WorldWideScience

Sample records for bauxite

  1. Bauxite and alumina

    Science.gov (United States)

    Bray, E.L.

    2009-01-01

    The article provides information on bauxite and alumina mining. U.S. states like Alabama, Arkansas and Georgia produced small amounts of bauxite and bauxitic clays for nonmetallurgical uses. Total metallurgical-grade bauxite imports in 2008 is cited. The leading suppliers of bauxite to the U.S. are Jamaica, Guinea and Brazil. The estimated domestic production of alumina in 2008 is mentioned. It also discusses consumption and prices of both bauxite and alumina.

  2. FOUR CENTURIES OF BAUXITE MINING

    Directory of Open Access Journals (Sweden)

    Rikard Marušić

    1993-12-01

    Full Text Available In the paper the results of many years of archival and field investigations in the history of bauxite mining of the three authors are presented. It was established that in Istria in the valley of the river Mirna beneath the Castle of Sovinjak bauxite was exploited already 400 years ago, and that 1808 about this ore the first scientific account was published. Accordingly, the statements in the professional literature that the first bauxite mine opened 1873 in the French Provence and that the bauxite ore for the first time was scientifically described 1821 have to be revised. About this necessary revision here the essential proofs are produced.

  3. Bauxite Mining and Alumina Refining

    OpenAIRE

    Donoghue, A. Michael; Frisch, Neale; Olney, David

    2014-01-01

    Objective: To describe bauxite mining and alumina refining processes and to outline the relevant physical, chemical, biological, ergonomic, and psychosocial health risks. Methods: Review article. Results: The most important risks relate to noise, ergonomics, trauma, and caustic soda splashes of the skin/eyes. Other risks of note relate to fatigue, heat, and solar ultraviolet and for some operations tropical diseases, venomous/dangerous animals, and remote locations. Exposures to bauxite dust,...

  4. THE BAUXITES AND JELAR - BEDS

    Directory of Open Access Journals (Sweden)

    Krešimir Sakač

    1993-12-01

    Full Text Available Minor bauxite deposits and occurrences were formed in technically disturbed environments in the middle part of the Adriatic geotectonic unit in Dinarides, contemporary with the clastic Jelar-beds in the Late Lutetian time. Uneven chemical composition of these Eocene bauxites, their sporadic occurrences in developed paleorelief as well as characteristic petrographic composition of the immediate overlying rocks point out at different genetical conditions (the paper is published in Croatian.

  5. China’s Bauxite Resources Development

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>In recent 10 years,China has witnessed a growing trend of investment in bauxite prospecting. In 1998,China proved bauxite reserves of 2.34billion tons, while in 2008, it proved bauxite reserves of 3.223billion tons

  6. The geomicrobiology of bauxite deposits

    Institute of Scientific and Technical Information of China (English)

    Xiluo Hao; Kwunlun Leung; Rucheng Wang; Weidong Sun; Yiliang Li

    2010-01-01

    Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evolution of continental surfaces. Geomicrobiological analysis makes it possible to verify that microorganisms have played a critical role during the formation of bauxite with the possibility already intimated in previous studies. Ambient temperature, abundance of water, organic carbon and bioavailable iron and other metal substrates provide a suitable environment for microbes to inhabit. Thiobacillus, Leptospirilum, Thermophilic bacteria and Heterotrophs have been shown to be able to oxidize ferrous iron and to reduce sulfate-generating sulfuric acid, which can accelerate the weathering of aluminosilicates and precipitation of iron oxyhydroxides. Microorganisms referred to the genus Bacillus can mediate the release of alkaline metals. Although the dissimilatory iron-reducing and sulfate-reducing bacteria in bauxites have not yet been identified, some recorded authigenic carbonates and "bacteriopyrites" that appear to be unique in morphology and grain size might record microbial activity. Typical bauxite minerals such as gibbsite, kaolinite, covellite, galena, pyrite, zircon, calcium ptagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecologyof such bauxitic microorganisms inhabiting continental (sub) surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.

  7. Calcification Transformation of Diasporic Bauxite

    Science.gov (United States)

    Zhao, Qiuyue; Zhu, Xiaofeng; Lv, Guozhi; Zhang, Zimu; Yin, Zhengnan; Zhang, Tingan

    2016-06-01

    The disposal of red mud, which is a solid waste that is generated during the extraction of alumina from bauxite, is one of major problems faced by the aluminum industry. Alkali in red mud seeping under the soil may pollute land and water. The Northeastern University, China, has proposed a calcification-carbonation method to deal with low-grade bauxite or red mud. Its main purpose is to change the equilibrium phase of red mud to 2CaO·SiO2 and CaCO3 hydrometallurgically, so that recomposed alkali-free red mud can be widely used. We conducted calcification transformation experiments using diasporic bauxite sampled from Wenshan, and investigated the effects of parameters such as diasporic bauxite grain size, temperature and treatment time on the calcification transformation digestion rate, which is also termed the calcification transformation rate (CTR). The main phase in the calcification transformation slag (CTS) is hydrogarnet with different grain sizes. The CTR increases with decrease in diasporic bauxite grain size, or increase in temperature or reaction time. The CTR reaches a maximum of 87% after 120 min reaction at 240°C. The Na2O/Al2O3 ratio decreases with increase in temperature and reaches 1.5. The sodium content in the CTS decreases with increasing reaction time and is lower than that in the red mud treated using the Bayer process (4-12%).

  8. Bauxite deposits in Suriname and Demerara (British Guiana)

    NARCIS (Netherlands)

    Kersen, van J.F.

    1956-01-01

    On the basis of the morphology and stratigraphic positions, the bauxite deposits in Suriname and Demerara (British Guiana) were divided into four main groups, namely: 1. Plateau type bauxite, 2. High-level type bauxite, 3. Medium-level type bauxite, 4. Low-level type bauxite. The age of these deposi

  9. Analysis of ASTER data for mapping bauxite rich pockets within high altitude lateritic bauxite, Jharkhand, India

    Science.gov (United States)

    Guha, Arindam; Singh, Vivek Kr.; Parveen, Reshma; Kumar, K. Vinod; Jeyaseelan, A. T.; Dhanamjaya Rao, E. N.

    2013-04-01

    Bauxite deposits of Jharkhand in India are resulted from the lateritization process and therefore are often associated with the laterites. In the present study, ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) image is processed to delineate bauxite rich pockets within the laterites. In this regard, spectral signatures of lateritic bauxite samples are analyzed in the laboratory with reference to the spectral features of gibbsite (main mineral constituent of bauxite) and goethite (main mineral constituent of laterite) in VNIR-SWIR (visible-near infrared and short wave infrared) electromagnetic domain. The analysis of spectral signatures of lateritic bauxite samples helps in understanding the differences in the spectral features of bauxites and laterites. Based on these differences; ASTER data based relative band depth and simple ratio images are derived for spatial mapping of the bauxites developed within the lateritic province. In order to integrate the complementary information of different index image, an index based principal component (IPC) image is derived to incorporate the correlative information of these indices to delineate bauxite rich pockets. The occurrences of bauxite rich pockets derived from density sliced IPC image are further delimited by the topographic controls as it has been observed that the major bauxite occurrences of the area are controlled by slope and altitude. In addition to above, IPC image is draped over the digital elevation model (DEM) to illustrate how bauxite rich pockets are distributed with reference to the topographic variability of the terrain. Bauxite rich pockets delineated in the IPC image are also validated based on the known mine occurrences and existing geological map of the bauxite. It is also conceptually validated based on the spectral similarity of the bauxite pixels delineated in the IPC image with the ASTER convolved laboratory spectra of bauxite samples.

  10. Bauxite Based Bricks for Steel Ladle

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the classification,technical requirements,test methods,inspection rules,packing,marking,transportation,storage,and quality certificate of bauxite based bricks for steel ladle linings.This standard is applicable to bauxite based bricks for working layer of steel ladle.

  11. Dynamic models of lateritic bauxite formation

    Science.gov (United States)

    Zhukov, V. V.; Bogatyrev, B. A.

    2012-09-01

    2D dynamic models of bauxite formation in the weathering mantle covering denudation areas drained by river systems are discussed. The role of relief-forming factors (tectonic uplift, river erosion and denudation of drainage divides), the interrelation of hydrogeological and lithologic structure of the bauxitebearing weathering mantle, and the dynamics of zoning formation above and below groundwater level are described in the models. Creative and destructive epochs of lateritic bauxite formation differing in tectonic regime are distinguished. During the creative epochs, lateritic weathering develops against a background of decreasing denudation and an increase in areas of bauxite formation. The destructive epochs are characterized by intense denudation, cutting down the areas of lateritic bauxite formation and eventually leading to the complete removal of the weathering mantle. Different morphogenetic types and varieties of bauxite-bearing weathering mantles develop during creative and destructive epochs. The morphology of the weathering mantle sections at the deposits of Cenozoic lateritic bauxite in the present-day tropical zone of the Earth corresponds to the destructive epoch, which is characterized by declining areas of lateritic bauxite formation and will end with complete denudation of lateritic bauxite.

  12. Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

    Science.gov (United States)

    Gong, Xuzhong; Ge, Lan; Wang, Zhi; Zhuang, Siyuan; Wang, Yuhua; Ren, Lihui; Wang, Mingyong

    2016-02-01

    Feasibility of high-sulfur bauxite electrolysis desulfurization was examined using the electrochemical characterization, XRD, DTA, and FTIR. The cyclic voltammetry curves indicated that bauxite water slurry (BWS) electrolysis in NaOH system was controlled by diffusion. Additionally, the desulfurization effect of NaCl as the electrolyte was significantly better than that of NaOH as an electrolyte. As the stirring rate increased, the desulfurization ratio in NaCl system was not increased obviously, while the desulfurization ratio in NaOH system increased significantly, indicating further that electrolysis desulfurization in NaOH solution was controlled by diffusion. According to XRD, DTA, and FTIR analysis, the characteristic peaks of sulfur-containing phase in bauxite after electrolysis weakened or disappeared, indicating that the pyrite in bauxite was removed from electrolysis. Finally, the electrolytic desulfurization technology of bauxite was proposed based on the characteristics of BWS electrolysis.

  13. Bauxite washing for the removal of clay

    Science.gov (United States)

    Ahmad, Ishaq; Hartge, Ernst-Ulrich; Werther, Joachim; Wischnewski, Reiner

    2014-11-01

    Clay impurities associated with bauxite negatively affect the Bayer process for alumina production. These impurities should be removed as far as possible by a beneficiation technique before the ore is used as feed for the Bayer process. In this current investigation, bauxite washing was conducted in the laboratory. Bauxite washing is a physical process that causes the disintegration and deagglomeration of the clay matrix, and bauxite is liberated from the clay (mainly rich in silica). Subsequently, separation occurs with the assistance of wet screening at a predetermined cut size. Three techniques were investigated in the laboratory: drum washing, water-jet washing, and ultrasonic washing. Various operating parameters were investigated for drum washing and water-jet washing, including materials retention time, drum rotation speed, solid concentration, water-jet spray duration, pressure, and height. We concluded that the retention time of bauxite inside the drum at a solid concentration of 55wt% and a drum rotation speed of 31 r/min is the dominant parameter for the removal of clay from the bauxite surface.

  14. Bauxite washing for the removal of clay

    Institute of Scientific and Technical Information of China (English)

    Ishaq Ahmad; Ernst-Ulrich Hartge; Joachim Werther; and Reiner Wischnewski

    2014-01-01

    Clay impurities associated with bauxite negatively affect the Bayer process for alumina production. These impurities should be removed as far as possible by a beneficiation technique before the ore is used as feed for the Bayer process. In this current investigation, bauxite washing was conducted in the laboratory. Bauxite washing is a physical process that causes the disintegration and deagglomeration of the clay matrix, and bauxite is liberated from the clay (mainly rich in silica). Subsequently, separation occurs with the assistance of wet screening at a predetermined cut size. Three techniques were investigated in the laboratory: drum washing, water-jet washing, and ultrasonic washing. Various operating parameters were investigated for drum washing and water-jet washing, including materials retention time, drum rotation speed, solid concentration, water-jet spray duration, pressure, and height. We concluded that the retention time of bauxite inside the drum at a solid concentration of 55wt% and a drum rotation speed of 31 r/min is the dominant parameter for the removal of clay from the bauxite surface.

  15. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    OpenAIRE

    Ma D; Guo M; Zhang M

    2013-01-01

    Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC), a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate...

  16. Image analyses in bauxitic ores: The case of the Apulian karst bauxites

    Science.gov (United States)

    Buccione, Roberto; Sinisi, Rosa; Mongelli, Giovanni

    2015-04-01

    This study concern two different karst bauxite deposits of the Apulia region (southern Italy). These deposits outcrop in the Murge and Salento areas: the Murge bauxite (upper Cretaceous) is a typical canyon-like deposit formed in a karst depression whereas the Salento bauxite (upper Eocene - Oligocene) is the result of the erosion, remobilization and transport of older bauxitic material from a relative distant area. This particular bauxite arrangement gave the name to all the same bauxite deposits which are thus called Salento-type deposits. Bauxite's texture is essentially made of sub-circular concentric aggregates, called ooids, dispersed in a pelitic matrix. The textural properties of the two bauxitic ores, as assessed by SEM-EDX, are different. In the bauxite from the canyon-like deposit the ooids/matrix ratio is higher than in the Salento-type bauxite. Furthermore the ooids in the Salento-like bauxite are usually made by a large core surrounded by a narrow, single, accretion layer, whereas the ooids from the canyon-like deposit have a smaller core surrounded by several alternating layers of Al-hematite and boehmite (Mongelli et al., 2014). In order to explore in more detail the textural features of both bauxite deposits, particle shape analyses were performed. Image analyses and the fractal dimension have been widely used in geological studies including economic geology (e.g. Turcotte, 1986; Meakin, 1991; Deng et al., 2011). The geometric properties evaluated are amounts of ooids, average ooids size, ooids rounding and the fractal dimension D, which depends on the ooids/matrix ratio. D is the slope of a plotting line obtained using a particular counting technique on each sample image. The fractal dimension is slightly lower for the Salento-type bauxites. Since the process which led to the formation of the ooids is related to an aggregation growth involving chemical fractionation (Mongelli, 2002) a correlation among these parameters and the contents of major

  17. Aluminum Reduction and Nitridation of Bauxite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhikuan; ZHANG Dianwei; XU Enxia; HOU Xinmei; DONG Yanling

    2007-01-01

    The application of bauxite with low Al2O3 content has been studied in this paper and β-SiAlON has been obtained from two kinds of bauxites (Al203 content 68.08 mass% and 46.30 mass% respectively) by aluminum reduction and nitridation method.The sequence of reactions has been studied using thermal analysis (TG-DTA),X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) with EDS.Compared with carbon thermal reduction and nitridation of aluminosilicates employed presently,the reaction in the system of bauxite-Al-N2 occurs at lower temperature.β-SiAlON appears as one of the main products from 1573K and exists' stably in the range of the present experimental temperature.The microstructure of β-SiAlON obtained at 1773 K is short column with 5-10μm observed by SEM.

  18. Shanxi Finding Another Large Bauxite Deposit

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>According to Department of Resources of Shanxi,a new breakthrough has been made on the prospecting in the province.The preliminary result shows that another large bauxite mine has been found in Shiqie River in Baode County with a deposit height of 0.81- 8.01m and an estimate reserve of 140 million tons.Meanwhile 3 large-and 3 medium-size bauxite deposits have also been found in the northwest part of Shanxi including Hejiaqianhe of Xin County with an estimate reserve of 37.1 million tons and Beiguli of Jiaokou County.

  19. Bacterial communities established in bauxite residues with different restoration histories

    OpenAIRE

    Schmalenberger, Achim; O'Sullivan, Orla; Gahan, Jacinta; Cotter, Paul D.; Courtney, Ronan

    2013-01-01

    peer-reviewed Bauxite residue is the alkaline byproduct generated when alumina is extracted from bauxite ores and is commonly deposited in impoundments. These sites represent hostile environments with increased salinity and alkalinity and little prospect of revegetation when left untreated. This study reports the establishment of bacterial communities in bauxite residues with and without restoration amendments (compost and gypsum addition, revegetation) in samples taken in 2009 and 2011 fr...

  20. Application of Hydrogen for the Reduction of Bauxite Mineral

    Science.gov (United States)

    Parhi, B. R.; Sahoo, S. K.; Bhoi, B.; Satapathy, B. K.; Paramguru, R. K.

    2016-02-01

    Reduction of oxides present in bauxite through hydrogen was investigated in the present study. The bauxite samples were subjected to reduction through molecular hydrogen and hydrogen plasma at 650oC and 800oC with different flow rates of hydrogen for different time periods respectively. The samples, after the reduction processes, were characterized by X-ray diffraction technique and chemical analysis. It was observed that the oxides of iron present in bauxite were only undergone through reduction while other oxides remain unreduced. An attempt was then made to separate pure Al2O3 present in bauxite samples through acid leaching process.

  1. Fight Between Bauxite Enterprises Over the Import Channels

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>China’s foreign dependence on bauxite is currently 60%,nearly the same as iron ore.China’s total imports of bauxite were 44.8449 million tons in 2011,up 49.73% year-on-year,the highest level over the same period in history. The Chinese electrolytic aluminum and aluminum oxide enterprises including Aluminum

  2. Spalling Resistant Bauxite Based Bricks for Cement Kiln

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2011-01-01

    @@ 1.Scope This standard specifies the term,definition,classification,labeling,technical requirements,test methods,inspection rules,packing,marking,transportation,storage,and quality certificate of spalling resistant bauxite based bricks for cement kiln.This standard is applicable to the spalling resistant bauxite based bricks for cement kiln.

  3. Mineralogy and geochemistry of bauxite and bentonite deposits from Mozambique

    NARCIS (Netherlands)

    Dos Muchangos, A.C.

    2000-01-01

    Results of mineralogical and geochemical studies of bauxites, kaolinitic clays and bentoniteS from Mozambique are presented in this thesis. The bauxite and kaolinitic clay deposits in Penhalonga area (in the central western part of Mozambique) are associated with Precambrian magmatic rocks and the b

  4. 40 CFR 421.10 - Applicability; description of the bauxite refining subcategory.

    Science.gov (United States)

    2010-07-01

    ... bauxite refining subcategory. 421.10 Section 421.10 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Bauxite Refining Subcategory § 421.10 Applicability; description of the bauxite refining... bauxite to alumina by the Bayer process or by the combination process....

  5. Compilation of gallium resource data for bauxite deposits

    Science.gov (United States)

    Schulte, Ruth F.; Foley, Nora K.

    2014-01-01

    Gallium (Ga) concentrations for bauxite deposits worldwide have been compiled from the literature to provide a basis for research regarding the occurrence and distribution of Ga worldwide, as well as between types of bauxite deposits. In addition, this report is an attempt to bring together reported Ga concentration data into one database to supplement ongoing U.S. Geological Survey studies of critical mineral resources. The compilation of Ga data consists of location, deposit size, bauxite type and host rock, development status, major oxide data, trace element (Ga) data and analytical method(s) used to derive the data, and tonnage values for deposits within bauxite provinces and districts worldwide. The range in Ga concentrations for bauxite deposits worldwide is

  6. Microstructure and properties of sintered mullite developed from Indian bauxite

    Indian Academy of Sciences (India)

    H S Tripathi; A Ghosh; M K Halder; B Mukherjee; H S Maiti

    2012-08-01

    Dense mullite aggregates with 72% Al2O3 have been synthesized by reaction sintering of two varieties of Indian bauxite and silica sol. The bauxites used are of inferior grade with different levels of accessory impurities such as Fe2O3, TiO2, CaO. The phase and microstructure development of sintered samples were investigated by XRD and SEM. It was found that morphology of the sintered grain is very much dependent on the impurity level. Mullite formed from bauxite-1 with low impurity is mostly equiaxed, whereas mullite developed from bauxite 2 with higher impurity particularly CaO is needle shaped. Presence of CaO in bauxite was found to be more detrimental than TiO2 and Fe2O3.

  7. Restraining Sodium Volatilization in the Ferric Bauxite Direct Reduction System

    Directory of Open Access Journals (Sweden)

    Wentao Hu

    2016-03-01

    Full Text Available Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported in previous studies. Based on the new direct reduction method for utilization of ferric bauxite, this paper has systematically investigated factors including heating temperature, heating time, and sodium carbonate dosage influencing sodium volatilization. For the purpose of reducing sodium volatilization, the Box–Benhken design was employed, and the possibility of separating iron and sodium after direct reduction was also investigated.

  8. Optimization of grinding in reverse flotation for bauxite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The reverse flotation for desiliconization form bauxite is better than direct flotation, and the grinding before flotation affects the flotation indexes to some extend. The grinding dynamic equation of bauxite based on the data of grinding experiment of diasporic bauxite was derived. The calculated value of the equation is identical with the experiment value. Further the grinding dynamic equation of intermediate grain size range suitable for reversal flotation has also been derived. The grinding time required could be calculated when the mass fraction of intermediate size grain is maximum. The formulation of grinding dynamic equation considerably simplified the grinding experiment, optimized the grinding process.

  9. Bauxite slurry pipeline: start up operation

    Energy Technology Data Exchange (ETDEWEB)

    Othon, Otilio; Babosa, Eder; Edvan, Francisco; Brittes, Geraldo; Melo, Gerson; Janir, Joao; Favacho, Orlando; Leao, Marcos; Farias, Obadias [Vale, Rio de Janeiro, RJ (Brazil); Goncalves, Nilton [Anglo Ferrous Brazil S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The mine of Miltonia is located in Paragominas-PA, in the north of Brazil. Bauxite slurry pipeline starts at the Mine of Miltonia and finishes in the draining installation of Alunorte refinery at the port of Barcarena-PA, located approximately 244km away from the mine. The pipeline runs over seven cities and passes below four great rivers stream beds. The system was designed for an underground 24 inches OD steel pipe to carry 9.9 million dry metric tonnes per annum (dMTAs) of 50.5% solid concentration bauxite slurry, using only one pumping station. The system is composed by four storage tanks and six piston diaphragm pumps, supplying a flow of 1680 m3/h. There is a cathodic protection system along the pipeline extension to prevent external corrosion and five pressure monitoring stations to control hydraulic conditions, there is also a fiber optic cable interconnection between pump station and terminal station. Pipeline Systems Incorporated (PSI) was the designer and followed the commissioning program of the start up operations. This paper will describe the beginning of the pipeline operations, technical aspects of the project, the operational experiences acquired in these two years, the faced problems and also the future planning. (author)

  10. Rheological Behavior of the Matrixes of Bauxite-Based Castables

    Institute of Scientific and Technical Information of China (English)

    Ye Fangbao; Rigaud M.; LIU Xinhong; ZHONG Xiangchong

    2003-01-01

    Rheology of castables is greatly affected and controlled by rheological behavior of their matrix. In this work, the rheological properties of bauxite-based castable matrix have been studied. The effects of super-fine silica and alumina addition, water/cement ratio, dispersants and bauxite particle-size on viscosity, shear rate and shear stress of the slurries have been investigated. Based on these results, the range of optimum composition of the matrix with good rheological behavior has been obtained.

  11. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    Directory of Open Access Journals (Sweden)

    Ma D.

    2013-01-01

    Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

  12. The Hidden Troubles in The Bauxite Import Need a Timely Solution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>As the main component in aluminum smelting, the bauxite at abroad is categorized as the gibbsite,being different from the diaspore bauxite at home.Until the end of 2005,the re- serves of the bauxite in China are ascertained to be 540 million tons,accounting for 2.3%of the globe.However,the exploitation of the bauxite in our country has reached 8%of the globe, much higher than the reserves available levels.

  13. Indonesia Tops the List of China’s Bauxite Import Sources

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>The Industry Injury Investigation Bureau of the Ministry of Commerce has issued an early warning that China’s dependence on foreign bauxite is as high as 60%, of which bauxite from Indonesia accounts for more than 70% of the total import. Bauxite imported from Indonesia has, to a certain extent, dominated the development of China’s aluminum industry.The bauxite reserve is tremendous in the world while that remains on the brink of exhaustion in China. As China expands its production scale of bauxite, its import also rises continuously.

  14. ROCKBOLTS SUPPORT OF THE DRIFTS AND CROSSCUTS IN BAUXITE

    Directory of Open Access Journals (Sweden)

    Srećko Majić

    1990-12-01

    Full Text Available The article discusses the excavation method in bauxite underground exploitation of the »Trobukva« mine in the »Bauxite Mine Posušje«, and the experiences in drift and crosscut supporting so far. Frame support is the only activity which is not mechanized and it has an important part in the production costs. Therefore the possibility of supporting by bolts and wire mesh has been developed. The estimation of bolting elements was performed for the Swellex boit and it proved, that bolt support compared with the frame support, beside the technical and safety advantages has also a considerable economic justification.

  15. Bauxite and Kaolin Deposits of the Irwinton district, Georgia

    Science.gov (United States)

    Lang, Walter B.; Warren, Walter C.; Thompson, Raymond M.; Overstreet, Elizabeth F.

    1965-01-01

    The Irwinton district is in the central part of Georgia at the inner margin of the Coastal Plain province. The oldest rocks exposed in the district are crystalline rocks of the Piedmont province. They are unconformably overlain by nonmarine sedimentary strata of Late Cretaceous age, including gravel, micaceous sand, and lenses of kaolin. Bauxite has been found in a few of the kaolin lenses near the top of the sequence of these strata. During a long period prior to deposition of the over- lying marine beds of the Claiborne and Jackson Groups (middle and upper Eocene), the Upper Cretaceous strata were subjected to subaerial erosion. The bauxite deposits are considered to have formed during this period. They range in thickness from a few inches to more than 10 feet and occupy areas ranging from a few square feet to more than 5 acres. Most of the known bauxite deposits lie along the valleys of Commissioners Creek and Big Sandy Creek in Wilkinson County. The kaolin lenses are much larger than the bauxite deposits; some of the lenses underlie more than 200 acres and are more than 20 feet thick. Bauxite was discovered in the district in 1907 and was mined from 1910 to 1928. A few additional carloads of ore were shipped in 1941 and 1942, but no ore has been mined since that time. Reserves of high-grade bauxite are very small. Reserves of all grades of bauxite plus bauxitic clay may be about 400,000 long tons. The Irwinton district is the principal source of high-grade kaolin in the United States. The presence of kaolin here has been known since early colo- nial time, and it has been mined continuously since 1897. Production in 1959 was 1,940,279 short tons. The reserves of kaolin are very large but have never been adequately measured. Reserves of first and second grade kaolin may be 67 to 84 million short tons. Kaolin of lower grade is present in larger quantity.

  16. Bauxite and bauxite residue, characterization and electron microscopy study; Bauxita e seu residuo, caracterizacao e estudo por microscopia eletronica

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, M.L.P.; Conceicao, F.T., E-mail: malu@sorocaba.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil); Toledo, S.P.; Kiyohara, P.K. [Universidade de Sao Paulo (IF/LME/USP), SP (Brazil)

    2012-07-01

    Through the Bayer process, bauxite is refined and alumina is produced. In this process, a highly alkaline residue, red mud is generated and its disposal represents an environmental problem. The aim of this paper is to present the characterization of Brazilian bauxite and Brazilian red mud by: X-ray diffraction, specific surface area, chemical composition analysis by ICP-MS, transmission electron microscopy (TEM) and energy dispersive X-ray spectrometry (EDS), and scanning electron microscopy (SEM) and discuss possible applications of this residue. The results identify as a constituent of both materials: Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, TiO{sub 2} and SiO{sub 2} and the presence of Na{sub 2}O in residue. The analysis by electron microscopy of Bauxite shows particles with hexagonal shape and red mud shows small particles size. (author)

  17. Soil Quality of Bauxite Mining Areas

    Science.gov (United States)

    Terezinha Gonçalves Bizuti, Denise; Dinarowski, Marcela; Casagrande, José Carlos; Silva, Luiz Gabriel; Soares, Marcio Roberto; Henrique Santin Brancalion, Pedro

    2015-04-01

    The study on soil quality index (SQI) aims to assess the current state of the soil after use and estimating its recovery through sustainable management practices This type of study is being used in this work in order to check the efficiency of forest recovery techniques in areas that have been deeply degraded by bauxite mining process, and compare them with the area of native forest, through the determination of SQI. Treatments were newly mined areas, areas undergoing restoration (topsoil use with planting of native forest species), areas in rehabilitation (employment of the green carpet with topsoil and planting of native forest species) and areas of native forests, with six repetitions, in areas of ALCOA, in the municipality of Poços de Caldas/MG. To this end, we used the additive pondered model, establishing three functions: Fertility, water movement and root development, based on chemical parameters (organic matter, base saturation, aluminum saturation and calcium content); physical (macroporosity, soil density and clay content); and microbiological testing (basal respiration by the emission of CO2 ). The SQIs obtained for each treatment was 41%, 56%, 63% and 71% for newly mined areas, native forest, areas in restoration and rehabilitation, respectively. The recovering technique that most approximates the degraded soil to the soil of reference is the restoration, where there was no statistically significant difference of areas restored with native forest. It was found that for the comparison of the studied areas must take into account the nutrient cycling, that disappear with plant removal in mining areas, once the soil of native forest features low fertility and high saturation by aluminum, also taking in account recovering time.

  18. Carbothermal Reductive Upgrading of a Bauxite Ore Using Microwave Radiation

    Science.gov (United States)

    Lu, T.; Pickles, C. A.; Kelebek, S.

    2012-04-01

    The utilization of microwave radiation as the energy source for the carbothermal reductive upgrading of a bauxite ore was investigated. The bauxite ore was mechanically mixed with carbon and reacted in a quartz crucible in a multimode cavity. The iron oxide in the bauxite ore was reduced to magnetite and/or iron and the magnetic fraction was separated using a Davis Tube Tester. Three experimental arrangements were utilized: (i) microwaving of the mixture, (ii) microwaving of the mixture plus charcoal layers under ambient conditions and (iii) microwaving of the mixture plus charcoal layers in argon. The utilization of the charcoal layers resulted in more uniform heating of the sample. The effects of irradiation time, sample mass and incident power on the mass of the magnetic fraction were determined. Both the iron and the aluminum contents of the magnetic fraction were measured and using these values, the iron removal from the bauxite ore and the alumina recovery in the non-magnetic fraction were calculated. It was shown that under mildly reducing conditions, almost half of the iron could be removed as magnetite. However, the formation of hercynite limited the iron separation as magnetite and higher iron removals could only be achieved through the formation of metallic iron under more highly reducing conditions.

  19. Industrial Preparation of Bauxite-based Mullite Raw Material

    Institute of Scientific and Technical Information of China (English)

    YANG Zhongzheng; DING Baohua

    2008-01-01

    Bauxite-based mullite grogs were prepared with grade II bauxite(≤3mm)and coal gangue(≤3mm)as starting materials with formula of w(Al2O3)=68%~72%.Mill the mixture to particle size≤0.044mm by wet milling to homogenize chemical composition. After shaping by wet extrusion and drying, the materials were fired at 1550℃, 1600℃ and 1700℃ for 6 hours respectively. After cooling apparent porosity and bulk density of fired materials were tested. The results show as follows: the appropriate sintering temperature for bauxite-based mullite with homogeneous and consistent composition and microstructure and properties is 1600℃,at which the mullite has apparent porosity≤1.5%,bulk density≥2.81g·cm-3and refractoriness under load is 1610-1650℃.Compared with the laboratory results, the sintering temperature is lowered about 100℃,bulk density increased 0.06g?cm-3.The industrial feasibility of preparing bauxite-based mullite grogs with the processing is confirmed.

  20. Guangxi Huaying Bauxite Mine Put Into Production Upon Completion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>On July 26,Guangxi Huaying bauxite mine was put into production upon its completion. With supportive function,the mine facilitates the 1.6-million-ton/year alumina project of Guangxi Huaying with annual capacity of 4 million tons of ores.The open-pit diaspore

  1. Effects of aluminate ion toxicity on plant growth and mineral nutrition in bauxite residue reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, R.D.

    1983-01-01

    Extraction of aluminum from bauxite ore with caustic sodium hydroxide produces an alkaline waste termed bauxite residue. Methods of vegetating bauxite residue impoundments were investigated utilizing alkaline tolerant species with readily available organic amendments. Species screening experiments identified Distichlis spicata var. stricta, an alkaline tolerant grass, as a potential species for bauxite residue reclamation. Additions of sewage sludge to bauxite residue increased growth over 10-fold. Low yields were associated with high shoot tissue concentrations of Fe and Al, and low concentrations of Mg, K, P, Ca and N. In field experiments at a bauxite residue impoundment in Mobile, Alabama, organic amendments (paper pulp waste, coastal bermuda grass mulch and sewage sludge) were tested as ameliorants to increase growth of Distichlis. In coarse textured bauxite residue amended with sewage sludge, a dense cover of Distichlis formed within 1.5 years. After 2.5 years, substantial declines in Distichlis cover occured. Additions of large quantities (6 cm) of sewage sludge to the surface of fine textured bauxite residue fostered growth of numerous local species. Most successful were Panicum dichotomiflorum and Cynodon dactylon. This research indicates the use of alkaline tolerant species with organic ameliorants has potential for bauxite residue reclamation. Problems with aluminum toxicity and Mn/sup 2 +/ deficiency must be overcome through additional research. The use of local, perhaps Al tolerant, species is also indicated if methods of effectively isolating roots from bauxite residue alkalinity are successful.

  2. REE in karst bauxites: the Campania example (southern Italy)

    Science.gov (United States)

    Mondillo, N.; Boni, M.; Balassone, G.; Rollinson, G.

    2012-04-01

    Global production of Rare Earth Element (REE) has dramatically increased in the last years, hence the strong interest to identify new deposits and to understand the processes responsible for their formation. Among REE concentrations related to weathering, the current targets are represented by the ion-adsorption deposit-types, occurring in China, in which REEs are adsorbed onto the surface of clays. Laterites have been also intensively investigated since the discovery of the secondary deposit of Mount Weld (Australia). Most REEs behave as immobile elements in laterites, and tend to be enriched compared to the underlying parent rocks. Many authors debate on a possible REE fractionation along the laterite profiles, resulting in the formation of supergene LREE-minerals. Bauxites are economic Al accumulations, derived from the weathering of alumosilicate-rich parent rocks resulting in the development of laterite profiles. Components as Ca, Mg, K, Si are leached and residual Fe, Al and Ti precipitate in form of hematite>>goethite, gibbsite [Al(OH)3] or amorphous Al hydroxides and anatase. Metabauxites can contain boehmite or diaspore [AlO(OH)]. Chemical composition (including REEs content) of lateritic bauxites generally mirrors the original composition of the parent rock. Geochemistry of REEs in karst bauxites, which lay on carbonate bedrocks and may be also allochthonous to them, is not so straightforward. Cretaceous karst bauxite deposits in the Apennine chain (Southern Italy) are presently uneconomic. A full mineralogical and geochemical study has been performed on several deposits of the Campania district, and three representative profiles have been sampled. In all deposits the bauxite ore has an oolitic-pisolitic texture, but contains also detrital intervals. The mineral association consists of boehmite, kaolinite and hematite, with less goethite and anatase. The main REE-bearing mineral is detrital monazite. In detail, we could detect (SEM) other LREE

  3. Geology and resources of the Andersonville, Georgia, kaolin and bauxite district

    Science.gov (United States)

    Cofer, Harland E.; Manker, John Phillip

    1983-01-01

    The kaolin and kaolin-rich sediments of the Andersonville district were deposited in an estuary environment with restricted circulation and little tidal or longshore current influence. Micaceous kaolinitic clays were deposited during late Paleocene time on broad, shallow water flats between deeper water distributary channels in the estuarine system. During the cycle of deposition, kaolinitic sediments were temporarily exposed to weathering leading to bauxitization and further kaolinization. Subsequently, subaerial and/or subaqueous erosion planed off and redeposited some of the weathering products as organic-rich clays and silts, berthierine-bearing clays, and rarely as colluvial bauxite and sedimentary bauxitic clays. Upon resubmergence, gibbsite-rich, porous bauxite, and bauxitic clays were exposed to silica-saturated water of the estuary. Gibbsite reacted with silica to form kaolinite and resulted in the formation of the transitional (bauxitic) clays overlying the bauxite. Kaolinitic sediments transported by streams again spread over the altered and redeposited material. At the close of the kaolin depositional period movement along the Andersonville Fault Zone and related faults changed the basinal configuration, and the area of the uplifted (southern) block of the fault was exposed to weathering and bauxitization for a limited period of time. General submergence again occurred and much of the district was covered by marine and brackish water, ending the period of commercial kaolin deposition. The kaolin and bauxite deposits in the Andersonville district form a broad belt 15 kilometers wide and 22 kilometers long trending in a northwest-southeastward direction. Most of the kaolin and bauxite of commercial value occur within a narrow 10-kilometer-wide zone in the belt. The reserves of kaolin suitable for refractory and chemical use are approximately 290 million tonnes. Paramarginal resources of sandy kaolin suitable for refractory, chemical, or aluminum

  4. Bauxite Based Refractory Bricks for Hot Blast Stove YB/T 5016-2000

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Chai Junlan

    2008-01-01

    @@ 1Scope This standard specifies the technical requirements, test method, inspection rules, packing, marking, transportation, storage and quality certificate of bauxite based refractory bricks for hot blast stove.

  5. Mineralogy, geochemistry and genesis of the Gheshlagh bauxite deposit, southeast of Gorgan

    Directory of Open Access Journals (Sweden)

    Razgar Faramarzi

    2012-04-01

    Full Text Available The Gheshlagh bauxite deposit is located 110 km southeast of Gorgan. The deposit has been developed as a stratiform horizon with more than 2 km length and a thickness of about 25 m along the contact of Ruteh and Elika carbonate formations. Textural analysis indicates both allochthonous and autochtonous origins for the bauxites. Bohemite, diaspore, anatase, rutile, hematite, goethite, kaolinite, svanbergite, pyrite, and quartz were identified in the ore paragenesis. Based on textural and mineralogical evidence, the deposit can be divided into five distinct units including upper bauxite, upper kaolinite, hard bauxite, lower kaolinite and lower bauxite. Accumulation coefficients of trace elements and geochemical indices such as Ti/Cr, TiO2/Al2O3, Zr/Ti and Nb/Y, combined with the geological evidence suggest the basaltic rocks of the Soltanmeidan Formation as the main source of bauxite materials. Combination of mineralogical and geochemical data shows that the deposit formed in two main stages. First, bauxite materials, Fe and Ti oxides and clay minerals developed as authigenic bauxitization processes of basaltic parent rock. Then, these materials were transported to karst depressions and were accumulated as a bauxite horizon.

  6. Adsorption behavior of Pb2+ and Cd2+ ions on bauxite flotation tailings

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-hua; LAN Ye; HUANG Chuan-bing

    2008-01-01

    The adsorption behavior of Pb2+ and Cd2+ ions on bauxite flotation railings was investigated to demonstrate the adsorptivity of the bauxite flotation tailings. The adsorption percentage of Pb2+ and Cd2+ ions as a function of adsorbent dosage, solution pH value and shaking time were determined by batch experiments. The maximum adsorption percentage of 99.93% for Pb2+ ions and 99.75% for Cd2+ ions were obtained by using bauxite flotation railings as adsorbent. The methods, such as zeta potentials, specific surface area measurements and the analysis of adsorption kinetics, were introduced to analyze the adsorption mechanisms of the Pb2+ ions on bauxite flotation tailings. The isoelectric point of bauxite flotation railings shifts from 3.6 to 5.6 in the presence of Pb2+ ions. The specific surface area of bauxite flotation tailings changes from 12.57 to 20.63 m2/g after the adsorption of Pb2+ ions. These results indicate that a specific adsorption of the cation species happens on the surface of bauxite flotation tailings. Adsorption data of Pb2+ ions on the surface of bauxite flotation tailings can be well described by Langmuir model, and the pseudo-second-order kinetic model provides the best correlation for the adsorption data of Pb2+ and Cd2+ ions on bauxite flotation railings.

  7. High Temperature Transformation of Iron Minerals in Bauxite

    International Nuclear Information System (INIS)

    Moessbauer hyperfine and X-ray diffraction studies have been carried on original bauxite sample and thermally treated (between 200 and 1200 deg. C) samples. Moessbauer spectrum of original bauxite shows the dominance of hematite (α-Fe2O3) along with Al-substituted hematite and goethite (α-FeOOH) of fine particle size. Moessbauer parameters for thermally treated samples indicate transformation of almost all of iron oxy-hydroxides into hematite up to 350 deg. C. Around 800 deg. C the formation of a new iron phase, assigned as iron substituted mullite (3Al2O3 2SiO3), occurs and its intensity increases with the rise in temperature and reaches a saturation around 1200 deg. C. Furthermore, our studies confirm that HCl leaching is quite effective for the iron oxide removal.

  8. Reduction and melting behavior of carbon composite lateritic bauxite pellets

    Science.gov (United States)

    Zhang, Ying-yi; Zhao, Jie; Qi, Yuan-hong; Cheng, Xiang-li; Zou, Zong-shu

    2015-04-01

    Direct reduction of low-grade lateritic bauxite was studied at high temperature to recover Fe and beneficiate Al2O3 slag. The results show that a metallization rate of 97.9% and a nugget recovery rate of 85.1% can be achieved when the reducing and melting temperatures are 1350 and 1480°C, respectively. Moreover, a higher-grade calcium aluminate slag (Al2O3 = 50.52wt%) can also be obtained, which is mainly composed of α-Al2O3, hercynite (FeAl2O4), and gehlenite (Ca2Al2SiO7). In addition, high-quality iron nuggets have been produced from low-grade lateritic bauxite. The nugget is mainly composed of iron (93.82wt%) and carbon (3.86wt%), with almost no gangue (slag).

  9. A novel collector RL for flotation of bauxite

    Institute of Scientific and Technical Information of China (English)

    卢毅屏; 张国范; 冯其明; 欧乐明

    2002-01-01

    The flotation properties of single minerals such as diaspore, kaolinite and pyrophllite in bauxites were investigated using RL as collector. The effects of regulators and unavoidable ions on flotation were studied. Based on the results of single minerals flotation, the separation experiments of mixed minerals and bauxite ore were carried out. The results of closed circuit test on the ore show that, using RL as collector, Na2CO3 and (NaPO3)6 as modifiers, the grade of Al2O3 and SiO2 are respectively 70.74% and 6.37% in concentrate (Al/Si 11.11), and the recovery of Al2O3 can reach 90.52%.

  10. THE IMPROVEMENT OF THE EXCAVATION METHODS IN BAUXITE DEPOSITS

    Directory of Open Access Journals (Sweden)

    Borislav Perić

    1990-12-01

    Full Text Available The underground bauxite excavation in Yugoslavia is getting more important recently due to gradual exploitation of shallow deposits. The main excavation method is sublevel caving method. That technology of exploitation is characterized by high excavation loosses reaching even to 50% due to mixing of bauxite with waste. By beds with competent limestone roof which are not liable to direct caving are formed unplanned open spaces so the work safety is often dangercd by sudden caving. That was the reason for carrying out the observations in situ and investigations on mathematical models to define boundary of excavated space stability. This investigation were the basis for the new conception of further excavation of the »Jukići-Didare« mine with the application of even three exploitation methods maximally adapted to the characteristics of the remaining part of deposit.

  11. THE SOLUBILITY OF MILAS BAUXITE ORE IN SULPHURIC ACI

    Directory of Open Access Journals (Sweden)

    Mustafa GULFEN

    2001-06-01

    Full Text Available The effects of calcination conditions,sulphuric acid concentrations and dissolvingtemperature and period as parameters to thesolubility of the bauxite ore from Gobekdagı reservesin Mugla-Milas region were investigated. The bauxitesamples were calcined in different periods at differenttemperatures. Then the solubility of the calcinedbauxite samples in sulphuric acid solution wasexamined. Dissolving activation energy (Ea wascalculated using the optimum kinetics equation andthe results obtained from the solubility studiesexamined dissolving temperatures and periods

  12. The Characterization of a Bauxite Waste From The Bayer Process

    Directory of Open Access Journals (Sweden)

    Nevin Yalçın

    2001-06-01

    Full Text Available The Bayer process for the alumina frombauxite produce a high quantity of waste in the formof mud. This waste -red mud- ııresent seriousproblems on environmental pollution. A possiblesolution for these wastes would be the utilization atthe ceramic industry. Because of this, thecharacterization of a bauxite 'vaste has beenperformed using various techniques. The particle sizedistribution licd bet1veen 1 and 30 J.lm. The meandeıısit

  13. High Temperature Property Development of Bauxite Based Bricks

    Institute of Scientific and Technical Information of China (English)

    A. Molin; K. Ghanbari Ahari; B. Josiek; J. Molin

    2003-01-01

    Physical properties and microstructural evolution on firing of 3 types of bauxite based refractory bricks were carried out using techniques such as porosimetry, XRD and SEM. The groups differed from each other by progressive refining of the matrix or bond phase. It is revealed that such a refinement of the matrix can improve the high temperature properties of the bricks made from poor grade materials.

  14. China’s Total Bauxite Resource Volume has Topped 4 Billion Tonnes

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>According to data published in the "Communiqué on Land and Resources of China for 2012" by The Ministry of Land and Resources, in the whole year of 2012, the volume of newly added identified bauxite resource amounted to 210 million tonnes, at the end of 2012 the total volume of domestic identified bauxite resource

  15. Binding of Vapour-Phase Mercury (Hg0) on Chemically Treated Bauxite Residues (Red Mud)

    Science.gov (United States)

    In this study, Hg capture using red mud, seawater-neutralized red mud, and acid-treated red mud is evaluated and compared to other, more conventional sorbent materials. Red mud (also known as bauxite residue) is a by-product of extracting alumina from ground bauxite ore by treati...

  16. Chongqing Bosai plans to make an investment of RMB 10 billion in bauxite

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Following the acquisition of Guyana bauxite mine with USD 600 million,Chongqing Bosai Group has planned to make an investment of RMB 10 billion in expansion of bauxite pro- duction in the coming 5 years and to purchase a

  17. Mineralogy and crystal chemistry of iron in the Timan bauxite and products of their technological processing

    Science.gov (United States)

    Kotova, O.; Silaev, V.; Lutoev, V.; Vakhrushev, A.

    2016-04-01

    Mineralogical and geochemical features of two series of samples of typical bauxites from two deposits of Middle Timan mining area (Vezhayu-Vorykva and Svetlinskoe) were studied. The phase composition of ferrous bauxites generally is boehmite, hematite, ultradisperse low-ordered goethite and berthierine. In a boehmite and kaolinite structural impurity of iron to 10%, and in the iron oxidehydroxides aluminum impurity is revealed. On iron content bauxites are subdivided into three mineral types for which quantitative data on valence states of ions of iron and proportions of their distribution last on nonequivalent structural positions in hematite, goethite and berthierine are obtained. Noble metals (Ag, Au, Ir, Rh, Pd) concentrating in bauxites are revealed for the first time. Obtained data can lead to decrease of power consumption during aluminum production and high quality ceramics, to provide production of valuable iron oxide, and also to minimize the ecological harm from accumulation of bauxite wastes.

  18. Effects of intense magnetic field on digestion and settling performances of bauxite

    Institute of Scientific and Technical Information of China (English)

    吕国志; 张廷安; 王小晓; 张旭华; 刘燕; 赵秋月; 豆志河

    2014-01-01

    The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 °C and magnetic field intensity 6 T, while for high iron bauxite are 500 °C and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 °C and 250 °C. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.

  19. pH variation mechanism of high sulfur-containing bauxite

    Institute of Scientific and Technical Information of China (English)

    陈兴华; 胡岳华; 李旺兴; 陈湘清; 曹学锋

    2015-01-01

    In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite (FeS2), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air.

  20. UNDERGROUND BAUXITE EXPLOITATION IN THE WESTERN DINARIDS ESSENTIAL FACTS AND COMMENTS

    Directory of Open Access Journals (Sweden)

    Slavko Vujec

    1994-12-01

    Full Text Available After a short information about the causes both for the deficiency of papers on bauxite underground mines and for the development of such mines, a concise sketch of the geologic structures of the bauxite regions in the Western Dinarids, inclusive the chemical composition of the bauxites, is given. The main portion of the paper is devoted to the description of the following bauxitic regions: Drniš (with the mines Kalun and Kumanovo, Obrovac (Dračevac, Ćukovac—Grižinice and Krš, Mostar (Orašnica, Tribošić, Trobukva, Dabrica, Jajce (Poljane, Crvene Stijene, Bosanska Krupa (Risovac, and Sinj (Visoka. Presented are the »bauxitic« history of the region as well as its mining characteristics, from the mode of opening to the used mining methods, with their adventages and disadvantages. Comments are made, but no conclusions drawn; the future remains open.

  1. Effect of bauxite addition on densification and mullitization behaviour of West Bengal clay

    Indian Academy of Sciences (India)

    N S Raut; P Biswas; T K Bhattacharya; K Das

    2008-12-01

    The effect of bauxite addition on the densification and mullitization of reaction sintered bauxite–clay mixture had been studied in the temperature range 1400–1500°C. The maximum bulk density (2.89 g/cc) and minimum apparent porosity (0.58%) was achieved by addition of 50 wt% bauxite. The impurities present in bauxite and clay formed liquid phase which helped in particle diffusion to aid densification. The X-ray diffraction of sample fired at 1500°C showed cristoballite phase gradually disappearing and at the same time mullite and -Al2O3 phase appearing at a higher level of bauxite addition. The in situ nascent alumina formed was reactive that facilitated the formation of secondary mullite by solution precipitation mechanism. The presence of bauxite also changed the morphology of the mullite particles. Two types of mullite were distinctly observed in the SEM photographs: elongated primary mullite and equiaxed secondary mullite.

  2. Mineralogy, Geochemistry and Stable Isotope Studies of the Dopolan Bauxite Deposit, Zagros Mountain, Iran

    Directory of Open Access Journals (Sweden)

    Somayeh Salamab Ellahi

    2016-02-01

    Full Text Available The Dopolan deposit is a Mediterranean-type bauxite located in the Zagros Fold-Thrust Zone, Iran. This deposit consists of five lithological members including iron-rich, clay-rich, oolitic, pisolitic and organic matter-containing bauxites. The mineralogy of the deposit includes diaspore, boehmite, and kaolinite, nacrite, with minor pyrite, anatase and rutile. Geochemical studies show that light rare earth elements (LREEs are enriched relative to heavy rare earth elements (HREEs in all members, supporting an authigenic origin. Mass changes based on Ti as an immobile element indicate that conventionally-immobile elements (Al, Nb, Ta, Zr, Hf are enriched in situ in the residual units, whereas mobile elements (K, Ca, Si were depleted during bauxitization. This study shows that the Khaneh–Kat argillitic dolomite is the likely parent rock. The δ18O (7.63‰to 9.35‰ and D values (49.91‰to 66.49‰ for kaolinite in the bauxite samples suggest equilibration with meteoric waters which supports a supergene origin. Bauxitization occurred in a warm climate with relatively constant isotopic composition suggesting climate stability during the development of bauxite horizons and remobilization of Al (with formation of secondary boehmite. The δ13C values of calcite (7.3‰ in the bauxite support the idea that the Khaneh–Kat Formation has experienced post-depositional isotope exchange with meteoric waters during the karstification process.

  3. Bio-mineralization and potential biogeochemical processes in bauxite deposits: genetic and ore quality significance

    Science.gov (United States)

    Laskou, Magdalini; Economou-Eliopoulos, Maria

    2013-08-01

    The Parnassos-Ghiona bauxite deposit in Greece of karst type is the 11th largest bauxite producer in the world. The mineralogical, major and trace-element contents and δ18O, δ12C, δ34S isotopic compositions of bauxite ores from this deposit and associated limestone provide valuable evidence for their origin and biogeochemical processes resulting in the beneficiation of low grade bauxite ores. The organic matter as thin coal layers, overlying the bauxite deposits, within limestone itself (negative δ12C isotopic values) and the negative δ34S values in sulfides within bauxite ores point to the existence of the appropriate circumstances for Fe bio-leaching and bio-mineralization. Furthermore, a consortium of microorganisms of varying morphological forms (filament-like and spherical to lenticular at an average size of 2 μm), either as fossils or presently living and producing enzymes, is a powerful factor to catalyze the redox reactions, expedite the rates of metal extraction and provide alternative pathways for metal leaching processes resulting in the beneficiation of bauxite ore.

  4. Extraction of Alumina from high-silica bauxite by hydrochloric acid leaching using preliminary roasting method

    Science.gov (United States)

    Valeev, D. V.; Mansurova, E. R.; Bychinskii, V. A.; Chudnenko, K. V.

    2016-02-01

    A process of dissolution Severoonezhsk deposit boehmite-kaolinite bauxite by hydrochloric acid, as well as the processes that occur during open-air calcination, were investigated. A dehydration process has been studied, and the basic phase transformation temperatures were identified. Temperature and time of calcination influence on bauxite dehydration speed were determined. It is shown that the preliminary calcination increases the extraction ratio of alumina into solution up to 89%. Thermodynamic modelling of physical and chemical processes of bauxite decomposition by hydrochloric acid and the basic forms of aluminium speciation in solution were obtained.

  5. Characterization and Beneficiation Studies of a Low Grade Bauxite Ore

    Science.gov (United States)

    Rao, D. S.; Das, B.

    2014-10-01

    A low grade bauxite sample of central India was thoroughly characterized with the help of stereomicroscope, reflected light microscope and electron microscope using QEMSCAN. A few hand picked samples were collected from different places of the mine and were subjected to geochemical characterization studies. The geochemical studies indicated that most of the samples contain high silica and low alumina, except a few which are high grade. Mineralogically the samples consist of bauxite (gibbsite and boehmite), ferruginous mineral phases (goethite and hematite), clay and silicate (quartz), and titanium bearing minerals like rutile and ilmenite. Majority of the gibbsite, boehmite and gibbsitic oolites contain clay, quartz and iron and titanium mineral phases within the sample as inclusions. The sample on an average contains 39.1 % Al2O3 and 12.3 % SiO2, and 20.08 % of Fe2O3. Beneficiation techniques like size classification, sorting, scrubbing, hydrocyclone and magnetic separation were employed to reduce the silica content suitable for Bayer process. The studies indicated that, 50 % by weight with 41 % Al2O3 containing less than 5 % SiO2 could be achieved. The finer sized sample after physical beneficiation still contains high silica due to complex mineralogical associations.

  6. Comparative Analysis of Processes for Recovery of Rare Earths from Bauxite Residue

    Science.gov (United States)

    Borra, Chenna Rao; Blanpain, Bart; Pontikes, Yiannis; Binnemans, Koen; Van Gerven, Tom

    2016-09-01

    Environmental concerns and lack of space suggest that the management of bauxite residue needs to be re-adressed. The utilization of the residue has thus become a topic high on the agenda for both academia and industry, yet, up to date, it is only rarely used. Nonetheless, recovery of rare earth elements (REEs) with or without other metals from bauxite residue, and utilization of the left-over residue in other applications like building materials may be a viable alternative to storage. Hence, different processes developed by the authors for recovery of REEs and other metals from bauxite residue were compared. In this study, preliminary energy and cost analyses were carried out to assess the feasibility of the processes. These analyses show that the combination of alkali roasting-smelting-quenching-leaching is a promising process for the treatment of bauxite residue and that it is justified to study this process at a pilot scale.

  7. Flotation de-silicating from diasporic-bauxite with cetyl trimethylammonium bromide

    Institute of Scientific and Technical Information of China (English)

    王毓华; 胡岳华; 刘晓文

    2003-01-01

    Using cetyl trimethylammonium bromide (CTAB) as collector, the flotation de-silicating from diasporicbauxite was investigated. And the Zeta potentials and contact-angles of silicate minerals and diaspore were also stuite and illite become more positive, and the contact angles of these three silicates also increase evidently in the pH range of 2-8, but the Zeta potentials and contact angles of diaspore change little. So, the floatability of the four minerals is in the following order: pyrophyllite>kaolinite≈illite>diaspore. The open-circuit flotation results also show that a bauxite concentrate with m(Al2 O3 )/m(SiO2 ) over 9.3 and Al2 O3 recovery over 76% can be obtained from diasporic-bauxite ore. The result of XRD of the bauxite concentrate shows that pyrophyllite is easier to be removed from diasporic-bauxite than illite and kaolinite due to its better floatability.

  8. West Inner Mongolia Coalfield to be the Largest Bauxite Mine in China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>With the acceleration of industrialization of extraction of alumina from high aluminum fly ash technology, the West Inner Mongolia coalfield is expected to become the largest bauxite mine with the largest aluminum reserves in China.

  9. Preparation and Microstructure of Bauxite-Based Sialon by Reduction Nitridation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Haijun; LIU Zhanjie; ZHONG Xiangchong

    2004-01-01

    The phase compostition and microstructure of Sialon prepared from Chinese bauxite have been studied.The use of Si powder is more effective than that of activated carbon for reduction-nitridation.For bauxite specimens with 40~50% Si addition,more than 90% of Sialon may be obtained when nitrided at 1450~1500℃;the main crystalline phase is O'-Sialon(Z=0.2).

  10. Smelting of bauxite residue (red mud) in view of iron and selective rare earths recovery

    OpenAIRE

    Borra, Chenna Rao; Blanpain, Bart; Pontikes, Yiannis; Binnemans, Koen; Van Gerven, Tom

    2016-01-01

    During acid leaching of bauxite residue (red mud), the increase in dissolution of rare-earth elements (REEs) is associated with an increase in iron dissolution, which poses problems in the downstream processing. Therefore, it would be beneficial to remove iron from bauxite residue by smelting reduction. The slag generated in the smelting reduction process could then be further processed for recovery of REEs. Smelting experiments were carried out at temperatures between 1500 and 1600 degrees C...

  11. Mineralogy, geochemistry and genesis of the Gheshlagh bauxite deposit, southeast of Gorgan

    OpenAIRE

    Razgar Faramarzi; Gholamhosien Shamanian; Behnam Shafiei

    2012-01-01

    The Gheshlagh bauxite deposit is located 110 km southeast of Gorgan. The deposit has been developed as a stratiform horizon with more than 2 km length and a thickness of about 25 m along the contact of Ruteh and Elika carbonate formations. Textural analysis indicates both allochthonous and autochtonous origins for the bauxites. Bohemite, diaspore, anatase, rutile, hematite, goethite, kaolinite, svanbergite, pyrite, and quartz were identified in the ore paragenesis. Based on textural and miner...

  12. The Effect of Pretreatment on Magnetic Separation of Ferruginous Minerals in Bauxite

    OpenAIRE

    Rao, R. Bhima; Besra, L.; Reddy, B. R.; Banerjee, G. N.

    1997-01-01

    Bauxite sample of Jamnagar, India, is suitable for refractory applications after separation of iron minerals. Different magnetic separators and intensities are studied on different treated samples. The results of these investigations indicate that removal of ferruginous minerals from crude sample requires a magnetic intensity of 14 000 Gauss. The calcined sample at 800℃ requires magnetic intensity of about 7000 Gauss, whereas the reduced bauxite needs less than 2000 Gauss for separation of ir...

  13. Experimental Simulation of Long Term Weathering in Alkaline Bauxite Residue Tailings

    OpenAIRE

    2015-01-01

    Bauxite residue is an alkaline, saline tailings material generated as a byproduct of the Bayer process used for alumina refining. Developing effective plans for the long term management of potential environmental impacts associated with storage of these tailings is dependent on understanding how the chemical and mineralogical properties of the tailings will change during weathering and transformation into a soil-like material. Hydrothermal treatment of bauxite residue was used to compress geo...

  14. Natural radioactivity in Egyptian and industrially used australian bauxites and its tailing red mud

    International Nuclear Information System (INIS)

    Red mud is produced in considerable masses as a waste product in the production of aluminum from bauxite. It may be used for industrial or agricultural purposes. According to it's genesis by weathering and sedimentation bauxites contain high concentrations of uranium and thorium. Three Egyptian bauxites, Australian industry used bauxite and its red mud tailing were analyzed by a high resolution gamma spectrometer, with a hyper pure germanium detector. The three Egyptian bauxites show high concentrations in uranium series, and around 120 Bq kg-1 for uranium -235. K-40 concentrations for these samples ranged from 289 to 575 Bq kg-1. Thorium series concentrations show lower values. The industrially used bauxite shows very low concentrations for all radioactive nuclides. Its tailing red mud as a low level radioactive waste LLRW, shows low concentrations for uranium - series, thorium - series and also 40K, so it is recommended to be used in industrial and agricultural purposes, which is not permissible for the normal red mud. (author)

  15. THE DIGESTION OPERATION IN THE ALKALI ALUMINAT SOLUTIONS OF ALUMINUM HYDROXIDES IN THE BOEHMITIC BAUXITES

    Directory of Open Access Journals (Sweden)

    Sami ŞAHİN

    1999-01-01

    Full Text Available At present more than 90 per cent of the world's alumina is produced by the Bayer process, a simple technology providing high purity final product. A part from some exceptional local conditions, bauxite is processed almost solely by this technology. As a benefication process, alumina production releases the aluminum oxide content of bauxite from other accompanying oxides thus providing alumina suitable for electrolysis in a cryolite melt. The basic theory of the Bayer process was elaborated by K.J. Bayer and described in his patents in 1887 and 1892. The first patent refers to the aid of seed crystals of aluminum hydroxide or of carbonic acid, that is, to the precipitation and carbonation processes. The second patent formulates the concept that the aluminum oxide content of bauxites can be dissolved in sodium hydroxide solutions, with the formulation of sodium aluminate, a process called digestion nowadays. The most important operations of the Bayer technology are bauxite preparation, crushing, grinding, digestion, red mud separation, thickening, washing, filtration, precipitation, calcination and evaporation. In spite of its great significance as regards the complete Bayer technology, the structure of sodium aluminate solutions has not been cleared up definitely yet. Boehmite is the most important aluminum mineral of karstic bauxites. Some experimental results showing the various effects on aluminum hydroxides by alkali process from boehmitic bauxites and the factors gowerning the digestion operation of aluminate solutions were investigated.

  16. Potential Health Impacts of Bauxite Mining in Kuantan.

    Science.gov (United States)

    Abdullah, Noor Hisham; Mohamed, Norlen; Sulaiman, Lokman Hakim; Zakaria, Thahirahtul Asma; Rahim, Daud Abdul

    2016-05-01

    Bauxite mining is not known to most Malaysian except recently due to environmental pollution issues in Kuantan, Pahang. Potential impacts are expected to go beyond physical environment and physical illness if the situation is not controlled. Loss of economic potentials, and the presence of unpleasant red dust causing mental distress, anger and community outrage. More studies are needed to associate it with chronic physical illness. While evidences are vital for action, merely waiting for a disease to occur is a sign of failure in prevention. All responsible agencies should focus on a wider aspect of health determinants rather than merely on the occurrence of diseases to act and the need to emphasize on sustainable mining to ensure health of people is not compromised.

  17. Beneficiation of low-grade diasporic bauxite with hydrocyclone

    Institute of Scientific and Technical Information of China (English)

    GAO Shu-ling; LI Xia-an; WEI De-zhou; FANG Ping; JIA Chun-yun; LIU Wen-gang; HAN Cong

    2008-01-01

    Low-grade diasporic bauxite was treated with hydrocyclone of small cone-angle. The effects of apex diameter, feed pressure and feed concentration on separation indexes were tested, and then the separation process was discussed by hydrokinetics tentatively. The results show that the increase of apex diameter changes the spacial locality of the envelope of zero vertical velocity, resulting in decrease of the ratio of Al2O3/SiO2 in overflow and increase of the recovery of Al2O3 in underflow, while feed pressure and feed concentration have no remarkable effect on the spacial locality of the envelope of zero vertical velocity, however, the separation indexes are improved by the increase of feed pressure, but are worsened by the increase of feed concentration.

  18. Potential Health Impacts of Bauxite Mining in Kuantan.

    Science.gov (United States)

    Abdullah, Noor Hisham; Mohamed, Norlen; Sulaiman, Lokman Hakim; Zakaria, Thahirahtul Asma; Rahim, Daud Abdul

    2016-05-01

    Bauxite mining is not known to most Malaysian except recently due to environmental pollution issues in Kuantan, Pahang. Potential impacts are expected to go beyond physical environment and physical illness if the situation is not controlled. Loss of economic potentials, and the presence of unpleasant red dust causing mental distress, anger and community outrage. More studies are needed to associate it with chronic physical illness. While evidences are vital for action, merely waiting for a disease to occur is a sign of failure in prevention. All responsible agencies should focus on a wider aspect of health determinants rather than merely on the occurrence of diseases to act and the need to emphasize on sustainable mining to ensure health of people is not compromised. PMID:27418864

  19. Predictive hydrogeochemical modelling of bauxite residue sand in field conditions.

    Science.gov (United States)

    Wissmeier, Laurin; Barry, David A; Phillips, Ian R

    2011-07-15

    The suitability of residue sand (the coarse fraction remaining from Bayer's process of bauxite refining) for constructing the surface cover of closed bauxite residue storage areas was investigated. Specifically, its properties as a medium for plant growth are of interest to ensure residue sand can support a sustainable ecosystem following site closure. The geochemical evolution of the residue sand under field conditions, its plant nutrient status and soil moisture retention were studied by integrated modelling of geochemical and hydrological processes. For the parameterization of mineral reactions, amounts and reaction kinetics of the mineral phases natron, calcite, tricalcium aluminate, sodalite, muscovite and analcime were derived from measured acid neutralization curves. The effective exchange capacity for ion adsorption was measured using three independent exchange methods. The geochemical model, which accounts for mineral reactions, cation exchange and activity corrected solution speciation, was formulated in the geochemical modelling framework PHREEQC, and partially validated in a saturated-flow column experiment. For the integration of variably saturated flow with multi-component solute transport in heterogeneous 2D domains, a coupling of PHREEQC with the multi-purpose finite-element solver COMSOL was established. The integrated hydrogeochemical model was applied to predict water availability and quality in a vertical flow lysimeter and a cover design for a storage facility using measured time series of rainfall and evaporation from southwest Western Australia. In both scenarios the sand was fertigated and gypsum-amended. Results show poor long-term retention of fertilizer ions and buffering of the pH around 10 for more than 5 y of leaching. It was concluded that fertigation, gypsum amendment and rainfall leaching alone were insufficient to render the geochemical conditions of residue sand suitable for optimal plant growth within the given timeframe. The

  20. Feasible conversion of solid waste bauxite tailings into highly crystalline 4A zeolite with valuable application

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Dongyang; Wang, Zhendong; Guo, Min [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Mei, E-mail: zhangmei@ustb.edu.cn [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China); Liu, Jingbo [The Department of Chemistry, Texas A and M University-Kingsville, Kingsville, TX 78363 (United States); The Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2014-11-15

    Highlights: • Concept to convert waste to valuable product is carried out in this study. • An industrially feasible and cost-effective approach was developed and optimized. • Highly crystalline and well-defined zeolite was produced under moderate conditions. • The zeolite derived from the bauxite tailings displayed high ion exchange capacity. • Bauxite tailings have potential application in heavy metal ions adsorbent. - Abstract: Bauxite tailings are a major type of solid wastes generated in the flotation process. The waste by-products caused significant environmental impact. To lessen this hazardous effect from poisonous mine tailings, a feasible and cost-effective solution was conceived and implemented. Our approach focused on reutilization of the bauxite tailings by converting it to 4A zeolite for reuse in diverse applications. Three steps were involved in the bauxite conversion: wet-chemistry, alkali fusion, and crystallization to remove impurities and to prepare porous 4A zeolite. It was found that the cubic 4A zeolite was single phase, in high purity, with high crystallinity and well-defined structure. Importantly, the 4A zeolite displayed maximum calcium ion exchange capacity averaged at 296 mg CaCO{sub 3}/g, comparable to commercially-available zeolite (310 mg CaCO{sub 3}/g) exchange capacity. Base on the optimal synthesis condition, the reaction yield of zeolite 4A from bauxite tailings achieved to about 38.43%, hence, this study will provide a new paradigm for remediation of bauxite tailings, further mitigating the environmental and health care concerns, particularly in the mainland of PR China.

  1. Feasible conversion of solid waste bauxite tailings into highly crystalline 4A zeolite with valuable application

    International Nuclear Information System (INIS)

    Highlights: • Concept to convert waste to valuable product is carried out in this study. • An industrially feasible and cost-effective approach was developed and optimized. • Highly crystalline and well-defined zeolite was produced under moderate conditions. • The zeolite derived from the bauxite tailings displayed high ion exchange capacity. • Bauxite tailings have potential application in heavy metal ions adsorbent. - Abstract: Bauxite tailings are a major type of solid wastes generated in the flotation process. The waste by-products caused significant environmental impact. To lessen this hazardous effect from poisonous mine tailings, a feasible and cost-effective solution was conceived and implemented. Our approach focused on reutilization of the bauxite tailings by converting it to 4A zeolite for reuse in diverse applications. Three steps were involved in the bauxite conversion: wet-chemistry, alkali fusion, and crystallization to remove impurities and to prepare porous 4A zeolite. It was found that the cubic 4A zeolite was single phase, in high purity, with high crystallinity and well-defined structure. Importantly, the 4A zeolite displayed maximum calcium ion exchange capacity averaged at 296 mg CaCO3/g, comparable to commercially-available zeolite (310 mg CaCO3/g) exchange capacity. Base on the optimal synthesis condition, the reaction yield of zeolite 4A from bauxite tailings achieved to about 38.43%, hence, this study will provide a new paradigm for remediation of bauxite tailings, further mitigating the environmental and health care concerns, particularly in the mainland of PR China

  2. Deep-sea foraminifera from the Cassidaigne Canyon (NW Mediterranean): Assessing the environmental impact of bauxite red mud disposal

    NARCIS (Netherlands)

    Fontanier, C.; Fabri, M.-C.; Buscail, R.; Biscara, L.; Koho, K.A.; Reichart, G.-J.; Cossa, D.; Galaup, S.; Chabaud, G.; Pigot, L.

    2012-01-01

    Benthic foraminiferal assemblages were investigated from two sites along the axis of the Cassidaigne Canyon (NW Mediterranean Sea). Both areas are contaminated by bauxite red mud enriched in iron, titanium, vanadium and chromium. These elemental enrichments are related to bauxite-derived minerals an

  3. Reforestation of bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    N. Krishnakumar

    2012-11-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted indegradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth.However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum(Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum(Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings of Eucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings of E. tereticornis showed 95% survival over the control seedlings and their growth was also significantlyhigher. Tissue nutrients (N, P, K were also found higher inAM fungi inoculated E. tereticornis than un inoculated control seedlings.

