Artykuły w czasopismach: „Gibbstie”

1

Gan, Bee K., Ian C. Madsen i James G. Hockridge. "In situX-ray diffraction of the transformation of gibbsite to α-alumina through calcination: effect of particle size and heating rate". Journal of Applied Crystallography 42, nr 4 (30.06.2009): 697–705. http://dx.doi.org/10.1107/s0021889809021232.

Pełny tekst źródła

Streszczenie:

A study was conducted on the gibbsite to α-alumina (α-Al2O3) transformation dynamics with particular reference to the influence of particle size and heating rate. Coarse- and fine-grained gibbsites were used to examine the transformation paths for the two materials, with particular reference to the upper and lower branch sequences described by Wefers & Misra [Oxides and Hydroxides of Aluminium, (1987), Alcoa Technical Paper No. 19 Revised, Aluminium Company of America]. The main techniques used to assess gibbsite calcination were thermogravimetric differential scanning calorimetry andin situX-ray diffraction, which provided complementary information on transformation behaviour. Whilst the quantitative phase analysis results indicated that the coarse- and fine-grained gibbsites followed both the upper and the lower branch sequences, detailed analysis of the results highlighted specific differences in the transformation behaviour for the two materials. With the loss of three molecules of water as gibbsite transformed to transition aluminas and finally α-Al2O3, there was a high degree of disorder in the crystal structure, resulting in broad and diffuse reflections in the diffraction patterns.

Style APA, Harvard, Vancouver, ISO itp.

2

Chandran, P., S. K. Ray, T. Bhattacharyya, P. Srivastava, P. Krishnan i D. K. Pal. "Lateritic soils of Kerala, India: their mineralogy, genesis, and taxonomy". Soil Research 43, nr 7 (2005): 839. http://dx.doi.org/10.1071/sr04128.

Pełny tekst źródła

Streszczenie:

In this study, we report the chemical and mineralogical characteristics of 4 benchmark Ultisols of Kerala to elucidate their genesis and taxonomy. The taxonomic rationale of the mineralogy class of Ultisols and other highly weathered soils on the basis of the contemporary pedogenesis is also explained. The Ultisols of Kerala have low pH, low cation exchange capacity, low effective cation exchange capacity and base saturation, with dominant presence of 1 : 1 clays and gibbsite. Presence of gibbsite along with 2 : 1 minerals discounts the hypothesis of anti-gibbsite effect. Since the kaolins are interstratified with hydroxy-interlayered vermiculites (HIV), the formation of gibbsite from kaolinite is not tenable. Thus, gibbsite is formed from primary minerals in an earlier alkaline pedo-environment. Therefore, the presence of gibbsite does not necessarily indicate an advanced stage of weathering. On the basis of a dominant amount of gibbsite, a mineralogy class such as allitic or gibbsitic does not establish a legacy between the contemporary pedogenesis and the mineralogy. The dominance of kaolin–HIV in the fine clays of Ultisols and their persistence, possibly since early Tertiary, suggests that ‘steady state’ may exist in soils developed on long-term weathered saprolite. Since the present acid environment of Ultisols does not allow desilication, the chemical transformation of Ultisols to Oxisols with time is difficult to reconcile as envisaged in the traditional model of tropical soil genesis.

Style APA, Harvard, Vancouver, ISO itp.

3

Vendrame, Pedro Rodolfo Siqueira, Robélio Leandro Marchão, Osmar Rodrigues Brito, Maria de Fátima Guimarães i Thierry Becquer. "Relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture". Pesquisa Agropecuária Brasileira 44, nr 8 (sierpień 2009): 996–1001. http://dx.doi.org/10.1590/s0100-204x2009000800031.

Pełny tekst źródła

Streszczenie:

The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite) ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera) were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta), in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.

Style APA, Harvard, Vancouver, ISO itp.

4

Bonato, J. A., i R. J. Morrison. "Weathering, bauxitisation and soil genesis from the Nakobalevu Basalt, South-East Viti Levu, Fiji". South Pacific Journal of Natural and Applied Sciences 30, nr 1 (2012): 1. http://dx.doi.org/10.1071/sp12001.

Pełny tekst źródła

Streszczenie:

The augite-olivine flows (5.3 Ma) capping Mount Nakobalevu, a few kilometres north-west of Suva, Fiji, have been subjected to rapid and deep weathering. The Nakobalevu K1 and K2 weathering profiles (at approximately 454 m altitude) show features of strong bauxitisation, and the attributes of a 'classical' lateritic profile. Aluminium and iron enrichment in the 2-3 m depth layers of the Nakobalevu weathering profiles is marked, with the presence of abundant gibbsite (as gravels and nodules, and in the silt and clay-sized fractions), goethite, kaolinite, haematite and magnetite (grains); the presence of fragmented (goethitic and gibbsitic) crustal materials in each of the studied horizons, and the distribution pattern of the Al2O3, Fe2O3 and SiO2, would infer the occurrence of several erosion and weathering cycles, some of which would have evolved under drier climatic regimes. Using Soil Taxonomy, the Nakobalevu Pedon (JBK-1) is a Typic Kandihumult, clayey, kaolinitic, isohyperthermic, which does not give any indication of the gibbsitic materials present.

Style APA, Harvard, Vancouver, ISO itp.

5

Carducci, Carla Eloize, Geraldo César de Oliveira, Walmes Marques Zeviani, Henrique Aparecido Laureano, Samara Martins Barbosa, Eduardo da Costa Severiano i Nilton Curi. "Preconsolidation stress of gibbsitic and kaolinitic Oxisols under a multipractice conservationist coffee system". Semina: Ciências Agrárias 42, nr 3 (19.03.2021): 1049–68. http://dx.doi.org/10.5433/1679-0359.2021v42n3p1049.

