RU2324669C1 - Method of making ceramic wall products, rough mixture for making ceramic wall products and filler for ceramic wall products - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: proposed method of making ceramic wall products uses the indicated mixture and filler. The method involves mixing of ground clay in percentage mass quantities of 60-97%, and filler in the form of hydrophobisised granules with dimensions 0.1-2.0 mm, obtained from scrap glass, ground together with magmatic acidic effusive vitreous rocks, obsidian, vitrophyre, or a mixture of the minerals in quantities between 5% and 80% relative to mass of the granules, and blowing agents of calcium carbonate and silicon carbide in quantities of 1-6% mass of the granules. In that case, quantity of the hydrophobisiser is 1-10% mass of the filler. Then further, there is moistening, formation of gummy products through a plastic technique, or through a half-dry pressing method, drying and burning at a temperature of 950-1075 °C.

EFFECT: larger source of raw materials and stronger low-shrinking and non-shrinking ceramic wall products.

3 cl, 2 tbl, 1 ex

Description

The invention relates to the production of wall ceramics and can be used to obtain insulation products - bricks, blocks, wall panels, etc.

A known method of manufacturing a wall ceramic product and a raw material charge for it, including ground clay (53-93 wt.%) And aggregate in the form of grains expanding during heating with an initial size of not more than 2 mm, consisting of vermiculite, or hydrophlogopite, or hydrobiotite (2-42 wt.%) And a scrubber - sand, or ash, or slag with a particle size of not more than 2 mm (4-45 wt.%). From the mixed mass, plastic products are molded in the form of bricks, blocks, wall panels, which, after drying, are fired in a tunnel oven at 950 ° C with an isothermal exposure of 2 hours [RF Patent No. 1780276, cl. 6 C04B 33/00, 1995].

The disadvantages of the method, the raw material charge and aggregate are: high density of the obtained wall ceramic products (1850 ... 1990 kg / m ³ ), which requires an increase in the cost of materials at the manufacturing stage and, as a consequence, makes the mass of wall structures heavier; high fire shrinkage (up to 5 ... 7.9 vol.%), which contributes to the occurrence of stresses and structural defects that adversely affect the strength characteristics of the calcined material. These shortcomings worsen the technological and operational characteristics of wall ceramic products.

Closest to the proposed solution are a method of manufacturing wall ceramic products, raw material charge and aggregate for them. The method consists in mixing ground clay - 60-97 wt.% And aggregate - the rest is in the form of hydrophobized granules with a size of 0.1-2.0 mm, obtained from cullet, ground together with 1-6% by weight of cullet with a blowing agent - calcium carbonate, the amount of water repellent is 1 ... 10% of the mass of cullet. Products are formed from the mixed mass, which after drying are fired in a tunnel oven at 950 ° C with an isothermal exposure of 2 hours [RF Patent No. 2277520, cl. 6 C04B 33/02, 2005].

The disadvantages of the prototype are the presence of general shrinkage during drying and roasting and the insufficient strength of the resulting wall ceramic products, as well as the limitation in the use of raw materials due to the impossibility of using refractory clays.

The present invention solves the problem of expanding the arsenal of technical means, including expanding the raw material base through the use of refractory clays, for the production of non-shrink and non-shrink wall ceramic products with preservation and increase of their strength.

The technical result is achieved by the fact that in the method of manufacturing wall ceramic products, comprising mixing ground clay in an amount of 60-97 wt.% With aggregate - the rest is in the form of hydrophobized granules with a size of 0.1-2.0 mm, obtained from cullet, ground with a blowing agent containing calcium carbonate, the amount of water repellent is 1-10% by weight of aggregate, moistening, molding raw products by plastic method or semi-dry pressing, drying and firing, according to the proposed solution during grinding cullet and blowing agent instead of 5.0 ... 80 wt.% cullet, magmatic acidic effusive glassy rocks are introduced, instead of part of the blowing agent, silicon carbide is introduced in an amount of 1-6% relative to the mass of igneous acidic effusive glassy rocks, and the total amount of blowing agent is 1 -6% by weight of a mixture of cullet and igneous acidic effusive glassy rocks, firing is carried out at a temperature of 950 ... 1070 ° C.

