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By V. Thangadurai

The critical problems in commercialization of the present solid oxide fuel cells (SOFCs) and useful electrical and physical properties of IT-SOFCs electrolytes are discussed briefly. The conductivity behavior of the perovskite-type and perovskite-related structure metal oxides are summarized. Perovskite-type La0.9Sr0.10ao.8Mgo.203_8 (LSGM) exhibits high ionic conductivity of 0.1 S/cm at 800 °C. In order to improve the electrical conductivity of LSGM and the In analogue of LSGM, substitutions have been made at the A-and B-sites. Substitution of trivalent La3+ by isovalent Pr3+ in LSGM and La09Sro ilno.sMgo.202.85 (LSIM), yield new mixed conductors. Among the investigated compounds in the present study, La0APro.4Sro.21no sMgo.2028 exhibits the highest total electrical conductivity of 3.2 x 10-5 S/cm at 200 °C in air with the lowest activation energy of 0.44 eV (200-700 °C). LSIM and Pr-substituted LSGM and LSIM perovskites show p-type electronic conductivity in the oxygen partial pressure range 10-5 ? 0.21 atm at 750 °C. The perovskite-type solid solution SrSn1-xFex03 exhibits compositionally driven phase transitions. For example, compound of the composition x = 0 to 0.3 crystallizes in an orthorhombic GdFeO3-like perovskite structure, where as that of x = 0.4-0.9 crystallizes in simple cubic SrTiO3-like, and that of x = 1 in orthorhombic structure. The electrical conductivity of SrSn1_xFex03 increases with the increasing Fe content and reaches a value of about 10-1 S/cm at 25 °C in air for x = 1. Compounds with low Fe content exhibit both ionic and electronic conductivity, while the higher Fe content 0.5) perovskites are electronic conductors over a wide range of oxygen partial pressure of 10-22? 0.21 atm at 750 °C.

Jan 1, 2005

By Robert Stefanko

The importance of underground stress instrumentation cannot be minimized. It was Lord Kelvin who said that unless you can assign a number to a quantity,, you know very little about it. Most engineers will agree although this kind of statement is resented by our friends in non-technical fields. Mining is undergoing a revolution from art to science. But how can mining methods be optimized if there is no way of measuring the effectiveness of a given mining method? Do we know how effective a' support is unless we can determine its reaction to the mine structure? How do we assess the need for modifications to existing systems and supports, and how do we measure the effectiveness of such changes? Cut and try techniques are too wasteful of time and energy, and rarely provide solutions to a given problem. The purpose of underground stress instrumentation is to provide answers to some of the above questions -- answers that cannot be obtained otherwise This does not mean that laboratory studies are not valuable -on the contrary. Laboratory and underground studies supplement one another. Rock mechanics had its conception with the study of stresses in homogeneous, isotropic, and elastic models subjected to various force systems. These analyses were valuable inasmuch as they pinpointed possible sources of trouble due to stress concentrations. If the results observed underground did not always agree with the experimental analysis, it was not an indictment of the latter. More probably, the discrepancy could be attributed to the lack of similitude between model and prototype. The more nearly one can simulate underground conditions in a model, the more apt one is to produce results which correlate well-with underground observations. It is impossible to completely simulate underground conditions because all of the significant design parameters have not been recognized and evaluated. What better way can one evaluate these parameters than by underground stress instrumentation?

Jan 1, 1963

By Xiyun Yang, Hui Xu, Xichang Shi, Xiang Xiao

"Rod-like magnetite particles were prepared by precipitation of iron salts with urea under the induction of magnetic field. Temperature and initial Fe3+/Fe2+ ratio have a significant effect on the composition of the product. Magnetite particles change from spherical into rod shape in the presence of a 0.35 T magnetic field, The addition of a small amount of spherical seeds increases the rod-like magnetite particles yield. The seeds are prepared by aging ferrous and ferric solution with sodium hydroxide as precipitator. The aspect ratio of the rod is controlled by varying the volume ratio of seed to iron salt.IntroductionMagnetite, an important member of magnetic materials, has attracted a lot of attentions for its super magnetic properties. The rod-like magnetite particles have high anisotropy and coercive force as well as super magnetic properties compared to other shapes, and are widely used as high magnetic density media, magnetic devices and microwave materials [1-4]. Recent studies have found that magnetic field can direct magnetite growing along easy magnetization axis to get one-dimension particles [5-6]. Chen et al. [7] synthesized single crystalline nanorod magnetite under magnetic field. Wang et al. [8] discovered that magnetite grew along easy-magnetization directions under 0.35T magnetic field. Vereda et al. [9-1 O] found that magnetic field had a dramatic effect on the morphology, inducing the aggregates to line along one direction to form rodlike particles.At present, most of the synthesis methods reported in the literature result in a low yield of rod particles and the aspect ratio are difficult to control. Recently, we developed a seed-mediated growth approach to making rod-like particles in an aqueous solution. The spherical magnetite generated by oxidation serves as a seed. These seeds are then added to a solution containing iron salt and urea, and provide nucleation sites for magnetite rod growth."

