at least as far back as 1906, many papers have been devoted to this subject but the symposium1 held in Philadelphia in 1944 is the richest source of information. In order to study season-cracking, several of the many variables were held constant so as to learn the effects of others. Season-cracking is generally understood to refer to the corrosion cracking of brass having internal stresses;²,³ it is a special case of the general stress-corrosion cracking. Inasmuch as applied stresses are more readily produced and controlled, they were used exclusively in this research and the resulting phenomenon must he called stress-corrosion cracking.²,³ Only constant tensile stresses were used. The agents believed to be most frequently responsible for season-cracking are ammonia. amines and compounds containing then]. Both moisture and oxygen also appear to he necessary. Therefore, an atmosphere containing ammonia, water-vapor and air was selected for these tests. Briefly, the work consisted of exposing sheet metal specimens, having a reduced section ¼ by 0.050 in., of copper-base alloys to the effect of static tensile stresses between 5,000 and 20,000 psi and simultaneous contact with a. continuously renewed atmosphere containing 80 pct air, 16 pct ammonia and 4 pct water vapor at 35°C. The gas mixture and the speci- mens were maintained above the dew-point. The time-to-failure in minutes was the primary measure of results. In order to limit the experiment to finite time, it was considered that a specimen which had neither failed nor undergone microscopically detectable cracking in 40,000 min. (4 weeks) while under a stress of 10,000 psi or more could be considered immune to cracking. This is merely a convenient limit and is not to be considered proof of immunity. Supplementary tests in the absence of stress using weight loss or microscopical appearance as measures of attack were made. Apparatus The apparatus used in this research is shown in Fig 1. To facilitate the description it may conveniently be divided into six parts: stress-producing units, test chamber, gas train, electrical controls, timers and gas analysis device. A stress-producing unit is shown in an exploded view at the left in Fig 2. At the right is an assembled unit with a specimen in place in the lower portion; it is this part that remains in the ammonia atmosphere during a test. The upper part contains a spring, a central threaded rod, a large nut and necessary washers, pins, and so forth. Stress is produced in the specimen by screwing down the top nut against the spring, thus putting a tensile load on the central rod and so on the specimen. The wrench that turns the nut by extending through the upper cap, is seen at the upper right of the figure. The magnitude of the load is gauged by measuring from the pin that extends through the side of the tube, to a fixed point on the large flange. Measurement is made with a vernier beam caliper, shown at the right of the figure. The necessary spring compression to give a desired stress is calculated from the calibration curve of the spring and the dimensions of the specimen. The test chamber, center Fig 1, consists of a thermally insulated steel box 32 in. long by 10 in. high by 7 in. wide. A horizontal baffle reaching nearly to each end divides the chamber equally. Below this baffle are inlets for air and ammonia, a heating coil and a fan. Thus the gases are warmed and mixed in the lower level and flow past the specimens in the upper level. A thermo-regulator and thermometer project into the upper space. The top is pierced by 12 ports flanked by 3/8 in. threaded studs. A test starts when a port is opened and a unit containing a stressed specimen is thrust through it and bolted down against a neoprene gasket. The test chamber is held at 35°C. The gas train, right rear Fig 1, carries ammonia and air continuously to the test chamber. Tank ammonia passes through two reducing valves, a needle valve, a flow meter and into the test chamber. The air from either the plant compressor or a small laboratory compressor passes through wool towers and flow controls to the flow-meter. It then bubbles through water at 34°C and through a heated line to the test chamber. Electrical controls, left rear, Fig 1, provide rectifiers and mercury relays for the test-chamber and humidifier-heating-control circuits and outlets for