Pełny tekst źródła

Streszczenie:

Our goal was to analyze the impact of a multipractice soil conservationist system on coffee production in tropical soils (LATOSSOLO VERMELHO-AMARELO caulinítico/kaolinitic Haplustox and LATOSSOLO VERMELHO-gibbsítico/gibbsitic Acrustox) in Minas Gerais, Brazil. In the experimental area, the soil management involved a set of multiple conservationist practices during cultivation for more than 3.5 yrs. Soil samples were collected at 0-5, 10-15, and 20-25 cm depths at two positions: planting rows and between rows. The soil physical and mechanical properties were determined, with a focus mainly on the preconsolidation stress model (preconsolidation stress versus matric tension). For the purpose of analysis, a split-split plot experimental design was implemented. A linear mixed regression model (LMR) was fitted, and Wald’s test was performed (P < 0.05). An improvement of soil physical quality for both Oxisols was observed at the planting row position. The effects of multipractice soil management after 3.5 yrs of cultivation in association with increased gibbsite content could promote new soil structure organization, as revealed by LMR, resulting in more resilient soils (between rows) and increasing the resistance to external pressures on gibbsitic Acrustox. Overall, the findings herein are in concordance with global trends towards conservationist practices that may alleviate soil compaction in agricultural systems to maintain environmental sustainability.

Style APA, Harvard, Vancouver, ISO itp.

6

O'Connor, B. H., D. Y. Li i H. Sitepu. "Texture Characterisation in X-Ray Powder Diffraction using the March Formula". Advances in X-ray Analysis 35, A (1991): 277–83. http://dx.doi.org/10.1154/s0376030800008922.

Pełny tekst źródła

Streszczenie:

AbstractTexture, i.e. preferred orientation (PO), of crystallites can cause serious systematic errors in quantitative analysis of crystalline materials using x-ray powder diffraction (XRPD) data. The singleparameter model of March (1932), proposed by Dollase (1986) for use in powder diffractometry is a promising mathematical formalism for correcting PO in XRPD analysis of uniaxially-oriented specimens. O'Connor et al. (1991) successfully applied the March formula in applying preferred orientation corrections for gibbsites, Al(OH)3, using Rietveld pattern-fitting and a line ratio method in which corrections are determined according to the intensity ratios of selected lines. The paper gives an appraisal of the general applicability of the methods considered by Li and O'Connor with particular reference to powder diffraction data for gibbsite, molybdite (MoO3), calcite (CaCO3) and kaolinite specimens. It is shown that some caution should be exercised when using the March formula to describe PO in Rietveld analysis.

Style APA, Harvard, Vancouver, ISO itp.

7

Kew, G. A., i R. J. Gilkes. "Properties of regolith beneath lateritic bauxite in the Darling Range of south Western Australia". Soil Research 45, nr 3 (2007): 164. http://dx.doi.org/10.1071/sr06128.

Pełny tekst źródła

Streszczenie:

A morphological key has been developed for regolith that is exposed during mining of lateritic bauxite in the Darling Range of south Western Australia. The key distinguishes materials with different mineralogical and chemical properties. Iron oxide cemented (Zh) regolith has a gibbsitic matrix, quartz-rich (Zm) regolith has a gibbsite and kaolin matrix, and clay-rich (Zp) regolith has a kaolin matrix. An Si affinity element map (Si, Hf, Th) and a K affinity element group (K, Ba, Rb) are associated with granitic quartz-rich regolith and an Al/Fe element affinity group (Al, Fe, Ti, P, Ni, Co, Cu, Mn, Zn, Ga, Cr, V) is associated with clay and iron rich regolith. Doleritic regolith is generally associated with the Al/Fe affinity group. Although granite and granitic regolith exhibit similar element affinity groups, the abundance of elements within each is highly variable, which reflects the diversity in composition of granite within the region. The degree of euhedral character of clay-size platy crystals (kaolinite/gibbsite) does not differ for materials distinguished by the key, as both quartz-rich (Zm) and clay-rich (Zp) regolith and both granitic and doleritic saprolite contain subhedral kaolin crystals. The crystal size of platy kaolin (approximately 0.5 µm) is similar for different mine pits and for different regolith materials (Zm and Zp) within mine pits. There is a difference in halloysite tube length (0.52–1.18 µm) between mine pits, which may be related to the presence of weathered mica or to the alteration of halloysite in gibbsite-rich regolith. The internal and external diameters of halloysite tubes (about 0.11 and 0.24 µm) are similar for different mine pits and different regolith types within mine pits. The resin used during thin section preparation contains chlorine, so that determination of chlorine by EMPA provides a measure of the porosity of regolith material. A systematic negative relationship exists between chlorine concentration and total oxide weight % of porous regolith matrix determined by EMPA; both measurements provide an indication of the porosity of the clay matrix in regolith.

Style APA, Harvard, Vancouver, ISO itp.

8

YANG, Hui-bin, Xiao-lin PAN, Hai-yan YU, Gan-feng TU i Jun-min SUN. "Dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in sodium hydroxide solution under atmospheric pressure". Transactions of Nonferrous Metals Society of China 25, nr 12 (grudzień 2015): 4151–59. http://dx.doi.org/10.1016/s1003-6326(15)64065-1.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

9

Bhattacharyya, T., D. K. Pal i P. Srivastava. "Formation of gibbsite in the presence of 2:1 minerals: an example from Ultisols of northeast India". Clay Minerals 35, nr 5 (grudzień 2000): 827–40. http://dx.doi.org/10.1180/000985500547269.

Pełny tekst źródła

Streszczenie:

AbstractThere are two different views regarding the genesis of gibbsite in tropical acid soils: (1) direct weathering of primary Al-silicate minerals; and (2) transformation through clay mineral intermediates. We investigated the genesis of gibbsite in two representative Ultisols from northeastern India. Gibbsite in these Ultisols appears to be the remnant of earlier weathering products of aluminosilicate minerals formed in a neutral to alkaline pedochemical environment. The mere presence of gibbsite in these soils, therefore, does not indicate their advanced stage of weathering. The formation of typically rod-shaped and well-crystallized gibbsite in both the coarse and fine soil fractions in the presence of large amounts of 2:1 minerals indicates that the anti-gibbsite hypothesis may not be tenable in these tropical acid soils. A schematic model for the formation of gibbsite and kaolin in Ultisols is proposed.

Style APA, Harvard, Vancouver, ISO itp.

10

Clemente, Celso Augusto, i Antonio Carlos de Azevedo. "Mineral weathering in acid saprolites from subtropical, southern Brazil". Scientia Agricola 64, nr 6 (grudzień 2007): 601–7. http://dx.doi.org/10.1590/s0103-90162007000600007.