Jan 1, 2011

By Guolin Zheng, Tiejun Chun, Jian Pan, Deqing Zhu, Xianlin Zhou, Dong Chen

"The high temperature oxidizing-chloridizing roasting is one of useful methods to separate nonferrous metals from pyrite cinder and metallurgy slag. However, as one kind of main nonferrous metals in pyrite cinder and metallurgy slag, copper’s chlorination behavior is not demonstrated. In the present study, chlorination behaviors of CuO, Cu2O and CuS at the temperature range of 1025-1175 ? in air by simulating the chloridizing roasting process of pyrite cinder and metallurgy slag have been investigated. It is shown that Cu2O and CuS is much easier to remove, CuO is refractory to remove. In addition, the presence of SiO2 and CaO increases the Cu removal rate from CuO while the presence of SiO2, Al2O3, CaO and MgO decreases the Cu removal rate from Cu2O. Fe3O4 influences the Cu removal rate from CuO and Cu2O positively.IntroductionAs two kinds of significant secondary resources, pyrite cinder and metallurgy slag contain not only abundant iron but also considerable copper, lead, zinc etc. Millions of tons of pyrite cinder and metallurgy slag were discharged from nonferrous metal and chemical industries annually [1, 2] in China. The pyrite cinder and metallurgy slag are formed by roasting of minerals at a high temperature, so the properties of them are distinctly different from the natural iron ores, and the iron in them is closely associated with copper, lead, zinc and other nonferrous metals. High-quality pyrite cinder and metallurgy slag containing high iron and low impurities can hardly be obtained, leading to their low utilization degree [3]. Chlorination is characterized by the high reactivity of chloridion, the high volatility and low melting point of metal chlorides, and the big differences in the formation of metal chloride. Therefore, chlorination is widely applied in extraction metallurgy."

Jan 1, 2012

By C. H. Lee, T. T. Wang

"Exampling of the tunneling task in the Tsengwen Reservoir Transbasin Diversion (TRTD) in southern Taiwan, this study investigates the application of the Drilling Survey System (DRISS) in both Drilling and Blasting (D&B)- and Tunnel Boring Machine (TBM)-excavated sections. In the D&B section, a nonlinear relationship exists between drilling energy and uniaxial compressive strength of rock mass, in which a reasonable coefficient of determination can be analyzed statistically. Additionally, the DRISS accurately predicted an unfavorable section with a valuable position. The magnitude of uniaxial compressive strength back calculated using DRISS data also matches those acquired from geological investigations with different approaches. Study results indicate that the DRISS is an effective tool for fore-probing of both D&B- and TBM-excavated tunnels. INTRODUCTIONModern advancements in geological and geophysical investigations, and drilling techniques, have provided valuable information for detecting and interpreting geological conditions of rock tunnels with a resolution of several to ten of meters (Brückl et al., 2001, 2008, Lorang et al., 2005). Nevertheless, construction risks remain considerable during tunnel excavation, especially when a tunnel was excavated by a Tunnel Boring Machine (TBM). Predictions of the local fault, shear zone, and other minor geological features, which may cause moderate collapse or excessive deformation of rocks surrounding the tunnel, before tunnel excavation is highly desirable for high-quality tunnel construction and economically efficient project management.Rather than conventional geophysical prospection methodologies, which always favor large-scale investigation with moderate precision, this study focuses on the drilling method probing ahead of a tunnel. The goal of such an investigation is not only to prevent catastrophic collapse, but also to provide quantitative or semi-quantitative information for estimation of the mechanical parameters of rock mass.For the tunneling task in the Tsengwen Reservoir Transbasin Diversion (TRTD) in southern Taiwan, a drilling survey system is adopted for fore probing. Data collected from both drilling and blasting (D&B) and TBM-excavated sections are analyzed statistically and discussed. The applications of the Drilling Survey System (DRISS) are addressed accordingly."

