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By John D. Sullivan

A DISCUSSION of the developments of the past decade in the field of refractories, and the effect of these developments on the performance and life of open-hearth furnaces, is perhaps best introduced by reference to Fig. 1. This shows the most important types of refractories doing into various parts of the furnace, together with their cost, and remarks on their use. It has been estimated that half of the refractory makers market comes from the iron and steel industry, and something like one-third of all refractory brick used finds its way into open-hearth furnaces. To melt steel, a furnace capable of withstanding temperatures close to 3000 deg. F. is required. The furnace is assembled of various refractory materials selected by experience and economic considerations. Furnace structures today, from a refractory standpoint, are considerably different from a quarter century ago. Furnace operators, interested in the performance of refractories, care little how they are made or where they come from so long as they give reasonable service. But, the entire history of the refractory is important and technical knowledge of the ceramic materials used in making the refractory is necessary to the manufacturers, so that the proper article gets into the hands of the ultimate consumer.

Jan 1, 1936

By Kazutoshi Haga, Batnasan Altansukh, Atsushi Shibayama

In this study, the dissolution behavior of copper and arsenic from five different copper concentrates containing 21-34.7 %wt. of Cu, 1.3-7.3 %wt. of As and 15.6-27.5 %wt. of Fe were investigated under high pressure oxidative leaching conditions. Leaching experiments were conducted using different leaching reagents such as ferric sulfate, sodium chloride, deionized water, sulfuric acid and ferric sulfate-sodium chloride mixture in order to compare the effectiveness of each on the dissolution of copper and arsenic from copper concentrates. The effects of ferric sulfate (0.1-1 mol/L), sodium chloride (0.1-0.5 mol/L) and leaching temperature (100-180C) were investigated under 1 MPa autoclave pressure , particle size >45 m, pulp density of 100 g/L, stirring speed of 750 rpm and leaching time of 60 min. Results showed that the most effective leaching reagents for the dissolution of copper are 0.34 M NaCl and a mixture of 0.1 M Fe2(SO4)3 - 0.34 M NaCl, in which As extraction did not exceed 7%. The copper concentration in the pregnant leach solution obtained after leaching using 0.1 M Fe2(SO4)3 - 0.34 M NaCl was 13-30 g/L, while the concentration of As and Fe were in a range between 0.3-1 g/L and 0.2-10 g/L at 160C. INTRODUCTION Copper sulfide minerals, such as chalcopyrite (CuFeS2), chalcocite (Cu2S) and covellite (CuS) are used for the production of copper in mining and metallurgical industries worldwide. The conventional pyrometallurgical processing followed by electrorefining is a common process for the production of high purity copper (Moskalyk, & Alfantazi, 2003; Padilla, Aracena, & Ruiz, 2012). However, the degradation of copper content and an increase in the amount of metal impurities, especially arsenic (As), antimony (Sb) and bismuth (Bi) in copper concentrates cause serious problems to the production of copper and environmental pollution (Basha, Selvi, Ramasamy, & Chellammal, 2008; Long, Peng, & Bradshaw, 2012). Hydrometallurgical processes are used to recover metals from refractory ores, concentrates and tailings by leaching (Long, Peng, & Bradshaw, 2012; Masloboev, Seleznev, Svetlov, & Makarov, 2018). During the last decades, hydrometallurgical processing for the recovery of copper from enargite-bearing copper ores and concentrates has been extensively investigated due to its relatively more environmentally benign and less capital costs than the conventional pyrometallurgical processes (Long, Peng, & Bradshaw, 2012; Masloboev, Seleznev, Svetlov, & Makarov, 2018; Choubey, Lee, Kim, & Kim 2018). However, several issues facing the hydrometallurgical processing are incomplete extraction of copper associated with the coprecipitation of iron compounds, difficult stabilization of toxic impurities and production of a contaminated copper product (Dreisinger, 2003; Safarzadeh, Moats, & Miller, 2014). Hence, a number of studies have been conducted on the selective dissolution of copper from copper ores and concentrates or selective removal of arsenic leaving a clean copper residue using various leaching reagents or lixiviants (Safarzadeh, Moats, & Miller, 2014; Mihajlovic, Strbac, Zivkovic, Kovacevic, & Stehernic, 2007; Tongamp, Takasaki, & Shibayama, 2009). More extensive studies on the selective extraction of copper from enargite- bearing copper ores and concentrates are much needed to improve copper recovery.

