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By Thomas Varley

IN THE congressional act establishing the Bureau of Mines one of the functions outlined was "to assist I the industry in the prevention of mineral waste." This had not only to do with the waste in mining but in milling and metallurgical practices, including smelting. The organization of the Bureau of 'Mines includes many divisions, each working in a particular field and charged with certain investigative work. The metallurgical division has the above duties under its immediate supervision, and the station located at Salt Lake City is directed by the chief of this division: There are ten experiment stations of the Bureau of Mines, located in various parts of the country, most of them being housed at state universities under cooperative agreements. Considerable care was exercised in locating the stations and in choosing the particular type of work to be investigated at each place. Inasmuch as the Bureau was designed to serve and cooperate with the industry it is only natural that the investigative work be of interest and importance to the territory immediately adjacent to the respective stations.

Jan 1, 1925

By L. M. Cathles, W. Joseph Schlitt

A mathematical model describing the leaching of low grade industrial waste dumps in developed and solved by finite difference techniques. The leaching behavior of model dumps of different sizes, permeabilities, and waste characteristics, under different operating conditions, is then investigated using the model. It is shown that leaching is fastest for dumps 50-100 feet (15-30m) high, that permeability is very important for the effective leaching of large dumps, that slow leach kinetics of the waste may not be detrimental, and that the leaching of large dumps may be facilitated if leach solutions are preferentially applied to the hot, near-edge portions of the dump.

Jan 1, 1980

By William L. Fink, Kent R. Van Horn

Aluminum forms not only binary compounds with most of the metallic elements but also forms many ternary or more complex constituents. Several of those occurring in the more important alloy systems have been identified under the microscope and the action of various etching reagents has been carefully studied.' The determination of the structure and composition of these complex constituents is a matter of some difficulty and little information is available. X-ray crystal analysis offers a promising method for the study of such constituents. First, and of considerable importance, is the possibility of recognizing the presence of a given constituent by means more positive than microscopic observation. Evidence can also be obtained concerning the nature and composition of the constituent in question and ultimately it should be possible, at least in some cases, to describe the structure including the relative locations of the various atoms. In this paper some results of an uncompleted study of the constituents of the aluminum-iron-silicon system are given and the methods employed are described. Inasmuch as iron and silicon are the chief impurities in aluminum, the constitutional relations of this system are of fundamental importance in the metallurgy of pure aluminum and its alloys; the system has been studied by several investigators and the more important contributions have been reviewed recently.² Fig. 1 shows the structure of the aluminum-rich alloys after prolonged annealing at 560" C., in accord with one of the most recent investigations.3 The ternary alloys examined in the course of the present investigation were all annealed at 550" or 560' C.; in fact, some of the specimens were the identical ones used by nix and Heath, who kindly supplied them for this work. Since the results

Jan 1, 1931

By L. G. Austin, P. T. Luckie, R. R. Klimpel

Application of the Charles and Bond Laws to batch grinding can be deduced as a special case of solution of the first-order batch grinding equation. With additional limitations on the feed size distribution, this special case also gives Rosin-Rammler distributions of constant slope, with the 36.79% retained point a simple function of time. In general, the assumptions concerning the breakage parameters S and B which are necessary to get Charles' and Bond's laws, are not valid except as a crude approximation. With less restrictive assumptions, it is still possible to get approximate Rosin-Rammler distributions, but the slopes change with time of grinding, and the 36.79% retained point is a more complicated function of time. An alternative form to Charles' law is suggested, which accomplishes the same result and has the same errors, but avoids the use of energy of grinding and deals with specific rate of grinding.