Pełny tekst źródła

Streszczenie:

Because weathering of minerals releases chemical elements into the biogeochemical cycle, characterization of their weathering products helps to better model groundwater quality, formation of secondary minerals and nutrient flux through the trophic chain. Based on microscopic and elemental analyses, weathering of riodacite from Serra Geral formation was characterized and weathering paths proposed. Three weathering paths of plagioclase phenocrystals were identified: plagioclase to gibbsite (Pg1); plagioclase to gels and gibbsite (Pg2); and plagioclase to gels, gibbsite and kaolinite (Pg3). Pyroxenes weathered to smectite and goethite (Py1), or to goethite and gibbsite (Py2), and magnetite weathered directly into iron oxides. Rock matrix comprises 90% of rock volume, and weathered to kaolinite and gibbsite, which explains why these minerals were the most abundant in the weathering products of these saprolites.

Style APA, Harvard, Vancouver, ISO itp.

11

Soares, L. C., E. Souza i M. I. Yoshida. "Estudo da retenção de íons cromo por gibbsita e peneira molecular (Chrome retention study by gibbsite and molecular sieves)". Eclética Química Journal 36, nr 1 (31.10.2017): 123. http://dx.doi.org/10.26850/1678-4618eqj.v36.1.2011.p123-141.

Pełny tekst źródła

Streszczenie:

Neste trabalho, relatamos o emprego de gibbsita e de uma peneira molecular comercial para a retenção de íons cromo. Os estudos envolveram, além destes materiais, soluções com diferentes concentrações do íon e variações na concentração e na temperatura das soluções e, também, do tempo de contato entre essas e as fases estacionárias. Os resultados desses experimentos e dos posteriores processos de lixiviação do íon indicam que tanto a gibbsita quanto a peneira molecular são materiais que apresentam alta capacidade de retenção deste íon e, além disso, são altamente resistentes aos processos de lixiviação.

Style APA, Harvard, Vancouver, ISO itp.

12

Wu, Zheng Ping, Li Jiao Zhou, Qi Yuan Chen i Zhou Lan Yin. "Reactive Ability and Bong Strength Analysis on Al(OH)₃ Crystals with Three Different Crystalline". Advanced Materials Research 396-398 (listopad 2011): 614–19. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.614.

Pełny tekst źródła

Streszczenie:

The crystal structure models of three kinds of different Al(OH)3 crystals, which are gibbsite, bayerite and nordstradite, are built respectively according to the corresponding experimental crystal lattice. Geometry optimizations are implemented by CASTEP program module using general gradient approximation (GGA) and local density approximation (LDA) methods respectively based on density functional theory (DFT). Total energy, electronic structure, atomic and bond populations are also calculated. The calculation results of total energy indicate that gibbsite is steadier than the other two from the point of view of energy, and the effect of basis set of GGA-PW91 is highest. At the same time, energy bond structure and density of states calculated at GGA-PW91 and LDA-CA-PZ levels show that the different of energy gap ΔE (ELUMO-EHOMO) at the first group of BZ is not obvious, and that the highest value of ΔE of gibbsite is more lower than the other two Al(OH)3 crystals. It may be likely to say that gibbsite may be more active than the other two crystals. According to the analysis of populations, it can be found that bond populations value of H-O and Al-O bonds of gibbsite is smallest in three different Al(OH)3 crystals, it is to say that the combination force of H-O and Al-O bonds of gibbsite is smallest and gibbsite may be more easier to be calcined theoretically.

Style APA, Harvard, Vancouver, ISO itp.

13

Wang, Jing, Qi Na He i Zhen Gao. "The Effect of Different Solvent on the Microstructure of Gibbsite during Hydrothermal Treatment". Advanced Materials Research 160-162 (listopad 2010): 76–80. http://dx.doi.org/10.4028/www.scientific.net/amr.160-162.76.

Pełny tekst źródła

Streszczenie:

Phase structure and micromorphology of gibbsite after hydrothermal treated in different solvents were studied. Results showed that there was a relationship between micromorphology and phase structure of as-synthesized product. The cubic slice-like boehmite microstructure can be obtained in water. The 3D flowerlike boehmite microstructure can be obtained in isopropanol or sodium carbonate solution. The global ammonium aluminum carbonate hydroxide (AACH) architectures assembled by the lathes can be obtained in urea solvent. Gibbsite can transform to boehmite after 12h hydrothermal treatment in water. In isopropanol or sodium carbonate solution, this time decreased to 6h. In urea solution, Aluminum hydroxide turned from gibbsite to the mixture of boehmite, gibbsite and AACH. Finally, AACH is synthesized. This procedure needs 24h.

Style APA, Harvard, Vancouver, ISO itp.

14

Watling, Helen, Joanne Loh i Helen Gatter. "Gibbsite crystallization inhibition". Hydrometallurgy 55, nr 3 (kwiecień 2000): 275–88. http://dx.doi.org/10.1016/s0304-386x(00)00061-x.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

15

Watling, Helen. "Gibbsite crystallization inhibition". Hydrometallurgy 55, nr 3 (kwiecień 2000): 289–309. http://dx.doi.org/10.1016/s0304-386x(00)00062-1.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

16

Deyu, Li, Brian H. O'Connor, Gerald I. D. Roach i John B. Cornell. "Use of X-Ray Powder Diffraction Rietveld Pattern-Fitting for Characterising Preferred Orientation in Gibbsites". Powder Diffraction 5, nr 2 (czerwiec 1990): 79–85. http://dx.doi.org/10.1017/s0885715600015384.

Pełny tekst źródła

Streszczenie:

AbstractA study has been conducted with gibbsite specimens, on the use of Rietveld X-ray powder diffraction (XRPD) pattern fitting for quantitating preferred orientation in powders. This study has shown that an earlier formula gives results which correlate closely with an empirical measure of morphology proposed recently for gibbsite powders, viz., the ratio of the XRPD intensities for the (002) line and the (110, 200) doublet lines. A method is proposed on the basis of this correlation for the correction for preferred orientation of line intensities in gibbsite powder patterns. The correction method appears to have excellent potential for XRPD quantification of gibbsite levels in mixtures, and could have general application for coping with preferred orientation effects in the quantitation of other phases.

Style APA, Harvard, Vancouver, ISO itp.

