JP5505081B2 - Blast furnace charging raw material manufacturing method and blast furnace charging raw material manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for producing a blast furnace charging raw material that improves the strength of massive iron ore containing crystal water. Furthermore, it is related with the manufacturing method and manufacturing apparatus of a blast furnace charging raw material which improve the reducibility of the iron ore containing crystal water.

Lumped iron ore is often used in an amount of 10 to 20 mass% as a blast furnace charging raw material, and massive iron ore containing crystal water is also used. At this time, the massive iron ore is usually used after being sieved to a particle size of 10 mm or more and 30 mm or less in order to maintain good ventilation in the blast furnace.
A massive iron ore containing crystal water is immersed in molten plastic, and the molten plastic is infiltrated into pores in the iron ore generated by thermally decomposing and removing crystal water. Patent Document 1 describes a method for improving the reducibility.

JP 2008-1111168 A

Crystallized water contained in the massive iron ore begins to decompose from about 200 ° C. and is removed from the iron ore. When the crystal water contained in the iron ore is decomposed and removed, cracks occur in the iron ore, the amount of pores increases, and the strength decreases.
Therefore, when the massive iron ore containing crystal water is charged into the blast furnace and heated, and the crystal water contained in the iron ore is decomposed and removed, the strength of the iron ore decreases in the blast furnace. As a result, the iron ore is pulverized in the blast furnace, gas permeability in the blast furnace is inhibited, and blast furnace operation is inhibited.
In particular, a massive iron ore containing 4 mass% or more of crystal water, such as Australian limonite ore, is greatly reduced in strength after the crystal water is decomposed and removed, so that it contains 4 mass% or more of crystal water. Patent Document 1 describes that blast furnace operation is inhibited when the amount of iron ore used is increased. Here, the analysis of crystal water is based on the Karl Fischer method (JIS M8211).

  Patent Document 1 describes a method for improving the reduction powderability and reducibility of massive iron ore containing crystal water. The method described in Patent Document 1 is a process in which massive iron ore containing crystal water is heated to thermally decompose the crystal water, and the pores in the iron ore generated by the thermal decomposition and removal of the crystal water are melted. This is a method in which the process of infiltrating plastics is simultaneously advanced in one treatment tank.

Furthermore, in Patent Document 1, the thermal decomposition of crystal water in iron ore starts at about 200 ° C. and becomes active around 300 ° C., and the melting of plastic starts at about 150 ° C., depending on the type, It is described that gasification of plastic starts from about 400 ° C.
That is, in order to allow thermal decomposition of crystal water and penetration of plastic into iron ore simultaneously in one processing tank, it is considered necessary to control the temperature of the processing tank to 300 to 400 ° C.

  In order to increase the decomposition rate of crystallization water so that the crystallization water is sufficiently thermally decomposed and the treatment time is shortened, it is more desirable to set the temperature higher than 300 ° C. On the other hand, in order to suppress the gasification amount of the plastic, to secure a sufficient amount of the plastic that penetrates into the iron ore, and to increase the utilization efficiency of the plastic, the temperature of the treatment tank is further increased from 400 ° C. at which gasification starts. A lower temperature is more desirable.

  However, it is difficult to simultaneously increase the temperature at which the iron ore containing crystal water is heated and to decrease the temperature in order to suppress the amount of plastic gasification in one treatment tank.

  The present invention solves the above-mentioned problems in infiltrating plastics in order to use iron ore containing crystal water as a raw material for blast furnaces, and makes the iron ore contain a larger amount of plastic than before. It aims at providing the manufacturing method and manufacturing apparatus of the raw material of a blast furnace charge which can improve the intensity | strength at the time of blast furnace charge of a stone, and a reducibility.

The gist of the present invention is as follows.
(1) A step of heating iron ore containing crystal water, pyrolyzing and removing the crystal water, and generating pores inside the iron ore, and a molten plastic in the pores inside the generated iron ore. A method for producing a raw material charged in a blast furnace having a step of producing an iron ore infiltrated with a plastic, wherein the temperature at which the molten plastic is infiltrated is 200 to 350 ° C., and the crystal water A method for producing a raw material charged in a blast furnace, characterized in that a temperature at which pyrolysis is removed at 350 to 550 ° C.

