Impact of silt chemical composition on deflocculation and coagulation of clay-rich paste
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Datum
2024-08-05Typ
- Journal Article
ETH Bibliographie
yes
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Abstract
This paper investigates the impact of the chemical composition of two silts, quartz and limestone, on the deflocculation/coagulation process for poured earth application. The driving mechanisms behind the evolution of the rheological behavior after the addition of sodium hexametaphosphate are highlighted through zeta potential measurementand the chemical changes with ICP-OES and 31P MAS NMR spectroscopy. The first results show that adding sodium hexametaphosphate into the quartz silt modifies its inter-particle forces through electrostatic repulsion forces induced by the adsorption of phosphate anions onto the quartz structure. For limestone paste, the deflocculation mechanism is affected by the dissolution of the calcite. This dissolution leads to a release of Ca2+ cations and an increase in the paste’s pH, reducing the paste deflocculation rate. These dissolved Ca2+ cations in the solution conduct to a partial coagulation making the delayed flocculation targeted initially with the addition of magnesium oxide less effective. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000672228Publikationsstatus
publishedExterne Links
Zeitschrift / Serie
Colloids and Surfaces A: Physicochemical and Engineering AspectsBand
Seiten / Artikelnummer
Verlag
ElsevierThema
Chemical properties; Rheology; Earth-concrete; Sodium hexametaphosphate; Deflocculation; coagulationOrganisationseinheit
03972 - Habert, Guillaume / Habert, Guillaume
ETH Bibliographie
yes
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