RU2134299C1 - Method of melting ferromanganese in blast furnace - Google Patents

Abstract

FIELD: production of ferromanganese in blast furnaces. SUBSTANCE: method involves charging manganese ore material, solid fuel, iron-bearing material and slag-forming components into blast furnace. Ferrite-calcic flux containing oxides of Fe, Si, Ca and other elements contained in iron ore material may be used as iron bearing material. Iron ore material has Cao/SiO O₂ ratio of at least 3 at total iron content of at least 27% and silicon dioxide (SiO O₂) of 1-7%. Amount of ferrite-calcic flux to be introduced is calculated from formula: Q(fcf)=[1,000-(Mn+C+Si+P+S)-Q(c)A(C)Fe(ca)-(Σ Q(mo) Fe(mo)-(Σ Q(ibc)] / Fe(fcf), where Mn, C, Si, P, S is content of respective elements in 1 ton of ferromanganese of predetermined composition, kg; Q(c), Q(mo), Q(fcf), Q(ibc) is specific consumption (per 1 ton of ferromanganese) of coke, manganese ores, ferrite-calcic flux, other iron-bearing components, kg/t; Fe(ca), Fe(mo), Fe(fcf), Fe(ibc) is content of iron in coke ash, one concrete manganese ore, ferrite calcic flux, other concrete iron-bearing component, weight part; A is content of ash in coke, weight part. Usage of ferrite-calcic flux as slag-forming component in blast-furnace burden during melting of ferromanganese allows raw flux and expensive iron-bearing components to be partially or completely excluded from blast-furnace burden. EFFECT: increased efficiency and reduced production costs. 2 cl, 1 tbl, 1 ex

Description

 The invention relates to ferrous metallurgy, in particular to the production of ferromanganese in blast furnaces.

 When smelting ferromanganese for the high-performance operation of the blast furnace, the correct selection of the slag regime is especially important.

It is known [1] that maintaining the basicity of slag within CaO / SiO ₂ = 1.1-1.6 allows for high physical heating of the hearth and smelting products and, thus, to create the most favorable conditions for the reduction of manganese oxide (MnO) and increase utilization rate of manganese, reduce slag yield and reduce coke consumption.

 With the traditional technology of smelting ferromanganese in a blast furnace, which includes the reduction and smelting, as a rule, of “acidic” manganese ores or their concentrates and iron-containing components (metal additives, pellets, etc.), the production of refractory slags of the required basicity is achieved by adding a basic flux to the charge - a mixture of conventional and dolomitic limestone [2].

 The disadvantage of this technology, which we adopted as a prototype, is the need to use a large amount of conventional and / or dolomitic limestone (0.5-1.0 t / t ferromanganese) in the mixture, as well as expensive and scarce iron ore pellets and metal additives, iron ore, which leads to an increase in slag yield, cost overruns of coke and an increase in the cost of ferromanganese.

 These shortcomings were tried to be eliminated using the fluxed manganese material (OMA) in the charge during ferromanganese smelting [3]. However, despite the fact that the use of OMA has significantly reduced the consumption of crude flux, this method has not been widely used in production, since, on the one hand, it was not possible to achieve a rational sintering regime of OMA, and on the other hand, this pathway leads to a significant (40-50%) higher cost of the manganese-containing part of the charge.

 The aim of the invention is a partial or complete withdrawal from the composition of the blast furnace mixture during smelting of ferromanganese crude flux (ordinary and dolomitic limestone) and expensive iron-containing components, increasing furnace productivity, reducing coke consumption and alloy cost.

This goal is achieved by the fact that in the method of smelting ferromanganese, which includes loading manganese-containing ore materials, solid fuel, iron-containing materials and slag-forming components into a blast furnace, according to the invention, it is proposed to use calcium ferritic flux (PCF) consisting of Fe oxides as a slag-forming component, Si, Ca and other elements included in iron ore material in which the ratio of CaO / SiO ₂ is not less than 3 at a content of Fe _commonly at least 27% SiO ₂ and from 1 to 7%.

PCF, in which the SiO ₂ content is increased or the CaO / SiO ₂ ratio is reduced, usually has low mechanical strength and its use worsens the gas-dynamic conditions in the furnace, which leads to a decrease in its productivity.

 The calcium ferritic flux proposed for use is a special case of the calcium ferritic flux described in [4].

 In the general case, to obtain PCF it was proposed [4] to use a mixture containing waste or a mixture of metallurgical waste, calcium and magnesium-containing materials, and solid fuel. The uniformity and fine grinding of the mixture, the necessary excess fuel, during the PCF production ensure the complete decomposition of limestone, the transition of lime into strong and non-decomposing minerals during storage, which guarantees its high strength, especially during overloads and long-term storage, and a minimum fines content of 5-0 mm.

 The resulting PCF is a fairly cheap and easily accessible material.

