Solidification of "Cement-Glass"

Abstract

Cement-glass, which is a mixture of sodium silicate (kNa₂O•mSiO₂•nH₂O), silicon phosphate (P₂O₅•2SiO₂) and cement, was developed to solidify radioactive waste pellets in containers. The optimum molar ratio of Si(OH)₄, NaOH and P₂O₅•2SiO₂ was found to be 2:2:1, based on compressive strength measurement of solidified samples. The compressive strength of solidified sodium silicate with silicon phosphate was increased when the amount of solidified SiO₂ per unit volume was increased by reducing the water content. Cement-glass had a higher Cs distribution factor than ordinary Portland cement.