Template-free synthesis and characterization of K-phillipsite for use in potassium extraction from seawater

Abstract K-phillipsite was prepared using a hydrothermal method. Soluble glass and sodium aluminate were used as raw materials in the absence of an organic template. Investigations regarding the K + ions were conducted at room temperature to determine the ion-exchange capacity in the seawater sample and the selectivity coefficient of the mixed K + –Na + solution. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersion spectroscopy (EDS). The K + ion-exchange capacity is 51 mg/g in seawater and the selectivity coefficient is 75.1 in the mixed K + –Na + solution. The sample has a selectivity preference for K + , and therefore can be used to selectively extract potassium from seawater. The sample composed of Si, Al, K, Na, and O exhibits a cross-like shape and is a typical K-phillipsite structure.