JP2002194449A - Method for manufacturing briquette for raw material for steelmaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing briquettes which are used as a raw material for steelmaking and enable effective recycling of grinding swarf. SOLUTION: A flocculent agglomerate B which contains grinding swarf of ferrous metal and grinding fluid containing oil and water is compacted to prepare a brittle compact C where the grinding swarf in a fibrous state is roughly sheared and excess water and oil are removed. The brittle compact C is pulverized to shear the grinding swarf more finely. The resultant pulverized powder is mixed with coke K and an auxiliary agent D for solidification to prepare powder E containing the coke K and the auxiliary agent D for solidification. The powder E is solidified into the briquette F by compression molding. Then water contained in the briquette is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing briquettes for a raw material for steelmaking, and more particularly to a technique for effectively utilizing ground chips of an iron-based metal.

[0002]

2. Description of the Related Art Chips generated when grinding ferrous metals such as bearing steel and carburized steel (hereinafter used as a concept including polishing, superfinishing and lapping) are grinding fluids containing water and oil. And a flocculent (fibrous) aggregate containing abrasive grains and the like. Since this flocculent aggregate contains a large amount of pure iron, it has been attempted to reuse it as a raw material for steelmaking. However, since this flocculent agglomerate contains a large amount of water, if it is put into a blast furnace as it is, the water causes a problem of bumping (steam explosion). 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 moisture, and the flocculent aggregate naturally 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 costs.

[0003] In addition, since the above-mentioned ground chips to which the oil component adheres hardly adhere to each other, it is difficult to solidify to a desired strength even if the flocculent aggregate is compression-molded. Further, the flocculent agglomerate containing a large amount of ground cuttings of an iron-based metal having a carbon content of 0.2% by weight or more has a large springback at the time of compression. It is difficult to solidify strongly. Therefore, there is a problem that even if the compression-molded flocculent material is put into a blast furnace, it flies up while scattering and is mostly collected by a dust collector. Furthermore, since the fibrous ground chips contained in the flocculent aggregate are difficult to be crushed by a hammer mill or the like, the flocculent aggregate cannot be finely sheared into powder. For this reason, it is also difficult to process the flocculent aggregate into briquettes or the like. Therefore, the actual state is that the flocculent aggregate is disposed of by a waste disposal contractor without being reused.

On the other hand, in a steel manufacturing process such as a melting process, dust containing iron and heavy metals is generated.
This is collected as dust collection dust (OG dust) (see, for example, JP-A-7-97638). However, if this dust is put into the blast furnace as it is, it will fly up while scattering and be collected again by the dust collector, so it is landfilled without reuse.

[0005]

However, such landfill disposal is not preferable from the viewpoint of effective utilization of resources. In addition, there is a problem that the environment is deteriorated and the disposal cost is high. In particular, dust collected contains heavy metals, so it is necessary to landfill it as a special industrial waste, and there is a problem that the disposal cost is higher. The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a briquette for a steelmaking raw material, which can effectively reuse ground chips. Another object of the present invention is to provide a method for producing a briquette for a raw material for steelmaking, which can effectively reuse dust collection dust together with grinding chips.

[0006]

In order to achieve the above-mentioned object, a method for producing a briquette for a raw material for steelmaking according to the present invention comprises a flocculent material containing ground metal chips and a grinding fluid containing oil and moisture. Compression molding the aggregate to obtain a brittle molded body from which fibrous ground chips are roughly sheared and excess water and oil are removed, and further grinding the brittle molded body to further finely grind the ground chips Then, a step of obtaining a powder containing the coke and the solidification aid by mixing this with coke and a solidification aid, and a step of solidifying a predetermined amount of the powder by compression molding to obtain a briquette, And drying the briquette in this order (claim 1).

[0007] According to the method for producing a briquette for a steelmaking raw material thus constituted, fibrous ground chips, which were conventionally difficult to shear, are easily rough-sheared by compression molding of the flocculent aggregate. Can be. Further, in the step of pulverizing the brittle molded body, since the fibrous grinding chips in the brittle molded body are preliminarily sheared by the compression molding, the grinding chips can be easily and effectively sheared. it can. For this reason, fine powder can be obtained easily and reliably. Moreover, by the action of coke and the like in the powder, briquettes for a steelmaking raw material which are extremely solidified can be obtained only by compacting the powder. Furthermore, since each of the above-described steps is performed while retaining the oil content contained in the grinding fluid, it is possible to prevent oxidation of pure iron, which is a component of grinding chips.

