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By P. B. Baxendell, R. Thomas

Work on the calculation of vertical two-phase flow gradients by Cia. Shell de Venezuela has been based mainly on the "energy-loss" method proposed by Poett-mann and Carpenter in 1952. The "energy-loss-factor" correlation proposed by Poettmann and Carpenter was based on relatively low-rate flow data. This correlation proved inapplicable to high-rate flow conditions. In an attempt to establish a satisfactory correlation for high rates, a series of experiments was carried out at rates up to 5,000 BID in Cia. Shell de Venezuela's La Paz field in Venezuela, using tubing strings fitted with electronic surface-recording pressure elements. As a result of these experiments a correlation between energy-loss factor and mass flow rate was established which is believed to be applicable to a wide range of conduit sizes and crude types at high flow rates (e.g., above 900 BID for 27/8-in. OD tubing). It is anticipated that the resulting gradient calculations will have an accuracy of the order of % 5 per cent. At lower flow rates the energy-loss factor cannot be considered as constant for any mass rate of flow, but varies with the free gas in place and the mixture velocity. No satisfactory correlating parameter was obtained. As a practical compromise for low flow rates, a modification of the curve proposed by Poettmann and Carpenter was used. In practice this was found to give gradient accuracies of approxirnately ± 10 per cent clown to flow rates as low as 300 B/D in 27/8-in. tubing. INTRODUCTION Production operations in Cia. Shell de Venezuela's light- and medium-crude fields are principally concerned with high-rate flowing or gas-lift wells. Under these conditions the analysis of well performance, the selection of production strings and the design of gas-lift installations are vitally dependent on an accurate knowledge of the pressure gradients involved in vertical two-phase flow. Initially, attempts were made to establish the gradients empirically as done by Gilbert,' but the results were not reliable due to scarcity of data over a full range of rates and gas-oil ratios. Several methods of calculation based on energy-balance considerations were attempted, but the computations were cumbersome and the results cliscouraging. In 1952 a paper was published by Poettmann and Carpenter' which proposed a new approach. Their method was also based on an energy-balance equation. but it was original in that no attempt was made to evaluate the various components making up the total energy losses. Instead, they proposed a form of analysis which assumed that all the significant energy losses for mutiphase flow could be correlated in a form similar to that of the Fanning equation for frictional 1osses in single-phase flow. They then derived an empirical relationship linking measurable field data with a factor which, when applied to the standard form of the Fanning equation, would enable the energy losses to be determined. The basic method was applied in Venezuela to the problem of annular flow gradients in the La Paz and Mara fields" This involved establishing a new energy-loss-factor correlation to cover high flow rates and, also, some adaptation of the method to permit mechanized calculation using punch-card machines. The final result was 1 set of gradient curves for La Paz and Mara conditions which proved to be surprisingly accurate. With the encouraging results of the annular flow calculations, several attempts were made to obtain a corresponding set of curves for tubing flow. Here, unfortunately, little progress could be made. The original correlation of Poettmann and Carpenter was based on rather 1imited data derived from low-rate observations in 23/8- and 27/8-in. OD tubing. It did not cover the higher range of production rates, and extrapolation proved unsuccessful. A new correlation covering high flow rates was required, but this proved to be extremely difficult to establish since tubing flow pressure measurements at high rates did not exist—due to the difficulty of running pressure bombs against high-velocity flow. The necessity for reliable tubing flow data increased with the development of the new concessions in Lake Maracaibo, where high-rate tubing flow from depths of 10,500 ft became routine. Thus. it was decided to set up a full-scale test to establish a reliable energy-loss factor for tubing flow conditions. A La. Paz field light-oil producer with a potential of approximately 12,000 B/D on annular flow was chosen. To obtain full pressure gradients, a special tubing string was installed which was equipped with electronic surface-recording pressure measuring devices,

