SU1502641A1 - Method of preparing charge for sintering - Google Patents

Abstract

The invention relates to the preparation of iron ore raw materials for metallurgical processing, in particular, to agglomeration, and can be used in the metallurgical industry. The purpose of the invention is to improve the quality of pelletizing and increase the productivity of the process. In preparing the charge for sintering, iron ore concentrate, fuel, fluxes and return are subjected to primary mixing, secondary mixing with wetting and pelletizing, and a fraction of 0.5–3.0 mm in the amount of 50–80% is recovered from the return, , served on the work in a dry form. This fraction is an additional pelletizing center on which strong granules are intensively formed. 1 tab.

Description

The invention relates to the field of preparation of iron ore raw materials to metallurgical processing, in particular to agglomeration, and can be used in the metallurgical industry.

The aim of the assembly is to improve the quality of pelletizing and increase the productivity of the process.

The essence of the invention is to, by separating a large fraction of a return of 0.5-3.0 mm, to provide the opportunity to homogenize the charge as much as possible and thereby speed up the mixing of the charge components, as well as speed up the work, as the finely dispersed and homogeneous highly moistened mixture compresses and sticks to dry pelletizing centers (embryos), which are particles of a return of a fraction of 0.5–3.0 mm. Filing a return of a fraction of 0.5–3.0 mm in the amount of 50–80 × to the workpiece involves introducing into the clumping material active and high-strength embryos to which the charge intensively adheres and durable granules of a fraction of 1-5 mm are formed,

It is known from the theory of pelletizing that the mixture and the rich concentrate are most efficiently crushed. Unlike non-metallic components, the charge (fuel, limestone) is thin, homogeneous and enriched with iron ore, participates more intensively in granulation, therefore, the introduction at the okomkova stage 3150

neither to a thin and homogeneous charge with a charge (dry recovery of the fraction 0.5-3, C) mm) allows to increase the strength of the raw granules and the effectiveness of the actual work of the pelletizing process, and after sintering and suitable sintering, and also most improve sinter machine performance.

In the proposed cr; special preparation of the charge for sintering, a necessary condition is the submission of a part of a dry return of a fraction of 0.5–3.0 mm in an amount of 50–80% of the total mass of return, and delivery to the pelletizing, directly to the wetting of the wet blend. at optimum humidity. This is dictated by the development of the return surface and its better wettability and adhesion qualities compared with, for example, fuel and limestone.

A return fraction of 0.5-3.0 mm is optimal, since this interval is the best from the standpoint of pelletizing, since particles of a particle size of 0.5-3.0 mm are nuclei of pelletizing. If the return of a fraction less than 0.5 mm is introduced, then in this case the role of return is reduced as pelletizing nuclei, since the particles become commensurate in size with the rest of the charge going for pelletizing, and the effect achieved on the quality of the granules and productivity of the sintering machine is minimal, comparable to the action of the prototype and known methods. If a refund fraction of more than 3.0 mm is applied to the pelletizing, then the obtained granules have sub-standard sizes (more than 5-8 mm) and the segregation of the pelletized materials becomes more significant.

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A prerequisite for this is that the method also serves to supply a certain amount of return, namely, 50-80% of the total return mass supplied to the charge. This interval ensures the most complete utilization of the entire fine part of the charge in pelletizing and the necessary stability of pelletizing, as well as creates the optimal gas permeability of the raw agglomerate on the machine belt, as a result of which the productivity of the method increases.

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If less than 50% of the 0.5–3.0 mm fraction is returned to the pelletizing of the charge, then the pelletizing nuclei are not enough for intensive process management. In the case of filing a return for pelletizing more than 80% of fraction 0, mm, the yield of fines fraction increases (-1 mm), which reduces the gas permeability of the mixture.

Example. The study of the method of preparing the mixture for sintering was carried out on laboratory equipment: a drum mixer with a diameter of 400 MMM, a drum pelletizer with a diameter of 600 mm, a sintering plant of the aglochash type with a diameter of 236 mm. A mixture weighing 15 kg was prepared from the following components: a concentrate from the Abagursky sinter plant, 0-0.1 mm, 60.0%, known to 6.0%, fuel (0-3 mm fraction of coke, 0%, fraction return 0-5 mm 30.0%.

The preparation of the charge is as follows.

Immediately after dosing, the return was screened with a fraction of 0.5-3.0 mm. After that, another part of the return, together with all the concentrate, lime and fuel, was loaded into the mixing drum and for 2 minutes the primary mixing was performed in a dry form. After: this operation, fine sprayed water in the amount of 7.0% was evenly applied to the mixture and was re-mixed in the wet state for 2 minutes. After the two-stage mixing was completed, the wet mixture was placed in a drum pelletizer rotating at a frequency of 10 rpm, and at the same time 50% dry fractions of 0.5–3.0 mm were fed into the pelletizer at a rate of 50%. The obtained materials were analyzed for strength and granulometric composition, after which they were sintered in an agglobalt, the strength of the finished agglomerate was determined, and the productivity of the method was calculated. The varied parameters of the method were the composition of the particle size of the dry final return fed to the pelletizer and its quantity. The experimental data obtained are given in the table.

From the table it can be seen that the most optimal parameter of the method is the feed rate of a part.

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the form of a fraction of 0.5–3.0 mm at the okomkov-return can be performed using

screen stabilizers and air classifiers. As a result, the introduction of the proposed method of preparing the charge for sintering is not a technical difficulty and can be implemented on the operating smell. This provides an increase in the strength of the granules from 0.55 to the data of a known method to 0.57-0; 62 kg / / gran, an increase in the strength of the agglomerate from 67.5 to 70.1%, while the relative performance of the method

rises to 111.5%, ore without significant costs

Claims (1)

Exceeding the boundary conditions of the method Q reconstruction, according to the size of the return fraction, i.e. less than 0.5 mm and more than 3.0 mm worsens the claims of the invention granulometric composition is pelleted - Method of preparation of the charge for the sintering mixture - according to al e1c a lot of fine, including pumping separate dosing fractions - from 0.5 to 52.8% and increases -15 the formation of iron ore concentrate, Tops yield KpynHL-ix lumps larger than 5.0 mm to 24.5%. When crowded, a fraction of 0.5-3.0 mm fed to pelletizing less than 50% does not show an increase in productivity, and the resulting granules have a significant size segregation. The method can be easily implemented on the operating equipment by a slight change in the dosing schemes and delivery, and the selection of the fraction of 0.5-3.0 mm from the total , fluxing additives and recirculation, primary mixing, secondary mixing with wetting and pelletizing, characterized in that 20 in order to improve the quality of pelletizing and increase the productivity of the process, additionally, before the primary mixing, a fraction of 0.5–3.0 mm in the amount of 25 50-80% of the mass of the entire return, going to the work of dough, and served on the work in a dry form.