SU1708856A1 - Method of blast-furnace smelting - Google Patents

Description

The invention relates to the metallurgy of ferrous metals and can be used in the blast furnace redistribution. materials.

The purpose of the invention is to reduce the consumption of coke due to the degree of utilization of the reducing power of gases in the blast furnace process.

The sorption capacity of wet quenching coke is 3.5-4 cm / g, for dry quenching coke -6.5-7 CMvr. Mixing wet quenching cokes for most of the temperatures studied gives a deterioration in the use of carbon monoxide, and when mixing dry extinguishing coke with agglomerate and introducing it into the CO layer, the maximum use is observed at mixing degrees of 10-50%.

Example 1. The proposed method carried out blast-furnace smelting of iron ore materials at a DP fSk 4 (3,200 m of the Karaganda Metallurgical Combine. Dry quenching coke of a 10-35 mm fraction in kolycheftva 17-18 kg / t of pig iron was fed into the path of iron ore material, where it was mixed with it and then it was loaded into the furnace. The mixed material was loaded in the first ore skip system with the CRKK system, which ensured its entry into the area of the ore ridge with a high content of C02 in the gas. For a comparative period, the coke was not mixed roizvodili.

The results are shown in table 1.

For example, Domain smelting with the introduction of a fraction of 10-35 mm (nut) into the layer of iron ore coke material.

The limits of the fraction are determined by the process of sifting out the small fractions from the metallurgical coke with obtaining the so-called nutlet on the sieves with cells

lOlO mm and 35x35 mm. This fraction is preferred for mixing with the agglomerate before the fraction of 0-10 mm. also eliminated from coke, since it does not provide additional gas resistance in the furnace (sinter and ore are usually screened out from fractions of 0.5 mm and 0-10 mm and practically do not contain fractions of +35 mm, and it is known that mixing almost equal fractions does not change em gas dynamics process). For the same reason, a fraction of +35 mm is undesirable.

Example 3. In a blast furnace, smelting limiting cast iron with carbon consumption for direct reduction of 88.7 kg / t of cast iron, a coke nut of 10-35 mm fraction with a CO2 content of sorbdione capacity is introduced into the mixture with iron ore material 10% of coke consumption for direct recovery. The mixture is loaded onto the ore ridge, corresponding. maximum content 00 in flue gas. The amount of nutlet is determined based on the carbon content of the coke (85.3%):

Bark 88.7j-O, / 0.863 10.4 kg / t pig iron

The consumption of metallurgical coke decreases by DK 1.17 X 10.4 12.2 kg / t of pig iron, where 1.17 is the coefficient. replacement coke (see table 2).

Thus, it is optimal to introduce a walnut in the amount of the mass of coke necessary for direct reduction. At the same time, the quality of cast iron does not change (the slag mode is the same, and the total consumption of metallurgical coke is techno-economic

Grows up to 563-12.2 550.8 kg / t of pig iron. With a total consumption of coke 550,8 + 10, 2 kg / t of pig iron.

Example 4. Casting iron according to the technology of Example 3, but with the input of 30% nut:

Bark - 88.7 X 0.3 / 0.853 - 31.2 kg / t of pig iron:

(1.17 + 1.11)

DK

X 31.2-35.6 kg / t 2

cast iron.

PRI me R 5. Smelting iron according to the technology of example 3, but with the introduction of 50% nut:

Core - 88.7 x 0.5 / 0.855 52.0 kg / t of pig iron;

AK 1.11 XX 52.0 - 57.7 kg / t of pig iron.

The use of a nutlet less than 10% is irrational due to the small amount of additive, and over 50% due to a decrease in the rate of replacement of coke.

Claims (1)

Invention Formula The method of blast smelting, including the introduction into the iron ore part of the charge and coke fraction 10-35 mm, the subsequent loading of batch materials, the flow to blow into the furnace, the separate release of smelting products and the removal of gases from under the blast furnace and so that, in order to reduce the consumption of coke by increasing the degree of utilization of the reducing ability of gases in the blast furnace process, the toxic, for which dry extinguishing toxic is used, is introduced into the charge in an amount of 10-50% of that required for direct reduction, and zag uzku mixture charge material is produced into the region with the maximum content of carbon dioxide in the gas. Table 1 The performance of a blast furnace volume 3200m Continued table. one Estimated technical and economic indicators of the blast furnace Table 82