Procedure for peparar cement with a low content of hexavalent chromium.

摘要

A method for preparing a cement, when hydrated, contains an amount of chromium less than 2 ppm hexavalent comprising the step of adding to the finished cement or to a processing intermediate thereof, disulphides of ammonium, alkali metals, alkaline and / or polysulphides of ammonium, alkali metals or alkaline earth metals.