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By M. L. Requa

EVERY forward step in civilization brings with it an increase in population and increasing demand for raw materials. Modern civilization, because of its industrial development, depends more and more for its well-being on ample supplies of raw materials; the higher the type of that civilization, the greater its dependence. No fact is more obvious than that the raw materials should be put to use with greatest prudence and efficiency. National life is not a matter of a decade or a century. Conservation is no longer a matter for political discussion; it is a vital element in the future welfare of all nations. Unfortunately, to the minds of many, conservation means the locking up of natural resources, their arbitrary withdrawal, bringing about, in short, a condition of industrial stagnation. This has occurred in past centuries through misdirected governmental effort. Two eminent engineers have variously defined conservation as follows:

Jan 1, 1925

By R. A. Swalin, L. A. Neimark

The research work presented in this paper had initially a two-fold goal. First, further data concerning the low-temperature recovery of cold work was desired. Recovery phenomena have been extensively studied in face-centered-cubic metals but at the time of initiation of this research, no investigation concerning the low-temperature recovery in body-centered-cubic metals had been made. During the course of the investigation a paper by Martin on the recovery of point defects in molybdenum appeared.&apos; Comparison of our results on tungsten with Martin&apos;s results on molybdenum will be made. Secondly, knowledge concerning the influence of a particular type of impurity addition on the recovery kinetics was desired. It has been known for a long time that extremely small amounts of certain impurity additions exert a profound influence on the recrystallization behavior and the resulting microstructure of tungsten. Small amounts of potassium silicate and aluminum chloride added prior to the reduction of tungsten oxide to the metal have been found by Smithells to raise the recrystallization temperature markedly,2 and yield an ultimate microstructure in which grains several millimeters long are produced in fine wires of say 10 mil diam. If the impurities are added singly, ordinary secondary recrystallization results with none of the spectacular properties of the wire to which special additions were made. Swalin and Geisler3 and Rieck4 have studied the recrystallization behavior of such doped wire in some detail. The former workers found that small amounts of these impurities raised the recrystallization temperature over 400°C and electron microscopic examination revealed no obvious inclusions in the microstructures. In fact. chemical analysis showed that there was <0.001 pct K, <0.002 pct Al, trace of Si, and <0.0003 pct 0 in the wire studied. The possibility that the role of the special impurities is to keep the structure open by void formation and that submicroscopic porosity acts as the inhibiting agent has been discussed.2&apos;3 Meijering and Rieck5 have suggested that the impurities are strung out as second-phase particles in a direction parallel to the drawing direction. It was thought that a kinetic study of recovery could perhaps elucidate the role of the impurities to some extent. When a metal is deformed by cold work three basic types of defects are thought to be introduced into the crystal lattice, namely, interstitials, vacancies, and dislocations. Van Bueren6 has proposed that recovery of cold-worked metal is a four-stage process, each step being the result of the annealing of a primary defect or a combination of defects and having a unique activation energy. The steps in order of increasing activation energy are attributed to a) the diffusion of interstitials recombining with vacancies, b) diffusion of vacancy pairs, c) the diffusion of single vacancies, and d) climb of dislocations. In metals with relatively low- or medium-range melting points the temperatures for recovery are low enough so that the first three steps may occur during room-temperature deformation. For tungsten, because of the high melting point and subsequently high recovery temperature, it was calculated, using Nowick&apos;s approach7 that this recovery would occur in the temperature range 200" to 600°C. It is also known that recovery of X-ray line broadening, presumably due to dislocation climb, occurs at about 600°C.8 EXPERIMENTAL METHOD Two types of cold-rolled 10-mil-diam tungsten wire were used in the investigation; a) pure tungsten, (called undoped) and b) G. E. No. 218 wire (called

Jan 1, 1961

By C. McLean, Erickson, S. G. Kolb, S. C. Moore

The Grossschloppen vein-uranium deposit, Bavaria, West Germany, was examined with underground workings during 1980-82 by Esso Erz GmbH, an affiliate of Exxon Minerals Company (EMC). Geologic evaluation entailed dense drilling of a portion of the deposit from workings constructed specifically for the program. Discovered in 1977, the deposit was initially explored by surface diamond drillholes which allowed definition of a 30-60 m wide vein system discontinuously mineralized along a 1000 m strike length and to at least a 450 m depth. The underground program was conceives as a cost-effective procedure to answer quest ions on vein correlation, grade continuity and variability. A 1200 m decline allowed access for detailed sampling of approximately 10% of the known area of mineralization. Fanned drillholes, logged by gamma probe, were spaced to provide intersections of veins at 10 to 20 m intervals. Six cross-cuts also penetrate the pitchblende and uranophane mineralization which occurs in 0.1 to 2.5 m thick quartz veins. Detailed cross-sections and level plans were constructed for resource estimates of the intensively studied portion of the vein system. The program resulted in the discovery of local, high grade areas and an average grade in the evaluated area nearly double that expected from surface drilling.