  4. Proposal for management and alkalinity transformation of bauxite residue in China.

    Science.gov (United States)

    Xue, Shengguo; Kong, Xiangfeng; Zhu, Feng; Hartley, William; Li, Xiaofei; Li, Yiwei

    2016-07-01

    Bauxite residue is a hazardous solid waste produced during the production of alumina. Its high alkalinity is a potential threat to the environment which may disrupt the surrounding ecological balance of its disposal areas. China is one of the major global producers of alumina and bauxite residue, but differences in alkalinity and associated chemistry exist between residues from China and those from other countries. A detailed understanding of the chemistry of bauxite residue remains the key to improving its management, both in terms of minimizing environmental impacts and reducing its alkaline properties. The nature of bauxite residue and the chemistry required for its transformation are still poorly understood. This review focuses on various transformation processes generated from the Bayer process, sintering process, and combined Bayer-sintering process in China. Problems associated with transformation mechanisms, technical methods, and relative merits of these technologies are reviewed, while current knowledge gaps and research priorities are recommended. Future research should focus on transformation chemistry and its associated mechanisms and for the development of a clear and economic process to reduce alkalinity and soda in bauxite residue. PMID:27023808

  5. Proposal for management and alkalinity transformation of bauxite residue in China.

    Science.gov (United States)

    Xue, Shengguo; Kong, Xiangfeng; Zhu, Feng; Hartley, William; Li, Xiaofei; Li, Yiwei

    2016-07-01

    Bauxite residue is a hazardous solid waste produced during the production of alumina. Its high alkalinity is a potential threat to the environment which may disrupt the surrounding ecological balance of its disposal areas. China is one of the major global producers of alumina and bauxite residue, but differences in alkalinity and associated chemistry exist between residues from China and those from other countries. A detailed understanding of the chemistry of bauxite residue remains the key to improving its management, both in terms of minimizing environmental impacts and reducing its alkaline properties. The nature of bauxite residue and the chemistry required for its transformation are still poorly understood. This review focuses on various transformation processes generated from the Bayer process, sintering process, and combined Bayer-sintering process in China. Problems associated with transformation mechanisms, technical methods, and relative merits of these technologies are reviewed, while current knowledge gaps and research priorities are recommended. Future research should focus on transformation chemistry and its associated mechanisms and for the development of a clear and economic process to reduce alkalinity and soda in bauxite residue.

  6. Hidden values in bauxite residue (red mud): Recovery of metals

    International Nuclear Information System (INIS)

    Highlights: • Current iron recovery techniques using red mud are depicted. • Advantages and disadvantages exist in different recovering processes. • Economic and environmental friendly integrated usage of red mud is promising. - Abstract: Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. The ever-increasing generation of red mud poses significant challenges to the aluminium industries from management perspectives given the low proportion that are currently being utilized beneficially. Red mud, in most cases, contains elevated concentrations of iron in addition to aluminium, titanium, sodium and valuable rare earth elements. Given the scarcity of iron supply globally, the iron content of red mud has attracted increasing research interest. This paper presents a critical overview of the current techniques employed for iron recovery from red mud. Information on the recovery of other valuable metals is also reviewed to provide an insight into the full potential usage of red mud as an economic resource rather than a waste. Traditional hydrometallurgy and pyrometallurgy are being investigated continuously. However, in this review several new techniques are introduced that consider the process of iron recovery from red mud. An integrated process which can achieve multiple additional values from red mud is much preferred over the single process methods. The information provided here should help to improve the future management and utilization of red mud

  7. Rhizobial characterization in revegetated areas after bauxite mining

    Directory of Open Access Journals (Sweden)

    Wardsson Lustrino Borges

    2016-06-01

    Full Text Available Abstract Little is known regarding how the increased diversity of nitrogen-fixing bacteria contributes to the productivity and diversity of plants in complex communities. However, some authors have shown that the presence of a diverse group of nodulating bacteria is required for different plant species to coexist. A better understanding of the plant symbiotic organism diversity role in natural ecosystems can be extremely useful to define recovery strategies of environments that were degraded by human activities. This study used ARDRA, BOX-PCR fingerprinting and sequencing of the 16S rDNA gene to assess the diversity of root nodule nitrogen-fixing bacteria in former bauxite mining areas that were replanted in 1981, 1985, 1993, 1998, 2004 and 2006 and in a native forest. Among the 12 isolates for which the 16S rDNA gene was partially sequenced, eight, three and one isolate(s presented similarity with sequences of the genera Bradyrhizobium, Rhizobium and Mesorhizobium, respectively. The richness, Shannon and evenness indices were the highest in the area that was replanted the earliest (1981 and the lowest in the area that was replanted most recently (2006.

  8. Hidden values in bauxite residue (red mud): Recovery of metals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanju; Naidu, Ravi, E-mail: ravi.naidu@unisa.edu.au

    2014-12-15

    Highlights: • Current iron recovery techniques using red mud are depicted. • Advantages and disadvantages exist in different recovering processes. • Economic and environmental friendly integrated usage of red mud is promising. - Abstract: Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. The ever-increasing generation of red mud poses significant challenges to the aluminium industries from management perspectives given the low proportion that are currently being utilized beneficially. Red mud, in most cases, contains elevated concentrations of iron in addition to aluminium, titanium, sodium and valuable rare earth elements. Given the scarcity of iron supply globally, the iron content of red mud has attracted increasing research interest. This paper presents a critical overview of the current techniques employed for iron recovery from red mud. Information on the recovery of other valuable metals is also reviewed to provide an insight into the full potential usage of red mud as an economic resource rather than a waste. Traditional hydrometallurgy and pyrometallurgy are being investigated continuously. However, in this review several new techniques are introduced that consider the process of iron recovery from red mud. An integrated process which can achieve multiple additional values from red mud is much preferred over the single process methods. The information provided here should help to improve the future management and utilization of red mud.

  9. Rhizobial characterization in revegetated areas after bauxite mining.

    Science.gov (United States)

    Borges, Wardsson Lustrino; Prin, Yves; Ducousso, Marc; Le Roux, Christine; de Faria, Sergio Miana

    2016-01-01

    Little is known regarding how the increased diversity of nitrogen-fixing bacteria contributes to the productivity and diversity of plants in complex communities. However, some authors have shown that the presence of a diverse group of nodulating bacteria is required for different plant species to coexist. A better understanding of the plant symbiotic organism diversity role in natural ecosystems can be extremely useful to define recovery strategies of environments that were degraded by human activities. This study used ARDRA, BOX-PCR fingerprinting and sequencing of the 16S rDNA gene to assess the diversity of root nodule nitrogen-fixing bacteria in former bauxite mining areas that were replanted in 1981, 1985, 1993, 1998, 2004 and 2006 and in a native forest. Among the 12 isolates for which the 16S rDNA gene was partially sequenced, eight, three and one isolate(s) presented similarity with sequences of the genera Bradyrhizobium, Rhizobium and Mesorhizobium, respectively. The richness, Shannon and evenness indices were the highest in the area that was replanted the earliest (1981) and the lowest in the area that was replanted most recently (2006).

  10. Pre-desilication and digestion of gibbsitic bauxite with lime in sodium aluminate liquor

    Science.gov (United States)

    Pan, Xiao-lin; Yu, Hai-yan; Dong, Kai-wei; Tu, Gan-feng; Bi, Shi-wen

    2012-11-01

    The effect of lime on the pre-desilication and digestion of gibbsitic bauxite in synthetic sodium aluminate liquor at different temperatures was investigated. The bauxite is comprised of gibbsite, aluminogoethite, hematite, kaolin, quartz, and minor boehmite. Lime increases the desilication efficiency of the bauxite during the pre-desilication process by promoting the conversion of sodalite and cancrinite to hydrogarnet. Desilication reactions during the digestion process promoted by lime result in the loss of Al2O3 entering the red mud, but the amount of aluminogoethite-to-hematite conversion promoted by lime leads to the increase of aluminogoethitic Al2O3 entering the digested liquor. The alumina digestion rate at 245°C is higher than that at 145°C due to the more pronounced conversion of aluminogoethite to hematite. The soda consumption during the digestion process decreases due to lime addition, especially at higher temperatures.

  11. Be-10 in terrestrial bauxite and industrial aluminum: An LDEF fallout

    Science.gov (United States)

    Gregory, J. C.; Albrecht, A.; Herzog, G.; Klein, J.; Middleton, R.; Harmon, B. A.; Parnell, T. A.

    1995-01-01

    Work has continued on the search for Be-10 on metals other than aluminum flown on LDEF. Much time-consuming extractive chemistry has been performed at Rutgers University on turnings obtained from the ends of two stainless steel trunnions from LDEF and the prepared samples will be run on the University of Pennsylvania accelerator mass spectrometer. We have continued to investigate our discovery of naturally-occurring Be-10 contamination in bauxite and industrial aluminums from different sources. Measurements of Be-10 in ores from three different sites, and from four different samples of commercial aluminum have been made. Our investigators indicate that the contamination in commercial aluminum metal originates in its principal ore, bauxite. The levels in some bauxite samples were much greater than the maximum possible for in situ production by cosmic ray secondaries. Absorption of atmospheric Be-10 by surface ores exposed to rainfall is a reasonable explanation.

  12. Kinetics of the Leaching Process of an Australian Gibbsitic Bauxite by Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Aichun Zhao

    2016-01-01

    Full Text Available Gibbsitic bauxite from Australia was leached by hydrochloric acid in this work. Analysis on kinetics for the extraction of Al2O3 was quantitatively studied. It was concluded that the hydrochloric acid leaching process of gibbsitic bauxite was controlled by chemical reaction. Moreover, the mechanism for the dissolution followed the equation, ln⁡k=39.44-1.66×104(1/T, with an apparent activation energy of 137.90 kJ/mol, according to the equation of k=Ae-Ea/RT. This work aims to provide a good theory support for the process control by using a new method of alumina production from the low grade bauxite.

  13. On the hydrology of the bauxite oases, Cape York Peninsula, Australia

    Science.gov (United States)

    Leblanc, M.; Tweed, S.; Lyon, B. J.; Bailey, J.; Franklin, C. E.; Harrington, G.; Suckow, A.

    2015-09-01

    One of the world's largest bauxite deposits is located in the Cape York Peninsula, North-East Australia. Little is known about the hydrology of these remote bauxite deposits. Here, we present results from a multidisciplinary study that used remote sensing, hydrochemistry, and hydrodynamics to analyse the occurrence of several large oases in connection with the bauxite plateaus. Across this vast region, otherwise dominated by savannah, these oases are sustained by permanent springs and support rich and diverse new sub-ecosystems (spring forests) of high cultural values to the local indigenous population. The spring water chemistry reveals a well-mixed system with minor inter-spring variation; TDS values of spring waters are low (27-72 mg L-1), major ion compositions are homogenous (Na-Si-DIC-Cl) and δ18O and δ2H values are reflective of rainwater origin with little evaporation prior to recharge. Dating of spring waters with anthropogenic trace gases (CFC-12 and SF6) indicates mean groundwater residence times ranging from <1 to 30 years. An artificial tracing experiment highlighted the existence of a flow pathway from the bauxite land surface to the sandy aquifer that feeds the springs through discontinuities in the ferricrete layer. In addition, the soil infiltrability tests showed the bauxite land surface has very high infiltrability (15 mm min-1), about four times greater than other adjacent land surfaces. Across the lower part of the Wenlock Basin, satellite data indicate a total number of 57 oases consistently located on the edge of the bauxite plateaus. This super-group of permanent hillslope springs and their ecosystems adds another important attribute to the list of natural and cultural values of the Cape York Peninsula.

  14. Kinetics of leaching of the aluminum hydroxide in bauxites by alkaline solutions at atmospheric pressure

    Science.gov (United States)

    Burtsev, A. V.; Lainer, Yu. A.; Gorichev, I. G.; Kipriyanov, N. A.; Izotov, A. D.

    2011-11-01

    The kinetics of leaching of the aluminum hydroxide from the gibbsite bauxites of Guinea (Kindia deposit) is studied under atmospheric conditions. The activation energy of the process is found to be 34.75 kJ/mol, which indicates that the process proceeds in a kinetic mode. The leaching of the aluminum hydroxide from bauxite in an alkaline solution is simulated using acid-base equilibria (ion exchange) and the electrochemical theory of the structure of a double electrical layer (Gram-Parsons theory).

  15. The Effect of Bauxite Substitution on High Temperature Strength Properties of Zirconia—corundum Mullite Material

    Institute of Scientific and Technical Information of China (English)

    ZHONGWei-bin; SUNGeng-chen; 等

    1994-01-01

    Investigations on the effect of bauxite substi-tution for industrial alumina on high temperature strength and thermal shock resistance of reaction-sintered zirconia-corundum-mullite material(ZrO2 15%) have indicated that bauxite substitution would lead to increase in modulus of rupture at 1000-1400℃ as well as improvement in thermal shock resistance,Hot strength value reaches a maximum at 15% buxite addition.The mecha-nism of mechanical behavior at elevated tempera-tures is discussed in association with changes in mi-crostructural characteristics.

  16. Soil physical properties of high mountain fields under bauxite mining

    Directory of Open Access Journals (Sweden)

    Dalmo Arantes de Barros

    2013-10-01

    Full Text Available Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery, and 4 replicates (N=24. In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations.

  17. Semi-industrial experimental study on bauxite separation using a cell-column integration process

    Science.gov (United States)

    Zhang, Ning-ning; Zhou, Chang-chun; Cong, Long-fei; Cao, Wen-long; Zhou, You

    2016-01-01

    The cyclonic-static micro-bubble flotation column (FCSMC) is a highly efficient mineral processing equipment. In this study, a cell-column (FCSMC) integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis. The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon (A/S) mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of "fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns". Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-column integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

  18. Novel predictors of soil genesis following natural weathering processes of bauxite residues.

    Science.gov (United States)

    Zhu, Feng; Xue, Shengguo; Hartley, William; Huang, Ling; Wu, Chuan; Li, Xiaofei

    2016-02-01

    Bauxite residue often has chemical and physical limitations to support plant growth, and improving its matrix properties is crucial to support sustainable vegetation in the long term. Spontaneous vegetation colonization on deposits in Central China, over a period of 20 years, has revealed that natural weathering processes may convert bauxite residue to a soil-like medium. Residue samples from different stacking ages were collected to determine the effect of natural processes on matrix properties over time. It was demonstrated that natural processes decreased pH (10.98 to 9.45), electrical conductivity (EC) (3.73 to 0.36 mS/cm), and exchangeable sodium percentage (ESP) (72.51 to 28.99 %), while increasing bulk density (1.91 to 1.39 g/cm(3)), improving the mean weight diameter (MWD) of water-stable aggregates (0.24 to 0.52 mm), and the proportion of >0.25-mm water-stable aggregates (19.91 to 50.73 %). The accumulation of organic carbon and the reduction of ESP and exchangeable Na had positive effects on soil aggregate formation, while exchangeable Ca and Mg were significantly beneficial to aggregation of water-stable aggregates. Climate, stacking time, and biological factors appear to improve the structure of bauxite residue. Our findings demonstrate soil genesis occurring following natural weathering processes of bauxite residues over time.

  19. Moengo on strike: the politics of labour in Suriname’s Bauxite industry

    NARCIS (Netherlands)

    A. de Koning

    2011-01-01

    This article examines one crucial period of contestation in colonial Suriname, the years 1941 and 1942, when sustained labour unrest in the bauxite town of Moengo led to the establishment of the first mining unions. It argues that these strikes laid the groundwork for future relations between labour

  20. Shadows of the Plantation? A social history of Suriname’s bauxite town Moengo

    NARCIS (Netherlands)

    A. de Koning

    2011-01-01

    This article explores the social history of Suriname’s first bauxite town, Moengo, founded in the late 1910s. It recounts the rise of a new industry that drew workers away from the plantations and urban artisanal occupations to work in a massive, highly organized and orchestrated organization-cum-so

  1. Separation of diaspore from bauxite by selective flocculation using hydrolyzed polyacrylamide

    Institute of Scientific and Technical Information of China (English)

    刘文莉; 胡岳华; 孙伟

    2014-01-01

    Selective flocculation is a new method to solve the problem of China’s bauxite de-silication besides flotation and reverse flotation. The method of selective flocculation of bauxite using hydrolyzed polyacrylamide as flocculant was experimented and evaluated. The results of diaspore and kaolinite single mineral settling tests show that the difference between settlement yield of kaolinite (settling 15 min) and diaspore (settling 3 min) increases from 16% to 60% by adding flocculant at pH=7. Results of selective flocculation experiment of bauxite show that the higher concentrate grade (65.75) and Al-Si ratio (7.34) could be obtained with sodium carbonate as dispersant compared with sodium hexametaphosphate; under the action of flocculating agent, the concentrate grade and Al-Si ratio increase to 67.99 and 9.01. These results could meet the requirements of Bayer production, and the simpler process was expected to cost far less than traditional flotation method and a promising de-silication method of bauxite.

  2. Defluoridation of groundwater using aluminum-coated bauxite: Optimization of synthesis process conditions and equilibrium study.

    Science.gov (United States)

    Salifu, Abdulai; Petrusevski, Branislav; Mwampashi, Emmanuel S; Pazi, Iddi A; Ghebremichael, Kebreab; Buamah, Richard; Aubry, Cyril; Amy, Gary L; Kenedy, Maria D

    2016-10-01

    There is no known effective treatment for fluoride-related health disorders, hence prevention through water defluoridation is necessary. This study explored the possibility of modifying the physico-chemical properties of bauxite, a locally available material in many countries including Ghana, by thermal treatment and an aluminum coating, for water defluoridation. The study mainly focused on investigating the effects of varying synthesis process conditions on the defluoridation efficiency of Granular Aluminum Coated Bauxite (GACB). GACB performed better than raw bauxite (RB) and was able to reduce fluoride concentration in groundwater from 5 ± 0.2 mg/L to ≤ 1.5 mg/L, World Health Organization (WHO) guideline. Based on nonlinear Chi-square (χ(2)) analysis, the best-fitting isotherm model for the fluoride-GACB system was in the order: Freundlich > Redlich-Perterson ≈ Langmuir > Temkin. The fluoride adsorption capacity of GACB (qmax = 12.29 mg/g) based on the Langmuir model was found to be either comparable or higher than the capacities of some reported fluoride adsorbents. Aluminum (Al) coating procedures optimized in this study could therefore be a useful approach for synthesizing an effective fluoride adsorbent using bauxite, a locally available material. Kinetic and isotherm analysis, thermodynamic calculations, as well as FTIR and Raman analysis suggested the mechanism of fluoride adsorption onto GACB was complex and involved both physical adsorption and chemisorption processes. PMID:27327859

  3. More than 100 Million Tons of Bauxite Discovered in Dianxi,Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>It is reported that the large bauxite mine is lo- cated in the mid part of the Sanjiang mining belt’s Yunnan section,a region with a complex geological structure that has been on the top list of China’s plan to exploit nonferrous and pre- cious metal.

  4. Semi-industrial experimental study on bauxite separation using a cellcolumn integration process

    Institute of Scientific and Technical Information of China (English)

    Ning-ning Zhang; Chang-chun Zhou; Long-fei Cong; Wen-long Cao; You Zhou

    2016-01-01

    The cyclonic-static micro-bubble flotation column (FCSMC) is a highly efficient mineral processing equipment. In this study, a cell-column (FCSMC) integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis. The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon (A/S) mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of “fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns”. Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-column integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

  5. Effect of Boric Acid on Properties of Calcined Flint Clay-Bauxite Castables

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; DAI Wenyong

    2010-01-01

    In order to prolong the working time of calcined flint clay-bauxite castables during construction at high temperature,boric acid was added into the castables.The effect of boric acid on working time and curing cold crushing strength of the castables at 25 ℃ and 35 ℃were investigated.After 24 h curing in mould and another 24 h curing at 110 ℃ after demoulding,the specimens were heat treated at 1 000 ℃,1 300 ℃,and1 500 ℃ for 3 h,respectively.The permanent linear change,bulk density,modulus of rupture,and cold crushing strength were determined.The result shows that there is no need to add boric acid when calcined flint clay-bauxite ca.stables works at 25 ℃ ; when calcined flint clay-bauxite castables works at 35 ℃,boric acid can increase the working time of the castables,but decrease the curing cold crushing strength a little.Adding boric acid into calcined flint clay-bauxite castables doesn' t worsen performance of the castablcs.

  6. Relationships among Preparative Technique,Phase Composition and Bending Strength of Bauxite Porcelain

    Institute of Scientific and Technical Information of China (English)

    REN Qiang; WU Xiu-Lan; HE Xuan-Meng; ZHU Zhen-Feng

    2007-01-01

    Bauxite porcelain can be sintered to make its bending strength reach 179Mpa by using sintered bauxite,clay and potash feldspar and albite as the main raw materials in oxidation atmosphere under the normal pressure.XRD,SEM and so on are utilized to study the relationships between factors like the composition of ingot,reduction particle size and heat insulating time at sintering temperature and the phase composition,microstructure and bending strength of ceramic body.The results show that the main phases in bauxite porcelain are corundum,mullite and glass,and the mullite is composed of two parts:primary mullite formed by clay conversion and secondary mullite whiskers precipitating from high temperature melt.The bending strength of ceramic body can be improved by enhancing the content of sintered bauxite in the formula:the smaller the particle size of the ceramic body is,the higher the bending strength will be.The high-temperature heat insulating technique is beneficial to the precipitation of certain quantitative secondary mullite whiskers so as to remarkably improve the strength of glass phase and ceramic body.

  7. Extreme magnesium isotope fractionation during bauxite formation on the Columbia River Basalts

    Science.gov (United States)

    Liu, X.; Teng, F.; Rudnick, R. L.; McDonough, W. F.; Cummings, M. L.

    2012-12-01

    The behavior of magnesium isotopes during intense weathering of continental basalt is investigated by analyses of two ~10 m deep drill cores through bauxite developed on Columbia River Basalts (CRBs) in western Oregon and Washington, United States. XRD analyses reveal that these cores consist of gibbsite, hematite, +/- halloysite, kaolinite, goethite and maghemite; quartz, which is not present in fresh basalt, occurs only at the top of the cores and its abundance decreases progressively with depth; no quartz is observed below 5 m depth in either core. Both profiles display strong Mg depletion (up to 99%) relative to fresh basalt and one profile shows re-enrichment of Mg near the surface. δ26Mg values in bauxites are extremely high (up to +1.7) relative to the fresh basalts, which have mantle-like δ26Mg of -0.24 ± 0.07. The Mg isotopic fractionation in these bauxites is unlikely to be caused by kinetic fractionation via chemical diffusion (as suggested for lithium isotopes for a different weathering profile by Teng et al. (1)) because Richter et al. (2) found no measureable Mg isotopic fractionation associated with Mg diffusion in water. Moreover, due to the intense weathering, Mg isotopic fractionation in these drill cores should not be influenced by dissolution of basalts. Therefore, it is likely that the observed extreme Mg isotopic fractionation is associated with secondary mineral formation. However, δ26Mg tends to lower values towards the surface in both cores, opposite the trend that is expected to be produced by progressive leaching of the basalt accompanied by secondary mineral formation. Both the presence of quartz and less radiogenic Nd isotopic compositions at the tops of the profiles suggest that eolian material has been added to the top few meters of these weathering profiles, causing the Mg isotopic composition to be lighter at the surface. Moreover, both Mg concentration and δ26Mg in bauxites influenced by eolian addition show correlations with

  8. Microbial community succession in alkaline, saline bauxite residue: a cross-refinery study

    Science.gov (United States)

    Santini, T.; Malcolm, L. I.; Tyson, G. W.; Warren, L. A.

    2015-12-01

    Bauxite residue, a byproduct of the Bayer process for alumina refining, is an alkaline, saline tailings material that is generally considered to be inhospitable to microbial life. In situ remediation strategies promote soil formation in bauxite residue by enhancing leaching of saline, alkaline pore water, and through incorporation of amendments to boost organic matter content, decrease pH, and improve physical structure. The amelioration of chemical and physical conditions in bauxite residue is assumed to support diversification of microbial communities from narrow, poorly functioning microbial communities towards diverse, well-functioning communities. This study aimed to characterise microbial communities in fresh and remediated bauxite residues from refineries worldwide, to identify (a) whether initial microbial communities differed between refineries; (b) major environmental controls on microbial community composition; and (c) whether remediation successfully shifts the composition of microbial communities in bauxite residue towards those found in reference (desired endpoint) soils. Samples were collected from 16 refineries and characterised using 16S amplicon sequencing to examine microbial community composition and structure, in conjunction with physicochemical analyses. Initial microbial community composition was similar across refineries but partitioned into two major groups. Microbial community composition changes slowly over time and indicates that alkalinity and salinity inhibit diversification. Microbially-based strategies for in situ remediation should consider the initial microbial community composition and whether the pre-treatment of chemical properties would optimise subsequent bioremediation outcomes. During in situ remediation, microbial communities become more diverse and develop wider functional capacity, indicating progression towards communities more commonly observed in natural grassland and forest soils.

  9. Mineralogy, Geochemistry and Mass Changes at the Mombi Bauxite Deposit, (SW Iran): Using Geochemical Characteristics of the Immobile Elements

    Science.gov (United States)

    Ahmadnejad, Farhad; Vahabzadeh, Bahman; Zamanian, Hassan; Sameti, Mona; Asadi Haroni, Hooshang

    2016-04-01

    The Mombi bauxite deposit is located 160Km northwest of Dehdasht in the Zagros fold belt of Iran. The bauxite horizons are mineralogically homogeneous, and contains high amount of boehmite, diaspore, hematite, kaolinite, and anatase. Total geochemical analysis of the bauxite shows that Al2O3, SiO2, Fe2O3 and TiO2 are the main components. The immobile elements of Al, Ti, Nb, Zr, Hf, Cr, Ta, Y and Th are enriched while Rb, Ba, K, Sr, and P are depleted during bauxitization process. Chondrite-normalized REE pattern in the bauxite ore indicates REE enrichment (ΣREE=162.8-755.28ppm, ave. ~ 399.36 ppm) relative to the argillized limestone (ΣREE=76.26-84.03 ppm, ave. ~ 80.145 ppm). These patterns also reflect enrichment in LREE relative to HREE. Both positive and negative Ce anomalies (0.48-2.0) are observed in the Mombi bauxite horizons. These anomalies are related to the oxidation state of Ce (from Ce3+ to Ce4+), ionic potential, and complication of Ce4+ with carbonate compounds in the studied horizon. The present study uses the geochemistry of immobile elements to calculate the mass changes occurred during weathering and bauxitization. The results reveal that elements such as Si, Fe, Mg, P, K, Ba, Sr and Zn are depleted, while Al, Zr, V, Cr, Ni, Ga, Y and LREEs indicate positive mass changes during the weathering and bauxitization. In addition, Nb, Hf, Ta, Bi, Rb, Cs, U and HRRE exhibit little changes, suggesting relatively immobile features. Inter-elemental relationship analyses of the bauxite by using R-mode factor analysis method suggest that the elemental behaviors of trace elements and REEs during bauxite mineralization are mainly controlled by the mineral compositions and chemical properties of the elements. R-mode factor analysis reveals a number of key findings: (i) some of the low solubility elements were concentrated in detrital zircon (Zr), in anatase (Ti), and possibly in boehmite and hematite during the later stages of bauxitisation; (ii) Fe was

  10. Bauxite-supported Transition Metal Oxides: Promising Low-temperature and SO2-tolerant Catalysts for Selective Catalytic Reduction of NOx

    OpenAIRE

    Xiuyun Wang; Wen Wu; Zhilin Chen; Ruihu Wang

    2015-01-01

    In order to develop low-temperature (below 200 °C) and SO2-tolerant catalysts for selective catalytic reduction (SCR) of NOx, a series of cheap M/bauxite (M = Mn, Ni and Cu) catalysts were prepared using bauxite as a support. Their SCR performances are much superior to typical V2O5/TiO2, the addition of M into bauxite results in significant promotion of NOx removal efficiency, especially at low temperature. Among the catalysts, Cu/bauxite exhibits wide temperature window over 50–400 °C, stron...

  11. The potential for constructed wetlands to treat alkaline bauxite residue leachate: laboratory investigations.

    Science.gov (United States)

    R, Buckley; T, Curtin; R, Courtney

    2016-07-01

    High alkalinity (pH > 12) of bauxite residue leachates presents challenges for the long-term storage and managements of the residue. Whilst the use of constructed wetlands is gaining in interest for its use in the treatment of alkaline waters, thus far, there is limited evidence of its suitability for treating NaOH dominated bauxite residue leachate. A series of batch trials were conducted to investigate the potential for constructed wetland conferred mechanisms (dilution water quality, contact with CO2, and substrate type) for treating NaOH solutions to levels permissible for discharge (p constructed wetland. Formation of a calcite precipitate was observed in some treatments and further characterisation by XRD and XPS suggested surface coating with Na2CO3. It is therefore suggested that, under suitable conditions, constructed wetland technology can reduce leachate pH to constructed wetland. PMID:27048325

  12. Kinetic study of non-isothermal decomposition of a composite diasporic-boehmitic bauxite

    Science.gov (United States)

    Samouhos, M.; Angelopoulos, P.; Pilatos, G.; Taxiarchou, M.; Papageorgiou, S.

    2016-04-01

    In the current study, the kinetic of the thermal decomposition of a composite diasporic-boehmitic bauxite is investigated under non-isothermal heating conditions by means of thermogravimetric analysis. The calculation of activation energy (Ea) has been performed by various methods and the attained values range from 185000 to 190000 J.mol-1 for conversion rate of 0.5. The first-order kinetic model can adequately be used to describe thermal decomposition of bauxite composite, while the pre-exponential factor value was found to be 2.088*1011 min-1. The calculated activation energy value together with pre-exponential factor and the solid state kinetic model factors enable the simulation of the thermal decomposition under various heating conditions by the implementation of an ordinary differential equation. The calculated values are in satisfactory agreement with the experimental ones.

  13. CROSSING SUPPORT OF THE DRIFT AND CROSSCUTS IN SUBLEVEL BAUXITE MINING

    Directory of Open Access Journals (Sweden)

    Srećko Majić

    1993-12-01

    Full Text Available The report discusses the excavation method in underground bauxite exploitation of the Bauxite Mine Posušjc, as well as the experiences in crossing support of drifts and crosscuts till now, where it came in about 6% cases to the breakage of the frame support and to crossing ceiling caving. On the basis of such biggest caving, the estimate and dimensioning of critical support elements (runner and bar were performed. The possibility of supporting by bolting and stell plate was also considered. For the central part of the crosscut the use of bolts was assumed, which are fixed in the up-face. and for the rest of crossing the expansion shell anchors. For the latter, the estimate for anchoring elements was elaborated. Technical, safety and economic advantage of the bolts support is proved when compared with the frame support (the paper is published in Croatian.

  14. MORPHOLOGICAL AND GEOLOGICAL INDICATORS OF THE POSSIBLE BAUXITE DEPOSITS IN THE KARST REGION OF WESTERN HERZEGOVINA

    Directory of Open Access Journals (Sweden)

    Ivan Blašković

    1995-12-01

    Full Text Available Investigation results of morphological and geological potential bauxite deposit indicators in the Mesihovina-Rakitno bauxitebearing sedimentary basin in Western Herzegovina are presented. Region with carbonate and clastic hangingwalls as well as those without overlying sediments have been studied. It was established that the expression and number of the indicators depend size as well as on character and thickness of hangingwall sediments. The morphological indicators are expressed as a particular relief forms situated right above the deposits or nearby and are a consequence of geological relations and exodynamic processes. Ihe numerous geological indicators resulted from complex geological events. The most important are: preore structural relations, the formation of paleorelief, peculiar way of hangingwall rocks sedimentation, lithification processes and the formation of the recent structural pattern. It has been observed that particular indicators should be recognized within a relatively thick succession of the overlying sediments which is of the great importance in the exploration of bauxite deposits.

  15. Rheological Behavior of Bauxite-Based SiC-Containing Castables

    Institute of Scientific and Technical Information of China (English)

    YE Fangbao; M. Rigaud; LIU Xinhong; ZHONG Xiangchong

    2004-01-01

    Low cement (LC) and ultra-low cement (ULC)bauxite-SiC castables are important and high performance monolithic refiactories andthey have been widely used iniron-making and incinerator linings. In this work, rheo-logical behavior of LC and ULC bauxite-based SiC-contain-ing castables has been studied, including the effects of SiC content and cement content on rheological properties of thecastables. The results show that with an increase of SiC and cement content, rheological properties of the castablesdeteriorate. On the other hand, moderate amounts of SiC(4% ~ 8% ) and of calcium aluminate cement (2% ~4% ) have very slight influence on rheological properties,(i. e. when the castables are sheared their torque andyield torque only slightly increase with the shearing speed). The rheological characteristics of the castables fol-low Bingham fiuid and always show shear thinning behav-ior.

  16. Ferruginous Microspherules in Bauxite at Maochang, Guizhou Province, China: Products of Microbe-Pyrite Interaction?

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yuefei; WANG Rucheng; LU Jianjun; LI Yiliang

    2006-01-01

    The Maochang bauxite in Guizhou Province is one of the important aluminum ore deposits in southwestern China. Ferruginous spherules, measuring about a few microns across, were found in the transitional layer of the deposit. The EDS and XRD results show that the microspherules are composed mostly of iron (hydr)oxide minerals (goethite) with only weak presence of aluminum and silicon.Occasionally, some pyrite micrograins with dissolved surface are found associated with goethite within the spherules. It is thus suggested that microspherules are linked to pyrite oxidization. It is also thought that microbial activities contribute not only to pyrite oxidization, but also to ball-like assemblage of the iron (hydr)oxides. The mechanism of the formation of ferruginous microspherules is also believed to be important in studying geomicrobiology of bauxite.

  17. β-Sialon Produced by Carbon Thermal Nitriding Reaction of Bauxite

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    β-Sialon was produced by carbon thermal nitriding reaction in N2 gas atmosphere when the mixtures of bauxite and anthracite were put into vertical furnace. According to the mass loss of raw materials and the result of X-ray diffration (XRD) of products, the influences of the process parameters on the compositions and relative contents of products, such as the fixed carbon content, the flow of N2, the soaking time and the temperature, were researched.

  18. Extra large bauxite mines with 120 million tons discovered in Guangxi Congzuo

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>According to Guangxi General Institute of Geological Prospecting,after 3 years of hard work,prospecting team has discovered extra large bauxite mines with resources of 120 mil- lion tons in Youjiang area in Guangxi. It is said that the newly-found extra large baux- ite mines are situated in the city of Congzuo. The ore belt lays generally northeast with 50

  19. Effects of minerals in ferric bauxite on sodium carbonate decomposition and volatilization

    Institute of Scientific and Technical Information of China (English)

    胡文韬; 王化军; 刘欣伟; 孙传尧

    2015-01-01

    Direct reduction is an emerging technology for ferric bauxite utilization. However, because of sodium volatilization, its sodium carbonate consumption is considerably higher than that in ordinary bauxite processing technology. TG-DSC and XRD were applied to detecting phase transformation and mass loss in direct reduction to reveal the mechanism on sodium volatilization. The results show that the most significant influence factor of ferric bauxite on sodium volatilization in direct reduction system is its iron content. Sodium volatilization is probably ascribed to the instability of amorphous substances structure. Amorphous substances are the intermediate-products of the reaction, and the volatilization rate of sodium increases with its generating rate. These amorphous substances are volatile, thus, more sodium is volatilized with its generation. A small amount of amorphous substances are generated in the reaction between Na2CO3and Al2O3; thus, only 3.15% of sodium is volatilized. Similarly, the volatilization rate is 1.87% in the reaction between Na2CO3and SiO2. However, the volatilization rate reaches 7.64% in the reaction between Na2CO3 and Fe2O3 because of the generation of a large amount of amorphous substances.

  20. Artificial neural network prediction of the aluminum extraction from bauxite in the Bayer process

    Directory of Open Access Journals (Sweden)

    Đurić Isidora

    2012-01-01

    Full Text Available This paper presents the results of statistical modeling of the bauxite leaching process, as part of Bayer technology for an alumina production. Based on the data, collected during the period between 2008 - 2009 (659 days from the industrial production in the alumina factory Birač, Zvornik (Bosnia and Herzegovina, the statistical modeling of the above mentioned process was performed. The dependant variable, which was the main target of the modeling procedure, was the degree of Al2O3 recovery from boehmite bauxite during the leaching process. The statistical model was developed as an attempt to define the dependence of the Al2O3 degree of recovery as a function of input variables of the leaching process: composition of bauxite, composition of the sodium aluminate solution and the caustic module of the solution before and after the leaching process. As the statistical modeling tools, Multiple Linear Regression Analysis (MLRA and Artificial Neural Networks (ANNs were used. The fitting level, obtained by using the MLRA, was R2 = 0.463, while ANN resulted with the value of R2 = 0.723. This way, the model, defined by using the ANN methodology, can be used for the efficient prediction of the Al2O3 degree of recovery as a function of the process inputs, under the industrial conditions of the alumina factory Birač, Zvornik. The proposed model also has got a universal character and, as such, is applicable in other factories practicing the Bayer technology for alumina production.

  1. Alumina Extraction From Low-Grade Diasporic Bauxite By Pyro-Hydro Metallurgical Process

    Directory of Open Access Journals (Sweden)

    Ahmet Alp

    2000-06-01

    Full Text Available Diasporic bauxite samples obtained from Isparta-Yalvaç region were crashed and sieved with a 100 mm sieve. After determining the composition by chemical analysis, grain size distribution of the samples were determined. Then the characterization of the sample was recorded by static and dynamic thermal analysis and XRD studies. Bauxite samples added CaO and Na2CO3 were calcined at 900 ºC. Alumina extraction studies were performed for 20, 40, 60, 80 minutes of calcination time and 15, 30, 45, 60 minutes of leach time and 25, 50, 75, 100 ºC of leach temperature. It was found that the maximum leach yield (85.04 % was obtained at 60 minutes of calcination time and 15 minutes of leach time and 50 ºC of leach temperature. These results demonstrated that the optimum conditions for dissolving to this type of iron-rich low grade diasporic bauxite minerals at low-temperature and alkaline concentration were determined.

  2. Mineralogical characteristics of the superlarge Quaternary bauxite deposits in Jingxi and Debao counties, western Guangxi, China

    Science.gov (United States)

    Liu, Xuefei; Wang, Qingfei; Zhang, Qizuan; Feng, Yuewen; Cai, Shuhui

    2012-06-01

    In recent decades, more than 0.5 billion tons of ores scattered in the Quaternary laterite in western Guangxi, China have been explored. The ores were derived from a bauxite horizon in Permian via physical break-up and re-sediment process. Utilizing various test methods, i.e., XRD, DTA, TG/DTG, SEM/EDS and EPMA, the mineralogical characteristics of the Quaternary bauxite ores in Jingxi and Debao counties were investigated. XRD was used together with TG/DTG to obtain relatively accurate ore mineral abundance. Diaspore is the major phase, whereas hematite, kaolinite, anatase, chamosite, gibbsite, goethite, illite and rutile are minor. Diaspore is characterized by a small particle size, low degrees of crystallinity and complex chemical composition. Both gibbsite and goethite have a varied particle size, and goethite crystals contain high Al substitution and Si. It is clarified that diaspore, chamosite and anatase were formed in a mildly reduced and alkaline depositional environment in Permian, while gibbsite, hematite, goethite and part kaolinite were precipitated from Al3+-, Si4+- and Fe3+-enriched solutions within an Quaternary oxidized environment. The ions Al3+, Si4+ and Fe3+ are mostly released from chamosite in its dissolution process. The different physicochemical conditions between the Permian depositional and the Quaternary weathering periods resulted in a complex mineral assemblage in the Quaternary bauxite.

  3. Investigation on deposition condition, sedimentary environment and genesis of Mandan and Deh-Now bauxite deposits, Dehdasht area, Kohgiloye and Boyer-Ahmad province: using mineralogical studies

    Directory of Open Access Journals (Sweden)

    Alireza Zarasvandi

    2011-04-01

    Full Text Available The Mandan and Deh-Now bauxite deposits are located 40 km northeast of Dehdasht in Kohgiloye and Boyer-Ahmad province in the Zagros simply folded belt. The deposits were formed in the oldest rocks of the area of late Cretaceous age. The bauxite horizon is situated between Sarvak and Ilam formations. The aim of this study is to determine the mineralogy and texture relations of the deposits in order to determine the environment and status of bauxite mineralization. In this way, samples were selected from these bauxite deposits for mineralogical studies based on microscopic and XRD techniques. The bauxite horizon in the Mandan deposit consists of white, gray, black, pisolitic, red and yellow bauxites. The sequence was repeated in the Deh-Now without black and gray bauxites. Mineralogy is similar in all bauxitic layers and the main textures are pisolitic-ooide, ooide-spheroid, pisolitic, pelitomorphic and pseoudomorphic. Bohmite, diaspore, kaolinite and calcite are the most important minerals in both bauxitic layers of the Mandan and Deh-Now deposits. Due to bohmite mineralization in the study area, erosional and intense weathering environment in the Touronian-Cenomanian could be suggested for the deposition of bauxite in these deposits. Existence of interclasts in the pisolites and ooides indicate that these bauxites were transformed from the primary in situ environment to karstic sedimentary basin as authigenic origin. These studies indicate that there are two mineralized facies with different environmental status: (1 oxidation facies with bohmite, diaspore, kaolinite and hematite minerals and (2 reduced facies with pyrite, diaspore and chlorite mineralization. The lack of reduced condition at the Deh-Now deposit shows that the deposit formed only in oxidation status.

  4. Carnian bauxite horizon on the Kopitov grič near Borovnica (Slovenia – is there a »forgotten« stratigraphic gap in its footwall?

    Directory of Open Access Journals (Sweden)

    Bogomir Celarc

    2008-12-01

    Full Text Available Beds underlying the Carnian bauxite on the Kopitov gri~ (Slovenia are by the author’s opinion not Carnian (Cordevolian, but Ladinian age. The considerable stratigraphical gap is presented between Carnian clastic rocks and underlying limestones and dolomites. Bauxite is result of the weathering during the emersion.

  5. 均质铝矾土煅烧技术的研究%Study on calcining technology for homogeneous bauxite

    Institute of Scientific and Technical Information of China (English)

    谭莹

    2011-01-01

    A simulation experiment study is carried out for homogenous bauxite in tunnel kiln. The ex- periment result shows that the optimal calcining schedule for homogenous bauxite is 1 550℃, 5h. Here the bulk density reaches 3.45g.cm^-3 and the internal microstructure of the bauxite reaches optimal state. Meanwhile the quality index of the specimen is better than that of calcined bauxite QA1-88 obviously. Key words: Homogeneous bauxite ; Calcining temperature ; Holding time ; Quality index%在隧道窑中对均质铝矾土进行了模拟实验研究,结果表明:均质铝矾土的最佳煅烧制度为1550℃、5h,体积密度可达到3.45g·cm^-3,且铝矾土内部微观结构达到最佳状态。同时样品的质量指标明显优于优质铝矾土熟料QA1—88指标。

  6. Influence of grazing practices on cow milk quality: a case study on the Comarnic-Poieni bauxite quarry, Romania.

    Science.gov (United States)

    Lorinţ, Csaba; Rădulescu, Monica; Buia, Grigore

    2012-04-01

    The current study represents a preliminary investigation made into the influence of cattle grazing in the area of a bauxite quarry (Comarnic-Poieni, Romania) on the cow milk chemistry. Weathering and surface runoff in the bauxite quarry contaminate the local chemistry of the soil, vegetation and water. During cattle transhumance, cyclic feeding patterns occur, with grazing alternating between clean pastures and the area of the quarry. Soil and water samples were collected from the contaminated area of the quarry. Raw milk samples were collected during two stages, corresponding to the periods of grazing on clean pasture and the quarry area, respectively. Based on the obtained data, the relationship between cattle grazing and the composition of milk was interpreted. Preliminary results indicated a direct correlation of increased concentration of Al in the milk, following grazing in the bauxite quarry.

  7. Neopterin: A candidate biomarker for the early assessment of toxicity of aluminum among bauxite dust exposed mine workers

    Directory of Open Access Journals (Sweden)

    Shubhangi K Pingle

    2015-01-01

    Full Text Available Introduction: Bauxite ore is a major source of aluminum (Al which contains approximately 35–60% Al by weight. Occupational and environmental bauxite dust exposure may cause toxicity by interaction with human biological systems resulting in oxidative stress (OS and cell death. A neopterin derivative as an antioxidant is able to modulate cytotoxicity by the induction of OS. Materials and Methods: A total of 273 subjects were selected for blood collection from three different major Al producing bauxite mines and were categorized into three groups as experimental (Exp (n = 150, experimental controls (ExC (n = 73 and control (Con (n = 50. Whole blood and serum samples were used for measurement of Al, neopterin, urea and creatinine values. Statistical analysis was performed using R-2.15.1 programming language. Results and Discussion: The result showed that age, body mass index and the behavioral habits, that is, smoking, tobacco and alcohol consumption have possible effects on neopterin level. Serum neopterin levels were found to be significantly higher (P <0.0001 in the experimental group as compared to other groups. Significantly positive correlation (P < 0.0001 was observed between neopterin and creatinine. It was also observed that neopterin level increases as the duration of exposure increases. Conclusion: On the basis of findings it was concluded that exposure to bauxite dust (even at low levels of Al changes biochemical profile leading to high levels of serum neopterin. Levels of serum neopterin in workers exposed to bauxite dust were probably examined for the 1st time in India. The outcome of this study suggested that serum neopterin may be used as potential biomarker for early detection of health risks associated with bauxite dust exposed population.

  8. 马尾山铝土矿床地质特征%Bauxite Deposit Geological Characteristics in Mawei Mountain

    Institute of Scientific and Technical Information of China (English)

    钱镭; 郑勇; 闫跃东

    2014-01-01

    通过对马尾山铝士矿区初步普查工作,共求获铝土矿资源量65.77万吨,同时在矿区内还共生有粘土矿产可综合利用.从成矿条件分析,马尾山铝士矿区早二叠世梁山期为滨岸沼泽相环境,具铝土质泥质相沉积特征.因此,在马尾山铝士矿区西南部的二仙崖一带、咸丰西南部的赶场溪一带和咸丰西部的龙家盖一带,成矿条件较好,资源潜力较大,应进一步开展铝土矿的矿产勘查工作.%Through preliminary mineral prospecting in Marwei mountain bauxite beds, 657 700 tons of bauxite have been explored.At the same time,within the same mining area,symbiotic clay mineral can be mined and utilized comprehensively.Though it is a smaller scale of orebodies,this bauxite mineral explora-tion,as the rare bauxite mineral in this area,has important guiding significance in the future corresponding and related work.Analyzed from the metallogenic conditions, this orebodies belongs to coastal swamp faci-es environment in the early permian liangshan period,which is characterized by bauxitic argillaceous faci-es.As a result, the better bauxite metallogenic conditions and better potential bauxite mining resources have been found in eerxianyan in the southwest part in of Xianfeng County,Ganchangxi in the southwest part of of Xianfeng County,Longjiagai in the western part of of Xianfeng County.The bauxite mineral ex-ploration work should be further carriedout.

  9. Effect of hydroxamic acid starch on reverse flotation desilicate from diasporic bauxite

    Institute of Scientific and Technical Information of China (English)

    胡岳华; 李海普; 蒋玉仁

    2002-01-01

    It is important to depress diaspore effectively in order to remove silicates from diasporic bauxite. A new water soluble polymer hydroxamic acid starch (HA-starch) was prepared. The effects of the product on the diaspore and kaolinite flotation were investigated and its reactive mechanism was studied by zeta potential measurement and FTIR. The results show that HA-starch can depress diaspore while make positive effect on kaolinite flotation at low pH value(pH below 6). The flotation recovery of diaspore was sharply decreased with the increase of concentration of HA-starch. The chemical adsorption of HA-starch on the surface of diaspore was revealed.

  10. Thermal Shock Resistance of Bauxite-based β-Sialon Bonded Corundum Materials

    Institute of Scientific and Technical Information of China (English)

    LIU Zhanjie; ZHANG Haijun; ZHONG Xiangchong

    2005-01-01

    Thermal shock resistant properties of reaction sintered bauxite-based β-Sialon bonded corundum have been investigated, and the results are compared with those of Al2 O3 based counterpart. It is found they all have very good thermal shock resistance. Their residual strength ratios after one thermal shock cycle at △T =1200℃ and △T = 1350℃ are 61% ~73% and 53% ~65% respectively. Their critical temperature difference (TSR) is 600℃~800℃. TSR parameters are calculated based on thermal expansion, modulus of elasticity,and fracture toughness determined. The reasons for improving TSR of these composite materials are discussed.

  11. Removal of anionic ions from single material solution by bauxite tailings modified with FeCl3·6H2O

    Institute of Scientific and Technical Information of China (English)

    LAN Ye; WANG Yu-hua; HUANG Chuan-bing

    2008-01-01

    The adsorbabilities of the unmodified and modified bauxite tailings for Cr(Ⅵ), As(Ⅴ) and F(Ⅰ) ions were investigated. Batch experiments were carried out to determine the removal rate as a function of adsorbent dosage, solution pH value and shaking time. The results show that the maximum removal rates of Cr(Ⅵ), As(Ⅴ) and F(Ⅰ) are respectively 99%, 99% and 90% by using the modified bauxite tailings. The isoelectric point of the unmodified bauxite railings is 3.6, and that of the modified bauxite tailings is 5.0, which shifts to lower pH values in Cr(Ⅵ) solution. This indicates a specific adsorption of the anionic species on the modified bauxite tailings. A new band of Cr2O72- appears in the FTIR, showing that Cr(Ⅵ) is adsorbed on the modified bauxite tailings in the form of chemistry adsorption. The adsorption data of Cr(Ⅵ) on the modified bauxite tailings are well described by Freundlich model. The investigations of kinetic models show that pseudo-second-order kinetic model provides the best correlation for the experimental data.

  12. Technology and mechanism of desilication from roasted diasporic bauxite in atmosphere

    Institute of Scientific and Technical Information of China (English)

    李光辉; 姜涛; 邱冠周; 范晓慧; 蒋昊

    2002-01-01

    The leaching desilication technology of roasted diasporic bauxite in atmosphere by caustic soda solution was investigated. The optimum parameters were: the grinding fineness of the roasted bauxite -0.076mm and 80%~85%, leaching time 2h, Na2Ok 100~150g/L, L/S 4~5, leaching temperature 90~95℃. The desilication rate 55.20% and concentrate A/S (mass ratio of Al2O3 to SiO2) 9.90, as good as those obtained at pressure, were obtained respectively. Investigation of two-stage leaching shows that it can both improve desilication rate of roasted ore and reduce leaching time. When time of the first stage and the second stage is 30min and 30min respectively, desilication rate can reach 59.65%. X-ray diffraction analysis of the concentrate has proved that desilication procedure is accompanied with the formation of sodium aluminosilicate hydrate. X-ray spectra also show that silica removed during leaching is amorphous silica. SiO2 occurring as quartz in raw ore or mullite formed during roasting can not dissolve in alkali solution.

  13. Separation of aluminosilicates and diaspore from diasporic-bauxite by selective flocculation

    Institute of Scientific and Technical Information of China (English)

    HUANG Chuan-bing; ZHANG Lin; WANG Yu-hua; LAN Ye

    2008-01-01

    The flocculation tests of four pure minerals (diaspore, kaolinite, illite, pyrophyllite) and bauxite ore were investigated by the sedimentation. The dispersion behavior of the four pure minerals shows a very good consistency with the variation of zeta potential. The concentrate with the mass ratio of Al2O3 to SiO2 (m(Al2O3)/m(SiO2)) 8.90 and the recovery of Al2O3 86.98% is obtained from bauxite ore (m(Al2O3)/m(SiO2)=5.68) in pH range of 9.5-10.0 by using sodium carbonate (5 kg/t) and sodium polyacrylate (7 g/t) as dispersant and flocculant respectively. Sodium carbonate acts as both pH modifier and favorable dispersant for aluminosilicates. The high performance of sodium polyacrylate on flocculation for diaspore is contributed to the carboxyl of sodium polyacrylate that interacts with active Al sites on diaspore by chemical absorption, and the hydrogen bond effects between hydroxyl group of macromolecule and surface Al--OH on diaspore to accelerate the sedimentation of diaspore.

  14. Experimental Simulation of Long Term Weathering in Alkaline Bauxite Residue Tailings

    Directory of Open Access Journals (Sweden)

    Talitha C. Santini

    2015-07-01

    Full Text Available Bauxite residue is an alkaline, saline tailings material generated as a byproduct of the Bayer process used for alumina refining. Developing effective plans for the long term management of potential environmental impacts associated with storage of these tailings is dependent on understanding how the chemical and mineralogical properties of the tailings will change during weathering and transformation into a soil-like material. Hydrothermal treatment of bauxite residue was used to compress geological weathering timescales and examine potential mineral transformations during weathering. Gibbsite was rapidly converted to boehmite; this transformation was examined with in situ synchrotron XRD. Goethite, hematite, and calcite all precipitated over longer weathering timeframes, while tricalcium aluminate dissolved. pH, total alkalinity, and salinity (electrical conductivity all decreased during weathering despite these experiments being performed under “closed” conditions (i.e., no leaching. This indicates the potential for auto-attenuation of the high alkalinity and salinity that presents challenges for long term environmental management, and suggests that management requirements will decrease during weathering as a result of these mineral transformations.

  15. The role of nano-perovskite in the negligible thorium release in seawater from Greek bauxite residue (red mud)

    DEFF Research Database (Denmark)

    Gamaletsos, P.; Godelitsas, Athanasios; Kasama, Takeshi;

    2016-01-01

    We present new data about the chemical and structural characteristics of bauxite residue (BR) from Greek Al industry, using a combination of microscopic, analytical, and spectroscopic techniques. SEM-EDS indicated a homogeneous dominant "Al-Fe-Ca-Ti-Si-Na-Cr matrix", appearing at the microscale. ...

  16. Genesis of the Doğankuzu and Mortaş Bauxite deposits, Taurides, Turkey: separation of Al, Fe, and Mn and implications for passive margin metallogeny

    Science.gov (United States)

    Öztürk, Hüseyin; Hein, James R.; Hanilçi, Nurullah

    2002-01-01

    The Taurides region of Turkey is host to a number of important bauxite, Al-rich laterite, and Mn deposits. The most important bauxite deposits, Doğankuzu and Mortaş, are karst-related, unconformity-type deposits in Upper Cretaceous limestone. The bottom contact of the bauxite ore is undulatory, and bauxite fills depressions and sinkholes in the footwall limestone, whereas its top surface is concordant with the hanging-wall limestone. The thickness of the bauxite varies from 1 to 40 m and consists of böhmite, hematite, pyrite, marcasite, anatase, diaspore, gypsum, kaolinite, and smectite. The strata-bound, sulfide- and sulfate-bearing, low-grade lower part of the bauxite ore bed contains pyrite pseudomorphs after hematite and is deep red in outcrop owing to supergene oxidation. The lower part of the bauxite body contains local intercalations of calcareous conglomerate that formed in fault-controlled depressions and sinkholes. Bauxite ore is overlain by fine-grained Fe sulfide-bearing and calcareous claystone and argillaceous limestone, which are in turn overlain by massive, compact limestone of Santonian age. That 50-m-thick limestone is in turn overlain by well-bedded bioclastic limestone of Campanian or Maastrichtian age, rich with rudist fossils. Fracture fillings in the bauxite orebody are up to 1 m thick and consist of bluish-gray-green pyrite and marcasite (20%) with böhmite, diaspore, and anatase. These sulfide veins crosscut and offset the strata-bound sulfide zones. Sulfur for the sulfides was derived from the bacterial reduction of seawater sulfate, and Fe was derived from alteration of oxides in the bauxite. Iron sulfides do not occur within either the immediately underlying or overlying limestone. The platform limestone and shale that host the bauxite deposits formed at a passive margin of the Tethys Ocean. Extensive vegetation developed on land as the result of a humid climate, thereby creating thick and acidic soils and enhancing the transport of

  17. Thorium partitioning in Greek industrial bauxite investigated by synchrotron radiation and laser-ablation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gamaletsos, P. [Faculty of Geology and Geoenvironment, University of Athens, Panepistimioupolis, 15784 Zographou (Greece); Godelitsas, A., E-mail: agodel@geol.uoa.gr [Faculty of Geology and Geoenvironment, University of Athens, Panepistimioupolis, 15784 Zographou (Greece); Mertzimekis, T.J. [Department of Physics, University of Athens, Panepistimioupolis, 15771 Zographou (Greece); Goettlicher, J.; Steininger, R. [Karlsruhe Institute of Technology, Institute for Synchrotron Radiation, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Xanthos, S. [Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Berndt, J.; Klemme, S. [Institut fuer Mineralogie, Corrensstrasse 24, Universitaet Muenster, 48149 Muenster (Germany); Kuzmin, A. [Institute of Solid State Physics, University of Latvia, Kengaraga st. 8, 1063 Riga (Latvia); Bardossy, G. [Hungarian Academy of Sciences, H-1051 Budapest (Hungary)

    2011-12-15

    Typical red-brown (Fe-rich) and high-quality white-grey (Fe-depleted) bauxite samples from active mines of the Parnassos-Ghiona area, central Greece, were investigated. According to XRF and ICP-MS analyses their actinide content, and particularly of Th, is relatively increased. Fe-depleted samples contain up to 62.75 ppm Th corresponding to 220 Bq/kg due to {sup 228}Ac ({sup 232}Th-series), whereas Fe-rich samples are less Th-radioactive (up to 58.25 ppm Th, 180 Bq/kg due to {sup 228}Ac). Powder-XRD patterns showed that Th-enriched (Fe-depleted) bauxite consists mostly of diaspore (AlOOH polymorph), anatase and rutile (TiO{sub 2} polymorphs). SEM-EDS indicated the presence of Ti-Fe-containing phases (e.g. ilmenite, FeTiO{sub 3}), chromite (Cr-spinel) and besides LREE-minerals (mostly bastnaesite/parisite-group) and zircon (ZrSiO{sub 4}) hosting a part of the bulk Th. The presence of Th in diaspore and in Ti-containing phases (not detected by SEM-EDS as in the case of REE-minerals and zircon) was investigated, into distinct pisoliths of Fe-depleted bauxite, using {mu}-XRF and {mu}-XAFS in the SUL-X beamline of the ANKA Synchrotron facility (KIT, Germany). XAFS spectra of Th salts and Th-containing reference materials were obtained as well. Accordingly it was revealed, for the first time in the literature, that Ti-phases, and particularly anatase, host significant amounts of Th. This novel conclusion was complementary supported by LA-ICP-MS analyses indicated an average of 73 ppm Th in anatase grains together with abundant Nb (3356 ppm), Ta (247 ppm) and U (33 ppm). The Th L{sub III}-edge XAFS spectra as compared to reference materials, give also evidence that Th{sup 4+} may not replace Ti{sup 4+} in distorted [TiO{sub 6}] fundamental octahedral units of anatase and ilmenite lattice (CN = 6). The occupation of either extraframework sites of higher coordination (CN = 6.9 or even CN = 7.4), according to EXAFS signals evaluation, or of defected/vacant (**) sites is more

  18. Self-organized geodynamics of karst limestone landscapes and coupled terra rossa/bauxite formation

    Science.gov (United States)

    Merino, E.; Wang, Y.; Banerjee, A.

    2012-12-01

    Why do flat limestones overlain by terra rossa or bauxite systematically adopt so-called karst geomorphology, which consists of sets of roughly regularly spaced wormholes, or funnels, or sinkholes, or tower karst? The idea that the funnels and sinkholes are located at the intersections of preexisting sets of subvertical fractures is untenable. New field and petrographic evidence (Merino & Banerjee, J. Geology, 2008) revealed that, rather than 'residual' or 'detrital' (the only options that have been on the table for decades), the terra rossa/bauxite clays and Al- and Fe-oxyhydroxides grow authigenically at the base of the terra rossa, replacing the underlying limestone at a generally downward-moving reaction front several centimeters thick. The clay-for-limestone replacement, which preserves solid volume (because it takes place by clay-growth-driven pressure solution of calcite), releases H+ ions. These dissolve more calcite, generating considerable leached porosity in a narrow zone that travels with the replacement front. We proposed (Merino & Banerjee, J. Geology, 2008) that the moving leached-porosity maximum created at the front could trigger the reactive-infiltration instability (Chadam et al, IMA J. Appl. Math., 1986), causing the replacement-and-leaching reaction front to become regularly fingered, with the fingers jumping in scale to funnels, these to sinks, and these, when deep enough and merged together laterally, to tower karst. This new geodynamics would account both for the world-wide association of terra rossa and bauxite with karst limestones, and for the stunning, self-organized geomorphology of karst itself. We are testing these ideas through linear stability analysis of a simplified reaction-transport system of equations and through numerical solution of the full non-linear system of reaction-transport equations applicable, including aqueous speciation. Preliminary calculations (Banerjee & Merino, J. Geology, 2011) suggest that the replacement

  19. Thorium partitioning in Greek industrial bauxite investigated by synchrotron radiation and laser-ablation techniques

    Science.gov (United States)

    Gamaletsos, P.; Godelitsas, A.; Mertzimekis, T. J.; Göttlicher, J.; Steininger, R.; Xanthos, S.; Berndt, J.; Klemme, S.; Kuzmin, A.; Bárdossy, G.

    2011-12-01

    Typical red-brown (Fe-rich) and high-quality white-grey (Fe-depleted) bauxite samples from active mines of the Parnassos-Ghiona area, central Greece, were investigated. According to XRF and ICP-MS analyses their actinide content, and particularly of Th, is relatively increased. Fe-depleted samples contain up to 62.75 ppm Th corresponding to 220 Bq/kg due to 228Ac ( 232Th-series), whereas Fe-rich samples are less Th-radioactive (up to 58.25 ppm Th, 180 Bq/kg due to 228Ac). Powder-XRD patterns showed that Th-enriched (Fe-depleted) bauxite consists mostly of diaspore (AlOOH polymorph), anatase and rutile (TiO 2 polymorphs). SEM-EDS indicated the presence of Ti-Fe-containing phases (e.g. ilmenite, FeTiO 3), chromite (Cr-spinel) and besides LREE-minerals (mostly bastnäsite/parisite-group) and zircon (ZrSiO 4) hosting a part of the bulk Th. The presence of Th in diaspore and in Ti-containing phases (not detected by SEM-EDS as in the case of REE-minerals and zircon) was investigated, into distinct pisoliths of Fe-depleted bauxite, using μ-XRF and μ-XAFS in the SUL-X beamline of the ANKA Synchrotron facility (KIT, Germany). XAFS spectra of Th salts and Th-containing reference materials were obtained as well. Accordingly it was revealed, for the first time in the literature, that Ti-phases, and particularly anatase, host significant amounts of Th. This novel conclusion was complementary supported by LA-ICP-MS analyses indicated an average of 73 ppm Th in anatase grains together with abundant Nb (3356 ppm), Ta (247 ppm) and U (33 ppm). The Th LIII-edge XAFS spectra as compared to reference materials, give also evidence that Th 4+ may not replace Ti 4+ in distorted [TiO 6] fundamental octahedral units of anatase and ilmenite lattice (CN = 6). The occupation of either extraframework sites of higher coordination (CN = 6.9 or even CN = 7.4), according to EXAFS signals evaluation, or of defected/vacant (**) sites is more probable. This is likely explained by the difficulty of

  20. Surface charge properties of red mud particles generated from Chinese diaspore bauxite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kun-yu; HU Hui-ping; ZHANG Li-juan; CHEN Qi-yuan

    2008-01-01

    Acid/basic potentiometric titration can be used to quantify the red mud surface charge properties. The amount of surface active -OH groups and surface charge density on the red mud particles generated from Chinese diaspore bauxite were evaluated from the acid/basic potentiometric titration data in 0.1 mol/L or 0.5 molL NaCI solution. The results show that the adsorption of sodium polyacrylate(SPA) on the red mud surface causes the increase of the surface active -OH groups, which makes the point of zero charge(PZC) shift to a lower pH value. However, the adsorption of polyacrylamide(PAM) causes little change. As the concentration of NaCl solution increases, the surface charge becomes more positive in acidic solution and more negative in alkaline solution, which can be attributed to the presence of a porous surface gel coating on the red mud particles.

  1. Caracterização de bauxita ativada antes e depois da saturação com óleo mineral isolante Characterization of activated bauxite before and after saturation with insulating mineral oil

    Directory of Open Access Journals (Sweden)

    Josélia Ednar Antunes Piluski

    2008-01-01

    Full Text Available A characterization of activated bauxite and of activated bauxite impregnated with insulating mineral oil was made. The activated bauxite is used as adsorbent material in percolators during the regeneration of insulating mineral oil. After regeneration an insulating mineral oil is obtained with physical and chemical characteristics similar to those of the new oil. Moreover, saturated activated bauxite impregnated with insulating mineral oil is also produced. It is a dangerous residue according to NBR 10004 (Class I and, thus, harmful to the environment. An alternative use of this waste in the ceramic industry is discussed.

  2. Efficiency of Integrated Geophysical techniques in delineating the extension of Bauxites ore in north Riyadh, Saudi Arabia

    Science.gov (United States)

    Almutairi, Yasir; Alanazi, Abdulrahman; Almutairi, Muteb; Alsama, Ali; Alhenaki, Bander; Almalki, Awadh

    2014-05-01

    We exploit the integration of Ground Penetrating Radar (GPR) techniques, magnetic gradiometry, resistivity measurements and seismic tomography for the high-resolution non-invasive study for delineating the subsurface Bauxite layer in Zabira locality, north of Riyadh. Integrated GPR, magnetic gradiometry resistivity and seismic refraction are used in the case of high contrast targets and provide an accurate subsurface reconstruction of foundations in sediments. Resistivity pseudo-sections are in particular useful for the areal identification of contacts between soils and foundations while GPR and magnetic gradiometry provide detailed information about location and depth of the structures. Results obtained by GPR, Magnetics and resistivity shows a very good agreement in mapping the bauxite layer depth at range of 5 m to 10 m while the depth obtained by seismic refraction was 10 m to 15 m due to lack of velocity information.

  3. Assessing the grass Schizachyrium gracile for capacity to ecologically restore the polluted soils of ecosystems in a bauxite mining area

    International Nuclear Information System (INIS)

    Abandoned bauxite mines in the tropical forest of the Dominican Republics only biosphere reserve are leaving behind extensive areas and landfills, whose negative impacts need restoring because of the ecological interest of the sites they occupy. Given that any realistic recovery program should be based on knowledge of the ecological succession, in this report we present the results derived from the study of two populations of a pioneer species of these ecosystems. (Author)

  4. Mixed volcanogenic-lithogenic sources for Permian bauxite deposits in southwestern Youjiang Basin, South China, and their metallogenic significance

    Science.gov (United States)

    Yu, Wenchao; Algeo, Thomas J.; Du, Yuansheng; Zhang, Qilian; Liang, Yuping

    2016-07-01

    Bauxite deposits at the base of the Upper Permian Heshan Formation in the Youjiang Basin, South China, contain zircons with dominant age peaks at 263-262 Ma. During the Middle to Late Permian, the Youjiang Basin consisted of a number of isolated and attached carbonate platforms separated by inter-platform troughs. The bauxite deposits are limited to the isolated carbonate platform facies and are not present on attached carbonate platforms and inter-platform troughs. Discriminant plots based on the trace element composition of the zircons indicate a combination of within-plate/anorogenic and arc-related/orogenic sources. Geochemical and isotopic data suggest that the metallogenic materials of the bauxite deposit came from felsic volcanic rocks of the Emeishan Large Igneous Provence (ELIP) in South China and from the Truong Son volcanic arc located between the South China and Indochina cratons. The northwestern and southeastern parts of the Youjiang Basin received larger amounts of ELIP detritus and volcanic arc detritus, respectively. Coarser siliciclastic material in proximal attached carbonate platform and inter-platform trough settings was delivered by rivers, but finer siliciclastics that accumulated on distally located carbonate platforms in isolated deep-water areas was probably transported by wind.

