SU1386668A1 - Method of producing fluxed iron-ore sinter - Google Patents

Abstract

This invention relates to ferrous metallurgy, in particular. for the production of blast furnace raw material - iron ore fluxed sinter from. multicomponent mixtures containing finely divided concentrates and coarse-grained ore. The purpose of the invention is to reduce the consumption of coke and increase the strength of the agglomerate due to the formation of a silicon-containing alumoferrite bond. After the multicomponent mixture is pelleted, the fraction (-3) mm is separated and its basicity and alumina modulus (Aljj Og / SiO j) are determined taking into account the values of these indicators, which must be maintained within 1.6-2.2 and 0, 2 - 0.5, respectively, set the parameters of the sintering mode, at which the oxygen content in the exhaust gases is 10-17%. Hardening of the agglomerate occurs due to the formation of an alumina-ferritic bond, which dissolves silicon and prevents the formation of bicarium silicate. 1 tab. W (L S

Description

from 00 about:

but

00

The invention relates to metallurgy of ferrous metals, in particular, with the production of blast furnace raw material - iron ore fluxed sinter from the ifiHoroKOMnoHeHTHbix charge containing {ground-grinding concentrates and lumpy ores.

i The purpose of the invention is to reduce the consumption of coke and increase the strength of the agglomerate due to the formation of a cream-containing alumoferrite binder.

The process is as follows.

Dosing of ore, coke, fluoric acid and iron ore concentrates is made, the components are mixed and the next pelletizing. After the pelletizing, charge is taken to part the fraction (-3) mm, its basis CaO / Sip H is determined by alumina AlgOg / SiO ,. Taking into account the values of these indicators, they set the parameters of sintering mode - fuel consumption and height

iron ore concentrates, silt ores and top furnace dust are included in the charge. The fuel consumption is 2.7-3.0%, and sintering is carried out at the oxygen content of the exhaust gases of 10-17%.

In the case when the basicity of the charge fraction (-3) mm exceeds the value

Q 2.2, it is necessary to adjust the alumina module in combination with a decrease in the basicity of this fraction by reducing the content of lumpy ores in the sinter charge or by reducing the total basic charge of the sinter charge (withdrawing a part of the flux from it), since in this case the total basicity of the agglomerate exceeds the optimum (1.30) required for domain redistribution.

0 Sintering was carried out on the Shitkh of a metallurgical plant, which, along with concentrates with a low CMM (up to 1 wt.%) Alumina content, included alumina-containing iron.

sintered layer. Hardening sinter-25 ore concentrates of enrichment plants.

This occurs due to the formation of an alumoferrite bond, which dissolves silicon and prevents the formation of dicalcium silicate, which leads to the self-destruction of aglospace. With the basicity of the charge fraction (-3) mm, greater than 1.6, and fuel consumption of more than 4%, the combination of dicalcium silicate, which intensively destroys the allomerate, increases in the composition of the binder. Therefore, with high basicity, low fuel consumption is required.

In the case where the basicity of the fraction: (-3) mm is less than 1.6, and the agglomerate is strengthened due to the formation of a glassy binder based on the ferro-montellite CaO FeOx uSiOn, the alumina modulus Al Og / SiO is not determined, since binding, without changing its properties, and, therefore, does not affect the strength of the agglomerate. At a low (up to 1.6) basicity of the fraction (h3) mm, fuel consumption of at least 4% is required, the height of the sintered layer is up to 300 mm, while the oxygen content in the exhaust gases is 5-7%.

With the basicity of the charge fraction (-3) mm, equal to 1.6-2.2, the alumina modulus in it is maintained in the range of 0.2-0.5 by changing the amount of the alumina-containing component in oshh those. To the main carrier of alumina

0

five

0

0

five

(CMC), Kachkanarsky, Kovdorsky and Lisakovsky GOKs, containing, respectively, 2.3, 2.81, 2.8 and 4.9% with the consumption of these concentrates in the ore part of the charge 20-30; 8-15; . 6-14 and 2-4 wt.%. In addition, 10–40% of the ore of Mikhailovsky GOK, containing 20% SiO, was introduced, in the granulometric composition of which about 40% were fragments larger than 3 mm, as well as limestone (1.5% by weight) and fuel.

