SU863685A1 - Method of agglomerating iron-ore materials - Google Patents

Description

(54) METHOD OF GLUMPING OF IRON-AUDIO MATERIALS The invention relates to black. Metallurgy, in particular, to the agglomeration of iron ore raw materials. A known method for producing agglomerates from a basic or highly basic mixture of iron ore ores, in particular hematites, consists in the use of the scientific research institute for alumina, silica and lime in quantities necessary to form the maximum amount of lime-alumina-silicate-ferrite U. The disadvantage of this method is the introduction of silica, reducing the iron content, into the mixture. It is known that reducing the iron content by 1% leads to a decrease in the productivity of blast furnaces by 2.5% and to an overrun of deficient coke by 1.5%. In addition, the use of lime and the preparation of the mixture in one stage can lead to a softening of the agglomerate. The known method of preparation of the district charge, according to which the agglomeration process is intensified in the hard phase and the productivity of the unit is increased by introducing the fused fusible slag-forming component into the charge in the form of plates 0.5–5 mm thick C23. This method facilitates the formation of a liquid phase, since ready-made low-melting substances — calcium ferrites — are introduced into the mixture. The disadvantage of this method is the need for capital expenditures associated with the construction of thermal units, as well as additional fuel consumption for the production of fillers. The closest to the proposed technical essence and the achieved result is a method of sintering iron ores with acidic waste rock, according to which up to 12% of aluminum oxides are introduced into the mixture to form an aluminosilicate bond L3j during sintering the mixture at a temperature of up to 1500 ° C. The disadvantage of the method is a low degree of absorption of calcium oxide by the melt, which negatively affects the quality of the agglomerate. The purpose of the invention is to increase the degree of dissolution of calcium oxide in the phase and quality of agglomerate. The goal is achieved by the fact that aluminum oxides are mixed with iron and calcium oxides in a stoichiometric ratio, according to the formula of cinnamon and dicalo ferrite, whose ratio is 3-10, while the amount of the mixture is maintained between 1.5-25% by weight charge.

In a two-phase alumina ferrite, the iron oxide molecule assimilates two calcium oxide molecules; in brownmellerite, one iron oxide molecule paired with one aluminum oxide molecule is assimilated by four oxide molecules. calcium.

In the ratio of brownmeelite to 2–10 gcd ferrite, a melt is formed at 1100– 1350 ° C, calcium ferrite crystallizes last and forms the strongest structural framework, providing agglomerate with increased strength.

The expediency of choosing the boundary values by the weight of the mixture and by the ratio of brownmellerite to dvuhkaliyevy ferrite is shown in examples 1-12 in table 1 and 2.

As can be seen from the table. 1 and 2, the method makes it possible to increase the strength of the agglomerate: the content of fines--5 mm is reduced by an average of 15-21 rel.%, The productivity of the agglomeration in terms of iron increases by 310 rel. %

Reducing the number of trivia in. sinter by 1% increases the productivity of blast furnaces by 1% and reduces coke consumption by 0.5%.

An increase in the input of a mixture of 25% leads to a remelting of the cake, the formation of excessive compaction in the lower horizons, the consequence of which is a decrease in the sintering rate.

and performance, when entering the mixture below 1.5%, there is no effect.

Example. At the first stage of the preparation of micht, a mixture is prepared at the rate of -3,

where C - C O, A -, F - Feri.O.j.

Table 3 shows the chemical composition of the components of the mixture.

The content of components in the mixture,%

Agloruda 24.58

Raw materials, 79.

Lime 24.63

Content,, CaO in the mixture relative to each other,%:

, 34.73

Ala.0i, 18,81

CaO 46.46

In the second stage, the mixture in an amount of 10% of the weight of the entire mixture is introduced into the aggloberate.

As can be seen from Table 1, an example, the output of fines 0–5 mm is reduced by 21 rel.% The productivity of sintering in g calculated by iron increases by 5 rel.%.

The results of the specific implementation for the weight amount of cMecrf, for each of the ratio of brown melllerite to dicalcium ferrite in examples 1-12 in tables 1 and 2.

The use of the proposed agglomeration method provides the possibility of obtaining a stronger agglomerate due to the high melt capacity for the absorption of calcium oxide. The method does not require additional capital expenditures.

100 98 81 79 81 85 98

100 100 103 105 110 105 90

Table 1 Poekateli Ratio C and F Output of fines 0-5 mm after the drum, rel.% Composition of the mixture Agloruda Raw materials containing A KO Lime

Claims (3)

1. German patent 1600899, CL.18 and 1/10, publishedL968. 2. USSR author's certificate No. 452592, cl. From 22 to 1/16, 1973. 3. Bazilevich R.V., Vegnam E.F. Agglomeration. M., Metallurgists, 1967, pp. 147-149. Table 2 Examples 23 5 10 11 100 90 85 90 105 Table 3 Content of components,% Fe, O, I A1.0j CaO 53 4.7 30 2010 -. -100