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By Robert D. Pike

In November 1939, on behalf of the Harbison-Walker Refractories Co., the author undertook the study of the problem of utilizing the dolomite of northwestern Ohio for the manufacture of calcined magnesia suitable for use in refractories. Grateful acknowledgment is made of the unfailing assistance and encouragement throughout this work from the executive and technical staff of Harbison-Walker Refractories Company. The dolomite of the Niagara formation that is exposed or near the surface of a wide area in northwestern Ohio1 constitutes a vast supply of almost pure dolomite. It offers a virtually unlimited supply of cheap raw material of uniform dependable analysis for the manufacture of magnesia. A typical analysis of dolomite from the vicinity of Luckey, Ohio, follows: Stone Completely Calcined CaO(Sro)a............. 30.35 57.806 Mgo................... 21.55 41.050 SiO2. ................... 0.30 0.572 R2O3................... 0.30 0.572 Ignition loss............. 47.50 a SrO about 0.06 pct. Brines containing magnesium chloride or sea water can be reacted with calcined dolomite to produce magnesia.2'3 In such reactions the MgCl2 of the brine supplies some of the magnesia and the amount of dolomite required is thereby reduced by an equivalent amount, but brines of commercial importance containing magnesium chloride are some distance away from the purest grades of the dolomite of northwestern Ohio. It was decided therefore to concentrate upon the development of a suitable process for separating the lime and magnesia of dolomite, depending upon the dolomite itself as the sole source of magnesia. This would make it possible to place a plant at the dolomite quarry, thus eliminating the cost of transporting the stone and also rendering the calcined magnesia available at a most convenient production point, considering the cost of delivery throughout the steel industry. The selection of a process depending solely upon the dolomite as a source of magnesia also necessarily entails production of the lime content of the dolomite as a by-product. It was recognized that if such a lime by-product could be produced in a suitable form, a plant location in northwestern Ohio would also be advantageous for marketing the lime. The problem, therefore, was the discovery and development of a low-cost process for separating the magnesia and lime of the dolomite of northwestern Ohio and producing each in a form relatively free from the other, and meeting the respective requirements of established markets. A satisfactory solution of this problem has been found, and it is the

Jan 1, 1948

By Robert D. Pike

In November 1939, on behalf of the Harbison-Walker Refractories Co., the author undertook the study of the problem of utilizing the dolomite of northwestern Ohio for the manufacture of calcined magnesia suitable for use in refractories. Grateful acknowledgment is made of the unfailing assistance and encouragement throughout this work from the executive and technical staff of Harbison-Walker Refractories Company. The dolomite of the Niagara formation that is exposed or near the surface of a wide area in northwestern Ohio1 constitutes a vast supply of almost pure dolomite. It offers a virtually unlimited supply of cheap raw material of uniform dependable analysis for the manufacture of magnesia. A typical analysis of dolomite from the vicinity of Luckey, Ohio, follows: Stone Completely Calcined CaO(Sro)a............. 30.35 57.806 Mgo................... 21.55 41.050 SiO2. ................... 0.30 0.572 R2O3................... 0.30 0.572 Ignition loss............. 47.50 a SrO about 0.06 pct. Brines containing magnesium chloride or sea water can be reacted with calcined dolomite to produce magnesia.2'3 In such reactions the MgCl2 of the brine supplies some of the magnesia and the amount of dolomite required is thereby reduced by an equivalent amount, but brines of commercial importance containing magnesium chloride are some distance away from the purest grades of the dolomite of northwestern Ohio. It was decided therefore to concentrate upon the development of a suitable process for separating the lime and magnesia of dolomite, depending upon the dolomite itself as the sole source of magnesia. This would make it possible to place a plant at the dolomite quarry, thus eliminating the cost of transporting the stone and also rendering the calcined magnesia available at a most convenient production point, considering the cost of delivery throughout the steel industry. The selection of a process depending solely upon the dolomite as a source of magnesia also necessarily entails production of the lime content of the dolomite as a by-product. It was recognized that if such a lime by-product could be produced in a suitable form, a plant location in northwestern Ohio would also be advantageous for marketing the lime. The problem, therefore, was the discovery and development of a low-cost process for separating the magnesia and lime of the dolomite of northwestern Ohio and producing each in a form relatively free from the other, and meeting the respective requirements of established markets. A satisfactory solution of this problem has been found, and it is the