In the step of obtaining the powder, the dust collected in the steel manufacturing step may be further mixed. Thus, a powder further containing dust collection dust can be obtained. In this case, it is preferable that the dust collected be mixed in an amount of 10 to 30% by weight (claim 3).
Thereby, a briquette having a desired hardness can be easily obtained.

[0009] Examples of the solidification aid include rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate,
It is preferable to use at least one selected from aluminum phosphate, vinyl acetate sludge, asphalt emulsion and bentonite (claim 4), whereby the powder containing oil can be easily and stably solidified. The solidification aid is preferably mixed in an amount of 1 to 10% by weight (claim 5), whereby the powder can be more easily and stably solidified.

In the method for producing a steelmaking raw material briquette, coke is preferably mixed in an amount of 5 to 50% by weight (claim 6), whereby a more solidified briquetting material for a steelmaking raw material can be obtained. . As the flocculent aggregate, it is preferable to use those that have been adjusted to have a water content not exceeding 50% by weight and an oil content not exceeding 10% by weight, respectively (claim 7). This facilitates handling such as transportation of the floc and the like, and allows easy and appropriate removal of excess moisture and oil content of the brittle molded body only by compression molding.

In the method for producing a briquette for a steelmaking raw material, it is preferable to adjust the moisture content of the brittle compact to 2 to 12% by weight and the oil content to 1 to 5% by weight. In this case, the brittle molded product can be solidified to an appropriate hardness, and the oxidation of the ground chips by a minimum residual oil content can be effectively prevented. In the method for producing briquettes for steelmaking raw materials,
It is preferable to rapidly cool the briquette immediately after the compression molding (claim 9). Thereby, briquettes can be easily and stably solidified.

It is preferable that the briquette has a substantially pillow shape (claim 10). In this case, a briquette for a steelmaking raw material which has high compressive strength and hardly causes partial breakage can be obtained. . Further, as the grinding chips, those containing 0.2% by weight or more of carbon may be used (Claim 11), and the cotton-like aggregate containing such grinding chips having a large springback is also used. It can be solidified firmly by eliminating the influence of springback.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a process chart showing a method for producing a steelmaking raw material briquette according to an embodiment of the present invention. In the production of the briquette A, first, the flocculent aggregate B (see FIG. 1 (a)) of the swarf generated when grinding the ferrous metal is pressurized and compressed. Preliminarily adjust the contents of water and oil, which are components of the grinding fluid contained in the above. The pressurization and compression of the flocculent 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 water content and the oil content by simple air blowing or air compression. At this time, the flocculent aggregate B has a water content within a range not exceeding 50% by weight.
It is preferable to adjust the oil content so that it does not exceed 10% by weight. This facilitates handling of the flocculent aggregate B, such as transportation and storage.

Next, the flocculent agglomerate B having the adjusted water and oil content is compression molded by, for example, pressing using a molding die 3 to obtain a brittle molded product C (see FIG. 1 (c)). ). By this compression molding, the spiral fibrous ground chips contained in the flocculent aggregate B are roughly sheared. Also,
Excess water and oil are removed, and the water content of the brittle molded product C is adjusted to 2 to 12% by weight, and the oil content is adjusted to 1 to 5% by weight. Accordingly, it is possible to effectively prevent the grinding chips from being oxidized by the minimum residual oil content. Further, since the water content of the flocculent agglomerate B is adjusted in advance to a range not exceeding 50% by weight and the oil content not exceeding 10% by weight in the preceding step, the water content and the oil content of the brittle molded product C are adjusted to It can be easily and properly adjusted only by compression molding. The brittle molded body C is formed in a shape such as a column, a sphere, and a prism that is easy to handle, and is hardened to such a degree that it does not collapse during transportation to the next step.

Next, the brittle molded product C is coke K
Along with the dust collected and generated in the steel manufacturing process and the collected dust S and the solidification aid D, they are fed into a chopper-equipped mixer (or Henschel mixer) 5 having a rotary blade 4 and pulverized (see FIG. 1 (d)). ). At this time, the brittle molded body C
50 to 70% by weight, coke K in 5 to 50% by weight, dust collecting dust S in 10 to 30% by weight, and solidifying aid D in 1 to
Mix at a rate of 10% by weight. Thereby, the brittle compact C
By further finely shearing (finish shearing) the ground swarf of (1), powder E containing powder of pure iron, coke K, dust collection dust S and solidification aid D can be obtained (see FIG. 1 (e)). ). The major diameter of the pure iron powder is about 3 to 1000 μm. When the brittle molded body C is ground, the fibrous ground cuttings in the brittle molded body C are rough-sheared in advance, so that they can be finish-sheared without any trouble. In the case where the fibrous ground cuttings in the brittle molded body C are not subjected to rough shearing, it takes a long time to grind them with a mixer (or Henschel mixer) 5 equipped with a chopper, which is economical. No merit can be obtained, and it is also difficult to obtain fine iron-based powder.

