Abstract
The aim of this study is to develop the recovery system of heavy metals in fly ash from an ash meltingfurnace. Though some recovery processes of heavy metals from fly ash have been already proposed, they variedaccording to the composition of fly ash. In this study, we firstly performed sequential extraction for fly ash to understandthe effect of the chemical state of heavy metal in fly ash on recovery process. As the results of sequential extraction, aneffective recovery process was proposed.
In the first extraction, 45wt% of Pb in fly ash was extracted by mixing the 20g of fly ash with 200m L distilled waterfor lh at the rotation of 90rpm. In the second extraction 80wt% of Zn in fly ash was extracted by mixing the residue ofthe first extraction with 1mol/L CH3COONH4 for lh at the rotation of 90rpm. We obtained two final products with 50% of Zn and 67% of Pb by precipitating heavy metals in the extracts respectively. The weight of the residue decreasedfinally to 16wt% compared with the weight of the original fly ash.
