SU990830A1 - Desulfurizing mix - Google Patents

Description

(54) DESULPHURIZING MIXTURE

one

The invention relates to the field of ferrous metallurgy and can be used in the production of steel to reduce its sulfur content.

From the technological point of view, the simplest method of despreading steel in a ladle is n (L1addle into the ladle of de-limeing mixtures based on lime or other materials containing basic oxides. It is known to use a whole range of such mixtures 1 and {2.

The disadvantages of the known mixtures are the limited sources of some of the components, their complex composition and the low rate of their melting (slag formation).

The most basic to the technical essence and the achieved effect to the proposed is desulfu {{{rusy mixture 3, containing the following components in the following ratio, wt.%:

Calcium Oxide 60-75

Calcium fluoride10-25

Aluminum metal5-15

A disadvantage of the known mixture is the low rate of slag formation.

The aim of the invention is to accelerate the slag formation of the desulfurizing mixture.

This goal is achieved by the fact that the desulfurtizing mixture, containing calcium oxide, fluorine calcium, and metallic aluminum, additionally contains magnesium oxide in the following ratio of composites, wt.% Calcium fluoride15-30

Magnesium oxide 1-14

Metallic aluminum 5-10 Calcium Oxide Else

The amount of fluoride cal1n is taken from a value (15%) at which a tack is formed with a melting point not higher than the melting point of steel to a value (30%), above which the slag jg effect on the casting ladle sharply increases.

The content of magnesium oxide is limited by the lower limit of 1%, the effect of which begins to manifest itself on the slag rate

and an upper limit of 14%, the excess of which leads to an increase in the viscosity of the slag.

The lower limit of the content of aluminum metal (5%) is due to the requirement of complete deoxidation of the steel entering the ladle at the first moment before the start of the deoxidation process. The upper limit of the content of metallic aluminum (10%) is limited by the value, above which its influence on the efficiency of steel processing with a mixture decreases sharply.

Comparative studies of the rate of slag formation proposed and known

Thus, the data table. 1 will show that the rate of slag formation is 1.3-1., 5 times more than the known.

The efficiency of the proposed mixture was tested on experimental smeltings of 17G1S steel, carried out in an oxygen converter shop on converters with a capacity of 350 tons. To prepare the mixture, dolomitized lime crushed to a fraction of 10-50 mm was used.

Mixture

Number of heats

Suggested 1

Desulphurizing mixtures were performed under laboratory TOfHbix conditions. The mixture was prepared from crushed to a fraction of 2-5 mm fluorspar, dolomitic lime, lime and aluminum powder. The thoroughly mixed mixture was placed on the surface of liquid steel in an induction furnace with a capacity of 50 kg at a metal temperature of 1600 ° C. The mixture consumption was 5 kg / t steel. During the experiment, the moment of complete melting of the mixture with the formation of a homogeneous slag was recorded.

Data on the rate of slag formation of mixtures are given in Table. one.

Table 10, 416

12 P 11 0.454 Q, 454

different content MDO (4-25%) and fluorspar. The mixture was introduced into the ladle at the time of the start of production of smelting and at the same time the necessary portion was placed in the metal

crushed aluminum metal. The composition of the mixture corresponded to tab, 1, its consumption was 5-6 kg / t of steel.

Results of testing the effectiveness of mixtures

are given in secrets. 2

table 2

The average value of the degree of desulfurization of the metal

35 36 Data table. 2 indicate a higher refining method proposed by the Leu, the degree of desulfurization is higher by 5-12% than the known one, which is due to the earlier formation of liquid slag, as was established in laboratory conditions (Table 1). The proposed mixture can be made from one component Substances such as lime, fluoride, magnesite and aluminum, or from multicomponent materials, such as pre-lime lime and other materials. Substances taken in this ratio, the ghoby was provided specified in the formula of the content of components without taking into account the accompanying mixtures. The use of the proposed desulfurizing mixture will make it possible to achieve an economic effect of 0.1 rubles / ton of usable slabs by reducing the content in the finished steel to increase the yield of heats by request.

Claims (3)

Continued table. 2 Claims Desulfurizing mixture containing calcium oxide, calcium fluoride and aluminum metal, characterized in {in that with the slag formation acceleration chain, it additionally contains magnesium oxide in the following ratio of components, wt.%: Calcium fluoride 15-30 Magnesium oxide 1- 14 Aluminum metal5-10 Calcium oxide Else Information sources taken into account during the examination 1. USSR author's certificate No. 208508, cl. C 21 S 7/00, 1967. 2. USSR author's certificate number 578351, cl. C 21 C 7/00, 1976. 3. US patent N 4142887, CL. 75-58, C 21 C 7/02, published. 1979