где Mn, C, Si, P, S - содержание соответствующих элементов в одной тонне ферромарганца заданного состава, кг;
Q_k, Q_mp, Q_фкф, Q_жк - удельный (на 1 тонну ферромарганца) расход соответственно кокса, марганцевых руд, ферритно- кальциевого флюса, других железосодержащих компонентов, кг/т;
Fe_зк, Fe_mp, Fe_фкф, Fe_жк - содержание железа соответственно в золе кокса, конкретной марганцевой руде, ферритно-кальциевом флюсе, другом конкретном железосодержащем компоненте, мас. доля;
A_к - содержание золы в коксе, мас. доля
В заявляемом способе в шихте для получения ферромарганца могут быть использованы как окисленные, так и карбонатные марганцевые руды.The amount of ferrite-calcium flux required to obtain 1 ton of ferromanganese (Q _fcf ) in each case is calculated based on the following ratio:

where Mn, C, Si, P, S is the content of the corresponding elements in one ton of ferromanganese of a given composition, kg;
Q _k, Q _mp, Q _FCCP, Q _lcd - specific (for ferromanganese 1 ton) coke consumption, respectively, of manganese ores, ferritic calcium flux, other iron-containing components, kg / ton;
Fe _{sk, mp} Fe, Fe _{FCCP, LCD} Fe - iron content, respectively, in the ash coke particular manganese ore, ferrite-calcium flux, iron-containing another specific component, wt. share;
A _to - the ash content in coke, wt. share
In the inventive method in the mixture to obtain ferromanganese can be used both oxidized and carbonate manganese ores.

 The use of FCF in the smelting of ferromanganese with specified parameters leads to a decrease in the consumption of scarce and expensive components and crude flux.

 The maximum consumption of PCF is determined by the iron content in ferromanganese and PCF according to the above formula.

 Taking into account the minimum possible (according to GOST) content of Mn in the ferroalloy 65%, it is obvious that the iron content in it can be 25-35%, which accordingly determines the maximum level of FCF consumption in the range of 250-400 kg / t alloy.

Example. In industrial conditions (JSC "Kosogorsky metallurgical plant) smelted ferromanganese according to the prototype method and the inventive method using PCF having the following parameters (%): 54.4 Fe _total , 14.1 FeO, 12.1 CaO, 3.9 SiO ₂ , 0.95 Al ₂ O ₃ 0.70 MnO.

 The initial process parameters and the results are shown in the table.

 A comparison of the results shows that the use of ferromanganese (per 1 ton) of 251 kg of PCF in the smelting helped to remove 124 kg of scarce metal additives, 144 kg of limestone and 195 kg of dolomite from the charge, as well as reduce coke consumption by 90 kg. At the same time, the furnace productivity increased from 167 tons to 187 tons / day.

Thus, the use of the invention allows:
- reduce the content or remove from the composition of the charge the scarce metal additives, as well as pellets or iron ore, which increase the output of slag, flux and coke consumption;
- significantly reduce or stop the supply of raw flux to the mixture;
- increase the basicity and melting temperature of primary slag, respectively improving the conditions for heating the smelting products and the conditions for the reduction of manganese oxide;
- to increase the productivity of the furnace, due to a decrease in the specific (per 1 ton of ferromanganese) flux consumption, output of slag, furnace and top gases;
- to increase the stability of the technological mode and the charge, the utilization of heat;
- reduce the specific consumption of coke;
- increase the utilization rate of manganese.

Literature
1. Volovik A.V., Tuluevskaya T.A. Slag regime in the smelting of ferromanganese in large blast furnaces // Steel. - 1967. - N 7. - c. 587-589.

 2. Velichko B. F., Gavrilov V. A., Gasik M. I. et al. Metallurgy of manganese of Ukraine // Kiev. - Technics. - 1996. - p. 242-243.

 3. Soldatkin A.I. Obtaining highly fluxed agglomerate from manganese ore // Sat. Proceedings of UkrNIIMet "Technology of production and properties of metals". - 1958. - issue. IV. - p. 49-71.

 4. RF patent N 2087557 C 22 B 1/16, C 21 C 5/06, publ. 08/20/97, bull. N 23b

Claims (2)

1. A method of smelting ferromanganese in a blast furnace, comprising loading manganese-containing ore materials, solid fuel, iron-containing materials and slag-forming components into a blast furnace, characterized in that calcium ferritic flux consisting of Fe, Si, Ca and oxides is used as a slag-forming component. other elements included in iron ore material in which the ratio of CaO / SiO ₂ is not less than 3 at a content of Fe _commonly at least 27 wt.% SiO ₂ and from 1 to 7 wt.%. 2. The method according to claim 1, characterized in that the calcium-ferrite flux is introduced into the blast furnace in an amount determined by the ratio

where Mn, C, Si, P, S is the content of the corresponding elements in 1 ton of ferromanganese of a given composition, kg;
Q _a, Q _{mp, FCCP} Q, Q _lcd - specific (per 1 ton of ferromanganese) flow respectively coke, manganese ore, ferrite-calcium flux, other iron-containing components, kg / t. Fe _{sk, mp} Fe, Fe _{FCCP, LCD} Fe - iron content in the coke ash, respectively, particular manganese ore, ferrite-calcium flux, iron-containing another specific component, mas.dolya;
And _to - the ash content in coke, wt.

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