RU2448070C2 - Composition to manufacture non-annealed chamotte refractory concrete - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: composition includes a chamotte filler, finely ground to specific surface of 2500-30000 cm²/g chamotte, cristobalite, water and a sodium silicate block in the form of nanosized particles. Additionally it contains the following components activated in a planetary mill - a chamotte filler, cristobalite and non-annealed chamotte clay, at the following ratio of components, wt %: chamotte filler 56-73; finely ground chamotte 6-10; finely ground cristobalite 4-8; finely ground non-annealed chamotte clay 4-6; activated chamotte filler 4-6; activated cristobalite 4-6; activated non-annealed chamotte clay 4-6; sodium silicate block in the form of nanosized particles 1-2; water based on B/T 0.12-0.14.

EFFECT: increased strength of products, simplified technology of manufacturing.

Description

The invention relates to the building materials industry and can be used in the manufacture of products from non-fired fireclay refractory concrete. The technical result is an increase in the strength of non-fired fireclay refractory concrete.

A known composition for the manufacture of heat-resistant concrete based on compositions from natural and man-made glasses [1].

A disadvantage of the known composition is the use as a binder of a silicate block with a particle size of more than 100 microns after grinding in a ball mill, which at the point of dissolution in concrete form liquid glass, which cannot be evenly distributed in the mass of hardening concrete, which leads to an increase in the smooth forming component and a decrease concrete service temperature.

Also known is the composition and method of manufacturing annealed refractories [2], including a sodium silicate block with a silicate module of 2.7-3, a refractory chamotte filler, finely ground chamotte, which provides for heating the components to 80-90 ° C with dry mixing, mixing heated to 80-90 ° C with water, compression molding at 40 MPa and drying at 250-300 ° C for 1-2 hours

The disadvantage of this method is that the particles of silicate blocks have a size of more than 100 microns, and therefore is not achieved uniform distribution in the mixture of the formed liquid glass and, therefore, the products have low strength values.

Closest to the claimed technical solution for the totality of features, i.e. prototypes is the composition and method of manufacturing non-fired chamotte heat-resistant concrete [3], including chamotte aggregate, finely ground chamotte, finely ground cristobalite and sodium silicate block in the form of nanosized particles, where it is planned to heat the components to 80-90 ° C with dry mixing, mixing heated up to 80-90 ° C with water, compression molding at 40 MPa and drying at 250-300 ° C for 1-2 hours

A disadvantage of the known composition and method is the low strength of the products due to the insufficient total content of micro and nanoparticles in the concrete mixture.

The aim of the invention is to simplify the technology of preparation and increase the strength of products from fireclay refractory non-fired concrete.

This goal is achieved in that the composition for the manufacture of non-fired chamotte heat-resistant concrete, including chamotte aggregate, finely ground chamotte, cristobalite and sodium silicate block in the form of nanosized particles and water, additionally contains finely ground unburnt chamotte clay and chamotte activated in the planetary mill and chamotte chamotte clay in the following ratio of components, wt.%:

Fireclay placeholder 56-73 Fine Chamotte 6-10 Fine Cristobalite 4-8 Fine ground fire clay 4-6 Activated Fireclay Placeholder 4-6 Activated cristobalite 4-6 Activated unburnt fireclay clay 4-6 Sodium silicate block in the form of nanosized particles 1-2 Water based on W / T 0.12-0.14

This goal is achieved by the fact that the composition for the manufacture of non-fired chamotte heat-resistant concrete contains, in addition to macroparticles in the form of finely ground additives, micro- and nanosized particles obtained by activating finely ground fireclay, cristobalite and unburnt chamotte clay, and also nanoparticles obtained by the dehydration in the planetary mill parts of sodium silicate block at a temperature of 200-1000 ° C.

The initial components that make up the raw mix for the manufacture of non-fired heat-resistant chamotte concrete with increased strength are as follows:

chamotte aggregate fractions of 0.14-1.25 mm;

finely ground fireclay, unburnt fireclay clay and cristobalite are obtained by dry grinding in a ball mill to a specific surface of 2500-3000 cm ² / g;

Nanosized particles from 1 to 10 nm in size from a sodium silicate block were obtained by fine grinding, then activating it by wet grinding in a planetary mill and dehydrating dispersion of hydrated particles of activated sodium silicate block;

water - any, except mineral waters.

Using the claimed combination of essential features allows you to get the specified technical result, namely an increase in compressive strength after drying to 67.5-86.2 MPa.

