Process for separating the components of hardened concrete waste for producing recycled cement

(22) 23.02.2021

(43) 16.03.2023

(57) The present invention lies within the field of construction materials and concerns a process for separating the constituents of hardened concrete, with the aim of extracting the cementitious fraction to be used in the production of thermoactivated recycled cement, involving the essential steps of: (a) crushing the concrete waste; (b) screening the crushed material to separate material smaller than about 1 mm; (c) fragmenting material larger than 1 mm; (d) screening material smaller than 1 mm into various granulometric fractions; (e) high intensity magnetic separation of the material; (f) grinding of the cementitious fraction resulting from the magnetic separation in the previous step to a size that allows its efficient thermoactivation; and (g) obtaining a thermoactivated recycled cement.

(71) Instituto Superior Tecnico, Lisboa (PT); Instituto Politecnico de Setubal, Setubal (PT); Universidade do Porto, Porto (PT)