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The volumes of Transactions, which are published annually, contain the list of officers, rules, etc., the Proceedings, and the papers revised for final publication. (In this revision, after the preliminary publication, authors are permitted to use the largest liberty; and the changes and additions made in papers are sometimes important. It should be borne in mind by those who study or quote a paper in the preliminary edition, that they may not have in that form the ultimate and deliberate expression of the author's views. It should be added, however, that in the majority of cases there are no important changes.) These volumes are for sale as follows, in paper covers:

Jan 1, 1910

By Josefin Lannefors, Anders Klingberg, Natalija Gorochovceva

"Development of new anionic collectors becomes more and more important. This can be explained, on the one hand, by the fact that over the years phosphate ores have become more fine grained and complex (example weathered). On the other hand, a development with a focus on sustainability (sustainable development) of new anionic surfactants is required by authorities and society. Within the sustainable development several characteristics of a collector have to be taken into an account: efficiency, selectivity, froth characteristics, environmental profile, raw materials used for the synthesis, manufacturing complexity, stability upon storage, etc.Several anionic surfactants based on ester and amide chemistry were synthesized, characterized and used as flotation agents for calcium phosphate containing ore. The surfactants were used in a formulation together with other anionics, since in a pure form, during the flotation, they did not provide right froth characteristics.A new anionic collector/formulation was developed, that fulfills all above listed requirements."

Jan 1, 2014

The Perth Mint receives gold and silver from various sources for evaluation and refining. The metals are received in many forms and vary widely in assay. Refining is carried out using the Miller Process and the and the resulting market quality bullion is sold in a range of weights and alloys to suit the international bullion market and public demand. INTRODUCTION The Perth Mint was established in the late nineties as a branch of the Royal Mint, London, to refine the gold from the newly established gold- fields in Western Australia. The branch was opened for business in June, 1899. After refining, the bulk of the gold was used in the manufacture of sovereigns and half-sovereigns. Nowadays, although most of the gold received comes from the W.A. goldfields, some gold is deposited by producers in other states and in Papua-New Guinea, as well as scrap and trade wastes from manufacturing jewellers and old jewellery from the general public. Silver is deposited in the form of old silverware, recoveries from-photographic processes etc. Gold or silver may be lodged at the Mint in person, through a bank or other agency or by registered post. Telegraphic advice is usually given when gold is sent by the latter, so that insurance may be effected.

Jan 1, 1982

By A. D. Schwope, L. R. Jackson, A. M. Hall

In the course of an extensive investigation of the comparative properties of several types of copper, data were obtained on the cold working and subsequent recovery and recrystallization of the copper. In this paper, relations between the degree of cold work and the course of re-crystallization are developed. In particular, it is shown that the course of recrystallization over long periods of time and at low temperatures can be predicted with reasonable accuracy from short-time high-temperature recrystallization data. Materials Used in The Investigation Three types of copper were used in this investigation; these were tough pitch, OFHC, and OFHC copper with 15 oz per ton of silver added identified herein as Lots C, D, and F, respectively. The material was supplied by the American Metal Co. Ltd., and processed by the Rome Cable Co. The analyses of the three types of copper are given in Table I. Originally, it started as wire bars 4 X 4 X 54 in. These bars were heated to 871° C in air and hot rolled to % in. rod. This rod was cold drawn to 0.204 in. rod (70 pct reduction) in three passes and annealed at 427°C for 4 hr. A portion of the 3/8 in. rod was saved for more detailed cold-drawing experiments. Starting with the annealed 0.204 in. rod, hard-drawn wires were produced by cold drawing to 0.081 in. wire in 7 passes (84.4 pct reduction in area). Half-hard wires were made by cold drawing the 0.204 in. rod to 0.102 in. wire, (75 pet reduction) in 6 passes and annealing at 427'C for 4 hr. This annealed wire was then drawn to 0.081 in. wire, (37.1 pet reduction) in 2 passes. Square rod was made by hot rolling wire bars to Re in. rod in 8 passes. This rod was then cold drawn to 0.445 in.-diam rod and annealed for 346 hr at 538°C. It was then cold drawn to 0.325 in. rod and again annealed at 538°Cf or 3 1/2 hr Hard square rods were then made by cold rolling this material to 0.257 X 0.257 in. rod, a reduction in area of 20.5 pct. Half-hard square rods were made by cold rolling to 0.268 x 0.268 in. square, annealing for 3 1/4 hr at 538°C and cold rolling to 0.257 x 0.257 in., a reduction of 8.5 pct. Soft wire or rod was made from all types of copper by annealing the hard-drawn material at 343°C for 3 hr in steam. The grain size of the annealed 0.081 in. wire varied slightly among the three lots: from o.o15+.oz5 mm in the silver-bearing OFHC to 0.035-0.045 mm in the OFHC copper. The annealed 0.257 in. wires were more uniform in grain size, averaging about 0.035-0.045 mm. Representative structures are shown in Fig I. Effect of Cold Drawing and Tensile Strain on Strength of Copper Conventional tensile tests were performed on the three types of copper in the various degrees of hardness described above. Results of these tests are tabulated in Table 2. The results in Table 2 are 6

