JP3745657B2 - Manufacturing method of briquette for steelmaking raw material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a briquette for a steelmaking raw material, and more particularly, to a technique for effectively utilizing ground metal-based metal chips.
[0002]
[Prior art]
Chips generated when grinding ferrous metals such as bearing steel and carburized steel (hereinafter used as concepts including polishing, super-finish polishing, lapping, etc.) are grinding fluids and abrasives containing moisture and oil. It is recovered as a cotton-like (fibrous) agglomerate containing. Since this flocculent aggregate contains a large amount of pure iron, attempts have been made to reuse it as a raw material for steelmaking. However, since this flocculent agglomerate contains a large amount of moisture, if it is put into a blast furnace as it is, it causes a problem that bumping (steam explosion) occurs due to the moisture. Therefore, it is conceivable to remove the water in the flocculent aggregate by centrifugation or the like. In this case, the oil contained in the flocculent aggregate is also removed together with the water, and the flocculent aggregate spontaneously generates heat. Pure iron, which is a component of grinding chips, is transformed into iron oxide. For this reason, in order to reuse this as a steelmaking raw material, it is necessary to reduce it, and the use of a reducing agent increases the cost.
[0003]
Moreover, since the grinding chips to which the oil is attached are difficult to adhere to each other, it is difficult to solidify to a desired strength even if the cotton-like aggregate is compression-molded. Furthermore, for cotton-like aggregates containing a large amount of iron-based metal grinding chips having a carbon content of 0.2% by weight or more, the spring back during compression is large. It is difficult to solidify strongly. Therefore, even if the compression-molded cotton-like aggregate is put into the blast furnace, it flies up while being scattered and the problem is that the majority is collected by the dust collector.
Furthermore, since the fibrous grinding chips contained in the cotton-like aggregates are difficult to pulverize with a hammer mill or the like, the cotton-like aggregates cannot be finely sheared into powder. For this reason, it is also difficult to process cotton-like aggregates into briquettes or the like. Therefore, the actual condition is that the flocculent aggregates are disposed of in a landfill outsourced to a waste disposal company without being reused.
[0004]
[Problems to be solved by the invention]
However, landfill disposal of such flocculent aggregates is not preferable from the viewpoint of effective use of resources. There are also problems of causing environmental degradation and high disposal costs.
This invention is made | formed in view of the said problem, and it aims at providing the manufacturing method of the briquette for steelmaking raw materials which can recycle | grind cutting chips effectively.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing a briquette for a steelmaking raw material according to the present invention compresses a cotton-like agglomerate containing a ferrous metal grinding chip and a grinding fluid containing oil and moisture, and forms a fibrous form. Of the pure iron, which is a component of the grinding chips, in which the grinding chips are coarsely sheared and excess water and oil are removed , the water content is adjusted to 2 to 12% by weight, and the oil content is adjusted to 1 to 5% by weight. A step of obtaining a brittle molded body that retains oil to prevent oxidation, and grinding the brittle molded body to further finely grind the grinding chips and mixing this with a solidification aid to aid the solidification The method includes a step of obtaining a powder containing an agent, a step of solidifying a predetermined amount of the powder by compression molding to obtain a briquette, and a step of drying the briquette in this order (Claim 1). .
[0006]
According to the manufacturing method of the briquette for steelmaking raw material comprised in this way, the fibrous grinding | polishing chip | piece which was difficult to shear conventionally can be roughly sheared easily by the compression molding of the said cotton-like aggregate. Further, in the step of pulverizing the brittle shaped body, since the fibrous grinding chips in the brittle shaped body are preliminarily sheared by the compression molding, the grinding chips can be easily and effectively sheared. it can. For this reason, a fine powder can be obtained easily and reliably. In addition, the solidification aid in the powder can be solidified to a desired strength simply by compression molding the powder. Furthermore, since each process described above is performed in a state where the oil component contained in the grinding fluid is retained, it is possible to prevent the pure iron that is a component of the grinding chips from being oxidized.
[0007]
As the solidification aid, it is preferable to use at least one selected from rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, bentonite. 2) Thereby, the powder containing oil can be solidified easily and firmly.