Jan 1, 1948

By Donald W. Petrasek

The effects of selected alloying elements on the elevated-temperature tensile properties of copper alloy -tungsten fiber reinforced composites were invcstigated. A cornparison of the elevated-temperature tensile properties of copper alloy - tungsten fiber reinforced composites, representing soluble systems. was made with copper - tungsten fiber reinforced composites, representing a mutually insoluble system. A linear relation between tensile strength and volume percent fiber content existed at elevated temperatures for all the systenzs investigated. The copper alloy composites were weaker in tension at high volume percent fiber contents than copper composites in which alloying with the fiber did not occur. The tensile strength of the alloyed tungsten fiber decreased with increasing penetration of the alloying element into Ihe tungsten fiber. THE technique of combining strong fibers with relatively weak matrix materials so that the fibers are load-carrying members has been utilized for many years in the reinforcement of plastics with glass fibers. This type of strengthening is currently being extended to include the reinforcement of metals with metallic fibers. Investigations of the room-temperature tensile properties of metal-fiber-reinforced metallic composites have been numerous,'-" but the study of tensile properties at elevated temperatures has been limited. In previous work done at the Lewis Research Center' composites consisting of mutually insoluble constituents were investigated. Composites were made of copper reinforced with uniaxially oriented tungsten fibers. The stress-strain behavior and tensile properties of the composites were related to the tensile properties of the base materials. The tensile strength of the composite was directly proportional to the volume percent of tungsten fiber present, and the full strength of the fiber was realized. Few metal fiber - metal matrix systems exist that are mutually insoluble, and those that do exist are not generally practical. An extension of this work was an

Jan 1, 1967

By G. Rowan, M. W. Clegg

The basic equations for the flow of gases, compressible liquids and incompressible liquids are derived and the full implications of linearising then discussed. Approximate solutions of these equations are obtained by introducing the concept of a disturbed zone around the well, which expands outwards into the reservoir as fluid is produced. Many important and well-established results are deduced in terms of simple functions rather than the infinite series, or numerical solutions normally associated with these problems. The wide range of application of this approach to transient radial flow problems is illustrated with many examples including: gravity drainage of depletion-type reservoirs; multiple well systems; well interference. INTRODUCTION A large number of problems concerning the flow of fluids in oil reservoirs have been solved by both analytical and numerical methods but in almost all cases these solutions have some disadvantages — the analytical ones usually involve rather complex functions (infinite series or infinite integrals) which are difficult to handle, and the numerical ones tend to mask the physical principles underlying the problem. It would seem appropriate, therefore, to try to find approximate analytical solutions to these problems without introducing any further appreciable errors, so that the physical nature of the problem is retained and solutions of comparable accuracy are obtained. One class of problems will be considered in this paper, namely, transient radial flow problems, and it will be shown that approximate analytical solutions of the equations governing radial flow can be obtained, and that these solutions yield comparable results to those calculated numerically and those obtained from "exact" solutions. It will also be shown that the restrictions imposed upon the dependent variable (pressure) are just those which have to be assumed in deriving the usual diffusion-type equations. The method was originally suggested by Guseinov,1 who (a) postulated a disturbed zone in the reservoir, the radius of which increases with time, and (b) replaced the time derivatives in the basic differential equation by its mean value in the disturbed zone. In this paper it is proposed to review the basic theory leading to the equations governing the flow of homogeneous fluids in porous media and to consider the full implications of the approximation introduced in linearising them. The Guseinov-type approximation will then be applied to these equations and the solutions for the flow of compressible and incompressible fluids, and gases in bounded and infinite reservoirs obtained. As an example of the application of this type of approximation, solutions to such problems as production from stratified reservoirs, radial permeability discontinuities; multiple-well systems, and well interference will be given. These solutions agree with many other published results, and in some cases they may be extended to more complex problems without the computational difficulties experienced by other authors. THEORY In order to review the basic theory from a fairly general standpoint it is proposed to limit the idealising assumptions to the minimum necessary for analytical convenience. The assumptions to be made are the following: 1. That the flow is irrotational. 2. That the formation is of constant thickness. 3. Darcy's Law is valid. 4. The formation is saturated with a single homogeneous fluid.

