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By Thomas T., Read

IT will be recalled that the first professor of metallurgy in the United States, appointed in 1855, never really gave any instruction in metallurgy and gradually turned into a professor of mineralogy. Metallurgy was included with. mining in the early curricula, two students who took the B.S. in mining engineering from the Polytechnic College of Pennsylvania in 1862 wrote their graduation theses on the metallurgy of copper and zinc, respectively. Even after Columbia School of Mines established, in 1868, a separate curriculum leading to the Ph.B. degree in metallurgy, very few students elected it,* preferring to take the mining degree, since they received in its curriculum nearly all the metallurgical instruction they would have in the metallurgical curriculum. For many years a large proportion of the men who attained prominence in metallurgical enterprises had taken mining rather than metallurgical degrees. METALLURGY Clifton Sorby's study of thin sections of rocks under the micro¬scope, beginning in 1850, and its subsequent development by Zirkel and others, had made microscopic petrography a recog¬nized department of geological research as early as 1873. . It was inevitable that the idea of studying polished metal surfaces-¬under the microscope by reflected instead of transmitted light would occur to investigators. Sorby himself did it in 1864, and Adolph Martens and Floris Osmond may -be especially named among the many European workers who, by the late eighties, had so developed the, necessary techniques that they were able to photograph polished metal surfaces at magnifications as high

Jan 1, 1941

By J. A. Finch, R. R. Cunningham

The amount of foam volume generated in relation to the gas flowrate has long been used to define the foaminess of a solution and to characterize surfactants. The vessel geometry and gas flowrate range can affect the foam volume results. A fixed area column was tested alongside a variable area conical vessel with two surfactants. It was found that the fixed area vessel will cause foam volume to expand or contract which masks the effect of the surfactant. The conical vessel showed two regimes of foam volume production dependant on gas flowrate. The low gas flowrate regime revealed the physiochemical nature of the surfactant while a high gas flowrate revealed kinematic properties. Foaming properties of a surfactant is best determined with a variable area vessel at low gas flowrate.

Jan 1, 2009

By G. Simard, M. J. Gagnon, A. Charette, G. Péloquin

"In the Bayer process, flocculants are introduced in the feed well to enhance the aggregation of red mud particles. To gain a better understanding of the flocculation process taking place in the feed well, shearinduced flocculation was achieved using concentric rotating cylinders (Couette system). Our previous work has shown the effect of the shear rate on the aggregate’s settling rate and on residual turbidity of the Bayer liquor. In this study, the data demonstrated that the aggregates at selected shear levels appear as a population with a widespread size distribution. By using an imagery apparatus, it was possible to measure the size, the shape, and the sedimentation velocity of the larger red mud aggregates. Marked differences were noticed in the characteristics of the aggregate populations obtained under various shear conditions. IntroductionIn the Bayer process, red mud particles are separated from the liquor in primary clarifiers and washing circuits under the action of synthetic polymers. The agitation in the feed pipe and in the feed well affects the flocculation since the aggregates are formed by the interaction between the red mud particles and the polymers. A minimum shear rate is needed to initiate the aggregation process of fine particles (Warren, 1975).Different systems have been used to study the effects of shear on the flocculation process (Tampo and Watanabe, 1979; Klimpel and Hogg, 1986; Scott et al., 1996; Biggs and Lant, 2000). The Couette flow system has been used in some studies on shear-flocculation (Oles, 1992; Farrow and Swift, 1996a, 1996b). The importance of the physical properties of the aggregates in determining the efficiency of the solid-liquid separation process within a given gravity thickener has been demonstrated (Farrow and Warren, 1989a)"

Jan 1, 2002

By O. W. Ellis

CERTAIN alloys1 that, as a result of quenching, are retained in the form of homogeneous solid solution are known to increase in hardness and strength on standing at room temperature or on heating at slightly elevated temperatures. Other alloys" that, on rapid cooling, are held in the form of homogeneous solid solution (as, for example, certain steels) behave in like manner on heating to somewhat higher temperatures. The observed increase in the hardness and strength of these alloys, referred to as "aging" or as "secondary hardness," is widely accepted as being occasioned, either in whole or in part, by the precipitation in submicroscopic form of such constituents as were held in supersaturated solid solution as a result of cooling in excess of a certain critical rate. In earlier discussions of the cause of age hardening or secondary hardness, the question of the hardness of the precipitated particles does not appear to have been raised. At present, however, the general opinion appears to be that age hardening and secondary hardness are occasioned by the precipitation of hard particles within the supersaturated solid substance.3 The authors may be wrong in their belief that the last is a prevailing opinion. Nevertheless, it is thought that the following experiments,

