In some aspects, the present disclosure pertains to methods for the electrochemical production of calcium silicate compounds in an electrochemical cell that comprises (a) a Ca-based electrode that comprises calcium metal or an inorganic calcium material, (b) an SiO.sub.x-based electrode that comprises a SiO.sub.x material, where x ranges from 1 to 2, and (c) a liquid electrolyte disposed between the Ca-based electrode and the SiO.sub.x-based electrode. In these methods, the electrochemical cell is operated under conditions such that calcium cations are produced at the Ca-based electrode and one or more calcium silicate (Ca—Si-oxide) compounds are produced at the SiO.sub.x-based electrode. In other aspects, the present disclosure pertains to systems for the electrochemical production of calcium silicate compounds.

A cement clinker composition incorporates calcium fluoride and iron oxide to reduce firing temperatures and increase strength. High fly ash, aluminum dross, aluminum scrap, high aluminum clays and combinations thereof may also be substituted for bauxite in the cement clinker composition

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, Al.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, Al.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: (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 0.01 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).

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, Al.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, Al.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: (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 0.01 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).

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 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).

A cement clinker composition incorporates calcium fluoride and iron oxide to reduce firing temperatures and increase strength. High fly ash, aluminum dross, aluminum scrap, high aluminum clays and combinations thereof may also be substituted for bauxite in the cement clinker composition

A cement clinker composition incorporates calcium fluoride and iron oxide to reduce firing temperatures and increase strength. High fly ash, aluminum dross, aluminum scrap, high aluminum clays and combinations thereof may also be substituted for bauxite in the cement clinker composition.