Jan 1, 1984

By A. H. Geisler, R. F. Mehl, S. Barrett

The studies of the mechanism of pre= cipitation and of the resulting property changes in aluminum-silver alloysl-3 have presented some new concepts of the aging reactioxl—concepts that may be fundamental in establishing a complete quantitative theory of age-hardening. With both aluminum-copper and aluminum-silver alloys, thin platelike aggregates form parallel to the Widmanstätten planes of precipitation.l,4 These platelets grow in lateral dimensions and in thickness with aging time until they arc thick enough to produce an X-ray diffraction line pattern. Their structure is that of a transition lattice which is coherent with the matrix, since the atomic spacings in the matrix and the precipitate are the same on each side of their common interface.2,4 The equilibrium precipitate forms later from and at the expense of the transition lattice. Since age-hardening occurs during the formation and growth of the transition lattice, the major contributor to the hardening no doubt is the stress condition in the matrix resulting from the matrix holding the precipitate in the coherent condition. The development of these stresses also appears to be responsible for an increase in the electrical resistance superimposed on the normal decrease resulting from a change in the concentration of the matrix during aging.3 The two consecutive reactions constituting the aging process are accompanied by characteristic microstructural alterations. The initial precipitation process results in the formation of a Widmanstatten figure, while the later transformation of the transition lattice to the equilibrium lattice is accompanied by a coalescence, in the case of aluminum-copper alloys,5 and by the appearance of light areas at the grain boundaries with aluminum-silver alloys showing a structural rearrangement of matrix and precipitate.3 This latter reaction is similar microscopically to the so-called "discontinuoils precipitation." Possibly discontinuous precipitation is a process that often if not always follows true precipitation of a coherent lattice and during which the transformation of the coherent transition lattice to the equilibrium lattice takes place accompanied by matrix recrystallization.3 Expermental Procedure The alloys were made using 99.97 per cent A1 or distilled magnesium, with

Jan 1, 1943

By R. F. Mehl, A. H. Geisler, S. Barrett

The studies of the mechanism of pre= cipitation and of the resulting property changes in aluminum-silver alloysl-3 have presented some new concepts of the aging reactioxl—concepts that may be fundamental in establishing a complete quantitative theory of age-hardening. With both aluminum-copper and aluminum-silver alloys, thin platelike aggregates form parallel to the Widmanstätten planes of precipitation.l,4 These platelets grow in lateral dimensions and in thickness with aging time until they arc thick enough to produce an X-ray diffraction line pattern. Their structure is that of a transition lattice which is coherent with the matrix, since the atomic spacings in the matrix and the precipitate are the same on each side of their common interface.2,4 The equilibrium precipitate forms later from and at the expense of the transition lattice. Since age-hardening occurs during the formation and growth of the transition lattice, the major contributor to the hardening no doubt is the stress condition in the matrix resulting from the matrix holding the precipitate in the coherent condition. The development of these stresses also appears to be responsible for an increase in the electrical resistance superimposed on the normal decrease resulting from a change in the concentration of the matrix during aging.3 The two consecutive reactions constituting the aging process are accompanied by characteristic microstructural alterations. The initial precipitation process results in the formation of a Widmanstatten figure, while the later transformation of the transition lattice to the equilibrium lattice is accompanied by a coalescence, in the case of aluminum-copper alloys,5 and by the appearance of light areas at the grain boundaries with aluminum-silver alloys showing a structural rearrangement of matrix and precipitate.3 This latter reaction is similar microscopically to the so-called "discontinuoils precipitation." Possibly discontinuous precipitation is a process that often if not always follows true precipitation of a coherent lattice and during which the transformation of the coherent transition lattice to the equilibrium lattice takes place accompanied by matrix recrystallization.3 Expermental Procedure The alloys were made using 99.97 per cent A1 or distilled magnesium, with

Jan 1, 1943

By Euclid P. Worden

In 1977, an article in World Mining1 reported a total of 2726 rotary blasthole drills in service. This figure included only those machines produced by three of the manufacturers building drills of this type. The total, therefore, is much higher. Rotary drilling in the mining industry is big business to the manufacturers and suppliers involved, and a significant cost item to mine operators. The time has come to take a hard look at rotary drilling technology with an eye to reducing costs by increasing drilling efficiency. The efficiency of any rotary drilling operation is best measured in terms of the rate of penetration achieved by the bit. In blast hole drilling, there are five factors which affect the rate of penetration. They are: (1) bit selection, (2) weight on the bit, (3) rotary speed, (4) hole cleaning, and (5) formation properties. Of these factors, all but one may be controlled by the operator. Looking at any one in detail may reveal possible improvements in the system. One of these factors -- proper hole cleaning - will be discussed in this paper. In order for a bit to perform at its maximum capability, each tooth or insert should strike fresh clean rock as it falls into its drilling position. If the tooth or insert lands on previously drilled cuttings, a major portion of the energy delivered to the bit is absorbed in redrilling this broken material. A major portion of the interest, therefore, should be directed to the proper cleaning of the bottom of the hole. In an in-depth study of the cleaning of large diameter holes, Allen2 reports that horizontal air velocities of 38.10 m/s are necessary to prevent the saltation of drilled cuttings on the bottom of the hole. The exact flow pattern on the bottom of the hole, however, is not generally known. The air leaves the bit through the jet nozzles and the mouths of the cones, but where it goes from there is uncertain. This problem should be investigated by the bit manufacturers because they can best utilize the results of such an investigation to provide a more effective product. Some work has been initiated in this area and competition will probably increase its intensity. Bailing velocity is the best criteria to measure the cleaning of the hole, including the bottom, and is the factor on which efforts toward improvement must be concentrated. The first consideration is "What should the bailing velocity really be?" In drilling deep holes for oil and gas, 15.24 m/s is the generally accepted figure. In blasthole drilling, the figures of 25.40 m/s for average rock to 35.56 m/s for iron ore were first mentioned by Capp3 in 1962. The recommendations are the same to this day. A number of questions could be asked in regard to the apparent disparity between these two sets of figures. Various investigators have derived formulas which support one or another of these criteria. A thesis on the subject was written by Alexander4 who derived a formula based on research which resulted in velocities in the lower end of the ranges quoted previously. He set out to compare this figure to laboratory tests and his tests indicated that the velocities given by the derived formula appeared to be high.1 Perhaps the best reason that the 25.40 to 35.56 m/s range has been used, is that these velocities seem to work. Below the accepted figures, low bit life and slow penetration rates occur. Above these figures, increasing amounts of abrasive wear on the drill pipe and stabilizers seem to appear. There is a fallacy to this entire approach, however. The entire velocity calculation is made using nominal bit and pipe sizes and compressor deliveries with no compensation made for losses in the system. Perhaps an examination of some of the things that are not presently considered could lead to some practical improvements in the operation.

