RU2047583C1 - Raw mixture for making building brick and a method of building brick making - Google Patents

Abstract

FIELD: building industry. SUBSTANCE: raw mixture has, wt.-% Kara-Kum sand dune 94; soda 3, and air lime 3. Mixture preparation is carried out by combined milling parental components up to specific surface value 1800-2000 cm²/g. Then blanks were pressed, dried and calcined at 1100 C. Physico-mechanical indices: compression limit strength is 28.4 MPa, water absorption is 21.4% mean density is 1,6 g/cm³. EFFECT: enhanced quality of product. 3 cl, 2 tbl

Description

 The invention relates to building ceramics and can be used for the manufacture of ceramic wall brick material.

Known raw mix for the manufacture of building bricks, including loess rock, clay, anorthite-ferrite [1]
The disadvantage of this mixture is the long mode of firing and cooling, amounting to 48 hours, the presence of efflorescence on the surface of the brick.

The closest in technical essence and the claimed invention is a raw material mixture for the manufacture of bricks, containing the following components, wt. [2]
Karakum Dune
sand with a surface area of 2000 cm ² / g 88 Clay 10 Soda 2
A known method of manufacturing bricks, which consists in pre-grinding sand to a surface area of 2000 cm ² / g, combining the metered amount of crushed sand with other components of the raw mix (clay and soda), moistening the mixture and aging it for 24 hours, pressing, drying and firing bricks [2]
A disadvantage of the known raw material mixture and method is the reduced compressive strength of the fired brick, which is 7.4 MPa, the reduced strength of the raw material after drying, is 2.5 MPa, and the long-term mode of drying the brick (24 hours).

 The purpose of the invention is increasing the strength of the brick after drying and after firing, reducing the drying time of the brick.

 This goal is achieved in that the raw material mixture for the manufacture of building bricks, including Karakum sand dune, soda and a binder, contains lime as a binder in the following ratio of components, wt.

Karakum sand dune 94 Air lime 3 Soda 3
This goal is also achieved by the fact that in the method of making bricks, which includes the steps of preparing the mixture, moistening and aging the mixture during the day, pressing the mixture, drying and firing the brick, the mixture is prepared by co-grinding the metered quantities of the initial components of the mixture to a specific surface of 1800-2000 cm ² / g.

 Comparative analysis with the prototype allows us to conclude that the proposed composition of the raw mix for the manufacture of bricks differs from the known introduction of a new component, namely lime.

Comparison of the proposed method with the prototype made it possible to establish that the proposed method differs from the known one in that the mixture is prepared by co-grinding all the initial components of the mixture (sand, lime, soda) to a surface area of 1800-2000 cm ² / g. Thus, the proposed technical solutions meet the criterion of "novelty." An analysis of the known compositions of the raw mix for making bricks [2] showed that some of the substances introduced into the proposed solution are known, for example, Karakum sand dune and soda. However, their use in these mixtures in combination with other components and by the known method does not provide the brick with the properties that they exhibit in the proposed solution, namely, increasing the strength of the brick after drying and after firing, reducing the drying time of the brick. Thus, this composition of the components and the production method gives the building brick new properties, which allows us to conclude that the proposed solution meets the criterion of "significant differences".

For experimental verification of the proposed composition and method, a raw mix was made (Table 1, composition 1). As air lime, lime obtained from the limestone of the Kelyatinsky deposit (Turkmenistan) was used. Lime content of active CaO + MgO 71.7%; Lime extinguishing time 24 min; extinction temperature 57 ^о С; amount of unextinguished grains in lime 6.14 wt. the residue on the sieve is 0.63 mm 15.36 gr. Karakum sand dune served as the sand of the Geok-Tepa deposit. The chemical composition of the used sand is presented in table.3.

The raw material mixture was prepared as follows. First, dosing of Karakum sand dune, soda and lime was carried out. Dosed quantities of sand, soda and lime were mixed and then crushed in a ball drum mill on a specific surface of 1800-2000 cm ² / g.

Joint grinding of the components favors a uniform distribution of the starting components (primarily lime and soda) over the volume of the mixture, as well as grinding of unextinguished grains contained in the lime. Next, the resulting mixture was combined with water (to a moisture content of 6.5%), aged for 24 hours. Samples cylinders with a diameter and a height of 50 mm were made from the finished mass at a pressure of 15 MPa. Samples were dried for 10 hours at 150-155 ^{° C} to a residual moisture of 1-1.5% Calcination was conducted in an electric muffle furnace where it was held for 4 hours at 1100 ° ^C.

 In the table. 2 presents the results of physical and mechanical tests of the obtained samples.

 The data in the table are confirmed by the test report of the proposed raw mix and method.

 From the table. 1 and 2 it follows that the proposed raw material mixture and method allows to obtain a brick with a strength after drying of 6.7 MPa, with a strength after firing of 28.4 MPa, to reduce the drying time of a brick to 10-12 hours

Using the invention allows:
to increase the productivity of the process in the manufacture of bricks (by reducing the drying time and increasing the strength after drying the raw brick);
reduce material costs, increase the seismic resistance of buildings and structures in seismically hazardous areas (by increasing the strength after firing bricks).

Claims (1)

 1. The raw material mixture for the manufacture of building bricks, including Karakum sand dune, soda and a binder, characterized in that it contains air lime as a binder in the following ratio of components, wt. Karakum sand dune 94
Soda 3
Air lime 3
2. A method of manufacturing a building brick, including crushing Karakum sand dune to a specific surface of 1800 2000 cm ₂ / g, mixing with soda and a binder, pressing blanks, drying and firing, characterized in that air lime is introduced as a binder, and mixing is carried out to obtaining a raw mix of the composition, wt. Karakum sand dune 94
Soda 3
Air lime 3
then carry out joint grinding of the components.

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