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By Burton Atkinson, David Johnston

Evaluation of Ellenburger reservoirs in West Texas has been an uncertain matker at best because of the lack of cores and suitable core-analysis method. Large amounts of oil arc produced from sections from which sample cuttings are obtained that contain litile porosity and no oil saturation. It has long been realized that the formation in some areas contained numerous fractures and solulion cavities that probably contained the major part of the oil present but the magnitude of the porous system conltaining oil has been unknown. Diamond coring cquipmene, used in the mining industry lor many years, has been developed for oil-field use to obtain high core recovery in fractured dolomite that is not possible with conventional coring equipment. A 36ft section of the core recovered from a fractured Ellenburger reseivoir waS analyzed by a unique but simple method to obtain the first defmite evaluation of one section of the producing formation. The cores and the method of analysis used are described and the results arc discussed in some detail. Discussion The first successful known analyses of cores recovered from the Ellenburger formation in the Permian Basin area were made on cores recovered with the use of diamond core heads. Conventionul coring methods previously used have had lour core recovery and standard methods of analysis have proved to be inadequate for evaluation of those cores that were recovered. Core Descriplion The Ellenburger formation to be dis cussed was cored using diamond core heads and oil-base drilling fluid. Of the total 103 ft cored to a depth of 8893 ft in the Ellenburger, 99 ft or 96 pct was recovered. The dolomite cores were described as gray to white, crystalline to coarscIy crystalline, with chert and calcite inclusions. Occasional shale partings ? to ¼ in. in width were noted. A small amount of green clay was found in some of the coarsely crystalline material. So intergranular porosity was found by inspection in any of the cores. The core urns highly fractured over most of its length with not more than two continuous feet that failed to contain fractures. The fractures Were nearly vertical and varied in width from those harely visible to as much as one millimeter. Scattered solution voids, or vugs, as large as 3 cm in diameter occurred in association with same •a

Jan 1, 1949

By J. M. Campbell, T. S. Buxton

The most widely used methods of predicting the volumetric properties of gas are based on the principle of corresponding states, which asserts that the compressibility factor is a universal function of reduced temperature and pressure. Previous studies have shown that the acentric factor, as proposed by Pitzer, l is an important addition to reduced pressure and reduced temperature as factors affecting the compressibility factor. Results of this study indicate that, if the pseudocritical temperature and pressure used to determine the reduced conditions are adequately predicted, characterization of natural gas-carbon dioxide mixtures with the acentric factor will allow reliable determination of the compressibility factor. Comparisons of predicted and experimental compressibility factors have shown that the pseudo-critical constant rules of Stewart, Burkhardt and Voo 2 are satisfactory for hydrocarbon mixtures. However, these rules fail to predict the pseduo-critical constants for hydrocarbon-carbon dioxide mixtures. Based on graphically determined pseudocritical temperatures for binary hydrocarbon-carbon dioxide mixtures, a correlation which gives the required correction to the Stewart, Burkhardt and Voo rules was prepared and a compressibility factor prediction technique was proposed. To test the proposed technique, compressibility factors for live mixtures of methane, carbon dioxide and either ethne or propane were experimentally determined at 100, 130 and 160F and pressures up to 7,026 psia. The predicted and experimental compressibility factors for these live mixtures had an average absolute deviation of 0.55 percent. INTRODUCTION Two-parameter generalized correlations based on the principle of corresponding states (PCS) are presently available for reliably predicting the compressibility factor of lean natural gas, i.e., natural gas with low concentrations of hydrocarbons heavier than methane. When these same correlations are used for mixtures of natural gas and carbon dioxide, large deviations between actual and predicted compressibility factors are observed. This study was undertaken to provide a means for accurately predicting the compressibility factor for such mixtures. In the past, two avenues of approach have been employed to extend the applicability of the PCS. The first has been to introduce additional parameters. The second has been to develop combination rules for predicting pseudocritical constants which do not suffer from the limitations of the commonly used molal average constants. In this study, both of these approaches have been considered and employed to arrive at a method for predicting the compressibility factor of mixtures of hydrocarbons and carbon dioxide. SELECTION OF A THIRD PARAMETER Failure of the original PCS to predict the compressibility factor for all pure gases, regardless of their mass, shape or polar moment, has led to the introduction of additional parameters into the PCS. Parameters have been introduced to correct for quantum deviations,3-5 non-spherical or globular shapes6-9 and for polar moments.8-12 In addition to these parameters which are based on some microscopic property and intended to correct for some specific cause of deviation, more general parameters based on some bulk property have also been introduced.1913-16 To use additional parameters to correct for each of the possible causes of deviation among the individual constituents of a gas mixture would require a rather complex form of the PCS. To maintain the PCS in as simple a form as possible, it is more desirable to have a single third parameter which is based on some bulk property influenced by several of the factors causing deviations. The third parameter selected for use in this study is a factor originally proposed by Pitzer.9

