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

ABSTRACT

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.

KEYWORDS:

• Uranium
• Wadi Um Hamed
• Southwestern Sinai
• Egypt
• pug leaching efficiency
• Kinetic modeling

Author contribution statement

Hend A. Radwan: Performed the experiments; provided the essential analysis. Abeer A. Faheim: Analyzed and interpreted the data; writing-original draft preparation. Enass M. El- Sheikh: Conceived and designed the experiments; Analyzed and interpreted the data; writing-original draft preparation; writing-review and editing. Zeinab H. Abd El-Wahab: Conceived and designed the experiments; Analyzed and interpreted the data; writing-original draft preparation, writing-review and editing Mohamed A. Gado: Analyzed and interpreted the data, writing-original draft preparation.

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Funding

The authors confirm that this research did not receive any funding from any source. This research did not receive any funding from any source.