JP2000256504A - Crushing of plastic and solid fuel and ore reducing agent obtained by the crushing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and efficiently crush a plastic material to fine powder by mixing a plastic material with coal and crushing the mixture. SOLUTION: (A) A plastic material such as polyethylene is mixed with (B) coal at a B/A weight ratio of preferably 95/5-5/95, more preferably 80/20-20/80 and the mixture is crushed with a hammer mill, etc., to effect the crushing of the plastic material. The crushed mixture of plastic material and coal obtained by this process is useful as a solid fuel for boiler, kiln, cupola, etc., having excellent transportability, storability and combustibility and an ore- reducing agent for a vertical furnace for the production of pig iron for blast furnace, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for pulverizing plastic, a solid fuel produced by the pulverization method, a reducing agent for ore, and a method for injecting pulverized plastic into a compact furnace.

[0002]

2. Description of the Related Art In recent years, a large amount of waste plastic has been discharged along with an increase in the amount of plastic used, and its disposal has become a major social problem. As one of means for effectively utilizing waste plastics without reclamation or incineration, a method of using waste plastics as a solid fuel is known.

[0003] That is, a method of pulverizing waste plastic into a solid fuel (see Japanese Patent Application Laid-Open No. 4-332792), pulverizing a solid obtained by heating and melting the waste plastic in the presence of a solvent, and then cooling and solidifying. (See Japanese Patent Publication No. 57-16160). On the other hand, when using waste plastic as a solid fuel, it is necessary to sufficiently pulverize it to improve transportability, storage properties, flammability, and the like.

However, plastics are not always excellent in pulverizability because plastics are tough and excellent in ductility and are easily softened by frictional heat during pulverization. Therefore, in order to obtain finely divided solid fuel and ore reducing agent from plastic,
Long time grinding and cooling are required. For this reason, it has been difficult to easily obtain a powdered solid fuel or a reducing agent for ore.

As a method for improving the pulverizability of plastics, a method of adding water at the time of pulverization to prevent softening due to frictional heat at the time of pulverization, and a method of adding a pulverization accelerator such as a thermosetting resin (Japanese Patent Application Laid-Open No. 8-16969). Is known.
However, in the former method, it is necessary to dry the obtained fine powder before using it as a fuel or a reducing agent for ore, and in the latter method, it is necessary to add an expensive thermosetting resin. However, there is a problem in economy, and the pulverizability is insufficient.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a method of pulverizing a plastic capable of easily pulverizing the plastic, the transportability produced by the pulverization method, Storage property, providing a finely divided solid fuel excellent in flammability, ore reducing agent, and
An object of the present invention is to provide a method for blowing a pulverized plastic into a compact furnace.

[0007]

Means for Solving the Problems The present inventors have studied various methods to achieve the above-mentioned object, and as a result, have found that by pulverizing plastic together with coal, plastic can be efficiently pulverized. . That is, it has been found that when the plastic is pulverized together with the coal, the hard and brittle pulverized pieces of the coal accelerate the pulverization of the plastic and can obtain a finer pulverized plastic which is extremely fine compared to the case where the plastic is pulverized alone.

[0008] The mixed fine powder of plastic and coal obtained by the above method is excellent in transportability, storability and flammability, and is suitable for solid fuels such as boilers, kilns and cupolas, and pig irons such as blast furnaces. It has been found that it is extremely useful as a reducing agent for ores in a mold furnace. That is, the first invention is
This is a method of pulverizing plastic, which comprises mixing and pulverizing plastic with coal.

In the first aspect of the present invention, it is preferable that the coal / plastic [weight ratio], which is a mixing ratio of coal and plastic, is 95/5 to 5/95 (the first aspect of the first aspect of the invention). Preferred embodiment). Further, the first invention described above,
In a first preferred aspect of the first invention, the plastic is heat-treated before being mixed with coal, and then cooled,
It is preferably a plastic heat-treated product obtained by solidification (second preferred embodiment and third preferred embodiment of the first invention).

