JP2002121625A - Briquette for raw material for steelmaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide briquettes for a raw material for steelmaking with which grinding-wheel swarf can be effectively recycled. SOLUTION: Flocculent agglomerates B containing pulverized pure iron and oil and also containing grinding-wheel swarf of ferrous metal are finely sheared and the resultant powder D is solidified using an auxiliary agent E for solidification and dried; and also the above flocculent agglomerates B are compressed and the resultant brittle compacts C are impregnated with an inorganic auxiliary agent E for solidification and solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a briquette for a steelmaking raw material, and more particularly to a technique for effectively utilizing ground metal chips of a ferrous 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. 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 briquette for a steelmaking raw material capable of effectively reusing grinding chips.

[0005]

A briquette according to the present invention for achieving the above object is a dried briquette containing powdered pure iron and oil, and is a cotton-like briquette containing ground cuttings of an iron-based metal. It is characterized in that a powder obtained by finely shearing the aggregate is solidified by using a solidification aid (claim 1). The briquette for steelmaking raw material thus configured is a dry solid material, so even if it is put into a blast furnace as it is, there is no danger of bumping or soaring, and handling such as transportation and storage is easy. Become something. In addition, since it contains an oil component, oxidation of powdery pure iron is prevented.

[0006] The solidification aids include rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate,
It is preferably at least one selected from aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite (claim 2), whereby the solidified solid containing oil is obtained. Become.

Another briquette of the present invention is a dry briquette containing powdered pure iron and oil, and is obtained by compression-molding a flocculent aggregate containing ground cuttings of an iron-based metal. The brittle molded product is characterized by being solidified by impregnating with an inorganic solidification aid (claim 3). Since this briquette is also a dry solid,
Even if it is put into the blast furnace as it is, there is no danger of bumping or soaring, and handling such as transportation and storage becomes easy. Also, because it contains oil,
Oxidation of the powdered pure iron is prevented.

[0008] In the briquette for the steelmaking raw material (Claim 3), the inorganic solidification aid is colloidal silica,
It is preferably at least one selected from sodium silicate and aluminum phosphate (Claim 4).
Despite containing oil, it becomes solidified firmly.

The above-mentioned briquettes for each steelmaking raw material preferably contain a solidification aid in an amount of 2 to 30% by weight (claim 5), whereby the briquettes are further solidified. Each of the briquettes is preferably substantially pillow-shaped (claim 6), whereby the compressive strength can be increased and partial breakage is less likely to occur.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a partially cutaway perspective view showing a briquette for a steelmaking raw material according to an embodiment of the present invention. The briquette A contains powdered pure iron and oil, and is obtained by finely shearing a flocculent aggregate containing a ground metal swarf and a grinding fluid containing oil and moisture. The powder is solidified using a solidification aid, and dried to remove the water.
The shape of the briquette A is substantially pillow-shaped.

FIG. 2 is a process chart showing a method of manufacturing the briquette A. In the production of the briquette A, first, the flocculent aggregate B (see FIG. 2 (a)) of the ground swarf generated when the ferrous metal is ground is compressed under pressure to obtain 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 sandwiching between a pair of rolls 2 while being conveyed by the belt conveyor 1 (see FIG. 2B).
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 whose water and oil content is adjusted is compression-molded by a press using a molding die 3 to obtain a brittle molded body C (see FIG. 2 (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 compact C is put into a mixer (or Henschel mixer) 5 equipped with a chopper mill and provided with a rotary blade 4 together with a solidification aid D, and pulverized (see FIG. 2 (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. 2 (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. 2 (f)), and a substantially pillow-shaped hydrous briquette F containing a large amount of pure iron.
Get. During the compression molding of the powder E, the solidifying aid D and the water in the powder E allow the powder of the pure iron to which the fat or oil has adhered to be firmly bound and solidified. In particular, when the powder E contains 5 to 6% by weight of water, 4% by weight of rice bran and 2% by weight of molasses, and the powder E contains 7 to 15% by weight of water and 2 to 10% by weight of vinyl acetate sludge, A 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. 2 (g)). Thereby, the water-containing briquette F can be easily and stably solidified. Thereafter, the briquette A for steelmaking raw material can be obtained by curing (drying) the water-containing briquette F and removing the water content (see FIG. 2 (h)) (see FIG. 2 (i)).
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.

FIG. 3 is a process chart showing another method of manufacturing the briquette A of the present invention. This manufacturing method mainly differs from the manufacturing method shown in FIG. 1 in that the step of pulverizing the brittle compact C is omitted. That is, in this manufacturing method,
Brittle compacts C are obtained from flocculent aggregates B in exactly the same manner as in the production method shown in FIG. 1 (see FIGS. 3 (a) to 3 (c)).