By H. N. Hall

Various factors must be considered in an engineering evaluation of gravity-drainage reservoirs. Among these are: (1) the effect of producing rate on total oil recovery; (2) the effect upon well productivity and ultimate recovery of the pressure level maintained during the producing life of the reservoir; (3) the economic advantage of full or partial pressure maintenance; and (4) estimate of the rate of gas production and injection and the possible purchase of gas under conditions of full pressure maintenance to ascertain compressor facilities needed. All of these factors can be evaluated only when a reliable method is employed for determining reservoir performance in gravity-drainage reservoirs. The purpose of this paper is to present a general method for calculating the performance of a gravity-drainage reservoir. This method is applicable for conditions of complete pressure maintenance, partial pressure maintenance and normal pressure depletion. Provisions are made to take into account variations throughout the reservoir of reservoir configuration, changes in permeability and fluid composition. Based on the method presented in this paper, an IBM 650 computer program has been developed. The past performance of an actual gravity-drainage reservoir producing under conditions of declining pressure and no gas injection was duplicated using this program. INTRODUCTION In tilted reservoirs the production of oil is influenced by drainage of oil from upstructure to downstructure locations. When this downstructure drainage of oil is sufficient to cause effective segregation of the gas and oil in a reservoir, the reservoir is usually classified as a segregation drive or gravity-drainage reservoir. (Discussion will be restricted to gravity-drainage reservoirs which have no encroachment of edge water.) The important feature in gravity-drainage reservoirs is the density difference between reservoir oil and gas. These phases tend to segregate in the reservoir with the result that in the gas cap the oil saturation is maintained at a higher level by drainage of oil from the gas-cap area. Oil can be produced from the oil zone at a low gas-oil ratio and reservoir energy is thereby conserved. The standard material balance in not adequate for predicting gravity-dramage reservoir performance because it does not take into account the difference in saturation above and below the gas-oil contact. Several authors'.' have presented methods for calculating the performance of gravity-drainage reservoirs in which reservoir pressure is maintained constant by gas injection into the gas cap. Using some simplifying assumptions, these methods can be employed with a desk calculator to give acceptable results. The problem of predicting the performance of gravity-drainage reservoirs under the conditions of declining reservoir pressure is many time more complex than that of constant pressure. fierefore, attempis to develop a method suitable for desk calculation have required excessively simplified assumptions. In the past several years, highspeed digital computers have become more widely available for reservoir engineering problems. These corn puters are well suited to problems such as the prediction of the performance of gravity-drainage reservoirs with pressure decline. Many of the simplifying assumptions necessary for hand computation can be eliminated so that a realistic approach to the gravity-drainage process can be made. CONCEPTUAL PICTURE OF OIL MOVEMENT IN GRAVITY-DRAINAGE RESERVOIRS Before attempting to develop an analytical treatment for conditions occuring in a gravity-drainage reservoir, a concept should be formed concerning the movement of fluids in the reservoir as oil is produced. A review of the literature'.' shows that it is customary to classify gravity-drainage operations into two categories—(1) with complete pressure maintenance, and (2) with declining pressure. The same line of reasoning will be followed in presenting the concept of the movement of fluids in the reservoir because it is easier to visualize the movement of fluids under conditions of complete pressure maintenance. After discussing complete pressure maintenance, an analogy will be made between that and the case of declining pressure. It should be kept in mind throughout that the final aim for the problem of solving gravity-drainage performance with digital computers will be to develop a general program for any kind of gravity-drainage reservoir. COMPLETE PRESSURE MAINTENANCE One feature which is generally common in gravity-drainage reservoirs is a gas cap located at the top of the structure. This is shown in Fig. 1(a). Fig. l(b) shows oil saturations that might occur through the reservoir. In the gas cap, oil saturation is lower than

By Donald B. Evans, Robert D. Pehlke

The solubility of nilrogen in liquid binary alloys of iron with Litanium. zivconium, columbium, vanndiurn, and tantalum was measured for alloy composiLions up to the solalbility limils of lhe alloy nitrides. All five alloying agents were found to decrease markedly the activity coefficient of nitrogen in liquid ivon. The metal/nitvogen mole ralios in the alloy nitrides formed were generally .found to be slighlly greater than 1.0, but in no case greater than 1.5. From the experimental data, the standard free energies of fortmation of titanium and zir-conium nitrides have been calculated for the Lemperaluve range 1550° to 1750 C. The solublily Products for columbium, tantalum, and vanadium nitrides are also reported. A number of research investigations have examined the effect of refractory metals on the solubility of nitrogen in liquid iron. Although data on zirconium are not available, investigators are in agreement that titanium, vanadium, columbium, and tantalum markedly increase the solubility of nitrogen in liquid iron. This fact alone makes desirable the acquisition of thermodynamic data for these elements in liquid iron. Since refractory metals are known to be stable nitride formers, they have been suggested as steel denitrifying agents, and some of their nitrides have recently been considered as containment materials for liquid iron and iron alloys. Most available thermodynamic data for these metals relate to their dilute concentrations, but effective thermodynamic treatment of these applications requires data at concentrations near the solubility limit of the alloy nitride. Although some work has been done at relatively high alloy concentrations in liquid iron (particularly for vanadium 2,3 and titanium 2,4), the results have been somewhat contradictory. Disagreement may be partly attributed to the fact that the compositions of most refractory metal nitrides have been shown to be nonstoichiometric, and to vary 2,5-8 depending on the temperature and nitrogen gas pressure with which the solid nitride phase is in equilibrium. One purpose of this study consequently has been to determine the compositions of the refractory metal nitrides precipitated from a liquid iron solution. EXPERIMENTAL PROCEDURE Rao and Parlee2 and Evans and Pehlke 9 have discussed the technique for measuring the solubility product of an alloy nitride phase in liquid iron by finding the point of departure of the nitrogen solubility from Sieverts' law. The method consists of measuring the solubility of nitrogen in a melt of iron containing a known concentration of a second metal as a function of the nitrogen gas pressure over the melt. In this study the second metal was one of the refractory metals titanium, zirconium, columbium, vanadium, or tantalum. When the nitrogen pressure at which the refractory nitride forms is reached, a deviation of the measured solubility of nitrogen in the melt from Sieverts' law is observed in the form of a "pressure halt." The concentration of nitrogen in the melt associated with this breakpoint in the nitrogen-absorption curve is then used to calculate the nitride solubility. The Sieverts method was used to measure nitrogen solubility as a function of nitrogen pressure and temperature. The experimental equipment for this technique has been previously described in detail. 1,9 Charge materials used were vacuum-melted high-purity iron (Ferrovac-E) and the best commercial grades of the refractory metals obtainable (in all cases at least 99.8+ pct pure). Recrystallized alumina crucibles were used to hold all melts except those containing zirconium, for which zirconia crucibles were necessary. Temperatures were measured by a disappearing-filament type optical pyrometer sighted vertically downward on the melt surface through a 1/4-in.-diameter sight hole in the crucible lid. By means of a technique previously described, 9 in which the refractory-metal nitride was precipitated at one temperature then redis-solved by raising the temperature 50°C and precipitated again at a higher temperature, it was possible to obtain data over a temperature range of up to 200°C on a single melt. It was found that this technique could not be used with melts containing zir-