[0010] In the first invention and the first preferred embodiment of the first invention, the plastic is mixed with an organic solvent in advance before mixing with coal.
Preferably, the mixture is heat-treated and then cooled and solidified to obtain a heat-treated plastic (fourth and fifth preferred embodiments of the first invention). In the fourth preferred embodiment and the fifth preferred embodiment of the first invention, the organic solvent is preferably a petroleum organic solvent and / or a coal organic solvent. Sixth
Preferred embodiment, seventh preferred embodiment).

[0011] The second invention is the first invention, the first invention described above.
A solid fuel characterized by being a mixed and crushed product of plastic and coal obtained by the method for pulverizing plastic according to any one of the first to seventh preferred embodiments of the present invention. A third invention is a mixed and crushed product of plastic and coal obtained by the method for crushing a plastic according to any one of the first to seventh aspects of the first invention and the first invention. An ore reducing agent characterized by the following.

A fourth invention is the first invention, the first invention described above.
Blowing the mixed and crushed product of plastic and coal obtained by the method for crushing plastic according to any one of the first preferred embodiment to the seventh preferred embodiment of the present invention into a raceway of a hard furnace for producing pig iron. This is a method of injecting pulverized plastic into a rigid furnace. In addition, the first
In each of the preferred embodiments of the invention to the fourth invention and the first to fourth inventions, the plastic and coal are supplied to a pulverizer in advance by mixing a mixture obtained by previously mixing the plastic and coal, and pulverizing the mixture. Alternatively, plastic and coal may be separately supplied to a pulverizer and then pulverized in a mixed state.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention relates to the present invention.
I. Plastics, II. Heat treatment, III. Coal, IV. Grinding method, V. Solid fuel and ore reducing agent will be described in more detail. [I. Plastics] As the plastics targeted by the present invention, in addition to a single kind of plastic or a mixture of a plurality of kinds of plastics, waste plastics and container / packaging materials contained in municipal solid waste, industrial waste, etc., and electricity Waste plastics generated during the dismantling process of products and automobiles can be used.

More specifically, the present invention can be applied to all plastics such as polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, polycarbonate, nylon and other thermoplastic resins, and thermosetting resins. Also,
One or more of the above plastics can be used.

Further, the plastic may contain a plastic containing a halogen element such as polyvinyl chloride, polyvinylidene chloride and chlorinated polyethylene. In this case, it is preferable to previously heat and melt the plastic at a temperature of 150 ° C. or more, and to dehalogenate the halogen as hydrogen halide such as hydrogen chloride. This is because, when a halogen element is contained in the pulverized plastic, the furnace may be damaged or the refractory in the furnace may be eroded when used as a solid fuel or a reducing agent for ore.

In plastics, paper, fibers, woods, and the like other than plastics are used as long as the crushability and flammability are not impaired.
Glasses, metals and the like may be included, but before pulverization according to the method of the present invention, by hand sorting or magnets, or by using a wind force to remove the minimum amount of these foreign substances, or, When the plastic is melted during the heat treatment described below, it is also possible to remove these foreign substances by filtration or the like.

[II. Heat Treatment] In the present invention, it is preferable to use, as the plastic, a plastic heat-treated product obtained by preliminarily heat-treating and cooling the plastic before mixing and pulverizing it with coal. This is because the heat treatment improves the pulverizability of the plastic, and when the plastic contains a halogen element, dehalogenation can be performed.

In the present invention, in order to improve the crushability of the plastic and obtain a high dehalogenation rate, the heat treatment temperature is
The temperature is preferably 150 ° C or higher, more preferably 150 to 400 ° C. When the heat treatment temperature is lower than 150 ° C, the effect of improving the pulverizability is small. Conversely, when the heat treatment temperature exceeds 400 ° C,
Oilification and gasification of plastics progress, and the yield of the plastic heat-treated product obtained as a solid decreases.

