SU1158594A1 - Disulfurizer - Google Patents

Abstract

1. A desulfurizer containing calcium oxide and carbon, which is in order to increase the desulfurization level of the iron-carbon melt, the desulfurizer additionally contains manganese oxide, sodium oxide, potassium oxide and silicon oxide in the following ratio of ingredients. May Calcium oxide 5-9 Carbon 4-13 24-38 Manganese oxide Sodium oxide 1-3 2-8 Calcium oxide Silicon oxide Remaining 2. Desulfurator pop 1, about 1 ton, and as an oxide-containing material Calcium carbon, manganese oxide, sodium oxide, potassium oxide, and silicon oxide; it contains sludge from gas cleaning of ferroalloy furnaces from smelting manganese: (L o ferroalloys and / or ninai j enrichment of manganese ores.

Description

SP

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This invention relates to ferrous metallurgy, namely to the production of iron-carbon melts, for example, cast iron.

The known mixture for the treatment of iron-carbon melt, including iron oxides, fluorite, carbon-containing material and lime flJ.

The disadvantage of such a mixture is its low desulfurizing ability.

The closest to the proposed technical essence and the achieved effect is a desulfurizer 2}, containing calcium oxide, carbon and calcium fluoride in the following ratio of ingredients, wt.% :. ..

Calcium Oxide 9-70

Carbon 5-15

Calcium fluoride 5-15

In the known desulfurizer, carbon prevents the formation of silicate and removes iron oxides from the reaction zone.

The disadvantages of the known desulfurizer are its comparatively high cost, the presence of harmful fluorine-containing inclusions into the environment during the treatment of the iron-carbon melt and the relatively low desulfurization capacity. The desulfurization rate does not exceed 75%.

The purpose of the invention is to increase the degree of desulfurization of the iron-carbon melt.

This goal is achieved by the fact that a known desulfurizer containing calcium oxide and carbon, additionally contains manganese oxide, sodium oxide, silicon oxide, with the following ratio of ingredients, wt.%:.

5-9

Calcium Oxide

4-13 Carbon 24-38 Manganese Oxide

1-3 sodium oxide

2-8 Potassium Oxide

The rest Silicon oxide At the same time, as a material containing calcium oxide, carbon, manganese oxide, sodium oxide, potassium oxide and silicon oxide, desulfurdtor contains slag gas cleaning of ferroalloy furnaces from smelting of manganese ferroalloys and / or sludge. Enriching manganese ores.

The component composition of the proposed desulfurizer is justified as follows. When the content of manganese oxides is more than 38%, the melting point of the desulfurizer increases sharply. the presence of manganese oxides in an amount of less than 24% reduces the MnO / Oj ratio to 0.5–0.8, which creates adverse conditions for the desulfurization reaction

(MpO) + FeS j (FeO) + (MnS),

since MnO binds to strong silicates (this further reduces the activity of MnO).

A concentration of potassium oxides less than 2% and sodium oxides less than 1% leads to a decrease in desulfurization ability due to a shift in the equilibrium of the reactions to the left side

+ s + (C) (K ,, s) + with

(K, O)

(NajO) + S + (C) () + {CO}

An increase in the content of sodium oxides and potassium oxides by more than 8 and 3%, respectively, 1 results in the binding of sodium and potassium oxides to silicates Na, SiOj and KjSiOj, i.e. vitrification of the melt and a decrease in desulfurization ability due to a sharp increase in viscosity.

The content of silicon oxides is related to the rationale above the limits of the content of manganese oxides, sodium, and, and must provide the required properties (low viscosity and melting point, high desulfurization ability).

The content of calcium oxides less than 5% leads to a significant increase in the activity of silicon oxide and a decrease in the degree of desulfurization, and the excess of calcium oxide content of more than 9% increases the viscosity of the desulfurizer melt and worsens the conditions of desulfurization.

The presence of less than 4% carbon in the desulfurization of the torus leads to a large heat loss of the iron – carbon melt, and a content of more than 13% of carbon leads to undesirable carburization of the melt.

Example. Cast iron desulfurization using the proposed desulfurization agent.

Desulfurization of pig iron containing 3.2% C, 0.40% Si, 0.20% Mn, 0.05% S,

3 .11585944

It was carried out in a 40-pound In-Nikopol, ferro-plant furnace furnace. As desulfu-BOB, manganeseparojpa manganese enrichment sludge from gas ores from Starosvinarevskoe slag cleansing of the ferroalloy furnaces from the storage facility, as well as their mixtures, were used. manganese ferroalloys, j. (see tab. I),

Table 1

After the iron was melted, a desulphurizer was set on its surface in an amount of 4% by weight of the iron, then after an extract for 15 minutes, samples of the iron were taken for chemical analysis (see, Table 2), I. table 2

Claims (1)

1. DESULFURATOR containing calcium oxide and carbon, characterized in that, in order to increase the degree of desulfurization of the iron-carbon melt, the desulfurizer additionally contains manganese oxide, sodium oxide, potassium oxide and silicon oxide in the following ratio of ingredients, wt.% .: Calcium oxide 5-9 Carbon 4-13 Manganese Oxide 24-38 Sodium oxide 1-3 Potassium oxide ’2-8 1 . . . Silica Rest 2. Desulfurizer by item "1, about t l which, in particular, as a material containing calcium oxide, carbon, manganese oxide, sodium oxide, potassium oxide and silicon oxide, it contains sludges from gas purification of ferroalloy furnaces from smelting of manganese: all ferroalloys and / or parchum enrichment of manganese ores. .... SU 1158594 9 'to the production of alloys, machining the same1 1158594