Mechanically Induced Reactivity of ZnFe2O4

ZnFe2O4 plays an important role as an adsorbent in the process of hot gas desulfurization. The influence of mechanical activation on the capacity S of ZnFe2O4 and on the following oxidation (regeneration) is investigated. The particle size is changed by mechanical activation in a characteristic way, and an inverse spinel structure is formed. With the mechanically induced degree of inversion the decomposition temperature of ZnFe2O4 is strongly diminished. The formation of the inverse spinel structure as well as the breakage of particle size lead to an essential increase of reactivity in the reaction with H2S. The following oxidation of the sulfurized zinc ferrite is also influenced by the primarily performed mechanical activation. For the investigations, ZnFe2O4 which had been treated in a planetary mill was used. The sulfurization was carried out with compressed powders. The characterization was performed mainly by X-ray diffraction (XRD), scanning electron microscopy (SEM), measurement of particle size and chemical analysis.