Jan 1, 2019

By María del Rosario González Moradas

El presente texto describe diversas técnicas de teledección como métodos para determinar alguna de las variables utilizadas desde el punto de vista geotécnico y que permiten una clasificación de los macizos rocosos. La metodología se ha basado en la búsqueda de las bandas más ventajosas a las combinaciones más adecuadas para la determinación de cada una de las variables geotécnicas citadas a través de las imágenes landsat 5 de dos épocas diferentes.

May 1, 2017

By Hongfa Hu, Stavros A. Argyropoulos, Stephan Ferenczy

"Physical as well as mathematical modeling was carried out to investigate the exothermic mass transfer in liquid metal systems. In these systems, the exothermicity induces unique heat, mass and momentum transfer phenomena. Moreover, these phenomena are deeply coupled and they are further complicated by the presence of a moving boundary.In the physical model used, ice cylinders were immersed into sulfuric acid solutions, because the intermixing of ice with sulfuric acid is very exothermic. In this low temperature system, velocity and temperature measurements in the sulfuric acid were made as well as measurements of the ice melting in the sulfuric acid.The mathematical model developed solved simultaneously the heat, mass and momentum equations numerically, utilizing the control-volume finite difference approach. The enthalpy method was adopted to track the moving boundary. Predictions made by the mathematical model were in close agreement with the results obtained by the physical model.The results from the mathematical model were further validated with experiments involving high temperature liquid metals. Specifically, data were obtained in an experimental setup involving (a) dipping silicon cylinders into high carbon liquid iron and (b) dipping nickel cylinders into liquid aluminum. Results from these experimental studies supported the predictions of the mathematical model."

Jan 1, 1999

By Enrique Hauser

Discussion of the paper of ENRIQUE HAUSER, presented at the New York meeting, February, 1916, and printed in Bulletin No. 110, February, 1916, pp. 521 to 534. GEORGE A. BURRELL, Pittsburgh, Pa. Mr. Hauser determined the influence of inert gases on the properties of fire-damp mixtures, and one might take some issue with his work on the effect of hydrogen, on those mixtures. It is valuable information to have, but as far as the practical application of it goes, it is not of much significance, because one does not find it in mines, at least not in any appreciable amount. The same Fig. 1.-APPARATUS FUR DETECTING COMBUSTIBLE GASES IN AIR. thing can be said of ethylene. Ethylene is formed in considerable quantities as a product of heat reaction, but normally, in the coal mines, as a result of a great many analyses we have made at the Bureau of Mines, we cannot say that ethylene is a combustible gas found in the fire-damp in coal mines.

Jan 5, 1916

By E. H. BURROUCHS

This bulletin is the third of the series of yearly petroleum bibliographies being published by the Bureau of Mines. The two preceding, Bulletin 149 and Bulletin 165, were for the years 1915 and 1916, respectively. In arranging the references the same general scheme has been followed, but as in those bulletins, several changes and additions have been made in the classifica.tion, the more important being in the classes " Development and production " and "Refining and refineries." German periodicals for 1917 were not procurable and references to articles in those and in other foreign journals that were not available have been credited to the sources from which they were procured.

Jan 1, 1920

The rocks of Waihi and the surrounding district are almost entirely rhyolitic and ande5itic in character. Sedimentary rocks, with the exception of some surface deposits of clay loosely compacted conglomerate, etc., and one or two thin and broken beds of a very poor lignite, occasionally changed by igneous agencies into a bituminous coal, are almost absent. In the shafts sunk by the Waihi and Grand Junction companies outside the outcropping andesitic area of the Martha Hill, more than one old surface or lake bottom has been passed through. At these points layers of sand, consolidated volcanic mud and tuff, accompanied by numerous broken fragments of imperfectly silicified wood have been enccuntered, but these occurrences may, for the purpose of this paper, be neglected.The youngest rock of the district are rhyolites, probably of Pliocene age. At least three distinct classes of rhyolitic lava, each possessing features of unusual interest, may be made out. None of these, however, is gold-bearing. The youngest flow, a light-coloured, fine-grained rock, is remarkable owing to its enclosing at times fragments of carbonised wood, varying in size from mere specks up to quite large pieces of almost pure charcoal. Rhyolitic tuff is also met with. The rhyolites cover a large extent of nearly flat country east, south, and west of Waibi, here and there rising into barren, stony hills.Below the rhyolites, geologically speaking, but for the most part. forming hills which bound the rhyolitic plain, or rise out of it as isolated patches, come ahdesites of older...

