Compositions comprising a mechanochemically carboxylated mineral filler and a cement and/or asphalt binder

A method for preparing a composition comprising a mechanochemically carboxylated mineral filler and a binder;

• wherein the binder is selected from the group consisting of cement, asphalt, and combinations thereof;
• the method comprising the following steps:
• (i) providing a mechanochemically carboxylated mineral filler obtained by a method comprising the following steps:
• a) providing a solid feedstock comprising a silicate mineral, wherein the solid feedstock is a particulate material which has a BET surface area of more than 0.01 m2/g and a D50 within the range of 0.1-5000 μm;
• b) providing an oxidizing gas comprising CO2;
• c) introducing said solid feedstock and said oxidizing gas into a mechanical agitation unit;
• and
• d) subjecting the material of said solid feedstock to a mechanical agitation operation in the presence of said oxidizing gas at an oxidizing gas pressure of more than 1 atm to obtain the mechanochemically carboxylated mineral filler;
• wherein the CO2 content of the mechanochemically carboxylated mineral filler is more than 1 wt. %, based on a total weight of the mechanochemically carboxylated mineral filler, wherein the CO2 content is determined as a mass loss above 120° C. measured by TGA-MS employing a temperature trajectory comprising increasing the temperature from room temperature to 800° C. at a rate of 10° C./min and then decreasing the temperature to room temperature at a rate of 15° C./min wherein in step (d) comprises grinding or milling;
• and
• wherein the mechanochemically carboxylated mineral filler has a D90 within a range of 20-100 μm and/or a D50 within a range of 0.5-50 μm;
• (ii) providing a binder selected from, cement, asphalt, and combinations thereof;
• and
• (iii) combining the mechanochemically carboxylated mineral filler of step (i) with the binder of step (ii).