SU1504272A1 - Method of producing ore pellets - Google Patents

Abstract

The invention relates to ferrous and nonferrous metallurgy and is intended for the production of pellets. The aim of the invention is to increase the strength of the pellets. The method includes loading the charge into a sealed pelletizer, moistening and pelletizing under pressure of 0.8-1.1 MPa, and the pellets are unloaded with a decrease in pressure at a rate of 1-2 kPa / s. 1 ill., 1 tab.

Description

The invention relates to ferrous and nonferrous metallurgy and can be used in the production of pellets from finely divided materials.

The purpose of the invention is to increase the strength of the surrounding.

The essence of the method is that the pellets obtained under pressure are discharged from the sealed pelletizer to the environment or to the discharge device, in which the pressure decreases at a rate of 1-2.0 kPa / s. This condition is very important for dop-pressure under pressure, because in the process of issuing an octapus, the greater the pressure differential between the working area of the pelletizer and the environment, the more effective the process of barodiffusion moisture is, which is undoubtedly useful for the subsequent drying process. However, at the same time, the unfavorable process of the wedging of the rizkosbrashirtsim gas is proceeding with gas flowing out of the pores at high speed. As a result, there is a weakening of the interparticle bonds of the raw octane and, as a result, a decrease in the strength of the granules, especially noticeable after pelleting at high pressures (more than 1.1 MPa). Therefore, it is very important to ensure such a rate of gas outflow from the pores of the pellet or, what is the same itself, to carry out the operation on Wednesday or in the discharge device, in which the pressure decreases at such a rate at which the moisture content is reduced by barodiffusion and there is no decrease in the strength of the openings clumps under pressure.

If, after pelletizing, the pellets are dispensed simultaneously with a decrease in pressure at a rate of less than 1 kPa / s, then this favorably affects the strength, but in this case, the production drops drastically.

The method of obtaining pellets due to the long time of issue oklt1) apei from pelletizer (more than 10 min),

The drawing shows a schematic diagram for the implementation of the method for producing okatppey.

The method is carried out using a device that contains a conveyor ter 1 for supplying charge 2, a charging device 3 which consists of an upper cone closure 4, an inter-cone space 5, a lower cone arrestor 6 and a drum feeder 7, a pelletizer 8, an airtight casing 9 С thermal insulation 10, path 11 for supplying the working medium and binding agent, throttle valve 12, seal 13, discharging device 14, which consists of an upper cone gate 15, an intercone space 16 and a lower cone gate 17, a conveyor 18 for supplying the finished pellets 19. To ensure a pressure reduction of 1.0-2.0 kPa / s at the time of delivery of the pellets from the pelletizer, the interconus space 16 is equipped with control pressure 20 and release valves 21. They serve to regulate the pressure in the cone space 16.

The method is carried out as follows

The conveyor 1 charge 2 is fed to the loading device 3, which serves to load the charge into the sealed pelletizer. The mixture successively passes the upper cone gate 4, the inter-cone space 5, the lower cone gate 6, the drum feeder 7 and nocTynaet into the sealed pelletizer 8. The bar closure is fitted with a sealed housing 9 and thermal insulation 10, for supplying the working medium, which creates pressure, and a binding agent (water, steam) to the pelletizer, in the housing 9 are made a path 1 1 and the throttle valve 12, which is necessary for regulating vania pressure. The sealing of the pelletizer 8 is provided with a seal 13. After pelletizing, the pellets enter the discharge device 14, successively passing the upper KOHycHbtfj gate 15, the inter-conical space 16, the lower cone gate 17, which pours onto the conveyor 18, and conditional

The incinerator 19 is transported to the roller hub; 1 dchiku and roasting machine.

To ensure delivery okat1. From the sealed pelletizer 8 to the conveyor 18, simultaneously with a decrease in pressure from CKopocTbFO 1.0 to 2.0 kPa / s, adjustment pressure 20 and release 21 valves are provided. Wet (after the pelleted octane pellets 8 come to the surface of the upper cone gate, where they accumulate for 100-250 seconds and in 10-15 seconds are poured into the inter-cone space 16,

After this, similarly, raw pellets accumulate on the surface of the lower cone gate 17, which releases them into the environment with a pressure of 0.1 MPa. This process is accompanied by equalization of pressures between the environment and the inter-cone space 16, subsequently, when the upper cone gate is lowered, the pressure in the cone space 16 is again under pressure within the pelletizer.

