JP2002146445A - Method for producing briquette for raw material for iron making - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a briquette for the raw material for iron making by which gound cut powder can effectively be reutilized. SOLUTION: A flocculent aggregate B containing ground cut powder of iron based metal and a grinding solution containing oil and water is subjected to compressive molding to produce a brittle compact C in which the fibrous gound cut powder is coarsely sheared, and also, the surplus water and oil are removed. This brittle compact C is pulverized to more finely shear the gound cut powder. The powder is mixed with a solidifying auxiliary D to produce powder E containing the solidifying auxiliary D. The powder E is solidified by compressive molding to produce a water-containing briquette E. Then, the water contained in the water-containing briquette F 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 steelmaking raw materials, and more particularly, to a technique for effectively utilizing ground metal chips of 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 concepts including polishing, super-finishing polishing, lapping, etc.) are ground containing water and oil. It is collected as a flocculent (fibrous) aggregate containing a liquid, 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, even if the compression-molded flocculent aggregate is put into a blast furnace, it flies up while scattering and is mostly collected by the dust collector. Furthermore, since the fibrous ground chips contained in the flocculent aggregate are difficult to pulverize with 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.

[0004]

However, such landfill disposal of flocculent aggregates 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. 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.

[0005]

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 Mixing this with a solidification aid to obtain a powder containing the solidification aid, solidifying a predetermined amount of the powder by compression molding to obtain a briquette, and drying the briquette. And a step of performing the above steps in this order (claim 1).

According to the method for producing a briquette for a steelmaking raw material having the above-described structure, the fibrous swarf, which has conventionally been difficult to shear, can be roughly 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. In addition, the powder can be solidified to a desired strength only by compression molding with the solidification aid in 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.

[0007] 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 2), whereby the powder containing oil can be easily and firmly solidified. In the method for producing a briquette for a steelmaking raw material, it is preferable to mix a solidification aid in an amount of 2 to 30% by weight (claim 3), whereby the powder can be solidified more strongly.

As the flocculent aggregate, it is preferable to use those whose water content is adjusted not to exceed 50% by weight and oil content is adjusted to not exceed 10% by weight (claim 4). 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 water 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 that the briquette immediately after the compression molding is rapidly cooled. Thereby, the briquette can be easily and stably solidified.

It is preferable that the briquette has a substantially pillow shape (claim 7). 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 ground chips, those containing 0.2% by weight or more of carbon may be used (Claim 8), and the cotton-like aggregate containing such ground chips with large springback is also used. It can be solidified firmly by eliminating the influence of springback.

[0011]

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 one embodiment of the present invention. In the manufacture of the briquette A, first, the flocculent aggregate B (see FIG. 1 (a)) of the swarf generated when the ferrous metal is ground is compressed under pressure, and the flocculent aggregate B 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). At this time, the flocculent aggregate B is preferably adjusted to have a water content not exceeding 50% by weight and an oil content not exceeding 10% by weight. , Storage and the like are easy to handle.

Next, the flocculent agglomerate B having the adjusted water and oil content is compression-molded by a press using a molding die 3 to obtain a brittle molded body C (see FIG. 1 (c)). . By this compression molding, the spiral fibrous ground chips contained in the flocculent aggregate B are roughly sheared. Further, since excess water and oil are removed, the water content of the brittle molded body C becomes 2%.
To 12% by weight and the oil content 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 body C is put together with a solidifying aid D into a mixer (or Henschel type mixer) 5 equipped with a rotary blade 4 equipped with a rotary blade 4 and pulverized (see FIG. 1 (d)). Thereby, the ground cuttings of the brittle compact C can be further finely sheared (finish shearing) to obtain a powder E containing pure iron powder and a solidification aid D (see FIG. 1 (e)). . The major diameter of the pure iron powder is 3 to 1000
It is about 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. If the fibrous ground chips in the brittle compact C are not subjected to rough shearing, it is very difficult to grind them with the mixer 5 and it is difficult to obtain fine powder E. It is possible.

Examples of the solidifying aid D include rice bran (rice bran), molasses such as sugarcane, starches such as potato starch and corn starch, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt One or more selected from emulsions and bentonites are preferably used. It is preferable that such a solidification aid D is contained in an amount of 2 to 30% by weight. In particular, the rice bran and molasses can be effectively prevented from deteriorating the pure iron powder contained in a large amount in the powder E, and the price thereof is low. is there. 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.

