JPS60110785A - Production of raw material for coke and production of coke - Google Patents

Abstract

PURPOSE:To produce a raw material blend for use in producing blast furnace coke by utilizing by-product iron source material formed in iron works, by melt- kneading a bituminous substance with said iron source, material. CONSTITUTION:5-30pts. Bituminous substance (e.g. pitch or asphalt having a softening point of 200 deg.C or below) is added to 100pts. iron source material having a particle size of 1mm. or below (e.g. blast furnace dust, converter dust, rolling sludge or finely divided iron ore). The mixture is kneaded at a temp. which is 50 deg.C higher than the softening point of the bituminous substance, whereby the bituminous material is allowed to penetrate into the raw material particle and the surface of the particle is coated with the bituminous material to obtain a raw material for use in the production of coke. The obtd. raw material is used in such a manner that, in the production of blast furnace coke, not more than 15% (outer percentage) said raw material is added to blended coal and that, in production of briquetted coke, not more than 20% (outer percentage) said raw material and a binder are added to blended coal and the mixture is briquetted and dry-distilled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing metallurgical coke.

The development of blast furnace pig iron making technology is remarkable, but ore and coke are alternately charged from the top of the furnace to create an ore layer and a coke layer inside the furnace, and hot air is blown through the slats at the bottom of the furnace to melt the metal. However, there is no change in the basic principle of extracting hot metal. Blast furnace pig iron making is expected to continue in the future due to its high productivity, but one of the drawbacks of this method is that it requires a raw material processing process that consumes a lot of energy before charging into the blast furnace. be. That is, there is a coke manufacturing process for producing solid coke from coal, and a sintering process for burning and solidifying fine ore. It is no exaggeration to say that in order to take advantage of the characteristics of the blast furnace pig iron making process and reduce pig iron costs in the future, it will depend on how the costs of these raw material processing steps can be reduced.

One method is to use by-product fine iron sources in the coke manufacturing process, such as fine ore that inhibits the productivity of the sintering process, blast furnace dust, converter dust, and rolling sludge generated in steel plants. It is possible to kill two birds with one stone by reducing the coke cost, and by pre-reducing ores during coal carbonization, and by charging the coke produced in this way into a blast furnace, the reduction rate can be increased and the reducing action in the furnace can be maintained well. There is an effect.

The so-called ferro-coke process, which produces coke by mixing iron ore with coal, has been known for some time, but the disadvantage of this technology is that when iron ore is mixed, the coking properties of the coal are significantly impaired. ``It was not possible to obtain high-strength coke, which was the original goal, and the effect on coal differed depending on the type of iron ore, so it was not possible to create a blending design to maintain coke quality. Furthermore, when producing ferrocoke, it is always common to see that the bricks of the coke oven are severely damaged. Due to these drawbacks, it has not been possible to incorporate iron ore or the like into charging coal as a raw material for coke production. However, the present inventors investigated the cause of ores inhibiting the coking property of coal and found that iron ore, which has a strong butyric property and is in contact with coal during coal carbonization, inhibits the caking property of coal. However, this is an important factor in coke formation.
It was found that the softening and melting properties decreased in the range of 0 to 500°C, and that the caking inhibiting effect was limited to the very surface layer of the coal that came into contact with the iron ore, and that It has been found that the reduction in caking properties can be prevented by forming a thin hydrocarbon protective film on the surface. On the other hand, coke oven bricks are damaged due to the formation of Fe09 i02 due to the reaction between iron and silica on the coke oven wall. contact can be prevented.

The present invention eliminates the drawbacks of the prior art, and eliminates the use of fine iron ore, which hinders productivity in the sintering process, and various iron source by-product materials generated in steel plants, without being affected by their properties, and by coke from coal. The company has established a method in which it can be blended as a raw material for coke production without impeding its coke-making properties, and can be used in the ordinary room furnace carbonization method without damaging wall bricks.

That is, the present invention provides a method for reducing the softening point of coal pitch, petroleum pitch, and asphalt corner for 100 parts of iron source raw material with a grain size of 1 mm or less, which is produced as a by-product in a steel mill, such as fine iron ore, blast furnace dust, converter dust, and rolling sludge. The present invention provides a method for producing a raw material for coke production, which comprises adding 5 to 30 parts of a bituminous material having a temperature of 200'C or less and kneading at a temperature 50C or more higher than the softening point of the bituminous material.

