SU981383A1 - Slag-forming mix for refining molten metal - Google Patents

Description

(54) SLAG FORMULATION FOR REFINING

one

The invention relates to ferrous metallurgy, namely to the field of refining a liquid metal from sulfur, oxygen, hydrogen and non-metallic inclusions by treating it in a ladle.

Known slag-forming mixture for the treatment of liquid metal L Oder, weight. %:

Lime15-20

Fluor-spar 45-50 Magnesite powder 30-40 The drawbacks of the mixture consist in a relatively low rate of slag formation, low desulfurization ability, especially in the temperature range 1300-1650 ° C, and the composition of the mixture contains a deficient material, fluorspar, and a high viscosity of the molten mixture.

Closest to the invention to the technical essence and the achieved result is a slag-forming mixture for treating liquid metal 2, containing, wt.%: Fluorspar 1-40 Aluminum oxide 5-30 Silicate lump containing LIQUID METAL

silica1-40

Lime Essential

Slag-forming mixture has the following properties:

Melting temperature 1290 ° C laziness Viscosity at

, 5 P

viscosity at

ten

1500С0 5 П

A disadvantage of the known mixture is the use of a scarce material, fluorspar, as well as a relatively low desulfuric capacity due to the low content of free oxide, which characterizes the desulfurization ability of the slag. In addition, the mixture has a low refining capacity relative to the gases dissolved in the metal, as well as a relatively high rate of slag formation.

The purpose of the invention is to increase the rate of slag formation, the efficiency of refining the liquid metal and

25 production of liquid active basic slag in the ladle.

This goal is achieved by the fact that in the slag-forming mixture for refining liquid metal, containing

alumina, silica and lime, magnesium oxide and chloride waste from titanium-magnesium production are additionally introduced, and the components are taken in the following ratio, wt%: Lime45-51

Alumina18-30

Silica 9-15

Magnesia 6-10

Chloride waste from titanium-magnesium production 6-10 In this case, chloride waste from titanium-magnesium production is a mixture of the following composition, wt.%:

Carbon2.0-3.0

Titanium dioxide 3, 0-5.0 Silicon dioxide 8, 0-10.0 Ferric chloride 0.5-1.0 Ferric chloride 12.0-18.0 Chloride

blue1.0-7.0

Calcium Chloride3, 0-5.0 Magnesium Chloride 7.0-14.0 Chloride

manganese 3.0-5.0

Chloride

chromium2.0-4.0

Chloride

niobium 0.02-0.20

Chloride

tantalum 0.02-0.20

Chloride

scandium 0.02-0.04

The amount of sodium chloride and

potassium 40.0-45.90

Titanium-magnesium chloride chloride waste is ready for use and does not require special preparation,

In the proposed mixture, magnesia reduces the melting point and viscosity of the slag, partially replacing the effect of fluorspar, increases the basicity of the slag, and the content and activity of free calcium oxide, thereby increasing the efficiency of refining the liquid.

Chloride waste from titanium-magnesium production, having a low melting point of 600-800 ° C, helps to increase the rate of slag formation and improve the physicochemical characteristics of the slag by lowering the melting temperature and viscosity of the slag, partially replacing the effect of fluorspar, and hydrogen and oxygen.

The content of the proposed slag-forming mixture of lime, alumina, silica, magnesium oxide and titanium-magnesium chloride waste was chosen on the basis of optimal conditions for obtaining a homogeneous liquid mobile basic slag in the temperature range 1350-1650 with high refining capacity.

Such a complex improvement in the physicochemical properties of the slag-forming leads to an increase in the rate of slag formation and the degree of refining of the liquid metal.

The mixture is prepared by mixing the starting components. The dry components of the mixture fractions of 0.5-1.0 mm are thoroughly mixed. Then the mixture in the amount of 0.5-1.5 weight,% of the metal being processed is loaded onto the bottom of the ladle or introduced into the ladle during the metal production.

To compare the effectiveness of the proposed slag-forming mixture, the treatment of liquid metal (cast iron СЧ15 and steel ZOL) produced in an induction furnace with a main lining with a capacity of 150 kg and test mixtures is carried out simultaneously.

Examine the properties of the known (1) and the proposed (2-4) slag-forming mixtures. The chemical composition and physicochemical properties of the known and proposed slag-forming mixture are given in the table.

As can be seen from the table, the slag melting point, which characterizes the rate of slag formation, and the viscosity at metal processing temperatures of the proposed mixture is lower than that of the known one. The content of free calcium oxide and the value of the equilibrium coefficient of the distribution of sulfur between the slag and the metal, characterizing the refining characteristics of the slag in the proposed slag-forming mixture is higher than that of the known.

In the process of interaction of the proposed slag-forming mixture with a liquid metal, a liquid-mobile highly basic homogeneous active slag is formed, reducing the content of sulfur, oxygen and hydrogen in the metal.

When using the proposed mixture, the duration of metal finishing in the furnace is reduced by 20-30 minutes. The degree of desulfurization of the metal is 60-75%, the oxygen content decreases by 25-30%, and hydrogen by 30-50%.

The advantages of the proposed slag-forming mixture should include its lower cost of 55 p. / T versus 65 p., / T known.

The expected economic effect from the introduction of the proposed slag-forming mixture for processing liquid metal is more than 90 thousand rubles. in year.

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Claims (2)

1. A spacing mixture for refining a liquid metal containing lime, silica, alumina, characterized in that in order to increase the rate of slag formation, the efficiency of refining the liquid metal and to obtain a liquid active base ass in the bucket, it additionally contains magnesium oxide and hlsside of titanium-magnesium production and the components are taken in the following ratio, weight. % s Lime45-51 Alumina18-30 Silica 9-15 Magnesium oxide 6-10} Slide titanium-magnesium production 6-10 2. A mixture according to claim 1, wherein there the titanium-magnesium chloride waste products have the following composition, wt.%; Carbon2.0-3.0 Titanium dioxide 3, 0-5.0 Silicon dioxide 8, 0-10,0 Ferric chloride 0, 5-1.0 Ferric chloride 12.0-18.0 Chloride "Aluminum1.0-7.0 Chloride Calcium 3.0-5.0 Magnesium Chloride7, 0-14,0 Manganese Chloride3, 0-5.0 Chloride chromium2.0-4.0 Chloride niobium 0.02-0.20 Chloride tantalum 0.02-0.20 Chloride scandium 0.02-0.04 The amount of potassium chloride and sodium is 40.0-45.90 Sources of information taken into account in the examination 1. Authors certificate of the USSR 773086, cl. C 21 C 5/54, 1980. 2. Authors certificate of the USSR 553295, cl. C 21 C 5/54, 1977.