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By AIME AIME

THE world was not quite ready for Hal Marsh when he emerged from the California Institute of Technology in 1922 with a Bachelor of Science degree in mechanical engineering, so, finding no promising job, he went back on a fellowship for another year. He wound up his responsibilities to it on a Saturday in June, 1923, went to work for the General Petroleum Corp. of California the next Monday morning, and has been there ever since. His present position is that of "production engineer." As such, his duties are miscellaneous and vague, but may mostly be described as investigation of equipment and methods pertaining to drilling and the production of oil, with occasionally a bit of design. He has written important papers for the A.I.M.E., American

Jan 1, 1936

By Damon H. McFadden

5.1-1. Geographic and Geologic Factors. Surface mines are located where the coal seam can be economically uncovered and where the product can be utilized competitively with other fuels. The planning and designing of a pit may follow various procedures. The sequence for consideration of the influential factors as considered here may not be complete for every pit, nor will it be necessary to be completely used in each design. It is suggested as a check and outline for the engineering approach. Controlling conditions for the layout should be listed and considered with the facilities and equipment for the exploitation. After these items, as listed below, have been discussed and the feasibility agreed upon, then the actual planning and design of the pit can be done. GEOGRAPHIC FEATURES. The location of the coal area sets the climatic stage. The rainfall, the temperature extremes, and the general weather conditions all affect the design of the pit. Overburden soil when wet may not be stackable and may be impossible to move by standard procedures. The coal seam itself may be so soft that it must not be traveled on when wet, as the losses may be the difference between a profitable venture and an unsuccessful one. Some equipment will work well on dry soil only, just as a dredge works only in the wet. The conditions must be checked and analyzed. Some equipment cannot handle frozen soil (wheel excavators), so temperature extremes must be noted. The extreme weather conditions may also govern the expected working days and therefore the ultimate production. The altitude (atmospheric pressure) may affect the equipment, and this should be checked. All of these conditions should be noted on the preliminary map of the area. GEOLOGIC FACTORS. The geologic and surface conditions of the coal field dictate the type of pit generally feasible. Rough terrain, rolling terrain,

Jan 1, 1968

By Gerhard Derge, Harold Markus

The first paper1 of this series described a technique of careful surface preparation by means of which reproducible results may be obtained from potential measurements of the behavior of tin in carbonate solutions with a pH range from 8.4 to 11.2. It then went on to establish the behavior of pure tin electrodes under these conditions and showed that the metal remains active at all times, though the steady potential attained after several hours decreases from 1.12† volts at a pH of 12.6 to 0.6 volts at a pH of 8.4. This behavior may serve as a norm with which all other data can be compared. In the second paper,2 small amounts of other anions were added to the carbonate solutions and the conclusion was reached that the common impurities encountered in alkaline materials packaged in tin do not increase corrosion. In fact, in some cases these anions may actually promote the formation of protective films. The present paper rounds out this survey by presenting data on the influence of cations added to the carbonate solutions, as well as the effect of alloy additions to the tin. In many cases the potential data are supplemented with weight-loss measurements. Information is also presented on the effects of some additional anions, the influence of gases above the electrolyte, the behavior of high-purity tin, and the effect of atmospheric oxidation on the corrosion resistance of the above-named alloys. Analysis of the entire body of data discloses some general rules applicable to corrosion in carbonate solutions. The experimental methods used are the same as those previously described. Experimental Data Cations.—The carbonates of the cations K+, Li+, NH4+, which are soluble, were studied in the same way as the anions, by adding 0.01 mol of the metal carbonate to one liter of 0.1 M sodium carbonate solution, pH 11.2, or to 0.1 M sodium bicarbonate, pH 8.4. The other metallic carbonates are only slightly soluble, of the order of 10-3 mols per liter or less, and the sodium carbonate solutions were saturated by adding excess reagent several days before the experiment, shaking frequently, and filtering just before use. The chemicals were c.p. grade in each case except the indium salt. This salt was prepared by solution of the metal in hydrochloric acid and precipitation by addition of Na2CO3. These cations may be divided into two classes, according to their effect on the potential behavior of the tin: (I) normal, (2) passive. To offer a basis of comparison, curves I of Figs. I and 2 are given to illustrate the behavior of tin in carbonate solutions saturated with CaCO3. These curves are the

