Mineral additives and production of lightweight composite materials from carbonatable calcium silicate

A process of production of an aerated composite material, comprising:

• forming a wet mixture or slurry, wherein the wet mixture or slurry comprises water,
• filler particles comprising CaO having a particle size of 0.1 μm to 1000 μm,
• ground calcium silicate particles,
• one or more minerals comprising a magnesium acetate salt, an aqueous solution of magnesium oxide and acetic acid, and/or submicron magnesium oxide powder, and
• an aerating agent,
• wherein, the wet mixture or slurry has a water/solid ratio (W/S) of 0.6 to 1.0;
• wherein the one or more minerals accounts for about 0.02% to about 20% by weight of the ground calcium silicate particles;
• casting the wet mixture or slurry in a mold;
• allowing the aerating agent to generate hydrogen gas thereby causing volume expansion of the slurry;
• pre-curing the obtained expanded mixture to a hardness enabling it to be taken out of the mold and moved;
• curing the pre-cured expanded mixture at 30° C. or more of temperature, a relative humidity of 1% or more, and an atmosphere of a CO2 gas concentration of 10 to 95% for 6 hours to 60 hours to produce a cured aerated material.