Jan 1, 1902

By SME SME

NORTH AMERICAN TUNNELING 2024 PROCEEDINGS

Jun 23, 2024

By John Marsden, Mike Botz

A variety of modeling techniques can be utilized to forecast metal production at heap leaching operations. These approaches reflect a wide range of complexity, flexibility, time to implement, cost, and accuracy. For many operators, a spreadsheet-based modeling technique is attractive since the calculations are directly accessible, models can often be developed by site staff, and the results are generally easy to extract and interpret. The authors have developed a spreadsheet-based modeling technique that provides a high degree of flexibility, while still considering detailed operating information for ore properties, leach kinetics, scaleup factors, lift height, and in-heap metal inventories. The technique involves establishing kinetic leach curves for each ore type to characterize metal extractions, followed by application of separate metal recovery curves to define the rate at which leached metals exit the heap in pregnant solution, taking into account delays due to the in-heap solution inventory. At any point in time, the difference between total metal extracted and total metal recovered is equal to the in-heap inventory of the leached metal. This modeling technique is particularly useful for larger multi-lift heaps where delays in metal recovery are appreciable due to in-heap solution holdup. The technique is also applicable to sites with multiple heaps, leach cycles, and/or metal recovery plants (e.g., carbon columns for gold; solvent extraction for copper). This paper describes the modeling technique, including input data required and methods for defining kinetic leach curves and metal recovery curves. The technique is compared against an alternative spreadsheet technique using a simplified in-heap solution inventory calculation to forecast metal production, which has proven to be effective at a number of sites.

Sep 3, 2019

[RALPH ADAIR Ore Dressing Consultant Bull Mtn. Rd., Asheville, N. C. Phone 4-1693 JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists It Broadway New York 4, N. Y. I. R. BERENT Engineering Consultants and Contractors Mineral Exploration, Mine Evaluation, Mine Designs and Mine Management 156, Ataturk Bulvari-Ankara, Turkey BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 8 Howard-Canfleld Bldg. Santa Barbara, Calif. COWIN & CO. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction I-lath St. S. W. B'ham, Ala., Phone 56-5566 MILTON H. FIES Consulting Engineer Rooms 1201-2. Albama Power Co. Bldg. Birmingham, Alabama]

Jan 1, 1952

By George P. Demopoulos, Nima Parsi Benehkohal, Marianna Uceda

Lithium-ion batteries (LIBs) find wide range of applications from portable electronics to electric cars and stationary storage or renewable energy. LIB electrode fabrication is done through mixing the active material (Li-ion host) with carbon (conductive component) and polyvinylidene fluoride (PVDF), which acts as a binder. These components are dissolved in N-methyl-2-pyrrolidone (NMP) to form a paste which is then doctor bladed onto the aluminum current collector. NMP is a toxic chemical and the overall fabrication process remains costly. Efforts are made of eliminating NMP by (1) replacing the binder and (2) using a new fabrication method. Of particular interest among these new methods is electrophoretic deposition (EPD). Via the application of DC potential, particles in suspension can be electrophoretically deposited on different conductive substrates in a relatively fast rate rendering EPD feasible for industrial application. A key aspect for successful application of EPD is the formulation of a stable suspension. Within the McGill HydroMET group, we explore the potential of EPD in fabricating LIB electrodes having demonstrated its effectiveness in the case of P25 nanotitania/carbon anodes. The performance of EPD fabricated TiO2/C electrodes is compared to standard PVDF-based electrodes and shown to have comparable charge capacity. This method is now being extended to other electrode materials. In this paper an introduction to the EPD method will be made and subsequently its use in fabricating LIB electrodes will be described. The performance of the fabricated batteries is evaluated via galvanostatic charging/discharging and cycling tests.