Jan 1, 1973

By Irving Cadoff, Richard Nolder

An analysis oj a series of samples of single -crystal silicon grown on sapphire shows that ,four distinct orientation relations exist. There are at least thirteen crystallographic planes which serve as substrates ,for epitaxial growth The model which assumes that silicon substitutes for aluminium and bonds with the oxygen atoms of the sapphire to form the first later for subsequent growth can account for the epitaxial geometry in all four cases. Multiplici-ties 01 specific orientations are found which are explained by the symmetry of both the sapphire and silicon crystal structures. It was reported in the previous paper' that single-crystal silicon films can be deposited on single-crystal a A1,03 (sapphire) with a wide variety of orientations. The silicon films, however, were found to deposit in only four different orientation relationships with respect to the sapphire substrate. The X-ray data have been analyzed to determine the plane and direction of atomic fit and an atomic model to account for the epitaxial relationships at the silicon-sapphire interface has been developed. These results are described in the present paper. EXPERIMENTAL The Laue X-ray data described in the previous paper were reduced to stereographic projections in a standard manner. These data were supplemented with X-ray reflection data obtained with -& E and A Full-Circle Goniometer (Electronics and Alloys, Inc.) mounted on a Phillips diffractometer unit. The silicon films were thin enough to result in characteristic reflections from the substrate as well as the silicon. The superimposed stereographic projections were analyzed to determine the orientation relationships. Ambiguities were resolved by referring to constructed models of various lattice planes for both silicon and sapphire. These lattice models were also used to develop the model for atom fit at the interface. DATA AND ANALYSIS 1) Crystal Structures. The crystallography of silico-n, which is of the diamond cubic class with a. = 5.4~, is straightforward. The sapphire structure is more complex and generally difficult to represent in pictorial form. It is of the rhombohedra1 class but usually referred to hexagonal axes. The transformation of indices between these two systems can lead to ambiguities which will have bearing on the analysis presented herein. Therefore, the basis used in this paper is described in the appendix. Referred to the hexagonal system, the parameters of sapphire are co = 12.95.&, a, = 4.75~, c/a = 2.73. All parameters are for room temperature. Figs. 1 and 2 illustrate schematically the hexagonal unit cell model of sapphire used for this analysis. The oxygen atoms are assumed to occupy positions in an idealized hexagonal array on basal planes. Their actual positions are in a slightly distorted hexagonal array. The aluminum-atom positions are scaled to their actual positions in the lattice with respect to the basal layers of oxygen atoms. It was found that an idealized model where the aluminum atoms are assumed to lie exactly at the octahedral interstices of the oxygen lattice, similar to that used by ~ronberg,' was not adequate for this study.

Jan 1, 1965

By Bruce Chalmers, D. C. Larson

Aluminum crystals with longitudinal-axis orientations of (111) . (110), and (100) were deforined in tension and annealed. The conditions of deformation were controlled so that the re crystallization nuclei originated in either the heavily deformed regions at saw cuts {artificial nucleation) or in the lightly deformed matrix (spontaneous nucleation). The artificial-nucleatioln experiments showed that in lightly deformed (110) and (100) crystals low-angle twist boundaries are most mobile, while in (111> crystals and heavily deformed (110) and (100) crystals high-angle tilt boundaries with near (111) rotations are favored. The spontaneous-nucleation experiments showed the existence of preferred orientations in the (111) crystals. The nonrandomness of the grain orientations is quantitatively determined through a comparison with the results which would he obtained from a randowl set of grain ovientations. PREVIOUS recrystallization studies have been performed on single crystals deformed in tension.1 7 The crystals used in these studies usually had random tensile-axis orientations and the extent of deformation was not a primary consideration. The present study concerns the recrystallization of single crystals with tensile-axis orientations of (Ill), (110), and (100). The emphasis of this work is on the influence of the tensile-axis orientation and the degree of deformation on both the nucleation and growth processes. The multiple-slip orientations were chosen because secondary slip or slip intersection promotes nucleation.1,5,8 These crystals recrystallize at lower strains than the crystals which are oriented for single slip. Also, the greatest variation in deformation behavior is exhibited by the multiple-slip orientations. The stress-strain curves for crystals with tensile-axis orientations of (111) are higher than the stress-strain curves for poly-crystals, and the stress-strain curves for crystals with tensile-axis orientations of (100) are lower (at large strains) than the stress-strain curves for the crystals which deform initially in single slip.g The recrystallization nuclei originated in either 1) the homogeneously* deformed matrix of the crys- tals or 2) the heavily and inhomogeneously deformed regions at saw cuts. The nuclei will be referred to hereafter as spontaneous and artificial nuclei, respectively. The two terms do not imply a difference in the nature of the nuclei; they imply simply a difference in the mode of introduction of the nuclei. During spontaneous nucleation very few (always less than ten) grains nucleate, while during artificial nucleation large numbers of grains nucleate. Only a fraction of the artificially nucleated grains penetrate very far into the deformed matrix during annealing. The grains that penetrate the farthest into the deformed matrix will be referred to as the dominant grains. EXPERIMENTAL PROCEDURE The thirty-five crystals used in this investigation were grown from the melt in milled graphite boats at a rate of 1.6 cm per hr. The crystals had dimensions of approximately 6 by 12 by 80 or 6 by 6 by 80 mm and the aluminum was of 99.992 pet purity. The as-grown crystals were annealed at 610°C for 24 hr and furnace-cooled. They were then heavily etched and electropolished in a solution of five parts methanol to one part perchloric acid. The crystal orientations were obtained by back-reflection Laue photographs and were accurate to ±2 deg. The tensile-axis orientations were (loo), (110), and (111). Two of the side faces of the (111) crystals were (110) lanes. The (110) crystals had both {100) and {110) side faces and the (100) crystals had (100) side faces. The crystals were deformed at a strain rate of 0.003 per min. Shear stress and shear strain were obtained by multiplying and dividing the tensile stress and strain, respectively, by the Schmid factor, m. For the (111) crystals m = 0.272 and for the (110) and the (100) crystals m = 0.408. The Schmid factor is effectively constant during deformation for all orientations. The deformed crystals were sawed into 1-in.-long specimens while the crystals were totally enclosed in a graphite boat. The sawing was performed very carefully in order to limit the plastic deformation to the sawed regions. The specimens were electropolished in the solution mentioned above to remove the sawed-end deformation as well as controlled amounts of surface material. A special stainless-steel grip was used to hold the specimens during the electropolishing treatment. The gripping faces were flat, with no teeth, to prevent the introduction of extraneous de-