In addition, the heat treatment is performed because of easy stirring.
Preferably, the reaction is performed in the presence of an organic solvent. The weight ratio of the organic solvent to the plastic in the mixture of the plastic and the organic solvent, that is, the preferred range of the organic solvent / plastic [weight ratio] is 0.1 to 10, more preferably 0.1 to 10.
It is in the range of 5-5.

When the weight ratio is less than 0.1, the viscosity of the system becomes high, handling becomes difficult, and dehalogenation hardly occurs. On the other hand, if the weight ratio exceeds 10, it is disadvantageous in terms of the size of the reaction vessel and the distillation cost for removing the organic solvent from the plastic processing product. The type of the organic solvent is not particularly limited as long as it dissolves and / or swells the plastic. However, petroleum organic solvents and / or coal-based organic solvents are preferred in terms of availability, price, and the like. It is preferable to use a solvent.

Also, when an organic solvent is used, the heat treatment temperature should be set to improve the solubility and agitation of the plastic.
The temperature is preferably 150 ° C or higher, more preferably 150 to 400 ° C. If the heat treatment temperature when using an organic solvent is less than 150 ° C, the effect of improving the solubility and agitating properties of the plastic is small, and if it exceeds 400 ° C, it becomes difficult to cool and reflux the evaporating organic solvent. As the oil and gasification of the plastic progress, the yield of the heat-treated plastic obtained as a solid decreases.

As the organic solvent, it is preferable to use an organic solvent having a boiling point of 150 ° C. or higher. Therefore, as the petroleum organic solvent, it is more preferable to use one or more selected from A heavy oil, C heavy oil, light oil and kerosene. As the coal-based organic solvent, it is preferable to use coal-based tar and / or a distillate of coal-based tar.

Specific examples of the coal-based organic solvent include coal-based tar, crude naphtha oil which is a distillate of coal-based tar,
Suitable are naphthalene washing oil, creosote oil and anthracene oil. These solvents may be used alone, or two or more of them may be used as a mixture.

According to the present invention, by heating the plastic in a state of being mixed with the organic solvent, the viscosity of the system is reduced, and not only the stirring of the object to be treated becomes easy, but also the uniform heating becomes possible. Excessive decomposition and oiling of plastic due to local heating can be suppressed, and the yield of solids can be increased. When an organic solvent is used, after the heat treatment, the used organic solvent is not removed, and the mixture is cooled and solidified, pulverized by the method of the present invention, and may be used as a solid fuel or a reducing agent for ore. Some or all of the solvent may be recovered by distillation and reused.

As the distillation method, any of normal pressure distillation and reduced pressure distillation may be used, but reduced pressure distillation is preferred because the removal rate of low boiling components is high. In the present invention, when the residual amount of the organic solvent in the obtained solid is reduced, it is possible to prevent secondary aggregation of the particles during and after the pulverization of the heat-treated plastic.

The residual amount of the organic solvent in the solid is not particularly limited, but is preferably in the range of 0.5 to 50% by weight from the viewpoint of prevention of secondary aggregation and economy. In the present invention, when heat treatment is performed, plastics and waste plastics as raw materials can be treated as they are. However, in order to facilitate supply into a reaction vessel for heat treatment, it is preferable to carry out coarse pulverization in advance.

[III. Coal:] The type of coal used in the present invention is not particularly limited, and any type of coal may be used. Specifically, for example, one or more selected from bituminous coal, anthracite, peat, lignite, and lignite can be used.

Of these, it is particularly preferable to use bituminous coal and / or anthracite in view of combustibility and the effect of promoting pulverization. The mixing ratio of coal and plastic at the time of pulverization is not particularly limited, but preferably, the mixing ratio of coal / plastic [weight ratio] of coal and plastic is preferably 95/5 to 5/95. More preferably, the weight ratio is from 80/20 to 20/80.

When the weight ratio is less than 5/95, it is difficult to obtain a sufficient effect of improving the pulverizability of the plastic accompanying the mixing and pulverization with coal. Conversely, when the weight ratio exceeds 95/5, It is not preferable because the pulverization amount of the plastic decreases. [IV. Pulverizing method:] In the present invention, the plastic and coal may be supplied to a pulverizer in advance by mixing the plastic and coal, and the plastic and coal may be pulverized. After supplying separately, the mixture may be pulverized in a mixed state.

As the pulverizer, any type of pulverizer may be used, for example, a hammer mill, a bin mill, a jet mill, a ball mill, a vibrating ball mill, a centrifugal ball mill, or the like. In particular, as a method for obtaining fine powder, it is preferable to use a hammer mill or a vibration ball mill.

The particle size of the mixed fine powder of plastic and coal obtained in the present invention is as follows: 80% sieve diameter [: D (8
0)], preferably D (80) is 1.5 mm or less,
More preferably, D (80) is 1.2 mm or less. This is because when D (80) is 1.5 mm or less, the pulverized product of the present invention excellent in all of transportability, storability and flammability can be obtained.

[V. Reducing agent for solid fuel and ore:] According to the present invention, very fine powdery combustibility, storage property,
A solid fuel and a reducing agent for ore having excellent transportability can be obtained. That is, for example, an 80% passing sieve diameter [:
D (80)], a solid fuel and a reducing agent for ore having excellent flammability, storability and transportability of 1.5 mm or less can be obtained.

The pulverized product obtained by the present invention is
Since it is mixed with coal and has excellent flammability, boilers,
It can be effectively used as a solid fuel for kilns, cupolas and the like, and as a reducing agent for iron ores in a solid furnace for producing pig iron such as a blast furnace. When used in the above-mentioned hardened furnace, it is also possible to charge from the furnace top of the hardened furnace, but from the viewpoint of utilization efficiency as an ore reducing agent and a fuel, the plastic and coal fine powder obtained by the present invention are used. It is preferable to blow the mixture into a raceway formed in front of the tuyere of the hard furnace.

It is also possible to blow a slurry obtained by mixing the fine powder mixture of plastic and coal obtained with the present invention with heavy oil into a raceway. As a method of blowing into the raceway, any of a blow pipe method and a tuyere blowing method can be used, and the blowing method is not particularly limited.

[0035]

EXAMPLES The present invention will be described below more specifically based on examples. First, a grindability evaluation test in this example will be described. [Pulverizability evaluation test:] A hammer mill type pulverizer (manufactured by Horai Iron Works) was equipped with a sieve with a mesh size of 2 mm (hole), and the sample was 300 g
And pulverized for 15 minutes, and the pulverized product (fine powder) was sieved on and under the sieve.

Further, under the sieve, the opening is 1.18 mm (square hole).
And a sieve having an opening of 0.6 mm (square hole). After the above sieving, the weight fraction of each of the four fractions having a particle size of more than 2 mm, a particle size of more than 1.18 mm, 2 mm or less, a particle size of more than 0.6 mm, 1.18 mm or less, and a particle size of 0.6 mm or less is measured. did.

Next, the following equation (1) [Rosin-Rammler-Bennet
Substituting the weight fraction and the sieve diameter of each of the above-obtained four fractions into the following equation (2) obtained by modifying the above equation, the proportional constant of the following equation (2) is obtained by the least square method. n and b were determined. R (Dp) = 100 · exp ｛− (Dp / De) ⁿ ｝ ……………… (1) log ｛log [100 / R (Dp)] ・ = n · logDp + log (b) …… ... (2) In the above formulas (1) and (2), R (Dp) is the weight% on the integrated sieve of the sieve Dp, and De is the particle size characteristic number [: a number corresponding to R (Dp) = 36.8% by weight] , N is an even number (: an index for evaluating the uniformity of the particle size distribution of the granular material), and b is a constant, which is an index for evaluating the fineness of the granular material.