In the manufacturing method of the steelmaking raw material briquette, it is preferable to mix 2 to 30% by weight of a solidification aid (Claim 3), whereby the powder can be solidified more firmly.
[0008]
As the flocculent aggregate, it is preferable to use a flocculent aggregate adjusted to have a moisture content not exceeding 50% by weight and an oil content not exceeding 10% by weight. Thereby, while handling of the said cotton-like aggregate etc. becomes easy, the excess water | moisture content and oil component of a brittle molded object can be removed easily and appropriately only by compression molding.
[0009]
The method of manufacturing a steel material for briquettes of the present invention, 2 to 12 wt% of the water content of the brittle molded body, of adjusting the oil content to 1 to 5% by weight, the hardness of moderate brittle molded body In addition to being solidified, it is possible to effectively prevent the grinding chips from being oxidized by the minimum residual oil.
In the manufacturing method of the steelmaking raw material briquette, it is preferable that the briquette immediately after the compression molding is rapidly cooled (Claim 5 ). Thereby, the briquette can be solidified easily and stably.
[0010]
As the briquette, preferably to obtain those substantially pillow-shaped (claim 6), in this case, it is possible to compressive strength to obtain a partial breakage hardly occurs steelmaking raw material briquettes with strong.
Further, as the grinding chips, those containing 0.2% by weight or more of carbon may be used (Claim 7 ), and the cotton-like aggregate containing such grinding chips having a large spring back is also concerned. It is possible to solidify firmly without the influence of springback.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a process diagram showing a method for manufacturing a steelmaking raw material briquette according to an embodiment of the present invention. In manufacturing the briquette A, first, the cotton-like aggregate B (see FIG. 1 (a)) of the grinding chips generated when grinding the ferrous metal is pressed and compressed, and the cotton-like aggregate B is then compressed. The contents of water and oil, which are the components of the grinding fluid contained in, are adjusted in advance. The pressure-compression of the cotton-like aggregate B is performed, for example, by being sandwiched between a pair of rolls 2 while being conveyed by the belt conveyor 1 (see FIG. 1B). At this time, the flocculent aggregate B is preferably adjusted so that the moisture content does not exceed 50 wt% and the oil content does not exceed 10 wt%. Handling such as storage becomes easy.
[0012]
Next, the flocculent aggregate B with the moisture and oil content adjusted is compression-molded by a press using the molding die 3 to obtain a brittle molded body C (see FIG. 1 (c)). By this compression molding, the spiral fibrous grinding chips contained in the cotton-like aggregate B are roughly sheared. Further, excess water and oil are removed, and the moisture content of the brittle shaped body C is adjusted to 2 to 12% by weight, and the oil content is adjusted to 1 to 5% by weight. Thereby, it is possible to effectively prevent the grinding chips from being oxidized by the minimum residual oil. In addition, since the moisture content of the cotton-like aggregate B is adjusted in advance in a range that does not exceed 50% by weight and the oil content does not exceed 10% by weight, respectively, the moisture and oil content of the brittle molded body C is adjusted. It can be adjusted easily and appropriately only by compression molding.
The brittle molded body C is formed in a shape that is easy to handle, such as a cylindrical shape, a spherical shape, and a prismatic shape, and is hardened to such an extent that it does not collapse during transportation to the next process.
[0013]
Next, the brittle molded body C is put into a mixer (or Henschel type mixer) 5 with a chopper mill provided with a rotating blade 4 together with a solidification auxiliary D and pulverized (see FIG. 1 (d)). As a result, the grinding chips of the brittle shaped body C can be further sheared (finished) to obtain a powder E containing pure iron powder and a solidifying auxiliary D (see FIG. 1 (e)). . The major axis of the pure iron powder is about 3 to 1000 μm. When the brittle shaped body C is pulverized, the fibrous grinding chips in the brittle shaped body C are coarsely sheared in advance, and can be finished and sheared without any trouble. When the fibrous grinding chips in the brittle shaped body C are not coarsely sheared, it is very difficult to pulverize them with the mixer 5, and it is impossible to obtain a fine powder E. Is possible.