The technical result is achieved in that in the raw material charge for the manufacture of wall ceramic products, including ground clay - 60-97 wt.% And aggregate - the rest is in the form of hydrophobized granules with a size of 0.1-2.0 mm, obtained from cullet, ground together with a pore former containing calcium carbonate, the amount of water repellent is 1-10% by weight of aggregate, according to the proposed solution, the core of the above aggregate instead of 5.0 ... 80 wt.% cullet contains igneous acidic effusive glassy rocks, instead Asti porogen contains silicon carbide in an amount of 1-6% by weight of the acidic effusive magmatic rocks glassy, and the total amount of blowing agent is 1-6% by weight of a mixture of cullet and acidic igneous rocks of volcanic glassy.

The result is achieved using a filler for wall ceramic products, in the form of granules with a size of 0.1-2.0 mm, consisting of a core and a shell made of water repellent, the core being a mixture of crushed glass breakage and a pore former containing calcium carbonate the amount of water repellent is 1-10% by weight of aggregate; according to the proposed solution, the core material instead of 5.0 ... 80% by weight of cullet contains magmatic acidic effusive glassy rocks, instead of a part of the pore former it contains crebide Nia in an amount of 1-6% by weight of the acidic effusive magmatic rocks glassy, and the total amount of blowing agent is 1-6% by weight of a mixture of cullet and acidic igneous rocks of volcanic glassy.

Comparison of the proposed solution with the prototype made it possible to establish that it differs in the introduction of a core aggregate instead of 5.0 ... 80 wt.% Cullet of magmatic acidic effusive glassy rocks, for example perlite, obsidian, vitrofire, or a mixture of these minerals, and instead of part of the blowing agent silicon carbide is introduced in an amount of 1-6% relative to the mass of magmatic acidic effusive glassy rocks, while the total amount of pore former in the core is 1-6% by weight of a mixture of cullet and magmatic acidic eff zivnyh glassy rocks, firing is conducted at a temperature of 950-1070 ° C. Thus, the proposed solution has the criterion of "novelty."

In the study of other technical solutions, the use of the filler granules introduced into the core of the granules instead of 5.0 ... 80 wt.% Cullet of magmatic acidic effusive glassy rocks, for example perlite, obsidian, vitrofire, or a mixture of these minerals, and instead of a part of the pore former introducing carbide silicon in an amount of 1-6% relative to the mass of magmatic acidic effusive glassy rocks, while the total amount of pore former in the core of the aggregate is 1-6% by weight of a mixture of cullet and igneous acidic eff uzivnyh glassy rocks holding firing at a temperature of 950-1070 ° C is detected, thereby the claimed solution should not be explicitly in the art, that allows to conclude that the inventive solution to the criterion "Inventive Level".

Characterization of mass components:

1. As the clay component used:

a) clay of the Lukoshkinskoye deposit (Belgorod region, Starooskolsky district) according to TU 21-4434-84. Refractoriness 1430 ... 1570 ° С. Plasticity 9-12. The color after firing is red,

b) refractory clay of the Latnensky deposit (Voronezh region). Grade LT-2, fire resistance 1670 ... 1690 ° С. Plasticity 18-22. The color after firing is light pink.

2. As cullet used the battle of green container glass, Voronezh.

3. The rocks of the lower Quaternary volcanic complex Arteni (Armenia) were used as magmatic acidic effusive glassy rocks: obsidian in the form of breccia; vitrophyres and pulverized perlite, formed during the mechanical processing of magmatic acidic effusive glassy rocks, not suitable for expansion.

Magmatic acidic effusive glassy rocks and cullet, if necessary, were crushed in a hammer mill and stored in storage bins.

4. As pore formers used silicon carbide grade M 7 according to GOST 3647-80 and calcium carbonates (chalk, limestone):

- technical dispersed chalk MTD-2 according to TU - 21-020350-06-92, OJSC "Building Materials", Belgorod;

- limestone of the Yashkinsky deposit;

The chemical composition of the raw materials is given in table 1.

5. When granulating a cullet powder additionally containing magmatic acidic effusive glassy rocks, ground together with pore formers, on a plate granulator, an aqueous solution of silicate glue (liquid glass) was used according to TU 2385-001-54824507-2000. The amount of the binder component for different sizes of granules is different and is determined visually: so much so that the formed granules of the desired size roll off the inclined surface of the plate feeder. The resulting cores consist of a mixture of ground glass breakdown, magmatic acidic effusive glassy component and pore-forming agents - calcium carbonate and silicon carbide, interconnected by liquid glass.

6. As a water repellent of the surface of the aggregate granules, paraffin of the petroleum grade P-2 (GOST 23683-89) in the molten state was used. By adjusting the thickness of the paraffin layer on the surface of the granulate, the most preferred spherical and rounded granules are obtained, forming similar pores in the mass of the finished product.