17

Torres Sánchez, Rosa M., A. Boix i R. C. Mercader. "Grinding Assistance in the Transformation of Gibbsite to Corundum". Journal of Materials Research 17, nr 3 (marzec 2002): 712–17. http://dx.doi.org/10.1557/jmr.2002.0102.

Pełny tekst źródła

Streszczenie:

After gibbsite was milled for 5 min in a Cr-steel oscillating mill, corundum was obtained by heating the powder for 3 h at 800 °C. We found that iron contamination, produced by the milling process, is essential to attain the transformation at this low temperature and is located at the surface of the gibbsite particles. The knowledge of the oxidation state and location of the contaminant elements, necessary to control the solid-state reactions and/or phase transformations induced by the milling, was realized in this work by a characterization performed by chemical analysis, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and isoelectric point determination. The iron contamination amounted to about 3% (as Fe2O3) for the sample milled for 60 min. That the iron contamination that occurred mainly on the gibbsite amorphous surface was concluded after a comparison of the isoelectric point determination of the milled samples with that of a mechanical mixture of gibbsite and hematite. X-ray diffraction studies showed that gibbsite looses its crystallinity after the first 5 min of milling.

Style APA, Harvard, Vancouver, ISO itp.

18

Frenzel, Johannes, Augusto F. Oliveira, Helio A. Duarte, Thomas Heine i Gotthard Seifert. "Structural and Electronic Properties of Bulk Gibbsite and Gibbsite Surfaces". Zeitschrift f�r anorganische und allgemeine Chemie 631, nr 6-7 (maj 2005): 1267–71. http://dx.doi.org/10.1002/zaac.200500051.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

19

Phambu, Nsoki. "Adsorption of Carboxylic Acids on Submicrocrystalline Aluminum Hydroxides in Aqueous Solution. Part I: Qualitative Study by Infrared and Raman Spectroscopy". Applied Spectroscopy 56, nr 6 (czerwiec 2002): 756–61. http://dx.doi.org/10.1366/000370202760077496.

Pełny tekst źródła

Streszczenie:

Adsorption of acetic, oleic, benzoic, and salicylic acids on submicrocrystalline aluminum hydroxide samples is investigated in aqueous solutions. Experimental infrared and Raman spectroscopic data are analyzed to determine the reactivity of the monocoordinated hydroxyl groups located on the edge faces of bayerite or gibbsite crystals. Two key parameters were (1) the effect of concentration of aqueous solutions of the acids, and (2) the variation in specific surface areas of different samples of bayerite and gibbsite powders. Strong preferential adsorption to bayerite was observed over the whole pH range. No adsorption to gibbsite was detected. Data from the literature indicate that acetate, oleate, and benzoate form bidentate complexes on bayerite while salicylate forms a monodentate complex. The infrared spectra show that only monocoordinated hydroxyl groups are reactive, in the bayerite samples, and the band at 1020 cm−1 corresponds to the deformation mode of the monocoordinated hydroxyl groups whose stretching vibration was at 3465 cm−1. It is suggested that the specific surface areas given by the adsorption isotherms is a condition necessary for adsorption, but not sufficient in itself. Adsorption requires the presence of Al-OH2+1/2 species as well as the presence of steps or of a packaging sequence ABABABA rather than a packaging sequence ABBAABBA of the hydroxyl planes. The gibbsite impurity present in the bayerite sample reacted completely, while the lateral OH in the gibbsite sample did not, reflecting the lower reactivity in gibbsite relative to extended domains of bayerite.

Style APA, Harvard, Vancouver, ISO itp.

20

Varadachari, Chandrika, Tarit Chattopadhyay i Kunal Ghosh. "The crystallo-chemistry of oxide-humus complexes". Soil Research 38, nr 4 (2000): 789. http://dx.doi.org/10.1071/sr99053.

Pełny tekst źródła

Streszczenie:

Complexation of humic substances with goethite, hematite, gibbsite, and boehmite has been explained from a viewpoint of crystal structure of the minerals. Theoretical analysis of crystal surface structures revealed the following. (i) Residual charge carried by O or OH on surfaces of gibbsite is –1/2; on boehmite it is –3/2 or –1/2; on goethite it is –4/3, –2/3, or –1/3; and on hematite it is –3/2, –1, or –1/2. Cations adsorbed to neutralise these charges can form bridging links with humic acid; higher charges form stronger links. (ii) Surfaces of goethite, hematite, and gibbsite also contain octahedral sites in which one O/OH position is vacant. These may provide centres for the formation of strong coordination bonds. (iii) Such vacant octahedral positions are absent in boehmite. It follows that in gibbsite, cation bridging links would be weak and vacant octahedral sites would be the dominant bonding sites; in goethite and hematite, both cation bridging and surface coordination sites would be present; in boehmite, cation bridging would be the only strong bonding mode. Derivations from crystallochemical analysis are supported by experimental observations. Infrared studies also show strong OH involvement in boehmite complexation in contrast to the weakness of OH involvement in gibbsite complexes.

Style APA, Harvard, Vancouver, ISO itp.

21

Hao, X., C. M. Cho i G. J. Racz. "Chemical retardation of phosphate diffusion in simulated acid soil amended with lignosulfonate". Canadian Journal of Soil Science 80, nr 2 (1.05.2000): 289–99. http://dx.doi.org/10.4141/s99-062.

Pełny tekst źródła

Streszczenie:

The availability and movement of inorganic phosphate fertilizer is usually low due to precipitation and adsorption reactions in soil. Lignosulfonate (LS), which is produced from acid sulfite pulping processes, has similar characteristics to soil organic materials. An experiment was designed to study the effects of LS on P movement in a simulated acid soil containing aluminum-saturated cation exchange resin and acid-washed fine sand. The resulting simulated soil had a cation exchange capacity of 22 cmolc kg−1 and either no or 10 g kg−1 gibbsite. Movement of surface-applied monopotassium phosphate was studied in soil columns, either with 20 g kg−1 LS or without LS. Lignosulfonate reduced phosphate fixation and sustained a higher water extractable phosphate concentration near the surface of the columns, but had no effect on downward phosphate movement in the columns with gibbsite. Lignosulfonate reduced the solution concentration of P near the surface and reduced downward phosphate movement in the columns without gibbsite. The resin-sand column with gibbsite closely reflected an acid soil, and this research showed that adding LS would increase fertilizer P availability in a gibbsite-rich acid soil. Adding Ca-LS to Al-rich soil is beneficial for another reason, improving Ca nutrition, which is poor for these soils. Key words: Chemical retardation, phosphate diffusion, lignosulfonate amendment

Style APA, Harvard, Vancouver, ISO itp.

