Résumé - Abstract
Sedimentary phosphate extraction in open pit operations generates large volumes of waste rocks (WR). The later correspond mainly to the overburden, slabs and interlayers, which are mixed and deposited on surface as WR piles. The present study investigates the potential valorization of each WR lithology based on their geological and geotechnical properties. The WR and soil samples were collected from drill cores and tranches performed in the unexploited Ben Guerir OCP mine in Morocco. The characterization results indicate compressive strength values ranging from 3 to 56.5 MPa for the limestones, 13 – 69 MPa for the flints, and 1 - 19.5 MPa for marly-limestone, with an average cohesion and friction angle of 1.46 MPa and 41°, respectively. The soils characterization showed an average plasticity index (PI) of 50% (according to the methylene blue value of 7.13) which classify them plastic and clayey soils. Based on the obtained results, it appears that these WRs can be valorized as substitute of natural raw materials in several sectors such as civil engineering, ceramics and cement. New extraction mode is suggested to favor progressive reclamation and circular economy.