JP2002129248A - Method for manufacturing briquette for raw material for steelmaking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing briquettes for a raw material for steelmaking by which grinding-wheel swarf can be effectively recycled. SOLUTION: A flocculent agglomerate B which contains grinding-wheel swarf of ferrous metal and grinding fluid containing oil and water is compacted to prepare a brittle compact C where the grinding-wheel swarf in a fibrous state is roughly sheared and excess water and oil are removed. The brittle compact B is impregnated with an auxiliary agent D for solidification to undergo solidification, followed by drying.

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 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, 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 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, a step of obtaining a brittle molded body in which the fibrous ground chips are roughly sheared and excess moisture and oil removed, and a step of impregnating the brittle molded body with a solidification aid, Drying the brittle molded body impregnated with a solidification aid 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, the brittle molded body can be solidified to a desired strength only by compression-molding the brittle molded body by the solidification aid impregnated in the brittle molded body.
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.

As the solidification aid, it is preferable to use at least one selected from colloidal silica, sodium silicate, and aluminum phosphate (claim 2), whereby a brittle molded article containing oil can be easily and firmly formed. Can be solidified. In this case, it is preferable that the solidification aid is mixed in an amount of 2 to 30% by weight (claim 3), whereby the brittle molded article can be solidified more firmly.

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 molding C is impregnated with a liquid solidification aid D. The impregnation of 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 (see FIG. 1 (d)). . As the solidification aid D used in this embodiment, it is preferable to use at least one selected from colloidal silica, sodium silicate, and aluminum phosphate, and the solidification aid D is impregnated with 2 to 30% by weight. Is preferred. 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. 1 (e)) to remove the water content (see FIG. 1 (f)). ), Briquettes A for steelmaking raw materials can be obtained (see FIG. 1 (g)). It is preferable to carry out this curing for about two days because the water content can be surely removed. At the time of the curing, room temperature or cooled air may be blown to rapidly cool the air.

The shape of the briquette A is as follows.
In addition to the above-mentioned column shape, etc., such as an egg shape, an almond shape, a rugby ball shape, etc., have a rounded peripheral edge, and have a substantially pillow shape in which the thickness gradually increases from the peripheral edge toward the center. (See FIG. 2). By molding into such a shape, it is possible to obtain a briquette A that is strongly resistant to a compressive load, hardly collapses, and hardly causes partial damage at corners and the like.

Since the briquette A obtained as described above is a porous material obtained by solidifying the brittle molded product C, the moisture 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 processing 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, flocculent aggregate B containing ground chips of bearing steel (SUJ-2)
84 to 8 for briquettes A manufactured using
It has been confirmed that it contains 5% by weight of 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. In addition, the method of producing the briquette A can solidify the flocculent aggregate B without requiring a step of pulverizing the flocculent aggregate B to make it finer.
Can be produced efficiently.

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.

[0018]

As described above, according to the method for producing a briquette for a steelmaking raw material according to the first aspect of the present invention, by compressing the flocculent agglomerates, fibrous ground chips which have conventionally been difficult to shear. Can be easily sheared. Also,
The brittle compact can be solidified to the desired strength by the solidification aid, and each step is performed while retaining the oil content contained in the grinding fluid. Oxidation can be prevented. Therefore, the flocculent aggregate containing the grinding chips can be reused as a high-quality raw material for steelmaking, which contributes to environmental preservation and reduces the disposal cost of the grinding chips. In addition, the flocculent can be solidified without finely pulverizing, so that briquettes can be efficiently produced.

According to the method for producing a steelmaking raw material according to the second aspect, at least one selected from colloidal silica, sodium silicate, and aluminum phosphate is used as the solidification aid, so that the brittle compact contains oil. Nevertheless, it can be solidified firmly. For this reason,
It is possible to obtain a steelmaking raw material that is easy to handle such as transport and storage. According to the method for producing a briquette for a steelmaking raw material according to the third aspect, since the inorganic solidification aid is mixed in an amount of 2 to 30% by weight, the brittle molded body 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 the fourth aspect, 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 for producing briquettes for steelmaking raw material according to the fifth aspect, the water content of the brittle compact is adjusted to 2 to 12% by weight and the oil content is adjusted to 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 of manufacturing 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 is not easily damaged, 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

 ──────────────────────────────────────────────────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 Inside Seiko Co., Ltd. (72) Shoichi Kashino 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. F-term (reference) 4K001 AA10 BA22 CA25 CA26 CA29

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 Obtaining a brittle molded body from which is removed, a step of impregnating the brittle molded body with a solidification aid, and a step of drying the brittle molded body impregnated with a solidification aid. A method of producing briquettes for steelmaking raw materials. 2. The method according to claim 1, wherein at least one selected from the group consisting of colloidal silica, sodium silicate and aluminum phosphate is used as the solidification aid. 3. The method according to claim 2, wherein the solidification aid is impregnated with 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.