The use of solid residues derived from different industrial activities to obtain calcium silicates for use as insulating construction materials

Calcium silicates have obtained through solid state reaction of the different residues generated in various industrial activities. As a source of calcium oxide: marble, mussel shells, and the reagent commercial calcium hydroxide were used. The source of silica was biomass ash and fired ceramic residue formed by crushing pieces of broken and defective ceramic products from a brick factory (chamotte). From the raw materials, biomass ash and marble, biomass ash and commercial calcium hydroxide, and chamotte and crushed mussel shell dust, mixed in a molar ratio CaO:SiO2 1:1 and sintered at 1100 °C (24 h), calcium silicates such as wollastonite, gehlenite and larnite were obtained. Both the raw materials and the synthesized material were characterized by XRD, XRF and TGA–DTA. In order to use the calcium silicates obtained as low temperature thermal insulating ceramic materials, the materials obtained were compressed under uniaxial loading at 81.7 MPa to obtain bricks measuring 60 mm × 30 mm × 10 mm. The properties of the bricks were studied. The ceramic materials present conductivity values between 0.10 W/m2 K and 0.18 W/m2 K and compressive strength of 29.8–59.3 MPa, respectively. The bricks met the UNE guidelines for use as low-temperature structural insulation ceramics.