SU1409666A1 - Method of melting steel in reducing open-hearth furnace - Google Patents

Abstract

The invention relates to ferrous metallurgy, and more specifically to the production of steel in the main open-hearth furnace. The purpose of the invention is to increase the yield of a suitable metal, reducing the melt melting rate, saving lime, oxidizing agents and ferroalloys. In the method of steelmaking in the main .. open-hearth furnace, including the filling of metal scrap, return slag, limestone, oxidizing agents, melting and finishing, as converter amphibian slag, converter slag is used, while before filling the scrap a furnace hearth is loaded with a mixture of converter slag, limestone and oxidizing agents at a ratio of mixture components of 3: 2: 1. 2 tab.

Description

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ABOUT

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. The invention relates to ferrous metallurgy, and more specifically to the smelting of steel in the main open-hearth furnace.

The purpose of the invention is an increase in the yield of the metal, a decrease in the duration of melting, saving lime, oxidizing agents, ferroalloys.

The goal is achieved by first loading the mixture of convex slag, limestone and oxidizers into the hearth furnace at a ratio of 3: 2: 1, then loading the metal part of the charge and then producing steel according to the known way.

The essence of the proposed method is that the converter slag, in contrast to the open-hearth, has more BbttoKyio basicity (45-55% CaO) and a significant amount of iron oxides (13-24%) and (3-8%) manganese, which are The process of interaction with the metal part of the charge is performed as fluxes and oxidizers, the mixture itself of converter pshak, limestone and oxidizers interacts more quickly with the metal part of the charge and thereby contributes to the formation of an early sufficiently basic and ferrous primary slag.

The proposed ratio of components in the mixture provides more complete removal of phosphorus during the period of melting and obtaining active ferrous slag with a basicity of 1.7-1.9.

The proposed amount, a converter slag equal to 3, is optimal, since the increase in the amount of slag fed to the furnace is irrational due to the increase in it. specific output and reduced productivity of the open-hearth furnace and a decrease in the amount of slag leads to a decrease in the basicity of the primary slag and its reactivity.

The amount of limestone that is loaded into the kiln at the ratio of 2 is not necessary to maintain the basicity of the slag within 1.7-159.

Sh) and the increase in the quantity of limestone fed to the furnace deteriorates the conditions of de-phosphorization, slows down the process of its removal, while reducing the amount of lime decreases the basicity of the slag and does not ensure the complete removal of phosphorus from the metal.

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The proposed amount of oxidizing agents (iron ore, sinter, scale) at a ratio of one is necessary to maintain the FeO content at the beginning of 12-16%. An increase in the ratio of oxidizing agents in the mixture, more than the indicated limit j, leads to the formation of stable slag foam, which prevents the intensification of the steelmaking process,

and reducing the amount of oxidants

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leads to the impossibility of achieving the required degree of phosphorus removal.

The concentration of the components of n | the simulated sm.esi were tested experimentally. , ...

PRI me R. In the open-hearth furnace with a cage of 600 tons, an industrial test of the proposed and known methods is carried out. . .

The results of the experimental heats with the use of a mixture of converter slag, limestone and heke oxidants in the steelmaking process in an open-hearth furnace of the Cherepovets metallurgical combine. presented in tab. one. . .

The technological parameters of steel production in the main open-hearth furnace are presented in Table. 2

Comparison of the results of pilot smeltings shows that with the proposed method (Table 1), the yield of the suitable metal increases by 2.3%, the duration of smelting is reduced by 32 minutes, besides, the use of f t, converter slag, in the smelting of steel in the main open-hearth furnace . saves 400 kg of lime, 250 kg of oxidants and. 26 kg of ferromanganese ..

Ф о р м. У. l a and 3 about 45

 The method of steelmaking in the main open-hearth furnace, including the filling of metal scrap, return slag, limestone, oxidizers, melting and finishing, about T l and h and y and so that, in order to increase the yield, it reduces the duration of smelting , economy and zvestnka, oxidizers and ferroalloys, converter slag is used as return slag, while before filling scrap to the furnace hearth, a mixture of converter slag, limestone and oxidizers is loaded at a ratio of the components of the mixture 3: 2: 1.

Table 1

Using a mixture of slag, limestone and oxidizing agents Without a mixture of slag when replacing 60% limestone with open-hearth slag (known)

7,295.1 313, -i 8.0 4.0 12.0 632.5 1-20 3-30 t-51

95 309.1 307.6 8.5

2.3 5.4 623.5 1-46 4-11 1-41 (March. Slag)

Way

Using a mixture of slag, lime and oxidizing agents Without a slag mixture, replacing 60% lime with a open-hearth slag (known)

0-35 1-49 1-48 0-15 0-31 1-1-50 0.97 0,016 0,033 2,0 575,4 91,6

0-21 2-01 1-49 0-11 0-33 12-22 1.02 0.013 0.034 2.1 565.4 89.3

2.3 5.4 623.5 1-46 4-11 1-41 (March. Slag)

Continued table. one

Claims (1)

For about m. At. A method for smelting steel in the main open-hearth furnace, including filling metal scrap, return slag, limestone, oxidizing agents, melting and lapping, heating, and so on, in order to increase the yield, reduce the duration of smelting, save limestone, oxidizing agents and ferroalloys, converter slag is used as return slag, and before the scrap is dumped, a mixture of converter slag, limestone and oxidizing agents is loaded onto the furnace hearth at a ratio of the mixture components 3: 2: 1. Way - - - —------- If- Consumption Consumption honest cast iron scrap in on, t t gita wok * Limestone Added to the filling, t Oxidizing agents Converted slag Total shih you Duration periods melting ki (h min) zap · ka equal blockage ¹ va prog roar Using a mixture of slag, limestone and oxide Teli Without mixture 7 295.1 313.4 8.0 4.0 12.0 632.5 1-20 3-30 1-51 slag when replacing 60% of limestone with open-hearth slag (known) 95 309.1 307.6 8.5 2,3 5,4 623.5 1–46 4-11 1-41 (March. slag) Way Continuation of the table. one ·, Ras- You- Pro- Content ele Os- The weight You- Drain Floating Before- kis start dol- cops, fl new year- STROKE cast iron laziness water le- living ---_ η ------ ——————— nost ny year- on, ka nie tel went fused but- • h min bone FROM R S ka kov go floating % ki _ ", Using a mixture of slag, limestone and oxidizing agents Without a slag mixture when replacing 60% of limestone with open-hearth slag (known) 0-35 1-49 1-48 0-21 2-01 1-49 0-15 0-31 1-1-50 0.97 0.016 0.033 2.0 575.4 91.6 565.4 89.3 T a 0 I am