RU2085545C1 - Method of porous building article making - Google Patents

Abstract

FIELD: building industry. SUBSTANCE: method involves roasting filling agent up to swelling, additional heating to filling agent surface melting, its placement to form, keeping in the closed volume under loading 0.2-0.5 MPa for 30-120 s, article striking and its rapid cooling to 500-700 C followed by cooling at rate 60-120 degree/min to normal temperature. Properties: compression article strength is 1.2-7.0 MPa, mean density is 150-600 kg/m³. Method is used for production of heat-insulating and structural heat-insulating articles making. EFFECT: improved method of building article making.

Description

 The invention relates to the building materials industry, mainly to the production of heat-insulating and structural-heat-insulating products with a porous structure.

A known method of manufacturing porous ceramic products, including the formation of preforms (plates) based on low-melting clay with a moisture content of 25-30% drying at a temperature of 600-700 ^o C and firing at a rate of temperature rise above the preforms of 200-300 deg / min to 1150-1250 ^o C, and under the workpieces at a speed of 40-50 ^o C to 1000-1100 ^o C [1]
There is also known a method of manufacturing porous building products consisting in the following:
From natural clay raw materials by clumping, crushing or molding on tape presses, individual elements (pieces) of mass 2-50 mm long and 5-20 mm in diameter are prepared. In a rotary kiln at a temperature of 1100-1200 ^o C and a time of 40-60 minutes, the pieces swell into granules. Granules with the indicated temperature roll into molds. The gluing of the grains is carried out by pollination or spraying the surface of the grains with a dry powder or an aqueous suspension of a low-melting mixture at the moment the grains exit the furnace into molds. After that, the parts are heated and aged in molds at a temperature sufficient to melt the surface layer of the powder and connect the individual grains at the points of contact with each other [2]
Closest to the claimed is a method of manufacturing expanded clay blocks using extruding claydite balls exiting the kiln directly while maintaining the burning temperature, they are loaded into the molds and subjected to pressing [3]
The disadvantages of the known methods include the difficulty of uniformly applying a fusible mixture to the surface of the granules, insufficient to melt the firing surface of the granules during expansion, the lack of exposure parameters of workpieces under load, and cooling products. These shortcomings will contribute to the formation of a material with a heterogeneous structure and, as a result, will lead to cracking, a decrease in mechanical strength and an increase in water absorption.

Obtained by the proposed method, the products have a uniform porous structure and stable properties. Obtaining a high technical effect is achieved by the fact that in the method of manufacturing porous building products, which includes firing the aggregate prior to expansion, laying it into a mold, heating the mold to reflow and sinter the aggregate, followed by cooling of the product. Immediately after firing, the aggregate is additionally heated until its surface is melted, laid in a mold, the product is held in a closed volume under a load of 0.2-0.5 MPa for 30-120 s, the product is stripped off and quickly cooled to 500-700 ^o C followed by cooling at a speed of 60-120 ^o C / min to normal temperature.

 The density of the product, its strength and the degree of filling of the form is controlled by the pressure during molding of the product.

 The following can be used as the initial porous granular material: expanded clay, schungizite, perlite, expanded by barothermal technology (barotelite), etc.

 Example 1

Barotelite was used as a raw material for the manufacture of building material. Immediately after firing, it was additionally heated until its surface was melted and laid in a mold. A load of 0.2 MPa was applied for 30 s. The product was pushed out of the mold by a punch and cooled according to the following regime: fast cooling to 500 ^° C and slow at a speed of 80 ^° C / min to normal temperature.

 The product had the following properties: compressive strength 1.2 MPa; average density of 150 kg / cubic meter.

 Example 2

Expanded clay was used as a raw material for the manufacture of a building product. Immediately after firing, it was additionally heated until its surface was melted and laid in a mold. The magnitude of the applied load was 0.5 MPa, and the loading time was 120 s. The product was pushed out of the mold by a punch and cooled according to the following regime: fast cooling to 700 ^o C and slow at a speed of 120 ^o C / min to normal temperature.

 Products had the following properties: compressive strength 7.0 MPa; average strength 600 kg / m3.

Claims (1)

A method of manufacturing porous building products from expanded clay, shungizite, obsidian, perlite and similar materials, including firing granular materials to achieve a pyroplastic state, loading them into a mold, keeping it in a closed volume under load, form stripping and cooling the workpiece, characterized in that before by loading the granules are additionally heated until their surface is melted, the blanks are kept in a closed volume under a load of 0.2 1.5 MPa for 30 120 s, and cooling is carried out by quickly th lowering the temperature to 500 - 700 ^o C and subsequent cooling to normal temperature at a rate of 60 120 degrees. / min