Valorization of Phosphogypsum in Crushing-Sand- Phosphogypsum -Cement-Lime Solid Bricks Grade SW

Abstract Phosphogypsum (calcium sulfate) is a naturally occurring part of the process of creating phosphoric acid (H3PO4), an essential component of many modern fertilizers. For every tonne of phosphoric acid made, from the reaction of phosphate rock with acid, commonly sulfuric acid, about 3 t of phosphogypsum are created. There are three options for managing phosphogypsum: (i) disposal or dumping, (ii) stacking, (iii) use-in, for example, agriculture, construction, or landfill.The need to reduce solid waste volume has caused scientists to invent new construction materials produced using waste materials. In this study, phosphogypsum (PG) from Tunisia, crushing sand (CS), natural hydraulic lime (NHL), cement (C) and water are used in solid bricks production. phosphogypsum, crushing sand, natural hydraulic lime and cement were mixed, humidified, compacted and cured for periods of 28, 56 and 90 days. The compressive strength, density, water absorption, saturation coefficient and leaching test of the bricks were measured.The obtained results showed that CS-NHL-C-PG bricks are found to be conforming to physical requirements of clay or shale building brick grade SW (severe weathering), bricks intended for use when high and uniform resistance to damage caused by cyclic freezing is desired and where the brick may be frozen when saturated with water. Therefore, CS-NHL-C-PG bricks can replace the clay or shale brick grade SW.