Microwave effect on ion-exchange and structure of clinoptilolite

The effect of microwave irradiation on the ion exchange degree and structure of clinoptilolite mineral has been examined in comparison with the conventional heat treatment in waterbath. Clinoptilolite-rich mineral from the Western Anatolia, Bigadic region was used for the experimental study. The mineral was mainly clinoptilolite (80–85%) and additionally, quartz (5–10%), and analcime + mordenite (< 5%) were found as co-existing minerals. The mineral was stable towards dehydration and maintains its original structure up to 800 °C. The BET and Langmuir surface areas of the sample were found to be 22 and 17 m2/g for N2 adsorption and 28 and 22 m2/g for Ar adsorption, respectively. For the exchange experiments, clinoptilolite rich mineral was treated with 1 N NaCl salt solution both in a microwave unit and waterbath for 10 min, 1 h and 2 h at 80 °C. The waterbath treatment with the same conditions was continued for two additional weeks. The chemical composition of the parent and Na-exchanged forms of the clinoptilolite rich minerals were analyzed by using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Microwave treatment was found to be more rapid and effective for ion exchange compared to conventional waterbath treatment. Additionally, the XRD results reveal that microwave irradiation has zero effect on the structure of the clinoptilolite rich mineral.