( 2 ) The method for producing a blast furnace charging raw material according to (1 ), wherein the molten plastic is obtained after the plastic is heated to 200 to 350 ° C.

( 3 ) A blast furnace charging raw material manufacturing apparatus used in the method for manufacturing a blast furnace charging raw material according to (1) or (2) , wherein a plastic melting tank for heating and melting plastic at 200 to 350 ° C. An iron ore treatment tank that thermally decomposes and removes crystal water by heating iron ore containing crystal water to 350 to 550 ° C, and an iron ore from which crystal water is pyrolyzed and removed from the molten plastic in the plastic melting tank there manufacturing apparatus of high RoSoIri material you anda molten plastic transfer tube for transferring to the iron ore processing tank present.

  When the blast furnace charging raw material manufacturing method or manufacturing apparatus of the present invention is used, the plastic content in the iron ore is higher than before in order to infiltrate the plastic in order to use iron ore containing crystal water as a raw material for blast furnace. It is possible to improve the strength or strength and reducibility of the massive iron ore containing crystal water necessary for stable operation of the blast furnace.

: It is a figure which shows an example of the iron ore processing process which concerns on this invention. : It is a figure which shows the experimental apparatus in Examples 1-3. FIG. 4 is a diagram showing an experimental apparatus in Example 4 and Comparative Example 1.

  Even for iron ore containing crystal water, the strength of iron ore can be improved by infiltrating the molten plastic into the pores in the iron ore. The reduction rate of iron ore can be increased by reducing components such as min.

  In order to further improve the strength of the iron ore and increase the reduction rate of the iron ore, it is desirable to infiltrate the molten plastic into the pores in the iron ore as much as possible. Therefore, as a result of intensive studies by the present inventors, instead of simultaneously removing the water of crystallization in the iron ore and infiltrating the plastic as in the prior art, first the iron ore is heated and the crystallization water in the iron ore is removed. After removing and generating sufficient pores in the iron ore, it was found that it was effective to infiltrate the molten plastic into the pores, and the present invention was made.

  Here, the iron ore as referred to in the present invention is a massive iron ore that is charged directly into a blast furnace without being formed into pellets or sintered ore. This massive iron ore is usually aligned to a particle size of 10 to 30 mm by sieving.

  Iron ore containing 4 mass% or more of crystallization water is particularly pulverized due to strength reduction caused by thermal decomposition of crystallization water in the blast furnace. Therefore, iron ore containing 4 mass% or more of crystallization water is subjected to the above heat treatment. The effect of suppressing iron ore pulverization and avoiding abnormal blast furnace operation caused by pulverization is particularly great.

  As the plastic, polyethylene, polypropylene, polystyrene or a mixture containing these can be used, and used waste plastic is also included. It is economical to use used waste plastic, and it is possible to efficiently recycle resources.

Further, as a plastic, polyethylene, polypropylene, polystyrene or a mixture containing these is heated to cool a gas generated by thermal decomposition, and a solid or liquid product obtained at room temperature and mixed in whole or in part is used. It is also possible. The solid or liquid product obtained in this way at room temperature has a very low viscosity in the molten state at 200 ° C. or higher, and penetrates fine pores in iron ore well.
When pores generated in iron ore are fine, it is effective to use a solid or liquid product obtained by cooling the gas generated by such thermal decomposition as a plastic, or in a mixture of all or part of it. It is.

  Since the thermal decomposition reaction of crystal water in iron ore is more active as the temperature is higher, the higher the temperature at which the crystal water in iron ore is thermally decomposed, the better. In addition, since the plastic gasification reaction is more active at higher temperatures, it is desirable to melt by heating at a low temperature at which the plastic gasification reaction is slow.

  Thermal decomposition of crystal water in iron ore starts at around 200 ° C, and the rate of thermal decomposition of crystal water in iron ore increases from 350 ° C or higher. To shorten the heat treatment time, iron ore is heated at 350 ° C or higher. It is desirable to treat stone. However, although the heat decomposition rate of crystal water in iron ore increases as the temperature increases, heating to a temperature higher than 550 ° C. does not increase the energy consumption, but the heat decomposition rate of crystal water due to temperature rise. The heating temperature is desirably 550 ° C. or less because the increase effect is small.