[0014]
Examples of the solidification aid D include rice bran (rice bran spirit), sugarcane and other molasses, starches such as straw starch and corn starch, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, bentonite One or more selected from among these are preferably used. Such a solidification auxiliary D is preferably contained in an amount of 2 to 30% by weight. In particular, the rice bran and molasses can be effectively prevented from changing the quality of pure iron powder contained in a large amount in the powder E, and the price thereof is also low, which makes it extremely suitable as a solidification aid D. is there. Further, when the asphalt emulsion is kneaded and then separated into asphalt and water, caking occurs and strength is developed. As this asphalt emulsion, an anionic asphalt is preferably used.
[0015]
Next, a predetermined amount of the powder E is compression-molded by a press using the molding die 6 (see FIG. 1 (f)) to obtain a substantially pillow-shaped water-containing briquette F containing a large amount of pure iron. At the time of compression molding of the powder E, the solidification aid D and the moisture in the powder E can be solidified by firmly bonding the powders of pure iron to which oils and fats adhere. In particular, when using powder E containing 5 to 6% by weight of water, 4% by weight of rice bran and 2% by weight of molasses, and 7 to 15% by weight of water and 2 to 10% by weight of vinyl acetate sludge, The water-containing briquette F solidified more firmly can be obtained.
The “substantially pillow shape” is a shape having a rounded periphery and gradually increasing in thickness from the periphery to the center, and includes an egg shape, an almond shape, a rugby ball shape, and the like. By forming into such a shape, it is possible to obtain briquette A that is not easily disintegrated strongly against a compressive load and that is difficult to cause partial breakage at corners and the like.
[0016]
Then, normal temperature or cooled air is blown onto the water-containing briquette F immediately after compression molding to rapidly cool it (see FIG. 1 (g)). Thereby, the said water-containing briquette F can be solidified easily and stably. Thereafter, the briquette A for steelmaking can be obtained by curing (drying) the water-containing briquette F and removing the water content (see FIG. 1 (h)) (see FIG. 1 (i) and FIG. 2). ). This curing is preferably performed for about 2 days because the contained water can be removed reliably.
[0017]
Since the briquette A obtained as described above is a porous material obtained by solidifying the powder E, the contained moisture can be easily and reliably removed by curing. For this reason, there is no possibility that bumping will occur or it will rise and be discharged even if it is put into the blast furnace as it is. Further, since the processing is performed in a state where a part of the oil of the grinding fluid is always held, oxidation of pure iron is effectively prevented. For example, it has been confirmed that briquette A manufactured using cotton-like aggregate B containing grinding chips of bearing steel (SUJ-2) contains 84 to 95% by weight of pure iron. Therefore, the melting yield is very high at 90% or more, and can be provided to steel makers as a high-quality steelmaking raw material for a fee. In addition, it is easy to transport and other solid materials.
[0018]
The above-described method for producing briquette A is particularly suitably applied to reuse grinding chips containing 0.2 wt% or more of carbon. Such grinding chips have a large spring back and are difficult to solidify. By applying the manufacturing method of the present invention, the briquette A solidified by eliminating the influence of the spring back can be obtained. Can be easily obtained. In addition, as a representative example of the grinding chips containing 0.2 wt% or more of carbon, there can be mentioned grinding chips of bearing steel.
The present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the solidification aid D is mixed simultaneously with the pulverization of the brittle molded body C. The pulverization and mixing of the solidification aid D may be performed in separate steps.
[0019]
【The invention's effect】
As mentioned above, according to the manufacturing method of the briquette for steelmaking raw materials of Claim 1, two steps of shear of the coarse shear by compression molding and the finishing shear by grinding | pulverization are performed with respect to the grinding chips in a cotton-like aggregate. Therefore, the flocculent aggregate, which has been difficult to be miniaturized in the past, can be easily and efficiently miniaturized. Moreover, the solidification aid in the powder can be solidified to a desired strength simply by compression molding the powder, and each step is performed in a state in which the oil contained in the grinding fluid is retained. Therefore, it is possible to prevent the pure iron that is a component of the grinding chips from being oxidized. Therefore, it is possible to reuse the flocculent aggregate as a high-quality steelmaking raw material, which is useful for environmental conservation and can reduce the disposal cost of the grinding chips.
