SU1068404A1 - Method for making refractory heat insulating products - Google Patents

Abstract

METHOD OF MAKING FIRE; RESISTANT HEAT-INSULATING PRODUCTS, including mixing exfoliated. perlite with a refractory filler and phosphate binder, molding and drying, characterized in that, in order to reduce thermal conductivity and shrinkage during drying, before mixing, the expanded perlite sand is impregnated with 0.040, 06.44 phosphate binder, but it is mixed with 0 5-0.6 hours of refractory filler and O, 5-0.6 hours of phosphate binder, the mixture obtained is dried at 180-250 ° C for 15-60 minutes, after which it is dried. is mixed with the remaining portions of the refractory aggregate and the phosphate binder, with a density: the latter is 1.18-1.24 g / cm (L

Description

Yes

ОО 4 The invention relates to building materials and is intended for the manufacture of refractory heat-insulating products based on expanded perlite. A known method of making refractory products, including rolling up the burnable material of a refractory powder onto the grain, mixing the granules with the binder, subsequent pressing and burning GI. The disadvantages of this method are the high thermal conductivity of the products and the large shrinkage during drying, as when mixing grated on which there is a layer of refractory powder, the bond penetrates only this layer, but does not penetrate into the granules, and after the granules burn out, large pores are formed, which leads to an increase in the coefficient of heat conduction awn material, especially at elevated temperatures. The use of this method for heat-resistant products made of perlite is unacceptable due to the considerable abrasion of perlite, which leads to an increase in the volume content of the binder. . The closest to the technical essence of the invention is a method of manufacturing a heat insulating material, including mixing bleach perlite with a filler and a phosphate binder for extrusion and heat treatment of L2. The disadvantages of the known method are the production of products with a large shrinkage during drying and high thermal conductivity, as in the manufacture of perlite products, the content of expanded perlite sand in the mass,. The water is smooth, more than 30%, and a high content of refractory binder. When applying the known method, the expanded perlite sand in masses containing a significant amount of binder, is strongly worn out, which leads to an increase in the volume mass of the products and, consequently, thermal conductivity and, as a result, significantly. the content of the binder and strong attrition of perlite, which is the descendent, sharply increases the shrinkage of the material during drying, the purpose of the invention is to reduce thermal conductivity and shrinkage during drying. This goal is achieved by the fact that, according to the method of manufacturing refractory heat-insulating products, including mixing expanded perlite with refractory filler and phosphate binder molding and drying, before mixing the expanded perlite sand is impregnated with 0.04-0.06 h, the phosphate bond, then it is mixed with 0.5-0.6 parts, a refractory filler and 0.5-0.6 parts of a phosphate binder, the mixture is dried at 180-250 ° C for 15-60 weeks, after which it is mixed with the remaining part mi refractory filler and-f sfatnogo binder, wherein the latter the density is 1.18-1.24 g / cm. Phosphate binder with a density of 1.18-1.24 g / cm penetrates into perlite sand, forming refractory bridges that do not melt during melting, perlite grains, resulting in a thermal conductivity of a material having pores separated by refractory bridges that becomes lower than thermal conductivity of the material with pores formed during the melting of perlite. In addition, the impregnation of pearlite grains improves the adhesion of the refractory powder to them and provides better mixing of the perlite with the refractory powder, Repeated, exfoliated perlite with 0.5-0.6 h applied to it, refractory filler, 0.5-0.6 h, The binder reduces the abrasion of perlite, which flows in a mass containing the entire amount of the binder, i.e. in a mass with high humidity. The heat treatment then carried out imparts water resistance to the grains of the mass sufficient to form the refractory layer on the grains not dissolve) with further mixing with the binder, causes the layer of refractory mass on the perlite grains to not shrink during the subsequent drying of the finished products and increases the strength of the pearlite grains. With the subsequent mixing of the obtained bulk material with the rest of the refractory filler and the rest of the binder, the abrasion of the pearlite grains will be insignificant Yelnia, since the mass comprises only a portion of uncured binder (i.e., its humidity is low), and pearlite grains previously coated hardened on them water resistant layer of refractory filler and a binder of phosphate. Example 1. For the production of products. Take. On 20 May.% Of expanded perlite and impregnated with 2% 30% phosphoric acid (density 1.18 g / cm), then perlite is mixed with refractory filler, taken in an amount of 15% and phosphoric acid in an amount of 25%, after which the mass is dried at 250 ° C for 15 minutes with stirring. The resulting mass is mixed with 15% of a refractory filler and 23% of phosphoric acid, pressed at a pressure of 0.5 MPa, and heat treated at in-flow for 3 hours. Example 2. 25% by weight of expanded perlite is impregnated with 2.5% by weight of an aluminum-chromophosphate binder (1.24 g / cm), mixed with 12.5% by weight of a refractory filler and 30% by weight of an aluminum-chromophosphate binder . The mass is dried at 30 minutes with stirring. The resulting dry mass is mixed with 10% by weight of a refractory filler and 20% by weight of an aluminum-chromophosphate binder, pressed at a pressure of 0.5 MPa and heat treated at 300 ° C for 3 hours. Example 3. 28% by weight of expanded perlite is impregnated with 3% by weight of an aluminum-chromophosphate binder (density 1.20 g / cm), mixed with 10% by weight of a refractory filler and 32% by weight of an aluminum-chromophosphate binder. The mass is dried at 60 minutes with stirring. The resulting dry mass is mixed with 8% by weight of a refractory filler with 19% by weight of an aluminum-chromophosphate binder, pressed under a pressure of 0.5 MPa, and thermally processed at 3 hours. Example 4 To obtain products, 37% by weight of expanded material is taken, perlite and impregnated in 10% by weight. The aluminum-chromophosphate binder, (density 1.20 g / cm), is mixed with 7 wt.% of the aluminum-chromophosphate binder. The mass is dried at 90 minutes with stirring. The obtained dry mass is mixed with 3 wt.% Of a refractory filler and 20 wt.% Of an aluminum-chromophosphate binder, pressed at a pressure of 0.5 MPa and thermally treated for 3 hours. Example 5. 11 wt.% Of the expanded perlite is impregnated with 1 wt.% Of an aluminum-chromophosphate binder (˜ 1.24 g / cm), mixed with 15 wt.% Of a refractory filler and 18 wt.% Of an alumochromophosphate binder. The mass is dried at 350 ° C for 2 min with stirring. The resulting dry mass is mixed with 40 wt.% Of a refractory filler and 15 wt.% Of an aluminum chromic binder, pressed at a pressure of 0.5 MPa and heat treated at 300 ° C for 3 hours. .The results of testing products manufactured by the described and known methods are presented in the table.