Jan 1, 1964

By Frank Foote, E. R. Jette

Precision lattice-constant measurements have been widely used in the study of cubic solid solutions but as yet have been rarely applied to noncubic solid solutions. (See, however, references I and 2.) With the high precision at present attainable in the measurement of lattice constants, the X-ray method should be readily applicable to noncubic solid solutions. In the work reported here, hexagonal close-packed magnesium was used as the solvent and either lead, bismuth or gold as the solute. In the magnesium-lead and magnesium-bismuth systems the a and c lattice constants were determined as a function of composition, densities were calculated from these lattice-constant data, these theoretical densities were compared with those directly measured and the solid solubility limit was determined on quenched specimens over a considerable range of temperature. In the magnesium-gold system, the solid solubility is very small but we have obtained an indirect check on the solubility limit previously reported. Materials and Preparation oF the Alloys The magnesium used was obtained from the Aluminum Company of America and was 99.987 per cent pure. Impurities as reported On the label were: Fe, Al, 0'004 per cent; Si, 0.009 per cent; Zn, trace; Cu, Pb, nil. The bismuth was Merck's analytical grade, minimum purity 99.95 per cent. Maximum impurities as listed on the label were: Fe, 0.008 per cent; Pb, 0.010 per cent; Ag, 0.010 per cent; Cu, 0.005 per cent; Sn, 0.003 per cent; Sb, 0.00; As, 0.000; S, 0.01 per cent. The gold was purified by double precipitation with sulphur dioxide. The lattice constants of these three metals have been previously reported.3 The lead used was test lead, silver free and with a maximum of 0.10 per cent heavy metal impurities. The lattice constant 01 this lead has been measured and found to be 4.94057 ± 0.00016 at 25°C. The alloys were prepared by melting together weighed amounts of the constituent metals in magnesia-lined alundum crucibles under an atmosphere of hydrogen purified by passing over magnesium heated to 500°C. The magnesia lining prevented contamination 01 the alloys with aluminum. Vacuum melting could not be used because of the volatility of magnesium. A high-frequency induction furnace was used for the melting operation and the stirring action of the current resulted in thorough mixing of the constituents. The melts were allowed to freeze in the crucible, the ingots obtained weighed about 10 grams. An extremely thin white film formed on the surface of the melts, sometimes covering only a part of the exposed surface. The ingots were filed clean, placed in small iror crucibles with close-fitting lids and indi. vidually sealed into Pyrex glass tubes Before sealing off, the tubes were alter

