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.sub.2, AI.sub.2O.sub.3, and Fe.sub.2O.sub.3; and, optionally, SO.sub.3, to form a raw meal comprising CaO, SiO.sub.2, AI.sub.2O.sub.3, and Fe.sub.2O.sub.3; and, optionally, SO.sub.3, wherein the molar ratios among the aforementioned oxides is given by Formula I: S(CaO).sub.1(SiO.sub.2).sub.a(Al.sub.2O.sub.3).sub.b(Fe.sub.2O.sub.3).sub.c(SO.sub.3).sub.d, wherein: a is comprised from 0.05 to 1, b is comprised from 0.1 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).

The present invention relates to the use of belite calcium sulfoaluminate ternesite cement for the production of components and buildings by means of 3D printing and a method for the production of components and buildings by the 3D printing of belite calcium sulfoaluminate ternesite cement.

The present invention relates to the use of belite calcium sulfoaluminate ternesite cement for the production of components and buildings by means of 3D printing and a method for the production of components and buildings by the 3D printing of belite calcium sulfoaluminate ternesite cement.

The invention provides novel carbonatable calcium silicate compositions and carbonatable calcium silicate phases that are made from widely available, low cost raw materials by a process suitable for large-scale production. The method of the invention is flexible in equipment and production requirements and is readily adaptable to manufacturing facilities of conventional cement. The invention offers an exceptional capability to permanently and safely sequesters CO.sub.2.

The invention relates to a method for producing cements by hydrothermally treating a starting material containing sources of CaO and SiO.sub.2 in an autoclave at a temperature of 100 to 300 C., and tempering the obtained intermediate product at 350 to 700 C., wherein water formed during tempering is dissipated by grinding the intermediate product and/or tempering taking place under a continuous gas stream. The invention also relates to cements obtained in this manner, hydraulic binders therefrom, and building materials which contain said binders.

Activators for supplementary cementitious material, comprising reactive belite, obtainable by hydrothermal treatment of a starting material, which contains sources for CaO and SiO2 in an autoclave at a temperature of 100 to 300 C. and tempering the obtained intermediate product at 350 to 495 C., hydraulic binders based on the supplementary cementitious material above, and by a method for activating the supplementary cementitious material by adding reactive belite obtainable by hydrothermal treatment of a starting material which contains sources for CaO and SiO.sub.2 in an autoclave at a temperature of 100 to 300 C. and tempering the obtained intermediate product at 350 to 495 C. and the use of the reactive belite containing material as activator.

Activators for supplementary cementitious material, comprising reactive belite, obtainable by hydrothermal treatment of a starting material, which contains sources for CaO and SiO2 in an autoclave at a temperature of 100 to 300 C. and tempering the obtained intermediate product at 350 to 495 C., hydraulic binders based on the supplementary cementitious material above, and by a method for activating the supplementary cementitious material by adding reactive belite obtainable by hydrothermal treatment of a starting material which contains sources for CaO and SiO.sub.2 in an autoclave at a temperature of 100 to 300 C. and tempering the obtained intermediate product at 350 to 495 C. and the use of the reactive belite containing material as activator.

Method of grinding cement clinkers comprising at least two kinds of clinker phases with differing grindability.

Method of grinding cement clinkers comprising at least two kinds of clinker phases with differing grindability.

A hydraulic binder which includes a clinker with a specific shape, the clinker including as main phases, given as weight percentages relative to the total weight of the clinker: (i) 70 to 95% of a belite phase having a particle size such that the Dv50 ranges from 5 to 15 m; (ii) 5 to 30% of a calcium aluminoferrite phase; and (iii) less than 5% of minor phases; the clinker having an Al.sub.2O.sub.3/Fe.sub.2O.sub.3 weight ratio of less than 1.5; and the clinker including less than 5% of alite phase and less than 5% of calcium sulphoaluminate phase; and at least 0.5% dry weight of an activator made of calcium sulphate, as a weight percentage relative to the total weight of phases (i) to (iii).