Jan 1, 1950

By R. E. Old

Through the use of pressure and production records, formation properties and bottom-hole sample data, the performance of an oil reservoir may be studied analytically to define and evaluate the natural forces acting on and within the reservoir. Use is made of material-halance methods and the equations for natural water encroachment. to estimate reserves. Methods for calculation of pressures are given. A study of the Jones sand, Schuler field, Arkansas, has been made and is given here to illustrate the value of the methods discussed. Introduction With the decreasing rate of discovery of new oil reserves, attention is necessarily focused on the efficient development, evaluation, and production of existing reserves. From the nation's viewpoint, the necessity of conserving resources is obvious. From the operator's viewpoint, the problem is to lengthen the period of profitable operation, in an attempt to increase the return on his investment. To do this the operator must take advantage of the natural forces acting on and within the reservoir. Natural water encroachment, the nemesis of profitable operation in the past, can be and is being harnessed to produce a greater oil recovery during the stage of flowing production. Proper evaluation of water encroachment rates and a fuller under- standing of reservoir behavior dictate the appropriate production procedures. Complacency in hit and miss production is obsolete. Oil production must and will approach the efficiency of other businesses, such as manufacturing. A manufacturer will not place an article on the market until he has fully investigated the processes involved, additional investment in equipment, costs of production, and expected profits. These may be modified by actual experience at a later date, but at least he begins with an idea of expected return. It is just as logical that an oil operator should investigate these same factors during the development and the early period of production of an oil reserve. The complexity of the problems existing in oil reservoirs should not be underestimated. Conversely, they should not be regarded as insoluble. Many completely defy solution, but there are others that can be solved completely or attacked intelligently to yield approximate results. The petroleum engineer has many tools, both figuratively and literally, at his disposal. Physical data such as core analyses, electrical logs, bottom-hole sample analyses, and bottom-hole pressures are accumulated extensively. Advances in the analytics of fluid flow have kept pace with the advances in measurement of physical data. It is the purpose of this paper to show how some of these records may be analyzed to define certain phases of reservoir behavior.

Jan 1, 1943

By R. E. Old

Through the use of pressure and production records, formation properties and bottom-hole sample data, the performance of an oil reservoir may be studied analytically to define and evaluate the natural forces acting on and within the reservoir. Use is made of material-halance methods and the equations for natural water encroachment. to estimate reserves. Methods for calculation of pressures are given. A study of the Jones sand, Schuler field, Arkansas, has been made and is given here to illustrate the value of the methods discussed. Introduction With the decreasing rate of discovery of new oil reserves, attention is necessarily focused on the efficient development, evaluation, and production of existing reserves. From the nation's viewpoint, the necessity of conserving resources is obvious. From the operator's viewpoint, the problem is to lengthen the period of profitable operation, in an attempt to increase the return on his investment. To do this the operator must take advantage of the natural forces acting on and within the reservoir. Natural water encroachment, the nemesis of profitable operation in the past, can be and is being harnessed to produce a greater oil recovery during the stage of flowing production. Proper evaluation of water encroachment rates and a fuller under- standing of reservoir behavior dictate the appropriate production procedures. Complacency in hit and miss production is obsolete. Oil production must and will approach the efficiency of other businesses, such as manufacturing. A manufacturer will not place an article on the market until he has fully investigated the processes involved, additional investment in equipment, costs of production, and expected profits. These may be modified by actual experience at a later date, but at least he begins with an idea of expected return. It is just as logical that an oil operator should investigate these same factors during the development and the early period of production of an oil reserve. The complexity of the problems existing in oil reservoirs should not be underestimated. Conversely, they should not be regarded as insoluble. Many completely defy solution, but there are others that can be solved completely or attacked intelligently to yield approximate results. The petroleum engineer has many tools, both figuratively and literally, at his disposal. Physical data such as core analyses, electrical logs, bottom-hole sample analyses, and bottom-hole pressures are accumulated extensively. Advances in the analytics of fluid flow have kept pace with the advances in measurement of physical data. It is the purpose of this paper to show how some of these records may be analyzed to define certain phases of reservoir behavior.

Jan 1, 1943

By L. R., McLeod

NO important changes in metallurgical practice are exhibited in the smelter that has been erected for treating the Morenci concentrate: the material is charged to reverberatory furnaces without roasting, and the matte subsequently blown in Peirce-Smith converters to separate the iron and sulphur from the copper. In fact the process is essentially the same, except for preliminary roasting of the concentrate, that was adopted in the new smelter that was built for the Arizona Copper Co. at Clifton, a few miles away, to treat Morenci concentrate just before the start of the first World War, and which went into service in October, 1913.

