Sorption of uranium after carbonate leaching by low cost activated carbon–aluminum ferrisilicate composite

ABSTRACT

Uranium adsorption from its solutions using synthetic aluminium ferrisilicate (AFS) composite was investigated. Several experiments were carried out to evaluate the performance of the synthetic composite upon uranium sorption. Raffinate solution from Anchase site collected from several hydrometallurgical processes of uranium ores, its content precipitated by sodium hydroxide solution; then the precipitate treated with sodium carbonate to reduce the impurities and to prepare the feed solution of uranyl species UO₂(CO₃)₃⁻⁴. The optimum operating parameters were 1085 mg U L⁻¹, pH 1.7, 60 min contact time, 1/100 (wt/v) (S/A) ratio and at room temperature achieved 92.16% adsorption efficiency. Uranium elution from loaded composite was achieved using sodium carbonate solution of 0.25 mol L⁻¹ concentration, 45 min contact time and phase ratio 1/100 (wt/v). Adsorption kinetics and isotherm models data also determined to describe the nature of uranium sorption process. The SEM micrographs and FT-IR spectroscopy charts used to describe uranium-composite interaction. The sorption process agreed with both pseudo second-order reaction and Langmuir isotherm.

KEYWORDS:

• Uranium
• adsorption
• carbonate liquor
• desorption and pseudo second-order kinetic model

Disclosure statement

No potential conflict of interest was reported by the author(s).