22

Essington, Michael E., Julia B. Nelson i William L. Holden. "Gibbsite and Goethite Solubility". Soil Science Society of America Journal 69, nr 4 (lipiec 2005): 996–1008. http://dx.doi.org/10.2136/sssaj2004.0287.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

23

Webster, Nathan A. S., Ian C. Madsen, Melissa J. Loan, Robert B. Knott, Fatima Naim, Kia S. Wallwork i Justin A. Kimpton. "An investigation of goethite-seeded Al(OH)3precipitation usingin situX-ray diffraction and Rietveld-based quantitative phase analysis". Journal of Applied Crystallography 43, nr 3 (15.04.2010): 466–72. http://dx.doi.org/10.1107/s0021889810008484.

Pełny tekst źródła

Streszczenie:

Anin situX-ray diffraction investigation of goethite-seeded Al(OH)3precipitation from synthetic Bayer liquor at 343 K has been performed. The presence of iron oxides and oxyhydroxides in the Bayer process has implications for alumina reversion, which causes significant process losses through unwanted gibbsite precipitation, and is also relevant for the nucleation and growth of scale on mild steel process equipment. The gibbsite, bayerite and nordstrandite polymorphs of Al(OH)3precipitated from the liquor; gibbsite appeared to precipitate first, with subsequent formation of bayerite and nordstrandite. A Rietveld-based approach to quantitative phase analysis was implemented for the determination of absolute phase abundances as a function of time, from which kinetic information for the formation of the Al(OH)3phases was determined.

Style APA, Harvard, Vancouver, ISO itp.

24

Camargo, Livia Arantes, José Marques Júnior i Gener Tadeu Pereira. "Mineralogy of the clay fraction of Alfisols in two slope curvatures: III - spatial variability". Revista Brasileira de Ciência do Solo 37, nr 2 (kwiecień 2013): 295–306. http://dx.doi.org/10.1590/s0100-06832013000200001.

Pełny tekst źródła

Streszczenie:

A good knowledge of the spatial distribution of clay minerals in the landscape facilitates the understanding of the influence of relief on the content and crystallographic attributes of soil minerals such as goethite, hematite, kaolinite and gibbsite. This study aimed at describing the relationships between the mineral properties of the clay fraction and landscape shapes by determining the mineral properties of goethite, hematite, kaolinite and gibbsite, and assessing their dependence and spatial variability, in two slope curvatures. To this end, two 100 × 100 m grids were used to establish a total of 121 regularly spaced georeferenced sampling nodes 10 m apart. Samples were collected from the layer 0.0-0.2 m and analysed for iron oxides, and kaolinite and gibbsite in the clay fraction. Minerals in the clay fraction were characterized from their X-ray diffraction (XRD) patterns, which were interpreted and used to calculate the width at half height (WHH) and mean crystallite dimension (MCD) of iron oxides, kaolinite, and gibbsite, as well as aluminium substitution and specific surface area (SSA) in hematite and goethite. Additional calculations included the goethite and hematite contents, and the goethite/(goethite+hematite) [Gt/(Gt+Hm)] and kaolinite/(kaolinite+gibbsite) [Kt/(Kt+Gb)] ratios. Mineral properties were established by statistical analysis of the XRD data, and spatial dependence was assessed geostatistically. Mineralogical properties differed significantly between the convex area and concave area. The geostatistical analysis showed a greater number of mineralogical properties with spatial dependence and a higher range in the convex than in the concave area.

Style APA, Harvard, Vancouver, ISO itp.

25

Yang, Hui-bin, Feng-qin Liu, Hong-liang Zhao i Rui Wu. "Hydrothermal process of synthetic gibbsite and the characteristics of Na in gibbsite crystal". Chemical Papers 72, nr 12 (10.07.2018): 3169–78. http://dx.doi.org/10.1007/s11696-018-0551-2.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

26

Oliveira, F. S., A. F. D. C. Varajão, C. A. C. Varajão i B. Boulangé. "A comparison of properties of clay minerals in isalteritic and in degraded facies". Clay Minerals 48, nr 5 (grudzień 2013): 697–711. http://dx.doi.org/10.1180/claymin.2013.048.5.03.

Pełny tekst źródła

Streszczenie:

AbstractThe mineralogical, geochemical and micromorphological features of an isalteritic clay facies, which originated from weathering of an anorthosite, were compared to those of clay facies derived from the degradation of a bauxite developed from the same rock. The isalteritic clay was formed by the hydrolytic alteration of plagioclase, whereas the degraded clays were formed by decomposition of gibbsite and neoformation of kaolinite. This resilification process resulted from the reintroduction of silica via the oscillation of the phreatic level and/or the decomposition of organic matter on the surface. The degradation process was gradual and yielded two different facies: (a) degraded clays with almost total decomposition of gibbsite, and (b) degraded clays with gibbsite nodules. Morphologically, the isalteritic clays differ from the degraded clays because they contain larger hexagonal and pseudo-hexagonal crystals. The degraded clays have more irregular crystal shapes, ranging from laths to anhedral shapes.

Style APA, Harvard, Vancouver, ISO itp.

27

Srisawad, Natpakan, Wasu Chaitree, Okorn Mekasuwandumrong, Piyasan Praserthdam i Joongjai Panpranot. "Formation of CoAl2O4Nanoparticles via Low-Temperature Solid-State Reaction of Fine Gibbsite and Cobalt Precursor". Journal of Nanomaterials 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/108369.

Pełny tekst źródła

Streszczenie:

Nanocrystalline cobalt aluminate (CoAl2O4) was synthesized by the solid-state reaction method with cobalt chloride hexahydrate (CoCl2 · 6H2O) as the source of Co and gibbsite (Al(OH)3) as the source of Al, respectively. The effects of particle size of the starting fine gibbsite (0.6 and 13 μm) and calcination temperatures (450, 550, and 650°C) on the properties of CoAl2O4were investigated by means of X-ray diffraction (XRD), thermogravimetry analysis and differential thermal analysis (TG/DTA), X-ray photoelectron spectroscopy (XPS), UV-visible absorption spectroscopy (UV-Vis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Increasing of calcination temperature promoted the insertion amounts of Co2+in alumina matrix in CoAl2O4structure, which resulted in the brighter blue particles and increasing of UV spectra band. The lowest temperature for the formation of nanocrystalline CoAl2O4particles was 550°C for the solid-state reaction of cobalt chloride and 0.6 μm fine gibbsite.