Jan 1, 1949

TUNGSTEN occupies an outstanding position amongst metals to-day, for by its use modern manufacturing methods have received a wonderful impetus. The important part played by tungsten in the recent war is not generally recognized. It was tungsten steel, in the shape of highspeed tools, that kept our soldiers supplied with munitions of war at more than one critical period. Tungsten added the necessary hardness and durability to various metals which were indispensable for carrying the war to a successful conclusion. In the words of...

Jan 1, 1921

By D. E. Severson

The coal solution refining process under investigation is basically a modi¬fication of the German Pott-Broche Process, on which patents date back to 1927, (5, 6). This process was used in Germany during World War II for the partial dissolution of coal in hydrocarbon solvent and removal of the ash by filtration to produce a raw material for carbon electrodes for aluminum plants. At the end of World War II the German synthetic fuel program, of which this process was a small part, was abandoned as not economical. In recent times the whole field of coal liquifaction has been given a new impetus; present technology indi¬cates that the economic processing and refining of coal may be possible in the United States. A number of approaches to coal liquifaction have been investigated, and several of these are currently being funded by the U. S. Office of Coal Research. One approach is direct thermal treatment of the coal as in the FMC Project COED, in which coal is thermally cracked to produce gas, liquid products and char. Another approach is the Hydrocarbon Research Institute's H-coal process in which coal is catalytically hydrogenated. Two other federally funded projects involve the extraction of coal by solvents. The Consolidation Coal Company's Project Gasoline, now in the pilot plant stage in Cresap, West Virginia, is an attempt to produce gasoline plus a residual char by partial solution of the coal substance. The coal de-ashing process being developed by the Pittsburgh and Midway Coal Company is a modification of the Pott-Broche process. Coal derived solvent is used with hydrogen to dissolve the entire coal substance, subsequent filtration removes the ash and the solvent is recovered for recycling.

Jan 1, 1968

By M. Barkhudarov

The results are presented of research aimed at validation and development of a general purpose CFD code FLOW-3D. FLOW-3D is a commercial code developed by FLOW SCIENCE, INC. A number of physical modeling experiments involving the filling of cavities of different geometries with coloured water have been performed in order to compare the measurements with the results of computer simulations. Other numerical calculations were also done to be compared with the known analytical solutions.