The brittle compact C obtained through these steps is impregnated with a liquid solidification aid D. The impregnation with the solidification aid D is performed, for example, by immersing the brittle molded body C in the solidification aid D injected into the tank 8 while conveying the brittle molded body C on the belt conveyor 7 (FIG. 3D).
reference). As the solidification aid D used in this production method, it is preferable to use at least one selected from colloidal silica, sodium silicate, and aluminum phosphate,
Thereby, the brittle molded body C can be easily and firmly solidified.

Next, the brittle compact C impregnated with the solidification aid D is cured (dried) (see FIG. 3E) (see FIG. 3).
(See (f)) to obtain briquettes A for steelmaking raw materials (Fig. 3 (g)).
reference). The briquette A obtained as described above can exhibit the same operation as the briquette A obtained by the manufacturing method shown in FIG. Further, the manufacturing method shown in FIG. 3 omits the step of pulverizing the brittle molded body C, so that the briquette A can be manufactured more efficiently.

The above-described method for producing each briquette 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.

[0022]

As described above, since the briquette for the steelmaking raw material according to the first aspect is a solid material from which moisture has been removed, even if the briquette is put into a blast furnace as it is, bumping or soaring may occur. In addition to this, handling such as transportation and storage becomes easy. In addition, the oily content prevents powdery pure iron from being oxidized. Therefore, it can be reused as a high-quality steelmaking raw material, which contributes to environmental preservation and can reduce the disposal cost of grinding chips.

According to the briquette according to the second aspect, the solidifying aid is selected from rice bran, molasses, starches, quicklime, colloidal silica, sodium silicate, aluminum phosphate, vinyl acetate sludge, asphalt emulsion, and bentonite. Since it is at least one kind, it is firmly solidified despite containing oil. For this reason, transportation,
Handling such as storage is further facilitated.

The briquette according to the third aspect is also a solid one from which water has been removed. Therefore, even if the briquette is put into a blast furnace as it is, there is no danger of bumping or soaring and handling such as transportation and storage. Will be easier. Further, oxidation of the powdery pure iron by the contained oil is prevented. Therefore, it can be reused as a high-quality steelmaking raw material, which contributes to environmental preservation and can reduce the disposal cost of grinding chips.

According to the briquette for steelmaking raw material according to the fourth aspect, the inorganic solidification aid is at least one selected from colloidal silica, sodium silicate, and aluminum phosphate. It becomes a solid that has been solidified. Therefore, handling such as transportation and storage is further facilitated. According to the briquette for a steelmaking raw material according to the fifth aspect, since the solidification aid is mixed in an amount of 2 to 30% by weight, the powder can be further solidified. Therefore, handling such as transportation and storage is further facilitated. According to the briquette for a steelmaking raw material according to the sixth aspect, since it is substantially pillow-shaped, the compressive strength can be increased, and partial breakage is less likely to occur. Therefore, handling such as transportation and storage is further facilitated.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a briquette.

FIG. 2 is a process chart showing a briquette manufacturing method of the present invention.

FIG. 3 is a process chart showing another method for producing a briquette of the present invention.

[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 Koyo Seiko Co., Ltd. (72) Yoshihiro Kiyoo 3-58 Minamisenba, Chuo-ku, Osaka-shi Koyo Inside Seiko Co., Ltd. (72) Inventor Shoichi Kashino 3-5-8 Minamisenba, Chuo-ku, Osaka Koyo Seiko Co., Ltd. F-term (reference) 4K001 AA10 BA22 CA26 CA29 4K013 EA18 EA39 4K070 AC05 AC34

Claims (6)

[Claims] 1. A dry briquette containing powdered pure iron and oil, which is obtained by finely shearing a flocculent agglomerate containing ground cuttings of an iron-based metal, to solidify a briquette. A briquette for a steelmaking raw material, which is solidified using an agent. 2. 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. 2. A briquette for a steelmaking raw material according to 1. 3. A dry briquette containing powdered pure iron and an oil component, the brittle compact obtained by compression-molding a flocculent agglomerate containing ground cuttings of an iron-based metal, wherein the brittle compact is an inorganic solid. A briquette for a steelmaking raw material, which is solidified by impregnation with a chemical auxiliary agent. 4. The briquette for a steelmaking raw material according to claim 3, wherein said inorganic solidification aid is at least one selected from colloidal silica, sodium silicate and aluminum phosphate. 5. The briquette for a steelmaking raw material according to claim 2, wherein said briquette contains 2 to 30% by weight of said solidification aid. 6. The briquette as claimed in claim 1, which is substantially pillow-shaped.