SU1467092A1 - Charge for smelting high-carbon ferromanganese - Google Patents

Abstract

This invention relates to ferrous metallurgy, specifically to the production of high carbon ferromanganese. The aim of the invention is to reduce the phosphorus content in ferromanganese. The mixture for smelting high-carbon ferromanganese contains, wt%: carbonaceous reducing agent 10-15, flux 5-22, own production waste 1-10, iron-containing material 2-5, initial or agglomerated manganese concentrate of thermomechanical dephosphorization 25-45 and manganese-containing raw material the rest. In this case, the ratio of phosphorus to manganese is 0.0030-0.0040. The use of the charge allows to obtain high carbon ferromanganese with a phosphorus content of 0.34-0.45%; 2 tab. a $ (L

Description

I

This invention relates to the steel industry, namely the production of high carbon ferromanganese.

The purpose of the invention is to reduce the phosphorus content in ferromanganese.

The proposed lookup for high-carbon ferro-manganese smelters contains manganese-containing raw materials, carbonaceous reducing agent, flux, own production, iron-containing material and the initial or agglomerated manganese concentrate of thermomechanical dephosphorization, which provides a ratio of phosphorus to mangants, and a template, and manganese manganese concentrate. wt.%:

Carbon Reducer; .10-15 Flux5-22 Own production waste 1-10 Iron-containing material 2-5 Raw or agglomerated manganese concentrate of thermomechanical dephosphorization 25-45 Manganese-containing raw material Else

The manganese concentrate of thermomechanical dephosphorization is obtained as a result of reductive roasting (temperature about 1100 C) manganese

3146

containing raw materials (oxide and / or carbonate manganese concentrates) in the presence of metal additives. The recovered phosphorus contained in the raw material interacts with metal additives, such as iron, to form strong compounds. Then, the calcination products are separated into oxide and metal components by magnetic, air separation or jigging. At the same time, the specific content of phosphorus in the thermomechanical dephosphorization concentrate is reduced by 30-60%.

The silicon oxide content in the manganese oxide concentrate of thermomechanical dephosphorization is 15–20%, and in the carbonate concentrate it is only 8–10%, which requires less flux for the smelting of the alloy.

In identical laboratory conditions, comparative studies have been carried out to obtain high-carbon ferromanganese from the known and proposed mixtures. The smelting of the alloy was carried out in a laboratory furnace There Man. Manganese sinter of the AI-fflB-V brand, manganese concentrate of thermomechanical dephosphorization, limestone, iron ore pellets and own production were used as the charge.

The chemical composition of the charge materials is given in table. one.

The specific phosphorus content in the initial manganese concentrate of thermomechanical dephosphorization is 0.00291 versus 0.00459 in the conventional agglomerate AMHB-1.

The weighed materials are mixed, loaded into a graphite crucible, heated in a furnace to 1550 ° C and kept at this temperature for about min.

The results of the studies are presented in Table. 2

From Table 2, it follows that with the introduction of the initial or agglomerated manganese concentrate of thermomechanical dephosphorization into the charge for smelting ferromanganese, the specific phosphorus content in the charge and the concentration of phosphorus in the alloy decrease. A standard phosphorus alloy can be obtained only from a mixture with the proposed ratio of components. So when the content in the mixture of 15-22% of the original or agglomerated margaptse

0

five

20

25 30

g

40

45

50

55

In the first concentrate of thermomechanical dephosphorization, the specific concentration of phosphorus in it (P / Mp) is 0.00301-0.00398, and the phosphorus content in the alloy is 0.34 - 0.45% (options 3-5 and 7). ferromanganese from known charge, 00459, is accompanied by the production of ferromanganese with a phosphorus concentration significantly exceeding the allowable value (0.52%, option 1).

The content of initial or agglomerated manganese concentrate in the mixture of thermomechanical dephosphorization less than 25% (for example, 22%) entails a corresponding increase in the proportion of manganese-containing raw material, which is accompanied by an increase in the specific phosphorus content in the mixture (, 00409) and the production of ferromanganese with a phosphorus concentration exceeding the permissible value (option 2).

Obtaining a thermomechanical dephosphorization concentrate is costly. Therefore, as its content in the charge increases, the cost of ferromanganese increases. As shown by the results of the research, the maximum amount of thermomechanical dephosphorization concentrate in the charge should not exceed 45%. In this case (option 5), the specific phosphorus content in binder (, 00301) allows to obtain a ferromanganese with a phosphorus content of 0.34%, which corresponds to the alloy marks FMN 78 and (MN 78K.