  5. Using one waste to tackle another: Preparation of a CO2 capture material zeolite X from laterite residue and bauxite

    International Nuclear Information System (INIS)

    Highlights: • Valuable zeolite X has been synthesized from laterite residue and bauxite. • High product purity has been achieved by optimizing the process conditions. • Prepared zeolite X shows comparable gas adsorption properties to commercial ones. • Prepared zeolite X can be used for carbon capture by vacuum swing adsorption. - Abstract: In this work, zeolite X, a benchmark adsorbent for carbon capture, has been successfully prepared from low cost waste minerals namely laterite residue and bauxite using alkali fusion process followed by hydrothermal treatment. The structure and morphology of the as-synthesized zeolite X were verified and characterized with a range of experimental techniques such as X-ray diffraction, scanning electronic microscopy and infrared spectroscopy. The surface area and (N2 and CO2) gas adsorption isotherms of this product were found comparable to that of commercial ones, demonstrating the effectiveness of synthesizing zeolite X from laterite and bauxite. Further improvement of the product purity was also accomplished by optimizing the process conditions

  6. Characterization of three Brazilian bauxites and the corresponding bayer liquors in regard to rare earth and other minor elements

    International Nuclear Information System (INIS)

    Full text: In this paper the results of chemical analysis of representative Brazilian bauxites are presented and discussed. Analyses were made on original mother rocks, ores, tailings from washing plants, Bayer liquors produced from this ores and also from the red muds. Samples of the ores were submitted to size, magnetic and density separation and these fractions were also analysed. Minor elements of interest assayed were rare earth, gallium and vanadium. Atomic absorption spectroscopy, x-ray fluorescence and emission spectroscopy were applied for the minor elements and also conventional wet chemical analyses mainly for major elements. A special technique for a rapid identification and semi-quantitative analysis of gallium and a permanent file for the results are presented as well. Brazilian bauxites are all of lateritic origin, constituted essentially by gibbsite and formed by intense tropical weathering of different rocks. This paper presents the chemical characterization of three Brazilian bauxites, namely Porto Trombetas, Cataguazes and Pocos de Caldas and the behaviour of their minor elements during the industrial processing in the mines and alumina mills. The grades of rare earths elements, gallium and vanadium show significant variations. This is most probably due to mother rocks characteristics than to bauxitization processes. The review deposits have the following mother rocks: Porto Trombetas Sedimentary - Cataguazes Metamorphic - Pocos de Caldas Alkaline (sienite). The samples from Pocos de Caldas show high grade for La+Ce with an average over 800ppm, Cataguazes has an average of 76 ppm La+Ce and Porto Trombetas 6,5ppm. Gallium grades are higher for Pocos de Caldas (average 135 ppm), followed by Porto Trombetas (62 ppm) and Cataguazes (37ppm). Vanadium grades are higher for Porto Trombetas (243 ppm) then Pocos de Caldas (165 ppm). Pocos de Caldas shows 50% enrichment in Ce in the washed ore and in Porto Trombetas most of the Y goes to the fines (product

  7. A study of inter-particle bonds in dry bauxite waste resulting in atmospheric aerosols

    Science.gov (United States)

    Wagh, Arun S.; Thompson, Bentley

    1988-02-01

    Bauxite and Alumina production are one of the main activities of several third world countries such as Jamaica, Brazil, India, Guinea, eastern European countries such as Hungary and Rumania and advanced countries such as Australia, West Germany, Japan and the United States. The mining operations lead to dust pollution, but the refining of bauxite to alumina yield large amounts of highly caustic sludge waste, called "Red Mud". Millions of tons of the waste produced in every country are stored in containment dams or natural valleys. This leads to ground water pollution, destruction of plant and bird life and is hazardous to human settlement in earthquake prone regions like Jamaica. As a result several companies have been looking into dry mud stacking which involves thickening the mud in the refining plants and sprying it on the slopes to sun dry it. Typically it involves a drying field of about two hundred acres, which could act as a potential source of caustic dust. In Jamaica one company has started disposing of the mud in this way. The aerosol formation from such areas depends mainly on the integrity of the top dry layers. Presently this is done by studying the approximate parameters such as the friability of the mud. However, following the recent advances in powder technology it has been possible for us to develop an instrument to study the average interparticle forces between the red mud particles. The instrument is based on the principle of a tensometer and a split cell is used to load specimens. A load cell is used to measure the force and a chart recorder is used for plotting separation and the force. The present study reports elemental composition of the dust and its health hazards. It also reports the physical measurement of the average interparticle force as a function of their separation in the Jamaican mud. The effect of ultraviolet radiation on the strength of the material is studied to see the effect of sun-drying of the waste. The five-fold increase

  8. Effect of Raw Bauxite Addition on Thermal Behaviour of Ultra-low Cement Al2O3-SiO2 Castables

    Institute of Scientific and Technical Information of China (English)

    HOU Wanguo; ZHOU Ningsheng

    2009-01-01

    This work investigated the thermo-gravimetric (TG) change and explosion resistance of ultra-low cement Al2O3 -SiO2 castables added with 0, 5%, 10%, 15% and 20% of ≤74 μm raw bauxite powders containing 72. 8% Al2O3, respectively. The castables were prepared using white fused alumina as aggregate, powders of white fused alumina, fused mullite, α-Al2O3 ultrafines, 3% CA cement and 5% microsilica as the matrix portion. TG change of the castables was investi-gated by a thermo-gravimetric analyzer for large size specimen. When the raw bauxite addition is less than 10%, the mass-losing behavior of the castables is simi-lar to that without raw bauxite, tending to reach a con-stant mass around 400 ℃ , before which the mass-loss is mild and producing little destructive influence. With more than 10% raw bauxite addition, however, the mass-loss increases significantly, and the temperature to reach a constant mass increases to 600 ℃ or higher, unfavorable to structural stabilization. With the raw bauxite addition up to 20%, no negative influence on explosion resistance is found.

  9. Removal of fluoride from water using a novel sorbent lanthanum-impregnated bauxite.

    Science.gov (United States)

    Vivek Vardhan, C M; Srimurali, M

    2016-01-01

    A novel sorbent, Lanthanum-Impregnated Bauxite (LIB), was prepared to remove fluoride from water. To understand the surface chemical composition and morphology, LIB was characterized using X-ray diffraction and scanning electron microscopy techniques. Experiments were performed to evaluate the sorption potential, dose of sorbent, kinetics, equilibrium sorption capacity, pH and influence of anions for defluoridation by LIB. Equilibrium isothermal studies were conducted to model the sorption and regeneration studies were carried out to evaluate the reusability of LIB. The results showed that LIB, at a dose of 2 g/L could remove 99 % of fluoride from an initial concentration of 20 mgF/L. Kinetic studies revealed the best fit of pseudo second order model. The sorption followed Langmuir isotherm model and the maximum sorption capacity of LIB for removal of fluoride was found to be 18.18 mg/g. Naturally occurring pH of water was found to be favorable for sorption. Usually occurring anions in water except nitrates influenced sorption of fluoride by LIB. PMID:27625980

  10. Effects of Polymeric Flocculants on Settlement of Bayer Red Mud Generated from Chinese Diaspore Bauxite

    Institute of Scientific and Technical Information of China (English)

    张琨瑜; 胡慧萍; 张丽娟; 陈启元

    2008-01-01

    A systematic investigation on the interaction between Bayer red mud particles generated from Chinese diaspore bauxite and commercial sodium polyacrylate (SPA) or polyacrylamide (PAM) was performed by red mud settling tests, conductivity-pH titration and Ubbelodhe viscosimetric measurement. The results indicate that the treatment with red mud by SPA gives a lower red mud settling rate and lower supematant turbidity than the treatment with red mud by PAM. There is an optimum polymer dosage of 300 g/t (based on the weight of dry red mud) when red mud slurry is treated by SPA or PAM, so "bridging" adsorption is one of the main interactions between red mud and SPA or PAM. With the increase of NaOH concentration, the hydrolysis degree of PAM dissolved in NaOH solution increases and its molecular weight almost does not change, but the settling rote of red mud treated by it drops rapidly. The settling rate of red mud treated by PAM dissolved in 10 g/L NaOH solution is 0.61 m/h while by PAM dissolved in distilled water it is 1.31 m/h, because the adsorption ability of the hydrolyzed PAM onto red mud surface declines primarily due to the formation of-CONH2~-COO-~-CONH2 intramolecular hydrogen bond.

  11. Synthesis of N, N-diethyl dodecyl amine and its flotation properties on bauxite

    Institute of Scientific and Technical Information of China (English)

    CAO Xue-feng; ZHANG Li-min; HU Yue-hua; LIU Chang-miao; OUYANG Kui

    2008-01-01

    N, N-diethyl dodecyi amine(DEN12) was synthesized from dodecyl amine, formic acid and acetic aldehyde. The collecting property of DEN12 on diaspore, kaolinite and illite was investigated by flotation test and infrared spectrum. The results show that in the presence of 2.0×10-4 mol/L DEN12, the recoveries of kaolinite and illite are all higher than 78% and the recovery of diaspore is 50% in the pH range of 5.5-6.0. The mass ratio of Al2O3 to SiO2 in concentrate obtained from separation artificial mixture is higher than 10, suggesting that DEN12 can be used as a collector to separate the aluminosilicates from diaspore in bauxite ores at the pulp pH below 8. The measurements of the infrared spectrum approve that the action between ahiminosilicates and tertiary amine collector is strong electrostatic adsorption and that of diaspore is weak electrostatic adsorption.

  12. Removal of radium from groundwater using a modified bauxite refinery residue.

    Science.gov (United States)

    Clark, M W; Akhurst, D J; Fergusson, L

    2011-01-01

    Radium (Ra) removal by an unconventional sorbent, a modified bauxite refinery residue (MBRR), is investigated for a groundwater extracted in Missouri, USA. The MBRR treatment causes substantial reductions of both gross α and combined Ra activities from 0.955 ± 0.005 and 0.66 ± 0.005 Bq L to below detection limits (0.037 Bq L or 1 pCi L). Column breakthrough occurs at 0.555 Bq L for gross α and 0.185 Bq L for combined Ra (15 and 5 pCi L; USEPA's maximum contaminant levels) after 54 and 40 d run time, respectively. At 84 d the MBRR media continues to remove 24.3% of raw water gross α and 39.7% of the combined Ra. The treatment effluent has an initial pH of 10.9, outside the USEPA guides (6.5-8.5); this may be readily mitigated by posttreatment acid injection, or by raw water blending. The MBRR simultaneously removes other potentially hazardous trace elements (e.g., Cu, Zn, and Fe) to extremely low concentrations. In addition, toxicity characteristic leaching procedure testing of spent MBRR suggests that metals are bound tightly, such that it is nonhazardous, permitting cost-effective disposal to landfill without special confinement or storage. Consequently, MBRR may be utilized as an alternative adsorbent for treating Ra-contaminated groundwater. PMID:22031566

  13. A laboratory scale study on arsenic(V) removal from aqueous medium using calcined bauxite ore

    Institute of Scientific and Technical Information of China (English)

    Debasish Mohapatra; Debaraj Mishra; Kyung Ho Park

    2008-01-01

    The present work deals with the As(V) removal from an aqueous medium by calcined refractory grade bauxite (CRB) as a function of solution pH,time,As(V) concentration and temperature.The residual As(V) was lowered from 2 mg/L to below 0.01 mg/L in the optimum pH range 4.0-7.0 using a 5 g/L CRB within 3 h contact time.The adsorption data fits well with Langmuir isotherm and yielded Langmuir monolayer capacity of 1.78 mg As(V)/g of CRB at pH 7.0.Presence of anions such as silicate and phosphate decreased As(V) adsorption efficiency.An increase temperature resulted a decrease in the amount of As(V) adsorbed by 6%.The continuous fixed bed column study showed that at the adsorbent bed depth of 30 cm and residence time of 168 min.the CRB was capable of treating 340 bed volumes of As(V) spiked water (Co=2 mg/L)before breakthrough (Ge=0.01 mg/L).This solid adsorbent,although not reusable,call be considered for design of adsorption columns as an efficiency arsenic adsorption media.

  14. Prospection analysis of development of high-sulfur bauxite of Guizhou%贵州高硫铝土矿开发利用前景分析

    Institute of Scientific and Technical Information of China (English)

    付世伟

    2011-01-01

    贵州铝土矿资源目前保有储量4.46亿t,其中属工业划分的高硫铝土矿超过1亿t,这部分资源的开发利用前景广阔.文章介绍了贵州铝土矿资源状况;分析了高硫铝土矿的分布区域、赋存条件、保有储量及矿石质量;分析了贵州高硫铝土矿的特点、高硫铝土矿对氧化铝工艺流程的影响以及暂不能有效利用的原因,同时介绍了开发利用高硫铝土矿的研究进展以及目前已经取得的研究成果.因此,文章对中铝贵州分公司及相似企业的铝土矿资源可持续发展决策具有一定的参考意义.%Guizhou has 446 million tons of available reserves of bauxite, including over 100 million tone high - sulfur bauxite ore. So developing the bauxite with hiSh sulfur is promising. In this paper, the author introduced the situation about bauxite resource in Guizhou, and analyzed the distribution area, host condition, available reserve and ore quality of high - sulfur bauxite, and analyzed characteristic property, influence on the alumina procedure and the cause for insufficient development at present about these high - sul fur bauxite resource. At the same time, the author introduced the progresa with achievement of research for developing high - sulfur bauxite. Therefore, this paper will have some certain significance to sustainable development decision - making on bauxite resource in Guizhou Branch of Chalco and similar enterprise.

  15. Concentration of bauxite fines via froth flotation Concentração de finos de bauxita por flotação

    OpenAIRE

    Renata Salles Kurusu; Arthur Pinto Chaves; Christian Fonseca de Andrade; Claret Antônio Vidal Abreu

    2009-01-01

    Companhia Brasileira de Alumínio (CBA) has bauxite processing plants at Poços de Caldas and Itamarati de Minas, and a new processing plant at Miraí that has been operating since June, 2008; all of them are in the State of Minas Gerais. The plants haveunits for the crushing, scrubbing and screening operations. The screened oversize is the concentrate or washed bauxite. At Itamarati de Minas, the fines are de-slimed and concentrated by gravity separation of the iron-titanium minerals in Reicher...

  16. Rapid preparation of ceramic moulds for medium-sized superalloy castings with magnesia-phosphate-bonded bauxite-mullite investments

    Directory of Open Access Journals (Sweden)

    Li Tingzhong

    2010-11-01

    Full Text Available Phosphate-bonded investments have already been widely utilized in dental restoration and micro-casting of artistic products for its outstanding rapid setting and high strength. However, the rapid setting rate of investment slurry has up to now been a barrier to extend the use of such slurry in preparation of medium-sized ceramic moulds. This paper proposes a new process of rapid fabrication of magnesia-phosphate-bonded investment ceramic moulds for medium-sized superalloy castings utilizing bauxite and mullite as refractory aggregates. In order to determine the properties of magnesia-phosphate-bonded bauxite-mullite investments (MPBBMI, a series of experiments were conducted, including modification of the workable time of slurry by liquid(mL/powder(g(L/P ratio and addition of boric acid as retard agent and sodium tri-polyphosphate (STP as strengthening agent, and adjustment of bauxite (g/mullite(g(B/M ratio for mechanical strength. Mechanical vibration was applied to improve initial setting time and fluidity when pouring investment slurry; then an intermediate size ceramic mould for superalloy castings was manufactured by means of this rapid preparing process with MPBBMI material. The results showed that the MPBBMI slurry exhibits proper initial setting time and excellent fluidity when the L/P ratio is 0.64 and the boric acid content is 0.88wt.%. The fired specimens made from the MPBBMI material demonstrated adequate compression strength to withstand impact force of molten metal when the B/M ratio is 0.89 and the STP content is 0.92wt.%. The experimental results confirmed the feasibility of the proposed rapid fabricating process for medium-sized ceramic moulds with MPBBMI material by appropriate measures.

  17. Protective Bauxite-Based Coatings and Their Anti-decarburization Performance in Spring Steel at High Temperatures

    Science.gov (United States)

    Wang, Xiaojing; Wei, Lianqi; Zhou, Xun; Zhang, Xiaomeng; Ye, Shufeng; Chen, Yunfa

    2013-03-01

    A decarburization protective coating was fabricated onto spring steel by using bauxite with functional additives. Metalloscope, XRD, and TG-DTA thermal analysis revealed that, at <1050 °C, the depth of the ferrite layer of the coated specimen decreased because of the shield effect and carbon concentration of the coating. The protective effect increased to 100% above 1050 °C, because Na2Al6P2O15 formed by the sintering process pulled the solid phase closer and filled the void through wetting power and surface tension between the liquid and solid phases and made the coating more compact.

  18. Study of the dielectric parameters of aluminium ore bauxite of Mainpat area of Chhattisgarh at X-band frequency

    Indian Academy of Sciences (India)

    S K Srivastava; B R Vishwakarama

    2004-08-01

    A simple method for measuring the dielectric parameter of materials in the form of powders at microwave frequencies is suggested. Measurement of the permittivity $\\varepsilon'$ and $\\varepsilon''$ at 9.967 GHz on powder samples of the aluminum ore bauxite gives interesting results. It is found that $\\varepsilon'$ and $\\varepsilon''$ increases with packing densities(). Further $\\varepsilon'$ and $\\varepsilon''$ also depend upon the percentage of Al23. These results show that the values of $\\varepsilon'$ and $\\varepsilon''$ can be used to set certain basic values for minability of the ore for a particular sample. Conductivities () and relaxation () are also calculated in the present studies.

  19. Moengo on strike: The Politics of Labour in Suriname’s Bauxite Industry

    Directory of Open Access Journals (Sweden)

    Anouk de Koning

    2011-10-01

    Full Text Available This article examines one crucial moment of contestation in colonial Suriname, the years 1941- 42, when sustained labour unrest in bauxite town Moengo led to the founding of the first mining unions. It argues that these strikes laid the groundwork for future relations between labour, company and the state and explores the kinds of socio-political alliances that were forged between labour and nationalist politicians on the one hand, and government and transnational company on the other, thereby situating this particular contestation in a larger struggle over a colonial system that aligned itself with metropolitan economic interests.Resumen: Moengo en huelga: Políticas Laborales en la Industria de la Bauxita en SurinameEn este artículo se aborda un momento crucial de la impugnación en el Suriname colonial entre los años 1941-42, cuando un persistente malestar entre los trabajadores del pueblo de la bauxita de Moengo condujo a la fundación de los primeros sindicatos mineros. Se sostiene que esas huelgas sentaron las bases de las futuras relaciones entre el trabajo, las compañías y el estado y se exploran los tipos de alianzas socio-políticas que se forjaron entre políticos laboristas y nacionalistas por un lado, y el gobierno y compañías transnacionales por el otro, situando por ello esta particular impugnación en una lucha de mayor alcance contra un sistema colonial que se identificaba a sí mismo con los intereses económicos metropolitanos.

  20. Coal-Bauxite-Iron Structure and Geochemical Features of Bauxites Ore-Bearing Rock Series in Southeast Guizhou%黔东南铝土矿含矿岩系“煤-铝-铁结构”及地球化学特征

    Institute of Scientific and Technical Information of China (English)

    张正伟; 李玉娇; 周灵洁; 吴承泉

    2012-01-01

    黔东南铝土矿赋存于下二叠统梁山组,其含矿岩系具有沉积型铝土矿典型的“煤-铝-铁结构”,即下部发育铝质页岩夹菱铁矿结核,中部由含铝岩组夹多层豆状或土状铝土矿组成,上部由碳质页岩、砂岩夹煤层组成.沉积环境为海陆交互相-滨海边缘沼泽相,具有稳定的构造背景.通过含矿岩系物质组成结构分析和元素地球化学研究认为:“煤-铝-铁结构”在铝土矿中的普遍出现,是沉积型铝土矿在矿化过程中物理化学环境多变导致的深度去硅去铁作用,加之外部环境提供充足的有机质物质来源,从而形成的非偶然结果.因此,含矿岩系的分层结构形成过程中的物理化学变化所导致的多种地质异常可作为找矿实践中的成矿标志.%The bauxite in southeast Guizhou is hosted within the Lower Permian series Liangshan Group. The ore-bearing rock series shows a typical coal-bauxite-iron structure of the sedimentary type bauxite deposit, i. e. the aluminum shale intercalated within siderite tuberculosis developed at the bottom, aluminiferous rock association intercalated within multiple-layer pisolitic or earthy bauxite in the middle, and carbonaceous shale and sandstone intercalated with coal seams from the lower to the upper in the profile of bauxite. Presumably, the sedimentary environment is of stable structural setting, belonging to marine-terrigenous facies to coastal-swamp facies. Coal-bauxite-iron structure is very common in bauxite deposits, and sedimentary bauxite is the product of deep desilication and deiorning caused by the changes of the physical and chemical environment during mineralizing process. In addition, external environment provides sufficient organic material source. Therefore, multiple geological anomalies triggered by chemical and physical changes during the formation of layered structure of ore-bearing rock series can be used as prospecting criteria for bauxites.

  1. An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr3+ removal capacity

    Institute of Scientific and Technical Information of China (English)

    Peng-cheng Lei; Xian-jiang Shen; Yang Li; Min Guo; Mei Zhang

    2016-01-01

    A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investiga-tions were carried out regarding the capacity of zeolite 4A to remove Cr(III) from aqueous solutions with relatively low initial concentrations of Cr(III) (5–100 mg·L−1). It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environ-mental pollution caused by the dumping of bauxite tailings. The Cr(III) removal capacity highly depends on the initial pH value and concen-tration of Cr(III) in the solution. The maximum removal capacity of Cr(III) was evaluated to be 85.1 mg×g−1 for zeolite 4A, measured at an initial pH value of 4 and an initial Cr(III) concentration of 5 mg·L−1. This approach enables a higher removal capacity at lower concentrations of Cr(III), which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr(III) by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr(III).

  2. Enabling safe dry cake disposal of bauxite residue by deliquoring and washing with a membrane filter press.

    Science.gov (United States)

    Kinnarinen, Teemu; Lubieniecki, Boguslaw; Holliday, Lloyd; Helsto, Jaakko-Juhani; Häkkinen, Antti

    2015-03-01

    Dry cake disposal is the preferred technique for the disposal of bauxite residue, when considering environmental issues together with possible future utilisation of the solids. In order to perform dry cake disposal in an economical way, the deliquoring of the residue must be carried out efficiently, and it is also important to wash the obtained solids well to minimise the amount of soluble soda within the solids. The study presented in this article aims at detecting the most important variables influencing the deliquoring and washing of bauxite residue, performed with a horizontal membrane filter press and by determining the optimal washing conditions. The results obtained from pilot-scale experiments are evaluated by considering the properties of the solids, for instance, the residual alkali and aluminium content, as well as the consumption of wash liquid. Two different cake washing techniques, namely classic washing and channel washing, are also used and their performances compared. The results show that cake washing can be performed successfully in a horizontal membrane filter press, and significant improvements in the recovery of alkali and aluminium can be achieved compared with pressure filtration carried out without washing, or especially compared with the more traditionally used vacuum filtration.

  3. An improved implementable process for the synthesis of zeolite 4A from bauxite tailings and its Cr3+ removal capacity

    Science.gov (United States)

    Lei, Peng-cheng; Shen, Xian-jiang; Li, Yang; Guo, Min; Zhang, Mei

    2016-07-01

    A simple and practical method for the synthesis of zeolite 4A from bauxite tailings is presented in this paper. Systematic investigations were carried out regarding the capacity of zeolite 4A to remove Cr(III) from aqueous solutions with relatively low initial concentrations of Cr(III) (5-100 mg·L-1). It is found that the new method is extremely cost-effective and can significantly contribute in decreasing environmental pollution caused by the dumping of bauxite tailings. The Cr(III) removal capacity highly depends on the initial pH value and concentration of Cr(III) in the solution. The maximum removal capacity of Cr(III) was evaluated to be 85.1 mg·g-1 for zeolite 4A, measured at an initial pH value of 4 and an initial Cr(III) concentration of 5 mg·L-1. This approach enables a higher removal capacity at lower concentrations of Cr(III), which is a clear advantage over the chemical precipitation method. The removal mechanism of Cr(III) by zeolite 4A was examined. The results suggest that both ion exchange and the surface adsorption-crystallization reaction are critical steps. These two steps collectively resulted in the high removal capacity of zeolite 4A to remove Cr(III).

  4. 河南陕县柿树沟铝土矿床控矿地质特征%Geological Characteristics of Shishugou Bauxite Deposit, Henan Province

    Institute of Scientific and Technical Information of China (English)

    陈全树

    2012-01-01

    Shishugou deposits occur in the upper carboniferous Benxi group carbonate unconformity surfaces, and are strictly controlled by sedimentary discontinuous surfaces. The bauxite is large and stable; Orebody is layered or lay-like structure; Ore structure types are massive or layered structures The main mineral compositions are diasporite and kaolinite; The harmful elements are less and associated with gallium elements, etc. Deposits by humid tropical climate change and formation of clay is closely related to mineralization, the different size depressions and dissolved buckets formed on the erosion surfaces are the positioning spaces of the bauxite; The gulf lagoon deposition is favorable conditions for the bauxite bed formation. The deposits belong to main bauxite after short distance handling-machinery sedimentary, and have good bauxite metallogenic prospects.%柿树沟铝土矿床赋存于上石炭统本溪组碳酸盐岩不整合面上,严格受沉积间断面控制.铝土矿规模较大、稳定,矿体为层状或似层状,矿石构造类型为块状、层状.主要矿物成分由一水硬铝石、高岭石组成,有害元素少,并伴生有Ga元素等.矿床受潮湿热带气候中形成的红土化与成矿密切相关,侵蚀面上形成大小不等的洼地及溶斗是铝土矿的定位空间,海湾泻湖相沉积是铝土矿床形成的有利条件.矿床属于经过短距离搬运-机械沉积为主的铝土矿,具有较好的铝土矿成矿前景,

  5. Use of red mud (bauxite residue) for the retention of aqueous inorganic mercury(II).

    Science.gov (United States)

    Rubinos, David A; Barral, María Teresa

    2015-11-01

    The effectiveness of the oxide-rich residue from bauxite refining (red mud) to remove inorganic Hg(II) from aqueous solutions was assessed. The aspects studied comprised the kinetics of the process (t = 1 min-24 h), the effect of pH (3.5-11.5), the interacting effect between salt concentration (0.01-1 M NaNO3) and pH and the Hg(II) sorption isotherm. Hg leaching from spent red mud was evaluated using the toxicity characteristics leaching procedure (TCLP) method. The sorption of Hg(II) onto red mud was very fast, with most of Hg(II) (97.0-99.7%) being removed from 0.5-50 μM Hg solutions in few minutes. The kinetic process was best described by Ho's pseudo-second order equation, pointing to chemisorption as the rate controlling step. Hg(II) sorption efficiency was very high (% removal between 93.9 and 99.8%) within all the studied pH range (3.5-11.5) and added Hg concentrations (5 and 50 μM), being optimal at pH 5-8 and decreasing slightly at both lowest and highest pH. The effect of background electrolyte concentration suggests specific sorption as the main interaction mechanism between Hg(II) and red mud, but the increasing non-sorbed Hg concentrations at low and high pH for higher electrolyte concentrations also revealed the contribution of an electrostatic component to the process. The sorption isotherm showed the characteristic shape of high affinity sorbents, and it was better described by the Redlich-Peterson and Freundlich equations, which are models that assume sorbent heterogeneity and involvement of more than one mechanism. The estimated Hg(II) sorption capacity from the Langmuir equation (q m ~9 mmol/kg) was comparable to those of some inorganic commercial sorbents but lower than most bio- or specifically designed sorbents. The leachability of retained Hg(II) from spent red mud (0.02, 0.25 and 2.42 mmol Hg/kg sorbed concentration) was low (0.28, 1.15 and 2.23 μmol/kg, respectively) and accounted for 1.2, 0.5 and 0.1% of previously sorbed Hg

  6. Provenance of lateritic bauxite deposits in the Wuchuan-Zheng'an-Daozhen area, Northern Guizhou Province, China: LA-ICP-MS and SIMS U-Pb dating of detrital zircons

    Science.gov (United States)

    Gu, Jing; Huang, Zhilong; Fan, Hongpeng; Ye, Lin; Jin, Zhongguo

    2013-07-01

    The provenance of the large and super-large scale bauxite deposits developed in the Wuchuan-Zheng'an-Daozhen (WZD) alumina metallogenic province in the Yangtze Block of South China is poorly understood. LA-ICP-MS and SIMS U-Pb dating of detrital zircons from bauxite ores and the underlying Hanjiadian Group in the WZD area provide new constrains on the provenance of the WZD bauxite and provide new insight on the bauxite ore-forming process. The ages of the detrital zircons in the bauxites and the zircons in the Hanjiadian Group are similar suggesting that the bauxites are genetically related to the Hanjiadian sediments. The detrital zircon populations of the four samples studied show four primary age peaks: 2600-2400 Ma, 1900-1700 Ma, 1300-700 Ma and 700-400 Ma. The age distribution of detrital zircons indicates that they are probably derived from various sources including Neoproterozoic, Mesoproterozoic, Paleoproterozoic, Archean and some minor Paleozoic sources. The most abundant age population contains a continuous range of ages from 1300 to 700 Ma, ages consistent with subduction-related magmatic activities (1000-740 Ma) along the western margin of the Yangtze Block and the worldwide Grenville orogenic events (1300-1000 Ma). Thus, it is suggested that the main provenances of the WZD bauxite and the Hanjiadian Group are the Neoproterozoic igneous rocks in the western Yangtze Block and the Grenville-age igneous rocks in the southern Cathaysia Block. In addition, this work verifies that the global Grenville orogenic events and subduction-related magmatic activities associated with the Yangtze Block had a significant influence on the formation of the WZD bauxite deposits.

  7. Concentration of bauxite fines via froth flotation Concentração de finos de bauxita por flotação

    Directory of Open Access Journals (Sweden)

    Renata Salles Kurusu

    2009-09-01

    Full Text Available Companhia Brasileira de Alumínio (CBA has bauxite processing plants at Poços de Caldas and Itamarati de Minas, and a new processing plant at Miraí that has been operating since June, 2008; all of them are in the State of Minas Gerais. The plants haveunits for the crushing, scrubbing and screening operations. The screened oversize is the concentrate or washed bauxite. At Itamarati de Minas, the fines are de-slimed and concentrated by gravity separation of the iron-titanium minerals in Reichert spirals followed by HIWMS. The tailings still contain bauxite, which can be separated by reverse froth flotation (flotation of the quartz and depression of the bauxite, using starch as a depressant and amine as a promoter; the pH must be around 10.0. The iron and titanium bearing minerals are depressed with the bauxite and an additional magnetic separation operation is necessary on the depressed bauxite. This paper describes the work performed on Itamarati de Minas samples on a bench scale at Escola Politécnica, University of S. Paulo.A Companhia Brasileira de Alumínio (CBA tem usinas de beneficiamento de bauxita em Poços de Caldas e Itamarati de Minas e uma nova unidade de produção em Miraí (junho de 2008, todas localizadas no Estado de Minas Gerais. As usinas de beneficiamento têm as operações unitárias de britagem, desagregação em escrubers e peneiramento. O oversize das peneiras é o concentrado ou bauxita lavada. Em Itamarati de Minas, os finos são deslamados e concentrados por diferença de peso específico em espirais de Reichert, complementadas por separação magnética de alta intensidade. Os rejeitos ainda contêm bauxita, que pode ser separada por flotação reversa da sílica e depressão da bauxita. Usam-se amido como depressor e amina como coletor. O pH precisa estar em torno de 10,0. Os minerais portadores de ferro e de titânio acompanham a bauxita, o que exige uma operação adicional de separação magnética para atingir

  8. Arsenic stabilization by zero-valent iron, bauxite residue, and zeolite at a contaminated site planting Panax notoginseng.

    Science.gov (United States)

    Yan, X L; Lin, L Y; Liao, X Y; Zhang, W B; Wen, Y

    2013-10-01

    Panax notoginseng (Burk.) F.H. Chen, a rare traditional Chinese medicinal herb, is a widely used phytomedicine used all over the world. In recent years, the arsenic contamination of the herb and its relative products becomes a serious problem due to elevated soil As concentration. This study aimed to evaluate the effects of different types and dosages of amendments on As stabilization in soil and its uptake by P. notoginseng. Results showed that comparing to control treatment, the As concentrations of P. notoginseng declined by 49-63%, 43-61% and 52-66% in 0.25% zero-valent iron (Fe(0)), 0.5% bauxite residue, and 1% zeolite treatment, respectively; whereas the biomasses were elevated by 62-116%, 45-152% and 114-265%, respectively. The As(III) proportions of P. notoginseng increased by 8%, 9%, and 8%, and the transfer factors of As from root to shoot increased by 37%, 42% and 84% in the optimal treatments of Fe(0), bauxite residue, and zeolite. For soil As, all the three amendments could transform the non-specifically adsorbed As fraction to hydrous oxides Fe/Al fractions (by Fe(0) and red mud) or specifically adsorbed As fraction (by zeolite), therefore reduced the bioavailability of soil As. With a comprehensive consideration of stabilization efficiency, plant growth, environmental influence, and cost, Fe(0) appeared to be the best amendment, and zeolite could also be a good choice. In conclusion, this study was of significance in developing As contamination control in P. notoginseng planting areas, and even other areas for medicinal herb growing.

  9. 高铁铝土矿铝铁分离研究现状%Research Status of Separation of Aluminum and Iron from High-ferric Bauxite

    Institute of Scientific and Technical Information of China (English)

    许斌; 李帅军

    2014-01-01

    介绍了我国高铁铝土矿的资源储量和分布。根据国内外对高铁铝土矿铝铁分离开展的研究,论述了选矿法、磁化焙烧法、直接还原法、拜耳法、酸法等工艺的研究现状。%This paper introduces the reserves and distribution of high-ferric bauxite in our country and discusses research status of several processes including mineral processing method, magnetization roasting method, direct reduction method, bayer method,acid method and etc based on the research of aluminum and iron separation from high-ferric bauxite conducted home and abroad.

  10. Comparison of the kinetic laws of the dissolution of bauxite and aluminum and iron(III) oxides and hydroxides in hydrochloric acid

    Science.gov (United States)

    Gololobova, E. G.; Gorichev, I. G.; Lainer, Yu. A.; Kozlov, K. V.

    2013-07-01

    The influence of the temperature and concentration of a hydrochloric acid solution on the dissolution kinetics of aluminum and iron(III) oxides and hydroxides and a natural sample of aluminum-containing raw materials, bauxite, is studied. The rate W of the transition of iron(III) ions from bauxite is higher than the rate of aluminum ion transition. The dependence of the fraction of a dissolved solid phase on time τ of dissolution of the oxides and hydroxides is determined, α = 1 — exp(- Asinh( Wτ)). The solubility of iron(III) chloride increases and that of aluminum chloride decreases as the HCl concentration increases. An empirical equation is proposed for the description of the dependence of the process rate on a series of parameters,.

  11. Influence of chemical weathering on the composition of the continental crust: Insights from Li and Nd isotopes in bauxite profiles developed on Columbia River Basalts

    Science.gov (United States)

    Liu, Xiao-Ming; Rudnick, Roberta L.; McDonough, William F.; Cummings, Michael L.

    2013-08-01

    Mineralogical, chemical, and Li and Nd isotopic compositions of two drill cores (8-9 m deep) through bauxites developed on the Miocene Columbia River Basalts document the changes associated with basalt weathering, provide insights into the processes involved, and allow us to examine the overall influence of chemical weathering on juvenile (basaltic) crust. Gibbsite, hematite, ±kaolinite, halloysite, goethite, and maghemite are the weathering products in the bauxites. Quartz is observed near the tops of the cores and its abundance decreases progressively with depth; no quartz is observed below five meters depth in either core. Most major and trace elements, including "mobile" and some "immobile" elements are severely depleted in the bauxites. Niobium is less mobile relative to the rare earth elements, thus chemical weathering attenuates the negative Nb anomaly in the continental crust. Li and Nd are strongly depleted relative to fresh basalt, and both increase systematically towards the surface in the quartz-bearing samples while δ7Li and ɛNd values decrease systematically towards the surface in these same samples. Both Li and Nd were likely lost from the bauxites through leaching. The systematic enrichment of Li, Nd, and quartz, as well as the less radiogenic Nd isotopic composition at the tops of both profiles reflects 20-60 wt.% addition of an eolian component to the soils. The eolian dust is unlikely to have experienced significant post-depositional weathering due to the relatively high Li contents near the tops of the profiles, and, therefore, the low δ7Li and ɛNd values suggest that the dust came from an old, weathered region of the continent. Our results demonstrate that lithium isotopes are sensitive tracers of chemical weathering, particularly in extreme weathering settings, and support the hypothesis that chemical weathering influences the mass and composition of the continental crust.

  12. Growth and nutritional status of Brazilian wood species Cedrella fissilis and Anadenanthera peregrina in bauxite spoil in response to arbuscular mycorrhizal inoculation and substrate amendment

    Directory of Open Access Journals (Sweden)

    Tótola Marcos Rogério

    2000-01-01

    Full Text Available The growth of Cedrella fissilis Vell. (Cedro Rosa and of Anadenanthera peregrina Benth (Angico Vermelho in bauxite spoil was studied to evaluate their response to substrate amendment or to inoculation with arbuscular mycorrhizal fungi (AMF. The plants were grown in bauxite spoil, topsoil or spoil amended with either topsoil or compost, and inoculated with the AMF Acaulospora scrobiculata, Gigaspora margarita or Glomus etunicatum. Root colonization was highly dependent on the interaction plant-fungus-substrate. In C. fissilis, root colonization by Gigaspora margarita dropped from 75% in bauxite spoil to only 4% in topsoil. Contrarily, root colonization of A. peregrina by the same fungus increased from 48% in spoil to 60% in topsoil. Root colonization of C. fissilis in topsoil was lower than in the three other substrates. The opposite was observed for A. peregrina. Inoculation of the plants with Acaulospora scrobiculata or Glomus etunicatum was very effective in promoting plant growth. Plants of both C. fissilis and A. peregrina did not respond to amendments of bauxite spoil unless they were mycorrhizal. Also, a preferential partitioning of photosynthates to the shoots of A. peregrina inoculated with G. etunicatum or A. scrobiculata, and of C. fissilis inoculated with any of the three species of AMF was observed. C. fissilis showed a greater response to mycorrhizal inoculation than A. peregrina. The mean mycorrhizal efficiency (ME for dry matter production by C. fissilis was 1,847% for A. scrobiculata, 1,922% for G. etunicatum, and 119% for G. margarita. In A. peregrina, the ME was 249% for A. scrobiculata, 540% for G. etunicatum, and 50% for G. margarita. The effect of mycorrhizal inoculation on plant growth seems to be related in part to an enhanced phosphorus absorption by inoculated plants. Moreover, the efficiency with which the absorbed nutrients were used to produce plant biomass was much greater in plants inoculated with A. scrobiculata or

  13. Using one waste to tackle another: Preparation of a CO{sub 2} capture material zeolite X from laterite residue and bauxite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Liying [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Du, Tao, E-mail: dutao0106@gmail.com [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Li, Gang [School of Mechanical and Chemical Engineering, The University of Western Australia, Crawley, WA 6009 (Australia); Yang, Fan; Che, Shuai [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China)

    2014-08-15

    Highlights: • Valuable zeolite X has been synthesized from laterite residue and bauxite. • High product purity has been achieved by optimizing the process conditions. • Prepared zeolite X shows comparable gas adsorption properties to commercial ones. • Prepared zeolite X can be used for carbon capture by vacuum swing adsorption. - Abstract: In this work, zeolite X, a benchmark adsorbent for carbon capture, has been successfully prepared from low cost waste minerals namely laterite residue and bauxite using alkali fusion process followed by hydrothermal treatment. The structure and morphology of the as-synthesized zeolite X were verified and characterized with a range of experimental techniques such as X-ray diffraction, scanning electronic microscopy and infrared spectroscopy. The surface area and (N{sub 2} and CO{sub 2}) gas adsorption isotherms of this product were found comparable to that of commercial ones, demonstrating the effectiveness of synthesizing zeolite X from laterite and bauxite. Further improvement of the product purity was also accomplished by optimizing the process conditions.

  14. The role of nano-perovskite in the negligible thorium release in seawater from Greek bauxite residue (red mud)

    Science.gov (United States)

    Gamaletsos, Platon N.; Godelitsas, Athanasios; Kasama, Takeshi; Kuzmin, Alexei; Lagos, Markus; Mertzimekis, Theo J.; Göttlicher, Jörg; Steininger, Ralph; Xanthos, Stelios; Pontikes, Yiannis; Angelopoulos, George N.; Zarkadas, Charalampos; Komelkov, Aleksandr; Tzamos, Evangelos; Filippidis, Anestis

    2016-02-01

    We present new data about the chemical and structural characteristics of bauxite residue (BR) from Greek Al industry, using a combination of microscopic, analytical, and spectroscopic techniques. SEM-EDS indicated a homogeneous dominant “Al-Fe-Ca-Ti-Si-Na-Cr matrix”, appearing at the microscale. The bulk chemical analyses showed considerable levels of Th (111 μg g-1), along with minor U (15 μg g-1), which are responsible for radioactivity (355 and 133 Bq kg-1 for 232Th and 238U, respectively) with a total dose rate of 295 nGy h-1. Leaching experiments, in conjunction with SF-ICP-MS, using Mediterranean seawater from Greece, indicated significant release of V, depending on S/L ratio, and negligible release of Th at least after 12 months leaching. STEM-EDS/EELS & HR-STEM-HAADF study of the leached BR at the nanoscale revealed that the significant immobility of Th4+ is due to its incorporation into an insoluble perovskite-type phase with major composition of Ca0.8Na0.2TiO3 and crystallites observed in nanoscale. The Th LIII-edge EXAFS spectra demonstrated that Th4+ ions, which are hosted in this novel nano-perovskite of BR, occupy Ca2+ sites, rather than Ti4+ sites. That is most likely the reason of no Th release in Mediterranean seawater.

  15. Environment-oriented low-cost porous mullite ceramic membrane supports fabricated from coal gangue and bauxite

    Energy Technology Data Exchange (ETDEWEB)

    Lü, Qikai [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo (China); School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Dong, Xinfa [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Zhu, Zhiwen [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo (China); Dong, Yingchao, E-mail: ycdong@iue.ac.cn [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo (China)

    2014-05-01

    Highlights: • Coal gangue was recycled to fabricate low-cost porous mullite membrane supports. • A unique volume-expansion occurred due to a mullitization-crystal-growth process. • A porous structure consists of glassy particles and embedded mullite crystals. - Abstract: Porous mullite ceramic supports for filtration membrane were successfully fabricated via recycling of coal gangue and bauxite at sintering temperatures from 1100 to 1500 °C with corn starch as pore-forming agent. The dynamic sintering behaviors, phase evolution, shrinkage, porosity and pore size, gas permeation flux, microstructure and mechanical property were systematically studied. A unique volume-expansion stage was observed at increased temperatures from 1276 to 1481 °C caused by a mullitization-crystal-growth process. During this stage, open porosity increases and pore size distributions broaden, which result in a maximum of nitrogen gas flux at 1400 °C. The X-ray diffraction results reveal that secondary mullitization took place from 1100 °C and the major phase is mullite with a content of ∼84.7 wt.% at 1400 °C. SEM images show that the as-fabricated mullite supports have a porous microstructure composed of sintered glassy particles embedded with inter-locked mullite crystals, which grew gradually with increasing temperature from rod-like into blocky-like morphologies. To obtain mullite membrane supports with sufficient porosity and acceptable mechanical strength, the relationship between porosity and mechanical strength was investigated, which was fitted using a parabolic equation.

  16. Hydration mechanism and leaching behavior of bauxite-calcination-method red mud-coal gangue based cementitious materials.

    Science.gov (United States)

    Zhang, Na; Li, Hongxu; Liu, Xiaoming

    2016-08-15

    A deep investigation on the hydration mechanism of bauxite-calcination-method red mud-coal gangue based cementitious materials was conducted from viewpoints of hydration products and hydration heat analysis. As a main hydration product, the microstructure of C-A-S-H gel was observed using high resolution transmission electron microscopy. It was found that the C-A-S-H gel is composed of amorphous regions and nanocrystalline regions. Most of regions in the C-A-S-H gel are amorphous with continuous distribution, and the nanocrystalline regions on scale of ∼5nm are dispersed irregularly within the amorphous regions. The hydration heat of red mud-coal gangue based cementitious materials is much lower than that of the ordinary Portland cement. A hydration model was proposed for this kind of cementitious materials, and the hydration process mainly consists of four stages which are dissolution of materials, formation of C-A-S-H gels and ettringite, cementation of hydration products, and polycondensation of C-A-S-H gels. There are no strict boundaries among these four basic stages, and they proceed crossing each other. Moreover, the leaching toxicity tests were also performed to prove that the developed red mud-coal gangue based cementitious materials are environmentally acceptable. PMID:27131457

  17. Formulation of calcium dialuminate (CaO·2Al2O3 refractory cement from local bauxite

    Directory of Open Access Journals (Sweden)

    A.B. Tchamba

    2015-06-01

    Full Text Available Three types of bauxites containing aluminum hydroxide of 58.1% gibbsite and 19.3% boehmite for BX3, 95.5% of gibbsite for BX55 and 84.5% of gibbsite for BX8 were used with lime at 95% of CaO through solid state sintering in one stage to prepare a refractory clinker at 1550 °C. The powder obtained after grinding the clinker showed in the XRD curves the presence of CaO·2Al2O3 and CaO·TiO2 phases in the cement samples. The density of cement powder varied between 2.95 and 3.17 g/cm3 and the specific area of powder obtained after grinding was between 0.72 and 0.85 m2/g. The properties of hydrated cement, W/C = 0.33, after stabilization of cement components for 48 h at 105 °C were showed by XRD, DTA, DTG and SEM (C3AH6, AH3, CA2 and CaO·TiO2. The Young's modulus of the cement made varied between 35.5 and 39.4 GPa, and these Young's moduli were compared to conventional CA14M cement.

  18. Use of bauxite residue (red mud) as a low cost sorbent for sulfide removal in polluted water remediation.

    Science.gov (United States)

    Sheng, Yanqing; Sun, Qiyao; Sun, Ruichuan; Burke, Ian T; Mortimer, Robert J G

    2016-01-01

    Sulfide is an important pollutant in aqueous systems. Sulfide removal from polluted waters is required prior to discharge. Red mud (RM) is a solid waste of bauxite processing that is rich in reactive iron oxides and consequently has the potential to be used to remove sulfide from aqueous systems. A series of experiments was undertaken using raw and sintered RM to remove sulfide from waters. RM was highly efficient at sulfide removal (average 75% sulfide removal at initial concentration of ∼5 mg L(-1), with 500 mg L(-1) RM addition) due to both physical adsorption (high specific area) and chemical reaction (with amorphous Fe). Sintered RM, which has a lower surface area and lower mineral reactivity, was much less efficient at removing sulfide (∼20% removal under equivalent experimental conditions). Furthermore, concomitant metal release from raw RM was lower than for sintered RM during the sulfide removal process. The results showed that raw RM is a potentially suitable material for sulfide removal from polluted waters and consequently could be used as a low cost alternative treatment in certain engineering applications. PMID:27438240

  19. 试论遵义高铁铝土矿与低铁铝土矿的分带性及形成机制%The zonation and genetic mechanism of Zunyi high-and low-ferrous bauxites

    Institute of Scientific and Technical Information of China (English)

    刘平; 廖友常

    2013-01-01

    遵义铝土矿带早石炭世沉积型铝土矿及其含铝岩系,皆沉积-堆积在紫云运动(晚泥盆世至早石炭世)时期形成的略微向南倾斜的夷平面上,其中的高铁铝土矿与低铁铝土矿具有明显分带性.铝土矿及其含矿岩系的原始物质,主要是由下奥陶统湄潭组伊利石页岩形成的含三水铝石的红土风化壳.铝土矿的分带性与红土风化壳物质搬运的距离有关,近处、高处为高铁铝土矿,远处、低处为低铁铝土矿.总体来看,搬运距离较短,属近源搬运、沉积-堆积而成的.%Early Carbonaceous sedimentary bauxite and its aluminum-bearing rock series in the Zunyi bauxite belt have totally undergone sedimentation-accumulation on the slightly southward inclined plantation formed during the late Devonian and Early Carbonaceous Ziyun movement,and the high-and low-ferrous bauxites apparently assume zonation.Original materials of bauxites and the ore-bearing rock series consist dominantly of gibbsite laterite crust formed by illite shale of the Lower Ordovician Meitan Formation.The zonation of bauxite is related to the material-transport distance of the laterite crust,i.e.,the high-ferrous bauxites occur in nearby and high places,and the low-ferrous bauxites appear in distant and low places.Generally speaking,the transport distance is relatively short? and the bauxites were formed by the near-source transport,sedimentation and accumulation.

  20. 铝土矿选矿产品碱性沉降技术研究%Alkaline Settlement Technology Research of Bauxite Benefication Products

    Institute of Scientific and Technical Information of China (English)

    陈湘清; 陈兴华; 郭鑫; 胡秋云; 闫琨; 张建强

    2011-01-01

    The traditional settlement method of bauxite benefication products was adding H2SO4 to reduce pH value, and then adding flocculant to settle. This method not only increased the cost of dressing, and salt accumulation would result in process and process indicators variation. For this problem, this paper presented the alkaline settlement technology of bauxite benefication product, which allowed the concentration and tailing of bauxite products to complete the settlement in the o-riginal pH of the slurry using the alkaline flocculant BXF. The results showed that the technology had good effect in industrial application, which would reduce the cost of production and improve process stability.%铝土矿选矿产品传统的沉降方法是加入硫酸类助剂调低pH值,再加入絮凝剂沉降,不仅增加了选矿成本,而且无机盐累积会造成对流程和工艺指标的不良影响.针对该问题,提出了铝土矿选矿产品的碱性沉降技术,采用高效碱性絮凝剂BXF可以使铝土矿精矿和尾矿在原始矿浆的pH值下完成沉降,工业应用效果良好,有利于生产成本的降低和生产流程的稳定.

  1. Bauxitas refratárias: composição química, fases e propriedades - parte II Refractory bauxites: chemical composition, phases and properties - part II

    Directory of Open Access Journals (Sweden)

    C. Pascoal

    2000-09-01

    Full Text Available A bauxita apresenta uma ampla faixa de aplicações industriais, de acordo com sua composição química e mineralógica. No setor de refratários, esta matéria-prima tem adquirido grande importância, uma vez que pode substituir parcial ou totalmente agregados de alumina eletrofundida em formados e monolíticos, devido a sua alta refratariedade e custo inferior. Entre os maiores produtores mundiais encontram-se a China, a Guiana e o Brasil. Embora seja um dos maiores produtores mundiais de bauxita refratária, no Brasil pouco se conhece de suas características químicas e mineralógicas, bem como suas propriedades em serviço a altas temperaturas. Esta seqüência de artigos apresenta uma revisão sobre as aplicações, fases cristalinas, características e propriedades a alta temperatura de bauxitas refratárias chinesas e sul-americanas. Nesta segunda parte serão consideradas suas propriedades mecânicas a alta temperatura e um problema freqüente na utilização de bauxitas refratárias, a expansão térmica secundária.Bauxite shows a wide range of applications, according to its chemical and mineralogical composition. In the refractory industry, this raw material has partially or totally substituted fused alumina in bricks and castables, due to its high refractoriness and low cost. The major producers of refractory grade bauxite are, in this order, China, Guyana and Brazil. Although Brazil is one of the major suppliers of this raw material, very few studies have been carried out to understand its chemical, mineralogical and high-temperature properties. These papers present a review regarding the applications of South American and Chinese refractory grade bauxites, including the microchemistry of their crystalline phases and their hot properties. This second part will focus mechanical properties at high temperatures, and a common problem in refractory bauxites, the secondary thermal expansion.

  2. Effect of sillimanite on properties of bauxite based castables%硅线石对矾土基浇注料性能的影响

    Institute of Scientific and Technical Information of China (English)

    李培佳; 李林; 贺智勇; 彭小艳; 杨粉荣

    2011-01-01

    以矾土为主要原料,加入硅线石粉、SiO2微粉、活性Al2O3微粉、水泥等制备矾土基浇注料,研究了硅线石加入量(质量分数分别为0、4%、8%和12%)对浇注料常温性能和抗渣侵蚀性能的影响.结果表明:随着硅线石加入量的增加,浇注料的常温强度和体积密度下降,显气孔率增大;在浇注料中加入硅线石有助于提高试样的抗渣侵蚀性能,但加入质量分数大于8%时,试样抗渣侵蚀性能下降,渣渗透深度和侵蚀深度增加;硅线石加入质量分数为4%~8%时,浇注料的综合性能较好.%Bauxite based castables was prepared using bauxite as main starting material,and adding sillimanite powder,SiO2 micropowder,active Al2O3 micropowder,and cement.The influences of sillimanite additions(mass percent:0,4% ,8% ,and 12%)on cold properties and slag resistance of bauxite based castables were investigated.The result shows that: (1)the cold strength and bulk density of castables decrease while the apparent porosity increases with the increase of the sillimanite addition ; (2)the sillimanite improves the slag resistance of bauxite based castables,but the slag resistance declines,and penetration depth and corrosion depth enlarge when sillimanite addition is over 8 % ;(3)the castables shows the best performance with 4%-8% sillimanite.

  3. Concentration of bauxite fines via gravity concentration Concentração de finos de bauxita por concentração densitária

    OpenAIRE

    Arthur Pinto Chaves; Mauricio Bergerman; Claret Antonio Vidal Abreu; Nilson Bigogno

    2009-01-01

    Companhia Brasileira de Alumínio (CBA) has a preparation plant at Itamarati de Minas, MG. This plant washes two different kinds of bauxite ore, one originating from the laterization of gnaisses and another from amphybolites. Both ores have the same behavior in the coarser size fractions but behave differently under 0.355 mm (42# Tyler). In these small sizes, gneissic ores are rich in quartz and amphybolitic ores are rich in iron and titanium bearing ores. The unit operations are: scrubbing of...

  4. Reversibility of uranium and thorium binding on a modified bauxite refinery residue: The effects of aging temperature

    International Nuclear Information System (INIS)

    Highlights: • Th binds to MBRR irreversibly from pH 3 to 8, improving with temperature and time. • 16–52% U binding is irreversibly bound, concentration and temperature dependent. • U binding maximal at pH range, pH 5–6, but aging increases 232U uptake at pH > 6. • U and Th compete for similar sites affecting U binding cwf. simple 0.2 mM U aging. • Increased U binding with aging is mostly from surface precipitate recrystallisation. - Abstract: The effects of aging on the pH-dependence and reversibility of uranium and thorium binding by a modified bauxite refinery residue (MBRR) were studied in laboratory uptake/leaching experiments. Natural uranium and thorium isotopes (predominantly 238UVI and 232ThIV) of 0.4, and 0.2 mM were loaded for an 8-day period at the natural equilibrium pH of the MBRR (approximately 8.5) and were allowed to age for 6 months in humid sealed containers at 4, 23, and 65 °C. After aging, anthropogenic 232UVI and 229ThIV were added as exchange isotopes and the pH decreased stepwise from 8 to 3 over several hours in pH dependent experiments. The relative concentrations of the isotope pairs (i.e. 238UVI and 232UVI; 232ThIV and 229ThIV) indicated that irreversibility of UVI and ThIV binding by the MBRR increased with aging and was dependent on the aging temperature and surface actinide loading. Linear combination fitting of the EXAFS data for the uranium loaded materials indicated that at low uranium concentrations sorption to minerals (particularly hematite) was a prime uranium removal mechanism, but at higher concentrations precipitation dominated. The data suggest that increased irreversibility and incorporation of UVI during aging is associated with re-crystallisation of precipitates

  5. Contrasting physiological responses of two co-occurring eucalypts to seasonal drought at restored bauxite mine sites.

    Science.gov (United States)

    Szota, Christopher; Farrell, Claire; Koch, John M; Lambers, Hans; Veneklaas, Erik J

    2011-10-01

    This study describes the physiological response of two co-occurring tree species (Eucalyptus marginata and Corymbia calophylla) to seasonal drought at low- and high-quality restored bauxite mine sites in south-western Australia. Seasonal changes in photosynthesis (A), stomatal conductance (g(s)), leaf water potential (ψ), leaf osmotic potential (ψ), leaf relative water content (RWC) and pressure-volume analysis were captured over an 18-month field study to (i) determine the nature and severity of physiological stress in relation to site quality and (ii) identify any physiological differences between the two species. Root system restriction at the low-quality site reduced maximum rates of gas exchange (g(s) and A) and increased water stress (midday ψ and daily RWC) in both species during drought. Both species showed high stomatal sensitivity during drought; however, E. marginata demonstrated a higher dehydration tolerance where ψ and RWC fell to -3.2 MPa and 73% compared with -2.4 MPa and 80% for C. calophylla. Corymbia calophylla showed lower g(s) and higher ψ and RWC during drought, indicating higher drought tolerance. Pressure-volume curves showed that cell-wall elasticity of E. marginata leaves increased in response to drought, while C. calophylla leaves showed lower osmotic potential at zero turgor in summer than in winter, indicating osmotic adjustment. Both species are clearly able to tolerate seasonal drought at hostile sites; however, by C. calophylla closing stomata earlier in the drought cycle, maintaining a higher water status during drought and having the additional mechanism of osmotic adjustment, it may have a greater capacity to survive extended periods of drought.

  6. Amelioration of bauxite residue sand by intermittent additions of nitrogen fertiliser and leaching fractions: The effect on growth of kikuyu grass and fate of applied nutrients.

    Science.gov (United States)

    Kaur, Navjot; Phillips, Ian; Fey, Martin V

    2016-04-15

    Bauxite residue, a waste product of aluminium processing operations is characterised by high pH, salinity and exchangeable sodium which hinders sustainable plant growth. The aim of this study was to investigate the uptake form, optimum application rate and timing of nitrogen fertiliser to improve bauxite residue characteristics for plant growth. Kikuyu grass was grown in plastic columns filled with residue sand/carbonated residue mud mixture (20:1) previously amended with gypsum, phosphoric acid and basal nutrients. The experiment was set up as a 4×4 factorial design comprising four levels of applied nitrogen (N) fertiliser (0, 3, 6 and 12mgNkg(-1) residue) and four frequencies of leaching (16, 8 and 4day intervals). We hypothesised that the use of ammonium sulfate fertiliser would increase retention of N within the rhizosphere thereby encouraging more efficient fertiliser use. We found that N uptake by kikuyu grass was enhanced due to leaching of excess salts and alkalinity from the residue profile. It was also concluded that biomass production and associated N uptake by kikuyu grass grown in residue is dependent on the type of fertiliser used.

  7. Thin Layer Chromatographic Study of Bauxite and Quantitative Estimation of Co-Existing Al3+, Fe2+ and Ti4+%薄层色谱法测定铝土矿中的主成分及其共存离子Al3+,Fe2+和Ti4+

    Institute of Scientific and Technical Information of China (English)

    MOHAMED NAJAR P A; JEURKAR J U; RAMANA RAO K V

    2005-01-01

    Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al3+, Fe2+, Ti4+, Si4+) in bauxite mineral have been examined on plain and modified layers of silica gel G, silica gel H and cellulose with mobile phases containing aqueous sodium chloride, formic acid and hydrochloric acid. Ternary separation of Al-Fe-Ti was achieved on chromatographic plates made of silica gel H. The Ph effect and presence of impurity elements in samples, nature of stationary phases on the ternary separation and detection limits of bauxite constituents were studied. Silicon in bauxite was detected on cellulose plates. Quantitative determinations of Al3+, Fe2+ and Ti4+ on silica gel H impregnated with sodium formate layers were achieved by titrimetry and spectrophotometry.

  8. Bauxitas refratárias: composição química, fases e propriedades - Parte I Refractory bauxites: chemical composition, phases and properties - Part I

    Directory of Open Access Journals (Sweden)

    C. Pascoal

    2000-06-01

    Full Text Available A bauxita apresenta uma ampla faixa de aplicações industriais, de acordo com sua composição química e mineralógica. No setor de refratários, esta matéria-prima tem adquirido grande importância, uma vez que pode substituir parcial ou totalmente agregados de alumina eletrofundida em formados e monolíticos, devido a sua alta refratariedade e custo inferior. Entre os maiores produtores mundiais encontram-se a China, a Guiana e o Brasil. Embora seja um dos maiores produtores mundiais de bauxita refratária, no Brasil pouco se conhece de suas características químicas e mineralógicas, bem como suas propriedades em serviço a altas temperaturas. Esta seqüência de artigos apresenta uma revisão sobre as aplicações, fases cristalinas, características e propriedades a alta temperatura de bauxitas refratárias chinesas e sul-americanas. Nesta primeira parte serão consideradas as aplicações da matéria-prima, as transformações que ocorrem durante a calcinação das bauxitas e a formação de fases cristalinas.Bauxite shows a wide range of applications, according to its chemical and mineralogical composition. In the refractory industry, this raw material has partially or totally substituted fused alumina in bricks and castables, due to its high refractoriness and low cost. The major producers of refractory grade bauxite are, in this order, China, Guyana and Brazil. Although Brazil is one of the major suppliers of this raw material, very few studies have been carried out to understand its chemical, mineralogical and high-temperature properties. These papers present a review regarding the applications of South American and Chinese refractory grade bauxites, including the microchemistry of their crystalline phases and their hot properties. This first part will focus the applications of this raw material, the changes that occur during calcination of the crude mineral, and the formation of the crystalline phases.

  9. Escrubagem da Bauxita de Paragominas - PA. parte 2: modelagem matemática Scrubbing Process of the Miltonia 3 Bauxite. part 2: mathematical modeling

    Directory of Open Access Journals (Sweden)

    Jaime Henrique Barbosa da Costa

    2012-12-01

    Full Text Available O objetivo desse trabalho foi desenvolver um modelo matemático empírico para 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. O modelo foi desenvolvido a partir de dados gerados em uma campanha de experimentos de escrubagem, em um tambor desagregador de laboratório, tomando-se, como base, o planejamento fatorial. A variável de resposta selecionada foi a quantidade de finos (partículas menores que 0,037 mm, no produto desagregado, sendo que tal quantidade foi relacionada com o grau de enchimento e com o tempo de residência da polpa através do modelo proposto. 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, visto que a maioria dos valores ficou dentro de uma faixa de ±10% desvio.The aim of this study was to 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. 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 to be the most important variable for 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

  10. 山西本溪组铝土矿成矿条件及成矿规律探讨%Benxi Formation Bauxite Mineralization Condition and Rule in Shanxi Province

    Institute of Scientific and Technical Information of China (English)

    王银川; 李昭坤; 翟自峰; 李瑞保; 李欣

    2011-01-01

    Carboniferous Benxi bauxite in Shanxi Province is also called the North G layer of bauxite. Through the analysis of its tectonic background and ancient geography and the distribution of bauxite, we point out that the Shanxi bauxite deposits are mainly distributed in the ancient land, ancient island edge mineralization basin, and the better the mineralization basin closeness the more advantageous for the mineralization. Ancient land wide outcropping of aluminum silicate rocks by weathering and decomposition, the elements such as K, Na, Ca, Mg among them are drenched and lost, the elements such as Fe, Al, Ti, Si, etc. Are relatively collected and left in the red weathering crusts. Through short distance mechanical transgressive action they are transported to sedimentary basin sediments, And through analysis of the surrounding material components of bauxite composition, it is further confirmed that the deposition in the edge of the ancient land of the original bauxite layer is buried below the surface in the restore environment. Deposit and mineralization are formed after drenching and straining and taking off silicons by acid solutions such as groundwater, surface water, etc. And then they are lifted by the earth's crust, through the role of seepage and oxidative modification to the original bauxite to achieve the enrichment of bauxite. And the bauxite is distributed on one side of the gentle slope close to the edge of ancient land. In the valley of the two sides of the low-lying mountain ore bodies are rich. While deep bury is not favorable for mineralization.%通过对山西石炭系本溪组铝土矿,即华北G层铝土矿形成的构造背景、古地理环境及铝土矿床的分布分析,指出了山西铝土矿矿床主要分布在各古陆、古岛边缘的成矿盆地中,且成矿盆地的封闭性越好越有利于成矿.古陆上广泛出露的铝硅酸盐岩经过风化分解,其中的K、Na、Ca、Mg等元素大多数被淋失,Fe、Al、Ti、Si等元素

  11. Effects of CeO2 on structure and properties of Ni-Mn-K/bauxite catalysts for water-gas shift reaction

    Institute of Scientific and Technical Information of China (English)

    JIANG Lilong; YE Binghuo; WEI Kemei

    2008-01-01

    Multiple-metal catalysts (Ni-Mn-Ce-K/bauxite) for Water-Gas Shift (WGS) reaction were prepared by impregnation, and the catalytic structure and properties were investigated by N2 physical, XRD, H2-TPR, and CO-TPD. The results indicated that the addition of 7.5% CeO2 improved the activity of the WGS reaction obviously, and also increased the specific surface area and pore volume of the catalysts. The addition of CeO2 decreases the reduction temperature, enhanced the adsorption and activation of H2O, and improved the adsorption content of CO. Besides, active sites were not changed and the number of active sites on catalysts did not increase obviously.

  12. 平果铝土矿资源可持续利用及发展探讨%DISCUSSION ON SUSTAINABLE UTILIZATION AND DEVELOPMENT OF PINGGUO BAUXITE RESOURCES

    Institute of Scientific and Technical Information of China (English)

    罗秀光

    2001-01-01

    In this paper, the confinement factors and development potential in sustainable exploitation of Pingguo bauxite resources were analyzed, a plan for land reclamation, sustainable exploitation of mineral resources and comprehensive utilization of solid waste within the mine area was put forward and four key projects for ecological construction of the mine were proposed.%分析了平果铝土矿资源可持续开发利用的制约因素和发展潜力,对矿山土地复垦、矿产资源可持续开发和固体废弃物资源综合利用进行规划,提出了矿区生态建设的四个重点工程。

  13. Research And Development Of A Pilot First Generation PGNAA OFF-BELT System For Analysing Of Composition Of Cement And Bauxite Raw Material

    International Nuclear Information System (INIS)

    With purpose of development of the PGNAA system which can operate on the field in the condition of considerably changing of temperature and moisture, a multi channel analyzer-MCA 2k was designed and developed, which can compatibly operate with BGO detector, connected with computer through USB 2.0 port. Beside that, a software for obtaining and displaying the prompt gamma spectrum, with the spectrum stability function and convenience in the data was also designed and developed. The first generation PGNAA system was experimented in the changing condition of temperature in the laboratory. The result give out that the prompt gamma spectrum was stability during temperature changing, the peak area of the elements in the samples changed about 7%. Besides that, the first generation PGNAA system was also experimented to analyze the cement and bauxite samples. The result was also matched with the other analysis methods such as chemistry method and INAA method with the difference about 10%. (author)

  14. Characteristic Research on High Pressure Roller Mill Product of a Bauxite%某铝土矿高压辊磨产品特性研究

    Institute of Scientific and Technical Information of China (English)

    阎赞; 周春生; 张国春

    2015-01-01

    针对某铝土矿,在矿石特性分析基础上,进行了高压辊磨产品和颚式破碎产品的邦德球磨功指数试验、比表面积和孔体积测定试验,研究了高压辊磨机粉碎铝土矿产品的特性。结果表明,高压辊磨产品的邦德球磨功指数低于颚式破碎产品的邦德球磨功指数,比表面积和单位孔体积高于颚式破碎产品的比表面积和单位孔体积,可见高压辊磨机可有效达到节能降耗的目的,提高铝土矿产品的利用率,相对于传统的颚式破碎机具有更广阔的应用前景。%The high pressure roller mill product of a bauxite is studied. A full study on ore characteristics was carried out, followed by bond ball mill work index test, specific surface area and pore volume tests conducted on high pressure roller mill products and jaw crusher broken products. The results showed that the bond ball mill work index of the high pressure roller mill products was lower than the jaw crusher broken products, and its specific surface area and pore volumewas higher than the jaw crusher broken products. Therefore, milling load can be greatly reduced by using high pressure grinding roller technology and the utilization of bauxite products can be greatly improved. High pressure grinding roller has a broad application prospect related to the traditional jaw crusher.

  15. 林州天然硅线石-红柱石复合矿粉对高铝质浇注料性能的影响%Influence of sillimanite-andalusite composite powder on properties of bauxite based castables

    Institute of Scientific and Technical Information of China (English)

    谢朝晖; 叶国田; 张艳利; 黄亚冬; 王春生

    2011-01-01

    以山西特级矾土熟料为主要原料制备高铝质低水泥浇注料,研究了分别用质量分数为0、3%、5%、7%的林州天然硅线石-红柱石复合矿粉等量替代矾土熟料粉对浇注料基质物相和浇注料性能的影响.结果表明:将硅线石-红柱石复合矿粉加入到高铝质低水泥浇注料中,明显改善了浇注料的物理性能,提高了材料的烧后冷态强度和高温强度,改善了浇注料的抗热震性能,而且适量加入还明显提高了材料的荷重软化温度.综合各项性能认为,加入硅线石-红柱石复合矿粉的质量分数以5%为佳.%Bauxite based low cement castables were prepared using special grade sintered bauxite produced in Shanxi Province as the main starting material. The natural sillimanite-andalusite composite powder (0,3%,5% ,and 7% of mass percent) from Linzhou was used to substitute the same mass of sintered bauxite powder,and its influence on the phase composition in matrix and the properties of castables were investigated. The results show that the physical properties of the bauxite based low cement castables are improved by adding sillimanite-andalusite composite powder in terms of CCS,hot strength,thermal shock resistance,and refractoriness under load. The optimum addition of sillimanite-andalusite composite powder is 5%.

  16. 黔北务正道地区铝土矿基础地质与成矿作用研究进展%Advances in Basic Geology and Metallogenic Regularity Study of Bauxite in Wuchuan-Zheng'an-Daozhen Area,Northern Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    杜远生; 周琦; 金中国; 凌文黎; 张雄华; 喻建新; 汪小妹; 余文超; 黄兴

    2013-01-01

    The formation age of Dazhuyuan Formation bauxite deposit layers in Wu-Zheng-Dao Area, is restricted by fusuline and foraminifer fossils in underlaid Huanglong Formation and sporopollen fossils in Dazhuyuan Formation and superjacent Liangshan Formation, and is early Permian, The sedimentary environment of Dazhuyuan Formation bauxite deposit is a bay or a transgression lake which is half closed towards North. The bauxite is formed under the conditions of hot climate in low-latitude, and it can be subdivided into dry and wet seasons. The water body in the sedimentary basin is of weak acid reducing condition. Both of the landplant ecosystem and the basin microbe ecosystem have crucial impacts on the mineralization of bauxite, Hanjiadian Formation and Huanglong Formation provide double provenances for bauxite. Weathered aluminous materials are transported into the basin through the colloidal effect to form aluminous rock. Bauxite layers undergo several times of exposing and leaching processes after their formations. The leaching process leads to formation of earthy and half-earthy bauxite in the vadose zone and compact bauxite in the hyporheic zone. Crushed mudcracks form clastic bauxite and colloid coacervation forms ooidal bauxite. During the weathering process, instead of preservation, aluminum and ore-forming elements all experience element loss of varying degrees, and the SiO2 loss degree is obviously higher than that of A12O3 to form bauxite layers. Therefore, the sedimentary system of the basin and paleogeography control the distribution and thickness of bauxite layers, and multiperiod leaching processes control the quality and thickness of bauxite.%务正道地区铝土矿底板地层黄龙组筵类化石及铝土矿层大竹园组、梁山组的孢粉化石限定,大竹园组的时代为早二叠世.大竹园组铝土矿的沉积环境为向北半封闭的海湾或海泛湖.铝土矿形成于低纬度热带气候条件下,气候具旱季、雨季之分,盆地

  17. 高比表面积铝土矿载体的制备及在CO氧化反应中的应用%High Surface Area Bauxite: Preparation, Characterization and Application in CO Oxidation Reaction

    Institute of Scientific and Technical Information of China (English)

    江莉龙; 马永德; 曹彦宁; 杨阳; 魏可镁

    2012-01-01

    The hydrothermaUy treated bauxite with high surface area was employed as the P1 based catalyst support. A series of Pt/bauxite catalysts were prepared by incipient-wetness impregnation method. The loading of Pt was varied from 0.5wt% to 2.0wt%. The catalysts were characterized by XRF, low temperature nitrogen adsorption-desorption, XRD, H2-TPR and CO-TPD. The catalyst performance for CO oxidation reaction was also investigated. The results indicate that Pt/bauxite catalysts have excellent property for CO oxidation reaction. Especially when the reaction temperature is at 200 t, CO conversion rate of 1.0% Pt/bauxite is 93.2%, while 1.0Pt/Al2O3 is only 9.4%, attributed to the interaction between Pt and Fe2O3 in the modified bauxite, and the interaction could decrease the reducing temperature of Pt oxide and Fe2O3 and also improve the adsorption-desorption behavior of Pt /bauxite catalysts for CO molecule, thus increasing the CO Oxidation activity.%采用水热法,对天然铝土矿进行改性,获得高比表面积的铝土矿载体(Bauxite).用等体积浸渍法制备了不同Pt含量的Pt/bauxite和1.0%Pt/Al203催化剂,以CO氧化为探针反应,考察了催化剂性能.采用XRF、XRD、低温N2-物理吸附、H2-TPR以及CO-TPD等对载体和催化剂样品进行表征.结果表明:Pt/bauxite催化剂具有优异的CO氧化性能,特别是当反应温度为200℃时,催化剂1.0%Pt/bauxite的CO转化率为93.4%,而1.0%Pt/Al2O3CO转化率仅为9.4%.其原因是铝土矿含有的Fe2O3是CO氧化反应的催化剂,且Fe2O3与负载的Pt之间发生了相互作用,降低了Pt和Fe2O3还原温度,提高了对CO的吸附能力且降低了CO的脱附温度,进而提高了催化剂的CO氧化反应性能.

