비소의 지오폴리머 고형화 특성

Abstract

The objective of this study is to investigate the immobilization properties of arsenic in solidification process using geopolymer binder. Metakaolin and fly ash were used as prime materials for geopolymer that was also called as activated metakaolin cement (or Si + Al cement). The immobilization of As in geopolymer was found to be very limited regardless of the oxidation state of As and the mixing ratio of As to the binders. These results may be ascribed to the low Ca contents in prime materials used and the structural property of geopolymer formed. It was generally accepted that As was immobilized into C-S-H (calcium silicate hydrates) via precipitation and sorption, when it was solidified with ordinary portland cement and/or lime. When Ca(II) or Fe(III) was used as stimulating agents, the As leaching was reduced by 15 ~ 25% than that of control experiment. These limited improvements of As immobilization might be resulted from the extremely high pH in geopolymer reaction.