By Arnulf Muan, Hobart M. Kraner

Ferromanganese alloys react with aluminu-silica brick in blast furnace hearths and cause the formation of new phases with low refractoriness and consequent failure of the refractory lining. The nature of these reactions is explained on the basis of petrographic observations, thermodynamic data, and Phase equilibrium considerations. Animproued hearth design resulted from these findings. The production of ferromanganese in blast furnaces presents many problems which are not encountered in the production of iron in the same furnaces. One of the most serious of these problems is the rapid failure of refractories caused by their reaction with the ferromanganese metal. The present paper describes such a "hearth attack", its symptoms, causes, and cure. Following an introductory discussion of operating practice in ferromanganese blast furnaces, results are presented of a petrographic examination of samples from a furnace which had to be shut down because of refractory failure. The causes of this failure are then analyzed on the basis of petrographic observations combined with thermodynamic and phase equilibrium data available in the literature. The latter type of data were subsequently used as a guide in recommending improvements in hearth designs which have since proven themselves successful in practical operations. I) FERROMANGANESE BLAST FURNACE PRACTICE It is considered good practice to blow in a furnace on iron and operate it in this way for a period of time preliminary to producing ferrornanganese. During this time, iron generally penetrates the bottom refractories six or more feet below the original working surface of the hearth. Not only does this metal pervade the joints to these depths, but the pores of the refractories are usually also filled by molten iron. The high throughput of the iron furnace provides ample heat to maintain a high temperature in the hearth refractories. This, together with a high ferrostatic pressure, causes porous clay brick of the hearth to shrink. During subsequent use of such a furnace in ferromanganese production, the iron in the pores of hearth brick if; replaced to some extent by ferromanganese. The replacement is usually not complete. This is probably due to the lower metal throughput and lower prevailing temperatures resulting from this in the brick of the hearth bottom. When the ferrornanganese furnace is banked—or when the temperature in the furnace falls due to a furnace delay—-manganese oxidizes even though the atmosphere is largely CO. Considerable expansion accompanies this oxidation of manganese from metal to oxide. The hearth refractories are then subjected to the disintegrating forces of the volume expansion. These forces may in extreme cases be large enough to lift the furnace off its mantle supports as was described in a previous paper.' When cooling takes place slowly, however, and the temperature remains at a fairly high level, the refractories undergo fluxing action by the MnO. This latter reaction and the reduction of SiO2 of the clay brick is the general subject of the present paper. The observations to be described herein were made on a ferromanganese furnace located at the Johnstown plant of Bethlehem Steel Co. The furnace was lined entirely with clay refractories and had operated on iron for 266 days and on ferromanganese for 96 days prior to being taken off because of a hearth wall failure. II) PETROGRAPHIC EXAMINATION AND CHEMICAL ANALYSIS The photograph reproduced in Fig. 1 shws a cross section of the upper part of an 18 by 9 by 4-1/2 in. bottom block removed from the blast furnace. This brick came from a depth of approximately 6 ft below the original working face of the bottom. It will be noted that the 4-1/2 in. dimension is almost the same as when the brick entered the furnace. Three characteristically different zones marked I, II, and III on the print of Fig. 1 are apparent. Results of chemical analyses of the original brick and samples from each of these zones are listed in Table I. Petrographically the various zones were characterized as follows: The central zone marked I was essentially un-reacted brick. The microstructure consisted of fine needles of mullite, and the pores in this entire area were filled with iron. This is characteristic of

