title: Morphological changes during enhanced carbonation of asbestos containing material and its comparison to magnesium silicate minerals.
abstract: The disintegration of asbestos containing materials (ACM) over time can result in the mobilization of toxic chrysotile ((Mg, Fe)3Si2O5(OH)4)) fibers. Therefore, carbonation of these materials can be used to alter the fibrous morphology of asbestos and help mitigate anthropogenic CO2 emissions, depending on the amount of available alkaline metal in the materials. A series of high pressure carbonation experiments were performed in a batch reactor at PCO2 of 139atm using solvents containing different ligands (i.e., oxalate and acetate). The results of ACM carbonation were compared to those of magnesium silicate minerals which have been proposed to permanently store CO2 via mineral carbonation. The study revealed that oxalate even at a low concentration of 0.1M was effective in enhancing the extent of ACM carbonation and higher reaction temperatures also resulted in increased ACM carbonation. Formation of phases such as dolomite ((Ca, Mg)(CO3)2), whewellite (CaC2O4·H2O) and glushinskite (MgC2O4·2H2O) and a reduction in the chrysotile content was noted. Significant changes in the particle size and surface morphologies of ACM and magnesium silicate minerals toward non-fibrous structures were observed after their carbonation.
authors.affiliation: Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA.
authors.forename: Greeshma
authors.initials: G
authors.lastname: Gadikota
authors.affiliation: Institute of Geosciences and Earth Resources - National Research Council, Pisa, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Natali
authors.affiliation: Institute of Geosciences and Earth Resources - National Research Council, Pisa, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Boschi
authors.affiliation: Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA; Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA; Lenfest Center for Sustainable Energy, Columbia University, 500 West 120th Street, New York, NY 10027, USA. Electronic address: ap2622@columbia.edu.
authors.forename: Ah-Hyung Alissa
authors.initials: AH
authors.lastname: Park
mesh_terms: D001194:Asbestos / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D017633:Magnesium Silicates / Q000737:chemistry*; D013696:Temperature; D018505:Waste Management
chemical_list: D017633:Magnesium Silicates; D001194:Asbestos; D002245:Carbon Dioxide
keywords: Asbestos containing material; Carbonation; Ligand; Magnesium silicate; Morphological changes