Jan 1, 1941

By Harold Markus, Gerhard Derge

The first paper1 of this series described a technique of careful surface preparation by means of which reproducible results may be obtained from potential measurements of the behavior of tin in carbonate solutions with a pH range from 8.4 to 11.2. It then went on to establish the behavior of pure tin electrodes under these conditions and showed that the metal remains active at all times, though the steady potential attained after several hours decreases from 1.12† volts at a pH of 12.6 to 0.6 volts at a pH of 8.4. This behavior may serve as a norm with which all other data can be compared. In the second paper,2 small amounts of other anions were added to the carbonate solutions and the conclusion was reached that the common impurities encountered in alkaline materials packaged in tin do not increase corrosion. In fact, in some cases these anions may actually promote the formation of protective films. The present paper rounds out this survey by presenting data on the influence of cations added to the carbonate solutions, as well as the effect of alloy additions to the tin. In many cases the potential data are supplemented with weight-loss measurements. Information is also presented on the effects of some additional anions, the influence of gases above the electrolyte, the behavior of high-purity tin, and the effect of atmospheric oxidation on the corrosion resistance of the above-named alloys. Analysis of the entire body of data discloses some general rules applicable to corrosion in carbonate solutions. The experimental methods used are the same as those previously described. Experimental Data Cations.—The carbonates of the cations K+, Li+, NH4+, which are soluble, were studied in the same way as the anions, by adding 0.01 mol of the metal carbonate to one liter of 0.1 M sodium carbonate solution, pH 11.2, or to 0.1 M sodium bicarbonate, pH 8.4. The other metallic carbonates are only slightly soluble, of the order of 10-3 mols per liter or less, and the sodium carbonate solutions were saturated by adding excess reagent several days before the experiment, shaking frequently, and filtering just before use. The chemicals were c.p. grade in each case except the indium salt. This salt was prepared by solution of the metal in hydrochloric acid and precipitation by addition of Na2CO3. These cations may be divided into two classes, according to their effect on the potential behavior of the tin: (I) normal, (2) passive. To offer a basis of comparison, curves I of Figs. I and 2 are given to illustrate the behavior of tin in carbonate solutions saturated with CaCO3. These curves are the

Jan 1, 1941

By T. J. DeMull

More than 1.81 mt (2 million tons) of low grade ore have been heap leached at the Alligator Ridge mine. Since inception of leaching in 1980, several modifications have been made to ore agglomeration, heap construction, and leach operation practice. These modifications have improved the percolation rate of the ore and the rate of gold extraction from the ore. Changes made in each of these areas are described and the effects of the changes are discussed.

Jan 1, 1984

By T. B. Counselman

Probably the earliest concentration of iron ore in this country was carried on in the northeastern magnetite areas. Magnetic concentration was relatively simple and gave a concentrate that, after agglomeration, and in spite of being high in phosphorus because of the dry concentrating methods then in use, was satisfactory blast-furnace feed. Production from the northeastern magnetite area languished after the discovery and development of the Lake Superior ores, where there was seemingly an unlimited tonnage of high-grade ore, first the Michigan ores, and subsequently the still larger deposits of Minnesota. For years only the higher grade, direct shipping ores of the Lake Superior district were mined. Those of Michigan, and of the Vermilion Range in Minnesota, were hard ores and came principally from underground mines. The softer ores of the Mesabi came partly from underground mines, but mostly from the enormous deposits that could be worked by open-pit methods. The costs of ore from these open-pit deposits, even with the high initial cost of stripping, were so low that the underground mines of the Mesabi could hardly compete. The so-called Old Range ores, of Michigan and of the Vermilion. Range of Minnesota, were hard and lumpy, and opened UP the burden in the blast furnace, therefore making possible harder driving with greater output. Also, some of these ores were of such grade and physical characteristics that they were suitable for charge ore in the open hearth. These ores, therefore, commanded a price premium, and could compete with the softer, finer, but cheaper, Mesabi ores. The big tonnage reserves, however, are on the Mesabi. and it is these big open-pit deposits that constitute our stock pile of iron ore, from which we are drawing so heavily during this war period. On the western end of the Mesabi the ore was found to be high in silica, and not suitable as furnace feed. As early as 1902, attempts were made to concentrate this so-called wash ore and by 1910 the first washing plant was put into operation. The Process was very simple, consisting essentially of a sizing and washing operation, with scalping screens, logwashers, and tables, which later were replaced by classifiers. Ore particles finer than 100 mesh were deliberately wasted, because these fines were undesirable in the furnace. Fortunately, these tailings were impounded, and already are being reworked. Before long some of the low-grade ores began to require more elaborate treatment than the simple washing operation and, tables having been discarded because of their low capacity, in favor of classifiers, jigs were next introduced. These were able to discard coarser pieces of tailing than classifiers. jigs are in active use today, various improvements having been made in their design and application. Various other machines and methods of concentration have been tried from time to time, and have in turn been discarded for more improved processes. The latest and most important process that has been

Jan 1, 1947

By T. B. Counselman

Probably the earliest concentration of iron ore in this country was carried on in the northeastern magnetite areas. Magnetic concentration was relatively simple and gave a concentrate that, after agglomeration, and in spite of being high in phosphorus because of the dry concentrating methods then in use, was satisfactory blast-furnace feed. Production from the northeastern magnetite area languished after the discovery and development of the Lake Superior ores, where there was seemingly an unlimited tonnage of high-grade ore, first the Michigan ores, and subsequently the still larger deposits of Minnesota. For years only the higher grade, direct shipping ores of the Lake Superior district were mined. Those of Michigan, and of the Vermilion Range in Minnesota, were hard ores and came principally from underground mines. The softer ores of the Mesabi came partly from underground mines, but mostly from the enormous deposits that could be worked by open-pit methods. The costs of ore from these open-pit deposits, even with the high initial cost of stripping, were so low that the underground mines of the Mesabi could hardly compete. The so-called Old Range ores, of Michigan and of the Vermilion. Range of Minnesota, were hard and lumpy, and opened UP the burden in the blast furnace, therefore making possible harder driving with greater output. Also, some of these ores were of such grade and physical characteristics that they were suitable for charge ore in the open hearth. These ores, therefore, commanded a price premium, and could compete with the softer, finer, but cheaper, Mesabi ores. The big tonnage reserves, however, are on the Mesabi. and it is these big open-pit deposits that constitute our stock pile of iron ore, from which we are drawing so heavily during this war period. On the western end of the Mesabi the ore was found to be high in silica, and not suitable as furnace feed. As early as 1902, attempts were made to concentrate this so-called wash ore and by 1910 the first washing plant was put into operation. The Process was very simple, consisting essentially of a sizing and washing operation, with scalping screens, logwashers, and tables, which later were replaced by classifiers. Ore particles finer than 100 mesh were deliberately wasted, because these fines were undesirable in the furnace. Fortunately, these tailings were impounded, and already are being reworked. Before long some of the low-grade ores began to require more elaborate treatment than the simple washing operation and, tables having been discarded because of their low capacity, in favor of classifiers, jigs were next introduced. These were able to discard coarser pieces of tailing than classifiers. jigs are in active use today, various improvements having been made in their design and application. Various other machines and methods of concentration have been tried from time to time, and have in turn been discarded for more improved processes. The latest and most important process that has been

Jan 1, 1947

By R. V. Whetsel, Valentin R. Garfias

Mexican petroleum production for 1928 was approximately 50,000,-000 bbl., the lowest in 12 years, showing a decrease from 1927 of over 14,000,000 bbl. The steady downward trend for the past 7 years has allowed Russia to outrank Mexico by a wide margin for third position and if the expected decline continues during 1929 it should place Persia ahead of Mexico as fourth in rank. The year 1928 was characterized by a continuation of the reentrench-ment previously begun by the oil industry in Mexico in an attempt to adjust itself to the adverse conditions caused by the steady depletion of the fields, the rapidly increasing competition from Venezuela and the United States and the as yet unsettled petroleum legislation and taxation situation. With the exception of the Isthmus of Tehuantepee, drilling in proved fields was considerably curtailed and although the number of wildcats completed exceeded those of the previous year, no extensive drilling programs were undertaken. Practically without exception, the major companies reduced personnel and operations to a point where they could meet existing conditions and mark time while awaiting a more stable basis for the future testing of unexploited regions. Many terminal and transportation facilities were abandoned during the year. Development Only 371 wells were completed during 1928, as against 583 in the previous year and 808 during 1926, and although the percentage of producers in 1928 was 34 per cent., compared to 26 per cent. in 1927, the initial production of -wells was considerably lower than during the previous year, a great number of the wells showing salt water and becoming "strippers" from the time they started to flow. Development is summarized in Table 1. Drilling in the Northern fields did not prove any new pools of importance, the most successful wells being located in the old producing areas of Cacalilao, Panuco and Topila. (Fig. 1 Very few of the producers made more than 1000 bbl. daily, and a great many less than 300 bbl. a day.

Jan 1, 1929

By C. G. Dunn

James, Jones, and Leak (JJL) conclude that growth-rate and orientation-distribution data obtained in a steep thermal gradient should be used with caution to account for isothermally produced recrystallization textures. I agree. However, it is not clear whether they conclude a) that the orientation dependence of rate of growth of secondaries in (commercial) silicon iron depends on both temperature and a temperature gradient or b) that, in applying rate data obtained in a steep thermal gradient, the isothermal annealing temperature must be close to the temperature for which the rate data apply. Also, it is not clear what tem-

