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By Otto H. Henry, Edward L. Badwick

Up to the present time, according to Hansen1 and Haughton,2 the constitution of the bismuth-indium system has not yet been published. The generally accepted value for the melting point of indium, as listed in most scientific journals and textbooks, is 155°C. Recently, however, H. M. Davis3 has determined a new melting point for indium of 257.3°C ± 0.1°C. Since bismuth has been used in preponderance as an alloying element in the majority of low-melting alloys, and indium has been used with considerable success in lowering the melting points of low-melting alloys,4,5 an interest has been developed in the application of these two metals, making a complete knowledge of the constitution of its alloys desirable. In this investigation, the melting point of indium reported by H. M. Davis has been found to be substantially correct. A value of 157.2°C ± 0.5°C was determined. The two eutectic compositions have been placed at 34 and 50 pct bismuth with their respective eutectic temperatures as 72.4'C ± 0.5°C and 90°C ± 0.5°C. The bismuth-indium phase diagram has been determined by thermal and microscopic analysis and is shown in Fig I. THERMAL ANALYSIS Granulated bismuth and indium shot, having a guaranteed purity of 99.99 and 99.95 pct, respectively, were melted in a carbon crucible by means of a laboratory heater. To minimize oxidation of the alloys, a heavy mineral oil (Nujol) having a high flash point was used. A platinum-platinum rhodium thermocouple 0f fine wire encased in a thin-walled Pyrex glass tube, about 1/8 in. in diameter, was connected to a type K potentiometer for temperature measurements. The thermo-couple was calibrated against the melting points of tin, bismuth, and the silver-copper eutectic and the boiling point of water. Since the temperature readings could be reproduced to 0.2°C, and the accuracy of the temperature standards in this range is slightly better than 0.5°C, it seems reasonable to assume that the temperature readings are reliable to approximately 0.5°C. The cooling rate could be controlled by varying the amount of insulation surrounding the crucible. Three or four layers of asbestos paper, 1/16r, in. thick, sufficed to give a cooling rate of from 1° to 2°C per minute. Undercooling was slightly noticeable. This condition was minimized by vigorous stirring, since the advantage of using slower rates was too small to justify the greater expenditure

Jan 1, 1947

Jan 1, 1967

By GEORGE L. CHRISTIAN

T HE Tonopah Extension assay office is a two- story, concrete structure on a solid foundation of andesite, situated about 100 yd. from the company's mill, so that it will not be affected by the stamps or the tube-mills; also it will not be affected by under- ground blasting. On the second floor are the mine superintendent's office and drafting and blueprint rooms. On the ground floor are the assayer's office,' mixing room, furnace room, crusher room, chemical laboratory, parting room, store room, and change and shower room for the mine superintendent, assayers, and engineers. The crusher room is outside of the main building, and has four concrete walls, thus eliminating the jar of the crusher; it is so situated that the least possible amount of dust spreads through the main building. An 8 by 10-in. jaw crusher, which crushes to ¼ in., was made by a local foundry. Attached to the top is a small galvanized-iron hopper covered with a ¼ in. screen, on to which the sample is dumped. The fines-pass through the screen into the hopper, while the oversize is dumped into the crusher. The crushed sample and fines from the screen drop down to a set .of splits suspended from an iron rod below the crusher jaws. The small sample is caught below in a small pulp pan. The rejects drop from the splits through a 2-in. pipe on to a bucket conveyor, which dumps into a galvanized-iron hopper in an upper corner of the room. The rejects drop through a 2-in. pipe to a reject bin outside the build- ing. This bin is constructed high enough for a truck to be loaded from it by means of a chute door on the side.

