SU1046296A1 - Slag-forming mix - Google Patents

Abstract

1. SLAGING MIXTURE for refining molten steel, containing calcium oxide and aluminum powder, characterized in that, in order to increase the degree of refining of metal, it additionally contains natural bischofite in the following ratio of components, wt.%; Aluminum powder 0.5-10 Natural bischofite 1-20 Calcium oxide Else 2. POP.1 mixture, characterized by the fact that natural bischofite has the following chemical composition, wt.%: Magnesium chloride 95-97 Calcium chloride 0 9 -1.8 Magnesium bromide. 1.5-2.0 Potassium Chloride Else

Description

The invention relates to ferrous metallurgy and can be used in enterprises of the metallurgical and engineering industries during out-of-furnace treatment of liquid metal. .

Mixtures for processing liquid metal containing granular magnesium and various additives are known.

The disadvantages of these mixtures are their fire and explosion hazard i. due to the high chemical activity of the granular magnesium contained in them.

Closest to the invention to the technical essence is a slag-forming mixture for refining liquid metal C2, containing, by weight,%:

Calcium Oxide 50-60 Aluminum Powder .15-20 Calcium Chloride 2-5 Chloride nat-. 2-5 Fluor spar Eliminations The disadvantages of the known mixture are the low degree of metal refining from hydrogen, the presence in the mixture of a significant amount of aluminum powder, which increases its amount in the metal and is unacceptable for steel grades tested on transverse specimens, and its high cost,

The aim of the invention is to increase the degree of metal refining. This goal is achieved by the fact that a slag-forming mixture for refining molten steel containing calcium oxide and aluminum powder contains natural bischofite in the following ratio of components

, Aluminum powder 0.5-10 Natural bischofite. 1-20 Calcium Oxide Else Moreover, natural bischofite has the following chemical composition, weight,%:

magnesium

95-97. calcium 0.9-1.8 magnesium 1.5-2.0 potassium Else

Natural bischofite also contains macronutrients of strontium, rubidium, tseg zy and other elements. In an amount not exceeding 1.0 wt.%.

The use of the proposed mixture of natural bischofite, which decomposes when introduced into the molten metal with the formation of magnesium and chlorine vapors, leads to intensive mixing of slag and metal, an increase in the interfacial surface of the slag metal, which increases the refining effect of the mixture. In addition, magnesium released during dissociation, reacting with oxygen and sulfur dissolved in the metal, binds them into strong compounds of MgO and MgS, which are assimilated by liquid slag. Chlorine reacts with hydrogen with o6t by forming the gaseous HC1 compound, which is intensively removed from the metal, ossified gaseous products of dissociation of compounds entering into bischofite, and gaseous products of interaction with the elements, dissolved steel, bubbled metal, removed non-metallic melt inclusions

. Chlorine, potassium and calcium impurities present in natural bischofite are also involved in metal refining, similar to MgCl2. enhancing the effect of degassing. Traces, A1, Ti, Mn, Si, Ba, Zg, Mo, Rb, Cs deoxidize and modify the metal,

The introduction and a mixture of bischofite over 20% leads to a vigorous sparging of metal in the ladle, which may result in metal emissions,

.Primer. For the preparation of 1, the proposed mixture was taken from the Volgograd -bearing site, the salt and ionic composition of which is given in Table 1,

Table

31.63 0.65 0.005 0.19 10.83 0.085 43.39

In addition, by spectral methods, 60 Of the mixtures of specific compositions,

th and atomic adsorption analysis., including the boundary values of the detected aliquities of A1, Ti, Mn, and elements, form briquettes of the size Si, Ba, Sr, Mo, Hb, C.S, Content .ram 200200-100 mm. Thereafter

for example, rubidium is in pre-briquettes calcined at D500dela 0.037-0.15%, 651650 ° C. 0.41 42.02 0.75 OD6 43.34

The mixture was tested by treating a liquid semi-finished product smelted in the main open-hearth furnace with a final sulfur content of 0.015-0.018% and intended for the production of steel grade 38XH3MFA in an acidic open-hearth furnace.

The mixture is injected into the metal stream.

--35, -. ,,

Thus, the use of pre-alumina and its oxidation products, the lagged mixture allows significant-. The economic effect of using the metal content in the metal of the proposed shpakoobrazuyuschey metal inclusions, oxygen, mixture in the smelting of 1 million tons of steel in hydrogen and sulfur, pollution-free metal for 40 years is 470 thousand rubles.

the time of its release from the furnace. Experienced. the batch of metal treated with the proposed mixture is 1350 tons (18 heats). For comparison, melts with metal treatment with a known mixture (7 heats. The test results are presented in Table 2.

table 2

Claims (2)

1. SLAG-FORMING MIXTURE for refining liquid steel, containing calcium oxide and aluminum powder, characterized in that, in order to increase the degree of refining of the metal, it additionally contains natural bischofite in the following ratio of components, wt.%: Aluminum powder 0.5-10 Natural bischofite 1-20 Calcium Oxide Else 2. The mixture according to π. 1, distinguishing with the fact that natural bischofite has the following chemical composition, wt.%: Chloride magnesium 95-97 Chloride calcium 0.9 -1.8 Bromide magnesium. 1.5-2.0 Chloride potassium Rest > for refining · [2], containing · 50-60 15-20 2-5 2-5 Rest