SU1388444A1 - Method of producing manganese sinter with residual carbon - Google Patents

Abstract

The invention relates to the preparation of raw materials for metallurgical processing, in particular, the agglomeration of manganese concentrates, and can be used in ferrous metallurgy. The purpose of the invention is to obtain a given amount of carbon in the agglomerate and increase its strength. Solid fuel is introduced into the charge to produce manganese sinter with residual carbon in an amount greater than that required for sintering. Excessively, a part of the fuel is taken with a grain size of 6-8 mm and a finely dispersed manganese concentrate is pre-rolled onto it, ensuring the porosity of the shell from the concentrate is 25-30%. The shell prevents the fuel from igniting, removes the concentration of carbon dioxide and limits the access of oxygen, which makes it possible to obtain a solid agglomerate with a given amount of residual carbon. 2 tab. i (Л с:

Description

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The invention relates to the preparation of raw materials for metallurgical processing, in particular, the agglomeration of manganese concentrates, and can be used in ferrous metallurgy.

The purpose of the invention is to obtain a given amount of carbon in the agglomerate and increase its strength.

The method is carried out as follows. :

The part of the fuel that is injected above the optimum for sintering and intended for; obtaining residual carbon in the agglomerate, boot with a particle size of 6–8 mm and, before entering into the mixture, a shell of fine carbon fiber, of thick concentrate, having a porosity of 25–30%, is rolled onto it. Then it is introduced into the fir for agglomeration.

The envelope is rolled onto the fuel from finely dispersed carbonate manganese concentrate, which, due to its very high specific surface, adheres well to the uneven surface of the fuel and during sintering, decomposes, envelops the todly grains with inert carbon dioxide, limiting the access of oxygen to it, - stored it in such a way from burnout. .

The choice of the grain size of the fuel introduced for the purpose of baking it into the agglomerate is determined by the need to increase the thermal inertia and reduce the surface of the exchange of fuel in order to obtain a given amount of residual carbon in the agglomerate.

Experiments on the determination of 40 optimal limits of the parameters of the method.

The results are shown in Table. one.

The above data show.

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agglomerate and reduce residual carbon in it.

As experiments show, a decrease in the density of the shell, i.e. The increase in porosity in excess of 35%, contributes to the access of air, sucked in the sintering process, to the fuel grains, which leads to their combustion. Excessive compaction of the casing to a porosity of less than 25% is technically inexpedient, leading to a significant decrease in the productivity of the installation in terms of the casing rolling. In the process of agglomeration, when dissociation of the carbonates of the shell rolled on solid fuel occurs, the shell may be destroyed when its porosity is below 25%. Due to the destruction of the shell for this reason, solid fuel burns out and the result is not achieved on obtaining the residual amount of carbon in the agglomerate.

Example. The method was tested on a unit installation with a sintering bowl with a diameter of 300 mm. Under identical conditions, comparable experiments on the production of sinter with residual carbon were carried out by a known method. .

The composition of the main charge is as follows,%: oxide, marg.dant concentrate of gravity heat eni 64; coke breeze 8; return 28. All components of the mixture were mixed among themselves, the mass fraction of moisture in the mixture was 10-12%. Coke breeze with a size of 6–8 mm was loaded into a bowl pelletizer with a diameter of 1 m, moistened and rolled onto it was a shell 3-5 mm thick from a thin, dispersed carbonate manganese concentrate.

that the agglomerate with the greatest strength45 surface is over 150.0. Granu0

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agglomerate and reduce residual carbon in it.

As experiments show, a decrease in the density of the shell, i.e. The increase in porosity in excess of 35%, contributes to the access of air, sucked in the sintering process, to the fuel grains, which leads to their combustion. Excessive compaction of the casing to a porosity of less than 25% is technically inexpedient, leading to a significant decrease in the productivity of the installation in terms of the casing rolling. In the process of agglomeration, when dissociation of the carbonates of the shell rolled on solid fuel occurs, the shell may be destroyed when its porosity is below 25%. Due to the destruction of the shell for this reason, solid fuel burns out and the result is not achieved on obtaining the residual amount of carbon in the agglomerate.

Example. The method was tested on a unit installation with a sintering bowl with a diameter of 300 mm. Under identical conditions, comparable experiments on the production of sinter with residual carbon were carried out by a known method. .

The composition of the main charge is as follows,%: oxide, marg.dant concentrate of gravity heat eni 64; coke breeze 8; return 28. All components of the mixture were mixed among themselves, the mass fraction of moisture in the mixture was 10-12%. Coke breeze with a size of 6–8 mm was loaded into a bowl pelletizer with a diameter of 1 m, moistened and rolled onto it was a shell 3-5 mm thick from a thin, dispersed carbonate manganese concentrate.

for a given content of residual carbon in it, it was obtained with a size of fuel baked in the agglomerate of 6–8 mm and a porosity of the shell of carbonate manganese concentrate equal to 25–30%. With an increase in the size of grains of a solid top: weld, the strength decreases due to an increase in the unbaked volumes in the piece of agglomerate. With a decrease in the grain size of the fuel, the possibility of its more complete combustion, the development of high temperatures in the layer, and melting increases, which leads to a decrease in strength

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The pellets were filled for 5-6 minutes, the shell porosity was 27%.

Then the granules were mixed with the main charge and all the material was loaded into a sintering bowl. The content of solid fuel with a knurled shell in the sintering mixture was 8.7%, the carbon content in the mixture, in excess of the required sintering, was 7.2%.

The bed height is 320 mm, the vacuum under the grill is 700 mm water column, the ignition time is 1.5 min. Evaluation of the quality of the agglomerate was carried out by known methods.

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The results of sintering known and proposed methods are given in table. 2

The method can be implemented on existing sinter plants for the production of manganese sinter. Before crushing the coke in crushers, a fraction of 6-8 mm is separated from its composition by sieving on a mechanical screen. The recovered coke is moistened with water during its transportation along a conveyor belt and transported to a feed bin under a bowl pelletizer. A fine manganese carbonate concentrate is dosed simultaneously with the coking agent. After the pelletizing of the materials and compaction of the obtained granules in the pelletizer, they are transported to the secondary mixing drum for mixing with the total charge.

The data table. 2 indicate the advantages of the proposed method in comparison with the known method: an increase in the specific productivity of sintering machine by 0.13, a decrease in the amount of fines by 6 abs.%. In addition, the size of the particles of solid fuel introduced into the mixture in excess of that required for sintering, mm

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The porosity of the shell, rolled 3. solid fuel,%

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The use of sinter with high strength and carbon baked in it, due to the close contact of the reducing agent with metal oxides, in the smelting of manganese alloys, improves the electric mode of the ferroalloy furnace with energy saving.

Claims (1)

Invention Formula The method of obtaining manganese sinter with residual carbon, including the introduction of solid fuel into the mixture in an amount exceeding that required for sintering, its pretreatment, mixing and sintering of the mixture on an sintering machine, in order to obtain a given amount of residual carbon in the agglomerate and increase its strength, for fuel, size of 6-8 mm, which is introduced In addition to the required for sintering, a shell of finely dispersed manganese carbonate concentrate is precoated, ensuring its porosity is 25-30%. Table 1 0.76 0.93 0.83 0.84 0.925 71,28,2 78,87,5 74,18,0 74.68.0 78,67,35 27 30 35 Known 0.65 Suggested, 0.93 Continuation of table 1 table 2 68 10.0 1.08 - 16 79.0 7.5 1.25 ten