Jan 1, 1921

By M. Gensamer

THE stresses which initiate deformation processes in metals are funda-mentally important in the study of the mechanical properties of metals. A point of inflection in the load-elongation curves obtained for single crystals1 has been rather too readily interpreted as a true yield point, and the critical resolved shearing stress on the plane of slip taken as a material constant. Even early work showed that the stress at this point varies with rate of loading, but it has not been generally appreciated that creep tests under static loads alone are suited for determining the existence or nonexistence of a yield point.2 It has now been shown by Miller that single crystals of zinc3 when loaded statically begin to yield at loads too small to measure; as a result there is no case now known, apart from that cited in the present paper, in which a true critical stress for yielding has been demonstrated for single crystals of metals. The case of iron has especial interest: the existence of an upper and lower yield point and of an elongation at the yield point in ordinary iron and steel marks this substance as unusual, though the effects have been found to a very minor degree in other metals and alloys. ? Most alloys do not show such marked phenomena when appreciable yielding begins, and accordingly modern practice is to speak of the yield strength of such materials, a stress read from the load-elongation curve after elongation has begun, rather than yield point. The special behavior of iron suggests that it is more likely that single crystals of iron should have a true yield point than other metals.

Jan 1, 1938

By AIME AIME

THE Charleston Section of the A. I. M. E. held a joint meeting with the National Coal Association and the American Society of Mechanical Engineers on May 6 and 7, at which 94 members and guests were registered. Mechanical operation of coal mines was the subject discussed. First on the program was a paper entitled "Rock Dusting in the Coal Mines of West Virginia," by R. M. Lambie, chief of the Department of Mines, and Gordon MacVean. It appears in full in the current issue of MINING AND METALLURGY, p. 290. J. E. Jones of the Old Ben Coal Corp. opened this discussion by describing the method of rock dusting employed in the mines of that company, giving many interesting details, incidentally referring to the use of rock dust in fighting mine fires. He described one case where a number of troughs was brought to within 150 ft. of the fire, and rock dust had been thrown in its direction. After each trough had been thrown the party advanced a few feet, where another trough was discharged. About 10 ft. were gained on each advance, until the party found they had advanced completely over the fire.

Jan 1, 1926

Jan 1, 1968

THE transformation, in a sample of levitation melted iodide titanium, has been studied with a Leitz hot-stage microscope. The specimen was etched in HF:HNO3: glycerine, (1:1:2) giving a structure shown in Fig. 1, and was then heated at approximately 5OC per min. At 870°C (±5OC) the etching product disappeared, the a-grain boundaries showed in relief, and some new grain boundaries (presumably of ß) appeared (Fig. 2, see arrow). Some evidence of ß-grain growth is indicated by the apparent longitudinal movement of a ß-grain boundary shown in Figs. 2 and 3 (see arrows). The specimen was later heated to 1000°C and then cooled at 2°C per min. At 845°C rumpling of the surface was first noticed, Fig. 4, and continued at constant temperature. The photomicrograph reproduced in Fig. 5 was taken 6 sec after Fig. 4, at 845°C. Fig. 6 shows the structure after cooling to room temperature. The room-temperature structure, showing a rumpled surface has been observed by previous investigators.' These structures presumably indicate a sheer transformation ß - a, athermally nucleated, but capable of isothermal progression.

