RU2515743C1 - Granulated composite filler for silicate wall products based on silicon zeolyte rocks and silicate wall product - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: granulated composite filler for silicate wall products with size of 0.5-10.0 mm, comprising a core and a shell, where the core is produced by granulation of the mixture of jointly ground siliceous zeolyte rock and sodium hydroxide to specific surface of 150-250 m²/kg, at their mass ratio of 0.70-0.95:0.05-0.30 with a binder - an aqueous solution of sodium silicate with density of 1.2-1.3 g/cm³ in the amount of 0.1-7.0 wt % from the mass of core components, and the shell is formed on the surface of the core by its rolling by a dry powdered mixture of jointly ground burnt lime and sodium fluosilicate at the mass ratio of 0.85-0.95:0.05-0.15, with subsequent hardening to strength of at least 2.1 MPa, and when during production of the core simultaneously with the specified binder they use alkylsulfonate heated to 50°C in the amount of 0.1-5.0 wt % of the mass of core components. The silicate wall product characterised by the fact that it is made using the above granulated composite filler.

EFFECT: reduced energy intensity of production of wall silicate materials, increased water resistance.

3 cl, 1 ex, 1 tbl

Description

The invention relates to the production of building materials and can be used to obtain silicate wall products - silicate brick, tiles, blocks, wall panels, etc., subjected to autoclaving during hardening.

Upon receipt of silicate wall products of autoclave hardening, various fillers are used. A known aggregate in the form of a clay siliceous rock calcined at 1180 ° C, crushed to a fraction of 0.4-1.2 mm, impregnated with a lime suspension. This aggregate is used in the preparation of silicate wall products that are autoclaved during hardening. The manufacturing technology of silicate wall products includes mixing of two components - lime-containing and aggregate, consisting of clay expanded rock, impregnated with a lime slurry, followed by wetting the mixture to molding moisture, molding the products and steaming them in an autoclave at a pressure of 1 MPa at a temperature of 178 ° C within 12 hours [RF Patent No. 2142440, cl. 6 C04B 28/18, 1998].

The disadvantages of this filler and silicate wall product is that this filler does not significantly reduce the time of autoclaving of silicate products, the resulting silicate materials have insufficient water resistance, and also a lot of energy is consumed when firing filler.

Closest to the proposed solution is the use of non-fired granular aggregate in the preparation of silicate wall products, such as silicate brick. Silicate raw mixes in addition to quicklime and silica sand include a composite aggregate in the form of annealed granules based on siliceous zeolite rocks and sodium hydroxide. The manufacturing technology of silicate products according to the prototype includes mixing the components — composite granular aggregate, lime and quartz sand, wetting the mixture to molding moisture, molding the products and steam them in an autoclave at a pressure of 1 MPa at a temperature of 178 ° C for 12 hours [RF Patent No. 2361839, cl. 7 C04B 28/18, 2009].

The disadvantages of the specified granular aggregate and silicate wall products is that the aggregate does not significantly reduce the time of autoclaving of silicate products; high energy costs due to the long duration of the process of autoclaving upon receipt of wall products and their insufficient water resistance are noted.

The present invention is aimed at reducing the energy intensity of obtaining wall silicate materials, increasing their water resistance.

This result is achieved using a granular composite aggregate for silicate wall products with a size of 0.5-10.0 mm, consisting of a core and a shell, where the core is obtained by granulating a mixture of co-milled to a specific surface of 150-250 m ² / kg siliceous zeolite rock and hydroxide sodium, with their mass ratio of 0.70-0.95: 0.05-0.30 with a binder - an aqueous solution of sodium silicate with a density of 1.2-1.3 g / cm ³ in an amount of 0.1-7.0 wt .% of the mass of the components of the nucleus, and the shell is formed on the surface of the nucleus by rolling it into a dry dust a mixture of coarsely ground quicklime and sodium silicofluoride in a mass ratio of 0.85-0.95: 0.05-0.15, followed by hardening to a strength of at least 2.1 MPa, in which, according to the proposed solution, upon receipt of the core simultaneously with the specified bunch use heated to 50 ° C alkyl sulfonate in an amount of 0.1-5.0 wt.% by weight of the components of the core.

Alkyl sulfonate at room temperature is a whitish paste, but when heated to 50 ° C, it liquefies and can be sprayed with nozzles.

Alkyl sulfonate is a mixture of sodium salts of alkyl sulfonic acids with a chain length of the alkyl radical C ₁₁ -C ₁₈ from n-paraffins; has the chemical formula R-SO ₂ Na. Experiments show that the efficiency in reducing the viscosity of sodium hydrosilicates with alkyl sulfonates is extremely high, the presence of small amounts of the reagent increases the mobility of silicon ions.

The state of the crystalline structure of silicates during autoclaving was monitored using a Supra 50 VP high-resolution scanning electron microscope (LEO, Germany), and lime assimilation kinetics using a DRON electron diffractometer.

The inventive silicate wall product is characterized in that it is obtained using the specified aggregate and has been machined on the contact surfaces with masonry or plaster mortars, for example, by milling, to a depth of 0.01-2.5 mm.

