JPS6069192A - Preparation of coke for metallurgy - Google Patents

Abstract

PURPOSE:To prepare coke having a controlled particle size, by adding dust coke to raw material coal in an amt. adjusted to the required particle size of coke to be obtained. CONSTITUTION:In the production of coke for metallurgy, a controlled amt. of dust coke is added to raw material coal in a coal blending process to control the particle size of coke to be obtained. For example, when dust coke crushed to a particle size of -100 mesh is added to raw material coal in an amt. of 0-10%, the relation between the amt. of dust coke added and the particle size of coke obtained by dry distillation shows that the former is affected by the latter to a great extent. When dust coke is added in less than 7.5%, a positive linear correlation is recognized and as the amt. of dust coke added is increased by 1% an average particle size of product coke is increased by 0.9mm..

Description

[Detailed Description of the Invention] The present invention relates to a method for producing metallurgical coke, and more specifically, the particle size of product coke is controlled by adding pulverized coke to coking coal to control the particle size of coke used in blast furnaces, etc. This invention relates to a method for producing metallurgical coke.

Coke is generally used as a fuel or reducing agent in metallurgical furnaces such as blast furnaces, but the quality of this coke is due to its low ash and PLS content, and because it is not crushed until it reaches the hearth, which helps ventilation. The ash content of coke, P,
S can be controlled relatively easily by selecting the coking coal, but controlling coke strength requires complex blending technology and blast furnace operation technology.

The strength of coke is important in maintaining air permeability in the blast furnace, and usually the drum strength (5 mn + index after 30 revolutions: D 1530. +15 mn index after 150 revolutions: D I +5150), tumbler strength -Intensity, CO2
It is measured by the rotational strength of coke after the gasification reaction (strength after reaction).

Furthermore, coke particle size is an important evaluation factor as it relates to air permeability in the blast furnace.The coke particle size is determined by sieve analysis of the coke before charging into the blast furnace, and the harmonic average particle size or drum strength. +50 index after the test (I
) I 5.3°). In addition, in cases where the coke strength has decreased, a method is sometimes adopted to compensate for the decrease in strength by increasing the coke particle size. The yield of coke lumps decreases. On the other hand, it is difficult to control the coke particle size during production, and the only way to do so is to change the carbonization conditions, such as adjusting the standing time after carbonization, or to use special blending conditions.In reality, it is impossible to control coke particle size. Ta.

In view of the technical background and problems as explained above, and as a result of various experiments and studies, the present invention has been developed by blending a small amount of fine coke with the coal raw material at the raw material blending stage, and by adding this fine coke. The object of the present invention is to provide a novel method for producing metallurgical coke that allows the particle size of coke to be controlled, which has been completed based on the knowledge that the particle size of product coke can be controlled relatively easily by adjusting the amount.

The feature of the method for producing metallurgical coke according to the present invention is that when producing metallurgical coke, fine coke is added to raw coal, and the amount of the fine coke added is adjusted according to the target product particle size. The purpose is to control the particle size of the coke product.

The method for producing metallurgical coke according to the present invention will be explained in detail.

That is, Fig. 1 shows that 1100 mesh (-0,1
Figure 1 shows the relationship between the particle size of the coke obtained by adding 0 to 10% of fine coke crushed to 5 mm) and carbonizing it and the amount of fine coke added. As is clear from the above, it is found that the amount of fine coke added has a large effect, and in particular,
A positive linear correlation is observed between the two when the amount of fine coke added is up to 7.5%. For example, in this case, if the amount of fine coke added is increased by 1%, the average particle size of the coke product can be improved by 0.9 mb+. Also, 1
Even if the amount of gold powder coke added exceeds 8%, as seen from the amount of 0% added, no further effect of controlling the particle size of the product coke can be expected. Therefore, once the target particle size of the product coke is set, the amount of fine coke to be added to the raw coal can be determined from the correlation shown in Figure 1, and by simply adjusting the amount of fine coke to be added, it can be applied over a relatively wide range. This can be achieved by easily controlling the particle size of the manufactured coke.

Furthermore, the amount of fine coke added is basically adjusted according to the target particle size of the product coke, but of course, even if the particle size condition is satisfied, there are other factors required for metallurgical coke. If quality is not ensured, it will be practically difficult to use. Therefore, the present inventor also investigated the relationship between coke quality and strength, which is particularly important. In other words, Figure 2 shows that raw coal has a
These are the results of measuring the drum strength (CD I+5") of the product coke obtained by adding fine coke powder crushed to 0.00 mesh (-0.15 mm) in the range of 0 to 10% and carbonizing it. However, when the amount of fine coke added is up to 5%, it shows a strength equal to or higher than that of the base (fine coke = θ%), and when the amount exceeds 5%, the strength tends to decrease, and therefore the product coke It can be said that it is desirable to keep the amount of fine coke required to adjust the particle size to 5% or less based on raw coal.

41 Examples of the method for producing metallurgical coke according to the present invention will be described.

Examples As shown in Table 1, the carbonization temperature was 1250 depending on the formulation (Table 2) with and without the addition of raw coal (pulverized coal and briquette coal) and pulverized coke (-100 mesh).
Blast furnace coke was produced at ~1280°C.

In addition, Example No. 2, No. 3, No. 5, and No.
.

The target particle sizes for 6 (invention) are 42 mm and 42 mm, respectively.
5mm, 40.5mm and 42.5+nm. As shown in Table 2, this result shows that it is possible to obtain product coke with approximately the target particle size, and the product coke has a larger particle size than the conventional method and has the same or higher strength. I can see that you are prepared.

As explained above, since the method for producing metallurgical coke according to the present invention has the above configuration, the particle size of the product coke can be adjusted by a simple method of adjusting the amount of fine coke added to raw coal. can be freely controlled to match the quality or operating conditions required in the metallurgical furnace, and in particular, it is possible to control products with large particle sizes, which was previously difficult, and its industrial value is extremely large. It is something.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the amount of fine coke added and the average particle diameter of coke after a drum test, and FIG. 2 is a diagram showing the relationship between the amount of fine coke added and coke strength (D I 1530). 8-

Claims (1)

[Claims] A metallurgical product characterized by adding fine coke to raw coal and controlling the particle size of the product coke by adjusting the amount of the fine coke added according to the desired product particle size when producing metallurgical coke. Coke manufacturing method.