RU2135428C1 - Refractory mixture for rammed linings of structural elements and equipment of blast furnace cast houses - Google Patents

Abstract

FIELD: ferrous metallurgy. SUBSTANCE: refractory mixture, which can be used in blast furnace cast houses to line trunks, ladles, and other structural elements and equipment, contains, wt %: silicon carbide, 10-17; graphite, 5-10; clay, 2-6; coal pitch, 3-5; plasticizer (sodium lignosulfonate), 1-3; electrocorundum with particle size 0.006-0.06 mm containing no more than 5% of fraction with particle size 0.006-0.01 mm, 10-20; chamotte or worked out lining, the balance. Chamotte can be used with 38-40% aluminum oxide. EFFECT: increased strength of trunk lining and reduced manufacture cost. 3 cl

Description

 The invention relates to ferrous metallurgy and can be used in blast furnaces for lining gutters, ladles and other linings of structural elements and equipment of foundries.

Widely known refractory mass for blast furnace troughs, based on the material system Al ₂ O ₃ - SiO ₂ - SiC - C. The content of Al ₂ O ₃ is in the range of 60 - 85%, and SiC - 12 - 33%. For example, the masses of the French company "Zafarge Refractaires" with a graphite content of 3 - 10%, SiC - 5 - 15% based on fused corundum. Masses have high heat resistance. However, their use is limited due to the high cost.

 Also known are carbonaceous chamotte-containing trough masses based on coke, the disadvantage of which is not sufficiently high resistance.

 The closest technical solution is a refractory packing material, including mullite 65 - 80%, silicon carbide 5 - 15%, graphite 2 - 5%, clay 2 - 6%, a binder based on an aqueous solution of silica - 5 - 10% as a base (U.S. Pat. No. 5,064,787, class C 04 B 35/52, 12/12/91 - prototype).

 The disadvantage of this composition is the high cost and lack of resistance to thermal shock.

 An object of the invention is to increase the durability of the lining of the gutters and reduce the cost of their manufacture.

The technical result is achieved by the fact that in the refractory mass for printed linings of structural elements and equipment of foundries of blast furnaces containing silicon carbide, graphite, clay, an aluminosilicate component - chamotte with an Al ₂ O ₃ content _of 38 - 40%, coal tar pitch is contained as a binder , a plasticizer and additionally electrocorundum as a filler with a particle size of 0.006-0.06 mm with a content of not more than 5% of a fraction with a particle size of 0.006-0.01 mm with the following components, wt.%:
Silicon Carbide - 10 - 17
Graphite - 5 - 10
Clay - 2 - 6
Coal tar pitch - 3 - 5
Softener - 1 - 3
Electrocorundum - 10 - 20
Fireclay or Spent Lining - Else
The mass as a plasticizer contains sodium lignosulfonate. The upper and lower contents of the components are selected experimentally. Coal pitch is used as a binder, which strengthens the mass at low temperature, clay mixed with finely divided electrocorundum, which act as a binder at high temperatures, forming ceramic material and binding aggregate particles during sintering.

 The proposed ratio of components makes it possible to obtain a set of necessary refractory properties at a relatively low cost of weight, since it is used instead of bauxite as the main aggregate, alumina - chamotte fraction 0.2 - 6.0 mm. As the rest of the filler, silicon carbide fractions of 0.015-0.1 mm and electrocorundum fractions of 0.006-0.06 mm are used. Sodium lignosulfonate is introduced in an amount of 1 to 3%, which ensures sufficient plasticity of the packed mass. With its introduction in greater quantities, shrinkage increases.

 The technology for preparing the refractory mass provides for the disposal of the spent mass. Pieces of the lining are crushed to a certain size and are used in the preparation of a new mass (up to 50%).

 Industrial tests of the developed mass on the chute of the blast furnace of the joint venture AK Tulachermet showed that the material has a set of thermomechanical properties and provides high lining resistance (see table at the end of the description).

 In the blast furnace shop of the joint venture AK Tulachermet, the technology of manufacturing high refractory mass from domestic materials was mastered and introduced. The introduction of the mass on the "swinging" bath of the DP-3 blast furnace shop allowed to increase the lining resistance 4 times without intermediate repairs and 13 times taking into account intermediate repairs in comparison with the applied carbon masses.

 The specific consumption of refractory mass per 1 ton of cast iron decreased by 3.5 times. 115 thousand tons of cast iron without intermediate repairs and 400 thousand tons of cast iron with 8 intermediate repairs were passed through the bath, which corresponds to the level of resistance of the masses similarly to the class of foreign production. The cost of its manufacture is 2.7 times lower compared to the imported mass, and the specific consumption is reduced by 1.22 times.

Claims (2)

1. Refractory mass for printed linings of structural elements and equipment of foundries of blast furnaces, including silicon carbide, graphite, clay, an aluminosilicate component and a binder, characterized in that it contains chamotte or spent lining as an aluminosilicate component, and coal tar pitch as a binder and additionally, a plasticizer and, as a filler, electrocorundum with a particle size of 0.006-0.06 mm, with a content of not more than 5% of a fraction with a particle size of 0.006-0.01 mm, in the following ratio , wt.%:
Silicon Carbide - 10-17
Graphite - 5-10
Clay - 2-6
Coal tar pitch - 3-5
Softener - 1-3
Electrocorundum - 10-20
Fireclay or Spent Lining - Else
2. The refractory mass according to claim 1, characterized in that it contains chamotte with an Al ₂ O ₃ content _of 38-40%.  3. The refractory mass according to claim 1, characterized in that it contains sodium lignosulfonate as a plasticizer.

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