Jan 1, 1941

By Frank Foote, E. R. Jette

Precision lattice-constant measurements have been widely used in the study of cubic solid solutions but as yet have been rarely applied to noncubic solid solutions. (See, however, references I and 2.) With the high precision at present attainable in the measurement of lattice constants, the X-ray method should be readily applicable to noncubic solid solutions. In the work reported here, hexagonal close-packed magnesium was used as the solvent and either lead, bismuth or gold as the solute. In the magnesium-lead and magnesium-bismuth systems the a and c lattice constants were determined as a function of composition, densities were calculated from these lattice-constant data, these theoretical densities were compared with those directly measured and the solid solubility limit was determined on quenched specimens over a considerable range of temperature. In the magnesium-gold system, the solid solubility is very small but we have obtained an indirect check on the solubility limit previously reported. Materials and Preparation oF the Alloys The magnesium used was obtained from the Aluminum Company of America and was 99.987 per cent pure. Impurities as reported On the label were: Fe, Al, 0'004 per cent; Si, 0.009 per cent; Zn, trace; Cu, Pb, nil. The bismuth was Merck's analytical grade, minimum purity 99.95 per cent. Maximum impurities as listed on the label were: Fe, 0.008 per cent; Pb, 0.010 per cent; Ag, 0.010 per cent; Cu, 0.005 per cent; Sn, 0.003 per cent; Sb, 0.00; As, 0.000; S, 0.01 per cent. The gold was purified by double precipitation with sulphur dioxide. The lattice constants of these three metals have been previously reported.3 The lead used was test lead, silver free and with a maximum of 0.10 per cent heavy metal impurities. The lattice constant 01 this lead has been measured and found to be 4.94057 ± 0.00016 at 25°C. The alloys were prepared by melting together weighed amounts of the constituent metals in magnesia-lined alundum crucibles under an atmosphere of hydrogen purified by passing over magnesium heated to 500°C. The magnesia lining prevented contamination 01 the alloys with aluminum. Vacuum melting could not be used because of the volatility of magnesium. A high-frequency induction furnace was used for the melting operation and the stirring action of the current resulted in thorough mixing of the constituents. The melts were allowed to freeze in the crucible, the ingots obtained weighed about 10 grams. An extremely thin white film formed on the surface of the melts, sometimes covering only a part of the exposed surface. The ingots were filed clean, placed in small iror crucibles with close-fitting lids and indi. vidually sealed into Pyrex glass tubes Before sealing off, the tubes were alter

Jan 1, 1941

By Robert Stefanko

Roof bolting in coal mines has progressed very rapidly in the last decade, and today this method of support is in general use. There are many theories concerning the functions of roof bolts, but the importance of beam building is indisputable. Proper tension in the bolts minimizes shearing along bedding planes and creates a thick, competent beam from individually weak layers. Bolting must be accomplished immediately upon exposure of the roof, and bolt tension must be maintained if roof failure is to be prevented. Seams are being mined today with roof bolt support where conventional timbering was not effective1. The widespread use of continuous mining equipment was made possible by roof bolts which permit long supported spans free of obstructions.2 Since adequate anchorage is the key to successful bolting, better methods for determining the efficiency of anchorage are continually being sought. Attempts have been made to measure bolt loads, thus assessing anchorage efficiency by employing sensing devices between the bolt head and roof. 3,4,5 None of the techniques appears to be very accurate, and all have at least one serious deficiency.