  On the other hand, although the gasification temperature of plastic is about 400 ° C. depending on the type, it is desirable to perform the plastic melting treatment and the plastic infiltration treatment into iron ore at 350 ° C. or less where gasification does not occur much. . However, in order for the plastic to melt and easily penetrate into the pores in the iron ore, it is preferable to lower the viscosity of the molten plastic by heating the plastic to 200 ° C. or higher.

  In order to set the temperature at which the crystal water in the iron ore is thermally decomposed to 350 ° C. or more and 550 ° C. or less and the temperature for melting the plastic to 200 ° C. or more and 350 ° C. or less, Although it is possible to control the temperature by treating pyrolysis removal and plastic melting / penetration step by step, it is divided into two treatment tanks rather than treating them in stages. It is preferable to control the temperature in a bath.

For example, the iron ore processing process shown in FIG. 1 comprising a plastic melting tank 2 and an iron ore processing tank 4 is configured, and the plastic is heated and melted in the plastic melting tank 2, and crystal water is supplied in the iron ore processing tank 4. The iron ore contained is heated to thermally decompose and remove the crystal water, and the molten plastic is charged into the iron ore treatment tank 4 through the molten plastic conveying pipe 9 from the plastic melting tank 2 using the molten plastic conveying pump 7, and the iron ore is preliminarily provided. It is efficient to allow the molten plastic to permeate into the pores generated in the iron ore obtained by pyrolyzing and removing the crystal water in the treatment tank 4 in the iron ore treatment tank 4.
Conversely, iron ore having pores from which crystal water has been thermally decomposed and removed can be introduced into the molten plastic in the plastic melting tank 2, and the molten plastic can be permeated into the pores for treatment. .

In the process shown in FIG. 1, the gas-state plastic volatilized from the iron ore treatment tank 4 is condensed in the temperature-controlled plastic recovery tank 6 through the gaseous plastic transport pipe 11 and recovered in a liquid state.
The molten plastic recovered in the plastic recovery tank 6 is transferred to the plastic melting tank 2 through the molten plastic transfer pipe 10 by the molten plastic transfer pump 8. The gaseous plastic that volatilizes from the plastic collection tank 6 is collected and burned through the gaseous plastic transport pipe 13.
The gaseous plastic that evaporates from the plastic melting tank 2 is collected and burned through the gaseous plastic transport pipe 47.
In addition, the plastic raw material is charged from the plastic raw material tank 1 to the plastic melting tank 2, and the iron ore raw material is charged from the iron ore raw material tank 3 to the iron ore processing tank 4, respectively. It is collected in the stone product tank 5.

The temperature in the iron ore treatment tank 4 when the molten plastic is infiltrated into the pores in the iron ore generated by thermally decomposing and removing the crystal water may be 200 ° C. or more at which the viscosity of the plastic becomes sufficiently low. desirable.
In addition, the iron ore containing crystal water is first heated in the iron ore treatment tank 4 and then the molten plastic is infiltrated into the pores in the iron ore in the iron ore treatment tank 4. If the temperature to be raised is increased, the crystal water remaining in the process of first pyrolyzing and removing is further thermally decomposed in the process of infiltrating the plastic and new cracks are generated. Thus, when new crack generation and plastic infiltration progress simultaneously, the penetration of the plastic is hindered by the vapor generated by the decomposition of crystal water, so that the plastic does not sufficiently penetrate into the newly generated crack.
Therefore, the temperature in the iron ore treatment tank 4 when the molten plastic is infiltrated is first heated by heating the iron ore containing crystal water so that no new cracks are generated when the plastic is infiltrated. The temperature in the iron ore processing tank 4 when the heat is removed by pyrolysis is set to be equal to or lower than the temperature.

  Furthermore, in order to allow the molten plastic to sufficiently permeate and contain pores in the iron ore produced by pyrolytic removal of crystal water, the temperature in the iron ore treatment tank 4 is vigorously increased. It is desirable that the temperature be 350 ° C. or less, which does not occur in

  Note that the gas generated when the plastic is heated in the plastic melting tank 2 is discharged through a gaseous plastic discharge pipe 12 and recovered or burned, for example, as shown in FIG. The gas generated when iron ore is heated in the iron ore processing tank 4 or the gas generated when molten plastic permeates the iron ore is, for example, 90 through the gaseous plastic transport pipe 11 as shown in FIG. The molten plastic is recovered in the plastic recovery tank 6 kept at a temperature of from 200 to 200 ° C. as molten plastic, and the molten plastic is transported to the plastic melting tank 2 through the molten plastic transport pipe 10 using the molten plastic transport pump 8. The temperature of the plastic recovery tank 6 is preferably 90 ° C. or higher so that water vapor derived from crystal water or the like does not condense, and 200 ° C. or lower in order to condense and recover the gaseous plastic efficiently. Is preferred.

  The plastic which is condensed and recovered after gasification is a liquid having a low viscosity at 90 ° C. to 200 ° C., and it is 90 ° C. to 90 ° C. to be transferred to the plastic melting tank 2 through the molten plastic transfer pipe 10 using the molten plastic transfer pump 8. Possible at 200 ° C. The gas that is not recovered in the plastic recovery tank 6 is discharged through the gaseous plastic discharge pipe 13 and recovered or burned. Excess molten plastic remaining in the iron ore treatment tank 4 after infiltrating the molten plastic into the iron ore in the iron ore treatment tank 4 is a molten plastic conveyance pump 7 capable of conveying the molten plastic from the iron ore treatment tank 4 in both directions. Alternatively, it is conveyed to the plastic melting tank 2 through the molten plastic conveying pipe 9 using a separately provided molten plastic conveying pump.

Examples of the method for producing a blast furnace charging raw material for improving the strength of the iron ore according to the present invention and the method for producing a blast furnace charging raw material for improving the reducibility will be described below.
Example 1
Using the test apparatus shown in FIG. 2, the iron ore after the thermal decomposition removal of the crystal water is infiltrated with plastic, and the strength and reducibility of the iron ore infiltrated with the plastic is iron ore containing the original crystal water. It was confirmed that it improved more.
As the iron ore, a massive iron ore having a particle diameter of 15 to 20 mm containing 8 mass% of crystal water was used. The analysis of crystal water is based on the Karl Fischer method (JIS M8211). The plastic used was a waste plastic containing 29 mass% polyethylene, 24 mass% polypropylene, and 28% polystyrene. The remaining components are other plastics such as polyvinyl chloride and impurities.

The test method for evaluating the strength of the iron ore was based on the method of indexing as RDI (Reduction Degradation Index) by the reduced powdering test method of sintered ore. That is, a reducing gas (CO = 30 vol%, N ₂ = 70 vol%) is used to reduce a sample of 500 g having a size of 15 to 20 mm at 550 ° C. for 30 minutes and cool it, and at a small rotating drum at 30 revolutions per minute. After rotating for 30 minutes, it was sieved and evaluated with a powder rate of 3 mm or less.

The test method for evaluating the reducibility of iron ore was based on the iron ore reduction test method (JIS M 8713). However, as a condition different from this iron ore reduction test method (JIS M 8713), an iron ore sample having a size of 15 to 20 mm was used. That is, a reducing gas (CO = 30 vol%, N ₂ = 70 vol%) was used to reduce a 500 g sample having a size of 15 to 20 mm at 900 ° C. for 180 minutes to obtain the reduction rate.

Based on FIG. 2, a method of infiltrating the plastic after heat-treating iron ore containing crystal water will be described.
A massive iron ore having a particle size of 15 to 20 mm containing 8 mass% of crystal water is charged into the iron ore treatment tank 23. Waste plastic containing 29 mass% of polyethylene, 24 mass% of polypropylene, and 28% of polystyrene is charged into the plastic raw material tank 21 and charged into the plastic melting tank 22 from the plastic raw material tank 21.

  The iron ore treatment tank 23 installed in the electric furnace was heated to 550 ° C., and the crystal water of the iron ore in the iron ore treatment tank 23 was removed by thermal decomposition. The plastic melting tank 22 installed in the electric furnace was heated to 250 ° C., the waste plastic in the plastic melting tank 22 was melted, and the molten plastic in the plastic melting tank 22 was stirred by the stirrer 31.

  First, as a first operation, 250 ° C. molten plastic in the plastic melting tank 22 was conveyed to the iron ore processing tank 23 through the molten plastic conveying pipe 41 using the molten plastic conveying pump 28. Next, as a second operation, the molten plastic in the iron ore processing tank 23 was conveyed to the plastic melting tank 22 using the molten plastic conveying pump 29 through the molten plastic conveying pipe 42. As a third operation, waste plastic was charged into the plastic melting tank 22 from the plastic raw material tank 21. This three-stage operation was repeated until the temperature in the iron ore treatment tank 23 reached 350 ° C., and the infiltration treatment was performed at 350 ° C.

The plastic in the gas state that volatilizes from the iron ore processing tank 23 is condensed in the plastic recovery tank 24 whose temperature is controlled to 150 ° C. through the gaseous plastic transport pipe 43 and recovered in the liquid state.
The molten plastic recovered in the plastic recovery tank 24 is transferred to the plastic melting tank 22 by the molten plastic transfer pump 30 through the molten plastic transfer pipe 46. The plastic in the gas state that volatilizes from the plastic recovery tank 24 is a plastic recovery tank 25 that is temperature-controlled to room temperature through a gaseous plastic transport pipe 44, part of which is condensed and recovered in a liquid state, and the rest is the plastic recovery tank Since it volatilizes from 25, it is led through a gaseous plastic discharge pipe 45 to a combustion-dissipating device for processing.

  The plastic in the gaseous state that volatilizes from the plastic melting tank 22 is a plastic recovery tank 26 that is temperature-controlled to a room temperature through a gaseous plastic transport pipe 47, and is partially condensed and recovered in a liquid state, and the rest is a plastic recovery tank. Since it volatilizes from 26, it is led through a gaseous plastic discharge pipe 48 to a combustion-dissipating device for processing.

  After performing the permeation treatment at 350 ° C., surplus molten plastic remaining in the iron ore treatment tank 23 is conveyed to the plastic melting tank 22 through the molten plastic conveyance pipe 42 using the molten plastic conveyance pump 29. At the end of the experiment, the molten plastic in the plastic melting tank 22 is collected in the molten plastic receiving tank 27.

After the iron ore treatment tank 23 was cooled to room temperature, the iron ore infiltrated with the plastic was taken out from the iron ore treatment tank 23 and evaluated for strength and reducibility.
Table 1 shows the evaluation results of the iron ore containing 8 mass% of crystal water before treatment and the evaluation results of the plastic infiltration treated ore.

  As an index of the plastic content in the iron ore, the carbon (C) content (mass%) in the plastic infiltrated ore was 10.4%. Compared to iron ore containing 8 mass% of crystal water before treatment, the plastic permeation ore has a quality improvement effect that RDI is reduced and the reduction rate is increased. At this time, the iron ore treatment tank was heated from room temperature to 550 ° C., the iron ore treatment tank was set to 350 ° C., and the treatment time required for the infiltration treatment was 45 minutes.

  The recovery rate of plastic recovered in the plastic recovery tank 25, plastic recovery tank 26, and molten plastic receiving tank 27 with respect to the amount of plastic charged from the plastic raw material tank 21 into the plastic melting tank 22 was 78%.

(Example 2)
Based on FIG. 2, a method of infiltrating the plastic after heat-treating iron ore containing crystal water will be described.
A massive iron ore having a particle size of 15 to 20 mm containing 8 mass% of crystallization water of the same type as the iron ore used in Example 1 was charged in the iron ore treatment tank 23 with a weight equal to that in Example 1. Waste plastic containing the same type of waste plastic used in Example 1 and containing 29 mass% polyethylene, 24 mass% polypropylene, and 28% polystyrene is charged into the plastic raw material tank 21, and is carried out from the plastic raw material tank 21 to the plastic melting tank 22. A weight equal to Example 1 was charged.

The iron ore treatment tank 23 was heated to 300 ° C., and the crystal water of iron ore in the iron ore treatment tank 23 was removed by thermal decomposition. The plastic melting tank 22 was heated to 300 ° C., the waste plastic in the plastic melting tank 22 was melted, and stirred with the stirrer 31.
The 300 degreeC molten plastic in the plastic melting tank 22 was conveyed to the iron ore processing tank 23 like Example 1, and the temperature in the iron ore processing tank 23 was 300 degreeC, and the infiltration process was implemented.

In the same manner as in Example 1, the plastic in the gas state that volatilizes from the iron ore processing tank 23 was condensed in the plastic recovery tank 24, recovered in a liquid state, and transported to the plastic melting tank 22. In the same manner as in Example 1, the plastic in the gas state that volatilizes from the plastic recovery tank 24 was partially condensed and recovered in the liquid state in the plastic recovery tank 25, and the rest was led to the combustion-dissipating device for processing.
In the same manner as in Example 1, the plastic in the gas state that volatilizes from the plastic melting tank 22 was partly condensed and recovered in a liquid state in the plastic recovery tank 26, and the rest was guided to the combustion-dissipating device.

After carrying out the infiltration treatment at 300 ° C., surplus molten plastic remaining in the iron ore treatment tank 23 is transported to the plastic melting tank 22 in the same manner as in Example 1, and the plastic melting tank 22 is transferred to the plastic melting tank 22 at the end of the experiment. A certain molten plastic was recovered in the molten plastic receiving tank 27.
After cooling the iron ore treatment tank 23 to room temperature, the strength and reducibility of the iron ore infiltrated with the plastic were evaluated in the same manner as in Example 1.
The evaluation results are shown in Table 2.

The plastic infiltration treated ore has a quality improvement effect that RDI is reduced and the reduction rate is increased compared to iron ore containing 8 mass% of crystal water before treatment. It did not reach.
The reason why the quality improvement effect of Example 1 was not achieved was that the crystal water of iron ore was not sufficiently thermally decomposed and removed, so that the occurrence of cracks was small and the amount of penetration of the plastic was small, and 550 in the RDI test. This is probably because the remaining iron ore crystal water was thermally decomposed and removed during the reduction at ℃, resulting in a new crack and a decrease in iron ore strength.

  The recovery rate of the recovered plastic with respect to the amount of plastic input as in Example 1 was 79%.

(Example 3)
Based on FIG. 2, a method of infiltrating the plastic after heat-treating iron ore containing crystal water will be described.
A massive iron ore having a particle size of 15 to 20 mm containing 8 mass% of crystallization water of the same type as the iron ore used in Example 1 was charged in the iron ore treatment tank 23 with a weight equal to that in Example 1. Waste plastic containing the same type of waste plastic used in Example 1 and containing 29 mass% polyethylene, 24 mass% polypropylene, and 28% polystyrene is charged into the plastic raw material tank 21, and is carried out from the plastic raw material tank 21 to the plastic melting tank 22. A weight equal to Example 1 was charged.

  The iron ore treatment tank 23 was heated to 400 ° C., and the crystal water of iron ore in the iron ore treatment tank 23 was removed by thermal decomposition. The plastic melting tank 22 was heated to 400 ° C., the waste plastic in the plastic melting tank 22 was melted, and stirred with the stirrer 31.

  400 degreeC molten plastic in the plastic melting tank 22 was conveyed to the iron ore processing tank 23 similarly to Example 1, and the temperature in the iron ore processing tank 23 was 400 degreeC, and the infiltration process was implemented.

In the same manner as in Example 1, the plastic in the gas state that volatilizes from the iron ore processing tank 23 was condensed in the plastic recovery tank 24, recovered in a liquid state, and transported to the plastic melting tank 22. In the same manner as in Example 1, the plastic in the gas state that volatilizes from the plastic recovery tank 24 was partially condensed and recovered in the liquid state in the plastic recovery tank 25, and the rest was led to the combustion-dissipating device for processing.
In the same manner as in Example 1, the plastic in the gas state that volatilizes from the plastic melting tank 22 was partly condensed and recovered in a liquid state in the plastic recovery tank 26, and the rest was guided to the combustion-dissipating device.

After carrying out the infiltration treatment at 400 ° C., surplus molten plastic remaining in the iron ore treatment tank 23 is transferred to the plastic melting tank 22 in the same manner as in Example 1, and in the plastic melting tank 22 at the end of the experiment. A certain molten plastic was recovered in the molten plastic receiving tank 27.
After cooling the iron ore treatment tank 23 to room temperature, the strength and reducibility of the iron ore infiltrated with the plastic were evaluated in the same manner as in Example 1.
The evaluation results are shown in Table 3.

  The plastic infiltration treated ore has a quality improvement effect that RDI is reduced and the reduction rate is increased compared to iron ore containing 8 mass% of crystal water before treatment. It did not reach. The cause that did not reach the quality improvement effect of Example 1 was that the penetration temperature in the iron ore treatment tank 23 was high, and part of the plastic that had penetrated into the iron ore was gasified. This is thought to be due to the decrease.