Deformation during drying,% Thermal conductivity W / m K at 125 C after holding 0.11 products at 1000 C 1540-1620 Fire resistance Apparently with density, 0.25-0.40 g / cm Compressive strength, kgf / cm, 6, 0-7.9

In each of the above examples, use chamotte from ground clay burned plastic clay. In addition, aluminum hydroxide aluminous grades GO and GK, zirconia, corundum were tested as refractory fillers. From a distance with these fillers, they are characterized by similar or similar deformations during drying, thermal conductivity and apparent density, but more high refractoriness. Specific 5

surface of all tested fillers 1700-2500. Phosphoric acid had a concentration of 30%, the dry residue content in the aluminum-chromophosphate binding density of 1.24 g / cm3 after drying at 105t2c is 32%, and the density i; 20 g / cm — 28%.

The drying parameters of the pretreated mixture depend on the type of phosphate binder used. Optimum temperature range 0.10.030.010.008080.0.0960.09.0940.09.0920.16.16 17101690 168016001710 0.280.250.230.200.43 7.5 7.0 5.8 3 ,one

and the drying time of the pretreated mixture for phosphoric acid and the aluminum-chromophosphate binder used in the examples should be 180-250 ° C for 1560 minutes. At the drying temperature of the pretreated mixture below even for a long time, the formation of hydrolytically stable bonds does not occur and the resulting screen of aluminophosphate salts does not form. Perlite granules are not water-resistant, which results in the subsequent mixing of the pre-treated mixture with the remaining part of the phosphate binder to the dissolution of the previously applied binder. At the same time, the amount of unhardened phosphate binder becomes so large that it causes significant shrinkage during heat treatment of products.

If the pretreated mixture is dried at temperatures above 250 ° C, then a loss of activity is observed on the aluminophosphate screen on the pearlite grains and, consequently, the thermal insulation products are obtained with low mechanical characteristics.

t.

The described method will allow to obtain non-shrinkable products with a relatively low content of emaciated mass of filler - expanded perlite. These products are characterized by thermal conductivity, both due to less abrasion of perlite and, consequently, less bulk weight of products, and due to the formation of bridges separating the pores formed during the melting of the expanded perlite.

Claims (1)

METHOD FOR MANUFACTURING FIRE- / RESISTANT HEAT-INSULATING PRODUCTS, including mixing expanded perlite with a refractory filler and a phosphate binder, molding and drying, characterized in that, in order to reduce thermal conductivity and shrinkage during drying, the expanded perlite sand6 is impregnated with phosphate 40 before being mixed. binder, jammed! it is mixed with 0.5-0.6 hours of refractory filler and 0.5-0.6 hours of phosphate binder, the resulting mixture is dried at 180-250 ° C for 15-60 minutes, after which it. mixed with the remaining parts of the refractory aggregate and phosphate binder, while the density of the latter is 1.18-1.24 g / cm ³ Ooh 1 1068404 technical content is