Latest trends in clay activation

摘要

The cement industry has become one of the largest GHG polluters in the world [1]. Most of the 2.9 billion t CO_2 emissions are generated in clinker manufacturing from the calcination/decarbonation of limestone (carbon carbonate), the key raw material. Today, in the cement production, these process emissions account for about 60% of total CO_2 emissions, while still about 40% arise from the combustion of fuels required to generate the process heat (direct emissions) and from electricity generation for the grinding mills and other equipment (indirect emissions). Anyhow, the gross CO_2 emissions per ton of cementitious material are in a decline, mostly due to alternative fuels and the substitution of clinker in cement. According to the Cement Sus-tainability Initiative (CSI) of the World Business Council for Sustainable Development (WBCSD) and the IEA (International Energy Agency) the gross CO_2 emissions per ton cement have fallen from 752 kg/t in 1990 to about 653 kg/t in 2010 and 540 kg/t in 2018.