  18. Modified Bauxite Supported Ruthenium Catalysts for Hydrogen Evolution in the Water-Gas Shift Reaction%改性铝土矿载体负载Ru催化剂上的水煤气变换制氢

    Institute of Scientific and Technical Information of China (English)

    江莉龙; 马永德; 曹彦宁; 杨阳; 魏可镁

    2012-01-01

    采用水热法对天然铝土矿进行改性,获得高比表面积的铝土矿(bauxite)载体.用等体积浸渍法制备了Ru含量为1.0%-4.0%(质量分数,下同)的Ru/bauxite催化剂和Ru含量为2.0%的Ru/Al2O3催化剂,以水煤气变换反应为探针反应,考察了催化剂性能.利用X射线荧光元素分析(XRF)、X射线粉末衍射(XRD)、低温N2物理吸附、H2程序升温还原(H2-TPR)以及CO程序升温脱附(CO-TPD)等对载体和催化剂样品进行表征.结果表明,不同Ru含量的Ru/bauxite催化剂具有优异的水煤气变换制氧性能,优于Ru/Al2O3催化剂.其原因是铝土矿本身含有的Fe2O3与负载的Ru之间发生了相互作用,降低了Fe2O3还原温度,提高了对CO的吸附能力且降低了CO的脱附温度,进而提高了催化剂的水煤气变换反应性能.%Hydrothermally treated bauxite with high surface area was used as a ruthenium-based catalyst support. A series of Ru/bauxite and 2.0% (mass fraction) Ru/AI2O3 catalysts were prepared by incipient-wetness impregnation. The loading content of ruthenium in the Ru/bauxite catalysts was varied from 1.0% to 4.0%. The catalysts were thoroughly characterized by X-ray fluorescence (XRF), low temperature N2 physical adsorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), and CO temperature-programmed desorption (CO-TPD). The performances of the catalysts for the water-gas shift reaction were also investigated. The results indicated that Ru/bauxite catalysts possess an excellent ability to evolve hydrogen in the water-gas shift reaction. This was attributed to the interaction between Ru and Fe2O3 in the modified bauxite, which could decrease the reduction temperature of Fe2O3, and also improve the adsorption-desorption behavior and decrease the desorption temperature of Ru/bauxite catalysts for CO molecules, resulting in higher activity in the water-gas shift reaction.

  19. Petrography and detrital zircon study of late Carboniferous sequences in the southwestern North China Craton: Implications for the regional tectonic evolution and bauxite genesis

    Science.gov (United States)

    Cai, Shuhui; Wang, Qingfei; Liu, Xuefei; Feng, Yuewen; Zhang, Ying

    2015-02-01

    derive from the northern marginal region of the E-NCC, an area characterized by contemporaneous volcanism. The co-existence of the 450 and 300 Ma groups of detrital zircons also suggests that the northern and southern marginal regions of the E-NCC underwent almost simultaneous late Carboniferous tectonic uplift and denudation, a tectonic change that led to the formation of the sedimentary basins within the E-NCC. Late Carboniferous phyllosilicate layers within the profile are likely to be the equivalent of economically important diaspore and clay dominated bauxites within the E-NCC, suggesting that the diaspore in these bauxites was derived from mica group minerals by resolution-precipitation processes.

  20. Exergoecology: A thermodynamic approach for accounting the Earth's mineral capital. The case of bauxite-aluminium and limestone-lime chains

    International Nuclear Information System (INIS)

    As man extracts minerals, the natural deposits become depleted in quantity and concentration, and hence the mineral wealth of the Earth decreases. This paper explains the exergoecological method used for calculating the mineral exergy bonus that Nature gives us for free for providing minerals concentrated in mines and not dispersed in the Earth's crust. The method is based on two concepts: Exergy and the Exergy cost. Exergy measures the minimum (reversible) work required to extract and concentrate the materials from a Reference Environment (RE) to the conditions found in Nature. This RE can be approximated to a completely degraded crepuscular planet with the absence of fossil fuels and mineral deposits. And the exergy cost accounts for the actual exergy required for accomplishing the same process with available technologies. These costs are complementary to the conventional extraction, land-recovering, processing and refining costs. The case studies of two industrial chains: bauxite-alumina-aluminium, and limestone-calcite-lime are presented and discussed. As the method provides values in energy units, the annual exergy decrease in the mineral endowment of the planet due to the extraction of minerals can now take into account the fossil fuel's exergy as well as the non-fuel mineral exergy costs.

  1. Preparação de compostos de alumínio a partir da bauxita: considerações sobre alguns aspectos envolvidos em um experimento didático Preparation of aluminum compounds from bauxite: considerations about some aspects involved in a didactic experiment

    Directory of Open Access Journals (Sweden)

    Vera R. Leopoldo Constantino

    2002-05-01

    Full Text Available Aluminum metal and aluminum compounds have many applications in several branches of the industry and in our daily lives. The most important raw material for aluminum and its manufactured compounds is bauxite, a rock constituted mainly by aluminum hydroxides minerals. In this work, a didactic experiment aiming the preparation of alumina and potassium alum starting from bauxite is proposed for undergraduate students. Both compounds are of great commercial, scientific and historical interest. The experiment involves applications of important chemical principles such as acid-base and precipitation. Some chemical properties and uses of aluminum compounds are also illustrated.

  2. 高铁铝土矿低温气基还原除铁初探%Removal of Iron from Ferric Bauxite by a Hydrogen Reduction Method at Low Heating Temperature

    Institute of Scientific and Technical Information of China (English)

    朱玉婷; 田真; 高峰

    2015-01-01

    The removal of iron from ferric bauxite (Xiaoyi, Shanxi) by hydrogen reduction at low heating temperature (200~550℃) combined with magnetic separation was studied. This method transforms non-magnetic and weak magnetic iron-related minerals to magnetic iron-related mineral, then these minerals can be removed by magnetic separation. Results show when the reduction temperature ranged from 300 to 550℃, the iron-related mineral can be modiifed and removed by magnetic separation easily. The optimal condition is heating at 400℃for 1 h in pure hydrogen atmosphere, then processing by week magnetic separation, the iron-removal rate of ferric bauxite increased from 4.17%(raw material) to 60.6%, the yield of bauxite was 78.72%.%以山西孝义铝土矿为原料,研究了高铁铝土矿低温(200~550℃)气基还原与磁选联合的除铁方法,此法将非磁性和弱磁性含铁矿物磁化并通过磁选脱除。研究表明,当还原温度在300~550℃时,含铁矿物被磁化,表现出良好的可磁选性;高铁铝土矿经过还原温度为400℃保温1 h的氢气还原处理,并经过一次弱磁粗选,除铁率由原矿的4.17%升高到60.6%,铝土矿回收率达到78.72%,为实验最优条件。

  3. 广西那坡县龙合矿区铝土矿地质特征%Geological characteristics of bauxite deposits in Longhe mining area of Napo in Guangxi

    Institute of Scientific and Technical Information of China (English)

    覃全光

    2015-01-01

    A large-scale accumulation type bauxite deposit was found through prospecting and exploration in Longhe mining area in Napo of Guangxi,and this deposit played the role of backup resource base in the de-velopment of aluminum industry in Guangxi.The accumulation type bauxite deposit occurred in karst accu-mulation laterite formation of Pleistocene Epoch inside karst depression and it was formed in Pleistocene Ep-och under the primary mineralizing processes of karstification and lateritization with fossil weathering crust type bauxite ore beds (rock strata)of Permian lower Heshan Formation as its ore-forming material source. The mineralization and enrichment were mainly controlled by factors such as ore source bed,formation li-thology,tectonic movement,climate and landform.%通过找矿勘探,在那坡县龙合矿区发现一处大型规模的堆积铝土矿矿床,为广西区铝工业发展提供后备资源基地。堆积铝土矿赋存于岩溶洼地内更新世岩溶堆积红土层中,成矿物质来源于上二叠统合山组底部的古风化壳型铝土矿(岩)层,主要成矿时代为更新世,主导成矿作用为岩溶作用、红土化作用。矿化富集主要受矿源层、地层岩性、构造运动、气候和地貌等因素控制。

  4. THE BAUXITE RESIDUE APPLIED IN SUGAR CANE = APLICAÇÃO DO RESÍDUO DA MINERAÇÃO DE BAUXITA EM CANA-DE-AÇÚCAR

    Directory of Open Access Journals (Sweden)

    João Antonio Galbiatti

    2009-01-01

    Full Text Available The experiment was carried through in protecting environment with the objective to evaluate the effect of the bauxite residue in the macronutrients and dry mass concentrations in the sugar cane. Vases of 10 L had been used that they had received the following rates from bauxite residue: 0, 28, 56, 84, 112 e 140 t ha-1, the used culture was the sugar cane (SP92 4221. The incorporation of the bauxite residue in the soil provided increase in the soil macronutrients concentration’s, being that only for sulphur levels above of 83 t ha-1 had provided reductions of this nutrient. Already for the macronutrients concentration’s determined in the leaf, levels above of 70,5; 125; 101; 56 t ha -1 diminished the nitrogen, phosphorum, potassium and sulphur concentration’s, respectively. However, for calcium and magnesium the use of the residue provided the reduction of foliar concentration. The level of the bauxite residue in which had the biggest production of dry mass was of 64 t ha-1. = O experimento foi realizado em ambiente protegido com o objetivo de avaliar o efeito do resíduo da mineração de bauxita nos teores de macronutrientes e massa seca da cana-de-açúcar. Foram utilizados vasos de 10 L que receberam as seguintes doses de resíduo de bauxita: 0, 28, 56, 84, 112 e 140 t ha-1, utilizando-se o clone de cana-de-açúcar SP92 4221. A incorporação do resíduo de bauxita no solo proporcionou aumento nos teores dos macronutrientes do solo, sendo que apenas para o enxofre doses acima de 83 t ha-1 proporcionaram reduções deste nutriente. Já para os teores de macronutrientes determinados na folha, doses acima de 70,5; 125; 101; 56 t ha-1 diminuíram os teores de nitrogênio, fósforo, potássio e enxofre, respectivamente. Para o cálcio e o magnésio, entretanto, a utilização do resíduo proporcionou a diminuição dos seus teores foliares. A dose do resíduo de bauxita na qual houve a maior produção de massa seca foi de 64 t ha-1.

  5. Concentration of bauxite fines via gravity concentration Concentração de finos de bauxita por concentração densitária

    Directory of Open Access Journals (Sweden)

    Arthur Pinto Chaves

    2009-09-01

    Full Text Available Companhia Brasileira de Alumínio (CBA has a preparation plant at Itamarati de Minas, MG. This plant washes two different kinds of bauxite ore, one originating from the laterization of gnaisses and another from amphybolites. Both ores have the same behavior in the coarser size fractions but behave differently under 0.355 mm (42# Tyler. In these small sizes, gneissic ores are rich in quartz and amphybolitic ores are rich in iron and titanium bearing ores. The unit operations are: scrubbing of the feed in drum scrubbers, desliming in cyclones, and screening of the scrubbed bauxite in high frequency screens (0.355 mm - the +0.355 mm product is a final concentrate. The -0.355 mm fraction is desliming in two stage cyclones and goes to a fines gravity concentration circuit of Reichert spirals complemented by magnetic separation of the light product from the spirals. The research work, including mineralogy, process development, batch tests and pilot plant tests, is described and compared to the actual results in the industrial circuit.A CBA (Companhia Brasileira de Alumínio tem uma usina de beneficiamento em Itamarati de Minas, MG. Essa usina trata dois tipos de bauxita diferentes, um originado da laterização de gnaisses e outro de anfibolitos. Ambos os minérios têm o mesmo comportamento nas frações granulométricas grosseiras, mas tornam-se diferentes abaixo de 0,355 mm (42 # Tyler. Nesses tamanhos menores, os minérios gnáissicos são ricos em quartzo e os anfibolíticos são minerais portadores de ferro e titânio. As operações unitárias de preparação são a desagregação da alimentação em desagregadores de tambor (“scrubbers”, a deslamagem em ciclones e o peneiramento do minério desagregado em peneiras de alta freqüência em 0,355 mm (42# Tyler - o produto retido em 0,355 mm é um concentrado final. O produto passante em 0,355 mm é deslamado em dois estágios de ciclones e vai para a separação final em espirais Reichert

  6. Development of sintering-resistant CaO-based sorbent derived from eggshells and bauxite tailings for cyclic CO2 capture.

    Science.gov (United States)

    Shan, ShaoYun; Ma, AiHua; Hu, YiCheng; Jia, QingMing; Wang, YaMing; Peng, JinHui

    2016-01-01

    Carbon dioxide, one of the major greenhouse gases, are believed to be a major contributor to global warming. As a consequence, it is imperative for us to control and remove CO2 emissions. The CaO, a kind of effective CO2 sorbent at high temperature, has attracted increasing attention due to some potential advantages. The main drawback in practical application is the deterioration of CO2 capture capacity following multiples cycles. In the present study, novel low-cost porous CaO-based sorbents with excellent CO2 absorption-desorption performance were synthesized using bauxite tailings (BTs) and eggshells as raw materials via solid-phase method. Effect of different BTs content on CO2 absorption-desorption properties was investigated. Phase composition and morphologies were analyzed by XRD and SEM, and CO2 absorption properties were investigated by the simultaneous thermogravimetric analyzer. The as-prepared CaO-based sorbent doped with 10 wt% BTs showed superior CO2 absorption stability during multiple absorption-desorption cycles, with being >55% conversion after 40 cycles. This improved CO2 absorption performance was attributed to the particular morphologies of the CaO-based sorbents. Additionally, during absorption-desorption cycles the occurrence of Ca12Al14O33 phase is considered to be responsible for the excellent CO2 absorption performance of CaO-based sorbents. In the meanwhile, the use of solid waste eggshell and BTs not only decreases the release of solid waste, but also moderates the greenhouse effect resulted from CO2. PMID:26549755

  7. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoming [State Key Laboratory of Advanced Metallurgy, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Na [Green Construction Materials and Circulation Economy Center, Architectural Design and Research Institute of Tsinghua University Co., Ltd., Beijing 100084 (China); Yao, Yuan, E-mail: yuanyaocas@163.com [School of Engineering and Computer Science, University of the Pacific, Stockton, CA 95211 (United States); Sun, Henghu; Feng, Huan [School of Engineering and Computer Science, University of the Pacific, Stockton, CA 95211 (United States)

    2013-11-15

    Highlights: • Al{sup IV} and Al{sup VI} both exist in the hydration products. • Increase of Ca/Si ratio promotes the conversion from [AlO{sub 4}] to [AlO{sub 6}]. • Polymerization degree of [SiO{sub 4}] in the hydration products declines. -- Abstract: In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, {sup 27}Al MAS NMR and {sup 29}Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si + Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al{sup IV} and Al{sup VI}, but mainly in the form of Al{sup VI}. Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO{sub 4}] to [AlO{sub 6}] and inhibits the combination between [AlO{sub 4}] and [SiO{sub 4}] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO{sub 4}] in the hydration products declines.

  8. Accuracy Assessment of Geometrical Elements for Setting-Out in Horizontal Plane of Conveying Chambers at the Bauxite Mine "KOSTURI" Srebrenica

    Science.gov (United States)

    Milutinović, Aleksandar; Ganić, Aleksandar; Tokalić, Rade

    2014-03-01

    Setting-out of objects on the exploitation field of the mine, both in surface mining and in the underground mines, is determined by the specified setting-out accuracy of reference points, which are best to define spatial position of the object projected. For the purpose of achieving of the specified accuracy, it is necessary to perform a priori accuracy assessment of parameters, which are to be used when performing setting-out. Based on the a priori accuracy assessment, verification of the quality of geometrical setting- -out elements specified in the layout; definition of the accuracy for setting-out of geometrical elements; selection of setting-out method; selection at the type and class of instruments and tools that need to be applied in order to achieve predefined accuracy. The paper displays the accuracy assessment of geometrical elements for setting-out of the main haul gallery, haul downcast and helical conveying downcasts in shape of an inclined helix in horizontal plane, using the example of the underground bauxite mine »Kosturi«, Srebrenica. Wytyczanie obiektów na polu wydobywczym w kopalniach, zarówno podziemnych jak i odkrywkowych, zależy w dużej mierze od określonej dokładności wytyczania punktów referencyjnych, przy pomocy których określane jest następnie położenie przestrzenne pozostałych obiektów. W celu uzyskania założonej dokładności, należy przeprowadzić wstępną analizę dokładności oszacowania parametrów które następnie wykorzystane będą w procesie wytyczania. W oparciu o wyniki wstępnej analizy dokładności dokonuje się weryfikacji jakości geometrycznego wytyczenia elementów zaznaczonych na szkicu, uwzględniając te wyniki dobrać należy odpowiednią metodę wytyczania i rodzaj oraz klasę wykorzystywanych narzędzi i instrumentów, tak by osiągnąć założony poziom dokładności. W pracy przedstawiono oszacowanie dokładności wytyczania elementów geometrycznych dla głównego chodnika transportowego

  9. 山西某露天铝土矿投资开发思路浅析%The investment and development conception analyses for a open-cast bauxite mine in Shanxi province

    Institute of Scientific and Technical Information of China (English)

    杨同海

    2014-01-01

    According to a open-cast bauxite mine investment and development practice in Shanxi Province, the risk analysis is carried out from five aspects of investment and development subject, development model, land requisition, size of mining, the mine ecological environment protection, puts forward corresponding measures and suggestions are proposed, so as to provide reference for similar mining investment.%结合山西某露天铝土矿投资开发实际,从投资开发主体、开发模式、土地征用、开采规模、矿山生态环境保护五个方面进行了风险分析,提出了相应的处理措施和建议,为类似矿业投资提供一定的参考。

  10. Determination of (226)Ra, (232)Th, (40)K, (235)U and (238)U activity concentration and public dose assessment in soil samples from bauxite core deposits in Western Cameroon.

    Science.gov (United States)

    Mekongtso Nguelem, Eric Jilbert; Moyo Ndontchueng, Maurice; Motapon, Ousmanou

    2016-01-01

    Determination of activity concentrations in twenty five (25) soil samples collected from various points in bauxite ore deposit in Menoua Division in Western of Cameroon was done using gamma spectrometry based Broad Energy Germanium (BEGe6530) detector. The average terrestrial radionuclides of (40)K, (226)Ra, (232)Th, (235)U and (238)U were measured as 671 ± 272, 125 ± 58, 157 ± 67, 6 ± 3 and 99 ± 69 Bq kg(-1), respectively. The observed activity concentrations of radionuclides were compared with other published values in the world. The outdoor absorbed dose rate in air varied from 96.1 to 321.2 nGy h(-1) with an average of 188.2 ± 59.4 nGy h(-1). The external annual effective dose rate and external hazard index were estimated as 0.23 ± 0.07 mSv year(-1) for outdoor, 0.92 ± 0.29 mSv year(-1) for indoor and 1.13 for the external hazard index, respectively. These radiological safe parameters were relatively higher than the recommended safe limits of UNSCEAR. Consequently, using of soil as building material might lead to an increase the external exposure to natural radioactivity and future applications research need to be conducted to have a global view of radioactivity level in the area before any undergoing bauxite ore exploitation. PMID:27536536

  11. Escrubagem da bauxita de Paragominas - PA: Parte 1: influência de variáveis operacionais na desagregação da bauxita Scrubbing process of the Miltonia 3 Bauxite - Part 1: influence of operating variables on bauxite disintegration

    Directory of Open Access Journals (Sweden)

    Jaime Henrique Barbosa da Costa

    2012-06-01

    Full Text Available O objetivo desse trabalho foi investigar a influência de variáveis operacionais na geração de finos (material com granulometria menor que 0,037 mm durante o processo de escrubagem, em escala de laboratório, da bauxita proveniente da jazida Miltônia 3 da Mina de Bauxita de Paragominas-PA, com vistas a fornecer subsídios para a modelagem matemática da operação. 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.The aim of this study was to investigate the bauxite scrubbing process on samples from Miltonia 3, a Vale operation in the State of Pará, 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 the feed and the product of the scrubbing test. The former was considered to be a characteristic material, while the second was the dependent variable, i.e. the result of the scrubbing process. According to experiments, the load fraction was the most important variable for the scrubbing process.

  12. 河南三门峡贯沟铝土矿矿物组成及其特征%Mineral Composition and Characteristics of the Guangou Bauxite Deposit in Sanmenxia City, Henan Province

    Institute of Scientific and Technical Information of China (English)

    冯跃文; 刘学飞; 李中明; 蔡书慧

    2012-01-01

    河南三门峡市贯沟铝土矿属喀斯特型铝土矿。研究区内地层发育相对完全,除上奥陶统、志留系、泥盆系和下石炭统地层缺失外,从太古界到新生界均有出露。铝土矿层主要产出于中石炭系本溪组下段。矿石以鲕粒和隐晶质结构为主,少量碎屑结构。矿物学分析显示,铝土矿矿石的主要组成矿物有硬水铝石、锐钛矿、伊利石,另外,还包括少部分高岭石、锆石等。硬水铝石呈隐晶质结构组成矿石的基质,少部分呈现细小的板状、长柱状形态。锐钛矿存在两种形态:第一种是锐钛矿与硬水铝石二者同期形成;第二种锐钛矿以脉状穿插在硬水铝石组成的基质中,形成稍晚于硬水铝石。伊利石主要呈鳞片状集合体形态组成矿石的基质。锆石主要分散在硬水铝石组成的基质中。进一步研究发现:硬水铝石电子探针分析显示晶体中存在Fe、Si和Ti等其它元素,其主体呈隐晶质与锐钛矿密切共生,指示硬水铝石主要为简单的成岩结晶成因。矿石中的锐钛矿和硬水铝石共生,互相包含和穿插,反映大量的锐钛矿是成矿期或成岩期结晶形成。对风化作用中形成的伊利石主要由云母转化而形成,该过程中矿物结构并未发生明显改变。%The Guangou bauxite deposit in Sanmenxia City, Henan Province is of karst type. Except the Ordovcian, Silurian, Devonian and Lower Carboniferous Strata, all the other Archean to Cenozoic strata outcrop in this region. The Guangou bauxite horizon occurs in the middle Carboniferous Benxi Formation. The ores are dominated by oolite and aphanitic textures, with a few clastic textures. Mineralogical analysis reveals that the main minerals in bauxite ores are diaspore, anatase and illite, with a little kaolinite and zircon. Diaspore is the base of ores in aphanitic texture, with some thin tabular and long bar textures. Anatase developed in two shapes, one paragenesis

  13. A geopolimerização como técnica para a aplicação do resíduo de bauxita Geopolymerization as a technique for bauxite residue applications

    Directory of Open Access Journals (Sweden)

    C. S. Bitencourt

    2012-03-01

    Full Text Available Encontrar aplicações sustentáveis para o resíduo de bauxita tem se mostrado um dos principais desafios da indústria do alumínio na atualidade. Com esse propósito, a geopolimerização pode se tornar uma solução interessante, uma vez que essa técnica seria capaz de tirar proveito de algumas das características mais típicas desse resíduo, como sua elevada alcalinidade e o seu significativo teor de compostos de silício e alumínio, produzindo materiais sólidos semelhantes em propriedades às cerâmicas tradicionais. Neste trabalho, o processamento, as propriedades e as possíveis aplicações dos geopolímeros compostos por resíduo de bauxita foram analisados. Além dos ensaios de porosidade aparente e resistência mecânica, as amostras preparadas também foram submetidas a um ensaio de lixiviação, de modo a já realizar uma avaliação prévia dos potenciais riscos ambientais decorrentes da utilização de um possível produto, e de quais procedimentos favoreceriam a sua passivação. Entre os principais resultados obtidos, verificou-se que a queima a 800 °C permitiu a algumas das composições desenvolvidas alcançarem valores de resistência à compressão da ordem de até 30 MPa, além de uma resistência à lixiviação muito próxima à de um tijolo de argila prensado comum, o que já permite considerar a construção civil como um dos setores mais favoráveis para a aplicação dos geopolímeros com resíduo de bauxita, principalmente pela enorme capacidade de consumo desse setor e da sua crescente demanda por produtos mais sustentáveis.Finding sustainable applications for the bauxite residue is one of the leading challenges in the aluminium industry. For this purpose, the geopolymerization could become an interesting alternative, because this technique could make use of some of the typical characteristics of the bauxite residue, such as its alkalinity and expressive silicates and aluminates contents, resulting in solid

  14. Feasibility study for on-line analysis of bauxite using a PGNAA system%利用 PGNAA 系统对铝土矿石进行在线检测的可行性研究

    Institute of Scientific and Technical Information of China (English)

    宋青锋; 龚亚林; 张伟; 赵龙; 尚庆敏; 谢福生

    2015-01-01

    利用一款基于瞬发γ中子活化原理设计的主要针对皮带散状物料元素进行在线检测的工业仪器,研究这款仪器用于测量铝土矿组成分析的可行性,实验主要进行了两组样品中 Ca、Si、Al、Fe、Ti 五种元素的测试,其中一组样品由高纯氧化物组成,一组样品由铝土矿和高纯氧化物组成,测量结果表明, CaO、SiO2、Al2 O3、Fe2 O3、TiO2的测量精度分别为±0.23%、±0.18%、±0.35%、±0.14%、±0.08%,能够满足原料自动配比及入厂原料质量控制的要求。%An industrial prompt-gamma neutron activation analysis(PGNAA)system,designed for the real-time elemental analysis of bulk materiel on a conveyor belt,has been studied to examine the feasibility of using such a system for bauxite composition analysis.Experiments were conducted to measure Ca Si Fe Al in two simple,one simple is comprised of pure oxide,and the other simple is comprised of bauxite and pure oxide.The static accuracy are ± 0.23% (CaO),± 0.18% (SiO2 ),± 0.35% (Al2 O3 ),± 0.14% (Fe2 O3 ), ±0.08%(TiO2 ).The instrument can meet the requirements of automatic mixing system of row material and quality controlling after entering factory.

  15. Towards an impact assessment of bauxite red mud waste on the knowledge of the structure and functions of bathyal ecosystems: The example of the Cassidaigne canyon (north-western Mediterranean Sea)

    International Nuclear Information System (INIS)

    Since 1967, the alumina plants in the Marseilles area (Barasse and Gardanne) have been discharging the mineral residue (i.e., red mud) resulting from the alkaline processing of bauxite into the submarine Cassidaigne canyon (north-western Mediterranean Sea) through pipes situated at 320-330 m in depth. The Barasse pipe stopped being used in 1988. From 1987 to 1996, many decrees and regulations were promulgated by the French State to rule the conditions under which the Gardanne alumina refinery was authorized to dispose of the bauxite residue in the sea. The refinery was required: (i) to study the hydrodynamic circulation in the Cassidaigne canyon to evaluate the potential dispersion and transport of fine elements discharged into the water mass and their impact on the pelagic ecosystem; (ii) to survey the marine environment every five years to control the expansion and thickness of the red mud deposit and compare the evolution of the benthic macrofauna at representative sampling sites in the environment affected by the red mud discharge with that of reference sites outside of the red mud plume; (iii) to study the effect of the discharge on fishing activities; and (iv) to investigate the toxicity of the red mud, particularly its persistence, accumulation, interaction and effect on the marine ecosystem, paying special attention to the bio-accumulation of chromium and vanadium. A Scientific Committee was created to insure an independent evaluation of the studies promised by the manufacturer in response to the State's regulations. Since the beginning of the 1960s, data have been accumulating on the structure and long-term functioning of the Cassidaigne bathyal ecosystem. This paper presents the collaborative efforts of the State-Manufacturer-Committee triplet and summarizes the main results obtained during the last period's sea campaigns (1991-2007). This paper also illustrates how national regulations concerning manufacturers, such as Gardanne alumina refinery, have

  16. EFFECTS OF THE USE OF BAUXITE MINING RESIDUES ON MICRONUTRIENT AND SODIUM LEVELS IN SUGARCANE = EFEITO DO USO DE RESÍDUO DO PROCESSAMENTO DE BAUXITA NOS TEORES DE MICRONUTRIENTES E SÓDIO EM PLANTAS DE CANA-DE-AÇÚCAR

    Directory of Open Access Journals (Sweden)

    Reginaldo Itiro Muraishi

    2008-01-01

    Full Text Available Population growth and the consequent demand for consumer goods as well as the increase in industrial development generates great amounts of residues. The aluminum extraction industry pruduces mainly residues from the industrial processing of bauxite, in amounts correlated with the industry size and they are disposed of in large containment lakes, causing significant environmental impact. Thus, the objective of the present study was to verify, in a protected environment, the effect of the addition of bauxite residues on sugarcane plants (SP92 4221, in relation to micronutrient levels in the plant. The following levels of bauxite processing residues were added to 10 litres containers: 0, 2, 4, 6, 8 and 10% of the volume of the containers, corresponding to 0, 28, 56, 84, 112 and 140 t ha-1. Results indicate that application of bauxite mining residues increased the levels of Mn and Na in the plants and decreased Zn, Cu and Fe absorption, and that higher levels of the residue inhibited the development of the crop. = O crescimento populacional, a demanda por bens de consumo e, conseqüentemente o aumento do desenvolvimento industrial produz quantidades expressivas de resíduos. A indústria de extração de alumínio gera principalmente resíduos provenientes do processamento industrial da bauxita, em quantidades que se correlacionam diretamente com o porte industrial. Esse descarte é depositado em grandes lagos de contenção, causando forte impacto ambiental. Assim, o objetivo do presente trabalho foi verificar, em ambiente protegido, o efeito da adição do resíduo de processamento de bauxita em plantas de cana-de-açúcar (SP92 4221, em relação aos teores de micronutrientes na planta. Foram utilizados vasos de 10 litros que receberam as seguintes doses de resíduo da mineração de bauxita: 0, 2, 4, 6, 8 e 10% do volume dos vasos, correspondendo respectivamente a, 0, 28, 56, 84, 112 e 140 t ha-1. Os resultados obtidos evidenciaram que a aplica

  17. Quantificação de macronutrientes no solo e em folhas de cana-de-açúcar em função de doses de resíduo da mineração de bauxita Nutrient diagnosis of sugarcane in function of residue rates of the bauxite mining

    Directory of Open Access Journals (Sweden)

    Fabio O. De Nobile

    2010-02-01

    Full Text Available O experimento foi realizado em ambiente protegido, com o objetivo de avaliar o efeito do resíduo da mineração de bauxita nos teores de macronutrientes, no solo e em plantas de cana-de-açúcar. Foram utilizados vasos de 10 L que receberam as seguintes doses de resíduo de bauxita: 0; 28;56; 84; 112 e 140 t ha-1, utilizando-se do clone de cana-de-açúcar SP92 4221. A incorporação do resíduo de bauxita no solo proporcionou aumento nos teores dos macronutrientes do solo, sendo que apenas para o enxofre doses acima de 83 t ha-1 proporcionaram reduções desse nutriente. Já para os teores de macronutrientes determinados na folha, doses acima de 70,5; 125; 101 e 56 t ha-1 diminuíram os teores de nitrogênio, fósforo, potássio e enxofre, respectivamente. Entretanto, para o cálcio e o magnésio, a utilização do resíduo proporcionou a diminuição dos seus teores foliares. A dose do resíduo de bauxita que teve a maior produção de massa seca foi de 64 t ha-1.The experiment was carried out in green house with the objective of evaluating the effect of the bauxite mining residue in the rates of macronutrients in sugarcane and soil. Containers of 10 L were used. They received the following rates of bauxite residue: 0; 28; 56; 84; 112 and 140 t ha-1 . The used culture was the sugarcane (SP92 4221. The incorporation of the bauxite residue in the soil provided an increase in the levels of the soil macronutrients, and only for sulphur levels above 83 t ha-1, it was possible to provide reductions of this nutrient. For rates of determined macronutrients in the leaf, levels above 70, 5; 125; 101; 56 t ha -1 diminished the rates of nitrogen, phosphorum, potassium and sulphur, respectively. However, for calcium and magnesium the use of the residue provided the reduction of leaf rates. The level of the bauxite residue which had the largest production of dry mass was 64 t ha-1.

  18. 渝南大佛岩矿区铝土矿碎屑锆石中钪的赋存形式研究%Existing Form of Scandium in Detrital Zircon from Bauxite of the Dafoyan Mine, Southern Chongqing

    Institute of Scientific and Technical Information of China (English)

    李军敏; 陈莉; 徐金沙; 闫武; 吕涛; 杨波; 陈阳

    2013-01-01

    以渝南大佛岩矿区含矿岩系铝土质黏土岩为研究对象,通过淋滤实验证明其中钪并非以独立矿物形式和大量离子吸附形式存在的.由于铝土矿含矿层位缺少有机质,也排除了钪与有机质结合的可能性.基于扫描电镜和能谱分析的结果,发现其中的碎屑锆石富含钪元素,钪广泛分布于碎屑锆石表面,且分布非常不均匀,最高重量百分比可达2.75%,最低低于检测线,且在锆石的凹坑、裂隙与锆石上重矿物的钪含量普遍较高.结合钪易与锆发生极性类质同象的特性,本研究认为该矿区原矿石碎屑锆石中的钪,很可能有类质同象、离子吸附和超显微非结构混入物三种形式.此研究成果将对今后渝南地区铝土矿伴生钪的开发利用提供理论参考依据.%The study of aluminum clay rock of Dafoyan mining area proves that the scandium does not exist in the form of independent minerals and ion adsorption.There is nearly no organic matter in bauxite ore-bearing horizon and we can also ruled out the possibility of the scandium integrate with organic matter.We find the scandium is rich in detrital zircon,base on the results of the SEM and the analysis of spectrum.The scandium widespread distribute on the surface of detrital zircons,and there are different percentage composition of scandium in different parts of the detrital zircon,the maximum is 2.75%,and the minimum is not detected scandium,moreover the percentage composition of scandium in the pits or cracks are higher frequently.So,we consider that there are likely three forms of scandium in detrital zircons:isomorphism,ion-adsorption and the microscopic structure of the mixed in with content.These researches will provide a theoretical basis for the development and utilization of the bauxite in southern Chongqing in future.

  19. Flotation of low-grade bauxite using organosilicon cationic collector and starch depressant%有机硅阳离子捕收剂和淀粉抑制剂分选铝土矿

    Institute of Scientific and Technical Information of China (English)

    余新阳; 王浩林; 王强强; 冯博; 钟宏

    2016-01-01

    The flotation of diaspore and three kinds of silicate minerals, including kaolinite, illite and pyrophyllite, using an organosilicon cationic surfactant (TAS101) as collector and starch as depressant was investigated. The results show that both diaspore and aluminosilicate minerals float readily with organosilicon cationic collector TAS101 at pH values of 4 to 10. Starch has a strong depression effect for diaspore in the alkaline pH region but has little influence on the flotation of aluminosilicate minerals. It is possible to separate diaspore from aluminosilicate minerals using the organosilicon cationic collector and starch depressant. Further studies of bauxite ore flotation were also conducted, and the reverse flotation separation process was adopted. The concentrates with the mass ratio of Al2O3 to SiO2 of 9.58 and Al2O3 recovery of 83.34% are obtained from natural bauxite ore with the mass ratio of Al2O3 to SiO2 of 6.1 at pH value of 11 using the organosilicon cationic collector and starch depressant.%以有机硅阳离子表面活性剂 TAS101为捕收剂,淀粉为抑制剂,研究一水硬铝石和3种硅酸盐矿物高岭石、叶腊石和伊利石的浮选行为。结果表明,在 pH 值范围为4−10时,TAS101对一水硬铝石和3种硅酸盐矿物均有较强的捕收能力。在碱性 pH 条件下,淀粉对一水硬铝石有较强的抑制效果但不会影响硅酸盐矿物的浮选。使用淀粉作为抑制剂,TAS101作为捕收剂能够实现一水硬铝石和3种硅酸盐脉石的浮选分离。对铝土矿浮选闭路试验进行进一步研究,采用反浮选流程,使用淀粉作为抑制剂,TAS101作为捕收剂,在 pH=11条件下进行浮选,当原矿 Al2O3与 SiO2的质量比为6.1时,可以获得 Al2O3与 SiO2的质量比为9.58,Al2O3回收率为83.34%的精矿。

  20. Determinação do ponto de carga zero da bauxita da região nordeste do Pará Determination of the zero point of charge of the northeast of Pará bauxite

    Directory of Open Access Journals (Sweden)

    R. L. S. Pinto

    2012-12-01

    Full Text Available No nordeste do Pará o transporte da polpa de bauxita é através de mineroduto, sendo a viscosidade um parâmetro de controle fundamental para o bombeamento do minério. Este estudo ilustra a influência do pH na reologia da polpa por meio da determinação do ponto de carga zero (pHpcz da bauxita. Foram efetuadas análise granulométrica, microscopia eletrônica de varredura, ensaios potenciométricos testando o cloreto de amônia como eletrólito indiferente e ensaios reológicos em diferentes valores de pH. Os resultados revelaram que o cloreto de amônia pode ser utilizado como eletrólito indiferente para esse tipo de análise e que ocorre a redução da viscosidade em valores de pH distantes do ponto de carga zero.In the northeast of Pará, Brazil, the transport of bauxite pulp is through pipeline, being the viscosity a parameter which can interfere in the pumping. This study illustrates the influence of pH on pulp rheology through of determination of the zero point of charge. Were done particle size analysis, SEM, EDS, potentiometric tests testing ammonia chloride as indifferent electrolyte and rheological tests at different pH values. The results revealed that ammonia chloride can be used as indifferent electrolyte and showed a decrease in viscosity when there is far of the zero point of charge.

  1. Research on the Performance of New Collector TR in Reverse Flotation of Bauxite%铝土矿反浮选新型捕收剂TR性能研究

    Institute of Scientific and Technical Information of China (English)

    周苏阳; 孙伟; 陈攀; 李长凯; 孟祥利

    2011-01-01

    The comparative study on flotation performance between the new collector TR and the traditional collector of 1231 for reverse flotation of bauxite was made to reveal that TR can realize the reverse flotation separation of kaolinite and diaspore in a wide range of pH value without any adjustment agent added. Moreover, TR consumption can also be lowed by about 50% than 1231. With the conventional adjustment agents, TR made the Al-Si ratio of concentrate at 10. 13 and recovery of 77.14%, which are much better than by 1231 as the collector. As well, the concentrate has less foam and is easily defoaming.%通过对铝七矿反浮选新型捕收剂TR和传统捕收剂1231重要浮选性能的对比研究,揭示了TR在不加任何其他调整剂的情况下,即能在广泛的pH范围内实现高岭石和一水硬铝石的反浮选分离,且TR的使用量比1231低约50%;TR在用常规调整剂的情况下,精矿铝硅比为10.13,回收率77.14%,明显优于使用1231作捕收剂时的指标,而且精矿泡沫量很小,消泡容易.

  2. Sampling Technique of Drilling in Aquiferous Strata at a Super-Large Bauxite Deposit in Guinea%几内亚某超大型铝土矿含水地层钻探取样技术

    Institute of Scientific and Technical Information of China (English)

    李旭庆

    2012-01-01

    Geological characteristics of the drilled aquiferous strata at a super-large Guinean bauxite deposit were investigated to address the sampling problems encountered during the drilling process. The aquiferous strata of this area can be classified into three categories, based on which, two different sampling devices were developed and tested,i, e. ,spiral drilling tool with ring quard and drilling tool of anti-suction with switchable mouth downside. The site tests indicate that the spiral drilling tool with ring quard is fit for the boreholes with the first category of geological features ,while the drilling tool of anti -suction with switchable mouth downside is fit for the boreholes with the second and third category of geological features. These drilling tools have tackled difficulties in sampling of such strata in this deposit area.%为解决在几内亚某特大型铝土矿矿区部分含水区域中钻探施工中出现的取样困难的问题,通过对含水钻孔地层的地质特征分析,将其分为三种类型,并据此研制和试验了两种不同的取样钻具:护带型螺旋钻具和可启闭防抽吸钻具。经过现场实验证明,护带型螺旋钻具适宜于第一种地质特征的钻孔,可启闭防抽吸钻具适宜于第二、三类地质特征的钻孔。在施工应用中,解决了在该矿区这类地层申钻探取样问题。

  3. Caracterização e determinação do comportamento de consolidação da polpa de bauxita Characterization and consolidation behavior of the bauxite slurry

    Directory of Open Access Journals (Sweden)

    Christine Rabello Nascimento

    2010-06-01

    Full Text Available A sedimentação e a consolidação do minério decorrente de uma parada no processo de bombeamento de polpas em dutos podem ocasionar dificuldades numa nova partida operacional. Nesse contexto, a coesão do material sedimentado tem relevância e está relacionada a determinados fatores, tais como a composição dos minerais na polpa, as características dos minerais e a distribuição de tamanhos das partículas. Esse trabalho tem por objetivo avaliar, mediante medidas reológicas, a variação da coesão das partículas sedimentadas de uma polpa de bauxita em função do tempo. O minério de bauxita utilizado foi devidamente caracterizado, sendo composto, predominantemente, por gibbsita, hematita e caulinita e contendo um elevado teor de finos - cerca de 45% das partículas tem tamanho inferior a 38 µm. Pelas curvas de tensão versus tempo, foi observado que antes de 4 horas, praticamente, todo material já havia se sedimentado. Após 24 horas de assentamento, ocorreu um ligeiro acréscimo da tensão na ruptura do sedimento.Ore particle settling and consolidation due a stop of slurry pumping may cause troubles in the restarting process. So, the cohesion of the sediment is an important issue, which is related to the mineral composition and the size's distribution of the particles in the slurry. The objective of this study is to evaluate by rheological measurements the changes in the cohesion of bauxite settled particles in function of time. The ore sample is comprised mainly of gibbsite, hematite and kaolinite, whose amount of fine grounded material is very high - about 45% of the particles are smaller than 38 µm. The settling practically finished before four hours and an increment of the tension in the rupture of the sediment was observed after 24 hours of rest.

  4. Orientation Screening and Desilicon Abilities of Silicon-releasing Microorganisms from Bauxite%铝土矿脱硅微生物的定向筛选及脱硅性能

    Institute of Scientific and Technical Information of China (English)

    钟婵娟; 肖国光; 曹飞; 孙德四

    2013-01-01

    from minerals than other strains in the culture media, and can form obviously bacteria-mineral complexes. Strains P04 and P17 belonged to Bacillus circullans in comparison of their characteristics with those of the modal strain. Strains P04, P17 and P19 can decompose silicate minerals in bauxite and release silicon from them. The maximum concentrations of SiO2 of supernatants in the media are 49.69, 32.78, 37.98 mg/L, respectively after bioleaching for 12 days, and the ratios of Al2O3 to SiO2(A/S) of bauxite increased from 5.17 to 10.99, 7.61,8.90 respectively. It is concluded that the silicate bacterium with higher abilities of producing acids and polysaccharides and forming obviously bacteria-mineral complexes has higher desilicon abilitiy.

  5. Characterization of the bauxite mining of the Poços de Caldas alkaline massif and its socio-environmental impacts Caracterização da mineração de bauxita no maciço alcalino de Poços de Caldas e seus impactos socioambientais

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    Dalmo Arantes de Barros

    2012-03-01

    Full Text Available The intensive use of mineral resources brings along significant changes to the environment. The mining sector is essential for world economics, as long as it is operated on a basis that is technically coherent, socially fair and environmentally correct. This study aimed to characterize the bauxite mining of the Poços de Caldas plateau, MG, investigating its respective socio-environmental impacts. Through the overview presented, one can conclude that in most situations, the bauxite miningat the Poços de Caldas plateau mitigates its negative social and environmental impacts in a satisfactory manner in addition to generating positive social impacts; and the restoration methods of the mining-disturbed ecosystems have been continually improved and should be replicated by small-and-medium-sized companies.O uso intensivo dos recursos minerais traz consigo alterações significativas no meio ambiente. O setor minerário é fundamental para a economia mundial, desde que operado em bases tecnicamente coerentes, socialmente justas e ambientalmente corretas. O presente trabalho teve como objetivo caracterizar a mineração de bauxita no planalto de Poços de Caldas - MG, analisando seus respectivos impactos socioambientais. Por meio do panorama apresentado, concluiu-se que a mineração de bauxita realizada no planalto de Poços de Caldas, na maioria das situações, mitiga seus respectivos impactos socioambientais negativos de forma satisfatória, além de gerar impactos sociais positivos; os métodos de restauração dos ecossistemas perturbados pela mineração vêm sendo aperfeiçoados continuamente e há necessidade que sejam reproduzidos nos empreendimentos de pequeno e médio porte.

  6. Fungos micorrízicos arbusculares em estéril revegetado com Acacia mangium, após mineração de bauxita Colonization of arbuscular mycorrhizae fungi in substrate, after bauxite mining, vegetated with Acacia mangium

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    Ana Lucy Caproni

    2005-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a composição das comunidades de FMAs em áreas revegetadas com Acacia mangium após a mineração de bauxita na região de Porto Trombetas, PA. Foram coletadas amostras de solo compostas nos períodos seco e chuvoso, em áreas revegetadas com Acacia mangium, que receberam inóculos de Glomus clarum e Gigaspora margarita, com 1 e 5 anos de idade. Os solos foram revegetados sem a reposição do horizonte superficial orgânico. Os esporos dos fungos micorrízicos arbusculares (FMAs foram extraídos e identificados através de suas características morfológicas. Analisou-se a densidade de esporos e de espécies em cada amostra, a densidade relativa e a freqüência de ocorrência de cada espécie por período de amostragem, além do índice de abundância e freqüência (IAF. Sob o plantio de mudas de A. mangium, a densidade de esporos de FMAs foi elevada e aumentou com a idade, enquanto o número de espécies não variou. Glomus clarum produz alta densidade de esporos na fase inicial do plantio e declina com o tempo, e Gigaspora margarita não esporula nas condições edafoclimáticas locais. A maioria das espécies de FMA não apresenta o mesmo padrão de esporulação nos períodos seco e chuvoso.The objective of this work was to monitor the establishment of Gigaspora margarita and Glomus clarum in reclaimed areas after the bauxite mining in Porto Trombetas, PA, Brazil. Soil samples were collected during the dry and rainy periods under one and five-year-old Acacia mangium trees grown from seedlings that had been inoculated with Glomus clarum and Gigaspora margarita. The exposed subsoil was managed without replacing the organic soil layer. FMA spores were extracted and identified through their morphologic characteristics. Spore density and frequency of each species were determined in each sampling The index of abundance and frequency (IAF were estimated for all samples. Under A. mangium the arbuscular

  7. Ocorrência de Fungos Micorrízicos Arbusculares em resíduo da mineração de bauxita revegetado com espécies arbóreas Arbuscular mycorrhizal fungi occurrence in bauxite mining residue planted to tree species

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    Ana Lucy Caproni

    2007-03-01

    Full Text Available Avaliou-se a ocorrência de fungos micorrízicos arbusculares (FMAs em tanques contendo resíduo da mineração de bauxita cultivados com espécies arbóreas inoculadas com Glomus clarum Nicol. & Schenck e Gigaspora margarita Becker & Hall na fase de viveiro. Acacia holosericea A. Cunn. ex G. Don juntamente com Sesbania virgata (Cav. Pers. ou uma mistura de várias espécies foram transplantadas em tanques contendo resíduo de bauxita. Coletaram-se amostras de resíduos em agosto/1998 (estação seca e abril/1999 (estação chuvosa, extraíram e identificaram-se os esporos de FMAs. Determinaram-se a densidade dos esporos de FMAs, a densidade relativa, a freqüência de ocorrência de cada espécie por período de amostragem e o índice de abundância e freqüência (IAF. A densidade dos esporos e a diversidade das espécies de FMAs foram baixas sob ambas as coberturas. Um maior número de esporos de Glomus clarum, e alto IAF, foram detectados no substrato cultivado com Acacia holosericea e Sesbania virgata na época seca. Isto também ocorreu em ambas as áreas na época chuvosa. Não foram encontrados esporos de Gigaspora margarita em ambas as áreas, nas duas épocas. Independentemente da inoculação, verificaram-se esporos de Archeospora leptoticha (Schenck & Smith Morton & Redecker, Entrophospora colombiana Spain & Schenck, Acaulospora mellea Spain & Schenck e Glomus macrocarpum Tulasne & Tulasne em abundância.The establishment of arbuscular mycorrhizal fungi (AMF was evaluated in two areas of bauxite mining residue planted to tree species inoculated with Glomus clarum Nicol. & Schenck and Gigaspora margarita Becker & Hall in the nursery phase. Acacia holosericea A. Cunn. ex G. Don and Sesbania virgata (Cav. Pers. and a mixture of several tree species were transplanted to deposits of containing bauxite mining residue. In August, 1998 (dry season and April, 1999 (rainy season residue samples were collected and AMF spores extracted and

  8. Aplicação da espectroscopia de reflectância difusa na quantificação dos constituintes de bauxita e de minério de ferro Application of diffuse reflectance spectroscopy in the quantification of the constituents of bauxite and iron ore

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    Ana Cláudia Carioca

    2011-06-01

    Full Text Available Esse trabalho teve como objetivo a aplicação da espectrofotometria de reflectância difusa no desenvolvimento de uma metodologia para a identificação e quantificação de minerais presentes na bauxita e nos minérios de ferro. Amostras selecionadas contendo uma variabilidade mineral foram coletadas na região do Quadrilátero Ferrífero e na região de Carajás e os teores dos diferentes minerais foram estimados a partir de uma combinação de métodos convencionais, tais como análise química, difração de raios X, espectroscopia Mössbauer, susceptibilidade magnética e microscopia ótica. Os dados espectrais obtidos na reflectância difusa nas regiões do visível e do infravermelho juntamente com a composição mineralógica foram analisados por algoritmos quimiométricos. A análise de correlação mineralógica apresentou resultados satisfatórios, tendo parâmetros estatísticos médios próximos de R² = 0,93, para bauxita, e de R² = 0,87, para minério de ferro. Por exemplo, para a goethita, presente no minério de ferro, o R² = 0,96; com erro-padrão médio de calibração (RMSEC = 3,6%, e, para a hematita, presente também no minério de ferro, o R² = 0,90 com o RMSEC = 7,3%. Os resultados sugerem que a espectroscopia de reflectância difusa é uma ferramenta promissora para a quantificação simultânea dos minerais presentes em bauxita e minério de ferro.This paper describes the application of diffuse reflectance spectroscopy in the development of a methodology for the identification and quantification of minerals in bauxite and iron ores. Selected samples containing a mineral variability were collected from the Iron Quadrangle (Minas Gerais mines and from the region of Carajás (Pará. The different mineral concentrations were estimated from a combination of conventional methods such as chemical analysis, Mössbauer spectroscopy, Xray diffractions, magnetic susceptibility and optical microscopy. Diffuse reflectance

  9. Determination of Fe_2O_3,TiO_2 and SiO_2 in bauxite by inductivelycoupled plasma-atomic emission spectrometry%ICP-AES法测定矾土中Fe2O3、TiO2和SiO2

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    郝荷芳; 苑利

    2011-01-01

    采用四硼酸锂熔融试样,电感耦合等离子体原子发射光谱法(ICP-AES法)测定矾土中Fe2 O3、TiO2和SiO2。通过对熔样方法选择、铝基体以及背景的研究,确定了分析条件。结果表明,该法具有良好的精密度和准确性,回收率在94%~108%。%A method based on inductively coupled plasma-atomic emission spectrometry(ICP-AES) was established for the determination of Fe2O3,TiO2 and SiO2 in bauxite.The sample was melted into lithium tetraborate.The analysis conditions were obtained by studying the melted methods,Al matrix and background.The recommended method showed satisfying precision and accuracy as well.The recovery percents detected by standard addition method were in range of 94%~108%.

  10. Development characteristics of the Xujiahe Formation bauxite in the northeast of Sichuan basin and its response to structural movement%川东北须家河组中铝土矿的发育特征及其对构造活动的响应

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    林良彪; 陈彦庆; 淡永; 钟怡江; 徐胜林

    2011-01-01

    四川盆地晚三叠世诺里期与瑞替期(须三段与须四段)之间是否存在安县运动以及该运动的影响范围有多大,一直存在分歧.本次研究首次在川东北须家河组三段上部(即须三段与须四段之间)发现了沉积型铝土矿层的存在.通过镜下观察,地化、电子探针、扫描电镜以及X射线等分析,认为:铝土矿以豆粒状产出状态为主,具豆粒结构、块状构造,豆粒间填隙物以灰、灰黑色胶状、蠕虫状高岭石为主,其次为褐铁矿染的干净明亮的放射状、球粒状菱铁矿,偶见闪锌矿;豆状铝土矿主要呈微-细晶粒状、鳞片状及絮状,其中,晶粒状、鳞片状铝土矿单偏光镜下无色、正中突起,解理明显,正交偏光镜下呈二级兰干涉色,结合X射线分析,将其定名为一水硬铝石,其A12O3含量为85.022%~87.763%;测井曲线上,自然伽玛异常增大,当密度接近于3g·cm-3时,中子孔隙度值出现相对高值.表明须三段与须四段之间存在一次时间较长的沉积间断,佐证了安县运动的存在,同时也表明安县运动影响范围已远远超出了龙门山前缘地区,进入了盆地内部,甚至影响了整个四川盆地.%Arguments on whether Anxian tectonic movement existed or not and on how widely its influence might range during Norian Period and Rhaetian Period of Late Triassic (between the 3rd and 4th member of Xujiahe Formation) in Sichuan basin have existed for long time. This study, for the first time, found the sedimentary bauxite layer on the top of the 3 rd member of Xujiahe Formation (between the 3rd and 4th member of Xujiahe Formation) in the northeast of Sichuan basin. On the basis of thin section, geochemical characteristics, electronic probe, SEM and X-ray etc. , the bauxite mainly occurred as pisolitic with both pisolitic structure and block structure. The main components of interstitial matter among pisolites are tremelloses and vermicular kaolinites. Also, clean

  11. Carbono orgânico, nitrogênio total, biomassa e atividade microbiana do solo em duas cronosseqüências de reabilitação após a mineração de bauxita Soil organic carbon, total nitrogen, microbial biomass and activity in two rehabilitation chronosequences after bauxite mining

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    Marco Aurélio Carbone Carneiro

    2008-04-01

    reas de referência a partir do primeiro ano, enquanto para o CO e o Nt estes só foram alcançados de modo consistente em períodos mais longos de reabilitação (18 anos. O coeficiente metabólico (qCO2 foi indicativo do estresse provocado pela mineração, mas não diferenciou os diferentes tempos de reabilitação. Os resultados deste estudo mostram que os atributos essenciais ao funcionamento adequado do solo são recuperáveis pela revegetação.Mining is a human activity with a harsh impact on ecosystems. The degradation degree depends on the intensity of soil impact, exploited soil volume and amount of mine spoil. Soil microbial activities are responsible for key functions in ecosystems and can indicate the degree of rehabilitation of mined areas. The purpose of this study was to evaluate the impact of bauxite mining in two chronosequences with different rehabilitation strategies (revegetation on the following soil attributes: organic carbon (C org, total nitrogen (Nt, microbial biomass and respiration, and enzymatic activities. The study was developed in mining areas owned by Alcoa S/A in two different environments: (a areas originally covered by a tropical prairie vegetation called "campo", at elevations up to 1,000 masl, and (b in hilly areas, on the plateau top, including remnants of the native vegetation cover, represented by a subtropical decidous forest, at elevations about 1.600 masl, called "serra". Rehabilitation differed depending on strategies and time, varying from recent mining to 19 years of rehabilitation. Composite samples were collected in eight "campo" and nine "serra" areas, in two layers (0-10 and 10-20 cm in the winter as well as in the summer, in three replicates. Bauxite mining caused a negative impact on org C, Nt and microbial biomass (C, N and P. The values of these attributes were reduced by up to 99 % in comparison with those in reference areas (native vegetation. In both "campo" and "serra", the C org, Nt, microbial biomass and

  12. Eficiência de fungos micorrízicos arbusculares isolados de solos de áreas de mineração de bauxita no crescimento inicial de espécies nativas Efficiency of arbuscular mycorrhizal fungi isolated from bauxite mine spoils on seedling growth of native woody species

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    José Geraldo Donizetti Santos

    2008-02-01

    sp. não foi eficiente. Para o açoita-cavalo, os dois isolados de Glomus sp. estudados foram ineficientes. Nenhum dos FMAs isolados da área de mineração de bauxita promoveu crescimento superior ao obtido com o tratamento-referência com G. etunicatum. No entanto, os isolados do campo Gigaspora sp., Paraglomus occultum e Acaulospora spinosa foram tão eficientes quanto G. etunicatum em promover crescimento das quatro espécies vegetais. Os resultados indicam que mesmo áreas tão degradadas como aquelas submetidas à mineração de bauxita podem conter populações de FMA eficientes, que podem contribuir para reabilitação da área.Arbuscular mycorrhizal fungi (AMF establishing efficient symbiosis with plants play an important role on ecosystem sustainability and can be useful for revegetation of degraded lands. Symbiotic efficiency is related to AMF genotypes and plant species, as well as to environmental conditions that may affect the expression of symbiotic relationships. Thus, the first step to an efficient AMF symbiosis management is to study fungal variability regarding the efficiency with different host species. In this study root colonization and efficiency of several AMF isolates, obtained from bauxite minespoil areas from two distinct environments ("serra" and "campo", were evaluated for seedling growth of pioneer species [aroeira (Schinus terebenthifolius and trema (Trema micrantha], and secondary species [açoita-cavalo (Luehea grandiflora and sesbânia (Sesbania virgata], in a low fertility soil. The experiment was carried out under greenhouse conditions, for 120 days. Each plant species, was treated with ten AMF inoculation types (AMF isolates or their mixtures: Acaulospora longula, Paraglomus occultum, Glomus sp., Gigaspora sp., Acaulospora spinosa, and the mixture of all "campo" species; Acaulospora scrobiculata, Paraglomus occultum, Glomus sp. and the mixture of all "serra" species. For a comparison two additional treatments were included: one

  13. Capacidade infectiva de fungos micorrízicos arbusculares em áreas reflorestadas após mineração de bauxita no Pará Infective capacity of arbuscular mycorrhizal fungi in reforested areas after bauxite mining in the Pará State, Brazil

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    Ana Lucy Caproni

    2003-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a capacidade infectiva das espécies de fungos micorrízicos arbusculares (FMA e relacionála com o número mais provável (NMP de propágulos infectivos e número de esporos extraídos diretamente do campo. Amostras de solo foram coletadas em áreas degradadas pela mineração de bauxita com cobertura de 2, 6, 12 e 16 anos após revegetação e em uma área de floresta primária, em Porto Trombetas, PA. Os esporos de FMA foram extraídos e identificados taxonomicamente por suas características morfológicas. A maioria das espécies apresentou comportamento diferente nas áreas em estudo. Glomus macrocarpum foi a que apresentou infectividade mais rápida e alto potencial infectivo, nos solos das cinco áreas estudadas. Esta espécie também apresentou alto NMP de propágulos e alto número de esporos em todas as áreas estudadas. A capacidade infectiva das espécies não está relacionada com a densidade de propágulos. As espécies de FMA possuem diferentes graus de tolerância às condições de solo e se comportaram de maneira diferente de acordo com a idade da revegetação.The objective of this work was to evaluate the infective capacity of arbuscular mycorrhizal fungi (AMF species and relate it to the most probable number (MPN of infective propagules and number of spores extracted directly from the field. Soil samples were taken from areas degraded by bauxite mining, 2, 6, 12 and 16 years after reforestation and from an area of primary forest. The spores were extracted and morphologically identified. Most of the species had different behavior for the areas of study. Glomus macrocarpum showed fast infectivity in soils with high infective potential, independently of the soil origin. This species also showed high MPN values of infective propagules and high number of spores in all areas. The infective capacity of the species did not relate to the density of infective propagules. AMF species have different

  14. Characteristics of bryophytes with gemmae from a karst bauxite mine:A case study of Lindai mine in Zhanj ie town,Qingzhen,Guizhou%贵州喀斯特铝土矿具芽胞苔藓种类特征--以贵州省清镇市林歹铝土矿区为例

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    殷声锋; 王智慧; 张朝晖

    2014-01-01

    对贵州省清镇市站街镇林歹铝土矿第二矿区的油菜种植区、矿土上部树林区、废石堆积区、矿土堆积恢复区4类环境进行苔藓植物采集,并对具芽胞苔藓种类进行统计分析,结果表明:(1)经鉴定发现苔藓植物10科22属37种,优势种(频度大于10%)为日本大丛藓Molendoajaponica Broth.(18.72%)和银叶真藓Bryumargenteum Hedw.(11.06%);(2)发现8种具芽胞苔藓,占总种数的21.62%,隶属于丛藓科 Pottiaceae 和真藓科 Bryaceae,其中日本大丛藓和芽胞银藓Anomobryumgemmigerum Broth.为常见具芽胞苔藓;(3)油菜种植区中具芽胞苔藓种类最多(6种),但出现频度不高,非该类环境中的优势种,日本大丛藓在 4类环境中均有发现;(4)在 4类环境中,相对恶劣条件下具芽胞苔藓出现的几率更大;(5)瘤根真藓 Bryum bornholmense Winkelm.& Ruthe.和毛状真藓 Bryum apiculatum Schwagr.的芽胞长于假根上,其余种类芽胞均见于叶腋处,呈扫帚状,芽胞形态上呈现多样性,有球形、棒形、棒槌形、芽形、纺锤状和火炬状。%Bryophytes were collected from four different habitats in Lindai #2 bauxite mine in Zhanjie town, Qingzhen City,Guizhou Province,and the bryophytes with gemmae were statistically analyzed.The result showed that,(1)120 samples were collected from sampling sites,and 10 families,22 genera and 37 species were identified.The dominant species (frequency >10%)were Molendoa japonica Broth (18.72%)and Bryumargenteum Hedw.(11.06%).(2)8 kinds of bryophytes had gemmae,which were attached to Potti-aceae and Bryaceae,accounting for 21.62% of the total.Of these,Molendoajaponica Broth and Bryumar-genteum Hedw.were common bryophytes with gemmae,found in 44 samples and 16 samples respectively. (3)The largest quantities of bryophytes with gemmae were found in areas where rape was cultivated (6 spe-cies);however,frequency was low and there was no dominant species.Additionally,Molendoa japonica Broth

  15. LEGAL ENVIRONMENTAL ASPECTS AND ITS INFLUENCE OVER THE COSTS OF BAUXITE MINING: THE EXAMPLE OF ALCOA, POÇOS DE CALDAS (MG, BRAZIL = ASPECTOS LEGAIS AMBIENTAIS E SUA INFLUÊNCIA NOS CUSTOS DA ATIVIDADE MINERÁRIA DE BAUXITA: O EXEMPLO DA ALCOA, POÇOS DE CALDAS (MG, BRASIL

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    Ana Carolina Santos Surgik

    2005-01-01

    Full Text Available The mining activity is regimented mainly in two levels. The regulatory stands are distributed in federal and provincial levels. In this case, provincial environmental law (of Minas Gerais is more restrictive, shifting mining activity costs through the statement of obligations related to environmental protection. According to the Mining Department of Companhia Geral de Minas (CGM/Alcoa Alumínio S/A, since 1979 it has been performed the rehabilitation of mined areas in Poços de Caldas. Despite this fact, CGM/Alcoa Alumínio S/A previous estimative about the budget, technical support and other material resources did not distinguish the financial needs related tothe rehabilitation of mined areas. In this context it was performed a research between 2000 and 2001, aiming to subsidize the budgetary planning on financial resources allocation to the rehabilitation of mined areas, in particular: a to describe the legal context related to the bauxite mining and; b to estimate the costs of mined areasrehabilitation. In the conclusion, it was identified that the previous costs estimative of CGM/Alcoa Alumínio S/A is under the real level. Possibly, it occurred due to the lack of environmental activities accounting documentation. = A atividade de mineração é regulamentada em níveis. Além dos dispositivos legais em nível federal, a legislação ambiental estadual de Minas Gerais é maisrestritiva e exigente, onerando a atividade através do estabelecimento de obrigações que visam à proteção ambiental. De acordo com o Departamento de Mineração da Companhia Geral de Minas (CGM/Alcoa Alumínio S.A., desde 1979 tem sido realizada reabilitação de áreas mineradas em Poços de Caldas. No entanto, estimativas anteriores da empresa sobre recursos financeiros, humanos e demais tipos de insumos não distinguiam os gastos com a reabilitação de áreas degradadas. Por isso, foi realizada uma pesquisa entre 2000 e 2001, com o objetivo de auxiliar o

  16. BEHAVIOR OF BRACATINGA (Mimosa scabrella AND SESBANIA (Sesbania sesban IN DEGRADED AREAS BY DISPOSAL RESIDUE FROM BAUXITE PROCESSING = COMPORTAMENTO DE BRACATINGA (Mimosa scabrella E SESBÂNIA (Sesbania sesban EM ÁREAS DEGRADADAS PELA DISPOSIÇÃO DE RESÍDUOS PROVENIENTES DO PROCESSAMENTO DA BAUXITA

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    Maria Madalena Ferreira Chaves

    2002-01-01

    Full Text Available Topsoil return in mining activities is a common and extensively usedprocedure. But, for some companies this operation may represent around 70-80% of all costs to reclaim degraded areas. This study evaluated the contribution of two leguminous species to improve the initial colonization of a damaged land by bauxite residue disposalafter processing in Poços de Caldas-MG. Plants of Mimosa scabrella ("bracatinga" e Sesbania sesban ("sesban" were planted in January of 1999. Plants were spaced in 2 x 1,5 m and each plot received 25 plants. The statistical alignment was of randomized blocks in the factorial proportion (3 x 4 x 2, with three of the gypsum dosage, four for the thickness layer of superficial soil laid over the residue and two species. Four repetitions were done, with five plants each. Measurements of total height were made and mortality rates were calculated. The results showed that the residue presented similarproperties to a sodium-salt soil, with high pH value and electric conductivity. It was also observed that the gypsum doses, the layer thickness, and the species has significant influences in the average values registered for the variables studied. An inversely proportional relation was observed between the mortality rate and the variable gypsum dosage and layer thickness of the utilized soil, in which the increase of gypsum dosage and layer width corresponded to decreased mortality rate for the species. For all the variables studied, "sesban" showed better performance than "bracatinga". = O retorno de horizontes superficiais do solo para áreas degradadas poratividade de disposição de resíduos tem sido prática rotineira e largamente utilizada. Para algumas empresas, no entanto, essa operação tem representado cerca de 70 a 80% dos custos finais de recuperação de áreas mineradas. O presente trabalho teve como objetivoavaliar a contribuição de duas espécies leguminosas na colonização inicial de um solo degradado pela

  17. Respostas de Acacia mangium Willd e Sclerolobium paniculatum Vogel a fungos micorrízicos arbusculares nativos provenientes de áreas degradadas pela mineração de bauxita na Amazônia Responses of Acacia mangium Willd and Sclerolobium paniculatum Vogel to native arbuscular mycorrhizal fungi from remaining areas of bauxite mining in Amazon

    Directory of Open Access Journals (Sweden)

    Ney Freitas Marinho

    2004-03-01

    Full Text Available A resposta de Acacia mangium Willd (mangium e Sclerolobium paniculatum Vogel (tachi à inoculação de fungos micorrízicos arbusculares (FMA, oriundos de áreas em recuperação após a extração de bauxita, foi avaliada em experimento com delineamento inteiramente casualizado, com 14 tratamentos (duas espécies leguminosas e sete tipos de solo e três repetições. Avaliou-se o número de esporos no solo, a colonização micorrízica, a matéria seca total, o P acumulado, a dependência micorrízica das mudas, e a abundância e a freqüência de espécies. O número de propágulos infectivos (NPI foi estudado em delineamento em blocos casualizados, com oito diluições de solo inóculo, cinco repetições e uma planta isca (Brachiaria decumbens Stapf. Utilizou-se substrato da mistura de um Planossolo mais areia lavada e fosfato de rocha araxá (0,60 g/kg. O número de esporos aumentou em função do tempo de cobertura das leguminosas. A colonização micorrízica foi mais intensa no tachi. Os valores de matéria seca dessa espécie foram inferiores aos de mangium, que por sua vez extraiu em torno de seis vezes mais P do substrato. Em geral, mangium, ao contrário do tachi, foi facultativa à presença dos FMA, sugerindo sua utilização na recuperação de áreas degradadas sem inoculação prévia. Dentre as 39 espécies de FMA identificadas, Glomus macrocarpum Tul. & Tul. apresentou maior índice de abundância e freqüência (IAF e maior NPI, destacando-se entre as espécies pioneiras, ao passo que outras apareceram apenas em estádios sucessionais mais avançados das áreas em recuperação.The responses of Acacia mangium Willd (mangium and Sclerolobium paniculatum Vogel (tachi to arbuscular mycorrhizal fungi (AMF inoculation collected from areas under reclamation after bauxite mining, was evaluated in an completely randomized design distributed in 14 treatments (two legume, species and seven soil types, with three replicates. Evaluated

  18. Eficiência e diversidade fenotípica de bactérias diazotróficas que nodulam caupi [Vigna unguiculata (L. Walp] e feijoeiro (Phaseolus vulgaris L. em solos de mineração de bauxita em reabilitação Efficiency and phenotypic diversity among nitrogen-fixing bacteria that nodulate cowpea [Vigna unguiculata (L. Walp] and common bean (Phaseolus vulgaris L. in bauxite-mined soils under rehabilitation

    Directory of Open Access Journals (Sweden)

    Rogério Melloni

    2006-04-01

    as leguminosae-nodulating, nitrogen fixing bacteria (LNNFB are essential because they are involved in nutrient cycling processes and, therefore, to the sustainability of these areas. Aiming to evaluate the efficiency and phenotypic diversity of LNNFB, soil samples were collected from different bauxite mining areas with distinct rehabilitation strategies and chronosequences in the summer of 1999. With these materials we installed experiments using bean and cowpea as trap species under greenhouse conditions. At flowering, the plants were harvested and the shoot dry weight, nodule number, nodule weight, nitrogenase activity, and phenotypic diversity of LNNFB isolates evaluated by culture characterization on 79 medium. There was no influence of the different rehabilitation strategies on the efficiency of LNNFB populations in promoting bean growth. After phenotypic characterization of 328 bean and 420 cowpea LNNFB isolates, it was found that the latter is better suited than bean for studies evaluating LNNFB nodulation, efficiency and diversity in these areas. Mining strongly decreases the LNNFB diversity, while there is little effect on nodulation of trap plants. Rehabilitation strategies contribute to increase LNNFB diversity in bauxite mined soils, mainly when legume species were introduced.