Jan 1, 1965

By Robert Gilman Brown

There are few disasters so difficult to deal with as an underground fire. It is inaccessible at best, and generally unapproachable ; and it finds most material in the very places where it can do most harm, namely, in large stopes and in " heavy " ground where timbers are massed, and in shafts and level-stations where there are inevitably strong drafts to make the burning yet more fierce. The fire constituting the subject of this note occurred in the shaft of the Standard mine at Bodie, California, and originated after the departure of the night-force at 3 a.m., being discovered by the men going to work at 6.30. At that time it had gained already considerable headway, and was throwing smoke plentifully from the collar of the shaft. It must be premised, for understanding of the situation, that in this shaft all hoisting is done to the 320-foot level, where the material is dropped by chutes 30 feet. to the tunnel-level, through which it is run to the mill. Hoist and sheaves are all placed

Jan 1, 1897

By Y. Takahashi, I. Iwasaki, S. Tanabe

Supported by the vigorous capital investment of the heavy and chemical industries and by the ever-increasing demand for durable consumer goods in the past decade, Japan has now emerged as the world's third largest steel producer, surpassed only by the United States and the Soviet Union. In 1968, the crude steel production is expected to exceed 50 million tons; the per capita steel consumption at that time will reach 886 lb, approaching the level of Western Europe. Characteristics of the Japanese steel industry is the high dependence of raw materials on overseas sources. Before World War II the industry relied on North China and Manchuria for coking coal, and on middle China, Hainan Island, the Philippines and the Malayan Peninsula for iron ores. After the war, the major sources of iron ores were shifted to the Philippines and the Malayan Peninsula, supplemented by shipments from the United States, Canada, India and Goa. The United States, in addition, became the primary source of coking coal.

Jan 1, 1967

By H. Conrad

The strain hardening associated with the creep of magnesium single crystals at room temperatu.Je was investigated by shear tests in which the direction of stressing was reversed a number of times after creep in a <100> direction. The strain hardening was strongly anisotropic; the largest amount occurring in the direction of flow and the least 180 deg to this. The time law for creep changed from a parabolic type to logarithmic for the first and subsequent reversals of stress. For a given stress the creep strain decreased significantly for the first and second reversals and then only slightly for subsequent reversals. The logarithmic creep constant a changed in a similar manner. A linear relationship was observed between the creep strain for a given reversal and the stress. The slope for the third reversal yielded a strain hardening coefficient 12 to 16 times greater than that observed for unidirectional flow. Al-though no recovery was observed upon resting at room temperature, the hardening resulting from stress reversals could be completely removed by heating to 450" C. PREVIOUS work1.&apos; indicated that the creep rate of magnesium single crystals tested in the temperature range of 78" to 364°K decreased with time. This was attributed to an increase in internal stress resulting from an accumulation of dislocations at internal obstacles. The object of the present investigation was to further evaluate the nature of this hardening by conducting tests in which the direction of stressing is changed after previous creep in shear in a given slip direction. Previous to 1950 three investigations indicated that a Bauschinger effect3 occurred for single crystals as well as polycrystals brass in tension compression,

