This study concerns the analysis of the incorporation of phosphogypsum (PG) into the fired clay bricks. In Tunisia, for several years, a set of phosphoric acid production factories have produced PG in large quantities (approximately 10 million tons per year). Currently, in Sfax (Center-East of Tunisia), the PG is stored into piles in the vicinity of the factory, by dry or wet process. The storage of PG, even though presenting a low radioactivity, causes pollution to the watertable and to the soil (due to the infiltration of acid and heavy metals). After characterization, the Tunisian PG, which plays the part of a grease-remover, was introduced into the clay bricks with different mass percentages of 0%, 5%, 15%, 25%, 30% and 40%. The study involved physical, chemical, mechanical and environmental tests on the obtained bricks.
The obtained results showed that with 30% of PG incorporation, the bricks successfully satisfied the standard requirements. The increase of the percentage of PG resulted in a decrease in the mechanical strengths of these mini-bricks, but it is still higher than the standards limits. The 25% ratio of substitution appeared to be the most effective considering the performed tests.