To obtain a granular aggregate in the implementation of the inventive method for the manufacture of wall ceramic products, crushed cullet was dosed with magmatic acidic effusive glassy rocks, calcium carbonate and silicon carbide by gravimetric method. The resulting mixture was loaded into a ball mill and grinding was performed until a specific surface of 300 ... 500 m ² / kg was reached. Granulation of the obtained mixture, drying of the granules and their processing with a water repellent was carried out similarly to the method described in RF patent No. 2277520.

The chemical composition of the components of ceramic masses Table 1 No. Component The content of oxides, wt.% SiO ₂ Al ₂ About ₃ TiO ₂ Fe ₂ About ₃ Cao MgO R ₂ O SO ₃ P.p. one. Clay Lukoshkinskaya 59.2 19.7 0.8 4,5 1,5 0.5 2.7 0.2 10.9 2. Clay Latnenskaya 67.6 35.5 2.1 1,0 0.7 0.6 0.4 0.1 11.5 3. Glass Fight 65,2 10.7 0.8 1,2 6.5 0.7 14.7 0.2 - four. Perlite 72.8 14.1 0.5 1,1 0.8 1,2 7.3 0.7 3.2 5. Obsidian 69.8 16.9 0.7 0.9 1,0 1.4 8.0 0.4 0.2 6. Vitrofir 71.2 13,4 - 1,2 1,1 - 6.9 0.6 2,3

Example. 7.8 kg (78%) of pre-dried crushed and sifted through a sieve with a mesh size of 0.1 mm Lukoshkinskaya clay was weighed, 2.2 kg (22%) of aggregate in the form of granules obtained from ground to specific gravity was added to this clay surfaces of 400 m ² / kg of components: cullet - 1.276 kg (60%), perlite - 0.850 kg (40%), total amount of blowing agent - 0.074 kg (3.5% of the mass of cullet and perlite), a mixture of 0.030 kg of silicon carbide (3.5% by weight of perlite) and 0.044 kg of limestone - the remainder of the blowing agent; granulated on a plate granulator and sifted through a sieve with a mesh diameter of 2.0 mm and remaining on a sieve of 0.1 mm and hydrophobized to obtain a casing - by treatment with molten paraffin in an amount of 5% relative to the weight of the granules, see table 2, mixture one.

The mixture of dry components (clay and aggregate) was moistened with water to the molding moisture, mixed until a uniform distribution of aggregate and clay. Samples of raw products from the resulting mixture were molded in a plastic manner on a belt press. Next, the samples were dried to a residual moisture content of 0.5 ... 2%, and then fired at a temperature of 955 ° C, similarly to the method described in RF patent No. 2277520, class. 6 С04В 33/02, 2005.

The composition of the charge and the properties of wall ceramic products table 2 Mix No. Components, wt.% Water repellent (paraffin),% The amount of magmatic acidic effusive glassy rocks introduced into the aggregate instead of part of the cullet, wt.% The amount of silicon carbide in relation to the mass of igneous acidic effusive glassy rocks,% Firing temperature, ° С Shrinkage, vol. % The limit of compressive strength, MPa Clay Lukoshkinskaya Clay Latnenskaya Pellet aggregate 0.1-2.0 mm in size one 2 3 four 5 6 7 8 9 10 I. Plastic method of forming products. Magmatic acidic effusive glassy rock - perlite. Calcium carbonate - limestone (3.5 wt.%). one 78 - 22 5 40 3,5 955 0 41.3 2 97 - 3 one 5 1,0 965 6.2 34.9 3 60 - 40 10 80 6.0 950 7.0 34.3 II. Semi-dry method of forming products. Magmatic acidic effusive glassy rock - obsidian. Calcium carbonate - chalk (1.0 wt.%). four - 78 22 5 65 3,5 1060 0.1 40,2 5 - 97 3 one 5 1,0 1070 8.1 30.3 6 - 60 40 10 80 6.0 1050 8.2 30,0 II. Plastic method of forming products. Magmatic acidic effusive glassy rock - vitrofire. Calcium carbonate - limestone (6.0 wt.%). 7 78 - 22 5 thirty 3,5 955 0.1 42.1 8 97 - 3 one 5 1,0 965 6.0 35.1 9 60 - 40 10 80 6.0 950 6.8 35,2 10 98 - 2 0.5 four 0.5 945 7.2 30,0 eleven 55 - 45 10 90 6.5 945 -3.8 20,2 12 (prototype) 78 - 22 10 no no 970 7.3 30.1