Jan 1, 1960

By L. M. Pidgeon, P. G. Thornhill

A LTHOUGH a considerable number of experi--ti mental investigations dealing with the roasting of sulfide minerals have been reported in the past,'"" the behavior of the single roasting particle does not appear to have received the attention it perhaps deserves. This is understandable in that the natural sulfide counterpart of the slab or sheet of metal normally used in high temperature oxidation studies is difficult to obtain and prepare, and is, in most cases, virtually impossible to maintain in one piece at roasting temperatures. The employment, on the other hand, of static aggregations of small particles in masses great enough to permit evaluation of the roasting reactions by means of thermobalances or gas analyses introduces other complications, such as localized overheating, sintering, and variable gas-solid contact. In this investigation a compromise between the above extremes was attempted. Closely sized (e.g., 30 to 40 mesh) particles of natural sulfide minerals were isothermally roasted, out of contact with one another, in an air-swept system. The progress of the roasting reactions was followed by examination in polished section of the treated particles and by X-ray and chemical analysis of their residual sulfide kernels. In this way some conclusions respecting the mechanism of roasting reactions were drawn. Roasting Furnace—The vertical tube furnace used for roasting the sulfide particles had a heated zone 10 1/2 in. long in which four retractable light gage stainless steel trays were suspended. Each tray, and an accompanying baffle, was mounted on a 2 in. lengtn of 3/8 in. stainless steel tubing. These assemblies were axially suspended on a 30 in. length of ¼ in. stainless tubing, by means of which they could be lifted from the hot zone to a water-cooled brass chamber at the top of the furnace. Since each tray unit could slide freely on the 30 in. tube, any desired number of the trays could be retained in the cooling chamber by the manipulation of a horizontal plunger during a momentary withdrawal of the four trays from the hot zone. Although three heating coils, each equipped with variable external resistance, were employed, it was found impossible to avoid a drop of 10o to 15oC between the temperature at the top tray and that of the lower three. Consequently, only the bottom three trays were used for roasting. Temperature readings inside the furnace were made by means of a thermocouple inserted down the tray support tube at tray levels, and a separate thermocouple, inserted adjacent to the middle heating coil, was connected to a Micromax temperature control unit. Experimental Method—The sulfide minerals were obtained in a form as free as possible from gangue and contaminating sulfides, and were crushed and screened to the required particle size range. The tray assembly was kept inside the furnace during the heating-up period and, when a steady temperature had been reached, the trays were withdrawn. Each tray was sprinkled with from 200 to 500 mg of the sulfide grains, and the assembly was lowered into the furnace without delay in order to minimize the time required to achieve the operating temperature. The furnace top was then clamped into position and the thermocouple inserted down the center tube to the required level. It was found that, when this procedure was used, the trays achieved their former temperature within 2 min, after which time the flow of dry air was begun at a rate of 1 liter per min, and timing of the run was started. At the required intervals of time the trays were successively withdrawn from the hot zone and stored in the cooling chamber by means of the retention plunger. On completion of the run the treated particles were removed from the trays to be set aside for examination. The roasted particles were mounted in Lucite on a Buehler press Operating at a temperature of 140°C

Jan 1, 1958

By J. H. Wernick, D. Dorsi, K. E. Benson

A LTHOUGH a considerable number of experi--ti mental investigations dealing with the roasting of sulfide minerals have been reported in the past,'"" the behavior of the single roasting particle does not appear to have received the attention it perhaps deserves. This is understandable in that the natural sulfide counterpart of the slab or sheet of metal normally used in high temperature oxidation studies is difficult to obtain and prepare, and is, in most cases, virtually impossible to maintain in one piece at roasting temperatures. The employment, on the other hand, of static aggregations of small particles in masses great enough to permit evaluation of the roasting reactions by means of thermobalances or gas analyses introduces other complications, such as localized overheating, sintering, and variable gas-solid contact. In this investigation a compromise between the above extremes was attempted. Closely sized (e.g., 30 to 40 mesh) particles of natural sulfide minerals were isothermally roasted, out of contact with one another, in an air-swept system. The progress of the roasting reactions was followed by examination in polished section of the treated particles and by X-ray and chemical analysis of their residual sulfide kernels. In this way some conclusions respecting the mechanism of roasting reactions were drawn. Roasting Furnace—The vertical tube furnace used for roasting the sulfide particles had a heated zone 10 1/2 in. long in which four retractable light gage stainless steel trays were suspended. Each tray, and an accompanying baffle, was mounted on a 2 in. iength of 3/8 in. stainless steel tubing. These assemblies were axially suspended on a 30 in. length of in. stainless tubing, by means of which they could be lifted from the hot zone to a water-cooled brass chamber at the top of the furnace. Since each tray unit could slide freely on the 30 in. tube, any desired number of the trays could be retained in the cooling chamber by the manipulation of a horizontal plunger during a momentary withdrawal of the four trays from the hot zone. Although three heating coils, each equipped with variable external resistance, were employed, it was found impossible to avoid a drop of 10O to 15OC between the temperature at the top tray and that of the lower three. Consequently, only the bottom three trays were used for roasting. Temperature readings inside the furnace were made by means of a thermocouple inserted down the tray support tube at tray levels, and a separate thermocouple, inserted adjacent to the middle heating coil, was connected to a Micromax temperature control unit. Experimental Method—The sulfide minerals were obtained in a form as free as possible from gangue and contaminating sulfides, and were crushed and screened to the required particle size range. The tray assembly was kept inside the furnace during the heating-up period and, when a steady temperature had been reached, the trays were withdrawn. Each tray was sprinkled with from 200 to 500 mg of the sulfide grains, and the assembly was lowered into the furnace without delay in order to minimize the time required to achieve the operating temperature. The furnace top was then clamped into position and the thermocouple inserted down the center tube to the required level. It was found that, when this procedure was used, the trays achieved their former temperature within 2 min, after which time the flow of dry air was begun at a rate of 1 liter per min, and timing of the run was started. At the required intervals of time the trays were successively withdrawn from the hot zone and stored in the cooling chamber by means of the retention plunger. On completion of the run the treated particles were removed from the trays to be set aside for examination. The roasted particles were mounted in Lucite on a Buehler press operating at a temperature of 146°C

