Life cycle assessment to produce LC³ cements with kaolinitic waste from the Amazon region, Brazil
Euler Santos Arruda, Nállyton Tiago de Sales Braga, Márcio Santos Barata
Abstract
The present study was developed with the aim of determining the environmental impact of the production process (cradle-to-gate) of Limestone Calcined Clay Cements (LC³) produced with kaolinitic residues from the Brazilian Amazon, through a life cycle assessment (LCA). For this purpose, 6 LC³ mixtures were prepared from combinations of clinker, gypsum, and metakaolin: limestone filler in the ratios 2:1, 1.5:1 and 1:1, replacing 45 and 60% Ordinary Portland Cement (OPC). The LC³ cements were compared with two cements already produced industrially. CO2 emissions associated with the transportation of raw materials to produce LC³ cements increased significantly, especially for the cements where 60% clinker was substituted, with CO2 emissions up to 2-3 times higher than for the reference cements. Despite that, LC³ cements showed a reduction in energy demand of up to 28% and total CO2 emissions of up to 38% compared to commercial cements. In this way, the conducted study demonstrates the high environmental potential of LC³ cements with kaolinitic residues from the Amazon region for reducing pollutant emissions in the manufacture of cement.