Jan 1, 1992

By F. Keller, A. H. Geisler

Some of the important changes that take lace in the structure of aluminum alloys are largely submicroscopic in character. This is especially true of the changes that accompany age-hardening and recrys-tallization. Although improved metal-lographic practices have been helpful in indicating some of these changes indirectly, results are limited by the resolving power of optical microscope lenses. The electron microscope, however, provides a new and important means for investigating the fine structure of metals in a range not possible heretofore. It is anticipated that this microscope will yield new and useful information to metallurgists when suitable techniques are developed to utilize its very high resolving power. Several unique methods have been devised to permit the examination of the structure of opaque samples by the electron microscope. These are all based 011 the principle of producing a very thin film that represents the prepared surface of the opaque metal sample, which can be examined in the transmission microscope; however, the available methods fall into three categories, depending on the manner in which the film is obtained. With the oxide-film method developed by Mah13-l7 a very thin surface layer of the metallographic sample is converted into oxide by a thermal, chcmical or anodic treatment. .After removal from the metal sample by one of the special techniques described by Evans,l9 this oxide film is examined in the electron microscope, and is found to portray the structure of the original metal surface. Films formed on aluminum,8,l7 nicke1,7 iron3,8,9 and a nickel-beryllium alloyl1 by heating; films formed on iron8,9 by chemical action; and films formed on aluminum3-'" by anodic oxidation, have been examined. The other two are more recent methods developed principally in this country; they consist in making the thin film in the form of a mold or replica of the surface contour of an etched sample. With the negative replica method the thin film is made directly on the sample; with the positive replica method it is made on a negative reproduction of the sample. With both methods, variations in the contour of the metal sample, caused mainly by etching, produce variations in the thickness of the surface replica. Because of the direct dependence of the amount of scattering of the illuminating electrons upon the thickness of the film penetrated, only the variations in thickness of the replica are responsible for tones in the electron image. Negative replicas are made by forming a thin film of some suitable material directly on the polished and etched metal sample, and derive their name from the fact that after removal from the sample they have the high and low points in the sample reversed, as shown in Fig. I. Nega-

Jan 1, 1944

By K. C. Vincent

In the course of, investigation of domestic manganese-mineral occurrences, examining engineers of the Bureau of Mines collected 2-ton lots of ore from properties in the Cleveland-district, Idaho. As only one of the ores was high enough in grade for direct marketing to-producers of ferromanganese, ore-dressing concentration methods were investigated to determine their amenability to treatment. High-grade ore. (38.7 percent Mn) from the Idaho Manganese Mining Co. was taken from a replacement deposit in limestone consisting of several horizontal beds 1 to 5 feet thick, about 1 mile northeast of Cleveland. The manganese minerals occur as an intimate intergrowth of manganese oxides, containing minor amounts of limonite, ?quartz, and calcite as rather fine inclusions. However, the major contaminants are claylike products of rock decomposition, which can be eliminated by thorough washing of the ore at relatively coarse sizes. The Hot Spot property is 1 mile south of Cleveland. The ore occurs as a replacement deposit of medium-grade- ore in limestone, .The sample taken by the Bureau of Mines assayed 26.0 percent Mn. The manganese minerals consist of nodules, principally pyrolusite with some psilomelane and manganite embedded in wad.' The low-grade wad, containing manganese and siliceous minerals in intimate association, was easily rejected by washing.

Jan 1, 1952

By C. M. Rule

High pressure grinding rolls (HPGR) technology has come a long way in its application for comminution duty in hard rock mineral processing in the last three years. Several major projects in copper, nickel, gold, molybdenum, platinum, and iron ore have opted for this technology. Advances in wear abatement technology have established the HPGR as a reliable machine with the required high utilization and availability. The HPGR captures the imagination as the next step change improvement in ore processing, based on the following benefits: ?Energy efficiency (potentially 10?30% more efficient)?very topical in an increasingly ?green? society, and in times of rapidly increasing energy costs and availability concerns. 2008 has shown this to be especially important in Southern Africa ?High (and stable) throughput with a relatively small footprint ?Lower operation cost ?Liberation benefits ?Creative ?mine-to-metal? system improvements made possible by HPGR. The platinum industry, renowned for its historically conservative approach, has not been left behind with two significant new HPGR installations, one in Platreef application and one in UG2 application, commissioned in 2008. While the decision for the Platreef application was driven primarily by comminution circuit capacity and design imperatives, the UG2 application seeks to develop a flowsheet that will have a significant recovery benefit in addition to capacity increase and reduced operating cost. The Platreef application of HPGR also provides the opportunity to introduce a novel comminution flowsheet and to demonstrate exceptionally low wear rates treating very hard, abrasive and variable ore types. The HPGR lends itself for inclusion in existing SABC circuits to increase the capacity of the plant and mills. With current PGM prices many operations are attracted to the HPGR technology benefits. The HPGR clearly has the potential to transform entrenched opinion and provide decision makers with significant alternative comminution options. This paper aims to provide an overview of the current applications and to speculate on the transforming stimulus that the HPGR exerts on industry.