Jan 1, 1967

By J. Moore Samuel

THE prospective change in ore receipts at the Copper Queen reduction works necessitated a careful study of conditions to determine the most economical method of smelting. The first step, calculating the known, probable, and possible results, showed the economy of a unimetallurgical flow sheet f which the three pyrometallurgical stages would be roasting, reverberatory smelting, and converting. The past and future ore receipts (not including converter flux) are as follows: AVERAGE MONTHLY FUTURE MONTHLY RECEIPTS, 1918 RECEIPTS TONS PER PER CENT. OF TONS PER PER CENT. OF MONTH TOTAL RECEIPTS MONTH TOTAL RECEIPTS Ore 84,553 82.3 43,000 44.0 Gravity concentrates 16,375 15.9 25,500 26.0 Flotation concentrates 1,883 1.8 29,400 30.0 Total 102,811 100.0 97,900 100.0 Of the 102,811 tons per month received in 1918, only 28,945, or 28 per cent., was treated in the roasters and an average f 14.1 roasters out of 20 were in operation; the remaining ore was treated in the blast furnaces. The change to "all reverb." practice, therefore, called for considerable additional roaster capacity, which could be obtained either by building additional units, or by remodelling the present units so as to give increased unit capacity. In view of the progress in roasting practice since the construction of the Copper Queen roaster plant and the heavy investment in that roaster plant, the second plan seemed to be the more desirable. The Copper Queen roaster plant consisted of twenty six-hearth, McDougall roasters, 18 ft. in diameter, equipped with cast-iron arms that originally were water cooled but now are air cooled. They have no top dry hearth and the feed is discharged through the top arch, near its periphery, by plunger feeders from two bins at opposite sides of the roaster.

Jan 7, 1921

THOSE NOT MARKED ARE MEMBERS; MARKED THUS t ARE ASSOCIATES. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. JUNIOR MEMBERS ARE MARKED II. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. AARONS, J. BOYD, Genl. Mgr., Chaffers G. M. Co., Boulder City, West. Australia. '05 ABADIE, EMILE R., Min. Engr Box 291, Porterville, Tulare Co., Cal. '76 ABBOTT, CLARENCE E., Genl. Supt., Iron Mines Div., 1405 Minnesota Ave., Bessemer, Ala. '04 ABBOTT, J. W., Min. Engr., "St. Omer," 123 N. Grand Ave., Los Angeles, Cal. '94 ABBOTT, Louis BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div., Jenkins, Ky. '15 ABBOTT, ROBERT R., Met. Engr., Peerless Motor Car Co., Cleveland, Ohio. '12 ABE, ASAKA Yamagano G. M., Satsuma-Gori, Satsuma, Japan. '14 || ABRAHAMS, A. I., Student 1391 Madison Ave., New York, N. Y. '14 tACKER, E. O'C., Met Bethlehem Steel Co., Bethlehem, Pa. '86 ACKER, Louis K., JR., Min. Engr 565 Highland Place, Bellevue, Pa. '08 ADACHI, JINZOO 11 Shiba Park, Shiba-ku, Tokyo, Japan. '88 ADAMI, C. J., Min. Engr., St. Joseph and Doe Run Lead Companies, Bonne Terre, Mo. '12

