Thermal evolution of nickel chlorite-like phase derived from montmorillonite.

A nickel chlorite-like compound was derived from montmorillonite by intercalation of nickel hydroxide layer between the silicate layers. The hydroxide layer was dehydrated in a temperature range of 300° to 400°C, and remained as the oxide between the silicate layers. The structural OH groups of montmorillonite arc converted into the oxide ions by the reaction with the remained nickel oxide layer in a temperature range of 400° to 500°C. This conversion leads to a pronounced thermal stabilization of the silicate layers up to 800°C, though the untreated montmorillonite suffers a destructive dehydration starting at temperatures about 650°C