FIELD: chemistry.
SUBSTANCE: invention relates to technology of building materials. Method of portland cement production includes obtaining alite clinker by burning original raw mixture in rotating furnace with introduction of cement dust-return caught from stack furnace gases, with difference Λ between values of index of saturation of raw mixture and dust with lime 0.2-0.4 and cement additive and grind of clinker with gypsum ingredient. Additive is introduced in amount of 0.05% of clinker weight, its amount is increased 1.5-5 times until Λ 0.1-0.15 is reached, then amount of raw mixture supplied to furnace is increased until Λ 0.16-0.2 is obtained, the above these operations being repeated successively until Λ less than 0.09 is obtained. Temperature values of burned material are fixed in zones of hard-phase reactions T1 H and agglomeration T1 A or temperature on the surface of furnace frame T2 H and T2 A. Addition of portland cement in amount of 0.1% of clinker weight is additionally introduced, an increase in temperature values is measured and, by regulation of addition amount, ΔT1 H to +120°C or ΔT2 H to +70°C, and ΔT1 A to +150°C or ΔT2 A to +100°C are supported. Burning is carried out until phase of alite with deviation of its content from formulae C3S or C54S18AM, or C51S18AM not greater than 2; 1.75 and 1.5 weight % respectively, with part of cell microstructure in phase volume not less than 20% and degree of statistical orientation of basal plane of crystalline grid of this phase to the centres of clinker grains not less than 60%. Invention is developed in the clauses.
EFFECT: increase in productivity as well as in portland cement strength.
9 cl, 3 tbl, 3 ex