Continuation of Table 2. one 2 3 four 5 6 7 8 9 10 II. Semi-dry method of forming products. Magmatic acidic effusive glassy rock: 34% obsidian + 33% perlite + 33% vitrofira. Calcium carbonate - limestone (4.0 wt.%). 13 - 78 22 5 65 3,5 1060 0.2 39.8 fourteen - 97 3 one 5 1,0 1070 7.0 30.9 fifteen - 60 40 10 80 6.0 1050 8.1 30,4 16 - 98 2 0.5 four 0.5 1080 8.3 29.8 17 - 55 45 10 90 6.5 1085 -3.7 17.0 18 (prototype) - 78 22 5 no no 1080 8.4 29.8

Products from mixtures 4-6 and 13-18 (Table 2) were obtained by semi-dry pressing.

After cooling, product samples were tested for strength, and the overall shrinkage was determined. The test results are shown in table 2 (mixture 1). Known compositions of masses 12 (plastic molding method) and 18 (semi-dry molding method of products) were made from more refractory clays - Lukoshkinskaya and Latnenskaya according to the prototype (RF Patent No. 2277520, class 6 С04В 33/02, 2005, table 2, composition 1 )

An analysis of the data in Table 2 of the test results of wall ceramic samples shows the following.

1. All mixtures 1-9 and 13-15 meet the requirements of TU 530-95 "Brick and ceramic stones."

2. Introduction to the composition of the core mass of hydrophobized aggregate in the form of granules consisting of cullet, ground together with magmatic acidic effusive glassy rocks, calcium carbonate and silicon carbide in the claimed quantities allows to obtain durable high-quality wall ceramic products with adjustable general shrinkage during drying and firing.

3. To reduce the amount of aggregate less than 3 wt.%, The amount in granules of igneous acidic effusive glassy rocks less than 5 wt.% With respect to the mass of cullet and silicon carbide less than 1.0% relative to the mass of igneous acidic effusive glassy rocks is impractical, t. to. the resulting ceramic products according to complex technical characteristics are not of sufficient quality due to the presence of shrinkage during drying and firing, and despite the fact that the products meet the requirements of TU 530-95, compositions 2, 5, 8 and 14 due to the presence of small cracks permissible sizes are taken as boundary, and the mixture 10 and 16 go beyond the scope of the claimed compositions of wall ceramic products.

An increase in the number of aggregate granules over 40 wt.%, The amount in granules of igneous acidic effusive glassy rocks over 80 wt.% Relative to the mass of cullet, as well as silicon carbide more than 6% relative to the mass of igneous acidic effusive glassy rocks is impractical, because . there is a decrease in the strength of the obtained wall ceramic materials due to an increase in the foaming temperature of the granules, which does not allow to compensate for the shrinkage of the products during firing. For this reason, despite the fact that the physicomechanical characteristics of the products meet the requirements of TU 530-95, compositions 3, 6, 9 and 15 are accepted as boundary, and the charges 11 and 17 go beyond the scope of the claimed compositions of wall ceramic products. It should be noted that when firing raw products from blends of compositions 11 and 17 due to the presence of defects in the volume expansion of the samples (the “-” sign in front of the general shrinkage figure, Table 2) and cracking, the strength of the fired wall ceramic products decreases.

The use of refractory clays and aggregate that does not contain magmatic acidic effusive glassy rocks and silicon carbide does not make it possible to obtain non-shrink wall ceramic products, because foaming of these granules occurs at a temperature of 830-840 ° C, and at this temperature, the ceramic matrix of the clay used in this case does not yet have pyroplastic properties (Table 2, mixtures 12 and 18).

The inventive method of manufacturing wall ceramic products has the following advantages:

1) at optimal ratios of components in raw materials, the compressive strength increases to 27%;

2) wall ceramic products obtained as a result of firing have a homogeneous closed-porous hardened structure with minimal volumetric shrinkage defects.