Jan 1, 2015

By Aris Tambunan, Nella Lubis, Nurafrianti Saala, Komang Widhiayanto, Herry Saputra, Rudolf Sitorus

Maximizing mining recovery rates and minimizing ore loss are pivotal objectives for economic efficiency and operational effectiveness. This study explores methods to address these imperatives by enhancing ore production and recovery through improved blasting techniques and spillage control in the Martabe Gold Mine Project in North Sumatra Province, Indonesia. Between 2018 and 2021, the average mining recovery rate stood at 93%, resulting in a potential annual ore loss of 7% and a potential quarterly financial impact of close to $2 million. Maintaining and enhancing mining recovery became crucial, with a planned 30% increase in total material movement for 2022. The mining recovery target for 2022 was set at 96% based on best achievement historical data from 2021 to increase ore tonnage by 203 KTon per annum. To achieve the primary objective of increasing ore production by improving mining recovery, the study focused on predicting and controlling the movement of blasted ore to reduce spillage and enhancing the grade control model to reflect actual conditions post-blasting. Several alternative solutions were explored, primarily emphasizing drilling and blasting activities. Essential methods included capturing the actual blasting movement to adjust the ore block based on blasting design data and post-blasting muckpile topography. This approach minimizes ore loss by providing output as ore block adjustment based on post-blast movement data. In addition, the tie-up design was adjusted to control ore spillage outside the pit ridge. The implementation of these methods yielded significant improvements. Adjusting the ore block based on actual blasting movement contributed $1,545,764 in benefits. Controlling ore spillage outside the pit ridge achieved a 10% reduction in spillage, contributing $79,184 in benefits. These enhancements successfully met the 2022 mining recovery target of 96%, marking a 3% increase from 2021. Consequently, ore loss was reduced by 178 KTon throughout 2022, resulting in a financial impact of $7.3 million. The study underscores the significance of precise blasting techniques and effective spillage control in enhancing mining recovery rates.

Jan 21, 2025

By T. A. Rickard

Do not write until you have something to say. Think first; then write. In order to be understood, you must know what you wish to say. Clear writing is the consequence of clear thinking. Therefore consider your subject well before you begin to write; ruminate on it; marshal the salient facts in your mind; saturate yourself with the ideas you wish to express and with cognate ideas; then express yourself deliberately. If you are bubbling over with your subject the words will come, but you might as well expect to sail without a breeze as hope to give life to words without the living thought. Here I may advert to the fact that among the uneducated it is a common expectation to acquire the knack of writing without taking the trouble to study the art of literature. I overheard a woman in a suburban train remark to her neighbor: "I'd like to be able to write well without stopping to think about it". She was one of many that would like to do a thing well without the trouble of thinking; but it cannot be done in respect of anything to which thought is essential. The possession of a good voice does not justify a person in expecting to sing successfully to a large audience; before singing in public one has to master the technique of singing; one has to learn first how to breathe properly, how to enunciate, and many other things. The successful singer is an artist, not a megaphone. Most of us would regard a man or a woman without any training in the art of singing as a fool or an impostor if he or she were to give a public concert, yet we do not recognize the equal foolishness and imposture of persons that write books before they have studied the technique of writing. That is why so many books are unreadable, and why many books by clever men are difficult to read. They start to write books before