Jan 1, 1942

By S. H. Ward

Since the advent of the first airborne electromagnetic system, it has been evident that such systems were inherently limited to shallow depths of exploration of the orderof 100 to 200 feet. Hence in 1948 the author and his associates commenced a study of the feasibility of applying natural audio frequency magnetic fields to investigation of the electrical properties of the subsurface in order to provide a system capable of overcoming this limitation. This research culminated, in the summer of 1958, in the development of a new airborne prospecting device — AFMAG. This device has detected surface massive sulphide bodies while flown at heights as great as 3000 feet. Hence, by inference, it is deduced that it could find similar sulphide bodies if they were buried 2500 feet below surface and the aircraft flown at 500 feet. Thus a considerable improvement over conventional airborne electro-magnetic systems is obtainable with AFMAG. Airborne exploration in mountainous terrain involving deep valley fill now becomes possible. Examples are presented of the results of actual airborne AFMAG test surveys over known deposits of massive sulphide mineralization. Interpretation of the data is discussed with particular reference to the knowledge of size, dip, depth, depth extent, and conductivity of causative bodies as deduced from the flight records. The possibility of mapping major geologic structures, for both mining and oil exploration purposes, is discussed with the aid of examples of airborne AFMAG data. INTRODUCTION Electrical prospecting with natural audio frequency electromagnetic waves as a source has, within the last three years, become a practical reality. Both airborne and ground survey instruments under the trademark "AFMAG" (for audio frequency magnetics) have been used successfully in the search for conductive mineral deposits. It is the object of this paper to discuss the principles of airborne AFMAG and to illustrate its application by means of examples obtained over known geological situations. WHY AFMAG? In view of the large number of good airborne electromagnetic systems available for purchase or contract surveying, one may well ask, "Why another new system?". Primarily the answer lies in the fact that AFMAG does not suffer from the very limited depth of exploration available with, and inherent in, any conventional airborne electromagnetic system. AFMAG is not conventional insofar as an artificial transmitter is not required. Only a receiving and detecting device is employed. The electromagnetic fields measured are those from millions of electrical discharges in the atmosphere (e.g;..- lightning strokes). Their random distribution in time and space make these fields difficult to employ and it is only with recent advances in the electronics of geophysical instrumentation that this has become possible. A second reason for AFMAG and one of its

Jan 1, 1961

By D. I. Bardos

The occurrence of Laves phases (AB,) in various binary alloy systems has been reviewed in recent papers.13 Iron forms Laves phases with Sc-, Ti-, V- and Cr-group elements. However, two of the corresponding Laves phases with cobalt, namely MoCo, and WCo,, are missing. Nickel forms binary Laves phases with Sc and Y, but not with any Ti-, V-, or Cr-group element. These conditions are schematically illustrated in Table I. That electron concentration is a significant factor in determining which type of Laves phase is formed in a given case was recognized long ago by Laves and Witte,4 This concept has been more recently applied to Laves phases formed by transition ele-ments. It now appears that the average electron concentration (average number of electrons per atom outside of the closed shells of the component atoms) may be an important factor also in determining whether or not a Laves phase can occur at all in a given system. As shown in Table I, in the transition element systems considered Laves phases are absent at electron concentrations of 8, or larger (to the right and below the double line in Table I). These absences clearly cannot be accounted for on atomic size considerations, as evidenced by the many inconsistencies apparent in Table 11. While the ideal radius ratio for Laves phases is 1.222, in the systems which do have Laves phases the ratios of CN 12 radii range from 1.10 to 1.46. The consistent absence of Laves phases at RA/RB< 1.10 might be attributed to the low values of these radius ratios. However, Table II shows that absences also occur irregularly throughout the radius ratio range covered. In a previous paper7 it was concluded that, in transition element systems forming u-phases, silicon may act as an acceptor of electrons, thus stabilizing the u-phase at electron concentrations higher than

