Abstract: An association complex formed in a liquid environment from a metal-based chromium (VI) reducer and a non-lignosulfonate-based complexing agent is introduced into cement clinker or hydratable cement particles. In preferred embodiments, the formation of the association complex provides storage stability to the chromium reducer within the cement, such that the level of chromium (VI) after water is added to the cement remains less than 2 ppm for certain duration after mixing with water and without the necessity for further additions of chromium reducer during said duration (e.g., 26-84 or more days after addition). Compositions having the association complex are also described.

Abstract: Exemplary compositions and methods for reducing hexavalent chromium in cementitious compositions involve the use of a liquid additive composition, comprising stannous chloride. Along with the stannous chloride may be used at least one co-additive comprising an antioxidant, oxygen scavenger, or mixture thereof, and/or at least one agent comprising a cement grinding aid, cement quality improver, or mixture thereof.

Abstract: Exemplary compositions and methods for reducing hexavalent chromium in cementitious compositions involve the use of a liquid additive composition, comprising stannous chloride. Along with the stannous chloride may be used at least one co-additive comprising an antioxidant, oxygen scavenger, or mixture thereof, and/or at least one agent comprising a cement grinding aid, cement quality improver, or mixture thereof.

Abstract: A chromium VI reducing composition comprising particles of solid material selected from the group consisting of iron (II) sulfate and tin sulfate, the particles being substantially uniformly dispersed within a liquid carrier. Methods for modifying hydratable cementitious materials using the chromium reducing composition are also disclosed and provide advantages over dry powder or dissolved forms of sulfate compositions when used in cement manufacturing.

Abstract: Methods and compositions involving hexavalent chromate-reducing agents, particularly hydroxylamine, hydrazine, or their salts or derivatives, for use in cement compositions and cement processing.

Abstract: Methods and compositions involving hexavalent chromate-reducing agents, particularly hydroxylamine, hydrazine, or their salts or derivatives, for use in cement compositions and cement processing.