RU2481286C2 - Composition for producing water-resistant porous aggregate - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to production of construction materials, in particular to production of porous aggregates based on liquid glass, meant for making light concrete, as well as fill insulation. The technical result is achieved due to that the composition for producing water-resistant porous aggregate, which contains liquid sodium glass with density of 1.41 g/cm³ and sodium chloride which is ground to particle size smaller than 0.3 mm, further includes burnt rocks which contain the following, wt %: SiO₂ - 38-40, Al₂O₃ - 16-18, Fe₂O₃ - 7-8, CaO - 11-13, SO₃ - 3-5, R₂O - 0.5-1, loss on ignition - 16-20, with the following ratio of components, wt %: liquid sodium glass with density of 1.41 g/cm³ - 50-70, sodium chloride ground to particle size smaller than 0.3 mm - 1-3, burnt rocks - 22-49.

EFFECT: high compression strength due to higher softening coefficient of the porous aggregate.

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Description

The invention relates to the production of building materials, in particular the production of porous aggregates based on liquid glass, intended for the manufacture of lightweight concrete, as well as heat-insulating fillings.

A known composition for producing expanded clay (porous aggregate) composition, wt.%: Waste coal flotation - 60, modified liquid glass - 40 / Denisov D.Yu. The use of coal flotation waste in the production of expanded clay / D.Yu. Denisov, I.V. Kovkov, V.Z. Abdrakhimov // Bashkir Chemical Journal. - 2008. - Volume 15. - No. 2. - S. 107-109 /.

The disadvantage of this composition of the ceramic mass is the relatively low strength of 1.7-1.9 MPa.

A known composition for producing a waterproof porous filler composition, wt.%: Sodium liquid glass with a density of 1.41 g / cm ³ - 50-75, sodium chloride, ground to a size of less than 0.3 mm - 1-3, the departure from coal enrichment by flotation with a clay component content of at least 71% - 22-49 / Patent No. 24067008 Russian Federation, IPC C04B 14/24. A method of obtaining a waterproof porous aggregate. / Mizyuryaev S.A., Ivanova N.V., Zhigulina A.Yu., Mamonov A.N .; applicant and patent holder Samara State University of Architecture and Civil Engineering; claimed on January 20, 2009; publ. 12/20/2010, BI No. 21 /.

The disadvantage of this composition is the relatively low compressive strength (0.14-0.26) and softening coefficient (55-92%).

This technical solution is taken as a prototype.

The technical result is to increase the compressive strength and softening coefficient of the porous aggregate.

The specified technical result is achieved by the fact that in the composition to obtain a waterproof porous filler, including sodium liquid glass with a density of 1.41 g / cm ³ and sodium chloride, ground to a size of less than 0.3 mm, burn rocks are additionally introduced with a content, wt.% SiO ₂ - 38-40, Al ₂ O ₃ - 16-18, Fe ₂ O ₃ - 7-8, CaO - 11-13, SO ₃ - 3-5, R ₂ O - 0.5-1, p .p.p. - 16-20 in the following ratio of components, wt.%:

sodium liquid glass with a density of 1.41 g / cm ³ 50-70 sodium chloride, ground to a size of less than 0.3 mm 1-3 clay-containing burnt rocks at least 50% and loss on ignition at least 16% 22-49

Burned rocks formed after spontaneous combustion of oil shale were used as a finely ground filler to obtain a water-resistant porous filler. Burned rocks form in the shale mining areas. Slate, which could not be separated from the waste in the mining process, is sent to the dump. In heaps with joint storage of waste rocks and shales due to the increased amount of organic compounds in the mixed waste masses, spontaneous combustion occurs, which leads to the formation of a large amount of waste - burnt rocks. Burned rocks are a product of low-temperature firing during spontaneous combustion of the rock (a mixture of clay and shale) in heaps in an oxidizing environment. The amount of burnt rocks in the heaps ranges from 75 to 90% of the dump volume. The chemical composition of burned rocks formed after spontaneous combustion of oil shale is presented in table 1.

