ABSTRACT
The binder most commonly used for immobilization of toxic and radioactive waste is Portland cement (Atkins and Glasser, 1992; Glasser, 1992; Roy, 1992; Hills et al., 1993; Macphee and Glasser, 1993; Bhatty et al, 1996; Miller and Klemm, 1997). Some species that may be constituents of toxic wastes, such as Zn , Pb , borates, phosphates, citrates, or some saccharides, may slow down or even prevent the hydration process if present in concentrations that are too high. Conversely some substances, such as CaCl2 and other chlorides, may accelerate hydration and make handling of the fresh mix difficult. To ensure proper setting and hardening it may be necessary to reduce the concentration of such interfering substances in the system to an acceptable level.
