An insight into mineral waste pulp for sulfur dioxide removal: A novel synergy-coordination mechanism involving surfactant

Abstract

• A novel and efficient process for promoting the elimination of SO 2 was developed. • The efficiency of ore pulps desulfurization was enhanced by 23.13 ± 4.09% with SDS. • Counter-ions and co-ions affected ore pulp dispersion and foam film stability. • Influenced mechanism of surfactant on ore pulp desulfurization was revealed. Desulfurization by ore pulp has proved to be an attractive pathway, by which sulfur dioxide (SO 2 ) removal from fuel gas and mineral acid leaching can be realized simultaneously in hydrometallurgy. However, the weak reaction between alkalescent ore pulp and the weak acid SO 2 aqueous solution, and large mass transfer resistance caused by the heterogeneity of pulp seriously impeded their applications. Increasing the dispersion and surface tension of pulp by surfactants is an effective way, which has been rarely reported. Herein, the influence of the representative cationic, anionic and nonionic surfactants on desulfurization performance by ore pulp containing electrolytic manganese residue (EMR), phosphate ores (PO), and copper tailings (CT) were investigated systematically. Due to the high performance of anionic surfactant in enhancing the dispersion of ore pulp, reducing the surface tension of pulp, and increasing foaming, the desulfurization efficiency of EMR, PO, and CT was increased by 21.56 ± 3.25%, 23.13 ± 4.09%, and 20.54 ± 1.01%, respectively. However, the charge neutralization of cationic surfactant and the non-dissociation of nonionic surfactant made their promotion lower than the anionic one. Further, the co-ions and counter-ions in pulp affected the performance of surfactants in desulfurization. Besides, transition metal ions catalyzed the oxidation of SO 2 and promoted the formation of H 2 SO 4 .