Academic literature on the topic 'Bauxite'
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Journal articles on the topic "Bauxite"
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Radusinović, Slobodan, and Argyrios Papadopoulos. "The Potential for REE and Associated Critical Metals in Karstic Bauxites and Bauxite Residue of Montenegro." Minerals 11, no. 9 (September 7, 2021): 975. http://dx.doi.org/10.3390/min11090975.
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Research for critical raw materials is of special interest, due to their increasing demand, opulence of applications and shortage of supply. Bauxites, or bauxite residue after alumina extraction can be sources of critical raw materials (CRMs) due to their content of rare earth elements and other critical elements. Montenegrin bauxites and bauxite residue (red mud) are investigated for their mineralogy and geochemistry. The study of the CRM’s potential of the Montenegrin bauxite residue after the application of Bayer process, is performed for the first time. Montenegrin bauxites, (Jurassic bauxites from the Vojnik-Maganik and Prekornica ore regions from the Early Jurassic, Middle Jurassic-Oxfordian and Late Triassic paleorelief) are promising for their REE’s content (around 1000 ppm of ΣREE’s). More specifically, they are especially enriched in LREEs compared to HREEs. Regarding other CRMs and other elements, Ti, V, Zr, Nb, Sr and Ga could also be promising. In bauxite residue, the contents of Zr, Sr, V, Sc, La, Ce, Y, Ti and Nb are higher than those in bauxites. However, raw bauxites and bauxite residue as a secondary raw material can be considered as possible sources of CRMs.
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Abikenova, G. K., D. D. Dauletov, S. A. Tverdokhlebov, and I. S. Danchenko. "Investigation of the possibility of using depleted bauxite in alumina production at the Pavlodar aluminum plant." Kompleksnoe Ispolzovanie Mineralnogo Syra = Complex Use of Mineral Resources 333, no. 2 (July 9, 2024): 80–88. http://dx.doi.org/10.31643/2025/6445.20.
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The topic of processing low-grade or low-quality bauxite is highly relevant in modern conditions due to the gradual depletion of high-quality bauxite reserves. Consequently, there is an increasing need to explore alternative sources of raw materials for aluminum production and its derivatives. Processing low-quality bauxite ores can become an effective solution, reducing dependence on limited high-quality resources and ensuring production stability in the long term. Such research has significant potential for developing technologies capable of optimizing aluminum production processes and enhancing its competitiveness in the global market. Bauxites from the Krasnooktyabrsky bauxite ore management with low aluminum oxide content (37 – 40% by mass) and a silicon module up to 2.0 are considered as potential blending materials for sintering bauxite in alumina production due to the depletion of high-quality bauxite reserves. This article presents the results of research on their processing into alumina at the Pavlodar Aluminum Plant. Laboratory and pilot-scale studies were conducted to assess the feasibility of using low-quality bauxite in alumina production and to determine the techno-economic indicators of processing. The research results confirmed the technological feasibility of processing depleted bauxites with a silicon module of 1.95 - 2.0 in the sintering section while maintaining the quality of sinter and extracting useful components. The maximum proportion of blending of depleted bauxites with the main bauxite was determined not to exceed 50%.
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Shokanov, Adilkhan, Mikhail Vereshchak, Irina Manakova, and Anastassiya Migunova. "Mössbauer and X-ray Diffraction Spectroscopy of High-Iron Bauxites from Kazakhstan." Materials 16, no. 20 (October 16, 2023): 6706. http://dx.doi.org/10.3390/ma16206706.
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The bauxite ores of Kazakhstan were analyzed using Mössbauer spectroscopy, X-ray diffraction and an X-ray fluorescence analysis. Experimental data on the structural–phase composition of bauxites were obtained, and the features of the iron-bearing minerals within them were revealed. The studied bauxites were high in iron. The magnetic part of bauxite was mainly represented by aluminohematite with a concentration of CAl = 3.34–5.73 at.%, alongside goethite in small amounts. The predominant phase in the bauxite samples was the alumina-bearing mineral gibbsite with a well-crystallized monoclinic lattice. The main siliceous mineral of bauxite is kaolinite, which showed distorted octahedral positions in a number of samples. Siderite amounts were found to vary in the range of 0–15 at.% in the present iron-bearing minerals. Ilmenite was also present in the bauxite of some deposits; anatase was found in all bauxites and was the final product of ilmenite decomposition in the weathering crust.
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Monsels, D. A. "Bauxite deposits in Suriname: Geological context and resource development." Netherlands Journal of Geosciences - Geologie en Mijnbouw 95, no. 4 (March 17, 2016): 405–18. http://dx.doi.org/10.1017/njg.2015.28.
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AbstractBauxite, the raw material of aluminum, has been one of the economically vital natural resources for Suriname. Mining operations started about a century ago, and subsequent development of a refinery industry and hydro-electric power made Suriname one of the foremost bauxite and alumina producers worldwide for a long period of time. This paper presents a concise survey of the main geological attributes of its bauxite deposits and examines significant aspects in the development of mining in the country where alumina dominated the export revenues until a decade ago. The lateritic bauxite deposits are spread across the northern part of the country and developed on various parent rocks during Late Cretaceous–Early Tertiary times. Bauxites in the coastal lowlands formed on Cenozoic sedimentary deposits, whereas plateau bauxites originated on various crystalline rocks in inland regions of the Precambrian Guiana Shield. The composition of parent rocks and timing of bauxitisation point to a genetic correspondence with West African bauxites and a strong control of paleoclimatic conditions on the distribution and properties of bauxite in both regions. The more accessible bauxite deposits in the coastal lowlands are almost mined out, whereas the plateau bauxites have been extensively explored but have not been brought into production to date. For economic and environmental reasons, the future of the bauxite industry in Suriname is currently uncertain.
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Daya, Audu M., Ahmad I. Haruna, Abubakar S. Maigari, and Isah Yahuza. "Resource Assessment and Possible Industrial Applications of Bauxite Occurrences in Parts of the Mambila Plateau, NE Nigeria." European Journal of Environment and Earth Sciences 3, no. 2 (March 10, 2022): 19–23. http://dx.doi.org/10.24018/ejgeo.2022.3.2.244.
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Bauxites are normally formed from underlying aluminosilicate rocks as a result of tropical weathering. In our previous 2 papers, we presented the Geology, possible host, mineralogy, and geochemistry of the bauxites of Mambila Plateau, NE Nigeria. The bauxite was formed from residual chemical weathering of trachyte and occurs as a blanket cover over saprolite. XRD results showed gibbsite as the major mineral with small amounts of hematite, kaolinite, and quartz. Geochemistry of the bauxite ore is characterized by enriched Al2O3 (39.50-78.20.0%), erratic amounts of SiO2 (2.89-5.13%) and Fe2O3 (5.98-21.96%). In this study, the resources of Mambilla Bauxite Deposits (Block I and Block II) have been estimated to be 7,529,312.5 metric tons using block method of vertical geological cross-section bearing in mind that the Mambilla Bauxite Deposits have been explored by pitting on a regular grid pattern of 100 m×100 m. The bauxite deposit in Block II has met the requirement for metallurgical grade bauxite as standard specification (IS: 5953-1985, Reaffirmed [1]). While, Block I deposit has not met such specifications. Sustained investment in bauxite exploration is required to upgrade the ore reserves for sustainable development of a mining enterprise.
