Process for producing sintered ore

Abstract

A process for sintered-ore production which comprises a granulation step, a drying step, and a sintering step. The granulation step comprises adding water and a binder to a raw material to be sintered which contains a carbonaceous material and granulating the mixture to produce raw granules to be sintered. The drying step comprises drying the raw granules to be sintered to thereby produce dried raw granules to be sintered which have a water content of 4.0 mass% or lower. The sintering step comprises introducing the dried raw granules into a sintering apparatus and sintering the granules.

Description

technical field [0001] The present invention relates to a method for producing sintered ore for blast furnaces. In particular it concerns the moisture content of the pelletized sintering raw material and the formation of wet areas during sintering. Background technique [0002] Sintered ore, which is used as the main raw material in blast furnace ironmaking, is manufactured through the process shown in Figure 1. Iron ore powder whose sintering raw material is less than 10mm and with an average particle size of about 1.0-5.0mm, recycled powder in ironworks, sintered ore under-sieve powder, limestone, dolomite and other CaO-containing raw materials, quicklime and other granulation aids, and coke powder, anthracite and other coagulation materials, etc. CaO-containing raw materials such as limestone and dolomite are hereinafter referred to as CaO-based auxiliary materials. The raw materials for sintering are stored in the hopper 1 . The above-mentioned raw materials are cut ...

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Problems solved by technology

On the other hand, in order to shorten the drying time, it is necessary to increase the temperature of the gas, but if the temperature is raised above 150°C, there is a problem that the belt will cause thermal elongation and S-shape swing

[0015] In addition, in the method described in Patent Document 2, which blows hot air into the buffer hopper to dry the stored sintering raw material particles, there is a problem that, similar to the above, although the drying of the part contacting with the hot air is carried out, it is not carried out. Drying of the part in contact with hot air, for example, even if the side wall of the buffer hopper is heated, only the part in contact with the side wall is dried, and the particles passing through the part away from the side wall are not dried

If the sintering raw material particles in such a non-uniform dry state are loaded on the pallet of the sintering machine and sintered, there are problems such as uneven sintering, which affects the yield and productivity.

[0016] In addition, in the method described in Patent Document 3 in which the granulated sintered raw material particles are loaded onto the trolley and then dried by supplying hot air from above the loaded layer, since the sintered raw material particles are dried in a static state, although It can prevent particles from collapsing during drying, but it will increase in size due to blowing hot air, and requires a huge investment in equipment

[0017] In the method described in Patent Document 4, in which hot air is fed from the discharge port side of the granulation process to dry, the granulated sintering raw material particles tend to collapse, which leads to insufficient drying, and normal sintering machine operations cannot be performed. The problem

[0018] In other words, these conventional proposals were developed for the purpose of drying the granulated sintered raw material and reducing the influence of the wet area, and no practical technology has been established yet.

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