The recovery rate of the recovered plastic was 70% with respect to the amount of plastic input as in Example 1.
The cause of this is that the weight of the plastic in the gas state that volatilizes from the plastic melting tank 22 increases, and the amount of the plastic in the gas state that is not recovered in the plastic recovery tank 26 but processed from the gaseous plastic discharge pipe 48 by the combustion-dissipating device. This is thought to be due to the increase.

(Example 4)
Based on FIG. 3, a method of infiltrating the plastic after heat-treating iron ore containing crystal water will be described.
The same ore as the plastic raw material tank 21, the iron ore processing tank 23, the plastic recovery tank 26, and the molten plastic receiving tank 27 used in Example 1 is used, and using the test apparatus shown in FIG. The stone was infiltrated with plastic, and the strength and reducibility of the iron ore infiltrated with plastic were evaluated. In this example, the iron ore processing tank 23 of Example 1 was used as the iron ore processing tank / plastic melting tank 23 '.

  The same kind of iron ore used in Example 1 and a massive iron ore containing 15 mass% of crystal water and having a particle size of 15 to 20 mm are placed in an iron ore treatment tank / plastic melting tank 23 ′ with a weight equal to that of Example 1. I entered. Waste plastic containing the same type of waste plastic used in Example 1 and containing 29 mass% of polyethylene, 24 mass% of polypropylene, and 28% of polystyrene was charged into the plastic raw material tank 21.

  The iron ore treatment tank / plastic melting tank 23 ′ was heated to 550 ° C., and the crystal water of iron ore in the iron ore processing tank / plastic melting tank 23 ′ was removed by thermal decomposition.

  Next, the plastic was charged from the plastic raw material tank 21 into the iron ore processing tank / plastic melting tank 23 '. The iron ore treatment tank / plastic melting tank 23 'is stopped heating and cooling by natural cooling is combined with the iron ore treatment tank / plastic melting tank 23' heating by an electric furnace to produce an iron ore treatment tank / plastic melting tank. The temperature in 23 ′ was controlled at 350 ° C., and the plastic was infiltrated into the iron ore at 350 ° C.

The plastic in the gas state that volatilizes from the iron ore processing tank / plastic melting tank 23 ′ is partly condensed and recovered in the liquid state in the plastic recovery tank 26 that is temperature-controlled to the room temperature through the gaseous plastic transport pipe 47. The remainder is volatilized from the plastic recovery tank 26, and this was led to the combustion and diffusion device through the gaseous plastic discharge pipe 48 for processing.
After carrying out the permeation treatment at 350 ° C., excess molten plastic remaining in the iron ore treatment tank / plastic melting tank 23 ′ was recovered in the molten plastic receiving tank 27 at the end of the experiment.

After the iron ore treatment tank / plastic melting tank 23 'is cooled to room temperature, the iron ore infiltrated with the plastic is taken out from the iron ore processing tank / plastic melting tank 23', and the strength and reducibility are the same as in Example 1. Evaluated.
The evaluation results are shown in Table 4.

  The plastic infiltrated ore had a lower RDI and an increased reduction rate than iron ore containing 8 mass% of crystal water before treatment. The quality improvement effect was almost the same as in Example 1. However, the iron ore treatment tank at this time was heated from room temperature to 550 ° C. and the iron ore treatment tank was brought to 350 ° C., and the treatment time required for the permeation treatment was 115 minutes. Since only the iron ore treatment tank / plastic melting tank 23 'performs the thermal decomposition treatment of crystal water, the plastic melting treatment, and the plastic penetration treatment into the ore, the treatment time becomes longer and the efficiency of the penetration treatment is reduced. occured.

(Comparative Example 1)
Based on FIG. 3, a method for infiltrating plastic into iron ore containing crystal water will be described.
Using the test apparatus shown in FIG. 3 used in Example 4, the iron ore containing crystal water was infiltrated with plastic, and the strength and reducibility of the iron ore infiltrated with the plastic were evaluated.

