Exchangeable cations and exchange capacity of interstratified minerals with vermiculite layers

The changeable cations and the exchange capacities of industry vermiculite samples from the Weli Mine of Xinjiang, the Lingbao Mine of Henan Province and the Tongguan Mine of Shaanxi Province have been studied. It is found that the changeable cations in phlogopite_vermiculite samples from the Weli Mine are mainly Na + and Ca 2+ , followed in importance by Mg 2+ , K +, Ba 2+ and Sr 2+ , while the changeable cations in phlogopite_vermiculite samples from the Tongguan Mine are mainly Mg 2+ and Ca 2+ , with Na + and K + possessing the second place. The cation exchange capacities of phlogopite_vermiculite and chlorite_vermiculite increase with the content of vermiculite crystal layer in interstratified structure. The cation exchange capacities are commonly between 56.92 mmol/100 g and 98.95 mmol/100 g, only half of the maximal value of cation exchange capacity of vermiculite. The cation exchange capacities of phlogopite_vermiculite are negatively related to the content of K 2O and positively related to the content of Na 2O and CaO.