Facile approach to synthesise zeolite X and its adsorption for Cu (II) and Zn(II)

Pure zeolite X was synthesised by a facile microwave‐assisted two‐step approach using high silicon fly ash, industrial‐grade reagents and tap water. First, a microwave heating method was conducted to extract silicon and the extract process was completed in 20 min, which was more effective. Then, a microwave approach was used to synthesis zeolite X. The whole analysis process is <2 h. The composition, phase structure, morphology, particle size distribution, specific surface areas and adsorption of heavy metal ions were evaluated comprehensively. The results show that single phase zeolite X with octahedral structure and an average diameter of 1.10 μm is obtained, and the Brunauer–Emmett–Teller surface area is 583.22 m 2 /g. Especially, the adsorption of Cu 2+ and Zn 2+ are as high as 81.33 and 67.21 mg/g, respectively. It can be concluded that the Letter provides a facile and fast method utilising high silicon fly ash to synthetise zeolite X, which is an excellent adsorbent to remove heavy metal ions.