COMPOSITION AND METHOD OF MAKING CORUNDUM REFRACTORY CONCRETE Russian patent published in 2018 - IPC C04B28/26 C04B40/00 B82B3/00 C04B111/20 C04B111/27 

FIELD: building materials.

SUBSTANCE: invention relates to heat-resistant concrete. Composition for making corundum heat-resistant concrete, including: binder, electro-cast corundum aggregate, finely ground electro-cast corundum, finely ground technical alumina, finely ground diatomite and heated water, contains as a binder a colloidal sodium polysilicate with a silicate module of 6.5, produced by introducing sodium silicate 16 % hydrosol of silica into the 20 % aqueous solution in a ratio of 1:1.6, stirring at 100 °C for 3.0 hours with exposure at the specified temperature not more than 0.5 h, and additionally a natural amorphous fine-dispersed silica with a content of 20 % of nanodispersed particles having the following chemical composition, wt. %: SiO₂ – 87.00; Al₂O₃ – 5.00; TiO₃ – 0.3; Fe₂O₃ – 2.25; P₂O₅ – 0.07; FeO less than 0.25; CaO – 0.72; MgO – 0.50; MnO – 0.02; K₂O – 1.03; Na₂O – 0.58; SO₃ less than 0.10; LOI – 2.26, with the following ratio of components, mass %: said colloidal sodium polysilicate 2–4,

electro-cast corundum aggregate 60–80, finely ground electro-cast corundum with a specific surface of 2500–3000 cm²/g 8–16, finely ground technical alumina with a specific surface of 2500–3000 cm²/g 4–6, finely ground diatomite with a specific surface of 2500–3000 cm²/g 3–5, said fine-dispersed silica 3–9, heated to 90 °C water on the basis of the calculation 0.12–0.14 BW. Method for manufacturing corundum heat-resistant concrete from the above composition, comprising injecting, with stirring in a high-speed mixer, into said colloidal sodium polysilicate finely ground said electrically melted corundum, technical alumina, diatomite, said silica and water heated to 80–90 °C, until a homogeneous suspension is obtained, mixing the obtained suspension with said corundum aggregate in a paddle mixer of forced action until a homogeneous mass is obtained, molding this mass by pressing at a specific pressure of 30 MPa and performing hardening in the drying process according to the mode: rise in temperature from 20 to 90 °C = 1.5 hours, exposure at 85–95 °C is 0.5 hours,

temperature rise up to 200 °C is 1 hour, exposure is 2 hours.

EFFECT: technical result is increased thermal properties and water resistance of concrete.

2 cl, 2 tbl