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Comparison of the efficiency of zinc stabilisation by direct incorporation to clinker or by addition during mixing



Author(s): D. Damidot
Paper category: conference
Book title: Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. van Breugel, Wei Sun and Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Publication year: 2012
Pages: 65 - 75
Total Pages: 11
Language: English


Abstract: Large quantities of zinc can be stabilized by a solidification/stabilization process based on the incorporation of zinc to Portland cement clinker contrarily to conventional processes based on the addition of zinc cations during mixing. A Portland cement doped with 3% Zn by mass showed adequate setting time and compressive strength. This was mainly due to the formation of Ca6Zn3Al4O15 at the expense of C3A. The kinetics of hydration of Ca6Zn3Al4O15 is fast and its low solubility restricts the zinc concentration of the aqueous. As a consequence a strong retardation of calcium silicate hydration is not observed. The incorporation of heavy metal in Portland cement clinker appears to be a promising method to immobilize waste containing high amounts of a given heavy metal. This method is also very flexible as the threshold limit of the amount of heavy metal that can be added to the clinker can be changed depending on the specified requirements.


Online publication: 2012-07-05
Publication Type: full_text
Public price (Euros): 0.00