RU2356870C2 - Refractory mixture for iron notches of blast furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to refractories industry, particularly to receiving of mixtures, providing for overlapping of iron notches of blast furnaces. Refractory mixture for iron notches of blast furnaces contains clunch, chamotte and coal tar, at that in the capacity of clunch it contains bentonite and bauxite at following components ratio, wt %: chamotte 68-85, coal tar 15- 32, bentonite 0.05-6, bauxite 0.1-11. Chamotte fraction is less then 0.09 mm is no less than 30% of its total weight.

EFFECT: improvement of mixture performance attributes, productivity improvement of blast furnaces, cost saving of cast iron.

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Description

The invention relates to the refractory industry, and in particular to the production of masses intended for closing openings of blast furnaces.

Known as a prototype is a refractory mass for closing cast iron notches of blast furnaces [1], including coke, refractory clay, chamotte and coal tar, which additionally contains coal tar pitch with a softening temperature of 200-300 ° C in the following ratio of components, wt.%:

Coke 20-55 Refractory clay 10-30 Fireclay 5-30 Coal tar 15-25 Coal pitch 2-14

Significant disadvantages of this refractory mass are:

- high cost of the resulting mass due to the high content of expensive components of coke and pitch of coal;

- decrease in the productivity of blast furnaces due to the height of the channel of cast-iron notches and the creation of emergency situations when releasing melting products due to the presence of coke in the refractory mass.

Also known is a carbon-containing anhydrous flying mass [2], including thermal anthracite, coal tar pitch, coke, which additionally contains graphite-containing material and anthracene oil in the following ratio, wt.%:

Graphite material 3-12 Anthracene oil 10-20 Coal tar pitch 8-18 Thermoanthracite 10-30 Coke Rest

The significant disadvantages of this carbon-containing anhydrous flying mass are:

- high cost of the resulting mass due to the high content of expensive graphite-containing material and anthracene oil;

- low resistance of the refractory mass during the production of cast iron, erosion of cast iron notches and, as a result, a decrease in the productivity of blast furnaces.

The desired technical results of the invention are:

- improving the operational properties of the mass;

- increase the productivity of blast furnaces;

- reduction in the cost of cast iron.

For this purpose, a refractory mass is proposed for closing cast iron doors of blast furnaces, containing refractory clay, chamotte and coal tar, characterized in that it contains bentonite and bauxite as refractory clay in the following ratio of components, wt.%:

Fireclay 68-85 Coal tar 15-32 Bentonite 0.05-6 Bauxite 0,1-11

moreover, the chamotte fraction of less than 0.09 mm is at least 30% of its total mass.

The claimed limits are selected experimentally.

Chamotte is introduced into the composition of the mass as the main refractory material, which prevents the cast iron notch from burning at the time of cast iron production, and when using less than 68%, the refractory mass characteristics sharply decrease, and with an increase of more than 85%, a decrease in ductility, an increase in energy costs when closing the notches of blast furnaces, moreover, when the fraction content is less than 0.09 mm less than 30% of its total mass, an increase in unauthorized emissions of pig iron from the duct of cast iron notches occurs at the time of cast iron production and the occurrence of emergency x situations.

Coal tar, humidity up to 4%; ash not more than 0.15%; density 1170-1200 kg / m ³ ; insoluble in toluene of at least 3%, is introduced into the composition of the mass as a plasticizer of the refractory mass, and when using less than 15%, it is not possible to obtain the required plasticity of the mass, and with an increase of more than 32% the refractory resistance of the resulting material sharply decreases.

Bentonite is introduced into the composition of the mass to improve its quality characteristics, and when using less than 0.05%, it is not possible to obtain the required ductility of the mass, and when using more than 6%, the cost of producing a refractory mass increases.

Bauxite is introduced into the composition of the mass as a material that increases the concentration of the finely ground fraction, and when using less than 0.1%, the resistance of this mass decreases sharply, and when using more than 11%, a sharp increase in the viscosity of the mass and an increase in production costs during casting occur.

The manufacture of the inventive refractory mass was carried out by mixing the components in the indicated proportions by means of a screw mixer.

The inventive refractory mass (compositions are shown in the table) was used on blast furnaces with a volume of 1310 and 1719 m ³ as the main material for closing cast-iron notches of blast furnaces, which allowed to improve the operational properties of the furnace, in particular: to increase the number of releases of cast iron due to the quick solidification of the material in the channel pig-iron lettuce of blast furnaces; to reduce consumables and improve working conditions for staff due to the easy removal of hardened clay mechanically from the duct of cast iron notches and, as a result, increase the productivity of blast furnaces by 0.24%, while reducing the cost of cast iron by 7.3 rubles / ton.

Components The composition of the refractory mass,% No. 1 Number 2 Number 3 Number 4 Number 5 Number 6 Fireclay 84 72 68 68 71.95 68.9 Coal tar fifteen 21 fifteen 31 twenty 29th Bentonite 0.5 3 6 0.3 0.05 2 Bauxite 0.5 four eleven 0.7 8 0.1

Information sources

1. AS of the USSR No. 574422, Cl. C04B 35/52.

2. AS of the USSR No. 1421425, cl. C04B 35/52, F27D 1/00.

Claims (1)

A refractory mass for closing cast-iron sheds of blast furnaces, containing refractory clay, chamotte and coal tar, characterized in that it contains bentonite and bauxite as refractory clay in the following ratio of components, wt.%:
Fireclay 68-85 Coal tar 15-32 Bentonite 0.05-6 Bauxite 0,1-11
moreover, the chamotte fraction of less than 0.09 mm is at least 30% of its total mass.