Jan 5, 1962

By J. U. Messenger

A technique is described whereby the resistance of an emudian to breaking can be quantitatively determined. Produced ailfield emulsions are usually the water-in-oil type and, accordingly, do not conduct an electrical current. However, there is a threshold of A-C voltage pressure above which an emulsion will break and current will flow. The more stable an emulsion, the higher the required voltage. A Fann Emulsion Tester, modified so that low voltages (0 to 10 v) can be accurately measured, is suitable. This technique has application in evaluating the effect of a demuksifier on the stability of an emulsion. Emulsions can, in essence, be titrated with demulsifiers by adding a quuntity of demulsifier, stirring, and measuring the voltage required to cause current to flow. Any synergistic effect of two or more materials added simultaneously can be followed accurately. A demulsifier that significantly lowers the threshold voltage (from 100 to 400 v to 0 to 10 v for the emulsions in this study) is effective and can cause the enlulsion to break. A demulsifier that will bring about this drop in the threshold voltage at low concentration ir very desirable. The technique is also well adapted for rapidly screening demulsifiers. INTRODUCTION Stable emulsions in produced reservoir fluids resulting from certain well stimulation and completion procedures are common problems. The use of suitable demulsifiers can often mitigate these difficulties. At the present time, a rapid and efficient method for selecting satisfactory demulsifiers is not available. It is badly needed. Reliance is now placed primarily on trial-and-error procedures. A new test method has been developed which permits a more rapid and precise selection of demulsifiers. It involves measuring the electrical stability potential of an emulsion before and after a demulsifier has been added. This paper describes this method and shows where it should have application in field emulsion problems. NATURE OF OILFIELD EMULSIONS Two immiscible components must be present for an emuhion to form; we are concerned here with crude oil and water. An emulsifier must be present for tin emulsion to be stable. J Emulsifiers can be substances which are soluble in oil and /or mter and which lower interfacial tension. They can be colloidal solids such as bentonite, carbon, graphite, or asphalt which collect at the interface and are preferentially wet by one of these phases. Unrefined crude oils can contain both types of emulsifiers, A popular theory is that, of the two phases in an emulsion, the dispersed phase will be the one contributing most to the interfacial tension.' Usually this phase contains the least amount of emulsifier. The stability of a water-in-oil emulsion is affected by the fol1owing: l) viscosity; (2) particle or droplet size; (3) interfacial tension between the phases; (4) phase-volume ratios; and (5) the difference in density between the phases. A stable emulsion is usually characterized by high-viscosity, small droplets, low interfacial tensions, small differences in density between its phases, and slow separatian of the phases. It also has low conductivity (high electrical stability potential). Water-in-oil and oil-in-water emulsions"' are both common; however, oil field emulsions are predominantly water-in-oil emulsions. The emulsions which commonly occur during oompletion and stimulation operations contain a combination of several of the following: acids, fracturing fluids (oil, water, acid), and formation water and oil. Produced emulsions usually contain formation water and oil. Emulsions form in oil wells because oil and water are mixed together at a high rate of shear in the presence of a naturally occurring or unavoidably produced emulsifier. During the completion and stimulation of productive zones, and while formation fluids are being produced, oil and water are very often commingled. These mixtures are formed into emulsions by agitation which occurs when the fluids are pumped from the surface into the matrix of the formation or produced through the formation to the surface. Restrictions to flow (such as perforations, pumps, and chokes)".'" increase the level of agitation; tight emulsions are more likely to form under these conditions. Often an emulsified droplet is an emulsion itself.'" Therefore, emulsion-breaking problems can be quite complex. The complexity can be even greater if a third phase (gas) is included. Demulsifiers operate by tending to reverse the form of the emulsion. During this process, droplets of water become bigger, viscosity is lowered, color becomes darker, separation of the phases faster and electrical stability potential approaches zero. Any of these effects could be followed as a means of determining emulsion stability. However, electrical stability potential is the most reproducible and most easily measured parameter for following the stability of a water-in-oil emulsion.