Jan 1, 1958

By H. Margolin, E. Ence

A. J. Goldak and J. Gordon Parr University of Alberta) —Margolin and Ence's paper reached us only a few days after we had submitted a paper on the structure of Ti2Cu to the AIME. Here, however, we only wish to point out an error in the paper (page 321): "Karlsson has reported the crystal structure of the first intermediate phase occurring in the Ti-rich portion of the Ti-Cu system to be face-centered tetragonal." Karlsson actually reported the structure of Ti3Cu (i.e., "the first intermediate phase") to be primitive tetragonal with four atoms per lattice point: Cu at 0, 0, 0; and Ti at 1/2, 1/2, 0; 0, 1/2, 1/2; and 1/2, 0, 1/2. Thus, Karlsson suggests a primitive lattice with an ordered arrangement of atoms located at corners and face-centers: Ence and Margolin suggest a random body-centered tetragonal structure—-with which our results agree. E. Ence and H. Margolin (azlt1zo.l-s' reply)— We do not agree that Karlsson has not reported the structure of Ti3Cu as face-centered tetragonal. The fact that Cu atoms are located at the corners and titanium at the face-centers does not indicate that the lattice is not face-centered. We are pleased that the discussers' results agree with our own.

Jan 1, 1962

By F. B. Harris

MINE surveying and engineering at the various properties of the United States Smelting Refining and Mining Company has developed and increased in importance steadily as mining methods have changed and expanded, both in the development of ore bodies and in the methods and styles of stoping. Most important to satisfactory engineering practice, and secondary -only to accuracy and precision, is the preservation of all data relative to surveys and calculations so that it is readily available for use at all times and in -such form that it is permanent, easily found, and usable. The first consideration for a proper, accurate, and practical start for surveys and efficient engineering at any property is an accurate triangulation net and system of co-ordinates. This has been our practice and the first step seas to select a base line, readily accessible and easily measured, situated preferably on an even grade where the difference of elevation between the two -end monuments was not too great and -the distance was long enough for practical use. Permanent concrete monuments were built for these base-line points so constructed that they could be easily recognized and were visible. Precise levels were run on this base 'line and the elevation (sea level datum) if possible was established at each end monument. The distance was carefully measured many times, back and forward, by using a tape that had been standardized by the National Bureau of Standards. The tape was supported at ,each 25-ft interval on stakes which had been brought to grade between each measuring point. All conditions were

Jan 1, 1948

A. Scott Reid, London, Eng. (communication to the Secretary*) :—As a constructor of several glass mine-models, .I have read with much interest the description of the model of the Montana-Toriopah mine-workings by Edmund D. North.