  19. Calculation of infiltration coefficient of precipitation based on long-term observation data of spring water:a case study of ore deposit bearing karst water in Dazhuyuan bauxite mining area in Wuchuan%利用泉水长观资料计算降水入渗系数--以务川自治县大竹园铝土矿区岩溶充水矿床为例

    Institute of Scientific and Technical Information of China (English)

    黄作明

    2016-01-01

    Dazhuyuan bauxite mining area in Wuchuan Autonomous County is a positive landform of mountain platform syncline.The deposits are ore deposits filled with karst water with deep depth of water level.At-mospheric precipitation is the only recharge source of the ground water.In the north,east and west there are escarpments or steep slopes.Metallogenic series and aquiclude occur on the foot of escarpments.A surface watershed is distributed along the upper edge of escarpments with an opening to the west,and forms a com-plete hydrogeological unit.The ground water in the syncline runs from east to west and collects at Meigudong for discharge.The bauxite layer directly touches the thin and discontinuous roof of shale of Liangshan For-mation (P2 l ),and the strong aquifer above of limestone of Maokouqixia Formation (P2m +q )is in direct contact with ore bed,while the karst pipelines are well developed.Therefore,it is more appropriate to apply the water balance method in terms of calculating the water inflow in the mine.The observational data of spring water is used to calculate infiltration coefficient,so as to predict the water inflow in the mine and to evaluate the water yield property of the aquifer.%务川自治县大竹园铝土矿区为高山台地向斜正地形,岩溶充水矿床,水位埋藏较深,大气降水是地下水的唯一补给源,北、东、西为陡崖或陡坡,崖脚为矿系和隔水层,沿陡崖上部边缘分布一条开口向西的地表分水岭,形成完整的水文地质单元,地下水在向斜内由东向西汇集于梅古洞排泄。铝土矿层直接顶板梁山组(P2 l )页岩,厚度小,不连续,其上部茅口栖霞组(P2 m +q )灰岩强含水层与矿层直接接触,并且岩溶管道发育。因此,计算矿坑涌水量的方法用水均衡法较为恰当,即利用泉水观测资料计算入渗系数,从而达到预测矿坑涌水量、评价含水层富水性的目的。

  20. Effect of hydroxamic acid polymers on reverse flotation of bauxite

    Institute of Scientific and Technical Information of China (English)

    李海普; 胡岳华; 王淀佐; 徐兢

    2004-01-01

    The effect of hydroxamic acid starch (HAS) and hydroxamic acid polyacrylamide (HPAM) on the flotation of diaspore and kaolinite was investigated by flotation test. It is found that HAS depresses diaspore but activates kaolinite in acidic pulp,while HPAM activates both diaspore and kaolinite in the pH range of 2.0 - 10.5. The measurement of zeta potential shows that both HAS and HPAM can increase zeta potential of negatively charged diaspore, which indicates the existence of chemical bonding or hydrogen bonding between the reagents and diaspore.By covering the collector dodecyl amine(DDA) on diaspore surface, HAS increases the hydrophilicity of minerals and depresses the flotation of diaspore,however HPAM activates the flotation of diaspore by increasing the adsorption of DDA on diaspore surface.

  1. China Bauxite Reserves Lasting for Less Than 10 Years

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>On the Forum of Sustainable Development of Aluminum Industry 2007 Bose,which was held in Bose,Guangxi at the beginning of Novem- ber,experts pointed out that with the invest- ment increasing in the aluminum industry and the expansion of scale in aluminum mine ex-

  2. Caracterização fenotípica e diversidade de bactérias diazotróficas associativas isoladas de solos em reabilitação após a mineração de bauxita Phenotypic characterization and diversity of diazotrophic associative bacteria isolated from soils rehabilitated after bauxite mining

    Directory of Open Access Journals (Sweden)

    R. S. A. Nóbrega

    2004-04-01

    eles.Grass species, which are frequently used for rehabilitation of degraded areas, can establish root associations with nitrogen fixing bacteria thus contributing to the ecosystem's sustainability. On the other hand, microbial diversity plays an important role in the resilience of biological processes, including N2 fixation. This study aimed at the phenotypic characterization of 72 diazotrophic Gram-negative bacteria. Samples were isolated from areas under different rehabilitation strategies after bauxite mining in Poços de Caldas, Minas Gerais, Brazil, and inoculated in NFb, Fam, and JNFb media. Type and reference strains of Herbaspirillum, Azospirillum and Burkholderia species were used for comparison as they are able to grow in such media. The similarity dendrogram based on seven cultural characteristics of the isolates in GNA medium presented a great diversity, as 50 groups were formed with 81 % similarity. NaCl tolerance in the potato/sucrose/acid malic medium varied from 0 to 50 g L-1 and allowed a separation of isolates and type strains into five groups. Cell diameters varied from 0.61 to 1.21 µm, and 13 isolates were not similar to the type strains. Fifteen groups with 75 % similarity were formed based on total proteins patterns obtained by polyacrylamide gel electrophoresis (SDS-PAGE. Neither was there any relationship among groups based on the different characteristics, nor between these and the areas of bacteria isolation. Fam and JNFb media detected the target species as well as other unidentified ones. The high phenotypic dissimilarity among isolates and type strains, mainly regarding total protein eletrophoresis profiles suggests that new species could be present within these populations.

  3. Densidade e diversidade fenotípica de bactérias diazotróficas endofíticas em solos de mineração de bauxita, em reabilitação Density and phenotypic diversity of endophytic nitrogen fixing bacteria in soils under rehabilitation after bauxite mining

    Directory of Open Access Journals (Sweden)

    R. Melloni

    2004-02-01

    diversidade fenotípica no ambiente estudado.Diazotrophic endophytic bacteria enhance plant growth through biological nitrogen fixation and production and release of plant growth regulating substances, which facilitate the revegetation of areas degraded by human activities. However, little is known about populations of such bacteria in soils or plants of mining areas. Aiming to study the effects of different vegetation types and rehabilitation periods on some endophytic diazotrophic bacteria species, soil samples were collected under two environmental conditions ("Campo" and "Serra" in bauxite mined areas undergoing different rehabilitation processes. Population densities were evaluated by the most probable number method in media (NFb, JNFb, and Fam for Azospirillum brasilense and A. lipoferum, Herbaspirillum spp. and A. amazonense, respectively and ranged from 0 to 2.0 x 10(4 bacteria g-1 soil. The vegetation types affected the diazotrophic populations. Highest densities were found in mined soils revegetated with the grass species brachiaria (Brachiaria decumbens, rye grass (Lolium multiflorum and capim-gordura (Melinis minutiflora. However, these densities are considered low compared to those found in agricultural soils. No relationship was found between the rehabilitation time and population density. Thirty-six cultural phenotypes were found on potato medium among 72 isolates out of all three culture media. At a similarity of at least 63 %, these isolates formed seven great groups, five of which (comprising 62.5 % of the total isolates contained the type strains of Burkholderia brasilensis, Herbaspirillum seropedicae, and Azospirillum spp. (A. brasilense, A. amazonense, A. lipoferum, A. irakense. In spite of its low density, this group of bacteria presented a high phenotypic diversity in the studied environment.

  4. Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF

  5. CPI Seeking to Break International Monopoly over Bauxite Mine Resources through an Overseas Arrangement

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>China Power Investment Group(CPI),one of the five power generation groups in China signed an Aluminum Development Project Concession Agreement with the government of Guinea on Sep.6,symbolizing a substantial step in developing its Guinean aluminum base with

  6. Effect of Water Addition on Rheological Behaviour of Bauxite Based Low-cement Castables

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xianxin; Michel RIGANU; ZHOU Ningsheng

    2004-01-01

    Water addition has direct impact on castables and needs to be under control placement and properties, In this work, two rheological properties, flow resistance and torque viscosity, have been measured against time, with different water addition in the same bauxile-based LC Castable mix. The flow resistance indicates the mobility,whereas the torque viscosity dictates the stability of a castable during installation. It has been observed that with 6.0 wt % water addition, such a mix possesses good vibration castable characteristics; with 6.5 wt% , it shows good self-flow castable characteristics; and with 7. 0wt %, it can be a good pumpable castable, in every case with comparable mechanical properties. While with 7.5wt % water addition, the properties of such castable aredefinitively impaired.

  7. Henan Cancelled Regional Restriction on Bauxite Resources Allocation for Aluminum Oxide Enterprises

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Henan Province People’s Government recently printed and issued notice to announce the decision to adjust Henan’s key mineral resources allocation policy.Why should the mineral resources allocation policy need adjustment,what’s new about the new policy?

  8. 40 CFR 421.11 - Specialized definitions.

    Science.gov (United States)

    2010-07-01

    ... STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Bauxite Refining Subcategory § 421.11... subpart. (b) The term bauxite shall mean ore containing alumina monohydrate or alumina trihydrate...

  9. Effect of bauxite mineralized soil on residual metal levels in some post harvest food crops in Jamaica.

    Science.gov (United States)

    Wright, Vincent; Jones, Stephen; Omoruyi, Felix O

    2012-10-01

    The concentrations of nine residual metals in some Jamaican foods were determined using inductively coupled plasma mass spectrometry technique. Cadmium concentration was highest in yellow yam (0.21 mg/kg). Sweet potato had the highest concentrations of lead (0.31 mg/kg), arsenic (0.70 mg/kg) and mercury (0.35 mg/kg). Samples from Grove Place exceeded the regulatory limits of 0.1 mg/kg for cadmium, lead and arsenic and 0.05 mg/kg for mercury. Significant correlations were found between soil and agricultural produce concentrations for cadmium and lead (r(2) ≥ 0.5). These results suggest that the elements were available in soluble forms in the soil for absorption by food crops. PMID:22864633

  10. Alumina Producers in Shandong Province Allied to Win Negotiation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Faced with the soaring bauxite price,five alu- mina producers in Shandong Province jointly established Shangdong Bauxite Import Compa- nies Club to gain a better position in price ne- gotiation with foreign counterparts by getting

  11. Studying the Effect of Adding Doekhla kaolin Clay andAlumina to Iraqi Bauxite on Some Physical and Mechanical and Thermal Properties

    Directory of Open Access Journals (Sweden)

    Alaa A. Abdul-Hamead

    2011-01-01

    Full Text Available ???? ????? ??? ????? ????? ????????? ?? ???? ????? ?????? ??? ??????? ????????? ( ??? ?????? ? ????? ????? ??? ???????? ??? ????? ??????? ?????? ???????? ??????? ???? ? ?? ??????? ?????? ???????? ????? ?????. ?? ????? ??? ?????? ???? ????????? ????? ???????? ?????? ????????? ?? ????? (40 ?? ?? ?????? ????????, ??????? ????????? ????? (2.5,5,7.5,10 % ???? ????? ?????.?? ???? ?????? ?????? ??????? ??????? ?????? ???????.???? ????? ???? ??????? ?????? ????? ??? ????? ???? ??? ????? ??????? (10 Ton ?????? ????? ?? (5-10% ?? ??? ??????.???? ???? ??????? ????? ?????? ????? (1200 °? ??? ?????? ??? ?? ???? ???? ??????? (5 °? ??? ????? ?? ???? ??????? ?????? ??? ??? ???????? ???? ?????????? ???????????? ?????????.????? ????? ???????? ??????? ?? ??? ?? ??????? ??????? ?????? ??????? ?? ???? ??????? ??????? ???? ???? ?????? ?? ???? ???? ?? ???????? ?????? ?? ??????? ?????? ?????? ??? ??????? ?????? ?????? ?????? ?????? ???????? ???? ??? ???????? ???????? ????? ?????? ????? ????? ??????? ???????.??? ????? ??????? ?? ???? ????????? ?? ????????? ????? ??? ???? ???? ????? ??? ???????? ??? ????? ???? ????????? ??????? ????? ?????? ??????? ???????.??? ????? ??????? ?? ???? ?????? ???????? ???????????? ???? ????? ??????? ???? ???? ???? ?????? ????????? ???? ????? (10

  12. Driving forces for metamorphic vein filling during bauxite dehydration: insights from Li and Al transfer illustrated by LIBS compositional profiles (Western Alps)

    Science.gov (United States)

    Verlaguet, Anne; Brunet, Fabrice; Goffé, Bruno; Menut, Denis; Findling, Nathaniel; Poinssot, Christophe

    2015-04-01

    In subduction zones, the significant amounts of aqueous fluid released in the course of the successive dehydration reactions occurring during prograde metamorphism are expected to strongly influence the rock rheology, as well as kinetics of metamorphic reactions and mass transfer efficiency. Mineralized veins, ubiquitous in metamorphic rocks, can be seen as preserved witnesses of fluid and mass redistribution that partly accommodate the rock deformation (lateral segregation). However, the driving forces and mechanisms of mass transfer towards fluid-filled open spaces remain somewhat unclear. The aim of this study is to investigate the vein-forming processes and the modalities of mass transfer during local fluid-rock interactions, and their links with fluid production and rock deformation, with new insights from Laser Induced Breakdown Spectroscopy (LIBS) profiles. This study focuses on karstic pockets (metre scale) of Triassic metabauxites embedded in thick carbonate units, that have been isolated from large-scale fluid flow during HP-LT Alpine metamorphism (W. Vanoise, French Alps). These rocks display several generations of metamorphic veins containing various Al-bearing minerals, which give particular insights into mass transfer processes. It is proposed that the internally-derived fluid (~13 vol% produced by successive dehydration reactions) has promoted the opening of fluid-filled open spaces (euhedral habits of vein minerals) and served as medium for diffusive mass transfer from rock to vein. Based on mineralogical and textural features, two vein types can be distinguished: (1) some veins are filled with newly formed products of either prograde (chloritoid) or retrograde (chlorite) metamorphic reactions; in this case, fluid-filled open spaces seem to offer energetically favourable nucleation/growth sites; (2) the second vein type is filled with cookeite (Li-Al-rich chlorite) or pyrophyllite, which were present in the host-rock prior to the vein formation. In this closed chemical system, mass transfer from rock to vein was achieved through the fluid, in a dissolution-transport-precipitation process. To investigate the modalities of mass transfer towards this second vein type, LIBS profiles were performed in the host-rock, taking Li concentration as a proxy for cookeite distribution. Cookeite is highly concentrated (45-65 vol%) in regularly spaced veins, and the LIBS profiles show that cookeite is evenly distributed in the host-rock comprised between two veins. The absence of diffusion profiles suggests that the characteristic diffusion distance for Li, Al and Si is greater than or equal to the distance separating two cookeite veins (2-4 cm). This is in agreement with characteristic diffusion lengths calculated from both grain boundary and pore fluid diffusion coefficients, for the estimated duration of the peak of metamorphism. Which driving forces are responsible for cookeite selective transfer towards veins? Chemical potential gradients between host-rock pores and veins may have developed in response to either (1) a stress difference: thermochemical calculations show that pressure-solution processes may affect preferentially cookeite and pyrophyllite; (2) a difference in interfacial energy, phyllosilicates showing very different morphologies in host-rocks (fibers) compared to veins (euhedral crystals); fluid-mineral interfacial energy may be maximal in the small host-rock pores, which can maintain higher cookeite solubility than large fluid-filled open spaces (i.e., veins).

  13. 西方世界和独联体的铝土矿生产%Production of bauxite in the Western World and the Commonwealth of Independent State

    Institute of Scientific and Technical Information of China (English)

    兰兴华

    2005-01-01

    在西方世界,大部分铝土矿的生产都集中在少数几个国家。2004年西方世界的铝土矿总产量为1.283亿t,6个主要生产国的产量占总产量的92%。澳大利亚是最大的生产国,产量为5380万t,占西方世界总产量的42%,其后依次为:巴西(占16.1%);几内亚(占12.2%);牙买加(占10.4%)、印度(占7.3%)和委内瑞拉(占4.2%),见下表。

  14. 铝土矿浮选三相泡沫稳定性研究%Study on stability three-phase foam of bauxite flotation

    Institute of Scientific and Technical Information of China (English)

    穆枭; 冯其明; 陈建华; 张国范

    2008-01-01

    针对铝土矿浮选精矿三相泡沫体系,研究了表面疏水的一水硬铝石对铝土矿三相泡沫稳定性的影响规律.研究表明,影响三相泡沫稳定性的因素主要有颗粒大小、固体浓度和颗粒的疏水性.

  15. Bossay to Invest $1 Billion to Build a Alumina Plant in Indonesia

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>Bossay Group will become the sole private en-terprise owning three overseas bauxite mines under Alumnum Corporation of China. On Sep-tember 15, after acquiring a bauxite mine in Guyana and a bauxite mine in Ghana,the group

  16. 40 CFR 421.16 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403. ... GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Bauxite Refining...

  17. STUDY ON REDUCTION OF TOE ROCKS AND BOULDERS IN BENCH BLASTING IN THE KARST FORMATION BAUXITE%减少喀斯特岩层铝土矿台阶爆破根底和大块的研究

    Institute of Scientific and Technical Information of China (English)

    陈寿如; 毛晖; 张劲松; 赵坤

    2003-01-01

    喀斯特岩层铝土矿的主要特点是岩溶洞、岩溶水多,裂隙发育,岩层和泥层相夹等,这些特点使露天台阶爆破中出现较多的根底和大块.试验中通过采取一系列技术措施,如空气间隔装药、合适的孔网参数、孔底起爆、增加炸药密度及改进药包包装等,取得了良好的爆破效果.文中介绍了试验方法及试验结果的分析.

  18. Technological Study of Producing Low Temperature Ceramic and Foam Material with Tailing of Flotation Bauxite%铝土矿选尾矿制备低温陶瓷泡沫材料工艺研究

    Institute of Scientific and Technical Information of China (English)

    陆占清; 夏举佩; 张召述; 刘帆

    2010-01-01

    本文研究出了用铝土矿选尾矿制备低温陶瓷泡沫材料工艺条件.探讨了尾矿活化条件、矿物组成、激发剂用量、水胶比、胶骨比的影响机理.分析了材料的矿物组成和微观结构.制备出了以尾矿为胶凝材料主原料、煤渣为骨料、铝粉为发泡剂的新型高强轻质泡沫复合材料.其抗压强度10.78 MPa、密度0.94 g/cm3、平均孔径2~5 mm.

  19. 河南省沁阳常平铝土矿地质特征及成因%Geological Characteristics and Genetic Types of bauxite in ChangPing,Qinyang City

    Institute of Scientific and Technical Information of China (English)

    韩桥波

    2014-01-01

    Bauxite ore is an important mineral resources in Henan province, based on the analysis of the geological characteristics, ore body characteristics,ore characteristics in ChangPing area, the area with lower iron content, higher Al2O3 content and A/S ratio. It is considered that bauxite deposits in Changping was formed by the gradual accumulation of the erogenous matter brought in by marine transgression in the sea and lake basin after forming weathering crust rich in abundant aluminum and iron matter by the strong chemical weathering and erosion of carbonate rock.%通过对沁阳常平矿区铝土矿地质特征、矿体特征、矿石特征等分析研究,认为该铝土矿具有低铁、高铝、低铝硅比特点。常平铝土矿成因是在碳酸盐岩遭受长期强烈化学风化剥蚀而形成大量富铝、铁物质古风化壳的基础上,由于海侵作用,并接受陆源物质的汇入,而在海湖盆地中逐渐沉积形成的。

  20. ECONOMIC GEOLOGY (2)NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20082329 Chen Wang(China University of Geosciences,Beijing 100083,China) Control Factors on Distribution of Carboniferous Bauxite Deposits in Western Henan Province (Geotectonica et Metallogenia,ISSN1001—1552,CN44—1595/P,31(4),2007,p.452—456,1 illus.,10 refs.) Key words:bauxite,mineralization con- trols,Henan Province

  1. Foreign Dependence of Aluminum Resources has Difficulty to be Reduced Significantly

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>Insufficient resource guarantee ability has long been a bottleneck restricting the development of nonferrous metal industry, and aluminum is no exception. According to data from the China Nonferrous Metal Industry Association, during the "Eleventh Five Year" period China’s bauxite import volume presented a spiral upward trend. In 2010 China’s bauxite import volume

  2. Baise City of Guangxi Province Plans to Build a Key Asian Aluminium Production Base

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Baise City of Guangxi Province is launching a project to build the aluminium industry into a pillar industry worth 100 billion yuan,and make Baise a key aluminium production base in China and Asia at large,said Ma Biao, Chairman of Guangxi Zhuang Autonomous Region in a conference that concludes the per- formance of the government in the first half of the year.Guangxi,abundant in bauxite,is one of the four bauxite bases in China.Its potential reserve of bauxite tops 1 billion tons,mainly in

  3. Clay minerals and Sr-Nd isotopes of the sediments along the western margin of India and their implication for sediment provenance

    Digital Repository Service at National Institute of Oceanography (India)

    Kessarkar, P.M.; Rao, V.P.; Ahmad, S.M.; Babu, G.A.

    - gion is occupied by Recent alluvium and the Warkala beds (ferruginised sand stones with inter- calated clays) of Tertiary age. Extensive laterisation of the parent rocks is a characteristic feature in western India. Bauxite- and laterite...

  4. PROSPECTING EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20152148 Chen Qiang(No.106 Geological Party,Guizhou Bureau of Geology and Mineral Exploration and Development,Zunyi563009,China);Ye Deshu Discussion of Reasonable Exploratory Grid of Sedimentary Bauxite Deposit in Wuzhengdao Area of Guizhou

  5. GEOPHYSICAL EXPLORATION

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20101939 Bi Bingkun (No.1 Geological Surveying Party,Henan Bureau of Geology and Mineral Resources Exploration and Development,Luoyang 471023,China) Application of the Electric Method to Bauxite Exploration,Henan Province

  6. 40 CFR 421.12 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

    Science.gov (United States)

    2010-07-01

    ... available. Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this... CATEGORY Bauxite Refining Subcategory § 421.12 Effluent limitations guidelines representing the degree...

  7. Regional Applied Research Effort Project (RARE) with Region 8 - Beneficial Use of Red and Brown Mud and Phosphogypsum as Alternative Construction Materials

    Science.gov (United States)

    Red and brown muds are the secondary materials generated from the extraction of alumina from bauxite, an aluminum-containing sedimentary rock (Ref. 2). Phosphogypsum is the secondary material generated by the phosphorous fertilizer industry from phosphate-containing sedimentary ...

  8. Cementitious artificial aggregate particles for high-skid resistance pavements

    OpenAIRE

    De Larrard, François; MARTINEZ CASTILLO, Rafael; Sedran, Thierry; HAUZA, Philippe; Poirier, Jean Eric

    2012-01-01

    For some critical road sections, a high skid resistance of wearing course is required to minimise the risk of traffic accidents. Nowadays this skid resistance is mainly brought by the use of special aggregates as calcined bauxite, a scarce and expensive material. The paper presents a patented technology, where a special high-performance mortar is produced and crushed at early age. These cementitious artificial aggregates (CAA) can display aggregate properties close to those of calcined bauxit...

  9. Physics and chemistry of minerals under laser processing

    Science.gov (United States)

    Kotova, O.; Leonenko, N.

    2016-04-01

    New experimental data of the influence of laser irradiation on the phase composition minerals of bauxite and red mud and their technological features have been represented. The mechanisms of formation of micro- and nanophases on mineral surfaces under the influence of laser irradiation were shown. It is underlined that changes of condition of surface atoms, concentration of metals, agglomeration of titanium minerals and new phase formation occurred under laser irradiation on bauxites and red mud.

  10. Resource-efficient and economically viable pyrometallurgical processing of industrial ferrous by-products

    OpenAIRE

    Balomenos, Efthymios; Giannopoulou, Ioanna; Gerogiorgis, Dimitrios; Panias, Dimitrios; Paspaliaris, Ioannis

    2014-01-01

    This work outlines an integrated methodology for converting metallurgical by-products into high added value products, through an essentially zero-waste process. Thermodynamic modelling and conceptual design for processing bauxite residues (red mud) from the primary aluminium industry and ferro-nickel production slags are presented as examples. Furthermore, results of semiindustrial scale experiments for processing bauxite residues are illustrated, along with a preliminary financial analysis a...

  11. [Study on the Influence of Mineralizer on the Preparation of Calcium Aluminates Based on Infrared Spectroscopy].

    Science.gov (United States)

    Fan, Wei; Wang, Liang; Zheng, Huai-li; Chen, Wei; Tang, Xiao-min; Shang, Juan-fang; Qian, Li

    2015-05-01

    In this study, effect of mineralizer on the structure and spectraproperties of calcium aluminates formation was extensively studied. Medium or low-grade bauxite and calcium carbonate were used as raw material and mineralizer CaF2 as additive. Calcium aluminates can be obtained after mixing fully, calcination and grinding. The prepared calcium aluminates can be directly used for the production of polyaluminiumchloride (PAC), polymeric aluminum sulfate, sodium aluminate and some other water treatment agents. The calcium aluminates preparation technology was optimized by investigating the mass ratio of raw materials (bauxiteand calcium carbonate) and mineralizer CaF2 dosage. The structure and spectra properties of bauxite and calcium aluminates were characterized by Fourier transform infrared(FTIR) spectroscopy analysis and the mineralization mechanism of the mineralizer was studied. FTIR spectra indicated that the addition of mineralizer promoted the decomposition and transformation of the diaspore, gibbsite and kaolinite, the decomposition of calcium carbonate, and more adequately reaction between bauxite and calcium carbonate. In addition, not only Ca in calcium carbonate and Si in bauxite were more readily reacted, but also Si-O, Si-O-Al and Al-Si bonds in the bauxite were more fractured which contributed to the release of Al in bauxite, and therefore, the dissolution rate of Al2O3 could be improved. The dissolution rate of Al2O3 can be promoted effectively when the mineralizer CaF2 was added in a mass ratio amount of 3%. And the mineralizer CaF2 cannot be fully functioned, when its dosage was in a mass percent of 1. 5%. Low-grade bauxite was easier to sinter for the preparation of calcium aluminates comparing with the highgrade one. The optimum material ratio for the preparation of calcium aluminates calcium at 1 250 °C was the mass ratio between bauxite and calcium carbonate of 1 : 0. 6 and mineralizer CaF2 mass ratio percent of 3%. PMID:26415430

  12. Research and Development of Bauxite—based Refractories

    Institute of Scientific and Technical Information of China (English)

    ZHONGXiang-chong

    1996-01-01

    The research work on the microstructure and high temperature mehanical properties of sintered Chinses bauxite(DK type) and the ef-fects of foreign oxide additions (K2O,CaO,TiO,Fe2O3,MgO,ZrO2·SiO2) carried out at our laboratories have been reviewed.Based on these basic research results,bauxite-based high performance refractories have been develped for high temperature applications with success-ful achievements.

  13. DISCUSSION ON ORIGIN CENTRALIZE REGULARITY AND INDUSTRY VALUE OF THE AlO(OH)3 ORE IN PINGGUO%试论平果三水铝石成因、富集规律及工业价值

    Institute of Scientific and Technical Information of China (English)

    卢文华; 韦永坚; 黎乾汉; 廖思福

    2001-01-01

    平果岩溶堆积型铝土矿系一水硬铝石铝土矿床,原矿中含有大量的准胶结物——红土。研究资料证实,红土中的三水铝石含量甚高,不少地段已达到工业利用的要求。其他矿物质来源于原生沉积铝土矿床,并与堆积矿同产于一个层位。%The karst accumulative bauxite in Pingguo is bauxite deposit of AlO(OH)3, The primary accumulative bauxite include many agglutinate--ruddle. Investigative datum confirm, the content of AlO(OH)3 bauxite in ruddle is very high many ruddle have attained industry require. The metallogenic matter are derived from the primary sedimentary bauxite, and granted accumulative bauxite located in the same position.

  14. Respostas de Acacia mangium Willd e Sclerolobium paniculatum Vogel a fungos micorrízicos arbusculares nativos provenientes de áreas degradadas pela mineração de bauxita na Amazônia Responses of Acacia mangium Willd and Sclerolobium paniculatum Vogel to native arbuscular mycorrhizal fungi from remaining areas of bauxite mining in Amazon

    OpenAIRE

    Ney Freitas Marinho; Ana Lucy Caproni; Avílio Antônio Franco; Ricardo Luís Louro Berbara

    2004-01-01

    A resposta de Acacia mangium Willd (mangium) e Sclerolobium paniculatum Vogel (tachi) à inoculação de fungos micorrízicos arbusculares (FMA), oriundos de áreas em recuperação após a extração de bauxita, foi avaliada em experimento com delineamento inteiramente casualizado, com 14 tratamentos (duas espécies leguminosas e sete tipos de solo) e três repetições. Avaliou-se o número de esporos no solo, a colonização micorrízica, a matéria seca total, o P acumulado, a dependência micorrízica das mu...

  15. Semi-Industry Experiments on the Foam Layer Thickness in the Separation of Low-grade Bauxite with Flotation Column%泡沫层厚度对低品位铝土矿柱式分选影响的半工业试验研究

    Institute of Scientific and Technical Information of China (English)

    周游; 周长春; 张宁宁; 刘小凯; 王松涛

    2015-01-01

    针对影响低品位铝土矿柱式分选的重要因素—泡沫层厚度,利用旋流—静态微泡浮选柱开展了半工业试验研究,探究了在“快速浮选—一次粗选—一次精选”工艺下粗选浮选柱和精选浮选柱中泡沫层厚度对浮选效果的影响.研究发现,泡沫层厚度对精选段的影响明显高于对粗选段的影响;粗选最佳泡沫层厚度为45 cm,精选最佳泡沫层厚度为50 cm,且在该泡沫层厚度下获得了A/S为6.36、回收率为77.95%的合格精矿.

  16. Developing alternative resources of rare earth elements in Europe - EURARE and the red mud challenge

    Science.gov (United States)

    Deady, Eimear; Mouchos, Evangelos; Goodenough, Kathryn; Wall, Frances; Williamson, Ben

    2015-04-01

    Rare earth elements (REE) are considered to be highly "critical" by the European Commission [1], owing to the concentration of global supply [2] and their use in a wide range of emerging technologies (e.g. smart phones, electric cars and wind turbines). The main source of REE is the mineral bastnäsite, which is primarily extracted from carbonatites. Alternative resources of REE have been identified in a variety of other environments such as alluvial placers, bauxites and ore tailings. The EURARE project (www.eurare.eu), funded by the European Commission, aims to improve understanding of potential REE resources in Europe with the overall objective of establishing the basis for a European REE industry. As a part of this project, alternative sources of rare earth elements in Europe are being considered. REE have been identified as being particularly enriched in karst-bauxites and hence in the red muds generated as a waste product from the processing of these bauxites to alumina through the Bayer process [3]. Karst-bauxites are widely distributed with deposits known across the Mediterranean and with intermittent exploitation occurring over many decades. REE become concentrated in the bauxite deposits by the bauxitisation process and are retained due to the geochemical barrier created by the limestone bedrock below. This can result in several processes, including the crystallisation of authigenic REE-bearing minerals, the accumulation of residual phases and the adsorption of ions onto clays and other mineral surfaces [4]. Red muds produced from alumina processing represent a potentially important concentration of REE as it has been demonstrated that the REE pass through the alumina extraction process into the waste, and the total REE concentrations are typically enriched by a factor of two compared with the original bauxite ore [5]. Bauxites and red muds from the Parnassus Ghiona region of Greece [6] and the Seydişehir-Akseki region of Turkey have been assessed as

  17. Utilization of multiple waste streams for acid gas sequestration and multi-pollutant control

    Energy Technology Data Exchange (ETDEWEB)

    Soong, Y.; Dilmore, R.M.; Hedges, S.W.; Howard, B.H.; Romanov, V. [U.S. Department of Energy, National Energy Technology Laboratory, Pittsburgh, PA (United States)

    2012-03-15

    A novel CO{sub 2} sequestration concept is reported that combines SO{sub 2} removal and CO{sub 2} capture and sequestration, using a bauxite-processing residue which is a waste product and with waste brine water from oil/gas production. The bauxite residue/brine mixture of 46/54 v/v exhibited a CO{sub 2} sequestration capacity of > 0.078 mol L{sup -1} when exposed to pure CO{sub 2} at 20 C and 2.73 MPa. At a higher temperature of 140 C, a bauxite residue/brine mixture of 80/20 v/v indicated a CO{sub 2} sequestration capacity of > 0.094 mol L{sup -1} when exposed to pure CO{sub 2} at 3.85 MPa. Under the same reaction conditions, an identical ratio of reaction mixture exposed to simulated flue gas at a similar initial pressure was capable of sequestering 0.16 mol of CO{sub 2} and > 99.9 % of the applied SO{sub 2}. Calcite formation was verified as a product of bauxite/brine mixture carbonation. The caustic bauxite residues (pH 12.5-13.5) and acidic wastewater brine (pH 3-5) are also effectively neutralized after participating as reactive reagents in the conceptual process. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Impact of mine waste dumps on growth and biomass of economically important crops.

    Science.gov (United States)

    Mathiyazhagan, Narayanan; Natarajan, Devarajan

    2012-11-01

    The present study aimed to investigate the effect of magnesite and bauxite waste dumps on growth and biochemical parameters of some edible and economically important plants such as Vigna radiata, V. mungo, V. unguiculata, Eleusine coracana, Cajanus cajan, Pennisetum glaucum, Macrotyloma uniflorum, Oryza sativa, Sorghum bicolour, Sesamum indicum, Ricinus communis, Brassica juncea, Gossypium hirsutum and Jatropha curcas. The growth rate of all the crops was observed in the range of 75 to 100% in magnesite and 15 to 100% in bauxite mine soil. The moisture content of roots and shoots of all the crops were in the range of 24 to 77, 20 to 88% and 42 to 87, 59 to 88% respectively. The height of the crops was in the range of 2.6 to 48 cm in magnesite soil and 3 to 33 cm in bauxite soil. Thus the study shows that both mine soils reflects some physical and biomolecule impact on selected crops. PMID:23741803

  19. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111761 Chen Hua(115 Geological Party,Guizhou Bureau of Geology and Mineral Exploration & Development,Guiyang 551400,China);Deng Chao Analysis on the Metallogenic Environment of Maochang Bauxite in Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(3),2010,p.198-201,2 illus.,1 table,8 refs.)Key words:bauxite deposit,Guizhou Province By long time physical and chemical process,the carbonate rock after Central Guizhou uplidft,becomes red clay,after further weathering,the red clay decomposed into the oxide,hydroxide of Al and Fe,in the dissolution hole and depression,it concentrates primary fragmentary tight and earthy karst bauxite ore.Because the variation of landform,it decomposes and cracks again,affords the material source

  20. Utilização de argilas para purificação de biodiesel

    Directory of Open Access Journals (Sweden)

    Andréia Juliana Almeida de Paula

    2011-01-01

    Full Text Available This work describes the results of the purification of methyl biodiesel, obtained by oxidized soybean oil, using different methods. After the ester separation from the glycerin by decanting, the ester was purified each time with distillation, washing with water and adsorption with bauxite, bentonite and attapulgite. The removal of total contamination, unsaponifiable material, concentrations of free glycerin and soap were analyzed in the purified ester phase. The best result of purification was observed with the use of bentonite and bauxite, in the removal of soap and free glycerin respectively.

  1. Some Aspects in the Development of High Performance Refractories for Iron and Steel Making in China

    Institute of Scientific and Technical Information of China (English)

    ZHONG Xiangchong; YE Fangbao

    2005-01-01

    In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China's refractories industry in production capacity, in quality improvement and in development of new products. Sophisticated high performance refractory materials mainly based on our rich reserves of magnesite, bauxite and flake graphite have been developed, such as carbon-bonded products, high purity oxide products, bauxite-based low creep and high strength high alumina bricks and LC, ULC and ZC castables. They have been used in blast furnaces, BOFs, EAFs, secondary refining and continuous casting with considerable improvement in service performance.

  2. Treatment of Red Mud From Alumina Production by High–Intensity Magnetic Separation

    OpenAIRE

    Fofana, Mohamad; Kmet, Stanislav; Jakabský, Štefan; Hredzák, Slavomír; Kunhalmi, Gabriel

    1995-01-01

    The paper gives attention to the possibilities of magnetic separation of red mud. The red mud can be characterised as an insoluble residue originated during the bayer method application in bauxite processing. Sample of red mud was obtained by leaching of bauxite from the Fria deposit (Guinea). The wet method of high–intensity magnetic separation was applied to the treatment. The magnetic product with the Fe content of 47% and recovery of 85% was obtained under magnetic field induction of 0.06...

  3. Progress in flotation de-silica

    Institute of Scientific and Technical Information of China (English)

    胡岳华

    2003-01-01

    Flotation de-silica from the diasporic-bauxite is one of the key basic research projects. It aimed to reveal the scientific mechanism between the crystal structure and surface properties, structure-properties of effective flotation reagent as well as the solution chemistry of flotation and interfacial interactions in the flotation system of diaspore and aluminosilicate minerals. It will underlay the new technology of reverse-flotation de-silica. The technology is important to enhance the mass ratio of Al2O3 to SiO2, decreasing the silica content and energy consumption in producing aluminum oxide and economically utilizing the diasporic-bauxite in China.

  4. Use of clays for purification of biodiesel; Utilizacao de argilas para purificacao de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Andreia Juliana Almeida de; Kruegel, Marlus; Miranda, Joao Paulo; Rossi, Luciano Fernando dos Santos; Costa Neto, Pedro Ramos da, E-mail: pedroneto@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Depts. de Quimica, Biologia e Mecanica

    2011-07-01

    This work describes the results of the purification of methyl biodiesel, obtained by oxidized soybean oil, using different methods. After the ester separation from the glycerin by decanting, the ester was purified each time with distillation, washing with water and adsorption with bauxite, bentonite and attapulgite. The removal of total contamination, unsaponifiable material, concentrations of free glycerin and soap were analyzed in the purified ester phase. The best result of purification was observed with the use of bentonite and bauxite, in the removal of soap and free glycerin respectively. (author)

  5. Pasta aluminosa para o fabrico de isoladores cerâmicos

    OpenAIRE

    Marques, Tiago Filipe Ramires

    2013-01-01

    Este relatório espelha o trabalho desenvolvido ao longo de um estágio na empresa Cerisol que produz isoladores em porcelana para alta tensão. A intenção principal do estágio era desenvolver uma pasta cerâmica aluminosa para o fabrico de isoladores, do tipo C130, designação dada segundo a norma ICE 60672-3 a porcelanas com elevado conteúdo em alumina. Preparou-se uma pasta usando bauxite calcinada como fonte de coríndon. Esta pasta, denominada de PB1 (pasta de bauxite 1), apresentou uma bai...

  6. NEWS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>Chalco Enters Agreement with Vietnam on Bauxite Project During a State visit to Vietnam headed by China’s President Hu Jintao, Xiao Yaqing, Chairman and CEO of China Aluminium Corp. (Chalco) signed an agreement with his Vietnamese counterpart on the development of a bauxite project in Vietnam. Top officials of the two countries attended the signing ceremony in Hanoi. This project is known to be the largest one between the two countries up to present and it is taken by leaders of both countries as an important progress in promoting the bilateral relations in economy and trade.

  7. Development and Application of Spinel and High—alumina/Spinel Castables

    Institute of Scientific and Technical Information of China (English)

    YANGDean; CHENGGuoxiang; 等

    1998-01-01

    The development and application of domestic spinel and high-alumian/spinel(including corun-dum/spinel and calcined-bauxite/spinel) castables were disucssed in this paper,It expounded the tech-nical characters and virtues of high grade and medi-um grade spinel and the importance of the develop-met and successful application of calcined-bauxite/spinel castalbes.Because of the technical and eco-nomical feasibility,the developement and application of spinel and high-alumina/spinel castables,in which domestic refractory workers play an important role ,have been flurishing.

  8. An ideal cascade for uranium 235 enrichment by centrifuge jet nozzle process

    International Nuclear Information System (INIS)

    The design of an ideal cascade for the process of isotope separation by centrifugation for the U235 enrichment, is presented. A selection of building materials used in fabrication of isotope separation plants, showing the importance of aluminium, due the bauxite mines in Northern Brazil, is done. (M.C.K.)

  9. A rapid colorimetric method for determination of vanadium in ores, minerals and beneficiated products

    International Nuclear Information System (INIS)

    A colorimetric method using N-benzyol-N-phenyl-hydroxylamine as reagent for direct determination of vanadium in vanadiferrous and titaniferrous iron ores and bauxite has been developed. The method gives results comparable with those of the colorimetric method using hydrogen peroxide and volumetric method using ferrous sulphate permanganate. (M.G.B.)

  10. Refractory Minerals in Henan Province

    Institute of Scientific and Technical Information of China (English)

    JIN Qinguo; LI Jing; LIU Jiehua; LIU Yanjun

    2004-01-01

    Henan province is very rich in refractory minerals of many varieties including silica, dolomite, graphite,pearlite, sepiolite, olivine, and sillimanite group minerals, besides the abundant reserves of fireclay and bauxite,which lay a good foundation for the development of the refractories industry of the province. The paper introduces the reserves, distribution and character of the refractory minerals in Henan province.

  11. Refractories Development for Iron and Steel Making in China

    Institute of Scientific and Technical Information of China (English)

    ZHONGXiang-chong

    1996-01-01

    The developments of high performance refractories for the fast developing iron and stel industry in China in recent years have been briefly reviewed.Most of the sophisticated new produts developed are based on the country's natural raw materials,mainly bauxite,magne-site and graphite which occur in abundance.

  12. Effect of different sources of alumina on the microstructure and mechanical properties of the triaxial porcelain

    Directory of Open Access Journals (Sweden)

    G. Gralik

    2014-12-01

    Full Text Available Porcelains composed of kaolin-quartz-feldspar are called triaxial porcelains. The use of alumina as a substitute for quartz in porcelains has been developed for some time. The results show a significant improvement in their mechanical properties, but alumina has a high cost. The possibility of using alternative materials as a source of alumina with lower cost was investigated. In this work, alternative raw materials were used as a source of alumina: refractory bauxite, primary aluminum hydroxide, reprecipitated aluminum hydroxide. Compositions with commercial alumina and quartz were also formulated to better understand the effects of adding these alternative materials. The raw materials were milled, dried, and characterized by analysis of the particle size distribution, X-ray diffraction, and X-ray fluorescence. The compositions were formulated by replacing the different sources of alumina in the formulation of porcelain. The compositions studied were shaped by pressing and sintered at different temperatures (1150-1400 ºC. The results showed that the use of bauxite and aluminum hydroxide as an alternative source of Al2O3 is viable. The impurities contained in refractory bauxite contributed to the lower values of flexural strength found in compositions having refractory bauxite as a source of alumina. The compositions with reprecipitated aluminum hydroxide showed a high mechanical resistance at low sintering temperatures, while compositions with aluminum hydroxide obtained by the Bayer process achieved good results of mechanical strength in a wide temperature range.

  13. China’s Growing Dependence on Foreign Supplies Makes it Urgently Necessary to Develop the Secondary Metal Industry

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>Recently, copper has been successfully produced under the secondary copper smelting project with an annual capacity of 300,000 tons launched by Guangxi Nonferrous Metals Group in Wuzhou Recycling Resources Processing Park. As China’s increasing dependence on foreign supplies for copper, bauxite and lead-zinc

  14. A palynological study on the Tertiary and Upper Cretaceous of British Guiana

    NARCIS (Netherlands)

    Hammen, van der T.; Wymstra, T.A.

    1964-01-01

    The pollen content of bore-hole samples and mine sections from the coast and from the bauxite belt of British Guiana has been studied. The pollen zonation is shown in fig. 6 and diagram IV. The description of the Upper Cretaceous and Tertiary pollen species is partly given in this article and partly

  15. 40 CFR 421.14 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true 421.14 Section 421.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Bauxite Refining Subcategory § 421.14...

  16. China‘s Refractories Heading for the New Century

    Institute of Scientific and Technical Information of China (English)

    ZHONGXiangchong

    1997-01-01

    The progress made by China's refractories industry in the past 15 years (1980-1995) has been briefly reviewed.The trends of development for the next 15 years (1996-2010) have been discussed with emphasis on the development of bauxite-based high performance products and oxide and non-oxide composites.

  17. Soil Microbial Community Successional Patterns during Forest Ecosystem Restoration ▿†

    OpenAIRE

    Banning, Natasha C.; Gleeson, Deirdre B.; Grigg, Andrew H.; Grant, Carl D.; Andersen, Gary L.; Brodie, Eoin L.; Murphy, D. V.

    2011-01-01

    Soil microbial community characterization is increasingly being used to determine the responses of soils to stress and disturbances and to assess ecosystem sustainability. However, there is little experimental evidence to indicate that predictable patterns in microbial community structure or composition occur during secondary succession or ecosystem restoration. This study utilized a chronosequence of developing jarrah (Eucalyptus marginata) forest ecosystems, rehabilitated after bauxite mini...

  18. The Current Situation of the Aluminum Industry in Henan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The aluminum industry in Henan has taken an important position in Chinese aluminum indus- try and even in the whole world. From the aspect of the reserve of bauxite,He- nan has significant share of the reserve.By the end of 2005,Henan has a total prospected

  19. Assessment of pollutants sequestration in flowing waters using Red Mud

    Science.gov (United States)

    Red Mud, a waste product of bauxite refinement, has already been reported as a non-conventional adsorbent of heavy metals and some other important nutrients, such as phosphorus. Its use has been explored since it is a low cost solid adsorbent with a strong binding capacity. Although there were equil...

  20. China Cancelled Export Tariff for Nine Kinds of Raw Materials

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>In the recently promulgated "Tariff Execution Plan for 2013", among new tariffs implemented since January 1, 2013, tariffs of nine kinds of raw material products including bauxite, coke,yellow phosphorus, fluorite, magnesium, manganese, silicon metal, silicon carbide and zinc exported by China will be lifted.

  1. Guangdong Aluminum to Raise RMB 3 billion for New Production Base in Guizhou

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>On July 7, a loan signing ceremony was held between the Guangdong Aluminum Group, China Construction Bank, Hua Xia Bank and Guangzhou Bank Consortium. It is reported that these banks will provide Guangdong Aluminum Group with RMB 30 billion for an alu-minum oxide and supporting bauxite mining project in Guizhou.

  2. High-Performance Grouting Mortar Based on Mineral Admixtures

    Directory of Open Access Journals (Sweden)

    Cong Ma

    2015-01-01

    Full Text Available A study on high-performance grouting mortar is reported. The common mortar was modified by mineral admixtures such as gypsum, bauxite, and alunite. The effects of mineral admixtures on the fluidity, setting time, expansion, strength, and other properties of mortar were evaluated experimentally. The microstructure of the modified mortar was characterized by X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. Moreover, the expansive performance and strength of the grouting mortar were verified by anchor pullout test. The results show that the best conditions for gypsum-bauxite grouting mortar are as follows: a water-to-binder ratio of 0.3, a mineral admixture content of ~15%, and a molar ratio K of 2. The ultimate bearing capacity of the gypsum-bauxite grouting mortar anchor increased by 39.6% compared to the common mortar anchor. The gypsum-bauxite grouting mortar has good fluidity, quick-setting, microexpansion, early strength, and high strength performances.

  3. Lignite and conditioned ash handling systems

    Energy Technology Data Exchange (ETDEWEB)

    Bibolini, P.; Di Giacomo, L.; Ruga, A.M. [Techint (Italy)

    2001-10-01

    This article discusses Techint's latest contract for the engineering and supply of a lignite and conditioned ash handling system. Techint Italimpianti, the materials handling unit of Techint Technologies has served the market for over 40 years as a leading supplier of a range of systems for the handling of iron ore, pellets, coal, cement, bauxite, and aluminium. 6 figs.

  4. Spectrophotometric determination of titanium with ascorbic acid in aluminium alloys and other materials. Determinacion espectrofotometrica de titanio con acido ascorbico en aleaciones de base aluminio y otros materiales

    Energy Technology Data Exchange (ETDEWEB)

    Bosch Serrat, F. (Departamento de Quimica Analitica. Facultad de Qauimica. Valencia (Spain))

    1994-01-01

    A spectrophotometric determination of titanium with ascorbic acid in aluminium alloys and bauxite is described. The proposed procedures permit to determine levels of titanium down to 5.10 ''3% with a good accuracy and precision. (Author) 13 refs.

  5. Western Mining Strips 2.7 billion Assets Off to Buy Into Qinghai Investment Group

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>According to an announcement by West Mining Co,Ltd on the 10th,the Company plans to strip off assets including coal,bauxite and carbon barely related to its main business-nonferrous metals in order to buy into Qinghai Investment Group Co.,Ltd.(hereinafter referred to as Qinghai Investment Group).

  6. Naturally occurring radioactive material from the aluminium industry-a case study: the Egyptian Aluminium Company, Nag Hammady, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Abbady, Adel G E; El-Arabi, A M [Physics Department, South Valley University, Faculty of Science, Qena (Egypt)

    2006-12-15

    The activity concentrations and the gamma-absorbed dose rates of the terrestrial naturally occurring radionuclides {sup 226}Ra and {sup 232}Th were determined in samples of bauxite, alumina and aluminium dross tailings industrial waste (used to produce two types of alums) using high purity germanium (HPGe) gamma ray spectrometry. The bauxite and alumina are imported by Egyptalum (The Egyptian Aluminium Company, Nag Hammady, Egypt) from Guinea and India. The activity concentrations in the bauxite range from 29 {+-} 1 to 112 {+-} 6 Bq kg{sup -1} for {sup 226}Ra, and 151 {+-} 8 to 525 {+-} 12 Bq kg{sup -1} for {sup 232}Th, with mean values of 62 {+-} 8 and 378 {+-} 50 Bq kg{sup -1}, respectively. With respect to alumina and tail, the mean values are 5.7 {+-} 1.1 and 8.4 {+-} 0.8 Bq kg{sup -1} for {sup 226}Ra and 7.2 {+-} 1.6 and 10.7 {+-} 1.2 Bq kg{sup -1} for {sup 232}Th. Potassium-40 was not detected in any of the studied samples. The measured activity concentrations of {sup 226}Ra and {sup 232}Th in bauxite are higher than the world average while in alumina and tail they are lower. As a measure of radiation hazard to the occupational workers and members of the public, the Ra equivalent activities and external gamma dose rates due to natural radionuclides at 1 m above the ground surface were calculated. The external {gamma}-radiation doses received by the Egyptalum workers are 97, 409, 8.5 and 12.7 {mu}Sv y{sup -1} for the Guinean and Indian bauxite, the alumina and tail, respectively, which is well below the recommended allowed dose of 1 mSv y{sup -1} for non-exposed workers.

  7. Comparison of Low Concentration and High Concentration Arsenic Removal Techniques and Evaluation of Concentration of Arsenic in Ground Water: A Case Study of Lahore, Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Yasar, Abdullah; Tabinda, Amtul Bari; Shahzadi, Uzma; Saleem, Pakeeza [GC University, Lahore (Pakistan)

    2014-10-15

    The main focus of this study was the evaluation of arsenic concentration in the ground water of Lahore at different depth and application of different mitigation techniques for arsenic removal. Twenty four hours of solar oxidation gives 90% of arsenic removal as compared to 8 hr. or 16 hr. Among oxides, calcium oxide gives 96% of As removal as compared to 93% by lanthanum oxide. Arsenic removal efficiency was up to 97% by ferric chloride, whereas 95% by alum. Activated alumina showed 99% removal as compared to 97% and 95% removal with bauxite and charcoal, respectively. Elemental analysis of adsorbents showed that the presence of phosphate and silica can cause a reduction of arsenic removal efficiency by activated alumina, bauxite and charcoal. This study has laid a foundation for further research on arsenic in the city of Lahore and has also provided suitable techniques for arsenic removal.

  8. Removal of arsenic from potable water by adsorptive media treatment techniques

    International Nuclear Information System (INIS)

    Summary: This study was conducted to investigate the arsenic removal efficiency of different adsorptive media from water. Different naturally occurring materials such as bauxite, plastic clay, plaster of Paris, lime, alum, and alumina etc. were used for the development of media to remove arsenic As/sup +5/ present in the artificially contaminated water. Different ratios of the selected materials were combined and ignited at 9000 C to enhance its arsenic removing efficiency. It was found that the media bauxite, plastic clay, lime (1:1:1) has a maximum removal (99%) of As +5 species from aqueous media and can be used on- site to reduce the arsenic contamination of potable water. Furthermore, the materials used in this experiment were cheaply and abundantly available within the country. The method is very simple and economically viable, for removal of arsenic from potable water. (author)

  9. Effect of spinel content on the properties of phosphoric acid bonded high alumina castables

    Institute of Scientific and Technical Information of China (English)

    Zichun Yang; Hongwei Duan; Lin Li; Shuqin Li; Wen Ni

    2003-01-01

    In order to study the effect of fused spinel on the properties of phosphoric acid bonded high alumina castables, samples with different contents of fused spinel were prepared. The results show that when the contents of the fused spinel are between 8% and 16% (mass fraction), the castables have good properties. The castables overcome the shortages of the phosphoric acid bonded high alumina castables with bauxite cement as a hardening promoter. The experiments demonstrate that most of the service properties of the castables with fused spinel are better than those of the normal phosphoric acid bonded castables which use bauxite cement as a hardening promoter. The examination of the materials indicates that free MgO inclusions in the spinel powder can promote the hardening of the castables.

  10. Survey of the market, supply and availability of gallium

    Energy Technology Data Exchange (ETDEWEB)

    Rosi, F.D.

    1980-07-01

    The objective of this study was to assess the present consumption and supply of gallium, its potential availability in the satellite power system (SPS) implementation time frame, and commercial and new processing methods for increasing the production of gallium. Findings are reported in detail. The findings strongly suggest that with proper long range planning adequate gallium would be available from free-enterprise world supplies of bauxite for SPS implementation.

  11. Development and Application of Mullite Brick With High Refractoriness under Load and Low Creep

    Institute of Scientific and Technical Information of China (English)

    ZHANGSheng; WANGRuikun; 等

    2000-01-01

    This paper introduces of the development and applica-tion of heavily burned mullited brick with high reractoriness under load low creep,which is made of andalusie fine and coarse grains (as aggregate),high alumina bauxite produced in Yangquan county,clay produced in Guangxi provine,industrial alumina powder and silliman-ite powder (as matrix material) and a little amount of ad-ditives and bonded with synthetic bond.

  12. Ionic liquid technology for recovery and separation of rare earths

    OpenAIRE

    Binnemans, Koen

    2015-01-01

    End-of-life neodymium-iron-boron and samarium-cobalt permanent magnets, fluorescent lamps and metal hydride batteries are valuable secondary resources of rare earths. These resources are characterised by relatively small volumes, but high concentrations of rare earths [1]. On the other hand, industrial process residues such as bauxite residue (red mud) and phosphogypsum contain low concentrations of rare earths, but are available in huge volumes [2]. Recovery of rare earths from end-of-life c...

  13. Adubação da batatinha experiências com alguns fosfatos Fertilizer experiments with potatoes comparison of some phosphorus sources

    Directory of Open Access Journals (Sweden)

    O. J. Boock

    1960-01-01

    Full Text Available De 1948 a 1950 foram conduzidas, em duas localidades do Estado de São Paulo, quatro experiências comparando o efeito, na batatinha (Solarium tuberosum L., de adubações com NPK em que o fósforo figurou nas formas de bauxita fosforosa (da llha Trauíra, Estado do Maranhão, farinha de ossos degelatinados ou superfosfato. A dose de fósforo, 120 kg/ha de P2O5, foi empregada exclusivamente nas formas mencionadas ou na de misturas contendo metade do nutriente como superfosfato e metade como farinha de ossos ou bauxita. Quando usados como fonte exclusiva de fósforo, em regra os dois últimos fósforos se mostraram muito inferiores ao superfosfato; por outro lado, os resultados obtidos indicam que, na cultura da batatinha, o emprêgo dos misturas estudadas não oferece vantagem econômica.This paper reports the results obtained in four experiments with potatoes, which were conducted from 1948 to 1950 in two locotities of the State of São Paulo and designed to compare superphosphate with bane meal and bauxite (a phosphorous bauxite from the State of Maranhão, Brazil in the presence of nitrogen and potassium. A dose of 120 kilograms of P2O5 to the hectare was opplied either exclusively as the mentioned types of phosphates or as mixtures containing half the amount of phosphorus in the form of superphosphate and half in that of bone meal or bauxite. When used as the only source of phosphorus, bone meal and bauxite were as a rule much inferior to superphosphate; on the other hand, the results obtained indicate thate there is no economical advantage in using the studied mixtures of phosphates instead of superphosphate.

  14. New technology of extracting the amount of rare earth metals from the red mud

    Science.gov (United States)

    Martoyan, G. A.; Karamyan, G. G.; Vardan, G. A.

    2016-01-01

    The paper outlined the environmental and economic problems associated with red mud - the waste generated in processing of bauxite ore for aluminum production. The chemical analysis of red mud has identified a number of useful elements including rare earth metals. The electromembrane technology of red mud processing with extraction of valuable elements is described. A possible scheme of separation of these metals through electrolysis is also given.

  15. Conflict and Astroturfing in Niyamgiri: The Importance of National Advocacy Networks in Anti-Corporate Social Movements

    OpenAIRE

    Kraemer, R.; Whiteman, G; Banerjee, S. B.

    2013-01-01

    Traditional models of transnational advocacy networks (TANs) and stakeholder management do not capture the nuance and dynamics of (counter-)organising processes around anti-corporate mobilisation. Based on the case of a resistance movement against a planned bauxite mine on tribal land in India, we develop a process theory of interactions between local, national and international actors within transnational advocacy networks. These encounters are not always friendly and are often characterised...

  16. World mineral production 2003-2007

    OpenAIRE

    Brown, Teresa; Hetherington, Linda; Hannis, Sarah; Bide, Tom; Benham, Antony John; Idoine, Naomi; Lusty, Paul

    2009-01-01

    World Mineral Production includes five year tables of production, by country, for the majority of economically important mineral commodities, including ferrous and non-ferrous metals, industrial minerals and hydrocarbons. Additional information has been added describing the characteristics, uses production trends, prices and industry events for 11 commodities including bauxite/alumina/aluminium, coal, copper, fluorspar, gold, iron ore, lead, nickel, platinum, uranium and zinc.

  17. World Mineral Production 2002-06

    OpenAIRE

    Hetherington, Linda; Brown, Teresa; Benham, Antony; Bide, Tom; Lusty, Paul; Hards, Vicky; Hannis, Sarah; Idoine, Naomi

    2008-01-01

    This publication includes five year tables of production, by country, for the majority of economically important mineral commodities, including ferrous and non-ferrous metals, industrial minerals and hydrocarbons. Additional information has been added describing the characteristics, uses production trends, prices and industry events for 11 commodities including bauxite/alumina/aluminium, coal, copper, fluorspar, gold, iron ore, lead, nickel, titanium, uranium and zinc. This is part ...

  18. Resources to Riches?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Africa's natural resources can be a cornerstone of development for some countries on the struggling continent Africa is a vast territory with abundant mineral and biological resources, and this is where great hope lies for a better future. Its valuable metallic reserves, which include gold, cobalt, platinum, chromium, manganese, titanium and vanadium, and mineral reserves, such as diamond, bauxite and phosphate, top the world. Its verified oil and natural gas deposits

  19. High-Performance Grouting Mortar Based on Mineral Admixtures

    OpenAIRE

    2015-01-01

    A study on high-performance grouting mortar is reported. The common mortar was modified by mineral admixtures such as gypsum, bauxite, and alunite. The effects of mineral admixtures on the fluidity, setting time, expansion, strength, and other properties of mortar were evaluated experimentally. The microstructure of the modified mortar was characterized by X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. Moreover, the expansive performance and strength of th...

  20. Immobilization of 60Co and 90Sr ions using red mud from aluminum industry

    OpenAIRE

    Milenković Aleksandra S.; Smičiklas Ivana D.; Marković Jelena P.; Vukelić Nikola S.

    2014-01-01

    The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption r...

  1. Use of electrokinetic and reactive barriers to treat heavy metals-contaminated soils

    OpenAIRE

    Spiga, Daniela

    2011-01-01

    The combined use of electrokinetic (EK) and reactive barrier (RB) of transformed red mud (TRM) (a by-product of bauxite refinement for alumina production) for the remediation of low permeability contaminated soils by chromium and arsenic was investigated. The combination of EK with RB is a possible way in order to enhance EK removal of Cr and As that are reported to be among the more difficult elements to remove by electrokinetics. The goal and the novelty of the research consi...

  2. Analysis of Proppant Hydraulic Fracturing in a Sand Oil Reservoir in Southwest of Iran

    OpenAIRE

    Reza Masoomi; Iniko Bassey; Dolgow Sergie Viktorovich; Hosein Dehghani

    2015-01-01

    Hydraulic fracturing is one way to increase the productivity of oil and gas wells. One of the most fundamental successes of hydraulic fracturing operation is selecting the proper size and type of proppants which are used during the process. The aim of this study is optimizing the type and size of used propant in hydraulic fracturing operation in a sand oil reservoir in southwest of Iran. In this study sand and ceramic (sintered bauxite) have been considered as proppant type. Also the various ...

  3. Acid rain may cause senile dementia

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, F.

    1985-04-25

    Aluminium, released from the soil by acid rain, may be a cause of several forms of senile dementia including Parkinson's disease and Alzheimer's disease. Many upland reservoirs, fed by acid rain, supply homes with water laced with significant amounts of aluminium. Studies in the Pacific have shown that communities living on soils that are extremely rich in bauxite, the rock containing aluminium, have a very high incidence of Alzheimer's disease.

  4. Morphological description of the brachial plexus in ocelot (Leopardus pardalis)

    OpenAIRE

    Kylma Lorena Saldanha Chagas; Lara Cochete Moura Fé; Luiza Correa Pereira; Érika Branco; Ana Rita de Lima

    2014-01-01

    The brachial plexus is formed by the ventral roots of the spinal nerves, which unite to form the nerve trunks. It is usually formed by contributions of the last three cervical nerves and the first two thoracic nerves. Due to the scarcity of information on neuroanatomy, this study aimed to determine the macroscopic morphology of the brachial plexus of the ocelot (Leopardus pardalis). In this work, we used two ocelot specimens from the area of the Paragominas Bauxite Mine, P...

  5. O uso de microondas para determinação de umidade de bauxita

    Directory of Open Access Journals (Sweden)

    Rodrigo Silva Magalhães

    2003-12-01

    Full Text Available Nesse trabalho, é apresentado um estudo de secagem de bauxitas por microondas, visando a determinar a influência da umidade inicial das amostras, a massa a ser secada e a granulometria das mesmas no processo de secagem. Para a determinação da influência da umidade inicial, foram utilizadas amostras com teor de umidade igual a 12,2 e 6,9%. A influência da massa e a granulometria foram determinadas com uma amostra, cujo teor inicial de umidade era igual a 13%. Através desses estudos, observou-se que os tempos ótimos de secagem por microondas das amostras de bauxita estudadas têm uma relação direta com a umidade inicial das mesmas. Observou-se que as variáveis, massa da amostra a ser secada e o tempo de secagem, são diretamente proporcionais, apresentando elevada correlação. Dessa forma, pode-se obter os tempos de secagem para cada amostra a ser secada, de acordo com a sua massa. Não foi observada relação entre o tempo de secagem e a granulometria da amostra.This work shows the results of a bauxite drying process using microwave oven. In this research the influence of initial humidity, mass and granulometric distribution of bauxite samples were studied. To determine the humidity influence two bauxite samples having 6,9% and 12,2% of humidity were utilized and for the mass and granulometric distribution the sample initial humidity was 13%. The results show that the optimum drying time by microwave has a directly correlation with the initial humidity. The sample mass and the drying time are also directly proportional with a very high correlation. The study suggests that the drying time can be obtained considering the mass of the bauxite sample.

  6. Development of a New Manure Amendment for Reducing Ammonia Volatilization and Phosphorus Runoff from Poultry Litter.

    Science.gov (United States)

    Moore, Philip A

    2016-07-01

    Treating poultry litter with alum is a best management practice that reduces phosphorus (P) runoff and ammonia (NH) emissions. However, alum prices have increased substantially during the past decade. The goal of this research was to develop inexpensive manure amendments that are as effective as alum in reducing NH volatilization and P runoff. Sixteen amendments were developed using mixtures of alum mud, bauxite ore, sulfuric acid, liquid alum, and water. Alum mud is the residual left over from alum manufacture when produced by reacting bauxite with sulfuric acid. A laboratory NH volatilization study was conducted using 11 treatments: untreated poultry litter, poultry litter treated with liquid or dry alum, or eight new mixtures. All of the litter amendments tested resulted in significantly lower NH volatilization than untreated litter. Dry and liquid alum reduced NH losses by 86 and 75%, respectively. The eight new litter amendments reduced NH losses from 62 to 73% compared with untreated litter, which was not significantly different from liquid alum; the three most effective mixtures were not significantly different from dry alum. Water-extractable P (WEP) was significantly reduced by all of the amendments, three of which resulted in significantly lower WEP than dry alum. The most promising new amendments were mixtures of alum mud, bauxite, and sulfuric acid. The potential impact of these amendments could be enormous because they could be produced for less than half the price of alum while being as effective in reducing NH emissions and P runoff. PMID:27380093

  7. Use of industrial byproducts as alumina sources for the synthesis of calcium sulfoaluminate cements.

    Science.gov (United States)

    Pace, Maria Lucia; Telesca, Antonio; Marroccoli, Milena; Valenti, Gian Lorenzo

    2011-07-15

    Calcium sulfoaluminate (CSA) cements show some desirable environmentally friendly features that include the possibility of using several industrial byproducts as raw materials in their manufacturing process. Alumina powder, from the secondary aluminum manufacture, and anodization mud, from the production process of anodized aluminum, have proved to be suitable as partial or total substitutes for an expensive natural material like bauxite. CSA clinker generating raw mixtures, containing limestone, natural gypsum, bauxite, and/or one of the alumina-rich byproducts, were heated 2 h in a laboratory electric oven at temperatures ranging from 1150 to 1300 °C. Conversion of reactants into 4CaO·3Al(2)O(3)·SO(3) (the key component of CSA cements), evaluated using X-ray diffraction (XRD) analysis, increased with an increase of both burning temperature and byproduct concentration. When examined through differential thermogravimetric and XRD analyses, a synthetic CSA clinker (made from the raw mixture incorporating alumina powder as a total replacement of bauxite) mixed with 20% gypsum showed a hydration behavior almost similar to that of an industrial CSA cement containing the same amount of gypsum. PMID:21707122

  8. POPULATION STRUCTURE AND PRODUCTION OF COPAIBA OLEORESIN BETWEEN VALLEYS AND HILLSIDES OF THE MINING AREA OFTROMBETAS RIVER - PARÁ1

    OpenAIRE

    Jonas Gebara; Antenor Pereira Barbosa; Isabel Maria Gonçalves Azevedo; Bruno Oliva Gimenez

    2016-01-01

    ABSTRACT We aimed in this work to study natural populations of copaiba (Copaifera multijuga Hayne) on the Monte Branco mountain at Porto Trombetas-PA, in order to support sustainable management and the exploitation of oleoresin from copaiba. We studied the population structure of copaiba on hillsides and valleys of the south face of Monte Branco, within Saracá Taquera National Forest, where bauxite ore was extracted in the biennium 2013-2014 by Mineração Rio do Norte (MRN). We produced a 100%...

  9. The Best of Both Worlds: Supply and Demand China's Role as a Source of Refractory Minerals for Global Markets

    Institute of Scientific and Technical Information of China (English)

    Mike O' Driscoll

    2003-01-01

    China has long been recognised as an important source of refractory raw materials for refractory markets worldwide.Bauxite,magnesia,fused alumina, and refractory clays in particular, have maintained China's strong position as the world's leading supplier of these minerals .However , important changes have taken place ir the structure of Chinese and global supply of these minerals. Moreover, the world refractory market and the minerals trading sector have also undergone a radical transformation that has influenced mineral supply , and shifted end product manufacture to China . This paper highlights these changes and sees how they have impacted on China as a world source of refractory minerals.

  10. Mining-related environmental impacts of carbon mitigation; Coal-based carbon capture and sequestration and wind-enabling transmission expansion

    Energy Technology Data Exchange (ETDEWEB)

    Grubert, Emily

    2010-09-15

    Carbon mitigation can occur by preventing generation of greenhouse gases or by preventing emissions from entering the atmosphere. Accordingly, increasing the use of wind energy or carbon capture and storage (CCS) at coal-fired power plants could reduce carbon emissions. This work compares the direct mining impacts of increased coal demand associated with CCS with those of increased aluminum demand for expanding transmission systems to enable wind power incorporation. Aluminum needs for expanded transmission probably represent a one-time need for about 1.5% of Jamaica's annual bauxite production, while CCS coal needs for the same mitigation could almost double US coal demand.

