JPS5921552A - Blast furnace molten slag granulation control - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for controlling t) when blast furnace molten slag is atomized by gas atomization.

Blast furnace slag is discharged in a molten state at approximately 1500℃.
There is. In order to effectively recover this retained heat, the gas atomization method is used to convert the heat into j''i'7i'7. This is done by detecting the slag, ejecting the slag from the slag, and colliding with the slag.

However, as shown in FIG. 2, M molten slag has a high viscosity, and when the temperature decreases (1<8), the viscosity increases dramatically and fluidity deteriorates. In addition, in addition to the low latent heat of solidification, the heat conduction is also as low as 10 to 20 km (a) hr'C.
If you touch something cold, only the contact area will solidify and it will become sweet, so it will change both the solution properties and the equipment 1 ear.B1
It was difficult to measure this, and it was not possible to control the appropriate force for granulation. Also, if you use normal liquid, do not use excessive amount of gas M (
1 (If you feed it, the particle size will only be fine, but in the case of blast furnace slag, slag (hereinafter referred to as F-wool) is used as a valve,
This has become a major problem due to the large amount of fraud that has occurred in the company's operations.

This book was written to solve this problem, and its gist is 19! +
In this method, the flight angle of the core after Qization with respect to the center of the gas discharge direction from the gas nozzle is Among them, the inclination angle is detected and the nuclear inclination angle is +11.
Control the amount of 7″ Tomize gas by 1″’j so that it converges within the song.
The main feature of this method is the N method for granulating blast furnace molten slag.

Hereinafter, the present invention will be explained in detail with reference to the attached drawings (=J).

FIG. 1 shows the control flow of the present invention. The molten slag flows down as a tundish 1 or as a slag column 2. Air distributed at the bottom of the tanditshu
The slag column 2 collides with the gas injected from the nozzle 3, and the slag column is crushed into f1 particles and sent flying. The flight angle of the particles at this time is determined by the ratio of slag clearing and air.

That is, when the amount of air is small for a slag can, granulation is insufficient, the particle size is large, and the angle of inclination is also large. When the amount of air used is increased, granulation becomes better, the particles become finer, and the angle of inclination becomes smaller. Furthermore, as the process progresses to 61, the granulation continues to be good for a while, and the angle of inclination continues to decrease, but eventually the generation of wool increases, and the generated particles The particles adhere to the wool, forming a mixture of particles and wool. As the air sensitivity decreases, the occurrence of wool and particles decreases, and the aforementioned mixed lump of wool and particles disappears. In this way, in the case of blast furnace slag, if there is too little air, granulation will be poor and coarse grains will be generated.7 If there is too much air, wool will increase, and the relationship between
The scattering angle of particles after conversion, 'l￥ and particle scattering -7j
The angle between the direction and the center of the gas discharge direction from the air nozzle,
In other words, it was found that there is a certain relationship between the slope and the angle of inclination. Therefore, the angle of inclination at the time of forming O\" is between two allowable limit angles, i.e., α1, which is the limit for G<7, and αZ, which is the allowable limit for wool generation. Hold[7tere°l
When this process is carried out, there is less wool generation and the tQ conversion is also lower 71=
It is possible. For example, the slag place +'! )! '
When tji is; 3 to 4 t/H (R:), when graining is carried out by suppressing the wool to 10% or less, αl and α2 are 45'' and 2 (1', respectively, and the inclination angle is 45° to 45°). 200
It's 14 to keep it within. In the present invention, this α1,
Detect α2 using, for example, an optical detection device 4, and actuate the adjustment tP6 via the control device 5 to determine the angle of inclination α during granulation.α1~α.

The air M- is controlled so as to be maintained between 1 and 1.
According to the present invention, the blast furnace molten slag can be made finer, with less reeule generation and granulation.
The effect is that it can be carried out with .

[Brief explanation of the drawing]

FIG. 1 is a granulation control flow diagram according to the present invention, and FIG. 2 is a diagram showing the relationship between temperature and particle size of blast furnace slag. Patent applicant Nippon Steel Corporation 1 ”-'-”'-'r

Claims (1)

[Claims] j☆1 In a method of atomizing furnace molten slag by gas atomization, an inclination angle is detected among the flying angles of particles after granulation with respect to the center of the gas discharge direction from a gas nozzle, and the inclination angle is determined to be f. 1. A method for controlling the granulation of blast furnace molten slag, the method comprising controlling the atomization gas so as to keep it within a predetermined range.