Jan 1, 2016

By M. F. Goudge

LIMESTONE surpasses any other rock or mineral in the number and diversity of its uses and in the quantity consumed fur industrial purposes. Either in the raw state or when calcined to lime it enters directly or indirectly into the manufacture of a great variety of products and its sphere of usefulness is continually expanding. The term "limestone" as here employed includes all varieties from high-calcium limestone, consisting almost entirely of the mineral calcite, to the highly magnesian variety, largely dolomite. Lime is also discussed .because lime is simply calcined limestone and often the material may be used in either the calcined or natural state. Limestone has been of service to man since prehistoric times but only in the last hundred years has it become one of the most important raw materials in industry. In every industrial country it comprises the greater part of the total stone produc-

Jan 1, 1937

By Alexander N. Winchell

"Location. The copper mines of Michigan are all in the northern part of that state on the Keweenaw Peninsula, which extends from the (Michigan) mainland for about seventy miles northeasterly toward the middle of Lake Superior. The mines occur in a belt or zone occupying the central portion of the peninsula from end to end.. The most productive mines for many years past have been those located not far from the city of Houghton in' the central part of the zone, in a section extending about ten miles southwest of Houghton and fifteen miles northeast. The most important mines in order of location, from the northeast to south¬west, are the following: Mohawk, Ahmeek, Allouez, North Kearsarge, Wolverine, South Kearsarge, Centennial, Calumet. and Hecla, Osceola, Franklin, Quincy, Hancock, Isle Royale, Superior, Baltic, Trimountain, and Champion. The first three named are in Keweenaw county and all of the others are in Houghton county. Still farther to the southwest are the Lake, Mass, Adventure, Michigan, Victoria, and White Pine mines. These are in Ontonagon county.History. The exploitation of these copper mines extends back into prehistoric times. There is little evidence that the American Indians carried on mining operations in this region in the period shortly before the advent of white men, but there is abundant evidence that the ancestors of the Indians, •or some earlier inhabitants of the region, carried on primitive mining operations. For example, Mr. S. O. Knapp, Agent of the Minne¬sota Mining Company, in the winter of 1847-48, made the first discovery of prehistoric mining. This event is described as follows by Foster and Whitney :"

Jan 1, 1920

By Brian FitzPatrick, Michael J. Weaver

Everyone has a role in site safety, even consultants. This paper presents a summary of how a geotechnical and environmental consulting firm, with field staff on construction and subsurface explorations sites, engaged their staff and leveraged relationships with contractors to assess the construction related risks to which its staff members are exposed. These findings were then integrated into their technical training materials for both new staff and those needing a refresher, so that safety is discussed at the same time as the technical work and not treated as a separate topic. The paper outlines the process of identifying and evaluating the construction related risks that staff members face and presents examples of how the consultant can engage contractors in the process. By doing this, knowledge can be shared and there is a better mutual understanding of the risks associated with common construction and exploration related field tasks. The work resulted in an increase in staff engagement in safety, a better understanding of the true risks that staff face in the field, better relationships with contractors, and lower safety metrics. HISTORY At Haley & Aldrich, Inc., we renewed our safety journey in May 2012. Like many others, we had concerns over injuries our staff experienced in the three previous years, and a potentially significant utility strike we experienced while excavating a trench. In 2009, 2010 and 2011 we experienced an increase in recordable injuries, including two significant injuries, which caused our Experience Modification Rate (EMR) (see note below), Total Recordable Incident Rate (TRIR), and Days Away-Restricted, and Transferred Rate (DART) to rise significantly. See Fig. 1 for details. This caused us to step back and review our approach to safety, and our “safety culture”. The rise in reportable incidents and injuries also corresponded to the beginning of a growth period for the company.