  11. Le plateau des Guyanes et son potentiel minier

    OpenAIRE

    Théveniaut, Hervé; Billa, Mario; Cassard, Daniel; Delor, Claude; Maldan, Frédérik

    2011-01-01

    Deux milliards d'années nous contemplent lorsqu'il est question de la Guyane. Ce sous-sol précambrien du bouclier des Guyanes possède une histoire riche, complexe et des ressources minérales que les géologues scrutent attentivement depuis des décennies. L'or, le fer, la bauxite, le diamant et d'autres substances sont présentes du Venezuela au Brésil en passant par la Guyane. Comprendre, rechercher, identifier pour mieux exploiter sont les objectifs qui s'inscrivent dans les attentes de la soc...

  12. Temperature and ph effects on adsorption materials used for arsenic removal from drinking water

    International Nuclear Information System (INIS)

    This study focused on removal of arsenic from drinking water using different media such as bauxite, lime and plastic clay. Media were treated with different temperature and pH to check adsorption capacity changes. According to the results obtained, temperature (30 degree C and 40 degree C), pH 9 and 1h retention time has resulted maximum removal of arsenic on the media. The adsorption data was analyzed and it was found to obey Langmuir model with a good value (0.99) of correlation coefficient. (author)

  13. The effect of sintering temperature on the structure and properties of corundum/mullite ceramics

    Directory of Open Access Journals (Sweden)

    Yu-Ming T.

    2015-01-01

    Full Text Available In this work, samples are prepared by adding secondary raw bauxite and some suitable amount pure silica. After dry pressing molding, using solid phase sintering method sinter them at 1380ºC,1410ºC,1440ºC,1410ºC,1500ºC,1530ºC, respectively. A performance of the material is characterized by using SEM and XRD, such as microscopic morphology, phase composition and the compressive strength, etc. Combining results of experiments, explore the mechanism of sintering temperature on the properties of ceramic materials.

  14. Stratigraphy of Julian and Tuvalian Substage in the Oslica at Muljava Area (Slovenia

    Directory of Open Access Journals (Sweden)

    Stevo Dozet

    2002-12-01

    Full Text Available The Julian and Tuvalian lithologic column in the Oslica area starts with dolomitic breccias with limonitic groundmass and with a bauxite giving evidence of areal expose on the boundary between Cordevolian and Julian. Afterwards, precepitation of carbonate rocks followed. In the lithological interval where the limestone breccias predominate, oncolitic horizons are most characteristic. The Carnian sedimentary succession in the Oslica is terminated by a dolomite with intercalations of marls, bedded micritic limestones and a darkgrey dolomite with a roundish disintegration. The lithological composition and sedimentological characteristics of the succession indicate an origin in the littoral environment.

  15. Pinjarra 1970: Shame and the Country Town

    Directory of Open Access Journals (Sweden)

    Robyn Ferrell

    2013-09-01

    Full Text Available Pinjarra in 1970 lay on an extraordinary cusp. It lagged along a fault line between one order and another; or rather, it squatted at a precipice, over which its cherished values had already been dashed to pieces. In 1967, Aboriginal people were at last, by national referendum, declared citizens of Australia. In 1969, Alcoa began to prepare the site in the hills behind Pinjarra for the open-cut mining of the largest bauxite deposit so far discovered in the world. The past met the future, and they didn’t recognise each other.

  16. Natural radioactivity contamination problems. Report no. 2. (final)

    International Nuclear Information System (INIS)

    Levels of naturally occurring radionuclides associated with the bauxite, columbium-tantalum, phosphate, tin, pumice, and titanium mineral extraction industries are reported. Data is also presented on radioactivity measurements in ground water, in selected geothermal waters, and in oil production brines. Radiation protection guidance is provided for uranium recovery from wet-process phosphate plants, for soil contamination limits, and for radiological exposure in natural caves. Dose pathways from incidental uses of naturally occurring radioactive materials are presented. Model state regulations for protecting public health and safety from use and disposal of naturally occurring radioactive material are outlined

  17. Aluminum-silicates flotation with quaternary ammonium salts

    Institute of Scientific and Technical Information of China (English)

    王毓华; 胡岳华; 陈湘清

    2003-01-01

    The zeta potential measurements show that the flotation separation of diaspore from kaolinite, illite and pyrophyllite could be achieved in the range of pH 46.5 with cationic collectors. A special quaternary ammonium salts(DTAL) shows better selectivity than that the dodecyl amine(DDA) does for the flotation of three silicates. The closed-circuit flotation results show that the reverse flotation de-silicate can be achieved with DTAL as collector, a new inorganic reagent(SFL) as depressant and MIBC as frother to obtain a bauxite concentrate m(Al2O3)/m(SiO2)>10, Al2O3 recovery>86%).

  18. Development of Andalusite Bricks for Hot Blast Stove

    Institute of Scientific and Technical Information of China (English)

    KANG Huarong; LI Xianming; DONG Shengying; XUE Wendong; LI Yong; SONG Wen

    2008-01-01

    Low-creep andalusite bricks are characterized by high refractoriness under load, good anti-creep property, high mechanical strength, low porosity, good thermal shock resistance, etc. In this study, low-creep andalusite brick specimens were investigated in the lab using mullite, bauxite and andalusite. Andalusite with the different panicle sizes were used in the experiment and the specimen with the best property was selected as the production standard. In addition, the industrial produced low-creep andalusite bricks were compared with other low-creep bricks. The results show that the developed low-creep andalusite bricks is an excellent material for hot blast stove.

  19. Morphology of the lumbosacral plexus of the ocelot (Leopardus pardalis)

    OpenAIRE

    Jessica Albuquerque Lopes; Lara Cochete Moura Fé; Ana Rita de Lima; Érika Branco; Luiza Corrêa Pereira

    2012-01-01

    Popularly known as the ocelot, Leopardus pardalis occurs throughout Brazil in all ecosystems, but prefers riparian regions and forests. The objective of this study was to learn more about the macroscopic, anatomical aspects of the plexus lumbossacral of this species. Three specimens were studied, two males and one female, from the region near the Bauxite Mine in Paragominas, PA. The specimens were donated to the Laboratório de Pesquisa Morfológica Animal (LaPMA) at UFRA after being run over (...

  20. Political Legitimacy of Vietnam’s One Party-State: Challenges and Responses

    Directory of Open Access Journals (Sweden)

    Carlyle A. Thayer

    Full Text Available This article focuses on the challenges to the authority of Vietnam’s one-party state that emerged in 2009 and state responses. Three separate challenges are discussed: opposition to bauxite mining in the Central Highlands; mass protests by the Catholic Church over land ownership issues; and revived political dissent by pro-democracy activists and bloggers. The Vietnam Communist Party bases its claims to political legitimacy on multiple sources. The bauxite mining controversy challenged the state’s claim to political legitimacy on the basis of performance. The Catholic land dispute challenged the state’s claim to legitimacy on rational-legal grounds. Revived political dissent, including the linkage of demands for democracy with concerns over environmental issues and relations with China, challenged the state’s claim to legitimacy based on nationalism. Vietnam responded in a “soft authoritarian” manner. Future challenges and state responses will be debated as Vietnam moves to convene its eleventh national party congress in 2010.

  1. Progress in Research and Development of Refractory Oxide-Nonoxide Composites

    Institute of Scientific and Technical Information of China (English)

    ZHONG Xiangchong

    2008-01-01

    Some of the progress made in our laboratories in collaboration with industry in research and development work on high performance oxide-nonoxide composites for metallurgical applications has been reviewed. (1) SiAlON bonded corundum composites for blast furnace usage have been produced by reduction-nitridation sintering at high temperature, using bauxite instead of alumina in the matrix. (2) Low carbon Al2O3-SiAlON slide plate materials successfully used in high quality steel continuous casting have been developed in which most or all of the graphite in Al2O3-C brick is replaced by bauxite-based β-SiAlON. (3) Al/Si metal bonded Al2O3-C material characterized by low carbon content, low firing temperature and in-situ formation of carbides and nitrides at high temperature during service are found to possess very high hot strength and very good thermal shock resistance and have also been successfully used as slide plates in ladles and tundishes for high quality steel casting.

  2. Optimizing Location of Bulk Metallic Minerals Processing Based on Greenhouse Gas Avoidance

    Directory of Open Access Journals (Sweden)

    Benjamin C. McLellan

    2011-12-01

    Full Text Available The bulk minerals iron ore and bauxite cause significant greenhouse emissions in their processing to steel and aluminum respectively. The level of these emissions is highly dependent on the source of electrical and thermal energy. However, they also cause significant greenhouse gas emissions from their transportation across the globe for processing. This study examines these minerals from the perspective of greenhouse gas avoidance, examining the location of processing as an option for reducing transportation-based and process-based emissions. The analysis proposes a “radius of reduction” to define the potential for transporting ore to reduce emissions by offshore processing. Overall scenarios for localized steel production indicate potential for 85% reduction of transport emissions in the steel industry and 14% of overall industry emissions. Local high-carbon electricity grids and inefficient production mean that the benefit of reduced transportation is partially counteracted by increased processing emissions. The transportation of all global bauxite to Norway and other nations with low-emissions electricity for production of aluminum could result in an overall reduction of industry emissions of up to 44%.

  3. Distribution and seasonality of the marine macrophytes from Antikyra Gulf (Viotia, Greece

    Directory of Open Access Journals (Sweden)

    P. MALEA

    2012-12-01

    Full Text Available The Gulf of Antikyra (Viotia with a bauxitic substrate was aggravated by wastes discharged from an Aluminium factory where the Parnassos bauxite is treated Seasonal collections of macrophytes from stations selected inside the Antikyra Gulf were carried out. 85 species of macroalgae were totally collected, out of which 16 belonged to Chlorophyceae, 12 to Phaeophyceae and 57 to Rhodophyceae. There has been no obvious difference in the qualitative composition of the macroalgae as we move away from the area where the wastes are being discharged. Moreover, the stations where depths are greater exhibit different qualitative composition that those with smaller depths. The presence of phanerogams and especially that of Halophila stipulacea, the Lessepsian immigrant, encountered for the first time in the Korinthiakos Gulf, was also evident. The biomass of the three phanerogams decreased with the order: Posidonia oceanica>Cymodocea nodosa>Halophila stipulacea. The biomass of C. nodosaand P. oceanica was higher in July, while that of H. stipulacea was lower in July and higher in March and September.

  4. Incorporation of zinc for fabrication of low-cost spinel-based composite ceramic membrane support to achieve its stabilization.

    Science.gov (United States)

    Li, Lingling; Dong, Xinfa; Dong, Yingchao; Zhu, Li; You, Sheng-Jie; Wang, Ya-Fen

    2015-04-28

    In order to reduce environment risk of zinc, a spinel-based porous membrane support was prepared by the high-temperature reaction of zinc and bauxite mineral. The phase evolution process, shrinkage, porosity, mechanical property, pore size distribution, gas permeation flux and microstructure were systematically studied. The XRD results, based on a Zn/Al stoichiometric composition of 1/2, show a formation of ZnAl2O4 structure starting from 1000°C and then accomplished at 1300°C. For spinel-based composite membrane, shrinkage and porosity are mainly influenced by a combination of an expansion induced by ZnAl2O4 formation and a general densification due to amorphous liquid SiO2. The highest porosity, as high as 44%, is observed in ZnAl4 membrane support among all the investigated compositions. Compared with pure bauxite (Al), ZnAl4 composite membrane support is reinforced by ZnAl2O4 phase and inter-locked mullite crystals, which is proved by the empirical strength-porosity relationships. Also, an increase in average pore diameter and gas flux can be observed in ZnAl4. A prolonged leaching experiment reveals the zinc can be successfully incorporated into ceramic membrane support via formation of ZnAl2O4, which has substantially better resistance toward acidic attack. PMID:25655422

  5. Control methods for remediation of ash-related problems in fluidized-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.

    1999-07-01

    The paper reports on investigations into control methodologies for mitigating ash-related problems such as particle agglomeration and bed defluidization during fluidized-bed combustion of low-rank coals. A laboratory scale spouted bed combustor is used to study the effectiveness of control methodologies. In the present work, two control methods are investigated viz., the use of alternative bed materials and pretreatment of coal. Bauxite and calcined sillimanite are used as alternative bed materials in the spouted bed combustor while burning South Australian low-rank coal. Samples of the same coal subjected to Al pretreatment, water washing and acid washing are also tested in the spouted bed combustor. Experiments showed that both methods are effective to different extents in reducing ash-related problems. Tests with calcined sillimanite and bauxite (as the bed material) showed trouble free operation for longer periods (7--12 hr at 800 C and 3--5 hr at 850 C) than with sand runs at the same bed temperatures. Al pretreatment and water-washing were also found to be effective and resulted in extended combustion operation. Al enrichment in ash coating of bed particles has been identified as the main mechanism for prevention of agglomeration and defluidization by these control methodologies. For water-washing, the principal reason behind agglomeration and defluidization control is the reduction in sodium levels.

  6. [Study on the influence of mineralizer on the structures and spectral properties of calcium aluminates].

    Science.gov (United States)

    Zheng, Huai-Li; Liu, Jun-Yu; Li, Lin-Tao; Li, Fang

    2009-11-01

    The present paper investigated the effect of mineralizer on the structure and properties of calcium aluminates formation. Calcium aluminates powder was synthesized under high temperature calcination by mixing bauxite, limestone and a certain amount of mineralizer. The product structure, compositional information and spectral properties were carefully characterized by XRD, IR and DTA-TG, and the mineralization mechanism of mineralizer was studied during the process of calcium aluminates preparation. The results showed that calcium aluminates powder could be obtained under lower temperature calcination after adding mineralizer to the raw materials. The main products of the reaction were CaAl10 O18 and CaAl2 Si2 O8 without mineralizer, however, the main products of the reaction were CaAl3 BO7 and Ca3 Al10 O18 with mineralizer, in which Al2 O3s could be extracted easily, while CaAl2 Si2 O8 was reduced greatly in which Al2 O3 could not be extracted easily. At the same time, it is easy for calcspar to decompose after adding mineralizer. It is favorable to Al-Si bond break and Al stripping from bauxite. These facts could improve the extraction rate of Al2 O3 from raw materials. Also, in the case of adding mineralizer to the raw mixes, the crystal structure and composition are changed, which is beneficial to reducing calcination temperature.

  7. Calcium looping spent sorbent as a limestone replacement in the manufacture of portland and calcium sulfoaluminate cements.

    Science.gov (United States)

    Telesca, Antonio; Marroccoli, Milena; Tomasulo, Michele; Valenti, Gian Lorenzo; Dieter, Heiko; Montagnaro, Fabio

    2015-06-01

    The calcium looping (CaL) spent sorbent (i) can be a suitable limestone replacement in the production of both ordinary Portland cement (OPC) and calcium sulfoaluminate (CSA) cement, and (ii) promotes environmental benefits in terms of reduced CO2 emission, increased energy saving and larger utilization of industrial byproducts. A sample of CaL spent sorbent, purged from a 200 kWth pilot facility, was tested as a raw material for the synthesis of two series of OPC and CSA clinkers, obtained from mixes heated in a laboratory electric oven within temperature ranges 1350°-1500 °C and 1200°-1350 °C, respectively. As OPC clinker-generating mixtures, six clay-containing binary blends were investigated, three with limestone (reference mixes) and three with the CaL spent sorbent. All of them showed similar burnability indexes. Moreover, three CSA clinker-generating blends (termed RM, MA and MB) were explored. They included, in the order: (I) limestone, bauxite and gypsum (reference mix); (II) CaL spent sorbent, bauxite and gypsum; (III) CaL spent sorbent plus anodization mud and a mixture of fluidized bed combustion (FBC) fly and bottom ashes. The maximum conversion toward 4CaO·3Al2O3·SO3, the chief CSA clinker component, was the largest for MB and almost the same for RM and MA. PMID:25915150

  8. Prevalent material parameters governing spalling of a slag-impregnated refractory

    Energy Technology Data Exchange (ETDEWEB)

    Blond, E.; Schmitt, N.; Arnould, O.; Hild, F. [LMT-Cachan (ENS de Cachan / CNRS-UMR 8535 / Univ. Paris 6), Cachan (France); Blumenfeld, P. [CRDM / ARCELOR Grande Synthe, Dunkerque (France); Poirier, J. [CRDM / ARCELOR Grande Synthe, Dunkerque (France); CRMHT-CNRS, Orleans (France)

    2004-07-01

    In steel ladle linings, bauxite refractories in contact with iron and steel slag are subjected to complex loadings. To identify the causes of degradation in different reactor linings, a coupling diagram made up of three poles is established: namely, slag impregnation (I), Thermomechanics (TM) and phase transformations (P). The variation of the microstructure and the gradient of the chemical composition resulting from the (I-P) coupling are characterized by microprobe analyses; a natural impregnation tracer is identified. The (I-T) coupling is studied by modeling the refractory lining behavior subjected to a cyclic thermal loading within the framework of the mechanics of porous continua. Parameters governing the location and amplitude of the maximum pore pressure are obtained and their influences are studied. The analysis of the (TM) pole leads to the identification of a thermo-elasto-viscoplastic model for bauxite in various states of slag impregnation. Numerical simulations show that the stress state developed during the heating stages can induce spalling, probably generated by a localized over-pressure of slag. (orig.)

  9. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110947 Chen Xinglong(Guizhou Bureau of Nonferrous Metal and Nuclear Geology,Guiyang 550005,China);Gong Heqiang Endowment Factors and Development & Utilization Strategy of Bauxite Resource in North Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(2),2010,p.106-110,6 refs.,with English abstract)Key words:bauxite deposit,Guizhou Province20110948 Dang Yanxia(Mineral Resource & Reservoir Evaluation Center,Urumiq 830000,China);Fan Wenjun Geological Features and a Primary Study of Metallogenesis of the Wucaiwang Zeolite Deposit,Fuyun County(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,28(2),2010,p.167-170,2 illus.,1 table,5 refs.)Key words:zeolite deposit,Xinjiang Nearly all zeolite deposits in the world result from low-temperature-alteration of glass-bearing volcanic rocks.The southern slope of the Kalamali Mountain is one of the regions where medium to acid volcanics are major lithological type,thus it is a preferred area to look for zeolite deposit.The Wucaiwang zeolite ore district consists of mainly acid volcanic-clastic rocks.

  10. Preparation and Characteristics of Polyaluminium Chloride by Utilizing Fluorine-Containing Waste Acidic Mother Liquid from Clay-Brine Synthetic Cryolite Process

    Directory of Open Access Journals (Sweden)

    Feng-shan Zhou

    2014-01-01

    Full Text Available Clay-brine process employing activated clay, NaCl, HCl, and HF as raw materials is the primarily advanced technology to synthesize cryolite in the present industrial grade. However, plenty of byproducts of fluorine-containing waste HCl at the concentration of about 10%~12% could not be utilized comprehensively and are even hazardous to the environment. This work proposed a new two-step technology to prepare inorganic polymer flocculants polyaluminium chloride (PAC from synthetic cryolite mother liquor. Many specific factors such as the variety of aluminide source, reaction temperature and time, reagent ratio, and manner of alkaline addition were taken into consideration and their influences on the performances of produced PAC were discussed. It was found that synthetic cryolite mother liquor could react with bauxite and calcium aluminate directly to prepare cheap PAC, with plenty amount of water insoluble CaF2 and CaSiF6 produced as well. However, once HCl was introduced into synthetic cryolite mother liquor as well as by utilizing bauxite as aluminide source and sodium aluminate as adjusting basicity agent, the resultant PAC would dissolve out higher amount of aluminum while producing little amount of water insoluble materials. The coagulation behavior of the specially produced PAC could even match the industrial grade PAC conforming to national standard.

  11. In-situ subaqueous capping of mercury-contaminated sediments in a fresh-water aquatic system, Part II-evaluation of sorption materials

    Energy Technology Data Exchange (ETDEWEB)

    Randall, Paul M., E-mail: randall.paul@epa.gov [U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, 26 W. Martin Luther King Drive, Cincinnati, OH 45268 (United States); Yates, Brian J.; Lal, Vivek; Darlington, Ramona [Battelle, 505 King Avenue, Columbus, OH 43201 (United States); Fimmen, Ryan [Geosyntec Consultants, 150 E. Wilson Bridge Road, Suite 232, Worthington, OH 43085 (United States)

    2013-08-15

    The function and longevity of traditional, passive, isolation caps can be augmented through the use of more chemically active capping materials which have higher sorptive capacities, ideally rendering metals non-bioavailable. In the case of Hg, active caps also mitigate the rate and extent of methylation. This research examined low cost, readily available, capping materials for their ability to sequester Hg and MeHg. Furthermore, selected capping materials were evaluated to inhibit the methylation of Hg in an incubation study as well as the capacity of a selected capping material to inhibit translocation of Hg and MeHg with respect to ebullition-facilitated contaminant transport in a column study. Results indicated that bauxite had a better capacity for mercury sorption than the other test materials. However, bauxite as well as soil capping materials did not decrease methylation to a significant extent. Materials with larger surface areas, higher organic matter and acid volatile sulfide (AVS) content displayed a larger partitioning coefficient. In the incubation experiments, the presence of a carbon source (lactate), electron acceptor (sulfate) and the appropriate strains of SRB provided the necessary conditions for Hg methylation to occur. The column study showed effectiveness in sequestering Hg and MeHg and retarding transport to the overlying water column; however, disturbances to the soil capping material resulting from gas ebullition negated its effectiveness.

  12. Effects of Mineral Structure on Growth Metabolism and Silicon-dissolving of Bacillus Mucilaginosus%矿物结构对胶质芽孢杆菌生长代谢及溶硅的影响

    Institute of Scientific and Technical Information of China (English)

    李漪; 王海林; 孙德四

    2013-01-01

    选用一株胶质芽孢杆菌,通过检测发酵培养液中代谢产物种类与含量、SiO2浓度、pH值、细菌数量以及分析胶质芽孢杆菌-矿物相互作用后矿物表面微观形态与结构的变化,研究该菌种在高岭土、石英与铝土矿环境中生长代谢规律及对不同矿物的分解作用机制.结果表明,该菌种在不同矿物环境中生长规律基本一致,生长周期有一定差异;铝硅酸盐矿物能显著促进与刺激该菌种生长代谢能力,其中高岭土对菌种作用最为明显;该菌种对高岭土分解效果最好,发酵15d后,浸出液中SiO2质量浓度达到41 mg/L左右;高岭土与铝土矿表面微观形态与石英相比变化明显,表明矿物结构是影响硅酸盐矿物微生物分解的重要因素.%A strain of silicate bacteria was chosen to carry out a study on the microbial growth metabolisms and the microbial degradation of different silicate minerals.The mechanism by which silicate bacteria decompose kaolin,quartz and bauxite was studied by measuring types and concentrations of metabolites,densities of SiO2,pH value and bacterial populations in the culturing media,and analyzed the morphologic changes and stuctures of tested minerals afer being leached by the strian.The results show that the strain has the same microbial growth curves in different minerals media.Tested aluminosilicate minerals can promote and stimulate tha ability of the microbial growth metabolism,kaolin has the most obvious effect on the microbial growth metabolism as compared with quartz and bauxite.The strain can decompose kaolin more easily than bauxite and quartz,the concentration ofSiO2 in kaolin supernatant is about 41 mg/L,but is 31 and 33 mg/L respectively in quartz and bauxite supernatant after a 15 d leaching.The mineral microscopic surfaces and structures of kaolin and bauxite are more obviously changed after interaction with the strain as compared witrh that of quartz.It is concluded that the

  13. Water yield issues in the jarrah forest of south-western Australia

    Science.gov (United States)

    Ruprecht, J. K.; Stoneman, G. L.

    1993-10-01

    The jarrah forest of south-western Australia produces little streamflow from moderate rainfall. Water yield from water supply catchments for Perth, Western Australia, are low, averaging 71 mm (7% of annual rainfall). The low water yields are attributed to the large soil water storage available for continuous use by the forest vegetation. A number of water yield studies in south-western Australia have examined the impact on water yield of land use practices including clearing for agricultural development, forest harvesting and regeneration, forest thinning and bauxite mining. A permanent reduction in forest cover by clearing for agriculture led to permanent increases of water yield of approximately 28% of annual rainfall in a high rainfall catchment. Thinning of a high rainfall catchment led to an increase in water yield of 20% of annual rainfall. However, it is not clear for how long the increased water yield will persist. Forest harvesting and regeneration have led to water yield increases of 16% of annual rainfall. The subsequent recovery of vegetation cover has led to water yields returning to pre-disturbance levels after an estimated 12-15 years. Bauxite mining of a high rainfall catchment led to a water yield increase of 8% of annual rainfall, followed by a return to pre-disturbance water yield after 12 years. The magnitude of specific streamflow generation mechanisms in small catchments subject to forest disturbance vary considerably, typically in a number of distinct stages. The presence of a permanent groundwater discharge area was shown to be instrumental in determining the magnitude of the streamflow response after forest disturbance. The long-term prognosis for water yield from areas subject to forest thinning, harvesting and regeneration, and bauxite mining are uncertain, owing to the complex interrelationship between vegetation cover, tree height and age, and catchment evapotranspiration. Management of the forest for water yield needs to acknowledge

  14. Production of ultra-pure steel intended for forged elements

    Directory of Open Access Journals (Sweden)

    A. Michaliszyn

    2012-12-01

    Full Text Available Purpose: The purpose of this research is to analyse the technology of making ultra-pure steel intended for casting forging ingots. Forging ingots, whose mass amounts to 8 Mg, are cast using the bottom pouring method after vacuum steel degassing in the ladle.Design/methodology/approach: Data from 24 melts were analysed. Researchers studied not only the final content of oxygen, sulphur and hydrogen after vacuum steel refinement but also the quantitative amount of nonmetallic inclusions in forgings made of ingots. A simulation was also conducted. Its purpose was to assess the optimal share of bauxite in the production of refining slag. The simulation was performed using thermodynamic software called FactSage 5.5.Findings: Analysing the final concentration of oxygen dissolved in liquid steel led to a conclusion that approx. 90% of analysed types of steel can be categorized as ultra-pure. The simulation results concerning refining slag formation show that the use of bauxite as a slag forming additive lead to an increase in the liquid phase, and what follows, a decrease in the share of solid precipitations – including the precipitations of lime.Research limitations/implications: It was concluded that all stages of ultra-pure steel production must be conducted conscientiously and meticulously. It is also necessary to improve the conditions of vacuum steel refining process by equipping steelworks with a new vacuum device, e.g. of VOD type.Practical implications: If all stages of steel making are conducted conscientiously and meticulously and the steelworks are equipped with a device for vacuum steel refinement, then the produced steel (from the point of view of quality can be competitive in the market of the ultra-pure steel intended for forged products.Originality/value: The simulation results concerning the production of refining slag show that the use of bauxite as a slag forming material leads to an increase in the share of liquid phase. Refining

  15. 铁铝尖晶石合成的热力学分析与制备方法比较%Thermodynamic Analysis and Methods Comparison of Hercynite Preparation

    Institute of Scientific and Technical Information of China (English)

    朱玉婷; 田真; 高峰

    2015-01-01

    The thermal reaction process and thermodynamic characteristics in the preparation of hercynite were analyzed in this study ,and hercynite was synthesized with ferric bauxite/Al2 O3 powder ,Fe2 O3 powder and praphite powder/glucose by sintering reaction and molten‐salt menth‐od ,respectively .The products were analyzed by XRD ,SEM and optical microscopy .The results show that the hercynite synthesized by sintering reaction under N2 atmosphere has better crystal‐lization .Molten‐salt method can lower the synthesis temperature of hercynite significantly ,which provides a more moderate method for the industrial production of hercynite .Using ferric bauxite as raw material ,hercynite can be synthesized by sintering reaction at a lower cost .%研究分析了合成铁铝尖晶石的热历程及其热力学特征,并以Al2 O3粉、Fe2 O3粉/高铁铝土矿为原料,以石墨/葡萄糖为还原剂,分别采用烧结法和熔盐法合成了铁铝尖晶石,利用X RD、SEM 及光学显微镜对样品进行了表征。结果表明:在氮气气氛下以Al2 O3粉和Fe2 O3粉为原料采用烧结法合成的铁铝尖晶石结晶良好,采用熔盐法可以显著降低铁铝尖晶石的合成温度,为铁铝尖晶石的工业生产提供了一种较为温和的方法;采用高铁铝土矿为原料,通过氮气气氛下的烧结法可以较为廉价地合成铁铝尖晶石。

  16. Comparison of deep desulfurization methods in alumina production process

    Institute of Scientific and Technical Information of China (English)

    刘战伟; 李旺兴; 马文会; 尹中林; 武国宝

    2015-01-01

    Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2− in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2− on alumina product quality is eliminated. However, the removal efficiency of2-23SOin sodium aluminate solution is very low by this method. Both S2− and2-23SO in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.

  17. Slurry pipeline design approach

    Energy Technology Data Exchange (ETDEWEB)

    Betinol, Roy; Navarro R, Luis [Brass Chile S.A., Santiago (Chile)

    2009-12-19

    Compared to other engineering technologies, the design of a commercial long distance Slurry Pipeline design is a relatively new engineering concept which gained more recognition in the mid 1960 's. Slurry pipeline was first introduced to reduce cost in transporting coal to power generating units. Since then this technology has caught-up worldwide to transport other minerals such as limestone, copper, zinc and iron. In South America, the use of pipeline is commonly practiced in the transport of Copper (Chile, Peru and Argentina), Iron (Chile and Brazil), Zinc (Peru) and Bauxite (Brazil). As more mining operations expand and new mine facilities are opened, the design of the long distance slurry pipeline will continuously present a commercially viable option. The intent of this paper is to present the design process and discuss any new techniques and approach used today to ensure a better, safer and economical slurry pipeline. (author)

  18. Social Metabolism and Environmental Conflicts in India

    Directory of Open Access Journals (Sweden)

    Joan Martinez-Alier

    2014-04-01

    Full Text Available This paper explains the methods for counting the energy and material flows in the economy, and gives the main results of the Material Flows for the economy of India between 1961 and 2008 as researched by Simron Singh et al (2012. Drawing on work done in the EJOLT project, some illustrations are given of the links between the changing social metabolism and ecological distribution conflicts, looking at responses in Odisha to bauxite mining, at conflicts on sand mining, at disputes on waste management options in Delhi and at ship dismantling in Alang, Gujarat. The aim is to show how a history of social metabolism, of socio-environmental conflicts, and of the changing valuation languages deployed by various social actors in such conflicts, could be written in a common framework.

  19. Sustainable development of the minerals sector in the APEC region

    Energy Technology Data Exchange (ETDEWEB)

    Jane Melanie; Kate Penney; Angelica Austin; Chris Rumley; Robert Curtotti

    2007-01-15

    The objectives in this report are to analyse the global market outlook for minerals over the medium term, identify key issues affecting the sustainability of the minerals sector in the APEC region and recommend possible actions to respond to these issues. These issues are structured around the APEC pillars of trade and investment liberalisation; business facilitation; and economic and technical cooperation. The report highlights the need for a strong and effective policy framework to allow APEC economies to capitalise on growth opportunities in global minerals markets. This is an updated version of ABARE Research Report 06.8. Minerals covered are: thermal coal. metallurgical coal, aluminium, alumina, bauxite, copper, gold, iron ores, lead, nickel, tin, uranium and zinc. 15 figs., 19 tabs.

  20. Aluminium leaching from red mud by filamentous fungi.

    Science.gov (United States)

    Urík, Martin; Bujdoš, Marek; Milová-Žiaková, Barbora; Mikušová, Petra; Slovák, Marek; Matúš, Peter

    2015-11-01

    This contribution investigates the efficient and environmentally friendly aluminium leaching from red mud (bauxite residue) by 17 species of filamentous fungi. Bioleaching experiments were examined in batch cultures with the red mud in static, 7-day cultivation. The most efficient fungal strains in aluminium bioleaching were Penicillium crustosum G-140 and Aspergillus niger G-10. The A. niger G-10 strain was capable to extract up to approximately 141 mg·L(-1) of aluminium from 0.2 g dry weight red mud. Chemical leaching with organic acids mixture, prepared according to A. niger G-10 strain's respective fungal excretion during cultivation, proved that organic acids significantly contribute to aluminium solubilization from red mud.

  1. Determination of Natural Radioactivity in Building Materials with Gamma Spectrometry

    International Nuclear Information System (INIS)

    In the setting of this work, the natural radioactivity of building materials used in Tunisia has been measured by gamma spectrometry. These products have been ground and dried at 100 degree for 12 h. Then, they have been homogenized, weighed and finally conditioned during 23 days in order to reach the radioactive equilibrium. The measures' results proved that all building materials studied except bauxite and the ESC clay, possess doses lower than the acceptable limit (1 mSv.an-1). However, the possibility of reinforcement of the natural radioactivity in some industry of building can exist. To insure that the cement, the most used in the world, don't present any radiological risk on the workers' health, a survey has been made in the factory - les Ciments de Bizerte - about its manufacture's process. The results of this survey showed that this product can be considered like a healthy product.

  2. Study of CO2 cyclic absorption stability of CaO-based sorbents derived from lime mud purified by sucrose method.

    Science.gov (United States)

    Ma, AiHua; Jia, QingMing; Su, HongYing; Zhi, YunFei; Tian, Na; Wu, Jing; Shan, ShaoYun

    2016-02-01

    Using lime mud (LM) purified by sucrose method, derived from paper-making industry, as calcium precursor, and using mineral rejects-bauxite-tailings (BTs) from aluminum production as dopant, the CaO-based sorbents for high-temperature CO2 capture were prepared. Effects of BTs content, precalcining time, and temperature on CO2 cyclic absorption stability were illustrated. The cyclic carbonation behavior was investigated in a thermogravimetric analyzer (TGA). Phase composition and morphologies were analyzed by XRD and SEM. The results reflected that the as-synthesized CaO-based sorbent doped with 10 wt% BTs showed a superior CO2 cyclic absorption-desorption conversion during multiple cycles, with conversion being >38 % after 50 cycles. Occurrence of Ca12Al14O33 phase during precalcination was probably responsible for the excellent CO2 cyclic stability.

  3. A STUDY ON THE BEHAVIOUR OF GALLIUM IN THE IRONMAKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    L. Savov; S. Garonin; O. Ivanov; Y.S. Yusfin; D. Janke

    2003-01-01

    Gallium is a valuable rare metal which is mainly being used in the production of GaAs.The demand for gallium is increasing but production is limited since gallium is ex-tracted only as a by-product of bauxite processing. On the other hand coal, ironmakingcoke and iron ore gangue contain traces of gallium. However little is known about thebehaviour of gallium in ironmaking. The aim of the study is to clarify the distributionof gallium between hot metal, slag and top gas by means of laboratory experiments. Itwas found that Ga2 O3 is not stable in blast furnace slags and that gallium is retainedin hot metal. Vacuum distillation experiments with hot metal showed that galliumis not transferred to the gas phase. Data on the input and output of gallium at twoindustrial blast furnaces, as well as chemical analyses of the gallium content of severalcokes are presented, too.

  4. Considering the Epistemic Uncertainties of the Variogram Model in Locating Additional Exploratory Drillholes

    Directory of Open Access Journals (Sweden)

    Saeed Soltani

    2015-06-01

    Full Text Available To enhance the certainty of the grade block model, it is necessary to increase the number of exploratory drillholes and collect more data from the deposit. The inputs of the process of locating these additional drillholes include the variogram model parameters, locations of the samples taken from the initial drillholes, and the geological block model. The uncertainties of these inputs will lead to uncertainties in the optimal locations of additional drillholes. Meanwhile, the locations of the initial data are crisp, but the variogram model parameters and the geological model have uncertainties due to the limitation of the number of initial data. In this paper, effort has been made to consider the effects of variogram uncertainties on the optimal location of additional drillholes using the fuzzy kriging and solve the locating problem with the genetic algorithm (GA optimization method.A bauxite deposit case study has shown the efficiency of the proposed model.

  5. Utilization of red mud for the purification of waste waters from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Luka, Mikelic; Visnja, Orescanin; Stipe, Lulic [Rudjer Boskovic Institute, Lab. for radioecology, Zagreb (Croatia)

    2006-07-01

    Sorption of the radionuclides and heavy metals from low level liquid radioactive waste on the coagulant produced from bauxite waste (red mud and waste base) was presented. Research was conducted on composite annual samples of waste water collected in the Waste Monitor Tank (W.M.T.) from Kro Nuclear Power Plant during each month. Activities of radionuclide in W.M.T. were measured before and after purification using high purity germanium detector. Also, elemental concentrations in W.M.T. before and after purification were measured by source excited energy dispersive X-ray fluorescence (E.D.X.R.F.). It has been showed that activated red mud is excellent purification agent for the removal of radionuclides present in low level liquid radioactive waste. Removal efficiency was 100% for the radionuclides {sup 58}Co and {sup 60}Co 100%, and over 60% for {sup 134}Cs and {sup 137}Cs. (authors)

  6. Termites as ecological indicators of mine-land rehabilitation in tropical Australia

    International Nuclear Information System (INIS)

    This paper presents examples from field research of termites as indicators of rehabilitation success in the wet-dry tropics at Nabalco's bauxite mine, Gove, Australia and in Sierra Leone, West Africa. Field studies indicate that soil-plant-animal interactions are crucial in determining the recovery of disturbed land and that termites play an over-riding role in the process. Termites are seen as ecological indicators for successful soil and vegetation development in humid tropical environments. In land rehabilitation, termites help to create healthy, self-regulated vegetation systems that integrate with the surrounding landscapes and build structures and functions equal to those of the pre-disturbed system. They are reliable in signaling the health and stress factors of a system and provide a predictable response

  7. FEATURES OF VENTILATION CONDITIONS BY MUSHROOM CULTIVATION IN MINING UNDERGROUND WORKINGS

    Directory of Open Access Journals (Sweden)

    Vladimir Rendulić

    1991-12-01

    Full Text Available The trial cultivation of mushrooms (Agaricus bisporus in one of the dead faces of the »Krš« pit of the Dalmatian bauxite mines Obrovac proved, that an optimal yield can be attained with the domestic mycelium. The decision has been brought to go on with investments into equipment for new growing-site locations in underground workings of the mine. In order to cultivate high-quality mushrooms, the ventilation of growing sites has been particularly considered. Compressive separate ventilation of growing fields has been applied using the main and the return ventilating pipeline, with the air current regulation according to the growing stage (the paper is published in Croatian.

  8. Use of red mud as addition for portland cement mortars

    International Nuclear Information System (INIS)

    The aim of the present research work was to investigate the possibility of adding red mud, an alkaline leaching waste that is obtained from bauxite during the Bayer process for alumina production, in the raw meal of Portland cement mortars. The red mud is classified as dangerous, according to NBR 10004/2004, and world while generation reached over 117 million tons/year. This huge production requires high consuming products to be used as incorporation matrix and we studied the influence of red mud addition on the characteristics of cement mortars and concrete. In this paper the properties of Portland cement mortars incorporating high amounts of red mud was evaluated: pH variation, fresh (setting time, workability or normal consistency and water retention), and hardened state (mechanical strength, capillary water absorption, density and apparent porosity). Results seem promising for red mud additions up to 20 wt%. (author)

  9. Prediction of Al2O3 leaching recovery in the Bayer process using statistical multilinear regresion analysis

    Directory of Open Access Journals (Sweden)

    Đurić I.

    2010-01-01

    Full Text Available This paper presents the results of defining the mathematical model which describes the dependence of leaching degree of Al2O3 in bauxite from the most influential input parameters in industrial conditions of conducting the leaching process in the Bayer technology of alumina production. Mathematical model is defined using the stepwise MLRA method, with R2 = 0.764 and significant statistical reliability - VIF<2 and p<0.05, on the one-year statistical sample. Validation of the acquired model was performed using the data from the following year, collected from the process conducted under industrial conditions, rendering the same statistical reliability, with R2 = 0.759.

  10. Assessment of the Completeness of Mineral Exploration by the Application of Fuzzy Arithmetic and Prior Information

    Directory of Open Access Journals (Sweden)

    György Bárdossy

    2005-06-01

    Full Text Available The completeness of an exploration project is of crutial importance for makingdecision to start or to give up a mining investment, or to continue the exploration to getcomplementary information. The authors discuss this problem on the example of theHalimba bauxite deposit, Hungary. Resource calculations were carried out in 12subsequent stages by fuzzy arithmetic with the aim to quantify the uncertainties of oretonnage and grade. Prior information and prior probabilities were applied to complete theexploration data. Ranges of influence for the main variables were calculated byvariograms. Spatial variability and spatial continuity of the ore bodies weremathematically evaluated. The authors found that the main geological, mining andeconomic factors must be evaluated separately and ranked according to their importance.

  11. Topography of the medullary cone of the crab-eating fox (Cerdocyon thous Linnaeus, 1766: Case report

    Directory of Open Access Journals (Sweden)

    Luane Lopes Pinheiro

    2011-12-01

    Full Text Available The crab-eating fox is the most common Canidae of South America. In general, its diet varies according to the season and inhabited region. In this study, the medullary cone of the crab-eating fox was described because of interests in comparative anatomy, with the goal of providing information that could assist in epidural anesthesia, which cannot be efficiently practiced without knowledge of this anatomical region. We investigated an adult male from the Bauxite Mine (Paragominas, PA, which was dissected in the lumbosacral region. The medullary cone was 10.13 cm long; the base began at the L6 and the apex was at the S3. Considering that the specimen studied had nine lumbar and four sacral vertebrae, we conclude that the sacrococcygeal region is probably the most suitable place for epidural anesthesia.

  12. Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Kávási, Norbert, E-mail: norbert@fml.nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Social Organization for Radioecological Cleanliness, Veszprém (Hungary); Vigh, Tamás [Social Organization for Radioecological Cleanliness, Veszprém (Hungary); Manganese Mining Process Ltd., Úrkút (Hungary); Németh, Csaba [Social Organization for Radioecological Cleanliness, Veszprém (Hungary); University of Pannonia, Veszprém (Hungary); Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori [National Institute of Radiological Sciences, Chiba (Japan)

    2014-02-15

    During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C–21°C), low or high wind speed (max. 2.4 m s{sup −1}) and low or elevated aerosol concentration (130–60 000 particles m{sup −3}). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m{sup −3} and 550(497) Bq m{sup −3} in the bauxite mine; 887(604) Bq m{sup −3} and 1258(788) Bq m{sup −3} in the manganese ore mine; 2510(2341) Bq m{sup −3} and 3403(3075) Bq m{sup −3} in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m{sup −3} and 8512(1955) Bq m{sup −3} in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m{sup −3} and 161(148) Bq m{sup −3} in the bauxite mine; 187(191) Bq m{sup −3} and 117(147) Bq m{sup −3} in the manganese-ore mine; 360(524) Bq m{sup −3} and 371(789) Bq m{sup −3} in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m{sup −3} and 1462(3655) Bq m{sup −3} in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves

  13. Wear Behavior of Aluminum Alloy 6061-Based Composites Reinforced with SiC, Al2O3, and Red Mud: A Comparative Study

    Science.gov (United States)

    Singla, Yogesh Kumar; Chhibber, Rahul; Bansal, Hitesh; Kalra, Anil

    2015-09-01

    Metal-matrix composites are widely used in shipping, aerospace, automotive, and nuclear applications. Research attempts have been made in the past to reduce the cost of processing of composites, decrease the weight of the composites, and increase the desired performance characteristics. In this research article, an attempt has been made in using red mud obtained as an industrial waste during the production of aluminum from bauxite ore. This article discusses the novel findings of the experimental study on the dry sliding wear behavior of aluminum alloy 6061-based composites reinforced individually with red mud, SiC, and Al2O3. The microstructural characterization of the composites provides the further insight into the structure—wear behavior of the processed composites.

  14. Guide to a Strategic Procurement Planning Approach on Regulated Commodity Markets

    Science.gov (United States)

    Seifert, Marcus; Wüst, Thorsten

    The access of Virtual Organizations to raw materials normally requires external resources. In many cases, the market for raw materials is regulated and the VO principles of trust, customer orientation etc. are not applicable. In consequence, the VO needs to provide reliable solutions for the customer while being dependent on the access to the required raw materials. The objective of the proposed paper is to present a guide to a strategic procurement planning for the manufacturing industry on regulated commodity markets. This guide can be used to evaluate specific sourcing options. The main goal of this guide is to identify the negative effects of market regulation at an early stage and reduce them by developing strategic alternatives. The successful application of this guide is demonstrated by the practical example of the refractory industry and one of their commodities, refractory grade bauxite.

  15. Assessment of recycled PET properties for application on oil wells as sand control agents; Avaliacao de propriedades de PET reciclado para aplicacao em pocos de petroleo como agente de contencao de areia

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Alexandre Zacarias Ignacio [PETROBRAS, Rio de Janeiro, RJ (Brazil); Delpech, Marcia Cerqueira [Universidade do Estado do Rio de Janeiro (IQ/UERJ), RJ (Brazil). Inst. de Quimica], e-mail: mcd@uerj.br

    2008-07-01

    The Sand Control is fundamental for oil production in unconsolidated sandstone formations. It consists of the installation of a filter made of stainless steel screens and grained materials (sand control agents) which are, normally, high density inorganic substances (sand, ceramic, bauxite). Shallow formations, near to the sea bed, are more sensitive and need different kinds of sand control agents with low density. The objective of this work was the evaluation of recycled poly(ethylene terephthalate), PET, as sand control agent for oil wells. Pack permeability and thermal stability tests results, after up to six months of exposure to sea water and crude oil, have indicated that the recycled PET kept the necessary characteristics for the proposed application. Also, it was observed that the PET grain pack did not presented significant property modifications in the exposure conditions, when compared to the non-exposed samples. (author)

  16. Rock excavation using surface miners: An overview of some design and operational aspects

    Institute of Scientific and Technical Information of China (English)

    Prakash Amar; Murthy Vemavarapu Mallika Sita Ramachandra; Singh Kalendra Bahadur

    2013-01-01

    Surface miner,a continuous mining machine,is being manufactured in India and abroad owing to enhanced demand of production in various mining industries like coal,limestone,gypsum,bauxite etc.Different types of surface miners are manufactured today based on cutting drum placement and design specifications.Selective mining without drilling and blasting,high production and small size products are some of the prominent attractive features obtained with these moving marvels.This machine can be used with good efficiency in soft to medium hard rock (100-120 MPa).This paper synthesizes the different applications,equipment models,features offered,operating methods,cutting performance assessment models as well as typical production performance of surface miner in coal and limestone mines of India.Engine hour metre reading,diesel and pick consumptions are linearly influenced by production.The emphasis for future research is also brought out.

  17. A World of Minerals in Your Mobile Device

    Science.gov (United States)

    Jenness, Jane E.; Ober, Joyce A.; Wilkins, Aleeza M.; Gambogi, Joseph

    2016-09-15

    Mobile phones and other high-technology communications devices could not exist without mineral commodities. More than one-half of all components in a mobile device—including its electronics, display, battery, speakers, and more—are made from mined and semiprocessed materials (mineral commodities). Some mineral commodities can be recovered as byproducts during the production and processing of other commodities. As an example, bauxite is mined for its aluminum content, but gallium is recovered during the aluminum production process. The images show the ore minerals (sources) of some mineral commodities that are used to make components of a mobile device. On the reverse side, the map and table depict the major source countries producing these mineral commodities along with how these commodities are used in mobile devices. For more information on minerals, visit http://minerals.usgs.gov.

  18. Development and Application of High Quality Unburned Brick for EAF Roof

    Institute of Scientific and Technical Information of China (English)

    CHENGBin; CHENCui-yu

    1995-01-01

    A high quality unburned brick for EAF (electric arc furnace) roof has been developed by using high grade bauxite chamotte as the main starting material ,adding industrial alumina powder to strengthen the matrix ,introducing a suitable amount of sillimanite and compound M and adopting high effective composite binder,The brick has apparent porosity 17%,bulk density 2.88 g/cm3,refratoriness under load (3% deformation) 1560℃ and thermal shock resis-tance over 30 cycles.The mechanism of improving the spalling resistance is also discussed,The brick has been applied at 30 t EAF roofs,resulting in average service life of 145 heats ,the maximum 210 heats.

  19. Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

    Science.gov (United States)

    Kávási, Norbert; Vigh, Tamás; Németh, Csaba; Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori

    2014-02-01

    During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C-21°C), low or high wind speed (max. 2.4 m s-1) and low or elevated aerosol concentration (130-60 000 particles m-3). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m-3 and 550(497) Bq m-3 in the bauxite mine; 887(604) Bq m-3 and 1258(788) Bq m-3 in the manganese ore mine; 2510(2341) Bq m-3 and 3403(3075) Bq m-3 in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m-3 and 8512(1955) Bq m-3 in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m-3 and 161(148) Bq m-3 in the bauxite mine; 187(191) Bq m-3 and 117(147) Bq m-3 in the manganese-ore mine; 360(524) Bq m-3 and 371(789) Bq m-3 in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m-3 and 1462(3655) Bq m-3 in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves. Consequently, correction is required on previously obtained radon data acquired by CF monitors at subsurface workplaces to gain comparable data for SF monitors. In the

  20. First Research on Marine and Nonmarine Sedimentary Sequences and Micropaleontologic Significance across Permian/Triassic Boundary in Iran (Isfahan and Abadeh)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Abundant ichthyoid remains, conodonts and holothurians sclerites were recovered near the Permian/Triassic boundary from a section south of Isfahan. Recovered ichthyoid remains include shark micro teeth and scales. The ichthyolith material is similar to a Fasanian ichthyolith from the Zakazane area in the Slovak karst of the Western Carpathians, which represents a subspecies of Acodina triassica.Conodont species are mostly neogondolellids. This fauna indicates that the sedimentary environment was marine, while to the north of localities near Isfahan and Zagross, terrestrial deposition was dominant at that time. Aluminasilicate and kaolin are present in a continental unit in Dopolan refractory main (Shahid Nilchian mine) and a section south of Chahriseh Village, north of Isfahan. Pisolitie, ironstone facies and bauxite clay are common near the Permian/Triassic boundary in the Chahriseh region.

  1. A world of minerals in your mobile device

    Science.gov (United States)

    Jenness, Jane E.; Ober, Joyce A.; Wilkins, Aleeza M.; Gambogi, Joseph

    2016-09-15

    Mobile phones and other high-technology communications devices could not exist without mineral commodities. More than one-half of all components in a mobile device—including its electronics, display, battery, speakers, and more—are made from mined and semiprocessed materials (mineral commodities). Some mineral commodities can be recovered as byproducts during the production and processing of other commodities. As an example, bauxite is mined for its aluminum content, but gallium is recovered during the aluminum production process. The images show the ore minerals (sources) of some mineral commodities that are used to make components of a mobile device. On the reverse side, the map and table depict the major source countries producing these mineral commodities along with how these commodities are used in mobile devices. For more information on minerals, visit http://minerals.usgs.gov.

  2. A GMDH Approach to Modelling Gibbsite Solubility in Bayer Process Liquors

    Directory of Open Access Journals (Sweden)

    Jennifer K. Muller

    2004-02-01

    Full Text Available Abstract: The most widely employed industrial process for producing alumina (Bayer process involves the dissolution of available aluminium hydroxide minerals present in raw bauxite into high temperature sodium hydroxide solutions. On cooling of the solution, or liquor in the industrial vernacular, Al is precipitated from solution in the form of gibbsite (Al(OH3. In order to optimise the process, a detailed knowledge of factors influencing gibbsite solubility is required, a problem that is confounded by the presence of liquor impurities. In this paper, the use of the Group Method of Data Handling (GMDH polynomial neural network for developing a gibbsite equilibrium solubility model for Bayer process liquors is discussed. The resulting predictive model appears to correctly incorporate the effects of liquor impurities and is found to offer a level of performance comparable to the most sophisticated phenomenological model presented to date.

  3. Iron and copper in Plagioscion squamosissimus (Piscis: Sciaenidae) of river Orinoco, Venezuela

    International Nuclear Information System (INIS)

    Bauxite exploitation of the Orinoco River in recent years is an important source of heavy metals discharge in the ecosystem, changing the natural biochemical flow of these elements and their concentrations in water, sediment and organisms. Iron and copper concentrations were measured in the fish Plagioscion squamosissimus in the Orinoco river, by sampling the fish population for three months (September-November 1998) in the main channel of the middle Orinoco. The internal organs of 30 fishes per month and site were stove-dried, pulverized and dried in disecator for 30 min to use as indicators with the acid digestion method for predicting the effect of heavy metals. We found relatively high values of iron and copper concentrations in fishes of the lagoon, and high seasonal variations in the iron concentration. (Author)

  4. Development and Application of Mullite—Composite Brick for Baths Pool of Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    ZHOULei; LIXian-ming; 等

    1994-01-01

    The paper deals with the development and production of mullite-composite bricks for baths pool of balst furnace,Fused corundum,synthetic mullite ,special grade bauxite and a certain amount of additives were used as raw materials to produce corundum-mullite brick and yellow-corundum brick,All of their physical and chemical properties surpass the designed values.Good results have been obtained from the applic-cation in the baths pool of No.7 blast furnace of Anshan I & S Co.(Angang).The silicon content in pig iron decreases by 0.1%-0.2% while the temperature of the hot metal increases by 20℃,The mineral composition and structure have been studied by means of XRD and SEM.

  5. Electron microscopy study of red mud after seawater neutralisation; Estudo por microscopia eletronica de transmissao de lama vermelha tratada com agua do mar

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, S.P.; Kiyohara, P.K. [Universidade de Sao Paulo (IF/LME/USP), SP (Brazil); Antunes, M.L.P., E-mail: malu@sorocaba.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil); Frost, Ray [Queensland University of Technology (United States)

    2012-07-01

    Red Mud, residue of Bayer process for extracting alumina from bauxite, is produced in large quantity. This residue is very alkaline and can cause damage to health and the environment. One way to minimize the environmental impact of this residue is neutralization by sea water. The Brazilian Red Mud was treated with sea water. It appears that the initial pH of the samples is reduced to 8. The analysis by x-ray diffraction allows to identify the formation of hydrotalcite and aragonite. The transmission electron microscopy images show that this consists of particles with dimensions between 0.02 to 2 μm. It was possible to identify by EDS/MET particles of magnesium, confirming the formation of hydrotalcite. (author)

  6. Aluminium leaching from red mud by filamentous fungi.

    Science.gov (United States)

    Urík, Martin; Bujdoš, Marek; Milová-Žiaková, Barbora; Mikušová, Petra; Slovák, Marek; Matúš, Peter

    2015-11-01

    This contribution investigates the efficient and environmentally friendly aluminium leaching from red mud (bauxite residue) by 17 species of filamentous fungi. Bioleaching experiments were examined in batch cultures with the red mud in static, 7-day cultivation. The most efficient fungal strains in aluminium bioleaching were Penicillium crustosum G-140 and Aspergillus niger G-10. The A. niger G-10 strain was capable to extract up to approximately 141 mg·L(-1) of aluminium from 0.2 g dry weight red mud. Chemical leaching with organic acids mixture, prepared according to A. niger G-10 strain's respective fungal excretion during cultivation, proved that organic acids significantly contribute to aluminium solubilization from red mud. PMID:26365318

  7. Analysis of Proppant Hydraulic Fracturing in a Sand Oil Reservoir in Southwest of Iran

    Directory of Open Access Journals (Sweden)

    Reza Masoomi

    2015-10-01

    Full Text Available Hydraulic fracturing is one way to increase the productivity of oil and gas wells. One of the most fundamental successes of hydraulic fracturing operation is selecting the proper size and type of proppants which are used during the process. The aim of this study is optimizing the type and size of used propant in hydraulic fracturing operation in a sand oil reservoir in southwest of Iran. In this study sand and ceramic (sintered bauxite have been considered as proppant type. Also the various types of resin-coated sand and resin-coated ceramic have been considered. Then the various scenarios have been designed to optimize the size and type of proppant used in hydraulic fracturing in a sand oil reservoir in southwest of Iran. Also in this study increasing the cumulative oil recovery in fractured and Non-fractured wells in a sand oil reservoir in southwest of Iran have been investigated.

  8. Effect of particle size on microstructure and strength of porous spinel ceramics prepared by pore-forming in situ technique

    Indian Academy of Sciences (India)

    Wen Yan; Nan Li; Yuanyuan Li; Guangping Liu; Bingqiang Han; Juliang Xu

    2011-08-01

    The porous spinel ceramics were prepared from magnesite and bauxite by the pore-forming in situ technique. The characterization of porous spinel ceramics was determined by X-ray diffractometer (XRD), scanning electron microscopy(SEM), mercury porosimetry measurement etc and the effects of particle size on microstructure and strength were investigated. It was found that particle size affects strongly on the microstructure and strength. With decreasing particle size, the pore size distribution occurs from multi-peak mode to bi-peak mode, and lastly to mono-peak mode; the porosity decreases but strength increases. The most apposite mode is the specimens from the grinded powder with a particle size of 6.53 m, which has a high apparent porosity (40%), a high compressive strength (75.6MPa), a small average pore size (2.53 m) and a homogeneous pore size distribution.

  9. Electron microscopy study of red mud after seawater neutralisation

    International Nuclear Information System (INIS)

    Red Mud, residue of Bayer process for extracting alumina from bauxite, is produced in large quantity. This residue is very alkaline and can cause damage to health and the environment. One way to minimize the environmental impact of this residue is neutralization by sea water. The Brazilian Red Mud was treated with sea water. It appears that the initial pH of the samples is reduced to 8. The analysis by x-ray diffraction allows to identify the formation of hydrotalcite and aragonite. The transmission electron microscopy images show that this consists of particles with dimensions between 0.02 to 2 μm. It was possible to identify by EDS/MET particles of magnesium, confirming the formation of hydrotalcite. (author)

  10. The Microstructure and Properties of Alumina—Rich Spinel and Its Products

    Institute of Scientific and Technical Information of China (English)

    SHIGan; SUNGeng-chen

    1995-01-01

    The paper describes the effect of chemical composition on the microstructure and properties of spinel specimens synthesized from bauxite and magnesite,The alumina-rich spinel with higher ratio of Al2O3/MgO,with smaller spinel grain,contains more titaniferous mineral and silicate phase compared to the spinel with lower Al2O3/MgO ratio.In the products obtained from alumina-rich spinel and magnesite clinker,the ratio of Al2O3/MgO of spinel decreases,ti-taniferous mineral and silicate phase in the spinel aggregate are changed,and its content tends to degradation,contrasted with original alumina-rich spinel,The products have good high temperature properties.

  11. Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of microsilica addition

    Directory of Open Access Journals (Sweden)

    Pattem Hemanth Kumar

    2014-06-01

    Samples with decreasing cement content 15–05 wt.% were formulated in combination of both slag and calcined bauxite as matrix components. Effects of varying 0–10 wt.% microsilica as a micro-fine additive in these castables were investigated in this work. Pore filling properties of microsilica improved apparent porosity and bulk density. Phase analysis through X-ray diffraction techniques demonstrates successful formation of spinel and mullite crystalline phases. Mechanical behavior was evaluated through cold crushing strength and residual cold crushing strength after five consecutive water quenching cycles. Scanning electron microscopy measurements were carried out in order to better understand the packing density and reaction mechanisms of fired castables. Slag containing castables portrays good thermal properties such as thermal shock resistance, permanent linear change and pyrometric cone equivalent.

  12. Reminiscences From a Career in Geomicrobiology

    Science.gov (United States)

    Ehrlich, Henry L.

    2012-05-01

    This is a memoir relating how the author became a geomicrobiologist and how he practiced his specialty. Born in Germany and receiving his early schooling in Berlin, he completed his secondary education, followed by college and graduate school training, after emigration to the United States in 1940. After attaining a PhD degree in 1951, he spent his entire professional career as a faculty member of the Department of Biology at Rensselaer Polytechnic Institute (RPI) in Troy, New York. He was introduced to geomicrobiology in 1959 by a question from a colleague in the Department of Geology at RPI concerning the recent discovery of acidophilic iron-oxidizing, autotrophic bacteria in acid coal mine drainage. This led him to investigate bacterial interaction with metal sulfides, Mn(II) and Mn(IV) on land and in the sea, chromate, and bauxite; to teach a course in geomicrobiology; and to write a textbook on the subject, first published in 1981.

  13. 食品添加剂明矾生产新工艺研究%Study on new technology of alum as food additive

    Institute of Scientific and Technical Information of China (English)

    何青峰; 杨玉梅

    2013-01-01

    介绍一种由氢氧化铝代替铝土矿生产食品添加剂明矾(十二水合硫酸铝钾)的新工艺.使用氢氧化铝与硫酸、硫酸钾在搪瓷反应釜内一步反应,再通过结晶、破碎、包装等工序,得到优质的明矾产品.解决了用铝土矿为原料生产明矾产品带来的重金属超标问题,并且大大缩短了工艺流程,减少了能源消耗同时杜绝了矿渣的产生.以氢氧化铝为原料生产食品添加剂明矾具有工艺流程短、环保、安全、产品质量好等特点.%A new technology,which uses aluminum hydroxide instead of bauxite for the production of food additive alum was introduced.In the process,aluminum hydroxide,sulfuric acid,and potassium sulfate completely reacted in an enamel reactor.And then high-quality alum could be obtained through the procedures,such as crystallization,crushing,and packing.The new technology solved the problem of exceeded heavy metals when using bauxite as raw material.Furthermore,it greatly shortened the process flow,reduced energy consumption and prevented the generation of slag.Therefore,the new technology has many advantages,such as short flow,environmental-friendly,safety,and high-quality.

  14. Water/rock interactions and mass transport within a thermal gradient Application to the confinement of high level nuclear waste

    International Nuclear Information System (INIS)

    The initial stage of a high level nuclear waste disposal will be characterised by a large heat release within the near-field environment of the canisters. This heat flux caused by radioactive decay will lead to an increase of temperature and a subsequent thermal gradient between the 'hot' canisters and the 'cold'geological medium. In addition, this thermal gradient will decrease with time due to the heat decay although it could last hundred years. What will be the consequences of such a thermal field varying both on space and time for the alteration of the different constituents of the near field environment. In particular, what could be the effects on the radionuclides migration in the accidental case of an early breach of a canister during the thermal stage? This study brings significant answers to these questions in the light of a performance assessment study. This work is supported by a triple methodological approach involving experimental studies, modelling calculations and a natural analogues study. This complete work demonstrates that a thermal gradient leads to a large re-distribution of elements within the system: some elements are incorporated in the solid phases of the hot end (Si, Zr, Ca) whereas some others are in those of the cold end (Fe, Al, Zn). The confrontation of the results of very simple experiments with the results of a model built on equilibrium thermodynamics allow us to evidence the probable mechanisms causing this mass transport: out-of-equilibrium thermodiffusion processes coupled to irreversible precipitation. Moreover, the effects of the variation of temperatures with time is studied by the way of a natural system which underwent a similar temperature evolution as a disposal and which was initially rich in uranium: the Jurassic Alpine bauxites. In addition, part of the initial bauxite escaped this temperature transformations due to their incorporation in outer thrusting nappes. They are used as a reference. (author)

  15. Interaction of mining activities and aquatic environment: A review from Greek mine sites.

    Science.gov (United States)

    Vasileiou, Eleni; Kallioras, Andreas

    2016-04-01

    In Greece a significant amount of mineral and ore deposits have been recorded accompanied by large industrial interest and a long mining history. Today many active and/or abandoned mine sites are scattered within the country; while mining activities take place in different sites for exploiting various deposits (clay, limestone, slate, gypsum, kaolin, mixed sulphide ores (lead, zinc, olivine, pozzolan, quartz lignite, nickel, magnesite, aluminum, bauxite, gold, marbles etc). The most prominent recent ones are: (i) the lignite exploitation that is extended in the area of Ptolemais (Western Macedonia) and Megalopolis (Central Peloponnese); and (ii) the major bauxite deposits located in central Greece within the Parnassos-Ghiona geotectonic zone and on Euboea Island. In the latter area, significant ores of magnesite were exploited and mixed sulphide ores. Centuries of intensive mining exploitation and metallurgical treatment of lead-silver deposits in Greece, have also resulted in significant abandoned sites, such as the one in Lavrion. Mining activities in Lavrio, were initiated in ancient times and continued until the 1980s, resulting in the production of significant waste stockpiles deposited in the area, crucial for the local water resources. Ιn many mining sites, environmental pressures are also recorded after the mine closure to the aquatic environment, as the surface waters flow through waste dump areas and contaminated soils. This paper aims to the geospatial visualization of the mining activities in Greece, in connection to their negative (surface- and/or ground-water pollution; overpumping due to extensive dewatering practices) or positive (enhanced groundwater recharge; pit lakes, improvement of water budget in the catchment scale) impacts on local water resources.

  16. Distribution and Abundance of Scandium in Aluminum- bearing Rock Series in Central Guihzou%黔中地区含铝岩系中钪的分布及丰度研究

    Institute of Scientific and Technical Information of China (English)

    陈华; 姚会禄; 陈启飞

    2012-01-01

    Aluminum- bearing Series in the central Guizhou is an important scandium -bearing stratum, its bauxite orebody and associated hard clay rock have abundant Sc2O3. The study show that the area of high grade of bauxite deposit, the content of scandium in the hard clay rock of its aluminum - bearing series is higher. A12O3 and A/S can reflects the quality and weak relation with Fe2O3, the abnormity of SC2O3 is scale of Sc2O3. Sc2O3 has deep relation with Si02, has obvious when the value is abnormal.%黔中地区含铝岩系是重要的含钪层,其铝土矿体和伴生硬质粘土岩中含有较为丰富的Sc2O3研究表明:铝土矿品位越高的区域,其含铝岩系中硬质粘土岩中钪的含量更高。铝土矿的Al2O3和A/S能直接反映Sc2O3质量和规模。Sc2O3与SiO2关系较为密切,与TFe2O3呈弱相关性,Fe203异常值时Sc2O3含量异常较明显。

  17. Recovery of value-added products from red mud and foundry bag-house dust

    Science.gov (United States)

    Hammond, Keegan

    "Waste is wasted if you waste it, otherwise it is a resource. Resource is wasted if you ignore it and do not conserve it with holistic best practices and reduce societal costs. Resource is for the transformation of people and society." Red mud is a worldwide problem with reserves in the hundreds of millions of tons and tens of millions of tons being added annually. Currently there is not an effective way to deal with this byproduct of the Bayer Process, the primary means of refining bauxite ore in order to provide alumina. This alumina is then treated by electrolysis using the Hall-Heroult process to produce elemental aluminum. The resulting mud is a mixture of solid and metallic oxides, and has proven to be a great disposal problem. This disposal problem is compounded by the fact that the typical bauxite processing plant produces up to three times as much red mud as alumina. Current practice of disposal is to store red mud in retention ponds until an economical fix can be discovered. The danger associated with this current method of storage is immense to the surrounding communities and environment, thus the interest from the Center for Resource Recovery and Recycling (CR3). The purpose of this document is to explain one way to remove the value added materials, primarily iron, from the Jamaican red mud using both pyrometallurgical and hydrometallurgical approaches. In the beginning, soda ash and carbon roasting were completed simultaneously at 800°C. This type of roasting produced results that were unacceptable. After the soda ash roast was completed independently of carbon roasting, a water wash produced results that separations of alumina at 90%, Iron at 99%, calcium at 99%, titanium t 100%, and sodium by 74%. Smelting produced separations of 97% for alumina, 99% for iron, 87% for sodium, 94% for calcium and 72% for titanium.

  18. Water/rock interactions and mass transport within a thermal gradient Application to the confinement of high level nuclear waste; Interactions solide/solution et transferts de matiere dans un gradient de temperature. Application au confinement des dechets nucleaires de haute-activite

    Energy Technology Data Exchange (ETDEWEB)

    Poinssot, Ch. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Entreposage et de Stockage des Dechets]|[Ecole Normale Superieure, 92 - Fontenay-aux-Roses (France). Laboratoire de Geologie

    1998-12-31

    The initial stage of a high level nuclear waste disposal will be characterised by a large heat release within the near-field environment of the canisters. This heat flux caused by radioactive decay will lead to an increase of temperature and a subsequent thermal gradient between the `hot` canisters and the `cold`geological medium. In addition, this thermal gradient will decrease with time due to the heat decay although it could last hundred years. What will be the consequences of such a thermal field varying both on space and time for the alteration of the different constituents of the near field environment. In particular, what could be the effects on the radionuclides migration in the accidental case of an early breach of a canister during the thermal stage? This study brings significant answers to these questions in the light of a performance assessment study. This work is supported by a triple methodological approach involving experimental studies, modelling calculations and a natural analogues study. This complete work demonstrates that a thermal gradient leads to a large re-distribution of elements within the system: some elements are incorporated in the solid phases of the hot end (Si, Zr, Ca) whereas some others are in those of the cold end (Fe, Al, Zn). The confrontation of the results of very simple experiments with the results of a model built on equilibrium thermodynamics allow us to evidence the probable mechanisms causing this mass transport: out-of-equilibrium thermodiffusion processes coupled to irreversible precipitation. Moreover, the effects of the variation of temperatures with time is studied by the way of a natural system which underwent a similar temperature evolution as a disposal and which was initially rich in uranium: the Jurassic Alpine bauxites. In addition, part of the initial bauxite escaped this temperature transformations due to their incorporation in outer thrusting nappes. They are used as a reference. (author)

  19. Investigations into the control of agglomeration and defluidisation during fluidised-bed combustion of low-rank coals

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Linjewile, T.M.; Zhang, D.; Manzoori, A.R. [University of Adelaide, Adelaide, SA (Australia). Dept. of Chemical Engineering

    1999-03-01

    A laboratory scale spouted bed combustor was used to study the effectiveness of various control methodologies in alleviating ash-related problems such as particle agglomeration and bed defluidisation during bed combustion of low-rank coals. The three control techniques investigated are: (1) the use of mineral additives; (2) alternative bed materials; and (3) pretreatment of coal. Mineral additives including dolomite, two clays and gibbsite, were injected into the spouted bed combustor while burning a South Australian low-rank coal at 800{degree}C. Samples of the same coal treated with Al, water washing and acid washing were also tested in the spouted bed combustor. In addition, experiments were also conducted with alternative bed materials including bauxite and calcined sillimanite. Experiments showed that the three techniques reported in this paper are effective to different extents in reducing particle agglomeration and defluidisation. Among the mineral additives tested, gibbsite and a clay additive rich in kaolinite and sillimanite were found to be most effective. The use of calcined sillimanite and bauxite as alterative bed materials extended the combustion time before defluidisation occurred by 7 and 10 times, respectively, compared to silica sand. While A1 pretreatment and water-washing were found effective for control of agglomeration and defluidisation, acid-washing did not improve the operation of the bed burning this particular coal. Al enrichment in ash coating of bed particles which suppress the formation of Na and S rich eutectics was identified as the main mechanism for prevention of agglomeration and defluidisation by these control techniques. 10 refs., 4 figs., 3 tabs.

