PROCESS FOR PREPARING PORTLAND CEMENT WITH REDUCED CONTENT OF HEXAVALENT CHROMIUM

摘要

The invention relates to a process for preparing a Portland cement having a content of hexavalent chromium of 2 ppm, at the most. According to the invention, the process consists in additivating the cement with 1...3% zeolitic composition obtained by mixing 70...80% zeolite having a fineness of about 3% residue on the sieve of 90 μ m, 20...30% industrial ferrous sulphate and 10% pure ascorbic acid as powder.