Synthesis and Influence Factors Study of 4A Molecular Sieve via Halloysite

A 4A Zeolite molecular sieve was successfully synthesized with a facile hydrothermal method. We used Yunnan soft kaolin as raw material, purified Halloysite and synthesized a 4A Zeolite molecular sieve directly. On this basis, we studied the effect of alkali concentration, solid-liquid ratio, aging temperature and crystallization temperature on the calcium ion exchange performance of 4A Zeolites. The results showed that the calcium ion exchange rate of 4A molecular sieve could reach 326 mg CaCO3/g when it was synthesized in a condition of 2 mol/L of molecular alkali, 60 degrees C aging temperature and 90 degrees C crystallization temperature. The x-ray diffraction results indicated that the molecular sieve prepared under optimum conditions was of good crystallinity. The field emission scanning electron microscopy results showed that the morphologies of synthesized samples prepared under optimum conditions was a cube structure.