Jan 1, 1962

By Louis A. Panek

INTRODUCTION AND SUMMARY With respect to the geomechanics aspects, the primary technical objectives in mining by an undercut-cave method are to achieve a controlled, sustained caving of the mineral body and to remove the fragmented ore with a minimum of dilution from surrounding unmineralized rock, while maintaining stability or control of the rock structure around the access openings. The structurally ideal ore body probably does not exist. If the rock mass is so weak as to cave on a short span, it may tend to be too sticky for easy drawing and handling, or create special problems in regard to support of the access openings. If the ore is strong, caving may be difficult and the caved fragments may be of such a large size as to require special equipment for transferring the ore from the caved zone. Given enough time and money to generate data and conduct trials, engineering and ingenuity can devise an appropriate combination of mine layout, sequence of extraction, and mechanical equipment to achieve a technically successful caving extraction operation to meet the foregoing requirements in many types of deposits. The large capital investment involved, however, reduces the freedom to make major changes once the mine development is well under- way, and the penalties for failure to accurately anticipate operating conditions militate against selecting any but the most obvious candidates for mining by an undercut-cave method. The demonstrated capability to extract large, deep, economically marginal deposits by this low-cost, high-volume method of mining provides an incentive to develop a rationale for predicting the cavability and stability characteristics of a deposit prior to mining, so that the undercut-cave method may be extended to a much wider range of mineral deposit characteristics. The ultimate goal is to establish as explicitly as possible the quantitative interrelationships between the measured rock-mass characteristics, the caving span, the size distribution of caved ore fragments, and the sizes and locations of stable access openings. Lacking an understanding of these relation- ships, a designer may readily change some factor in the wrong direction (e.g., excessively reduce the distance between the extraction level and the undercut to increase the convenience of operations for the undercutting crew, increasing the frequency of repairs to the extraction-level support system) or create unnecessary problems elsewhere in the system by introducing a design change that can achieve only minimal improvement in the factor of direct interest (e.g., unnecessarily complicate the ore-transfer system by changing the orientations of the openings, with- out succeeding in the objective of improving the ground support conditions). Although successful predesign is the prime objective, subsequent modifications in mine lay- out and sequence of extraction operations are inevitable. In developing the modified solution, systematic experimentation based on an understanding of the underlying structural relationships, coupled with monitoring measurements of selected diagnostic structural-behavior parameters, can achieve an acceptable solution in a minimum number of steps, which is far superior to the typical operational trial-and-error approach, in view of the cost of implementing each successive change. Since a drill-core sample of ore rock from a successful undercut-cave operation may exhibit a uniaxial crushing strength in excess of 100 MPa, the caving of such a rock mass is now commonly believed to be ascribable to the presence of discontinuities such as joints or fractures throughout the ore body. An essential part of the present investigation was therefore to characterize the natural discontinuities at each of the test sites by measuring their attitudes and spacings. The term "fracture" is used herein in a general sense to include any planar discontinuity without implication as to its suggested mode of origin. Most, but not all, of the fractures are properly termed joints. As a point of departure we may consider the possibility that the rock mass is transected by three families of joints, each family possessing a distinct orientation, such that parallelepipeds of intact rock are delineated by the jointing. Even if cementation is absent between adjoining parallelepipeds, the undercutting of the rock mass will not necessarily initiate sustained caving--owing to the all-around confinement, an arch may tend to stabilize over the undercut unless prevented from doing so by the failures of key blocks of intact rock. Thus, although the jointing can be assumed to weaken the rock mass, creating preferred directions of

Jan 1, 1981

By D. O. Hobson, P. L. Rittenhouse

We have recently found that many lots of Zircaloy-2 and -4 tubing tested in tension deform to cross section shapes that are "polyhedral" rather than circular. The noncircular cross sections seem to result from a circumferential variation in plastic proper -ties and, therefore, in texture. We examined the diffracted X-ray intensity from (OOOl), {1010), {ll20}, and {1011} planes parallel to the tubing surface around the entire circumference. Tubing that deformed to a circular cross section showed <5 pct variation in diffraction intensity around the circumference from any of these planes. Greater intensity variations were found for all the tubing materials that developed non-circular cross sections during deformation. In each instance the number of intensity maxima and minima was consistent with the number of sides of the &apos;polyhedral" cross section. THE effects of crystallographic texture on the mechanical properties of zirconium, zirconium alloys, and other anisotropic hexagonal materials such as titanium and hafnium have been intensively studied. If the natural crystallographic anisotropy of these materials could be controlled by selected fabrication operations, a material could be produced with a texture, or preferred orientation, in which the maximum strength directions are in the stress directions of the structure. The permissible stress levels of the structure could then be increased. Rittenhouse and Pickle-simerl have shown that highly textured Zircaloy-2 plate can vary from 52,000 to 70,000 psi in tensile yield and from 62,700 to 122,000 psi in compressive yield strengths as a function of specimen orientation. Similar texture effects have been observed in Zircaloy tubing, whose mechanical properties differ depending upon whether the tubing has basal poles predominantly radial or tangential and upon the mode of testing. These same texture effects might be troublesome if the texture in the tubing is not uniform around the tube walls. This paper is concerned with the effects of nonuniform texture on the strain behavior of commercial Zircaloy tubing. BACKGROUND Previously, various lots of commercial Zircaloy tubing were tested under selected stress conditions as part of a program to determine the four quadrants of the yield locus. One of the testing procedures was uniaxial tension and it is the influence of texture variations on the tensile deformation behavior of the tubing that is of interest here. The effect of texture on the strain behavior in tubing is very apparent from a uni-axial tensile test.2 This behavior is illustrated schematically in Fig. 1 for three different tubing textures: 1) basal poles predominantly in the radial direction; 2) basal poles predominantly in the tangential direction, and 3) basal poles equally distributed between the radial and tangential directions. In the first example most of the grains are oriented for prism slip to operate to allow axial lengthening and diametral reduction of the tube. Reduction in wall thickness requires {1122} twinning, a more difficult operation than slip.* In the second example, the texture is such that *The singleCrystal analogy will be used quite often in this paper when strong texturesare being discussed. The textured material is assumed to react as if it were a single crystal aligned in the same orientation and under the same stress system as the predominant texture._____________________________________________ prism slip operates to give axial lengthening and wall thinning. Diametral reduction requires twinning and again should be more difficult to accomplish. A specimen with basal poles equally distributed between the radial and tangential directions should exhibit about equal diametral and wall strains.* Table I shows the *Diametral strain is accomplished by a combination of circumferential and longitudinal strains. But, for the purposes of this paper, it will be considered as a strain causing a change in the length of a specified diameter.__________ strain behavior of two lots of tubing with different textures. The first tube has a texture with basal poles equally distributed between the radial and the tangential directions. The ratio of true thickness strain to true diametral strain is almost unity. The second tube has a predominantly radial basal pole texture and it is apparent that most of the total strain has occurred by diameter reduction, just as one would predict. There is over three times as much diametral strain as thickness strain. RESULTS We found that specimens from certain lots of commercially fabricated tubing did not retain round cross sections during uniaxial testing. Instead, the speci-