Jan 1, 2019

By I. M. Wolf, S. A. Usmar, L. A. Cornish

The limiting criterion in the use of stainless steel for certain forming operations such as coining is its hardness, which determines parameters such as required striking pressure, wear on dies, and integrity of pattern detail. Attention is given here to the development of ultra-soft ferritic stainless steels for coinage. In the first instance, the influence of carbon content on the striking properties of a series of commercial and experimental 17%Cr alloys was evaluated. It was found that a lower carbon content permitted the striking of relatively highly profiled and intricate patterns, provided that the hardness did not exceed 125 HV. Hardnesses as low as 115 HV were achieved in the fully annealed condition, but these alloys required high striking pressures. In a further study, three grades of experimental 14%Cr ferritic stainless steels were produced with a view to optimizing the ductility. When the residual impurities were minimized, hardness values of about 100 HV and lower were achieved. Micro-alloying additions allowed the heat-treatment response and grain size to be controlled. Excellent tensile properties, with elongations of up to 42 per cent, were achieved in the fuly annealed condition, and highly profiled patterns were produced in coining trials.

Jan 1, 1993

By J. L. Jambor, J. E. Dutrizac, J. B. O'Reilly

The present-day metallurgical community is quite familiar with the use of jarosites [MFe3(S04)2(0H)6 where M = K, Na, NH4, Ag, 1/2Pb, etc.] as a means of controlling iron, alkalis and sulphate in hydrometallurgical circuits. This modern precipitation technology has found an increasingly widespread application in the zinc industry111 and is gradually also being extended into the hydrometallurgical processing of copper and cobalt121 . The chief advantage of jarosite precipitation is that the iron precipitate settles and filters well, and gives low losses of divalent metals in the washed residue. Although this jarosite precipitation technology was developed only within the past twenty years, man's involvement with jarosites extends back to antiquity, and jarosites have played an important role as a source of silver in several ancient metallurgical centres. In the early days of this century, argentojarosite was an important local source of silver at the Tintic Standard mine, Dividend, Utah, where over 200 000 oz of silver were recovered from highgrade natural jarosite over a three-month period 131 . At the Matagente mine in Peru, pockets of argentiferous plumbojarosite up to 40 m thick were mined and processed by the Indians prior to the arrival of the Spaniards14-51 . In Cyprus there are vast jarosite deposits associated with the ancient mining sitesl51 , but exploitation of these jarosites has been insignificant because of their low silver values. The most extensive mining of silver-bearing jarosite, and certainly the oldest documented instance of such jarosite exploitation, was in the vast pre-Roman workings at Rio Tinto, Spain. This mine, the greatest single miningmetallurgical site currently known from the ancient world and also the oldest site of more or less continuous metal production, has witnessed many metallurgical firsts. Aside from the initial processing of jarositic ores for their silver values, the development of large-scale hydrometallurgy also seems to have occurred at Rio Tinto. As early as 1737, copper was recovered by cementation on scrap iron from the mine waters at Rio Tintol51 . Large-scale heap leaching of calcined ore commenced with the British operations in 1876 and, by 1900, raw pyrite was heap leached to recover associated copper values161 .

Jan 1, 1999

By Jon J. Indall

I. INTRODUCTION The challenge of moving the use of nuclear energy from military to civilian use was first issued by President Dwight Eisenhower in his December 8, 1953 “Atoms for Peace” speech delivered at the United Nations. Eisenhower stated: “The United States knows that if the fearful trend of atomic military build up can be reversed, this greatest of destructive forces can be developed into a great boon, for the benefit of all mankind. * * * * The more important responsibility of this Atomic Energy Agency would be to devise methods whereby this fissionable material would be allocated to serve the peaceful pursuits of mankind. Experts would be mobilized to apply atomic energy to the needs of agriculture, medicine, and other peaceful activities. A special purpose would be to provide abundant electrical energy in the power-starved areas of the world. In the 1950’s and 1960’s, the Atomic Energy Commission promoted the use of nuclear power as the answer to our nation’s energy problems. Nuclear power would provide energy too cheap to meter. The utility industry responded and numerous plants were planned with over one hundred constructed from the 1970’s to the 1990’s. Capital costs for nuclear power plants escalated due to permitting changes and public opposition, and the Three Mile Island incident caused new nuclear plant construction to cease. Today, we once again are experiencing a nuclear renaissance. Concerns over global warming and rapid projected increases in the demand for electricity have caused many nations to begin construction of new nuclear fleets. The price of uranium to fuel these reactors, which had dropped to an historical low of $7.10 in 2001, has surged to $56.00 as of October 2006. This paper will review some of the social, environmental, and government issues that are all playing a role in the resurgence of the nuclear fuel industry.