Jan 1, 1980

By A. A. Burr, D. G. Ebeling

The effects of casting texture, grain orientation and grain size upon the performance of Alnico permanent magnets is described. Single-crystal specimens were produced by special sintering and grain coarsening techniques to study the effect of crystal orientation. In addition to texture and orientation effects, an analysis of the results indicates that the permanent magnet performance is impaired by a refinement of the grain size. AN excellent historical review of the development of Alnico permanent magnets has been prepared by Bozorth.1 The desirable permanent magnet characteristics of Fe-Ni-A1 alloys were discovered in 1932 by Mishima.2,3 The work of Ruder&apos; showed that the alloys were age-hardenable, and Betteridge5 defined the best composition and heat treatment for the magnetically isotropic alloy known as "Alnico 3." Horsburgh and Tetley0 increased the energy product by the addition of cobalt and copper, "Alnico 2," and Oliver and Sheddon7 demonstrated that cooling in a magnetic field improved the residual induction of this alloy. Jonas8,9 then disclosed the great practical benefits of heat treating an alloy of higher cobalt content in a magnetic field and the resulting alloy, "Alnico 5," has become the standard of the industry. This paper describes the fundamental aspects of a procedure which can be used to further improve the properties of these anisotropic permanent magnet alloys. A study of the casting techniques used in the production of anisotropic Alnico permanent magnets indicated that the magnetic quality was affected by the as-cast macrostructure. Improved performance was observed in magnets containing a high percentage of columnar grains whose long axes were parallel to the magnetic axis of the casting. McCaig10 studied the effect of such columnar grain structures upon the magnetostriction characteristics of similar alloys, however no data was presented showing the effects on other magnetic properties. The following paragraphs describe two experiments which were conducted to determine the effect of various grain orientations upon the energy product. Special composite molds were prepared of highly conductive and highly refractive components to remove the heat of solidification from the casting in a controlled manner. Representative macrostructures produced by these techniques are shown in Fig. 1, along with the relative volumes of favorably oriented columnar grains. The alloy, Alnico 5, has the highest permanent magnet performance of any commercial magnet material. It has the nominal weight composition of 8 pct Al, 14 pct Ni, 24 pct Co, 3 pct Cu, and 51 pct Fe. A heat of this material was cast into molds producing the type A and B grain structures shown in Fig. 1 and pairs of the resulting magnets were placed in heat-treating boats so as to eliminate any biasing effects of boat position. After a standard heat treatment the type A magnets, with 16 pct of the volume composed of favorably aligned grains, had a maximum energy value of 3,940,000 gauss-oersteds, while the type B magnets with 73 pct aligned grains averaged 5,090,000. This large im-

Jan 1, 1954

By T. E. Watkins, M. D. Nelson

INTRODUCTION Deeper drilling for oil is becoming more and more the rule rather than the exception. With deeper drilling come additional problems, perhaps the greatest being those brought on by the higher temperatures encountered down the hole. particularly in the Gulf Coast region of Texas and Louisiana. Temperature gradients of the order of 1.8° to 2.0°F/100 ft are not unusual, and a gradient of 2.3"F.&apos;100 ft is found in some areas of Texas. With a mean surface temperature of 74oF, the following temperatures could be expected for a geothermal gradient of 2.0°F; 100 ft: at 10,000 it. 271°F. 12,000 ft, 314°F: 14,000 ft, 354,oF; and 16.000 ft. 394°F. Severe gelation of lime-base drilling fluid in wells that have high bottom hole temperatures has become perhaps the most serious difficulty enconntered in drilling under such conditions. Lime-base drilling fluids have been very succesefully and widely used in the drilling of wells in the Gulf Coast region because of their inherent stability toward contaminants. their ability to suppress the swelling dispersion of bentonitic shales, and their ease of maintainance. The gradual recognition: during the past few years, that these muds were. in themselve. the cause of many difficulties experienced in drilling has led to wide-pread efforts by the drilling industry. to determine the reasons for the failure of these mud systems and to develop mud systems capable of performing satisfactorily under high-temperature conditios. MANIFESTATIONS OF HIGH-TEMPERATURE GELATION it is generally possible to recognize the symptons of high-temperature gelation early enough that advance predictions can be made of serious difficulties. in mud control, and the useful life of the drilling fluids can be extended by proper treatment. Following i.; a list of the manifestations of high-temperature gelation: (1) The drill string &apos;takes weight&apos; while going in the hole after a trip. In early stages of high-temperature gelation it is possible to notice a slight reduction in drill string weight as the drill pipe is lowred near the bottom of the hole. (2) Excessive pump pressure is required to .tart the circulation of drilling fluid at or near the bottom of the hole when going hack to bottom after a trip. As the severity of the gelation increases it may be necessary to break circulation a number of times when going in the hole. (3) The drilling fluid from the bottom of the hole is thick and often granular or lumpy when pumped up after making a round trip. In a severely gelled drilling fluid system such a condition may be irreversible; that is, it cannot be stirred or chemically treated to produce a satisfactory drilling fluid. (4) Completion tool.. such as logging tools or perforating guns will not sink to the bottom of the hole. On some occasions completion tools will become stuck and require a fishing job to retrieve them if the wire line attached to them is broken. It is often difficult to determine whether the condition of the drilling fluid is responsible for sticking the tool or whether the wire line becomes key seated in a crooked hole and causes the allow difficulty. When there are 110 other symptoms of high-temperature gelation. then the difficulty may usually be attributed to the latter cause. (5) In extreme cases of high-temperature gelation it is necessary to "wash" and "ream" when going back to bottom after coming out of the hole. (6) In many -instance. it has been found to be extremely difficult and expensive to 1111 production packers 2nd tubing in moderately deep oil wells which had been drilled with a lime-base drilling fluid. In such instances-the original mud had apparently "set" to a consistency approaching that of a weak cement. CAUSES OF HIGH-TEMPERATURE GELATION Extensive test; have indicated that a lime-base mud does not develop a highly gelled condition at temperatures below 250°F. whereas above that temperature such condition often develops rapidly. (Fig. 1) concurrently. the following changes are evident ill the mud: (1) The alkalinity of the mud decreases to a very low value. with both caustic soda and lime being consumed. (2) The quartz content of the mud decreases sharply. (3) The bentonitic content of the mud decreases or di-appears, with concurrent decrease or loss of base exchange capacity of mud solids. (4) New compounds formed in the mud have been found to be cal-cium silicate, calcium aluminum silicate, and calcium sodium aluminum silicate. (5) The mud loses the ability to form a filter cake of low permeability. The above characteristics have been discussed, in part. by other authors

