Process for producing a cement clinker at low temperature

Abstract

The invention provides a process for producing a cement clinker comprising: (i) mixing one or more starting materials providing each at least one or more of CaO, SiO, AlO, and FeO; and, optionally, SO, to form a raw meal comprising CaO, SiO, AlO, and FeO; and, optionally, SO, wherein the molar ratios among the aforementioned oxides is given by Formula I: (CaO)(SiO)(AlO)(FeO)(SO), wherein: 'a' is comprised from 0.05 to 1, 'b' is comprised from 0.01 to 0.6, “c” is comprised from 0.001 to 0.25, and “d” is comprised from 0 to 0.3 and wherein at least 35% (p/p) of the starting materials of the raw meal have a critical microwaves absorbance temperature (Tc) comprised from 15 to 650° C. and a critical microwaves absorbance time (tc) comprised from 1 min to 1 h; (ii) heating the raw meal by irradiating with microwaves during 15 min to 3 h to reach a sintering temperature comprised from 300 to 950° C.; (iii) maintaining the microwave sintering temperature of step (ii) during 1 min to 3 h by further irradiating with microwaves; and (iv) cooling the clinker obtained in step (iii).