Jan 1, 1938

Jan 1, 1938

By J. L. Byers

THE metals of the platinum group, ruthenium, rhodium, palladium, osmium, iridium and platinum, have certain characteristic effects on the structure and appearance of the cupellation bead. These effects are dependent not only on the particular member of the group present, but also on its concentration. The extent and quality of these effects, however, have not received investigation worthy of their importance. Bannister and Patching investigated the qualitative effects of some of these metals in 1913. This paper deals with a possible rapid qualitative and quantitative delineation of the effects exerted on the cupellation bead by the various metals in the platinum group. More particularly, the paper correlates quantitatively the presence of such metals with their characteristic structural and surface effects. Inasmuch as the various members of the group are more frequently associated with gold than with silver, the gold button will receive the greater consideration. The past two decades have seen a much greater interest manifested in this particular group of metals, because of the increased industrial demand for them. There has been a constantly growing need for assays that will not only express the silver and gold values but also indicate the presence of the other metals. If these indications could be used as quantitative criteria, their value would be greatly increased, because the methods of chemical analysis for the elements of the platinum group are lengthy, involved and unreliable except when the analysis is made by an expert and experienced rare-metal analyst. The materials for the X-ray diffraction examination of the different beads were prepared by filing and screening to -200 mesh, and were then rayed in a General Electric X-ray diffraction unit. The filed samples were treated magnetically in order to eliminate any possible steel particles. Sodium chloride and C.P. gold and silver were used as standard comparators.2 (See Table 1.)

Jan 1, 1932

By H. D. Hoskold

This paper is presented in fulfillment of the promise made in my paper, " Remarks upon Surveying-Instruments,"" etc., and much of the material which would constitute an appropriate introductioil here is omitted, because it has been already published by the Institute, in connection with my own contributions- or those of Mr. Scott and others, in vols. xxviii. to xxxi. of the Transactions, and in the special Institute volume on Mine-Surveying Instruments. In these preceding publications will be found, for instance, descriptions of the writer's " miner's transit-theodolite" of 1863,† and his later " angleometer,"‡ both of which were steps of the progress in engineering instruments and methods which originated in the work of Bourns, before 1842, on the " BoxTunnel " of the Great Western railway in England, in which he had to make connections by direct telescopic sights down the shafts. About 1870 the writer devised a practical and much superior plan, and made detailed drawings for an instrument to meet all the conditions he had proposed prior to that year. The detailed plans were communicated to a celebrated optical firm in London; but, owing to their loss (in Paris or Germany, it is believed) and to other reasons, the matter was, for the time, allowed to lapse. Following upon Bourns's idea, my friend, the late Mr. Beansland, introduced, in 1856, a new system and a portable astronomical instrument.§ Such instruments, however, were neither common nor convenient, and did not come into general use among engineers.

Jan 1, 1902

By Thomas S. Bishop

From time to time the mining engineer will be faced with the necessity of having to make a haulage study to determine not only the most suitable method of hauling material but also the most effective and economical type of equipment to use for his particular operation. Specifically, this chapter outlines a general description of various types of haulage units and their components, guidelines on the selection of equipment, material both operational and cost wise to be accumulated, discussions on the various factors involved in the development of the estimated production and cost analysis, examples of the above, and the necessary reference material. This material and examples are given in such a form as to permit the engineer to proceed on almost a step-by-step basis in the determination of the applicable haul speeds and other related portions of the haul cycle and resulting number of trips per hour. In recent years, the analytical methods used for the application of the various haulage units have undergone a considerable change. Several vehicle manufacturers and a few of the mining companies employ electronic digital computers to speed up the calculations and improve the accuracy of production estimating. The haulage computer program simulates the travel of the vehicle over the described haul roads by calculating incremental velocities, travel times, and travel distances from the known torque vs. speed characteristics of the vehicle. This is, in a sense, a numerical integration of the vehicle's performance and, of course, varies for each and every application. These travel times are then combined with easily estimated fixed times such as loading, turning and dumping, spotting, and any indicated delay times, resulting in a total cycle time for the vehicle. Usually, the travel times comprise the major portion of the time cycle; therefore, the concise computerized calculations eliminate much of the guess work in estimating vehicle productivity. Field studies have correlated this analysis

