Nouveaux adsorbants préparés par activation chimique des schistes bitimineux marocains par l’acide phosphorique : influence des conditions expérimentales sur les propriétés des adsorbants

Adsorption of uranium and thorium on new adsorbent prepared from Moroccan oil shale impregnated with phosphoric acid

“…The raw material used in this work is Moroccan oil shale of Tarfaya (layer R3). This material is composed from the organic matter chemically linked to the mineral matter essentially formed by calcite, dolomite, silicate and clays (table 1) [13][14][15].…”

“…Elemental analysis of this precursor (Table 2) shows the presence of C, O, H, S, Si, Fe, Al and other elements [13]. The precursor R3H, a particle size of 80-100µm in diameter, was mixed with the phosphoric acid at 80%, with a weight ratio H 3 PO 4 /precursor = 3.…”

“…The precursor R3H, a particle size of 80-100µm in diameter, was mixed with the phosphoric acid at 80%, with a weight ratio H 3 PO 4 /precursor = 3. The choice of the activating agent and the weight ratio was dictated by results obtained after many studies trials in the laboratory and according to our previous studies [13][14][15]. The activation experiments were performed under various conditions to obtain the optimal condition for activation.…”

“…The mixture was heated in furnace under various atmosphere gases (nitrogen or air) at different temperatures (250-450°C) after preprocessing at 120°C in oven under air [13]. Thermally treated product, referred by P, was washed with distilled water in a Soxhlet extractor, to eliminate excess acid and soluble matter then dried at 110°C.…”

“…The precursor was obtained by elimination of the carbonates in the native rock by 6N HCl. The obtained powder (R3H) was mixed with 30 N phosphoric acid and treated in different conditions [13]. The change of microtexture between the precursor and the obtained adsorbents was examined by different analytical methods.…”