Effect of oxides and nitrates of lead on the sintering and densification of hydroxyapatite adsorbents

International audience ; The effect of lead oxide (PbO2) and lead nitrate [Pb(NO3)(2)] on sintering and densification of calcium hydroxyapatite (CaHAP) was studied using surface area reduction and shrinkage. The effect of concentration of these additives was studied using 2% and 10% (w/w) mixtures. The addition of (PbO2) and [Pb(NO3)(2)] accelerated the surface area reduction especially when the sintering was accompanied with densification. These additives lowered the densification temperature of HAP. Much lower final densification was achieved when 10% of these additives were used. The rate of densification of pure HAP had only one peak, whereas the mixture had two or more peaks indicating that the additives bring about multiple speeds in the densification process.