Example. The pre-metered portion of the chamotte aggregate containing fractions of 0.14 mm - 8-14%, 0.315 mm - 10-18%, 0.63 mm - 15-21% and 1.25 mm - 20-34%, mixed in dry form with finely ground to a specific surface of 2500-3000 cm ² / g in a ball mill with chamotte, unburnt chamotte clay and cristobalite. Then, finely ground fireclay, unburnt fireclay clay and cristobalite are separately loaded into the drums of a planetary mill and activated by wet grinding for 20 min to obtain microparticles of 1 μm or less in size, as well as nanosized particles of 10-20 nm in size 1-3% of the mass of activated components. Nanosized particles of sodium silicate block in the form of an aqueous mixture with a particle size of 1-10 nm are obtained in a bubbler and steam trap as follows. The finely ground sodium silicate block is activated in a planetary mill, weighed and loaded into cuvettes located in a quartz tube, which in turn is located inside the tube furnace. On the one hand, sharp water vapor is supplied to the quartz tube, and the other side is connected to a condensate cooler, a condensate collector and a bubbler with water. In the process of heating the furnace to 200-1000 ° C (for this example, 800 ° C), dehydration dispersion occurs and nanoparticles with a size of 1-10 nm are carried away with water vapor in the refrigerator, and then in the condensate collector and bubbler with water. The turbidimetric and nephelophotometric method determines the quantitative content of nanoparticles in the bubbler and condensate collector and, upon reaching a sufficient amount for the above concrete mix, the aqueous mixture of nanoparticles from the bubbler and steam trap is heated to 80-90 ° C and used to prepare nanocomposite cementitious and heat-resistant chamotte concrete.

The resulting aqueous mixture of sodium silicate block nanoparticles from a bubbler and steam trap activated in a planetary mill chamotte, cristobalite and unfired chamotte clay are mixed with chamotte filler and finely ground chamotte, unfired chamotte clay and cristobalite, 64 wt. 8, cristobalite 6, unburnt chamotte clay 5, activated chamotte 5, cristobalt 5, unburnt chamotte clay 5 and a heated aqueous mixture of nanosized particles of sodium silicate block 1.5 for 2-3 minutes, with continuous mixing, water heated to 80 ° C is added and mixing is continued for 3-4 minutes. Products are pressed from the resulting mass at a specific pressure of 40 MPa and heat treatment of the products is carried out by thermal shock at 250-300 ° C in a drying chamber for 1-2 hours.

The presence in the proposed composition of components in the form of macro-sized, micro-sized and nanosized particles and their gamogen distribution in the concrete mix and quantitative ratio ensures high density, strength and low shrinkage in the product after drying. With an increase in the number of micro and nano-sized particles more than that proposed in the concrete during drying and first firing, shrinkage increases, compressive strength decreases, and when their number is less than the proposed reduction, compressive strength decreases, although shrinkage is not observed.

The proposed composition provides structurally stable products without preliminary firing, increasing the strength after drying by thermal shock by 10-20%

due to a sufficient number and uniform distribution of reactive micro and nanoparticles in the mixture during mixing and their full participation in the formation of the structure of heat-resistant fireclay concrete.

Literature

1. Gorlov Yu.P., Merkin A.P., Seifman M.I., Toturbiev B.D. Heat-resistant concrete based on natural and man-made glass compositions. - M .: Stroyizdat. 1986.- 144 p.

2. A method of manufacturing non-fired refractories. Toturbiev B.D., Batyrmurzaev Sh.D. A.S. USSR No. 1701693, B.I. No. 48, 12.30.91.

3. The composition and method of manufacturing non-fired fireclay refractory concrete. Batyrmurzaev Sh.D., Daitbekov A.M., Batyrmurzaev A.Sh., Gadzhiea R.A., Manturova Kh.Z., Batyrmurzaev D.A., Magomedova D.G. RF patent No. 2377217. Bull. Number 36. 2009 year

Claims (1)

Composition for the manufacture of non-fired chamotte heat-resistant concrete, including chamotte aggregate, finely ground to a specific surface of 2500-30000 cm ² / g chamotte, cristobalite, water and a sodium silicate block in the form of nanosized particles, characterized in that it contains chamotte additionally activated in a planetary mill aggregate, cristobalite and unburnt chamotte clay in the following ratio of components, in wt.%:
Fireclay placeholder 56-73 Fine Chamotte 6-10 Fine Cristobalite 4-8 Fine ground fire clay 4-6 Activated Fireclay Placeholder 4-6 Activated cristobalite 4-6 Activated unburnt fireclay clay 4-6 Sodium silicate block in the form of nanosized particles 1-2 Water based on W / T 0.12-0.14