Reduction of SnO2 Powder by Innovative Process of Pulsed-Discharged Spouted Bed

This study presents the first demonstration of Pulsed-Discharged Spouted Bed (PDSB) system, developed as a novel low-carbon smelting approach by integrating pulsed electrical discharging with spouted bed technology. The system was applied to the reduction of SnO2 powder at a repetition rate of 250 Hz with 22 kV of applied voltage. Combustion gas was introduced from bottom of the spouted bed as both reducing and fluidizing agents. The reduction times varied from 5 to 30 min. Phase and microstructure analyses confirmed the formation of metallic tin with porous morphologies, formed through melting and rapid solidification. Quantitative analysis via Rietveld refinement method indicated that the extent of reduction increased with longer reduction time. The reduction mechanism of SnO2 was presumed to follow the nucleation and growth of reduced phases.