ALKALINE COMPLEXING ADDITIVE BASED ON NATURAL CLAY MINERALS AND METHOD FOR ITS PRODUCTION Russian patent published in 2022 - IPC B01J20/12 C04B28/22 C04B103/65 E02B3/16 

FIELD: additives.

SUBSTANCE: invention relates to an alkaline complexing additive and a method for its production. Alkaline complexing additive based on natural clay minerals is a hydrophilic dry mineral powder, consisting of 20-80% by weight of the substance of clay particles containing calcium and magnesium hydroxide in the form of coatings and intrusions, compounds of calcium metasilicates of the CaSiO₃ type and calcium carbonate silicates CaCO₃⋅SiO₂, pozzolans in the form of silica, metals in oxide and hydrate forms, which determine the astringent properties of the substance. The method for producing an alkaline additive consists in initiating point exothermic reactions of the formation of Ca and Mg hydride at the boundaries of the interparticle interaction of aggregates of natural clay minerals and grains of powdered quicklime, leading to concomitant hydrolysis reactions of the clay mineral, which results in the formation of pozzolans and the formation of metasilicates and silicates of Ca carbonate, as well as to the destruction of clay mineral aggregates. To do this, in the environment of clay minerals with a moisture content of 10-25% with the presence of aggregates with a size of not more than 50 mm, quicklime powder with a grain size of less than 100 microns is introduced at a range of percentage ratio of the mass of quicklime to the mass of clay mineral 10-60%. The reaction conditions are controlled by the particle size of the lime, the conditions for mixing the mixture with the establishment of a rational humidity regime in the reactor and the optimum temperature range of the mixture of 60-180°C, as well as the condensation of water vapor or the removal of water vapor from the reaction core by ventilation of the gaseous medium in the reactor.

EFFECT: simplification of the requirements for moisture content (i.e., expansion of the range) and fractional composition of the initial clay raw material, which significantly reduces the cost of its preparation, as well as an increase in the chemical activity, reactivity and alkalinity range of the final substance.

3 cl