Jan 7, 1924

By O. P. Arora, M. Metzger, G. R. Ramagopal

Single-phase aluminum containing 0.0001 to 0.06 pct Cu was studied in strong acid, mainly through observations of hydrogen evolution. The strong influence of copper was exerted almost entirely through the imposition after a certain delay time of an auto-catalytic localized-corrosiott reaction. Additions of cupric ion to the acid produced lower accelerations. The significance of the quantity and distribution of copper was discussed, and the implications for intergranular corrosion and neutral chloride pitting were indicated. AN investigation of intergranular corrosion in single-phase high purity aluminum exposed to hydrochloric acid indicated the copper content of the metal to have an influence on corrosion at lower levels than previously suspected.&apos; The work reported here was a closer examination of the action of copper but dealt with general corrosion to gain the advantage of having a continuous measure of corrosion through the volume of hydrogen evolved, the reduction of hydrogen ion to hydrogen gas being the principal or only cathode reaction in strong hydrochloric acid. Previous work on the hydrochloric acid corrosion of aluminum was sometimes insufficiently structure-conscious and the need for care in evaluating it arises from the low solubility of the iron impurity,&apos; and of some alloying elements, and the known or possible presence in many of the compositions studied of second phases leading to greatly increased corrosion rates.3 These increases are attributed to the presence of low hydrogen-overvoltage cathodes provided by the second phase.3&apos;4 For the present single-phase work, a few studies which used high-purity base material and small copper additions5-&apos; provide the essential information most unambiguously. The corrosion rate was shown to be increased markedly by the introduction into the acid of small quantities of the ions of copper (and of certain other metals) which cement on the aluminum and provide cathodes of low overvoltage.5 When there was sufficient copper in the aluminum, the same result was produced during the course of corrosion leading to a rate which increased with time as the reaction was stimulated by one of its products (autocatalytic reaction). In 2N (7pct) HC1, an accelerating rate was observed at 0.1 pct Cu but not at 0.01 pct.5,7 The present work dealt with corrosion rate and morphology and their correlation with the quantity and distribution of copper catalyst for copper contents from 0.0001 to 0.06 pct. PROCEDURE A lot of high-purity aluminum containing 0.0021 pct Cu, 0.001 pct Fe and 0.003 pct Si (Alloy A) was alloyed with copper to yield aluminum containing 0.014 pct Cu (B) and 0.06 pct Cu (C). Later it was found necessary to include the lower copper Alloy K which contained 0.0001 pct Cu, 0.0004 pct Fe and 0.0004 pct Si. The upper limit for any other element can be confidently estimated as 0.0005 pct. No element other than copper appears to be present in quantities sufficient to have an effect on general corrosion as great as the observed effect of the copper in A, B, and C. The only other heavy metal detected by spectrographic examination was silver (< 0.0001 pct). The acid was made up from a selected lot of 37 1/2 pct CP hydrochloric acid containing 0.1 ppm heavy metals (mainly Pb), 0.05 ppm Fe, and < 0.008 ppm As and from water distilled from 1 megohm-cm demineralized water and believed to have contained negligible quantities of heavy metals influencing corrosion. Acid strength was adjusted to within 0.05 pct HCl of the stated value by using precision specific gravity measurements. Test blanks 10 by 41 mm were sheared from 1.65-mm cold-rolled sheet. Edges were finished by filing. The blanks were annealed in air at 645°C for 24 hr in alundum boats and rapidly water quenched. The anneal is thought to have produced a substantially homogeneous solid solution—for iron, copper, or silicon, for example, the annealing temperature was 200°C or more above the solvus-and the quench is considered to have preserved the high-temperature structure except for the condensation of lattice vacancies into dislocation loops.&apos; The 0.06 pct Cu alloy did not appear unstable in respect to slow precipitation reactions at room temperature since two pairs of tests failed to show significant differences between specimens heat treated 3 1/2 years earlier and specimens heat treated 1 or 2 days before.