Jan 1, 1953

By A. N. Crownover, H. T. Kennedy, E. P. Miesch, C. H. Bowman

The paper presents correlations of (l) molar volume of gaseous hydrocarbon mixtures with pressure, temperature, composition and properties of the C,-plus fraction; (2) shrinkage of oils during flash and differential liberation of gas, including the calculation of formation volume factor under various conditions; and (3) bubble-point pressure with temperature, composition and characteristics of C, plus. The data on which the correlations are based comprise 1,615 measurements on 900 hydrocarbon systems, including numerous systems containing nitrogen, hydrogen sul-fide and carbon dioxide. In each correlation, the number of data points covered and the accuracy is substantially greater than in previously available work. Thus, the equation yielding molar volumes of gases has an average deviation of 2.04 per cent, applied to mixtures having temperatures up to 313F and pressures up to 9,800 psis, compared to 2.37 per cent for the Benedict-Webb-Rubin equation applied to the same data, and 4.53 per cent for the method based on the law of corresponding states. he equations resented are all explicit in the dependent variable, and require no iteration on the digital cow puter. INTRODUCTION The ease and accuracy of determining the composition of hydrocarbon mixtures, compared to the difficulty of measuring their properties under reservoir conditions, makes it desirable to utilize composition as the key to physical behavior to the greatest possible extent. As a result, there are available correlations between composition, or easily measured characteristics dependent on composition, and practically every important engineering property of reservoir fluids. The task confronting us is one of finding more exact relationships between important variables rather than extending correlations to new properties. This paper describes new correlations of molar volumes of gases, formation volume factors, and bubble-point pressures with composition, temperature and where possible, pressure. Each correlation is obtained by employing a sufficiently large amount of data so the calculated properties are probably as least as accurate as the measurement on which they are based. MOLAR VOLUME OF GASES Although many equations of state have been proposed for pure gases, only a few methods are applicable to hydrocarbons at conditions comparable to those in petroleum reservoirs. Still fewer arc useful in describing the behavior of mixtures, with which the petroleum engineer is largely concerned. The correlation presented here involves procedures similar to those of Alani and Kennedy The van der Waals equation is modified to make a and b functions of temperature instead of being constants for each material.This is a cubic equation, which may have either one or three real roots. The lowest root corresponds to liquid volume, while the highest applies to gas. When the procedure was applied to 703 pressure-temperature points of 164 gases of known composition and volume, the average deviation was 12.08 per cent, and the standard deviation 8.15. The above calculations were made using the constants derived for liquids by Alani and Kennedy and the mixture equation developed by them. A closer approximation to measured molar volumes is obtained by employing different sets of constants for different areas on the pressure-temperature chart, and by changing the relationship between a,,, and b,,, for mixtures and the a, and b, for individual hydrocarbons. The various sets are shown in Table 1, and the areas for which they are recommended are plotted in Figs. 1 through 7. In these figures, the area designated by zero is in the critical region for pure materials, and the values obtained for them may be unreliable. For normal mixtures, however, the area may be added to any of the bounding areas without substantial error. The new relationships employed are

Jan 1, 1966

By W. G. Matteson

The origin of the salt domes of the Gulf coastal plain has been investigated by many of the most able geologists, but the problem cannot be said to have been satisfactorily solved. Since 1860, numerous theories have been presented, only to be discarded, at least in part, as more complete infomation revealed their fundamental weakness. Real progress toward solution dates from 1902, when Hill1 advanced the theory of secondary deposition of the domal materials from saturated solutions of hot saline waters ascending from great depths under hydrostatic head along structural lines of weakness. Shortly thereafter, Harris,² using Hill&apos;s hypothesis as a basis, explained the doming and pronounced uplift associated with these salt cores as the result of forces exerted by growing salt crystals. This was a marked advance over the ideas of Coste3 and Hager,4 since no evidence of igneous intrusives, as they assumed to explain the uplifts, had been found associated with the domes. Harris5 developed his theory until it offered such apparently plausible explanations of so many details of dome phenomena that his hypothesis and conclusions received widespread acceptance, despite some serious objections, and today his theory, somewhat modified, is considered by many able investigators to be the best explanation of the origin of these domes. The immense production of oil per acre, the recognition of the high lubricating quality of the oil, the development and recognition of the efficiency and advantages of oil-burning vessels, with the subsequent exceptional demand for fuel oil, and the resultant advance in the price of coastal crude, have been responsible for a prospecting and develop- 1 Robert T. Hill: Beaumont Oil Field with Notes on Other Oil Fields of the Texas Region. Jnl. Franklin Inst. (1902) 164, 143. 2Gilbert D. Harris: Rock Salt in Louisiana. Louisiana Geol. Survey Bull. 7 (1907) 76. ³E. Coste: Volcanic Origin of Natural Gas and Petroleum. Jnl. Canadian Min. Inst. (1903) 6, 73. 4Lee Hager: Mounds of the Southern Oil Fields. Eng. & Min. Jnl. (July 28, 1904) 78,137, 180. 6Gilbert D. Harris: Geologicel Occurrence of Rock Salt in Louisiana and East Texas. Econ. Geol. (1909) 4, 12.

