Title :

Development of a stoichiometric magnesium potassium phosphate cement (MKPC) for the immobilization of powdered minerals

Author(s) :

De Campos, M. [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
DAVY, Catherine [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Djelal, Nora [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Rivenet, Murielle [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Garcia, J. [Auteur]

Journal title :

Cement and Concrete Research

Volume number :

142

Pages :

106346

Publication date :

2021-04

ISSN :

00088846

HAL domain(s) :

Chimie/Matériaux

English abstract : [en]

Ordinary Portland Cement (OPC)-based materials are not systematically adapted for immobilizing industrial hazardous waste, e.g. for aluminium powder or plutonium waste sludge. In such case, Magnesium Potassium Phosphate ...
Show more >Ordinary Portland Cement (OPC)-based materials are not systematically adapted for immobilizing industrial hazardous waste, e.g. for aluminium powder or plutonium waste sludge. In such case, Magnesium Potassium Phosphate Cements (MKPC) represent an interesting alternative. The originality of this research is to develop a formulation of a MKPC paste for hazardous waste immobilization, which incorporates a maximum amount of such waste, preferably in powdered form. To this purpose, a stoichiometric MKPC paste is selected, and its properties are improved by powdered waste addition. Firstly, the physico-chemical mechanisms generating expansion in stoichiometric MKPC paste are analyzed. Swelling is attributed to a pH gradient in the paste, due to the progressive sedimentation of MgO particles in the fresh mix. Secondly, over-stoichiometric MgO is replaced by varying amounts of minerals simulating the waste, of different mineralogy and granulometry, in order to achieve sufficient workability and no swelling. An optimal formulation is proposed, which incorporates powdered fly ash at a fine-to-cement mass ratio (F/C) of 1. Its mechanical performance and endogenous dimensional changes are comparable to typical over-stoichiometric pastes, and they stabilize between 7 and 28 days.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

CNRS
Centrale Lille
ENSCL
Univ. Artois
Université de Lille

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Chimie, matériaux et procédés pour un nucléaire durable (CIMEND)

Submission date :

2022-03-24T09:02:23Z
2024-02-06T18:41:55Z