Transformation Behaviors of U(VI) on Irons Hydroxide Colloids

The presence of the colloid will affect uranium heap leaching. The objective of this study was the examination of the ability of colloid retardation to uranium by irons hydroxide colloids simulated heap leaching process. Batch studies have been carried by observing the effects of pH, contact time, uranium concentration. Iron hydroxide colloids can exist stably at pH 1.5-3.0. The size of the colloid samples is between 20 nm and 1000 nm. The sorption equilibrium was attained at 24 h. The load uranium capacity on iron hydroxide colloids are between 2.43×10-3 and 3.84×10-3 mmol/mol. The colloid morphology of before and after loaded uranium were identified using S-4800 scanning electron microscopy (SEM/EDS). The load uranium capacity on iron hydroxide colloids is least at pH=2, it implies that the appropriate pH of uranium heap leach is 2.0 on the point of retardation of colloid to uranium migration.