Jan 1, 1917

By E. S. Messer

A knowledge of the magnitude of the irreducible inter.;titial water in a porous medium is so important to petroleum engineering that its determination has become routine in core analyses. The method of determination, being a production problem, should encompass the basic requirements of simplicity in technique and calculations, with reproducible results obtainable in a short interval of time. The results of the evaluation tests outlined in this report indicate that the evaporation method for determining the irreducible water is a technique which meets the requirements. The procedure consists, as the name implies. of permitting the saturant in the pore spaces to evaporate until only an irreducible volume remains. The determination of this volume can be made either graphically or by a mathematical comparison of fluid flows; the time required for each determination being dependent on the fluid used. When fluids other than those having reservoir characteristics were used, a volume factor had to be calculated which was based on the relative volume of various liquids adsorbed on grain surfaces and retained in pores. This factor made possible the calculation of an irreducible water volume when more volatile fluids such as toluene and benzene were used as the saturants. Also presented is the theoretical discussion necessary for the calculation of the capillary pressure as determined from the evaporation curve. A comparison is made between the calculated values and those obtained by experimental means. INTRODUCTION In all geological formations there exists, in the pore spaces of the rock structure, water that is held in a state of equilibrium between capillary and hydrostatic forces. "Interstitial water" is the term given to this water and is defined as that water coexisting in the pore space with the oil prior to exploitation. The term ''connate water" has often been used synonymously with this term; however, this can be true only by a specific definition since, geologically, it means the water in place at the time the rock structure was formed. The quantity of the interstitial water is a variable factor in any formation, since it depends on the hydrostatic forces present in any multiple-phase system. These forces may become unbalanced by the introduction of an extraneous force such as the raising or lowering of the "water table" or the migration of oil into a water-filled formation. Any unbalanced force results in a change in the interstitial water. There exists, however, an irreducible interstitial water. for a particular sand, that is the fraction of the pore space occupied by water when the capillary pressure at the particular point in question is at an equilibrium with the hydrostatic head of the oil sand in the reservoir. For this discussion the term "irreducible water saturation" will be used in place of "irreducible interstitial water saturation" for the sake of brevity; however, they are understood to be identical. A great amount of work has been devoted to the theory and methods for studying the irreducible water saturation and its related capillary pressure. As a result of the publications of Leverett;' Hassler, Brunner and Deahl;2 Calhoun and Lewis;3 and others, the role of capillary pressure studies is being accepted by the industry as a tool for studying suhsurface phenomena. Many techniques have been developed and published for determining the capillary pressure and irreducible water. In general, these techniques may be grouped into three classifications. One of the first was the capillary pressure method described by Leverett1 and expanded by Bruce and Welge.4 The experimental results were compared with water saturation of cores obtained using oil-base mud. Thornton and Marshall compared the irreducible water saturation of core samples determined by the capillary pressure method and by salinity and reported good agreement between the two methods. The second classification for determining the irreducible water and capillary pressure may be referred to as the "centrifugal force method." The general technique is similar to the capillary pressure method except that the force driving the reservoir fluid from the sample is of a centrifugal nature. A complete description of this method was presented by J. J. . McCullough and F. W. Albaugh.6 A process, the reverse of the capillary pressure method, was presented by W. R. Purcell.7 Mercury under pressure is driven into the pores of the rock and the saturation of the core determined at each applied pressure. The resulting capillary pressure curve is used to evaluate the irreducible water saturation. The techniques mentioned are singular in their approach to the irreducible water saturation. In all cases. an external force was applied to the core. The forces employed in the evaporation method are the vapor pressure of the liquid causing evaporation, the kinetic diffusion forces. adsorptive forces and. to a lesser degree, the viscous forces resisting flow to the surface. The basic definition of irreducible water is that water held in a state of equilibrium between capillary and hydrostatic forces This water has been described by previous investigators as being held in the microcapillaries too small to support fluid flow. Actually, this fluid volume is made up of the water in the microcapillaries and as a film adhering to the surface of the crystals. All capillaries. therefore, possess some liquid as a film, the thickness of the film being dependent on the properties of the fluid and solid. A discussion of experiments with references pertaining to the measurement of this immobile layer next to the solid surface can be found in the text by J. J. Bikerman.8 Eversole and Lahr calculated the thickness of this layer to be in the order of 10 ' to 10' cm for aqueous solutions and glass. Between two quartz surfaces they found the thickness to be 2 x 10 cm. The work of Volkova, on the capillary movement of water and toluene in quartz grains, indicated the thickness of the Immobile layers to be near 10' cm. Since any measurement is an average value, it is easy to understand that an absolute value would depend on the roughness of the surfaces involved and the complexity of the system. A calculated effective pore radius of 2 x 10 cm is obtained at the, irreducible saturation of a porous media in a water-air system when a capillary pressure of 100 psi is applied. Since the separation of the sand grains is of the same approximate magnitude as the immobile layer.