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YALCIN, Mustafa Gurhan. "GEOLOGICAL CHARACTERISTICS OF BOLKARDAĞI BAUXITE DEPOSITS IN AYRANCI, THE TAURUS MOUNTAIN, TURKEY." Mühendislik Bilimleri ve Tasarım Dergisi 11, no. 2 (June 28, 2023): 776–93. http://dx.doi.org/10.21923/jesd.1233223.
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The aim of this study is to determine the stratigraphic position of the bauxite deposits in the Ayrancı region, where the most important bauxite mineralization of the Bolkardağı region is located. In this context, the age of bauxite will be determined by determining the erosion surface associated with stratigraphic features during the formation of bauxite and the age of bauxite according to its side rocks. In the region, there are Permian-Cretaceous aged rocks belonging to the Bolkardağı Union, one of the main tectonic units forming the Central Taurus Mountains. Miocene units covering these rocks are surfaced in the study area. Karamanoglu ophiolite and older units are uncomfortably covered by Miocene aged Mazı and Divlek formations. Bauxite deposits are clearly seen in the Upper Permian aged Dedeköy formation. According to the field studies, the bauxites were formed in the Late Triassic - Early Jurassic interval, on the Upper Permian aged carbonate rocks and Lower Triassic aged shale - sandstone - limestone units and then deposited in caves and dolines within the carbonate rocks. The fact that bauxites are located above dolomites and below, within and above limestones is thought to be due to the different behavior of carbonate rocks.
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Taranenkova, Viktoriia, and Iryna Tymoshenko. "Investigation of Bauxites of Various Deposits as Raw Materials for Special Alumina Cements." ce/papers 6, no. 6 (December 2023): 314–18. http://dx.doi.org/10.1002/cepa.2884.
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AbstractThe study deals with the bauxites of deposits of Turkey, Guinea and Guyana, which are used in alumina production, as raw materials for special alumina cements. The chemical and mineralogical compositions of bauxites of various deposits have been determined and bauxites quality relative to alumina cements obtaining has been analyzed. It is ascertained that: Turkish bauxite contains more than 9 wt. % SiO2; Guinean bauxite (deposit Kindia) has a reduced content of Al2O3 (below 45 wt. %); and Guyanese bauxite (deposit Aroaima) complies with requirements for alumina cement completely. Cements of different purity, based on the bauxites being studied, have been obtained and the possibility of using the low‐grade bauxites as raw materials for special alumina cements has been proved. Medium‐purity cements with high content of Al2O3 can be used for heat‐resistant concretes, and low‐purity cements with high content of Fe2O3 can be applied for a new kind of functional materials – sacrificial binders in passive safety systems (core‐catchers) of nuclear power plants.
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Winarno, Tri, Rinal K. Ali, Harrys Simangunsong, and Almiftahurrizqi Almiftahurrizqi. "Characteristics and Genesis of Laterite Bauxite in Sompak District and Surrounding Areas, Landak Regency, West Kalimantan." Indonesian Journal on Geoscience 10, no. 1 (January 5, 2023): 37–49. http://dx.doi.org/10.17014/ijog.10.1.37-49.
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West Kalimantan has very large bauxite resources, reaching 2.07 billion tons, equivalent to 57.32% of the total bauxite resources in Indonesia with bauxite reserves of 0.84 billion tons or equivalent to 66.77% of the total national mineral reserves. The researched area covers Sompak District and surrounding areas, Landak Regency, West Kalimantan. This research aims to determine geological conditions, laterization, and characteristics of laterite bauxite in the studied area. Methods used in this research are geological mapping, lateritic mapping, and petrographic and geochemical analyses. The lithology of the researched area is composed of granodiorite, porphyry quartz diorite, granite, porphyry andesite, porphyry basalt, alluvial, and swamp deposits. Laterite profiles in the researched area generally consist of topsoil, latosol, bauxite, and clay zone. The laterite bauxite derived from granodiorite is classified as a medium grade, laterite bauxite from porphyry quartz diorite is classified as high-grade bauxite, laterite bauxite from andesite porphyry is classified as low-medium grade bauxite, and laterite bauxite from porphyry basalt in the studied area is classified as high grade bauxite. Laterite bauxites in the researched area were formed from weathered parent rocks which were intermediate - alkaline igneous rock.
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Prakash, P., and K. L. V. Ramana Rao. "Geomorphic Controls of the Chittamgondi Bauxite Deposit, Visakhapatnam District, Andhra Pradesh." Journal Geological Society of India 48, no. 3 (September 1, 1996): 257–63. http://dx.doi.org/10.17491/jgsi/1996/480302.
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Abstract Bauxite cappings occur discontinuously, along a linear stretch amidst the Eastern Ghuts comprising khondalite and charnockite groups of rocks, in the States of Andhra Pradesh and Orissa. These cappings/deposits, by virtue of their proximity to the eastern coastline of India, are christened as the East Coast Bauxite deposits. The East Coast Bauxites of Andhra Pradesh include the Anantagiri, Chintapalli, Gurtedu and Paderu groups of deposits. The Anantagiri group comprises Galikonda, Chittamgondi, Raktakonda and Kutuki deposits. The Chittamgondi bauxite deposit, charucterised by multi-directional slopes, is preserved in a sickle shaped synformal structure. Furthermore, the maximum thickness of bauxite, viz., 54 m, amongst the East Coast Bauxite deposits, investigated so far, has been recorded in it. As has already been established for other East Coast Bauxite deposits, the geomorphological setup and morphometry have played a pivotal role in the formation of the Chittamgondi bauxite deposit.
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Buccione, Roberto, Stefano Vitale, Sabatino Ciarcia, and Giovanni Mongelli. "Geochemistry and Geometrical Features of the Upper Cretaceous Vitulano Para-Autochthonous Karst Bauxites (Campania Region, Southern Italy): Constraints on Genesis and Deposition." Minerals 13, no. 3 (March 10, 2023): 386. http://dx.doi.org/10.3390/min13030386.
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In the Vitulano area, Upper Cretaceous bauxite bodies fill small depressions and karst cavities within Cretaceous shallow-water limestones. These bauxites were studied to understand the processes that led to their formation. Geochemical, mineralogical, and petrographic analyses were carried out on the bauxite samples, together with image analysis providing geometric parameters. The texture of Vitulano bauxite consists of ooids and sub-circular aggregates dispersed in a predominantly Ca-rich matrix. Ooids are generally formed by a single large core, often surrounded by an alternation of different aggregates of boehmite and Al-hematite reflecting different climate periods. The composition is dominated by the major elements Al2O3 and CaO with lower concentrations of Fe2O3 and SiO2. Boehmite, calcite, hematite, and anatase are the main mineralogical phases identified. Image analysis provided values of fractal dimension D that gives information on carbonate platform exposure times since it is linked to long-lasting sub-aerial events and diffusion-limited cluster aggregation processes. The tectonic evolution of the area played an important role in the genesis of the Vitulano bauxites since it favored the erosion, transport, and re-deposition of pre-existing bauxite material from the surrounding Campania bauxites. Based on this hypothesis, Vitulano bauxites are defined and classified as para-autochthonous, and this was supported by Eu/Eu* vs. Sm/Nd and Eu/Eu* vs. TiO2 Al2O3 indices displaying a similarity between Vitulano and the other Campania bauxites.
Dissertations / Theses on the topic "Bauxite"
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Richter, Willian 1985. "Purificação de biodiesel B5 com bauxita termoativada." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256082.