Jan 1, 1962

By W. C. McClain

The amount of vertical subsidence occurring over a longwall operation is a function of the thickness of material removed, the quantity and quality of any fill material, the width of the extraction, and the depth. The relationship between these variables is empirically determined, and subsidence can be predicted using only a few easily established constants which are subject to local conditions, such as the angle of draw. Associated with the vertical subsidence are both tensional and compressional horizontal strains. The component of strain in the direction of face advance is temporary, while the component perpendicular to the direction of working is permanently retained by the ground. It is these horizontal strains and the vertical strain (tilt) which result in damage to surface structures. It is possible to ameliorate the consequences of mining subsidence by utilizing the well-proved techniques described in this paper in the underground operations and on the surface. INTRODUCTION In the past, American mining practice in stratified deposits has been mostly restricted to production by the room-and-pillar system where a sizable percentage of the salable product is left in place as pillars. These pillars are usually regularly spaced and provide a permanent support for the roof of the mine and the surface above. The longwall system employs an advancing face which may be as much as several hundred yards long and some sort of breaking and loading machine which moves back and forth along the length of the face. The roof is supported behind the face only to a distance required to provide working space for the production machine. The supports are then withdrawn and the roof is allowed to cave. The longwall system therefore possesses the various advantages of complete extraction, thus effectively increasing reserves, while at the same time eliminating the necessity and cost of installing artificial supports such as roof bolts and heavy steel girders over large areas. Longwall mining has long been practiced in Europe, where it has undergone an involved development, culminating in the recent perfection of powered-loading machines and automatic self-propelled supports, offering high productivity. With ever-in creasing

Jan 1, 1967

By Marius R. Campbell

VARIOUS classes of coals are recognized in this country at the present time. These classes depend largely upon physical characteristics rather than upon chemical composition, and consequently they cannot be accurately defined. The divisions into anthracite, semi-anthracite and semi-bituminous are fairly satisfactory; but the term bituminous embraces so large a variety of coal that it is of little value, and the term lignite is so loosely applied that it has little or no place in a scientific classification. At present there is no way of accurately defining the vari¬ous classes of coal, because no adequate scheme of classification, which applies to lignites as well as bituminous coal and anthracite bas been proposed. The object of this paper is to present such a scheme, which is based upon data obtained dur¬ing the past year by Prof. N. W. Lord,1 in charge of the chemical laboratory of the United States Geological Survey coal-testing plant at the Louisiana Purchase Exposition, St. Louis. All the classifications of coals proposed prior to 1877 were based either on physical characteristics or on proximate analyses, including all of the impurities. These schemes were illogical and highly unsatisfactory, for the physical properties of a coal give little indication of its true composition; and impurities, such as ash and sulphur, are largely the results of acci-

Sep 1, 1905

By T. Koulomzine

The theory of the Askania magnetometer, as well as a complete discussion of all factors influencing magnetometer readings, is very ably described by J. Wallace Joyce. We will assume that the reader is thoroughly familiar with this theory and we will use whenever possible the same notations for the physical values involved in the theory. On the other hand, we believe that the principal formulas of the magnetometer can be deduced much more easily by the use of differential calculus than by the methods employed by Joyce. Consequently, we are presenting herewith a resume of the theory of the vertical magnetometer in order to determine the correct formula of the temperature coefficient which we propose to compensate.

Jan 1, 1949

By Everett D. Jackson

The largest deposits of chromite in the United States occur in tabular layers in the lower part of the Stillwater Complex, Montana. Nearly 900,000 long tons of chromite concentrates have been produced from mines and mills in this area, and reserves equivalent to more than 2,500,000 long tons of Cr2O3 remain in the ground. Layered concentrations of chromite (known as chromitite zones) occur only within olivine-rich layers of the Peridotite member of the Ultramafic zone of the Stillwater. As many as thirteen chromitite zones, lying conformably one above another, have been found, but only five of them are thick enough to be of any conceivable economic interest, and only two of them have been mined to date. Individual chromitite zones can be recognized by their distinctive internal character and by their stratigraphic position in the Peridotite member. The chemical composition of chromite varies consistently between and within the different chromitite zones. The zones range in thickness from about an inch to more than 12 feet, and the Cr2O3, content of their chromite ranges from 36.6 to 49.2 weight per cent. In any given area, the G chromitite zone is the thickest, but the chromite of the H chromitite zone has the highest grade. Laterally, the thickness of the chromitite zones is related to the thickness of the Peridotite member; in general all are thicker in the eastern part of the Stillwater than in the western part.