Jan 1, 1960

By H. M. Howe

Page 1. Introduction............................514 2. Definitions.............................517 3. Brevity of the Heating........................517 I. THE HARDENING OF THE BORE..............517 4. The Hardening of the Bore.....................517 5. The Thickness of the Hardened Layer.................517 6. Martensitization..........................518 7. The Hardening Repetitive ......................519 8. The Temperature Cycle.......................519 9. The Hardened Layer is the Merged Layer............... 521 10. The Progressiveness of Merging....................521 11. The Progressive Thickening of the Hardened Layer from Round to Round. 523 12. Merging and Hardening are Cumulative................523 13. Three Additional Causes of the Progressive Thickening of the Hardened Layer 525 14. Progressive Roughening of the Bore..................525 15. Avoidance of an Endothermic Transformation.............525 16. Asymptotic Retardation of the Thickening of the Hardened Layer.....527 17. The Troostitic Layer........................ 529 18. The Usual Lack of Martensitic Markings................529 19. The Thickness of the Hardened Layer Should Increase with the Quantity of Heat Taken up by the Walls of the Bore.................530 20. The Decrease of the Thickness of the Hardened Layer from Breech to Muzsle 531 21. Phstic Deformation as a Contributory aCause of Hardening........531 22. In What Way May Plastic Deformation Hasten Hardening?....... 535 23. Possible Need of Coarsening.....................535 24. Carburization as a Cause of Hardening..........:.....536 25. Does Hardening Increase Erosion?..................-538 11. THE CRACKING OF THE BORE ...............539 26. Appearance of the Bore and Cracks in Elevation............539 27. The Cracks in Elevation in the Rear Ring...............539 28. The Cracks in Elevation in the Forward Ring.............540 29. The Copper Network in the Grooves.................540 30. The Cracking of the Lands......................541

Jan 1, 1918

By F. V. Lenel

R. P. Seelig.*—Dr. Lenel is to be congratulated on his presentation of a particularly interesting paper describing the use of the powder metallurgy process for the production of magnetic pole pieces. The only thing that might be added is that we have been successful in producing pole . pieces with a narrow hysteresis curve by the use of considerably lower sintering temperatures than the ones used by Dr. Lenel. It is quite possible that this use of lowe- temperatures has considerably widened the field of commercial application for pole pieces made from metal powders. Development work is currently being done on an a.c. application of a sintered iron part. However, I am in full agreement with Dr. Lenel that if eddy currents are an important factor in the application, we cannot substitute sintered material for laminated sheet-metal structures. Mr. Peters&apos; remarks concerning the limitations of machine parts were well taken. The emphasis of the limitations makes it easier to define clearly what we can do and-what the advantages are of machine parts made of metal powders. When I mention metal-powder machine parts, I mean those of relatively high density, although complete elimination of porosity is not possible at this time. The limitations of the field for this type of parts are largely economical. I believe that Mr. Langhammer has made that point very clear. The following questions are very often asked: How large a part can you make? How close can you hold the dimensions ? How fast can a part be produced? In a majority of the cases, it depends on the cost at which the part can be produced. A large variety of shapes and sizes of a number of materials can be formed. However, the main requirement in this field of endeavor is whether this can be done more economically by powder metallurgy than by other manufacturing methods. As a general indication, it may be stated that densities up to 95 per cent of that of rolled material can now be produced commercially in simpler parts. Tolerances of plus or minus 0.001 in. are common, but where special conditions justify, closer tolerances can be held; we are producing a part of which one dimension is held to 0.0003 inch. Finally, as far as maximum size is concerned, technically this would depend on the capacity of the press and furnace equipment available. Actually, we find that the economical limit of powder-metallurgy machine parts is approximately one pound. From there on, each individual case must he studied on its own merits.

