Exploiting carboxymethyl cellulose-starch/alumina nano gel to eliminate Fe(III) from ore leachates of rare earth elements

Abstract

AbstractThe present study describes the development of a novel nano gel of Carboxymethyl Cellulose Starch and Alumina (CMC-St/Al2O3) to purify the leach liquor of rare earth elements (REEs) minerals from Fe(III), which is considered the most contaminating metal in the REE liquor. CMC-St/Al2O3 nano gel was recognized by different analytical techniques such as FT-IR, SEM, TEM, X-ray diffraction, particle size, and thermal analysis. In a batch study, the best conditions for purifying REE from Fe(III) contaminants using CMC-St/Al2O3 nano gel were determined. For an initial concentration of 100 mg L−1, 97.6% of Fe(III) was efficiently adsorbed onto CMC-St/Al2O3 after 15.0 min, pH = 2, and 25 °C. Due to the competition effect, the sorption efficiencies of the binary systems decreased to 68.4%, 72.97%, and 84.71% for the systems Fe(III)/La(III), Fe(III)/Sr(II), and Fe(III)/Cs(I), respectively. 99.9% of Fe(III) is eluted by 0.50 mol L−1 H2SO4. The sorption process was fitted with pseudo-second-order and the Langmuir model based on the error functions: Coefficient of determination (R2), Reduced Chi-square (χ2), The sum of square errors (SSE), and Corrected Akaike Information Criterion (AICc) as well as Residual error plots. The sorption process was spontaneous and exothermic. Finally, a CMC-St/Al2O3 nano gel was used to separate Fe(III) from the monazite liquor minerals and Sela leachate, mineralized from the Rosetta area and Gabal El Sela at Halaib environs, Egypt, with efficiencies of 89.03 and 92.7%, respectively.