Uranium and Potentially Toxic Metals During the Mining, Beneficiation, and Processing of Phosphorite and their Effects on Ground Water in Jordan

Abstract

Representative samples were collected from various stages of phosphorite mining and beneficiation from the Al-Abiad and Al-Hasa mines in central Jordan and the Eshidiyya mine in southern Jordan. After open pit mining, the rock is crushed and dry-sieved to pass 12 mm in order to concentrate the ore. The sieved material is then agitated, washed with fresh water, and wet sieved to pass 4 mm. Samples were analyzed by ICP-MS for major elements and As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, U, V, and Zn. We found that throughout the above-mentioned processes, potentially toxic metals are partially removed from the ore. However, most of the contaminants are still retained within the final phosphorite product. The slime and slime water were analyzed; we found no effect of the slime water on the nearby ground water regime. The phosphorite is converted to fertilizer through reactions with sulfuric acid and then ammonia to produce diammonium phosphate (DAP). Gypsum is produced as a reject. The potentially toxic metals follow the behavior of P and are enriched by a factor of more than 1.5 in the DAP compared with the input phosphorite. The trace metal content in the phosphogypsum is very low.