Jan 1, 1945

By Donald Warren, J. F. Libsch

HIS investigation originated as a result of a pre-vious experimental study&apos; of the magnetic properties of Fe-Co alloys fabricated by the powder metallurgy technique. Densities of powder compacts prepared for the magnetics investigation varied from 7.45 to 7.70 g per cu cm or from 93 to 95 pct of the experimental value of 8.08 g per cu cm for a fused alloy of the same composition.&apos; While this range of density is considered sufficiently high for most applications, the highest possible density is to be desired for maximum magnetic properties. By applying a technique similar to the one described above to a pure electrolytic iron powder, Rostoker³ was able to achieve a density of 7.895 g per cu cm, which is the highest density ever reported for sintered iron. While Rostoker&apos;s work involved the sintering of an elemental powder rather than a mixture, it was believed that higher densities should also have been obtained for alloys using the above technique because of the recoining operation and the high sintering temperature. Consequently, it was decided to investigate the various factors affecting the density of this alloy with the idea that such a study might lead to higher densities and, as a result, powder alloys having magnetic properties identical with those of the fused alloys. It was believed that the principal reason that near-theoretical densities for the powdered alloy were not obtained was the interference of gases with the normal sintering mechanism. When present during the sintering operation, gases can exert several harmful effects: they can remain on the particle surface and interfere with surface diffusion and plastic flow; they can be released and, under certain conditions, expand the void spaces through gas pressure; or they can remain trapped in the pores and exert a hydrostatic pressure that retards elimination of the pores. Jones,4 Rhines,5 Goetzel," and others have given the effect of gases in the sintering of powder compacts an extensive treatment. Among the more important sources of gases in the sintering process are dissolved gases, adsorbed gases, air entrapped during pressing, and gaseous products of chemical reactions. During sintering adsorbed gases are partly released at a relatively low temperature, while those gases entrapped during pressing cannot escape until their pressure is increased sufficiently through increasing temperature to expand the interpartjcle openings. The remaining adsorbed gases, gaseous reduction products, and dissolved gases produce a similar effect at the higher temperatures. If, in the sintering process, gas evolution occurs after the interpore channels have been sealed, an exaggerated expansion of the void spaces results. This is particularly true if the temperature is high enough for extensive plastic flow. In his fabrication of powder bars from tantalum, Balke7 had to consider the effect of adsorbed hydrogen and provide for its escape during sintering by limiting the compacting pressure to a maximum of 50 tons per sq in. The effect of gases entrapped during pressing was first noted by Trzebiatowski8 when he found that gold and silver powders decrease in density with increasing sintering temperature if pressed at 200 tsi, while they exhibit the usual increase when pressed at 40 tsi. Recent investigators9-11 have also noted that entrapped gases have an effect on the expansion of copper compacts during sintering. Proper provision for the escape of gaseous products of reduction must be made in order to avoid deleterious effects. Myers" states that in the sintering of electrolytic tantalum powder, the temperature was gradually raised to 2600°F with a pause at 2000°F to permit reduction of the oxides. Experimental Details For the present study, 50 pct Co-50 pct Fe compacts in the form of circular disks 1½ in. in diam and 0.15 in. thick were fabricated by the pressing and sintering of a mixture of the elemental powders. It was decided to follow the sintering process by means of liquid permeability measurements, because it was thought that such measurements might serve as a measure of relative pore sizes, as well as a possible indication of the point at which most of the interpore channels become sealed. However, since the permeability as measured by the flow of a liquid, such as ethylene glycol, does not give an absolute indication of the point where the pores have become isolated, a method for determining the percentage of pores connected to the surface was set up. As an additional cross check on the permeability measurements, metallographic methods were used to study the relative pore size. Finally, the property of ultimate interest, the density, was measured. Raw Materials: The powders used consisted of an annealed, 99.9 pct pure, —150 mesh grade of electrolytic iron powder, and a 98 pct pure, —200 mesh grade of reduced and comminuted cobalt powder. The cobalt powder was not further processed either by hydrogen reduction or annealing. The screen analyses for the iron and cobalt powders are given in Table I, while the chemical analyses for each type of powder are listed in Table 11. Table 111 gives the hydrogen loss measurements for the powders according to the M.P.A. Standard Method and for a higher temperature as well. Preparation of Compacts: Equal amounts of the elemental powders were mixed by rotation for 1 hr and then pressed into compacts approximately 0.15

Jan 1, 1952

By Russell G. Haworth

Three companies, United States Potash Company, Potash Company of America, and International Minerals and Chemical Corporation, are now operating potash mines and reGneries in the Carlsbad, New Mexico, area. The three mines are located approximately twenty miles east of Car1sbad. The deposits have been found ideal for mechanized mining methods. This summary has been compiled from information made available by the three operating companies. Prospecting Since outcrops of potash are nonexistent, prospecting is accomplished by drilling and coring of the salt section to establish the grade, thickness, and outline of the potash beds contained in the salt deposits. Information regarding the nature of the formations in the cover of 400 to 600 ft thick over the salt and potash beds is also obtained from drill cuttings in the same operation. By proper interpretation of assembled data the best location for shafts may be determined. The overburden varies in character but consists in general of interbedded shales, sand, gravels, limestones, and anhydrite beds. Water, in unpleasant quantities, especially in the sands and limestones, often completes the geologic section. Some of the shaftas in the area have been sunk without undue difficulties, others have been delayed by flows of water. Most of the shafts are concreted from the surface to the salt section. Each of the three mines in the Carlsbad area has one shaft for hoisting ore and one for hoisting men and supplies. Mining Methods Information acquired from initial drilling and prospecting affected the choice of mining methods. Since the tabular, slightly rolling deposits were similar to coal seams, the room-and-pillar system used in coal mining was adopted by all the companies. Pillars have not been removed in any of the mines on a large scale. One company has conducted experimental robbing of pillars in one restricted area. Where it is known that overlying strata contain water in large amounts, it is not considered practical to risk flooding of the mines by removing pillars without fill. Some thought is now being directed toward development of economical methods of filling for pillar recovery. The problem is not identical at the three mines and local conditions will govern the methods employed for eventual pillar recovery. The important point is that, with large reserves, it has not been necessary to resort to mining of pillars for adequate production. The ore deposits are laterally extensive but are irregular in shape and lie at a depth of 700 to 1100 ft below the surface. The major operations of all mines are on the same bed strati-graphically, except for the langbeinite level at International Minerals and Chemical Corporation. The deposits are apparently not connected and in many parts of the deposits being mined, "salt horses" or barren zones occur. From 400 to 700 ft of salt with minor beds of polyhalite and anhydrite lie immediately above the ore horizon. The ore differs from the salt only in the potassium chloride content and color due to small amounts of iron associated with the sylvite, giving the ore a somewhat mottled red and white cast. Thickness of the ore varies from 5 to 14 ft. Rooms and break-throughs in the mines vary from 24 to 40 ft in width, the overlying salt forming an excellent roof and providing safe mining conditions. Almost no timber is used in any of the mines for roof support. Drilling is normally the first step in mining the face of a room. Electric motor driven auger drills are used in the area. Jack hammers were used to some extent when the mines were first opened but the ore is easily drilled if bits are sharp and the coal type

