Restoration of Cation-Exchange Capacity of Nickel Montmorillonite by Hydrothermal Treatment

Abstract

Cation-exchange capacity (CEC) was decreased by heating nickel montmorillonite. Ion exchange of nickel montmorillonite, hydrothermally treated, in a ZrOC12.8 H2O solution revealed the restoration of the decreased CEC. The degree of the restoration varied with the conditions of hydrothermal treatment, such as temperature and time. For example, the CEC of nickel montmorillonite heated at 300 °C for 1 h was restored to be O.89 meq/g by hydrothermally treating at 150 °C for 5 h, and to 1.09 meqfg at 200 °C for 5 h. The observed results indicate that the CEC of nickel montmorillonite can be decreased by heating the clay and restored by treating hydrothermally the clay.