RU2567412C2 - Charge for casting of ferrosilicon manganese in ore-smelting electric furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: charge contains in wt %: manganese raw material 55-60, flux 20-25, lean coal 15-20, sludge after production of technical silicon or sludge of high-silicon ferrosilicon - rest.

EFFECT: invention ensures development of charge composition with high restoration ability of manganese extraction to alloy.

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Description

The invention relates to the field of ferrous metallurgy, and in particular to the production of ferrosilicon manganese in ore-thermal electric furnaces.

Known mixture for smelting ferrosilicon manganese Nikopol ferroalloy plant, including carbon reducing agent, flux and manganese-containing raw materials [Reference electro-thermal processes / B.I. Emlin, M.I. Gasik. M .: Metallurgy, 1978, 288 S.], with the ratio of components, kg (wt.%):

manganese raw materials 1971 (63.6) flux (dolomite) 171 (5.5) flux (quartzite) 470 (15.2) carbon reducing agent 486 (15.7)

The disadvantage of this mixture is the presence in the slag of a high content of manganese. The reducing ability of this mixture does not allow reducing the MnO content in the slag below 15%, which negatively affects the degree of extraction of manganese in the alloy.

As a prototype adopted the mixture for the smelting of ferrosilicon manganese [RF Patent No. 2449038, IPC C22C 33/04, publ. 04/27/2012, Bull. No. 12], including a carbon reducing agent, flux, ferrosilicon, slag from the production of manganese alloys with a ratio of components, wt.%:

carbon reducing agent 3-10 flux 7-20 ferrosilicon 1-7 slag from the production of manganese ferroalloys rest

The disadvantage of this charge is that when used as a manganese-containing component of the slag of manganese ferroalloys, the slag ratio will increase by 2-3 times. The use of ferrosilicon as a charge component will increase the cost of production.

The objective of the invention is to develop a composition of the mixture with greater reducing ability to extract manganese in the alloy.

The problem is solved in that in the proposed mixture, consisting of lean coal as a reducing agent, slag from the production of industrial silicon or high-silicon ferrosilicon is additionally introduced in the following mass ratio of components,%:

manganese raw materials 50-60 flux 18-25 lean coal 15-20 industrial silicon slag or high-silica ferrosilicon slag rest

It should be noted that in the production of ferrosilicon manganese, the coke nut is mainly used as a reducing agent.

The process of reducing oxides of the charge is carried out at the first stage with carbon of lean coal, and their reduction with silicon and silicon carbide contained in the slag according to the corresponding reactions (1) and (2):

The essence of the proposed technical solution consists in the use of industrial waste, namely, slag from the production of industrial silicon or high-silicon ferrosilicon, containing silicon and silicon carbide for smelting ferrosilicon manganese, reduce the manganese content in the slag, reduce the specific energy consumption and involve technogenic waste in processing - slags from the production of industrial silicon and high-silicon ferrosilicon stored in dumps, worsening the environment.

The mixture was tested during smelting of ferrosilicon manganese grade MnC17 on an industrial furnace with a capacity of 9 MBA.

The use of the proposed reduction charge allows to increase the productivity of furnaces by 28.6%, reduce specific energy consumption by 22.2%, and increase the extraction of silicon in the alloy by 12.9%.

The proposed mixture has been tested in industrial conditions and proposed for implementation in ferroalloy plants in the smelting of ferrosilicon manganese.

The main results of smelting ferrosilicon manganese grade MnC 17 are presented in the table.

OPTIONS INDICATORS BASE SUGGESTED The productivity of the furnace is 1 MW of used power, bases. t / MW /%

$$\frac{5.25}{100.00}$$

$$\frac{6.75}{128.6}$$

Specific energy consumption, kW · h / t /% $$\frac{4571}{100.00}$$

$$\frac{3556}{77.8}$$

Manganese recovery,% 76,4 89.3

Claims (1)

A mixture for smelting ferrosilicon manganese in ore-thermal electric furnaces containing manganese raw materials, a reducing agent and a flux, characterized in that it contains lean coal and slag from the production of industrial silicon or high-silicon ferrosilicon slag at a ratio of components, wt.%:
manganese raw materials 55-60 flux 20-25 lean coal 15-20 industrial silicon slag or high-silica ferrosilicon slag rest