The invention provides novel, microstructured clinker and cement materials that are characterized by superior grindability and reactivity. The disclosed clinker and cement materials are based on carbonatable calcium silicate and can be made from widely available, low cost raw materials via a process suitable for large-scale production. The method of the invention is flexible in equipment and processing requirements and is readily adaptable to manufacturing facilities of conventional Portland cement.

The invention provides novel, microstructured clinker and cement materials that are characterized by superior grindability and reactivity. The disclosed clinker and cement materials are based on carbonatable calcium silicate and can be made from widely available, low cost raw materials via a process suitable for large-scale production. The method of the invention is flexible in equipment and processing requirements and is readily adaptable to manufacturing facilities of conventional Portland cement.

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).

The invention provides novel, microstructured clinker and cement materials that are characterized by superior grindability and reactivity. The disclosed clinker and cement materials are based on carbonatable calcium silicate and can be made from widely available, low cost raw materials via a process suitable for large-scale production. The method of the invention is flexible in equipment and processing requirements and is readily adaptable to manufacturing facilities of conventional Portland cement.

The invention provides novel, microstructured clinker and cement materials that are characterized by superior grindability and reactivity. The disclosed clinker and cement materials are based on carbonatable calcium silicate and can be made from widely available, low cost raw materials via a process suitable for large-scale production. The method of the invention is flexible in equipment and processing requirements and is readily adaptable to manufacturing facilities of conventional Portland cement.

The invention discloses a rapid-hardening high-belite calcium sulfoaluminate cement clinker and relates generally to a rapid-hardening high-belite calcium sulfoaluminate cement clinker and methods to use and to manufacture the clinker. The clinker of the present invention comprises 20% to 35% by weight of C.sub.4A.sub.3S 3% to 9% by weight of C.sub.4AF, 37% to 47% by weight of C.sub.2S, 0.5% to 4.6% by weight of f-CaO and 14% to 26.3% by weight of CaSO.sub.4. The chemical compositions of the clinker are 12.9% to 16.1% by weight of SiO.sub.2, 12% to 19% by weight of Al.sub.2O.sub.3, 1% to 3% by weight of Fe.sub.2O.sub.3, 49% to 54% by weight of CaO and 12% to 18.43% by weight of SO.sub.3. It is manufactured by calcining, at a temperature of 1300 C.50 C. in a rotary kiln, the raw meal, comprising 33% to 62% by weight of limestone, 10.5% to 28% by weight of fly ash, and 19% to 45% by weight of FGD gypsum. A group of rapid-hardening high-strength cements of various strength classes can be manufactured by mixing and grinding 26% to 97% by weight of clinker, 3% to 19% by weight of anhydrite and 0% to 55% by weight of granulated blast furnace slag.

The invention provides a new class of carbonatable calcium silicate-based, white clinkers and the ground cement produced from these clinkers, as well as methods of their production and use thereof. The disclosed white clinkers and the ground cement exhibit a high brightness and are suitable for use in products with high aesthetic considerations.

A process for preparing dicalcium silicate includes providing a starting material comprising calcium carbonate (CaCO.sub.3) and silicon dioxide (SiO.sub.2), wherein a molar ratio of calcium:silicon (C:S) is from 1.5:1 to 2.5:1. At least one of an inorganic alkali metal salt and an alkaline earth metal salt is added as a mineralizing agent to the starting material in an amount of from 0.5 wt.-% to 20 wt.-%, based on a total weight of the starting material. The starting material is reacted with the mineralizing agent in a gas atmosphere having a CO.sub.2 partial pressure of from 0.05 MPa to 0.2 MPa at a temperature of from 900 C. to 1100 C. so as to obtain a dicalcium silicate product. The dicalcium silicate product comprises a content of an unreacted starting material of <5 wt.-% and a total carbon content of <1.5 wt.-%, each based on a weight of the dicalcium silicate product.

The present invention relates to a method for producing a binder comprising the following steps: a) providing a starting material, from raw materials, that has a molar (Ca+Mg)/(Si+Al+Fe) ratio from 1 to 3.5, a molar ratio Ca/Mg from 0.1 to 100, and a molar Al/Si ratio from 100 to 0.1, wherein constituents that are inert during the hydrothermal treatment in an autoclave are not taken into account for determination of the ratios, b) mixing the raw materials, c) hydrothermal treating of the starting material mixture produced in step b) in an autoclave at a temperature from 100 to 300 C. and a residence time from 0.1 to 24 h, wherein the water/solids ratio is 0.1 to 100, d) tempering the intermediate product obtained in step c) at 350 to 600 C., wherein the heating rate is 10-6000 C./min and the residence time is 0.01-600 min.

The present invention relates to a method for producing a binder comprising the following steps: a) providing a starting material, from raw materials, that has a molar (Ca+Mg)/(Si+Al+Fe) ratio from 1 to 3.5, a molar ratio Ca/Mg from 0.1 to 100, and a molar Al/Si ratio from 100 to 0.1, wherein constituents that are inert during the hydrothermal treatment in an autoclave are not taken into account for determination of the ratios, b) mixing the raw materials, c) hydrothermal treating of the starting material mixture produced in step b) in an autoclave at a temperature from 100 to 300 C. and a residence time from 0.1 to 24 h, wherein the water/solids ratio is 0.1 to 100, d) tempering the intermediate product obtained in step c) at 350 to 600 C., wherein the heating rate is 10-6000 C./min and the residence time is 0.01-600 min.