RU2297400C2 - Ceramic mix - Google Patents

Abstract

FIELD: manufacture of wall ceramics and ceramic articles of light tints on base of local red-burning clay raw material.

SUBSTANCE: proposed ceramic mix contains red-burning clay raw material, carbonate rock and modifying agent above 100% at the following ratio of components, mass-%: red-burning clay material, 75-95; carbonate rock, 5-25; modifying agent, 0.6-2.

EFFECT: extended range of raw materials; improved physical-mechanical properties of articles.

3 cl, 4 tbl

Description

The present invention relates to the production of wall ceramics and can be used for the manufacture of ceramic products (face brick, stones, decorative products, etc.) in light colors from crane-burning clay raw materials.

It is known that when finely ground carbonate rocks are added to red-burning clay raw materials, the color of the crock changes from pink to light yellow. The amount of carbonate rocks added depends on the content of iron and calcium oxides in the clay raw material and is determined by the following ratio of oxides in mass:

- for a shard of pink color

- for a shard of yellow color

- for a shard of light yellow color

(Sokov V.N., Labzina Yu.V., Fedoseyev G.P. Laboratory workshop on the technology of finishing, heat-insulating and waterproofing materials. M: Higher school, 1991. C.22).

At the same time, the content of carbonate rock in the clay mass is mainly 20-45%, which significantly worsens the physical and mechanical properties of the calcined products - increases water absorption and decreases strength. In addition, to brighten the shard, it is necessary to increase the firing temperature of products by 50-100 ° C, and this, as practice shows, often leads to deformation of products.

The composition of the ceramic mass is known, in which additional clarification of the ceramic crock is carried out by introducing 20% chamotte into the mixture containing red-baked low-melting clay and finely ground limestone (Alperovich I.A. assortment of ceramic materials and artificial porous aggregates. Collection of works of VNIIistrom. 61 (89), 1987, pp. 11-17).

The disadvantage of this composition is the high cost of chamotte, for which it is necessary to build a production line, which will lead to higher prices for products. In addition, the introduction of chamotte from red-baked clay raw materials does not provide clarification of the shard when the content of Fe ₂ O ₃ in the composition of fusible clays changes, i.e. the above composition can be used only for a specific type of clay raw materials.

To brighten the shard from red-burning clays, a complex additive was developed, which, when introduced in an amount of 15-25% (by weight), provides a shard of light yellow or cream color (GL Moysov. On the production of volume-painted ceramic bricks at enterprises of the Krasnodar Territory // Installation and special work in construction, 2001, No. 10). However, the use of this additive significantly increases the cost of bricks (including due to transportation costs), which is economically inefficient and cannot be widely used in the manufacture of products from bulk-painted clay masses.

Closest to the proposed ceramic mass is the mass. proposed by I.A. Alperovich (I. Alperovich, Facing ceramic bricks of a wide range of colors // New materials and processes in the production of ceramic wall products and drainage pipes. Collection of works of VNIIstrom. Issue 63 (91), M; 1988 p. 69-76).

Masses contain the following components: by volume,% by weight,% I II I II Clay raw materials 70 60 78 69 Fine Limestone thirty thirty 22 22 Sodium Glass Erklez - 10 9

The firing temperature is 1000-1050 ° C. With these parameters, the author obtained samples of a light cream color of a uniform color.

Considering the fact that in most products from fusible, red-hot clay raw materials, when more than 15% carbonate rock is added to it, strength is significantly reduced and water absorption increases, the use of the proposed mass under production conditions is inefficient. In this regard, the inventors carried out work using clay raw materials of five deposits and various types of carbonate rocks.

The Novo-Petrovskoye (Krasnodar Territory), Bolshelogovskoye (Rostov Region), Sukho-Chaltyrskoye (Rostov Region), Malo-Stupkinskoye (Ivanovo Region) and Kamenskoye (Novosibirsk Region) deposits were used as red-hot clay materials. The low-melting, red-burning clay raw materials of these deposits are by their quality characteristics the most common for the production of ceramic products (bricks and stones).

The raw materials mined in the immediate vicinity of the enterprises producing ceramic bricks (shell, chalk, limestone, limestone screenings) were used as carbonate rocks.

The main characteristics of clay raw materials and the chemical composition of the components used in the experimental work are shown in tables 1 and 2.

