SU759490A1 - Charge for producing refractory materials - Google Patents

Description

The invention relates to the production of high-resistant refractories, such as steel-casting supplies, glass-making supplies, protective layers for fire-resistant refractories, intended for service in the conditions of casting aggressive steels, non-ferrous metals, and melting of critical glasses.

Formulations containing Kia-10 nit or sillimanite, clay and kaolin (1], [2] and [3]) are known.

The disadvantage of refractories made of these compounds is the formation of silica in the form of cristobalite and glass phase in the process of roasting, which reduces the chemical and thermal stability of refractories.

The closest technical solution to this is the mass for iz / Yu preparing refractory products, containing calcined distensillimanite concentrate - base, melted distamnidimanite concentrate -.

20 - 35 wt.%, Kaolin - 7 - 12% .25

The disadvantage of this mass is relatively low density and heat resistant. The aim of the invention is to increase the density and heat resistance of the Fire- 30

stops, manufactured from the claimed mixture.

This goal is achieved by the fact that the mixture for the manufacture of refractories, including aluminosilicate sillimanite group and clay, and / or kaolin, additionally contains zirconium dioxide and rare earth oxide in the following ratio of initial components, wt.%:

Aluminosilicate

sillimanite

groups

Clay and / or

kaolin

Dioxide'

zirconium

REE oxide

52-79,4

0.5-6.0

20-45

0.1-7.0

Prepare the following mixtures for the manufacture of prototypes.

Content, weight.%: Ζγ0 ₂ 27 41 4 3 Silimanite 67.5 - 5 3. Kyanite - 52 - Υ ₂ 0 ₃ 0.1 6.5 - Υ - - 3.5 Kaolin 5.4 0.5 0.5

The resulting compositions are subjected to grinding in a vibrating mill, carbide

759490

balls. The resulting mixture is moistened, 'briquetted and calcined in the furnace at a temperature of 1550-1600 ° C. The burned briquettes are crushed and cylinders with a diameter and height of 15 mm are pressed from the obtained masses on a hydraulic press with a specific pressure of 1000 kg / cm ² , which are burned at a temperature

1500-1550 ° C.

Properties of samples from the mixture of the proposed and known compositions are given in the table.

Indicators Prototype 'Suggested formulations one 2 3 Porosity,% 9.3 6.2 2.0 4.5 Heat resistance of heating 1800 ° Svoda Low > 20 > 20 > 20 Compressive strength, kg / cm ⁴ 1800 1200 1500 1300

From the data in the table it can be seen that the obtained values of the density 'and heat resistance of the samples from the claimed mixture' exceed the same values obtained from samples of known composition. ^one

The phase composition is represented by high-temperature crystalline phases of mullite, zircon, and zirconium dioxide, i.e., the stability in the aggressive media of refractories made from this mixture will be greater than that known.

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Claims (1)

Claim The mixture for the manufacture of refractories, including aluminosilicate sillimanite group and clay, and / or kaolin, characterized in that, in order to increase the density of refractories, their heat resistance and stability in aggressive media, it also contains • zirconium dioxide and rare-earth oxide in the following ratio of components, weight;%: Aluminosilicate sillimanite groups 52-79,4 Clay and / or kaolin 0.5-6.0 Dioxide zirconium 20-45 Rare earth oxide element 0.1-7.0