Jan 1, 2009

By Ram Song, Yohei Harada, Shinji Kumai, Kazuho Otsuka

"Recently, vertical-type high-speed twin-roll casting (HSTRC) has been developed. The HSTRC shows extremely high cooling rates over 1,000 K/s even at the mid-thickness area. The fabricated strip has many metallurgical characteristics; super-saturation of alloying elements, fine solidified structure, and homogeneous distribution of fine constituent particles. In Al-Mn based alloys, the Mn alloying element can be supersaturated in the a-Al matrix and also form Mn-containing constituent particles during solidification. The Mn supersaturation and the distribution of primary/secondary particles in cast products affect the metallurgical behavior in the down-stream processing and can improve mechanical properties of the final products. In this study, Al-Mn based alloy strips were fabricated by HSTRC with various Mn contents. The solidified microstructure, constituent particles and its distribution, and Mn solubility were investigated in the as-cast condition. Due to the high cooling rate of HSTRC, fine constituent particles were homogeneously distributed, and coarse intermetallics were not observed. Mn solid solubility was estimated by electrical conductivity. The estimated Mn solubility was equivalent between strip surface and mid-thickness area.INTRODUCTION Al-Mn based alloys, as non-heat treatable wrought aluminum alloys, are widely used in packaging and heat exchanger for automobile industry. Besides Mn, Al-Mn based alloys often contain Fe and/or Si as alloying elements or natural impurities. During solidification, Mn can be super-saturated in the Al matrix, and also form Mn-containing constituent particles. Additionally, in the subsequent thermal-mechanical processes such as homogenization, rolling, and intermediate annealing, Mn in solid solution precipitates out of the Al matrix as secondary particles. The size, distribution, type, and the amount of dispersoids including constituent particles affect to texture evolution, recrystallization behavior, and final mechanical properties of wrought Al-Mn based alloys (Huang et al., 2016; Huang & Marthinsen, 2015; Engler et al., 1995; Muggerud et al., 2013). Therefore, controlling the initial level of Mn super-saturation and the distribution of constituent particles are important in the cast Al-Mn based alloys."

Jan 1, 2018

By R. V. Higgins

Tarner (1),3/ Muskat (2), and Schilthuis (1) have presented methods of calculating oil recovery by the expansion of dissolved gas with and without return of gas to the reservoir. Although electronic computers have eliminated the tedious and time-consuming calculations (4) required by each of these methods, many petroleum engineers do not have access to electronic computers. For these engineers a short method is presented that uses the Tarner method as a base. Moreover, for engineers who have access to computers and have not as yet prepared a program, the short Tamer method requires less computer time than the long iterative methods. In the proposed short method, no plotting of the calculated data is required to determine a point of intersection described in the original Tarner presentation, as only one calculation is needed to determine the value sought, or two calculations if greater accuracy is desired.

Jan 1, 1960

Jan 1, 1957

[University of Alabama University, Alabama Mining and Metallurgical Society Meets first and third Mondays each month WILLIAM L. ALLMAN, President L. M. LOTOTZIY, Secretary J. R. CUDWORTH, Faculty Sponsor RICHARD L. BOWRON, Counselor University of Arizona Tucson, Arizona Miners' Society HARRY GARRETT, President AL WALLACH, Secretary A. J. THOMPSON, Faculty Sponsor E. D. GARDNER, Counselor Birmingham-Southern College Birmingham, Alabama Geology Journal Club WALTER WOLF, President LELAND CULLIGAN, Secretary R. S. POOR, Faculty Sponsor A. J. BLAIR, Counselor]