Jan 1, 1970

By Ralph Hultgren

IN solid solutions atoms of differing sizes occupy the same crystalline lattice, requiring that some of them be compressed and others expanded. The energy involved has been called misfit strain energy and is an important concept of crystal chemistry. If the atomic sizes and elastic constants of interatomic bonds are known, the misfit energy may be calculated,&apos; provided certain simplifying assumptions are allowable. Usually, isotropic crystals are assumed and interatomic distances are taken to be the statistical average determined from X-ray diffraction. Such calculations yield values of the misfit energy of the order of 1 or 2 kcal per atom in alloys such as Au-Cu at compositions of 50 atomic pct. However, evidence has accumulated in recent times that atoms change their sizes with composition of alloys, implying electronic rearrangement of the bonds. The size changes have been found particularly by application of the X-ray method developed by Warren, Averbach, and Roberts.&apos; Thus, Averbach, Flinn, and Cohen3 determined radii in Au-Cu alloys. Oriani4 showed that these new radii led to a calculated misfit energy in disordered AuCu, which was decreased from the values calculated by the usual theory more than twenty-fold, to only 80 cal per g atom. Thermodynamic calculations from the phase diagram5 also show misfit energy to be no more than a few hundred calories per g atom in this alloy. The question of what electronic rearrangements are possible therefore becomes compelling in estimating misfit energy. In the following pages the results of certain calculations on the AuCu tetragonal superlattice are submitted. Conclusions drawn from these should be applicable in large degree to disordered solid solutions. As in all ordered states, bonding distances in the superlattice are individually known, rather than being merely average distances as found from lattice constants of disordered states. Moreover, only the Au-Au and Cu-Cu distances are strained; the elastic constants of these are known in the elementary state. In the usual calculation it is necessary to assume elastic constants for Au-Cu bonds. Misfit energy has thus been calculable without the need of many simplifying assumptions usually made. It is still assumed that equilibrium bond lengths and elastic properties of the bonds are the same in the alloy as in the pure metals. As previously discussed, this is probably not correct. Also assumed is that the bonds are not affected by strain of neighboring bonds. A calculation of Young&apos;s modulus from compressibility data shows this to be far from true; extensive electronic rearrangements take place. It would seem that misfit energy cannot be calculated from elasticity data for the elements. The usual methods may, however, give an upper limit which is often much higher than the true value. The question of electronic rearrangement is, of course, a complex one. Pauling&apos;s theory gives a simple, approximate treatment of the relation between type of bond and bond distance. This has been applied with some success to the Au-Cu system, as will be shown in a later section. Misfit Energy in Au-Cu Alloys Hume-Rothery and Raynor6 discuss the Au-CU system as a type example of strain energy. The gold atom is 12.8 pct larger in diameter than the copper atom, near the size factor limit beyond which solid solubility is severely restricted. They therefore consider the misfit energy to be large, a conclusion for which they believe they find evidence in the phase diagram. Gold and copper are completely miscible in the solid state, but the alloy has a minimum melting point at an intermediate composition. From this Hume-Rothery and Raynor conclude that the strain energy is nearly large enough to prevent miscibility; the phase diagram tends toward a eutec-tic type. In Ag-Cu, which has almost identical size relationships, solid miscibility is quite limited; whereas in Au-Ag, where atomic sizes are nearly the same, there is complete miscibility without a minimum in the melting point. From their arguments the heat of formation of Au-Cu would be expected to be endothermic or only slightly exothermic, that of Ag-Cu to be endothermic, and that of Au-Ag to be exothermic. Deviations, from Ve-gard&apos;s law of additivity of atomic radii support these conclusions, since Au-Cu and Ag-Cu both have pronounced positive deviations, and Au-Ag has a negative deviation. Nevertheless, Au-Cu alloys form exothermically; indeed, considerably more exothermically than Au-Ag, Table I. Hence, strain energy must be much less important in this case than Hume-Rothery and Raynor have supposed.

