title: Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore.
abstract: The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P=5 bar, T=120 °C and t=90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th).
authors.affiliation: Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland. Electronic address: g.zakrzewska@ichtj.waw.pl.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Zakrzewska-Koltuniewicz
authors.affiliation: Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
authors.forename: Irena
authors.initials: I
authors.lastname: Herdzik-Koniecko
authors.affiliation: Institute of Macromolecular Chemistry "Petru Poni", Aleea Grigore Ghica Voda, nr. 41A, 700487 Iasi, Romania.
authors.forename: Corneliu
authors.initials: C
authors.lastname: Cojocaru
authors.affiliation: Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
authors.forename: Ewelina
authors.initials: E
authors.lastname: Chajduk
mesh_terms: D007811:Lanthanum / Q000737:chemistry*; D008669:Metallurgy / Q000379:methods*; D019216:Metals, Heavy / Q000737:chemistry*; D059027:Recycling; D013464:Sulfuric Acids / Q000737:chemistry; D015018:Ytterbium / Q000737:chemistry*
chemical_list: D019216:Metals, Heavy; D013464:Sulfuric Acids; D007811:Lanthanum; D015018:Ytterbium; C033158:sulfuric acid
keywords: Leaching process; Response surface methodology; Uranium; Uranium ore