In order to ensure the effective operation of the proposed method of obtaining pellets, it is necessary, after the pressure in the cone space 16 is equal to the atmospheric pressure, to ensure, by means of the injection valve 20, the pressure bends to the level determined by the equation

R p - Vr

g 1 (g g,

where P is the pressure in the sealed

pelletizer (0.8-1.1 MPa); V - pressure reduction rate

(1.0-2.0 kPa / s);

g is the time of pellet transfer from the upper cone gate 15 to the inter-cone space 16 (5-15 s),

This creates the necessary pressure in the inter-conical space 16 at the moment it enters it, simultaneously with a decrease in pressure at a rate (1.0-2.0 kPa / s). After that, it is necessary to ensure the discharge of the lower cone gate 17 into the environment with speed I, 0-2,0 kPa / s. To do this, reduce the pressure in the cone space with the help of the bleed valve 21 at a speed of 1.0-2.0 kPa / s to a value determined by the formula P, P + Vr,

51504272

 - atmospheric pressure (0.1 MPa); Y is the rate of pressure decrease

(1.0-2.0 kPa / s); g is the time of transfer of pellets from the lower cone gate 17 to the conveyor 18.

The operations of increasing and decreasing pressure can be performed using a compressor or an ejector included in the technological scheme for producing pellets under pressure. The method can be carried out without stimulants giving

The mixture was moistened to 10.5%, stirred | 1 was placed in a pelletizer, after which the working space was sealed and pressurized gas (oxygen) was fed into it. The pelletizing process was carried out in a transfer mode (0.5 ar) for 10 minutes. After the process was completed, the depressurization of the pelletizer working space was carried out by bleeding the pressure through a pressure reducing valve and pellets were released from the pelletizer to the receiving table. Researched

Lenin, with the help of a multi-cone section of the depressurization duration, according to the loading device. The number of the conic was calculated by the rate of decrease

pressure on the strength characteristics of the obtained pellets.

kihih gates, can be calculated by the formula

n - (P - Pj / rV, where P, is the pressure in the pelletizer; PO is the atmospheric pressure; g is the pouring time of the open crankshaft from the conical gate into the cone space; V is the rate of pressure decrease (1.0-2.0 kPaUs), carried out simultaneously with the release of pellets from the pelletizer to the environment. Examples of implementation: The studies were carried out on a sealed laboratory pelletizer.

The data obtained are presented in table 20.

Formula of invention

The method of obtaining the bulk, including loading of the charge into the sealed pelletizer, its moistening and pelletizing under pressure of 0.8-1.1 MPa, unloading of the fine, drying and firing, characterized in that, with the aim of increasing the strength of the outer, the pellets were unloaded with a decrease in pressure at a rate of I, 0-2.0 kPa / s.

one

2

3

I

2

3

0.5

0.5

0.8 0.8 0.8 1.1 1.1 1.1 1.1 0.8

1.1

The data obtained are presented in the table.

Formula of invention

The method of obtaining the bulk, including loading the charge into the sealed pelletizer, its moistening and pelletizing under pressure of 0.8-1.1 MPa, unloading of the fine powder, drying and roasting, characterized in that, in order to increase the strength of the fine, the pellets are unloaded with decreasing pressure at a rate of I, 0-2.0 kPa / s.

, 22, 21 J5, 20, 18, 12, 26, 23

100

102

104

100

102

103

99.7

99.5

and

Claims (1)

Claim A method for producing pellets, including loading the charge into a sealed pelletizer, moistening it and pelletizing under a pressure of 0.8-1.1 MPa, unloading the pellets, drying and firing, characterized in that, for the purpose of increasing the strength of the pellets, the pellets are unloaded with a decrease in pressure at a speed of 1.0-2.0 kPa / s. Example Speed Pressure to reduce pressure during unloading of pellets, kPa / s of the working area of the pelletizer, MPa Strength of raw pellets in discharges - compression, vanishing, times kg / ok Relative performance compared to prototype 1 1 0.8 4,5 1.22 100 2 2 0.8 4.4 1.21 102 3 3 0.8 4.3 1.15 104 4 1 1,1 4.6 1, 20 100 5 2 1,1 4,5 1.18 102 6 3 1,1 4,5 1.12 103 7 0.5 0.8 4.7 1, 26 99.7 8 0.5 1,1 4.8 1, 23 99.5