  The same kind of iron ore used in Example 1 and a massive iron ore containing 15 mass% of crystal water and having a particle size of 15 to 20 mm are placed in an iron ore treatment tank / plastic melting tank 23 ′ with a weight equal to that of Example 1. I entered. Waste plastic containing the same type of waste plastic used in Example 1 and containing 29 mass% of polyethylene, 24 mass% of polypropylene, and 28% of polystyrene was charged into the plastic raw material tank 21.

  Subsequently, the plastic from the plastic raw material tank 21 is charged into the iron ore processing tank / plastic melting tank 23 ′, the temperature in the iron ore processing tank / plastic melting tank 23 ′ is controlled to 450 ° C., and the iron ore is heated at 450 ° C. The plastic was infiltrated into the stone.

In the same manner as in Example 4, the plastic in the gas state that volatilizes from the iron ore processing tank / plastic melting tank 23 'is partially condensed and recovered in the liquid state in the plastic recovery tank 26, and the rest is led to the combustion-dissipating device. And processed.
After carrying out the infiltration treatment at 450 ° C., excess molten plastic remaining in the iron ore treatment tank / plastic melting tank 23 ′ was recovered in the molten plastic receiving tank 27 at the end of the experiment.

After the iron ore treatment tank / plastic melting tank 23 ′ was cooled to room temperature, the iron ore infiltrated with the plastic was taken out from the iron ore treatment tank / plastic melting tank 23 ′, and the strength and reducibility were evaluated.
The evaluation results are shown in Table 5.

  The plastic infiltrated ore obtained a quality improvement effect in which RDI decreased and the reduction rate increased compared to iron ore containing 8 mass% of crystal water before treatment, but the quality improvement effect of Examples 1 to 4 It did not reach. The cause that did not reach the quality improvement effect of Examples 1 to 4 is that when the osmosis treatment is performed in the iron ore treatment tank / plastic melting tank 23 ', thermal decomposition of crystal water occurs at the same time. This is thought to be because the penetration of the plastic into the iron ore was hindered by the generated crystal water vapor.

DESCRIPTION OF SYMBOLS 1 Plastic raw material tank 2 Plastic melting tank 3 Iron ore raw material tank 4 Iron ore processing tank 5 Iron ore product tank 6 Plastic recovery tank 7 Molten plastic conveyance pump 8 Molten plastic conveyance pump 9 Molten plastic conveyance pipe
10 Molten plastic transfer pipe
11 Gaseous plastic transport pipe
12 Gaseous plastic discharge pipe
13 Gaseous plastic discharge pipe
21 Plastic raw material tank
22 Plastic melting tank
23 Iron ore processing tank
23 'Iron ore processing tank and plastic melting tank
24 Plastic collection tank
25 Plastic collection tank
26 Plastic collection tank
27 Molten plastic receiving tank
28 Molten plastic transfer pump
29 Molten plastic transfer pump
30 Molten plastic transfer pump
31 Stirrer
41 Molten plastic transfer pipe
42 Molten plastic transfer tube
43 Gaseous plastic transport pipe
44 Gaseous plastic transfer pipe
45 Gaseous plastic discharge pipe
46 Molten plastic transfer pipe
47 Gaseous plastic transport pipe
48 Gaseous plastic discharge pipe

Claims (3)

Heating the iron ore containing crystal water, pyrolyzing and removing the crystal water, and generating pores inside the iron ore, and infiltrating the molten plastic into the pores inside the iron ore generated , A process for producing iron ore infiltrated with plastic, and a blast furnace charging raw material in order , wherein the temperature when impregnating the molten plastic is 200 to 350 ° C., and the crystal water is pyrolyzed The manufacturing method of the raw material charged with a blast furnace characterized by making the temperature at the time of removal into 350-550 degreeC . The method for producing a raw material charged in a blast furnace according to claim 1, wherein the molten plastic is obtained after heating the plastic to 200 to 350 ° C. A blast furnace charging raw material manufacturing apparatus used in the method for manufacturing a blast furnace charging raw material according to claim 1 or 2 , comprising a plastic melting tank for heating and melting plastic at 200 to 350 ° C, and crystal water. The iron ore treatment tank that thermally decomposes and removes the crystal water by heating the iron ore to 350 to 550 ° C., and the iron ore in which the iron ore in which the crystal water is pyrolyzed and removed from the molten plastic in the plastic melting tank exists high RoSoIri material production apparatus you anda molten plastic transfer tube for transferring the stone processing tank.

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