METHOD FOR THE REDUCTION OF THE SOLUBLE CHROMATE CONCENTRATION IN CEMENT, AND PREPARATION COMPRISING CEMENT AND WATER-SOLUBLE METAL SULFATES

摘要

The aim of the invention is to create an iron (II) sulfate-containing reducing agent which is to be used especially for reducing the chromate concentration in cement as well as a suitable method for producing said reducing agent. Said aim is achieved by a method for producing an iron(II) sulfate-containing reducing agent, according to which iron(II) sulfate-containing salts are crystallized from an iron(II) sulfate-containing sulfuric acid, and the obtained suspension (thick sludge) that comprises the iron(II) sulfate-containing salts and the sulfuric acid is reacted directly with iron and/or one or several iron compounds so as to obtain the iron(II) sulfate-containing reducing agent without separating the sulfuric acid from the iron(II) sulfate-containing salts.