Jan 1, 1968

By Zay Jeffries

A SURVEY of rare metals and minerals for the past year places uranium as one of two partners, the other being the neutron, in what historians will probably say is the greatest discovery in physics at least during the year and probably for a consider- ably longer period. The uranium atom has been made to divide into parts somewhat after the style of reproduction of the amoeba. When an amoeba divides into two parts, however, it produces two amoebae substantially alike and each substantially like the parent: furthermore, there is no considerable change of energy when this happens. When the uranium atom divides it yields other atoms such as barium and krypton with the complete destruction of the original uranium atom but with the liberation of a tremendous amount of energy. This will be discussed more at length later.

Jan 1, 1940

By A. Gatti

A dispersion of AI2O3 was produced within chromium by the hydrogen reduction of a solid solution of Cr2U3-A1203. The yesulting powder. was compacted, extruded, and the material tested in tension at various temperatures and in creep at 1800°F. The material is ductile above 1200°F and is at least twice as strong as electrolytic chvomium at all temperatures. Its creep resistance, rupture strength, and ductility at 1800°F warrant further work to improve its Low -temperatutre properties. BECAUSE of its high melting point and excellent corrosion resistance, chromium has long been considered as a base for high-temperature alloys. Most chromium base alloys, however, are extremely brittle at low temperatures. Elements such as nickel and iron lower the melting point of chromium and thereby limit its high-temperature usefulness. Chromium-alumina materials made by othersl, 2 have shown good high-temperature creep resistance but poor ductility and thermal shock resistance. Pure ductile chromium3 is weak at high temperatures and reverts to a brittle state if exposed to nitrogenous atmospheres. In sintered aluminum powder (SAP)4 and internally oxidized alloys of silver, copper, and nickel, fine dispersions of oxide phases can control hardness, recrystallization, and yield stress. The possibility of formation of a ductile, high-strength material by precipitating dispersions of alumina in a chromium matrix appears worthy of investigation. MATERIAL Powder Production—Chromium oxide and alumina in amounts to produce a final alloy of Cr + 16 pct AI2O3 by weight were colloid milled, filtered, dried and high fired for 16 hr at 1600°C in air. The resulting solid solution of oxides was ball-milled to a fine powder and the chromium oxide reduced to chromium by heating in pure dry hydrogen for 64 hr at 1400°C. Final Materials Produced by Powder Metallurgy Techniques—-Chromium powder, containing a disper-sion of alumina, was pressed into 1 1/8-in. diam slugs at 25 tons per sq in. and sintered 16 hr at 1400° C in pure dry hydrogen. The sintered slugs were encased in a stainless steel can, 2 in. in diam, and extruded at 1200° C through a 1/2-in. die. The 16 to 1 extrusion ratio produced a final chromium-alumina rod 1/4 in. in diam about 30 in. long. Samples of the rod were plunge-ground to small rupture bars of 0.82-in. gage length with a 0.01-sq-in. cross section. RESULTS Microstructure Studies—Fig. 1 is the microstruc-ture of the material in the as-sintered condition while Fig. 2 is the microstructure of the material as-extruded. Comparison of the as-sintered and as-extruded micrographs show the redistribution and realignment of the alumina inclusions by the extrusion