Jan 1, 1966

By Regis M. N. Pelloux, N. J. Grant

Five or six alloys each in the systems Ni-C.v, Ni-Mo, and NL-W, spaced to cover the single phase areas as well as a part of the adjacent two-phase field, were prepared as uacuum-melted alloys. Tensile tests at room temperature and stress rupture tests at 1200° and 1500°F we.ve run for time periods to give fracture in 0.1 to 500 hr. Observations mere made of solid-solution and second-phase strengthening or uleakening, coupled with studies of ductility and the role of structure on the noted behavior patterns. THE development of stable creep-resistant alloys while broad and systematic is also highly empirical. A number of simple rules have been suggestedL-" but these are based on scant data. Whereas rules for low-temperature alloy strengthening can be applied with some success in more simple systems, the extension to behavior at high temperatures (greater than about 0.4 of the absolute melting temperature) is very poorly understood and has encountered important exceptions and deviations in terms of atom size or valency effects. In particular, the occurrence of both solid-solution weakening4,5 and second-phase weakening2 at high temperatures is of interest. MATERIALS AND PROCEDURE Nickel was chosen as the base material because of its important role in current high-temperature alloy applications, because of its freedom from a phase transformation, and because of wide solubilities for many elements of interest. The selected alloys were single- and two-phase structures in the Ni-Cr,6 Ni-Mo,7 and Ni-w 8 systems. The alloys were vacuum melted and cast, utilizing high-purity raw materials, in the form of 15 lb ingots. They were readily forged into 1/2-in. bar stock (except the two highest chromium alloys). The alloy compositions are shown in Table I. Typical impurity values are: Carbon: Max 0.03 pct (except for 30 and 35 pct Cr alloys which had 0.07) Nitrogen: Max 0.005 pct (except for two of the Cr alloys which had 0.05) Sulfur: Max 0.004 pct Silicon: Max 0.05 pct Each alloy was solution treated (air quenched) to produce comparable grain size. The two-phase alloys were then overaged in an effort to produce a stable structure for testing at 1200° and 1500°F, The results are summarized in Table 11. Following the heat treatments outlined in Table 11, the bars were machined to a gage section of 1.25-in. long by 0.250-in. diam. In addition to room-temperature tensile tests, stress-rupture tests were run at 1200" and 1500°F for time periods from 0.1 to about 500 hr. RESULTS Room-Temperature Mechanical Properties—The ultimate tensile strength, total elongation, and reduction of area values for all the alloys are plotted vs atomic percent of the solute element in Fig. 1. It can be seen that for the same amount of solute element the ultimate tensile strength increases in the order chromium, molybdenum, tungsten. Elongation increases (reduction of area decreases) with increasing amounts of solute for all the solid solution alloys, the values ranging from 50 to 70 pct. The ultimate tensile strength values for the two-

Jan 1, 1961

By Harry A. Roe

THE power drag scrapers and the slackline cableway excavator have been called "long-range excavators." Broadly, their field of usefulness is restricted to work in which their long range of action permits them to operate economically, and which other, possibly more conventional, excavating units cannot do. Both of these machines dig or lift material and transport it to a remote dumping point. They combine these two functions in a single machine, nearly always in a single straight-line motion. [ ] The purpose of this paper is to examine the important features that distinguish the machines in this group from each other, as well as from other groups. The Machines The "power drag scraper" is a long-range excavating machine that employs a bottomless drag scraper operated back and forth between digging and dumping points by two haulage cables. The typical arrangement is that of Fig. 1. This is the "slusher" of the underground mine, as well as the "dragline scraper" of the sand and gravel industry, and other open-pit mining operations.

Jan 1, 1937

By L. W. Kempf

THE thermal expansion characteristics of aluminum alloys have been examined by several investigators, among whom may be mentioned Shakespear,1 Schulz,2 Hidnert,3 Hidnert and Sweeney4 and McCullough.5 Shakespear compared the expansion of a series of aluminum alloys containing 14 per cent copper, with separate additions of about 1 per cent each of manganese, tin and zinc with that of pure copper. Schulz examined the expansion of aluminum and zinc and some aluminum-zinc alloys. Hidnert determined with a high degree of precision the expansion characteristics of pure aluminum, some aluminum-copper, aluminum-zinc, aluminum-silicon and some commercial alloys. Hidnert and Sweeney examined the expansion characteristics of aluminum-beryllium alloys. McCullough, by an interferometer method, determined the expansivity of some aluminum-copper, aluminum-magnesium, aluminum-iron, aluminum-nickel, aluminum-silicon and aluminum-manganese alloys. Incidental to an investigation carried out during the past six years and leading to the development and exploitation of an aluminum piston alloy of relatively low thermal expansivity, the expansion characteristics of a wide variety of alloys were examined. Some of the data which might be of general interest are gathered in this paper.

Jan 1, 1933

By H. M. Howe, A. G. Levy

§ 1 Introduction.—This paper gives the results of our micro-graphic determinations of the position of Ae3 in a series of 14 hypo-eutectoid steels of varying carbon content, one of them very rich in phosphorus, and of SEe for one hyper-eutectoid steel. We have proceeded chiefly by noting the temperature at which the reabsorption of the pro-eutectoid element is found to be complete after a 30-min. holding, but in part also by noting the temperature at which its precipitation begins. Observations on these same steels by Messrs. Burgess, Crowe, and Rawdon, of the United States Bureau of Standards, are given in a paper1 issued simultaneously with this, while in a third paper2 one of us compares these data with those of earlier observers. These three papers are treated as one whole by numbering their sections, tables, and illustrations continuously, and by setting the folding plates of micrographs at the end of the last paper. The Composition of the Steels Experimented On is given in Table I. § 2. Notalion and Definitions.—Following Osmond's development of Tschernoff's notation, in which " Ac3 " is the upper limit of the hypo-eutectoid part of the transformation range as observed in heating up, and " Ar3 " is that same limit as observed in cooling down, and following the usual custom of calling the upper limit of the hyper-eutectoid part of that range " SE," we may go farther and call this latter limit " SEc" when observed in heating up and " SEr " when observed in cooling down. Further, we may call the equilibrium position of these lines, i. e., the position which they would have in pure iron-carbon alloys if all