Jan 1, 1962

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace,4 the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is, although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By Jr. Babcock

The Pyke asbestos deposits were discovered by Kennecott Explorations (Australia) Pty. Ltd., in 1969 during the course of base metal exploration on the South Island of New Zealand. Extensive occurrences of chrysotile asbestos were found associated with the Red Mountain Ultramafics in the headwaters of the Pyke River, and to the north and south along the ultramafic belt for a distance of 70 kilometers. Surface evaluation and drilling by Kennecott in 1970 and 1971 identified numerous small deposits of good grade fibre in the Little Red Hills between the Pyke and Barrier Rivers. Additional drilling and three adits have been completed by other companies since that time. The property is presently held by Lime and Marble, Ltd. Of Nelson, New Zealand, and Kennecott Explorations (Australia) Pty. Ltd. This paper will present the regional and local setting of the asbestos deposits, including the geology and nature of mineralization. In addition, the exploration methods used by Kennecott in the discovery and evaluation of these deposits will be outlined. Subsequent work by other companies will be mentioned, but not described in any detail. This subsequent work did not alter Kennecott&apos;s conclusions or produce any serious changes in the interpretation of geology and mineralization. The author acknowledges the contribution of the many employees of Kennecott Explorations (Australia) Pty. Ltd., who have been involved in the project, particularly Ramon Farmer, N. G. Comer, and A. W. McConie, who were responsible for completion of field work and reporting on the project. The responsibility for the conclusions and interpretations of this report are solely that of the author and result from his involvement in discovery of the deposits and management of the exploration program.

Jan 1, 1978

By C. T. Holland

Coal mining has been an important industry in the Appalachian area for many years. This is particularly true in the northern part of the area, namely, in Pennsylvania, West Virginia, and Ohio. Also, in the south a great deal of mining activity has been carried on in Alabama, Kentucky, and southwest Virginia. Some of the by-products of this activity has been the production of mineralized water from the mines in copious quantitites. The southern Appalachians have been somewhat more fortunate in that the water there has had a considerable amount of alkalinity in it, which has to a large extent eliminated some of the more undesirable aspects of mine drainage. Northern Appalachia, including central and western Pennsylvania, the Monongahela basin in West Virginia, and the Appalachian area in eastern Ohio have not been so fortunate in that coals in those areas and the top and bottom rock have, in many cases, shown considerable quantities of pyrite, and the water does not carry the carbonates found farther south.

Jan 1, 1969

By Fabio Loyola

La planta de adsorción de carbón de Pampa Larga (CIC_PL) es la principal planta que contribuye a la producción de Yanacocha. Las pérdidas de oro ocurren a partir de la solución gastada que va a la planta de tratamiento de agua y luego se descarga al medio ambiente. Se identificaron dos oportunidades de mejora para lograr un mejor desempeño de la planta. Una oportunidad está relacionada con mejorar la adsorción de oro sobre el carbón en una solución con alto contenido de cobre. La otra oportunidad está relacionada con mejorar el control operativo de la planta de carbón, al usar el manual corporativo de carbón activado, como también aumentar la actividad del carbón y optimizar la cantidad de carbón en los tanques del circuito de adsorción.

Sep 29, 2023

By S. Ngidi

Palabora Mining Company operates a low grade underground copper mine situated in the Limpopo Province, South Africa. Full production was first reached in May 2005 after a successful transition from an open pit operation to an underground block cave operation. The operation faces a number of technical and operational challenges, not the least being fragmentation of a competent rock mass and external dilution. The cave is subdivided into three main sectors being the east, the west and the central sectors. Caving was initiated from the weaker central sector, which has the majority of its drawpoints located directly under the open pit bottom currently filled with about 130 million tons of waste material from the pit wall failure incurred in 2004. About 48% of the ore reserve has to be extracted from the western sector, which has a much courser fragmentation compared to the other two sectors and only 25% from the central sector with the finest fragmentation. The main constraint during the ramp-up stage has been secondary breaking of drawpoint blockages. Ground-breaking secondary breaking and cave management initiatives and practices have made it possible for Palabora to realize and sustain high production rates.

