الوصف

The current phosphate mine wastes at El-Liffiya-Maghrabi sector, Abu-Tartur plateau, are represented by low-grade phosphorites along with overburden of glauconite and shale deposits. Although phosphorites contain sufficient concentrations of the valuable plant-nutrients (e.g. 18.29 wt% P₂O₅, 35.29 wt% CaO, and 14.43 wt% SO₃), it holds unallowable levels of some toxic heavy metals (e.g. 45.8 ppm As, 26.1 ppm Cd, 180 ppm V, and 52.3 ppm U). This in turn constrains the potential agronomic application of such deposits as being nature-disturbing materials. On the other side, contents of such metals in the overburden are lower than phosphorites (e.g. 9.1–15.1 ppm As, 0.2–2.4 ppm Cd, 0.4–1.2 ppm U, and 102–172 ppm V). Consequently, mixing phosphorite with its overburden was followed as a procedure to decline the contents of heavy metals and to valorize the nature-disturbing mine wastes as a potentia