JPS59172585A - Preparation of blast furnace coke - Google Patents

Abstract

PURPOSE:To prepare blast furnace coke economically, by mixing formed coal obtained by forming under pressure a mixture of raw material coal and dust coke collected by a dust collector, into a blended coal to which low quality coal has been added, followed by dry distillation and dry quenching. CONSTITUTION:Blended coal is prepared by mixing 6% or smaller low quality coal into a mixed coal for coke to be quenched by wet process. Dust coke collected in a dust collector of a dry coke quencher is mixed with the blended coal in an amount of 4% or smaller and the mixture is formed into shape under pressure, dry-distilled and dry-quenched into the aimed blast furnace coke. The low quality coal can be blended in an amount to compensate for the increase of coke strength by dry quenching of coke, leading to cost reduction. Dust coke produced in an increased amount by addition of a larger amount of the low quality coal is recovered in the form of lump coke by addition of collected dust coke to raw material coal for forming.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing blast furnace coke in a coke oven having coke dry extinguishing equipment.

Traditionally, in Japan, only wet extinguishing was used to extinguish red-hot coke in coke ovens, but in recent years dry extinguishing has become increasingly popular for the purpose of saving energy and preventing pollution.

It is known that this dry extinguishing reduces the average coke particle size compared to conventional wet extinguishing, but increases the strength of the coke. And the degree to which this coke strength increases (well, the scale of dry fire extinguishing equipment).

There are some differences depending on the model, etc., but DIigO is used in front of the blast furnace.
It is said that the increase will be around 0.4 to 0.5%.

In order to correspond to this increase in coke strength, a large amount of cheap inferior quality coal is blended into the coal blend, but by increasing the amount of inferior quality coal, the powder ratio of the generated coke increases and the yield of lump coke decreases.

In addition, the coke powder collected by the dust collector of coke dry fire extinguishing equipment is extremely fine powder with a particle diameter of 0.8 mm, making it difficult to reuse it as part of the raw material for sintering, etc. .

As a result, the recovered fine coke had to be sold externally at a low price.

Since increasing the amount of inferior coal has the drawbacks mentioned above, the effect of increasing the amount of coal is not fully exhibited.

As a result of testing using an actual furnace, the inventors found that the throughput capacity was 12.
0 T/H coke dry extinguishing treatment has a lower D value immediately after extinguishing compared to conventional coke wet extinguishing treatment.
I 1.0-1.3%, strength after CO2 reaction 10-12%
, DI: 0.4-0.5 inches, co before the blast furnace, the strength increases by 5-6 inches after the reaction, and if the increase in coke strength due to dry extinguishing treatment is replaced with an increased blend of poor quality coal, poor quality coal 5-6%
It has been confirmed that approximately 1% more coke powder is generated.

In view of the current situation, this invention aims to economically produce coke for blast furnaces using a coke oven equipped with dry coke extinguishing equipment, by adding inferior quality coal to the blended coal to account for the increase in coke strength due to dry extinguishing. The coke powder generation tank by increasing the blending of inferior quality coal proposes a method of collecting fine coke collected in the dust collector of dry fire extinguishing equipment as C lump coke by adding it to molded coking coal. It is.

That is, this invention provides a method for producing coke for blast furnaces by mixing briquette coal with blended coal. The gist of this method is to add 4% or less of fine coke collected by the dust collector of a dry fire extinguishing equipment to molded raw coal, then pressurize the molded coal, mix it, carbonize it, and perform dry fire extinguishing.

In this invention, compared to the coke blend coal used for wet extinguishing, a blended coal with an increased amount of inferior quality coal of 6 or less is used because if the increased amount exceeds 6%, the coke strength will increase due to dry extinguishing treatment. This is because the strength of the coke decreases. In addition, the reason why the amount of dust-collecting fine coke from the dry fire extinguishing equipment added to the molten coking coal is set to 4% or less is because if the amount added exceeds 4%, the strength of the coke produced will not only decrease, but also the molten coal will This is because the strength decreases and the briquette is damaged before it is charged into a coke oven, making it impossible to fully demonstrate the effects of the briquette blend.

Next, embodiments of the invention will be described.