Component Feature:

1. As a component for the raw material mixture and the protective shell of the composite aggregate used quicklime lime production of JSC "Building materials", Belgorod, according to GOST 9179-77.

2. As a component of the raw mix used natural quartz Volsky sand according to GOST 6139-2003.

3. As a silica-containing component for the manufacture of the core aggregate used siliceous zeolite rock according to TU 5743-002-020069662-96, selected from the open pit of the Khotynetsky deposit, Oryol region. Chemical composition, wt.%: SiO ₂ - 75.3; Al ₂ O ₃ - 10.4, Fe ₂ O ₃ - 3.8, TiO ₂ - 0.6, CaO - 1.6; MgO - 1.2; R ₂ O - 1.8; p.p.p. - 5.3; mineralogical composition, wt.%: clinoptilolite - 54.3; quartz - 10.9; montmorillonite - 7.1; hydromica - 4.6; cristobalite and amorphous phase 23.1. The basicity modulus is 0.034, i.e. This material belongs to acid rocks.

4. Sodium hydroxide according to GOST 2263-79.

5. Sodium silicofluoride Na ₂ SiF ₆ according to TU 6-09-1461-91.

6. Alkyl sulfonate according to TU 2481-308-05763458-2001.

7. Tap water in accordance with GOST 23732-79.

8. When granulating the powder together with ground siliceous zeolite rock with sodium hydroxide on a plate granulator, an aqueous solution of sodium silicate (water glass) was used in accordance with TU 2385-001-54824507-2000 with a density of 1.2-1.3 g / cm ³ .

To obtain cores of granular aggregate when implementing the inventive method for producing silicate wall products, crushed silica zeolite-containing rock was dosed with sodium hydroxide by gravimetric method. The resulting mixture was loaded into a ball mill and mixed and milled until a specific surface of 200 m ² / kg was reached. Granulation of the resulting mixture was carried out using a plate granulator by spraying on the surface of the powder an aqueous solution of sodium silicate with a density of 1.25 g / cm ³ . Alkyl sulfonate was sprayed onto a granulator plate through an additional nozzle from a separate tank heated to 50 ° C. Its quantity was regulated by a flow meter. The speed of rotation and the angle of inclination of the granulator plate controlled the diameter of the granular material. The obtained cores were sent to pouring lime powder, ground together with sodium silicofluoride at a ratio of 0.9: 0.1 by weight. Granular material was separated on a sieve with a mesh size of 0.5 mm and sent for storage at ambient temperature. The strength gain of the granular aggregate was controlled at ambient temperature by a cylinder test in accordance with GOST 9758.

Example. Preparation of granular aggregate cores. Siliceous zeolite rock (8 kg) and sodium hydroxide (2 kg), i.e. in a ratio of 0.80: 0.20 by weight (table., mixture 1), they were ground in a mill together to a specific surface of 200 m ² / kg. The obtained powder material was fed to a plate granulator. On the surface of the powder by spraying was applied an aqueous solution of sodium silicate with a density of 1.25 g / cm ³ . At the same time, from a container heated to 50 ° C, an alkyl sulfonate in an amount of 0.3 kg (3% by weight) was sprayed through a flow meter. The rotation speed and the angle of inclination of the granulator plate controlled the diameter of the resulting cores, which in this case was 4.4–4.5 mm.

Obtaining a protective shell on the nuclei. The resulting cores were sent for dusting with a powder of lime (9 kg), ground together with sodium silicofluoride (1 kg), i.e. in the ratio of 0.90: 0.10 to obtain granules with a size of 5.0 mm (table., mixture 1). Dusting was carried out in a drum mixer.

Part of the obtained granular material after storage for 36 hours at ambient temperature was tested for strength by compression in a cylinder according to GOST 9758; the rest was used in the preparation of silicate mixtures for the manufacture of samples of building products. The compressive strength of the granules was 2.7 MPa.

Preparation of silicate raw mix. The components were dosed by the weight method: 1.15 kg of quicklime (11.5 wt.%, Table 1, mixture 1), 5.85 kg of sand (58.5 wt.%) And 3.0 kg (30 wt. %) of the granular aggregate was mixed, quenched in a screw mixer and dampened to a molding moisture content of 12%.

The samples were molded at a pressure of 20 MPa according to the prototype [RF Patent No. 2361839, class. C04B 28/18, 2009].

Hydrothermal processing of the samples was carried out in an autoclave at a pressure of 1 MPa and a temperature of 178 ° C for 5, 6, 7, 8, and 12 hours.

The core aggregate of the prototype (see RF patent No. 2361839, example No. 1) did not contain an alkyl sulfonate, and in general the granular aggregate had a crushing strength in the cylinder of 2.9 MPa.

The obtained samples of wall products were tested for strength (according to GOST 10180) and water resistance - the relative loss of strength during compression of the samples after 25 cycles of soaking. The test results are shown in table. (Mixture 1).

Data analysis table. The test results of the properties of samples of silicate building products shows the following.