Jan 1, 1958

By Blandford C. Burgess

Mica is an orchid among minerals. It is formed in pegmatites, one of the most bizarre of igneous formations, and is exceeded by few other minerals in the perfection it may attain as to size, color, and cleavage. First used for window glazing, as an ornament and article of trade, it has become one of the most essential insulators of electricity, heat, and shock. Most internal combustion engines use mica condensers or capacitors and such machines of war as planes, tanks, and submarines are immobile without it. The original manuscript of this guide was written in April 1943 at the peak of war emergency. It was not used because shortly thereafter a decision was made to buy on a one price basis eliminating differentials for both quality and size. This is now presented with the thought that from the standpoint of preparedness we can only consider another war imminent and every effort should be made to set up in usable form the experience gained during the Second Morld War. Colonial Mica Corp. was set up by Metals Reserve Co. as a wholly owned government agency to encourage production of domestic mica and to purchase it. It soon became the exclusive buyimg agency for such mica. The writer as Southern Manager called on all the private agencies buying mica to assist in formulating buying policies, methods, and prices. A meeting was held for that purpose in Asheville, N. C., July 20, 1942. In the general discussion the first two hours of the meeting it was decided that the following factors should be considered in pricing strategic mica: clearness, flatness, trimming, color, classification (size and quality), free splitting, hardness, and air inclusions. Most of the mica miners have been buying strategic mica, according to the mine, as No. 1, No. 2, or Nos. 1 and 2 combined. In addition to these grades of strategic mica they have been buying three lower grades of mica, electric (vegetable-stained), black-spotted and black-stained. A number of mines were named one by one and the buyers present gave their opinions as to the basis they would use in buying the sheet mica from each. It was suggested that in addition to the prices already published, prices be posted up to 10 pct higher for special quality and preparation and prices be posted 25 pct lower than the published prices for the lowest acceptable grades of strategic mica, giving the buyers authority to make intermediate prices according to the quality and preparation. It was thought desirable at the same time to announce prices for nonstra-tegic mica where such quality is being obtained in mines producing strategic mica and where it would be necessary to take the output in order to get the strategic mica. It was also suggested that the price of electric and black-spotted mica be 50 pct below the price of the lowest grade of strategic mica and the price of black-stained mica be 60 pct below the price of lowest grade strategic mica. The few experienced buyers available were employed but they were inadequate for the job and others had to be trained. All needed a guide or primer of some kind to attain systematic procedure and consistent prices in their respective buying areas. The Mica Buyers Guide was formulated for that purpose based on experience gained in the first six months of buying. The Preface to the original guide was as follows: The purpose of this guide is to serve as a text in training beginners and as a handbook for experienced buyers of the instructions which have been issued up to this time. At the meeting of prospective buyers last summer, it developed that the first essential to attain uniformity must be some kind of check sheet. Our "Mica Buyers Report" was developed for this purpose and forms the backbone of this guide. Price is determined according to size, quality and preparation. Size can be measured, but no system of measurement or machine has been devised which can be substituted for the trained eye of the buyer to deterrnine quality and preparation. Although the "One Price" system was instituted and the "Guide" not used, the buyers were required to continue making out a "Mica Buyers Report" (Fig1) with each lot of mica purchased. The form proved its value and there is no doubt that in another such emergency some similar form should be

