Life Cycle Assessment of Alternative Road Base Materials: the Case of Phosphogypsum

• Published in: IOP conference series. Earth and environmental science 2019-08, Vol.323 (1), p.12092
• Main Authors: Saadé-Sbeih, M, Feraille, A, Alaoui Soulimani, A
• Format: Article
• Language: English
• Subjects: Acid production; Coastal waters; Coastal zone; Environmental impact; Environmental management; Fertilizers; Heavy metals; Life cycle analysis; Life cycle assessment; Life cycles; Phosphogypsum; Phosphoric acid; Sustainability; Waste management
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/323/1/012092

Phosphogypsum (PG) is the most abundant by-product generated by the phosphate fertilizer industry. Formed during the production of phosphoric acid from natural phosphate rock, PG is mostly disposed in stacks or released into coastal regions' waters. Due to the expected increase in the world PG production - currently estimated to be around 250 Mt per year - and the environmental impacts of actual waste management scenarios, there is a call for a paradigm shift, by considering PG not as a waste but as a resource. About 15% of the total PG production is nowadays used as fertilizer, retarder, road base material or building material. The load of radionucleids and heavy metals contained in PG however questions the sustainability of such valorization routes. This paper aims to compare the environmental impacts of different PG valorization scenarios through life cycle assessment. Based on Moroccan conditions for phosphoric acid production, it discusses the key parameters influencing the assessment as well as assumptions regarding the allocation of emissions and resource use over PG and phosphoric acid.