RU2517133C2 - Production of foamed construction materials - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of construction materials and can be used for fabrication of ceramic bricks, stones and blocks. Proposed method comprises preparation of foam-ceramic mix from clay stock, water, foaming agent, binding agent, drying, annealing and forming. Note here that, additionally, foaming agent PB-2007 is admixed as a plasticising agent while finished product ground to 1.25-5.0 mm fraction or perlite sand are used as binding additive. Then, obtained mix is poured in flat moulds and dried, first, at 30-35°C and, then at 50-56°C to make an integral blank to be withdrawn from the mould, annealed at 800-1600°C and formed to blocks.

EFFECT: higher heat- and noise-isolation properties, decreased weight.

Description

The invention relates to the building materials industry, in particular the production of ceramic foam materials and can be used in the manufacture of ceramic bricks, stones and blocks.

Ceramic building materials (hereinafter referred to as bricks) are usually used for the construction of bearing and self-supporting walls and partitions, single-storey and multi-storey buildings and structures, internal partitions, filling voids in monolithic-concrete structures, laying foundations, the inside of chimneys, industrial and domestic stoves.

From RU 2376133 (B28B 1/50, publication date 12/20/2009) it is known to manufacture porous ceramic bricks, according to which clay, water and shot are loaded in predetermined proportions through a funnel 4 into mixer 1, in which they are mixed together to achieve specified properties of the dough - its plasticity and saturation with its fraction. From the mixer, the dough enters the hopper and from it into the high-speed mixer, where additional mechanical mixing and aeration of the mass occurs, which leads to a uniform distribution of the fraction in the dough mass, which is squeezed out of the mouthpiece in the form of a bar onto the conveyor belt using the hopper and a screw press. The timber from the dough moves under a moving belt with electromagnets, which leads to the extraction of fractions from it and the porization of the timber from the dough. In the manufacture of porous bricks, a foaming agent is not used. This method does not allow to achieve a product density below 1000 kg / m ³ .

A method of manufacturing wall ceramic products known from RU 2240294 (С04В 33/00, С04В 38/06, publication date 11/20/2004) involves mixing a mixture containing brick clay and a burnable additive treated with a sodium-containing component, plastic molding, drying and firing. Buckwheat husk is used as a burnable additive in an amount of 20-56% of the charge volume, as a sodium-containing component for the treatment of a burnable additive, a 10% aqueous solution of soapy liquor (liquid by-product of soap manufacture) is used, in addition, soapy liquor is additionally introduced into the mixture in the amount of 1.3-1.7% by weight of clay. The disadvantage of this solution is low manufacturability. In the implementation of the method, pressing is used, and not casting, and consequently, compaction occurs and, as a result, the high density of the finished product.

The method of producing ceramic foam products (see RU 2349563, С04В 38/02, publication date 03/20/2009) is aimed at increasing strength, reducing heat conductivity. The result is achieved in that in the method for producing ceramic products, comprising co-mixing finely ground clay, aggregate, burn-out, stabilizing and fluxing additives, water glass, plasticizer, water and a blowing agent, molding, drying and firing of products according to the invention, as a burn-out additive sawdust fractions of 0.25-0.315 mm, as a filler, a ceramic brick fight, as a fluxing additive, ground glass and aluminum etching waste with a density of 1.05-1.3 g / cm ³ , at Ohm clay, ceramic brick batter and ground glass are ground to a particle size of 70-100 microns before mixing the components, and separately prepared foam is used as a foaming agent, Portland cement is additionally introduced; drying molded samples is carried out at 40-60 ° C, and firing at a temperature of 980-1050 ° C.

The second stage is the molding in collapsible metal molds. In this case, forms are used for molding, the bottom of the walls of which are previously lined with paper.

The third stage is drying. In the drying process after stripping, the raw material is turned upside down to change the direction of moisture loss.

The final stage is the firing of ceramic foam, which is carried out at a temperature of 980-1050 ° C (optimal 1030 ° C) for 12 hours.

The disadvantages of the known method of producing ceramic products include the use of a large number of components. The resulting product is not environmentally friendly due to the use of cement, liquid soap. The method does not allow to obtain hollow-porous ceramic products with a density of less than 1000 kg / m ³ . Based on the set of essential features, this decision was taken as a prototype.

The problem to which the invention is directed is due to the requirements for ceramic bricks - porosity, which provides good heat and noise insulation and lightness, which allows for the construction, especially high-rise buildings, to reduce the load on the frame and foundation of the building structure.

The technical result, which manifests itself in the implementation of the proposed method, is to increase heat, noise insulation properties, facilitate building materials.

