KR100206495B1 - Method for caking of tar sludge and method of coke from caking tar sludge - Google Patents

Abstract

The tar sludge solidification method which manufactures the solid body which is easy to store, transport and input by heat-treating tar sludge is provided.

The prepared solid body may be carbonized alone or mixed with general coal having a weak coking force and then carbonized to produce coke having excellent coking force.

By solidifying the tar sludge, it is easy to store, transport, and input, and by using the coke to manufacture the coke to expand the utilization of the tar sludge, it is possible to reduce the expensive high-coking coal use in the coke production.

As described above, the present invention facilitates transport and storage by heat treating and solidifying the tar sludge, and the thus prepared tar sludge solid material can function as a caking additive and a caking additive for imparting coking properties.

Description

Solidification Method of Tar Sludge and Coke Manufacturing Method Using Solidified Tar Sludge

1 is a photo showing the microstructure of the coke produced by carbonizing 100% ordinary coal.

Figure 2 is a photograph showing the microstructure of the coke prepared by adding the tar sludge solid produced by the method of the present invention to 35% by weight of the normal coal and carbonized.

The present invention relates to a method for solidifying tar sludge and a method for producing coke using the solidified tar sludge.

Coke, which is consumed in large quantities in steel mills, is produced by hot-drying coal and tar is obtained as a by-product.

Tar is a mixture of liquid tar and solids such as pulverized coal and pulverized coke. Among them, solids are deposited in the bottom by the specific gravity difference in the tar precipitation tank, which is called tar sludge.

This tarslurry is composed of a solid tar component consisting of a liquid tar component and a chemically stable solid particle, which is a mixture of aromatic hydrocarbon compounds with high fluidity, and thus has high viscosity, affects tar use, and reduces the volume of the storage tank periodically. Needs to be.

On the other hand, the tar sludge has a high calorific value and is produced through the blast furnace tuyere by preparing fuel from petroleum by-products such as powdered coke, tar sludge, activated sludge sludge, tar ore emulsion (Japanese Patent Laid-Open Publication No. 5-117728), or Coal in the crushing process by pulverizing tar sludge and burning it in an industrial furnace by heating it to 80-120 ° C (Japanese Patent Publication No. 55-066992), or by adding tar sludge before pulverizing raw coal in the manufacture of coke. It is known to be used as a coke-making raw material such as to improve the degree of mixing with the tar sludge and to increase the density of the coke furnace charged coal (Japanese Patent Laid-Open No. 4-270790).

However, the use of tar sludge as a fuel will be increasingly controlled by environmental regulations that are gradually strengthened, and even when used in combination with the charged coal during the manufacture of coke, the low viscosity tar sludge is mixed with the loaded coal as it is. Too much volatile matter causes the formation of pores during dry distillation, resulting in a decrease in the strength of the coke produced.

Accordingly, the present invention is to provide a new tar sludge pretreatment method that solves the conventional problems caused by using tar sludge as a raw material for producing coke.

Furthermore, another object of the present invention is to provide a method for producing coke with improved coking strength by using solidified tar sludge.

According to one aspect of the present invention, there is provided a tar sludge solidification method comprising the heat treatment of the tar sludge under air blowing for 0.5-1 hours at 230-330 ℃ temperature.

According to another aspect of the present invention, the tar sludge is heat-treated to obtain solidified tar sludge, and the solidified tar sludge is mixed with general coal to 35% by weight or more based on the total weight, and then the mixture is carbonized under an inert atmosphere. There is provided a coke manufacturing method comprising a.

Hereinafter, the present invention will be described in detail.

The present inventors intended to facilitate the transport and storage for coke production by solidifying the tar sludge by heat treatment, and furthermore, to prepare the coke with excellent coking strength by mixing the solidified tar sludge with ordinary coal having a weak coking force. It was.

Tar sludge that can be used in the present invention is extracted from the tar settling tank and pulverized by a grinder composed of 70% tar component, 30% solids, 97% or more of the solids is a tar sludge having a particle size of 0.5mm or less .

Most of the solids that make up the tar sludge are fine coke and may contain some coal. In addition, the tar sludge property is a liquid viscous liquid, and separation by self weight occurs for a long time.

In order to solidify the tar sludge in the present invention, the tar sludge is treated with air blowing at a temperature of 230-330 ° C. for 0.5-1 hour.

The heating temperature range is determined in consideration of the time and energy consumption required to produce a solid.

Such heating temperature can be applied in the range of 130-430 ℃, but if the heating temperature is lowered, up to 10 hours is required for the solidified sludge solids to be solidified so as not to cause problems during storage, transportation and charging process for coke production. If the heating temperature is to be increased and the heating temperature is increased, the desired solid can be produced in a short time, but this increases the energy consumption and increases the manufacturing cost.