Style APA, Harvard, Vancouver, ISO itp.

28

Meshcheryakov, Eugene P., Sergey I. Reshetnikov, Mariya P. Sandu, Alexey S. Knyazev i Irina A. Kurzina. "Efficient Adsorbent-Desiccant Based on Aluminium Oxide". Applied Sciences 11, nr 6 (10.03.2021): 2457. http://dx.doi.org/10.3390/app11062457.

Pełny tekst źródła

Streszczenie:

The review describes the main methods of obtaining hydroxides and aluminium oxides (AO) of various structures from gibbsite. The promising techniques of obtaining AO adsorbents are discussed, namely the technique of thermal activation in the mode of pneumatic transport with gibbsite by heated air (TCA Gb) and the technique of thermal activation of gibbsite in centrifugal flash reactors (CTA Gb). The main methods of improving the adsorbent properties of AO, such as the optimisation of texture characteristics and phase composition, as well as the influence of the modification of aluminium oxide adsorbents, obtained using CTA and TCA technologies with cations of alkaline metals, are considered. It is shown that the modification allows a controlled variation of the characteristics of donor and acceptor active sites on the surface of adsorbents and, thus, a substantial increase in their adsorption activity, in particular, with respect to water vapour.

Style APA, Harvard, Vancouver, ISO itp.

29

Lloyd, S., S. M. Thurgate, R. M. Cornell i G. M. Parkinson. "Atomic force microscopy of gibbsite". Applied Surface Science 135, nr 1-4 (wrzesień 1998): 178–82. http://dx.doi.org/10.1016/s0169-4332(98)00283-9.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

30

Enright, Eoin P., Teresa Curtin, John Haines i Kenneth T. Stanton. "Gibbsite scaling on polymer surfaces". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 227, nr 3 (27.09.2012): 196–207. http://dx.doi.org/10.1177/1464420712461220.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

31

Kingsley, Jeffrey P., i William R. Wilcox. "Adsorption of oxalate on gibbsite". Hydrometallurgy 16, nr 1 (kwiecień 1986): 105–7. http://dx.doi.org/10.1016/0304-386x(86)90055-1.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

32

Briley, Elizabeth, Patricia Huestis, X. Zhang, K. M. Rosso i Jay A. LaVerne. "Radiolysis of thermally dehydrated gibbsite". Materials Chemistry and Physics 271 (październik 2021): 124885. http://dx.doi.org/10.1016/j.matchemphys.2021.124885.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

33

Savko, A. D., V. M. Novikov, N. M. Boeva, A. V. Krainov, A. V. Milash, E. A. Zhegallo, M. Yu Ovchinnikova i N. S. Bortnikov. "Mamon stratum of the upper devonian of the Voronezh anteclise - new kaolin-bearing province". Доклады Академии наук 489, nr 6 (23.12.2019): 621–25. http://dx.doi.org/10.31857/s0869-56524896621-625.

Pełny tekst źródła

Streszczenie:

The lithofacies analysis of the Mamon showed showed that secondary kaolin deposits, forming a new kaolin-bearing province in the southern part of the Voronezh anteklise, are associated with a complex of deluvial-proluvial, lacustrine-boggy, and floodplain-oxbow deposits. The main ore minerals are kaolinite, quartz and secondary iron oxides and gibbsite. The presence of both terrigenous and autistic kaolinite was revealed. An important role in the formation of the latter, as well as gibbsite, played an organic substance.

Style APA, Harvard, Vancouver, ISO itp.

34

Ding, Yuan Fa, Xiang Dong Su, Da Qiao Hu, Jian Kang Liu, Li He i Dan Ning Li. "Experimental Study of Solid Dispersion in a Seeded Precipitation Tank with Slight Agitation for Gibbsite Crystallization". Applied Mechanics and Materials 456 (październik 2013): 537–40. http://dx.doi.org/10.4028/www.scientific.net/amm.456.537.

Pełny tekst źródła

Streszczenie:

In order to explore the energy saving measures in gibbsite crystallization process for alumina production by Bayer method, industrial experiment was carried out to investigate the solid dispersion in a slight agitation seed precipitation tank for gibbsite crystallization. The experimental results showed that little difference of solid concentration, only 48.19 g·l-1is found in the range from 5 meters depth to the tank bottom, which is the most zone of the tank, and there is a somewhat large difference in the top 5 meters zone near the surface that is about 149.66 g·l-1. Therefore, under the condition of slight agitation, solid content would not concentrate to the tank bottom completely with the normal work flow. It is suggested that the work of production would not be interrupted in less agitation than before, and the electrical energy saving rate is about 34%. The effects of reduced agitation on the yield and the quality of gibbsite crystallization should be studied carefully in subsequent works.

Style APA, Harvard, Vancouver, ISO itp.

35

Rozic, Ljiljana, Tatjana Novakovic, Nadezda Jovanovic, Ana Terlecki-Baricevic i Zeljko Grbavcic. "The kinetics of the partial dehydration of gibbsite to activated alumina in a reactor for pneumatic transport". Journal of the Serbian Chemical Society 66, nr 4 (2001): 273–80. http://dx.doi.org/10.2298/jsc0104273r.

Pełny tekst źródła

Streszczenie:

The dehidration kinetics of gibbsite to activated alumina was investigated at four different temperatures between 883 K and 943 K in a reactor for pneumatic transport in the dilute two phase flow regime. The first order kinetic behavior of this reactionwith respect to the water content of the solid material was proved and an activation energy of 66.5 kJ/mol was calculated. The effect of residence time on the water content is given and compared with theoretical calculations. The water content and other characteristics of the products depend on two main parameters, one is the short residence time and the other is the temperature of the dehydration of gibbsite. The short residence time of the gibbsite particles in a reactor for pneumatic transport prevents crystallization into new phases, as established from XRD analysis data. Reactive amorphous alumina powder, with a specific surface area of 250 m2/g, suitable as a precursor for catalyst supports is obtained.