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Orientador: Daniel Barrera-ArellanoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A crescente preocupação com o meio ambiente ao longo dos anos é notória. Aspectos relevantes são a destinação de subprodutos e a emissão de gases e partículas para a atmosfera. Com a aprovação da lei n°. 11.097 de janeiro de 2005, o Brasil passou a inserção de biodiesel como substituto de diesel derivado de petróleo, que é menos poluente que os combustíveis fósseis. Porém, o acréscimo de biodiesel acarreta alguns problemas que não ocorrem com o uso de diesel puro. Destacam-se entre esses problemas os resíduos de reação e a deposição de compostos naturais, formados ou incorporados ao longo da sua cadeia de produção e distribuição. Assim o emprego de adsorvedores alternativos, como a bauxita ativada, para a remoção destes compostos tanto em biodiesel puro (B100) ou nas blendas torna-se uma opção rápida e de fácil implementação, uma vez que a sua instalação poderá ser feita no final da cadeia, nos postos de distribuição. Deste modo, o objetivo deste trabalho foi estudar um processo alternativo de purificação de biodiesel B5 sob uma coluna de bauxita ativada em processo laboratorial e piloto. O estudo empregou técnicas analíticas descritas e aprovadas pela Agência Nacional do Petróleo, Biocombustíveis e Gás Natural. Obtiveram-se também as curvas de rupturas no tratamento laboratorial para avaliar a eficiência do processo. As respostas obtidas para a determinação de contaminantes totais durante os processos mostraram uma diminuição similar nos processos laboratoriais e piloto, onde foi observada uma redução acima de 50% na escala piloto após o vigésimo primeiro dia de tratamento. Para a determinação de água foi observado uma redução de aproximadamente 90% no teste laboratorial e uma pequena redução nos primeiros dias no tratamento piloto. Os atributos de viscosidades dinâmica, cinemática e massa específica não se alteraram para ambos os processos, permanecendo dentro do estipulado pela legislação. No processo laboratorial foi observada uma redução na acidez, enquanto que na escala piloto este atributo permaneceu inalterado. Contudo, pode-se concluir com o estudo realizado que há possibilidade de utilização da bauxita ativada como agente purificador de blenda de biodiesel B5
Abstract: The growing concern for the environment over past years is notorious. Pinpoints are the allocation of by-products and the emissions of gases and particles into the atmosphere. With the approval of the law n °.11.097 from January 2005, Brazil introduced biodiesel as a substitute for petroleum products which is less polluting than fossil fuels. However, the usage of biodiesel entails some problems that do not occur with pure diesel. Prominent among these problems are the residues of reaction and the deposition of natural compounds, formed or incorporated throughout its chain of production and distribution. Thus, the use of alternative adsorbents such as activated bauxite for removing these compounds in pure biofuels (B100) or their mixtures, biodiesel B5, becomes a quick and easy to implement solution, since its installment can be made at the end of the chain at the distribution depots. Hence, the aim of this study was to investigate an alternative method of purifying biodiesel B5 in a column of activated bauxite in laboratory and pilot process. The study employed analytical techniques described and approved by the National Agency of Petroleum, Natural Gas and Biofuels. Disruption curves in laboratory processing were obtained to assess the efficiency of the process. The data obtained for total contaminants during the process showed a similar decrease in both pilot and laboratory processes where a decrease of over 50% was observed in the pilot scale after the twenty-first day of treatment. For the determination of water, a reduction of approximately 90% in the laboratory test and a small decrease in the first days of pilot treatment, were observed. The attributes of dynamic viscosity, kinematic and density were unaltered for both processes, remaining within legislation. In the laboratory process a reduction in the acidity was observed, while in the pilot it remained unchanged. In conclusion, the study reveals that the use of activated bauxite as a purification agent for B5 biodiesel blend is an optimal possibility
Mestrado
Tecnologia de Alimentos
Mestre em Tecnologia de Alimentos
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Mengler, Faron. "Gully erosion on rehabilitated bauxite mines." University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0176.
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[Truncated abstract] Landforms rehabilitated after bauxite mining can be vulnerable to soil loss by water erosion processes. On most rehabilitated sites, management controls such as deep ripping, contour mounding and landscaped sub-catchments limit erosion. Despite these measures, severe gully erosion that is anecdotally associated with steep slopes can damage rehabilitated areas and affect downstream drinking water resources. A review of erosion dynamics reveals that gullies develop episodically and in a non-linear manner. They often initiated as a near surface process and are influenced by natural climatic drivers. Despite this, local site characteristics including soil and landform can predispose an area to gully erosion. Moreover, erosion models, becoming more-widely utilized within the mining industry, may provide useful tools with which to measure, analyse, and manage gully erosion. One of these models, SIBERIA was tested to determine its suitability for application a tool to help manage erosion risk. We first surveyed 26 eroding and erosion-prone rehabilitated hillslopes to determine the common form and setting for gully erosion on these rehabilitated bauxite mines. A conceptual model was developed to include and explore the interplay between the common causes of the gullies surveyed. The conceptual model accounts for slope steepness but suggests that additionally, certain triggers and threshold effects operating under different site conditions are as influential (or even more influential) than slope steepness as determinants of gully erosion occurrence and severity. ... Soil properties and soil erodibility had some subtle influence on landform stability and erosion risk. The most-erodible media occurred where either: mine floor material was mixed with topsoil/ overburden; and/or the topsoil/overburden layer was thin or its coverage is patchy resulting in slaking subsoil, hardsetting soil and surface crusts. When erodible surface media were combined with steeper (>8[degrees]) or longer (>50 m) slopes or with any major erosion trigger, rill and gully development was greatly intensified. The SIBERIA simulation model was calibrated and its simulated outputs were compared to known locations of gully erosion on a steep, rehabilitated pit from the Willowdale mine. At a resolution of one metre, SIBERIA was able to simulate the approximate dimensions of gullies. However, SIBERIA could not simulate the exact location of individual gully headcuts. Additionally, SIBERA was able to simulate the effect of different microtopographic surface treatments but this was only achieved by increasing the grid resolution to 25 cm and reducing the size of the area simulated due to model constraints. Locations of gully headcuts were overlain onto a grid-based, Digital Elevation Model (DEM) using a Geographic Information System (GIS). The spatial distribution of gully headcut locations was compared to DEM derivatives such as slope and flow accumulation. Positive, and predictive relationships allow between the steepness of the slope of the pre-mining landform and the cell count of the area contributing to flow (catchment), as determined by GIS, may allow a mine scale indication of erosion risk using simple GIS desktop analysis.
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Jayalatharachchi, Vishakya. "Understanding desilication products in bauxite refinery residues." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/101127/1/Vishakya_Jayalatharachchi_Thesis.pdf.
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This research developed standard methods for quantifying and identifying alkali compounds in red mud, with a particular focus on desilication compounds. X-ray diffraction and infrared spectroscopy were used as they are relatively accessible and fast characterisation techniques for industry to use. This research is of particular importance as it will enable better predictions to be made on the suitability/stability of red mud in land rehabilitation programs.
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Desplat, Olivier. "Etude d’un procédé innovant de densification de poudres de bauxite." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM030.