[0020]
According to the method for producing briquettes for steelmaking raw materials according to claim 2, rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, bentonite as the solidification aid. Since at least one selected from the above is used, this can be solidified solidly even though the powder contains oil. For this reason, the briquette for steelmaking raw materials with easy handling, such as conveyance and storage, can be obtained.
According to the manufacturing method of the briquette for steelmaking raw materials of Claim 3, since 2-30 weight% of above-described solidification adjuvant is mixed, powder can be solidified still more firmly. Therefore, it is possible to obtain a steelmaking raw material briquette that is easier to handle such as transportation and storage.
[0021]
According to the method for manufacturing a briquette for steelmaking raw material according to claim 4, the flocculent aggregates are adjusted so that the water content does not exceed 50% by weight and the oil content does not exceed 10% by weight. Therefore, the handling such as transportation of the cotton-like aggregate is facilitated, and excess moisture and oil content of the brittle molded body can be easily and appropriately removed only by compression molding.
[0022]
Further , according to the method for producing briquettes for steelmaking raw materials of the present invention , the brittle molded body is adjusted to have a moisture content of 2 to 12% by weight and an oil content of 1 to 5% by weight. In addition to being solidified, it is possible to effectively prevent the grinding chips from being oxidized by the minimum residual oil.
According to the method for manufacturing a steelmaking raw material briquette according to claim 5, since the briquette immediately after the compression molding is rapidly cooled, the briquette can be solidified easily and stably.
[0023]
According to the method for manufacturing a briquette for steelmaking raw material according to claim 6 , since the briquette is obtained in a substantially pillow shape, the compressive strength is high and partial breakage is unlikely to occur, handling such as transportation and storage. However, it is possible to obtain a steelmaking raw material briquette that is easier.
According to the method for manufacturing a briquette for steelmaking raw material according to claim 7 , even for ground cutting chips having a large springback containing 0.2 wt% or more of carbon, solidify solidly without the influence of the springback. Can do.
[Brief description of the drawings]
FIG. 1 is a process diagram showing a method for producing a steelmaking raw material briquette according to an embodiment of the present invention.
FIG. 2 is a partially broken perspective view of a briquette.
[Explanation of symbols]
A Briquette B Cotton-like aggregate C Brittle shaped body D Solidification aid E Powder

Claims (7)

A cotton-like agglomerate containing ferrous metal grinding chips and a grinding fluid containing oil and moisture is compression-molded, the fibrous grinding chips are coarsely sheared, excess moisture and oil are removed , and water content A step of obtaining a brittle molded body having an oil content for preventing the oxidation of pure iron which is a component of the grinding chips by adjusting the rate to 2 to 12% by weight and the oil content to 1 to 5% by weight ;
Crushing the brittle shaped body to further finely shear the grinding chips, mixing this with a solidification aid to obtain a powder containing the solidification aid,
A step of solidifying the powder of a predetermined amount by compression molding to obtain a briquette;
And a step of drying the briquette in this order.   The steelmaking raw material according to claim 1, wherein at least one selected from rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite is used as the solidification aid. Method for manufacturing briquettes.   The manufacturing method of the briquette for steelmaking raw materials of Claim 2 which mixes 2-30 weight% of said solidification adjuvant. The method for producing briquettes for steelmaking raw materials according to claim 1, wherein the flocculent aggregates are adjusted so that the moisture content does not exceed 50 wt% and the oil content does not exceed 10 wt%.   The manufacturing method of the briquette for steelmaking raw materials of Claim 1 which rapidly cools the briquette immediately after the said compression molding.   The manufacturing method of the briquette for steelmaking raw materials of Claim 1 which obtains a substantially pillow-shaped thing as said briquette.   The manufacturing method of the briquette for steelmaking raw materials of Claim 1 which uses what contains 0.2 weight% or more of carbon as said grinding chips.

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