Study on Separation of Palladium From High Level Liquid Waste by Potassium Manganese Ferrocyanide

Glass solidification is a favorable treatment method for high level liquid waste (HLLW) from spent fuel reprocessing in industrial application, and the presence of palladium (Pd) in HLLW may seriously affect the glass solidification process. Ferrocyanide with a perovskite-like face-centered cubic structure has strong adsorption affinity towards Pd. In this study, silica-based composite KMnFC/SiO2 was prepared by pore crystallization of potassium manganese ferrocyanide (KMnFC) into porous SiO2. A series of characterization of the synthesized adsorbent were carried out such as XRD, TG-DTA, and SEM-EDS. It was verified that the adsorbent was successfully prepared and it has good Microscopic structure along with element distribution. A series of adsorption experiments were carried out. The adsorption of Pd is not easily affected by the concentration of nitric acid, which shows good acid resistance. Through the adsorption isotherm and adsorption kinetic curve, it is proved that the adsorption process of Pd by KMnFC/SiO2 is chemical monolayer adsorption. The adsorbent has strong adsorption selectivity for Pd in multi-ionic solution. Under the condition of complete adsorption of Pd, the adsorption rate of the adsorbent for other elements except Ru is less than 20%.