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La bauxite est un minerai utilisé pour l’élaboration de l’aluminium ou en tant que matière première pour les ciments techniques. Elle est employée, sous sa forme naturelle, en blocs. Ces blocs se font de nos jours de plus en plus rares et leur manutention peut entraîner des pertes sous formes de poussières non valorisées. L’objectif de ce projet est de recycler ces fines particules minérales sous forme de compactés afin d’améliorer l’usage des ressources naturelles minérales qui se raréfient. Ces compactés sont obtenus par compression directe puis avec un procédé innovant couplant vibration et compression. La poudre de bauxite est mélangée à du ciment et de l’eau, puis subit une phase de compaction. Ces compactés doivent avoir des propriétés spécifiques en termes de masse volumique, porosité et résistance mécanique. La micro-tomographie à rayons X est utilisée pour décrire le réarrangement granulaire et l’homogénéité 3D des porosités. La distribution poreuse est caractérisée par analyse d’image et comparée avec les résultats de porosimétrie mercure. Cette étude concernant l’évolution des paramètres texturaux des compactés amène une compréhension des phénomènes liés à la phase de compression. Le stockage et la maturation de ces compactés sous température et humidité contrôlées ont également été étudiés. L’optimisation des paramètres de compression et de formulation, comme la quantité d’eau ou de ciment dans le mélange et la pression de compression, a mené à l’amélioration des propriétés des compactés. Dans un second temps, la phase de compression et les propriétés des compactés ont été améliorées en utilisant une phase préliminaire de vibrations. Cette phase a été optimisée grâce à l’étude de plusieurs paramètres spécifiques comme le type, l’amplitude et la fréquence des vibrationsThe bauxite is used in aluminium elaboration or directly as a raw material for calcium aluminates in technical cements. It is used, as a raw material, as blocks. Recently bauxite blocks are rarer and rarer and their handling can lead to dust wastes that are not re-used. The objective of this project is to recycle the fine mineral particles in compacts to improve the use of natural mineral resources that are running out. These products are compacted by direct compaction and also with an innovative vibration and compaction process. The bauxite is mixed with cement and water, and then the mixture is compacted. They must have specific properties with higher density and mechanical resistance. X-Rays micro-tomography is used to describe the particle rearrangement and the 3D density homogeneity. The porous distribution is then characterized by image analysis and compared with the mercury intrusion porosimetry results. This study on textural parameters evolution of the compacts leads to improve an understanding about the phenomenon during the compaction stage. The storage with controlled temperature and humidity will also be studied. The optimization of the compression and mixture parameters, as amount of water or cement in the mixture and compression pressure, led us to get compacts with improved properties. In the final study, we improved the compression stage and the compacts properties by another stage using in-situ vibrations. The vibrations stage has been optimized studying several vibrational parameters especially the type, the duration, the amplitude and the frequency of the vibrations
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Poli, Delci Magalhães. "Leitos cultivados utilizando crostas de eletrofusão da bauxita." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/286836.
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Orientador: José Teixeira FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
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Resumo: O trabalho foi desenvolvido no campo experimental da Faculdade de Engenharia Agrícola da Universidade Estadual de Campinas, Campinas, SP, posição geográfica definida pelas coordenadas 22° 53' 22" LS e 47° 044' 39" LW. O estudo procurou verificar se a utilização de crostas de eletrofusão da bauxita como substrato, em leitos cultivados construídos ou "Constructeds Wetlands" com os vegetais aquáticos emergentes Typha sp, Canna limbata e Cyperus prolifer, interfere na dinâmica do pH, fósforo e nitrogênio presentes em águas residuárias domésticas. Foram utilizados 6 tanques artificiais, sendo constituído por 3 séries de duas unidades, com fluxo vertical e saídas subsuperficiais, nominados por série Typha, leitos 3.1 e 3.2; série Canna, leitos 2.1 e 2.2; série Cyperus 1.1 e 1.2 e preenchidos com crostas de eletrofusão da Bauxita. A dimensão de cada tanque é de 4 metros de comprimento por 3 metros de largura por 1 metro de altura, totalizando 12 m³. Em cada uma das séries foram plantados os vegetais Typha sp, Canna limbata e Cyperus prolifer respectivamente. O período de monitoramento foi de setembro de 2009 a fevereiro de 2010. O desempenho do foi avaliado considerando o desenvolvimento dos vegetais, quantidades e qualidades químicas das águas residuárias. As águas foram coletadas semanalmente, em dias aleatórios, nas entradas e saídas dos tanques durante o período monitorado; os vegetais foram colhidos, somente uma vez, no final do período. As vazões médias diárias e os pH médios ocorridos no período monitorado, observados no afluente e nas saídas da série Typha foram 962 l/dia, 864 l/dia e 804 l/dia; os pH foram 6,9; 8,6 e 9,0. Na série Canna as vazões foram 954 l/dia, 797 l/dia e 735 l/dia; os pH foram 6,9; 9,2 e 9,3. Na série Cyperus as vazões foram 792 l/dia, 723 l/dia e 664 l/dia; os pH foram 6,9; 9,0 e 9,1. Os tempos de detenções hidráulicas, considerando os leitos nas séries citadas foram: 4,2 dias e 4,6 dias; 4,0 dias e 4,6 dias e 4,3 dias e 4,4 dias. As porcentagens médias de retenções de nitrogênio total nos leitos, considerando as massas que entraram, por intermédio dos afluentes, durante o período monitorado foram: a) Série Typha 27% e 19%; b) Série Canna 35% e 19%; c) Série Cyperus 32% e 21%. As remoções realizadas pelos vegetais foram: a) Série Typha 26% e 9%; b) Série Canna 42% e 11%; Série Cyperus 22% e 15%. Em relação ao fósforo, as porcentagens médias de retenções, considerando as massas que entraram nos leitos por meio dos afluentes, foram: a) Série Typha 70% e 31%; b) Série Canna 73 e 19%; Série Cyperus 74% e 27%. As remoções realizadas pelos vegetais foram: a) Série Typha 11% e 4%; b) Série Canna 17% e 4%; c) Série Cyperus 7% e 11%. As massas vegetais totais secas produzidas foram: a) Série Typha 39,9 Kg e 11.2 Kg; b) Série Canna 50,5 Kg e 26,4 Kg; Série c) Cyperus 24 Kg e 15 Kg. O estudo mostrou que o substrato promoveu alterações na eficiência e eficácia da retenção e remoção de nutriente, crescimentos dos vegetais, produção de matéria seca e qualidades da água efluente
Abstract: The study was conducted in the experimental field of the Faculty of Agricultural Engineering, State University of Campinas, Campinas, SP, geographical position defined by coordinates 22° 53' 22" LS and 47° 04' 39" LW. The study examined whether the use of bauxite electrofusion crusts, as a substrate in constructed wetlands with emergent vegetables Typha sp, Canna limbata and Cyperus prolifer, interferes on the dynamics of pH, phosphorus and nitrogen present in domestic wastewater. It was used 6 artificial beds, consisting of 3 sets of two units with vertical flow and subsurface outflows, nominated by Typha series, 3.1 and 3.2 beds; series Canna, 2.1 and 2.2 beds, series Cyperus, 1.1 and 1.2 and filled with Bauxite electrofusion crusts. The size of each bed was 4 meters long by 3 meters wide by 1 meter high, totaling 12 m³. In each series the vegetables Typha sp, Canna limbata and Cyperus prolifer were planted respectively. The monitoring period was from September 2009 to February 2010. The performance was evaluated considering the development of plants, the chemical quantities and qualities of wastewater. The waters were collected weekly, on random days, at the entrances and exits of the beds during the monitoring period; the plants were harvested only once, at the end of each period. The average daily flow rates and average pH occurred during this period, observed in the tributary and the outflow of the series Typha were 962 l/day, 864 l/day and 804 l/day, the pH were 6.9, 8.6 and 9.0. In the series Canna flow rates were 954 l/day, 797 l/day and 735 l/day, the pH were 6.9, 9.2 and 9.3. In the series Cyperus flow rates were 792 l/day, 723 l/day and 664 l/day, the pH were 6.9, 9.0 and 9.1. The hydraulic detention time, considering the beds in the series cited were 4.2 days and 4.6 days, 4.0 days and 4.6 days and 4.3 days and 4.4 days. The average percentage of total nitrogen retention in the beds, considering the masses that came through the tributaries during the monitoring period was: a) Series Typha 27% e19% b) Series Canna 35% and 19%, c) Series Cyperus 32% and 21%. The removals conducted by the plants were : a) Series Typha 26% and 9%, b) Series Canna 42% and 11%; Series Cyperus 22% and 15%. Regarding the phosphorus, the average percentage of retention, considering the masses that entered the bed through the tributaries was: a) Series Typha 70% and 31%, b) Canna Series 73 and 19%; Series Cyperus 74% and 27 %. The removals conducted by the plant were: a) Series Typha 11% and 4%, b) Series Canna 17% and 4%, c) Cyperus Series 7% and 11%. The total dry plant mass produced were: a) Series Typha 39.9 Kg is 11.2 Kg b) Series Canna 50.5 kg is 26.4 kg; Series c) Cyperus 24 Kg is 15 Kg. The study has shown that the substrate promoted changes in the efficiency and effectiveness of nutrient removal and retention, growth of vegetables, dry material production and quality of effluent water
Mestrado
Análise Ambiental e Dinâmica Territorial
Mestre em Geografia
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Costa, Jaime Henrique Barbosa da. "Modelagem matemática da operação de escrubagem da bauxita de Paragominas-PA." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3134/tde-20102010-152632/.