Style APA, Harvard, Vancouver, ISO itp.

36

Meor Sulaiman, Meor Yusoff, Khaironie Mohamed Takip, Nur Aqilah Sapiee i Ahmad Khairulikram Zahari. "Synthesis of Aluminium Hydroxide and Alumina by Hydrothermal and Solvothermal Methods". Materials Science Forum 840 (styczeń 2016): 359–63. http://dx.doi.org/10.4028/www.scientific.net/msf.840.359.

Pełny tekst źródła

Streszczenie:

The paper describes some work done on the SEM and XRD characteristic studies of aluminium hydroxide and alumina synthesized by the solvothermal and hydrothermal methods. Hydrothermal process produced boehmite phase aluminium hydroxide while the solvothermal process produced gibbsite phase aluminium hydroxide. Transition reaction study by in-situ XRD shows that the gibbsite is transformed into boehmite before it is converted into alumina. This transformation stage involves a dissolution-recrystallization process. The SEM results show the changes in morphology of the crystals as a result of both these processes.

Style APA, Harvard, Vancouver, ISO itp.

37

Wang, Suyun, Xin Zhang, Trent R. Graham, Hailin Zhang, Carolyn I. Pearce, Zheming Wang, Sue B. Clark, Wei Jiang i Kevin M. Rosso. "Two-step route to size and shape controlled gibbsite nanoplates and the crystal growth mechanism". CrystEngComm 22, nr 15 (2020): 2555–65. http://dx.doi.org/10.1039/d0ce00114g.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

38

Loiko, Olessya P., Anne B. Spoelstra, Alexander M. van Herk, Jan Meuldijk i Johan P. A. Heuts. "ATRP mediated encapsulation of Gibbsite: fixation of the morphology by using a cross-linker". Polymer Chemistry 8, nr 19 (2017): 2909–12. http://dx.doi.org/10.1039/c7py00226b.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

39

Vendrame, P. R. S., O. R. Brito, E. S. Martins, C. Quantin, M. F. Guimarães i T. Becquer. "Acidity control in Latosols under long-term pastures in the Cerrado region, Brazil". Soil Research 51, nr 4 (2013): 253. http://dx.doi.org/10.1071/sr12214.

Pełny tekst źródła

Streszczenie:

High acidity and aluminium saturation are among the main limiting factors for crop production in tropical soils. The aim of this work was to measure the acidity of Latosols under pastures in the Brazilian Cerrado and to assess the influence of clay mineralogy as a controlling parameter of soil acidity. Topsoils (n = 73, 0–0.2 m depth) of Latosols developed on different parent materials were sampled in two sub-regions of the Cerrado region. The main chemical characteristics were determined by standard procedures, and kaolinite and gibbsite contents were determined by dissolution with sulfuric acid and thermogravimetric analyses. The exchangeable concentrations of calcium (Ca), magnesium (Mg), and potassium (K) varied considerably among soil samples, with ranges of 0–13.9 cmolc kg–1 (mean ± standard deviation 1.77 ± 1.91 cmolc kg–1) for Ca; 0.2–3.2 cmolc kg–1 (1.13 ± 0.68 cmolc kg–1) for Mg; and 0–1.0 cmolc kg–1 (0.24 ± 0.24 cmolc kg–1) for K. The mean concentration of exchangeable aluminium (Al) was 0.55 ± 0.61 cmolc kg–1 (range 0–2.3 cmolc kg–1). The content of kaolinite (282 ± 96 g kg–1) was higher than of gibbsite (106 ± 77 g kg–1). The amount of exchangeable Al and Al saturation rate varied according to the mineralogy of the clay fraction of the soils. The content of exchangeable Al3+ remained low when gibbsite was the predominant mineral, whereas it increased with kaolinite content. The ratio kaolinite/(kaolinite + gibbsite) could be used as a useful indicator of the sensitivity of soils affected by acidity and Al toxicity.

Style APA, Harvard, Vancouver, ISO itp.

40

Antelo, Juan, Sarah Fiol, Silvia Mariño, Florencio Arce, Dora Gondar i Rocio Lopez. "Copper adsorption on humic acid coated gibbsite: comparison with single sorbent systems". Environmental Chemistry 6, nr 6 (2009): 535. http://dx.doi.org/10.1071/en09066.

Pełny tekst źródła

Streszczenie:

Environmental context. Adsorption processes control the mobility and bioavailability of nutrients and contaminants in soils, sediments and aquatic systems. Natural organic matter and aluminium oxides are important reactive materials present in natural systems and their mutual interaction may alter the surface properties of both materials, playing an important role on the fate of different contaminants, such as copper, in the environment. The present study illustrates the importance of these interactions, showing that the presence of natural organic matter has a synergic effect on the copper adsorption on the aluminium oxide surface. Abstract. Copper adsorption processes on aluminium oxides may significantly control the mobility and transport of copper ions in soils and surface waters. The binding of protons and copper to humic acid (HA) and to gibbsite as single sorbent systems was investigated and the results then used to test the validity of the Linear Additivity Model (LAM) for describing copper binding to gibbsite/HA systems. More copper was adsorbed in the gibbsite/HA/Cu2+ ternary system, at pH 4 and 6 and ionic strength 0.1 M, than in the corresponding binary systems. Although copper adsorption on gibbsite at pH 4 is rather small, the enhancement in sorption was noteworthy, and can be attributed to the formation of ternary complexes and changes in the electrostatic potentials at the mineral surface or at the HA as a result of their mutual interaction. The LAM predicted satisfactorily the experimental results at pH 6, whereas it underestimated the copper binding at pH 4.

Style APA, Harvard, Vancouver, ISO itp.

41

Varajão, Angélica F. Drummond C., Robert J. Gilkes i Robert D. Hart. "Amorphous alumino-silicate materials in a Brazilian hydromorphic lateritic soil". Soil Research 40, nr 3 (2002): 465. http://dx.doi.org/10.1071/sr00008.

