RU2212386C1 - Raw meal for fabricating silicate bricks - Google Patents

Abstract

FIELD: manufacture of building materials. SUBSTANCE: raw meal is composed of 29.5-32.6% limestone-sand binder, 32.7-33.3% quartz sand, and 21.5- 44.9% fired silica marl cl.5.0 to 0.0 mm. EFFECT: increased strength of crude product, reduced average density, and reduced heat conductance of autoclaved brick. 3 tbl, 16 ex

Description

 The invention relates to the construction materials industry and can be used in the manufacture of silicate brick.

Known raw mix for the manufacture of silicate products, containing in wt. %: finely divided tuff 11.4-15.73; lime 5.7-7.26; tufa fractions 0.14-5.0 mm 46.4-66.2; zeolite rock of clinoptilolite composition (finely dispersed) 2.28-4.84; zeolite rock of clinoptilolite composition (fractions 0.315-1.25) 1.5-6.7; zeolite rock of clinoptilolite composition (fractions 1.2-5.0 mm) 1.5-12.7; water is the rest. The resulting products have a bulk density of 1730-1800 kg / m ³ and a raw strength of 0.2-0.4 MPa (ac 1735238, IPC 5 C 04 V 28/22, BI N 12.1992, p. 96).

 The reasons that impede the achievement of the technical result indicated below include the fact that when using the known raw material mixture, raw materials with low strength are obtained, and the products obtained have a high density, which negatively affects the thermal insulation properties.

Known raw mix for the manufacture of silicate brick, containing in wt. %: quartz sand 50-80 and calcined carbonate 20-50 as a lime-containing binder (US Pat. RF N 2081861, IPC 6 C 04 B 28/20, BI N 17, 1997, p. 103). Products based on this composition have a density of 1750-1950 kg / m ³ and compressive strength of the autoclaved product 21-27 MPa.

 The reasons that impede the achievement of the technical result indicated below include the fact that when using the known raw material mixture, products with a high density are obtained, which negatively affects the thermal insulation properties.

A known mixture for the manufacture of lightweight silicate brick, which is included in wt.%: Lime 5.89-8.78; velvet sand 32.26-47.95; porous mudstone sand of a certain grain size 29.0-45.75; burnt mudstone 3.69-11.27; the rest is water. Light silicate brick based on this mixture has a density of 1190-1420 kg / m ³ and sintering strength of 12-18 MPa (Ac N 1114646, IPC 3 C 04 V 15/06, BI 35, 1984).

 For reasons that impede the achievement of the following technical result when using a known mixture, include the fact that the resulting product does not have sufficient compressive strength.

 The composition of the same purpose closest to the claimed invention for the totality of features is the composition of the raw material mixture for the manufacture of silicate brick, including in wt.%: Lime-sand binder - 20 and an additive consisting of non-ground quartz sand - 60 and pre-calcined flask - 20 ( Ac 1557131, IPC 5 C 04 B 28/20, BI N 14, 1990).

 For reasons that impede the achievement of the following technical result when using the known composition of the raw mix adopted for the prototype, include the fact that the resulting product has a high density and insufficient strength of the raw material.

 The invention solves the problem of the manufacture of silicate brick based on the use of local raw materials, namely, siliceous marl rocks.

 The technical result is an increase in the strength of raw materials, a decrease in average density and a decrease in the thermal conductivity of autoclaved bricks.

 The specified technical result in the implementation of the invention is achieved by the fact that the raw material mixture for the manufacture of silicate brick, including lime-sand binder, quartz sand and calcined mineral additive, contains as a mineral additive siliceous marl grade from 5.0 to 0.0 mm in the following ratio components in wt.%: lime-sand binder 29.5 - 32.6, quartz sand 32.7 - 33.3, calcined siliceous marl class from 5.0 to 0.0 mm 21.5 - 44.9.

 When an addition of calcined siliceous marl is introduced into the raw material mixture, instead of or a 50% sand replacement, it interacts with calcium hydroxide, which partially destroys the marl structure, as a result of which free (amorphous) silica contained in the marl can partially combine under compression at ordinary temperatures with calcium hydroxide, forming an astringent compound - hydrosilicates, which are firmly connected with existing quartz grains and marl particles, providing an increase in the strength of raw, but at the same time Even the conservation of the porous structure of marl particles decreases the average density of the finished autoclaved product.

 The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information and identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find a source characterized by features identical to the essential features of the claimed invention.

 Therefore, the claimed invention meets the condition of "novelty."

 The prior art determined by the applicant has not revealed the effect of the transformations provided for by the distinctive and essential features of the claimed invention to achieve a technical result, thus, the claimed invention meets the condition of "inventive step".

