SU1397518A1 - Method of sintering iron-ore materials - Google Patents

Abstract

The invention relates to the sintering of iron ore materials and can be used in the sintering production of ferrous metallurgy. The aim of the invention is to increase the gas permeability of the batch and increase the productivity of sintering machines. A layer of inert material, for example, a return, which has a lower temperature equal to the ambient temperature, and the upper part above the ignition temperature of solid fuel, is placed on the surface of the charge layer. The ratio of the height of the heated part of the layer and the height of the cold part is maintained equal to (3-5): 1. The invention allows an increase in the productivity of the plant and an increase in the quality of the agglomerate. 1 tab. (L

Description

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The invention relates to the agglomeration production of ferrous metallurgy and to the agglomeration of iron ore materials.

The purpose of the invention is to increase the gas permeability of the bed of the agglomerated layer and increase the productivity of sintering machines,

The method is as follows.

During the agglomeration of iron ore materials, several alternating zones are formed along the height of the agglomerated layer — the finished sinter zone, the melt zone, the high-temperature heating zone, the drying zone, and the overwetting zone. The conditions of formation and movement of each zone have an impact on the performance of the agloprocessing process. The creation of sintering conditions at the initial stage of the process is the same as that on the main stage, which increases the productivity of the sintering plant by maintaining the layer structure. lay a layer of inert material (e.g., return), the fuel heating in the mixture with the heat of the heated return is more effective than the heat of the furnace gas (in, because the oxygen content in the furnace gases is 5- 10%, and in air, 21%. However, as a result of contact of high-temperature air heated to a temperature above ignition of solid fuel when passing through a layer of heated return, and a cold charge, rapid evaporation of moisture in the upper horizon occurs. with high water-holding capacity and temperature, it is carried away to the underlying horizons of the layer and heats up the bones, the agglomerate is over-humidified, the granules are destroyed and the productivity of the sintering unit is reduced.

To reduce the negative effect of the overwetting zone on the intensity of the agglomeration between the return layer of the heated ignition temperature of the solid fuel, a cold return layer is laid with the temperature equal to the ambient temperature. When the exhauster is turned on, the atmospheric air, the passage through the heated recycle, heats up above the ignition temperature of the solid fuel. However, the direct contact

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This high-temperature gases and wet charge in the initial stage of ignition is not, because the cold return layer takes the heat of the heated air. Due to the fact that, unlike the charge, the return has a lower heat capacity and thermal conductivity, the front of the heat wave is stretched, which contributes to a smooth increase in temperature at the interface between the return and charge layers.

Accordingly, the smooth increase in temperature also changes the amount of steam entering the lower horizons of the layer being measured. A decrease in the temperature difference between the granules of the charge and water vapor reduces the rate of condensation of moisture, which contributes to its greater transfer to the reservoir with waste gases and an increase in the gas permeability of the layer.

When laying the return layer on the surface of the charge mixture, the ratio of the heated and cold parts of the inert material is from 3: 1 to 5: 1. The lower limit of the height of the layer of cold inert material corresponds to the agglomeration technology using a heated return with a temperature of 700-900 s at a constant speed filtering gases through the layer; The high limit of the height of the layer of cold inert material corresponds to the temperature of the heated inert material from 900 ° C to the melting point. This provides a constant rate of heating the surface of the charge,

An example. For sintering, an aglo-mixture is used, containing in the iron ore part 75% of the concentrate and 25% of the ore. The return content is 25%, fuel 4%. After pelletizing, the agglomerate is baked in a bowl with a diameter of 130 mm. The ignition is carried out with warm heated return at. The fineness of the return is constant and equal to 10-5 mm. The height of the heated return layer is 60 mm. Between the layer of the mixture and the layer of heated return stack a layer of cold return with a particle size of 10-5 mm. The height of the ferrous return layer is varied from 0 to 60 mm.

The results of sintering are presented.

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Studies show that the best parameters of the sintering process take place at the height of the heated return layer: 60 mm and height

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cold return equal to 20 mm, i.e. with a ratio of heights of 4: 1,

Claims (1)

The invention makes it possible to increase the productivity of the sintering plant and improve the quality of the agglomerate. Formula of Invention The method of sintering iron ore materials, including laying the charge on a pallet of sintering tape, laying a layer of inert material on the surface of the charge and igniting solid fuel of the charge with the heat of a heated inert material, eight. characterized in that, in order to increase the gas permeability of the batch and increase the productivity of sintering machines, the layer of inert material is placed on the surface of the batch with a temperature of the lower part equal to the ambient temperature, and the upper part is higher than the ignition temperature of the solid fuel parts of the layer of inert material is (3-5): J, Yield,% 72.4 72.3 72.5 72.3 71.9 71.5 71.1 70.0 Specific productivity 1.35 1.37 1.48 1.42 1.40 1.38 l, 33 1.20