Jan 1, 1914

By Hugh P. Tiemann

The desirability of employing the centigrade scale for the measurement of temperatures is becoming more and more recognized in this country, particularly in view of the fact that this scale is used almost exclusively in technical papers and publications—exclusively in those published in French or German. There are, however, a large number of factories and laboratories which still employ the Fahrenheit scale. It therefore frequently becomes necessary to convert one into the other and the accompanying chart (Fig. I) has been found very convenient for this purpose. The formulas for conversion follow: (1) °F. = 9o /5+ 32 (2) oC = 5 (oF - 32 ) (1) 100° C X 9 900/5 =180 .'. 180 + 32 = 212° F. 5 (2) 5 (212° F - 32) = 5 X 180 =100o C 9 9

Jan 1, 1916

By Kendall Y. Keuhey

The Mercur Mine, developed and operated by Getty Mining Company, is designed to process 3,000 tons/day of gold ore from the historic Mercur Hill mining district. The mill process involves crushing, grinding, and cyanide carbon-in-leach for recovery of gold from ores ranging from 0.08 to 0.10 oz/ton. During the mining of normal grade ore, a substantial tonnage of material containing 0.02 to 0.05 oz/ton is mined and would be available for heap leaching. Also, Getty Mining is developing methods to test and prepare lower grade material for heap leaching by rejecting a coarse rock fraction from the grinding SAG mill circuit. This lower grade fraction is suitable for heap leaching, and its removal will upgrade the regular mill feed. Other test methods are directed toward leaching techniques on some 4.0 million tons of tailings that resulted from roasting and/or cyanide leaching Mercur ores in the early 1900's. The natural carbons associated with the Mercur deposits require special treatment to reduce their gold adsorption effects when leached with cyanide.

Jan 1, 1984

COLUMBIA SECTION S. S. FOWLER, Chairman., J. C. HAAS, Vice-chairman, LYNDON K. ARMSTRONG, Secretary-Treasurer, 720 Peyton Bldg., Spokane, Wash. W. H. LINNEY. J. F. MCCARTHY. On July 15, 16, and 17, 1918, through the good offices of Secretary Stoughton, and the courtesy of War Department officials, Columbia Section was able to secure a series of moving pictures which were presented under the auspices of the Spokane Engineering and Technical Association.. The title was "The Way Out," representing the activities of individuals who had lost an arm, a leg, or both, yet whose apparent misfortunes were made the stepping stones to advancement in various human activities. The exhibitions were given at Natatorium Park in the evening, each of the three performances being attended by 1000 per-sons. Later the films were shipped to Kellogg, Idaho, where they were shown in the principal playhouse one evening to a full house. On July 31, 1918, the Columbia Section participated in the luncheon and other entertainment in honor of Alfred D. Flinn, Secretary of the Engineering Council, who made a trip through the country to meet different classes of engineers, members of the National Societies, for whom he had a message. The entertainment was under the auspices of the Spokane Engineering and Technical Association, Mr. Peter Mogensen presiding. The luncheon was held in the Elizabethan Room, Davenport Hotel, at noon, 35 engineers being present, of whom about one-third were our members.