Next, from the obtained linear equation, the diameter of the sieve through which 80% by weight of all the particles pass [the diameter of the sieve passing 80%, D (8
0), which was used as an index of the fineness of the pulverized particles. That is, the smaller the value of D (80), the better the pulverizability of the test sample. (Comparative Example 1) Coal (bituminous coal, about 5 cm square block) 30
The above-mentioned grindability evaluation test was performed on 0 g, and the 80% passing sieve diameter [: D (80)] was calculated.

The test results are shown in Table 1 and FIG. (Comparative Example 2) The above-mentioned grindability evaluation test was performed on 300 g of a commercially available polyethylene sheet cut into about 10 cm squares, and the 80% passing sieve diameter [: D (80)] was calculated. Table 1 shows the test results.

Comparative Example 3 A commercially available polyethylene sheet cut into about 10 cm squares, 100 g, a commercially available plate-like polypropylene cut into about 10 cm squares, 100 g, and a commercially available plate-like polystyrene, cut into about 10 cm squares The resulting plastic mixture was subjected to the above-described pulverizability evaluation test, and an 80% sieve diameter [: D (80)] was calculated.

Table 1 shows the test results. (Comparative Example 4) 180 g of polyethylene resin pellets, 156 g of polypropylene resin pellets, 216 g of polystyrene resin pellets, and pellets of polyethylene terephthalate resin
After mixing 12 g and 36 g of polyvinyl chloride resin pellets (all commercially available), the mixture was charged into a 2.5-liter stainless steel reaction vessel and stirred at a temperature of 320 ° C. for 3 hours.

Hydrogen chloride generated during heating and stirring was trapped in a water tank and titrated with a 2N-NaOH standard aqueous solution using phenolphthalein as an indicator. As a result, the amount of generated hydrochloric acid was 20.3 g, and the dechlorination rate calculated from the theoretical hydrochloric acid content was 93.5%. After completion of heating and stirring, the reaction vessel is cooled and a solid heat-treated product (plastic heat-treated product)
(A)).

The heat-treated plastic (A) obtained above
Approximately 300 g of the sieve was weighed and subjected to the crushability evaluation test described above, and the 80% passing sieve diameter [: D (80)] was calculated. Table 1 shows the test results. (Comparative Example 5) 180 g of polyethylene resin pellets, 156 g of polypropylene resin pellets, 216 g of polystyrene resin pellets, and pellets of polyethylene terephthalate resin
After mixing 12 g and 36 g of polyvinyl chloride resin pellets (all commercially available), the mixture was put into a 2.5-liter stainless steel reaction vessel together with 1200 g of heavy oil, and stirred at a temperature of 320 ° C. for 3 hours.

Hydrogen chloride generated during heating and stirring was trapped in a water bath and titrated with a 2N-NaOH standard aqueous solution using phenolphthalein as an indicator. As a result, the amount of generated hydrochloric acid was 21.2 g, and the dechlorination rate calculated from the theoretical hydrochloric acid content was 97.6%. After the heating and stirring, vacuum distillation was performed to remove about 1000 g of heavy oil, and then the reaction vessel was cooled and a solid heat-treated product (referred to as a plastic heat-treated product (B)) was taken out.

The heat-treated plastic (B) obtained above
Approximately 300 g of the sieve was weighed and subjected to the crushability evaluation test described above, and the 80% passing sieve diameter [: D (80)] was calculated. The test results are shown in Table 1 and FIG. (Comparative Example 6) A total of about 1 kg of plastic containers, plastic trays and wraps used at home were collected, washed with water,
After drying, it was ground to about 2 cm square.

Approximately 600 g of the pulverized material obtained was 1200 g of heavy oil.
And into a 2.5 l stainless steel reaction vessel.
Stirred at a temperature of ° C for 3 hours. Hydrogen chloride generated during heating and stirring was trapped in a water bath, and titrated with a 2N-NaOH standard aqueous solution using phenolphthalein as an indicator. As a result, the amount of generated hydrochloric acid was 10.5 g.

