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=Volume 11 - 2023 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=In this research, the recovery of uranium from the phosphate ore of Sheikh Habil-Iran mine using flotation/calcination-leaching processes has been investigated. The 75-150 μm phosphate ore particles size, sodium oleate as a collector with a concentration of 2000 g/ton of rock, pH=10, 5 min flotation time were obtained as optimum parameters of flotation by reverse method led to phosphate ore with a grade of 180 ppm UO2, 36.1% P₂O₅, 7.22% SiO2 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 UO2 and 31.9% P₂O₅. The L/S (liquid to solid ratio) =5, 3 M sulfuric acid concentration, 80°C temperature, and 5 h leaching time were obtained as optimum leaching parameters by response surface methodological approach. The efficiency of uranium recovery from phosphate ore pretreated by flotation and calcination methods were 84.2 % and 75.2%, respectively. The results indicated that the flotation has superiority over calcination as a pre-treatment method of phosphate ore of Sheikh Habil-Iran mine.