Additive for reduction of water-soluble Cr(VI) content in cement, a process of its preparation, cement or dry plaster mixture containing the additive and a process of its preparation

摘要

The additive for reduction of water-soluble Cr(VI) content in cement or in dry plaster mixtures comprising from 10 to 75 % by weight of iron sulphate hydrate and to 100 % by weight of natural zeolite is added to clinker during grinding, whereby it is possible to reduce Cr(VI) content in cement to the value lower than 2 ppm. The subject of invention comprises also cement and dry plaster mixtures containing this additive for reduction of water-soluble Cr(VI) content.