The basicity of the fraction (-3) mm, the alumina modulus, the height of the layer, the carbon consumption for sintering and the oxygen content in the exhaust gases are given in the table.

Optimal sintering conditions of the sintering mixture were evaluated by the yield of suitable agglomerate and fines — fractions (-5J mm. At the same time, optical studies of the finished agglomerate were performed and the material composition of the binder was determined.

Example. The basicity of the fraction (-3) mm is 1.4-1.5 with a total basicity of the mixture of 1.30 and a content of 10-12% of Mikhailovskaya sintering in it. The alumina modulus of the fraction (-3) mm is equal to 0.3, special adjustment of its values is not carried out, and its value is determined by the amount of alumina-containing concentrates in the mixture, wt.% 5 CMC 20; Kachkanarsky 8; cove

Dorso 10; lisakovsky 2, which corresponds to the total content of alumina in the mixture of 1.7-2.0 wt.%, and in the composition of the fraction (-3) mm 2.5-2.6 wt.%. Taking into account the values of basicity, the fuel consumption for sintering is 4.5% with a height of the sintered layer of 260 mm. The sintering process proceeds at a low oxidation potential of the gas phase — the oxygen content in the exhaust gases is 5–7%. The obtained agglomerate is distinguished by high strength, a yield of 65.5%, fines of 6.2-6.5%, and the strengthening of the agglospace is achieved due to the formation of a vitreous bond of ferromonticellite, xSiO 1 composition.

Example 2. The basicity of the bond (-3) mm varies within the range of 1.6-2.2 by the amount of Mikhailovskaya ore in the sinter bed from 20 to 40%. At the same time, the alumina modulus of the fraction (-3) mm is maintained at 0.3 due to an increase in the concentration of concentrates in the mixture to% by weight: CMC 30; Kovdorsky 14. Optimum fuel consumption is 2.7%. The agglomerate is sintered in a layer of high 600 mm in an atmosphere with a high oxidizing potential of the gas phase — when the oxygen content in the exhaust gases is 10-17%. The finished sinter has a high strength due to the uniform formation of silicon-containing aluminum-ferrite CaOi2-3 (Fe, Al) 0 g and glass throughout the entire sinter volume; yield of 66.2% with a fines content of 5.4% (experiment 8). With a smaller amount of fuel, the agglomerate is underheated, with a larger amount of binder in the composition of the binder, calcium silicate appears and the strength of the agglomerate decreases.

Froze Under the conditions of Example 2, a mixture with a basicity of 2.0 fractions (-3) mm is sintered with different values of the alumina module from

ten

20

{five

866684

0.1 to 0.6. The values of the alumina modulus are varied by the ratio of the contents in the mixture of high and low alumina concentrates. When the AlOg / SiOj value is 0.1, the CMC, Kachkanarsk, Kovdor and Lisakovsk deposits are deduced from the charge, and for AlnO / SiO2 0.6, the contents of these concentrates are 30, 15, 12 and 5 wt.% ( table).

Experimental sintering (tests 13-15) show that the optimum strength is agglomerates obtained from a mixture with an alumina modulus of a fraction (-3) mm, equal to 0.2-0.5, on a bond of silicon-containing aluminoferrite.

The use of the invention will improve the strength of the agglomerate from a multicomponent mixture, including concentrates and ores from different deposits, while simultaneously reducing fuel consumption during the sintering process.

Claims (1)

Invention Formula Method for the production of fluxed iron ore sinter, including the regulation of the basicity of the mixture containing concentrates, ore, flux and fuel and having an alumina-containing component in its composition, its pelletizing, sintering with air prod, that due to the formation of a silicon-containing alumoferrite binder, in the fraction of the charge (-3) mm with its basicity of 1.6-2.2, the alumina modulus is maintained in the range of 0.2-0.5 by changing the amount of alumina holding of the component, and sintering the batch is carried out in an atmosphere with oxygen content in the waste gases of 10-17%. Phi-pyromo tichplit CaO-KeO-SiOj; shp 10frr. (Fe, A1) CKS - IeOtox A1205 in homemeat slags. - Dvukaltts evy silicate CTSA cream iysoderzhaniya sipikoferrit 7CaO 2SiO, l4 fgjpy