Method for the Preparation of a Carbonated Mineral Component, Carbonated Mineral Component, and Method for the Preparation of a Binder Composition
A method for preparing a carbonated mineral for use in cement is provided; wherein a mineral component with a (CaO+MgO)/SiO 2 weight ratio of 1.2 to 5.0 is ground to a powder; mixed with water to form a paste; the paste is placed in a reactor in an atmosphere containing CO 2 ; the paste is carbonated in the reactor; and the resulting material is dried to constant weight; or the mineral component is ground to a Blaine fineness between 3′000 cm2/g and 10′000 cm2/g to obtain a powder; during grinding a CO2 rich gas is injected so that the component carbonates; the powder is mixed with water at a weight ratio between 0.3 and 1.5 to obtain a paste, or pre-humidified by adding water at a weight ratio between 0.03 and 0.2; the resulting material is dried to constant weight at 60-85° C.; and the resulting material is deagglomerated and sieved.
1 - 20 . (canceled)
21 . A method for preparing a carbonated mineral component, comprising the steps of:
providing a mineral component including CaO, MgO and SiO 2 in a weight ratio (CaO+MgO)/SiO 2 of about 1.2 to about 5.0 and having an amorphous content of at least about 66% by weight;
carbonating the mineral component to form a hardened material using a first sequence of steps or, alternatively, a second sequence of steps;
drying the hardened material to a constant weight; and
deagglomerating and sieving the hardened material to form the carbonated mineral component;
wherein the first sequence of steps comprises:
grinding the mineral component to obtain a powder;
mixing the powder with water to form a paste;
placing the paste in a reactor in an atmosphere that includes a CO 2 rich gas; and
carbonating the paste in the reactor to form the hardened material;
and the second sequence of steps comprises:
grinding the mineral component in a mill;
during grinding of the mineral component, injecting the CO 2 rich gas into the mill to carbonate the mineral component, yielding a carbonated powder; and
either a) mixing the carbonated powder with water at a solid to water weight ratio of about 0.3 to about 1.5, or b) pre-humidifying the carbonated powder using a solid to water ratio of about 0.03 to about 0.2, to obtain the hardened material.
22 . The method of claim 21 , wherein the step of drying the hardened material to the constant weight is preformed at a temperature of about 60° C. to about 85° C.
23 . The method of claim 21 , wherein the mineral component comprises at least about 35% by weight of the CaO.
24 . The method of claim 21 , wherein the CO 2 rich gas is a combustion gas from a cement plant.
25 . The method of claim 21 , wherein the weight ratio of (CaO+MgO)/SiO 2 is 1.26 to 5.0.
26 . The method of claim 21 , wherein, after grinding the mineral component, the powder or carbonated powder has a Blaine fineness between about 3000 cm 2 /g and about 10,000 cm 2 /g,
27 . The method of claim 26 , wherein the Blaine fineness is between 5000 cm 2 /g and 8000 cm 2 /g.
28 . The method of claim 21 , wherein the powder or carbonated powder is mixed with the water at a solid to water weight ratio between 0.3 and 1.5.
29 . The method of claim 21 , comprising the first sequence of steps, wherein the reactor is operated at atmospheric pressure, a temperature of 50-90° C., and a relative humidity of 56-95%.
30 . The method of claim 21 , comprising the first sequence of steps, wherein the paste is carbonated in the reactor for a duration between 12 and 52 hours.
31 . The method of claim 30 , wherein the duration is between 18 and 30 hours.
32 . The method of claim 21 , wherein the hardened material is sieved to particle sizes of 63 μm or less to exclude coarse aggregates.
33 . The method of claim 21 , wherein the mineral component is selected from one or more of ground granulated blast-furnace slag, ground steel slag, fly ash, and ground concrete demolition waste.
34 . A carbonated mineral including carbonated and non-carbonated constituents;
the non-carbonated constituents including CaO, MgO and SiO 2 in a weight ratio (CaO+MgO)/SiO 2 of about 1.2 to about 5.0 and having an amorphous content of at least about 66% by weight.
35 . The carbonated mineral of claim 34 , wherein the carbonated mineral has a degree of carbonation of about 5% to about 20% by weight.
36 . The carbonated mineral of claim 35 , wherein the degree of carbonation is about 8% to about 16% by weight.
37 . The carbonated mineral of claim 34 , wherein the carbonated mineral has a Blaine fineness of 3000 cm 2 /g to 10,000 cm 2 /g.
38 . A method of preparing a binder composition, comprising the steps of:
providing a carbonated mineral component including CaO, MgO and SiO 2 in a weight ratio (CaO+MgO)/SiO 2 of about 1.2 to about 5.0; and
mixing the carbonated mineral component with a cementitious component selected from the group consisting of a Portland cement, a Portland cement clinker, and combinations thereof.
39 . The method of claim 38 , wherein the carbonated mineral component is added to the cementitious component and ground together with the cementitious component to obtain the binder composition.
40 . The method of claim 38 , wherein the carbonated mineral component has a Blaine fineness of 3000 cm 2 /g to 10,000 cm 2 /g.