Jan 1, 1931

By Zhihe Dou, Zimu Zhang, Guozhi Lv, Yan Liu, Xiaoli Jiang

"Cyclic heat stewed slag washing water carries high content of alkali and calcium and may cause serious tube scaling and impose an adverse impact on normal production. This study proposes a solution to utilize washing water by absorbing and mineralizing CO2, potentially restraining scaling and being able to create calcium carbonate powders. Effects of water flux on water quality, utilization ratio of CO2 and yield of calcium carbonate powder have been investigated; meanwhile, features of calcium carbonate powder are also represented. On the other hand, effects of factors such as as injection flux, pressure of CO2 on utilization ratio of CO2, morphology and purity of calcium carbonate are also investigated. The results show unambiguously that after soften injection of CO2, calcium ions were removed effectively via precipitation, alleviating the scaling problem. High purity yet fine carbonate powder could be achieved.IntroductionNowadays, 0.34 tons of blast furnace slags will be produced when producing 1 ton of pig iron; ensuing that, 0.12 tons of steel slag will be generated with 1 ton steel production while 1.57 billion tons of steel output all over the world in the year of 2012. It is therefore a critical issue to realize zero discharge of steel slags to achieve sustainable development and cyclic economy of iron and steel industry. In recent years, research institute of MCC and China JINGYE engineering company developed a heat stewed steel slag self-decomposition technology GENERATION III to solve the problem of instability of steel slags and realize the zero discharge. However, the problem of circulation line scaling which may cause the clogging, even exploding, need to be solved. The principles of the technology are: directly spraying water to the high temperature steel slag when it is poured into the hot closed pot, realizing the selfdecomposition via utilizing the waste heat of steel slag. The washing water is recycled to achieve a cyclic utilization. The process is shown in Figure 1."

Jan 1, 2014

By Charles G. Kemsley

IN view of the truly remarkable development of special steels for special purposes, the mining industry has for years looked forward to a time when steel makers would come forward with a product which would be an improvement over the straight carbon steel which has always held the field for drilling rock. In order to avoid making changes in conventional shop practice, the industry has perhaps been too insistent upon obtaining a water hardening steel which could be handled in the blacksmith shop by long established methods. As early as 1932 or 1933, an oil-hardening tool-steel of the one per cent carbon, plus chrome, plus molybdenum type was applied to hollow drill steel. It was known as a hard as well as a tough steel, and one that, theoretically, should give a good account of itself as a rock drill, if properly heat-treated; and so it has proved in actual trials. There were numerous deterrents which retarded adoption of this steel. For several years there has been a constant improvement in the drilling qualities of the straight carbon steel, and, considering the higher unit price ? of the alloy, there has been considerable doubt in the minds of some mining? men as to what advantage there might be in the use of alloy over straight carbon for hollow drill steel. The alloy being an oil-hardening steel, its adoption meant having two kinds of steel in the mine, for a time, and that spelled trouble, unless some positive means of identification was adopted. The hardening and forging ranges of alloy steel being narrow also made necessary much closer control over these operations if poor results were to be avoided. These thoughts undoubtedly prevented its use becoming wide-spread, for, as a matter of actual record, less than fifteen per cent of all the hollow drill steel used in Canada today is alloy.

Jan 1, 1942

By Nobuyoshi Yabuki

Building Information Modeling is a prevailing methodology in the building industry and half (by length) of the world's shield tunnels are in Japan. Accordingly, for shield tunnels from 2005 to 2007, we developed a product model called IFC-ShieldTunnel, which is based on Industry Foundation Classes (IFC), in order to meet the future demand for such a product model. IFC-ShieldTunnel was developed by adding new elements that are specific to shield tunnels and that are not included in the original IFC. The added elements include shafts, segments (A, B, and K types), waterproofing elements, segment joint elements, and ring joint elements. Furthermore, soil layers and void elements were created. Recently, we updated the product model by re-organizing the entities and correcting errors. We deployed the updated IFCShieldTunnel model in the construction of an actual shield tunnel in Tokyo for about a year from August 2010 in order to check its feasibility. In the verification process, first, segments were modeled using Autodesk Revit Structure 2011 and property data were assigned to each segment element. Next, a mapping between the original attributes of the entities of IFC and properties of IFC-ShieldTunnel segments was developed. Using this mapping and IFC?s IfcBuildingElementProxy function, we were able to convert the IFC data from Revit Structure 2011 to IFC-ShieldTunnel automatically. Segment data were also converted from Revit Structure to Google SketchUp by IFC-ShieldTunnel. Furthermore, the construction scheduling and cost data were converted from Revit Structure to EXCEL for 4D and 5D analyses of construction. We interviewed engineers who used IFC-ShieldTunnel and received positive comments about the utilization of the product model. Overall, our test demonstrated the feasibility of IFC-ShieldTunnel. In future work, we plan to apply IFC-ShieldTunnel to more projects and test its practicality.

