REDUCING AGENT FOR THE SOLUBLE CHROMATE CONTENT OF CEMENT AND METHODS FOR THE PRODUCTION THEREOF

摘要

Producing reducing agent containing iron(II) sulfate comprises concentrating spent sulfuric acid and separating the sulfuric acid from the resulting precipitate. Independent claims are also included for: (a) reducing agent produced as above; (b) composition comprising cement, water-soluble metal sulfates and optionally water, containing 0.01-5 weight % of a reducing agent as above.