The physicochemical nature of the technical solution to achieve the problem is as follows: the introduction of magmatic acidic effusive glassy rocks and silicon carbide into the mass of hydrophobized granules increases the temperature range of their foaming. The foaming temperature of the granules of the selected composition, taking into account the thermoplasticity of the clay component that makes up the matrix of wall ceramics, allows to obtain practically non-shrinking products. The process of foaming granules of the claimed composition creates a uniform bursting effect, which actively prevents the occurrence and development of fire shrinkage of wall ceramic products in the heat treatment process. A distinctive feature of the inventive raw material charge is that the process of expansion of the granules occurs when the pyroplastic state of the ceramic matrix is reached. When the temperature rises from 950 to 1070 ° C, magmatic acidic effusive glassy rocks and cullet pass into the liquid phase and actively interact with clay particles over the entire surface of the pore, providing the formation of reinforcing crystalline structures. The introduced glassy rocks and the thermal decomposition products of silicon carbide in the presence of molten glass phase formed from cullet powder at the firing temperature of ceramic products (950-1070 ° C) form a solid solid crystal structure. X-ray phase studies show that this structure is formed from crystals of wollastonite, anorthite and mullite. By this time, the clay component of the raw material mass creates a strong structural skeleton of the material, which secures the practically shrink-free structure of the product. The authors found that the high density of vitrified pore walls formed at temperatures of 950 ... 1070 ° C through the interaction of clay particles adjacent to the pores with molten glass phase from the material of the granules determines the high performance characteristics of the resulting wall ceramic products. When cooling the calcined product, these hardened-porous sections uniformly distributed over the volume of the obtained ceramic products prevent crack formation, this explains the high strength of the products and low water absorption even with a significant decrease in the density of the finished products compared to the prototype (proved by microscopic and petrographic studies). Ensuring uniform closed porosity with a strengthened internal structure in ceramic products also leads to a significant improvement in their strength characteristics compared to the prototype.

The raw material mixture for obtaining wall ceramic products according to the prototype, which does not additionally include magmatic acidic effusive glassy rocks and silicon carbide, does not allow to achieve a high result, implemented in the claimed method, because there is a mismatch between the foaming temperature of the granular material and the thermoplastic properties of the ceramic matrix (proved by dilatometric studies of samples of wall products during their heat treatment).

Obtained by the present method wall ceramic products have good decorative characteristics.

The use of the inventive raw material charge solves the problem of expanding the arsenal of technical means in the manufacture of durable, low-shrink and non-shrink wall ceramic products (bricks, blocks, wall panels, etc.), allows you to expand the raw material base by using natural environmentally friendly minerals and clays with large shrinkage properties during heat treatment, previously not used for the production of wall ceramic products, and this technology is not demanding on the purity of the initial materials .

Claims (3)

1. A method of manufacturing wall ceramic products, comprising mixing ground clay in an amount of 60-97 wt.% With aggregate in the form of hydrophobized granules with a size of 0.1-2.0 mm, consisting of a core, including cullet, ground with a pore former containing calcium carbonate and shells made of water-repellent, the amount of water-repellent is 1-10% by weight of aggregate, moistening, molding raw products by plastic or semi-dry pressing, drying and firing, characterized in that when grinding cullet and poros The igniter is additionally introduced with magmatic acidic effusive glassy rocks in an amount of 5-80 wt.% from a mixture of cullet and said rocks, and silicon carbide in an amount of 1-6% relative to the mass of said rocks, with the total amount of a blowing agent consisting of silicon carbide and calcium carbonate, is 1-6% by weight of a mixture of cullet and these rocks, and firing is carried out at a temperature of 950-1070 ° C. 2. The raw material mixture for the manufacture of wall ceramic products by the method according to claim 1, including ground clay - 60-97 wt.% And aggregate in the form of hydrophobized granules with a size of 0.1-2.0 mm, consisting of a core, including glass, ground with a pore-forming agent containing calcium carbonate and shells from a hydrophobizing agent, the amount of hydrophobizing agent is 1-10% by weight of aggregate, characterized in that the nuclei of the above aggregate additionally contain magmatic acidic effusive glassy rocks in an amount of 5-80 wt.% of the mixture Lobo and said rock and silicon carbide in an amount of 1-6% by weight of said rocks, and the total amount of blowing agent, consisting of silicon carbide and calcium carbonate, is 1-6% by weight of a mixture of cullet and said rocks. 3. The raw material charge aggregate according to claim 2, in the form of granules with a size of 0.1-2.0 mm, consisting of a core and a shell made of water repellent, the core comprising a mixture of crushed glass breakage and a blowing agent containing calcium carbonate, the amount of water repellent 1-10% by weight of aggregate, characterized in that the core material contains magmatic acidic effusive glassy rocks in an amount of 5-80 wt.% From a mixture of cullet and said rocks and silicon carbide in an amount of 1-6% relative to the weight of these rocks, and the total amount is porous The catalyst, consisting of silicon carbide and calcium carbonate, accounts for 1-6% of the weight of the mixture of cullet and these rocks.