Decomposition of the potassic rocks by sub-molten salt method and synthesis of low silica X zeolite

In this work, the potassic rock (PR), an ore rich in aluminosilicate and alkali metal sources, was decomposed to active amorphous material in mild condition for the first time via sub‐molten salt method. Low silica X (LSX) zeolite was successfully synthesized using the amorphous precursor from PRs as starting material. The effects of temperature, time, and mass concentration of alkali on the decomposition of PRs powder, and the effects of molar ratios of SiO2/Al2O3 and H2O/(Na2O + K2O) on the synthesis of LSX zeolite, were investigated. X‐ray powder diffraction, scanning electron microscopy, energy dispersive X‐ray spectrometer, and Fourier transform infrared spectroscopy were employed to characterize the precursors and as‐prepared zeolites. The results indicated that the highly active amorphous precursor can be obtained in (Na, K)OH sub‐molten salt medium with 80% of mass concentration of alkali at 190 °C for 3.0 h. The LSX zeolite can be synthesized in 5.85Na2O:1.65K2O:Al2O3:(2.1–2.3)SiO2:(113–125)H2O system using the slurry obtained from the decomposition of PRs. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.