RU2380440C2 - Restoration mixture for melting of ferrosilicon - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: restoration mixture consists of coke nut, cannel coal of grade D with yield of volatiles more than 40% porosity more than 15% and with increased filtering property, and wood chips in the capacity of ripper in following mass ratio of components, % (by carbon): cannel coal of grade D 25-55, wood chips 5-7, coke nut is the rest.

EFFECT: invention provides development of restoration mixture with increased filtering property for silicon single-oxide.

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Description

The invention relates to the field of ferrous metallurgy, and in particular to the production of ferroalloys by carbon thermal reduction.

As a carbon reducing agent, mainly coke nut is used.

Known reducing agent for the carbon thermal process, consisting of coke nut and coal, such as lean or slightly sintering [1, 2, 3].

However, the coke residue of not all types of coal is able to capture silicon monoxide from blast furnace gas.

The disadvantage of such mixtures is the low filtering ability, which negatively affects the degree of extraction of silicon in the alloy.

The objective of the invention is the development of a reducing mixture having high filtering ability for silicon monoxide.

The problem is solved in that in the proposed recovery mixture, consisting of coke nut and hard coal, long-flame grade D coal with a yield of more than 40% volatility and porosity of more than 15% is introduced as a filtering component, and wood chips are introduced as the charge cultivator in the following mass ratio (carbon),%:

- long flame coal - 25-55;

- wood chips -5-7;

- coke nut - the rest.

The essence of the invention lies in the use of coals of grade D with increased porosity of the coke residue.

The essence of the invention lies in the use of coals of grade D with increased porosity of the coke residue, which ensure the capture of silicon monoxide from blast furnace gas.

In the process of heating long-flame coal, a significant amount of volatile substances is released from it in the form of hydrocarbons, which protect wood chips from combustion. Wood chips in a reducing atmosphere turn into charcoal.

The reducing mixture, consisting of coke nut (58-70%), grade D coal (25-35%) and wood chips (5-7%), was tested for carbon in the production of high-silica ferrosilicon grade FS75 on industrial furnaces with a capacity of 20-29 MVA.

The use of the proposed reducing mixture allows to increase the productivity of furnaces by 8.6-11.4%, reduce specific energy consumption by 9.4-10.9%, and increase the extraction of silicon in the alloy by 1.8-2.1%.

The proposed recovery mixture is tested under industrial conditions and proposed for implementation in ferroalloy plants in the smelting of ferrosilicon.

The main results of FS75 grade ferrosilicon heats are presented in the table.

INDICATORS OPTIONS BASE SUGGESTED The capacity of the furnace at 1 MW used

power base. t / MW Specific energy consumption, kW · h / t

The extraction of silicon,% 91.6 93.7

Information sources

1. A.S. USSR No. 530909, M.cl ² C22C 7/00, Bull. No. 37, publ. 10/05/76 g.

2. A.S. USSR No. 755875, M.cl ³ C22V 5/10, Bull. No. 30, publ. 08/15/80

3. RF patent No. 2236481, IPC ⁷ C22C 33/04, Bull. No. 26, publ. 04/20/04

Claims (1)

Recovery mixture for smelting ferrosilicon, characterized in that it contains coke nut, long-flame grade D coal with increased filtering ability, a yield of volatiles of more than 40% and a porosity of more than 15%, and wood chips as a cultivator in the following mass ratio of components,% (by carbon):
long flame coal grade D 25-55 wood chips 5-7 coke nut rest