Processing of Gattar Pilot Plants Tailing Piles for Removing Residual Uranium, Eastern Desert, Egypt

Abstract

Gattar uranium mineralization in eastern desert is of comparatively low grade containing about 300 ppm uranium. A pilot plant for leaching of uranium and produce commercial yellow cake was set up in 2000. A huge amount, of residues resulted during leaching process with uranium assay about 85 ppm uranium. The present study was performed mainly to leach of uranium from the already present residues resulted from previous uranium vat leaching from gattar uranium mineralization. Vat leaching, is a static process in which the mineralized granite is crushed, disposed in vats and irrigated with a sulfuric acid solution with proper concentration to leach the uranium. The flowsheet adopted is of sulfuric acid leach-ion exchange process, the leaching was optimized to leach uranium with low acid concentration. Uranium is finally recovered by precipitation with sodium hydroxide. The uranium leaching from the residues (tailings) were examined by re-crashed coarse size via a batch experiments as a function of contact time, grind size, L/S ratio and lixiviant concentration at ambient temperature. To verifying the feasibility of uranium leaching in large-scale applications, column leaching of uranium was carried out. The results indicate the feasibility of treating the residue of the vat leaching through dynamic leaching. recovery of about 83% of uranium in the residue was obtained using a 1.5%w/w consumption of acid, grain size is ˂10 mm and total liquidsolid ratio is 0.8 m 3 /t.

Techno-economic study on reagents consumption during uranium leaching, a case study: Gattar pilot plant, Egypt

“…The addition of fresh solution and recycling into the leaching process has an immediate positive impact on the uranium extraction rate at various sprinkling intensities in all time periods. The addition of fresh solution is more successful during the time periods of (14-21), (24)(25)(26)(27)(28)(29)(30), and (37-41) days, as shown in Fig 5.…”

“…Uranium was recovered by acid leaching from the waste tailing of uranium mineralization in (G-II) after re-crashing the uranium mineralized ore to -10 mm, using 20 g/l sulphuric acid solution. The leachability of uranium in the column under acid leaching conditions reached a maximum value of 83.9 [26].…”