Table 1 Ceramic properties of clay raw materials Name of the field Plasticity,% Sensitivity to drying The content of clay particles,% The mineral composition of the clay fraction Novo-Petrovskoe 15.8 Medium sensitive 49.85 Hydromica Bolshelogovskoe 8.2 Highly sensitive 35.10 Montmorillonite-hydromica Sukhoi-Chaltyrskoe 12.0 - // - 47.45 Montmorillonite-hydromica Little Stupkinskoe 11.8 - // - 39.10 Hydromica-montmorillonite admixture of kaolinite Kamenskoe 7.3 - // - 29.45 Hydromica-montmorillonite Chatsovskoe (prototype) 8.6 Medium sensitive 32.72 Hydromica-kaolinite with an admixture of montmorillonite

table 2 The chemical composition of the components Name of the field SiO ₂ Al ₂ O ₃ Fe ₂ About ₃ TiO ₂ Cao MgO SO ₃ total K ₂ O Na ₂ O p.p.p. Amount Clay raw materials Novo-Petrovskoe 62.40 15,80 6.52 0.90 1.13 1.91 0.56 2.71 2.62 6.48 100.39 Bilylogovskoe 63.90 10.46 4.19 0.70 5.75 1.65 0.14 2.28 1.79 8.43 99.29 Sukhoi-Chaltyrskoe 57.82 12.29 6.01 1.05 8.02 1.27 1.20 2.25 1.47 8.80 Little Stupkinskoe 66.13 11.52 4.61 0.89 5.47 1,08 0.41 1.22 1.76 6.91 100.02 Kamenskoe 63.27 11.95 5.00 0.85 5.55 1.26 0.28 2.05 3.10 657 Chatsovskoe (prototype) 74.56 11.39 4.36 0.61 0.85 1.06 0.04 2.20 0.98 3.35 99.40 Carbonate rocks Shell 5.58 0.24 0.32 0.10 52,46 0.12 0.04 - - 41.12 Chalk Kulbakinsky 0.62 0.18 0.29 - 55.07 0.51 - - - 43.27 99.94 Limestone (Sudogda) 0.92 0.06 0.09 - 52.24 2.42 0,03 - - 43.55 99.31 Limestone Screenings 1,64 0.34 0.30 0.01 54.69 0.18 0.10 - - 42.95 Venevsky limestone (prototype) 0.54 0.32 0.33 - 55.01 0.68 Words - - 43.72 100.60 Glass Erklez Glass Erklez 71.2 1.89 0.11 - 6.62 3.04 - - 16.97 - 99.83

The preparation of the ceramic mass for experimental work was carried out as follows:

- clay raw materials were dried and crushed in a disk eraser to particle sizes less than 1 mm;

- carbonate rocks and glass erklez — were dried and crushed in a ball mill to a fineness of grinding, characterized by a residue on a sieve with holes of 0.063 mm, not more than 2%.

- the components of the charge were dosed by weight, mixed thoroughly, moistened to a molding moisture, and 5 × 5 × 5 cm cubic samples were made.

The samples were dried to a residual moisture content of 0.5-1% and calcined at a temperature of 1000 and 1050 ° C.

The main characteristics of the samples made by the composition proposed in the prototype, but using various deposits of clay raw materials and carbonate rocks, are given in table.3.

Table 3 Physico-mechanical properties and color of samples made of ceramic masses according to the composition proposed in the prototype name of raw materials Fe ₂ About ₃ Firing temperature, ° С The limit of compressive strength, MPa Water absorption,% Color samples Note No. of masses clay carbonate rock CaO on the surface in kink one 2 3 four 5 6 7 8 9 10 The composition of the mixture,% by weight, clay - 78, carbonate rock - 22 The composition of the mixture,% by volume: clay - 70, carbonate rock - 30 202-10 Chatsovskoe Venevskoe 0.26 1000 25.8 12.8 Cream - Prototype 1050 22.8 13.3 Light cream - N-P Novo-Petrovsky * Shell 0.41 1000 25.9 16.5 Brown-cream (uneven) Uneven 1050 34.0 14.0 Burning Dark brown B-l Bolshelogovskoe a piece of chalk 0.20 1000 7.2 23.1 Creamy with pink Cream 1050 8.9 22.5 Light cream Light cream S-h Sukhoi-Chaltyrskaya a piece of chalk 0.28 1000 8.8 21.8 Creamy with pink Cream 1050 10,2 20.9 Light cream Light cream Ms Little Stupkinskaya Limestone (Sudogda) 0.23 1000 9.6 20,0 Cream pink Cream 1050 11.7 19.1 Cream Cream N-o Kamenskoe Limestone Screenings 0.24 1000 5.3 24.8 Cream pink Cream 1050 6.8 22.7 Cream Light cream