Full textAbstract:
O objetivo deste trabalho foi investigar, sob o enfoque da modelagem matemática, a operação de escrubagem da bauxita proveniente da jazida Miltônia 3, da Mina de Bauxita de Paragominas-PA, com vistas a fornecer parâmetros para previsão de seu desempenho e otimização. Para isso, foi realizada uma campanha de experimentos de escrubagem, em um tambor desagregador de laboratório, baseada em planejamento fatorial. Os parâmetros operacionais avaliados foram os seguintes: grau de enchimento, tempo de residência da polpa e velocidade de rotação. A variável de resposta selecionada foi a quantidade de finos (partículas menores que 0,037 mm) no produto desagregado. O programa de experimentos permitiu a análise da influência de cada variável operacional selecionada na desagregação da bauxita. De acordo com os resultados obtidos, o parâmetro operacional que produziu o efeito mais significativo na variável de resposta foi o grau de enchimento. O modelo desenvolvido foi validado através da comparação entre os valores obtidos em ensaios de escrubagem em uma unidade piloto e aqueles previstos pelo modelo. Os valores da quantidade de finos, no produto desagregado, previstos pelo modelo apresentaram uma excelente aproximação com os dados experimentais da operação em escala piloto.The aim of this study was to investigate and model the bauxite scrubbing of bauxite samples from Miltonia 3, a Vale operation at Pará state, Brazil. The experimental program included the design of a standard laboratory test, from which parameters were derived for predicting the operation of a scrubber in steady state conditions. Three main variables were selected for the laboratory experimental program using the factorial design technique. These were load fraction, residence time and rotation speed. The amount of fines was determined through screening both feed and product of the scrubbing test. The former was considered as a material characteristic while the second was the dependent variable, i.e. the result of the scrubbing process. An empirical model was developed according to which the load fraction was found the most important variable to the scrubbing process. Residence time was also included in the model due to its importance in designing scrubbers for industrial plants. To validate the model a comprehensive pilot plant program was carried out with the same bauxite sample from Miltonia 3 deposit used in the laboratory investigations. The comparison between experimental data and model calculated values indicated a good agreement, as most values were within ±10% deviation range.
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Bortoleto, Daniel Armelim. "Avaliação da heterogeneidade da bauxita de Juruti (PA) visando à otimização de protocolos de amostragem." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3134/tde-29122015-151004/.
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O controle de qualidade na indústria mineira visa à extração de recursos naturais com confiabilidade e efetividade a um custo mínimo. A compreensão e a aplicação da teoria da amostragem (Theory of Sampling ou TOS), desenvolvida por Pierre Gy, de forma integrada ao gerenciamento do processo, são essenciais para alcançar esse objetivo. Por este motivo, ressalta-se a importância de expor os benefícios de uma amostragem correta a todos os níveis hierárquicos de um empreendimento mineiro, a fim de se obter o engajamento da equipe técnica e operacional, assim como o orçamento necessário para financiar treinamentos e compra de equipamentos adequados para uma amostragem precisa e acurada. Uma amostra jamais apresentará características idênticas àquelas do material de origem, devido à existência do erro fundamental de amostragem, que está associado à heterogeneidade constitucional do material. Ainda existem os demais erros que surgem no decorrer das operações de amostragem, como, por exemplo, o erro de segregação e agrupamento, associado à heterogeneidade distribucional e onde a força da gravidade assume papel preponderante. Cada etapa do processo de amostragem gera um erro que deve ser conhecido para a determinação da confiabilidade das estimativas. Neste contexto, os testes de heterogeneidade são uma ferramenta imprescindível para adquirir o conhecimento sobre a variabilidade natural da jazida e para conduzir a amostragem de uma forma correta, gerando amostras representativas. O presente trabalho estuda a heterogeneidade do minério de alumínio da região oeste do Pará, a partir dos resultados obtidos em diferentes experimentos descritos na literatura com base na teoria da amostragem. Os resultados dos experimentos permitem, então, otimizar os protocolos de amostragem, assim como determinar as massas mínimas representativas para amostras de bauxita.Quality control in the mineral industry context is directed to extraction of natural resources with reliability, effectiveness and minimum cost. The understanding and application of the Theory of Sampling (TOS), developed by Pierre Gy, integrated with, process management are essential for reaching this objective. For this reason, it is important that all levels of personnel in a mining enterprise are made aware of the benefits of correct sampling so as to gain the engagement of the technical and operational team and equally, the necessary budget for training and purchase of appropriate equipment for sampling that is precise and accurate. Samples will never present exactly the same characteristics as the lot from which they originate because of the constitutional heterogeneity which generates the fundamental sampling error. Other errors arise in sampling operations; for example, the grouping and segregation errors related to distributional heterogeneity, where gravity assumes the most important role. Each stage of the sampling process produces an error which must be known for determining the reliability of the estimates. In this context, the heterogeneity tests are an essential tool for knowing the natural variability of the deposit, and to conduct sampling in a correct manner to generate representative samples. The present work studies the heterogeneity of the aluminum ore in western Pará, based on the results of different heterogeneity experiments described by the TOS. Results allow the optimization of sampling protocols as well as the determination of the minimum masses representative samples of bauxite.
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Vilela, Vívian Maria de Faria Nasser. "Anfíbios anuros em áreas em processo de restauração florestal após mineração de bauxita, Poços de Caldas-MG." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-16082012-161724/.
