METHOD FOR PRODUCING PORTLAND CEMENT Russian patent published in 2016 - IPC C04B7/42 C04B18/14 

FIELD: construction.

SUBSTANCE: invention relates to production of construction materials, specifically to preparation of initial cement crude mixture with addition of fluorine-containing mineralising agent based on fine fluorocarbon-containing wastes of electrolytic production of aluminium, its sintering with subsequent grinding clinker and produce Portland cement. Method of producing Portland cement, including production of Portland cement clinker by mixing and sintering initial cement crude mixture containing calcium, aluminosilicate, ferrous components and fluorine-containing mineralizer in the form of fluorocarbon-containing wastes of electrolytic production of aluminium, further cooling and grinding Portland cement clinker, differing by the fact that mixing is carried out while feeding fine fluorocarbon-containing wastes in the mixture for producing Portland cement clinker in amount of 0.05÷0.095 wt% in terms of fluorine, note here that the molar ratio of sodium fluoride is maintained to aluminium fluoride 2.2÷2.7, and grinding of clinker with gypsum or with an active mineral additive and plaster. As fine fluorocarbon-containing wastes of electrolytic production of aluminium used are: dust of electrostatic precipitators, floatation tailings of coal froth, mixture of dust of electrostatic precipitators and flotation of coal froth, mixture of gas purification slime, dust of electrostatic precipitators and flotation of coal froth, mixture of gas purification slime and dust of electrostatic precipitators, mixture of gas purification slime and rejects of flotation of coal foam. Invention is developed in subclaims.

EFFECT: technical result-reduction of specific consumption of fluorine-containing mineralizer at burning clinker, low cost of Portland cement, enabling use of fluorine-containing mineralizer at cement plants with high content of alkali in the main raw material, increased efficiency of kiln clinker.

7 cl, 9 tbl