Jan 1, 1968

By C. M. Loeb, A. M. Gaudin, J. H. Brown

THE object of most size reduction operations in the mineral industry is to liberate the grains of valuable minerals in the ore from those of the gangue. This is usually accomplished by crushing and grinding the entire mass of ore until there is only a small probability that any single particle contains more than one mineral. During this size reduction only limited control exists over size or composition of the particles exposed to the breaking action, and there is no control over the paths followed by cracks generated during the operation. This lack of control usually results in overgrinding and in production of large quantities of very fine material. The first detriment, overgrinding, is costly in itself, but when combined with the second factor it is doubly so. Not only is the fracture of a free particle unnecessary—the fracture of these particles may also make subsequent separation operations difficult, inefficient, and wasteful. It has been pointed out' that if the object of size reduction is to liberate the valuable mineral component of the ore then, ideally, fracture should follow intergranular paths to the exclusion of trans-granular ones. This would result in liberation of the valuable minerals with as little size reduction as possible. This ideal comminution operation is referred to as intergranular comminution, and it was the object of the investigation to determine the extent to which it could be developed by heat treatments. There are many indications in the literature that heating rocks prior to crushing may be favorable. Reports by Holman,2 Yates3 and Myers' are pertinent. These investigators showed that heating certain rocks prior to crushing them did, in fact, improve their crushing characteristics in that fewer fines were produced, although the fact that intergranular comminution was being effected apparently was overlooked. In addition, Sosman noted that if there is appreciable anisotropism in the thermal coefficients of expansion of even a pure mineral, then considerable permanent separation of the grains of the rock can be expected as a result of heating the rock to a high temperature.' By the same token, if there are ap- preciable differences in the thermal expansion coefficients of the various minerals of a multi-component rock, similar results should be obtained by heating this rock. This has been tested, partially, by Brenner," who obtained patents covering the heat treatment of some pegmatitic rocks in order to facilitate comminution of these materials. It has also been demonstrated that this may occur in taconite." Also, the possibility of causing decomposition of one mineral in a rock as a means of promoting intergranular fracture has been considered. Seigle2 and Schiffman et al. have obtained patents on such processes as applied to calcareous iron ores. These reports all indicate that heat treatments prior to crushing may contribute materially to intergranular comminution, but they also indicate that no organized attempt has been made to determine the controlling factors of the method or to determine its applicability in general. The present article is a report on the initial phase of such an investigation. The authors have reviewed the claims of prior investigators and have attempted, also, to establish the factors that might determine the applicability of heat treatments in the mineral industry. In this work 2000-g samples of various rocks were heated in a small laboratory furnace and crushing and sizing operations were carried out in standard laboratory equipment. All samples of each rock were as nearly identical as possible in particle size, grain size, and composition and contained only lumps coarse enough to contain many grains each. Tests on Granite A number of tests were made on a coarse grained Finnish granite obtained in the form of coarse chips from a local monument yard. This rock exhibited little variation from piece to piece in either composition or grain size. The minerals contained were quartz, orthoclase, small amounts of hornblende, and minute quantities of mica. Grain size ranged from about 1 mm to about 3 mm. Temperature of the Heat Treatment: In some cases the granite was heated to a particular temperature and crushed, hot, immediately upon withdrawal from the furnace—in others the rock was allowed to cool before crushing, but without quenching to room temperature after heating. In most tests on granite the heating period was about 2 hr with the furnace at the highest temperature for about 1 hr. Cases in which these periods were varied greatly will be presented separately.

