Process for the heat treatment of natural clays and / or zeolites

摘要

A process for the heat treatment of natural clays and / or zeolites, wherein the clay and / or the zeolite is calcined in the calcining zone in a temperature range of 350 to 1050 ° C under reducing conditions and trivalent iron is at least partially converted into divalent iron and / or divalent iron present in the starting material remains in this valence state and then the clay and / or the zeolite is cooled in a cooling zone.