RU-2861432-C1 - RAW MATERIAL MIXTURE AND METHOD FOR PRODUCING SLAG-ALKALI BINDER USING RAW MATERIAL MIXTURE

RU2861432C1RU 2861432 C1RU2861432 C1RU 2861432C1RU-2861432-C1

Abstract

FIELD: building materials. SUBSTANCE: invention can be used to produce alkali-activated binders and concrete materials based thereon. Claimed is a raw material mixture for a slag-alkali binder. The mixture consists of blast furnace granulated slag with a specific surface area of 345 m 2 /kg, citrogypsum with a specific surface area of 290 m 2 /kg, an alkali activator - caustic soda NaOH in an amount of 3.9 mas.% and water - the balance. The invention also relates to a method for producing a slag-alkali binder. EFFECT: development of a slag-alkali binder with controlled setting and hardening time. 2 cl, 2 tbl, 3 ex

Inventors

Kozhukhova Nataliia Ivanovna
Glazkov Roman Alekseevich
Alfimova Nataliia Ivanovna
NIKULIN IVAN SERGEEVICH
NIKULICHEVA TATIANA BORISOVNA

Dates

Publication Date: 20260505
Application Date: 20250707

Claims (3)

1. Raw mix for slag-alkali binder, including the following components: blast furnace granulated slag with a specific surface area of 345 m2 /kg, citrogypsum with a specific surface area of 290 m2 /kg, alkaline activator – caustic soda NaOH and water in the following mass ratios of components, mass %:
- blast furnace granulated slag 75.8-76.8 - citrogypsum 1.5-2.5 - alkaline activator, caustic soda NaOH 3.9 - water rest
2. A method for producing a slag-alkali binder using a raw mix according to claim 1, comprising dry grinding of granulated blast-furnace slag with a specific surface area of 345 m2 /kg in an amount of 75.8-76.8 wt. %; obtaining a solid-phase component by adding citrogypsum with a specific surface area of 290 m2 /kg in an amount of 1.5-2.5 wt. % to the ground slag and mixing the components until homogeneous for 1.5-2 min; then preparing an alkaline activator by mixing caustic soda NaOH in an amount of 3.9 wt. % and water until the solid component is completely dissolved; then mixing the components: the solid-phase component and the freshly prepared alkaline activator by introducing the alkali activator into the solid-phase component for 3 min and simultaneously stirring the mixture until a homogeneous suspension is obtained.

Description

The invention relates to the building materials industry and can be used to produce alkaline-activated binders and concrete materials based on them. A method for producing slag-alkali binder by wet combined grinding of slag and an alkaline component is known [Krivenko P.A. et al. Technology for producing slag-alkali binder by wet grinding // Cement. 1993. No. 4. pp. 31-33]. The disadvantage of this method for producing slag-alkali binder is the uncontrolled and excessively short setting times caused by the activating mechanochemical processes of the slag-alkali suspension. A binder is known that contains granulated blast furnace slag and an alkaline component - soda ash [Alkaline and alkaline-alkaline earth hydraulic binders and concretes / Ed. by V.D. Glukhovsky - Kyiv: Vishcha shkola. 1979. 218 p.]. The disadvantage of this type of binder is low compressive strength. A method is known for producing an alkali-activated binder based on slag by dry grinding to a specific surface of 300...350 m2 /kg and subsequent mixing with alkali solutions [Glukhovsky V.D., Pakhomov V.A. Slag-alkali cements and concretes. Kiev: Budivelnik. 1978. pp. 29-30]. The disadvantage of this method is the long time it takes to begin and end the setting process. The technical objective of the proposed technical solution is to expand the range of tools by developing a raw mix and a method for producing a slag-alkali binder using the stated raw mix. The technical result consists of two technical solutions expressed in the composition of the raw mix and the method for producing a slag-alkali binder using the declared raw mix with a controlled setting and hardening time of the binder. The stated problem is solved due to the fact that the raw mix for the slag-alkali binder consists of the following components: blast-furnace granulated slag with a specific surface area of 345 m2 /kg, citrogypsum with a specific surface area of 290 m2 /kg, an alkaline activator - caustic soda NaOH and water in the following mass ratios of the components, mass %: - blast furnace granulated slag75.8-76.8- citrogyps1.5-2.5- alkaline activator, caustic soda NaOH3.9- waterrest The method for producing slag-alkali binder is carried out as follows: initially, dry grinding of granulated blast-furnace slag is carried out; then, a solid-phase component is obtained by adding 1.5-2.5 wt. % citrogypsum to the ground slag in an amount of 75.8-76.8 wt. % and mixing the components until homogeneous for 1.5-2 min; then, an alkaline activator is prepared by mixing water and caustic soda NaOH in an amount of 3.9 wt. % until the solid component is completely dissolved; then, the components are mixed: the solid-phase component and the freshly prepared alkaline activator by introducing the alkali activator into the solid-phase component for 3 min and simultaneously stirring the mixture until a homogeneous suspension is obtained. For all slag-alkali binder compositions, a mixture with an equal water-solid ratio was prepared, containing an alkaline activator, providing a Na2O content in the binder of 3%. Characteristics of the materials used 1. Granulated blast furnace slag is a bulk material obtained by cooling molten metallurgical slag with water or a directed air flow. Before use, the slag was pre-crushed to a specific surface area of 345 m2 /kg (the chemical composition is presented in Table 1). 2. Citrogypsum is a waste product of the biochemical production of citric acid, which is formed as a result of the microbiological synthesis of chalk mass using the Aspergillus niger culture in the form of a finely dispersed powder with a specific surface area of 290 m2 /kg (the chemical composition is presented in Table 1). 3. Water according to GOST 23732-2011 “Water for concrete and building mortars. Technical conditions”. 4. Alkaline activator - sodium hydroxide NaOH, GOST R 55064-2012. "Industrial sodium hydroxide. Specifications." Table 1 Chemical composition of blast furnace granulated slag and citrogypsum Using this raw mix composition at the specified ratio allows for a controlled reduction in the initial and final setting times of the slag-alkali binder. This controlled reduction in setting time is achieved by introducing a gypsum-containing component in the selected dosage range, characterized by rapid setting times. This, in turn, leads to intensive yet controlled structure formation and hardening of the binder. As a result, the setting time of the resulting slag-alkali binder is reduced by 39.7 to 51% (initial setting) and by 12.5 to 27% (final setting). Example 1 Example 1 discloses a method for producing a slag-alkali binder with a % ratio of raw mix components: - blast furnace granulated slag76.8- citrogypsum1.5- alkaline activator, caustic soda NaOH3.9- water17.8 At the first stage, granulated blast furnace slag is ground to a specific surface area of 345 m2 /kg, then 1628 kg of ground slag are mixed with 31.8 kg of citrogypsum for 1.5-2 min until a homogeneous state i