Case Studies
Substances used in the composition of the raw material mixture to obtain silicate brick:
- lime-silica binder;
- quartz sand with a particle size modulus of 1.08 (particle size distribution in wt.%:
class (-2.5 + 1.25 mm) - 0.2; class (-1.25 + 0.63 mm) - 1.8; class (-0.63 + 0.315 mm) - 30; class (-0.315 + 0.16 mm) - 42; class (-0.16 + 0.0 mm) - 26 and a bulk density of 1200 kg / m ³ ;
- siliceous marl rock (marl with a ratio of SiO ₂ : R ₂ O ₃ > 4 belongs to the siliceous group. See Geological Dictionary. Volume I, M., 1973, Nedra Publishing House, p. 422) Gorodishchensky manifestation of the Republic of Tatarstan represented in the natural state by minerals, wt.%: montmorillonite - 30; quartz - 36; clinoptilolite - 13; calcite - 21; has the following chem. composition in wt. %: SiO ₂ 63.86; Al ₂ O ₃ - 5.52: TiO ₂ - 0.26; Fe ₂ O ₃ - 1.59; MnO - 0.01; CaO - 12.93; MgO - 0.83; Na ₂ O - 0.06; K ₂ O - 0.97; P ₂ O ₅ - 0.08; SO ₃ - 0.06; CO ₂ - 9.07; water is the rest. Siliceous marl is fired at a temperature of 1000 ^o C for 15 min, crushed to a particle size class of less than 5.0 mm with a particle size distribution in wt.%: Class (-5.0 + 2.5 mm) - 29.56; class (-2.5 + 1.25 mm) - 26.43; class (-1.25 + 0.63 mm) - 16.49; class (-0.63 + 0.315 mm) - 11.21; class (-0.315 + 0.16 mm) - 6.94; class (-0.16 + 0.0 mm) - 9.37 with a fineness modulus of 3.3; The calcined siliceous marl has the following physical and mechanical properties: average density 890 kg / m ³ , bulk density in the calcined state of class (-5.0 + 0.0 mm) 620 kg / m ³ and frost resistance greater than MRZ 25. The amount of sand and marl take in volume, taking into account their bulk density. In the examples, the values are given in wt. %

 Example 1

For a comparative assessment of the technical characteristics of silicate products manufactured using marl rock, an experiment was carried out to obtain a silicate product without the use of marl rock (Table 1, composition 1), it can be seen from the above example that the sample has a high average density and thermal conductivity of the autoclaved sample
Example 2

Samples are prepared at room temperature. Lump lime and quartz sand in a ratio of 1: 1 are mixed and subjected to joint grinding to a particle size of -0.2 + 0.0 mm in a ball mill. Then, the resulting mixture in an amount of 32.6 wt.% Is mixed with 44.9 wt.% Marl, calcined at a temperature of 1000 ^o C for 15 minutes, moistened with water to a moisture content of 22.5 wt.% And stirred. Then the resulting mass is placed in a blanking vessel, where it is located for 2 hours. From the mixture prepared in this way, solid cylindrical samples (diameter 60 mm, height 60 mm) are made by semi-dry pressing at a pressure of 200 kg / cm ² and subjected to autoclaving at a steam pressure of 1 MPa and a temperature of 175 ^o C according to the 2 + 8 + 2 mode . Then the resulting material is used for its intended purpose. The composition and data of the physicomechanical properties of the obtained samples are given in Table 1 (composition 2).

 Example 3

 The composition for the silicate material (product) is prepared according to example 1 with the difference that they take 29.8 wt.% Lime-siliceous binder, 32.7 wt. % quartz sand and 22.3 wt.% burnt silica marl and water to moisten 15.2 wt.%. The composition and physico-mechanical properties of the silicate product are given in table 1 (composition 3).

 Example 4

 The composition for the silicate material (product) is prepared according to example 1 with the difference that they take 29.5 wt.% Lime-silica binder, 33.3 wt.% Quartz sand, 21.5% of calcined siliceous marl and water for moistening 15, 7 wt. % The composition and physicomechanical properties of the obtained silicate product are given in table 1 (composition 4).

 Examples 5-6.

 To determine the optimal amount of ingredients by composition, additional experiments were carried out in which siliceous marl was taken in an amount of 21 and 20 wt.%, Respectively. The composition and physical and mechanical properties of the obtained samples are given in table. 1 (composition 5-6).

 Examples 7-11.

