RU2663980C1 - Method of manufacturing the aerated ceramics - Google Patents

Abstract

FIELD: ceramics.SUBSTANCE: invention relates to the method for manufacturing aerated ceramic products and can be used in industrial and low-rise construction as bearing and self-supporting structural elements, and also as decorative construction materials. In the proposed method, the raw material mixture includes the clay component, water, the pore-forming, diluent, waste away, reinforcing and coloring additives. Using the high-speed feed mixer under excessive pressure, the mixture is converted into the aerated clay mass, which is molded, dried, cut, burned, and then cooled and processed.EFFECT: invention allows to reduce the duration of the technological process of manufacturing articles by means of using the agrillic component based on clay materials, to reduce the labor intensity of technological operations and to produce the products with the structure that is uniformly colored along the volume and/or with decorative and protective coatings, as well as with the spherical pores, which are distributed throughout the volume that have the size of less than 5 mm with the average density of less than 1,000 kg/m.7 cl, 3 dwg

Description

The invention relates to the production of aerated (cellular) ceramics for construction purposes and can be used as structural heat-insulating and heat-insulating products in the construction of buildings and structures, as supporting and self-supporting structural elements, as well as decorative elements for the outer and inner cladding of building envelopes .

Aerated ceramic products can be made in the form of blocks, stones, plates, bricks, shaped elements of individual shapes, as well as lightweight aggregate and coloring filler for dry building mixtures.

State of the art

A known method of producing ceramic foam products, including the preparation of clay mass by mixing a raw material mixture consisting of a clay component, water and additives, including pore-forming additives, molding the clay mass, drying and firing. (RU 2349563 C2, C04B 38/02, 20.03 .2009). In the known method, a burnable additive in the form of sawdust is used as a pore-forming additive. The disadvantage of this method is the use of Portland cement as one of the additives, which may be the reason for the accelerated appearance of salt deposits on the surface of products. Moreover, the known method is not environmentally friendly due to the use of Portland cement and waste from aluminum pickling as additives in the raw material mixture, as well as due to environmental pollution during the burning of sawdust.

A known method of manufacturing foamed building materials, including preparing a clay mass by mixing a raw material mixture consisting of a clay component, water and additives, including a pore-forming additive, molding the clay mass, drying and calcining it (RU 2517133 C2, C04B 38/08, B28B 5/04, 05.27.2014). The known method allows the manufacture of lighter foam-ceramic building materials while increasing their heat-insulating and noise-insulating properties than the first analogue. This is explained by the use of a foaming agent as a pore-forming additive, in particular, PB-2007. In this case, the pore-forming additive is used as the basis for the preparation of technical foam, which is introduced into the raw material mixture when it is mixed. The disadvantages of this method include the need to use a sufficiently large amount of expensive foaming agent to produce foam, as well as the increased complexity of the process of uniformly mixing separately prepared foam and clay mass in the mixer.

A known method of manufacturing products of porous (aerated) ceramics, including the preparation of aerated clay mass (ATM) by mixing a raw material mixture consisting of a clay component, water and additives, including pore-forming additives, molding ATM, drying ATM, cutting obtained after drying ATM , ATM firing and machining of the obtained aerated ceramic products (AKI). (RU 2621796 C1, С04В 33/04, С04В 33/16, С04В 38/10, С04В 40/00, 07/07/2017). In this method, a high-speed mixer is used to prepare the ATM, under the influence of the rotation of the blades of the mixers of which intensive mixing of the raw material mixture takes place until ATM is formed with the formation of air bubbles in it. In this method, the pore-forming additive is made in the form of an aqueous hydrocarbon solution of surface-active substances (surfactants). In addition, a fluidizing additive in the form of electrolytes based on either glass of sodium liquid or glass of potassium liquid, or based on calcined technical soda, or based on their combinations, is used as one of the additives. An additional thinner additive is also used in the form of crushed powder material based on either fireclay, or natural sands, or sands from crushing screenings, or ground glass, or battle of clay ceramics, or dehydrated clay, or ash, or slag, or pyrite cinders, or by-products iron ore enrichment products, or combinations thereof. Moreover, in this method, a reinforcing additive in the form of fiber is additionally used.

This device is inherent in the set of features closest to the set of essential features of the invention, therefore, this method is adopted by the author as a prototype.

The disadvantage of the prototype is that the operation of cutting AKI is performed immediately after firing and is quite time-consuming due to the high temperature of the AKI. The disadvantage of the prototype also includes the complexity of transporting ATM from the mixer to the place of its placement in the mold, which limits the options for the possible placement of technological equipment for mixing and molding clay mass in the production room.

The problem to which the present invention is directed is to create a method for producing AKI based on widespread clay rocks with various mineral and chemical compositions, with the possibility of manufacturing AKI and AKI painted with a full volume with decorative and protective coatings, while reducing the complexity of manufacturing AKI.