Jan 1, 1910

Jan 1, 1968

"Copper was first made in Butte by the use of iron for its precipitation from mine water in 1890. In consequence of a fire breaking out in the St. Lawrence mine of the Anaconda Copper Mining Company in November, 1889, a large quantity of water was poured into the workings, with the intention of flooding the mine and extinguishing the fire. This proved to be impracticable, but this water, on being pumped to the surface, was found to be high in copper sulphate,—tradition says 75/100 of 1 per cent. The Anaconda Copper Mining Company gave Wm. Ledford a lease on this water. He first (lug holes into the ground, filled them with scrap iron and allowed the water to flow through them. Later he built an open-top flume which he partially filled with iron and passed the water through the by the iron precipitation method. An assay in- the year 1890 from Gagnon mine water, showed .0016 per cent or 28 lbs. copper per day. The mine was then opened to the 1,000 level.None of the mine waters encountered in the solid rock in the mines of Butte contained copper in sufficient quantity to produce the metal profitably by the iron precipitation method. An assay in the year 1890 from Gagnon mine water, showed .0016 per cent or 28 lbs. copper per day. The mine was then opened to the 1,000 level."

Jan 1, 1913

By AIME AIME

[The American Institute of -Mining Engineers does not assume responsibility for any statement of fact or opinion advanced in its papers or discussions.] A detailed list of the' papers contained in this section is given in the Table of Contents, pages i. and ii. Comments or criticisms upon all papers given in this section whether private corrections of typographical or other errors or communications for publication as "Discussions," or independent papers on the same or a related subject, are earnestly invited. ERRATA. The following corrections and. additions to papers contained in Bi-Monthly Bulletin No. 7, January, 1906,-were received too late for incorporation in the text of said papers ; but will be introduced in their: proper places: in the volume of the Transactions: These corrections are here published in order to bring them -promptly to the notice of the Institute. Page Line Cover, title-page and at the top of pages in the preliminary section "No. 1 " should be "No. 7 ". 1. Bottom For :" Dr. P. H. Shimer" read "Dr. P. W. Shinier " 69. Fig. 3. "N" of compass-record should be ?S". A new block for this illustration has been made as shown on p. xxxviii of this Bulletin. 78. 3 from bottom. For " slope " read " stope." 89. Fig. 2, small diagram in upper left-hand corner. Omit use 50 ft. to 1" scale ". For "Thro' 250 " read " Thro' 200 ". Add dotted line extend¬ing from upper right-hand corner of the square

Mar 1, 1906

Jan 1, 1970

By A. J. de Witte

INTRODUCTION The importance of determining dips of subsurface formations in wells, especially in wildcat wells, is self-evident and need not be enlarged upon. Various dipmeter instruments have been described in technical literature1,2,3,4 over the years. The introduction of the continuous dip-meters3,4 has made the earlier types obsolete. Continuous dipmeter logs are run by at least two different major service companies. Included as part of the service are a limited number of dip calculations—usually 10—made at different levels from the log. Very frequently this is the total result of a dip survey. It is believed that dipmeter surveys would be of considerably more advantage if geologists and engineers were able to make their own calculations from the original records. Determination of dips from the dipmeter record starts with the correlation of three log curves taken at different sides of the borehole. It cannot be over-emphasized that the quality of the results hinges primarily on this correlation. Nobody should be better qualified to correlate logs than a subsurface geologist or field engineer. The next requirement is to have an easy yet accurate way of computing the dip from the correlated points. Service companies use a mechanical device for this purpose. Directions for a graphical method were given in a recent article by B. 0. Prescotts. This paper describes a different graphical technique which, in our experience, is simpler, faster and at least as accurate. The entire manipulation is carried out on the stereonet in a number of easy moves. The paper is divided into two parts. This first part contains the introductory sections and full explanation of the geometry involved. The second part reviews the reading of data from an actual field log and summarizes the practical rules for computation of dips, the whole process being illustrated by an example. Following the outlined procedure, one could calculate a good many levels in a relatively short time, thus being able in particular to check suspected anomalies such as fault zones or unconformities in as close detail as the log will permit. GENERAL EXPOSITION OF THE METHOD Prnciple of the Dipmeter The position of a plane in space is defined by the location of three points, not on a straight line. Referring to Fig. I, if a borehole traverses a bedding plane, we can determine the strike and dip of the bed by finding three points which are not in line along this plane. Such points as A, B, and C are obtained with the dipmeter. The device consists of three electrodes (or caliper arms)1, 2, and 3 spaced at 120 angles, as schematically indicated, whose readings are separately recorded (Curves 1, 11, 111, to the right). When electrode 1 passes the boundary of the bed, Curve I will kick, etc. From these curves, we know the relative distances of points A, B, C, measured along the axis of the hole. If A is at zero, then B and C are at levels d1 and d2 up the hole,