Therefore, in the present invention, the preferable heat treatment condition for solidifying the tar sludge was 230-330 ° C.

The heat treatment temperature is reached by heating at a temperature increase rate of about 5 ℃ per minute from room temperature, it is preferred to solidify by cooling to room temperature within 30 minutes after 0.5-1 hour treatment at the heat treatment temperature.

On the other hand, the heat treatment is carried out under the air blowing, in this case, the yield and softening point of the solid produced according to the blowing speed of the air under the same conditions change.

Experimental results showed that the higher the air blowing rate, the lower the yield of solids and the higher the softening point.

The tar sludge solid formed by the heat treatment is ground to a size of 1 mm or less and made available as a coke raw material.

The tar sludge solidified by the present invention can be used as a raw material for coke production by mixing with coking coal having a weak coking force.

Generally, coke requires some strength in use, so it is manufactured by distilling carbon dioxide having strong coking force, for example, by mixing bituminous coal and general coking with low coking force. Therefore, ordinary bullets with weak coking power cannot be used for coke production. On the other hand, bituminous coking coal has a higher price than that of ordinary coal, so it is necessary to reduce its use as much as possible.

In the present invention, coke having excellent coking strength can be produced by using a mixture of ordinary coal and the tar sludge solid produced according to the present invention without using expensive coking coal as described above.

In the present invention, the tar sludge solid is added to the normal coal by 35% by weight or more, and then the mixture is carbonized in an inert atmosphere to prepare coke. Preferably, at least 50% by weight of tar sludge solids is added.

When the content of the tar sludge solids is less than 35%, the cohesiveness becomes weak.

When coke is manufactured using only the tar sludge solids, the yield is slightly reduced, but the caking is very excellent.

Coke carbonization according to the method of the present invention can be carried out by heat treatment of the mixture of the tar sludge solids and ordinary coals under conventional dry distillation conditions well known in the art, preferably at about 600 ℃ for 1 hour. .

EXAMPLE

The tar sludge was stirred with a rod for 5 minutes in a 25 kg storage container to uniformly disperse the high-viscosity tar sludge settled at the bottom, and 50 g of the sample was collected from the tar sludge into a flask reactor with a diameter of 35 mm and a diameter of 1 mm for blowing air. A red steel tube was inserted so that its end touched the bottom of the flask. The amount of air blown was 320 mm and 750 ml per minute, and the temperature was raised to 5 ° C. per minute and heat-treated at a predetermined time and temperature to obtain a solid. The solid was pulverized into powder having a size of 1 mm or less, and the softening point thereof was measured by a ring ball method according to ASTM E28.

The yield and softening point of the tar sludge solids according to the air flow rate, the heat treatment temperature and the heat treatment time are shown in Table 1 below. In case of heat treatment at the temperature below 230 ℃, the tar sludge solid should be heat treated for up to 10 hours to avoid problems in the storage, transportation and charging process for coke production. On the other hand, if the heat treatment temperature is increased to more than 330 ℃ can produce the desired solid in a shorter time, all of these may cause a rise in manufacturing cost.

Example 2

The same branched flask used in the heat treatment by mixing the tar sludge solid prepared in Example 1 with non-coking non-coking coal (MW, IM = 3.08%, ash = 8.90%, VM = 33.56%, C = 54.46%) Nitrogen was blown into the mixture and carbonized at 600 ° C. for 1 hour while maintaining an inert atmosphere. Table 2 shows the carbonization yield and caking phase of the mixed raw materials according to the ratio of adding the tar sludge solid to the coal.

As shown in the table above, coking can be produced by adding coking force as tar sludge solids are added to the ordinary coal, which can not be used alone as a coke raw material because it has no caking property.

2 is a photograph showing the microstructure of the coke prepared after the tar sludge solids of the present invention is added to the coal by 35%, and compared with these, the coke tissue prepared by adding the tar sludge solids of the present invention is general. It can be seen that it is much more dense than coke made with only carbon.

Claims (4)

A tar sludge solidification method comprising heat treating tar sludge under air blowing at a temperature of 230-330 ° C. for 0.5-1 hour. Tar sludge is heat-treated under air blowing to obtain solidified tar sludge, and the solidified tar sludge is mixed with general carbon to 35% by weight or more, and then the mixture is carbonized in an inert atmosphere. Coke production method using sludge. The method of claim 2, wherein the carbonization is performed by heat treatment at about 600 ° C. for 1 hour. 3. The method according to claim 2, wherein the solidified tar sludge is mixed with the general coal to 50% by weight or more based on the total weight.