Removal of SO2 from flue gas using blast furnace dust as an adsorbent

To control the SO 2 emission and achieve the target of “waste controlled by waste”, a novel desulfurization method with blast furnace dust slurry was proposed. The effects of reaction temperature, oxygen concentration, and solid–liquid ratio on SO 2 removal efficiency were investigated. The optimal conditions were reaction temperature of 35 ℃, oxygen concentration of 10 vol.%, and solid–liquid ratio of 0.5 g/300 mL. Under the optimal conditions, the desulfurization efficiency reached 100% for 4 h. Response surface methodology (RSM) results showed that oxygen concentration significantly influenced the SO 2 removal efficiency. Finally, the possible desulfurization mechanism of blast furnace dust was proposed based on the EDX, XRD, SEM–EDS, ICP, and IC. The blast furnace dust (main components are CaZn 8 (SO 4 ) 2 (OH) 12 Cl 2 ·(H 2 O) 9 , Mn 6.927 Si 6 O 15 ·(OH) 8 , ZnO, Fe 2 O 3 ) reacted with H + to form Zn 2+ , Fe 3+ , and Mn 2+ which shows a key effect on the SO 2 liquid catalytic oxidation. This study provides a promising, feasible, and low-cost desulfurization technology by reusing blast furnace dust.