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By Walter Kauenhowen

The crude-oil production of Germany without Austria during 1938 amounted to 3,864,518 bbl., representing an increase of 21.7 per cent over the 3,173,373 bbl. produced in 1937. Adding the Austrian production, the crude-oil production of the new German Reich totaled 4,259,717 bbl. during 1938, representing an increase of 25.3 per cent compared with the respective figures of the previous year. According to published official data, and using a conversion factor of 1 metric ton equaling 7 bbl., the oil production of Germany in 1938 was as shown in Table 1. A semiofficial publication1 states that the program of the crude-oil industry for the second year (1938) of the four-year plan was successfully accomplished. According to the same source, new drilling developments at the following localities were promising: Reitbrook near Hamburg, Heide in Holstein, Eicklingen-Sandlingen near Celle, Steimbke near Nienburg, Worms in the Rhine Valley, Gifhorn near Braunschweig, Mölme near Oberg, and at other places. The drilling activity for oil is illustrated by the figures in Table 2.

Jan 1, 1939

By L. V. Pirela, S. M. Farouq Ali

Some interest has been expressed recently in the application of solvents in conjunction with a thermal drive, such as a steamflood. At least one field project of this type has been reported. This paper makes the first attempt to provide some of the basic information necessary for choosing a solvent for such an application. Results of displacements conducted at elevated temperatures are also discussed. This paper shows that, in the case of alcohol-hydrocarbon-water or brine ternary systems, the system miscibility may increase, decrease, or both increase and decrease within the same system when the temperature increases. The distribution coefficient was consistently found to increase in favor of the oleic phase with an increase in temperature, which is advantageous from the standpoint of oil recovery. Results of solvent displacements in a sandstone core showed that even a relatively small temperature effect in the favorable direction (increase in miscibility and distribution coefficient) can lead to a 50 percent increase in oil recovery. On the other hand, if the system miscibility decreases with the temperature, even though the distribution coefficient increases, the oil recovery at the higher temperature may not increase. INTRODUCTION Miscible displacement has been the subject of many investigations. Miscible-phase solvent flooding, employing solvents such as alcohols that are miscible with both oil and water, has received considerable attention. Investigations conducted by Gatlin and Slobod,l Taber, Kamath and Reed,2 Holm and Csaszar,3 and Farouq Ali and Stah14 have helped in understanding the mechanism of solvent flooding. While the use of alcohols and similar solvents as oil recovery agents is economically unattractive, these solvents nevertheless provide a means of understanding the mechanistic aspects of important miscible-phase oil recovery processes such as the Maraflood process (discussed by Gogarty5). As shown by Taber et a1.,2 the phase behavior of a solvent-oil-water system is of .utmost importance in determining the efficiency of the oil displacement. This paper makes the first attempt to obtain the ternary phase behavior data for nine alcohol-hydrocarbon-water/brine systems at elevated temperatures. Results of core tests at elevated temperatures are also presented which corroborate the effect of temperature on oil recovery, as judged on the basis of phase-behavior data. The use of solvents at elevated temperatures has been suggested earlier by Farouq Ali.6 At least one field test of this type has been reportedO7 With the widespread use of thermal recovery techniques, it is possible in some situations (especially in steamflooding) that the use of a suitable solvent in conjunction with the heat carrier may be economically feasible. This paper attempts to provide some of the basic information needed for judging such feasibility. LOCATION OF THE PLAIT POINT The phase behavior of a typical ternary system consisting of a solvent, hydrocarbon and brine (or water) can be represented by a triangular diagram such as the one shown in Fig. 1 (for temperature TI). Point Pon the binodal curve represents the plait point, being the limit of tie lines such as Y1 Y2 The compositions of the coexisting oleic and aqueous phases are given by points Y2 and Y1, respectively, for any mixture composition along Y1Y2. The characteristics of ternary diagrams have been discussed by Findlay8 and others. Taber et aL3 have shown that the position of the plait point in a particular ternary system plays the decisive role in determining whether or not theoleic phase would be displaced in a continuous manner during an alcohol displacement. The area above the binodal curve also is important, since it represents

Jan 1, 1969

By Cyril Smith

IN the study of the structure or the properties of a series of alloys or nonmetallic compounds, it is often advantageous to express the com-position not as percentage by weight, according to which the material is always made up and analyzed, but as the atomic percentage of the two constituents. The conversion from the one to the other is repre-sented by the formulas: 100A 100x Y x 100 ? x/A A [1] A+ B x + A/B(100-x) X _ 100yA 100y [2] yA+(100-y)B or y+A(100-y) where x and y are the weight and atomic percentages respectively of the element of atomic weight A, and (100 - x) and (100 - y) are the per-centages by weight and by atoms respectively of the element of atomic weight B. While calculations according to these formulas are simple, they are' time consuming if several conversions have to be made. In 1931 Water-man' constructed a nomograph for performing the conversion, but this did not permit an accuracy greater than about 1 per cent to be obtained in the neighborhood of 50 per cent. Olander2 has proposed a graphic method simpler than Waterman's and one that gives a uniform precision throughout the entire scale. The possible accuracy is about 0.5 per cent of the whole, depending on the size and accuracy of the coordinate paper used. Recently, Hermann3 has described a slide rule for making the calculations. These devices make use of the simple rearranged equation:

Jan 1, 1933

ARIZONA Phoenix Arizona Mining Journal. B Carnegie Public Library. B Tucson University of Arizona, Mining Engineering Society. B CALIFORNIA Berkeley University of California, Mining Asso. B University of California, Library. B & T Los Angeles Chamber of Mines and Oil. B Public Library. B & T Oakland Oakland Free Library. T Sacramento California State Library. B. San Francisco Bureau of Mines Experiment Station. 13 California State Mining Bureau. T Mechanic's Mercantile Library. B Mining and Scientific Press. B Stanford University Stanford University Geological and Mining Society. B San Diego Public Library. B

Jan 1, 1923

By Cyril Smith

IN the study of the structure or the properties of a series of alloys or nonmetallic compounds, it is often advantageous to express the com-position not as percentage by weight, according to which the material is always made up and analyzed, but as the atomic percentage of the two constituents. The conversion from the one to the other is repre-sented by the formulas: 100A 100x or 1 x/A+100-x/B B(100-x) _ 100yA 100y [2] X. yA + (100 - y)B or y (100 - y) where x and y are the weight and atomic percentages respectively of the element of atomic weight A, and (100 - x) and (100 - y) are the per-centages by weight and by atoms respectively of the element of atomic weight B. While calculations according to these formulas are simple, they are time consuming if several conversions have to be made. In 1931 Water-man1 constructed a nomograph for performing the conversion, but this did not permit an accuracy greater than about 1 per cent to be obtained in the neighborhood of 50 per cent. Ölander2 has proposed a graphic method simpler than Waterman's and one that gives a uniform precision throughout the entire scale. The possible accuracy is about 0.5 per cent of the whole, depending on the size and accuracy of the coordinate paper used. Recently, Hermann3 has described a slide rule for making the calculations. These devices make use of the simple rearranged equation

Jan 1, 1933

By B. C. Craft, Murray F. Hawkins, John R. Rayne

A reservoir mechanism of sulfur recovery by the Frasch process is presented. Improving the economic, of recovery appears to be largely a well, rather than a reservoir problem. A most important factor is the limitation of the lateral extraction of .sulfur about the wells due to the almost vertical .flow of the injected hot water. Model studies are described which confirin the mechanism of sulfur recovery by presently used methods. Studies on a five-spot system indicate improved econo171ics regarding recovery, recovery rate, therinal efficiency, and well spacing. INTRODUCTION Sulfur mining by the Frasch process is one of the most important methods of sulfur production. Developed by Herman Frasch in 1894, it enjoyed a rapid growth and presently supplies 40 per cent of the world's sulfur and about 80 per cent of the U. S. sulfur." The Frasch process of mining the underground native sulfur deposits involves melting the sulfur in place by introducing super-heated water into the sulfur bearing formations, and producing the sulfur as a liquid. Many problems are encountered in mining these native sulfur deposits, and sulfur production depends chiefly upon the nature of the sulfur deposit and the underground thermal efficiency of the heat transfer system. THE RECOVERY MECHANISM Sulfur is typically found in salt dome cap rock as crystal aggregates occurring within the cavities, seams, and pores of limestone and gypsum formations.' Sulfur-bearing limestone is typically cavernous, vugular, and fractured. Porosity averages about 20 per cent and sulfur saturation averages approximately 25 per cent by weight.1,15 Vhe sulfur bearing formations are very heterogeneous in nature and physical characteristics vary widely within small distances. Total cap rock thickness may vary from 50 to more than 1,000 ft, and net productive thicknesses from a few feet to a few hundred feet. In most cases the upper portion of the limestone formation is barren of sulfur, varying from 5 to 200 ft in thickness.1,15,33 The immediately overlying sediments and the underlying dense anhydrite formation provide permeability barriers to the flow of water from the cap rock section.'" Sulfur wells are drilled with conventional oilfield drilling rigs. Fig. 1 illustrates the casing program of a completed sulfur well. The cap rock sections are drilled with core bits and continuous core logs are recorded. After coring, the cap rock section is underreamed to a diameter of 9 7/8 in. The bottom of the 8-in. casing is welded closed and rests on the bottom of the drill hole, which extends through the cap rock to a few feet above the bottom of the sulfur-bearing formation. The 8-in. pipe contains 5 ft of 3/4-in. perforations on 6-in. centers and 15 ft of 1-in. perforations on 1-ft centers. The 20-ft perforated section is set opposite the lower 20 ft of the sulfur-bearing formation. The 4-in. sulfur pipe is set inside the 8-in. water line on a seat ring at the top of the 5-ft section of 3/4-in. perforations. The mining water, heated to about 330°F under a pressure of 250 psi, is forced down the annulus between the 8-in. and 441-1. pipes and through the 1-in. perforations to the sulfur-bearing formation. Compressed air, at 400 psi pressure, is supplied through a 1-in. air line near the bottom of the well to provide air-lift of the liquid

Jan 1, 1957

By B. C. Craft

Louisiana experienced deeper and increased drilling during 1934, resulting in the discovery of five new fields: Bosco, Acadia and St. Landry Parishes; Lake Hermitage, Plaquemines Parish; Roanoke, Jefferson Davis Parish; Gillis, Calcasieu Parish; and Four Isle, Terrebonnc Parish. New sands were discovered at New Iberia, Iberia Parish; Lake Washington, Plaquemines Parish; Sligo, Bossier Parish; and in the Rodessa gas field, Caddo Parish. Other miscellaneous events worthy of mention are the continued leasing of prospective oil and gas lands in North and South Louisiana, extensive geophysical work in the Gulf Coastal area, and increased interest in the development of flank production on piercement type domes, resulting in the acquisition of flank acreage and the leasing of several shallow domes in the Gulf Coast and Interior salt-dome areas. The total oil production for Louisiana during 1934 was 32,529,082 bbl., an increase of 6,929,280 bbl. over 1933. The total daily production at the end of the year from 2421 wells was 102,752 barrels. North Louisiana During the year, 144 oil wells and 68 gas wells were completed in North Louisiana as compared with 111 oil wells and 47 gas wells during 1933. The North Louisiana oil production was 9,274,050 bbl. as compared with 10,023,580 bbl. during 1933, a decline of 749,530 bbl. The normal decline in the old fields and especially in the Zwolle area was partly offset by increased production in the Converse field, Sabine Parish, and by acid treatment of wells in the Zwolle, Converse and Caddo fields. There were no new fields discovered during 1934. During the year R. W. Norton enlarged the boundaries and reserves of the Rodessa gas field. A series of gas-bearing sands, was discovered in J. B. French, No. 1-B, sec. 34, 23 N. 16 W., below the oolitic lime found at 5500 ft. in which formation all previous wells had been completed. The total depth of this well was 5825 ft. Subsequent drilling has resulted in

Jan 1, 1935

By Gordon S. Duncan

(New York Meeting, February, 1912 THE U. S. Geological Survey, I believe, has almost completed a study of the Harney Peak quadrangle, preliminary to the publication of a report on that, district. As I was engaged for some months on an investigation of the mode of occurrence of the ore-bearing formation in this area, it has seemed to me timely to make public the results of my study, as a contribution to the consideration of this subject. It seems scarcely necessary to describe the locality and general geology of the Black hills of South Dakota, for since 1846 many have contributed information concerning this region, some of the reports bearing such well-known names as those of Walter P. Jenney, Henry Newton, S. F. Emmons, and C. R. Van Hise, while we have only to glance at Bulletin No. 4 of the South Dakota School of Mines, in which Prof. C. C. O'Harra, of that institution, has given us a bibliography of contributions to the geography and geology of the section, to find that other well-known men have studied the district, and have given us the benefit of their researches. The U. S. Geological Survey has made geological maps of nearly the whole of the Black hills, the only quadrangle yet to be completed being, as stated, the Harney Peak district. During the late summer and autnmn of 1910, it was my lot to examine and report. on a considerable area in this neighborhood, which once had been prospected, and in some cases exploited, for tin. This paper gives an account of certain geological phenomena, noted at that time, which greatly influenced my conclnsions. The predominating formation of the district is pre-Cambrian, represented by a highly-cleaved mica-schist, usually very garnetiferous, and sometimes hornblendic. Rising like an island from the surrounding schist is a large mass of granite, known as

Jul 1, 1912

By C. E. Lundin

The Ce-H system was investigated in the temperature range, 573° to 1023°K, and the pressure range, 10-3 to 630 Torr, as a function of 'composition up to 72 at. pct H. Families of isothermal arid isopleth curves were plotted from the pressure-terr~perature-composition relationships. From these curves the solubility relationships were determined for the system. The isopleths are analytically represented by equilibrium dissociation pressure equations. The relative partial molal enthalpzes and entropies of solution of hydvogen in the systerrz were calculated fronz the dissociation pressure equulions and are tabulated. The integral free energies, enthalpies, and entropies of mixing in the Ce-H system were determined from the relative partial quantities and are also tabulated. The standard free energy, enthelpy, and entvopy of reaction of the dihydride phase at kcal per kcal per mole H2, and ?S° = -34. 1 cal per deg mole H2, respectively. The equilibrium dissociation pressure equation in the two-phase region is: UNTIL recently very little was known of the detailed solubility and thermodynamic relationships of the Ce-H system. Two previous investigations1,2 are noteworthy. However, significant discrepancies and omissions exist on analyzing them. The work of Mulford and Holley1 on cerium did not clearly delineate the boundaries of the two-phase region, Cess - CeH2-x. The plateau partial pressures were not thoroughly defined and were considerably displaced in pressure compared to those from the work of Warf and Korst.2 These latter authors concentrated their studies primarily from 823° to 1023°K in the pressure range of 1 to 760 Torr. No data were determined to outline the regions of primary solid solubility and the hydride phase. Also the establishment of the plateau partial pressures was rather limited in scope. In neither work was a treatment conducted of the relative partial molal enthalpies and entropies of solution of hydrogen in the single-phase regions and the integral thermodynamic quantities of mixing throughout the system. Therefore, it was the objective of this research to determine the complete equilibrium solubility relationships and thermodynamic data for the system by pressure-temperature-composition studies. EXPERIMENTAL PROCEDURE The cerium metal for this study was donated by the Reno Metallurgy Research Center of the Bureau of Mines. Total impurity content was 0.13 pct with only 60 ppm O. The metal was checked metallographically and contained only minor amounts of second phase compared to cerium from other sources. Specimen preparation was done in a dry box flushed with argon gas. The surface of a small rectangular piece of cerium (about 0.2 g) was filed with a clean, mill file. Final weighing was done in a tared enclosed vial containing argon gas. The specimen was then loaded quickly into the reaction chamber which was purged several times with high-purity hydrogen gas and then allowed to pump to about 10-6 Torr. The furnace was heated to the reaction temperature and the run started. The equipment used to conduct the hydriding was a Sievert's-type apparatus. Basically it consisted of a source for pure hydrogen, a precision gas-measuring burette, a heated reaction chamber, a McLeod gage, and a mercury manometer. Pure hydrogen was supplied by the thermal decomposition of uranium hydride. The 100-ml precision gas burette was graduated to 0.1-ml divisions and was used to measure the quantity of gas and admit it to the chamber. The reaction chamber was a quartz tube. Prior to each run, the cerium specimen was wrapped in a tungsten foil capsule to prevent reaction of the cerium with the quartz. Control of the temperature was achieved within ±1°K. Pressures in the manometer range were measured to ±0.5 Torr and in the McLeod range (10-3 to 5 Torr) to ±3 pct. The compositions of hydrogen in cerium were calculated in terms of hydrogen to cerium atomic ratio. These compositions were estimated to be ±0.01 H/Ce ratio. The technique used to study the equilibrium pressure-temperature-composition relationships of the Ce-H system was to develop experimentally a family of isothermal curves of composition vs pressure. The range of pressure through which each isotherm was developed was from 10-9 to about 630 Torr in the temperature interval, 573° to 1023°K. RESULTS AND DISCUSSION The hydriding characteristics of cerium are iso-morphous with those of the elements of the light-rare-earth group (lanthanum, cerium, praseodymium, and neodymium) wherein the region from the dihydride to trihydride is continuously single phase.' The structure of this phase is fcc.3 The heavy rare earths form a trihydride,2 which is hcp, separated by a two-phase region from the fcc dihydride phase. The Ce-H system is represented by the family of experimental isotherms in Fig. 1. Due to the small scale required to draw the curves, the experimental points are omitted; however, a total of 240 experimental data points were taken to prepare these curves. The solubility relationships can be deduced therefrom. Three distinct regions of partial pressure and composition can be seen. The region of cerium solid solution is represented by the rapidly rising isotherms in the dilute composition range. In accordance with Gibbs Phase Rule only one solid phase, the cerium solid so-

Jan 1, 1967

By Jack Fox

Three years ago we attended the V International Mining Congress in Moscow. This year we attended the VI International Mining Congress in Madrid. By almost any criterion, this was a most successful convention. There were 1717 registrants, not counting the ladies. I don't know how many of the latter there were, but they certainly made a welcome addition to the group. Once again, the International Organizing Committee put together a very impressive technical program which the Spanish National Committee backed up with a brand new Palacio de Congresos admirably equipped with simultaneous translation devices and an organization that provided an excellent social program, a tremendous set of post- meeting excursions, and very impressive opening ceremonies, entertainment and closing ceremonies. There was also an exhibit on the subject of Spanish and Spanish American mining history in the Palacio de Congresos.

Jan 1, 1970

By H. P. Schwede, H. G. Doll

This paper describes a method to provide identification of particular depths in a borehole through the use of radioactive markers. The correlation of a marker, placed in the wall of a borehole, with known points of the electrical log and with the casing collars in the cased hole permits accurate positioning of tools with respect to a formation, regardless of absolute depth. Such a process is particularly useful in gun perforation of a casing in a well. Technique and equipment are discussed and illustrated. Examples are given of practical application in the field. Introduction During the past decade the search for petroleum has increased the importance of testing zones at depths in wells which have become progressively deeper. The development of new techniques, such as electrical logging, has permitted the identification of producing formations which consist of comparatively thin strata. When thin beds are to be produced at great depths, the problem of positioning tools accurately to place the well in production becomes acute.l Continuous consideration is being given in the petroleum industry towards the improvement of depth measurements in a borehole. The accuracy in absolute depth measurements, whether made in an open or cased hole, whether determined by a cable or a drill pipe, depends upon a number of factors, such as tension, temperature, and calibration. For example, the effects of tension from the weight of 10,000 ft of drill pipe and the thermal expansion of this length . of pipe, where its average temperature has increased SO"', will Produce an elongation as much as 8 ft.2 The effects Of such factors can be minimized through the use of care in depth measurements, the application of corrections based on experience, and continuous calibration or checking. The fact that different methods and different tools are used to determine the depths of formations in wells will sometimes give rise to a difference between measurements. It is evident that an important requirement in a well is the ability to locate at will any subsurface point. While absolute depth measurements have ion in recent years, it is reassuring to have other means to verify, for example, that a casing is perforated at a particular place with reference to a zone within a formation. Such a check on measurements may be had by placing a reference marker at a point known with respect to the electrical log of the borehole. That point is usually chosen to be in proximity to the 'One to be perforated. Thus, only short in depth measurements are made and any inaccuracy becomes very small and of minor importance' The use of reference markers located at fixed points predetermined in each zone where future operations are contemplated enables the operator to position any tool

Jan 1, 1948

By H. G. Doll, H. P. Schwede

This paper describes a method to provide identification of particular depths in a borehole through the use of radioactive markers. The correlation of a marker, placed in the wall of a borehole, with known points of the electrical log and with the casing collars in the cased hole permits accurate positioning of tools with respect to a formation, regardless of absolute depth. Such a process is particularly useful in gun perforation of a casing in a well. Technique and equipment are discussed and illustrated. Examples are given of practical application in the field. Introduction During the past decade the search for petroleum has increased the importance of testing zones at depths in wells which have become progressively deeper. The development of new techniques, such as electrical logging, has permitted the identification of producing formations which consist of comparatively thin strata. When thin beds are to be produced at great depths, the problem of positioning tools accurately to place the well in production becomes acute.l Continuous consideration is being given in the petroleum industry towards the improvement of depth measurements in a borehole. The accuracy in absolute depth measurements, whether made in an open or cased hole, whether determined by a cable or a drill pipe, depends upon a number of factors, such as tension, temperature, and calibration. For example, the effects of tension from the weight of 10,000 ft of drill pipe and the thermal expansion of this length . of pipe, where its average temperature has increased SO"', will Produce an elongation as much as 8 ft.2 The effects Of such factors can be minimized through the use of care in depth measurements, the application of corrections based on experience, and continuous calibration or checking. The fact that different methods and different tools are used to determine the depths of formations in wells will sometimes give rise to a difference between measurements. It is evident that an important requirement in a well is the ability to locate at will any subsurface point. While absolute depth measurements have ion in recent years, it is reassuring to have other means to verify, for example, that a casing is perforated at a particular place with reference to a zone within a formation. Such a check on measurements may be had by placing a reference marker at a point known with respect to the electrical log of the borehole. That point is usually chosen to be in proximity to the 'One to be perforated. Thus, only short in depth measurements are made and any inaccuracy becomes very small and of minor importance' The use of reference markers located at fixed points predetermined in each zone where future operations are contemplated enables the operator to position any tool

Jan 1, 1948

By W. M. Myers

Certain minerals possess inherent color and other properties that make them suitable for the pigmentation of paints, mortar, plaster, concrete, face brick, and other materials. Their production is one of the most ancient of mineral industries and their use by primitive man is well known. These natural pigments have some economic factors in their favor, particularly wide geographic distribution, low cost of production, ease of preparation, chemical stability, and permanence in use so that they continue to form the basis of a small but useful industry. When used in paints such pigments act as a filler and supply body and opacity in addition to color. Natural mineral pigments are prepared for the market by the comparatively simple operations of washing, grinding, blending, and calcining. Any one, or all of these processes may be applied to a single pigment. The development of synthetic pigments and the use of by- product materials have introduced competition with the products of nature and are having a growing influence on the economic position of the mined minerals.

Jan 1, 1949

By W. J. Reagan

IN a study of the life of ingot molds, it is essential to eliminate all of the variables. In the commercial manufacture of steel this is almost an impossibility. In this study many of the variables have been eliminated, and because of the unusually consistent furnace practice, with small variations in the type of steel manufactured, and a similar type of mold design for all ingot sizes, it is possible to determine with some degree of accuracy the cause of variations in ingot-mold life. All of the ingot molds in this study were used in the production of basic open-hearth killed steel with chemical analyses within the following range: C, 0.50-0.85 per cent; Mn, 0.60-0.80; Si, 0.20-0.30; S, 0.04 max.; P, 0.04 max. All ingot molds were of the closed-bottom type and used for bottom casting only. None of the molds in the study failed from cutting of the sides due to top casting; in fact, on only rare occasions are any molds used for top casting. The general type of this mold is shown in Fig. 1. All sizes have rather a heavy band of metal, about 6 in. wide, at the top to give mechanical strength at this point, and all have cast lugs. Cross sections of the vari-ous sizes from top and bottom sections are shown in Fig. 2. Ratios of wall thickness to ingot weight, ratio of ingot diameter to ingot length, and other figures of interest are shown in Table 1. In. the majority of cases, the cause of failure in this type of mold is due to heavy fire cracking on the "flats" at a point from 3 to 6 in. from the bottom radius of the mold. Fig. 3 pictures this type of failure. The start of failure at these points usually begins with a very small section of the interior surface becoming involved. As a rule, a section of 1 or 2 sq. in. is the first noticeable 'indication that mold failure is taking place. Gradually the small section increases until a sizable cavity develops, causing a protuberance on the bottom of the ingot, which eventually becomes too large to be stripped. The mold is then removed from service. At the time of failure, this cavity often reaches a size of about 5 sq. in. and about 1/2 in. deep. Sometimes cavities are found on only two or three sides and at other times all twelve sides appear to be involved.