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Dentre as atividades envolvidas no processo de mudança do uso da terra, está a mineração de bauxita, cuja atividade leva à constante perda de hábitat. Uma forma de reparar a degradação antrópica à diversidade e ao funcionamento dos ecossistemas naturais é utilizar o processo de restauração ecológica. Este trabalho utilizou armadilhas-de-queda para estudar o efeito da restauração florestal após a mineração de bauxita na abundância de anuros de serapilheira. Os pontos amostrais encontram-se em um mosaico vegetacional no planalto de Poços de Caldas, MG, sendo dois locais em processo de reabilitação, cinco em processo de restauração e dois locais em remanescentes secundários de Floresta Estacional Semidecidual Montana. Foram coletados dados referentes a características da vegetação (área basal; densidade; abertura do dossel e espessura da serapilheira) e a altitude em cada ponto amostral. O Critério de Informação de Akaike corrigido (AICc) foi usado para avaliar a eficácia de nove modelos construídos a priori na predição da abundância das duas espécies coletadas que apresentaram suficiência amostral, separadamente. A abundância de Rhinella pombali foi inversamente relacionada com a densidade da vegetação e com a altitude. O modelo com a abertura do dossel influenciou positivamente a abundância de Ischnocnema juipoca. A restauração florestal possibilitou a recolonização por duas espécies de anuros - E. juipoca e R. pombali, evidenciando a importância dessa atividade na reconstrução de habitats para a biodiversidade nativa.Bauxite mining is one of the activities involved in land-use change that leads to total habitat loss. The process of ecological restoration is a way to repair anthropic damages to biodiversity and to natural ecosystems functioning. In this work, pitfall traps with drift fences were used to verify the influence of restoration of forest areas priorly submitted to bauxite mining on the abundance of leaf litter anurans. Sample sites were located in vegetation patches on the plateau of Poços de Caldas-MG, Brazil: two in areas under rehabilitation process, five in areas under restoration process and two in secondary fragments of Montane Semideciduous Seasonal Forest. Data concerning characteristics of vegetation (basal area, density, canopy openness and litter thickness) and height were collected in each sample site. The corrected Akaike Information Criterion (AICc) was used to evaluate the efficiency of nine models constructed a priori to predict abundance of two species collected that presented sampling sufficiency, analysed as separate groups. Abundance of Rhinella pombali was inversely related to height and vegetation density. The canopy openness model positively influenced abundance of Ischnocnema juipoca. Recolonization by two anuran species E. juipoca and R. pombali was possible due to forest restoration, which shows the importance of this process in reconstructing habitats for native biodiversity.
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Ahmad, Ishaq [Verfasser]. "Beneficiation of Bauxite by Washing Processes / Ishaq Ahmad." München : Verlag Dr. Hut, 2012. http://d-nb.info/1020298588/34.
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Petersen, Tanya M. "Characteristics of desilication products in bauxite refining residue." Thesis, Petersen, Tanya M. (1992) Characteristics of desilication products in bauxite refining residue. Masters by Research thesis, Murdoch University, 1992. https://researchrepository.murdoch.edu.au/id/eprint/52451/.
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The production of alumina from bauxite by the Bayer process generates a large volume of residue (red mud). This residue contains a percentage of complex zeolitic sodium aluminium silicates, formed by the precipitation of silica from the Bayer liquor and are known as the desilication product or DSP. The presence of DSP in red mud contributes significantly to making the residue highly alkaline and high in sodium and therefore a potential environmental hazard upon disposal.
This thesis documents the findings of a study with the objective of examining the nature and behaviour of a DSP-type mineral, determining its stability, including the way in which the release of sodium occurs and the potential for cation exchange. By so doing, a clearer picture of the DSP in red mud and its reaction to environmental factors, such as the pH of water percolating through the red mud disposal sites, was sought. An insight into the possibility of predisposal treatments, such as mixing the mud with acid waste or with material that would induce a favourable cation exchange was similarly gained.
A laboratory-synthesised DSP mineral was used in these studies, because of the difficulty of working with red mud, in which DSP is cloaked with other residue minerals. The similarity of various synthetic DSPs (including the synthetic material used for this work) to that found in red mud was examined. It was found that the DSP formed at Alcoa's Kwinana plant (Western Australia) was a composite of the minerals noselite/nosean and sodalite, with sulphate being the main anion incorporated into the DSP. The synthetic mineral used in the study was therefore a mixture of the three aforementioned minerals.
The sensitivity of synthetic and non-synthetic DSP to the citrate-bicarbonate-dithionite {CBD} method, used in leaching away the iron oxide that masks the DSP in red mud was examined. No significant effect on the DSP after leaching by CBD was observable. This confirmed that studies of DSP in red mud after removal of iron oxides by the CBD method were valid.
In the study of DSP stability, its behaviour at various levels of acidity and alkalinity was noted, to determine
under what disposal conditions the potentially harmful release of sodium is most likely to occur and to provide
information relevant to acid-waste treatment of red mud before or at disposal. Synthetic DSP samples were subjected to a range of pH conditions, from very alkaline to very acidic, over a range of time periods up to three weeks duration. The results of these tests indicated that DSP is stable to pHs as low as 8.5, with no significant release of sodium to the environment after 3 weeks.
The study of cation exchange behaviour in DSP was undertaken to determine if exchanging sodium (which is toxic to plants) for some likely cations such as potassium or ammonium (plant nutrients) may feasibly be used to rehabilitate red mud, since zeolitic minerals like those in DSPs are noted for their ion exchange properties. The exchange of sodium from within synthetic DSP for potassium, ammonium and calcium ions was investigated. It was concluded that the cubic crystal habit of the DSP examined restricted the exchange of sodium ions with cations such as calcium, but allowed other cations (particularly potassium) to penetrate and replace up to 30% of the sodium ions contained within the lattice. Therefore treatment of red mud with waste solutions high in potassium prior to disposal would be beneficial. The exchangability of sodium for ammonium was also significant (16%), meaning that treatment of red mud with waste solutions containing ammonium would also be beneficial to revegetation of the red mud lakes.
Overall the study shows that red mud could be neutralised to a pH of 8.5 and treated with a waste solution high in potassium and/or ammonium in order to make the disposal sites more amenable to rehabilitation and revegetation.
Books on the topic "Bauxite"
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Sehnke, Errol D. Bauxite mines worldwide. Washington, D.C: U.S. Dept. of the Interior, U.S. Bureau of Mines, 1995.
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United Nations Industrial Development Organization., ed. Bauxite testing laboratories. New York: United Nations, 1985.
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United Nations. Industrial Development Organization., ed. Bauxite testing laboratories. New York: United Nations, 1985.
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Mines, Indian Bureau of, ed. Monograph on bauxite. Nagpur: Govt. of India, Ministry of Mines, Indian Bureau of Mines, Training, Mining Research and Publication Division, Publication Cell, 1992.
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Knierzinger, Johannes. Bauxite Mining in Africa. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-52706-2.
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Bárdossy, György. The Halimba bauxite deposit. Budapest: Geological Institute of Hungary, 2007.
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Bárdossy, György. The Halimba bauxite deposit. Budapest: Geological Institute of Hungary, 2007.
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Bárdossy, György. The Halimba bauxite deposit. Budapest: Geological Institute of Hungary, 2007.
