SU1191478A1 - Method of preparing charge for sintering - Google Patents

Abstract

A METHOD FOR PREPARING THE GRAINING CHARGE TO Sintering, including preheating it, restoring the upper layer and burning with furnace gases, which, in order to increase the metallization of the sinter and increase the productivity of the sintering machines and Home furnaces, before ignition, 15–50% of the layer of the layer is laid. and restore to a depth of 6-10% of the total height of the layer.

Description

CX) 1 The invention relates to the metallurgical industry, namely to the production of sinter in sinter plants, and can be used in the sintering of ores and concentrates. The aim of the invention is to increase the metallization of the sinter and to increase the productivity of the sintering machines and blast furnaces. In the method of sinter preparation preparation, including its preheating, restoration of the upper layer and ignition by furnace gases, before ignition of the fuel, 15–50% of the layer of the charge is melted and restored to a depth of 6–10% of the total layer height,. It is advisable to carry out the refining treatment by melting of the charge no more than 50% of the surface area of the charge entering the ignition. An increase in the surface area of the mixture in excess of 50% leads to an excessive melting of the surface of the barrels, a decrease in the filtration rate of gases, an iron content of metal and a sharp decrease in the productivity of the sintering plant. When the charge surface is melted by less than 15%, the degree of metallization decreases by a factor of 2 or more, which makes the melting almost meaningless due to a sharp decrease in the efficiency of heat treatment. In addition, higher oxides of the charge in the layer at 6-10% of its depth from the total height of the layer are subjected to melting and metallization. A decrease in the depth of the melted layer below 6% of the total height of the mixture leads to a sharp decrease in the metal content of iron in the sinter and the specific productivity of the sintering plant. With an increase in the depth of melting (over 10% of the total height of its layer), the heat treatment time increases, which leads to a decrease in the specific productivity of the sintering machine and excessive consumption of solid fuel. Example. The proposed method was tested on a laboratory sintering plant with sintering diameter of 210 mm. The height of the mixture was 200 mm, the vacuum under the spiked grid 900782 was 1000 mm water. (8.82-9.80 KPA). The reductive melting of the front by ignition of the fuel was carried out at the expense of the plasma arc energy generated by a plasma torch with a power of 50-60 kW with a supply of 1 m / h of propane to the plasma zone. High-temperature heat treatment in a reducing atmosphere is subjected to 1/51/6 of the ignition area on the side of the loading device. In this case, the charge located in the immediate vicinity of the plasma zone melts and is reduced by ionized jets of plasma torches to ferrous oxide and then to metallic iron, forming the structure of the finished metallized agglomerate. The ignition of the fuel both according to the proposed method and the prototype was carried out with a gas burner, which has the ability to control the excess air coefficient within 1 o i 1. The total ignition time of both the prototype and the proposed method in all five cases was 2 minutes . A mixture of the following composition was subjected to sintering: Korshunovsky concentrate56.73 Lisakovsky concentrate 7-93 Sokolovsko-Sarbaisk ore-processing 17.28 Atasuyska ferromanganese ore3,12. Krasnokamensk. aglo-ore1,61 Tashtagolsk domain ore (screenings) 0.43 Screenings of Abagur agglomerate 0.33 Okalina3.75 Koloshnikov dust .0.48 Pellets (screenings) 1.01 Sokolovsky-Sarbai concentrate7, 33 Coke breeze of fraction 3-0 was used as fuel. mm The fuel content in the charge without return was 6.0%, and the return content was 32-35%. The yield was rated for grade over 5 mm, and mechanical strength as a 5-0 mm fraction after dropping the agglomerate on a steel plate from a height of 2 m five times. The table shows the performance of the sintering process depending on the preparation method. Thus, comparing the data of 19 5 -10 784 obtained at various methods of sinter charge preparation of the table, it follows that when the charge was ignited by the proposed method, mechanical strength in comparison with the prototype improved by 8.3-8.9% (abs.) increased by 25-27 times, the content of fines from the 5-0 mm fraction in the finished sinter decreased by an average of 8.6% (abs.). and the yield of sinter increased by 8.1–9.3%, and the specific productivity of the sinter plant increased. by 10.7-15.1% (rel.)

Heat treatment time, with

The proportion of the upper part of the treated mixture from the upper layer,%

The share of the treated surface of the charge,%

Specific productivity, t / m. h

Vertical sintering speed, mm / min

Vrsod fit,%

Mechanical strength

(content FR 0-5 mm

in agglomerate),%

Metal content in

sinter upper

layer%

Degree of metallization

charge,%

ten

20

22

24 30

eight . ten

15

13.0 15

thirty

50

55

1.23 1.25 1.291.0

23,823,622,717,3

67,167,768,376.0

14,414,715,014,1

13,2214,014,85,0

24,526,927,39,1

Claims (1)

METHOD FOR PREPARING THE AGLOMERATION BATCH FOR SINTERING, including its preliminary heating, restoration of the upper layer and ignition with furnace gases, characterized in that, in order to increase the metallization of the agglomerate and increase the productivity of the sintering machines and blast furnaces, 15-50% of the surface of the charge layer is melted and restore to a depth of 6-10% of the total height of the layer. > ί · ί to I ! .l F 1000 mm water column (8.82-9.80 KPA). Reductive fusion before ignition of the fuel was carried out due to the energy of the plasma arc 5 created by the plasmatron with a power of '50-60 kW with the supply of 1 m ³ / h of propane to the plasma zone. 1/510 1/6 of the ignition area from the side of the loading device is subjected to high temperature heat treatment in a reducing atmosphere. At the same time, the mixture located in the immediate vicinity of the plasma zone is melted and reduced by 15 ionized jets of plasma torches to iron oxide and then to metallic iron, forming the structure of the finished metallized agglomerate. Ignition of fuel as 20 according to the proposed method, and according to the prototype was carried out by a gas burner having the ability to control the coefficient of excess air in the range of 1 4 1. The total ignition time for both the prototype and the proposed method in all five cases was 2 minutes The mixture of the following composition was sintered: