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By M. P. Tixier

In several log interpretation methods, water saturation is evaluated by use of the ratio of the readings of a short spacing resistivity device and a long spacing resistivity device plus information on the mud filtrate and connate water resistivities, which is often derivable from the SP. These methods are valid over a certain range of conditions, usually specified by moderate invasion and R.. greater than R,. Since these methods involve no explicit evaluation of the formation factor, F, the saturafiion so found may be used in the standard Archie equation to derive a computed formation factor which, as a check, may be compared with the formation factor known from other independent measurements. Discrepancies in the two values of formation factor generally indicate that the ratio method is not within its range of applicability. If the computed F is too low, the corresponding S, is too low; if the computed F is too great, the corresponding S, is too great. By means of this "porosity balance" check, and some knowledge of the probable conditions of invasion, the interpretation can often be improved. The poqosity balance check is discussed for the cases of the Induction-Electrical Log Interpretation Method, the Rocky Mountain Method, and the R.,/R, Method. For the first method, a discussion is also given for the case of shaly sands. INTRODUCTION Al though many logging tools are available to obtain a practical value of porosity, the only logging method reflecting the water saturation is electrical logging. Water saturation is commonly computed from electrical log data by means of the basic Archie formula, Where F is the formation factor, R, the resistivity of the formation water, and R, the true resistivity of the formation. One difficulty in this procedure is a possible error in the evaluation of R, from the logs— for example, in the case of very deep invasion. There is no possibility, inherent in the procedure, which would provide a check of the accuracy of R, and, hence, of the computed saturation. Other approaches have been proposed which are based essentially on the ratio of the readings made with two dzerent devices: one device, with a short radius of investigation, provides a value close to the resistivity of the invaded zone; the second device, with a long radius of investigation, gives a value close to the true resistivity of the bed. By these methods, the determination of saturation is made independently of any direct knowledge of the formation factor. Therefore, if the formation factor (or porosity) is known from other sources (core analysis, neutron log, MicroLog . . .), it becomes possible to take advantage of this additional information in order to check the value of saturation derived from these latter methods. Inasmuch as this proposed check procedure relies on a knowledge of the value of formation factor or porosity, it has been deemed appropriate to call this verification a porosity balance. The purpose of this paper is to discuss the principle and the application of the porosity balance, depending on the method of interpretation being used. Basis of the Method There are in existence three interpretation methods by means of which the water saturation can bc found without a knowledge of the formation factor (or porosity). As just stated, they are based on the fact that the ratio of the two resistivities (one measuring the resistivity close to the hole, the other measuring the resistivity far from the hole) is independent of the formation factor since it affects the two resistivity measurements in the same way. Chronologically, the resistivity ratio methods are: (1) the Rocky Mountain Method, which has been used since 1943 and was explained in a paper in 1949;' (2) the R../R, Method or Shaly Sand Method, presented in 1954, which permits the calculation of the water saturation in both clean and shaly sands2; and (3) the Induction-Electrical Log Method, presented in 1957 for the interpretation of the induction-electrical log combination." Each method requires certain definite conditions in order for the interpretation to be reliable. The porosity balance method will let us know whether these conditions are fulfilled. In clean formations we know that the fundamental Archie relation (Eq. 1) must always be verified. This relation can be rewritten:

By N. A. Gjostein

The formal descnption of the decay of an isolated scratch can be written in terms of an appropriate Fourier integral. With the application of certain approximations, this description leads to the second-moment analysis developed by King and Mullins. It is shown that the second-moment analysis does not adequately describe the behavior of a decaying, isolated scratch, and that it is difficult to obtain internally consistent values of the surface self-diffusion coefficient, D,,from this analysis. This inconsistency arises from contributions of higher-order moments to the decay process. Two new analytical methods, based on the Fourier integval representation of a scratch profile, have been developed for determining values of D, from the decay kinetics of isolated scratches. In the profile-matching method, a given initial profile is resolved into its Fourier components, the components are allowed to decay exponentially over an annealing time interval, At, and finally they are synthesized to form a decayed profile. The predicted profile is adjusted to fit the experimental profile by varying only the parameter, D,At; the contribution from volume diffusion is directly taken into account and the integrals involved in the Fourier analysis are evaluated by numerical integration on an electronic computer. In the kinetic method, the widths, W, of a series of predicted profiles are determined for various volume-diffusion contributions, and the results are plotted in the form W vs DSAt. For a fixed ratio of surface to volume diffusivities, R, these plots are linear; the slope of the lines increases as R decreases. A simi-lar analysis can be performed on the depths of the predicted profiles. In this case, plots of (l/df3 vs D,At are found to be nonlinear. The proper value of Ds is found by superimposing the data for the experimental widths and depths on Plots of this kind and adjusting Ds until a fit is obtained with the line having the appropriate value oj R. An analysis of the slopes of these plots for R —= (surface diffusion only) reveals that they do not give the correct value, 2276, for width tf second-moment standard profile. This finding allows one to modify the second-moment analysis in such a way as to obtain internally consistent values of Ds. ThERE are several processes, involving a flow of matter along a surface, due to gradients in curvature of the surface, that may be used to determine the surface self-diffusion coefficient, Ds. These processes are commonly known as 1) thermal grooving, 2) single and 3) multiple scratch decay, 4) blunting of field-emitter tips, and 5) sintering. In this series of papers, the first three of these processes are examined in detail in an attempt to subject the phenomenological theories governing these processes to a critical test and, furthermore, to make a critical comparison of the values of D, obtained from these techniques. Although the thermal grooving technique has been established'' as a reliable method for determining D, , this has not been the case for the process of scratch flattening. Mullins and coworkers374 have proposed phenomenological laws governing the growth of the width and the decay of the amplitude of an isolated scratch, but only in one study5 has the width-growth law been supported by experimental evidence. In paper I of this series detailed experimental evidence is presented that points up the deficiencies of the second-moment analysis; the origins of these deficiencies are also discussed. Following this development, some new analytical procedures, based on representing the scratch profile by Fourier integrals, are presented as a means of obtaining reliable values of D, from the kinetics of the scratch-flattening process. Further applications of the Fourier integral approach are reported in papers 11' and 111,~ where the method has been useful in interpreting the anisotropy of flattening rates of isolated scratches (paper 11) and in describing the multiple scratch decay process (paper 111). THEORY OF SCRATCH DECAY Following ~ullins" approach we consider an arbitrarily shaped scratch profile, Fig. 6, at some time, t. The profile is designated by a function z(x,t) which can be expressed in terms of a Fourier integral as follows:

Jan 1, 1967

By Ross C. Anderson, William I. Weisman

THE manufacture of anhydrous sodium sulphate or salt cake from natural deposits in the United States has been in general somewhat of a marginal undertaking. Competition from foreign sources and from large quantities of byproduct sodium sulphate produced domestically in the manufacture of hydro-chloric acid and other chemicals has existed and continues.

Jan 7, 1953

In the four articles presented on the following pages, a panel of comminution experts offer readers the benefit of their experience with autogenous grinding and forecast some of the future developments to be expected in this fast-growing field. The articles are based on an AIME panel discussion in which the authors participated.

Jan 1, 1970

Lester Guttman (General Electric Research Lab-boratory)—Seybolt has measured the thermodynamic activity of silicon in dilute solution in a iron. The anomaly which appears at 800 °C in the approximate range 1 to 6 wt pct Si is most naturally attributed, as Seybolt has done, to the existence of a region of

Jan 1, 1960

By Louis Stott

IT is well known that the oxide of beryllium was identified as a new "earth" in 17971 and the metal first isolated in 18272. The history of the many difficulties encountered by early investigators, the laboratory achievements of Lebeau3, Fichter4 and Oesterheld5, and the eventual development of methods for commercial production are well covered in the literature, particularly in the authoritative published work of Siemens and Halske6 reviewing their comprehensive investigation of the element. Accordingly it has seemed desirable to restrict this paper to the properties and uses of beryllium and its alloys.

Jan 1, 1936

By C. L. HUSTON

MY ANCESTRAL connection with the manufacture of boiler plate runs back through four generations, and my personal acquaintance with the practice reaches back to the time, in my ,boy- .hood days, when iron plates' were made in a mill operated entirely by water power. -The mill originally was driven by an old-fashioned "'breast" water wheel 20 ft. in diameter and with a20-ft. face, geared direct to the roll train. When the mill slowed up and there was danger of its stalling, the men would jump upon the rim and help the wheel around with their weight, to prevent a "sticker." Later, as large plates were called for, a flywheel was set out of line so that it could' be speeded up by gears from the water wheel and connected back again,. by reducing- gears, to the roll train. The flywheel, with its cast-iron rim and wooden spokes, made 90 r.p.m. and the roll train 45 r.p.m. In 1870, our company installed our first steam-driven plate mill two-high rolls, 84 in. long. In these early mills the hot metal was manipulated by hand.

Jan 1, 1920

By T. W. Beck

Roof bolter occupations in underground coal mines continue to experience overexposure to respirable dust. One potential source of dust in roof bolting operations is the exhaust from the roof bolter dust collection system. A wet exhaust conditioner (water box) has been developed to reduce dust emissions from the exhaust of the vacuum dust collection system on roof bolting machines. The exhaust conditioner consists of a muffler chamber and a water chamber with four internal partitions to direct airflow over the surface of the water. The National Institute for Occupational Safety and Health conducted a series of laboratory tests to assess the respirable dust capture ability of this device as compared to the standard exhaust muffler. To determine the dust collection efficiency, both devices were placed in the exhaust stream of a simulated roof bolter dust collection system. Gravimetric samplers were operated upstream and downstream of the exhaust conditioner and muffler to evaluate the ability to capture both respirable coal and limestone dust. Researchers observed a 41 % reduction in dust concentrations for the water exhaust conditioner in the laboratory configuration. Significant levels of dust deposition in the sampling chambers may have contributed to this effective capture rate.

Jan 1, 2012

By Jay J. Burns

TWO zinc concentrating mills are operated by the St. Joseph Lead Co. in St. Lawrence County, N. Y. The Edwards mill is operating at present only sixteen hours a day treating 400 tons daily. The metallurgy at Edwards presents no unusual problems therefore this discussion is mainly limited to the metallurgy of the Balmat ore. The Balmat mill has a capacity of 1,250 tons per day and the operating crew consists of three shift bosses each with five millmen per shift. Two crusher operators work on each of two shifts and one cleanup man on day shift. The repair crew is made up of a foreman and three repairmen, one of the repairmen being capable of taking over any operating job in the mill from shift boss down. Each millman is capable of handling the next job in line and several men in the yard crew are broken into handling the start-off job in the mill so that temporary shortages of men do not cause extensive overtime. Sphalerite, pyrite, and galena, the principal ore minerals, occur in a gangue of calcite, dolomite, and silicates, especially diopside, plus tremo-

Jan 1, 1947

By R. E. Cuthbertson

AN early appreciation by the management that Climax ore presented a challenging problem of economic concentration was responsible for the establishment, in June 1926, of an ore-testing department at the experimental plant of the Colorado School of Mines at Golden, some ninety miles from Climax. An engineering office was later organized in the same community for the design of all ore-treatment units erected at Climax during the period of rapid growth. Work of the ore-testing and design staffs was effectively co-ordinated under a common head. The primary reason for having the ore-testing and plant design departments in Golden, was to place these activities under the able supervision of A. J. Weinig, consultant for the Climax Molybdenum Co., and director of the experimental plant. A secondary consideration was the availability of excellent facilities for research in ore dressing in a highly favorable environment. Concentration of molybdenite by flotation from an ore of simple mineral composition does not appear, superficially, to present a serious problem in ore dressing but experience belies this apparent simplicity. The molybdenite content of average Climax ore is low and it is finely

Jan 1, 1946

By H. A. BURK

THE ores of the Tonopah, district are hard, compact and' highly siliceous. They contain from .1 to 2, per cent. of sulfide material, of which argentite is the valuable mineral; occasionally pyrargyrite is found in the richer ore. The sulfide is, chiefly pyrite with small amounts of chalcopyrite,. and sometimes sphalerite. The ore also contains a small amount of gold-about 1 per cent. by weight of the silver present. The major gangue constituent is quartz but frequently considerable rhodonite-called by the miners pink manganese-is present. For primary crushing, jaw and gyratory crushers are used. These crushers are of such capacity that, in most cases, one 8-hr. shift will supply the mill for 24 hr. The Extension Co., at the Victor ore house, passes the ore through a 13 by. 24-in. Blake type McFarland crusher set at 13 in., and at the No. 29 re house, a 14 by 24-in. Blake type Traylor crusher is used. The ore is thus crushed to stamping size in one reduction. The capacity of each crusher is about 40 tons per hr.; the power consumption is 0.6 kw. per ton.

Jan 1, 1921

By J. Parke Channing

THE growth of and profession depends on meeting and solving new problems. It is a continuous process. 'A period free from new, or hitherto unknown, questions will be a period of arrested development in the profession it affects. The present generation has witnessed a' mechanical development that has been truly marvelous: Almost every day marks the advent of a new, or the improvement of an old; process, method or machine. Wonders are now commonplace. The impossible is regularly accomplished. Yet, with all our progress in every realm of science and with our development in the engineering field, advances which have made possible the marvelous growth in industry, we have not made commensurate gains in methods affecting the human factor. Without the cooperation of the worker, we shall always fall short of our goal in a mechanical or statistical sense. If we do not make the individual members of the human family strong, healthy, happy, and ambitious for better things for themselves and their children, we will have failed utterly, for that is the real reason for our existence as men and the purpose of our organized effort as an engineering group. Thomas A. Edison