Jan 1, 1959

By Robert Adams

Secondary or scrap materials appear at all stages in the industrial process and in a bewildering variety of forms, grades, and values. It is useful to begin analyzing them by dividing the broad concept of "Secondary Supply" into three parts First, the concept must encompass the stock, or pool, of secondary materials. In the process of satisfying his wants, man produces desired products from the materials and natural resources found around him. As long as the rate of production is greater than the rate of obsolescence of a given product, the total stock or pool of materials embodied in that product will increase in size This stock concept relating to secondary materials is directly analogous to the "resource" concept used for primary raw materials in the preceding chapter, and includes all materials embodied in existing products (Obviously, this excludes those materials which are destroyed in the consumption process, viz , fuel oil burned to provide heat.) Consumption of a primary material in a productive process tends to reduce the resource base of that primary material In direct contrast, however, the production or use of products increases the resource base of the secondary material. Thus, we find that a country which has no resource of a primary material can, by importing products that contain the material, build up a large enough stock to provide a basis for secondary recovery. The estimated growth of the pool of copper in use in the United States through 1967 is shown in Table 5.B.1.a The estimate of 39 3 million tons at the end of 1967 includes only technologically recoverable copper and is, therefore, somewhat less than the stock concept described previously, which does not distinguish between recoverable and unrecoverable material. Nevertheless, Table 5 B.1 does give an idea of how a nation's secondary resource of a material can grow over the years. A second aspect of the concept of secondary supply is the generation of secondary materials. This includes materials generated as scrap in production as well as the movement of a material out of the stock of existing products via wear, damage, or obsolescence The quantity of materials generated is usually either nearly or completely independent of the technologic capabilities and economic forces which prevail in the secondary recovery market.b The justifications for and the qualifications to this statement are considered later. The final aspect of the concept of secondary supply consists in the secondary recovery process It is at this point that the technologic and economic forces of the secondary recovery market become the controlling fac-

Jan 1, 1976

By Robert E. Hoffman, John B. Hudson

The self-diffusion coefficient of pure lead has been measured at five pressures between atmospheric and 40 kb. over a temperature range of about 150°C near the melting point at each pressure. Measurements were made using a radiotracer technique, samples being sectioned electrochemically after the diffusion anneal to determine the diffusion penetration curve. Pressure was applied in a "belt" type pressure device similar to that used by Hall et al., in the diamond synthesis. The self-diffusion coefficient, D, can be represented by an equation of the form at constant pressure, and an equation of the format constant temperature. An apparent correlation between the effects of pressure on self-diffusion and on the melting point of the material observed by Nachtrieb et al., at pressures below 10 kb. was found to be only approximate as measurements are carried to higher pressures. OVER the course of the past 30 years a large number of studies1-' of the rate of atom movements in solid metals have been carried out. These studies have in general been aimed at increasing the understanding of the detailed atomic process by which atom movements in metals can take place. The largest portion of these studies consisted of measurements of the self-diffusion coefficient, D, as a function of temperature. From such studies con- siderable information regarding the energetics of the motive process has been deduced. Recently such measurements have been extended to the pressure dimension. However, the existing work in this area is scanty and has in the past been limited to the pressures attainable in oil or gas bombs—i.e., up to about 10 kilobars (kb). In the present work, the self-diffusion behavior of pure lead has been investigated using the "belt" type high-pressure apparatus designed by Hall7 over a pressure range from atmospheric to 40 kb at temperatures extending over about a 150°C range close to the melting point at each pressure.

Jan 1, 1962

Paper withdrawn from publication September 8,1977, after book was printed. Pages 258.272 are therefore omitted.

Jan 1, 1977

By James R. Finlay

At first blush one is tempted to say that iron-mines are like any other mines, and that principles governing miniug-property in general will apply to them. But there are certain considerations which seem to repay reflection. Gold and copper are more or less independent of transportation. The proof of this is that those metals are profitably mined and shipped from the remotest corners of the earth. Their value is determined by the cost of production on the ground. This is quite true of gold, not quite so true of copper, not at all true of iron. If New York were a. fishing-village and Chicago a swamp, Calumet & Hecla might still be a bonanza. The main element of its value is the 60 lb. of fine copper per ton which it produced for years. But the Mesabi Range is absolutely dependent upon the industrial activity in the United States. Iron-manu-facture in Europe would give it no value whatever. If Chicago and New York had a population of Peruvians or Hindus, the Hull-Rust mine would be as worthless a bit of landscape as any tundra in Alaska. I have discussed these facts more or less casually and dimly in my book on the cost of mining and in my report to the Tax Commissioners of Michigan.1 I shall try here to bring them out in more detail. I have already referred to some differences in the problem of mining as between the more precious metals, e.g., gold, and the less precious and more abundant minerals, like iron and coal; but it is interesting to note that the literature of the eco-