Next, a predetermined amount of the powder E is compression-molded by a press using a molding die 6 (see FIG. 1 (f)), and a substantially pillow-shaped hydrous briquette F containing a large amount of pure iron.
Get. At the time of compression molding of the powder E, the solidifying aid D and the moisture in the powder E allow the powder of the pure iron to which the fats and oils have adhered to be firmly bound and solidified. In particular, the powder E contains 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.
%, And 2 to 10% by weight of vinyl acetate sludge, the more strongly solidified hydrous briquette F
Can be obtained. 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 A 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 wet briquette F immediately after compression molding
Is cooled rapidly by blowing air at room temperature or cooled (see FIG. 1 (g)). Thereby, the water-containing briquette F can be easily and stably solidified. Thereafter, the wet briquette F is cured (dried) to remove the water content (see FIG. 1 (h)), whereby the briquette A for the steelmaking raw material can be obtained (FIG. 1 (i) and FIG. 2).
reference). 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 a porous material obtained by solidifying the powder E, the contained water 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. In addition, since the processing is performed while always holding a part of the oil content of the grinding fluid,
Oxidation of pure iron is effectively prevented. For example, for briquettes A manufactured using flocculent aggregates B containing ground cuttings of bearing steel (SUJ-2), 84 to 95% by weight
It has been confirmed to contain pure iron. Therefore, the melting yield is as high as 90% or more, and it can be provided as a high quality steelmaking raw material to a steelmaker for a fee. Moreover, it is easy to carry and other handling in solid form.

The above-described method for producing briquettes A is particularly suitably applied to recycle grinding 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,
Although the solidification aid D is mixed simultaneously with the pulverization of the brittle molded body C, the pulverization of the brittle molded body C and the mixing of the solidification auxiliary D may be performed in separate steps.

[0019]

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 solidification aid in the powder allows the powder to be solidified to a desired strength only by compression molding, and the respective steps are performed in a state in which the oil contained in the grinding fluid is held. Therefore, it is possible to prevent the oxidation of pure iron, which is a component of the grinding chips. 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.

According to the method for producing a briquette for a steelmaking raw material according to claim 2, 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, it is possible to solidify the powder even though the powder contains oil. For this reason, briquettes for steelmaking raw materials that can be easily handled such as transportation and storage can be obtained. According to the method for producing a briquette for a steelmaking raw material according to the third aspect, the solidification aid is mixed in an amount of 2 to 30% by weight, so that the powder can be further solidified. For this reason, briquettes for steelmaking raw materials that are easier to handle such as transportation and storage can be obtained.

According to the method for producing a briquette for a steelmaking raw material according to claim 4, the flocculent aggregate has a water content of 50%.
Since the oil content is adjusted so as not to exceed 10% by weight and not to exceed 10% by weight, handling such as transportation of the floc is easy and brittle molded article is formed only by compression molding. Excess water and oil can be easily and appropriately removed.

According to the method of manufacturing briquettes for steelmaking raw material according to the fifth aspect, the brittle compact is adjusted to have a moisture 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 for producing a briquette for a steelmaking raw material according to the sixth 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 producing a briquette for a steelmaking raw material according to the present invention, since the briquette has a substantially pillow shape, the briquette has a high compressive strength and hardly causes partial breakage, 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 eighth aspect, even for a grinding chip having a large springback containing 0.2% by weight or more of carbon, the influence of the springback is eliminated to solidify firmly. 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

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mitsuma Matsuda 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Inside Koyo Seiko Co., Ltd. (72) Yoshihiro Kiyoo 3-58 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. (72) Inventor Shoichi Kashino 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. F-term (reference) 4D067 DD02 DD11 EE27 EE34 GA10 GB03 4K001 AA10 BA22 CA01 CA25 CA29 CA31

Claims (8)

[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 A step of obtaining a brittle molded body from which the brittle molded body has been removed, and grinding the brittle molded body to further finely shear the ground cuttings, mixing this with a solidification aid, and forming a powder containing the solidification aid. Obtaining a briquette by solidifying a predetermined amount of the powder by compression molding to obtain a briquette, and drying the briquette in this order. 2. The solidification aid includes rice bran, molasses,
The method for producing a briquette for a steelmaking raw material according to claim 1, wherein at least one selected from starches, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite is used. 3. The method for producing a briquette for a raw material for steel according to claim 2, wherein the solidification aid is mixed in an amount of 2 to 30% by weight. 4. The briquette for a raw material for steelmaking according to claim 1, wherein the flocculent is adjusted to a water content not exceeding 50% by weight and an oil content not exceeding 10% by weight. Manufacturing method. 5. The method for producing a briquette for a steelmaking raw material according to claim 1, wherein the brittle molded product is adjusted to have a water content of 2 to 12% by weight and an oil content of 1 to 5% by weight. 6. The method according to claim 1, wherein the briquette immediately after the compression molding is rapidly cooled. 7. The method according to claim 1, wherein the briquette is obtained in a substantially pillow shape. 8. The grinding chip has a carbon content of 0.2% by weight.
The method for producing a briquette for a steelmaking raw material according to claim 1, wherein the briquette is used.