JP3746978B2 - 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 a concept that includes polishing, superfinishing polishing, lapping, etc.) are used for grinding fluids and abrasives containing moisture and oil. It is collected as containing cotton-like (fibrous) aggregates. 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 flocculent aggregate is put into the blast furnace, there arises a problem that the dust flutters up and is mostly recovered 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]
On the other hand, in a steel manufacturing process such as a melting process, dust containing iron and heavy metals is generated, and therefore, this is recovered as dust collection dust (OG dust) (for example, JP-A-7-97638). No. publication). However, if this dust collection dust is put into the blast furnace as it is, it will fly up and be collected again by the dust collector, so it is disposed of without being reused.
[0005]
[Problems to be solved by the invention]
However, such landfill disposal is not preferable from the viewpoint of effective use of resources. There are also problems of causing environmental degradation and high disposal costs. In particular, since dust collection dust contains heavy metals, it needs to be disposed of as a special industrial waste, and there is a problem that the disposal cost is further increased.
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.
Moreover, this invention aims at providing the manufacturing method of the briquette for steelmaking raw materials which can also reuse dust-collecting dust with a grinding chip effectively.
[0006]
[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, the brittle molded body is pulverized to further finely grind the grinding chips, and this is mixed with coke and a solidifying auxiliary to produce the coke. And a step of obtaining a powder containing a solidifying 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 ( Claim 1).
[0007]
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. Moreover, the steelmaking raw material briquette that is solidified extremely simply by compression molding the powder can be obtained by the action of coke in 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.
[0008]
In the step of obtaining the powder, the dust collected in the steel manufacturing process may be further mixed (Claim 2). Thereby, the powder which further contains dust collection dust can be obtained.
In this case, the dust collection dust is preferably mixed in an amount of 10 to 30% by weight (Claim 3), whereby a briquette having a desired hardness can be easily obtained.
[0009]
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. 4) Thereby, the powder containing oil can be solidified easily and stably.
The solidification aid is preferably mixed in an amount of 1 to 10% by weight (Claim 5), whereby the powder can be solidified more easily and stably.
[0010]
In the manufacturing method of the steelmaking raw material briquette, it is preferable to mix 5 to 50% by weight of coke (Claim 6), whereby the steelmaking raw material briquette solidified more strongly can be obtained.
As the flocculent aggregate, it is preferable to use a flocculent agglomerated so that the water content does not exceed 50% by weight and the oil content does not exceed 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.
[0011]
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 8 ). Thereby, a briquette can be solidified easily and stably.
[0012]
As the briquette, it is preferable to obtain a substantially pillow-shaped briquette (claim 9 ). In this case, a briquette for steelmaking raw material that has high compressive strength and is unlikely to cause partial breakage can be obtained.
Moreover, as said grinding | polishing chip, you may use what contains 0.2 weight% or more of carbon (Claim 10 ), About the cotton-like aggregate containing such grinding | polishing chip | tip with a big spring back, the said It is possible to solidify firmly without the influence of springback.
[0013]
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). However, there is a method of adjusting the moisture and oil content by simple air blowing or air compression. 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.
[0014]
Next, the flocculent aggregate B in which the moisture and oil contents are adjusted is compression-molded by using, for example, 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.
[0015]
Next, the brittle shaped body C is put into a mixer (or Henschel type mixer) 5 with a chopper provided with a rotating blade 4 together with coke K, dust collection dust S generated and recovered in the steel manufacturing process, and solidification aid D. And then pulverized (see FIG. 1 (d)). At this time, 50 to 70% by weight of the brittle molded body C, 5 to 50% by weight of coke K, 10 to 30% by weight of dust collection dust S, and 1 to 10% by weight of the solidifying auxiliary D are mixed. To do.
Thereby, the grinding chips of the brittle shaped body C can be further finely sheared (finished shear) to obtain a powder E containing powder of pure iron, coke K, dust collection dust S, and solidification aid 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. In the case where the fibrous grinding chips in the brittle shaped body C are not subjected to rough shearing, it takes a long time to pulverize this with the mixer (or Henschel type mixer) 5 with a chopper, economically. It is difficult to obtain merit and fine iron-based powder.
[0016]
The solidification aid D is selected from among molasses such as rice bran and sugarcane, starches such as straw starch and corn starch, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, bentonite. One type or two or more types are preferably used. In particular, the rice bran and molasses are very suitable as the solidification aid D because it effectively promotes solidification of the powder E and its price is low. 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.
Moreover, as said dust collection dust S, what contains 10 to 55 weight% of iron content (total Fe) which generate | occur | produced and collect | recovered, for example at the steelmaking process is used.
