Reagent-assisted decontamination of sandy soil by activation leaching at 80–140°C

A three-step processing scheme is proposed for decontaminating sandy soil: water-gravity separation of a fine fraction, reagent-assisted processing, and repeated water-gravity separation of a fine fraction. Reagent-assisted decontamination was conducted using 1–4 M sulfuric acid with liquid/solid phase ratio 1/1 over 7 h at 110–140°C in an autoclave. A sandy fraction, comprising 77.6 wt.%, was separated by water-gravity separation from the initial soil whose specific activity was ~1100 kBq/kg. Its reagent processing and repeated water-gravity separation made it possible to lower the specific activity of ¹³⁷Cs to 1.1 ± 0.2 kBq/kg.