Aug 1, 2013

By Graham W. Gibbs

The current state of knowledge concerning mesothelioma risk estimates is reviewed. Estimates of the risk of mesothelioma exist for the commercial asbestos fiber types chrysotile, amosite and crocidolite. Data also exist on which to assess risks for winchite (sodic tremolite) and anthophyllite asbestos. Uncertainty in estimates is primarily related to limitations in measurements of exposure. Differences in the dimensions of the various fiber types and of the same fiber types at different stages of processing add a further complication. Nevertheless, in practical terms, crocidolite presents the highest asbestos related mesothelioma risk. The risk associated with sodic tremolite (winchite) appears to be similar. In chrysotile miners and millers, the mesothelioma risk has been linked with exposure to asbestiform tremolite. Exposure to chrysotile in a pure form seems likely to present a very low if any risk of mesothelioma. While the majority of mesothelial tumors result from exposure to the asbestos minerals, there are other well established and suspected etiological agents. While a practical threshold seems to exist for exposure to chrysotile, it is unlikely to exist for the amphibole asbestos minerals, especially for crocidolite. To date there is no indication of an increased risk of mesothelioma resulting from non-commercial fiber exposure in the taconite industry. © 2007 Elsevier Inc. All rights reserved. Keywords: Mesothelioma; Amosite; Grunerite; Taconite; Crocidolite; Tremolite; Anthophyllite; Winchite; Risk estimation; Etiology

Jan 1, 2007

By Helvio P. G. Santafé Jr., Ruben J. S. Rodriguez, Sergio N. Monteiro, Teresa E. Castillo

"The coir fiber extracted from the husk of the coconut fruits are worldwide available in tropical regions as a low cost lignocellulosic by-product for many applications including composite filler in automobile parts. Possible uses above room temperature require information on the thermal behavior of these coir fiber composites. Therefore, the objective of this work was to perform thermogravimetric, TGA and DTG, analysis on polyester matrix composites incorporated with different volume fractions of coir fiber. In general, it was found that thermal degradation associated with weight loss occurred in three stages. Changes were also observed in the DTG peaks that could be attributed to the coir fiber participation through the decomposition of its lignocellulosic structure.IntroductionThe development of new materials has always been motivated by the need of improved properties. This was the case of modem composites with combination of properties that surpass those of conventional monolithic metallic alloys, ceramic or polymers, from which composites are made. A typical example is the synthetic fiber reinforced composite with specific strength i. e, ultimate stress divided by density, higher than any other monolithic material. Today, however, our global society is concerned with serious environmental problems and thus demanding that new materials be developed with distinct characteristics. They are known as environmentally correct and are expected to be sustainable, which corresponds to the condition of being biodegradable, renewable, recyclable and neutral with respect to C02 emission, considered the main responsible for global warning [1]. Synthetic fiber composites cannot meet these requirements. Consequently, new composite reinforced with cellulose-based natural fiber are being developed [2-8] and are already replacing the synthetic ones in several engineering fields including the automobile industry [9-11]. These composites have additional advantages owing to the lignocellulosic fiber benefits of being diversified, abundant, less expensive, lighter and of societal interest [8]. In some cases even technical advantages such as non-abrasive effect to processing equipments and more flexibility exist in comparison to synthetic fibers."

Jan 1, 2011

"What can we do in ground engineering to reduce damage to the environment, to repair historic pollution, to reduce our demand on basic resources and to reduce the carbon footprint of our industry? Some developments in geotechnical engineering are already heading in the right direction. These include reductions of ground pollution from grouting, improved dewatering procedures and advances in mix-in-place processes, ground improvement and jet grouting.There is increased interest in certain promising technologies (for example, drilled partial or full displacement piles), but this approach remains for the moment somewhat avant-garde. These piles require substantially greater power to install, and the overall sustainability balance for general application has yet to be shown to be in their favour. They are particularly suited to polluted sites where the problem of dealing with spoil would be costly and where, in the past, driven cast in-situ piles would have been employed. Drilled displacement piles offer some environmental benefit over driven piles in that they cause far less drawdown of potentially contaminated near-surface ground into sensitive, underlying aquifers.There is also great interest in various means of increasing the frictional capacity of bored piles, both conventional auger and continuous flight auger (CFA) piles, by threading or ribbing the soil/pile interface. The increase in adhesion capacity allows reduction in the pile dimensions necessary for a specific load. This obviously leads to less construction waste, but also to less permanent material consumption in the piles and also in the pile caps.The role of ground improvement remains significant for brown land sites and lower capacity foundations. Information technology (IT) has improved the quality assurance of stone column construction, for example. From the sustainability point of view, this is a good news method; here is no cement, no pollution and little obstruction to future redevelopment. We now need to introduce recycled crushed materials instead of natural aggregate as general practice and the technique’s green credentials will be really compelling."

Jan 1, 2009

By C. M. Egert, S. Rajic

"We have developed a monolithic micro-spectrometer suitable for a variety of sensing applications including industrial process monitoring. The device consists of a solid structure with a volume less than 6 cubic centimeters. All optical components of the spectrometer including two aspheric mirrors, a diffraction grating, and entrance and exit surfaces are fabricated onto the surface of the structure. All light paths are internally contained within the structure. The result is a small, rugged spectroscopic sensor ideally suited for use as a process monitor. Due to its monolithic nature the device requires no post-fabrication alignment; nor can it be knocked out of alignment during use. Although many materials and thus wavelength regions were possible, the prototype device discussed here was produced in PMMA by precision diamond turning. However, lower cost manufacturing approaches involving injection molding are under development to produce an affordable sensor.Due to its rugged monolithic design, small footprint, and low cost the monolithic micro-spectrometer is ideally suited for distributed monitoring applications often required for industrial processes. It is expected that modified versions of this sensor designs will be required for specific applications so as to maximize the performance and resolution over the operating range. For example, the prototype device described here operates over a wavelength range of 500 nm to 1000 nm. The performance of this device as a real-time surface monitoring sensor will be discussed in detail. Our approach of using wavelength dependant scattering resulted in the reduction to practice of a miniature, monolithic, rugged, low-cost, micro-instrument in a sensor sized package. The process sensor applications community has been faced by the cost versus performance issue. Simple go/no-go sensors are typically inexpensive but they provide very limited and sometimes dubious data. Scaled down traditional instruments offer very good measurand information but are typically cost prohibitive, fragile, and still relatively large. This work will bridge the gap between these two extreme sensing alternatives."

Jan 1, 1997

By George D. Lessner

I'm sure that everyone at this meeting is aware of the current problems facing the U.S. metals mining industry. Prices are depressed and expected to remain depressed for quite some time. On the other hand, industrial minerals, including talc, are doing quite well. The profitability of industrial minerals has sparked considerable interest on the part of many companies in expanding into industrial minerals. Our company is one of those actively seeking to expand its position in industrial minerals. It is appropriate that the A.I.M.E. asked me to speak to you regarding entry into the talc business. So how do you get into the talc business? Earlier speakers have explained how to locate, mine, process, and market talc, so you have the "how ton.

Jan 1, 1984

By John D. Grothe

Laboratory experiment as a basis of commercial plant design has been the subject of much analysis and thought and on which a large number of articles and papers have been published. We would be forced to choose between an unduly brief exposition if we wanted to cover it completely, or no exposition at all. We must therefore concentrate upon the essentials without ignoring at the same time too many of the qualifying factors which, by the choice of what we want to examine, may become side issues. In doing so, we do not imply that these side issues are therefore any the less important. In every case, what is said here applies with almost equal force to the pilot plant which may be necessary as it does to the commercial plant. In discussing a recent paper by Derek C. Shelton on the Santa. Barbara Mill in Chihuahua at a meeting of the Inst. of Mining & Metallurgy (London), D. J. Ottley said on the matter of relating laboratory results and small scale tests to full scale plant results that he would like' to draw the attention of members to the great difficulty of scaling up mineral dressing plants and processes. He felt that this was an important yet neglected subject which merited considerable fundamental scientific attention from mineral dressers and plant design engineers in particular. How much of this fundamental scientific attention has, as a matter of fact, been accorded to the subject, mainly by our sister profession, Chemical Engineering. The close similarity to chemical engineering problems that we meet, particularly in hydrometallurgical operations, suggests that Chemical Engineering publications offer a rich source of information and discussions of methods useful to us. We have only to think of pressure leaching, ion exchange, liquid-liquid extraction, precipitation and so on, all problems in chemical engineering unit processes or of the new Freeport Sulphur Nickel plant in Cuba or the Sherritt Gordon plant and many others.