This object is achieved in that in a method for the manufacture of AKI, including the preparation of ATM by mixing in a high-speed mixer a raw mixture consisting of a clay component, water, and also a pore-forming additive in the form of an aqueous hydrocarbon solution of a surfactant, a diluting additive made in the form of electrolytes based on or glass of sodium liquid, or glass of potassium liquid, or based on soda ash, or based on their combinations, a thinner additive, made in the form of powdered powder different materials based on either fireclay, or natural sands, or sands from screenings of crushing, or ground glass, or battle of clay ceramics, or dehydrated clay, or ash, or slag, or pyrite cinders, or by-products of iron ore beneficiation, or combinations thereof , and reinforcing additives in the form of fibers, molding ATM, drying ATM, cutting obtained after drying ATM, firing AMG and machining of the obtained AKI, characterized in that as a clay component use a mixture of clay rocks in a crushed state with maxim particle size of not more than 30.5 mm, which is made on the basis of either low-melting clay, or refractory clay, or loam, or refractory clay, or kaolin, or loess, or loess loam, or tripoli, or diatomite, or mudstone, or siltstone or shale or bentonite clay; mixing the raw material mixture is carried out in a high-speed mixer under excess pressure; however, the AKI obtained after firing is cooled, and then subjected to mechanical processing and dedusted.

Moreover, in some cases, after drying the ATM, the ATM surface layer is moistened and grouted.

Moreover, in some cases, a protective coating is applied to the surface of the AKI using either a hydrophobizing polymer composition, or using mineral putty, or using polymer putty, or using mineral plaster, or using polymer plaster.

Moreover, in some cases, a coloring additive is introduced into the raw material mixture, which is made in the form of a powdered inorganic compound based on either iron oxide or copper oxide or cobalt oxide or chromium oxide or nickel oxide or titanium oxide or magnesium oxide, or zinc oxide, or sodium oxide, or potassium oxide, or combinations thereof.

Moreover, in some cases, the surface or parts of the surface of the AKI are painted with either a water-based emulsion, or acrylic, or latex, or silicone, or alkyd, or silicate paint.

Moreover, in some cases, a decorative coating is applied to the surface of the dried ATM and / or to the surface of the AKI using either glaze, or engobe, or overglaze ceramic paint, or underglaze ceramic paint.

Moreover, in some cases, applying a decorative coating to the surface of the AKI is carried out using either sublimated printing, or using decal, or using an ultraviolet inkjet printer, or using direct digital printing to form a polymer layer without using heat treatment, or using devices, which will become known when using the proposed method.

The technical result when using the proposed method is to reduce the duration of the production cycle of manufacturing AKI, reducing the complexity of technological operations and expanding the use of AKI based on clay rocks.

The specified technical result of reducing the duration of the production cycle for the manufacture of AKI is achieved by the fact that, in contrast to the prototype, in preparing the raw material mixture, the proposed method uses a clay component based on a mixture of several clay rocks of various mineral and chemical composition in a crushed state with a maximum particle size of not more than 30, 5 mm, which allows ATM to obtain the required mobility, but with a lower water content and thereby reduce the drying time of the ATM, while reducing the longitudinal the viability of the entire production cycle of the manufacture of AKI in comparison with the prototype.

The indicated technical result to reduce the complexity of technological operations is achieved by the fact that the preparation of ATM and its molding are carried out under excessive pressure in a high-speed mixer, which allows the pneumatic feeding of ATM to the place of its molding over considerable distances. In addition, the specified technical result is achieved by the fact that in the proposed method, machining of chilled after firing AKI is performed, which makes it possible to produce AKI with various surface shapes with lower labor costs and higher processing accuracy, while reducing the cost of purchasing cutting tools by increasing them service life.

The specified technical result on the expansion of application of AKI based on clay rocks in comparison with the prototype is achieved in some cases due to the fact that after drying the ATM, the ATM surface layer is moistened and grouted, which allows to obtain various types of surface textures of finished AKI. Moreover, AKI with flat and, in particular, with dust-free surfaces can be used as elements in construction using 3D printers and a bonding layer between them. In this case, AKI with faces that have a locking principle of connecting with each other, for example, end joints, cross joints, corner joints and other joints, can be used in the construction of building structures without the use of binding solutions (for example, a link to the electronic resource http: // 3dwiki.ru/3d-pechatnye-keramicheskie-bloki-polybricks-zamenyat-privychnye-kirpichi/ from 03.07.2014). At the same time, moistening the surface layer and grouting it allows to reduce the complexity of applying decorative and / or protective coatings to the surface of the AKI.