Jan 1, 1921

By W. R. Atkins

THE Negaunee mine is at the east end of the Marquette Range, in the city of Negaunee, on the Upper Peninsula of Michigan. Iron ore was first discovered on this property in 1883 by diamond drilling. A shaft was sunk soon afterward, and the mine has been worked continuously ever since. The total shipments from 1887 to&apos; Jan. 1, 1945, were 20,417,587 long tons. The mine was taken over by the present operators, The Cleveland-Cliffs Iron Co., in 1903. During the past four years, 1941 to 1944 inclusive, the property has produced an average of nearly a million tons a year, and has employed more than 400 men. GEOLOGY The ore body at the Negaunee mine lies in a large syncline dipping about 15° to the west, the ore coming to ledge at the east end of the trough. The ore occurs in the Negaunee formation of the middle Huronian age, which consists of ferruginous cherts and slates through which intrusions of diorite have occurred. Although these intrusions of diorite have an important bearing on the formation of ore on the range, they are not important in this ore body. Some faulting has taken place along the diorite intrusions, or dikes as they are called locally, and also other faults are known to exist across the formation. These faults do not complicate either mining or development of the ore body. The footwall consists of jasper underlain with Siamo slate; the hanging wall is jasper and ferruginous chert. Fig. I shows a typical cross section of the ore body. The ore body is quite regular, about 120 ft. thick in the middle of the syncline and thinning out toward both sides of the fold. Its width ranges from 400 to 800 ft., the average being about 600 ft. The footwall is uniform in dip and strike, but irregular lenses of ore often extend 50 to 75 ft. up into the overlying jasper capping. METHOD OF MINING Ore in the Negaunee mine has been mined by top slicing almost exclusively since 1903. This method of mining has been employed because it is especially adapted to the size and shape of the Negaunee ore body, and to the soft, sticky nature of the ore as well as the generally soft, broken jasper capping. Development The ore body has been developed from six different levels with intervals varying between l00 and 125 ft. On the average, the dip causes a horizontal offset of 350 ft. per level, and under these circumstances it has been necessary to carry on considerable development in rock to make available the ore lying along the north and east footwalls. This is not as disadvantageous as might be supposed, because of reduced pressure and the accompanying saving in maintenance costs. The development of the

Jan 1, 1946

By T. R. Ingraham

When aluminum sulfate was decomposed in an evacuated apparatus and the sample cooled, Q alumina was found. The thermodynamics of the decomposition reaction were resolved by measurements of the total pressure of SO3, SO2, and O2 generated over the sample at various temperatures. The results were correlated with other published data to calculate the rmges of thermodynamic stability of the various compounds involved. The thermal decomposition of aluminum sulfate was studied by Wijhler, Pluddeman, and Wöhler1 and by Warner and Ingraham.2 The results of both studies were critically reviewed by Kellogg,3 who observed that "each set of data shows considerable scatter and strong curvature on a plot of log pso3 vs 1/T".3 He agreed with Warner and Ingraham2 that both the discrepancy in the two sets of results and their curvature may arise from the indefinite properties of the particular form of A12O3 which is formed during the decomposition. While studying the thermal stability of other sulfate systems, we had noted the presence of nonequilibrium oxide properties in both the cobalt4 and manganese5 systems, but neither had shown any appreciable curvature on a logPSO, vs 1/T relationship, and the data from both systems agreed reasonably well with prior work. It therefore seemed reasonable to reexamine the technique which had been used in our earlier work on aluminum sulfate.2 The principal difference was that a tightly compacted pellet had been used for the earlier aluminum sulfate work, whereas a loose powder, contained in a platinum boat, was used for our work on other sulfate systems. In addition, a better technique had been developed for dehydrating the samples. From work done on the nickel system,6 we had become aware of the highly protective nature of some sulfate layers on their oxjdes, and hence of the necessity of providing a large surface area of P3e sample when equilibrium was to be attained in a reasonable time. That observation suggested that perhaps a steady state, rather than equilibrium, had been reached in the earlier work on aluminum sulfate. This paper reports a repetition of the experimental work with large, finely divided samples of anhydrous aluminum sulfate. APPARATUS AND PROCEDURE The apparatus used in the experimental work was described in earlier papers.2,7 The source material was Anachemia reagent-grade Al2(sO4)3 - 18H2O which was first partly dehydrated by heating at 400°C for 48 hr and then completely dehydrated by repeated baking of an aluminum sulfate-oleum slush to dryness at 450°C. ? Alas was prepared by decomposing some of the sulfate in a muffle furnace at 800° C overnight. Approximately equal amounts of the 7) alumina and aluminum sulfate were used in the experiments. The finely divided samples were handled under dry box conditions, and in addition some of the aluminum sulfate was decomposed in the apparatus while it was under vacuum, to ensure its complete dehydration prior to sealing the apparatus. The samples were heated to a series of constant temperatures on both increasing- and decreasing-tem-perature programs. Two to three days were required to obtain steady readings of the total decomposition pressure on an increasing-temperature program, and 5 to 6 days on a decreasing-temperature program. Three samples were examined on both programs. Within experimental error, the results for each sample and each program could not be distinguished.

