关键词: 含砷废渣;地聚物;固化;冻融

Abstract: A geopolymer based on phosphorous slag and fly ash was used to solidify the arsenic-containing waste residue discharged from a nonferrous metallurgical plant.The resistance to freeze-thaw of the solidified forms was researched and the change of mass,compressive strength and arsenic leaching ratio under different thawing methods and different freeze-thaw cycles were investigated.Meanwhile,the morphology and phase compositions of solidified form were analyzed by means of X-ray diffraction (XRD) and Scanning electron microscopy (SEM).The results show that the mass of the solidified form changed little and the compressive strength decrease,but it still higher than 15 MPa after 15 frezzing-thawing cycles.The arsenic leaching ratio increase,but the arsenic leaching ratio only reach to 0.27％ after 15 freezzing-thawing cycles.It is showed by XRD and SEM that the mineral phase in the solidified form have not changed basically and no fragmentation existed after freeze-thaw cycles.This show that the solidified form has stronger freeze-thaw resistance.

Key words: arsenic-containing waste;geopolymer;solidification;freeze-thaw