RU2327666C1 - Method of manufacture of wall ceramics using sedimentary high-silica rocks, stock for wall ceramics, and aggregate for wall ceramics - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: said utility invention relates to the wall ceramics production and may be used for the production of heat-insulating materials: bricks, blocks, wall panels, etc. The method involves mixing 60-97 weight % of ground clay with aggregate, the remaining being hydrophobised granules with a size of 0.1-2.0 mm. The aggregate consists of a core including crushed glass ground with cellulating agent (calcium and/or magnesium carbonate), and a water repellent shell, the water repellent quantity being 1-10% of the aggregate weight. During crushed glass and cellulating agent milling, natural sedimentary high-silica rocks are added, in an amount of 5.0-80 weight % of crushed glass and the said sedimentary rocks in the mixture, and alkali metal hydroxide in an amount of 1.5-4.0% of the weight of the said sedimentary rocks is added, the cellulating agent quantity being 1-6% of the crushed glass mixture. After that, the raw products are moistened, formed using the soft-mud or semi-dry pressing method, dried, and burned at 890-925°C.

EFFECT: expansion of technical means during production of high-strength low-shrinkage or non-shrinking wall ceramics.

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 and / or magnesium, while the amount of water repellent is 1 ... 10% by weight 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 firing, insufficient strength of the resulting wall ceramic products, which limits the use of many types of clays with large shrink properties during heat treatment.

The present invention solves the problem of expanding the arsenal of technical means for the production of non-shrink and non-shrink wall ceramic products with the preservation and increase of their strength, allows you to expand the raw material base by using environmentally friendly natural materials as diatomite, flask, tripoli and clays with great shrinkage properties heat treatment, previously for the production of wall ceramic products not used

The technical result is achieved by a method of manufacturing wall ceramic products, including 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 - calcium carbonate and / or magnesium, 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, while according to the proposed solution when Ole cullet and blowing agent instead of 5.0 ... 80 wt.% cullet introduce natural sedimentary high-siliceous rocks and additionally introduce alkali metal hydroxide in an amount of 1.5-4.0% relative to the mass of natural sedimentary high-siliceous rocks, and the amount of blowing agent is 1-6% of a mixture of cullet and natural sedimentary high-siliceous rocks, while firing is carried out at a temperature of 890-925 ° C.

The technical result is achieved by the fact that in the raw material mixture 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 with a blowing agent - calcium and / or magnesium carbonate, while 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 natural sedimentary high-siliceous rocks and Tel'nykh alkali metal hydroxide in an amount of 1.5-4.0% by weight of natural sedimentary rocks vysokokremnezemistyh, and the amount of pore forming agent 1-6% of a mixture of cullet and vysokokremnezemistyh natural sedimentary rocks.

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 - calcium and / or magnesium carbonate , the amount of water repellent is 1-10% by weight of aggregate, according to the proposed solution, the core material of the aggregate instead of 5.0 ... 80 wt.% cullet contains natural sedimentary siliceous rocks and additionally contains a gap hydroxide precious metal in an amount of 1.5-4.0% relative to the mass of natural sedimentary high-siliceous rocks, and the amount of pore-forming agent is 1-6% of a mixture of cullet and natural sedimentary high-siliceous rocks.

Comparison of the proposed solution with the prototype made it possible to establish that it differs in the introduction of a core aggregate in place of 5.0 ... 80 wt.% Cullet of natural sedimentary high-siliceous rocks and additional alkali metal hydroxide in an amount of 1.5-4.0% relative to the mass of natural sedimentary high-siliceous rocks, while the amount of blowing agent is 1-6% of the mixture of cullet and natural sedimentary high-siliceous rocks, as well as the firing temperature of the products proposed by the authors. Thus, the proposed solution has the criterion of "novelty."

In the study of other technical solutions, the use of the introduction of the natural aggregate sedimentary siliceous rocks, for example, diatomite, flask, tripoli, etc., proposed by the authors of the core aggregate. or mixtures of these minerals instead of 5.0 ... 80 wt.% cullet and additional alkali metal hydroxide, in an amount of 1.5-4.0% relative to the mass of natural sedimentary high-siliceous rocks, as well as firing products at a temperature of 890-925 ° C has not been identified, so the claimed solution does not follow explicitly from the prior art, which allows us to conclude that the proposed solution meets the criterion of "inventive step".

Characterization of mass components:

1. As a clay component used loam Shebekinsky deposits of the Belgorod region. Refractoriness 1180 ... 1270 ° С. Water solubility - 28.7% (according to GOST 9169-75). The main clay mineral is montmorillonite. The color after firing is greenish yellow. The chemical composition of the loam of the Shebekinsky deposit is presented in Table 1.

2. As cullet used the battle of green container glass, Voronezh. The initial battle of container glass was crushed in a hammer mill, washed and dried in a washing and drying drum, stored in a storage bin.

