title: Why amorphous FeO-SiO2slags do not acid-leach at high temperatures.
abstract: It has been shown previously that amorphous FeO-SiO2slags are not amenable to high pressure oxidative acid leaching - unlike their crystalline counterparts. Independent studies of glass and silicate mineral dissolution at ambient conditions suggest that acid attack can be hindered by the formation of a passive silica layer. The current work extends this finding to the case of high temperature dissolution of amorphous FeO-SiO2slags by providing evidence for the formation of a passive silica layer within slag particles under high pressure oxidative acid leaching conditions (250°C, 70g/L initial H2SO4, 0.62MPa [90psi] O2). Based on the percolation model of glass dissolution, a mechanism of amorphous slag leaching is proposed.
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada.
authors.forename: Ilya
authors.initials: I
authors.lastname: Perederiy
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON, M5S 3E5, Canada. Electronic address: vladimiros.papangelakis@utoronto.ca.
authors.forename: Vladimiros G
authors.initials: VG
authors.lastname: Papangelakis
keywords: Amorphous silicate; Amorphous slag; High pressure oxidative acid leaching; Incongruent dissolution; Slag dissolution mechanism