  20. Remediation of ash problems in fluidised-bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Vuthaluru, H.B.; Zhang, D.K. [Curtin University of Technology, Perth, WA (Australia). School of Chemical Engineering

    2001-03-01

    The paper reports the control methods for mitigating particle agglomeration and bed defluidisation during fluidised-bed combustion of low-rank coals. A laboratory scale spouted-bed combustion system is used to study the effectiveness of several control methods including the use of alternative bed materials, mineral additives, pretreatment of coal and coal blending. Sillimanite, bauxite, calcite and magnesite were used as alternative bed materials whereas mineral additives viz. clay, kaosil and bauxite were injected into the combustion system while burning South Australian low-rank coal at 800{degree}C. Samples of the same coal subjected to water-washing, Al pretreatment and Ca pretreatment are also tested in the spouted-bed combustor. In addition, experiments were conducted with several coal blends prepared at ratios of 50:50 and 90:10 from two lignites and one sub-bituminous coal. Experiments showed that all the control methods are effective to different extends in reducing ash problems and resulted in extended combustion operation. Tests with alternative bed materials and mineral additives showed trouble free-operation for longer periods (7-12 h at 800{degree}C) than with sand runs at the same bed temperature. Wet pretreatment and coal blending were also found to be effective and resulted in extended combustion operation (9-12 h at 800{degree}C). Chemical analyses indicated that formation of low temperature eutectics was suppressed by Al/Ca/Mg-rich phases in ash coating of bed particles. This was identified as the main mechanism for prevention of ash problems observed with the use of alternative bed materials, mineral additives, pretreated coals and coal blends. 23 refs., 9 figs., 7 tabs.

  1. Development Status of Mineral Resources in Five Countries of the Indochina Peninsula and Investment Preferences for China%中南半岛五国矿产资源开发现状及中国的投资取向

    Institute of Scientific and Technical Information of China (English)

    程新; 沈镭; 高天明

    2011-01-01

    The Indochina Peninsula includes Vietnam, Laos, Cambodia, Myanmar, and Thailand. This paper first outlines resource situations in the Indochina Peninsula, analyzes the distribution of advantageous mineral resources and their development situations in the five countries. Thailand is abundant in antimony, potassium, and tin resources. The reserve of Thai antimony was more than 420 thousand tons in 2009, accounting for 20% of the world’s total reserve. It is mainly distributed in northern Thailand, such as LamPang, Phrae, and Chiang Mai Provinces. Its production in 2008 was 422 ton. Potassium is also rich in Thailand, and has not been mined at large scales. Tin and iron ore were not well exploited, either. Their productions mainly rely on imports. Coal, phosphate, and bauxite are rich in Vietnam. Coal is primarily anthracite and lignite; anthracite is distributed in C?m Ph?, thành ph? H? Long, Qu?ng Ninh Provinces, northeast Vietnam. Lignite is distributed in the Red River basin; the coal reserve in the area is more than 200 billion ton. Bauxite is Vietnam’s dominant mineral, and its reserve is huge. The reserve of phosphate is more than 1.4 billion ton. Due to backward mining technology, its mineral resources were not effectively developed and utilized. Potassium is abundant in the Vientiane plain, and its prospective reserve is more than 10 billion ton. Copper, bauxite, and tin reserves are more than other mining resources in Laos. Cambodia and Myanmar are rich in oil, non-ferrous metals, and gem. The degree of mineral resources development in these five counties is very low, even ranking one of the most undeveloped areas in the world. We discussed their mining investment environment in this region. All the counties have special departments for mining management, enact related laws to protect the interests of the owner, and provide some preferential policies to attract mining investment. We suggest that every country should optimize their mining

  2. Suriname.

    Science.gov (United States)

    1984-10-01

    A summary description of Suriname's population, geography, history, government, economy, and foreign relations is provided. Suriname, a tropical country, situated on the northern coast of South America, consists of a coastal zone, a central forested region, and a sparsely populated southern savanna zone. Most of the country's approximately 400,000 inhabitants live in the coastal zone, which contains most of the country's agricultural land. The population is ethnically diverse and is 37% Hindustani, 31% Creole, 15.3% Javanese, 10.3% Bush Negro, 2.7% Amerindian, 2.7% Chinese, and 1% European. European settlement began in 1651. Between 1667-1815 the country was rule alternately by the Netherlands and Great Britian. In 1975 Suriname obtained independence from the Netherlands and was governed as a parliamentary democracy between 1975-80. In 1980 the government was overthrown by a military coup, and the constitution was suspended. Although there have been several changes in government structure and leadership since 1980, the country continues to be ruled by military decree. In 1984 a Supreme Council, composed of representives of the military, labor federations, and business organizations and chaired by the army commander, Desire D. Bouterse, was established. Although ultimate authority resides in the commander and in the military, there is also a Council of Ministers, composed of labor and business leaders and headed by the Minister-President, L.F. Ramdat-Misier. The government exerts considerable control over the news media. During the colonial era, a plantation economy, based on the production of cocoa, coffee, sugar, and cotton, was established. The system was supported first by African slave labor, and then by Asian contract agricultural laborers. Suriname's current economy is based largely on the mining, processing and exporting of bauxite. The bauxite industry is dominated by the Suriname Aluminum Company, a subsidiary of the Aluminum Company of America, and by the

  3. AGRONOMIC EFFICIENCY OF NATURAL PHOSPHATES AND THEIR INFLUENCE ON SOIL AVAILABLE PHOSPHORUS ON TWO CERRADO SOILS EFICIÊNCIA AGRONÔMICA DE FOSFATOS NATURAIS E SUA INFLUÊNCIA NO FÓSFORO DISPONÍVEL EM DOIS SOLOS DE CERRADO

    Directory of Open Access Journals (Sweden)

    Huberto José Kliemann

    2007-09-01

    Full Text Available

    To evaluate the agronomic efficiency of natural phosphates soybean was grown in two oxisols under cerrado vegetation, using apatites (Araxá, Patos de Minas, Tapira, Abaeté, and Catalão, phosphoric bauxites (Pirocaua and Phospal, Gafsa hyperphosphate, nd IPT thermophosphate, using triple superphosphate as a control. he agronomic efficiency indexes found were: a apatites - Araxá nd Abaeté, 27%; Patos de Minas, 13%; Tapira, 5%, and Catalão, %; b phosphoric bauxites - Pirocaua, 41% and Phospal, 50%; c hermophosphate IPT, 97% and hyperphosphate of Gafsa, 102%. he acid extractor Mehclich-1 overestimates available P when nsoluble apatites are applied to soils. Bray-1 and Bray-2 extractors referably solubilize the aluminum phosphates from phosphoric auxites. Critical levels of soil available phosphorus are suitably stimated by Bray-1 extractant when apatitic phosphates and by ehlich-1 extractant phosphoric bauxites are applied.

    KEY-WORDS: Oxisols; soybeans; phosphates sources; chemical extractors; soybean.

    Conduziram-se experimentos de avaliação de fosfatos naturais em latossolo vermelho-escuro distrófico (textura média e latossolo roxo distrófico (textura argilosa, fase cerrado, no Estado de Goiás. Usaram-se a soja como planta-teste, curvas de resposta com superfosfato triplo (SFT como padrão e como fontes de fósforo as apatitas de Araxá, Patos de Minas, Tapira, Abaeté e Catalão, as bauxitas fosfóricas de Pirocaua (Maranhão e Phospal (Senegal, o hiperfosfato de Gafsa e o termofosfato IPT. Obtiveram-se os seguintes índices de eficiência agronômica (IEA: a apatitas – Abaeté e Araxá: 27%; Patos de Minas: 13%; Tapira: 5%; e Catalão: 2%; b termofosfato IPT: 97% e o hiperfosfato reativo de Gafsa, 102%; c bauxitas de Pirocaua, 41% e Phospal: 50%. Os extratores Mehlich-1, Bray-1

  4. A study on the recycling of aluminium alloy 7075 scrap

    Energy Technology Data Exchange (ETDEWEB)

    Oezer, Goekhan [Yildiz Technical Univ., Yildiz (TR). Balkan Centre of Advanced Casting Technologies (BACAT); Marsoglu, Muezeyyen [Yildiz Technical Univ., Yildiz (Turkey). Dept. for Metal and Materials Science Engineering; Burgucu, Sarp

    2012-07-01

    Aluminium and its alloys have recently become an important metal whose area and amount of usage increase more and more, due to their mechanical properties, recycling ability, and penetrability. If it is considered that the bauxite, which is the raw material of aluminium is rare on earth, and also the area and amount of aluminium usage increases over time, the importance of aluminium recycling goes up. aluminium recycling has become crucial by means of both, the potential of the scrap's dependant increase on usage and the primary aluminium production, as it is providing energy and cost savings. 7xxx grades of scrap are collected with other scrap of aluminium alloys in one turn and recycled all together. As the regain of these alloys is not done by isolation of the various grades, the finally recycled ingots result in lower grades. High value aluminium scrap is regrettably not recovered, as it was anticipated. This study is dealing with 7075 aluminium alloys originated from discharged blow molding tools and the rest piece cuttings of blocks and plates. The material has been subjected to an induction furnace, and has been remelted into small ingots and hardened according to 7075 aluminium alloy parameters (hardening aluminium tooling). [German] Aluminium und seine Legierungen sind in den letzten Jahren aufgrund ihrer mechanischen Eigenschaften, ihrer Recyclingfaehigkeit und ihrer Durchlaessigkeit immer bedeutendere metallische Werkstoffe geworden. Unter Beruecksichtigung, dass Bauxit als Rohmaterial selten auf der Erde vorkommt und der Verbrauch mit der Zeit steigt, waechst die Bedeutung des Recyclings von Aluminium. Aluminiumrecycling, zumal es Energieund Kosteneinsparungen ermoeglicht, ist sowohl fuer die schrottabhaengigen Verwendungspotentiale und die PrimaerAluminiumproduktion gleichermassen bedeutend geworden. Die 7xxxx Schrottlegierungen werden in einem Arbeitsgang mit dem Schrott aus anderen Aluminiumlegierungen gesammelt und recycled. Da die

  5. Deciphering post-Deccan weathering and erosion history of South Indian Archean rocks from cryptomelane 40Ar-39Ar dating

    Science.gov (United States)

    Bonnet, Nicolas; Arnaud, Nicolas; Beauvais, Anicet; Chardon, Dominique

    2015-04-01

    Since the extrusion of Deccan traps ~ 63 Ma ago, weathering and erosion processes have shaped the landscapes of this Peninsula India. This resulted in pervasive bauxitic weathering on traps and deep lateritic weathering of their basement on either side of the Western Ghats Escarpment, which separates a coastal lowland from an East-dipping highland plateau. Mn-rich lateritic profiles formed by supergene weathering of Late Archean manganiferous protores in the different greenstone belts are exposed on relict paleosurfaces, which are preserved at different elevations on the highland plateau and in the coastal lowland, allowing for direct comparison of paleosurfaces and geomorphological processes across one of the most prominent relief in the Indian peninsula. Detailed petrological and geochemical investigations of samples collected in the different Mn-rich lateritic profiles allowed for precise characterization of cryptomelane [Kx Mn8-xIV MnxIII O16, nH2O], a Mn-oxide suitable for 40Ar-39Ar dating. The ages obtained document major weathering periods at ~ 53-50 Ma, ~ 40-32 Ma, and ~ 30-23 Ma in the highland profiles, and ~ 47-45 Ma, ~ 24-19 Ma and a younger age at ~ 9 Ma in the coastal lowland profiles. The age clusters are in good agreement with major regional and global Cenozoic paleoclimatic events, e.g., the Eocene climatic optimum and the early beginnings of Asian monsoons at ~ 40 Ma. The old ages obtained both in the coastal lowland and high plateau indicate synchronous lateritic (mostly bauxitic) weathering on both sides of the escarpment. The ages also indicate that most of the incision and dissection of plateau landsurfaces must have taken place during successive periods after 45, 32 and 23 Ma, while the coastal lowland surface was only weakly incised after 19 Ma. Our results thus document post-Eocene divergent erosion and weathering histories across the escarpment since it was formed at least 47 Ma ago, suggesting installation of a dual climatic regime on

  6. NOVAS APLICAÇÕES DE SISTEMAS SFE "HOME MADE": III. ENERGIA QUÍMICA E ELÉTRICA

    Directory of Open Access Journals (Sweden)

    Fernando M. LANÇAS

    1997-12-01

    Full Text Available Este trabalho apresenta três aplicações da SFE com diferentes fluídos supercríticos, matrizes e sistemas de extração. Um sistema estático "home made" foi utilizado na pesquisa de fontes alternativas de insumos químicos e energéticos tais como o bagaço de cana-de-açucar e o carvão mineral. Foram usados, respectivamente, o etanol (sem e com catalisador e o tolueno como fluídos extratores e hidrogênio como gás de pressurização. Na extração dos contaminantes do óleo mineral adsorvidos em bauxita, foi utilizado o dióxido de carbono como fluído extrator em um sistema "home made"/dinâmico. Estudos visando a maximização do rendimento de alguns dos processos também foram realizados, utilizando o planejamento fatorial e a metodologia da superfície de resposta. Os produtos de maior interesse neste trabalho (fração de resinas, obtidos do processo de extração do bagaço de cana-de-açucar e aqueles contaminantes do óleo isolante adsorvidos em bauxita extraídos com fluídos supercríticos foram caracterizados usando cromatografia gasosa de alta resolução com detector de ionização de chama (CGAR - DIC e cromatografia gasosa de alta resolução com detector seletivo de massas (CGAR - EM após fracionamento por cromatografia líquida preparativa em 8 frações distintas.This work presents three aplications of SFE with different supercritical fluids, samples and extraction systems. A home made static system was utilized in the search for alternative chemicals and energetics resources such as sugar cane bagasse and mineral coal. Ethanol (with and without catalyst and toluene were used, respectively ,as extraction fluids and hydrogen as pressurization gas. The adsorbed contaminants of mineral oil in bauxite were also extracted with carbon dioxide as extractor fluid in a home made dinamical system. Maximization of yields in some processes was studied using factorial design and response surface methodologies. The products

  7. Manupulation of microstructure, phase evolution and mechanical properties by devitrification of andesite for use as proppant

    Science.gov (United States)

    Koseski, Ryan P.

    Small, roughly spherical ceramic particles, approximately 1mm in size are used for a number of applications including casting sands, catalysts, and cement fillers. The oil and natural gas industry utilizes such materials in tonnage quantities yearly as extraction aids. Particles intended for this application are referred to as proppants. Proppants are composed of materials that differ by density, strength and cost, and are selected on a site by site basis. Recently, competing usage and depletion of reserves of one of the most popular category of proppant materials, sintered aluminosilicates (e.g. kaolinite, bauxite) have driven the need for alternative raw materials for proppant manufacturing. Andesite, a by-product of mining operations in the south-west United States was identified as an abundant, readily available, and low cost alternative proppant material that can be fused and net-shaped into a glass which when crystallized results in microstructures which may offer substantial toughening and fracture characteristics which may serve to their advantage for use as proppants that do not decrease the permeability ("blind") the particle bed. This study addressed the devitrification behavior and its role on the mechanical properties of andesite-based glass-ceramic spheres for use as proppants. Timetemperature- transformation studies were performed to evaluate the devitrification behavior of andesite glass. Crystalline phase evolution and microstructural development were evaluated using quantitative x-ray diffraction, scanning electron microscopy, differential thermal analysis, and spectrophotometry. The andesite glass devitrification commenced with the precipitation of iron oxides (magnetite) which served as seeds for the epitaxial growth of dendritic pyroxenes. Mechanical properties, such as diametral compressive strength, fracture toughness, hardness, and fracture morphology were correlated with crystalline phase evolution. Selected heat treatments resulting in the

  8. Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers

    Directory of Open Access Journals (Sweden)

    Evan Jamieson

    2016-05-01

    Full Text Available The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash. Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers.

  9. Comment on: "Geomorpho-tectonic evolution of the Jamaican restraining bend" by Leomaris Domínguez-González, Louis Andreani, Klaus P. Stanek and Richard Gloaguen [Geomorphology, 228 (2015) 320-334

    Science.gov (United States)

    Mitchell, Simon F.; James-Williamson, Sherene; Miller, David J.; Mandal, Arpita

    2016-06-01

    We provide comments on the paper: "Geomorpho-tectonic evolution of the Jamaican restraining bend" by Domínguez-González et al. (2015). The literature review given is lacking in significant elements, particularly recent papers detailing the geology and uplift history of Jamaica. The paper undertakes a GIS analysis of a DEM and produces a drainage network for Jamaica, yet the networks created do not match the actual drainage network of the island. River profiles were extracted using 150 m contours and many of the knickpoints identified are not related to tectonics. The recognition of different erosional (and thus evolutionary) stages does not take into account the differing geology and the different geomorphological processes that were in operation, and the proposed model for the progressive uplift of different parts of Jamaica must therefore be treated with caution. This is particularly the case where their uplift model agrees neither with recent models based on provenance analysis or on the origin of Jamaican bauxite deposits. This paper demonstrates the problems of relying on remote sensing using inadequate datasets, no ground truthing and incomplete consideration of previous research.

  10. Economic impact of world mining

    International Nuclear Information System (INIS)

    Mining plays a vital role in the economic development of many countries. The emerging economies are now major players in the production and availability of key commodities such as copper (70%), bauxite (40%), iron ore and precious metals. Mining also has a positive impact on the economy of many countries. Another impact of mining can be measured in terms of employment opportunities and income generation. Commercial scale mining provides employment and skills transfer to more than 2 million workers. The multiplier effect increases this benefit by a factor of between 2 and 5. The World Bank Mining Department has carried out an in-depth study on economic and social impact of mining at the community level in Chile, Peru, Bolivia, Papua New Guinea and Mali. This study demonstrates that there are substantial social and economic benefits to the community. The most positive cases are related to the growth of local small- and micro-enterprise activities. However, mining remains controversial, as true sustainable development is not only a matter of financial flows. Mining has also been associated with a number of economic and social problems. As a result there are questions about the sustainability of the economic outcome of mining. The contribution of mining to sustainable development needs to be considered in terms of economic and technical viability, ecological sustainability and social equity. To achieve this, governments, mining companies and local communities must work together to address these issues. (author)

  11. Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars

    International Nuclear Information System (INIS)

    Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

  12. An Alternative to Clay in Building Materials: Red Mud Sintering Using Fly Ash via Taguchi’s Methodology

    Directory of Open Access Journals (Sweden)

    Suchita Rai

    2013-01-01

    Full Text Available “Red mud” or “bauxite residue” is a highly alkaline waste generated from alumina refinery with a pH of 10.5–12.5 which poses serious environmental problems. Neutralization or its treatment by sintering in presence of additives is one of the methods for overcoming the caustic problem as it fixes nearly all the leachable free caustic soda present in red mud. In the present study, feasibility of reducing the alkaline nature of red mud by sintering using fly ash as an additive via Taguchi methodology and its use for brick production, as an alternative to clay, is investigated. The analysis of variance (ANOVA shows that sintering temperature is the most significant parameter in the process. A pH of 8.9 was obtained at 25–50% of red mud and 50–75% fly ash with water and temperature of . Alternatively 50% of red mud can be mixed with 50% of fly ash with water at temperature of to get a pH of about 8.4. The mechanism of this process has been explained with also emphasis on chemical, mineralogical, and morphological analysis of the sintered red mud. The results would be extremely useful in utilization of red mud in building and construction industry.

  13. Utilization of preparation refuse in the Federal Republic of Germany

    Energy Technology Data Exchange (ETDEWEB)

    Leininger, D.; Erdmann, W.; Schieder, T.; Koehling, R.; Petry, R.

    1982-11-11

    Because of the lack of suitable sites as well as because of environment and landscape protection, the objective of the German hard-coal mining industry is to find alternative ways of utilization of its preparation refuse, to reduce the quantities for disposal on waste heaps to the absolute minimum. Untreated washery refuse, however, can be only sold as a bulk material for improving the mechanical properties of the supporting soil in the construction of dams and dykes. Yet, by mechanical and thermal treatment, the preparation refuse can be converted into high-quality building materials which have a good chance to be sold at a profit if the quality characteristics required by the building construction and civil engineers are maintained. In the field of securing the valuable components of raw materials by recycling them the production of Al/sub 2/O/sub 3/ from washery refuse is possible, though not yet profitable with the present bauxite prices. The costs of refuse utilization depend on the degree of treatment as well as on the specific conditions as to raw material supply, plant operation and infrastructure.

  14. Matures fields of Northeast of Brazil: who to work with and renew them; Rejuvenescimento dos campos maduros de Alagoas sob a otica de intervencao em pocos

    Energy Technology Data Exchange (ETDEWEB)

    Payao, Edson da C.; Fernandes, Emanoel F. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    There are mature fields in Alagoas, such as Furado and Pilar, discovered in 1969 and 1981, respectively. Drilling was resumed in 1998 and the Well Intervention Team was called upon to meet the newfound challenges: pronounced well deviation of up to 75 deg, a horizontal well, and the difficulties that ensue; to perform hydraulic fracture at deep horizons, with high pressure on the surface (in excess of 8,000 psi), premature screen out, tortuosity, secondary fractures (fissuring), etc. These setbacks can be overcome by employing: calibration test with high output; bauxite slugs; sand to decrease filtering; high performance gel. Deep damage in areas where there is water contact inside the well. Problems were overcome using TCP with extreme under balance (EUB) to bypass perforation damage and prevent the sort of damage caused by completion activity. Multidisciplinary approach towards determining onshore production rig interventions; these must be carried out with zeal and an eye to new opportunities, thus underscoring the importance of the data collected onsite. New equipment and completion methods. Upgrading and newer procedures. The yield curve rose once again, bringing renewed enthusiasm and resulting in highly attractive costs for PETROBRAS. (author)

  15. Radionuclides in Bayer process residues: previous analysis for radiological protection

    Energy Technology Data Exchange (ETDEWEB)

    Cuccia, Valeria; Rocha, Zildete, E-mail: vc@cdtn.b, E-mail: rochaz@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Arno H. de, E-mail: heeren@nuclear.ufmg.b [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2011-07-01

    Natural occurring radionuclides are present in many natural resources. Human activities may enhance concentrations of radionuclides and/or enhance potential of exposure to naturally occurring radioactive material (NORM). The industrial residues containing radionuclides have been receiving a considerable global attention, because of the large amounts of NORM containing wastes and the potential long term risks of long-lived radionuclides. Included in this global concern, this work focuses on the characterization of radioactivity in the main residues of Bayer process for alumina production: red mud and sand samples. Usually, the residues of Bayer process are named red mud, in their totality. However, in the industry where the samples were collected, there is an additional residues separation: sand and red mud. The analytical techniques used were gamma spectrometry (HPGe detector) and neutron activation analysis. The concentrations of radionuclides are higher in the red mud than in the sand. These solid residues present activities concentrations enhanced, when compared to bauxite. Further uses for the residues as building material must be more evaluated from the radiological point of view, due to its potential of radiological exposure enhancement, specially caused by radon emission. (author)

  16. Institutional arrangements for the reduction of proliferation risks formulation, evaluation, and implementation of institutional concepts. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The purpose of this supporting analysis is to provide a foundation for developing a model, an international or multinational institution capable of accomodating the back end of the fuel cycle, while meeting US nonproliferation goals. The analysis is based on a review of selected, defunct and extant institutions which, although not necessarily concerned with nonproliferation, have faced a trade-off between acceptability and effectiveness in meeting their objectives. Discussion of the various institutions is divided into three categories: international organizations, multinational consortia, and cartels or producer associations. Examples of international organizations include the International Seabed Authority, Intelsat, the United Nations and the International Atomic Energy Agency (IAEA). The International Seabed Authority is discussed. Multinational consortia are organizations that have been developed primarily to meet common commercial objectives. Membership includes at least three member nations. Examples include the Scandinavian Airline System (SAS), URENCO, Unilever, Royal Dutch Shell, Eurochemic, Eurodif, Euratom, European Coal and Steel Community, and Serena. Cartels or producer associations are multinational agreements that restrict market forces; viz, production, market share, customers or prices. Examples include the Intergovernmental Council of Copper Exporting Countries (CIPEC), the Organization of Petroleum Exporting Countries (OPEC), and the Fifth International Tin Agreement (ITA), as well as agreements governing diamonds and uranium, bauxite and coffee. OPEC, CIPEC and ITA are discussed.

  17. Screening, identification and desilication of a silicate bacterium

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hong-bo; ZENG Xiao-xi; LIU Fei-fei; QIU Guan-zhou; HU Yue-hua

    2006-01-01

    The strain Lv1-2 isolated from the Henan bauxite was characterized by morphological observation, biochemical and physiological identification, and 16S rDNA sequence analysis. The influences of temperature, initial pH value, the volume of medium, shaking speed and illite concentration on the desilicating ability of the strain Lv1-2 were investigated. The results show that the bacterium is a Gram-negative rod-shaped bacterium with oval endspores and thick capsule, but without flagellum. The biochemical and physiological tests indicate that the strain Lv1-2 is similar to Bacillus mucilaginosus. In GenBank the 16S rDNA sequence similarity of the strain Lv1-2 and the B. mucilaginosus YNUCC0001 (AY571332) is more than 99 %. Based on the above results, the strain Lv1-2 is identified as B. mucilaginosus. The optimum conditions for the strain Lv1-2 to remove silicon from illite are as follows: temperature is 30℃ ;initial pH value is 7.5; medium volume in 200 mL bottle is 60 mL; shaking speed of rotary shaker is 220 r/m; illite concentration is 1%.

  18. Institutional arrangements for the reduction of proliferation risks formulation, evaluation, and implementation of institutional concepts. Appendices

    International Nuclear Information System (INIS)

    The purpose of this supporting analysis is to provide a foundation for developing a model, an international or multinational institution capable of accomodating the back end of the fuel cycle, while meeting US nonproliferation goals. The analysis is based on a review of selected, defunct and extant institutions which, although not necessarily concerned with nonproliferation, have faced a trade-off between acceptability and effectiveness in meeting their objectives. Discussion of the various institutions is divided into three categories: international organizations, multinational consortia, and cartels or producer associations. Examples of international organizations include the International Seabed Authority, Intelsat, the United Nations and the International Atomic Energy Agency (IAEA). The International Seabed Authority is discussed. Multinational consortia are organizations that have been developed primarily to meet common commercial objectives. Membership includes at least three member nations. Examples include the Scandinavian Airline System (SAS), URENCO, Unilever, Royal Dutch Shell, Eurochemic, Eurodif, Euratom, European Coal and Steel Community, and Serena. Cartels or producer associations are multinational agreements that restrict market forces; viz, production, market share, customers or prices. Examples include the Intergovernmental Council of Copper Exporting Countries (CIPEC), the Organization of Petroleum Exporting Countries (OPEC), and the Fifth International Tin Agreement (ITA), as well as agreements governing diamonds and uranium, bauxite and coffee. OPEC, CIPEC and ITA are discussed

  19. The Technological Enhancement of Normally Occurring Radioactive Materials in Red Mud due to the Production of Alumina

    Directory of Open Access Journals (Sweden)

    Maurice O. Miller

    2016-01-01

    Full Text Available This study investigates the level of technological enhancement of normally occurring radioactive materials (TENORM in the red mud waste due to the production of alumina in Jamaica. Technological enhancements factors (TEF were determined for the uranium, thorium, actinium series, their progenies, and the nonseries potassium-40 using gamma spectrometry. The study concluded that bauxite production technologically enhances the uranium progenies Th-234, Pb-214, Bi-214, and Pa-234 and the thorium-232 progenies Ac-228, Pb-212, and Bi-212 in red mud. The actinium series was technologically enhanced, but K-40 and the thorium daughter, Tl-208, were reduced. The spectrometric comparison of Tl-208 (at 510 keV was unexpected since its other photopeaks at 583 keV, 934 keV, and 968 keV were markedly different. An explanation for this anomaly is discussed. An explanation regarding the process of accumulation and fractionation of organically derived phosphate deposits and potassium-feldspar is offered to explain the spectrometric differences between the alumina product and its waste material, red mud.

  20. N-(6-(hydroxyamino)-6-oxohexyl) decanamide collector: Flotation performance and adsorption mechanism to diaspore

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Lanqing [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Yueyang Chinese Herbal Utilization, Yueyang Vocational Technical College, Yueyang 414000 (China); Wang, Shuai [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Zhong, Hong, E-mail: zhongh@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Liu, Guangyi, E-mail: guangyiliu@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2015-08-30

    Graphical abstract: The potential absorption model of NHOD on diaspore surface. - Highlights: • A novel surfactant NHOD was first introduced as diaspore flotation collector. • NHOD exhibited superior collecting power to diaspore against gangue. • NHOD's has double active centers to mineral surfaces and double hydrophobic groups. • NHOD molecules formed intermolecular hydrogen bonds on diaspore surfaces. - Abstract: In this paper, a novel surfactant, N-(6-(hydroxyamino)-6-oxohexyl)decanamide (NHOD) was synthesized and used as a collector for flotation separation of diaspore and aluminosilicate minerals. The adsorption mechanism of NHOD onto diaspore was also investigated by FTIR spectra, zeta potential measurement and XPS. The flotation results demonstrated that NHOD exhibited superior collecting power to diaspore and selectivity against kaolinite and illite and could effectively realize flotation recovery of diaspore from bauxite ores contained aluminosilicate minerals under neutral conditions. The results of XPS, FTIR spectra and zeta potential illustrated that at around pH 7.0, NHOD might chemisorb on diaspore surfaces through Al−O coordination bonds formed by binding its −C(=O)NHOH or −C(=O)NH− chelate groups with aluminum atoms on diaspore surfaces. NHOD's unique properties, such as characteristic bond patterns onto diaspore surfaces, two hydrophobic groups, and intermolecular hydrogen bonds between neighboring NHOD molecules coated on diaspore surfaces, rendered it to be a superior flotation collector for diaspore.

  1. Technological Research on Direct Reduction of Obsolete Red Mud in Alumina Industry%难处理氧化铜矿强化浸出的研究概况

    Institute of Scientific and Technical Information of China (English)

    郑永兴; 文书明; 刘健; 邓永帅

    2011-01-01

    氧化铜矿石的结构与组成变化较大,单一的酸浸或氨浸往往不能取得理想的指标.但是如果不处理这部分氧化铜矿,对铜资源短缺的我国就会造成一种巨大的损失.在查阅大量相关文献资料的基础上,阐述了难处理氧化铜矿的强化浸出方法及应用,以期对同行有所裨益.%Using the dissolved obsolete red mud of Indonesian bauxite ore, adding the self - made additives, adopting the new technological flowsheet of coal - based direct reduction roasting - magnetic separation of iron slag - cold bond agglomeration and by the way of X - ray and SEM - EDS, the characteristics of metal iron grain growth in the course of direct reduction was studied and more emphasis was put on effects of additive types and roasting conditions on the characteristics of metal iron grain growth. Finally, the high - quality sponge iron with the metallization rate of 92.9% ,iron content of 93.7% and iron recovery of 94.42% was obtained. This new technology will exploit a new way for comprehensive utilization of obsolete red mud in alumina industry.

  2. An active dealkalization of red mud with roasting and water leaching.

    Science.gov (United States)

    Zhu, Xiaobo; Li, Wang; Guan, Xuemao

    2015-04-01

    The research has focused on the dealkalization of red mud after active roasting and water leaching, which is obtained from bauxite during alumina production. The main factors such as roasting temperature, roasting time, water leaching stage, leaching temperature, leaching reaction time and liquid to solid ratio were investigated. The mechanism of dealkalization was in-depth studied by using ICP-AES, XRD, TG-DSC, SEM-EDS and leaching kinetic. The results show that the dealkalization rate reached 82% under the condition of roasting temperature of 700 °C, roasting time of 30 min, four stage water leaching, liquid to solid ratio of 7 mL/g, leaching temperature of 90 °C and reaction time of 60 min. The diffraction peak of Na6CaAl6Si6(CO3)O24 · 2H2O in red mud was decreased during the active roasting process, whereas the mineral phases of NaOH · H2O and Na2Ca(CO3)2 were appeared. The content of alkali obviously decreased and the grade of other elements increased during the process of active roasting and water leaching, which was in favor of next application process of red mud. The water leaching was controlled by internal diffusion of SCM and the apparent activation energy was 22.63 kJ/mol. PMID:25559862

  3. 高铁铝土矿中温金属化焙烧装置监控系统设计*%The Process Control System for Pilot Test of Grinding and Classification

    Institute of Scientific and Technical Information of China (English)

    程晓峰; 孙路路; 张颖新

    2013-01-01

    This paper introduced a monitoring system for high ferrous bauxite metallic roasting .The system used S7-200 as main controller and the Smart700 as HMI.It also described the control strategies and selection method of actuator .The monitoring system achieved automatic control of temperature , pressure and reaction atmosphere for the metallic roasting process .%结合高铁铝土矿中温金属化焙烧工艺设计开发了一套监控系统。该系统采用S7-200小型PLC作为主控制器,Smart700触摸显示屏作为人机界面单元,通过合理的控制策略和采集及执行元件的选择实现了焙烧过程中温度、压力以及反应气氛的自动控制。

  4. DETERMINATION OF RESOLUTION LIMITS OF ELECTRICAL TOMOGRAPHY ON THE BLOCK MODEL IN A HOMOGENOUS ENVIRONMENT BY MEANS OF ELECTRICAL MODELLING

    Directory of Open Access Journals (Sweden)

    Franjo Šumanovac

    2007-12-01

    Full Text Available The block model in a homogenous environment can generally serve for presentation of some geological models: changes of facies, changes of rock compactness-fragmentation, underground cavities, bauxite deposits, etc. Therefore, on the block model of increased resistivities in a homogenous environment of low resistivity, the potentials of the electrical tomography method were tested for the purpose of their detection. Regarding potentials of block detection, resolution methods depend on: depth of block location, ratio between block resistivity and the environment in which it is located as well as applied survey geometry, i.e. electrode array. Thus the analyses carried out for the most frequently used electrode arrays in the investigations are the following: the Wenner, Wenner-Schlumberger, dipole-dipole and pole-pole arrays. For each array, maximum depths at which a block can be detected relative to the ratio between block resistivity and parent rock environment were analyzed. The results are shown in the two-dimensional graphs, where the ratio between the block resistivity and the environment is shown on the X-axis, and the resolution depth on the Y-axis, after which the curves defining the resolution limits were drawn. These graphs have a practical use, since they enable a fast, simple determination of potentials of the method application on a specific geological model.

  5. MSWI Fly Ash Based Novel Solidification/Stabilization Matrices for Heavy Metals

    Institute of Scientific and Technical Information of China (English)

    DENG Faqing; QIAN Guangren

    2008-01-01

    The possibilities of MSWI fly ash as a major constituent of novel solidification/stabilization matrices for secure landfill were investigated by mixing MSWl fly ash with rich aluminum components,which was added as bauxite cement or metakaolinite instead,to form Friedel and Ettringite phases with high fixing capacities for heavy metals.The physical properties,heavy metals-fixing capacity,mineral phases and its vibration bands in the novel matrices were characterized by compressive strength,TCLP(toxic characteristic leaching procedure),XRD (x-ray diffraction),DTG (derivative thermogravimetry),and FTIR (fourier transform infrared spectroscopy),respectively.The Tessier's five-step sequential extraction procedure was used to analyze the fractions of chemical speciation for Pb,Cd and Zn ions.The experimental results indicate that Friedel-Ettringite based novel solidification/stabilization matrices can incorporate Pb,Cd and Zn ions effectively by physical encapsulation and chemical fixation,and it exhibits a great potential in co-landfill treatment of MSWI fly ash with some heavy metals-bearing hazardous wastes.

  6. Comparison of microbial communities in pilot-scale bioreactors treating Bayer liquor organic wastes.

    Science.gov (United States)

    McSweeney, Naomi J; Plumb, Jason J; Tilbury, Amanda L; Nyeboer, Hugh J; Sumich, Matt E; McKinnon, Anthony J; Franzmann, Peter D; Sutton, David C; Kaksonen, Anna H

    2011-04-01

    Western Australian bauxite deposits are naturally associated with high amounts of humic and fulvic materials that co-digest during Bayer processing. Sodium oxalate remains soluble and can co-precipitate with aluminium hydroxide unless it is removed. Removal of sodium oxalate requires a secondary crystallisation step followed by storage. Bioreactors treating oxalate wastes have been developed as economically and environmentally viable treatment alternatives but the microbial ecology and physiology of these treatment processes are poorly understood. Analysis of samples obtained from two pilot-scale moving bed biofilm reactors (MBBRs) and one aerobic suspended growth bioreactor (ASGB) using polymerase chain reaction- denaturing gradient gel electrophoresis of 16S rRNA genes showed that members of the α-, β- and γ-Proteobacteria subgroups were prominent in all three processes. Despite differing operating conditions, the composition of the microbial communities in the three reactors was conserved. MBBR2 was the only configuration that showed complete degradation of oxalate from the influent and the ASGB had the highest degradation rate of all three configurations. Several strains of the genus Halomonas were isolated from the bioreactors and their morphology and physiology was also determined.

  7. Application of ultrasonic pulse velocity technique and image analysis in monitoring of the sintering process

    Directory of Open Access Journals (Sweden)

    Terzić A.

    2011-01-01

    Full Text Available Concrete which undergoes a thermal treatment before and during its life-service can be applied in plants operating at high temperature and as thermal insulation. Sintering occurs within a concrete structure in such conditions. Progression of sintering process can be monitored by the change of the porosity parameters determined with a nondestructive test method - ultrasonic pulse velocity and computer program for image analysis. The experiment has been performed on the samples of corundum and bauxite concrete composites. The apparent porosity of the samples thermally treated at 110, 800, 1000, 1300 and 1500ºC was primary investigated with a standard laboratory procedure. Sintering parameters were calculated from the creep testing. The loss of strength and material degradation occurred in concrete when it was subjected to the increased temperature and a compressive load. Mechanical properties indicate and monitor changes within microstructure. The level of surface deterioration after the thermal treatment was determined using Image Pro Plus program. Mechanical strength was estimated using ultrasonic pulse velocity testing. Nondestructive ultrasonic measurement was used as a qualitative description of the porosity change in specimens which is the result of the sintering process. The ultrasonic pulse velocity technique and image analysis proved to be reliable methods for monitoring of microstructural change during the thermal treatment and service life of refractory concrete.

  8. Radiometric analysis of raw materials and end products in the Turkish ceramics industry

    Science.gov (United States)

    Turhan, Ş.; Arıkan, İ. H.; Demirel, H.; Güngör, N.

    2011-05-01

    This study presents the findings of radiometric analysis carried out to determine the activity concentrations of natural radionuclides in raw materials (clay, kaolin, quartz, feldspar, dolomite, alumina, bauxite, zirconium minerals, red mud and frit) and end products (glazed ceramic wall and floor tiles) in the Turkish ceramics industry. Hundred forty-six samples were obtained from various manufacturers and suppliers throughout the country and analyzed using gamma-ray spectrometer with HPGe detectors. Radiological parameters such as radium equivalent activity, activity concentration index and alpha index were calculated to assess the radiological aspects of the use of the ceramic end products as decorative or covering materials in construction sector. Results obtained were examined in the light of the relevant national and international legislation and guidance and compared with the results of similar studies reported in different countries. The results suggest that the use of ceramic end product samples examined in the construction of dwellings, workplaces and industrial buildings in Turkey is unlikely to give rise to any significant radiation exposure to the occupants.

  9. Effects of thermal treatments on the characterisation and utilisation of red mud with sawdust additive.

    Science.gov (United States)

    Liu, Yanju; Naidu, Ravi; Ming, Hui; Dharmarajan, Rajarathnam; Du, Jianhua

    2016-06-01

    Extremely large amounts of red mud (bauxite residue) are generated globally every year from alumina refining industries, which are being disposed of on engineered landfills. The objective of this study is to investigate the effects of thermal treatments on red mud for development of utilisation strategies. Thermal treatments of red mud samples and their characterisations were investigated under inert (N2) and oxidative (air) conditions with and without sawdust addition at 200-600°C. After calcination, the resulting samples were analysed using thermogravimetric-infrared spectroscopy (TG-IR) for functional group transformations, thermogravimetric analysis (TGA) for thermal loss profiles and X-ray diffraction (XRD) for mineral transformations. The characterisation results showed that in N2 environment, boehmite in red mud was transferred to transition alumina at around 400°C while losing water from structural components. The addition of sawdust for incubation and calcination of red mud in air increased the surface area, whereas that in nitrogen atmosphere lead to reduction of hematite to magnetite at around 500°C. The incorporated carbon materials played a major role in increasing the surface area especially for pore size less than 2.5 nm. This treated red mud with altered mineral composition and improved properties for binding contaminants can be used for environmental remediation and in the process of metal recovery such as iron. PMID:26951343

  10. Morphology of the lumbosacral plexus of the ocelot (Leopardus pardalis

    Directory of Open Access Journals (Sweden)

    Jessica Albuquerque Lopes

    2012-11-01

    Full Text Available Popularly known as the ocelot, Leopardus pardalis occurs throughout Brazil in all ecosystems, but prefers riparian regions and forests. The objective of this study was to learn more about the macroscopic, anatomical aspects of the plexus lumbossacral of this species. Three specimens were studied, two males and one female, from the region near the Bauxite Mine in Paragominas, PA. The specimens were donated to the Laboratório de Pesquisa Morfológica Animal (LaPMA at UFRA after being run over (authorization numbers 485/2009 and 522/2009. The animals were fixed in an aqueous solution of 10% formaldehyde and then the hind limb was dissected by removing some muscles to expose the nerves. In two animals, the femoral nerve originated in the fourth lumbar nerve (L4 and transformed into the saphenous nerve. The obturator nerve and sciatic nerve originated in the last lumbar nerve (L5, and the latter was divided into branches that formed the tibial and common peroneal nerves, which dorsally formed the cranial gluteal and caudal gluteal nerves.

  11. Osmium isotopic tracing of atmospheric emissions from an aluminum smelter

    Science.gov (United States)

    Gogot, Julien; Poirier, André; Boullemant, Amiel

    2015-09-01

    We present for the first time the use of osmium isotopic composition as a tracer of atmospheric emissions from an aluminum smelter, where alumina (extracted from bauxite) is reduced through electrolysis into metallic aluminum using carbonaceous anodes. These anodes are consumed in the process; they are made of petroleum coke and pitch and have high Re/Os elementary ratio. Due to the relatively large geological age of their source material, their osmium shows a high content of radiogenic 187Os produced from in situ187Re radioactive decay. The radiogenic isotopic composition (187Os/188Os ∼ 2.5) of atmospheric particulate emissions from this smelter is different from that of other typical anthropogenic osmium sources (that come from ultramafic geological contexts with unradiogenic Os isotopes, e.g., 187Os/188Os < 0.2) and also different from average eroding continental crust 187Os/188Os ratios (ca. 1.2). This study demonstrates the capacity of osmium measurements to monitor particulate matter emissions from the Al-producing industry.

  12. Properties and application of carbon composite brick for blast furnace hearth

    Directory of Open Access Journals (Sweden)

    Jiao K.X.

    2015-01-01

    Full Text Available A type of carbon composite brick was produced via the microporous technique using natural flack graphite, α-Al2O3 and high-quality bauxite chamotte (Al2O3≥87 mass% as raw materials with fine silicon powder as additive. The composition and microstructure of the obtained carbon composite were characterized using chemical analysis, XRD and SEM with EDS. The high temperature properties of thermal conductivity, oxidization and corrosion by molten slag and hot metal of the composite were analyzed. Based on these, the type of carbon composite brick worked in a blast furnace hearth for six years was further sampled at different positions. The protective layer was found and its chemical composition and microscopic morphology were investigated. It is found that the carbon composite brick combines the good properties of both the conventional carbon block and ceramic cup refractory. The protective layer near the hot face consists of two separated sublayers, i.e. the slag layer and the carbon layer. A certain amount of slag phase is contained in the carbon layer, which is caused by the reaction of coke ash with the refractory. No obvious change in the chemical composition of the protective layer along the depth of the sidewall is found. This work provides a useful guidance for the extension of the lifetime of blast furnace hearths.

  13. MINERAÇÃO E CAMPESINATO NO MUNiCípIO DE JURUTI/PA, BRASIL

    Directory of Open Access Journals (Sweden)

    João Santos Nahum

    2012-01-01

    Full Text Available We focus on a chapter of the agrarian issue in the Amazon, characterized by territorial disputes between a mining company and the smallholders in the city of Juruti (PA. Here, for the first time in the history of large-scale projects in the Amazon, smallholders, especially riparian farmers and extractivists, supported by outreach from the Catholic Church'sPastoral Land Commission (CPT, the rural workers' union, and political and community leaders, organized and built a coalition representing their interests and protested against a mining project. The coalition collectively managed supporters' land rights, their right to a percentage of profits from the mining of bauxite, as well as using it directly. We raise secondary data, which supported our analysis of geographical focus, from literature review and consultation sites. The information and primary data were collected and systematized through field work, where, as the Brazilian saying goes, we put "the dirt of the place under our fingernails" and thus describe the processes surveyed. In the first part of the paper we describe the conditions and possibilities that allowed the mining activities in Juruti. In the second part we analyze the territorial disputes between ALCOA (Aluminium Company of America and the smallholders, organized in ACORJUVE (Community Association of the Gleba Old Juruti Region. Then we present some final considerations, without the worry of completing the analysis.

  14. Ecological restoration of litter in mined areas

    Science.gov (United States)

    Teresinha Gonçalves Bizuti, Denise; Nino Diniz, Najara; Schweizer, Daniella; de Marchi Soares, Thaís; Casagrande, José Carlos; Henrique Santin Brancalion, Pedro

    2016-04-01

    The success of ecological restoration projects depends on going monitoring of key ecological variables to determine if a desired trajectory has been established and, in the case of mining sites, nutrient cycling recovery plays an utmost importance. This study aimed to quantify and compare the annual litter production in native forests, and in restoration sites established in bauxite mines. We collected samples in 6 native forest remnants and 6 year-old restoration sites every month for a period of one year, in the city of Poços de Caldas/MG, SE Brazil. 120 wire collectors were used (0,6x0,6) and suspended 30cm above the soil surface. The material was dried until constant weight, weighed and fractionated in leaves, branches and reproductive material. The average annual litter production was 2,6 Mg ha-1 in native forests and 2,1 in forest in restoration sites, differing statistically. Litter production was higher in the rainy season, especially in September. Among the litter components, the largest contributor to total production was the fraction leaves, with 55,4% of the total dry weight of material collected, followed by reproductive material which contributed 24,5% and branches, with 20%. We conclude that the young areas in restoration process already restored important part, but still below the production observed in native areas.

  15. Morphological description of collateral branches from the abdominal aorta of lesser anteater (Tamandua tetradactyla

    Directory of Open Access Journals (Sweden)

    Breno Costa Macedo

    2013-03-01

    Full Text Available Tamandua tetradactyla, Xenarthra, is a native species from South America which, due to the few number of studies on its biology, still has many unknown aspects in its morphology. Taking into account the importance of morphological data for various studies, this paper aimed to elucidate the branching of the abdominal aorta in this species to foster the development of further studies. To do this, 4 specimens were used, 2 male and 2 female, all young, from the Bauxite Mine – Paragominas, Para, Brazil, donated after death due to running over to the Animal Morphology Research Laboratory (LaPMA of Universidade Federal Rural da Amazonia (UFRA. The arterial system was filled with contrasted latex and the animals were fixed in a formaldehyde solution (10%, and then dissected, in order to evidence the abdominal aorta and its collateral branches. The parietal branches consisted of 1 pair of caudal phrenic arteries, 2 pairs of intercostal arteries, and 3 pairs of lumbar arteries. Among the visceral branches, stood out: celiac artery; cranial mesenteric artery; adrenal arteries; renal arteries; caudal mesenteric artery; and external, internal, and median sacral iliac arteries, formed from the final portion of the abdominal aorta. Testicular and ovarian arteries originated from the renal arteries, differing from that described in various species.

  16. Soil microbial community successional patterns during forest ecosystem restoration.

    Science.gov (United States)

    Banning, Natasha C; Gleeson, Deirdre B; Grigg, Andrew H; Grant, Carl D; Andersen, Gary L; Brodie, Eoin L; Murphy, D V

    2011-09-01

    Soil microbial community characterization is increasingly being used to determine the responses of soils to stress and disturbances and to assess ecosystem sustainability. However, there is little experimental evidence to indicate that predictable patterns in microbial community structure or composition occur during secondary succession or ecosystem restoration. This study utilized a chronosequence of developing jarrah (Eucalyptus marginata) forest ecosystems, rehabilitated after bauxite mining (up to 18 years old), to examine changes in soil bacterial and fungal community structures (by automated ribosomal intergenic spacer analysis [ARISA]) and changes in specific soil bacterial phyla by 16S rRNA gene microarray analysis. This study demonstrated that mining in these ecosystems significantly altered soil bacterial and fungal community structures. The hypothesis that the soil microbial community structures would become more similar to those of the surrounding nonmined forest with rehabilitation age was broadly supported by shifts in the bacterial but not the fungal community. Microarray analysis enabled the identification of clear successional trends in the bacterial community at the phylum level and supported the finding of an increase in similarity to nonmined forest soil with rehabilitation age. Changes in soil microbial community structure were significantly related to the size of the microbial biomass as well as numerous edaphic variables (including pH and C, N, and P nutrient concentrations). These findings suggest that soil bacterial community dynamics follow a pattern in developing ecosystems that may be predictable and can be conceptualized as providing an integrated assessment of numerous edaphic variables. PMID:21724890

  17. Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers:quantitative determination by digital image analysis%Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers: quantitative determination by digital image analysis

    Institute of Scientific and Technical Information of China (English)

    P A MOHAMED NAJAR; R G SONALI; M T NIMJE; K V RAMANA RAO

    2012-01-01

    Thin layer chromatography (TLC) of cobalt and nickel has been performed on silica gel layers induced with alkali mediated cellulose extract.A novel combination of 10% aqueous solutions of Tween-20 and potassium thiocyanate in 1∶ 1 (v/v) was identified as the best mobile phase for the selective separation of Co2+ from Ni2+ on the impregnated Silica Gel G layers.The chromatographic characteristics of the cations were studied and the limits of detection as well as the limits of quantification for Co2+ and Ni2+ were determined.The quantitative estimation of the cations was achieved from the digital image analysis of respective chromatograms.The proposed quantitative method was successfully applied with 0-0.50% error for the determination of Co2+ from Ni2+ in spiked samples of bauxite,soil and rock containing common cations such as Al3+,Fe2+,Ti4+,Zn2+,Mn2+,Cu2+,Cr6+,Mg2+ etc.under the optimized chromatographic conditions.

  18. Glassceramics frits attainment from industrial solid wastes; Obtencao de fritas vitroceramicas a partir de residuos solidos industriais

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Matheus Chianca

    2006-07-01

    This work studies the residue obtained from the process of aluminum metal extraction activities, a great interest process, because of Brazil own some of the biggest bauxite mineral reserves in all the world. As a useful choice for no residue generation, and a support for environmentally friendly technologies, this work studies the white dross residue (WDR), from the process of aluminum metal reduction by thermal plasma. The phase equilibrium diagram of Al{sub 2}O{sub 3}-Ca O-SiO{sub 2} system was used to calculate the compositions. The WDR were incorporated in a ceramic product without modifying its principal characteristics. The fusion and devitrification treatments were studied. XRD (X-ray diffractometry), SEM (scanning electron microscopy) and FTIR (transformed Fourier infrared) were used to investigate the glass and glassceramic samples. These techniques showed that is possible to get glassceramic with up to 30 mass% of WDR after molten at 1300 deg C and annealed at 900 deg C. In addition, the WDR showed to be a promising material in attainment of crystalline phases in less times of heat treatment for annealing. (author)

  19. Use of object-oriented classification and fragmentation analysis (1985-2008) to identify important areas for conservation in Cockpit Country, Jamaica.

    Science.gov (United States)

    Newman, Minke E; McLaren, Kurt P; Wilson, Byron S

    2011-01-01

    Forest fragmentation is one of the most important threats to global biodiversity, particularly in tropical developing countries. Identifying priority areas for conservation within these forests is essential to their effective management. However, this requires current, accurate environmental information that is often lacking in developing countries. The Cockpit Country, Jamaica, contains forests of international importance in terms of levels of endemism and overall diversity. These forests are under severe threat from the prospect of bauxite mining and other anthropogenic disturbances. In the absence of adequate, up-to-date ecological information, we used satellite remote sensing data and fragmentation analysis to identify interior forested areas that have experienced little or no change as priority conservation sites. We classified Landsat images from 1985, 1989, 1995, 2002, and 2008, using an object-oriented method, which allowed for the inclusion of roads. We conducted our fragmentation analysis using metrics to quantify changes in forest patch number, area, shape, and aggregation. Deforestation and fragmentation fluctuated within the 23-year period but were mostly confined to the periphery of the forest, close to roads and access trails. An area of core forest that remained intact over the period of study was identified within the largest forest patch, most of which was located within the boundaries of a forest reserve and included the last remaining patches of closed-broadleaf forest. These areas should be given highest priority for conservation, as they constitute important refuges for endemic or threatened biodiversity. Minimizing and controlling access will be important in maintaining this core.

  20. Genetic analyses determine connectivity among cave and surface populations of the Jamaican endemic freshwater crab Sesarma fossarum in the Cockpit Country

    Directory of Open Access Journals (Sweden)

    Manuel Stemmer

    2016-01-01

    Full Text Available The Jamaican freshwater crab Sesarma fossarum (Decapoda: Brachyura: Sesarmidae is endemic to western central Jamaica where it occurs in cave and surface streams of karst regions. In the present study, we examine the population genetic structure of the species, providing evidence for intraspecific differentiation and genetic substructure among twelve sampled populations. Interestingly, crabs from caves appear genetically undistinguishable from representatives of nearby surface waters, despite previously observed and described morphometric differentiation. In contrast, genetic isolation takes place among populations from rivers and caves belonging to different watersheds. In one case, even populations from different tributaries of the same river were characterized by different genotypes. Overall, the species shows low haplotype and nucleotide diversities, which indicates a high homogeneity and point towards a relatively recent intraspecific radiation and diversification. Our results on the genetic diversification of S. fossarum helps to reconstruct unknown subterranean water flow and cave connections in its native range, allowing prediction of its further dispersal and differentiation potential. Unfortunately, its natural habitat of Jamaican cockpit karst, which also is home to several other endemic species and is a globally-recognized Key Biodiversity Area, is under imminent threat of intensive bauxite mining.

  1. The influence of titanium and iron oxides on the coloring and friability of the blue fired aluminum oxide as an abrasive material

    Directory of Open Access Journals (Sweden)

    E. R. Passos

    2016-03-01

    Full Text Available Abstract The quality of abrasive grains is crucial to increase the lifespan of roughing, polishing and cutting tools. The purpose of the work herein was to evaluate the variables of the blue fired aluminum oxide heat treatment process. This heat treatment process improves the physical properties of the brown fused aluminum oxide and results in a blue coloring, which uniquely identifies it within the abrasives industry. The work herein includes information beginning with the electro-fusion process of bauxite (the manufacturing of the brown fused aluminum oxide to the Blue Fired process. It also compares the fracture resistance index between these materials. This index is the inverse of the friability. Besides the content of titanium and iron oxides, process variables such as time, temperature and atmospheric conditions are important to monitor in order to reach standard requirements. Experimental evidence measuring these parameters is presented in the article herein. The blue coloring of this aluminum oxide is explained by the optical phenomena of electron transition, and not by the formation of aluminum titanate, as some technical literature has stated. Furthermore, it was proved that the coloring of blue fired material should not be used exclusively as an indicator of the optimal abrasive characteristics of this class of aluminum oxide.

  2. Mechanical Properties of Solid-State Recycled 4xxx Aluminum Alloy Chips

    Science.gov (United States)

    Tokarski, Tomasz

    2016-08-01

    The direct production of aluminum from bauxite ores is known to be a very energetic-intensive operation compared to other metallurgical processes. Due to energy issues and the rapid increase in aluminum demand, new kinds of aluminum production processes are required. Aluminum waste recycling, which has an advantage of lowering the cost of electric power consumption, is considered to be an alternative route for material manufacturing. In this work, the way of reusing aluminum EN-AC 44000 alloy scraps by hot extrusion was presented. Metal chips of different sizes and morphology were cold compacted into billet form and then hot extruded. Mechanical properties investigations combined with microstructure observations were performed. Mechanical anisotropy behavior of material was evaluated on the base of tensile test experiments performed on samples machined at 0°, 45°, and 90°, respectively, to the extrusion direction. It was found that the initial size of the chips has an influence on the mechanical properties of the received profiles. Samples produced from fine chips revealed higher tensile strength in comparison to larger chips, which can be attributed to a refined microstructure containing fine, hard Si particles and Fe-rich intermetallic phases. Finally, it was found that anisotropic behavior of chip-based profiles is similar to conventionally cast and extruded materials which prove good bonding quality between chips.

  3. In situ diffraction studies of scale formation under Bayer processing conditions

    International Nuclear Information System (INIS)

    Full text: The Bayer process is used to extract alumina (AI203) from bauxite ore. The efficiency of the proc severely compromised by the build-up of insoluble species (scale) on the surfaces of mild process equipment, which impedes the material flow through, and heat transfer to, the pr streams [1]. In precipitation areas operating at 60-8 C gibbsite, AI(OHh, scales predominate the spent liquor heaters which typically operate at 150-2500C, sodalite and cancrinite-type s aluminosilicate scales are formed (1). An improved understanding of the scale formation mechanism may lead to the development of a practical and economic method for scale prevention. Characterisation of the structure, composition and crystallographic orientation of phases present early stages of formation is crucial for this understanding, making x-ray and neutron diffraction important analytical techniques. In situ synchrotron x-ray diffraction experiments were performed Australian Synchrotron during AI(OHh deposition on mild steel substrates using a purpose built stainless steel flow cell (3). The high resolution data enabled identification of three polymors AI(OH)3 (gibbsite, bayerite and nordtsrandite) in the deposited material, each displaying ori growth along (001). Additional in situ synchrotron XRD experiments, where AI(OH)3 precipitatiol 'seeded' with various iron oxides and oxyhydroxides, have also been performed and some ' results will be discussed. Similar neutron diffraction experiments on Wombat are planned investigations of seeded aluminosilicate precipitation at 150-2500C using an Inconel hydrothermal cell.

  4. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing.

    Science.gov (United States)

    Liapis, Ioannis; Papayianni, Ioanna

    2015-01-01

    Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  5. Application of a low-yield neutron generator for rapid evaluation of alumino-silicate ores from Nigeria by FNAA

    International Nuclear Information System (INIS)

    A rapid analytical procedure based on low-yield of neutrons produced by a sealed-tube; 14 MeV neutron generator has been used for the determination of the Al and Si contents of alumino-silicate ores from Nigeria. Primary fast neutron flux reaching the sample and standard were monitored by high-purity Al foils and checked by a BF3 neutron counter system. Analytical grade Al2O3 and SiO2 chemical powders were used as standards while the analytical quality control of the procedure was checked by Bauxite (BCS-395) and Portland Cement (BCS-372) certified reference materials. The deviations of our measured values from the certified values were found to be 1.6% and 1.3% for Al and Si. Detection limits of the set-up for Al and Si were deduced to be 2.7 and 0.9 wt%; Respectively. Results are hereby presented for some industrial raw materials

  6. Mechanical Properties of Solid-State Recycled 4xxx Aluminum Alloy Chips

    Science.gov (United States)

    Tokarski, Tomasz

    2016-06-01

    The direct production of aluminum from bauxite ores is known to be a very energetic-intensive operation compared to other metallurgical processes. Due to energy issues and the rapid increase in aluminum demand, new kinds of aluminum production processes are required. Aluminum waste recycling, which has an advantage of lowering the cost of electric power consumption, is considered to be an alternative route for material manufacturing. In this work, the way of reusing aluminum EN-AC 44000 alloy scraps by hot extrusion was presented. Metal chips of different sizes and morphology were cold compacted into billet form and then hot extruded. Mechanical properties investigations combined with microstructure observations were performed. Mechanical anisotropy behavior of material was evaluated on the base of tensile test experiments performed on samples machined at 0°, 45°, and 90°, respectively, to the extrusion direction. It was found that the initial size of the chips has an influence on the mechanical properties of the received profiles. Samples produced from fine chips revealed higher tensile strength in comparison to larger chips, which can be attributed to a refined microstructure containing fine, hard Si particles and Fe-rich intermetallic phases. Finally, it was found that anisotropic behavior of chip-based profiles is similar to conventionally cast and extruded materials which prove good bonding quality between chips.

  7. Monitoring of radionuclides in carbon steel blooms produced by EAF process

    Directory of Open Access Journals (Sweden)

    Sofilić T.

    2011-01-01

    Full Text Available Because natural and artificial isotopes in steel might originate from steel scrap or from the residue of the material that was used in the technological process, thus monitoring especially artificial radionuclides 60Co, 137Cs and 192Ir deserve special attention. The analysis by g-spectrometry has been applied to determine the presence of natural isotopes 40K, 226Ra, 232Th and 238U as well as of the artificial isotope 60Co, 137Cs and 192Ir and their activity in the produced steel round blooms in the Steel Mill of CMC Sisak d.o.o. At the same time the content of radionuclides in the other materials (ferroalloys, bauxite, fluorite, lime, coke, graphite electrodes, refractory blocks used in the same steel making process was investigated. The measured values regarding the presence of individual isotopes and their activity in steel were as follows: 40K all values were less than 1.6 Bqkg-1; 232Th all activities values were less than 0.02 Bqkg-1; 226Ra all activities values were less than 0.01 Bqkg-1; 238U all activities values were less than 1.10 Bqkg-1; 60Co all activities values were less than 0.02 Bqkg-1; 192Ir all activities values were less than 0.02 Bqkg-1 and 137Cs all activities values were less than 0.30 Bqkg-1.

  8. Immobilization of trace elements in municipal solid waste incinerator (MSWI) fly ash by producing calcium sulphoaluminate cement after carbonation and washing.

    Science.gov (United States)

    Wang, Lei; Jamro, Imtiaz Ali; Chen, Qi; Li, Shaobai; Luan, Jingde; Yang, Tianhua

    2016-03-01

    The possibility of producing calcium sulphoaluminate cement (CSA) by adding municipal solid waste incinerator (MSWI) fly ash to raw meal was investigated. After subjecting MSWI fly ash to accelerated carbonation and washing with water (ACW), various amounts (i.e., 5, 10 and 15 wt%) of the treated ash were added to raw meal composed of a mixture of bauxite, limestone and gypsum. The mixtures were sintered in a laboratory-scale muffle furnace at temperatures of 1250°, 1300°, 1325° and 1350 °C for various durations. The influence of different quantities of MSWI fly ash on the mineralogy, major phase composition and strength development of the resulting clinker was studied, as was the effect of ash treatments on leaching and volatilization of trace elements. The ACW treatment reduced the volatilization ratio of trace elements during the clinkerization process. Volatilization ratios for lead, cadmium and zinc were 21.5%, 33.6% and 16.3%, respectively, from the ACW fly ash treatment, compared with ratios of 97.5%, 93.1% and 85.2% from untreated fly ash. The volatilization ratios of trace elements were ordered as follows: untreated fly ash > carbonated fly ash > carbonated and water-washed fly ash. The ACW process also reduced the chloride content in the MSWI fly ash by 90 wt% and prevented high concentrations of trace elements in the effluents. PMID:26644396

  9. 微膨胀高铝砖的生产与应用%Production and application of tiny expansive high alumina brick

    Institute of Scientific and Technical Information of China (English)

    孙华云; 李明晶; 王佑宝

    2013-01-01

    This paper describes the high alumina brick made of high quality bauxite and mullite compound as major raw materials ,with kyanite ,andalusite ,sillimanite and pyrophyllite as expanding agents,with soft clay as bonding agent ,and with certain amount of additives ,then calcined under appropriate temperature ,which has been sucessfully used for ladle lining to produce low carbon steel and strainless steel .Tiny brick expension appears at the high temperature and allows a good integrity of the ladle lining for a better erosion resistance .%采用优质高铝矾土和莫来石合成料为主要原料,添加蓝晶石、红柱石、硅线石(简称三石)和叶蜡石等作膨胀剂,使用软质黏土作结合剂,再外加适量添加剂,经适宜温度焙烧制成高铝砖,并成功应用于冶炼低碳钢、不锈钢等钢包内村。该砖在高温区使用时产生微膨胀,使钢包内衬具有良好的整体性,从而提高抗侵蚀性。

  10. ASEAN.

    Science.gov (United States)

    1992-03-01

    ASEAN is a group of counties encompassing 3 million sq. km with 333 million inhabitants, of whom approximately 65% are literate. The group was formed August 8, 1967, and includes Brunei, Indonesia, Malaysia, the Philippines, Singapore, and Thailand. Malay, Indonesian, Filipino, Thai, Chinese, and English are spoken by Malay, Thai, Chinese, Indian, and other ethnic groups who variously are of the Islamic, Buddhist, Christian, Taoist, and Hindu faiths. Life expectancy is approximately 85 years, with the marked exception of Indonesia. The gross domestic product is $303 billion, growing at a rate of 7.6%. Per capita income is $950. The group's natural resources include petroleum, natural gas, timber, tin, nickel, copper, iron, bauxite, and other minerals. The agricultural products rice, rubber, cassava, sugar, coffee, corn, pineapple, bananas, coconuts, and palm oil, as well as electronics, petroleum, textiles, minerals, chemicals, food processing, wood products, fabricated steel, and ships are areas of economic production. Machinery and other capital goods, chemicals, oil, and food are imported, and office machinery and electronics, petroleum, textiles, telecommunications equipment, natural rubber, processed seafood and fruits, wood products, tin, palm oil, sugar, and coffee are exported. In-depth information is also given on the people and history, intraregional and international cooperation, political conditions, the economy, defense, foreign relations, and relations with the US. PMID:12178041

  11. Dextrocardia with situs solitus and inversion apex-basis axis in lesser anteater (Tamandua tetradactyla: case report

    Directory of Open Access Journals (Sweden)

    V.L.C. Pinheiro

    2014-02-01

    Full Text Available Dextrocardia is a rare cardiac anomaly where the heart is situated on the right antimeres of the thorax. This study had the objective of describing a case of dextrocardia with situs solitus and apex-basis axis inversion in a lesser anteater (Tamandua tetradactyla between five evaluated animals, all from the area of Mine Bauxite - Paragominas - Para. The arterial system was filled with contrasted latex and the animals were fixed with 10% formaldehyde and a posterior dissection was done. The heart of an animal was found in right antimere with inversion of the base-apex axis. The right atrium was more developed then the left and the pulmonary veins arrived directly in the left ventricle. The main vases of the base were identified with some topographic alterations resulting in: aorta dorsal to the cava caudal vein, pulmonary artery dorsal and cranial to aorta, pulmonary veins ventral to the pulmonary artery, cava caudal vein in ventral plain and cava cranial vein in dorsal plan in relation to the other vessels. Internally there were four cardiac chambers, with absence of septal communication.

  12. Chemical stabilization of metals in mine wastes by transformed red mud and other iron compounds: laboratory tests.

    Science.gov (United States)

    Ardau, C; Lattanzi, P; Peretti, R; Zucca, A

    2014-01-01

    A series of static and kinetic laboratory-scale tests were designed in order to evaluate the efficacy of transformed red mud (TRM) from bauxite refining residues, commercial zero-valent iron, and synthetic iron (III) hydroxides as sorbents/reagents to minimize the generation of acid drainage and the release of toxic elements from multi-contaminant-laden mine wastes. In particular, in some column experiments the percolation of meteoric water through a waste pile, alternated with periods of dryness, was simulated. Wastes were placed in columns together with sorbents/reagents in three different set-ups: as blended amendment (mixing method), as a bed at the bottom of the column (filtration method), or as a combination of the two previous methods. The filtration methods, which simulate the creation of a permeable reactive barrier downstream of a waste pile, are the most effective, while the use of sorbents/reagents as amendments leads to unsatisfactory results, because of the selective removal of only some contaminants. The efficacy of the filtration method is not significantly affected by the periods of dryness, except for a temporary rise of metal contents in the leachates due to dissolution of soluble salts formed upon evaporation in the dry periods. These results offer original information on advantages/limits in the use of TRM for the treatment of multi-contaminant-laden mine wastes, and represent the starting point for experimentation at larger scale.

  13. Application of Bayer red mud for iron recovery and building material production from alumosilicate residues

    International Nuclear Information System (INIS)

    Red mud is a solid waste produced in the process of alumina extraction from bauxite. In this paper, recovery iron from Bayer red mud was studied with direct reduction roasting process followed by magnetic separation, and then building materials were prepared from alumosilicate residues. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery efficiency of iron were carried out. The optimum reaction parameters were proposed as the following: ratio of carbon powder: red mud at 18:100, ratio of additives: red mud at 6:100, roasting at 1300 deg. C for 110 min. With these optimum parameters, total content of iron in concentrated materials was 88.77%, metallization ratio of 97.69% and recovery ratio of 81.40%. Then brick specimens were prepared with alumosilicate residues and hydrated lime. Mean compressive strength of specimens was 24.10 MPa. It was indicated that main mineral phase transformed from nepheline (NaAlSiO4) in alumosilicate residues to gehlenite (Ca2Al2SiO7) in brick specimens through X-ray diffraction (XRD) technology. The feasibility of this transformation under the experimental conditions was proved by thermodynamics calculation analysis. Combined the recovery of iron with the reuse of alumosilicate residues, it can realize zero-discharge of red mud from Bayer process

  14. Landscape matrix mediates occupancy dynamics of Neotropical avian insectivores

    Science.gov (United States)

    Kennedy, Christina M.; Campbell Grant, Evan H.; Neel, Maile C.; Fagan, William F.; Marpa, Peter P.

    2011-01-01

    In addition to patch-level attributes (i.e., area and isolation), the nature of land cover between habitat patches (the matrix) may drive colonization and extinction dynamics in fragmented landscapes. Despite a long-standing recognition of matrix effects in fragmented systems, an understanding of the relative impacts of different types of land cover on patterns and dynamics of species occurrence remains limited. We employed multi-season occupancy models to determine the relative influence of patch area, patch isolation, within-patch vegetation structure, and landscape matrix on occupancy dynamics of nine Neotropical nsectivorous birds in 99 forest patches embedded in four matrix types (agriculture, suburban evelopment, bauxite mining, and forest) in central Jamaica. We found that within-patch vegetation structure and the matrix type between patches were more important than patch area and patch isolation in determining local colonization and local extinction probabilities, and that the effects of patch area, isolation, and vegetation structure on occupancy dynamics tended to be matrix and species dependent. Across the avian community, the landscape matrix influenced local extinction more than local colonization, indicating that extinction processes, rather than movement, likely drive interspecific differences in occupancy dynamics. These findings lend crucial empirical support to the hypothesis that species occupancy dynamics in fragmented systems may depend greatly upon the landscape context.

  15. 中国铝酸盐水泥的生产与发展

    Institute of Scientific and Technical Information of China (English)

    张宇震

    2003-01-01

    @@ 1铝酸盐水泥的诞生 铝酸盐水泥是耐火材料行业中不可缺少的一种水硬性粘结剂.该产品最早是1865年后期在法国出现,由氧化铝和石灰经熔融后破碎制成的铝酸钙水泥(calcium aluminate cement-CAC).19世纪末期英国首先发布了"石灰石-矾土(limestone bauxite cement)"水泥的专利.而首次进行这种水泥商业性生产则是在1913年法国的拉法基公司(Lafarge),生产方法为熔融法.铝酸盐水泥早期强度高,耐火性能优良,具有抗硫酸盐和弱酸侵蚀的能力,广泛应用于耐火材料行业.

  16. Technological Proposals for Recycling Industrial Wastes for Environmental Applications

    Directory of Open Access Journals (Sweden)

    Isabel Romero-Hermida

    2014-08-01

    Full Text Available A two-fold objective is proposed for this research: removing hazardous and unpleasant wastes and mitigating the emissions of green house gasses in the atmosphere. Thus, the first aim of this work is to identify, characterize and recycle industrial wastes with high contents of calcium or sodium. This involves synthesizing materials with the ability for CO2 sequestration as preliminary work for designing industrial processes, which involve a reduction of CO2 emissions. In this regard, phosphogypsum from the fertilizer industry and liquid wastes from the green olive and bauxite industries have been considered as precursors. Following a very simple procedure, Ca-bearing phosphogypsum wastes are mixed with Na-bearing liquid wastes in order to obtain a harmless liquid phase and an active solid phase, which may act as a carbon sequestration agent. In this way, wastes, which are unable to fix CO2 by themselves, can be successfully turned into effective CO2 sinks. The CO2 sequestration efficiency and the CO2 fixation power of the procedure based on these wastes are assessed.

  17. Carboniferous paleogeographic and paleoclimatic reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Scotese, C.R. (Univ. of Texas, Arlington, TX (United States). Dept. of Geology); Raymond, A. (Texas A and M Univ., College Station, TX (United States). Dept. Geology)

    1992-01-01

    The Carboniferous was an important transitional period in earth history. The Paleozoic oceans separating the continents of Gondwana, Laurentia, Baltica, Kazakhstan, and Siberia had closed by the late Carboniferous forming the late Paleozoic supercontinent of Pangea. Plate motions which appear to have been rapid during the Early Carboniferous (6--10 cm/yr), slowed to a temperature gradient increased as the Earth's climate changed from hot-house to ice-house conditions. Sea level, which stood high during the Early Carboniferous, fell as a result of continental collision and mountain-building, and then began to rise and fall rhythmically as the South Polar ice-cap waxed and waned. These environmental changes intersected important evolutionary events, namely, the explosive colonization of the emergent land areas by plants and the rise of terrestrial vertebrates. In this paper the authors present paleogeographic reconstructions for 6 intervals during the Carboniferous. These maps illustrate the latitudinal position of the continents deduced from paleomagnetic data and the distribution of climatically restricted lithofacies (coal, bauxite, evaporite, calcrete, and tillite), the inferred location of active plate boundaries, and the changing configuration of mountains, land, shallow seas, and deep ocean basins. For each of these paleogeographic maps a climatic simulation was run using the Parametric Climate Model. These simulations predict the distribution of high and low pressure cells, prevailing wind directions, pole-to-equator temperature gradient, relative wetness/dryness, as well as zones of coastal upwelling.

  18. Intensifying digestion of diaspore and separation of alumina and silica

    Institute of Scientific and Technical Information of China (English)

    李小斌; 彭志宏; 刘桂华; 周秋生

    2003-01-01

    It was found that there lies a linear relationship among the thermodynamic data of complicate inorganic compounds with similar components. A method for estimating the thermodynamic data of complicate compound and a thermodynamic database involving alumina production were developed. It was found that the alumina digestion rate of activated diasporic bauxite by means of heat field increased much due to the structure aberration, i.e, from perfect structure to unstable corundum. The results from thermodynamic calculation and experiments showed that it was feasible for desilication at atmospheric pressure, and the effects on equilibrium concentration of SiO2 included temperature, mole ratio of Na2O/Al2O3 (αk), caustic and Na+ concentration. The technology of desilication of green liquor at atmosphere and separation of alumina and silica in aluminate solution with high concentration were established. The reaction activity of compounds containing silica and the converting law among compounds were studied, and the prototype technology of desilication products by hydrotreatment was also developed.

  19. Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of calcined alumina

    Directory of Open Access Journals (Sweden)

    Pattem Hemanth Kumar

    2014-12-01

    Full Text Available A new class of conventional and low-cement ferrochrome slag-based castables were prepared from 40 wt.% ferrochrome slag and 45 wt.% calcined bauxite. Rest fraction varied between high alumina cement (HAC acting as hydraulic binder and calcined alumina as pore filling additive. Standard ASTM size briquettes were prepared for crushing and bending strengths evaluation, and the samples were then subjected to firing at 800, 1100 and 1300 °C for a soaking period of 3 h. The microstructure and refractory properties of the prepared castables have been investigated using X-ray diffraction (XRD, scanning electron microscopy (SEM, cold crushing strength, modulus of rupture and permanent linear changes (PLCs test. Castables show good volume stability (linear change <0.7% at 1300 °C. The outcomes of these investigations were efficacious and in accordance with previously reported data of similar compositions. High thermo-mechanical and physico-chemical properties were attained pointing out an outstanding potential to increase the refractory lining working life of non-recovery coke oven and reheating furnaces.

  20. Application of Bayer red mud for iron recovery and building material production from alumosilicate residues.

    Science.gov (United States)

    Liu, Wanchao; Yang, Jiakuan; Xiao, Bo

    2009-01-15

    Red mud is a solid waste produced in the process of alumina extraction from bauxite. In this paper, recovery iron from Bayer red mud was studied with direct reduction roasting process followed by magnetic separation, and then building materials were prepared from alumosilicate residues. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery efficiency of iron were carried out. The optimum reaction parameters were proposed as the following: ratio of carbon powder: red mud at 18:100, ratio of additives: red mud at 6:100, roasting at 1300 degrees C for 110min. With these optimum parameters, total content of iron in concentrated materials was 88.77%, metallization ratio of 97.69% and recovery ratio of 81.40%. Then brick specimens were prepared with alumosilicate residues and hydrated lime. Mean compressive strength of specimens was 24.10MPa. It was indicated that main mineral phase transformed from nepheline (NaAlSiO4) in alumosilicate residues to gehlenite (Ca2Al2SiO7) in brick specimens through X-ray diffraction (XRD) technology. The feasibility of this transformation under the experimental conditions was proved by thermodynamics calculation analysis. Combined the recovery of iron with the reuse of alumosilicate residues, it can realize zero-discharge of red mud from Bayer process. PMID:18457916

  1. ECONOMIC BENEFITS ASSOCIATED WITH MINERAL PRODUCTION IN GHANA

    Directory of Open Access Journals (Sweden)

    Wisdom Erasmus Boatri

    2014-07-01

    Full Text Available Ghana is endowed with many natural resources which have contributed significantly to the nation’s economic development. In this study, the economic benefits of Gold, Diamond, Bauxite and Manganese in terms of production, revenue from export as well as contributions to government revenue in the form of taxes between the years 1990 to 2011 and their projections from 2012 to 2030 were analysed and compared. Data was collected from Ghana Chamber of Mines, Ghana Mineral Commission, Bank of Ghana, Environmental Protection Agency and other relevant institutions combined with secondary related materials. Statistica software was used for the data analysis where a liner regression models were developed to describe the trend of the various minerals economic benefits. The immense benefit that comes with mining will continue if the state improves on policies of less mined minerals and implement prudent economic policies. Effective monitoring of regulatory institutions linked with the sector for implementing environmental policies and adoption of international standards of mining would help to prevent negative pressure from anti mining institutions.

  2. Updated Life-Cycle Assessment of Aluminum Production and Semi-fabrication for the GREET Model

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Qiang [Argonne National Lab. (ANL), Argonne, IL (United States); Kelly, Jarod C. [Argonne National Lab. (ANL), Argonne, IL (United States); Burnham, Andrew [Argonne National Lab. (ANL), Argonne, IL (United States); Elgowainy, Amgad [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    This report serves as an update for the life-cycle analysis (LCA) of aluminum production based on the most recent data representing the state-of-the-art of the industry in North America. The 2013 Aluminum Association (AA) LCA report on the environmental footprint of semifinished aluminum products in North America provides the basis for the update (The Aluminum Association, 2013). The scope of this study covers primary aluminum production, secondary aluminum production, as well as aluminum semi-fabrication processes including hot rolling, cold rolling, extrusion and shape casting. This report focuses on energy consumptions, material inputs and criteria air pollutant emissions for each process from the cradle-to-gate of aluminum, which starts from bauxite extraction, and ends with manufacturing of semi-fabricated aluminum products. The life-cycle inventory (LCI) tables compiled are to be incorporated into the vehicle cycle model of Argonne National Laboratory’s Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model for the release of its 2015 version.

  3. Standardized equipment system for mining mineral resources

    Energy Technology Data Exchange (ETDEWEB)

    Reinel, H.

    1986-08-01

    Technical specifications are presented of surface mining equipment developed by TAKRAF (GDR) for small to medium sized mines (coal, gravel, kaolin, bauxite, sulfur, limestone etc. with production capacity of less than 1 Mm/sup 3//y). The continuous bulk flow equipment consists of small bucket wheel excavators, small bucket chain excavators, mobile transfer conveyors and shiftable belt conveyors. Bucket wheel excavators (series SRs 65 to SRa 320) have a production capacity between 200 and 2300 m/sup 3//h and weigh between 45 and 290 t. The SRs 320 is suitable for mining medium thick coal seams. The ERs 50 to ERs 250 bucket chain excavator series has a production capacity between 225 and 1100 m/sup 3//h and weight between 54 and 275 t. Both bucket wheel and bucket chain excavator series have the same standard undercarriage, loading boom, slewing system and driver's cabin. Bulk conveying capacities of BRs 650 to BRs 1200 mobile transfer conveyors correspond to those of excavators. Shiftable belt conveyors (0.8 m to 1.4 m belt widths, 3100 m maximum conveyor length) complete the equipment system.

  4. A new chelating ion-exchanger containing p-bromophenylhydroxamic acid as functional group

    International Nuclear Information System (INIS)

    A new chelating resin based on macroreticular acrylonitrile-divinylbenzene copolymer and containing hydroxamic acid functional groups has been synthesized. It is highly-stable in acidic and alkaline solutions. The sorption characteristics of Cu(II), Cd(II), Pb(II), Zn(II), U(VI), Cr(VI), V(V), Co(II), Ni(II), Ca(II) and Mg(II) have been investigated over the pH range 1.0-6.0. The effect of various electrolytes at different ionic strengths on the Ksub(d) values for Cu(II), Cd(II), Pb(II) and Zn(II) has been studied systematically. Chromatographic separations of copper(II) and nickel(II) from cobalt(II), and of uranium(VI) from chromium(VI) by selective sorption at controlled pH, have been developed. The ion-exchanger can be used for purification of inorganic salts, and analysis of brass and bauxite. (author)

  5. Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars; Avaliacao da lama vermelha como material pozolanico em substituicao ao cimento para producao de argamassas

    Energy Technology Data Exchange (ETDEWEB)

    Manfroi, E.P.; Cheriaf, M.; Rocha, J.C., E-mail: elizmanfroi@yahoo.com.b, E-mail: malik@valores.ufsc.b [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Civil

    2010-07-01

    Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

  6. Bioaccumulation of metals by Rhodophyta species at Antikyra Gulf (Greece) near an aluminium factory

    Energy Technology Data Exchange (ETDEWEB)

    Malea, P. [Thessaloniki Univ. (Greece). Inst. of Botany; Haritonidis, S. [Thessaloniki Univ. (Greece). Inst. of Botany; Stratis, I. [Inst. of Analytical Chemistry, School of Chemistry, Thessaloniki (Greece)

    1994-11-01

    The bioaccumulation of Fe, Cu, Zn, Cd, Pb, Na, K, Ca and Mg by seven species of red algae (Rhodophyta) was studied after their seasonal collection from 9 stations in Antikyra Gulf (Greece). This area is characterized by its bauxite substrate and the discharge of wastes from an aluminium factory. Corallina elongata, Jania rubens and Liagora viscida showed elevated concentrations of Cu, Na and Mg and low Fe, Na and K concentrations, whereas Pterosiphonia complanata, Laurencia obtusa and Vidalia volubilis displayed entirely contrary behaviour. These interspecific differences are discussed in relation to morphology, ecology, plant structure and the binding sites available on the algae. Among the nine metals, only Cd concentrations in P. complanata showed significantly positive correlation with the respective concentrations in the sediment; no metal in L. obtusa and P. complanata showed a significant correlation with the concentrations of the dissolved metals in seawater. Significant positive or negative correlations with the concentrations of several metals in L. obtusa and P. complanata were also observed, which may be attributed to metal interactions in binding to plant tissues. The concentrations of Fe, Cu, Zn, K, Na and Ca in Laurencia obtusa were higher in summer or autumn; Pb and Mg followed an opposite pattern of seasonal variation, whereas Cd levels were higher in spring and summer. The red algae of Antikyra Gulf generally exhibited higher Fe, Ca, Cu, Cd and Pb concentrations than those of similar species from other geographical areas. (orig.)

  7. Chemical elements in pearl oysters (Paxyodon ponderosus), phytoplankton and estuarine sediments from eastern Amazon (Northern Brazil): Bioaccumulation factors and trophic transfer factors

    Science.gov (United States)

    Vilhena, Maria P. S. P.; Costa, Marcondes L.; Berrêdo, José F.; Paiva, Rosildo S.; Souza, Crisvaldo C. S.

    2016-04-01

    The current study was conducted near Barcarena County, which is a mid-sized urban center where aluminum ore processing industries (bauxite) and Vila do Conde cargo terminal are located. It aims to discuss the bioaccumulation factors as well as factors related to the trophic transfer of chemical elements in water, oyster, phytoplankton and bottom sediments from an estuary in the Brazilian Northern coast. The bioaccumulation factor (BAF), trophic transfer factor (TTF) and biota-sediment-water were used to correlate the contents of chemical elements found in organisms. The sediment, surface water, phytoplankton and pearl oysters chemical composition was analyzed by ICP-OES and ICP-MS. Pearl oysters showed K, Ca, Mg, P, Mn, Fe, Zn, Al, Ba and Pb accumulation, which concentration increase is associated with their diet (phytoplankton). Al concentrations are 14 times higher in pearl oysters (Paxyodon ponderosus), assuming that they are associated with wastewater emissions and with industrialization processes in the area. BAF and BSAF values are 1000 times higher than the metal concentrations in water and bioavailable fraction concentrations. The oyster-phytoplankton trophic transfer factor indicates that P, Ba, Ca, Na, Cd and Zn showed the largest transfers (from 5 to 19). These trophic transfers may be sufficient to cause significant ecotoxicological effects on the region biota.

  8. Morphological description of the brachial plexus in ocelot (Leopardus pardalis

    Directory of Open Access Journals (Sweden)

    Kylma Lorena Saldanha Chagas

    2014-06-01

    Full Text Available The brachial plexus is formed by the ventral roots of the spinal nerves, which unite to form the nerve trunks. It is usually formed by contributions of the last three cervical nerves and the first two thoracic nerves. Due to the scarcity of information on neuroanatomy, this study aimed to determine the macroscopic morphology of the brachial plexus of the ocelot (Leopardus pardalis. In this work, we used two ocelot specimens from the area of the Paragominas Bauxite Mine, PA, Brazil/Empresa Terra LTDA, with permission from SEMA – BP Nos. 455/2009 and 522/2009. The animals were donated to the Research Laboratory of Animal Morphology (LaPMA, Federal Rural University of Amazonia (UFRA, after they were accidentally run over. They were fixed by intramuscular injection of 10% formaldehyde. After fixation, the animals were dissected, allowing visualization of the thoracic nerves, as well as the identification of the ventral rami of the cervical and thoracic spinal nerves forming the brachial plexus. The brachial plexus was found to be formed by four trunks, which originated the ventral branches of cervical spinal nerves C6, C7 and C8 and the first thoracic (T1. These trunks gave rise to the suprascapular, subscapular, musculocutaneous, axillary, radial, median, ulnar, thoracodorsal and lateral thoracic nerves.

  9. Hungary.

    Science.gov (United States)

    1992-12-01

    Hungary is a country of 93,000 sq km with 10 million inhabitants, of whom 99% are literate. Its constitution was written on August 20m 1949, substantially revised in 1989, and amended in 1990. The terrain is flat with low mountains in the North and Northeast and north of Lake Balaton, with a climate which is temperate. Primarily Magyar is spoken by the 92% population of Magyar, though Gypsies, Germans, Slovaks, Jews, southern Slavs, and other ethnic groups are also resident. Inhabitants are variously of Roman Catholic, Calvinist, Lutheran, and other faiths. Life expectancy is 67-75 years. GDP is $35 billion, declining at a rate of 3%. Per capita income is $3300. The country's natural resources include fertile land, bauxite, and brown coal. Meat, corn, wheat, potatoes, sugar beets, vegetables, fruits, sunflower seeds, machinery, buses and other transportation equipment; precision and measuring equipment; textiles; medical instruments; and pharmaceutical are areas of economic production. Energy, raw materials, machinery, and transportation equipment are imported, and machinery, buses, and other transportation equipment; medical instruments; pharmaceutical; textiles; other consumer manufactures; and agricultural products are exported. In-depth information is also given on the people and history, government and principal officials, political conditions, the economy, defense, foreign relations, relations with the U.S., and names of principal U.S. officials in the country.

  10. Determination of the apparent porosity level of refractory concrete during a sintering process using an ultrasonic pulse velocity technique and image analysis

    Directory of Open Access Journals (Sweden)

    LJUBICA M. PAVLOVIĆ

    2010-03-01

    Full Text Available Concrete which undergoes a thermal treatment before (pre-casted concrete blocks and during (concrete embedded in-situ its life-service can be applied in plants operating at high temperature and as thermal insulation. Sintering is a process which occurs within a concrete structure in such conditions. Progression of sintering process can be monitored by the change of the porosity parameters determined with a nondestructive test method - ultrasonic pulse velocity and computer program for image analysis. The experiment has been performed on the samples of corundum and bauxite concrete composites. The apparent porosity of the samples thermally treated at 110, 800, 1000, 1300 and 1500 C was primary investigated with a standard laboratory procedure. Sintering parameters were calculated from the creep testing. The loss of strength and material degradation occurred in concrete when it was subjected to the increased temperature and a compressive load. Mechanical properties indicate and monitor changes within microstructure. The level of surface deterioration after the thermal treatment was determined using Image Pro Plus program. Mechanical strength was estimated using ultrasonic pulse velocity testing. Nondestructive ultrasonic mea¬surement was used as a qualitative description of the porosity change in specimens which is the result of the sintering process. The ultrasonic pulse velocity technique and image analysis proved to be reliable methods for monitoring of micro-structural change during the thermal treatment and service life of refractory concrete.

  11. Effects of Multiple Soil Conditioners on a Mine Site Acid Sulfate Soil for Vetiver Growth

    Institute of Scientific and Technical Information of China (English)

    LIN Chu-Xia; LONG Xin-Xian; XU Song-Jun; CHU Cheng-Xing; MAI Shao-Zhi; JIANG Dian

    2004-01-01

    A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use in sulfide-bearing mined areas. An acidic mine site acid sulfate soil (pH 2.8) was treated with different soil conditioner formula including hydrated lime, red mud (bauxite residues), zeolitic rock powder, biosolids and a compound fertilizer. Soils treated with red mud and hydrated lime corrected soil acidity and reduced or eliminated metal toxicity enabling the establishment of vetiver grass.Although over-liming affected growth, some seedlings of vetiver survived the initial strong alkaline conditions. Addition of appropriate amounts of zeolitic rock powder also enhanced growth, but over-application caused detrimental effects. In this experiment, soil medium with the best growth performance of vetiver was 50 g of red mud, 10 g of lime, 30 g of zeolitic rock powder and 30 g of biosolids with 2000 g of mine soils (100% survival rate with the greatest biomass and number of new shoots), but adding a chemical fertilizer to this media adversely impacted plant growth. In addition, a high application rate of biosolids resulted in poorer growth of vetiver, compared to a moderate application rate.

  12. Mapping the global journey of anthropogenic aluminum: a trade-linked multilevel material flow analysis.

    Science.gov (United States)

    Liu, Gang; Müller, Daniel B

    2013-10-15

    Material cycles have become increasingly coupled and interconnected in a globalizing era. While material flow analysis (MFA) has been widely used to characterize stocks and flows along technological life cycle within a specific geographical area, trade networks among individual cycles have remained largely unexplored. Here we developed a trade-linked multilevel MFA model to map the contemporary global journey of anthropogenic aluminum. We demonstrate that the anthropogenic aluminum cycle depends substantially on international trade of aluminum in all forms and becomes highly interconnected in nature. While the Southern hemisphere is the main primary resource supplier, aluminum production and consumption concentrate in the Northern hemisphere, where we also find the largest potential for recycling. The more developed countries tend to have a substantial and increasing presence throughout the stages after bauxite refining and possess highly consumption-based cycles, thus maintaining advantages both economically and environmentally. A small group of countries plays a key role in the global redistribution of aluminum and in the connectivity of the network, which may render some countries vulnerable to supply disruption. The model provides potential insights to inform government and industry policies in resource criticality, supply chain security, value chain management, and cross-boundary environmental impacts mitigation. PMID:24025046

  13. A review of 4 norm industries in Ireland

    International Nuclear Information System (INIS)

    Full text: This presentation will review the progress achieved so far by the Irish national regulatory agency, the Radiological Protection Institut e of Ireland (R.P.I.I.) in the investigation of work activities where the presence of natural radiation sources (NORM) could lead to a significant increase in exposure to workers or members of the public which cannot be disregarded from the radiation protection point of view. Since the coming into force in Ma y 2000 of the Radiological Protection Act, 1991 (Ionising Radiation) Order, 2000 (S.I. No. 125 of 2000) which implements the Eu B.S.S. Directive 96/29/EURATOM, four major NORM industries currently active in Ireland have been investigated. According to the literature, they are all considered liable to involve work practices resulting in exposure to NORM. They include: the gas extraction and production industry, the peat- and coal-firing power generation industry and the bauxite/alumina refining industry. For the gas industry, monitoring of the radon concentrations in the extracted gas was carried out over a two-year period using Cr-39 passive alpha track detectors and sludge samples collected offshore in a separator were analysed by gamma spectrometry. Gamma dose rate measurements were also carried out at an onshore facility where disused equipment such as pipes is stored. The results will be presented and indicate that doses to workers or members of the public will not exceed the national regulatory limit of 1 mSv per year. The occupational dose received by any worker at the largest peat-fired power plant of the country was assessed. Preliminary results were presented at the IRPA 2004 conference (Organo et al. 2004) and have since been updated. An annual effective dose of less than 150 mSv was calculated taking into account external and internal pathways (gamma dose rate measurements, radon gas and peat dust inhalation) and plausible exposure scenarios. The use of coal fly ash in the manufacturing of building

  14. EFICIÊNCIA DE FOSFATOS NATURAIS RELACIONADA À PRODUTIVIDADE DE MILHETO EM SOLOS DE CERRADO AGRONOMIC EFFICIENCY OF ROCK PHOSPHATES ON MILLET YIELD IN SAVANNAH SOILS

    Directory of Open Access Journals (Sweden)

    Huberto José Kliemann

    2007-09-01

    Full Text Available

    Um experimento em estufa foi realizado para avaliar a eficiência agronômica de três fosfatos naturais, em cinco solos da região dos cerrados. Construíram-se curvas de resposta padrão (0 kg ha-1, 100 kg ha-1, 200 kg ha-1, 400 kg ha-1 e 800 kg ha-1 de P2O5 com superfosfato triplo (ST, incluindo duas doses (200 kg ha-1 e 800 kg ha-1 de P2O5 das fontes de fosfatos alternativos (fosforita de Arad - Israel, fosfato de alumínio e cálcio - Senegal, e apatita de Araxá - Brazil. Usou-se o milheto (Pennisetum thyphoides como planta-teste. A ordem de eficiência dos fosfatos naturais aplicados aos solos utilizados neste estudo fo a seguintei: fosforita > fosfato de alumínio e cálcio > apatita. O extrator Mehlich-1 solubilizou os fosfatos apatíticos, super-estimando o fósforo (P disponível nos solos. Os níveis críticos para os extratores Mehlich-1 e resina, aos quais foram adicionados dados do fósforo (P disponível nos tratamentos com fosfatos naturais, diferiram entre si, mas, foram mais altos do que os obtidos com o superfosfato triplo isoladamente. Os dois extratores comportaram-se de modo similar, com respeito à extração de P disponível no solo.

    PALAVRAS-CHAVE: Fosfatos naturais; desempenho; cerrado; milheto.

    A greenhouse experiment was undertaken to assess the agronomic efficiency of rock phosphates in five savannah soils. Standard response curves (0 kg ha-1, 100 kg ha-1, 200 kg ha-1, 400 kg ha-1, and 800 kg ha-1 of P2O5 with triple superphosphate (TSP were used, including two rates (200 kg ha-1 and 800 kg ha-1 of P2O5 of alternative phosphate sources (Arad phosphorite - Israel, phosphoric bauxite - Senegal, and Araxá apatite - Brazil. Millet (Pennisetum thyphoides was used as test crop. Data show the following ranking for agronomic efficiency: phosphorite

  15. 铁尾矿贝利特硫铝酸盐水泥的制备及性能研究%Preparation of Belite-sulphoaluminate Cement with Iron Tailings and its Properties

    Institute of Scientific and Technical Information of China (English)

    郑永超; 刘艳军; 李德忠; 李青

    2013-01-01

    以首云矿业股份有限公司铁尾矿、低品位矾土等为原料制备铁尾矿贝利特硫铝酸盐水泥,为铁尾矿的高附加值利用探索新的途径.研究结果表明:在生料中铁尾矿、矾土、煅烧石灰石、Al2 O3、CaSO4·2H2O的配比为10∶ 17∶ 48∶ 15∶10,煅烧温度为1 350℃,煅烧时间为20 min条件下,可制备出矿物成分以C4A3S、C2S、C4AF为主,f-CaO含量小于1.5%的铁尾矿贝利特硫铝酸盐水泥熟料.向该熟料中配入与其质量比均为8%的天然石膏和石灰石制成水泥,再按胶砂比为1∶3、水胶比为0.6制成水泥胶砂,胶砂的3d抗压强度达38.1 MPa、28 d抗压强度达52.5 MPa.%With iron tailings and low grade bauxite from Shouyun Mining Company as raw materials,the belite-sulphoaluminate cement clinker was prepared,which proposes a new way for exploring the high added value of iron tailings.The results showed that with the ratio of iron tailings,bauxite,calcined limestone,Al2 O3,CaSO4 · 2H2O of 10∶ 17∶ 48∶ 15∶10 in the raw meal,and at the calcination temperature of 1 350 ℃ for 20 min,belite-sulphoaluminate cement clinker with major components of C4A3S,C2S,C4AF and f-CaO content of less than 1.5% was prepared.Then,natural gypsum and limestone were added into the clinker with the quality ratio of 8% to prepare the cement raw meal.With the cement-sand ratio of 1∶3,and water-cement ratio of 0.6,the cement-mortar product reached the compressive strength of 38.1 MPa,at 3 d,and 52.5 MPa at 28 d.

  16. Recovery Act: Innovative CO2 Sequestration from Flue Gas Using Industrial Sources and Innovative Concept for Beneficial CO2 Use

    Energy Technology Data Exchange (ETDEWEB)

    Dando, Neal; Gershenzon, Mike; Ghosh, Rajat

    2012-07-31

    . Incorporation of the laboratory results showed that for the application at the aluminum smelter, the in-duct scrubber system is more economical than traditional methods. However, the reverse is true for the refinery case, where the bauxite residue is not effective enough as a sequestrant, combined with challenges related to contaminants in the bauxite residue accumulating in and fouling the scrubber absorbent. Sensitivity analyses showed that the critical variables by which process economics could be improved are enzyme concentration, efficiency, and half-life. At the end of the first part of the Phase 2 project, a gate review (DOE Decision Zero Gate Point) was conducted to decide on the next stages of the project. The original plan was to follow the pre-testing phase with a detailed design for the field testing. Unfavorable process economics, however, resulted in a decision to conclude the project before moving to field testing. It is noted that CO2 Solutions proposed an initial solution to reduce process costs through more advanced enzyme management, however, DOE program requirements restricting any technology development extending beyond 2014 as commercial deployment timeline did not allow this solution to be undertaken.

  17. 聚合氯化铝的制备及其污水处理性能研究%Preparation of poly aluminum chloride and their performance of treating polluted raw water

    Institute of Scientific and Technical Information of China (English)

    史兵方; 吴启琳; 刘细祥

    2014-01-01

    以百色低品位的软铝石为为原料,用酸溶法制备聚合氯化铝(PAC),其结构经红外光谱(IR)所证实。考察了培烧温度、培烧时间、反应时间、盐酸加入量和反应温度等因素对Al2 O3溶出率的影响,并对PAC处理某纸厂中段污水的性能进行了研究。研究结果表明,在焙烧温度为750℃,焙烧时间为1 h,酸溶时间为3 h,n (Al2O3):n(HCl)为1:4,酸溶温度为100℃条件下,煅烧后的熟料的Al2O3的溶出率的达81.7%;在pH=6.0, PAC投入量为120 mg·L-1时,纸厂中段污水的COD的去除率为56.02%,剩余浊度达到4.51 NTU以下,净水效果较好。%Polymeric aluminum chloride(PAC),which was derived from the starting material bauxite widely distributed in Baise, was prepared by acid-leaching technology and characterized by IR. Various effecting factors of preparation such as calcining temper-ature,calcining time,acid leaching time,the ratio of raw materials to hydrochloric acid and acid leaching temperature were investi-gated by single factors experiment. Consequently,the coagulation/flocculation performance of PAC was also measured. Studies show that the optimum technological conditions obtained by experiments were as follows:the calcining temperature of bauxite 750℃,cal-cining time 1 h,acid leaching time 3 h,the ratio of raw materials to hydrochloric acid 1∶4,acid leaching temperature 100℃. Under these experimental conditions,the maceration rate of Al2 O3 was about 81. 7%. The PAC was applied to the treatment of the raw wa-ter product from a paper industry. The removal rate of COD was achieved 56. 02%,the residual turbidity was less than 4. 51 NTU when the coagulant dosage was 120mg·L-1 and pH was 6. 0. The results showed that PAC clean the raw water with satisfactory re-sults.

  18. Iron's Role in Aluminum: A Powder Metallurgy and Sustainability Approach

    Science.gov (United States)

    Saller, Brandon Dale

    The family of Al-Fe alloys is both scientifically and technologically interesting for several reasons. First, the low equilibrium solid solubility (0.03 at.%) and diffusivity of Fe in Al suggest that the alloys containing these two elements should be thermally stable. Many studies have tried to extend this low solubility value via non-equilibrium processing routes. Second, published results suggest that there is a range of intermetallic phases, including the metastable orthorhombic Al6Fe and the equilibrium monoclinic Al13Fe4, for example, the formation of which depends on solidification and subsequent processing conditions. Third, from a sustainability standpoint, both Al and Fe are present in bauxite (aluminum ore), however up to 40 wt.% Fe-oxide present in bauxite is discarded as a waste product, creating red mud pits. In order to understand the multiple facets and implications of iron's role in aluminum, a systematic investigation was performed into the precipitates that form as a function of thermal exposure and their subsequent effect on the tensile behavior of the alloy. In this study, Al-2at.% Fe and Al-5at.% Fe powders were synthesized via helium gas atomization and argon gas atomization, respectively. Cooling rates upwards of 106 K/s were achieved resulting in an intermetallic-free starting structure. Powders were subsequently severely plastically deformed via either cryomilling or high-pressure torsion to obtain nanostructured/ultrafine-grained powder or a consolidated specimen, respectively. Characterization via electron microscopy established a map of the powder microstructure as a function of atomization cooling rate. In addition, electron backscatter diffraction revealed a large number of low-angle grain boundaries, which influenced nucleation and precipitation of the metastable Al6Fe phase. X-ray diffraction and atom probe tomography results provide the most comprehensive evidence to date of forcing of 2at.% Fe into solution with the Al matrix via

  19. MICRONUTRIENTS IN SOIL IRRIGATED OF WASTE WATER SERVED AND THE SUGAR CANE FERTILIZED WITH ORGANIC AND INDUSTRIAL RESIDUES = MICRONUTRIENTES NO SOLO IRRIGADO COM ÁGUA SERVIDA E NA PLANTA DE CANA-DE-AÇÚCAR FERTILIZADA COM RESÍDUOS ORGÂNICOS E INDUSTRIAIS

    Directory of Open Access Journals (Sweden)

    Fabio Olivieri de Nobile

    2013-01-01

    Full Text Available Population growth, with consequent demands for consumer goods and increased industrial development generate significant amounts of waste and increase the indiscriminate use of water. The environmental impact caused by the improper disposal of waste in the environment, causes great difficulty to control, implying high costs in its remediation. The agricultural use of organic and industrial residues is an alternative of exploitation with fertilization and source organic matter to the soil. In this direction, the objective of this research was to evaluate the use of the urban solid waste and biofertilizer as nutrient source, and residue of the bauxite processing as agricultural liming materials of the soil, irrigated with potable water and wastewater. The experiment was conducted in vase was lead, under soil Alfisol, being evaluated the micronutrient concentrations in the soil and leaves of sugar cane (Cu, Fe, Mn and Zn. The gotten data had evidenced the fertilization with biofertilizer increased texts of significantly Cu and Zn in the soil (409% e 520% mg.dm-3, respectively, the application of residue of the processing of the bauxite raised the manganese concentrations, had not been observed changes for Fe. Already in sugar cane leaves the use of residue of the processing the sugar cane raised texts of all the micronutrients, the application of biofertilizer and made up of urban solid waste raised texts of Cu in leaves (0.80 and 1.00 mg.dm-3 respectively however had a reduction of the text of Mn (124.66 and 84.66 mg.dm-3 respectively. The quality of irrigation water, drinking or served, did not influence the micronutrients concentrated in the soil as well as the contents of these elements in the plant. = O crescimento populacional, com as consequentes demandas por bens de consumo, e o aumento do desenvolvimento industrial geram quantidades expressivas de resíduos e aumento do uso indiscriminado de água. O impacto ambiental originado pela disposi

  20. Variáveis biométricas da cana-de-açúcar fertilizada com resíduos orgânico e industrial e irrigada com água servida e potável Biometric variable of sugar cane fertilized with organic and industrial residues irrigated with potable and wastewater

    Directory of Open Access Journals (Sweden)

    Fabio O. de Nobile

    2011-02-01

    Full Text Available O uso agrícola de resíduos orgânicos e industriais é uma alternativa de aproveitamento como fertilizante e fonte de matéria orgânica ao solo. Neste sentido, o objetivo deste trabalho foi avaliar o uso do composto de lixo e biofertilizante como fonte de nutrientes, e o resíduo do processamento da bauxita como corretivo da acidez do solo, para a cultura da cana-de-açúcar (cana-planta, irrigada com água potável e servida. Para tanto foi conduzido experimento em vaso, utilizando-se de solo Argissolo Vermelho-Amarelo distrófico, cultivado com a variedade RB855536. Foram avaliadas variáveis biométricas da planta, tais como: altura de plantas, diâmetro do colmo, perfilhamento, número de folhas, matéria seca de raiz e parte aérea. Os dados obtidos evidenciaram que a qualidade da água de irrigação, potável ou servida, não influenciou as variáveis avaliadas. A aplicação de composto de lixo e de biofertilizante constituiu-se numa fonte eficiente de nutrientes para as plantas de cana-de-açúcar, mas é necessária a aplicação adicional de fertilizantes para a obtenção de produção de colmos, similar ao do tratamento com adubação mineral convencional. Já o resíduo do processamento da bauxita mostrou-se eficiente na correção da acidez, apresentando as variáveis físicas semelhantes ao tratamento com adubação mineral, com exceção da matéria seca de raiz.The agricultural use of organic and industrial residues is an alternative of exploitation with fertilization and source of organic matter to the soil. In this direction, the objective of this research was to evaluate the use of the urban solid waste and biofertilizer as nutrient source, and residue of the bauxite processing as agricultural liming materials of the soil for sugar cane (cane plant and culture yields, irrigated with potable water and wastewater. For in such an experiment in vase was lead, under Alfisol soil, cultivated with the variety RB855536. It had

  1. IMPACTO DE ÁGUAS DE IRRIGAÇÃO E RESÍDUOS DE DIFERENTES ORIGENS NOS TEORES DE MICRONUTRIENTES NO SOLO E NA CANA-DE AÇÚCAR

    Directory of Open Access Journals (Sweden)

    Reginaldo Itiro Muraishi

    2012-05-01

    Full Text Available O objetivo deste trabalho foi avaliar o uso do composto de lixo e biofertilizante como fonte de nutrientes, e oresíduo do processamento da bauxita como corretivo da acidez do solo, irrigada com água potável e servida. Para tanto foiconduzido experimento em vaso, utilizando-se solo Argissolo Vermelho Amarelo, sendo avaliadas as concentraçõesmacronutrientes no solo (Cu, Fe, Mn e Zn na camada de 0-20 cm e nas folhas de cana-de-açúcar (B, Cu, Fe, Mn e Zn. Osdados obtidos evidenciaram que a adubação com biofertilizante aumentou significativamente os teores de Cu e Zn no solo(0,56 e 0,63 mg dm-3, respectivamente, a aplicação de resíduo do processamento da bauxita elevou as concentrações demanganês, não foram observados mudanças para Fe. Já nas folhas de cana-de-açúcar o uso de resíduo do processamento dacana-de-açúcar elevou os teores de todos os micronutrientes, a aplicação de biofertilizante e composto de lixo elevou osteores de Cu nas folhas (0,80 e 1,00 mg dm-3 respectivamente entretanto houve uma redução do teor de Mn (84,66 e 89,66mg dm-3 respectivamente. A qualidade da água de irrigação, potável ou servida, não influenciou as concentrações demacronutrientes no solo, bem como os teores desses elementos na planta.The agricultural use of organic residues and industrial is an alternative of exploitation with fertilizationand source organic matter to the soil. In this direction, the objective of this research was to evaluate the use of the urbansolid waste and biofertilizer as nutrient source, and residue of the bauxite processing as agricultural liming materials of thesoil, irrigated with potable water and wastewater. For in such a way experiment in vase was lead, under soil Alfisol, beingevaluated the micronutrient concentrations in the soil (Cu, Fe, Mn and Zn in the layer of 0-20 cm and leaves of sugar cane(Cu, Fe, Mn and Zn. The gotten data had evidenced the fertilization with biofertilizer increased texts of Cu

  2. Mineralogy and geochemistry of boehmite-rich coals: New insights from the Haerwusu Surface Mine, Jungar Coalfield, Inner Mongolia, China

    Science.gov (United States)

    Dai, S.; Li, D.; Chou, C.-L.; Zhao, L.; Zhang, Y.; Ren, D.; Ma, Y.; Sun, Y.

    2008-01-01

    Boehmite-rich coal of Pennsylvanian age was discovered earlier at the Heidaigou Surface Mine, Jungar Coalfield, Inner Mongolia, China. This paper reports new results on 29 bench samples of the no. 6 coal from a drill core from the adjacent Haerwusu Surface Mine, and provides new insights into the origin of the minerals and elements present. The results show that the proportion of inertinite in the no. 6 coal is higher than in other Late Paleozoic coals in northern China. Based on mineral proportions (boehmite to kaolinite ratio) and major element concentrations in the coal benches of the drill core, the no. 6 coal may be divided into five sections (I to V). Major minerals in Sections I and V are kaolinite. Sections II and IV are mainly kaolinite with a trace of boehmite, and Section III is high in boehmite. The boehmite is derived from bauxite in the weathered surface (Benxi Formation) in the sediment-source region. The no. 6 coal is rich in Al2O3 (8.89%), TiO2 (0.47%), Li (116????g/g), F (286????g/g), Ga (18????g/g), Se (6.1????g/g), Sr (350????g/g), Zr (268????g/g), REEs (172????g/g), Pb (30????g/g), and Th (17????g/g). The elements are classified into five associations by cluster analysis, i.e. Groups A, B, C, D, and E. Group A (ash-SiO2-Al2O3-Na2O-Li) and Group B (REE-Sc-In-Y-K2O-Rb-Zr-Hf-Cs-U-P2O5-Sr-Ba-Ge) are strongly correlated with ash yield and mainly have an inorganic affinity. The elements that are negatively or less strongly correlated with ash yield (with exceptions of Fe2O3, Be, V, and Ni) are grouped in the remaining three associations: Group C, Se-Pb-Hg-Th-TiO2-Bi-Nb-Ta-Cd-Sn; Group D, Co-Mo-Tl-Be-Ni-Sb-MgO-Re-Ga-W-Zn-V-Cr-F-Cu; and Group E, S-As-CaO-MnO-Fe2O3. Aluminum is mainly distributed in boehmite, followed by kaolinite. The high correlation coefficients of the Li-ash, Li-Al2O3, and Li-SiO2 pairs indicate that Li is related to the aluminosilicates in the coal. The boehmite-rich coal is high in gallium and F, which occur in boehmite and the

  3. Geochemical and mineralogical constraints on the distribution and enrichment of the rare earth elements during pedogenesis and tropical weathering

    Science.gov (United States)

    Hardy, Liam; Smith, Martin; Moles, Norman; Marsellos, Antonios

    2015-04-01

    Current European manufacturing relies heavily on imports from the USA & China for unprocessed rare earth elements (REEs) and rare earth oxides (REOs). It has been suggested that the EU holds viable reserves of REEs that, with adequate research, could satisfy 10% of EU industrial demand, by the recycling of mine waste from bauxite production (red muds) alone (Deady, E. (BGS), 2014). Focus has been turned to the potential for Mount Weld type laterite deposits being exploited in the EU, but limited exploration and understanding of EU laterite (& paleo laterite) formations currently makes them unattractive to investment. Although previously researched, the full range of factors influencing the transition of rare earth (primarily lanthanide series, Y & Sc) elements between mineral and clay phases in allochthonous soils, saprolites and laterites is not fully understood, especially in present and Paleo-European environments (Herrington, Boni, Skarpelis, & Large, 2007) (Deady, E. (BGS), 2014) but several deposits globally are suggested to have formed at economically viable concentrations due to this secondary remobilisation & transition from mineral to clay phase and subsequent seasonal leaching and evaporation system, to form depositional buffer zones other than the soil base. (Hoatson, Jaireth, & Miezitis, 2011) (Berger, Janots, Gnos, Frei, & Bernier, 2014). This project intends to use new techniques in sequential extractions, ICP-MS, Quantitative XRD & SEM analysis to expand current knowledge around lateritic & allochtonous ore forming, & weathering processes. Heavy REE content and mineralogical variations in clays will be examined, with examples from a selection of profiles across Southern Europe (and potentially paleo soils from Scandinavia) to define the main influencing factors on REE concentration. Are the specific sites enriched simply by the nature of their source rock (protolith), by the soil formation (pedogenesis), or by biogenic & meteorological factors

  4. Direct toxicity assessment - Methods, evaluation, interpretation.

    Science.gov (United States)

    Gruiz, Katalin; Fekete-Kertész, Ildikó; Kunglné-Nagy, Zsuzsanna; Hajdu, Csilla; Feigl, Viktória; Vaszita, Emese; Molnár, Mónika

    2016-09-01

    Direct toxicity assessment (DTA) results provide the scale of the actual adverse effect of contaminated environmental samples. DTA results are used in environmental risk management of contaminated water, soil and waste, without explicitly translating the results into chemical concentration. The end points are the same as in environmental toxicology in general, i.e. inhibition rate, decrease in the growth rate or in yield and the 'no effect' or the 'lowest effect' measurement points of the sample dilution-response curve. The measurement unit cannot be a concentration, since the contaminants and their content in the sample is unknown. Thus toxicity is expressed as the sample proportion causing a certain scale of inhibition or no inhibition. Another option for characterizing the scale of toxicity of an environmental sample is equivalencing. Toxicity equivalencing represents an interpretation tool which enables toxicity of unknown mixtures of chemicals be converted into the concentration of an equivalently toxic reference substance. Toxicity equivalencing, (i.e. expressing the toxicity of unknown contaminants as the concentration of the reference) makes DTA results better understandable for non-ecotoxicologists and other professionals educated and thinking based on the chemical model. This paper describes and discusses the role, the principles, the methodology and the interpretation of direct toxicity assessment (DTA) with the aim to contribute to the understanding of the necessity to integrate DTA results into environmental management of contaminated soil and water. The paper also introduces the benefits of the toxicity equivalency method. The use of DTA is illustrated through two case studies. The first case study focuses on DTA of treated wastewater with the aim to characterize the treatment efficacy of a biological wastewater treatment plant by frequent bioassaying. The second case study applied DTA to investigate the cover layers of two bauxite residue (red mud

  5. Production and characterization of red mud based on glasses for the immobilization of nuclear wastes; Obtencao e caracterizacao de vidros a base de lama vermelha visando a imobilizacao de rejeitos nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Heveline

    2015-07-01

    Glasses based on red mud, a residual material from bauxite processing, were developed and characterized in this work. In order to promote its use, a minimum 60 wt% of red mud was used in the production of the glasses. According to XRD results, materials containing considerable amorphous phases were produced when using red mud as raw material. These amorphous phases were observed even though crystalline phases associated to Fe coming from the red mud itself were present. The material denominated 60L40S, which has a nominal composition of 60 wt% red mud showed the best properties comparing with the others compositions studied. However, these materials presented a high melting temperature. Changes in the composition of this material were made with the objective of lowering this temperature. Results indicated that the changes made to the material were successful in the reduction of the melting temperature. However, a reduction in the chemical properties of the resulting material was observed. Elements usually found in the chemical composition of nuclear wastes were added to the glasses produced. It was done with the objective of determining the effect of these elements on the chemical and physical properties of the red mud based glasses obtained. It was found that it was possible to add up to 15 wt% of these elements to the materials produced. The addition of these simulant materials promoted a reduction in the melting temperature of the resulting material. Above 15 wt%, the added elements precipitate in the structure of the resulting material. Even though the reduction in the chemical durability of the 60L40S material when simulant elements were added, it was observed that this material contained the simulant elements confined in its structure when in contact with water. This is a promising result, since it indicates that the 60L40S has the potential to immobilize elements from nuclear wastes . (author)

  6. Development of NORM Management in Australia

    International Nuclear Information System (INIS)

    Australia has had a long involvement with NORM, mainly because of mining and processing of mineral ores. Radium mining was carried out in the early 20th century. After 1949, there was a rapid expansion in uranium mining (particularly in the Northern Territory) and mineral sand mining. Australia is a Federation of the Commonwealth, six States and two Territories, which independently regulate within their jurisdiction. Early mineral extraction and processing operations were unregulated, resulting in the existence of a large number of legacy sites. Regulation of uranium mining started in the 1970s, and mineral sand mining after 1980. The regulations vary in detail between jurisdictions. Most other NORM situations are not regulated in any of the States or Territories. A major review of the Western Australian mineral sand industry in the 1980s led to considerable reductions in doses to workers. Remediation of many of the old uranium mine sites in the Northern Territory has been carried out over the last 15 years and is continuing. International awareness of NORM as a potential source of risk to workers, members of the public and the environment has increased significantly in recent years. After an extensive stakeholder consultation process and the development of a position paper summarizing the NORM situation in Australia, a Safety Guide was developed, to enhance awareness and provide general guidance on NORM management. The Safety Guide recommends a graded approach to NORM management, based on exclusion, exemption, clearance and regulation. It includes sections on general radiation protection principles, impact assessment, assessment of the need for regulation, development of a NORM management plan, and annexes on NORM management in the oil and gas, bauxite processing and phosphate industries, written by experts from the industries. These industries were chosen because of their experience with NORM management and the availability of good data. (author)

  7. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing

    Energy Technology Data Exchange (ETDEWEB)

    Liapis, Ioannis, E-mail: iliapis@sidenor.vionet.gr [AEIFOROS SA, 12th km Thessaloniki-Veroia Rd, PO Box 59, 57008 Ionia, Thessaloniki (Greece); Papayianni, Ioanna [Laboratory of Building Materials, Department of Civil Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2015-02-11

    Highlights: • Addition of 10% perlite decreases specific weight of the slag by approx. 7.5%. • Slag-crucible interaction and thin coating layer result in variations in XRF. • XRD shows high glass content and smaller crystalline sizes due to rapid cooling. • SEM shows higher homogeneity and lower crystallisation for SiO{sub 2}/CaO-rich samples. • Physical properties (LA, PSV, AAV) of modified slag show limited deterioration. - Abstract: Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  8. Technological Research on Direct Reduction of Obsolete Red Mud in Alumina Industry%氧化铝工业废弃赤泥直接还原技术研究

    Institute of Scientific and Technical Information of China (English)

    高建阳

    2011-01-01

    利用印尼铝土矿溶出废弃赤泥,配入自制添加剂,采用煤基直接还原焙烧-渣铁磁选分离-冷固成型的新工艺流程,通过X-ray,SEM-EDS手段,研究了印尼铝土矿溶出废弃赤泥煤基直接还原过程中金属铁晶粒长大特性,并着重讨论了添加剂种类、焙烧条件对金属铁晶粒长大特性的影响.生产出优质海绵铁,其金属化率为92.9%,铁品位为93.7%,铁回收率为94.42%,为氧化铝工业废弃赤泥综合利用提供了一条新途径.%Using the dissolved obsolete red mud of Indonesian bauxite ore, adding the self - made additives, adopting the new technological flowsheet of coal - based direct reduction roasting - magnetic separation of iron slag - cold bond agglomeration and by the way of X - ray and SEM - EDS, the characteristics of metal iron grain growth in the course of direct reduction was studied and more emphasis was put on effects of additive types and roasting conditions on the characteristics of metal iron grain growth. Finally, the high - quality sponge iron with the metallization rate of 92.9% ,iron content of 93.7% and iron recovery of 94.42% was obtained. This new technology will exploit a new way for comprehensive utilization of obsolete red mud in alumina industry.

  9. An active dealkalization of red mud with roasting and water leaching

    International Nuclear Information System (INIS)

    Highlights: • The dealkalization of active roasting and water leaching from red mud was put forward. • The main factors on dealkalization during active roasting and water leaching were investigated. • The mechanism of dealkalization from red mud was in-depth studied in the process. - Abstract: The research has focused on the dealkalization of red mud after active roasting and water leaching, which is obtained from bauxite during alumina production. The main factors such as roasting temperature, roasting time, water leaching stage, leaching temperature, leaching reaction time and liquid to solid ratio were investigated. The mechanism of dealkalization was in-depth studied by using ICP–AES, XRD, TG-DSC, SEM–EDS and leaching kinetic. The results show that the dealkalization rate reached 82% under the condition of roasting temperature of 700 °C, roasting time of 30 min, four stage water leaching, liquid to solid ratio of 7 mL/g, leaching temperature of 90 °C and reaction time of 60 min. The diffraction peak of Na6CaAl6Si6(CO3)O24·2H2O in red mud was decreased during the active roasting process, whereas the mineral phases of NaOH·H2O and Na2Ca(CO3)2 were appeared. The content of alkali obviously decreased and the grade of other elements increased during the process of active roasting and water leaching, which was in favor of next application process of red mud. The water leaching was controlled by internal diffusion of SCM and the apparent activation energy was 22.63 kJ/mol

  10. Preparation of Calcium Sulphoaluminate by Industrial Wastes and Analysis of Activation on Fly Ash in Concrete%工业废渣制备硫铝酸钙及对混凝土中粉煤灰的激发性能研究

    Institute of Scientific and Technical Information of China (English)

    叶强; 马兵; 马骥

    2012-01-01

    Instead of calcium sulphoaluminate by free Desulfurization Gypsum, bauxite by fly ash, it inuestigates the activation of fly ash in C25 ,C30 ,C40. It shows that calcium sulphoaluminate can be prepared in 1280℃ without soaking. Calcium sulphoaluminate can active the hydra-tion of fly ash effectively, in the early hydration period, ettringite can be formed quickly which contribute to the strength of 3d and 28d. In different grade concrete, compressive strength increase 19.7% ,23.2% ,54.9% respectively.%通过利用工业废渣脱硫石膏代替天然石膏,粉煤灰代替部分铝矾土制备硫铝酸钙矿物,同时研究了硫铝酸钙对不同标号(C25,C30,C40)混凝土中粉煤灰的激发性能.研究表明利用工业废渣在1280℃不需保温即可制备纯硫铝酸钙矿物.此外,研究表明硫铝酸钙在不同掺量粉煤灰的混凝土中可以促进粉煤灰的早期水化,同时生成钙钒石,有效的提高混凝土3d、28d的强度.对于C25,C30,C40级混凝土的28d强度分别提高了了19.7%,23.2%,54.9%.

  11. Production and characterization of red mud based on glasses for the immobilization of nuclear wastes

    International Nuclear Information System (INIS)

    Glasses based on red mud, a residual material from bauxite processing, were developed and characterized in this work. In order to promote its use, a minimum 60 wt% of red mud was used in the production of the glasses. According to XRD results, materials containing considerable amorphous phases were produced when using red mud as raw material. These amorphous phases were observed even though crystalline phases associated to Fe coming from the red mud itself were present. The material denominated 60L40S, which has a nominal composition of 60 wt% red mud showed the best properties comparing with the others compositions studied. However, these materials presented a high melting temperature. Changes in the composition of this material were made with the objective of lowering this temperature. Results indicated that the changes made to the material were successful in the reduction of the melting temperature. However, a reduction in the chemical properties of the resulting material was observed. Elements usually found in the chemical composition of nuclear wastes were added to the glasses produced. It was done with the objective of determining the effect of these elements on the chemical and physical properties of the red mud based glasses obtained. It was found that it was possible to add up to 15 wt% of these elements to the materials produced. The addition of these simulant materials promoted a reduction in the melting temperature of the resulting material. Above 15 wt%, the added elements precipitate in the structure of the resulting material. Even though the reduction in the chemical durability of the 60L40S material when simulant elements were added, it was observed that this material contained the simulant elements confined in its structure when in contact with water. This is a promising result, since it indicates that the 60L40S has the potential to immobilize elements from nuclear wastes . (author)

  12. POPULATION STRUCTURE AND PRODUCTION OF COPAIBA OLEORESIN BETWEEN VALLEYS AND HILLSIDES OF THE MINING AREA OFTROMBETAS RIVER - PARÁ1

    Directory of Open Access Journals (Sweden)

    Jonas Gebara

    2016-02-01

    Full Text Available ABSTRACT We aimed in this work to study natural populations of copaiba (Copaifera multijuga Hayne on the Monte Branco mountain at Porto Trombetas-PA, in order to support sustainable management and the exploitation of oleoresin from copaiba. We studied the population structure of copaiba on hillsides and valleys of the south face of Monte Branco, within Saracá Taquera National Forest, where bauxite ore was extracted in the biennium 2013-2014 by Mineração Rio do Norte (MRN. We produced a 100% forest inventory of the specie and of oleoresin extraction in order to quantify the potential production of the remaining area. The density of copaiba individuals with DBH > 30 cm was 0.33 individuals per hectare in the hillside and 0.25 individuals per hectare in the valley. Both environments presented a density of 0.28 individuals per hectare. The average copaiba oleoresin yield was 0.661±0.334 liters in the hillside and 0.765±0.280 liters in the valley. The average value of both environments together (hillside and valley was 0.714±0.218 liters. From all individuals with DBH over 30 cm, 38 (58% produced some amount of oleoresin, averaging 1.113±0.562 liters in the hillside, 1.329±0.448 liters in the valley and 1.190±0.355 liters in both environments together. The results show the need for planning the use of the surroundings of the study area in order to reach the required volume of copaiba to make feasible the sustainable management of oleoresin extraction in the region.

  13. Some topics on geochemistry of weathering: a review

    Directory of Open Access Journals (Sweden)

    Milton L.L. Formoso

    2006-12-01

    Full Text Available Weathering is a complex process comprising physical disaggregation, chemical and biological decomposition of rocks and minerals transforming complex structure minerals in simpler ones. Hydrolysis of silicates is perhaps the most important process but associated certainly to biological weathering. It is discussed the role ofwaters: activities/concentrations of chemical species, pH, Eh, importance of complexes. Weathering is not only a destructive process. It can concentrate chemical species and form mineral deposits (kaolin, bauxite, Fe, Mn, P, Nb, Au. Weathering studies are important in pedology, engineering geology, hydrogeology, paleoclimatology and ecology. The use of stonemeal is based upon the study of rock weathering.Intemperismo é um processo complexo compreendendo desagregação física, decomposição química e biológica de rochas e minerais transformando minerais de estrutura complexa em estruturas mais simples. Hidrólise de silicates é talvez o mais importante mas certamente associado ao intemperismo biológico. É discutido o papel da água: atividades/concentrações de espécies químicas, pH, Eh, importância dos complexos. Intemperismo não é somente um processo destrutivo. O intemperismo pode concentrar espécies químicas e formar depósitos minerais (caolim, bauxita, Fe, Mn, P, Nb, Au. Estudos de intemperismo são importantes em pedologia, geologia de engenharia, hidrogeologia, paleoclimatologia e ecologia. O uso de rochagem é baseado em estudo de intemperismo de rocha.

  14. The Spectrum of Renal Osteodystrophy: A Clinical, Biochemical, Radiological and Histopathological Study

    Directory of Open Access Journals (Sweden)

    Vijay Gupta, Vijay Verma, Rajesh K. Gupta, Dheeraj K. Gandotra, Annil Mahajan, R.K. Saini, V.K. Gupta, V.K. Dubey

    2004-07-01

    Full Text Available The chief mineral source of Jammu province is bauxite, an aluminium ore, so a possibility of waterbeing heavily polluted with aluminium is prevalent. Hence, in an effort to relate this regional geographicalaspect with aluminium bone disease (ABD in chronic renal failure (CRF, 50 cases of CRF wereprospectively evaluated. Patients were subjected to a thorough history and clinical examination.Biochemical parameters along with raiological skeletal survey and iliac crest bone biopsies wereundertaken. Sixty-eight per cent of CRF patients were also consuming aluminium containing phosphatebinders (ACPB at that time. The study revealed an occurrence of ABD in 10% of CRF patients. Itwas found predominantly superimposed upon osteomalacia (8% and mixed osteodystrophy (2%.Superimposed ABD on osteomalacia was found more frequently in pre-dialysis (10.8% than afterhaemodialysis group (7.69%. Moreover, the incidence of ABD superimposed on osteomalacia andmixed osteodystrophy was higher in the ACPB group (14.7% than the post-haemodialysis group(7.69%. Correlating, the pre-dialysis, post-haemodialysis and ACPB ingestion status of CRF patientson one hand and histologically proven ABD on the other, it was deduced that the majority of cases ofCRF having ABD was seen in ACPB ingestion group (14.7% followed by pre-dialysis (10.8% andpost-haemodialysis (7.69% groups. Thus it was concluded that in the present work, ACPB ingestionwas the major source of aluminium deposition in bones of patients with CRF rather than the waterused in dialysis or possible pollution of drinking water with aluminium in our province.

  15. Contaminant mobility and carbon sequestration downstream of the Ajka (Hungary) red mud spill: The effects of gypsum dosing

    Energy Technology Data Exchange (ETDEWEB)

    Renforth, P., E-mail: Phil.Renforth@earth.ox.ac.uk [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX3 0DP (United Kingdom); Mayes, W.M. [Centre for Environmental and Marine Sciences, University of Hull, Scarborough, YO11 3AZ (United Kingdom); Jarvis, A.P. [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Burke, I.T. [School of Earth and Environment, University of Leeds, Leeds, LS2 9JT (United Kingdom); Manning, D.A.C. [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Gruiz, K. [Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 1111 Budapest, St. Gellert sq. 4 (Hungary)

    2012-04-01

    A number of emergency pollution management measures were enacted after the accidental release of caustic bauxite processing residue that occurred in Ajka, western Hungary in October, 2010. These centred on acid and gypsum dosing to reduce pH and minimise mobility of oxyanion contaminants mobile at high pH. This study assessed the effectiveness of gypsum dosing on contaminant mobility and carbon sequestration through assessment of red mud and gypsum-affected fluvial sediments via elemental analysis and stable isotope analysis. There was a modest uptake of contaminants (notably As, Cr, and Mn) on secondary carbonate-dominated deposits in reaches subjected to gypsum dosing. C and O stable isotope ratios of carbonate precipitates formed as a result of gypsum dosing were used to quantify the importance of the neutralisation process in sequestering atmospheric carbon dioxide. This process was particularly pronounced at sites most affected by gypsum addition, where up to 36% of carbonate-C appears to be derived from atmospheric in-gassing of CO{sub 2}. The site is discussed as a large scale analogue for potential remedial approaches and carbon sequestration technologies that could be applied to red mud slurries and other hyperalkaline wastes. The results of this work have substantial implications for the aluminium production industry in which 3-4% of the direct CO{sub 2} emissions may be offset by carbonate precipitation. Furthermore, carbonation by gypsum addition may be important for contaminant remediation, also providing a physical stabilisation strategy for the numerous historic stockpiles of red mud. - Highlights: Black-Right-Pointing-Pointer Gypsum was dosed into a tributary of the river Danube, Hungary, following a red mud spill in 2010. Black-Right-Pointing-Pointer This remediation resulted in toxic element removal and atmospheric CO{sub 2} capture. Black-Right-Pointing-Pointer Red mud may have value for carbon capture and may be a resource rather than a waste.

  16. Combined Application of QEM-SEM and Hard X-ray Microscopy to Determine Mineralogical Associations and Chemcial Speciation of Trace Metals

    Energy Technology Data Exchange (ETDEWEB)

    M Grafe; M Landers; R Tappero; P Austin; B Gan; A Grabsch; C Klauber

    2011-12-31

    We describe the application of quantitative evaluation of mineralogy by scanning electron microscopy in combination with techniques commonly available at hard X-ray microprobes to define the mineralogical environment of a bauxite residue core segment with the more specific aim of determining the speciation of trace metals (e.g., Ti, V, Cr, and Mn) within the mineral matrix. Successful trace metal speciation in heterogeneous matrices, such as those encountered in soils or mineral residues, relies on a combination of techniques including spectroscopy, microscopy, diffraction, and wet chemical and physical experiments. Of substantial interest is the ability to define the mineralogy of a sample to infer redox behavior, pH buffering, and mineral-water interfaces that are likely to interact with trace metals through adsorption, coprecipitation, dissolution, or electron transfer reactions. Quantitative evaluation of mineralogy by scanning electron microscopy coupled with micro-focused X-ray diffraction, micro-X-ray fluorescence, and micro-X-ray absorption near edge structure (mXANES) spectroscopy provided detailed insights into the composition of mineral assemblages and their effect on trace metal speciation during this investigation. In the sample investigated, titanium occurs as poorly ordered ilmenite, as rutile, and is substituted in iron oxides. Manganese's spatial correlation to Ti is closely linked to ilmenite, where it appears to substitute for Fe and Ti in the ilmenite structure based on its mXANES signature. Vanadium is associated with ilmenite and goethite but always assumes the +4 oxidation state, whereas chromium is predominantly in the +3 oxidation state and solely associated with iron oxides (goethite and hematite) and appears to substitute for Fe in the goethite structure.

  17. Global direct pressures on biodiversity by large-scale metal mining: Spatial distribution and implications for conservation.

    Science.gov (United States)

    Murguía, Diego I; Bringezu, Stefan; Schaldach, Rüdiger

    2016-09-15

    Biodiversity loss is widely recognized as a serious global environmental change process. While large-scale metal mining activities do not belong to the top drivers of such change, these operations exert or may intensify pressures on biodiversity by adversely changing habitats, directly and indirectly, at local and regional scales. So far, analyses of global spatial dynamics of mining and its burden on biodiversity focused on the overlap between mines and protected areas or areas of high value for conservation. However, it is less clear how operating metal mines are globally exerting pressure on zones of different biodiversity richness; a similar gap exists for unmined but known mineral deposits. By using vascular plants' diversity as a proxy to quantify overall biodiversity, this study provides a first examination of the global spatial distribution of mines and deposits for five key metals across different biodiversity zones. The results indicate that mines and deposits are not randomly distributed, but concentrated within intermediate and high diversity zones, especially bauxite and silver. In contrast, iron, gold, and copper mines and deposits are closer to a more proportional distribution while showing a high concentration in the intermediate biodiversity zone. Considering the five metals together, 63% and 61% of available mines and deposits, respectively, are located in intermediate diversity zones, comprising 52% of the global land terrestrial surface. 23% of mines and 20% of ore deposits are located in areas of high plant diversity, covering 17% of the land. 13% of mines and 19% of deposits are in areas of low plant diversity, comprising 31% of the land surface. Thus, there seems to be potential for opening new mines in areas of low biodiversity in the future. PMID:27262340

  18. Research on Purification of Polyaluminum Chloride by Aluminum-carbon Micro-electrolysis Technology%铝碳微电解技术净化聚合氯化铝的研究

    Institute of Scientific and Technical Information of China (English)

    李荣寨

    2015-01-01

    The polyaluminum chloride produced by bauxite powder and by-product hydrochloric acid has many heavy metals and organic impurities. Referring to the principles of Fe-C micro-electrolysis, by artificially adding activated carbon and creating AL-C micro-electrolysis condition, the heavy metals and organic impurities of polyaluminum chloride can be removed. Under the condition of using the aluminum carbon ratio 1:1, the dynamic operation, the control parameters with the residence time at 1 hour, and the treatment costs about 6.67 yuan/ton, Pb2+content of polyaluminum chloride decreased from 23.3ppm to 5.8ppm, which is below the GB 10ppm requirements.%铝矿粉与副产盐酸生产的聚合氯化铝中重金属杂质和有机杂质往往较多,借鉴铁碳微电解原理,人为投加活性炭,创造铝碳微电解条件,用来去除聚合氯化铝中的重金属和有机杂质。在采用铝碳比1:1,动态操作,停留时间在1小时的控制参数,处理费用约6.67元/吨的条件下,原液铅Pb2+含量23.3ppm,处理后铅Pb2+含量下降到5.8ppm,低于国标10ppm的要求。

  19. Alternative granular media for the metal casting industry. Final report, September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Guichelaar, P.J.; Ramrattan, S.N.; Tieder, R.E. [Michigan Technological Univ., Houghton, MI (United States)

    1995-09-01

    Silica sand for foundry use is inexpensive to purchase, readily transported and widely available. As a result, it is universally used. However, three factors are becoming increasingly significant as more environmental regulations are promulgated. First, the disposal of waste foundry sand has become an excessively burdensome cost. Second, the phase changes which occur in the silica structure on heating and cooling cause thermal breakdown of the sand into smaller unusable fractions. Third, silica is a relatively weak mineral. Alternatives to silica sand which can withstand the rigors of repetitive reuse must be seriously evaluated as a way to control production costs of the domestic metal casting industry. Chromite sands, olivine sands and carbon sands have each been successfully used to solve operating problems and thus have developed their specific niches in the foundry materials inventory. However, there are several other materials that are candidates for replacing silica sand, such as fused alumina, sintered bauxite and sintered oil well proppants. These media, and others that are generically similar, are manufactured for specific purposes. Compositions and shapes could be readily tailored for used in a metal casting environment of total recycling and materials conservation. This study examines materials that are readily available as alternatives to silica sand from a functionality perspective and a cost perspective. Some of the alternative materials are natural and others are synthetic and thus referring to them as ``sands`` has the potential to cause confusion; the generic term ``granular medium`` is used in this study to mean any material that could functionally substitute for silica sand in the foundry process.

  20. An active dealkalization of red mud with roasting and water leaching

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaobo, E-mail: zhuxiaobo0119@126.com [School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000 (China); Henan Key Discipline Open Laboratory of Mining Engineering Materials, Henan 454000 (China); Li, Wang; Guan, Xuemao [School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000 (China); Henan Key Discipline Open Laboratory of Mining Engineering Materials, Henan 454000 (China)

    2015-04-09

    Highlights: • The dealkalization of active roasting and water leaching from red mud was put forward. • The main factors on dealkalization during active roasting and water leaching were investigated. • The mechanism of dealkalization from red mud was in-depth studied in the process. - Abstract: The research has focused on the dealkalization of red mud after active roasting and water leaching, which is obtained from bauxite during alumina production. The main factors such as roasting temperature, roasting time, water leaching stage, leaching temperature, leaching reaction time and liquid to solid ratio were investigated. The mechanism of dealkalization was in-depth studied by using ICP–AES, XRD, TG-DSC, SEM–EDS and leaching kinetic. The results show that the dealkalization rate reached 82% under the condition of roasting temperature of 700 °C, roasting time of 30 min, four stage water leaching, liquid to solid ratio of 7 mL/g, leaching temperature of 90 °C and reaction time of 60 min. The diffraction peak of Na{sub 6}CaAl{sub 6}Si{sub 6}(CO{sub 3})O{sub 24}·2H{sub 2}O in red mud was decreased during the active roasting process, whereas the mineral phases of NaOH·H{sub 2}O and Na{sub 2}Ca(CO{sub 3}){sub 2} were appeared. The content of alkali obviously decreased and the grade of other elements increased during the process of active roasting and water leaching, which was in favor of next application process of red mud. The water leaching was controlled by internal diffusion of SCM and the apparent activation energy was 22.63 kJ/mol.