3. As natural sedimentary siliceous rocks used:

- diatomite of the Zabaluisky deposit (Ulyanovsk region);

- flask of the Alekseevsky deposit (Mordovia);

- Tripoli of the Fokinsky field (Bryansk region).

Natural sedimentary high-siliceous rocks, if necessary, were crushed in a hammer mill and stored in storage bins.

4. As a blowing agent used calcium carbonates (chalk, limestone), magnesium carbonate (magnesite) and their natural mixture (dolomite):

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

- limestone of the Yashkinsky deposit;

- magnesite, Satka, Chelyabinsk region SM-1 according to TU 14-8-64-73;

- Dolomite, Schelkovo field of the Moscow region.

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

5. As the alkali metal hydroxide used sodium hydroxide according to GOST 2263-79.

6. When granulating cullet powder, additionally containing natural sedimentary high-siliceous rocks and sodium hydroxide, ground together with a pore former, an aqueous solution of silicate glue (liquid glass) was used on a plate granulator 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 obtained cores consist of a mixture of ground glass breakage, a natural sedimentary high-siliceous component, an alkali metal hydroxide and a pore-forming agent - calcium and / or magnesium, interconnected by liquid glass.

7. 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 natural sedimentary high-siliceous rocks, sodium hydroxide and pore former by the gravimetric method. The resulting mixture was loaded into a ball mill and produced joint grinding to achieve a specific surface of 300 ... 500 m ² / kg 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. p / p 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 Loam Shebekinsky 58.9 7.6 0.4 1,2 10.1 2,8 3.4 0.4 15,2 2 Glass Fight 65,2 10.7 0.8 1,2 6.5 0.7 14.7 0.2 - 3 Chalk Belgorod 1.3 0.7 0.1 0.1 54.7 0.3 - - 42.8 four Limestone Yashkinsky 1.7 0.8 0.1 0.4 52.3 1,1 1,2 0.2 42,2 5 Magnesite Satkinsky 1,2 0.9 0.2 0.4 0.8 46.0 0.5 0.3 49.7 6 Dolomite Schelkovsky 0.8 0.2 0.1 0.2 30.9 22.8 0.7 0.2 44.1 7 Diatomite 82.8 6.1 0.1 3,1 0.8 0.6 1.3 0.1 4,5 8 Flask 76.9 8.1 0.2 4.2 2.1 0.9 1.8 0.2 3.9 9 Tripoli 74,2 7.2 - 2,4 6.6 1,1 0.6 0.1 8.6

Example. 7.8 kg (78%) of Shebekinsky loam, pre-dried, crushed and sieved through a sieve with a hole size of 0.1 mm, was weighed, 2.2 kg (22%) of aggregate was added in the form of granules obtained from co-milled to a specific surface of 400 m ² / kg of components: cullet - 1.260 kg (60%), diatomite - 0.841 kg (40%), sodium hydroxide - 0.025 kg (3.0% by weight of diatomite), chalk - 0.074 kg (3.5% by weight cullet and diatomite); granular, sieved through a sieve with a mesh diameter of 2.0 mm and remaining on the sieve of 0.1 mm and hydrophobized to obtain a shell - by treatment with molten paraffin in an amount of 5% relative to the weight of the granules, see table 2, mixture 1.

In the table. 2 shows the composition of the charge and the properties of wall ceramic products.

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. The samples were dried to a residual moisture content of 0.5 ... 2%, and then fired at a temperature of 910 ° C, similarly to the method described in RF patent No. 2277520, class. 6 С04В 33/02, 2005.

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 10 (plastic molding method) and 14 (semi-dry molding method of products) were made according to the prototype (RF Patent No. 2277520, class 6 С04В 33/02, 2005, table 2, composition 1).

Products from mixtures 4-6 and 11-13 (table 2) were obtained by semi-dry pressing.

Analyzing the results of physical and mechanical tests of a series of experimental samples, we can conclude that the formation of the porous structure of fired ceramic materials with aggregate is facilitated by the joint grinding of cullet, natural sedimentary high-siliceous rocks, sodium hydroxide and pore former until a specific surface of 300 ... 500 m ² / kg is reached .

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

1. All mixtures 1-14 meet the requirements of TU 530-95 "Brick and ceramic stones."

2. The introduction into the composition of the ceramic mass of the aggregate in the form of cullet, ground together with natural sedimentary high-siliceous rocks, sodium hydroxide and pore former, granular and hydrophobized, in the claimed quantities and grain size of 0.1 ... 2.0 mm, as well as subsequent firing at a temperature of 890-925 ° C, it allows to obtain durable high-quality wall ceramic products with adjustable shrinkage during firing.

3. Calcined ceramic products obtained from raw mixtures 3, 6, 9 and 13 have a negative shrinkage, i.e. there is a uniform increase in linear and volumetric dimensions with acceptable surface defects of the calcined samples in comparison with the dimensions of the original raw products.