1. Introduction to the composition of the silicate mixture of the inventive granular aggregate with a size of 0.5-10 mm, consisting of a core in the form of co-milled siliceous zeolite rock, sodium hydroxide and an additive of alkyl sulfonate, which is coated with a coating of ground lime and sodium silicofluoride, interconnected by liquid glass allows you to get durable waterproof silicate wall products with increased water resistance, while by reducing the time of autoclave processing, the floor energy consumption is almost halved eniya wall products.

2. Reducing the amount of alkyl sulfonate in the core of the granular aggregate to 0.1 wt.%, Reduces the reactivity of the obtained granules, which allows to reduce the autoclave processing time by almost 2 hours (mixture 2), the water resistance of the resulting products slightly increased, this composition is accepted as boundary.

A further decrease in the amount of alkyl sulfonate in the core of the granular aggregate of silicate wall products leads to a significant decrease in the effectiveness of this additive in reducing the duration of autoclaving, so the composition of mixture 4 is beyond the scope of the claimed.

3. The increase in the amount of alkyl sulfonate in the core of the granular aggregate to 5.0 wt.% Shows its effectiveness in increasing the mobility of sodium silicates, which contributes to the accelerated silicate formation, healing of structural defects, increase the strength of wall silicate materials, a significant reduction in the duration of autoclaving. However, there is a decrease in the mechanical strength of the granular material, which is an extremely important indicator in the manufacture of pressed products. Therefore, this composition is accepted as boundary (mixture 3).

A further increase in the alkyl sulfonate in the core of the granular aggregate leads to a significant decrease in the physico-mechanical properties of the granular aggregate, and it becomes unsuitable for the production of pressed silicate wall products, so the composition of mixture 5 is beyond the scope of the claimed.

With an optimal ratio of components (mixture 1, table), the obtained silicate wall products have the following advantages compared with the known ones: with an increase in strength characteristics due to a decrease in the structure defectiveness and accelerated formation of calcium hydrosilicates, the water resistance of the materials obtained is increased and the autoclaving time is halved, this significantly reduces the necessary energy consumption in their production.

When using raw silicate mixtures with boundary ratios of the components (mixture 2, table), the obtained silicate products practically retain water resistance and strength characteristics in comparison with the similar properties of the prototype.

During the autoclave treatment of silicate products, in the cores of a granular aggregate, water-soluble sodium silicates are synthesized, which in the presence of alkyl sulfonate in the claimed amounts acquire high mobility and, penetrating through the protective shell of the granules, ensure that the silicate matrix is saturated with water-soluble silica ions to a depth of 6-12 mm or more, extremely accelerate the processes of mineral formation and contribute to the set of strength of the structure. It is known that the presence of mobile silica ions contributes to the accelerated growth of tobermorite crystals, and the processes of mineral formation as a whole are accelerated.

Practice shows that the use of the inventive composite granular aggregates reduces the time of autoclaving by almost 2 times.

The presence of mobile silicon ions during the autoclave treatment of silicate products promotes more complete binding of free calcium oxide and increases their water resistance (mixture 1, table).

When introduced into the composition of silicate wall products during the autoclave treatment, the composite aggregate of the prototype also releases sodium silicates, however, they exhibit low mobility and penetrate the surrounding silicate matrix to a depth of not more than 0.25-1 mm, i.e. they work only in the boundary zones of contact between the silicate matrix and the granulated material, they impregnate only the shell of the granule and hardly interact with the silicate matrix in volume.

The inventive composite granular aggregate, which is part of the silicate raw mix, and therefore in the pressed wall products, partially dissolves during autoclaving, releasing hydrosilicates, which are almost completely absorbed by the silicate matrix. Caverns remain in place of the granules, which during surface treatment of a silicate product, for example, by milling to a depth of 0.01-2.5 mm, increase contact with masonry and plaster mortars; the strength of masonry increases by an order of magnitude. The study of the strength characteristics of such silicate brickwork shows their high strength, which allows us to recommend their use in earthquake-resistant construction.

Claims (3)

1. A granular composite aggregate for silicate wall products with a size of 0.5-10.0 mm, consisting of a core and a shell, where the core is obtained by granulating a mixture of co-milled to a specific surface of 150-250 m ² / kg siliceous zeolite rock and sodium hydroxide, their mass ratio of 0.70-0.95: 0.05-0.30 with a binder - an aqueous solution of sodium silicate with a density of 1.2-1.3 g / cm ³ in an amount of 0.1-7.0 wt.% from the mass of the components of the core, and the shell is formed on the surface of the core by rolling it with a dry, dusty mixture of co-ground lime lime nitric and sodium silicofluoride in a mass ratio of 0.85-0.95: 0.05-0.15, followed by hardening to a strength of at least 2.1 MPa, characterized in that when producing the core simultaneously with the specified binder, use preheated to 50 ° C alkyl sulfonate in an amount of 0.1-5.0 wt.% By weight of the components of the core. 2. Silicate wall product, characterized in that it is made using the granular composite aggregate according to claim 1. 3. The silicate wall product according to claim 2, characterized in that it has been machined along the contact surfaces with masonry or plaster mortars, for example, by milling, to a depth of 0.01-2.5 mm.