Jan 1, 1936

By B. M. Larsen, W. E. Shenk, T. E. Brower

Shortly after our previous paper on this subject was printed1 we located a source of uncertainty in the results arising from the unexpected fact that hydrogen slowly reduces silica at 1100" C. in presence of iron, even when the iron nowhere touches the silica, although in absence of iron it does not do so. This difficulty has been completely obviated by the use of a small high-frequency furnace, which enables us to heat the specimen for analysis without raising the temperature of the silica vessel to a point at which any appreciable reduction of the silica glass occurs. We now describe this modification of procedure, and present some typical results obtained with it. For any given specimen of steel, the results are entirely definite and reproducible, but their precise significance is still open to some question, as indeed is true of all methods of oxygen determination SO far developed. Further elucidation of this question is to be expected from the cooperative comparison of the several methods now under way under the auspices of the Bureau of Standards at the instance of the Iron and Steel Division of the A.I.M.E. Apparatus The final form of apparatus we have used is identical with that described and illustrated in our previous paper, except for the substitution for the Globar furnace of a small high-frequency furnace actuated by a vacuum tube oscillator2 0f about 1.5 kw. capacity, and for a slight modification of the containing vessel. This transparent silica vessel is illustrated in Fig. 1 of this paper. Its enlarged portion is about 5 cm. in diameter and 13 cm. long. The silica tube for inlet of hydrogen is fused into this bulb and ends beneath the metal "bucket" holding the steel sample. This sample is in the form of fine millings. The "bucket" is suspended by a platinum wire from the cap of Pyrex glass. The high-frequency

Jan 1, 1934

By A. G. Metcalfe, Koeneman

A study of the structure of chemically deposited nickel by Goldenstein, Rostoker, Scpssberger, and Gutzeit has been reported recently. In this work it was shown that the nickel deposit produced by the catalytic nickel-reduction process was an amorphous solid. Crystallization occurred at elevated temperatures when the original powder pattern which showed only a diffuse ring with a d-spacing of 2.01A became sharp, revealing nickel and nickel-phosphide lines. The phosphide was indexed provision%lly on a tetragonal lattice of parameters a = 9.01A and c = 4.42A, which is in reasonable agreement with the structure of Ni3P proposed by No-wotny and Henglein.3 The transformation from the amorphous to the solid state occurs abruptly (e.g., after 7 min holding at 400°C) with the evolution of considerably more than 1000 cal per gm-mole. A more detailed analysis of these effects requires a knowledge of the solubility of phosphorus in nickel. Konstanti-now3 mapped out the phase diagram in 1908 but did not determine the solid solubility. The eutectic was placed at 11 pct P and 880°C. The purity of typical catalytic nickel deposits is very high.' Spectrographic analysis for heavier elements showed only trace amounts of aluminum, calcium, iron, magnesium, lead, and silicon. The term "strace" is a qualitative definition for less than 0.1 pct and probably less than 0.01 pct. Analysis for the interstitial elements yielded 0.04 pct C, 0.0023 pct 0, 0.0005 pct N, and 0.0016 pct H. Some of this material with 7.5 pct P was used in the present work. EXPERIMENTAL METHODS Alloys were prepared from carbonyl-nickel shot and a master composition containing 7.5 pct P. Cold-crucible, nonconsumable-arc melting was used.