Jan 1, 1969

By AIME AIME

ON the morning of Monday, Nov. 9, 1936, two motorcycles, with sirens screeching, - escorted a procession of 70 automobiles from the Colonia Railway Station in Mexico City to the Hotel Geneve. Riding in&apos; the cars were just over 200 visitors- members of the A.I.M.E. and their guests. They had come, via St. Louis, in two special trains from 24 different states for the 146th General Meeting of the Institute. During the morning they and 200 others, who had come from the United States by automobile or from various cities and mining camps in Mexico, duly registered with !efficient Mme. Irma Ordoiiez de Obregon and her assistants. Then started a week of strenuous but delightful activity that will never be forgotten by the participants. They were to cover more than 500 miles by automobile, always with a motor escort, and often

Jan 1, 1937

History of Production, of Salt Creek Oil Field, Wyoming Discussion of the paper of EDWARD L. ESTASROOK and CLARENCE M. RADER, presented at the Casper Meeting of the Petroleum Division and issued, as Paper No. 1503-G, with MINING AND METALLURGY, September, 1925. C. E. REISTLE, Laramie, Wyo.-The application of water analysis to petroleum engineering problems is successful in many cases, particularly if the water in the sands is of uniform chemical constituency and if each sand water varies definitely from the others in its chemical properties. At Salt Creek, the sand waters are not of uniform chemical character, and the waters in the various sands do not differ greatly; so a water from one sand might easily be classified as a water from some other sand. The water from the Shannon sand contains sulfates; this alone makes it possible to differentiate between the Shannon and the First and Second Wall Creek and Lakota sands. However, it is not so easy to differentiate between water of the First and Second Wall Creek sands. As a rule, the Second Wall Creek sand contains a higher concentration of mineral matter, but in Table 19, sample 2; of the First Wall Creek sand and sample 7 of the Second Wall Creek sand have approximately the same amount of total solids. As a rule, the chlorides are higher in the Second sand waters than in the First sand; but, the chlorides in sample 6 of the Second sand show practically the same amount as sample 3 of the First sand. The use of reaction properties does not. solve this trouble, as they generalize the conditions even more. For instance, the reaction properties of sample 3 of the First sand are almost identical with the reaction properties of sample 6, of the Second sand. The authors suggest that the chemical characteristics of the water in a sand are not uniform because of the concentration of the water by underground evaporation. In that case should not the ratio of the various chemical constituents remain the same? Gas does remove some mineral matter, as evidenced by deposits in the gas lines and packing in the absorbers of the natural gasoline plants, but why does the gas act selectively, removing one salt and not all of the salts in the ratio that they occur?

Jan 12, 1925

By F. S. White, E. L. Kinsella

THE solids fluidization process brought out by the Standard Oil Development Co. in the early forties for catalytic cracking of petroleum enabled rapid transfer of large quantities of heat from gases to solids under closely controlled temperature conditions. As the technique developed, it was natural that applications for the process outside the petroleum industry would be sought. The calcination of limestone to &apos; quicklime requires the transfer of a large quantity of heat at high and closely controlled temperatures. For these reasons, this possible application was one of the first to be investigated. Laboratory work conducted by the Dorr Co. indicated that lime produced by solids fluidization would be of exceptional quality. Calculation of theoretical heat balances showed that savings in fuel could be expected. Accordingly, a pilot plant of 10 tons per day capacity was erected by the New England Lime Co. at Adams, Mass., to substantiate the process. Operation of the pilot plant, previously described,1 showed that excellent lime could be produced with a saving in fuel. The work also indicated the necessity of preparing feed to remove the finer fractions if dust losses were to be held to a tolerable level. A single-stage fluidized solids drier-stripper was developed to accomplish this sizing.2 Subsequently a commercial lime reactor was erected at Adams, beginning operation in June 1949, followed by air sizer facilities completed in November 1951. This paper will describe these two applications of solids fluidization. The raw material for preparation of lime by the fluidizing process is a high calcium crystalline lime stone having the approximate chemical composition shown in Table I. The stone is first prepared by crushing and grinding in conventional equipment to pass a 6-mesh sieve. After crushing, the material is sent to the FluoDry unit for drying and dedusting. Fluidized Drying and Sizing As shown in Fig. 1, the FluoDry unit consists of a 1/4-in. cylindrical steel shell, 9-ft ID by 22-ft 6-in. overall height. Attached horizontally at the bottom is a 6-ft diam combustion chamber, approximately 7 ft 6 in. long. A refractory constriction dome, consisting of first-quality fire brick shapes, partitions the inside into two sections. The lower section is called the windbox and the upper the bed compartment. The vertical wall of the shell is lined with 6-in. first-quality rotary kiln blocks. In the bottom of the windbox a hoppered section is formed with castable refractory to permit the windbox to be readily cleaned via a 6-in. screw conveyor. The combustion chamber is similarly lined with refractory shapes. On the 6-in. diam section, 4 1/2 in. of insulating brick, HW-26, are used. The inner combustion chamber is lined with 4 1/2-in. Korundal brick to withstand the high flame temperatures encountered. An 8-in. steel feed pipe, entering vertically through the top and fitted with an air-operated cone valve,

Jan 1, 1952

By Herbert K. Kutter

This paper is concerned with the physical phenomena in the fracture process of presplitting and only indirectly with the establishment of the optimum presplitting parameters. Its nature is therefore qualitative, rather than quantitative. Before examining the problem of presplitting, it is first necessary to study the phenomena which occur when an explosive charge is detonated in a borehole. To do this it is desirable to consider the action of the explosion wave separately from that of the expanding gases.l In the theoretical analysis such a separation poses no problems. Experimentally this was accomplished by use of an underwater-spark discharge to generate the stress wave and by pressurized oil to simulate the pressure of the explosion products. The main role of the wave is to generate a densely radially fractured zone around the borehole. The subsequent gas pressure, exerted against the walls of a highly (radially) fractured cavity, generates a quasi-static stress field (henceforth referred to as static stress field). This stress field was found to be the same as that of a pressurized cylindrical "equivalent cavity" with a radius equal to that of the crack tips. Under these conditions the quasi-static stresses become appreciable and cause further extension of the radial cracks. It was further found that, under gas pressure, the longest of the radial cracks would extend first, and extension of two diametrically opposed radial cracks requires the least pressure. From these observations concerning the single shot the transition to a whole series of more or less simultaneous shots, as in presplitting, can readily be made. In the case of multiple shots, as in presplitting, exactly the same effects occur, but at numerous locations and sufficiently close in time that they interfere with

