SU1235914A1 - Method of treatment vanadic pig iron in converter - Google Patents

Description

I

The invention relates to ferrous metallurgy, and more specifically to methods for the redistribution of cast iron in converters, and; can be used in the redistribution of vanadium iron with the simultaneous production of high-carbon metal - an intermediate for smelting steel and vanadium-containing slag for the production of vanadium pentoxide and ferrovanadium.

The aim of the invention is to reduce the content of manganese oxide and metallic inclusions in the intermediate layer and more desulfurization of the pig iron.

Vanadium cast iron containing 4.2% carbon, 0.53% vanadium, 0.3% silicon, 0.4% manganese, 0.050% sulfur, 0.1 phosphorus, the rest is iron, is poured into the converter at. For slagging and cooling of the process, 200 kg of metal scrap, 300 kg of mill scale, 130-160 kg of freshly burnt lime, 50 kg of chamotte oil are introduced into the converter.

Blowing the pig iron with oxygen from above is carried out for 4 minutes with an intensity of 4 M UT-MIN. As a result of blowing, high-carbon semi-product with a temperature of 1450-, containing on average 2.8% carbon, 0.03% vanadium, 0.05% manganese, traces of silicon, 0.040% sulfur, 0.080% phosphorus, the rest is iron and lime-ferruginous are obtained. vanadium pshak with basicity 1, containing on average 25% calcium oxide, 12.5% silica, 9.4% manganese oxide, 15.6%. iron oxides, 9.4% magnesium oxide, 6.3% alumina, 18.8% - vanadium pentoxide.

3.5 3.5 1 2

71.5 73.5 35.0 50.0

142

After the end of the upper oxygen purge, the semi-finished product for 2-5 min. Is evacuated by air from below with a continuous and uniform increase.

intensity of air supply from 0.05-0.1 to 0.25-0.5. min. After the bottom air purge, the intermediate contains 2.65% carbon, 0.03% vanadium, 0.31% manganese, traces of silica, 0.008% sulfur, 0.080% phosphorus, and the rest is iron. Intermediate slag contains 31.6% calcium oxide, 15.8% silica, 3.0% manganese oxide, 4.9% iron oxides, 11.8% oxide, 7.9% alumina, and the rest is p-vanadium oxide.

The temperature of the intermediate product before downloading the intermediate slag is in the range of 1400-1420 ° C. The degree of desulfurization of the intermediate product is 80%, and the recovery rate of leselose and manganese from slag in the semi-product is 75% for each of the elements. Vanadium's reverse transition from

slag in the intermediate does not occur. The amount of metallic inclusions in the intermediate slag is on average 5%.

After downloading the intermediate.

slag-containing slag is introduced into slag-forming materials, at the rate of obtaining slag with a basicity of 3-6, and transferred to the usual mode of the upper oxygen purge of the intermediate with

obtaining a given steel grade and final slag with a content of about 10% vanadium nickel titanium, as in the known method of redistribution of vanadium pig iron.

Dunn1) 1e, characterizing the process of redistribution of vanadium iron according to the known and proposed methods are given in the table.

67.0 72.0

4.0

4.5

35.0 6.0 55.0 5.5

89.5 91.5 95.0 94.5

2.0

2.2 2.3

3.5

five

6

3.5

3.5

3.0-3.5 80, 0 85.0 86.0 75.0 70.0 35.0

From the data in the table, it can be seen that the values of the basicity of the intermediate slag 1.8-2.2 and the duration of the purge of the intermediate product with air for 2-5 minutes are optimal, since they ensure the achievement of the best indicators of the redistribution process of vanadium iron. .

Increasing the content of vanadium pentoxide in the intermediate slag to 23–25% and reducing the content of metallic inclusions to 4.5–6% greatly simplifies the chemical and chemical technology.

Editor G. Volkova

Companion V.Saramutin

Tehred M. Khodanych Proofreader I.My ska

Order 3061 / 23Ction 552 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Continuation of the table Content- Degree

cue mevanadation

cast iron tula, 2 slags in slag, Z

75.0 79.0 80.0 70.0 65.0

5.0 5.5 6.0 6.0 8.0 10.0

.94.0 92.0 90.0 91.3 88.2 93.0

metallurgical slag processing .and increases vanadium through-put recovery.

Reducing the content of manganese oxide in the slag from 7–12 to 2-3% allows stable ferrovanadium with a manganese content of less than 2%, the cost of which is significantly higher than the cost of ferrovanadium with a higher manganese content, and also improves the quality of steel by further desulfurizing iron. .

Claims (1)

METHOD FOR REDUCING VANADIUM PIG IRON IN THE CONVERTER, including blowing cast iron with oxygen from above to obtain a high-carbon intermediate with a temperature of 1450-1480 ° C and the main vanadium intermediate slag, downloading intermediate slag, final purging of the intermediate with oxygen to obtain steel, and the resulting vanadium that, in order to reduce the content of manganese oxide and metallic inclusions in the intermediate slag and a deeper desulfurization of cast iron, the intermediate slag with a basicity of 1, 8- '2.2 is induced to the moment of completion of the iron purge with oxygen, after which the intermediate, together with the intermediate slag, is blown with air for 2-5 minutes with a continuous and uniform increase in the intensity of air supply from 0.05-0.1 to 0.25- 0.5 m ^ tx x min. with <g ω oe joint venture X