Example 1 In the coal blend used for wet fire extinguishing whose composition and properties are shown in Table 1, poor quality coal A was blended in proportions of 0%, 2%, 4%, and 6%. The average particle size of the coke collected by the dust collector of the dry fire extinguishing equipment was 0.0.
A softening point of 18 obtained by heat-treating heavy petroleum oil as a binder in a molding raw material consisting of 3 fl of 2% fine coke.
Pitch 11% at 0°C and Coulter/I/7% were added outside, heated and kneaded and then pressure molded using a double roll molding machine.The resulting briquettes were mixed at 25% each and placed in a furnace. 7
．． The coke was charged into a coke oven with a length of 125 m and a capacity of 46 on in the oven for carbonization, and the resulting coke was subjected to wet extinguishing and a processing capacity of 120 T.
The fire was extinguished using a /H dry fire extinguisher, and the crushing strength (nx) and strength after CO2 reaction of the resulting coke were measured according to the JIS method. The results are shown in FIGS. 1 and 2.

As shown in Figure 1.2, as the proportion of poor quality coal in the charcoal used for wet extinguishing increases, wet extinguishing (A-line)
, the coke strength decreases in both dry extinguishing (line b), but when dry extinguishing is used up to a low quality coal content of 6%, the coke strength increases before the blast furnace DI': 0.4 factor, the strength after CO2 reaction It is easily estimated that the coke strength will be within the range of 5 to 6% and will maintain the coke strength when wet extinguishing coke produced from a coal blend that does not contain inferior coal.

Table 1 Raw material composition and properties Example 2 The blended coal of Table 1 used in Example 1 was blended with 4 pieces of inferior quality coal, the blended coal of Table 1 and inferior quality coal B, and Example 1
The pitch and coal tar used in the above, and the fine coke with an average particle size of 0.3 collected by the dust collector of the coke dry fire extinguishing equipment were mixed in the proportions shown in Table 2, heated and kneaded, and then molded under pressure. 25 pieces of four types of charcoal were mixed and coked under the same conditions as in Example 1, and the coke strength DI of the resulting coke immediately after extinguishing was ? : was measured, and the relationship between the blending ratio of fine coke in the briquette and the coke strength nI::, and the briquette strength are shown in FIGS. 3 and 4.

From Figure 3.4, it can be seen that if the amount of fine coke collected in the dust collector of the coke dry fire extinguishing equipment added to the coal briquette is 4% or less, there is almost no decrease in the strength of the produced coke and it can be added sufficiently. . This means that the proportion of fine coke in the charged coal is equivalent to 1%, which can correspond to the increase in coke generation due to the addition of inferior quality coal to the coal blend. This shows that it can be effectively used as a raw material for coke without having to be sold to other countries.

Table 2 Molding raw material blend ratio (circulation) As mentioned above, this invention increases the amount of poor quality coal in the blended coal to compensate for the increase in coke strength due to coke dry extinguishing treatment, and generates coke powder by increasing the amount of poor quality coal. This problem can be addressed by adding the fine coke collected in the dust collector of the dry fire extinguishing equipment to the molded coking coal and recovering it as lump coke, making it possible to produce extremely economical coke for blast furnaces. .

[Brief explanation of the drawing]

Figure 1 is a chart showing the relationship between poor quality coal blending ratio and coke strength, Figure 2 is a chart showing the relationship between poor quality coal, CO, and strength after reaction, and Figure 3 is a chart showing the relationship between poor quality coal, CO, and strength after reaction. A chart showing the relationship between coke blending ratio and coke strength, Figure '54 is a chart showing the relationship between fine coke blending ratio in briquette coal and briquette strength. In the figure, 3 curves...In case of wet fire extinguishing, 5 curves...
When using dry fire extinguishing. Applicant Sumikin Chemical Co., Ltd. Agent 1) Yoshihisa Figure 1 Figure 3 Blend ratio of coke in molded coal (C%) Figure 4 Figure 4 Blend ratio of coke in molded coal (%)

Claims (1)

[Claims] In the method of producing coke for blast furnaces by mixing coal blends with briquette coal, blended coals with 6 grams or less of inferior quality coal added compared to the coke blend coals used for wet extinguishing, and dust collection for coke dry extinguishing equipment. A method for producing coke for a blast furnace, characterized in that pulverized coke collected in an apparatus is added to an amount of 4 g or less of molten coking coal, molten coal is pressurized, and the molten coal is mixed, carbonized, and dry extinguished.