The specified technical result on the expansion of application of AKI based on clay rocks is achieved in some cases due to the possibility of manufacturing AKI, painted throughout. This is due to the addition of a coloring agent to the raw material mixture, which is made in the form of a powdered inorganic compound. In this case, it becomes possible to paint AKI in different color shades. So, for example, to obtain volumetric staining in green color shades, mixtures of copper oxide and cobalt are used, and to obtain blue color shades, mixtures of cobalt, chromium and copper oxides are used.

The specified technical result on the expansion of the application of AKI based on clay rocks in comparison with the prototype is achieved in some cases due to the possibility of manufacturing AKI with decorative and / or protective coatings. At the same time, such paints as water-based, acrylic, latex, silicone, alkyd or silicate are used to paint the surface or part of the surface of the AKI. To decorate the surface of the dried ATM or AKI surface, either glaze, or engobe, or overglaze ceramic paint, or underglaze ceramic paint is used. Protective coatings of the finished AKI surfaces are carried out using either hydrophobizing polymer compositions or mineral putties, or polymer putties, or mineral plasters, or polymer plasters. In this case, such coating methods as sublimated printing or decal are used. In addition, the coating is carried out, for example, using ultraviolet inkjet printers, or direct digital printing with the formation of a polymer layer without using heat treatment, or using other devices that will become known at the date of use of the proposed method.

The essence of the proposed method is as follows.

At the first stage of AKI manufacturing, the raw mix is prepared. The composition of the raw mix is formed from a clay component, water and special additives: pore-forming, thinning, thinning and reinforcing additives. In some cases, a coloring additive is introduced into the raw material mixture, which is made in the proposed method in the form of a powdered inorganic compound based on either iron oxide or copper oxide or cobalt oxide or chromium oxide or nickel oxide or titanium oxide or magnesium oxide or zinc oxide or sodium oxide or potassium oxide, or combinations thereof. As a clay component in the proposed method, a mixture of clay rocks of various mineral and chemical composition in a crushed state with a maximum particle size of not more than 30.5 mm, which is made on the basis of either low-melting clay, or refractory clay, or loam, or refractory clay, or kaolin, or loess, or loess loam, or tripoli, or diatomite, or mudstone, or siltstone, or shale, or bentonite clay. The moisture content of the clay component is set to not more than 75%. The clay component is used as a plastic matrix that can hold other components of the raw material mixture in a uniformly distributed state, form a cellular structure during aeration, maintain its shape in a dried state, and acquire the properties of a stone during heat treatment. In addition, as a clay component in the proposed method uses by-products formed during the cutting of AGM after drying. In the proposed method, when preparing the raw material mixture, either drinking water or natural surface water, or ground water, or industrial water, or water after washing the equipment for the production of AKI, or sea water, or saline water, or magnetized water, or a combination thereof, is used.

At the second stage of AKI manufacturing, ATM is prepared from the raw mix, for which the raw mix is mixed at a temperature of not more than 85 ° C. For mixing the raw material mixture, a high-speed mixer with a stirrer speed of not more than 3400 rpm is used. Mixing is carried out under excess pressure until a uniform distribution of all components is achieved over the volume of the resulting clay mass. Next, the mass is subjected to further mixing in order to aerate it. Mixing is carried out in a high-speed mixer with a working air pressure of not more than 7 atmospheres until the density of the obtained ATM is more than 150 kg / m ³ . The pressure in the mixer is created by forcing compressed air into it. Moreover, in the proposed method, the preparation of clay mass and the manufacture of ATM from it is carried out both in one high-speed mixer and in separate high-speed mixers, depending on the required performance and on the layout of the production line. Typical mixing devices operating on the principle of barotechnology, for example, turbulent-type high-speed mixers or cavitation high-speed mixers, are used as a high-speed mixer for AGM.

At the third stage of AKI manufacturing, AGM is formed and dried, for which purpose the obtained AGM is placed in a mold. In this case, rigid forms are used, for example, airborne and / or collapsible, in particular, lubricated with special compounds that reduce adhesion. After laying the AGM in the form, carry out the drying of the AGM. The basis for determining the optimal drying regime of the AGM is an indicator of the critical humidity gradient, determined by the difference in humidity between its center and surface, referred to a unit of length. After reaching the required humidity, the AGM is freed from its form. It should be noted that the preservation of the porous structure of the formed AGM is ensured by the ability of the clay component to create stable suspensions in a dispersion medium, and then coagulate, forming strong spatial bonds. In the proposed method, in some cases, for example, to prepare the surface for applying a decorative and / or protective coating, or for other purposes, after drying the AGM, its surface layer is moistened and grouted.

At the fourth stage of manufacturing AKI, the obtained after drying AGM is cut into individual products. It should be noted that in the proposed method obtained by cutting AGM by-products are used in the manufacture of AKI again as a clay component.

