SU707973A1 - Slag - Google Patents

Description

The invention relates to ferrous metallurgy, more specifically to ferroalloy production. Slags containing oxides of manganese, chromium and iron in amounts, wt.%: CaO 40-45, 40 45, MtiO 10-20, and used for refining metal from non-metallic VC, are known, for desulphurisation, defosporation, as well as sources of alloying elements introduced into the charge for blast-furnace smelting of iron and containing manganese, chromium and other CLC Slag carbon ferromanganese slag is known, which contains these ingredients in the following amounts, wt%: MpO 12-17; SiO, j.-33 36; CaO 39-42; MgO 1.5-2.5; Afc-jOs, 3-4,5; FeO 0.05-0.20; 0,0130, 022. The high viscosity of the slag (2.03, 5 pz at 1400 ° C), the long duration of smelting and the low extraction of manganese during the smelting of the carbon of that ferromanganese (62-65%) does not allow its further use. 2, Disadvantage Known compounds are low manganese oxide concentrations. With the above ratio of components, the slag has a low liquid mobility, which complicates the recovery of manganese and worsens the process of separating the metal from the slag. The purpose of this invention is to create such a slag composition containing calcium, silicon and manganese oxides as a base, which would contribute to an increase in the through use of manganese by accelerating its recovery in the smelting of iron and steel. To achieve this goal, oxides of sodium, potassium and barium are additionally introduced into the slag; the content of all these ingredients should be in the following ratio, wt.%: MpO 12-25; SiOa 32-38; CaO 33-45; MgO 1.5-2.5; . 2.0-8.5; FeO 0.05-0.25; 0,010-0,030; (Na, jO + K "O) 0.5-3.5; BaO 0.2-2.0. Below are examples of the invention, not excluding other options in the scope of the invention. Example 1. A mixture consisting of manganese ore, and according to the second variant of Mass phosphate slag, coke and limestone, was loaded into an electric furnace. According to the second variant, sodium, porridge and barium oxides were additionally added. Melting led by technology

carbon ferromanganese production. The chemical composition of the smelting products is given in Table 1.

Table 1

As can be seen from the table, the proposed composition of the slag can be obtained by the technology of smelting carbon ferromanganese, but in contrast to the known composition, it contains: + KjO) within 0.5-3.5 and BaO 0.5-2.0, B the proposed slag content of manganese oxide was 12-25%.

Example 2. In the blast furnace was loaded charge containing iron

+

+ + + +

+ +

+ +

Ore, coke, limestone, manganese 5 Ore and in the second variant, manganese slag of the composition based on obtaining cast iron with manganese content of 0.4-0.5%. The basicity of the final slag was 1.27.

Table 2 presents the chemical compositions of cast iron, obtained using manganese ore and manganese slag of the composition described in the mixture.

table 2

0.38 0.1652.5

0.38 0.1553.7

0.38 0.1653.0 0.41 0.1380.5

0.44 0.1262.3 0.41 0.1383.0

Example 3. During the smelting of steel POMP on doped waste after downloading the oxidizing slag, manganese slag of the composition, wt.% MpO 22.7; SiO2. 34.4; CaO 34.8; MDO 1.6; ,9; BAO 0.88; +) 0.97 and coking.

During this period, the reduction reactions take place:

ЗМпО + 4С. + SOA; metal carbonization reactions:

3Fe + C and metal deoxidation reactions:

FeO-t-C Fe CX5, 2FeO + Si-2Fe- -5iO

The amount of donkey was introduced at the rate of 1213% MP in the finished metal.

The final composition of the metal was as follows, wt.%:

Si 0.9

From 1/1

Р 0.08

S 0.015

0.91

1.05

0.05

0,010

in the numerator, the composition of the metal obtained by doping with ferromanganese domain doping, in the denominator, with manganese slag. Even a slight increase in the concentration in the slag (by 0.1–3.5%) of sodium and potassium oxides helps to reduce the melt viscosity at low temperatures, and the introduction of barium oxide increases the concentration of manganese oxide and reduces the phosphorus content in the melt. This is primarily due to the presence of single-charge cations in the slag, which, embedded in the lime-silica complexes, loosen them, make the groups more mobile, which leads to an increase in slag flowability and accelerates the reduction reactions.

The use of the described slag as a manganese-containing component of the charge in the smelting of foundry and marginal cast irons makes it possible to increase the extraction of manganese to 85-90% as compared with the existing 52-55%. This increases the through-use of manganese by 7-9%. It should be noted that the presence of high concentrations of calcium oxide in the slag composition reduces the consumption of lime in the blast furnace charge, and the presence of Margay in its soured form reduces the amount of reducing agent introduced into the charge based on the reduction of higher manganese oxides to MnO.

Claims (1)

1. Author's certificate V 380719, cl. C 2 C 5/54, 1973. 2, Steel Magazine 7, p. 611, 1975.