title: Procedure to use phosphogypsum industrial waste for mineral CO2 sequestration.
abstract: Industrial wet phosphoric acid production in Huelva (SW Spain) has led to the controversial stockpiling of waste phosphogypsum by-products, resulting in the release of significant quantities of toxic impurities in salt marshes in the Tinto river estuary. In the framework of the fight against global climate change and the effort to reduce carbon dioxide emissions, a simple and efficient procedure for CO(2) mineral sequestration is presented in this work, using phosphogypsum waste as a calcium source. Our results demonstrate the high efficiency of portlandite precipitation by phosphogypsum dissolution using an alkaline soda solution. Carbonation experiments performed at ambient pressure and temperature resulted in total conversion of the portlandite into carbonate. The fate of trace elements present in the phosphogypsum waste was also investigated, and trace impurities were found to be completely transferred to the final calcite. We believe that the procedure proposed here should be considered not only as a solution for reducing old stockpiles of phosphogypsum wastes, but also for future phosphoric acid and other gypsum-producing industrial processes, resulting in more sustainable production.
authors: Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Seville, Spain.
authors: C
authors: C
authors: Cárdenas-Escudero
authors: V
authors: V
authors: Morales-Flórez
authors: R
authors: R
authors: Pérez-López
authors: A
authors: A
authors: Santos
authors: L
authors: L
authors: Esquivias
mesh_terms: D002133:Calcium Sulfate / Q000737:chemistry*; D002245:Carbon Dioxide / Q000302:isolation & purification*; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007220:Industrial Waste / Q000032:analysis / Q000517:prevention & control*; D010758:Phosphorus / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D013030:Spain
chemical_list: D007220:Industrial Waste; C077769:phosphogypsum; D002245:Carbon Dioxide; D010758:Phosphorus; D002133:Calcium Sulfate