Extraction of silver from AgI-bearing iron ore sintering dust by thiourea leaching
Year: 2026
Type: article
Abstract: As a typical solid waste from ferrous metallurgy, iron ore sintering dust (IOSD) may contain considerable silver, whose occurrence state often complicates its extraction. This study investigated the extraction of silver from IOSD by thiourea leaching, where AgI was the main silver-bearing phase. Given that the silver–thiourea (TU) complex [Ag(TU) 3 ] + remains stable under acidic conditions according to the thermodynamic analysis, the effects of thiourea concentration, leaching time, leaching temperature, and stirring rate on the silver extraction from IOSD pretreated by water leaching were investigated. It was found that increasing thiourea concentration, leaching time, and stirring rate promoted the silver leaching efficiency by enhancing the complexation driving force, reaction progress, and interfacial mass transfer, respectively, whereas elevating temperature exhibited a limited effect as the increased thiourea decomposition at higher temperatures counteracted the kinetic acceleration. Under the optimal conditions of thiourea concentration of 10 g/L, leaching temperature of 45 °C, leaching time of 60 min, and stirring rate of 400 rpm at initial pH 1.5, a remarkable silver leaching efficiency of 94.48% was achieved. The redox evolution of the leaching system was characterized by in-situ oxidation-reduction potential (ORP) monitoring and the whole process was found to follow a non-oxidative and coordination-promoted dissolution mechanism. The results are expected to provide useful theoretical and technical insights into the recovery of silver from IOSD and other relevant metallurgical solid wastes.
Institutions: Central South University, Baogang Group (China)
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,350
Award: G7129033144
OpenAlex ID: W7212359281