The present invention also provides iron source raw materials J with particle diameters of 1 m+m or less that are by-produced in steel plants such as fine iron ore, blast furnace dust, converter dust, and rolling sludge when producing coke for blast furnaces.
, by adding 5 to 30 parts of a bituminous substance such as coal pitch, petroleum pitch, or asphalt with a softening point of 200°C or less to 0 parts, and kneading at a temperature 50°C or more higher than the softening point of the bituminous substance. The present invention provides a method for producing coke, characterized in that the raw material for producing coke is blended with the blended coal in an amount of 15% or less in an outer frame, and carbonized under normal carbonization conditions.

Furthermore, when manufacturing molded coke, this Hikari 1 has a grain size [■ below iron source raw material 10
By adding 5 to 30 parts of a bituminous substance with a softening point of 200'C or less, such as coal pitch, petroleum pitch, or asphalt, to 0 parts, and kneading at a temperature 50'C or more higher than the softening point of the bituminous substance. To provide a method for producing coke, which comprises blending the obtained raw material for coke production with a binder in an amount of 20% or less in an outer frame to a coal blend to produce briquette coal, and carbonizing the briquette coal. be.

According to the present invention, it has become possible to utilize not only ores but also by-product iron sources such as blast furnace dust, converter dust, rolling sludge, etc., which have various properties that are generated throughout the steelworks.

The present invention will be explained in more detail below.

The total particle size of the iron source material is 1 mm or less, preferably 0.3 mm.
Adjust as below. Normally, the raw materials targeted by the present invention are often fine powders with a particle size of 0.15 + am or less, so there is no need to re-pulverize them. The reason why the particle size is adjusted in this way is that the shrinkage rate is different between coal and iron source raw materials because these raw materials act as inert substances during coke lump formation. If the particle size is large, it will promote crack formation in coke and reduce its strength.
This is because coke quality deteriorates due to factors other than caking.

Next, 5 to 30 parts of bituminous material having a softening point of 200° C. or less is added to 100 parts of the raw material, and kneaded at a temperature 50° C. or more higher than the softening point. The reason for limiting the softening point of bituminous materials is 2.
This is because a substance with a softening point higher than 00°C has poor infiltration properties with respect to the substance that has turned into pseudo-particles during kneading, and the particle surfaces are not sufficiently coated.
The reason for kneading at a temperature 50°C or more higher than the softening point is the same as above. The bituminous materials used for such treatment include coal tar, asphalt coal tar pitch,
Petroleum pitch, coal liquefied product, naturally occurring sand oil, etc. may be used. When using a coal-based or petroleum-based pitch with a softening point higher than 200'O, softer tar or It can be used by mixing with heavy oil to lower the softening point, and in the present invention, these substances are collectively referred to as bituminous substances. The reason why the blending ratio of bituminous material is set to 5 to 308 Il is because if it is less than 5 parts, bituminous material will not be sufficiently distributed to each particle at the target raw material particle size.
If the amount exceeds 30 parts, this is to prevent unnecessary addition of expensive bituminous materials, and if the amount is added in excess, it will become highly adhesive, making it difficult to carry out the nodding operation in the first mixing step.

The products obtained through the above treatments are used as raw materials for coke production. When used in a regular coke oven,
It can be handled using the same blending procedure as charging coal. The reason why the product is blended within 15 parts per 100 parts of coal blend is that if it exceeds 15 parts, it will shrink due to the difference in shrinkage rate between the coal blend and the raw material during the shrinkage process after the solidification temperature during the coking process. This is because the reduction in crushing strength due to the resulting crack formation has a large effect.

When used as a raw material for molded coke production, the difference in shrinkage rate between the blended coal and the raw material becomes smaller due to the compaction of the coal through the molding operation, and as long as it is 20 parts or less, it can be used without reducing coke strength. It is. In short, when using this product as coke raw material 1, there is a limit to the mixing ratio, considering the difference in shrinkage rate between the blended coal and the product during coke lump formation, but it may be within the range. For example, it can be used in the same way as ordinary coking coal.

According to the method of the present invention described above, the pulverized iron FA raw material generated within a steelworks can be used in the coke manufacturing process without inhibiting the coking properties of other coal blends.

Hereinafter, the present invention will be specifically explained with reference to Examples.

[Example 1] Pentane debonito asphalt with a softening point of 140°C shown in Table 2 as a bituminous material was added to the iron source material shown in Table 1 in an outer frame.
3% was added and kneaded by heating at a temperature of 210° C. in a kneader to obtain a coke raw material product.