Additional experiments were carried out to determine the possibility of using the marl rock of other deposits. A marl rock of the Tatarsko-Shatrashansky deposit of the Republic of Tatarstan was used, calcined at 1000 ^o C for 15 minutes, crushed to a class less than 5.0 mm, fineness modulus 3.3, containing in wt.%: SiO ₂ - 54.58; Al ₂ O ₃ - 5.27; TiO ₂ 0.26; Fe ₂ O ₃ - 2.08; CaO - 15.78; MgO - 1.10; Na ₂ O - 0.19; K ₂ O - 0.74; P ₂ O ₅ - 0.04; CO ₂ - 6.94; water - the rest and presented in a natural state by minerals in wt.%: montmorillonite - 33; quartz - 30; clinoptilolite - 18; calcite - 19; the average density in the calcined state of 840 kg / m ³ ; a bulk density in the calcined state of the class (-5.0 + 0.0 mm) of 600 kg / m ³ and frost resistance greater than Mrz 25.

 The composition and data on determining the properties of a silicate product with annealed siliceous marl of the Tatarsko-Shatrashansky deposit are given in table. 2 (compositions 8-10). Composition 7 - control, without marl. Composition 11 - to determine the optimal amount of ingredients.

 Examples 12-16.

Was also used the marl of the manifestation of Big Axa of the Republic of Tatarstan, annealed at a temperature of 1000 ^o C for 15 minutes, crushed to a class less than 5.0 mm, particle size modulus 3.2, containing in wt.%: SiO ₂ - 67.17; Al ₂ O ₃ - 4.38; TiO ₂ 0.22; Fe ₂ O ₃ - 1.46; MnO - 0.01; CaO 11.87; MgO - 0.55; Na ₂ O - 0.03; K ₂ O - 1.02; P ₂ O ₅ - 0.07; SO ₃ - 0.08; CO ₂ - 8.85; water - the rest and presented in a natural state by minerals in wt. %: montmorillonite - 32; quartz - 35; clinoptilolite - 13; calcite - 20; the average density in the calcined state of 790 kg / m ³ ; the bulk density in the calcined state of the class (-5.0 + 0.0 mm) is 590 kg / m ³ and frost resistance is greater than Mrz 25.

 The composition and data on the determination of the properties of a silicate product using a pre-calcined silica marl manifestation of Big Axa are given in table 3 (compositions 13-16). Composition 12 - control, without marl. Composition 16 - to determine the optimal amount of ingredients.

From the data given in table. 1-3, it follows that the silicate brick obtained on the basis of the claimed composition (examples 2-4 table 1, examples 8-10 table 2, examples 13-15 table 3), has a lower average density (less than 1500 kg / m ³ ) and thermal conductivity compared with the prototype. In examples 5-6, 11, 16 it is shown that the introduction of less than 21.5 wt.% Into the composition of the raw material mixture of siliceous marl is impractical, because a further decrease in average density and thermal conductivity does not occur.

 In examples 2, 8, 13 it is shown that a complete replacement of quartz sand with siliceous marl is possible.

Its introduction into the composition of more than 44.9 wt.% Is impractical, as this will lead to a decrease in the compressive strength of the autoclaved sample due to the higher content of active SiO ₂ (soluble silicic acid) in the mixture, which is formed not only as a result of exposure of lime to quartz grains , but also found in large numbers in a free state in marl. If in a silicate brick made on the basis of a classical mixture (lime-silica binder + quartz sand), the content of soluble silicic acid is in the range of 4.5-10% and it is completely spent on the formation of a binder, then in silicate brick, in which the marl content will be more than 44.9 wt.%, the amount of soluble silicic acid increases to 15% or more, which causes its excess, and it is not involved, this leads to a decrease in the crystalline phase in the product and, as a consequence, a decrease in strength under compression.

 The compressive strength of the obtained products from the claimed material meets the requirements of GOST 379-95.

The use of marl rock in the composition for silicate bricks, previously annealed at 1000 ^o C, in amounts of 21.5-44.9 wt.% Will allow to obtain light silicate bricks with an average density of 1260-1500 kg / m ³ and low thermal conductivity, which is important when their use as a structural and heat-insulating material; will get a more durable raw; will contribute to the expansion of the raw material base for the production of silicate bricks based on local raw materials.

The present invention is industrially applicable, as it satisfies the following conditions:
the claimed composition of the raw mix is intended for use in industry, namely in the building materials industry in the manufacture of silicate brick;
for the inventive raw material mixture in the form as described in the claims, the possibility of obtaining the mixture using the examples described in the application is confirmed.

 Therefore, the claimed invention meets the condition of "industrial applicability".

Claims (1)

The raw material mixture for the manufacture of silicate brick, including lime-sand binder, quartz sand and calcined mineral additive, characterized in that it contains silica marl of the class 5.0 - 0.0 mm as a mineral additive in the following ratio of components, wt. %:
Lime and sand binder - 29.5 - 32.6
Quartz sand - 32.7 - 33.3
Calcined silica marl class from 5.0 to 0.0 mm - 21.5 - 44.9

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