SU1636450A1 - Method of blowing metal in basic oxygen furnace - Google Patents

Abstract

The invention relates to ferrous metallurgy, and more specifically to methods of blowing metal in oxygen converters. Lel - an increase in the bottom tuyeres burner and a reduction in the specific consumption parameters of the process by intensifying and stabilizing the mixing of the metal. In the method of metal blowing in the converter, which includes supply of oxygen from the top and neutral gas through tuyeres in the converter bottom, the supply of neutral gas is carried out with a periodic change in intensity from 0.01-0.03 to 0.17-0.25 me / t. min and cycle period of 30-40 s, with the average specific consumption of neutral gas being supported in the range of 0.5-1.2 m3 / min. For each square meter of the converter bottom area. The application of the method allows to increase the yield by 0.5-0.6%, reduce the consumption of ferroalloys by 1.3-1.5 kg / g, and by 9-11 kg / t, the removal of metal from the converter, increase the resistance tonnes (Lb. 1 tab. with S (L

Description

The invention relates to ferrous metallurgy and can be used in the smelting of metal in a converter with a combined purge.

The purpose of the invention is to increase the durability of bottom tuyeres and to reduce the specific consumption parameters of the process by intensifying and stabilizing and mixing the metal in the converter.

The essence of the invention is that the cyclical supply of neutral gas makes it possible to achieve a self-oscillating mode of mixing of the bath, which makes it possible to bring the oxidation and reduction reactions of the metalule and donkey to equilibrium. In the case of the supply of neutral gas with an intensity of 0.01-0.03 m- / g.min, the microflows of the bath are inhibited, mixing the metal with the slag. The slag is saturated with oxides: t of iron, contributing to the accelerated dissolution of lime and increasing the basicity of the slag. At the same time, at this intensity of supply of neutral gas, a porous gas-permeable skull is formed on the bottom of the converter, protecting the bottom Lurmas from excessive wear. Increase the intensity of the supply of neutral gas to 0.17 0 00

oh

4- SP

316

0.25 MS / t. min intensifies the mixing of the metal. Reducing slag peroxidation stabilizes blowdown, eliminates metal emissions from the converter during blowdown, and reduces wear on the lining of the converter walls. A short-term increase in the intensity of the purge also prevents the formation of excessively dense skull on the bottom tuyeres, which leads to a decrease in the carrying capacity of the bottom tuyeres.

To prevent metal from penetrating through the bottom tuyeres, the intensity of the supply of neutral gas should not be lower than 0.01 nm / t-min. The intensity of the supply of neutral gas more than 0.03 Nm3 / t-min does not allow

the bottom area meter is not sufficient to achieve complete bath mixing during metal purging in the converter. The supply of neutral gas with a specific flow rate of more than 1.2 m3 / min per square meter of bottom area leads to excessive gas overhead for mixing and an increase in the removal of metal from the converter during the purge. Example 1. Converter capacity is 350 tons. Oxygen consumption on top is 3.35 m3 / t-min. The intensity of the supply of neutral gas varies from 0.02 to 0.17 m3 / t.min with a cycle of 30 s. The specific consumption of the mixing gas is 0.7 m3 / min per 1 m2 of the converter bottom surface. Ferromanganese economy is 1.4 kg / ton, lime 11 kg / ton.

develop a steady skull, prep-20. At the same time, the yield of liquid increases

0.6% due to the reduction of metallic inclusions and ferrous oxide in the final donkey. The removal of metal from the converter is reduced by 0.4%. The wear of the bottom tuyeres is 0.3 mm when the lining is worn 0.3 mm (in terms of the lining durability 610 heats).

erosion of bottom tuyeres, and also leads to an increase in the mixing of the metal with the slag, which makes it difficult to dissolve lime and induce high-base slag.

35

Neutral gas supply pulses with an intensity of less than 0.17 m3 / t-min do not allow the entire metal bath to be mixed in a short time. As a result, 30 of which the reduction in specific process indices does not reach maximum values. The supply of neutral gas with an intensity of more than 0.25 me / t-min leads to an increase in the removal of metal and slag from the converter and, due to strong cooling, to cracking and chipping of the bottom lining in the zone of bottom tuyeres.

When the cycle of supplying pulses of a neutral gas is less than 30 s, the resulting metal flows do not mix the entire metal bath, but only the part adjacent to the tuyeres. The stirring of the bath does not stabilize at a particular site, but only partially in certain areas of the metal bath. Such a cycle of supplying neutral gas leads to erosion of the blowing devices, since the slag crust does not have time to germinate.

A cycle of supplying a neutral gas greater than 40 seconds leads to resonant metal microflows, which drastically reduce the durability of the converter lining and lead to a deterioration of technical and economic indicators.

Specific consumption of neutral gas below 0.5 m3 / min for each square

0 In this case, the yield of liquid increases

five

five

0

Q

0.6% due to the reduction of metallic inclusions and ferrous oxide in the final donkey. The removal of metal from the converter is reduced by 0.4%. The wear of the bottom tuyeres is 0.3 mm when the lining is worn 0.3 mm (in terms of the lining durability 610 heats).

Example 2. Converter capacity is 350 tons. Oxygen yield on top 3.5 m3 / t “min. The supply of neutral gas is carried out with a cycle of 40 seconds with a change in intensity from 0.03 to 0.25 m3 / t, min. The consumption of neutral gas is 1.2 m3 / min per 1 m2 of the bottom area. The economy of ferroalloys is 1.5 kg / t, lime 10 kg / t. The liquid yield is increased by reducing metallic inclusions and ferrous oxide in the final slag by 0.6%. The wear of the bottom tuyeres is 0.38 mm with a lining wear of 0.38 mm. Removal of metal from the converter decreased by L

U, J / o.

Technological indicators of the bottoms carried out by the proposed method, with the output beyond the optimum values, as well as the bottoms according to the technology of the known method are shown in the table.

Thus, the use of the proposed method of steel smelting (melting 5-11) allows to increase the liquid yield by 0.5-0.6%, save ferroalloys by 1.3-1.5 kg / t, lime 9-11 kg / t , reduce the wear of metal from the converter by 0.3-0.4% while achieving the resistance of the bottom tuyeres to the resistance of the lining of the converter walls.

Claims (1)

Invention Formula A method of blowing metal into the converter, including the supply of oxygen from above and neutral gas through tuyeres in the converter bottom, characterized in that, in order to increase the durability of the tuyeres and reduce the specific process indicators by intensifying and stabilizing the process 1636450 mixing the melt, the flow of neutral gas through the tuyeres in the bottom of the converter is carried out with a periodic change in intensity from 0.01-0.03 to 0.17-0.25 M3 / T1min and a cycle period of 30-40 s, with the average specific consumption of neutral gas support in the range of 0.5-1.2 m3 / min per square square meter of converter area.