Zeolite formation by hydrothermal treatment of waste solution from selectively leached kaolinite

Abstract Zeolite formation has been achieved by hydrothermal treatment of the waste solution from selective leaching by 2 M NaOH solution of kaolinite calcined at 1000°C for the preparation of mesoporous γ-Al 2 O 3 . The spent leaching solution was hydrothermally treated at 100°C and at 150°C for 12–72 h. The initial product (hydroxysodalite) is converted to zeolite P after longer reaction times.