METHOD FOR PRODUCING HIGH-ALUMINA CEMENT FOR LOW-CEMENT HEATPROOF MOULDING MATERIAL Russian patent published in 2023 - IPC C04B7/38 

FIELD: cement production.

SUBSTANCE: production of high-purity high-alumina cement by sintering. Invention can be used for production of new-generation low-cement heatproof moulding material. The method for producing high-alumina cement for low-cement heatproof moulding material includes grinding the components, dosing, mixing, moistening, briquetting, followed by firing the resulting briquettes, and fine grinding of the firing products. Finely dispersed chalk and metallurgical alumina, represented by a crystalline phase γ-Al₂O₃ are used, and are crushed to obtain a median particle size D50 equal to 10 mcm, the dosage of the components is chosen based on the requirement to ensure the chemical composition of the charge with a molar ratio of Al₂O₃:CaO in the range of 1.28:1.00-1.40:1.00. After mixing, the mixture is moistened to a moisture content of 25%, briquetting is carried out by vibroforming at a specific pressure of 0.05-0.1 MPa; dried briquettes are fired at the following parameters: heating rate 250°C/h, exposure at a temperature of 1200-1350°C for 1 hour or at a temperature of 1200-1300°C for 2 hours, and the resulting clinker is first ground until it completely passes through a 2.5 mm sieve, and then it is subjected to fine grinding until at least 90% of the crushed high-alumina cement clinker passes through a 008 sieve.

EFFECT: obtaining clinker with the Ca phase content no less than 80% by weight, which ensures high setting speed and fast curing.

1 cl, 1 dwg, 5 tbl