Implementation of sonochemical leaching for preparation of nano zero-valent iron (NZVI) from natural pyrite mechanochemically reacted with Al

Nano zero-valent iron (NZVI) was prepared using sonochemical leaching of the obtained powder from mechanochemical treatment of natural pyrite with metal powder of aluminum. At the first step, the Fe-Al₂S₃ compound was prepared via co-milling of natural pyrite and aluminumin a planetary ball mill. At second step, the aluminum sulfide was separated from the Fe-Al₂S₃ compound to produce NZVI using sonochemical leaching method with 1.5 M NaOH solution for 45 min at 80 °C. The results from XRD and XRF analysis revealed that more than 83% of aluminum sulfide was extracted during separation step and iron phase remained as a main constituent phase in the leaching residue (NZVI). The FE-SEM images and the BET surface area verified that the produced NZVI has particles size less than 100 nm with BET surface area of 116 m²/g.