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Raahauge, Benny E., and Fred S. Williams, eds. Smelter Grade Alumina from Bauxite. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-88586-1.
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J, MacDonald D., ed. Pretreatment of bauxite with hydrogen. Washington, DC: Bureau of Mines, U.S. Dept. of the Interior, 1990.
Find full textBook chapters on the topic "Bauxite"
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Gooch, Jan W. "Bauxite." In Encyclopedic Dictionary of Polymers, 70. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_1140.
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Keersemaker, Marco. "Bauxite." In SpringerBriefs in Earth Sciences, 31–42. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-40268-6_6.
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Abzalov, Marat. "Bauxite Deposits." In Modern Approaches in Solid Earth Sciences, 411–25. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-39264-6_34.
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Hose, H. R. "Bauxite Mineralogy." In Essential Readings in Light Metals, 21–29. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-48176-0_2.
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Hose, H. R. "Bauxite Mineralogy." In Essential Readings in Light Metals, 21–29. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118647868.ch2.
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Wanyo, Michael, Anthony T. Filidore, and Benny E. Raahauge. "Physical Bauxite Processing: Crushing and Grinding of Bauxite." In Smelter Grade Alumina from Bauxite, 133–55. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-88586-1_3.
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Crowson, Phillip. "Aluminium/Bauxite/Alumina." In Minerals Handbook 1992–93, 1–13. London: Palgrave Macmillan UK, 1992. http://dx.doi.org/10.1007/978-1-349-12564-7_1.
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Atkins, Patrick R., Chris Bayliss, and Sam Ward. "Bauxite Mining Sustainably." In Essential Readings in Light Metals, 60–65. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-48176-0_8.
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Evans, Ken, Eirik Nordheim, and Katy Tsesmelis. "Bauxite Residue Management." In Light Metals 2012, 63–66. Cham: Springer International Publishing, 2012. http://dx.doi.org/10.1007/978-3-319-48179-1_11.
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Crowson, Phillip. "Aluminium/Bauxite/Alumina." In Minerals Handbook 1994–95, 1–13. London: Palgrave Macmillan UK, 1994. http://dx.doi.org/10.1007/978-1-349-13431-1_1.
Full textConference papers on the topic "Bauxite"
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Nikolakopoulos, Konstantinos G., Aggeliki Kyriou, Evlampia Kouzeli, Saeid Asadzadeh, Nicole Köllner, Friederike Körting, Justus Constantin Hildebrand, Steven Micklethwaite, and Ekaterina Savinova. "3D representation of a bauxite mine in the frame of m4mining project." In Earth Resources and Environmental Remote Sensing/GIS Applications XV, edited by Karsten Schulz, Konstantinos G. Nikolakopoulos, and Ulrich Michel, 25. SPIE, 2024. http://dx.doi.org/10.1117/12.3031850.
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Beavogui, Marie Constance, Boris Grigorievich Balmaev, Oumar Barou Kaba, Ahmed Amara Konaté, and Irina Viktorovna Loginova. "Bauxite enrichment process (Bayer process): Bauxite cases from Sangaredi (Guinea) and Sierra Leone." In PROCEEDINGS OF THE 16TH INTERNATIONAL CONFERENCE ON INDUSTRIAL MANUFACTURING AND METALLURGY (ICIMM 2021). AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0074812.
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Grahita, Lanjar, Zulfiadi Zulhan, and Taufiq Hidayat. "High Temperature Reduction of Bauxite Residue." In RawMat 2021. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/materproc2021005128.
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Wang, Sicheng, Tuan Nguyen, Hong Peng, Fang You, and Longbin Huang. "On the Mechanism of Sodic Removal from Bauxite Residue and Bauxite Desilication Products (BDP) Using Microbiogenic Acids." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.5617.
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Abdulvaliyev, R. A., and A. Akcil. "Change in the phase composition of low-quality bauxites as a result of chemical activation." In Challenges of Science. Institute of Metallurgy and Ore Beneficiation, Satbayev University, 2021. http://dx.doi.org/10.31643/2021.10.
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As a result of separation of a fine fraction of gibbsite-kaolinite low-quality bauxite from the Krasnogorsky deposit, it is possible to increase its silicon module. When bauxite is chemically activated in a solution of sodium bicarbonate, the fine fraction is effectively separated from the large one and the phase composition changes – the calcium silicate phase disappears and the calcite phase is formed. With an increase in the activation temperature, the content of kaolinite and siderite decreases, the content of quartz and hematite increases. Studies have shown that at chemical activation temperatures of 120 oC, lasting more than 120 minutes and 200 oC, lasting more than 40 minutes, a dawsonite phase is formed in bauxite, which compacts the mineral structure. When determining the mode of chemical activation, it is necessary to take into account the negative possibility of the formation of dawsonite.
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Hagni, Richard D., and Ann M. Hagni. "PHOSPHORUS MINERALOGY OF THE JAMAICA BAUXITE ORES." In 50th Annual GSA North-Central Section Meeting. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016nc-274964.
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Herath, Hashindra K., Brian F. Platt, James V. Cizdziel, and Inoka H. Widanagamage. "BAUXITE: TO REMEDIATE HEAVY METAL CONTAMINATED WATER?" In Joint 69th Annual Southeastern / 55th Annual Northeastern GSA Section Meeting - 2020. Geological Society of America, 2020. http://dx.doi.org/10.1130/abs/2020se-345334.
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Everett, Jim. "An Information System for a Bauxite Mine." In InSITE 2007: Informing Science + IT Education Conference. Informing Science Institute, 2007. http://dx.doi.org/10.28945/3062.
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Bauxite is mined and transported by conveyor to a processing plant, screened and washed, then placed into blended stockpiles to feed the alumina refinery. While being stacked to the stockpile, the ore is sampled. Completed stockpiles must be acceptably close to target grade (composition), not only in alumina, but also in residual silica, carbon and sodium carbonate. The mine is an open-cut pit. Each day the choice of ore to mine, from multiple locations in the pit, is based upon estimates of grade. Estimated grade, from exploration drilling of the area before mining, has both systematic and random error. This paper describes an information system to guide the daily choice of ore to mine. Continually updating the comparison between forecasts and sampled product, the system provides adjusted forecasts. Ore is selected to bring the exponentially smoothed grade to target, in each of the control minerals.
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Lee, Sheldon H. D., Richard F. Henry, and Kevin M. Myles. "Removal of Alkali Vapors by a Fixed Granular-Bed Sorber Using Activated Bauxite as a Sorbent." In ASME 1985 International Gas Turbine Conference and Exhibit. American Society of Mechanical Engineers, 1985. http://dx.doi.org/10.1115/85-gt-167.
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Studies have been conducted to develop a fixed granular-bed sorber for the removal of alkali vapors in a pressurized fluidized-bed combustion (PFBC) combined-cycle system. A laboratory-scale pressurized alkali-vapor sorption test unit was used to characterize activated bauxite, the most effective sorbent identified earlier, for its alkali vapor sorption capability in a gas stream with temperature (≤900°C), pressure (10 atm absolute), and composition closely simulating the actual PFBC flue gas. A scale-up of laboratory tests is being conducted in a 15.2-cm-dia (6-in.-dia) PFBC system to demonstrate the granular-bed sorber concept. The NaCl-vapor sorption chemistry of activated bauxite is described. The extent of alkali-vapor evolution from the activated bauxite bed itself is discussed, along with an evaluation of the significance of its alkali vapor contribution to a downstream gas turbine. Details of the design of a high-temperature/high-pressure alkali sorber system for the demonstration of the sorber are presented.