Jan 1, 1921

By William P. Blake

THE phenomena of concentric arrangement of minerals in rock-masses, generally known as "orbicular structure," have of late received much attention from investigators. Lawson, of the University of California, has described the orbicular gabbro at Dehesa, San Diego county, Cal. Kessler and Hamilton, of Stanford University, working independently upon the same subject, published their descriptions,2 giving also a list of many other localities in Europe and America where orbicular rocks are found, adding copious references to the literature of the subject. The orbicular diorite of the type locality in Corsica., familiar to mineralogists and petrologists under the name "Napoleonite," was described by Vogelslang in 1862.3 Chrustschoff, of St. Petersburg, has also given much atten¬tion to the subject, and is the author of a classification of the various known forms of orbicular structure.4 No complete and satisfactory explanation of the origin of or¬bicular aggregations in rocks has yet been offered. The patent fact is generally recognized that the constituent minerals have crystallized from a more or less molten or plastic magma, but why these minerals should be arranged in concentric spheres or crusts has not been clearly shown. Vogelslang, for example,

Jul 1, 1905

By S. H. Williston

IT is not often that bore hole surveys can be checked by actual civil engineering methods. A recent Arizona survey was checked by normal surveying methods and the comparison of the results should be of value to both oil and mining men. During the summer of 1948 the Phelps-Dodge Corporation, at its Copper Queen property near Bisbee, Ariz., drilled a 1245 ft, 8 in. diam, churn drill- hole in a mineralized area and cased part of it, intending to use it to transfer mill tailings for stope fill. The hole, as frequently occurs, was not straight, and, in endeavoring to locate the bottom in- the underground workings, they found no evidence of the hole at the underground coordinates directly below the surface location. The noise of the drilling tools was reasonably clear, but the direction of sound was uncertain. Preliminary tests with available equipment were not successful in locating the bottom of the hole. Be- cause of the mineralized character of the area and the fact there was some casing in the hole, any magnetic method of well surveying would give results ' of doubtful value.

Jan 1, 1950

By M. E. Kukura, L. G. Stevens

As described in a previous presentation and in various patents, the Minerals Sciences Div. of UOP, Inc., has developed a modified reduction roast ammonia leach process for nickel laterites. This process gave considerable improvement in extraction over the conventional Caron approach as practiced in Cuba, Australia, and the Philippines. This greatly improved response was obtained with a wide variety of ores. This paper describes the pilot plant flowsheet and reviews the design features unique to the UOP process. Operating results from pilot plant campaigns are compared with bench scale results. Operating problems and their solutions are also discussed.

Jan 1, 1976

Three. meetings for the presentation and discussion of papers were held in 1914, as follows: The 107th Meeting, including the Annual Business Meeting, in New York, Feb. 16 to 19; the 108th Meeting, Aug. 10 to 14, in Salt Lake City, and the 109th Meeting, Oct. 8 to 10, in Pittsburgh, Pa., under the auspices of Iron and Steel Committee, Committee on Coal and Coke, Committee on Petroleum and Gas, Committee on Non-Metallic Minerals. Local Sections ' Three new local sections were established during the year, namely; / Pennsylvania Anthracite Section, Chicago Section, and Utah Section.

Jan 1, 1917

Mining headlines in 1952 dealt mainly with expansion as the industry aimed for an ever increasing production to meet the nation's needs. Huge sums were expended for equipment, research, and development. Headlines told part of the story. Negotiations between San Manuel Copper Co. and the RFC finally resolved in a $94 million loan for the development of low grade Arizona ores. Magma Copper, parent firm was to supply an additional 8 million. Kennecott Copper Co., deepening its Deep Ruth Shaft of its Ruth, Neyy mine, announced that the shaft would be in full production in 1953.

Jan 2, 1953

An ore search for commercial titanium-bearing ore deposits is in progress by the Crane Co., manufacturers of valves, because they expect this metal to be important in valve manufacturing in the future. The company will eventually be mining and making titanium sponge. At present they are buying titanium tetrachloride from the Stauffer Chemical Co, at Niagara Falls and making titanium by reaction with magnesium. Production from the Babbitt concentrator of Reserve Mining Co. is scheduled to begin in late 1951 or early 1952. The capacity is to be 300,000 tons of pellets per year made from magnetic taconite concentrates.

Jan 7, 1951

Reynolds Jamaica Mines, Ltd., has received a $3+ million loan from ECA for the development of what are termed the largest bauxite deposits in the world in Jamaica, B.W.I. This amount is in addition to $11 million already provided. The new agreement calls for delivery of 750,000 tons a year beginning in early 1952. Inco has announced a new alloy containing 35 pet Ni which can be used for many purposes served by the old alloys which ran up to 70 pet Ni. The new alloy "Incoloy" is 35 pet Ni, 20 pet Cr, and the balance iron.

Jan 8, 1951

By Lewis M. Cook, Robert H. Morse

The use of portable radon detectors has become routine in reconnaissance uranium surveys where water and sediment samples are analyzed in field labs for radon and radium, and in detailed work where drill hole locations are pinpointed by field determinations of radon in soil gas from shallow holes. During the drilling program itself, however, very few operators are taking advantage of radon and radium analyses to decide whether a barren drill hole was a near miss or whether the immediate area can be written off. The technique is effective both above and below the water table.

Jan 6, 1979