Jan 1, 1959

By F. A., King

THE problem of the proper size and capacity of the open-hearth furnace has been a predominant issue ever since its inception some sixty years ago. The original furnaces, built in 1868 at Landore, England, were only to 3 to 4 tons capacity, and from' this there has been a steadily increasing and almost uniform rate of expansion until furnaces producing 300 tons are in successful operation today. At the end of the first half of this 60-year period, or about the year 1900, 50-ton furnaces we're common. Up to this time the problems of expansion had been largely those relating to suficient capital and the engineering development of larger units. But as 75, 100-ton and larger furnaces were proposed apprehension grew and other questions assumed leading consideration.

Jan 1, 1928

THERE are three chief production zones of tungsten ore in China. In the Province of Kiangsi mines are located at Kanchow, East River, and West River. Their combined production is understood to amount to 300 to 350 tons of ore per month, and their original exportation is made through the port of Kiukiang, largely to Shanghai. The second zone is in Kwangtung Province, the mines there being at Tayulin. Produc-tion reaches about 200 tons per month and cargo is gen-erally exported through the port of Hong Kong. In the Province of Hunan approximately 25 tons of ore are produced monthly in the mines at Ton-on. Tungsten ore from Kiangsi and Kwangtung Prov-inces is generally about 70 per cent WO, (tungstic acid), while that from Hunan is of lower quality, run-ning about 65 per cent WO3. Kiangsi ore is received from the mines in 100-1b. and Hunan in 224-lb. gunny sacks. No repacking is done except as it is made neces-sary by the condition of the sacks. Kiangsi Province contains the Chinese districts pro-ducing the largest amount of salable wolframite or tungsten. Many districts west and south of Kiangsi have been found to have wolframite deposits.-Com-merce Reports.

Jan 1, 1928

By Dr. O’Neil Thomas J., Donald W. Gentry

"October. This is one of the peculiarly dangerous months to speculate in stocks. The others are July, January, September, April, November, May, March, June, December, August and February." -Mark Twain Although the preceding chapters describe the type of preliminary evaluation frequently performed in the mining industry, it has been assumed that input data are known with certainty-clearly an enormous simplification. In reality, estimates of ore grade, mining cost, metal price, etc., are subject to varying degrees of uncertainty due to the inability to predict the future with much precision. Management would probably not, for example, be equally attracted to two projects each offering a 20% DCFROI-one for a new gold venture in Nevada and the other for an undersea manganese nodule operation in the Pacific. The high risk with the latter investment tells the obvious; there is more to investment decision-making than a deterministic analysis using "best estimates" of input parameters. The science of decision theory normally distinguishes between decisions under uncertainty, where probabilities of various outcomes are unknown; and decisions under risk, where such probabilities can be estimated. The first case is rarely en- countered in practical capital investment analysis in mining, so the remainder of this chapter focuses on that class of problems where rational probability distributions for the future states of input variables can be estimated. RISK IN MINING Risk in the context of this chapter is the unforeseen deviation of individual cash flows from expected values for a capital project. For a mining venture, the source of this uncertainty could be any number of factors relating to such items as ore grade, ore reserve tonnage, operating costs, product prices, etc. With conventional *Adapted from O'Neil, T.J., 1979, "Procedures for the Preliminary Financial Evaluation of Metal Mining Ventures," Computer Methods for the 80s, A. Weiss, ed., AIME, New York, pp. 556-573.

Jan 1, 1984

By Edward Steidle

NOTHING stands still. We go forward or backward. As a distinct group of educators, our immediate concern is with the preparation of young men and women for participation in the mineral industries on a professional basis. I am going to have the temerity to state emphatically that for a long time as a whole we have remained in a static position. We are now confronted with the choice of advancement or retrogression. We are still in a position to make a choice and our ultimate fate will depend upon the course of action we elect to follow. Wars always have been great catalysts and social and scientific advancements mature under military stimulus in a fraction of the time normally consumed. We are now in the midst of a conflict whose duration or final effects cannot be estimated. However, the record already demonstrates that this war as never before is a mineral war in which incentive, strategy, and outcome are directly related to the distribution and utilization of minerals. The inevitable result is a drain upon our resources now reflected in our record production and a growing public consciousness of the importance of minerals in the role of human affairs. It is evident that we must seek new mineral frontiers beyond the borders of the United States and take every other precaution to forestall a "have-not" position in the world.

Jan 1, 1943