Table 1 The chemical composition of burned rocks formed after spontaneous combustion of oil shale SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ Cao SO ₃ R ₂ O P.p.p. 38-40 16-18 7-8 11-13 3-5 0.5-1 16-20

Burned rocks, unlike clay components, although they contain more than 50% clay minerals, do not have plasticity and binding ability.

It is known that the main condition for expanding the composition when it is heated is the combination of the pyroplastic state of the composition with intense gas evolution inside the material to be fired over time. The pyroplastic state of the composition will be ensured by liquid glass and clay content in the burned rocks (at least 50%), and gas evolution - the content in burned rocks - by organics (pp, table 1).

The following components were used to prepare the raw mix:

1) marketable sodium liquid glass with a density of 1.41 g / cm ³ (see GOST 13075-81);

2) sodium chloride (GOST 13830-97, manufactured by Bassol OJSC), ground to a size of less than 0.3 mm;

3) as a finely ground clay-containing component - burned rocks containing 50% clay minerals, more than 16% pp and ground to pass through a sieve of 0.14 mm

Information confirming the possibility of carrying out the invention. Compositions (table 2) for the production of porous aggregate was prepared by thoroughly mixing all the components, similar to the technology presented in the prototype. The mixture was produced in a forced action mixer in the following order. First, a finely ground clay-containing component and sodium chloride were loaded into the mixer, which were thoroughly mixed, then sodium liquid glass was poured into the finished dry mixture with the mixer turned on in a thin stream. Mixing was carried out until a homogeneous mass, but less than 5 minutes.

table 2 The compositions of the composition for the production of porous aggregate Components The content of components, wt.% Prototype one 2 3 Sodium Liquid Glass 75 60 fifty 50-75 Sodium chloride 3 2 one 1-3 Fine-ground clay-containing component - waste from coal preparation - - - 22-49 Fine clay component - burned rocks 22 38 49 -

The resulting mixture with a system of knives was cut into individual granules, which were heat treated at 250-300 ° C in an oven granulator, swelling at the same time and forming spherical highly porous granules. The obtained granules were placed in an electric furnace heated to a temperature of 790 ° C, and kept there for 10 minutes. After isothermal exposure, the granules were cooled at a cooling rate of 40 ° C / min. Physico-mechanical properties of the porous aggregate are presented in table 3.

Table 3 Physico-mechanical properties of the porous aggregate Indicator Structure Prototype one 2 3 Compressive strength, MPa 2.00 2.05 2.12 0.14-0.26 Bulk density, kg / m ³ 120 150 195 85-170 Losses at 5 minutes boiling,% 0.11 0.1 0.09 0.12-0.7 Softening coefficient,% 93 93.5 94 55-92

As can be seen from table 3, the porous aggregates of the proposed compositions have higher compressive strength and softening coefficient than the prototype.

The technical solution using the proposed compositions allows to increase the compressive strength and softening coefficient of the porous aggregate.

The use of industrial raw materials in the production of porous aggregate contributes to the utilization of industrial waste, environmental protection, the expansion of the raw material base for ceramic materials.

Claims (1)

Composition for producing a water-resistant porous aggregate, including sodium liquid glass with a density of 1.41 g / cm ³ and sodium chloride, ground to a size of less than 0.3 mm, characterized in that it additionally contains burned rocks with a content, wt.%: SiO ₂ 38-40, Al ₂ O ₃ 16-18, Fe ₂ O ₃ 7-8, CaO 11-13, SO ₃ 3-5, R ₂ O 0.5-1, pp 16-20 in the following ratio of components, wt.%:
sodium liquid glass with a density of 1.41 g / cm ³ 50-70 sodium chloride, ground to a size of less than 0.3 mm 1-3 clay-containing burnt rocks at least 50% and loss on ignition at least 16% 22-49