Examples of the solidifying aid D include waste molasses such as rice bran and sugarcane, starches such as potato starch and corn starch, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion and bentonite. One or two or more selected from the following are preferably used. Particularly, the rice bran and molasses are very suitable as the solidification aid D because the solidification of the powder E is effectively promoted and the price is low. In addition, when the asphalt emulsion is kneaded and then separated into asphalt and water, caking is generated and the strength is developed. As the asphalt emulsion, an anionic asphalt is preferably used. Further, as the dust collection dust S, for example, iron (total Fe) generated and recovered in a steelmaking process is 10 to 55%.
What contains by weight is used.

Next, a predetermined amount of the powder E is compression-molded by using, for example, a roll-type molding machine or a cylinder-type molding machine 6 (see FIG. 1 (f)) to obtain a substantially pure iron-containing material. A pillow-shaped briquette F is obtained. During the compression molding of the powder E, the pure iron powder to which the fats and oils are adhered can be firmly bound and solidified by the coke K, the solidification aid D, and the moisture in the powder E. . The “substantially pillow shape” refers to a shape having a rounded peripheral portion and a gradually increasing thickness from the peripheral portion toward 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 strongly resistant to a compressive load and hardly collapses, and is hard to be partially damaged at a corner or the like.

Then, the briquette F immediately after compression molding is blown with room temperature or cooled air to rapidly cool it (see FIG. 1 (g)). Thereby, the briquette F can be easily and stably solidified. Thereafter, the briquette F is cured (dried) to remove the water content (see FIG. 1 (h)), whereby a briquette A for a steelmaking raw material can be obtained (see FIGS. 1 (i) and 2). . It is preferable to carry out this curing for about two days because the water content can be surely removed.

Since the briquette A obtained as described above is obtained by solidifying the powder E, the water content can be easily and reliably removed by curing. For this reason, there is no possibility that bumping or soaring and discharge will occur even if the blast furnace is directly charged into the blast furnace. Further, since the machining is performed while a part of the oil of the grinding fluid is always held, the oxidation of the pure iron is effectively prevented. For example, bearing steel (SUJ-
It has been confirmed that the briquette A produced using the flocculent aggregate B containing the grinding chips of 2) contains 70% by weight or more of pure iron. Therefore, the dissolution yield is 9
It is extremely high at 0% or more, and can be provided as a high-quality steelmaking raw material to steelmakers for a fee. In addition, since it contains carburizing material and coke K as a reducing agent, it has higher added value. Further, it is easy to carry and other handling in solid form.

In particular, in the above-mentioned production method, 5 to 50% by weight of coke and 1 to 10% by weight of a solidification aid are mixed respectively, so that the more solidified briquette A for steelmaking raw material is produced. Obtainable. Further, since the mixing ratio of the dust collection dust is set to 10 to 30% by weight, briquettes having a desired hardness can be easily obtained.

The above-described method for producing briquettes A is particularly suitably applied to the reuse of ground chips containing 0.2% by weight or more of carbon. Such grinding chips have a large springback and are difficult to solidify. However, by applying the manufacturing method of the present invention, briquette A solidified firmly by eliminating the influence of the springback is applied. Can be easily obtained. As a typical example of the ground chips containing 0.2% by weight or more of carbon, ground chips of bearing steel can be given. The present invention is not limited to the above-described embodiment. For example, in the above-described embodiment,
Coke K, dust collection S at the same time as the brittle compact C
And the solidification aid D are mixed, but the pulverization of the brittle molded 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.

[0022]

As described above, according to the method for producing a briquette for a steelmaking raw material according to the first aspect, the grinding shear in the flocculent aggregate is subjected to rough shearing by compression molding and finish shearing by grinding. Since the two-stage shearing is performed, the flocculent aggregate, which has conventionally been difficult to miniaturize, can be easily and efficiently miniaturized. In addition, the coke contained in the powder makes it possible to obtain an extremely solidified briquette for steelmaking raw materials, and since each step is performed while retaining the oil content contained in the grinding fluid, grinding chips Oxidation of pure iron as a component of can be prevented. Therefore, the flocculent aggregate can be reused as a high-quality steelmaking raw material, which contributes to environmental preservation and reduces the disposal cost of grinding chips. In addition, briquettes for steelmaking raw materials with high added value that include a carbonized material and coke as a reducing agent can be obtained.