4. To reduce the amount of granular aggregate in raw materials mixtures less than 3 wt.%, As well as the amount of natural sedimentary high-siliceous rocks in relation to the mass of cullet less than 5 wt.% And reduce the firing temperature less than 890 ° C is impractical, because the resulting ceramic products according to complex technical characteristics are not sufficiently high quality due to the presence of shrinkage during drying and firing, and despite the fact that the physical and mechanical characteristics of the products meet the requirements of TU 530-95, compositions 2, 5, 8 and 12 due to the presence of cracks of acceptable size are taken as boundary.

An increase in the amount of granular aggregate in raw material mixtures of more than 40 wt.%, As well as the amount of natural sedimentary high-siliceous rocks with respect to cullet mass of more than 80 wt.% And an increase in firing temperature of more than 925 ° C are impractical, because the strength of the resulting wall ceramic materials decreases due to the appearance of defects in the expanding structure of the fired products and violation of geometric dimensions. For this reason, despite the fact that the physico-mechanical characteristics of the products meet the requirements of TU 530-95, compositions 3, 6, 9 and 13 are accepted as boundary ones.

The inventive raw material mixture for the manufacture of wall ceramic products has the following advantages:

1) with optimal ratios of components in raw materials, the compressive strength of the resulting products increases to 26%;

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 goal is as follows: the introduction of a hydrophobized aggregate, consisting of co-ground cullet and blowing agent, additional natural sedimentary high-siliceous rocks and sodium hydroxide, allows you to adjust the temperature range of their foaming. The foaming temperature of the granules of the selected composition, taking into account the degree of thermoplasticity of the clay component constituting the matrix of wall ceramics, allows to obtain products with adjustable shrinkage during firing. 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. When the temperature rises from 890 to 925 ° С, natural sedimentary high-siliceous rocks, sodium hydroxide and cullet pass into the liquid phase and actively interact with clay particles over the entire pore surface, providing the formation of reinforcing crystalline structures in the “pore-ceramics” contact zones, because . introduced natural sedimentary high-siliceous rocks and sodium hydroxide in the presence of molten glass phase, formed from cullet powder, form a solid strong crystalline structure even at low temperatures at the firing temperature of ceramic products. X-ray phase studies show that this structure is formed mainly from wollastonite and anorthite crystals. 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 890 ... 925 ° C by 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 areas, evenly distributed over the volume of the obtained ceramic products, prevent crack formation, this explains their high strength and low water absorption even when the density of the finished products is reduced 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 natural sedimentary high-siliceous rocks and sodium hydroxide, does not allow to achieve a high result, implemented in the claimed method, because reinforcing crystals are formed in insignificant amounts (proved by X-ray phase studies).

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 environmentally friendly natural materials - diatomite, flask, tripoli and clays with great shrinkage properties during heat treatment, previously not used for the production of wall ceramic products, and this technology is not demanding on purity of raw materials.

Claims (3)

1. A 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, consisting of a core including glass, ground with a pore former - carbonate calcium and / or magnesium, and a shell made of water-repellent, the amount of water-repellent is 1-10% by weight of aggregate, moistening, molding raw products by plastic method or by semi-dry pressing, drying and firing, characterized in that when moles of cullet and blowing agent are additionally introduced natural sedimentary high-siliceous rocks in the amount of 5.0-80 wt.% from the content in the mixture of cullet and these sedimentary rocks and alkali metal hydroxide in an amount of 1.5-4.0% relative to the mass of these sedimentary rocks while the amount of blowing agent is 1-6% of the mixture of cullet and the specified sedimentary rocks, firing is carried out at a temperature of 890-925 ° C. 2. The raw material mixture for the manufacture of wall ceramic products according to claim 1, 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, consisting of a core, including cullet, ground with a pore-forming agent - calcium and / or magnesium carbonate, and a shell made of water-repellent, the amount of water-repellent is 1-10% by weight of aggregate, characterized in that the core of the above aggregate additionally contains natural sedimentary siliceous rocks in an amount of 5.0 -80 wt.% From a mixture of cullet and these sedimentary rocks and alkali metal hydroxide in an amount of 1.5-4.0% relative to the mass of these sedimentary rocks, the amount of blowing agent is 1-6% of a mixture of cullet and these sedimentary rocks . 3. The filler of the raw material charge according to claim 2 for the manufacture of wall ceramic products, in the form of granules with a size of 0.1-2.0 mm, consisting of a core and a shell of a hydrophobizing agent, the core comprising a mixture of crushed glass breakage and a pore former - calcium carbonate and / or magnesium, while the amount of water repellent is 1-10% by weight of aggregate, characterized in that the core material contains natural sedimentary siliceous rocks in an amount of 5.0-80 wt.% from a mixture of cullet and said sedimentary rocks and alkali metal hydroxide in an amount e 1.5-4.0% by weight of said sediment, the amount of blowing agent is 1-6% of the mixture of said cullet and sedimentary rocks.