Jan 1, 1957

By Arnulf Muan, R. W. Taylor

Activities of iron in Fe-Pt alloys have been dctermined by equilibrating mixtures of platinum metal and iron oxide at known oxygen Pressures in a thermobalance at 1300°C. Conzpositions and iron activities of the oxide phase at equilibrium are known from previous work, and compositions of the Fe-Pt alloy phase formed at equilibrium were detcvt?zined from the observed weight changes of the samples. The activity curve obtained shows a strow negative deviation from Raoult's law. THE present investigation was undertaken as part of a research program dealing with phase equilibrium relations existing among the oxides of iron and titanium at 1300°C. At low oxygen pressures of the gas phase in equilibrium with these oxides, the iron activity of the system is high, and considerable alloying of iron with the platinum used as a container material takes place. Thermodynamic data for Fe-Pt alloys at 1300°C are needed in order to evaluate quantitatively the extent of such reactions. Larson and chipmanlhave determined activities of iron in Fe-Pt alloys at 1550°C by equilibrating platinum metal with CaO-iron oxide-SiOzmelts in which the iron activities were known. Compositions of the resulting Fe-Pt alloys were determined by chemical analysis. Mundiath and Gerassimov2 have studied thermodynamic properties of Fe-Pt alloys by electromotive force measurements in the temperature range 550" to 1000°C. The experimental method used in the present investigation is a slight modification of that used by Grube and Ratsch3 in studies of NiCr-alloys. 1) EXPERIMENTAL METHOD 1) General. Mixtures of platinum metal and iron oxide were equilibrated at 1300°C in atmospheres of known oxygzn przssures, and the course of the reactions was followed by measuring the weight changes of the mixtures. The principles involved in the derivation of composition-activity relations from these measurements are illustrated by the composition triangle for the system Fe-FeZO3-Pt shown in Fig. 1. Take as an example a mixture of FeZO3 (hematite) and platinum such that the total composition is represented by point T. If this mixture is heated to 1300c in air (poz = 0.21 atm) and the oxygen pressure is then reduced gradually, the oxygen content of the oxide phase decreases and increasing amounts of iron enter the metal phase. As the oxide phase and the metal phase for all practical purposes are insoluble in each other, their compositions are represented by points moving toward Fe along the joins Fe-Fe,03 and Fe-Pt, respectively. The total composition of the mixture during this process also changes, but only with respect to oxygen content, because the vapor pressures of iron and platinum are negligible at 1300°C. Hence the change in total composition is described by a straight line (constant Fe/Pt ratio) radiating from the 0 apex of the composition triangle Fe-Pt-0, of which the triangle in Fig. 1 is a part. Only one such line ("oxygen reaction line", T-T",) is shown in Fig. 1. The total composition of the alloy-iron oxide mixture at any instant must, in addition, be located on the straight line (conjugation line) connecting the two points representing the compositions of the two coexisting phases. It therefore follows that the total composition of the mixture at any instant is represented by the point of intersection between the conjugation line and the oxygen reaction line. An example of the situation prevailing at a chosen oxygen pressure, po2, is shown in Fig. 1 by points a' (alloy composition), b' (oxide composition) and T' (total composition). Point b' is known from the work of Darken and Gurry,4 and point T' is experimentally determined by the observed weight change of the mixture (distance T-T). Hence, point a', the composition of the alloy, is determined from the above data as the intersection between the join Pt-Fe and the extension of the straight line bl-7'. The activity of iron in the alloy at equilibrium is identical to that of the iron oxide phase, if the same

Jan 1, 1962

Official Program

Jan 8, 1950