Jan 1, 1950

By Henry Ferguson

THIS paper is a preliminary statement, intended to present the more important results of the recent studies of the ore deposits of the Alleghany district in advance of the publication of the complete report, now in preparation. The Alleghany district (Fig. 1) has been a producer of gold since the early days of California gold mining. As in other California gold camps, placers yielded the bulk of the earlier production, but during the last 30 years lode deposits have been the only important source of output. The district differs from other California gold-quartz districts in that nearly all the production is from small shoots of high-grade ore. The mining camps of Alleghany and Forest are on the western flank of the Sierra Nevada range about 20 miles west of the crest. The gently sloping lava-covered plateau which controls the upland topography has been trenched by deep canyons of the westward flowing streams, which are cut to depths of as much as 2000 ft. below the crests of the ridges. The district is about 18 miles from Nevada City but the automobile road which connects the two places is 31 miles long. The senior writer first visited the district in 1913 and published a short description of the lode deposits.1 The increasing importance of the district made further study desirable. A detailed topographic map was therefore made by W. B. Upton, Jr., of the U. S. Geological Survey, in the spring of 1924, and the senior writer spent parts of the field seasons of 1924 and 1925 in the district. For the second field season the Geological Survey was fortunate in securing the services of R. W. Gannett, who had already done geologic work in the district for several of the mining companies. Owing to the death of Mr. Gannett in October, 1925, just before the close of his field work, the work of preparation of the entire report fell to Mr. Ferguson. He takes this opportunity of acknowledging how deeply he is indebted to Mr. Gannett for his excellent work in the field, and his realization of how greatly the completion of the report on the district has suffered from lack of Mr. Gannett&apos;s assistance in the office. In October, 1.928, after the completion of the first draft of the manuscript, Mr. Ferguson made a short visit to the district.

Jan 1, 1929

By J. Wes Blakely

In the mid-1950s the importation of foreign oil began to encroach on traditional coal markets such as railroad steam engine fuel, home heating, electrical generating plants, and others. Many of the smaller coal companies with substantial coal reserves subsequently found that they could no longer continue to mine economically and merged in various ways with larger established coal mining concerns. As the seats of top management and authority were removed from the mines to large metro centers such as New York, Pittsburgh, and Chicago, the more personal relationship between mine workers and management that had existed prior to these mergers began to be eroded and replaced by "remote control" mine management. The disappearance of this face-to-face contact of upper management with mine employees tended to create barriers blocking simple effective communications between coal mine management and labor. In examining the human relations aspects of the coal mining industry, many elements, some concerned with work and others not, have depicted the industry as almost devoid of good applied human relations and communications practices, and, in truth, little has been done to alleviate this situation. In past years many coal producing companies, with the exception of one of the largest, failed to adequately define the term "communications &apos; as it applied to their companies, whether internally or externally. Internally many still place heavy reliance on written communications such as company-wide newspapers to do the job of communicating with their employees which they feel ought to be done. One company puts an inordinate belief in its company "newspaper" as the primary instrument to stimulate its work force into increasing productivity. Primarily aimed at the workers, who greatly outnumber the salaried administrative people, this publication mainly documents the fortunes of individual mine workers who are felt to have achieved something with their lives, e.g., a mine worker who had managed to put four children through universities, the

Jan 1, 1981

By F. J. Haller

IN 1943, we found, in the new Mather operation, a very unusual and disappointing condition in the footwall rock where all of our main haulageways were to be located. With the exception of a few hundred feet out of the thousands then planned and since driven, all of the openings require support. In general, the ground is not particularly heavy, at least by our standards, but it must be supported and the back carefully covered. Also, our operations require rather wide plat openings (16 to 18 ft) and rather flat curves at the turn-outs, all of which adds to the problem. When this completely unforeseen condition was discovered, ordinary timbering was the only answer, because of the impossibility of obtaining adequate steel supplies in time due to war shortages. Then by the time steel supplies were obtained and a practice developed, we found ourselves with between four and five miles of main haulage drifts and plat openings of a permanent nature, all of which were supported by hardwood timber, some of which had already rotted to an unsafe degree. Also, our drifting program was adding some two miles per year to the above figure. F. J. HALLER, Member AIME, is Superintendent, Mather Mine, Cleveland-Cliffs Iron Co., Ishpeming, Mich. AIME Columbus Meeting, September 1949. TP 2840 A. Discussion (2 copies) may be sent to Transactions AIME before May 31, 1950. Manuscript received Aug. 22, 1949. Revision received Jan. 17, 1950. To give all of the details of our experiments, studies, and experiences would fill a large book, but we were satisfied that our organization had done an excellent job, starting from scratch. You can appreciate our surprise when we discovered that we had added very little to an existing record. Attention was called to a footnote in a copy of "Carnegie Pocket Companion" year 1923. The note read: "Full information as to uses of H-Beams is given in pamphlet entitled &apos;Steel Mine Timbers.&apos; " A search of our Engineering Library brought to light a pamphlet printed in 1911 showing extensive use of steel for this purpose. Except for welding in place of riveting, we have added very little to the designs in that book. We have, however, developed an experience which proves, at least to our own satisfaction, that steel mine supports pay off under the proper conditions. We are now convinced, in spite of the relatively high initial cost of materials, that steel sets, because of comparatively low installation cost, are actually cheaper than either treated or untreated wood sets, if they are properly designed and adapted. Several Sections in Use: Convenience guided our first experiments in steel sets, since for a number of years, we had used the 4-in. WF, 10 lb per ft section in 10-ft lengths as safety forepoles along with wood forepoles. This section replaced the 40-lb rail which had formerly been used for the purpose. Having the 4-in. WF sections on hand, it was natural that our first experiments in steel sets involved their use. Later, the rolling of the 10-lb section was discontinued in favor of the much stronger 13-lb section, which is now standard for both legs and caps in areas of no particular weight, but which, none the less, require permanent support. Our experiments involved the use of the 10- and 13-lb sections as legs and 6- and 8-in. I beams, 16 and 23 lb per ft, respectively, as caps. Experience soon indicated that, if the ground were heavy enough, and the opening wide enough to require a cap stronger than 13-lb, the 8-in, 23-lb should be used, eliminating the 6-in. I beam. We now know that the 8-in. WF section of the same weight, which we propose to use in the future, is considerably stronger for the amount of money involved. Comparative Strengths: Tables I to IV giving strengths of several species of timbers as compared with the structural sections that we now use have been prepared in accordance with accepted practice. Experience indicates that failure due to compression perpendicular to the grain of the wood does not destroy the effectiveness of a wood set frequently enough to be a practical factor. Therefore, no table of these values is included.

