| abstract |
The present invention relates to a pozzolanic admixture containing ammonia-laden fly ash, method for making the pozzolanic admixture and method for controlling ammonia gas (NH 3 ) emission from cementitious slurries using the pozzolanic admixture. The associated hypochlorite and ammonia reaction produces monochloramine and chloride salts at relatively low concentration levels harmless to concrete and concrete applications. The resulting monochloramine and chloride salt products are stable and do not dissipate into the air, thereby, eliminating odorous emission that is produced from cementitious slurry containing untreated ammonia laden fly ash. This invention relates to the method of adding hypochlorites (OCl − ) in the form of calcium hypochlorite—Ca(OCl) 2 , lithium hypochlorite—LiOCl, sodium hypochlorite NaOCl or trichloro-s-triazinetrione—C 3 N 3 O 3 Cl 3 to the ammonia-ladden fly ash at dosage levels, based on ammonia concentration in ash and stoichiometry, for a complete or partial oxidation of ammonia to eliminate, or respectively reduce, ammonia gas evolution from the high pH cementitious slurries. |