According to the method for manufacturing a briquette for a steelmaking raw material according to the second aspect of the present invention, the dust collected can be solidified and reused together with the grinding chips. Can be reduced. According to the method for producing a briquette for a steelmaking raw material according to the third aspect, since the dust collection dust is mixed in an amount of 10 to 30% by weight, a briquette having a desired hardness can be easily obtained.

According to the method for producing a briquette for a steelmaking raw material according to claim 4, rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate,
Since at least one selected from aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite is used, the powder can be easily and stably solidified even though the powder contains oil. According to the method for producing a briquette for a steelmaking raw material according to the fifth aspect, since the solidification aid is mixed at 1 to 10% by weight, the powder can be more easily and stably solidified.

According to the method for producing a steelmaking raw material briquette according to the sixth aspect, since coke is mixed in an amount of 5 to 50% by weight, a more solidified briquetting material for a steelmaking raw material can be obtained. According to the method for producing a briquette for a steelmaking raw material according to claim 7, the flocculent is adjusted so that the water content does not exceed 50% by weight and the oil content does not exceed 10% by weight. Because the use of such as the transportation of the flocculent aggregate is easy,
Excessive water and oil content of the brittle molded body can be easily and properly removed only by compression molding.

According to the method for producing briquettes for a steelmaking raw material of the present invention, the brittle compact is adjusted to have a water content of 2 to 12% by weight and an oil content of 1 to 5% by weight. The solidified material can be solidified to an appropriate hardness, and the oxidized grinding chips can be effectively prevented by the minimum residual oil content. According to the method of manufacturing a briquette for a steelmaking raw material according to the ninth aspect, the briquette immediately after the compression molding is rapidly cooled, so that the briquette can be easily and stably solidified.

According to the method for manufacturing a briquette for a steelmaking raw material according to the tenth aspect, since the briquette is obtained in a substantially pillow shape, the briquette has a high compressive strength and is hardly partially broken, and is transported and stored. Thus, briquettes for steelmaking raw materials that can be more easily handled can be obtained. According to the method for producing a briquette for a steelmaking raw material according to the eleventh aspect, even with respect to grinding chips having a large springback containing 0.2% by weight or more of carbon, the influence of the springback is eliminated and the solidified solid is firmly solidified. Can be.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for producing a steelmaking raw material briquette according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of a briquette.

[Explanation of symbols]

 A Briquette B Cotton-like aggregate C Brittle molded body D Solidification aid E Powder K Coke S Dust collection dust

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mitsuma Matsuda 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. (72) Yoshihiro Kiyoo 3-58 Minamisenba, Chuo-ku, Osaka-shi Koyo Inside Seiko Co., Ltd. (72) Shoichi Kashino 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. F-term (reference) 4K001 AA10 BA14 BA22 BA24 CA25 CA26 CA29 DA01 HA01 HA04

Claims (11)

[Claims] A flocculent agglomerate containing iron-based metal swarf and a grinding fluid containing oil and water is compression-molded, whereby the fibrous swarf is roughly sheared and excess water and oil And a step of obtaining a brittle molded body from which the brittle molded body has been removed, and the brittle molded body is crushed to further finely shear the ground chips, and this is mixed with coke and a solidification aid to form the coke and the solidification aid. A method for producing a briquette for a steelmaking raw material, comprising: a step of obtaining a powder containing the same; a step of solidifying a predetermined amount of the powder by compression molding to obtain a briquette; and a step of drying the briquette. . 2. The method for producing a briquette for a steelmaking raw material according to claim 1, wherein in the step of obtaining the powder, the dust collected in the steel production step is further mixed. 3. The method according to claim 2, wherein the dust is mixed with 10 to 30% by weight. 4. The solidification aid is at least one selected from rice bran, molasses, starch, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite. 2. The method for producing a briquette for a steelmaking raw material according to item 1. 5. The method according to claim 4, wherein the solidification aid is mixed in an amount of 1 to 10% by weight. 6. The method according to claim 1, wherein the coke is mixed in an amount of 5 to 50% by weight. 7. The briquette for a steelmaking raw material according to claim 1, wherein the flocculent is prepared by adjusting the water content to a value not exceeding 50% by weight and the oil content to a value not exceeding 10% by weight. Manufacturing method. 8. The method according to claim 1, wherein the brittle compact is adjusted to have a water content of 2 to 12% by weight and an oil content of 1 to 5% by weight. 9. The method according to claim 1, wherein the briquette immediately after the compression molding is rapidly cooled. 10. The method according to claim 1, wherein said briquettes are substantially pillow-shaped. 11. The method for producing a briquette for a steelmaking raw material according to claim 1, wherein said ground swarf contains at least 0.2% by weight of carbon.