[0017]
Next, a predetermined amount of the powder E is compression-molded using, for example, a roll molding machine or a cylinder molding machine 6 (see FIG. 1 (f)), and has a substantially pillow shape containing a large amount of pure iron. Obtain briquette F. When the powder E is compression-molded, the pure iron powder to which the fats and oils adhere can be solidified by the coke K, the solidification auxiliary D, and the moisture in the powder E to be solidified. .
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 a briquette F that is not easily disintegrated strongly against a compressive load and that is difficult to cause partial breakage at corners or the like.
[0018]
Then, normal temperature or cooled air is blown onto the briquette F immediately after compression molding to rapidly cool it (see FIG. 1 (g)). Thereby, the briquette F can be solidified easily and stably. Thereafter, the briquette F is cured (dried) and its moisture content is removed (see FIG. 1 (h)) to obtain briquette A for a steelmaking raw material (see FIGS. 1 (i) and 2). . This curing is preferably performed for about 2 days because the contained water can be removed reliably.
[0019]
Since the briquette A obtained as described above is 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 ground cutting powder of bearing steel (SUJ-2) contains 70% by weight or more 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. And since it contains the coke K as a carburizing material and a reducing agent, it becomes a thing with higher added value. In addition, it is easy to transport and handle in solid form.
[0020]
In particular, in the manufacturing method, since 5 to 50% by weight of coke and 1 to 10% by weight of a solidification aid are mixed, respectively, it is possible to obtain briquette A for a steelmaking raw material that has been solidified more strongly. it can. Moreover, since the mixing ratio of the dust collection dust is 10 to 30% by weight, a briquette having a desired hardness can be easily obtained.
[0021]
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 coke K, the dust collection dust S, and the solidification aid D are mixed simultaneously with the pulverization of the brittle molded body C. However, the pulverization of the brittle shaped body C and the mixing of the coke K and the like may be performed in separate steps. Moreover, you may implement without mixing the dust collection dust S. FIG.
[0022]
【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. In addition, the coke contained in the powder makes it possible to obtain a steelmaking raw material briquette that has been solidified extremely strongly, and since each process is carried out while retaining the oil contained in the grinding fluid, It is possible to prevent the pure iron, which is a component of, 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. And the briquette for steelmaking raw materials with a high added value containing the coke as a carburizing material and a reducing agent can be obtained.
[0023]
According to the method for manufacturing a briquette for steelmaking raw material according to claim 2, dust collection dust can be solidified and reused together with grinding chips, which is useful for environmental conservation and reduces dust collection dust disposal costs. be able to.
According to the manufacturing method of the steelmaking raw material briquette of Claim 3, since the said dust collection dust is mixed 10 to 30weight%, the briquette of desired hardness can be obtained easily.
[0024]
According to the method for producing a briquette for steelmaking raw material according to claim 4, 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, it can be solidified more easily and stably even though the powder contains oil.
According to the manufacturing method of the briquette for steelmaking raw materials of Claim 5, since the said solidification adjuvant is mixed 1 to 10weight%, powder can be solidified more easily and stably.
[0025]
According to the method for manufacturing a briquette for steelmaking raw material according to claim 6, since coke is mixed in an amount of 5 to 50% by weight, a briquette for steelmaking raw material solidified more firmly can be obtained.
According to the method for producing a briquette for a steelmaking raw material according to claim 7, the flocculent aggregate is 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.
[0026]
According to the method for producing briquettes for steelmaking raw material of the present invention, the brittle molded body is adjusted to 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 manufacturing method of the steelmaking raw material briquette according to the eighth aspect, since the briquette immediately after the compression molding is rapidly cooled, the briquette can be solidified easily and stably.
[0027]
According to the method for manufacturing a briquette for steelmaking raw material according to claim 9 , since the briquette has a substantially pillow shape, the compressive strength is high and partial breakage is unlikely to occur. However, it is possible to obtain a steelmaking raw material briquette that is easier.
According to the method for manufacturing a briquette for a steelmaking raw material according to claim 10 , even for a ground spring having a large spring back containing 0.2 wt% or more of carbon, solidifying solidly by eliminating the influence of the spring back. 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 compact D Solidification aid E Powder K Coke S Dust collection dust

Claims (10)

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 coke and a solidification aid to obtain a powder containing the coke and 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 manufacturing method of the briquette for steelmaking raw materials of Claim 1 which mixes the dust collection dust collect | recovered at the manufacturing process of steel further in the process of obtaining the said powder.   The manufacturing method of the briquette for steelmaking raw materials of Claim 2 which mixes 10-30 weight% of said dust collection dusts.   The steelmaking raw material according to claim 1, wherein the solidification aid is at least one selected from rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite. Method for manufacturing briquettes.   The manufacturing method of the briquette for steelmaking raw materials of Claim 4 which mixes the said solidification adjuvant 1 to 10weight%.   The manufacturing method of the briquette for steelmaking raw materials of Claim 1 which mixes 5-50 weight% of said cokes. 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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