Comparison of Cation Exchange in Ganophyllite and [Na + Al]-Substituted Tobermorite: Crystal-Chemical Implications

Komarneni, Sridhar; Guggenheim, Stephen

doi:10.1180/minmag.1988.052.366.08

Cited by 13 publications

(4 citation statements)

References 13 publications

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“…The high selectivity of (Al+Na)-substituted tobermorite for cesium has been confi rmed by Komarneni et al (1987b), Komarneni and Guggenheim (1988), Tsuji and Komarneni (1989), Miyake et al (1989), who defi ned the detailed ion-exchange characteristics of (Al+Na)-and (Al+K)-substituted tobermorites for K + and Cs + cations, respectively, as regards their kinetic, equilibrium, and thermodynamic aspects. Tsuji et al (1991) determined the exchange properties of (Al+Na)-substituted tobermorites for Cs + and Li + cations, as well as their water sorption capacity as a function of the aluminum for silicon substitution.…”

Section: Technological Propertiesmentioning

confidence: 96%

Modular Microporous Minerals: Cancrinite-Davyne Group and C-S-H Phases

Bonaccorsi

2005

Reviews in Mineralogy and Geochemistry

103

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In this chapter, we illustrate and discuss two distinct groups of microporous phases: the cancrinite group and the C-S-H compounds of the tobermorite and gyrolite families. The compounds in the fi rst group present a three-dimensional purely tetrahedral framework with, apart from a single exception, Si:Al ratio equal to 1; in the mineralogical classifi cations they are included among feldspathoids and are generally “regarded …… distinct from zeolites, in part, at least, because of the presence of large volatile anions” (Coombs et al. 1998). The members of the second group are characterized by mixed frameworks built up by silicon (and aluminum) tetrahedra and calcium polyhedra. A common feature of both groups is the modular character of their frameworks, which are built up through various stacking ways of a single module (as in the minerals of the cancrinite-davyne family) and two or more modules as in the case of the C-S-H phases

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Section: Technological Propertiesmentioning

confidence: 96%

Modular Microporous Minerals: Cancrinite-Davyne Group and C-S-H Phases

Bonaccorsi

2005

Reviews in Mineralogy and Geochemistry

103

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“…The mineralogy of the C-S-H gels is complex; they have a morphology similar to the phyllosilicates and both their crystal structure and chemistry is variable. Examples of these so called gel minerals are tobermorite, gyrolite and reyerite (Komarneni and Guggenheim, 1988;Merlino, 1988a, b). The hydrated alumina minerals present are most usually in the form of hydrogarnet (3CaO.AI203.6H20) which is randomly dispersed through the paste along with a small amount of the mineral ettringite (Ca6A12(SO4)3.(OH)12.26H20).…”

Section: Mineralogical Composition Of Concretementioning

confidence: 99%

An applied mineralogical investigation of concrete degradation in a major concrete road bridge

1990

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A core of concrete taken from a major road bridge in the Strathclyde Region, Scotland, has been subjected to an applied mineralogical investigation, which involved stable isotope analysis, petrography, X-ray diffraction and scanning electron microscopy.The structure is actively undergoing severe degradation due to mineral growth which is related to chemical reactions between the concrete and pore fluid. The physical growth of minerals causes disfigurement and structural weakening.Pyrite and pyrrhotine hosted by dolerite aggregate appear to have been oxidized, providing sulphate for the deposition of ettringite and minor gypsum, in spheroidal cavities within the cement paste. The rainwater which passes through the structure mobilising sulphate from original gypsum in the paste and oxidizing the iron sulphides is also involved in the further leaching of elements from the cement paste and in the deposition of calcite. The isotopic values of calcites forming a crust on the concrete and a stalactite under the bridge are similar with ~13C= -19%o PDB and 618%~= +16%o SMOW. We suggest that atmospheric carbon dioxide was the carbon source. The carbon isotopic fractionation of -12%v from atmospheric carbon dioxide of 6t3C = -7%0, (O'Neil and Barnes, 1971) can best be explained as due to a kinetic fractionation related to the hyper-basicity of the pore water. The equilibrium formation temperature of about 45~ calculated from the oxygen isotope values and assuming a 61SO value of meteoric water of -8%0 SMOW, is considered unreasonable. The exceptionally low 6180 values are attributed mainly to reaction kinetics and the calcite inheriting its oxygen, two-thirds from atmospheric carbon dioxide and one third from the meteoric formation water (O'Neil and Barnes, 1971). A 61sO value of atmospheric carbon dioxide of +41%o SMOW and a 8180 value of meteoric water of -8%0 SMOW, lead to a calculated 61So value for the calcites of +10%o SMOW. The calcites analysed have a value of +16%o and this may be due to partial reequilibration towards a calculated value of +21%o for calcite in equilibrium with the meteoric water at 20~ K E V W O R D S: concrete deterioration, pet rography, ettringite, calcite, stable isotopes.

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“…4),5) The substituted tobermorites constitute a new family of inorganic ion exchangers and are characterized by their high selectivity for Cs cations, 6) with the Cs + selectively exchanging with Na + ions that are located in the interlayer. 5) This is why tobermorite can assume new functions when various ions are incorporated into the SiO 4 tetrahedral structure of tobermorite, such as selective scavenging of heavy metal ions. In this paper, we aimed to synthesize phosphorussubstituted tobermorite in which some Si 4+ ions in the interlayer were substituted for P 5+ (Fig.…”

Section: +mentioning

confidence: 99%

“…Tobermorite [Ca 5 Si 6 O 16 (OH) 2 ·4H 2 O], which is a kind of calcium silicate hydrate, is an important material in substances such as sand lime brick, ALC (Autoclaved Lightweight aerated Concrete), thermal insulating material and building boards. Tobermorite has a layered structure.…”

Section: Introductionmentioning

confidence: 99%

A novel synthesis of phosphorus-substituted tobermorite with calcium silicate hydrate

Kamei

Ihara

Ouchi

et al. 2014

J. Ceram. Soc. Japan

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Phosphorus-substituted tobermorite was easily synthesized by hydrothermal treatment using phosphorus-doped calcium silicate hydrate as a starting material. The crystalline phase of phosphorus-substituted tobermorite was identified by X-ray diffraction pattern analysis. The diffraction patterns of phosphorus-substituted tobermorite showed good agreement with the powder patterns in tobermorite. The single phase of tobermorite was confirmed. With increasing P/(P+Si) molar ratio, the lattice constants, i.e., the a and c-axis distances, of phosphorus-substituted tobermorite decreased. A maximum P/(P+Si) molar ratio of 0.10 was incorporated in the structure of tobermorite. Increasing the P/(P+Si) molar ratio was confirmed by the adsorption bands of HPO 4 2¹ and PO 4 3¹ groups by infrared adsorption measurement. The morphology was observed by scanning electron microscopy. The primary particles were thin plate-like crystals of about 0.1¯m (thickness) © 1.0¯m (width). The secondary particles were formed into approximate spheres of about 20¯m in size by aggregation of the thin plate-like crystals.

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Comparison of Cation Exchange in Ganophyllite and [Na + Al]-Substituted Tobermorite: Crystal-Chemical Implications

Cited by 13 publications

References 13 publications

Modular Microporous Minerals: Cancrinite-Davyne Group and C-S-H Phases

Modular Microporous Minerals: Cancrinite-Davyne Group and C-S-H Phases

An applied mineralogical investigation of concrete degradation in a major concrete road bridge

A novel synthesis of phosphorus-substituted tobermorite with calcium silicate hydrate

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