title: Formation mechanisms of Fe3-xSnxO4by a chemical vapor transport (CVT) process.
abstract: Our former study reported that Fe-Sn spinel (Fe3-xSnxO4) was easily formed when SnO2and Fe3O4were roasted under CO-CO2atmosphere at 900-1100 °C. However, the formation procedure is still unclear and there is a lack of theoretical research on the formation mechanism of the Fe-Sn spinel. In this work, the reaction mechanisms between SnO2and Fe3O4under CO-CO2atmosphere were determined using XRD, VSM, SEM-EDS, XPS, etc. The results indicated that the formation of Fe3-xSnxO4could be divided into four steps: reduction of SnO2to solid phase SnO, volatilization of gaseous SnO, adsorption of gaseous SnO on the surface of Fe3O4, and redox reaction between SnO and Fe3O4. During the roasting process, part of Fe3+in Fe3O4was reduced to Fe2+by gaseous SnO, and meanwhile Sn2+was oxidized to Sn4+and entered into Fe3-xSnxO4. The reaction between SnO2and Fe3O4could be summarized as Fe3O4+ xSnO(g)→ Fe3-xSnxO4(x = 0-1.0).
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Zijian
authors.initials: Z
authors.lastname: Su
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Liu
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Yingming
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Li
authors.affiliation: School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang