Investigating the reprocessing potential of abandoned zinc-lead tailings ponds: A comprehensive study using physicochemical, mineralogical, and 3D geometallurgical assessments

The Touissit-Boubker mine (TBM) in Morocco processed Zn and Pb-containing sulfides, resulting in substantial tailings stored in open facilities from 1962 to 2002. These tailings present both environmental challenges and economic prospects. Our study focuses on characterizing two primary TBM tailings impoundments, T12 and T17, and exploring their reprocessing potential. Samples were collected using reverse circulation drilling (RCD) method and analyzed for their physical, chemical, mineralogical, and environmental characteristics. Results informed a 3D block model estimating Zn, Pb, and Ag residual resources. Physical characterization shows that T12 exhibits a D-80 particle size of similar to 122.3 mu m, while T17 measures similar to 162.8 mu m. High Zn (similar to 2 %), Pb (similar to 1.5 %), and Ag (similar to 14 ppm) content is noted. Carbonates host mineralization, while major sulfides (pyrite, sphalerite, galena) show intense alteration. T12 displays higher sulfide liberation than T17, with modest liberation in larger fractions (>200 mu m) and increasing significance in smaller fractions (<50 m). Acid-base accounting confirms non-acidic residues due to abundant neutralizing minerals. The 3D block model estimates a total tonnage of 23.2 Mt, with 370 Kt of Zn, 140 Kt of Pb, and 160 thousand Kg of Ag. This study offers new insights into previously unexplored TBM tailings through drilling, suggesting the potential for significant economic and environmental benefits through reprocessing.