Jan 1, 1951

By E. S. Messer

A knowledge of the magnitude of the irreducible inter.;titial water in a porous medium is so important to petroleum engineering that its determination has become routine in core analyses. The method of determination, being a production problem, should encompass the basic requirements of simplicity in technique and calculations, with reproducible results obtainable in a short interval of time. The results of the evaluation tests outlined in this report indicate that the evaporation method for determining the irreducible water is a technique which meets the requirements. The procedure consists, as the name implies. of permitting the saturant in the pore spaces to evaporate until only an irreducible volume remains. The determination of this volume can be made either graphically or by a mathematical comparison of fluid flows; the time required for each determination being dependent on the fluid used. When fluids other than those having reservoir characteristics were used, a volume factor had to be calculated which was based on the relative volume of various liquids adsorbed on grain surfaces and retained in pores. This factor made possible the calculation of an irreducible water volume when more volatile fluids such as toluene and benzene were used as the saturants. Also presented is the theoretical discussion necessary for the calculation of the capillary pressure as determined from the evaporation curve. A comparison is made between the calculated values and those obtained by experimental means. INTRODUCTION In all geological formations there exists, in the pore spaces of the rock structure, water that is held in a state of equilibrium between capillary and hydrostatic forces. "Interstitial water" is the term given to this water and is defined as that water coexisting in the pore space with the oil prior to exploitation. The term ''connate water" has often been used synonymously with this term; however, this can be true only by a specific definition since, geologically, it means the water in place at the time the rock structure was formed. The quantity of the interstitial water is a variable factor in any formation, since it depends on the hydrostatic forces present in any multiple-phase system. These forces may become unbalanced by the introduction of an extraneous force such as the raising or lowering of the "water table" or the migration of oil into a water-filled formation. Any unbalanced force results in a change in the interstitial water. There exists, however, an irreducible interstitial water. for a particular sand, that is the fraction of the pore space occupied by water when the capillary pressure at the particular point in question is at an equilibrium with the hydrostatic head of the oil sand in the reservoir. For this discussion the term "irreducible water saturation" will be used in place of "irreducible interstitial water saturation" for the sake of brevity; however, they are understood to be identical. A great amount of work has been devoted to the theory and methods for studying the irreducible water saturation and its related capillary pressure. As a result of the publications of Leverett;' Hassler, Brunner and Deahl;2 Calhoun and Lewis;3 and others, the role of capillary pressure studies is being accepted by the industry as a tool for studying suhsurface phenomena. Many techniques have been developed and published for determining the capillary pressure and irreducible water. In general, these techniques may be grouped into three classifications. One of the first was the capillary pressure method described by Leverett1 and expanded by Bruce and Welge.4 The experimental results were compared with water saturation of cores obtained using oil-base mud. Thornton and Marshall compared the irreducible water saturation of core samples determined by the capillary pressure method and by salinity and reported good agreement between the two methods. The second classification for determining the irreducible water and capillary pressure may be referred to as the "centrifugal force method." The general technique is similar to the capillary pressure method except that the force driving the reservoir fluid from the sample is of a centrifugal nature. A complete description of this method was presented by J. J. . McCullough and F. W. Albaugh.6 A process, the reverse of the capillary pressure method, was presented by W. R. Purcell.7 Mercury under pressure is driven into the pores of the rock and the saturation of the core determined at each applied pressure. The resulting capillary pressure curve is used to evaluate the irreducible water saturation. The techniques mentioned are singular in their approach to the irreducible water saturation. In all cases. an external force was applied to the core. The forces employed in the evaporation method are the vapor pressure of the liquid causing evaporation, the kinetic diffusion forces. adsorptive forces and. to a lesser degree, the viscous forces resisting flow to the surface. The basic definition of irreducible water is that water held in a state of equilibrium between capillary and hydrostatic forces This water has been described by previous investigators as being held in the microcapillaries too small to support fluid flow. Actually, this fluid volume is made up of the water in the microcapillaries and as a film adhering to the surface of the crystals. All capillaries. therefore, possess some liquid as a film, the thickness of the film being dependent on the properties of the fluid and solid. A discussion of experiments with references pertaining to the measurement of this immobile layer next to the solid surface can be found in the text by J. J. Bikerman.8 Eversole and Lahr calculated the thickness of this layer to be in the order of 10 ' to 10' cm for aqueous solutions and glass. Between two quartz surfaces they found the thickness to be 2 x 10 cm. The work of Volkova, on the capillary movement of water and toluene in quartz grains, indicated the thickness of the Immobile layers to be near 10' cm. Since any measurement is an average value, it is easy to understand that an absolute value would depend on the roughness of the surfaces involved and the complexity of the system. A calculated effective pore radius of 2 x 10 cm is obtained at the, irreducible saturation of a porous media in a water-air system when a capillary pressure of 100 psi is applied. Since the separation of the sand grains is of the same approximate magnitude as the immobile layer.

Jan 1, 1951

By D. M. S. Bhatia, Richard D. Hagni

Five sulfide minerals from the Magmont mine, southeast Missouri were sampled for 31 trace elements in over 300 samples by laser microprobe spectrographic analysis of polished sections. The concentration of several trace elements shows a pattern of progressive variation with depth (space) and variation with different paragenetic stages (time) of each mineral. Factor analysis of the geochemical data shows sympathetic correlation both in space and in time of Bi, Cd, Ge, and Sn in galena and sphalerite, and Ni and Co in sphalerite and marcasite.

Jan 1, 1981

By T. W. Harris

This paper was written in conjunction with the work being undertaken by the Technical Committees on Classification of Coal, and an effort has been made to compile information relative to the use of coal for stationary steam generation in order to use this information to assist the Committee on Classification of Coal for the ultimate purpose of elimination of losses both by the reduction of individual effort and waste in the consumption of material. Under the auspices of the National Association of Purchasing Agents, a questionnaire was drawn up to develop this information from stationary steam plants throughout the United States in order to consolidate the information developed from the many hundreds of boiler tests on coals consumed by various coal-burning equipment. These questionnaires covered: 1. The company reporting, location and method of delivery to the plant. 2. Complete coal data, including description of coals used (with sufficient space to include first, second and third preference) on source of coal used, complete analysis and factors affecting choice of coal used. 3. Plant data, divided into: (a,) hand-fired, (b) overfeed stokers, (c) underfeed stokers, (d) traveling grate stokers, (e) pulverized coal; and included complete description of furnace data, draft data, coal-burning rate, type of stoker, type of pulverizer, efficiency data and remarks. The questionnaire was drawn up by consultation with various combllstion engineers, including B. J. Cross, Test Engineer of the Combustion Engineering Co., W. H. Fulweiler, of the United Gas Improvement Co. and the U. S. Bureau of Mines. In all, 11,538 copies of the questionnaire have been distributed, of which 4369 were sent in duplicate. Our estimate of the total volume of bituminous coal consumed in stationary steam boilers over the 12 months of 1930 is approximately