Jan 1, 1950

By Chas. A. R. Lambly

In the extreme northeast corner of the State of Washington, on the Canadian border, lies the Metaline mining district. This district is old in history, but young in production. Geology The Metaline district is a zinc-lead area of the replacement type in dolomite and limestone. The ore bodies of the Josephine horizon are in many ways similar to the ore bodies of the famous Tri-State zinc fields. The beds are faulted and folded and have varying low dips in varying directions, and underlie large areas of the district. History Production started in 1927 on a very limited basis. The property is now mining and milling 700 tons per day. The mine is opened by adit tunnels and a vertical shaft. As the ore horizons gained depth, it was necessary to sink inclines to follow the ore horizon (see Fig 1). From 1927 to date, approximately 600,000 ft of diamond drill was put down This work indicated that suficient tonnage existed to justify a redesigning of the whole operation, surface and underground. After four years of general study, the following program was planned: 1. A new mine entrance, which would be an incline, that could follow the ore body down at whatever pitch was necessary. The incline will be equipped with conveyors for the moving of ore and waste to the surface and with tractor-type locomotives for man and supply transportation. 2. The new incline also required a new type of mining which was developed and is now in use. It is called contour mining and will be described in a future paper. 3. The new incline exit would necessitate the moving of the mill and mine shops across the Pend Oreille River. This part of the program is now underway. The Incline The sinking of the incline was to start as soon as World War II ended and was as follows: The first leg of the incline was to be sunk from the surface 1600 ft on a 17" slope. The collar and first level at elevation 2180 ft, the second level at elevation 2000 ft, the third level at elevation 1875 ft, and the fourth level at elevation 1700 feet. From the 1700 ft elevation the incline was to flatten out to 12" for 400 ft to give the necessary depth for the ore pockets below the 1700 ft level and the necessary clearance for future sinking (see Fig 1 and 2). Due to lack of manpower in 1946, the program was changed and was as follows: A drift was driven from the old mine workings on the 1700 ft elevation in an easterly direction. At 1300 ft the drift was turned N 50" E and at this point a raise was driven 180 ft on a 50" slope. This raise intersected the Josephine horizon and commercial ore was encountered. At the 2000 ft mark, a main raise was driven, 245 ft on a 50" slope, and the 1875 ft elevation was cut. Exploration drifts were started on this level and production followed on a limited basis. The main drift at the 2500 ft point was turned N 35" E and ran parallel to and 10 ft east of and under the proposed incline line. At the proposed intersection of the drift and incline on the 1700 ft elevation, it was planned to raise the incline to intersect the 245 ft raise and to continue on to the surface, a distance of 1600 ft. When this proposed intersection point was reached, a heavy flow of water, approximately 800 gpm, was encountered and all work on the main drift face was stopped. This water flow flooded the main pump station in the old mine and the two lower levels with approximately 20,000,000 gal of water. The water was controlled and finally drained from the cave areas and lower levels after six months of pumping. After the heavy flow of water was encountered in the main heading, it was decided that the incline would have to be started from the surface, as originally planned, so that too much time would not be lost. The surface overburden had to be removed, a total of 6000 yards. A temporary dry house for 6 men was built. An 8 in. churn drill hole was intersected in the first raise driven from the 1700 foot elevation tunnel. Air and water lines were placed in this hole, and air and water were delivered to the collar of the incline from the mine working. The incline started down at 15 ft wide and 7 ft high through the Leadbetter slates. After sinking 4 sets, it was