Jan 1, 1968

Trans. Pamphlet Volume Number Title Author Meeting and Page* 1033 Relation of Air Presaure to Drilling H. W. Seamon New York 66, 743. 766 Speeds of Hammer Drills . Feb. 1921 1034 Time Factor in Depletion of Mines J. W. Roberts New York 66, 711 Feb., 1921 1035 Calculation of Ore Tonnage and Grade J. E. Harding New York 66, 117, 122 from Drill-hole Samples Feb., 1921 1038 Diacuasion of Papers Presented in 1920 1041 Run-off and Mine Drainage H. N. Eavenson New York 66. 624. 630 Feb.. 1921 1043 The Health of the Underground Worker A. J. Lanza New York Feb, 1921 1045 Dust-ventilation Studies in Metal D. Harrington New York 66, 272, 288 Mines Feb., 1921 1046 Discussion of Papers Presented at New York Meeting, 1921 1072 Breakage and Heat Treatment of Rock- B. F. Tillson New York 66. 758 drill Steel Feb., 1921 1073 Discussion of Papers Presented at New York Meeting, 1921 1076-M Analysis of Some Drill-ateel Teats F. B. Foley New York 66,789 Feb.. 1921 1077-M Application of Magnetic Analysis to C. W. Burrows New York 66, -796 Rock Drills Feb., 1921 1078-M Heat Treatment of Rock-drill Steel G. H. Gilman New York 66.779 Feb., 1921 1080 What is the Ideal Drill Steel? F. H. kingdon New York 66, 807 Feb.. 1921 1081 Rock Drill-Steels, etc. W. T. Ober New York 66,814 Feb.. 1921 1082-C Underground Mine Development, Its J. B. Dilworth Wilkes-Barre 66,715, 761 Definition and Valuation Sent.. 1921 1081 Drill Steel from Hollow Ingots P. A. E. Armstrong New York 66,809 Feb., 1921 1068 Authors&apos; Replies to Recent Discussion 1092 Heat Treatment of Rock Drill Steel A.E.Perkins New York 66,811 Feb., 1921 1096-M Octagonal Ventilation Shaft of Davis- J. L. Bruce Wilkes-Barre 66. 252, 608 Daly Copper Co. Sept., 1921 1100-C Determination of Electrical Equip- G. Bright Wilkes-Barre 66,580,606 ment for a Mine Hoist Sept., 1921

Jan 1, 1927

By J. W. Fuller

DURING the last 20 years, experimenters have sought to utilize pulverized coal in boiler plants, but refractory and slag troubles have usually overbalanced any, gains in efficiency that were obtained. These troubles were caused largely by lack of knowledge of the proper methods of coal preparation and lack of a furnace design that would be adaptable to pulverized-coal firing. When this information was obtained the results were so much more satisfactory that within the last 5 years approximately, 80,000 boiler hp. have been installed in plants ranging from 1000 to 20,000 boiler hp. rated capacity, which are operating at an average of 174 per cent. of rating. The first commercial installation for burning pulverized coal under boilers was made at the Parsons shops of the M. K. & T. railroad in 1916. Of eight 250-hp. water-tube boilers thus fitted, six were operated continuously for 3 yr., when oil was obtained at such a low price as to warrant its use. Since then, this plant has been operating alternately on pulverized coal and oil, depending on prevailing prices. Recently gas has been discovered within 20 mi. of this plant, so that this fuel may also be used. No change in furnace design was made when changing from pulverized coal to oil or gas firing. One of the principal advantages of this method of firing is its ability to utilize, with maximum efficiency, all kinds of coal, irrespective of quality or physical characteristics. In fact, quite a number of the present pulverized-coal installations were made for the purpose of utilizing coal that could not be marketed or used in any other way. The Pacific, Coast Coal Co., at Black Diamond, Wash., formerly hand fired the boilers, using approximately 125 tons of prepared steam-size coal daily. The Black Diamond steam coal is the best quality of coal for steaming purposes mined in that section of the country, and there is a market for all that can be produced. By installing a pulverizing plant, it was possible to substitute coal of a size and quality that had no commercial value, so that 125 tons daily of the best steam coal formerly used at the mines is now marketed.

Jan 12, 1921

By D. J. Carney, R. L. Stephenson

M. O. Holowaty (Inland Steel Co., Chicago)—Messrs. Stephenson and Carney should be commended on the presentation of this very interesting paper. They have introduced new ideas on sampling of sinter and have thereby made a valuable contribution to the qualitative evaluation of sinter. The paper undoubtedly presents a novel approach to the problem of sinter sampling and this is to be regarded as its main value. Sampling of sinter from the pallets prior to the discharge is by no means new. This sampling procedure was used in the past by Philbrook; Hamilton and Ameen and others. The sampling basket used by the authors of this paper, however, permits one actually to obtain a good sample of the sintering mixture. The basket which can also be described as a removable pallet goes then through the entire process of sintering and thus offers a sample which is positively representative of the batch in question. The authors&apos; method of evaluating physical properties of sinter seems to be not altogether clear, however. It is felt that the following points should be clarified: I—In the section describing the shatter test the authors state that a 5-lb sample was used in the actual tests. There is no mention of the initial size of sinter particles used and the method of obtaining this 5-lb sample from the sinter cake weighing about 100 to 120 lb. It is also surprising that the sample was dropped from a height of 3 ft instead of the conventionally used 6 ft. Unfortunately there is no mention of the number of drops to which the sample was subjected. 2—The tumbler test used by Messrs. Stephenson and Carney in testing the samples of iron ore sinter was performed in a standard ASTM coke tumbling drum. The drum measures 3 ft in diam and is equipped with two 3-in. lifter bars. The distance of fall in this testing drum is identical with the distance used in the previously described shatter test. The number of drops in the tumbling drum is approximately double the number of revolutions. The basic difference then between the drop-shatter test used by Stephenson and Carney and the tumbling test seems to be the number of drops to which the sample is subjected and the abrasive action to which the sinter particles are exposed in the rotating drum. In any case, the choice between the shatter test and the tumbler test seems to be only a matter of taste and convenience. 3—The authors of the paper state that "in order to insure getting results that were representative . . . the entire sample obtained by means of the sampling basket was used as the starting material for the tumbler test. If the sample broke in pieces, all the pieces were used regardless of their size." The initial size of the material is known to be a very important factor, influencing seriously the final size of the particles. This should be particularly important in case of hard sinters. It seems also very troublesome and inconvenient to charge 12-in. cubes of sinter weighing about 100 lb into the testing drum. This could be eliminated by taking a standard fraction of somewhat smaller particles.

