Optimization method for directional preparation technique and efficient use of semi-coke for blast furnace injection

Patent metadata

Field	Value
Publication number	US-2022275280-A1
Application number	US-202017631426-A
Country	US
Kind code	A1
Filing date	Jul 17, 2020
Priority date	Jul 17, 2020
Publication date	Sep 1, 2022
Grant date	—

Abstract

An optimization method for a directional preparation technique and efficient use of semi-coke for blast furnace injection. Firstly, the volatile and the ash content of target semi-coke are preset, and then the volatile and the ash removal percentages of a raw coal are calculated; after ash removal, several sets of dry distillation carbonization temperatures and carbonization times are obtained according to the volatile removal percentage, and the relationships between a combustion rate, abrasiveness, explosiveness and jet flow property and the carbonization temperature are respectively established to obtain the optimal actual carbonization temperature; and semi-coke for blast furnace injection is obtained at an actual carbonization temperature. The directional preparation is suitable for the semi-coke for blast furnace injection, and an optimal coal-compounding scheme is obtained, thus achieving the efficient and safe injection of blast furnace iron-making fuels, and energy conservation and emission reduction.

First claim

1 : A directional preparation technology of semi-coke for blast furnace injection, comprising performing dry distillation on raw coal to remove part of volatile matters to prepare the semi-coke for blast furnace injection, and comprising the following steps:
S 11 . according to a limit value W A standard of an ash percentage of target semi-coke, obtaining a relational expression between an ash removal percentage W A removal in the raw coal and a volatile matter removal percentage W B removal during dry distillation, as shown in Formula (1):

W

A
removal

=

W

A
coal

-

W

A
standard

(

1
-

W

B
removal

)

1
-

W

A
standard

(
1
)

in the formula, W A coal represents a percentage of ash in the raw coal;
the limit value of the ash percentage meets W A standard ≤12%;
S 12 . according to Formula (1) obtained in step S 11 , presetting a volatile matter removal percentage during dry distillation, wherein if the preset volatile matter removal percentage W B removal meets Formula (2), ash removal treatment is performed on the raw coal, otherwise, the ash removal treatment does not need to be performed on the raw coal:

W

B
removal

≥

W

A
standard

-

W

A
coal

W

A
standard

;

(
2
)

S 13 . performing dry distillation on the raw coal treated in step S 12 to remove part of volatile matters, wherein a method for determining a carbonization temperature of dry distillation comprises: guided by the preset volatile matter removal percentage W B removal in step S 12 , preliminarily determining a plurality of groups of carbonization temperatures and carbonization times of dry distillation, then, according to the plurality of groups of the carbonization temperatures and carbonization times, performing dry distillation and carbonization on the raw coal at different carbonization temperatures and carbonization times to prepare semi-coke, and respectively obtaining relationships between parameters comprising combustion rate, grindability index, explosibility index and jet flow index of the semi-coke and the carbonization temperature;
S 14 . according to the relationship between the explosibility index and the carbonization temperature in step S 13 , determining a lower limit value of the carbonization temperature, and then, in temperature intervals higher than the lower limit value of the carbonization temperature, according to the relationships between the combustion rate, the grindability index and the jet flow index and the carbonization temperature, selecting a temperature interval in which the combustion rate, the grindability index and the jet flow index are all excellent as an actual carbonization temperature of dry distillation of the raw coal;
S 15 . according to the carbonization time obtained in step S 13 and the actual carbonization temperature obtained in step S 14 , performing dry distillation and carbonization on the raw coal, and then, cooling to obtain the semi-coke for blast furnace injection.

2 : The directional preparation technology of semi-coke for blast furnace injection according to claim 1 , wherein in step S 11 , the limit value of the ash percentage meets W A standard ≤9%.

3 : The directional preparation technology of semi-coke for blast furnace injection according to claim 1 , wherein in step S 12 , a method for ash removal treatment comprises, but is not limited to, treatment by a heavy medium coal preparation technology.

4 : The directional preparation technology of semi-coke for blast furnace injection according to claim 1 , wherein in step S 13 , the carbonization temperature and the carbonization time are preliminarily determined through a pyrolysis behavior of dry distillation and carbonization of the raw coal in a carbonization furnace.

5 : The directional preparation technology of semi-coke for blast furnace injection according to claim 1 , wherein in step S 13 , CFD numerical simulation is used to establish a relationship between a heating gas temperature and the carbonization temperature, and then, heating gas temperatures corresponding to different carbonization temperatures are obtained according to the relationship between the heating gas temperature and the carbonization temperature.

6 : The directional preparation technology of semi-coke for blast furnace injection according to claim 1 , wherein in step S 13 , the explosibility index is a length of a return flame generated after ignition of the semi-coke determined by a long-tube type coal powder explosibility determining device, and a carbonization temperature with an explosibility index ≤200 mm is selected as a lower limit value of the carbonization temperature.

Assignees

• Univ Beijing Science & Technology

Inventors

• Zhang Jianliang
• Liu Zhengjian
• Wang Guangwei
• Xu Runsheng
• Jiao Kexin
• Li Kejiang
• Wang Zhenyang
• Wang Cui
• Ning Xiaojun

Classifications

• C21B5/003

  Injection of pulverulent coal · CPC title

• C21B5/007

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

• C10B53/04 Primary

  of powdered coal · CPC title

• C10B57/14

  Features of low-temperature carbonising processes · CPC title

• C10B57/04

  using charges of special composition · CPC title