SU1696498A1 - Refining mixture - Google Patents

Abstract

The invention relates to ferrous metallurgy and can be used in the after-furnace treatment of steel for blowing into a ladle. The purpose of the invention is to increase the ds-sulphurizing capacity of the mixture, reduce its cost and utilize industrial waste. Refining mix contains May. %: dust waste gas cleaning aluminum production 55-65; dusty waste gas cleaning lime production 25-35; aluminum powder 5-15. The use of a refining mixture allows a 3–6% increase in the desulfurization ability of the mixture, a 3.4-fold reduction in the cost of the mixture and the utilization of production waste. 4 tab.

Description

SP

with

The invention relates to ferrous metallurgy and can be used, for example, during secondary treatment of steel in a ladle.

The purpose of the invention is to increase the desulfurization ability of the mixture, reduce its cost and utilize industrial waste.

The refining mixture containing aluminum, alumina-containing and lime-containing materials, contains alumina and lime-containing materials in the form of dust-like waste gas cleaning aluminum and lime production in the following ratio of components, wt.%:

Aluminum dust

production55-65

Lime dust

production25-35

Aluminum powder 5-15

The introduction of lime and alumina shedding materials in the form of gas cleaning dust from lime and aluminum production reduces the production costs of the mixture and simplifies its production.

Dust gas cleaning aluminum production is a dark brown powder with a bulk weight of 0.3 g / cm. Granulometric composition less than 0.2 mm 90%, 0.2-0.5 10%. It is obtained as a result of the precipitation of aluminum production dust on electrostatic precipitators.

Lime dust is a white powder with a bulk weight of 0.6 g / cm3. Particle size less than 0.4 mm 90%, 0.4-0.5 mm 10%. It is obtained in the result of the result

dust collection bag filters.

Increasing the amount of dust by more than 65% reduces the basicity of the mixture (1.2), which negatively affects its desulfurization ability. A decrease in the proportion of dust less than 55% leads to an increase in the melting point of the mixture (more than 1,300 ° C), which also adversely affects the desulfurization of the steel.

Lime dust contains about 60% CaO, which is the main element for desulfurization. The amount of dust in the range of 25-35% makes it possible to have the optimum melting point of the mixture and the necessary basicity (1.3-1.5).

The aluminum powder is introduced into the mixture to locally deoxidize the steel at the interface of the mixture and the melt. Increasing the amount of aluminum by more than 15% is impractical due to the increased uptake of aluminum by steel, which leads to chemical composition defects and deteriorated casting conditions. A decrease in the aluminum content of less than 5% leads to an insufficient acidity of the steel, which makes it difficult for sulfur to diffuse to the reaction site and lead to a deterioration of the steel desulfurization process.

The desulfurization mixture is prepared in a pleasant manner. The components of the mixture are metered by weight using a weighing device and mechanically stirred in a batch mixer with a periodic rotating rollers for 20-30 minutes.

The compositions of the mixtures are given in table 1; The compositions of powdered wastes of aluminum and lime production are in Tables 2 and 3, respectively.

The proposed mixture will be tested when processing in the bucket 100-ton smelting. After the metal is released, the mixture is blown into the ladle in a stream of argon at a pressure of 6 atm. Argon consumption is 0.05-0.20 m3 / t, mixture consumption is 2-10 kg per 1 ton of steel.

The results of processing the steel of the proposed and known mixtures are given in Table 4.

The application of the proposed mixture instead of the known one will reduce the cost of processing 1 ton of steel while simultaneously processing and using the wastes of lime and aluminum production. In addition, the degree of desulfurization of the proposed mixture is higher than the known.

Claims (1)

Invention Formula Refining mixture containing aluminum, alumina-containing and lime-containing materials, so that, in order to increase the desulfurization ability of the mixture, reduce its cost and utilize industrial waste, it contains dusty gas cleaning of aluminum production as an alumina-containing material and as lime-containing material - waste gas cleaning lime production in the following ratio, wt.%: Dust waste gas cleaning aluminum production55-65 Dust waste lime gas cleaning production25-35 Aluminum powder 5-15 Table 1 Table 3