Song M.,Tsinghua University |
Song M.,Key Laboratory for Solid Waste Management and Environment Safety Ministry of Education of China |
Liu J.,Tsinghua University |
Liu J.,Key Laboratory for Solid Waste Management and Environment Safety Ministry of Education of China |
And 2 more authors.
Journal of Material Cycles and Waste Management | Year: 2014
With the air pollution control standards getting increasingly stricter, gas cleaning processes with higher capture efficiency of pollutants in iron-ore sintering gas cleaning were applied in China, and fine residue, an emerging hazardous waste containing high content of heavy metals as well as Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were produced. Disposal of the residues in secure landfill after adequate solidification/stabilization was the main solution. The feasibility of solidification/stabilization process using cement and chelating agent was investigated in this study. Leaching concentration of Lead (Pb) and Selenium (Se) exceeded the identification limit, and the content of PCDD/Fs was rather low, so the immobilization of Pb and Se was the main objective of solidification/stabilization. The result showed that leaching concentrations of Pb in the solidified products were lower than 5 mg/L when the addition of cement was 20 % or chelating agent 1 %. However, leaching concentration of Se fluctuated between 0.6 and 0.8 mg/L even the cement addition reached 45 % or chelating agent 3 %. Geochemical modelling using PHREEQC indicated that Se in the residue mainly existed as highly soluble SeO4 2−. © 2014 Springer Japan.