Preparation of a uranium leach liquor from a refractory ore using nitric acid solution

ABSTRACT

The preparation of uranium leach liquor from refractory ore using nitric acid solution has been investigated. The particle size, nitric acid concentration, solid-to-liquid ratio, shaking time, temperature, and diffusion leaching model all have significant effects on the process. The optimum process operating parameters were particle size: 1 mm; nitric acid concentration: 50 g/l; liquid to solid ratio: 5: 1; room temperature and leaching time: 4 h. Under these experimental conditions, the leaching efficiency of uranium was about 83%. By using shrinking core model to determine the leaching model and the rate-determining step we found that temperature, concentrations of nitric acid and the mesh size are the main factors that influence the leaching rate.

KEYWORDS:

• Uranium
• leaching
• refractory ore
• nitric acid HNO₃
• shrinking core model

Acknowledgments

The author would like to express its deep thanks to Prof. Dr. Hisham F. Ali and Ass. Prof. Dr. Mohammed H. Taha for their useful scientific discussions during the preparation of the experimental work for this research [27].

Disclosure statement

No potential conflict of interest was reported by the author.