An increase in the charge of the initial or agglomerated manganese concentrate of thermomechanical dephosphorization over 45% is impractical, since the phosphorus concentration in the alloy varies slightly, and the cost of the alloy increases.

The thermomechanical dephosphorization concentrate can be introduced into the charge separately and / or as a manganese sinter (option 7).

The amount of the other components of the charge (reducing agent, flux, iron-containing materials, own production waste) is interrelated and depends on the content of manganese and silicon oxides in the manganese-containing raw material and the manganese concentrate by thermomeric dephosphorization. So,

when the reducing agent contains less than tO% in the charge, the extraction of manganese in the alloy is low, and the concentration of phosphorus in it exceeds the allowable value (option 2). An increased amount of reductant in the charge (more than 15%) is accompanied by a decrease in its electrical resistivity, which leads to a breakdown in the operation of the electric furnace.

In the smelting of ferromanganese grades FMN78 - FMN75S9, the basicity of slag (CaO + MgO / SiCjji) is in the range of 0.8-1.1. This is ensured by the introduction of a flux in the form of lime into the composition of the mixture. The content of lime in the charge less than 15% causes a decrease in the basicity of the slag, which is accompanied by a low extraction of manganese and an increase in the content of silicon and phosphorus in the alloy (option 2).

An increase in the amount of limestone in the charge of more than 22% is undesirable, since it is necessary to expend additional amount of electricity to dissociate calcium oxides.

The optimal amount of waste of its own production, as shown by the practice of production of ferromanganese, should not exceed 10%. An increase in domestic waste more than 10% is accompanied by an increase in the electrical resistivity of the charge, which also leads to disruption in the operation of the electric furnace.

The use in the charge of less than 1% of its own production waste has virtually no effect on the extraction of manganese in the alloy.

A decrease in the amount of iron-containing material in the mixture to less than 2% leads to an increase in the manganese content in ferromanganese more than 80% (option 2). However, the alloy of such a composition is scattered.

The increase in the charge of the proportion of iron-containing material in excess of 5% is accompanied by a decrease in the concentration of mar 670926

manganese in the alloy (option 6), which can lead to non-standard ferromanganese.

The amount of manganese-containing raw material is determined by the content of the initial or agglomerated manganese concentrate of thermomechanical dephosphorization in the charge and

10 concentration of phosphorus in the alloy. Accordingly, the amount of manganese-containing raw material in the charge is 3-47%.

Thus, the proposed mixture

15 for smelting high carbon ferromanganese provides standard phosphorus grades of the alloy.

Claims (1)

Formula iso rete n i Charge for smelting high carbon ferromanganese, including. manganese-containing raw material, carbonaceous reducing agent, flux, own production waste and iron-containing material, characterized in that, in order to reduce the phosphorus content in the ferromanganese, it additionally contains the initial or agglomerated manganese concentrate of thermomechanical dephosphorization, providing the ratio of phosphorus to manganese 0, 0030-0,0040, in the following ratio, wt.%: Carbon Restorer 10-15 Flux15-22 Domestic Waste1-10 Iron material2-5 Original or agglomerated manganese concentrate of thermomechanical dephosphorization 25-45 Manganese additional raw materialsEalse Table 1 Manganese sinter; Amnv-1 i Original manganese I concentrate of thermomechanical fooforement; Known to  Iron ore: Waste of its own; Production i Agglomerated manganese-I manganese concentrate I thermomechanical I dephosphorization 45.5 19.1 5.2 1.9 2.1 0.2009 0.00459 49.215,7 1,41,6 2,9 52.0 4.2 0.60.03 56.6 53.3-0, 143 0.00291 0.02 49.8 15.5 1.3 1.7 2.8 0.15 0.00301 13.5 16.5 12.6 about e at raw material 57.4 phos Z 9 1A 0.5 I 22 53.5 10 15 12 25 47 12.5 18.5 5.5 3.5 35 25 15 22 10 5 45 3 0.00459 0.00409 0.00393 0.00357 0.00301 The thermomechanical dephosphorization concentrate is introduced into the agglomeration form 0.143 0.00291 0.02 Table2 12.5 18.5 5.5 3.5 15 22 10 5 15.5 22.5 10,5 5,5 12.5 18.5 5.5 3.5 35 25 45 3 45.5 0 S 35 25 0.00295 0.00354