Once date stones are separated, washed with distilled water, they were dried to 105 C° overnight. A grinding operation was then carried out leading to the obtention of granular particles having a diameter less than 4mm.The resulting product was subjected to calcinations in a closed crucible at 600C° during two hours [11]. The chemical activation was achieved by mixing tow aqueous solutions of ZnCl2 (2N) and H3PO4 (3N) [12, 13] .The mixture was heated up to 110 C° for one hour. The rinsing water was