Continuation of table 3 one 2 3 four 5 6 7 8 9 10 The composition of the mixture,% by weight: clay - 69; carbonate rock - 22; erklez -9. The composition of the mixture,% by volume: clay - 60; carbonate rock - 30, erklez - 10 202-12 Chatsovskaya Venevskoe 0.23 1000 27.8 13.1 Light cream - Prototype 1050 33.5 11.2 Also - - N-P-e Novo-Petrovskoe Shell 0.35 1000 27.8 15.1 Brown Uneven 1050 44,2 12.8 Burning Dark brown B-l-e Bolshelogovsky a piece of chalk 0.17 1000 8.8 22.0 Light cream Light cream 1050 10.7 20.1 Light cream with beige uneven Also S-h-e Sukhoi-Chaltyrskoe a piece of chalk 0.23 1000 9.5 20.5 Light cream Light cream 1050 11.8 19.8 Light cream with beige spots. Also M-S-E Little Stupkinskoe Limestone (Sudogda) 0.2 1000 10.8 19.0 Light cream Light cream 1050 14.5 18.1 Light cream with beige spots. Also BUT EH Kamenskoe Limestone Screenings 0.21 1000 6.2 21,2 Light cream Light cream 1050 8.8 20,0 Light cream Also Note: * Light cream color samples were obtained by adding 45% of the shell, while the compressive strength of the samples was 4.6 MPa, and water absorption was 28.7%.

As a result of the work carried out, it was established:

- The greatest influence on the color of the crock during volumetric staining is exerted by the content of iron and calcium oxides in the clay mass. At a ratio of Fe ₂ O ₃ / CaO = 0.20-0.28, monotonous cream-colored samples were obtained (at 1050 ° C). With an increase in the Fe ₂ O ₃ / CaO ratio to 0.41, the samples have a non-uniform brown color. The addition of 10% erkleza contributes to the clarification of the shard at a firing temperature of 1000 ° C, however, an increase in temperature to 1050 ° C leads to the appearance of dark spots due to the formation of an increased amount of the liquid phase on the surface of the samples.

- The strength of the cream and light cream color samples obtained from the experimental clay masses is 4.6-11.7 MPa, water absorption is 19.1-28.7%. In the prototype, the compressive strength of the samples is 22.8 MPa, and the water absorption is 13.3%. This indicates that the addition of 30% carbonate rocks (Fe ₂ O ₃ / CaO = 0.26) is possible only when using clay raw materials with high natural strength, which is typical for kaolinite-hydromica clay raw materials, which are not typical for the production of ceramic bricks and rare.

Thus, the disadvantages of the proposed composition of the ceramic mass are:

- limited scope (only for high-quality clay raw materials);

- insufficient temperature range of firing - is provided by obtaining a given color only at one specific temperature, which does not allow to obtain a stable color and the necessary physical and mechanical properties of products during firing in industrial furnaces;

- low strength samples and high water absorption with the addition of 30% carbonate rocks (Fe ₂ About ₃ / CaO = 0.17-0.28) in clay raw materials, which cannot provide high-quality ceramic products in production conditions.

The aim of the invention is to expand the resource base and reduce the content of carbonate rocks in the production of facing ceramic products in bright colors from red-hot clay raw materials using volumetric painting technology.

This goal is achieved by the fact that a modifying reagent consisting of a complex of alkali metal salts (phosphates, fluorides) is additionally introduced into the ceramic mass consisting of red-baked clay raw materials and carbonate rock with a ratio of Fe ₂ O ₃ / CaO = 0.3-0.5 , carbonates, chlorides), while the ceramic mass contains the following components,%, by weight:

Red-baked clay raw materials - 76-94 Carbonate rock - 5-25 Modifying reagent - 0.6-2

The modifying reagent has a catalytic effect that enhances the clarification of the shard during the firing process, which reduces the content of carbonate rocks in the ceramic mass by 1.5-4 times.

приводит к снижению прочности и повышению водопоглощения изделий. При уменьшении же содержания карбонатной породы

не достигается заданный цвет черепка и его однородность.At the indicated ratio of components in mass after firing, ceramic products were obtained from light cream to cream and light yellow. When going beyond the boundary, the purpose of the invention is not achieved. Increased carbonate rock content

leads to a decrease in strength and increased water absorption of products. With a decrease in the content of carbonate rock

the desired color of the crock and its uniformity is not achieved.

A decrease in the content of the modifying reagent reduces the effect of clarification of the shard, and an increase in the amount of reagent over a specified limit leads to the appearance of plaque on the surface of the products.

As you know, most brick factories that produce ceramic bricks use highly sensitive clay raw materials for drying. In order to eliminate fracturing during drying during bulk staining of the crock, it is proposed to add up to 10% of kaolinite or kaolinite-hydromicaceous clay raw materials to the composition of the masses.

Examples of experimental verification of the present invention are shown in table 4.

All these components of the modifying reagents were ground in a ball mill less than 0.1 mm and added in the form of an aqueous solution or in the form of a powder to a dispersed carbonate rock, after mixing, the clarifying additive was introduced into the mixture. Clay raw materials were ground less than 1 mm, thinning additives were sieved through a sieve with a hole size of 1.25 mm.

All components of the charge were moistened to 18-19% and molded samples — cubes 50 × 50 × 50 mm in size. The samples were dried indoors to a moisture content of 5-6%, then in a drying oven at a temperature of 100 ° C. Volume-painted samples were fired in an electric furnace at a temperature of 1000 and 1050 ° C.

The results of experimental studies, shown in table 4, show that the introduction of 0.6-2.0 wt.% Modifying reagent allows you to get a shard from light cream to light yellow in color from ceramic masses having a ratio of Fe ₂ About ₃ / CaO = 0.32-0.5 (without a modifying reagent, this can be achieved with a ratio of Fe ₂ O ₃ / CaO <0.25). In the above examples, it is shown that the modifying reagent helps to reduce the content of carbonate rocks in the clay mass by 1.5-4 times, as a result of which the strength of the samples increases from 5.3-11.7 to 17.1-25.9 MPa, t. e. 2-3 times, and water absorption decreases from 19.1-24.8 to 13.9-18.0%. In addition, the modifying reagent extends the temperature range of firing samples (up to 50 ° C), which allows us to recommend the proposed composition of the mass for industrial implementation in existing ceramic enterprises.

Industrial batches of brick made of ceramic masses with the addition of a modifying reagent were produced on the technological lines of the enterprises of Slavyansky Brick OJSC (Krasnodar Territory) and Rostov UMG LLC Mostransgaz (Rostov-on-Don). The obtained results confirmed the effectiveness of the use of the proposed ceramic mass in existing enterprises (see the acts of production of industrial batches of bricks and photographs of brick samples produced from naturally colored clay and ceramic masses with the addition of carbonate rock and a modifying reagent).

Comparison of the results given in table. 4, with the prototype shows that the claimed composition of the ceramic mass is different from the known. Thanks to the differences, a new positive effect is achieved, expressed in the possibility of widespread adoption of the technology for the production of volumetric brick in existing ceramic enterprises. In addition, the proposed composition of the ceramic mass in comparison with the prototype has other advantages:

- reduced energy consumption when grinding carbonate rocks by reducing their content in the composition of the clay;

- improved physical and mechanical properties of products (strength, water absorption);

- intensified processes that contribute to the clarification of the shard during the firing period.

Thus, the search conducted by the applicant and the prototype selected from the list of analogues made it possible to identify distinctive features in the claimed technical solution. Therefore, the claimed composition of the ceramic mass meets the criteria of the invention of "novelty."

Industrial applicability is confirmed by the production of industrial batches of bricks at two existing ceramic enterprises (see the acts of production of industrial batches of bricks).

Claims (2)

1. Ceramic mass for producing light-colored products based on red-baked clay raw materials and carbonate rocks, characterized in that it contains a modifying reagent, including a complex of salts of phosphates, fluorides, carbonates, chlorides of alkali metals, in the following ratio, wt.%: Red-baked clay raw materials 75-95 Carbonate rock 5-25 Modifying reagent, in excess of 100% 0.6-2 2. The mass according to claim 1, characterized in that as a component contributing to the improvement of the plastic and drying properties of the clay mass during volumetric staining of products based on clay materials highly sensitive to drying, kaolinite or kaolinite-hydromica clay raw materials are added in an amount of 2-10 wt. .%.