SU765242A1 - Engobing coating for refractory materials - Google Patents

Description

(54) ANHOBYRING COATING FOR GHG PEDOORS

one

The invention relates to the production of carbide-containing, cordierite-containing and fireclay refractories, used as fire-retardant for firing porcelain, abrasive and building ceramic products.

Used for this purpose, the firebox loses its physical and technical properties during operation due to exposure to mechanical loads, the gaseous medium and temperature differences.

A refractory composition containing a high-alumina component in the form of distensillimanite is known: the clay component and calcined alumina Tl.- However, using this composition as a coating, the calcined alumina with a grain size of more than 0.04 mm has a low reactivity and promotes rapid sedimentation of the suspension in the process. coating. Presence of corundum

O1ShSI kalsh1 szh11aet fire resistance of the coating.

The closest technical solutions to this are compositions for eng-ousable fire-retardant coatings containing a high 7; all-earth component (50-89.5 weight, ° - o) and a muddy component 2.

However, these coatings have low mechanical strength (due to the high porosity of the poker (ti), high permeability, contributing to the destruction of the fireproof zone at high temperature under the action of the gaseous medium, low refractoriness of the large porosity,

15, as a result of which, during operation, the fire extinguishing agent is pinched to a friend, and the products to be calcined are stalked to the base, which causes rejection and an increase in the production process, as well as increased abrasion.

The aim of the invention is to reduce the porosity, gas flow and the mechanical strength of the coating before firing. This is achieved by the fact that a coating for refractory materials containing high-alumina material and clay or JcaojiHH additionally contains 1 electro-corundum with a grain size of 4 O, O56 mm at the following ratio of components, wt.%: High-grade material 50-89.5 Clay or 10%. -28.0 Electrocorundum with a grain size of $ O, O560.5-30.0, and, as a high-alumina material, it contains distansillimanite, sillimash1T, kyanite, gshgaozem, or them. mixture, and as electrocorundum normal, doped with carbon dioxide or their mixture. The properties acquired by the aecoboobing coating are explained by the fact that, when a normal chromium electrocorundum is introduced into the mixture, their mixture significantly increases the sintering interval of the components of the composition due to the presence of electrooxide titanium or chromium oxides in the composition, which contributes to the compaction of the active coating without significant its refractoriness at low sintering temperatures. The ancoating coating is prepared by the joint grinding of raw materials.

1. Mechanical strength of samples dried at, kgf / cm

2. Mechanical bending strength of samples

 fired at a temperature of 142 ° C, icr / CM

3. Porosity%

The results of the analysis of the comparative characteristics of the proposed and known compounds indicate a significant increase in the mechanical strength of the coating, both in the air-auger and in the air.

13.5-14.7

21.9

90-127.2 28O 35O 2O ,, 4 22-23 19.3

sore as well as reduced porosity. This increases the resistance of the barrel during operation.

Claims (2)

Testing of the coating under operational conditions showed that engobe, of 24 in a ball mill, before the 1OOOO sieve passes through the holes per cm, then it is applied to the surface of refractory products - capsal by dipping, followed by drying and firing at a temperature of 143 ° C before sintering the components P01FITS. The anchobing coating applied to the surface of the refractory evenly covers its surface, has a porosity of 20–25% lower than that of the engobe, in which the electrocorundum is replaced by alumina. There is no sintering of igneous with each other under static load up to at a texture of up to 0.9 kgf / cm Guo 1380-1390 C. Below are examples of the compositions of the unbinding coating,%: D Kyanit28 Alumina39 Electrocorundum 28 Clay veselovsk 5 2 Alumina85 Electrocorundum doped with O1 chrome. 5 Lataenska 5 Kaolin5 Table 1 shows the comparative characteristics of the engobe coatings of the composition proposed and known. Prepared from a known composition, cause a strong blending of refractory products with each other and ceramic products to fire equipment (due to the insufficient refractoriness of the engobe), which does not ensure the fulfillment of the technical requirements for the quality of the coated coating. The proposed coating places b on a refractory base tightly, has a good coalescence with the refractory skull, low gas permeability and high mechanical strength (the limit of flexural strength is more than 350 kgf / cm). The coating reliably protects the carbide cream, which is low in content and refractory, from oxidation of silicon carbide and iron, increasing the service life of the refractory (for example, caps by more than 25%). In addition, it provides insulation when using caps in stacks. The proposed anti-ribbing coating reliably and effectively protects the ignition equipment from the negative impact of mechanical loads, gaseous medium and temperature fluctuations, increases the service life of the ignition equipment (for example, caps of more than 25%) and improves the quality of production; for example, porcelain products, baked with by a genius of such a firepower, by 5-10%. Applying a coating of antiblocking coating helps to reduce the waste of products for clogging, as well as to increase the durability of fire 7 26 due to high fur nical strength layer and reducing oxidation of the refractory during the firing process. Claims i. The ancoating coating for refractories containing high-alumina material and clay or kaolin, is characterized in that, in order to reduce porosity, gas permeability, increase the mechanical strength of the coating {it also contains electrocorundum with a grain size of 0.056 mm in the following ratio of components, weight%: Highly 50-50 , 5 earthy material 0.1-28.0 Clay or kaolin Electrocorundum with a grain size of 4 0,056 mm0,5-30,0 2. The coating according to p. I, is about high-alumina material it contains distacilman t Scilly {Anita | kyanite, alumina or their mixture, and as electrocorundum - normal, chromium dioxide, or their mixture. Sources of information taken into account in the examination 1. US patent number 3135616, cl. 106-65,1964. 2. Trudy GIKI, vol. 1.1955, SLZ2O, Rosgizmespromprom, M.