Jan 1, 1961

By Y. C. Liu

Both the habit plane of martensite and the orientation relationship between the matrix and martensite platelets of different habit planes have been investigated in binary titanium alloys with molybdenum, chromium, and iron. The effect of the mode of deformation on the martensite habit plane was studied. A micrograph of an exposed mar-tensite platelet is presented. IN the study of martensitic transformation in Ti-Mn alloys,&apos; two martensite habit planes—{334), and {344)8—were reported. The {334), habit was also observed in unalloyed titanium upon transformation,&apos; although there is disagreement with respect to the exact indices. The other habit plane, {344),, has not been reported in martensitic transformation in any other alloys. The present investigation was made to determine whether other binary titanium alloys with P-stabil-izing elements would exhibit a crystallography of transformation similar to that of Ti-Mn alloys. Furthermore, since martensite platelets can be induced by deformation under certain conditions, it was of interest to investigate whether the mode of deformation, compressive or tensile, would influence the formation of martensite platelets on a specific plane in an alloy system which possesses two martensite habit planes. Experimental Procedure The material used for the preparation of the binary alloys of iodide titanium with molybdenum, chromium, and iron had the following purities: 99.99 pct iodide titanium, 99.9 pct molybdenum, 99.423 pct chromium, and 99.9 pct iron. The compositions of alloys listed in this paper are in nominal weight percentage. All specimens used were prepared and treated according to the procedure described in reference 1, unless stated. For the subzero temperature treat,ment the following experimental schedule was followed. After specimens had undergone the grain-growth treatment, they were quenched into an ice-water bath and were then metallographically examined. In specimens of higher alloy content, no martensitic transformation was observed. In those in which mar-tensitic transformation did occur, only specimens in which the martensite platelets existed as fine needles in localized regions were used. All specimens were reannealed 17 hr at 1200°C, quenched into ice water. and the capsule was broken. They were held in the ice water for from 5 to 10 sec, then transferred to a liquid-argon bath. This stepped quenching procedure was found to be more efficient than direct quenching into liquid argon. In the latter case, as soon as the hot specimen was immersed in the liquid argon, a protective, insulating layer of argon gas formed, and the specimen continued to glow vividly in the bath for some time. In the study of the habit behavior of martensite produced by deformation, specimens were deformed at room temperature either by compression, tension, or rolling. Martensite habit planes were determined by the two-surface analysis procedure described in reference 1. A stereographic net of 153/4 in. diam was used throughout the investigation. The method for determining the orlentation relationship between martensite and the matrix follows that used by Greninger and Troiano.&apos; A diamond-polishing table with its auxiliaries was used in order

Jan 1, 1957

By M. E. Bell

The term "operational research" was probably first used to describe work started under E. C. Williams, now Director, SHAPE Air Defense Technical Center, late in 1937 or 1938, at the Bawdsey Research Station of the British Air Ministry, a laboratory center concerned with the development of radar equipment. After the practicability of the early techniques had been demonstrated, a large (for those days) program of development and installation was authorized. It was very soon realized, both by the Royal Air Force and by the scientists that almost as important as the gear itself was the way in which it should be used. Accordingly, it was decided that some scientists should cooperate to study the way in which the equipment should be deployed and operated in conjunction with the Royal Air Force. To distinguish this work from the normal work of a research and development establishment, the term "operational research" was coined. It merely meant at this time that this particular section of scientists was to be concerned with the use of the gear rather than with its technical development and it seemed natural to those concerned to adopt the word "operations" which has a specific connotation in the armed forces.&apos; This method was later extended to peacetime business enterprise, government operations and other human activities. Operations research appears to have penetrated the extractive industries more slowly and less completely than other industries, the military, or the government. This may be due (1) to a difference in the attitude of management towards operations research, or towards research of any kind, for that matter; (2) to unsuitability of the extractive industries for application of the operations research method; (3) to inaccessibility of the data; (4) or to a lack of trained personnel who are interested in applying operations research to the mineral industries.