Jan 1, 1951

By F. J. Haller

IN 1943, we found, in the new Mather operation, a very unusual and disappointing condition in the footwall rock where all of our main haulageways were to be located. With the exception of a few hundred feet out of the thousands then planned and since driven, all of the openings require support. In general, the ground is not particularly heavy, at least by our standards, but it must be supported and the back carefully covered. Also, our operations require rather wide plat openings (16 to 18 ft) and rather flat curves at the turn-outs, all of which adds to the problem. When this completely unforeseen condition was discovered, ordinary timbering was the only answer, because of the impossibility of obtaining adequate steel supplies in time due to war shortages. Then by the time steel supplies were obtained and a practice developed, we found ourselves with between four and five miles of main haulage drifts and plat openings of a permanent nature, all of which were supported by hardwood timber, some of which had already rotted to an unsafe degree. Also, our drifting program was adding some two miles per year to the above figure. F. J. HALLER, Member AIME, is Superintendent, Mather Mine, Cleveland-Cliffs Iron Co., Ishpeming, Mich. AIME Columbus Meeting, September 1949. TP 2840 A. Discussion (2 copies) may be sent to Transactions AIME before May 31, 1950. Manuscript received Aug. 22, 1949. Revision received Jan. 17, 1950. To give all of the details of our experiments, studies, and experiences would fill a large book, but we were satisfied that our organization had done an excellent job, starting from scratch. You can appreciate our surprise when we discovered that we had added very little to an existing record. Attention was called to a footnote in a copy of "Carnegie Pocket Companion" year 1923. The note read: "Full information as to uses of H-Beams is given in pamphlet entitled &apos;Steel Mine Timbers.&apos; " A search of our Engineering Library brought to light a pamphlet printed in 1911 showing extensive use of steel for this purpose. Except for welding in place of riveting, we have added very little to the designs in that book. We have, however, developed an experience which proves, at least to our own satisfaction, that steel mine supports pay off under the proper conditions. We are now convinced, in spite of the relatively high initial cost of materials, that steel sets, because of comparatively low installation cost, are actually cheaper than either treated or untreated wood sets, if they are properly designed and adapted. Several Sections in Use: Convenience guided our first experiments in steel sets, since for a number of years, we had used the 4-in. WF, 10 lb per ft section in 10-ft lengths as safety forepoles along with wood forepoles. This section replaced the 40-lb rail which had formerly been used for the purpose. Having the 4-in. WF sections on hand, it was natural that our first experiments in steel sets involved their use. Later, the rolling of the 10-lb section was discontinued in favor of the much stronger 13-lb section, which is now standard for both legs and caps in areas of no particular weight, but which, none the less, require permanent support. Our experiments involved the use of the 10- and 13-lb sections as legs and 6- and 8-in. I beams, 16 and 23 lb per ft, respectively, as caps. Experience soon indicated that, if the ground were heavy enough, and the opening wide enough to require a cap stronger than 13-lb, the 8-in, 23-lb should be used, eliminating the 6-in. I beam. We now know that the 8-in. WF section of the same weight, which we propose to use in the future, is considerably stronger for the amount of money involved. Comparative Strengths: Tables I to IV giving strengths of several species of timbers as compared with the structural sections that we now use have been prepared in accordance with accepted practice. Experience indicates that failure due to compression perpendicular to the grain of the wood does not destroy the effectiveness of a wood set frequently enough to be a practical factor. Therefore, no table of these values is included.