Jan 1, 1914

By H. G. Doll

The S.P. log is shown to be a measurement of the potential drop along the drill hole, caused by ohmic effect in the mud. The notion of static S.P. is brought forward, and its relation to the S.P. log is discussed. Other factors influencing the shape and amplitude of the log are considered; attention is given to conditions encountered in practice. Numerous figures are given illustrating graphically the results; these figures are of particular interest for comparison with field examples. The S.P. log, although indicating permeability, is not an absolute measurement of permeability, nor of porosity, of the formations traversed by a drill hole. It is affected by several parameters, such as resistivity of formations and mud, thickness of formations, and others, which should be appraised carefully. Simple rules have been established for a better distinction of the boundaries of permeabl: sections, particularly in difficult cases, such as those encountered in highly resistive formations. A systematic application of the established principles will assist in obtaining more information from the S.P. log than was possible thus far; for instance, under favorable conditions, presence of oil may be detected, or amount of shale in sands may be estimated. Introduction The S.P. log, or spontaneous potential log, has been known and widely used during the last 15 years for the location of permeable beds traversed by drill holes.1,2 In electrical logging practice, the S.P. log is shown on the left hand side track of the record (as may be seen in later examples) where it can be easily correlated and interpreted with the resistivity curves located to the right. Usually, the S.P. log consists of a base line, more or less straight, having excursions or "peaks" to the left. The base line frequently has been found to correspond to impervious beds, while the peaks are usually found opposite permeable strata. Measurements which will indicate positively the presence of permeability in the formations, and which will give accurately the boundaries of the permeable zones, are of great importance in oil-field practice. Thus far, the S.P. log is the best approach to such determinations; unfortunately, its interpretation is not always evident. With respect to the base line of the S.P. log, it may be noticed that this line is not always at a definite location on the chart. Sometimes it may shift abruptly, while other times a gradual drift is apparent. As far as the peaks are concerned, their shape is not uniform; some are rounded while others are sharp. Also, from other data, it may be found that occasionally the peaks extend appreciably beyond the boundaries of permeable zones into zones which are not everywhere permeable. A comparison with permeability measurements made on cores has often confirmed that there was no definite correspondence between the magnitudes of the peaks and the permeability values. In the same geological horizon, it generally will be found that most of the thick and permeable for-

Jan 1, 1949

By Michael B. Bever, Barton Roessler

The effects of deformation by wire drawing at 78OK on initially ordered and initially disordered specimens of the alloy Cu3Au were investigated. The resistivity, stored energy, drawing force, and microhardness were measured as functions of strain; microstructural changes were observed. The results are interpreted in terms of the structural imperfections and the changes in atomic configuration resulting from deformation. A few experiments on the effects of room-temperature annealing after deformation at 78°K were made; they suggest vacancy-promoted ordering in disordered alloys. BARTON ROESSLER, Junior Member AIME, formerly Graduate Student and Alcoa Fellow, Department of Metallurgy, Massachusetts Institute of Technology, Cambridge, Mass., is with Westinghouse Research Laboratories, Pittsburgh, Penn. MICHAEL B. BEVER, Member AIME, is Professor of Metallurgy, Massachusetts Institute of Technology. Based in part on o thesis by B. ROESSLER submitted in October, 1959 to the Massachusetts Institute of Technology in partial fulfillment of the requirements for the degree of Doctor of Science. Manuscript submitted April 6, 1961. IMD AN investigation of the effects of deformation at room temperature on the alloy Cu3 Au was reported in a recent paper,' which included a review of the literature on the deformation of order-disorder alloys. In general, plastic deformation of ordered alloys reduces the degree of long-range order and causes corresponding changes in their properties. Deformation of disordered alloys changes their properties in a manner characteristic of solid solution alloys; these changes can in part be attributed to the destruction of short-range order. The effects of deformation on solid solution alloys are of two kinds: 1) generation of structural imperfections, which occurs as a result of deformation in any metallic system including pure metals, and 2) changes of atomic configuration, which are characteristic of solid solutions and particularly of order -disorder systems. These two types of effect are not independent of each other and the state of a deformed solid solution alloy is determined in a complex manner by the way in which the structural imperfections cause changes in atomic configuration both during and after deformation.

