Interactions between lead and different binders

The present study describes the interactions between lead nitrate, representative of soluble lead compounds, and seven cements based on either ordinary Portland cement (OPC) or ground-granulated blast furnace slag (GGBFS). Suspensions of cements contaminated by lead nitrate were investigated by means of electrical conductivity, powder X-ray diffraction, Fourier Transform-infrared spectrometry, scanning electron microscopy, inductively coupled plasma-optic emission spectroscopy, and ionic chromatography. Pastes cast with these contaminated cements were submitted to leaching tests. The presence of fly ash was not favourable toward lead fixation and the best retention of lead was obtained with GGBFS-based cements. The most efficient binder was SPINOR, an ultrafine GGBFS-based cement.