Pełny tekst źródła

Streszczenie:

Two ancient lateritic soil profiles from Brazil that are now experiencing hydromorphic conditions were investigated by chemical extractions, X-ray diffraction, differential thermal and thermogravimetric analysis, and analytical transmission electron microscopy (ATEM) to identify if the hydromorphic conditions had affected soil minerals. The soils are composed of gibbsite and kaolinite with less quartz, anatase, goethite, pedogenic chlorite, and amorphous alumino-silicate phases. These last 2 constituents occur in the middle and upper horizons of both soil profiles, together with considerable amounts of organic carbon. Analytical TEM showed that the amorphous phases enveloped corroded gibbsite and kaolinite crystals and may indicate the transformation of these minerals to amorphous phases. The amorphous phases have a similar microfabric to that of allophane and ATEM analyses of the amorphous phases gave an Al/Si atom ratio that was always >2, and commonly about 10. These atom ratios are consistent with the bulk chemical results obtained using pyrophosphate, oxalate, and dithionite extractants, but not with the theoretical ratio for allophane. The Al/Si atom ratio of the amorphous phases was related to the Al content of the mineral enveloped by the amorphous phases, i.e. gibbsite or kaolinite. This association supports the interpretation that the amorphous phases formed from the crystalline minerals. The saturated condition of the profiles, together with the high concentration of organic matter in the upper horizons, favours dissolution of the original gibbsite and kaolinite in the laterite and their transformation to amorphous alumino-silicate phases with a high Al content.

Style APA, Harvard, Vancouver, ISO itp.

42

Fernandez-Martinez, Alejandro, Jinhui Tao, Adam F. Wallace, Ian C. Bourg, Mark R. Johnson, James J. De Yoreo, Garrison Sposito, Gabriel J. Cuello i Laurent Charlet. "Curvature-induced hydrophobicity at imogolite–water interfaces". Environmental Science: Nano 7, nr 9 (2020): 2759–72. http://dx.doi.org/10.1039/d0en00304b.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

43

Loiko, Olessya P., Anne B. Spoelstra, Alexander M. van Herk, Jan Meuldijk i Johan P. A. Heuts. "Encapsulation of unmodified Gibbsite via conventional emulsion polymerisation using charged co-oligomers". RSC Advances 6, nr 84 (2016): 80748–55. http://dx.doi.org/10.1039/c6ra16364e.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

44

Verdes, Giles, Robert Gout i Sylvie Castet. "Thermodynamic properties of the aluminate ion and of bayerite, boehmite, diaspore and gibbsite". European Journal of Mineralogy 4, nr 4 (11.08.1992): 767–92. http://dx.doi.org/10.1127/ejm/4/4/0767.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

45

Obrenovic, Zoran, Radislav Filipovic, Marija Milanovic, Ivan Stijepovic i Ljubica Nikolic. "Obtaining of transition phases of alumina starting from sodium aluminate in Bayer process". Chemical Industry 65, nr 3 (2011): 271–77. http://dx.doi.org/10.2298/hemind110128018o.

Pełny tekst źródła

Streszczenie:

Transition (active) phases of alumina were synthesized starting from sodium aluminate solution prepared out of Bayer liquor. The neutralisation of sodium aluminate solution was performed by sulphuric acid. Powder X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and low-temperature nitrogen absorption studies were employed to trace the formation of the transition phases of alumina. The results show that the properties of the powders (phase composition, morphology and specific surface area) are strongly influenced by the initial pH value of the system, as well as by the duration of neutralisation step. It is possible to obtain powders with heterogeneous structure with dominant phase of bayerite, gibbsite or boehmit by tuning the pH and concentration of the starting sodium aluminate solution. The transition (active) phases of alumina (?- and ?-alumina) with high specific surface area (264-373 m2/g) are formed through the thermal dehydratation of aluminium hydroxide (bayerite and gibbsite) and aluminium oxyhydroxide (boehmite or pseudoboehmite) at the temperature of 500?C. Namely, bayerite and pseudoboehmite transforms to ?-phase of alumina upon heating, while gibbsite transforms to ?-phase, maintaining the parent morphology.

Style APA, Harvard, Vancouver, ISO itp.

46

Loiko, Olessya P., Anne B. Spoelstra, Alexander M. van Herk, Jan Meuldijk i Johan P. A. Heuts. "An ATRP-based approach towards water-borne anisotropic polymer–Gibbsite nanocomposites". Polymer Chemistry 7, nr 20 (2016): 3383–91. http://dx.doi.org/10.1039/c6py00225k.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

47

Gardolinski, J. E. F. C., G. Lagaly i M. Czank. "On the destruction of kaolinite and gibbsite by phenylphosphonic, phenylphosphinic and phenylarsonic acids: evidence for the formation of new Al compounds". Clay Minerals 39, nr 4 (grudzień 2004): 391–404. http://dx.doi.org/10.1180/0009855043940142.

Pełny tekst źródła

Streszczenie:

AbstractKaolinite and synthetic γ-Al(OH)3 (gibbsite or hydrargillite) were reacted with phenylphosphonic, phenylphosphinic and 2-nitrophenol-4-arsonic acids. The products were studied by powder X-ray diffraction, transmission electron microscopy/selected area electron diffraction/ energy dispersive X-ray/Fourier transform infrared and simultaneous thermogravimetric/differential thermal analysis. The acids were not intercalated but, instead, easily destroyed the structure of the minerals. Lamellar Al phenylphosphonate and aluminium phenylphosphinate and phenylarsonate with polymeric linear-chain structures were formed from kaolinite. The reaction between gibbsite and the same acids yielded almost identical products. No evidence of formation of grafted kaolinite derivatives after the reaction with phenylphosphonic acid was found.

Style APA, Harvard, Vancouver, ISO itp.

48

Kitamura, Makoto, i Mamoru Senna. "Electrorheological properties of mechanically activated gibbsite". International Journal of Inorganic Materials 3, nr 6 (wrzesień 2001): 563–67. http://dx.doi.org/10.1016/s1466-6049(01)00068-x.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

49

Wijnhoven, Judith E. G. J. "Coating of Gibbsite Platelets with Silica". Chemistry of Materials 16, nr 20 (październik 2004): 3821–28. http://dx.doi.org/10.1021/cm049437m.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

50

MacKenzie, K. J. D., J. Temuujin i K. Okada. "Thermal decomposition of mechanically activated gibbsite". Thermochimica Acta 327, nr 1-2 (marzec 1999): 103–8. http://dx.doi.org/10.1016/s0040-6031(98)00609-1.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „Gibbstie”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych