Physical and Chemical Characterization of Iranian Natural Kaolin and Synthesis of Clinoptilolite Zeolite by Hydrothermal Process

Methods of mineral adsorbents recognition and surveying methods of making new adsorbent are essential due to importance of applying effective and inexpensive methods for wastewater treatment. Zeolite and Kaolin are among the conventional adsorbents which have been used for removing many pollutants. In this study, synthesis of zeolite materials by hydrothermal transformation of natural Iranian kaolin was investigated at 850ºC for 2 hr.
In this study, physical properties of kaolin was determined using different experiments such as laser particle size analyzer (PSA) and chemical properties was studied by SEM, XRD and FTIR methods. Synthesis of Zeolite materials by hydrothermal transformation of natural Iranian kaolin in NaOH solutions was investigated at 850ºC for 2 hr.
The experiment results showed; kaolin density = 2.608 gr/Cm3, particle size = 0.37-52.76 µm, specific surface area (BET) = 9.17± 0.0748 m2/g and pHpzc = ~8.5. SEM results showed flak shape for kaolin particle. X-ray diffraction illustrated quartz as a major phase of the kaolin. The presence of AL and Si functional groups was proved by FTIR. SEM results demonstrated raised surface and irregular shape for the zeolite particles. XRD and FTIR results confirmed the crystalline structure of quartz and presence of SiO2 and AL3 and Si-AL functional groups, respectively
The results revealed that application of hydrothermal method using calcinations process in the presence of NaOH is an appropriate and inexpensive method for zeolite production and this synthetic zeolite has the highest similarity to Clinoptilolite.