SU808542A1 - Slag-forming mixture - Google Patents

Description

This invention relates to ferrous metallurgy, in particular to mixtures for metal processing in metallurgical smelting plants. Known flux for electroslag remelting, containing, wt.%: Calcium fluoride 8O, lime 2O l. The flux provides a high degree of desulfuration of the alloys, however, it contains a high amount of aggressive to the refractory lining of fluorspar, which releases fluorine compounds to the atmosphere and has a high cost. Known slag-forming mixture 2 containing, wt.%: Newly restored slag from ferro-titanium production 30-60 Lime burned 30-b 0 Fluorspar Else. However, Dovosstanovlenny slag made from ferro-titanium produced in the known mixture is expensive and expensive. The closest in composition is slag-forming mixture 3, containing, in wt.%: Fluorspar 24-47 Carbon 3-6 Lime Other when electroslag processing decreases. The purpose of the invention is to increase the degree of refining and overheating of the iron during electroslag treatment. The goal is achieved by the fact that cupola slag slag is introduced into the mixture containing lime, fluorspar and carbon in the following ratio of components, wt.%: Lime or lime in K-30 Fluorspar 5-2O Carbon 5-10 Shpak cupola. . smelting 4O-.O. A mixture of this composition ensures the formation of a donkey, which allows electroslag smelting and the treatment of molten iron with a high degree of refining and high superheating. , keeping a mixture of slag cupola melt, consisting (in practical data

th) of 40-55% SiOg, 8-20% ledOz; 0-30% FeO; 10-30% CaO; 0.1-5.0% McjO and 0.3-8.0% MnO. provides together with the remaining ingredients Formation of slag containing 18-36% -3 6-12% A 8-16% FeO; 0.8-1.6% M (| O; 1.2-2.4% M &A; 5-2O% 22-36% CaO and 5-10% C,

The presence in the proposed mixture of lime or lime 10–30% and fluorspar 5–2% gives the slag a high desulfurizing ability, and also helps to clean the alloy from non-metallic inclusions, gases and other harmful impurities. A change in the content of a component by a mixture by 2% above or below the established limits leads to a change in the content of CaO and CaF in the slag and the redistribution of the content of the remaining components and reduces the degree of iron casting.

The limits on the carbon content of o6yci are determined by its deoxidizing properties, allowing for the recovery of Fe, S-i and Mn from the slag.

increases carbon content in iron alloy.

The slag of cupola melting adds oxides such as h e to the mixture.

Mohr, MmO, CaO and FeO, the presence of co. Secondly, it provides the required process temperature, imparts modifying properties to the slag that forms, ensures the reduction of the pig iron in the melt

iron, silicon and manganese. The content in the slag mixture of cupola melt more than 80% leads to a decrease in the content in the mixture of fluorspar and lime or lime, and reduces its refining ability. In addition, cupola slag melt introduces an increased content of Si MpO, the restoration of elements from which leads to their excessive content in the metal. The decrease in the content in the slag mixture vagranch-

NO melting below 40% increases the cost of the mixture.

In tab. 1 shows examples of mixtures

and the properties of the coa formed from them.

Table 1 In addition, the presence of carbon in the slag at a high process temperature contributes to the carburization of the iron-carbon melt, i.e. it is possible to produce synthetic iron in an economically advantageous way. Insertion of less than 5% carbon into the mixture does not provide for carburizing cast iron. Excess carbon content is only 1% above the upper limit excessively

1О558О 12900,48 2012,57,5 60 126ОО, 41 302О10 40 12400,37

In tab. 2 shows the changes in the composition of cast iron in the process of remelting, 49 56

78

pertura process and mechanical properties of cast iron. 0,6x10 0,9x1O 1,3x10

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Claims (3)

Thus, the proposed slag-forming mixture has a high viscosity and melting point, which ensures a high superheating temperature of the iron and intensifies the flow of metallurgical reactions between the slag and the iron. The allocation of fluoride compounds in the application of the proposed mixture is insignificant, and the degree of desulfurization is 49-78%. Processing the cast iron of the proposed mixture allows maintaining or slightly increasing the content of carbon in the pig iron, silicon, manganese, as well as increasing its mechanical properties. Slag-forming mixture for electroslag treatment of cast iron containing 2 lime, fluorspar and carbon, characterized in that, in order to increase the degree of refining and overheating of the cast iron, slag is introduced into the cupola melting in the following ratio of ingredients, wt.%: Lime or limestone to 10-30 Fluorspar 5-20 Carbon 5-10 Spack of cupola melt40-80 Sources of Information taken into consideration during the examination 1. KluevM. M. and Kablukovsky A.F. Metallurgists of electroslag remelting, M., Metallurgists, 1969, p. 71 2. USSR author's certificate number 35397O, cl. C 21 C 5/54, 1970. 3. USSR author's certificate number 533645. -kl. C 21 C 7 / OO. 1975.