Jan 1, 2007

By Galen G. Waddell

The Deep Creek zinc and lead mine afforded an excellent example of a relatively small underground mine operation that approached the low mining costs of large, highly mechanized mines. An open stope mining method incorporating sublevel benches and vertical long holes was used (fig. 1). Detailed descriptions are given on the exploration program, stope development, stoping procedures, and pillar removal. Pressure grouting was used to check the inflow of water and thus prolong the life of the mine. Statistics on mining costs and on electric power consumption, haulage from mine to mill, and milling costs are included.

Jan 1, 1963

Consumption and intensity of use trends for 12 metals, by industrial end use, were estimated for 1972 through 1982 by the Bureau of Mines and U.S. Department of Commerce. The trends were then forecast through 1993 using standard statistical methods. The intensity of use measure selected is the quantity of metal consumed per constant dollar output of a specific industrial sector. The metals studied were aluminum, chromium, cobalt, copper, lead, manganese, nickel, the platinum-group metals, tin, titanium, tungsten, and zinc. Average annual growth rates for the following 4 of the 12 metals increased from 1972 to 1982 as follows: aluminum, 1.00%; platinum-group metals (consisting of platinum, palladium, and iridium), 8.83%; titanium, 7.82%; and tungsten, 6.09%. Consumption for the remaining eight metals decreased at average annual rates ranging from 0.58% (copper) to 5.37% (manganese).

Jan 1, 1986

By R. J. Gochin, M. A. Diaz

A modified Hallimond tube is described which allows the determination of the ultimate recovery R and the flotation rate constant k in a single, continuous experiment. The range of fine particles which can be satisfactorily floated with the modified apparatus can be extended by increasing the length of the bottom part of the tube. Findings suggest that pyrite and arsenopyrite can be separated in alkaline suspension using the so-called F series of collectors. Lime was found to act as a depressant. The collectors operate under pH and dosage control and do not require other depressants. Collectors used in the study were thio-amine (a cationic surfactant) and alkyl propionamide (a non-ionic surfactant)

Apr 1, 1995

By Luis Espinoza

La unidad minera Tintaya al igual que la Unidad Minera Antapaccay, son las operaciones de la división Perú de Xstrata Copper dedicados a la producción y comercialización de concentrado y cátodos de cobre. Sin embargo, la mina está en su última etapa de vida. En este sentido, surge el proyecto de integración de la unidad Antapaccay, donde se busca prolongar la vida útil de la mina y por consiguiente, el de la actividad económica minera en la provincia de Espinar. Por ello, el presente trabajo, describe los efectos de esta expansión de la explotación minera a través de la Unidad Minera Antapaccay que utiliza las instalaciones de Tintaya, manteniendo los planes de inversión social y el desarrollo económico local y regional.

Sep 21, 2013

By George Petersen G.

El siguiente texto describe la genealogía de la pegmatita, composición, precios y las regiones compuesta de este mineral en el litoral peruano. Las pegmatitas son rocas ígneas que se forman al enfriarse la magma, constituyéndose en un etapa de transición y sistema mixto entre los depósitos líquidos magmáticos. Su textura es de grano grueso y está asociada a las rocas ácidas como el granito y la granodiorita. De acuerdo a su genealogía se dividen en dos grupos: facies pegmatítico-magmática y enumatolítica. Las pegmatitas del litoral peruano contiene minerales no metálicos como ortoclasa, mica y cuarzo. Las zonas que comprenden mica son Matarani. Quilca y Atico (Arequipa), la zona de feldespatos se encuentra en Samanco (Chimbote), y la zona de cristal de roca y minerales radioactivos, en la región de Casma (Ancash).