Jan 9, 1918

By James F. Howe

EveRy engineer and user of wire rope is desirous of information that will enable him to determine whether the performance of any particular piece of rope is satisfactory, and what conditions can be changed so as to increase the life of a rope. In most cases, it is far from easy to analyze the conditions of service and tell which is the greatest factor in determining the life of wire rope. If we start on a layout for an entirely new rope system, the task of making conditions satisfactory is simplified so far as the engineering details are concerned; but if the plant requiring wire rope is in operation, any change is likely to involve the expenditure of considerable money to replace and change over machinery that must be kept in constant operation, because a large monetary loss will result from a shutdown for even a few days. Often wire rope is kept operating under bad conditions, as the user thinks that it is cheaper and quicker to replace the rope than to make alterations in the hoisting machinery. A typical case is a metal mine operating in what is now almost the center of a large mining city, where it owns a few acres of mineral rights. It was expected that the shaft would go to a depth of 1000 ft. (305 m.), so a moderate-sized rope, about 1 1/4in. (31.7 mm.), was used on a 6-ft. drum with a 7-ft. head-frame sheave and rather short lead from drum to head sheave. This mine has gone deeper each year until it is now 2500 ft. deep and the rope speed has been increased from 1500 ft. per min. to over 3000 ft. The original rope just filled the drum in one layer, now it overwinds three layers. The original ropes were probably 6 X 19 crucible steel and lasted from 12 to 18 mo.; now, the highest grade plow steel is used, yet the average service is only about 6 mo. The cause is not hard to find. If the engineers had known at the outset what would be done with this hoist, the design would have been very different. Conditions at this mine, from a wire-rope standpoint, have gradually become worse and it is difficult to see how rope service on this hoist can be compared with the service of previous years with any fairness to the wire-

Jan 1, 1923

By James F. Howe

EveRy engineer and user of wire rope is desirous of information that will enable him to determine whether the performance of any particular piece of rope is satisfactory, and what conditions can be changed so as to increase the life of a rope. In most cases, it is far from easy to analyze the conditions of service and tell which is the greatest factor in determining the life of wire rope. If we start on a layout for an entirely new rope system, the task of making conditions satisfactory is simplified so far as the engineering details are concerned; but if the plant requiring wire rope is in operation, any change is likely to involve the expenditure of considerable money to replace and change over machinery that must be kept in constant operation, because a large monetary loss will result from a shutdown for even a few days. Often wire rope is kept operating under bad conditions, as the user thinks that it is cheaper and quicker to replace the rope than to make alterations in the hoisting machinery. A typical case is a metal mine operating in what is now almost the center of a large mining city, where it owns a few acres of mineral rights. It was expected that the shaft would go to a depth of 1000 ft. (305 m.), so a moderate-sized rope, about 1 1/4in. (31.7 mm.), was used on a 6-ft. drum with a 7-ft. head-frame sheave and rather short lead from drum to head sheave. This mine has gone deeper each year until it is now 2500 ft. deep and the rope speed has been increased from 1500 ft. per min. to over 3000 ft. The original rope just filled the drum in one layer, now it overwinds three layers. The original ropes were probably 6 X 19 crucible steel and lasted from 12 to 18 mo.; now, the highest grade plow steel is used, yet the average service is only about 6 mo. The cause is not hard to find. If the engineers had known at the outset what would be done with this hoist, the design would have been very different. Conditions at this mine, from a wire-rope standpoint, have gradually become worse and it is difficult to see how rope service on this hoist can be compared with the service of previous years with any fairness to the wire-

Jan 1, 1923

By Charles Jones

(San Francisco Meeting, September, 1915) IN any discussion of this very large subject we are confronted at the outset with so many obstacles that at best only a fragmentary and rather disconnected presentation can be made of it, and my hope is that building from the few facts I have to offer a more complete knowledge may be secured. In the whole intermountain and Pacific. Coast region, west of Pueblo, Col., and from Canada to Mexico, there is no production of pig iron, and steel production is confined to the manufacture of a small amount of open-hearth steel from scrap. When we consider the area, the resources, and the several centers of population, this condition seems anomalous, even in. the face of every counter argument as to cheap water transportation, or other means of transport from the Atlantic Seaboard or from the iron and steel centers of the Middle West. This comatose condition, if such a term may be applied, is certainly riot due to a lack of all the essential materials and factors for success in iron and steel smelting, but is rather, I think, due largely to the general fact that it is only within a comparatively few years that the centers of population on the Pacific Coast have attained a size that would entitle them to the position of distributing or freight centers, or that the "back country" has been enough built up to make it sufficiently interesting to the railroads to foster trade from the local centers to the interior points rather than seek to supply such local centers and the interior by a transcontinental haul.

Jan 9, 1915