Jan 1, 1951

By J. Wes Blakely

In the mid-1950s the importation of foreign oil began to encroach on traditional coal markets such as railroad steam engine fuel, home heating, electrical generating plants, and others. Many of the smaller coal companies with substantial coal reserves subsequently found that they could no longer continue to mine economically and merged in various ways with larger established coal mining concerns. As the seats of top management and authority were removed from the mines to large metro centers such as New York, Pittsburgh, and Chicago, the more personal relationship between mine workers and management that had existed prior to these mergers began to be eroded and replaced by &apos;remote control mine management. The disappearance of this face-to-face contact of upper management with mine employees tended to create barriers blocking simple effective communications between coal mine management and labor. In examining the human relations aspects of the coal mining industry, many elements, some concerned with work and others not, have depicted the industry as almost devoid of good applied human relations and communications practices, and, in truth, little has been done to alleviate this situation . In past years many coal producing companies, with the exception of one of the largest, failed to adequately define the term “communications” as it applied to their companies, whether internally or externally. Internally many still place heavy reliance on written communications such as company-wide newspapers to do the job of communicating with their employees which they feel ought to be done. One company puts an inordinate belief in its company "newspaper" as the primary instrument to stimulate its work force into increasing productivity. Primarily aimed at the workers, who greatly outnumber the salaried administrative people, this publication mainly documents the fortunes of individual mine workers who are felt to have achieved something with their lives, e.g., a mine worker who had managed to put four children through universities, the

Jan 1, 1981

By W. P. Haynes

ESTIMATED United States crude-oil production during 1943 established a new annual peak of 1,500,000,000 barrels, a daily average of 4,118,000 barrels. This would be an increase of 315,000 barrels per day, or 8 per cent over 1942 and 7 per cent over 1941, the previous peak. During the first ten months of the year, production jumped from 3,782,000 barrels per day in January to 4,400,000 in October. Available data for the last two months of the year indicate a leveling off of this trend, with daily rates slightly above 4,400,000 barrels.

Jan 1, 1944

By R. E. Hobart

The development of the Hauto power plant and the claims made by various engineers that electricity was more economical than steam for power purposes in and about the mines, led the Lehigh Coal and Navigation Co., in 1911, to conduct a test to ascertain the consumption of power used by a large steam hoisting engine. The question being one on which no reliable information could be found, and the opinion of various engineers differing to such an extent, it was decided that a test under actual operating conditions was necessary. This was arranged for at one of the collieries. The engine selected was 2 30 by 60-in. (76.2 by 152.4-cm.) piston-valve engine of modern type, and comparatively new. The boiler plant from which the hoist received its power was about 600 ft. (182 m.) from the engine, the latter being fed by a 10-in. (25.4-cm.) steam line insulated with magnesia pipe covering. Two batteries of the boiler plant, aggregating 1200 hp., were cut off and fed into a separate steam line leading direct to the hoist engine. Steam auxiliaries, consisting of feed-water pump and blowers, were fed by the boilers in test, and their consumption charged against the hoist. A barrel weighing device was installed, as it was felt that this would be the most accurate way of determining the consumption of water. The fuel, No. 3 buckwheat, was carefully weighed, and every precaution was taken to make the test accurate in every particular. The test was run for 1 week, or a total of 168 hr. A record was kept of the number of trips hoisted or lowered, and continuous indicator cards were taken. One particular set of cards was taken with the hoist operating balanced, and also with the hoist operating with no counterweight other than the empty cage, the coal in the car being weighed. The speed of the hoist was taken by means of a graphic recording instrument which registered the number of revolutions every 5 sec. From this record, speed-time curves were plotted.

Jan 1, 1918

By Ernest Stütz

(New York Meeting, October, 1913.) THE problem of increasing blast-furnace efficiency through diminution of flue-dust production while operating with burdens consisting largely of fine ores has of recent years attracted the attention of metallurgists, whether directly or indirectly interested in the economies of iron smelting, and the various methods evolved from theory or practice have been. submitted to wide discussion. After the very thorough and, at that time, exhaustive view of the whole subject, which was afforded to the industry by the meeting of this Institute in February, 1912, the subject was again taken up at the meeting of the Verein deutscher Eisenhüttenleute at Düsseldorf in December, 1912. While American and German conditions are not entirely identical, it may be of interest to give here the words of the gentleman summing up the discussion at the Düsseldorf meeting : ?The chief advantage offered by the use of briquettes lies in the fact that disturbances in the furnace, caused mostly by the presence of fine ores in the burden, are avoided, and that blast pressure can be considerably reduced. The resulting economies cannot be overrated, as, with lower blast consumption per ton of product, the installation will be able to take care of increased production. In consequence of lower pressure and speed of blast, heat is more efficiently utilized,, flue gas temperature is lowered, and coke particles are less liable to be carried along with the flue dust, of which considerably less is produced. Finally, by increased regularity of operation and higher temperature in the lower parts of the furnace, the quality of the product is improved. The question of briquetting iron ores has grown to be one of the most important in the iron industry, and it is not any more a question of what is the cost &apos;of briquetting a ton of ore, but what, in. using ore briquettes, is the cost, of: production of a ton of iron."

Jan 7, 1913

By W. C. Knopf, G. Samsel

For several years International Minerals & Chemical Corp. has used a radiation method to assay potassium content of products from potash and feldspar beneficiation. The procedure is rapid, accurate, and inexpensive and is easily handled, if necessary, by nontechnical personnel. Data are presented to show the accuracies that may be expected if the technique is used for control of pilot plants or large- scale plants. Natural potassium is composed of three isotopes -K39, K40 and K41. Five other isotopes, artificially produced, have been detected. In natural potassium only the K40 isotope, with a half life of 1.4 x 109 years, is radioactive. Its modes of decay are beta and gamma rays, positrons, and x-rays. Only the more abundant beta rays, however, are important in radiation measurements using geiger tubes.

Jan 10, 1958