Jul 20, 1961

By Krishna R. Reddy, Jyoti K. Chetri, Girish Kumar

Geotechnical engineering encompasses a major portion of the civil and infrastructure projects. The large amounts of energy and resources typically used in these projects leads to undesirable emissions and wastes which contribute substantially towards global environmental impacts (e.g., global climate change). This could further include secondary economic and societal issues which are often unaccounted in traditional engineering design of the geotechnical projects. In order to address this issue, it is imperative to integrate the broader environmental, economic and social implications into decisions of a geotechnical project. Recent years have seen a major impetus on life cycle assessment to evaluate the environmental sustainability of the geotechnical designs. However, there are no tools that can quantify the life cycle triple bottom line sustainability of potential design alternatives in a project with holistic considerations towards broader economic (indirect costs and benefits) and social impacts (stakeholder preferences, socio-environmental and socio-economic impacts). This study presents a new framework for quantitative assessment of life-cycle sustainability (QUALICS) for alternative designs in engineering projects. The framework integrates two multi-criteria decision analysis methods namely, the Integrated Value Model for Sustainable Assessment (MIVES) and Analytic Hierarchy Process (AHP), to support decision making on the potential design alternatives. In this study, a brief overview of the framework is presented. A case study demonstrating the use of QUALICS framework is discussed with its application to the sustainability assessment of two deep foundation systems, caissons and piles, over their design life. The technical designs of both systems are developed based on bearing capacity, both primary and secondary settlements, and structural integrity. The results from the sustainability assessment of the two deep foundation systems are discussed, and the most sustainable option based on different stakeholder preferences and site-specific conditions are identified.

Jan 1, 2019

By G. L. Simmons

Aqueous pressure oxidation at low temperature, although desirable from a process engineering and operations point of view, presents unique problems when temperatures approach 160°C (320°F). In developing the pressure oxidation process for the Lone Tree Mine, elemental sulfur formation and agglomeration with pyrite proved to be a problem. This paper discusses some of the unique features of the Lone Tree sulfide deposit and its amenability to low temperature oxidation. Problems encountered during pilot plant operation and their solutions are discussed.

Jan 1, 1993

By Joseph Gersic

MINFO has been developed to serve as a frontend for three databases created to store basic minerals information gathered during the minerals resource assessment conducted by U.S. Bureau of Mines(USBM) for the Malheur and Jordan resource areas of southeastern Oregon(MJRA). The primary database is the Minerals Location Inventory (MLI.DBF) which contains of information assembled from field work performed during this project, the USBM Minerals Availability System/Mineral Information Location System(MAS/MILS) database, the Oregon Department of Geology and Mineral lndustries(DOGAMT) Mineral Information Location(MILOC) database, and the U.S. (Geological Survey(USGS) Mineral Resource Database System(MRDS), In addition, assay results are contained in the geochemical database (ELEMENTS.DBF) and modified X-ray diffraction analysis information is contained in the minerals database (MINOR.M.DBF). MINFO includes four types of program modules: ? Enter/Edit Data was developed to allow the addition of new information and to encourage correction of errors by providing a convenient means of entering and editing data and a large degree of automatic checking and filtering of entries. ? ACAD/DBF Link links each site symbol posted on the map in the drawing file to a record in the database. This provides the user with the ability to use a mouse or other pointing device to graphically select a site for viewing and editing. Edits are performed directly in the database file, ? Reports contains 7 formats of data output for creating files for printing, transfer to other database formats, and exporting to other software packages such as spreadsheets and word processing programs. ? Maps includes 5 programs for creating AutoCAD script files which can be used to create maps of selected information in conjunction with AutoCAD. Mineral location mapping files derived from MLI.DBF can be created in 2 formats. Mapping files can be generated from each of the 2 sets of geochemical analyses contained in ELEMENTS.DBF. X-ray diffraction analyses can also be translated into instructions for creating and posting piecharts at sampling sites.

Jan 1, 1994

By J. M. D. Wilson

The literature relating to binders in iron ore pelletizing is reviewed from the point of view of their established or proposed bonding mechanisms in green and dry pellets.

Jan 1, 1981

In mining industries, materials loading and handling costs represent a significant component of the total (capital and operation) costs. A variety of methods have been applied in surface mine equipment selection in order to select the suitable loading and haulage system with the lowest total cost. The optimal size and number of equipment calculation are very important task for mining engineering because loading and haulage equipment are major proportion of open pit mining cost. Capital and operating cost are considered in objective function with respect to interest rate, insurance and tax in non-linear form. Shovel and truck annual productivity constraint, fleet matching constraint and number of truck per shovel constraint are incorporated in this optimisation problem with continuous variables. This formulation will yield total cost minimisation per hour and good accuracy compared to previous methods.

Dec 6, 2010