Jan 8, 1963

By Robert S. Young

During the last quarter-century, exploration for metallic deposits in Maine has been sporadic with peaks generally coinciding with periods of high metal prices. Known cases of regional or semi-regional evaluations are few; most efforts have been local and usually intensive. On the basis of broad geologic groups, the State has been divided into five fundamental environments: ( 1) coastal metamorphic belt; (2) southern volcanic belt; (3) Silurian slate belt; ( 4) northern volcanic belt; and ( 5) Devonian slate belt. Although not restricted to these areas, exploration in recent years has been concentrated in the northern and southern volcanic belts. Notable examples of recent exploration activity, directed to sulfide minerals, include: ( 1) the Knox County nickel-copper-bearing ultramafic rocks; (2) the Harborside (Cape Rosier) copper-zinc deposit; (3) the Second Pond (Black Hawk) zinc-copper-lead-silver deposit; ( 4) the Big Hill-Barrett lead-zincsilver- copper-gold zones; (5) the Parmachenee copper-zinc belt; ( 6) the Moxie Lake nickeliferous peridotite; and (7) the Attean quartzmonzonite molybdenum-copper occurrences. The Second Pond and Harborside prospects appear to be close to production. Systematic investigations for non-metallic deposits appear to have been aimed principally toward limestone, asbestos, diatomaceous earth, and spodumene-bearing pegmatites. Advances in prospecting methods, high metal prices, a favorable business outlook, increasing cooperation from large landholders, and some discoveries support the probability of increased exploration activity in Maine during the coming decade.

Jan 1, 1968

By CLAYTON C. BALL

In the year 1948, more than ever before, the coal industry established itself on the threshold of a new and exciting future expansion. While production did not equal the wartime and peacetime peaks of 1944 and 1947, it was, in review, a good coal year. During the latter part of the year a combination of mild weather, record stock piling, and general business slackening reduced coal demand to the extent that marginal mines suspended operations, while mines remaining active found it necessary to renew their attention to producing better products at lower operating costs.

Jan 1, 1949

By Robert Stefanko

With passage of the Clean Streams Act of the Commonwealth of Pennsylvania and its impact on the coal industry, considerable research has been conducted to explore various approaches to the problem, including deep-well disposal. Available drillhole data from gas and oil wells were used to develop cross -sectional maps for various portions of the state and potential disposal zones were evaluated. Bethlehem Mines Corp., faced with a severe water problem at its Marianna operation in Washington County, cooperated with the Dept. of Mining at The Pennsylvania State University in establishing a 1500-ft well into the Salt Sands for the purpose of determining the feasibility of mine water disposal. The thickness, porosity, and permeability of the formation at the well site proved to be below what had been anticipated from drillhole data. Further, subsequent hydraulic fracturing did not improve the flow characteristics of the well; pumping pressures remained in the range of 1800-2000 psig for disposing of water at the rate of 150 gpm. The legal problems of disposal at the site were very formidable. When the Salt Sands proved to be less than satisfactory, permission could not be obtained to dispose in other promising formations. The paper details many of the problems associated with the experimental well and makes an assessment of the potential for deep-well disposal of mine water. The concept of disposing of liquid industrial wastes by deep-well injection is not a new one. Brines associated with crude oil long have been disposed of in this manner, with the additional benefit of aiding secondary oil recovery. More recently, with the expansion of nuclear energy, the lethal, highly radioactive wastes which are by-products of the fission process have created severe disposal problems. During the past ten years, a variety of industries have resorted to subsurface disposal, some of the details of which are given e1sewhere.l,2 The list reveals wide variations in injection rate, pumping pressure, cost, and waste disposition. Included are successful installations in Western Pennsylvania. Enactment of more restrictive clean-water legislation in Pennsylvania recently had a great impact on the coal industry. Among its provisions was the reclassifica-tion of most mine water as industrial waste whose dis-posal is prohibited in any stream of the Commonwealth. This had the effect of accelerating research in a variety of areas, although treatment methods still retained primary interest. When a feasibility study of deep-well disposal was proposed to the Pennsylvania Dept. of Mines and Mineral Industries, the Coal Research Board (CRB) approved it. This paper summarizes the efforts on this project. Acid mine water is a chemically complex liquid. having no definite quantitative relationship among its constituents. However, it is the iron disulfide (FeS2) associated with practically all coal seams that produces the objectionable products present in acid mine water when combined with air and water. The principal contaminants are sulfuric acid (H2SO,) and ferric hydroxide (Fe(OH)2. Ferric hydroxide is a rust-colored gelatinous precipitate that coats stream bottoms and destroys aquatic life. However, other ions and bacteria are present in acid mine water in varying amounts.

Jan 1, 1971