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Kar, M. K., and J. Safarian. "Smelting of different hydrogen-reduced bauxite residue-calcite pellets for iron and alumina recovery." In 12th International Conference of Molten Slags, Fluxes and Salts (MOLTEN 2024) Proceedings, 1543–52. Australasian Institute of Mining and Metallurgy (AusIMM), 2024. http://dx.doi.org/10.62053/nhuu7429.
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Bauxite residue is one of the most important by-products from the alumina industry with no commercial use till now. The utilisation of bauxite residue through pelletising with different lime additions, hydrogen reduction, and smelting has been studied in this work. Three different types of green pellets were made with varying calcite-to-bauxite residue ratio and subsequently sintered at elevated temperatures. The sintered pellets were isothermally reduced at 1000°C under hydrogen gas followed by smelting of the reduced pellets in argon at 1500°C. Smelting of the reduced pellets leads to the recovery of metallic iron and the formation of a leachable calcium aluminate slag. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterise the phases and microstructural analysis. The iron produced in the smelting process has a high purity, above 99.5 wt per cent. While the iron content of the slags is quite low, and the slags shows variations of krotite (CaAl2O4), gehlenite (Ca2Al2SiO7), and perovskite (CaTiO3) phases based on the variation of calcite addition. It was found that the more calcite addition in pelletising yields higher percentage of krotite phase as compared to lower calcite-containing pellets. Employing quantitative XRD analysis, the krotite phase fraction was found approximately 85 wt per cent for higher calcite-added pellet, and around 74 wt per cent for lower calcite-added pellet. FactSage™, ver 8.1 (Thermfact and GGT- Technologies) thermodynamic software was used to evaluate the obtained experimental data, they both revealed that the components of the bauxite residue are mostly distributed into the calcium aluminate slag phase.
Reports on the topic "Bauxite"
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Khan, Sarosh R. Caribbean Economic Alchemy: Has Magic Returned to Bauxite? Inter-American Development Bank, January 2015. http://dx.doi.org/10.18235/0008452.
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After a long period of stagnating prices, the global bauxite market is experiencing changes which are expected to drive prices higher. To a large extent, these changes are driven by increasing demand from Chinese manufacturing. However, constraints on exports imposed by major bauxite producers, such as Indonesia and India have affected the supply side as well, and represent an opportunity for Caribbean bauxite exporters to increase their share of a growing market. This Policy Brief provides an overview of the aforementioned changes in market conditions and proposes a new approach to organizing bauxite mining for the Caribbean bauxite exporters.
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Etheridge, E. L. Design bases: Bauxite-sulfuric acid feed facilities 100-K Area. Office of Scientific and Technical Information (OSTI), June 1993. http://dx.doi.org/10.2172/10148140.
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Marty, Richard. Formation and zonation of ferruginous bauxite deposits of the Chapman quadrangle, Oregon. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.5397.
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Fassio, Joseph. Geochemical Evolution of Ferruginous Bauxite Deposits in Northwestern Oregon and Southwestern Washington. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.5708.
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Hoffman, Charles. A stratigraphic and geochemical investigation of ferruginous bauxite deposits in the Salem Hills, Marion County, Oregon. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.3192.
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Jackson, Ronald. A Mineralogical and Geochemical Study of the Ferruginous Bauxite Deposits in Columbia County, Oregon, and Wahkiakum County, Washington. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.2132.
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Wei, Fulu, Ce Wang, Xiangxi Tian, Shuo Li, and Jie Shan. Investigation of Durability and Performance of High Friction Surface Treatment. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317281.
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The Indiana Department of Transportation (INDOT) completed a total of 25 high friction surface treatment (HFST) projects across the state in 2018. This research study attempted to investigate the durability and performance of HFST in terms of its HFST-pavement system integrity and surface friction performance. Laboratory tests were conducted to determine the physical and mechanical properties of epoxy-bauxite mortar. Field inspections were carried out to identify site conditions and common early HFST distresses. Cyclic loading test and finite element method (FEM) analysis were performed to evaluate the bonding strength between HFST and existing pavement, in particular chip seal with different pretreatments such as vacuum sweeping, shotblasting, and scarification milling. Both surface friction and texture tests were undertaken periodically (generally once every 6 months) to evaluate the surface friction performance of HFST. Crash records over a 5-year period, i.e., 3 years before installation and 2 years after installation, were examined to determine the safety performance of HFST, crash modification factor (CMF) in particular. It was found that HFST epoxy-bauxite mortar has a coefficient of thermal expansion (CTE) significantly higher than those of hot mix asphalt (HMA) mixtures and Portland cement concrete (PCC), and good cracking resistance. The most common early HFST distresses in Indiana are reflective cracking, surface wrinkling, aggregate loss, and delamination. Vacuum sweeping is the optimal method for pretreating existing pavements, chip seal in particular. Chip seal in good condition is structurally capable of providing a sound base for HFST. On two-lane highway curves, HFST is capable of reducing the total vehicle crash by 30%, injury crash by 50%, and wet weather crash by 44%, and providing a CMF of 0.584 in Indiana. Great variability may arise in the results of friction tests on horizontal curves by the use of locked wheel skid tester (LWST) due both to the nature of vehicle dynamics and to the operation of test vehicle. Texture testing, however, is capable of providing continuous texture measurements that can be used to calculate a texture height parameter, i.e., mean profile depth (MPD), not only for evaluating friction performance but also implementing quality control (QC) and quality assurance (QA) plans for HFST.
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Hassan, N. M., J. C. Marra, and E. A. Kyser. Adsorption decontamination of radioactive waste solvent by activated alumina and bauxites. Office of Scientific and Technical Information (OSTI), October 1994. http://dx.doi.org/10.2172/10186149.
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Irazábal Briceño, Irene, and Natascha Nunes da Cunha. Atención a la conflictividad minera en América Latina y el Caribe: una guía para la acción. Inter-American Development Bank, October 2024. http://dx.doi.org/10.18235/0013205.
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La minería es un pilar fundamental para el desarrollo económico de América Latina y el Caribe, especialmente en el contexto de la transición energética global, que ha incrementado la demanda de minerales clave como cobre, litio, niquel, hierro y bauxita, entre otros. Al mismo tiempo, la minería ha sido históricamente una fuente de conflictos sociales que involucran a múltiples actores. Para que la minería contribuya plenamente al desarrollo sostenible debe ser moderna, innovadora, inclusiva y responsable tanto social como ambientalmente. A pesar de los numerosos e importantes esfuerzos por implementar estándares sociales y ambientales que den cuenta de los desafios y las oportunidades que enfrenta la actividad, las tensiones y resistencias hacia la minería persisten. En ese sentido, la gestión de la conflictividad asociada a la minería es crucial para asegurar que la extracción de estos recursos minerales beneficie tanto a las comunidades locales como a los objetivos globales de sostenibilidad. Este documento analiza las dinámicas complejas de los conflictos mineros, los costos asociados para actores privados y públicos y la necesidad de estrategias proactivas, basada en un abordaje sistémico, para transformar los conflictos en oportunidades de desarrollo. Además ofrece una guía para que los responsables de políticas integren la gestión de la conflictividad en la planificación de largo plazo en las regiones ricas en recursos minerales.