Jan 1, 1954

By H. W. Hitzrot

SEPARATING a mixture of particle sizes of material suspended in a liquid medium is by no means an exact science. Selecting machines for individual classifying operations is even more difficult. The plant operator&apos;s own background is of course invaluable, and considerable help may be obtained from technical articles, talks with sales engineers, and handbooks on ore dressing. These several sources of information, however, are difficult to marshal in proper perspective for the major decision on classification units that an operator may be called upon to make. To the present writer&apos;s knowledge this assembly of facts is not available in handbooks, and technical papers are scarce on classification equipment developed in the past five or six years. It is believed that this paper will be helpful to users of classification equipment at this particular period in the development of hydro-classification. For easy reference the following classification units now available and in use in metallurgical and industrial operations are listed below, with a brief description of each. Unit-type classifiers, bowl classifiers, and bowl desiltors are all rectangular tanks, slightly tilted, with reciprocating rakes or screws to remove settled sands. The unit-type classifier, Figs. 1 and 2, is available in widths from 14 in. to 20 ft and lengths up to 40 ft. The shallow bowl of the bowl classifier, Fig. 3, equipped with rotating rakes, is superimposed on the lower end of the tank. Reciprocating rake compartments for this design range from 18 in. to 20 ft wide. Bowl diameters vary from 4 to 28 ft. The flat-bottomed bowl of the desiltor, Fig. 4, of relatively large diameter, is equipped with rakes rotating outward and partly over a pit, which is created by extension of the rectangular tank into and under the bowl section. Bowl desiltors are available with reciprocating rake sections 4 to 20 ft wide and bowls from 20 to 50 ft in diam. The bowl desiltor is used for applications beyond the range of the bowl classifier. The hydroseparator, Figs. 5 and 6, is a circular tank equipped with slowly rotating rake arms, set on a slope, with interrupted rake or spiral blades to move the settled solids to a central discharge cone. Tank diameters vary from 4 to 250 ft. Tank depths at center are 2 to 3 ft for small units and up to 25 ft for larger units. Hydraulic classifiers of the sizer and super-sorter types, Figs. 7 and 8, are narrow, deep, rectangular tanks divided by vertical baffles into a series of pockets. Hydraulic water is added near the bottom of each pocket. Perforated constriction plates, spiral flow arrangements, or jets are used to disseminate the water under pressure (hydraulic water) throughout the bed of material in the pocket. Discharge valves on each pocket are operated automatically by a pneumatic mechanism, a pincer-type mechanism, or a pressure control and motor combination actuated by a hydrostatic tube within the pocket. Hydraulic classifiers are available in 4, 5, 6, and 8-pocket units of varying constriction plate areas to suit conditions. There is now a jet sizer of unit pocket design that can be made up in 1 to 25 sections or more to accommodate sizing requirements. The hydroscillator, Fig. 9, is a rectangular tank set on a slope of 3 to 4 in. per ft. A bowl is superimposed on the lower end. The bowl bottom is an oscillating rubber-covered disk, perforated to allow hydraulic water introduced beneath the disk to set up a teeter bed and thus produce an oversize or rake product exceptionally free of slimes, and material minus the mesh of separation. A shallow dam at the periphery of the bowl allows the coarse or oversize fraction to spill over and drop down into the tank compartment, where it is moved up the deck by reciprocating rakes. The material, minus the mesh of separation, overflows a circular and stationary weir which is several inches higher than the dam on the oscillating disk. It is carried off in a circular launder in the usual manner. These units are available in bowl diameters from 4 to 14 ft and with reciprocating rake compartment widths to suit the tons per hour to be handled. Centrifugal classifiers include the solid bowl centrifuge and the cyclone classifier. The solid bowl centrifuge, Fig. 10, consists of a truncated cone fixed to a horizontal shaft and rotating at high speed. An internal spiral rotating at slightly less speed continuously removes solids deposited on the inner surface of the cone, or bowl. Feed enters the cone by means of the hollow center shaft. Overflow leaves through ports at the large end of the cone, and oversize solids, moved by the spiral, exit through ports at the small end. Centrifugal classifiers of this type are available in cone diameters from 18 to 54 in. The cyclone classifier, Fig. 11, is a stationary cone having a cylindrical upper section and a lower cone section. Feed is introduced tangentially into the upper cylindrical section under pressure from a hydrostatic head or by means of a pump. Centrifugal force thus induced effects a classification within the cone, the fine sizes being carried off in the overflow through an opening at the top of the cylindrical section. Coarse solids at relatively high pulp density exit through a control valve at the apex of the lower cone section. Cyclone classifiers are available in 3, 6, 12, 14, 24, and 30-in. diam. The cone classifier, Fig. 12, is a steel-plate cone with sides usually about 60" from horizontal. It contains no rotating mechanism. Feed enters a feed-well at center and classification is effected by gravity and pulp density. Fines are carried off in the flow over a peripheral weir at the top of the cone. Settled solids exit through an opening at the apex. An apex valve actuated through levers and rods by the pulp density in the lower cone section is usually supplied. Diameters are usually maximum at 8 ft.

Jan 1, 1955