关键词: 地质聚合物;循环流化床粉煤灰;固化;Zn2+

Abstract: It was studied the immobilization of Zn 2+in circulating fluidize bed fly ash(CFA)based geopolymer.It was firstly studied the effect of Zn 2+on the strength of CFA based geopolymer,then the degree and mechanism of the immobilization via leaching test, SEM-EDS, XRD, and FT-IR.Zn2+was added in the form of Zn(NO3)2· 6H2O with amount of 0.5wt%, 1.0wt%, and 1.5wt%(weight percent of CFA).The experiments prove that CFA based geopolymer exhibited good compatibility, the matrix of geopolymers are dense with/without Zn dosage.The strength of blank sample is 85.2 MPa at 90 d,and strength of 1.5wt% Zn2+desaged sample is half of blank sample.It is also indicated that immobilization rates of geopolymers with large dosage of Zn 2+are all higher than 99%.It is assumed that Zn2+is immobilized by physical(ZnO phase)and chemical(new phase contained Zn)process.

Key words: geopolymer;circulating fluidized bed fly ash;immobilization;Zn2+