Jan 1, 1940

By W. H. Smith

IN connection with some recent work on the effect of impurities on the ductility of chromium, it appeared desirable to know the solid solubility of carbon in chromium. A literature survey indicated that this information was not available. Although considerable work has been done on the Cr-C phase diagram,&apos;.&apos; previous investigators have been more concerned with the structure and phase boundaries of the carbide phases than with the terminal solid solution. The phase diagram shown in Fig. 1 is taken from the work of Bloom and Grant&apos; and represents the most recent determination. As indicated by the dashed line, the a solid-solubility limit was not determined. Experimental Procedure Alloys of chromium were prepared from hydrogen-treated and vacuum-degassed electrolytic chromium plus spectrographic grade carbon. The oxygen and nitrogen content of the alloys was <0.002 pct. After melting, analysis of the alloys showed them to contain 0.02, 0.08, 0.15, and 0.55 pct C. Pieces of the alloys were heated in a protective atmosphere to various temperatures and then quenched after holding for a time sufficient to insure equilibrium. Microscopic examination of the as-quenched alloys for the presence of a second phase was used as a measure of the solubility limit. The heats were made in a multiple hearth arc-furnace using a zirconium-gettered static argon atmosphere. A zirconium melt was made before each Cr-C heat. Triple melting was used to insure ingot homogeneity as shown by microscopic examination. The alloys were prepared by adding portions of a 4.5 pct C-Cr master alloy to high purity chromium. The carbon contents listed previously were those obtained by analysis. The nitrogen and oxygen contents after arc melting were both <0.002 pct. Sections 1/8X1/4X1/2 in. were cut from the 100-g ingots and a hole drilled in one end in order to suspend the sample from a molybdenum wire. After the surface was carefully cleaned, a sample of each melt was hung in a mullite tube heated externally by a platinum resistance furnace connected to a vacuum system. The lower portion of the mullite tube was sealed to Pyrex and closed off several inches below the furnace. This was filled with sili-cone oil kept cold by circulating cold water around the outside of the Pyrex. Quenching into the oil bath was achieved by melting a fuse wire supporting the sample. It required about 4 sec for the sample to cool from 1400" to 600°C. This severity of quench was considered satisfactory to freeze-in the high temperature equilibrium. For tests made at temperatures of 900" to 1200°C, heating was done in vacuum; for tests above 1200°C, an argon atmosphere was used. The holding time employed ranged from 12 hr at 900°C to 6 hr at 1400°C. Experiments were performed at temperatures of 900°, 1000°, 1100°, 1200°, 1300°, and 1400°C. Microscopic examination for evidence of a second phase was done at X1500. Experimental Result The microstructures of a 0.08 pct C-Cr alloy as-cast and after quenching from 1300°C are shown in Figs. 2 and 3. A 0.15 pct C-Cr alloy quenched from 1300°C is shown in Fig. 4. The data obtained from the quenching experiments is shown graphically in Fig. 5. If the Van&apos;t Hoff equation is obeyed, a plot on a logarithmic scale of the mol fraction of solute vs the reciprocal of the absolute temperature should give a straight line. For dilute solutions the weight percentage can be substituted for the mol fraction without introducing any appreciable error. The Van&apos;t Hoff equation can then be written as where H is the heat of solution in calories per mol. The slope of the straight line on the log pct C vs 1/T plot gives the value of AH. Assuming that the Van&apos;t Hoff equation is obeyed, which is probably justified for the dilute solution of carbon in chromium, the heavy straight line shown on Fig. 5 represents the best fit of the data. This line was obtained as follows. On Fig. 5 the results of the microscopic examination of all alloys following quenching were plotted and designated as to whether one or two phases were seen. Below 1100°C all alloys showed a second phase on quenching. The heavy vertical lines shown in Fig. 5 therefore represent the possible range of the ter-

Jan 1, 1958

By Nick Barton

The ability to estimate that support is unnecessary for various dimensions of opening in certain rock mass environments is of particular relevance in the mining industry, where most excavations are not expected to remain open indefinitely. As Hoek1 observes: "the basic aim of any underground excavation design should be to utilize the rock itself as the principal structural material, creating as little disturbance as possible during the excavation process and adding as little as possible in the way of concrete or steel support". Approximately two hundred case records have been analysed for the purpose of determining the amount of permanent support normally used when a given span is excavated in known rock mass conditions Some thirty cases concerned unsupported openings. Excavations that can stand unsupported appear to have certain common characteristics as regards rock mass quality. However, the mechanical properties of the rock mass are not the only factors controlling the choice of design. The dimension of the opening (span or height) and the type of excavation are two important variables.

Jan 1, 1975

By C. Burton Clark

The important role of the petrographic microscope in the petrology of refractories is discussed, based on 45 years of industrial experience by the author. Highlights of his career are used to illustrate improvements in equipment and techniques during the period. Two specific investigations are described which emphasize the interrelated use of the petrographic microscope with other instruments such as the x-ray diffractometer and scanning electron microscope. Emphasis is placed on the use of phase equilibrium diagrams for guidance in predicting and interpreting reactions that occur under non-equilibrium conditions in the manufacture and use of refractories.

