Optimization of the leaching process for uranium recovery and some associated valuable elements from low-grade uranium ore

• Published in: International journal of environmental analytical chemistry Vol. 103; no. 17; pp. 5259 - 5281
• Main Authors: Radwan, Hend A., Faheim, Abeer A., El-Sheikh, Enass M., Abd El-Wahab, Zeinab H., Gado, Mohamed A.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 20.12.2023; Taylor & Francis LLC
• Subjects: Acid rain; Amberlite (trademark); Ammonia; Anion exchange; Anion exchanging; Anions; Chemical precipitation; Chemical reactions; Copper; Curing; Curing (processing); Egypt; Energy dispersive X ray analysis; Energy value; Heavy metals; Hydroxides; Kinetic modeling; Kinetics; Leaching; Metals; Optimization; Oxalic acid; Oxides; Precipitates; Precipitation; pug leaching efficiency; Recovery; Sedimentary rocks; Shale; Shrinking core model; Southwestern Sinai; Sulfuric acid; Sulphuric acid; Uptake; Uranium; Uranium ores; Wadi Um Hamed; Work study; X ray analysis; X-ray spectroscopy
• ISSN: 0306-7319; 1029-0397
• DOI: 10.1080/03067319.2021.1936513

The present work study the acidic pug leaching technique for U-extraction in addition to some associated valuable metals from a collected technological sample of ferruginous shale from Wadi Um Hamed, Um Bogma Formation, Abu Thor locality, southwestern Sinai, Egypt. A representative sample of the ore material was found to assay 9000, 700 and 4000 ppm of REEs, U and Cu, respectively, in addition to some major and minor oxides. Numerous steps were performed upon the studied sample to process parametric studies such as sulphuric acid concentration (50-150 kg/ton), curing time (0.5-5.0 h) and curing temperature (50-150°C) in order to find the optimum condition. Under the optimal conditions (150 kg/ton sulphuric acid for 4.0 h at 150°C), the first step involved Fe-removal as hydroxide from the pregnant leaching solution using pH adjustment method followed by U-recovery through sorption/desorption and precipitation steps with the help of Amberlite IRA-400-Cl (strongly basic anion exchange resin) via column method. In the third step, REEs- recovery from U-free effluent was investigated using oxalic acid precipitation process while Cu-recovery by precipitation as hydroxide with ammonia solution took place. Energy dispersive X-ray analysis performed on the different obtained precipitates showed successive recovery of all above mentioned elements. Finally, U-uptake data were subjected to kinetic modelling. The kinetics of leaching reaction followed shrinking core model with chemical reaction as controlling mechanism based on activation energy value.