SU1294858A1 - Method of melting metal manganese with low content of silicon - Google Patents

Abstract

The invention relates to ferrous metallurgy, in particular to the silicone-thermal production of manganese ferroalloys. The purpose of the invention is to reduce the silicon content in the metal and increase the through extraction of manganese. The method consists in the following. 5–20 minutes before the end, the smelting from the furnace produces slag in an amount of 30–70% and a material containing metal oxides in an amount of 3–15 wt.% Is added, whose thermodynamic strength is lower than that of silicon dioxide. As oxides, copper, vanadium, molybdenum, nickel, manganese and cobalt oxides are used. The method allows to obtain manganese metal with a silicon content of up to 0.1%. 1 hp f-ly, 1 tab.

Description

The invention relates to ferrous metallurgy, in particular to the silicone-thermal production of manganese ferroalloys.

The aim of the invention is to reduce the silicon content in the metal and increase the through extraction of manganese.

The method consists in the fact that 5–20 minutes before the end of the smelting, 30–70% of slag is released from the furnace and the material containing metal oxides is injected, whose thermodynamic strength is lower than that of silicon dioxide. As oxides, copper oxides are used,: vanadium, molybdenum, nickel, manganese and cobalt in the amount of 3-15% by weight of the metal in the furnace.

Selected time limits Due to the fact | that the addition of furnaces to the furnace earlier than 20 minutes before the end of smelting leads to a premature increase in the mass of the melts and, as a consequence, to the additional power consumption that is required to maintain the required temperature. Entering additives into the furnace later than 5 minutes before the end of smelting does not provide a sufficiently complete (close to equilibrium) oxidation of K15emi and the achievement of a uniform distribution of additives in the slag volume.

The technology of smelting manganese metal is characterized by a high slag ratio (3–3.5), therefore,. If additives are introduced directly into such a large amount of slag, their effectiveness will be very weak. It is proposed to partially slag (30-70%) before the introduction of additives to release. Experiments show that the best results are obtained when the proposed amount of slag is released from the furnace. An increase in this proportion of over 70% leads to the opening of the metal mirror and the oxidation of manganese. A reduction of less than 30% worsens the conditions for a more complete oxidation of silicon.

Thermodynamic calculations show that silicon is most fully oxidized when copper, vanadium, molybdenum, nickel, manganese, and cobalt oxides are introduced into the SiOn-No. IO slag system. those oxides for which the heat of formation is significantly lower than that of the crsm dioxides

five

0

neither The introduction of materials containing the listed metal oxides should be carried out 5–20 minutes before the end of smelting. In this case, they oxidize silicon most completely and at a high rate. The amount of additives determined experimentally. A reduction in their amount of less than 3% has practically no refining effect on the metal, since the effective concentration of the added oxide in the slag melt is low. Increasing the amount of additives by more than 15% increases the rate of slag and requires additional heat both for melting and for passing reactions.

The choice of input oxides and their amount allows you to adjust the composition of the resulting manganese metal, i.e. it is possible to expand the range of alloys with low silicon content with a partial replacement of 5 copper, vanadium, molybdenum, manganese, cobalt and nickel.

Refinery released from the furnace

slag in the amount of 30-70% contains

o significant amount of manganese

n (20-35%) and is used to smelt low-phosphorus masterpieces based on manganese, which leads to an increase in the through use of manganese and the process becomes low-waste.

PRI me R 1. In a 150 kVA arc furnace, manganese metal was smelted according to the proposed and known methods.

The mixture consisting of the ultimate manganese siloxane, manganese slag and lime is loaded into an electric furnace according to a known method.

5–20 minutes before the end of smelting, part of the slag from the furnace is poured into the ladle, and the material containing metal oxides is added to the remaining melt. Plag released in the first stage was reduced in the ladle with liquid silicon-manganese or aluminum.

The table presents the results of smelting manganese metal. Metallic manganese treated with oxides of copper, nickel, molybdenum, vanadium, cobalt, contains 0.2–5% of these elements, which greatly expands the scope of its use. Losses them with slag are insignificant. The chemical composition of manganese metal smelted on offer5

0

five

0

five

my method contains,%: Mn 91-96; C 0.05-0.1; Si 0.03-0.1; Р 0.05-0.07 and 0.2-5 of one of these elements, the rest is iron.

Manganese slag containing 20–35% manganese oxide is treated with Liquid silicomanganese. The result is a low silicon silicate silica with a phosphorus concentration of less than 0.1%. Extraction of manganese in this division 75-78%.

The same slag is treated with liquid aluminum. Recovery of manganese from slag reaches 80%. The metal contains less than 0.05% C and traces of phosphorus. It is used to alloy critical grades of steel.

Example. 2. In an electric arc furnace with a capacity of 5000 kVA, two melts of manganese metal were carried out using the proposed method: the basicity of slag was 1.75 with a content of manganese oxide in it of 25-27%. Received 4.0 tons of metallic manganese with a silicon content of less than 0.1%. Copper oxides are used as additives. Extraction of manganese in view of its redevelopment from slag at the level of

62-65%, i.e. 10-12% higher than mined by a known method.

Claims (2)

1. A method of smelting manganese metal with a low silicon content, including loading a part of silicon manganese into the furnace hearth, pouring liquid slag, introducing fluxing additives, melting the charge, loading the remaining part of the silico manganese, holding the melts and producing melting products, characterized by , in order to reduce the silicon content in the metal and increase the through extraction of manganese, 30–70% of slag is discharged 5–20 minutes before the end of the smelting and the material containing metal oxides, thermodynamic whose strength is lower than that of silicon dioxide. 2. The method according to claim 1, characterized by the fact that oxides use copper, vanadium, molybdenum, nickel, manganese and cobalt oxides, introduced in an amount of 3-15% by weight of the metal in the furnace. The result is km out Finite PP with a content of 15-17Z. For a long time, not 4n – 4n) r-aneka concentra- tion - manganese qing and rassa-iostn. Plasma grains, smelting s-20 minutes before the end of smelting, are up to 3SZ M used for the second time in the production of higher quality phosphorus siphychomaria. The nature of the amena is indicative of one. 1 is contained in a mole in a metal, from P and N. E and a. E. The copper content in alloy 1 2, EC (it is used for special steels). Editor N. Lazarenko Order 564/28 Compiled by A. Shkirmontov Tehred L.Oleynik Proofreader S.Cherni Circulation 605 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035., Moscow, Zh-35, Raushsk nab, d. 4/5 Production and printing company, Uzhgorod, Projecto st., 4 Table continuation