Immobilisation of heavy metal in cement-based solidification/stabilisation: a review.

The interfacial chemistry of solidification/stabilization of metals in cement and pozzolanic material systems

Influence of lead, zinc, iron (III) and chromium (III) oxides on the setting time and strength development of Portland cement

Preparation of iron rich cements using red mud

The aim of this work is to investigate the effect of the addition of Cu, Cd, Ni, Pb and Zn nitrate salts on the compressive strength of a CEM I Portland cement. Concentrations of 0.018 or 0.18 mol/kg of cement of each trace element were tested. After 2 days age, the compressive strength was reduced by various extents by addition of heavy metals, with the exception of Ni. This difference is due to a delay in tricalcium silicate hydration (C3S) as shown by an isothermal calorimetry test. Trace elements also influence the 28-days compressive strength, whereas the measured degree of hydration of these cement pastes is the same. As shown by scanning electron microscopy and X-ray diffraction, Cu and Pb are predominantly absorbed in the calcium silicate hydrate gel (C–S–H) while Cd, Ni and Zn are mainly precipitated as hydroxides within the intergranular porosity. Thus, trace elements precipitated as hydroxides have only a slight effect on the compressive strength. In contrast, Cu and Pb cause an increase in mechanical resistance by changing the C–S–H nanometric assembly and its density.

Managing trace elements in Portland cement – Part I: Interactions between cement paste and heavy metals added during mixing as soluble salts

The effects of several heavy metal oxides on the formation of ettringite and the microstructure of hardened ettringite

A reply to J. Bensted's discussion of the paper “the effects of several heavy metal oxides on the formation of ettringite and microstructure of hardened ettringite”☆

K. Akama

Papers

The effects of several heavy metal oxides on the formation of ettringite and the microstructure of hardened ettringite

A reply to J. Bensted's discussion of the paper “the effects of several heavy metal oxides on the formation of ettringite and microstructure of hardened ettringite”☆