AUTHOR=Abdeshahi A. , Outokesh M. , Nejad D. Ghoddocy , Zare M. Habibi , Sadeghi M. H. 

TITLE=Recovery of uranium from phosphate ore in the Sheikh Habil-Iran mine: part I— multivariable optimization of leaching process using the response surface method

JOURNAL=Frontiers in Chemistry

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1292620

DOI=10.3389/fchem.2023.1292620

ISSN=2296-2646

ABSTRACT=<p>In this research, the recovery of uranium from the phosphate ore of the Sheikh Habil-Iran mine using flotation/calcination-leaching processes has been investigated. A 75–150 μm phosphate ore particle size, sodium oleate as a collector with a concentration of 2,000 g/ton of rock, pH = 10, and 5 min flotation time were obtained as the optimum parameters of flotation using the reverse method, leading to phosphate ore with a grade of 180 ppm UO<sub>2</sub>, 36.1% P₂O₅, 7.22% SiO<sub>2</sub>, and CaO/P₂O₅ = 1.23. The optimum calcination parameters were selected as 100 μm phosphate ore particles size at D80, 900°C temperature, and 2 h heating time, which resulted in phosphate ore with a grade of 173 ppm UO<sub>2</sub> and 31.9% P₂O₅. An L/S (liquid to solid ratio) = 5, 3 M sulfuric acid concentration, 80°C temperature, and 5 h leaching time were obtained as the optimum leaching parameters using the response surface methodological approach. The efficiency of uranium recovery from phosphate ore pre-treated by flotation and calcination methods was 84.2% and 75.2%, respectively. The results indicated that flotation has superiority over calcination as a pre-treatment method of phosphate ore in the Sheikh Habil-Iran mine.</p>