Effects of inorganic constituents on thermal and mechanical properties in several types of phosphogypsum: a case study of Gafsa-site (TN)

• Published in: Euro-Mediterranean journal for environmental integration 2023-03, Vol.8 (1), p.29-39
• Main Authors: Krichen, M., Jraba, Abderraouf, Ksibi, Hatem, Elaloui, Elimame
• Format: Article
• Language: English
• Subjects: Acids; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Building materials industry; Civil engineering; Compressive strength; Construction; Earth and Environmental Science; Earth Sciences; Environmental Chemistry; Environmental Management; Environmental Science and Engineering; Image processing; Light microscopy; Mechanical properties; Moisture content; Optical microscopy; Original Paper; Phosphates; Phosphogypsum; Phosphoric acid; Physical properties; Radioactivity; Raw materials; Stress-strain curves; Thermal conductivity; Thermal properties; Thermodynamic properties; Uranium; Waste Management/Waste Technology; Waste Water Technology; Water content; Water Management; Water Pollution Control
• ISSN: 2365-6433; 2365-7448
• DOI: 10.1007/s41207-022-00339-x

The management of Tunisian phosphogypsum (PG) is a difficult environmental problem to solve, considering the huge quantities produced per year (10 Mt wet PG per year). In recent years, the problems of storage and valorization of PG in Tunisia have become one of the main concerns of local research. Several application attempts have been highlighted in the literature, mainly in the field of civil engineering. Estimation of the physical properties of different PG materials, including thermal conductivity, is a crucial step to characterizing PG materials for efficient reuse. It has been shown that improvement in the quality of PG as an additive or as a main material depends on the locality of the ore and the industrial processes used to produce phosphoric acid. However, there is high variability in the reported values of the thermal properties of PG around the world. Therefore, the properties of the Tunisian material can lead to a satisfactory integration in the construction field. Since the samples prepared in this study with different proportions of water showed adequate compressive strength, the products could be suitable for applications such as building bricks. Reflected light microscopy as well as image processing with ImageJ revealed closely distributed crystal structures, indicating good adhesion. The effect of the water content from the stress–strain curves and, thus, the drying mode of the samples seem to be influential parameters for the material stiffness.