Utilization of phosphogypsum in CO2 mineral sequestration by producing potassium sulphate and calcium carbonate

Abstract

Industrial activities for the phosphoric acid production cogenerate a large amount of phosphogypsum waste, emitting significant quantities of toxic gas in the surrounding environment. In the context of recovered materials to handle greenhouse gases more precisely CO2 as one of the most toxic gases responsible for the global climate change, an affordable and effective method for CO2 mineral sequestration using phosphogypsum by-product is developed in this investigation. The obtained results show the high efficiency of portlandite Ca(OH)2 resulting from the dispersion of phosphogypsum in alkaline potash solution followed by releasing of potassium sulphate as a co-product. Furthermore, the carbonation experiments show a total conversion of the Ca(OH)2 to calcium carbonate as final product at ambient temperature and atmospheric pressure. The approach suggested in this research shows permanent and safe solution to face the storage of phosphogypsum and carbon dioxide, which were causes a serious problems for the ecosystems and human health. As well as, the valorization of the co-products in different fields, e.g., potassium sulphate as a fertilizer while calcium carbonate has various uses as raw material for construction.

Keywords

• Potassium sulphate
• Phosphogypsum
• CO2 sequestration
• Mineral carbonation
• Calcium carbonate