Calcined clay (production)

The activity generating the emissions is calcined clay production. The reference product is calcined clay. The product "calcined clay" represents a pozzolanic material used in cement production. Calcined clay is produced by grinding and heating of natural clay between 500°C and 900°C. This thermal treatment (activation) converts crystalline clay materials to amorphous alumino silicates. When added to cement, amorphous silica reacts with calcium hydroxide formed during calcium silicate hydration from cement, forming C-S-H (hydrated calcium silicate). Secondary reactions may occur due to the reactive alumina content of calcined clay, forming also C-A-H (hydrated calcium aluminate). The addition of calcined clay to cement result in higher sulphate-resistance of the hydrated paste and in low permeability of the cementitious matrix, thus increasing the durability of cementitious products. The reference product amount is 1. The cut-off classification is allocatable product. The activity type is ordinary ordinary transforming activity. Please refer to the ecoinvent documentation here for full details: https://ecoquery.ecoinvent.org/3.11/cutoff/dataset/21472/documentation.