Abstract: A process for the manufacturing of a slurry containing nucleating agents which comprises reacting at least one source of a Ca containing compound with at least one source of a Si containing compound, in an aqueous media and in the presence of a doping agent selected from the group consisting of P, B, S, and mixtures thereof; wherein: (i) the reaction is carried out at a temperature comprised from 100 to 350° C.; (ii) the total molar ratio Ca/Si is 1.5-2.5, and (iii) the total molar ratio doping agent/Si is 0.01-2; provided that: (a) when the sole doping agent is P, the total molar ratio P/Si is 0.1-2; (b) when the sole doping agent is B, the total molar ratio B/Si is 0.01-2, and (c) when the sole doping agent is S, the total molar ratio S/Si is 0.1-2.

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, SiO2, Al2O3, and Fe2O3; and, optionally, SO3, to form a raw meal comprising CaO, SiO2, Al2O3, and Fe2O3; and, optionally, SO3, wherein the molar ratios among the aforementioned oxides is given by Formula I: (CaO)1(SiO2)a(Al2O3)b(Fe2O3)c(SO3)d, 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.

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, SiO2, AI2O3, and Fe2O3; and, optionally, SO3, to form a raw meal comprising CaO, SiO2, AI2O3, and Fe2O3; and, optionally, SO3, wherein the molar ratios among the aforementioned oxides is given by Formula I: S(CaO)1(SiO2)a(Al2O3)b(Fe2O3)c(SO3)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.

Abstract: The present invention describes the preparation of nanotubes made from portlandite, the naturally occurring form of calcium hydroxide, Ca(OH)2. Portlandite nanotubes are obtained by a process comprising the following steps: a) reacting calcium chloride with calcium oxide in aqueous solution, thus obtaining an aqueous dispersion; b) feeding as such the aqueous dispersion obtained in step a) to a hydrothermal reaction, thus obtaining portlandite nanotubes. The invention also concerns the use of the portlandite nanotubes as a component for cementitious compositions to provide reinforced mortar or concrete.

Abstract: A process for the manufacturing of a slurry containing nucleating agents which comprises reacting at least one source of a Ca containing compound with at least one source of a Si containing compound, in an aqueous media and in the presence of a doping agent selected from the group consisting of P, B, S, and mixtures thereof; wherein: (i) the reaction is carried out at a temperature comprised from 100 to 350° C.; (ii) the total molar ratio Ca/Si is 1.5-2.5, and (iii) the total molar ratio doping agent/Si is 0.01-2; provided that: (a) when the sole doping agent is P, the total molar ratio P/Si is 0.1-2; (b) when the sole doping agent is B, the total molar ratio B/Si is 0.01-2, and (c) when the sole doping agent is S, the total molar ratio S/Si is 0.1-2.

Abstract: The cement comprises a belite clinker (A) and a second component (B) made up of particles of at least one ceramic material. Preferably this second component has a particle size under 100 nm, and is present in a ratio between 0.2% and 15% by weight of the belite component (A). This cement has the advantages of conventional belite cement and also has better mechanical properties. The process for obtaining a building cement comprises the steps of: (a) producing a belite cement (A) clinker from low lime content fly ash by adding lime (CaO) to the clinker until reaching a CaO/SiO2 molar ratio greater or equal to 2 and hydrothermally treating the mixture; (b) grinding the obtained clinker; and (c) adding to the clinker a second component (B) made up of at least one ceramic material with a particle size under 100 nm.