Jan 1, 1960

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigations beginning with No. 4251, of which this is the third. The data are accompanied by maps showing the location of holes drilled and deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township-map. The description of each half township is followed by a description of each deposit developed in that half township.

Jan 1, 1948

By Bowen Li, Matthew D. Andriese, Jiann-Yang Hwang, Zhiwei Peng

"Magnetic iron sulfide ore particles heat rapidly by microwave (MW) irradiation generating plasma during oxidation of surfaces. The high temperatures produced by the exothermic event decompose local portions of samples forming a differentiated flux of partially melted silicate (si-mt) with entrained metal-sulfide (sul-mt) droplets. The si-mt forms crystals of olivine (01) in Ca-rich pyroxene (Cpx) melt that resorbs a portion of iron sulfide (Po). The immiscible sul-mt droplets of (Fe,Ni,Cu)1-xS contain magnetic subsolidus Ni-pyrrhotite (Ni-Po) with Cr-bearing ferrospinel (Mag). Sub-micron sized flecks of Au are found on the surface of a sul-mt droplet with scanning electron microscope (SEM).IntroductionSulfide ore deposits supply the world's mineral resource in the production of non-ferrous metals. Particularly, Cu-Ni deposits are chemically enriched in metals from high sulfur saturation during magmatic formation that creates the proper geochemical environment for metals enrichment [1, 2]. The sulfur and oxygen fugacity control redox conditions of a differentiated silicate/sulfur magmatic melt with the concentration of iron playing a dominate role in the chemical partitioning of metals in sulfide liquid [3, 4]. The initial magnetic crystallization of (Fe,Ni)i-xS monosulfide solution (mss) from metal-sulfide liquid has an exclusive effect on the fractionation of mineral assemblages (zoning) [5].Phase equilibria of sulfide melt (sul-mt) components are related by a miscibility gap with mss forming Ni-rich pyrrhotite (Ni-Po) followed by the crystallization of (Fe,Cu)1-xS intermediate sulfide solution (iss) [6]. Precious metals form stable chacogenides and are retained in solution until the final liquid solidifies. The redistribution of metals now occurs by subsolidus cooling of mss and iss that exsolve low-temperature Fe-Cu-Ni bearing mineral assemblages [7]. The proper interpretation of ore genesis increases processing capabilities by isolating chemically enriched zones during extraction and should be used to aid in sustainable mine site development [8-11]."

Jan 1, 2013

By R. L. Miller

The potential for recovery of enriched uranium from spent nuclear fuel which has been consolidated into a nuclear waste form was explored in the studies reported here. The waste form of interest is iron-enriched basalt (IEB)--a silicate-based, fused-cast ceramic. IEB samples were prepared containing fuel assembly materials that simulate the core debris of Three Mile Island Unit II;1,2 the nominal composition of the consolidated waste form is given in Table 1. Ore Types The IEB samples, or man-made uranium ores (MMUO), are in two different mineralogical forms. Each MU0 was made by melting the constituent materials and holding at about 1500°C for 1 h. The MMUOs were then heat treated to control crystallization and crystal growth and then cooled to room temperature.

Jan 1, 1983

By Baha Abulnaga

Slurry pipelines are used in a number of countries to convey processed ore mixed with water over long distances from remote mine sites to ports or plants for further processing. In Egypt and Sudan, numerous mineral resources are scattered in remote areas. Through the years, Egyptian geologists have identified 268 sites for metallic ores and 386 sites for industrial nonmetallic minerals. A large portion of these sites are in the Eastern Desert in an area called the Nubian Shield. Similar sites are found in the Sudan where mining contributes to less than 1 percent of the gross domestic product (GDP). There are three important components of infrastructure needed to develop these resources ? power, water and transportation. While Egypt is able to satisfy 70 percent of its needs in iron ore from the Gadideh Mine in the Western Desert, it needs to expand its other resources to reduce imports heavily sedimented. Dredging of these sediments and transporting them by slurry pipelines would enhance an industry of bricks or agricultural development based on tailings technology often used in mining. This article explores the potential for slurry technology for opening new mines in the desert or recuperating the sediments of the Nile. The technology by itself would be new to both countries and would benefit from collaboration, particularly to de-silt the Nasser-Nubia Lake.

Jan 3, 2010