After heating and stirring, vacuum distillation was conducted to about 1000
After removing g of heavy oil, the reaction vessel was cooled and a solid heat-treated product (referred to as heat-treated plastic (C)) was taken out. Of the heat-treated plastic (C) obtained above,
Weigh 300 g and conduct the above-mentioned grindability evaluation test.
The passing sieve diameter [: D (80)] was calculated. Table 1 shows the test results.

(Comparative Example 7) 150 g of a commercially available polyethylene sheet cut to about 10 cm square and 150 g of a commercially available plate-like epoxy resin cut to about 10 cm square as a thermosetting resin
Was mixed, and the above-mentioned plastic mixture was subjected to the above-mentioned pulverizability evaluation test, and the 80% sieve diameter [: D (80)] was calculated.

Table 1 shows the test results. (Example 1) 150 g of the coal used in Comparative Example 1 and 150 g of the cut piece of the polyethylene sheet used in Comparative Example 2 were weighed and put into a pulverizer, and the above-mentioned pulverizability evaluation test was performed.
The 80% passing sieve diameter [: D (80)] was calculated.

Table 1 shows the test results. (Example 2) 150 g of the coal used in Comparative Example 1 and 150 g of the plastic mixture used in Comparative Example 3 were weighed and put into a pulverizer, and the above-mentioned pulverizability evaluation test was carried out. D (80)] was calculated.

Table 1 shows the test results. (Example 3) 150 g of the coal used in Comparative Example 1 and 150 g of the heat-treated plastic (A) obtained in Comparative Example 4 were weighed and put into a pulverizer, and the above-mentioned pulverizability evaluation test was performed.
The 80% passing sieve diameter [: D (80)] was calculated.

Table 1 shows the test results. (Example 4) 150 g of the coal used in Comparative Example 1 and 150 g of the heat-treated plastic (B) obtained in Comparative Example 5 were weighed, put into a crusher, and subjected to the crushability evaluation test described above.
The 80% passing sieve diameter [: D (80)] was calculated.

The test results are shown in Table 1 and FIG. (Examples 5 to 8) The total amount of coal and the plastic heat-treated product (B) obtained in the same manner as in Comparative Example 5 was set to 300 g, and both were charged into a pulverizer at a ratio shown in Table 1 and the pulverization was performed. An evaluation test was conducted to determine the 80% sieve diameter [: D (80)].

The test results are shown in Table 1 and FIG. (Example 9) 150 g of the coal used in Comparative Example 1 and 150 g of the heat-treated plastic (C) obtained in Comparative Example 6 were weighed and put into a pulverizer, and the above-mentioned pulverizability evaluation test was performed.
The 80% passing sieve diameter [: D (80)] was calculated.

Table 1 shows the test results. (Example 10) 100 g of the coal used in Comparative Example 1, 100 g of a commercially available polyethylene sheet cut to about 10 cm square, and 100 g of commercially available epoxy resin cut to about 10 cm square as a thermosetting resin were mixed. The obtained plastic mixture was subjected to the above-mentioned pulverizability evaluation test, and the 80% sieve diameter [: D (80)] was calculated.

Table 1 shows the test results. (Reference Example 1) From the particle size distribution (see Table 1) obtained by the classification operation in the grindability evaluation test of Comparative Examples 1 and 2, coal: 50% by weight and polyethylene sheet: 50% by weight were pulverized together. The theoretical particle size distribution in the case [: the particle size distribution when coal and plastic do not interfere with each other at all during pulverization] is calculated by the following formulas (3) to (6). (80)] was calculated.

