The Potential of Grinding in Increasing the Reactivity of Bottom Ash for use as SCM
DOI:
https://doi.org/10.46421/entac.v20i1.6042Keywords:
Bottom Ash, Fly Ash, Portland Cement, Supplementary Cementitious Materials, GrindingAbstract
Reducing CO2 emissions from the cement industry is crucial, and a key strategy involves lowering the clinker factor by increasing the content of supplementary cementitious materials (SCMs) in cement. Currently, blast furnace slag and fly ash (FA) are the main SCMs used, but their quantities are insufficient to meet climate targets in the coming decades. Therefore, it is necessary to seek alternative sources of SCMs. Bottom ash (BA), generated in thermoelectric plants and currently disposed of in industrial landfills in Brazil, emerges as a promising alternative. This study investigates the impact of grinding on the reactivity of BA. BA was ground in a ball mill (380 rpm) for different periods (10 to 60 minutes) and its reactivity was evaluated in comparison to FA using the R³ method with isothermal calorimetry. The results show an inverse linear relationship between particle diameter and BA reactivity. After 20 minutes of grinding, BA achieved the reactivity of FA, surpassing it with grinding times of 30 to 60 minutes. Thus, considering its chemical composition and reactivity, the use of bottom ash as a supplementary cementitious material is promising.
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