Jan 1, 1934

By J. L. Smith, A. L. Albee

This article presents a series of guidelines by which the geologist can evaluate the likelihood of surface faulting and its probable extent at any given site in Southern California and Nevada. The information is intended primarily for geologists concerned with establishing design criteria for proposed nuclear plants. The geologic problems involved in the location of a nuclear power plant are fundamentally no different from those for other types of installations. They fall into four main categories: foundation stability, landslides and slope stability, shaking due to earthquakes, and surface faulting. For problems in the first three categories the foundation engineer, the geologist, and the seismologist can provide criteria for plant location and design, and these problems can generally be economically handled by appropriate design measures for a project of the magnitude of a nuclear plant. However, problems in the last category — surface faulting — are more difficult to handle and require a unique evaluation. Accordingly, this paper will deal primarily with the problem of establishing design criteria for surface faulting, particularly as it affects nuclear facilities. A nuclear reactor is a power source that for greater safety is contained in a heavy, air-tight structure, just as gas, oil, water, and other power sources must be contained. Surface faulting is significant in that it may reduce the integrity of the containment by affecting critical exterior piping or by breaching of the containment. A similar significance exists relative to dams or tanks for the storage of water, gas, or oil, except that in these latter examples the breaching of the container automatically releases the fluids to do their damage. This is not necessarily the case with the rupture of a reactor containment structure because the function of the containment is totally protective, i.e., it is necessary only in the event that radioactive products are released from the reactor, and there are many other safeguards to pre- vent this release even if the containment is ruptured. At the present time, nuclear power plants must be located near large sources of water for cooling the steam generated. The construction of an industrial facility of any kind on the coast line is esthetically distasteful to most people since, unfortunately, there is not enough coast to fulfill all the needs and all the desires of all the people. In most cases where industrial facilities encroach on the lives of citizens, there is no mechanism other than zoning laws by which a person can effectively protest. But in the case of a nuclear facility, the public hearing required by the Atomic Energy Commission provides a forum for dissent, as in recent case histories, and the question of safety provides objectors with a weapon for fighting the construction of the plant. The nature of a public hearing for a nuclear plant is such that the prospective owner and operator must prove that there is no undue hazard, whereas the objectors need only demonstrate that there is a reasonable doubt. It is in this situation that geology becomes the Achilles Heel of nuclear power plant location. For his investigation, the geologist has natural exposures of rock at the ground surface and a limited number of trenches and drill holes to give him a fairly complete picture of the distribution of the various rock types. From the surficial data, he must infer three more dimensions — depth below the surface, past time, and future time. Unlike many problems faced by engineers, the geologist has only this one set of data from which to reach a conclusion — he is unable to reproduce the natural sequence of events in order to obtain another set of data for comparison. Hence, by the very deductive nature of a geologic conclusion, it is difficult to prove a geologic conclusion beyond a reasonable doubt even to other geologists — and perhaps one should say especially to other geologists because the experience and background of a geologist will strongly influence his conclusion, and no two geologists have exactly the same experience and training. The engineer and the public official would like the geologist to conclude that faulting cannot occur at a given site or to assign a numerical value to the probability of its occurrence — but no responsible geologist can do either of these things. Since government officials and others must make decisions that affect the public safety, it would seem that the geologic profession must attempt to establish criteria and

Jan 1, 1968

Mine Transitman.-Engineer, about 30 years of age, experienced in coal mine underground surveys. Must be good draftsman and possess sufficient personality to get results from the men. Location, Illinois. No. R 419. Coal Mining Engineer: Coal mining engineer of proved ability for position of manager f high-grade bituminous coal property. Location, Canada. No. R 427. Chemist or Metallurgical Engineer.-Chemist or metallurgical engineer for special library work. Man with scientific training with the ability and education -of a young instructor in a university. Duties would consist of working out a new method of indexing scientific information, more particularly in obtaining information for use of a Committee on the Heat Treatment f Steel. Location, Washington, D. C. No. R 470. Topographical Draftsman.-Civil engineering training and topographical and surveying experience. Unmarried man, under 40 years of age. Knowledge of Spanish not necessary. Discharged army or navy man preferred. Location, oil fields, Mexico. Salary, $5 per day, living and traveling expenses. No. R 483. Mechanical Draftsman.-Engineering training, familiarity with drawings of pumps, piping, etc., need not necessarily be a designer. Unmarried man, under 40 years of age. Discharged army or navy man preferred. Location, Mexico. Salary $5 per day with living and traveling expenses. No. R 484. Engineer Translator.-Engineer of Portuguese nationality who has received his technical training abroad, and has been filling engineering positions in this country, to translate material for catalogs of an engineering character. No. R 486.

