3D Modeling and Resources Estimation of Coal Old Piles in Jerada Mine, Oriental Morocco

Besides being a cause of environmental problems, tailings and waste rock can also be potential sources of valuable minerals and metals. The Jerada mine (JM) in the eastern region of Morocco operated by Moroccan Coal Mines (MCD) for coal extraction is one of the many overburden mines in Morocco with large amounts of overburden since 2000 without rehabilitation plans. The main objective of this study is the coupling between 3D model as a tool to estimate the ore resources and evaluate the economic potential of coal mine waste rock (CMWR) piles and metallurgical study in the valorization of abandoned rejects. The study will initially focus on the 3D modeling of the CMWR piles and the estimation of their resources based on drill sampling to highlight the vast quantities of CMWR piles deposited on site. Physical–chemical characterization was performed using XRF, XRD, SEM, total C-S measurement and QEMSCAN. Eight CMWR piles (T01, T02, T03, T04, T05, T06, T07 and T08) were the target of our work to uncover the huge tonnages of coal stored in these stockpiles. The 3D model blocks show a total volume of 8.64 Mm3 of waste, which corresponds to 15.3 Mt on the piles. Chemical analyses have highlighted the presence of significant concentrations of carbon, T08 with nearly 50% of the tonnage 7.36 Mt and a %C that is close to 8.5 wt%; T01 and T02 with 5.31 Mt and a %C of 12.75 wt% and T03, T04, T05, T06 and T07 regrouping 1.84 Mt. It should be noted that the %S in the T08 approaches 2 wt% with a high degree of oxidation, which may represent a source of acid mine drainage (AMD). The high carbon content and the large tonnages obtained indicate that the waste can be reused by re-exploitation or reused in other fields to limit and reduce its environmental impact.