Jan 1, 1982

By Jesús Ylazaca

El presente trabajo describe el método de control de calidad del mineral o el denominado "Ore control", realizado en la unidad minera Yauli, cuya finalidad es maximizar el valor del mineral minado para lograr una mayor rentabilidad. En este sentido, el "ore control" es la gestión que optimiza las diferentes etapas de la exploración, explotación y concentración del mineral para lograr una buena calidad de producto (concentrados), a fin de satisfacer las necesidades del cliente. Los controles involucran a la Gerencia y el total de supervisores y trabajadores de operaciones, quienes deben ser proactivos ejecutando acciones preventivas más que correctivas.

Sep 12, 2005

In the USA, the National Institute for Occupational Safety and Health (NIOSH) does a lot of work and has provided news of interesting new developments. Marcia L. Harris describes an ?Explosibility Meter: ?In underground mines, coal dust explosions are prevented by the addition of rock dust sufficient to render the coal dust inert. Federal [US] regulations require 65% and 80% incombustible content in samples taken in intake airways and return airways, respectively, assuming a nominal coal dust size of 20% minus 200 mesh. The Coal Dust Explosibility Meter (CDEM), a hand-held instrument developed by NIOSH uses optical reflectance to measure the explosibility of a rock dust and coal dust mixture.? The CDEM is now commercially available. It provides real-time results during rock dust surveys instead of waiting weeks for laboratory results1. ?With real-time results, the potential for a disaster can be mitigated immediately. The CDEM displays the percent incombustible content as well as a colour indicating the relative explosibility of the coal and rock dust mixture. A red read-out indicates that more incombustible material is required to inert the coal and rock dust sample, while a green read-out indicates that the dust sample is sufficiently inert. When the mixture is marginally explosible, a yellow read-out is indicated. The red-yellow-green output depends upon the particle size distribution of the rock and coal dust mixture with the finer size fraction being more explosible.?

Jan 1, 2008

By G. Sachs, E. J. Ripling, S. I. Liu, J. J. Lynch

It is a generally recognized fact that by repeated straining the fracture stress of any metal is reduced to a fraction of its value for static loading. The value of this fatigue strength depends upon numerous factors, such as the states of strain and stress, the limits of straining, and the number of repeated loadings or cycles The large volume of previous investigations on fatigue is concerned entirely with large numbers of cycles, say exceeding 10,000 and up to 500,000,000. However, the changes in fracture stress and fracture strain occurring after a small number of repeated loadings have attracted little attention. Apparently the only investigations of this type are those byLudwik4.5 who subjected steel, copper, and aluminum wire to repeated torsion. In each test the torque was varied between identical values in the two directions of twisting. Depending upon the magnitude of the moment, fracturing occurred after a number of cycles, up to 10,000. The results of Ludwik&apos;s tests will be discussed later Such torsion does not readily yield actual stress and strain values. Therefore a pre- liminary study was made of the effects of repeated direct stresses, that is, tension and compression stresses. Because such tests are considerably more tedious than torsion tests, only high stresses were used in the preliminary work, yielding definite changes in metal properties after a few cycles. It was found in these tests that strains could be controlled more readily than stresses in the investigated range of high stresses. This paper, consequently, deals with the effects of strains of equal magnitude but different signs. The metal was first prestrained in static tension by a certain amount then subjected to compression to yield the same amount of strain after unloading. This loading cycle was repeated up to a maximum of seven times. After various cycles, the stress-strain curves in tension were determined, up to fracturing. As material for these tests, the aluniinum alloy 24ST was selected because it exhibits a comparatively small amount of necking in the tension rest This alloy permitted, therefore rather accurate cont.rol at the high strains necessary to produce fatigue failures at less than seven cycles. The results of this invest~gation appear sufliciently interesting to extend the method of attack in various directions It is intended to study (11 the effects of cycles up to a tew thousands and (2) the effects of strains of different magnitude in tension and compression respectively &apos;The latter variable also includes a. a special case the effects of compressive strains.

Jan 1, 1949