The essence of the invention lies in the fact that, unlike the closest analogue

After preparing the ceramic foam mixture, drying is carried out, then firing, then the product is shaped; as components use clay raw materials, a plasticizing additive, a foamed mass, an astringent additive, clay with any mineral composition is used as clay raw materials; as a plasticizing additive - for example, PB-2007 foaming agent or other substance with the indicated properties; the foamed mass is obtained by mixing water and the PB-2007 foaming agent in a ratio of 5% of the volume of water; as a binder additive, the finished product ground to a fraction of 1.25-5.00 mm or waste from its production or perlite sand or sawdust is used.

Plasticizing additive is used to impart ductility to raw materials. The use of foam in the manufacture of ceramic foam products provides a cellular structure with closed pores, which improves heat-shielding properties and reduces thermal conductivity. To exclude the process of shrinkage and achieve stability during drying, a binder additive is added to the prepared mass. In addition, in the aggregate, a composition based on a foaming agent and a cementitious additive serves to achieve a low density of the mixture and impart a porous structure. The claimed sequence of stages of the method allows to increase the manufacturability of the production of foamed building materials and to obtain products with the declared properties.

The proposed method of manufacturing foamed building materials is as follows.

The first stage is the preparation of a ceramic foam mixture

The clay raw material is cleaned of impurities, then thoroughly mixed with water in a mixer, in which the plasticizing additive is preliminarily diluted. The amount of water depends on the mineral component of the clay raw material and is approximately 40-70%. As a plasticizer, any substances possessing the indicated properties can be used, for example, PB-2007. The mass is stirred until then, until it passes into a state of homogeneous mass, to a state of creamy consistency.

Then add the foamed mass obtained on the basis of water and PB-2007 foaming agent with a density of 50-200 kg / m ³ in a ratio of 10-20 / 100. The foaming agent is mixed with water in a ratio of 5% of the volume of water. For example, to obtain a density of 500 kg per 1 m ³ , 250-300 liters of water are necessary, depending on the mineral composition of the clay. The density of the foam can be from 50-200 g / l. A foaming agent composition is used to achieve a low density of the mixture and impart a porous structure. The use of other foaming agents on a synthetic or organic basis is acceptable.

To exclude the process of shrinkage and achieve stability during drying, as well as to achieve a low density of the mixture (250-400 kg / m ³ ) and impart a porous structure to the prepared mass, an astringent additive is added. As such an additive, perlite sand is used in a ratio of 1: 1 or sawdust or finished product ground to fractions of 1.25-5.00 mm or its waste.

In the case of using a finished product ground to fractions of 1.25-5.00 mm as a binder additive (in the absence of waste), it is prepared similarly to the product. To do this, the clay raw material is cleaned, then in the mixer thoroughly mixed with water 1/100 in relation to the volume of water with an admixture of plasticizer. Then add the foamed mass obtained from the composition on the basis of the foaming agent PB-2007 with a density of 50-200 kg / m ³ in a ratio of 10-20 / 100. To obtain lower densities (250-400 kg / m ³ ), if clay raw materials give a large percentage of shrinkage, perlite sand is added. After this, the resulting mass is poured into molds with low sides (not more than 5-10 mm), dried, then the resulting workpiece in the form of a plate of 5-10 mm is fired, then crushed into the desired fractions and added further as a knitting additive.

The second stage - drying

The resulting mixture is poured into airborne forms pre-lubricated with a lubricant. Then the forms are placed in drying chambers. The relative humidity of the drying chamber is 85-92%. Temperature: initial - 30-35 ° С, final - 50-56 ° С. Thus, the raw will be in the dryer for 48-168 hours until it reaches a solid state and a residual moisture content of 4-6%. After drying, a single preform is obtained.

The third stage - firing

The process takes place in a tunnel or cap furnace. Billets of products freed from the on-board mold are placed on trolleys and automatically passed through the oven. The firing process occurs at a temperature of 800-1600 ⁰ C for about 12-24 hours, depending on the mineral composition of the clay raw materials.

The fourth stage - shaping the product

The resulting workpiece is sawn into blocks of a certain size in accordance with GOST by known means and method. Thus, the present invention allows to achieve a technical result, which consists in increasing heat, noise insulation properties, facilitating building materials. Obtained by the claimed method, the brick is light, in contrast to the prototype, its weight is 500-600 g. and porous, with a density of 800-1000 kg / m ³ .

Claims (1)

A method of manufacturing foamed building materials, including the preparation of a ceramic-foam mixture from clay raw materials, water, an additive in the form of a foaming agent, a binder, drying, firing, molding, characterized in that the mixture further includes a PB-2007 foaming agent as a plasticizing additive, and as binders use crushed to a fraction of 1.25-5.00 mm finished product or perlite sand, after which the resulting mixture is poured into airborne molds and dried at a temperature at the initial stage of 30-35 ° C, at the final m - up to 50-56 ° C, yielding a single blank which is then released from the mold board is calcined at a temperature of 800-1600 ° C, and then molded into blocks.