Jan 1, 1962

By R. J. Tailleur, M. Rosenberg

Oil well drilling muds prepared with lubricating aids such as oil, graphite or mica will not produce a sufficiently strong protective lubricant film for the bit bearing surfaces under high load conditions encountered in drilling operations. Consequently, the damage to the bearing surfaces resulting from the absence of such a film frequently results in a shortening of the drill bit life. Several different types of extreme pressure lubricating additives for use in muds have been developed. These arlrlitives are capable of providing a protective lubricating film for bearing surfaces subjected to high load pressures. A modified version of the Timken lubricant tester, an instrument commonly used for testing the extreme pressure lubricating properties of oils, is used for measuring and controlling the lubricating qualities of the mud. Comparison tests made in the laboratory with 55/8-in. tricone bits drilling on steel plates immersed in extreme pressure lubricating muds and conventional muds showed that the bearing life of those bits tested in the lrrbricating mud was three to four times greater than obtained with conventional muds. Drilling tests made with extreme pressure lubricating muds in West Texas increased over-all bit life three to fourfold, reduced drilling torque and wear on drill pipe and drill collars. INTRODUCTION Roller bit cones contain roller, ball and journal-type bearings that are subjected to very heavy loading during drilling operations in which the only lubricant available for these bearings is either water or drilling mud. These bearings must be able to operate satisfac- torily in order for the cutting structures on the surface of the cones to be fully utilized. Frequently, the bearings wear to the point that the cones freeze and the bit must be pulled before the cutting structures on the cones become worn. In some instances the bearings continue to turn with severe wear but the cones, which are held on the bit by the bearings, drop off; and this causes an expensive fishing job. In other instances the bearings wear to the point that the cones pinch in causing an undergauge hole and delays to ream the hole. The advantage of increasing bit bearing life is self-evident. Because of inability to control the internal wear of bits while drilling, it was felt that improvement of the lubricating qualities of the circulating mud would be helpful. However, the often-discussed lubricating property attributed to muds has been a rather vague and intangible one. The literature has implied that the oil-emulsion muds are more effective lubricants than non-emulsion muds. Actually, there has been no direct method of measuring the lubricating property of muds which would indicate that one mud was better than another; there has been no way to determine whether the lubricating property of any mud was adequate. Furthermore, in comparing lubricating properties of muds, two qualities should be considered—the coefficient of friction and the extreme pressure lubricating qualities. For example, graphite can reduce the coefficient of friction, but does not provide a strong enough lubricating film to protect bit bearings subjected to high loads. The primary object of the investigation reported herein was to find a method for prolonging the bearing life of drill bits; and considering the heavy loads used in drilling, it was felt necessary to find both a method of measuring lubricating properties under high load conditions and methods of establishing effective lubrication under these conditions. Extreme pressure lubrication deals with that realm of lubrication where metal surfaces are in rubbing contact with each other under very high pressures. These pressures may be quite high, as for example,

By Reno H. Sales, Charles Meyer

AT Butte, successive zones of sericitized and argillized quartz monzonite occur around every ore-bearing fracture regardless of its size, attitude, or relative age. The two types of alteration always occupy the same relative positions; sericite adjacent to the ore-bearing vein, clay minerals always between the scricitized rock and fresh quartz monzonite, except where overlap of alteration effects between adjacent fissures has eliminated the lower grade mineralogical products, as is the case in much of Butte's Central zone of pervasive sericitization. As long as active circulation continued in the channel, each zone migrated away from the fissure, that is, it grew at its outer edge and simultaneously receded at its veinward edge because of encroachment by the next innermost zone. The different mineralogical and chemical responses within the wall rocks to the attack by the ore fluid are dependent not on a drastic about-face change of composition of the fluid in the channel relative to its ability to alter the quartz monzonite but on continuously varying conditions of physico-chemical environment within the wall rock outwardly from the vein.' Introduction From the economic viewpoint it is highly desirable that much effort be expended for the purpose of increasing our knowledge of ores and their origin. It has been the observation of the senior writer, many times expressed, that the mining companies have spent too little money in research on the geology of nature's deposits of copper, lead, and zinc, which we know to be of limited extent and which, when exhausted, must be replaced by new discoveries. Experience at Butte and elsewhere has forced the conclusion that observation and mapping in the field must be supplemented by laboratory work if we are to arrive at a reasonably correct understanding of the geology of ore bodies and their environments. It is only through the medium of such correct understanding of geology that we shall be able to accomplish the maximum toward aiding mine operations and at the same time provide a proper background for field examination work whether it be geological or geophysical. The Anaconda Copper Mining Company's answer to the need above expressed has been to equip a geological laboratory at Butte. The reason why Butte was selected is obvious, for situated there is one of the world's largest and geologically most interesting concentrations of copper and zinc. Furthermore, because of the great extent of underground workings both laterally and vertically, the opportunities for observation and study of ore occurrences probably are unequaled anywhere. The laboratory was established with five principal objectives in view. These were: 1. As an aid to Anaconda Company mine operations at Butte and elsewhere, this work to supplement that of the mine geologists. 2. To aid in acquiring as complete an understanding as possible of the behavior of Butte veins and ore bodies laterally and in depth.