The product was added to the coal blend shown in Table 3 at an angle of 3.5°10.1 in the outer frame.
They were mixed at a ratio of 5%, and the maximum flow rate was measured using a Kiessel plastometer. On the other hand, for comparison, the raw materials shown in Table 1 were blended as they were without any treatment) and sardines were added, and the maximum fluidity was measured in the same manner. Figure 1 shows the results for Australian iron ore, and Figure 2 shows the results for blast furnace dust. In either case, if added to a coal blend without any treatment, the caking property will be drastically inhibited, but if treated using the Kihatsu IJJ method, the fluidity will decrease slightly compared to the base blend coal at 15% addition. There is no problem in practical use.

To 95 parts of the base blended coal shown in Table 3, 5 parts of the iron source raw materials shown in Table 1, either as they are or processed in the same manner as described above, are blended at a ratio of 5 parts to JIS M 88.
A carbonization test was carried out in accordance with the canning method of No. 01. As shown in Table 4, NO9! is the base blend coal. No, 2.
No. 3 is a product in which the bituminous raw materials shown in Table 2 are blended as is, and has a crushing and tearing strength of 0400 degrees D115 and abrasion strength TI compared to No. 001. decreased significantly, especially T
, significant at 3oo. No, 4. No. 5 is from wood 1
Processed according to the law, No. 2. No.3
It can be seen that the iron aX material can be used as a raw material for coke without impairing the coking property even when compared with N001. In addition, DI30 is JIS
5 Indicates the weight percentage of the full drum after 30 rotations of the drum according to the drum test method specified in K 2151. Full 41 after 400 rpm at
It shows a weight ratio of 61011 or more, the former meaning crushing property in terms of coke strength, and the latter meaning abrasion property.

[Example 2] In the blend shown in Table 3, 20% of Canadian coal was substituted with Australian slightly caking coal and used as a base blend coal for manufacturing a molded bed. As the iron source material, Austsyrian iron ore powder shown in Table 1 was used. Coal pitch with a softening point of 60°C was used as a binder for the production of molded beds, and molded coal was manufactured using a double roll molding machine with the composition shown in Table 5, and the resulting molded coals were made so as not to fuse together. Put it in the coke powder layer, JI
It was carbonized according to the canning method of SM 8801. No,
No. 7 is a case in which iron ore powder is blended as is, No. 8 is a case in which iron ore powder coated with bituminous material is blended in the same manner as in Example 1. Compared to No. 8 base blend coal, if ore powder is mixed without treatment, the coking property deteriorates and strong coke cannot be obtained, but if treated by the single ffi IJ method, the coke strength can be improved. That is clear.

According to the above examples, if the method of the present invention is followed, pulverized iron ore and iron source materials generated as by-products in steel mills can be used as blended raw materials for producing coke for blast furnaces without impairing the coking properties of blended coal. It is clear that it can be done, and the effect of reducing the load on the sintering process and reusing resources is extremely large.

[Brief explanation of the drawing]

Figures 1 and 2 show the effects on caking properties when Australian iron ore and blast furnace dust are treated with the method of the present invention and added to blended coal, respectively, compared with untreated.
It is a graph showing the relationship between the addition ratio to blended coal and the logarithm value of maximum fluidity (DDPM) measured with a Gieseler plastometer. Patent Applicant: Kawasaki Steel Co., Ltd. Figure 1 Amount added to blended coal (〆) Figure 2 Amount of port calories added to blended coal (%)

Claims (3)

[Claims] (1) For 100 parts of iron source raw materials with a grain size of 1non or less, which are by-products in steel plants such as fine iron ore, blast furnace dust, converter dust, rolling sludge, etc., softening point of coal pitch, petroleum pitch, asphalt, etc. is 200 ° C or less 5~ of blue-loving substances
30 parts of the bituminous material is added and kneaded at a temperature 50°C or more higher than the softening point of the bituminous material. (2) When producing coke for blast furnaces, coal pitch, petroleum pitch, A raw material for coke production obtained by adding 5 to 30 parts of a bituminous substance with a softening point of 200'C or less, such as asphalt, and kneading at a temperature 50'0 or more higher than the softening point of the bituminous substance, is made into a coal blend. 1. A method for producing coke, characterized in that the outer frame contains 15% or less of the coke and is carbonized under normal carbonization conditions. (3) When producing molded coke, iron sources with a particle size of 1III11 or less, ljl, which are by-produced in steel plants such as fine iron ore, blast furnace dust, converter dust, and rolling sludge, are used.
100 parts, add 5 to 30 parts of a bituminous substance with a softening point of 200°C or less, such as coal pitch, petroleum pitch, or asphalt, and knead at a temperature 50°C or more higher than the softening point of the bituminous substance. A method for producing coke, which comprises blending the raw material for coke production with a binder in an amount of 20% or less in an outer frame to a coal blend to produce briquette coal, and carbonizing the briquette coal.