At the fifth stage of manufacturing AKI, heat treatment (firing) of cut products is performed. In the proposed method, firing is performed at a temperature of not more than 1650 ° C, while the firing mode is calculated based on the properties of the components of the raw material mixture. During firing, in the process of heat transfer and mass transfer, complex phase and chemical transformations are carried out in products from AGM, due to which they acquire new basic physical and mechanical properties of the finished AKI.

At the sixth stage of the manufacture of AKI, the AKI obtained after firing is cooled, they are machined to give them the necessary geometric shape and the dust is removed from the AKI. In some cases, after dedusting, coloring and / or protective coatings are applied to the surface or part of the surface of the AKI. At the end of the sixth stage of manufacturing, finished AKIs are packaged and, for example, are sent to the finished goods warehouse.

The technical nature and practical applicability of the proposed method for the manufacture of AKI is illustrated by the following description and drawings, where in FIG. 1 shows a photograph showing an AGM molded in the form of a brick with dimensions of 250 × 120 × 65 mm; in FIG. 2 shows a photograph showing the finished AKI in the form of bricks with dimensions 250 × 120 × 65 mm; in FIG. Figure 3 shows a photograph showing an enlarged fragment of the porous structure of an AKI.

In accordance with the proposed method, AKI were made with the following characteristics:

design factor from 4.1 to 30.8 softening coefficient from 0.81 to 0.99 thermal conductivity coefficient, W / (m⋅С) from 0.04 to 0.51 size distributed throughout spherical pores less than 5 mm average density, kg / m ³ less than 1000

Moreover, the use in the proposed method of a raw material mixture on the basis of clay rocks proposed by the author of the composition allowed to expand the range of AKI compared to the prototype due to the manufacture of AKI painted throughout the volume, as well as through the manufacture of AKI with decorative and / or protective coatings while reducing their complexity manufacturing and while reducing the duration of the production cycle of the manufacture of AKI. Also, the experimental results showed that AKI made using the raw material mixture proposed by the author on the basis of clay rocks of various mineral and chemical composition are non-combustible building materials with a frost resistance rating of at least F35 and allow building structures with fire hazard class K0 and fire resistance limit to be erected REI240.

Claims (7)

1. A method of manufacturing aerated ceramic products, including the preparation of a clay mass by mixing in a high-speed mixer a raw material mixture consisting of a clay component, water, a pore-forming additive made on the basis of a hydrocarbon surfactant, a fluidizing additive made in the form of electrolytes based on or glass of sodium liquid, or glass of potassium liquid, or based on soda ash, or based on their combinations, a thinner additive made in the form of powdered material based on either fireclay, or natural sands, or sands from screenings of crushing, or ground glass, or battle of clay ceramics, or dehydrated clay, or ash, or slag, or pyrite cinders, or by-products of iron ore enrichment, or their combinations, and a reinforcing additive in the form of fiber, molding a clay mass using a rigid form, drying the clay mass, cutting the obtained aerated clay mass and firing it, characterized in that the mixture is used as a clay component clay rocks of various mineral composition in a crushed state with a maximum particle size of not more than 30.5 mm, which is made on the basis of either low-melting clay, or refractory clay, or loam, or refractory clay, or kaolin, or loess, or loess loam, or tripoli or diatomite or mudstone or siltstone or shale or bentonite clay; mixing the raw material mixture is carried out in a high-speed mixer under excess pressure; however, the aerated ceramic product obtained after firing is cooled, and then subjected to mechanical processing and dedusted. 2. The method according to p. 1, characterized in that after drying the aerated clay mass, its surface layer is moistened and grouted. 3. The method according to p. 1, characterized in that a coloring additive is introduced into the raw material mixture, which is made in the form of a powdered inorganic compound based on either iron oxide or copper oxide or cobalt oxide or chromium oxide or nickel oxide or oxide titanium, or magnesium oxide, or zinc oxide, or sodium oxide, or potassium oxide, or combinations thereof. 4. The method according to one, to any one of paragraphs. 1-3, characterized in that a protective coating is applied to the surface of the aerated ceramic product using either a hydrophobizing polymer composition, or using mineral putty, or using polymer putty, or using mineral plaster, or using polymer plaster. 5. The method according to one, to any one of paragraphs. 1-3, characterized in that the surface or parts of the surface of the aerated ceramic products are painted or water-based, or acrylic, or latex, or silicone, or alkyd, or silicate paint. 6. The method according to one, to any one of paragraphs. 1-3, characterized in that on the surface of the dried aerated clay mass and / or on the surface of the aerated ceramic product is applied a decorative coating using either glaze, or engobe, or overglaze ceramic paint, or underglaze ceramic paint. 7. The method according to p. 6, characterized in that the decorative coating on the surface of the aerated ceramic products is performed using either sublimated printing, or using decal, or using an ultraviolet inkjet printer, or using direct digital printing with the formation of a polymer layer without using heat treatment, or using devices that will become known at the date of use of the proposed method.

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