Jan 1, 1949

By Charles Meyer, Reno H. Sales

AT Butte, successive zones of sericitized and argillized quartz monzonite occur around every ore-bearing fracture regardless of its size, attitude, or relative age. The two types of alteration always occupy the same relative positions; sericite adjacent to the ore-bearing vein, clay minerals always between the scricitized rock and fresh quartz monzonite, except where overlap of alteration effects between adjacent fissures has eliminated the lower grade mineralogical products, as is the case in much of Butte's Central zone of pervasive sericitization. As long as active circulation continued in the channel, each zone migrated away from the fissure, that is, it grew at its outer edge and simultaneously receded at its veinward edge because of encroachment by the next innermost zone. The different mineralogical and chemical responses within the wall rocks to the attack by the ore fluid are dependent not on a drastic about-face change of composition of the fluid in the channel relative to its ability to alter the quartz monzonite but on continuously varying conditions of physico-chemical environment within the wall rock outwardly from the vein.' Introduction From the economic viewpoint it is highly desirable that much effort be expended for the purpose of increasing our knowledge of ores and their origin. It has been the observation of the senior writer, many times expressed, that the mining companies have spent too little money in research on the geology of nature's deposits of copper, lead, and zinc, which we know to be of limited extent and which, when exhausted, must be replaced by new discoveries. Experience at Butte and elsewhere has forced the conclusion that observation and mapping in the field must be supplemented by laboratory work if we are to arrive at a reasonably correct understanding of the geology of ore bodies and their environments. It is only through the medium of such correct understanding of geology that we shall be able to accomplish the maximum toward aiding mine operations and at the same time provide a proper background for field examination work whether it be geological or geophysical. The Anaconda Copper Mining Company's answer to the need above expressed has been to equip a geological laboratory at Butte. The reason why Butte was selected is obvious, for situated there is one of the world's largest and geologically most interesting concentrations of copper and zinc. Furthermore, because of the great extent of underground workings both laterally and vertically, the opportunities for observation and study of ore occurrences probably are unequaled anywhere. The laboratory was established with five principal objectives in view. These were: 1. As an aid to Anaconda Company mine operations at Butte and elsewhere, this work to supplement that of the mine geologists. 2. To aid in acquiring as complete an understanding as possible of the behavior of Butte veins and ore bodies laterally and in depth.

Jan 1, 1949

YEAR OF ELECTION 1944. SELWYN GWILLYM BLAYLOCK Trail, B.C., Canada 1922. FEDERICO GIOLITTI Torino, Italy 1917. HERBERT HOOVER New, York, N. Y. 1941. DANIEL COWAN JACKLING San Francisco, Cal if. 1939. HENRY KRUMB New York, N. Y. 1942. ESSINGTON LEWIS Melbourne, Vic., Australia 1921. C. McDERMID London, England 1942. PAUL DYER MERICA New York, N. Y. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico 1938. A. M. PORTEVIN Paris, France. 1937. JOHN V. W. REYNDERS New York, N. Y. 1937. GEORGE S. RICE Washington, D. C. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1934. T. A. RICKARD Victoria, B.C., Canada

Jan 1, 1944