Jan 1, 1950

By Leslie W. Austin

ROTARY kiln operators will agree that some of the most severe conditions a refractory must stand occur in the hot zone of a kiln burning Portland cement, dead burn dolomite, magnesite, periclase, and similar materials. Frequently the operator is faced with factors beyond his control which drastically shorten the life of refractories. Shutdown due to mechanical failure can be serious if the period is of sufficiently long duration to cause the dropping of coating or the loosening of the lining. A change in slurry can affect the coating and cause ring buildup. A change in type of fuel and its effect upon the flame can cause a shift in location of the hottest zone. Weekend shutdowns or any other interruption can cause the operator trouble and may damage the refractories, since stopping and starting a rotary kiln is certainly more difficult than stopping and starting a motor. Some operators have tried to set an estimate of damage for each shutdown in equivalent days of running time. Conditions affecting the refractory may be roughly grouped in four classes: chemical attack, mechanical stress, thermal shock, and abrasion. Chemical Attack: The drive to obtain maximum production through a kiln demands maximum operating temperatures, temperatures which are limited more by the ringing up or melting of the clinker. This can cause interface temperatures at the junction of coating and refractory which require the use of a basic kiln block to withstand the chemical attack. Chemical changes take place within the refractory itself, especially in chemically bonded or unburned kiln blocks: These changes cause the formation of the ceramic or burned bond. Migrating liquids or fluxes from the kiln charge have an effect within the refractory and lead to mineral or glass formation. The alkalies, sodium and potassium, migrate into the refractory as silicates, chlorides, sulphates or other salts. They may move under capillary action or may be caused to move by volatilization with condensation in the cooler portion. Mechanical Stress: Concentrated stress may be caused by several factors or combinations thereof. 1-The rings of refractories must be kept tight and rigid within the kiln, and this alone demands considerable force to hold the blocks in place. So that the force will not be concentrated, the blocks should fit the circle as perfectly as possible, with the faces in contact overall. 2-As the kiln is heated, thermal expansion takes place at the hot end of the kiln block. Since this disturbs the plane face it too can cause a concentrated stress at the two ends of the block, and shearing stress can be set up within the brick itself because of the difference in expansion between the two ends. 3-If a lining becomes loose and moves in the shell very severe stress can be set up, and as the kiln rotates this load changes and gives the effect of repeated loading. Permanent expansion of the refractory can also cause severe loading. 4-Not least important, flexing of the kiln is frequently the cause of concentrated stresses. Thermal Shock: Thermal shock, the result of heating and cooling too rapidly, occurs on starting and stopping or when a large patch of coating drops, exposing the bricks. Again, its destructive effect is often the result of phase change, liquid to solid or the reverse; dense refractories loaded with glass-forming impurities are particularly susceptible. Thermal shock is a problem with refractories set in the wall or roof of a stationary furnace, and becomes even more serious in a rotary kiln, the tendency to spall being magnified with movement and concentration of stress. Uniform rate of feed and loading insures both better coating and a more uniform stress. Abrasion: If the refractories do not take a coating, abrasion can become a most destructive factor. Movement of the lining in shell or movement of loose blocks causes abrasion, which is also most destructive if the refractories do not take a coating. An analysis of the problem of basic lining for the hot zone reveals, therefore, a number of desirable characteristics: high refractoriness, basic chemical reaction, resistance to spalling, good strength at all stages, ability to take coating, true sizing, volume stability, and abrasion resistance. Increased demand

Jan 1, 1952

By S. R. Bardsley, S. T. Algermissen

Induction, nuclear and sonic well-logging methods were employed in a Green River formation oil-shale analysis and evaluation study conducted in northeastern Uintah County, Utah. The physical and chemical properties of an oil-shale section, previously cored and assayed by conventional methods, were used to evaluate the response of the various logs. The logging program was designed to measure variable properties of oil shale which relate to oil-yield potential in order that a relationship between assay-oil yield and log-determined properties could be identified, thereby permitting a direct determination of yield potential from logs alone. All of the major oil-shale zones and section ttlarkers are recognizable on the logs used in the study. The relationship between the response of the Density and Sonic logs and the assay-oil yield in gallons per ton was suficient to perinit the derivation of equations expressing the relationships. These equations can be used to determine the potential oil yield in gallons per ton of an oil-shale zone or section. The Neutron log response distinguishes the rich oil-shale intervals from the lean intervals, but does not appear to permit establishment of a quantitative relationship. The Garnma-Ray and Induction logs indicate only a qualitative relationship to oil-shale yields. Logging oil shale by Gamma-Gamrna Density and/ or Sonic logging methods will permit a fast, economical and accurate means of evaluating the potential yield of oil-shale deposits. Considerable sums of money have been allocated to Green River formation oil-shale evaluation during the past years by both private enterprise and Federal and state governments. The result of the work accomplished to date is commendable, but the task of fully exploring and evaluating one of the world&apos;s greatest reserves of potential energy for economical exploitation is enormous and much information is still needed. Present methods of evaluation consist primarily of sampling and assaying the oil shale for potential yield. The data received are excellent, but are both costly (inasmuch as it requires funds specifically allocated for the evaluation purpose) and time-consuming (as each representative sample must be assayed in the laboratory by specially trained personnel). At the present time, the Green River formation oil-shale province is one of the most active areas in the Rocky Mountain region for exploratory oil and gas drilling. This activity could play a twofold role and serve the function of spear-heading many oil-shale evaluation programs, as it could provide both cutting samples for assaying, geophysical data and modern well logs. This paper deals with a recent study conducted on Green River formation oil shale in which the application of induction, sonic and nuclear well logs to oil-shale evaluation was tested and proved. THEORY AND DEFINITIONS Oil shale may be described as siliceous marlstone, rich in solid organic matter called "kerogen". Kerogen is only slightly soluble in organic solvents, but it will decompose and yield oil vapors and gas when heated to destructive distillation temperatures at about 800 F. The mineral constituents of Green River formation oil shale are found in essentially uniform proportions with one another. The dominant types are, in the general order of abundance, dolomite, calcite, feldspars and quartz. Kerogen is also essentially uniform in its composition, and is about 80 per cent carbon and 10 per cent hydrogen by weight. The ratio of kerogen to the mineral constituents determines the richness or potential yield of the oil shale. This ratio also determines the total physical and chemical properties of the rock and provides a basis by which oil-shale richness may be determined from well logs. Because Green River formation oil shale was deposited in a lacustrine environment, the lithology is laterally consistent over wide areas. The vertical section consists predominantly of thin bands of alternating rich and lean oil shale which have been described by Bradley&apos; as varves. The varves are occasionally broken by thin bands of volcanic ash and tuff and by zones of lean vugular oil shale. The effect that the thin non-oil shale beds and vugular zones would have on the well log analysis was a prime concern in the study. To cope with this possible problem, the logs used in the study were of two types: (1) logs believed to respond favorably to those properties of oil shale which are dependent upon the kero-gen-to-mineral ratio, these logs being the Gamma-Gamma Density log, the Sonic log and the Neutron log; and (2) logs that would respond to litho-logies and properties within the oil-shale section not associated with yield that might result in anomalous responses by the yield-measuring logs. Logs of the second type were the Gamma-Kay log, the Induction log and the Caliper log. THE PRESENT STUDY The present logging study was con-