Jan 5, 1919

By Valentin Garfias

ALTHOUGH Mexico still ranks second in importance as produce for petroleum, the output in 1924 was 7 ½ per cent. less than in 1923 and 30 per cent. less than the peak production of 1921. The decrease may be partly accounted for by labor troubles and revolutionary activities early in the year, although undoubtedly the main factor was the continuous rise of the salt-water level in the South Fields, causing a decline of 24,000,000 bbl. in the production of light oil. Since the middle of 1923, the production of heavy crude has been greater than that of the lighter grade and, in 1924, the output of heavy crude was 2 ½ times that-of the light oil. DEVELOPMENT Drilling operations in the Mexican fields were probably more active in 1924 than in any other year, the greatest activity taking place in the Cacalilao and neighboring fields; toward the end of the year there was an added number of wells drilling in wildcat areas. The number of wells drilled in proved territory was almost twice that of the previous year, the increase taking place in the heavy-oil fields north of Panuco, as only 78 of the 710 wells completed were drilled in the Southern Fields. The percentage of successful completions decreased from 45 per cent., during 1923, to about 38 per cent., during 1924; there was also a noticeable decrease in the average flush production of the new wells. It is interesting to note that notwithstanding the increased drilling activity, the total production declined over 10,000,000 barrels. In the heavy-oil district, 632 wells were completed but only 231, or 36 ½ per cent., were commercially productive. The develop-ment in the Cacalilao area reached its peak in April and May, or about the time the first serious salt-water encroachments took place. Development in the old Panuco and Topila fields was more active than during the previous year, although the salt-water level continued to rise, the high price of crude making such development advisable especially for companies having to protect large-investments.

Jan 3, 1925

By Y. C. Kim, S. L. Barua

Underground coal mine planning has traditionally focused on the mine design aspects concerning safety and efficiency in the quest to produce low cost coal. Very little attention has been given to coal quality control aspects of mine planning at most US underground coal mines. With the enactment of the Clean Air Act of 1970, the generally high sulfur content of coal has become a major concern for the coal-fired power plants in the east. Similarly, the ash and the Btu content of coal are equally important for boiler efficiency. Coal mine planning must incorporate coal quality control aspects as well as traditional safety and efficiency aspects. According to an article in Coal Age (March, 1982), nearly one-half of the US coal exported to Europe does not meet the contract specifications regarding ash, sulfur and Btu contents. Although one of the reasons cited for this problem was "inadequate sampling at the US ports," the more fundamental cause probably lies in the inadequate quality control of run-of-mine (ROM) coal at the source. To perform adequate quality control of ROM coal, mines need predicted short-term in-situ coal quality information. Such predictions are generally based on whatever available sampling information is around the mine workings. Unfortunately, the closest sampling information, in the form of diamond drill hole assays, is often several thousand feet away in most underground coal mines and is inadequate for short-term coal quality prediction purposes. This is because the diamond drill holes (DDH) were traditionally placed in the coal deposit during the mine development phase to determine coal seam continuity and overlying roof conditions. They were not placed for short- term mine planning. A study was undertaken by the University of Arizona for the Homer City Owners in Pennsylvania to show that there is a need for more closely spaced samples, if the short-term coal qualities are to be predicted with any "reasonable" degree of accuracy. Prior to this study, a short-term quality prediction model, STPM, had to be developed. This model uses not only DDH, but also other sample information obtainable during face development work to predict the qualities of in-situ coal that are available in the immediate future.

Jan 1, 1985

THE story of Miami really is two stories. First, that of an excellent Porphyry Copper mine, ably managed as a business enterprise, and always among the leaders in technical progress. Concentrating its first ore in 1911, it had by 1925 paid dividends totaling $30,000,000 or $40 per share on stock that had cost the public $5 per share in March, 1908. The ore, containing 2.5 per cent copper at the start, had become progressively leaner but the recovery had tended to improve. Production costs had gone up during the World War and the early post-war period; and had come down again. In all these respects it had followed the norm. If the mine had been abandoned as exhausted and the company had been liquidated late in 1925 (a program that had been given earnest consideration in 1924), Miami would have gone down into history a first-rate mining venture; as an active and progressive participant in the great Porphyry achievement. But Miami was not liquidated in 1925; instead it started to write the record of its second and really amazing story. Near the old mine was a large body of low-grade ore containing, in place, less than 20 lb. of copper to the ton, and without, incident- ally, any considerable sweetening of gold and silver. Any method of underground mining that was cheap enough would certainly entail some dilution, so that ore as sent to the concentrator necessarily would average much less than 20 lb. As a matter of record, the average for 1929 was 16.6 lb., from which 11.726 lb. was recovered as concentrate. As already said, the exhaustion of the older orebody during 1925 was foreseen; but in 1924 the decision was reached to enlarge the concentrator and develop a new mine. An expenditure of $2,500,000 was entailed in this program. By October, 1925, the

Jan 1, 1933