Co-processing of Grinding Sludge as Alternative Raw Material in Portland Cement Clinker Production
Titel:
Co-processing of Grinding Sludge as Alternative Raw Material in Portland Cement Clinker Production
Auteur:
T. Punmatharith M. Rachakornkij A. Imyim M. Wecharatana
Verschenen in:
Journal of applied sciences
Paginering:
Jaargang 10 (2010) nr. 15 pagina's 1525-1535
Jaar:
2010
Inhoud:
This research aimed to investigate the potential of partial substitution of cement raw meal with grinding sludge as an alternative raw material in Portland cement clinker production. Cement raw mixtures with up to 3% raw mix replacement were put through a burning process in a high-temperature furnace. One reference and three modified mixtures, containing 1, 2 and 3% dry weight of grinding sludge were examined. XRF analysis results showed that CaO, SiO2, Al2O3 and Fe2O3 in ordinary cement raw meal were within typical concentration ranges. The grinding sludge had high concentrations of iron, cadmium, chromium and nickel and was consequently classified as a hazardous waste. High Fe2O3 made the grinding sludge a good candidate for alternative raw material. Higher replacement of grinding sludge was found to improve burnability, reduce formation of major of cement compositions (dicalcium silicate, C2S and tricalcium aluminate, C3A), lower in silica and alumina ratios, but promote the formation of tricalcium silicate (C3S) and tetracalcium aluminateferrite (C4AF). Microstructural analysis of the synthesized Portland clinker revealed that the grinding sludge promoted formation of secondary C2S as well as caused color change of C3S. Thai regulatory leaching procedure was performed on the synthesized clinker and mortar samples. The concentrations of heavy metals in the leachate were found below the limits. Moreover, the maximum substitution of grinding sludge was found to be 2% of grinding sludge. Thus, this sludge has potential applications as an alternative raw material in cement production.
Uitgever:
Asian Network for Scientific Information (provided by DOAJ)