Jan 1, 1939

Jan 1, 1942

By C. W. Wright

The author proposes that events demand an inventory of our sources of "key" mineral commodities, here and abroad-to provide a realistic future strategic picture-to assist mine owners at home and abroad in planning future development.

Jan 1, 1961

STANDING COMMITTEES Executive-SIDNEY J. JENNINGS, chairman. Membership-KARL EILERS; chairman. Finance-GEORGE D. BARRON, chairman. Library-E. GYBBON SPILSBURY, chairman. Papers and Publications-BRADLEY STOUGHTON, chairman. Nominations-R. V. NORRIS, chairman. Institute of Metals Division-WILLIAM M. CORSE, chairman; FRED L. WOLF, secretary, Ohio Brass Co. Mansfield, Ohio.

Jan 12, 1918

Jan 1, 1927

Executive. CHARLES F. BAND, Chairman. JAMES F. KEMP, JOSEPH W. RICHARDS, ALBERT R. LEDOUX, BENJAMIN B. THAYER. Membership. BENJAMIN B. THAYER, Chairman. WALTER R. INGALLS, JOHN H. JANEWAY, JR., JOHN D. IRVING, HERMAN A. PROSSER. Finance. EDWARD L. YOUNG, Chairman. KARL EILERS, JAMES GAYLEY. Library. JAMES F. KEMP, Chairman 1 JOHN HAYS HAMMOND,3; E. GYBBON SPILSBURY,2 ALEX. C. HUMPHREYS,4 BRADLEY STOUGHTON.

Jan 5, 1913

[EXECUTIVE COMMITTEE OF THE BOARD OF DIRECTORS LOUIS S. CATES, Chairman DONALD H. NCLAUGHLIN, Vice-Chairman JOHN L. CHRISTIE JOHN R. SUMAN CLYDE E. WEED]

Jan 1, 1946

Jan 1, 1932

ALASKA Established Nov 19, 1947 Regular meetings last Monday of each month Ted C Mathews, Chairman Patrick H O&apos;Neill, Vice-Chairman Ralph B Norris, Secretary-Treasurer Box 643, Fairbanks, Alaska District Vice-Chairmen Leonard M Berlin, Juneau Alaska Harold Strandberg, Anchorage, Alaska Frank E Love, Nome, Alaska

Jan 1, 1949

Jan 1, 1939

By R. S. Sandhu, S. H. Advani, J. K. Lee, B. L. Aboustit

A comprehensive finite element formulation for thermo-elastic consolidation based on a general variational principle is presented Sample one dimensional problems associated with isothermal consolidation, heat conduct ion, and thermo-elastic consolidation are presented. In addition, evaluations of thermo-elastic consolidation for an underground coal conversion field site are conducted.

Jan 1, 1982