SU1488335A1 - Method of producing iron ore pellets - Google Patents

Description

The invention relates to ferrous metallurgy, in particular to the preparation2

ke of iron ore for blast smelting. The purpose of the invention is to increase the strength of the pellets and the performance of the method. The goal is achieved by the fact that the mixture is fed to the working surface of the pelletizer at an angle

0

10-30 to its surface with two counter-flows, the positively directed flow and the second flow are directed into the flow of embryos circulating along the ascending part of the plate, at a speed of 8-24 m / s. The center distance of the flow of the mixture is 0.2-0.4 diameters of the pelletizer plate. 2 ill., 1 tab.

The invention relates to ferrous metallurgy, in particular to the preparation of iron ore raw materials for blast furnace smelting.

The purpose of the invention is to increase the strength of the pellets and the performance of the method.

On fzg. 1 shows the implementation of the proposed method of producing iron ore pellets; in fig. 2 is a view A of FIG. one.

The proposed method for producing iron ore pellets is as follows (Fig. 1).

The wetted charge 1 by the conveyor 2 is fed in the direction of the working surface of the pelletizer 3. Immediately before loading the charge 1 into the pelletizer 3, it is divided into two streams: the first 4 and the second 5, which by means of the transporting agent 6, I flowing out of the nozzles 7 in the cross

5TS 1488335

current, served on the work surface of the pelletizer with oncoming jets. In the pelletizer, the charge is added to the wetting and pelletization, with the formation of embryos 8 and conditioned pellets 9, which are moved by the conveyor 10 to the calcining unit (not shown).

To eliminate the loss of the charge in the form of a spill of the second stream 5, a protective drainage tray 11 is installed under the nozzle 7. To form the second stream 5 of the charge directly on the surface of the conveyor 2 a scraper divider 12 is installed, made in the form of a metal plate installed at an angle to the direction of movement of the charge 1. After separation of the charge stream 5 enters the inclined chute feeder 13, through which the charge moves until it meets with the transporting agent 6, which accelerates the charge to

3

1488335

four

speed 8 · - 24 m / s and feed it at an angle of 10-30 ° to the surface of the plate in the upward flow of materials.

In the process of pelletizing (figure 2) $

wet charge 1 on the surface of the pelletizer plate 3 an upward flow of materials 14 (upward part of the plate) is drawn, carried by the friction force of the rotating plate, from which materials are continuously crumbled to form a downward flow 15. (downward part of the plate).

The mixture of the first 4 and second 5 streams is fed at an angle of 10-30 to the surface of the pelletizer; for this, the nozzle 7 is movable and allows you to adjust the angle of the charge supply. The supply path of the transporting agent 20 has 6 regulating valves to regulate the flow rate

charge.

The first flow 4 of the charge is supplied at a speed of 5–20 m / s in the opposite direction to the second flow 5 of the charge, in which the velocity of the materials reaches 8–24 m / s. Moreover, between the axes of the threads support a distance equal to 0.2 - 0.4 of the diameter of the plate 30 pelletizer. Compressing air with pressure 0 ^ 6 - 1.0 MPa * is used as accelerating wet mixture of flows 4 and 5 of transporting agent 6. Mass flow for the first flow 4 is 3-5%, and for the second flow 5 4-652, or water vapor similar parameters, which additionally moistens the charge, or a tape throwing device. dd

Directed at an angle of 10-30 to the surface of the pelletizer 3 flows 4 and 5 of the charge: the first at a speed of 5-20 m / s in the flow of embryos circulating in the descending part of the plate, and the second at a speed of 8-24 m / s in the flow of embryos circulating in the ascending part of the plate, due to the opening angle of the free jets of the transporting agent 6 evenly

. They are distributed over the surface of lumping materials, which have an intensifying effect on the compaction of the pellet nuclei and on the entire course of the pelletizing process.

Example. The method of obtaining iron ore pellets was carried out on a laboratory disc pelletizer with a diameter of 0.6 m, established

at an angle of 45 ° to the surface of the horizon and rotating at a frequency of 12 rpm. Investigated the work of iron ore concentrate (b'e _{o6b <} = 62.88%). '

The conditions of the experiments were as follows. Precoated charge mixture with a moisture content of 10.5%, after which embryos with a particle size of 1-2 mm were isolated by sieving. Then, the embryos with a charge of 1.5 kg were again loaded onto the surface of the disc pelletizer and an additional charge (5 kg) was supplied for the addition of embryos to conditioned pellets (fractions 5-15 mm). Moreover, the supply of the charge was carried out according to the known and proposed methods.

To do this, the wet mixture was fed with two opposing streams using compressed air with a pressure of 0.8 MPa, the speed of which at the nozzle exit reached 30 m / s. The gas flow rate measured by a pan-shaped anemometer on the plate surface changed to 27 m / s.

In the studies, the speed of the second flow of the charge supplied to the upward flow of materials and the center distance of the flow of the charge were changed. After the experiments, the strength of the raw pellets, the yield and the relative productivity of the method were determined.

Experimental data obtained in comparison with a known method, are presented in the table.

The results show that the proposed method for producing iron ore pellets allows to obtain granules of higher strength (1.28 - 1.41 kg / okat) compared to the known - 1.25 kg / okat, i.e. increase the strength by 2.4-12.8%; Acceleration of the work process increases the productivity of the method by 1.8-6.6%.

Claims (2)

Claim A method of producing iron ore pellets, which includes feeding a wet charge to the working surface of the pelletizer at an angle of 10-30 to its surface, characterized in that, in order to increase the strength of the pellets and the productivity of the process, the mixture is fed by two oppositely directed flows, 1488335 moreover, the second stream is directed to the stream of embryos circulating along the ascending part of the plate, with the speed 8-24 m / s, while the center distance of the flow of the charge is 0.2-0.4 of the diameter of the pelletizer. Speed second flow batch feed. in the sunrise flow material., m / s Centerline distance oncoming streams charge, in dia. tareli okomkov. Technical and economic indicators of the method of obtaining iron ore pellets The strength of the pellets in compression, kg / okat The relative performance of the method,% Proposed ny with p about s with s b five 0.1 1.20 88.4 five 0.2 1.25 94.5 five 0.3 1.26 100.0 five 0.4 1.25 96.6 five 0.5 1.23 92.8 eight 0.1 1.22 93.5 eight 0.2 1.26 101.8 eight 0.3 1.29 102.4 eight 0.4 1.30 103.2 eight 0.5 1.25 96.1 15 0.1 1.23 96.1 15 0.2 1.28 102.3 15 0.3 1.33 104.2 15 0.4 1.35 · 104.8 15 9.5 1.25 96.9 24 0.1 1.24 96.9 24 0.2 1.34 104.3 24 oh w 1, 39 105.5 24 0.4 1.41 106.6 24 0.5 1.26 100.0 27 0.1 1.25 100.0 27 0.2 X - 27 oh w X - 27 0.4 X - 27 0.5 1.25 ®8,1 And s in e with t new way b 0 - 1.25 100 The beginning of the destruction of the pellets. 1488335 2 v. Vida