Jan 1, 2007

? CONSTRUCTION AND MINING COSTS ARE HIGH IN THE ARCTIC ? VERTICAL KIMBERLITE PIPES WITH HIGH STRIP RATIOS ? SITE SPECIFIC GEOMETRIC CONSTRAINTS ? OPEN PIT FOLLOWED BY UNDERGROUND MINING ? HIGH KIMBERLITE UNIT COSTS TRACK INSTALLED ON PIT WALL ? INTENDED TO REPLACE MAIN HAUL RAMP ? 5 MIN HOIST CYCLE TIME ? KEY ADVANTAGES - REDUCED CYCLE AND STRIPPING RATIO ? TECHNOLOGY EXISTS IN OTHER APPLICATIONS

May 1, 2003

By H. Ito, T. Takasu

Effects of a mechnochemical treatment to oxide Ni ores have been investigated to enhance the extractive ratio of Ni from them in acid leaching process. High intensity grinding by a planetary boll mill showed strong effect to enhance the extractive ratio of Ni, for example , 10% of extractive ratio of Ni in sulfuric acid leaching(0.05mo1/1,at room temperature) increased to more than 90% with 60min. of planetary boll milling. Effects of additives(sulfur and some oxidants) on the mechnochemical treatment have also studied. Sulfur showed almost no effect to enhance the total Ni extractive ratio but increases the selectivity of Ni extraction. More than a half of Ni could be extracted by water when Ni ore was grinded at addition of Na2S207 in the milling treatment. Some effects of mechnocemical treatments to Ni ore are summarized in this paper.

Jan 1, 2005

By M. J. Collins

"Autoclaves were first used in the metallurgical industry in 1893 to recover alumina from bauxite. In the 1940s and 1950s, several high temperature and pressure processes were invented in the laboratory of Professor Frank Forward at The University of British Columbia, in parallel with advances in equipment and processes by the Chemical Construction Corporation. Sherritt Gordon Mines Limited enlisted these groups to help develop the nickel sulfide ammonia leach process that was commercialized in 1954. Autoclave processes that have since been commercialized include high-pressure acid leaching of laterites, zinc pressure leaching, and pressure oxidation of refractory gold feedstocks. RÉSUMÉ En 1893, l’industrie métallurgique est la première à utiliser les autoclaves pour l’extraction de l’alumine dans la bauxite. Dans les années 1940 et 1950, plusieurs procédés à haute température et à haute pression sont inventés dans le laboratoire du Pr Frank Forward de l’université de la Colombie-Britannique (UBC) ; parallèlement, la Chemical Construction Corporation fait de grands progrès en matière d’équipement et de procédés. Sherritt Gordon Mines Limited fait appel à ces groupes pour qu’ils aident la société à développer le procédé de lixiviation du sulfure de nickel dans de l’ammoniaque, commercialisé en 1954. Les procédés de lixiviation en autoclave commercialisés depuis incluent notamment la lixiviation acide à haute pression de latérites, la lixiviation sous pression du zinc et l’oxydation sous pression des matières premières de l’or réfractaire.INTRODUCTION Autoclaves are chemical reactors that are built to contain processes taking place at elevated pressure. They are used in metallurgical refineries throughout the world to take advantage of the increased reaction kinetics and different reaction products that can be obtained in aqueous systems above the boiling temperature at atmospheric pressure. The word autoclave comes from the French “auto” and the Latin “clavis” and literally means self-locking—that is, the core distinguishing feature of an autoclave is that it includes a means for pressure regulation (e.g., a pressure relief valve). Denis Papin (Figure 1a), one of the inventors of the steam engine, was the first to make use of a safety valve to control steam pressure. He is credited with inventing the autoclave in 1679. Papin’s “digester” (Figure 1b) was a type of pressure cooker that was originally used to liquefy bones. Most commercial autoclaves are horizontal, multicompartment vessels with mechanical agitation, as shown in Figure 2a; however, the steam-agitated Pachuca vessels used to leach laterite ore in Moa, Cuba (Figure 2b), are also classified as autoclaves according to the self-locking definition provided above."

Jan 1, 2018