Table 1 shows the calculation results. Theoretical particle amount of particle size> 2 mm: 0.2% by weight × 0.5 + 60.9% by weight × 0.5 = 30.6% by weight 2 mm ≧ theoretical particle amount of particle size> 1.18 mm: 11.6% by weight × 0.5
+ 25.5% by weight × 0.5 = 18.6% by weight 1.18mm ≧ Diameter> 0.6mm Theoretical particle amount: 46.3% by weight × 0.
5 + 12.3% by weight × 0.5 = 29.3% by weight 0.6mm ≧ Theoretical particle amount of particle size: 41.9% by weight × 0.5 + 1.3
Weight% × 0.5 = 21.6% by weight (Reference Examples 2 to 9) From the particle size distribution (see Table 1) obtained by the classification operation in the grindability evaluation test of Comparative Examples 1 to 6, Table 1 was obtained.
The theoretical particle size distribution at the time of blending and pulverizing coal and plastic or plastic heat-treated products shown in Examples 2 to 9 of Example 2 [: Particle size distribution when coal and plastic do not interfere with each other at all during pulverization] is referred to. Calculation was performed in the same manner as in Example 1, and based on the results, the theoretical 80% sieve diameter [: D (80)] was calculated in each case.

Table 1 shows the calculation results. Reference Example 4
The calculation result of No. 8 is shown in FIG. 1 in comparison with Examples 4 to 8.
Comparing the examples and the reference examples corresponding to the examples, in each case, the example has a smaller value of the 80% passing sieve diameter than the reference example, and the pulverizing effect of the examples is excellent. You can see that there is.

That is, according to the present invention, it is possible to improve the pulverizability of the plastic by pulverizing the plastic together with the coal. (Example 10) Using a large-sized reaction vessel and a crusher, plastics were treated in the same manner as in Examples 2 to 4 and 9, respectively, and four types of pulverized plastics which were a mixture of finely divided plastic and finely divided coal were used. I got

Next, each of the four types of the above-mentioned plastic pulverized products was used as a reducing agent for iron ore or a solid fuel for combustion in a blast furnace, a boiler, a kiln and a cupola. As a result, the plastic pulverized product obtained in the present invention could be blown into the raceway of the blast furnace and used as a reducing agent for iron ore.

Further, it can be used as a solid fuel for combustion in boilers, kilns and cupolas, and has excellent flammability.

[0062]

[Table 1]

[0063]

[Table 2]

[0064]

According to the present invention, it is possible to improve the pulverizability of plastics and obtain extremely fine powdery solid fuel and ore reducing agent excellent in flammability, storage property and transportability. Furthermore, according to a more preferable aspect of the present invention, it has become possible to obtain a solid fuel and an ore reducing agent having a small amount of residual chlorine and having no pollution and having the above excellent performance.

[Brief description of the drawings]

Fig. 1 When plastic is pulverized together with coal,
It is a graph which shows the comparison of the measured value and theoretical value of the 80% passage sieve diameter.

Continuing from the front page (72) Inventor Tatsuya Shinzawa 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside Kawasaki Steel Research Laboratory (72) Inventor Toshihide Suzuki 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Made by Kawasaki Inside the Technical Research Institute of Iron and Steel Corporation (72) Inventor Makoto Samurato 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside the Chiba Works, Iron and Steel Corporation (72) Kazuya Miyagawa 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Corporation Chiba Works (72) Inventor Hideaki Unzaki 1st Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Corporation Chiba Works F-term (reference) 4D004 AA07 AA08 AC05 BA03 CA04 CB13 CC20 4F301 AA11 AA12 AA15 AA16 AA17 AA21 AA25 AA26 AA27 BE01 CA32 4H015 AA02 AA10 AA17 AB01 BB01 BB10 CA03 CB01 4K001 BA22 CA01 CA09

Claims (4)

[Claims] 1. A method for pulverizing plastic, comprising mixing and pulverizing plastic with coal. 2. A solid fuel, which is a mixed and crushed product of plastic and coal obtained by the method of crushing plastic according to claim 1. 3. A reducing agent for ore, which is a mixed and crushed product of plastic and coal obtained by the method of crushing plastic according to claim 1. 4. A method according to claim 1, wherein the mixed and crushed product of plastic and coal obtained by the method of crushing plastic is blown into a raceway of a hardening furnace for producing pig iron. How to blow plastic crushed material.