Blast furnace operation method

Patent metadata

Field	Value
Publication number	US-9873923-B2
Application number	US-201414785165-A
Country	US
Kind code	B2
Filing date	Mar 28, 2014
Priority date	Apr 19, 2013
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A method of operating a blast furnace by blowing a pulverized coal at an amount of not less than 150 kg/t−p from tuyeres through a lance into a blast furnace, wherein when the operation is performed under a condition that lump coke charged from a furnace top has a strength defined in JIS K2151 (DI 150 15 ) of not more than 87%, the pulverized coal blown through the tuyere contains not more than 60 mass % as a weight ratio of coal having a particle size of not more than 74 μm and has an average volatile matter of not more than 25 mass %, and a blast temperature blown through the tuyere is not higher than 1100° C., oxygen is simultaneously blown into the furnace with the blowing of the pulverized coals through the lance and a gas having an oxygen concentration of 60 vol %-97 vol % is used as a carrier gas for the blowing of the pulverized coal.

First claim

The invention claimed is:

1. A method of operating a blast furnace by blowing a pulverized coal at an amount of not less than 150 kg/t−p from tuyeres through a lance into a blast furnace, wherein when the operation is performed under two or more of the following three conditions a, b and c:
a. employing lump coke having a strength defined in JIS K2151 (DI 150 15 ) of not more than 87%, the lump coke being charged from a furnace top;
b. the pulverized coal blown through the tuyere containing not more than 60%, by mass, as a weight ratio of coal having a particle size of not more than 74 μm, the pulverized coal having an average volatile matter of not more than 25%, by mass; and
c. a blast temperature blown through the tuyere is not higher than 1100° C.;

oxygen is simultaneously blown into the furnace with the blowing of the pulverized coals through the lance and a gas having an oxygen concentration of 60%-97%, by volume, is used as a carrier gas for the blowing of the pulverized coal.

2. The method of operating a blast furnace according to claim 1 , wherein when the strength (DI 150 15 ) of the lump coke is not more than 85%, a gas having an oxygen concentration of 70%-97%, by volume, is used as a carrier gas.

3. The method of operating a blast furnace according to claim 1 , wherein when the strength (DI 150 15 ) of the lump coke is not more than 83%, a gas having an oxygen concentration of 80%-97%, by volume, is used as a carrier gas.

4. The method of operating a blast furnace according to claim 1 , wherein the strength (DI 150 15 ) of the lump coke is not less than 78%.

5. The method of operating a blast furnace according to claim 1 , wherein a weight ratio of a pulverized coal having a particle size of not more than 74 μm is not less than 30%, by mass.

6. The method of operating a blast furnace according to claim 1 , wherein the blast temperature is not less than 900° C.

7. The method of operating a blast furnace according to claim 1 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

8. The method of operating a blast furnace according to claim 2 , wherein a weight ratio of a pulverized coal having a particle size of not more than 74 μm is not less than 30%, by mass.

9. The method of operating a blast furnace according to claim 3 , wherein a weight ratio of a pulverized coal having a particle size of not more than 74 μm is not less than 30%, by mass.

10. The method of operating a blast furnace according to claim 4 , wherein a weight ratio of a pulverized coal having a particle size of not more than 74 μm is not less than 30%, by mass.

11. The method of operating a blast furnace according to claim 2 , wherein the blast temperature is not less than 900° C.

12. The method of operating a blast furnace according to claim 3 , wherein the blast temperature is not less than 900° C.

13. The method of operating a blast furnace according to claim 4 , wherein the blast temperature is not less than 900° C.

14. The method of operating a blast furnace according to claim 5 , wherein the blast temperature is not less than 900° C.

15. The method of operating a blast furnace according to claim 2 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

16. The method of operating a blast furnace according to claim 3 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

17. The method of operating a blast furnace according to claim 4 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

18. The method of operating a blast furnace according to claim 5 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

19. The method of operating a blast furnace according to claim 6 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

20. The method of operating a blast furnace according to claim 14 , wherein the amount of the pulverized coal blown is not more than 300 kg/t−p.

Assignees

• Jfe Steel Corp

Inventors

• Murao Akinori
• Fujiwara Daiki
• Watakabe Shiro
• Sato Michitaka
• Watanabe Takashi
• Shimomura Akio

Classifications

• C21B5/003 Primary

  Injection of pulverulent coal · CPC title

• F27D2003/185

  Conveying particles in a conduct using a fluid · CPC title

• F27D3/18

  Charging particulate material using a fluid carrier · CPC title

• F27D3/16

  Introducing a fluid jet or current into the charge (F27D3/18 takes precedence) · CPC title

• C21B5/007

  Conditions of the cokes or characterised by the cokes used · CPC title