Preparation of Ammonium Tungstophosphate-Calcium Alginate Composite Adsorbent and its Adsorption Properties of Rubidium

A spherical composite adsorbent AWP-CaALG was prepared by the calcium alginate(CaALG) and ammonium tungstophosphate(AWP). The composite adsorbent was characterized by XRD, FT-IR and TG-DTG-DTA, it proves that the crystal structure of AWP isn't destroyed and the adsorption ability of the composite adsorbent can be retained up to 120 C. Effects of adsorbent dosage, adsorption time, pH, temperature, concentration of Rb and K were investigated. The results show that the adsorption capacity of composite adsorbent to rubidium is 20.64mg/g.The adsorption equilibrium is gained after 24h. When the concentration ratio of K to Rb is 16, the adsorption rate of Rb can still be up to 94.1% and the Rb/K separation coefficient is 86.