KR20070022022A - Briquette as steelmaking raw material and process for producing the same - Google Patents

Abstract

It is an object of the present invention to provide a briquette for steelmaking raw materials and a method for producing the same, which can effectively reuse shot debris.

According to the structure of this invention, after solidifying adjuvant is dripped at the shot residue which consists of a metal powder containing iron powder and a shot ball, the said shot residue is compression-molded. The compressed shot debris is dried. In addition, shot sludge is mixed with the grinding sludge containing the grinding debris of the iron-based metal and the grinding liquid containing oil and water to obtain a planar aggregate. The planar agglomerates are compression molded to produce brittle moldings in which fibrous grinding debris is roughly sheared and excess water and oil are removed. The brittle molded product is solidified by impregnating a solidification aid, and then dried.

Briquettes, grinding sludges, solidification aids, shot balls, shot residues for steelmaking materials

Description

Briquettes for steelmaking raw materials and its manufacturing method {BRIQUETTE AS STEELMAKING RAW MATERIAL AND PROCESS FOR PRODUCING THE SAME}

The present invention relates to a briquette for steelmaking raw materials and a method of manufacturing the same. In particular, the present invention relates to a technique for effectively utilizing shot residues generated when shot blasting is performed on ferrous metals.

The shot dregs generated when shot blasting is performed on ferrous metals generally contain about 75 to 95% by weight of ferrous metal powder and used short balls. For this reason, the said shot dreg can become an effective resource as a steelmaking raw material. However, this short dreg is likely to ignite or scatter. Moreover, since it contains a large amount of shot balls, it is difficult to solidify by compression molding or the like. For this reason, it is inconvenient to handle transportation, storage and the like, and it is disadvantageous both technically and costly to reuse it. Therefore, the short dregs are actually disposed of as industrial waste.

However, the disposal of such short residues is undesirable from the viewpoint of effective use of resources. In addition, there is a problem that the disposal cost is high while causing environmental deterioration.

This invention is made | formed in view of the said problem, and an object of this invention is to provide the briquette for steelmaking raw materials which can effectively reuse a short dreg, and its manufacturing method.

Briquettes for steelmaking raw materials of the present invention for achieving the above object is a dry briquette containing an iron-based metal, it is made by solidifying the short residue comprising an iron-based metal powder and a plurality of short balls with a solidification aid.

Since the briquette for steelmaking raw materials of such a structure solidifies short dregs using a solidification aid, it can exhibit moderate mechanical strength and it is easy to handle transportation, storage, and the like. In addition, since it is a dry solid material, there is no fear that bumping may occur or fly off as it is thrown into the furnace. In addition, since many shot balls made of pure iron of 90% by weight or more are included, the amount of reducing agent used in steelmaking can be reduced. Therefore, the shot dregs can be reused as a high quality steelmaking raw material, and it is helpful for environmental conservation and can reduce the waste disposal cost of the shot dregs.

The short balls are preferably bonded to each other through an iron-based metal powder impregnated with the solidification aid. As a result, the short balls, which have conventionally been difficult to engage, can be easily and firmly combined.

It is preferable that the said steelmaking briquette contains 0.5-5 weight% of said solidification adjuvant. As a result, the shot residue can be easily and reliably solidified by the extrusion molding while ensuring the quality as a steelmaking raw material.

The said briquette for steelmaking raw materials may further contain grinding debris and oil of an iron type metal. In this case, oxidation of the pure iron in a briquette is prevented by the said oil content. Therefore, the grinding debris and the shot dregs can be reused as a high quality steelmaking raw material.

It is preferable that the briquette for steelmaking raw materials containing the said oil contains 5 to 25 weight% of shot debris. As a result, an appropriate bulk density and mechanical strength can be ensured. That is, if the short dregs are less than 5% by weight, the bulk density becomes small, so there is a possibility that the briquettes do not fall smoothly upon introduction into the furnace, depending on the type of the furnace. In addition, when the shot residue exceeds 25% by weight, when the shot residue is ubiquitous, briquettes are liable to break from the localized shot residue.

In the briquette for steelmaking raw materials containing the said oil component, it is preferable that it is a steel short ball as said shot dregs. In this case, since there is little content of iron oxide, it becomes more suitable as a raw material for steelmaking. That is, the shot dreg generally includes a shot ball made of steel and powder, the shot ball contains 90 wt% or more of pure iron, and the powder contains 60 to 65 wt% of oxidized iron powder. Therefore, the more content of the said powder in a briquette, the more content of iron oxide. For this reason, it is necessary to increase the amount of reducing agent used during steelmaking, and it is disadvantageous in terms of cost. However, when the shot ball from which the powder is removed is used as shot residue, the content of iron oxide in the briquettes decreases. We can reduce the use of.

It is preferable that it is at least 1 sort (s) chosen from a sodium silicate, colloidal silica, aluminum phosphate, an asphalt oil agent as said solidification adjuvant. This makes it possible to solidify the shot dregs, the grinding chips and the like easily and firmly.

The manufacturing method of the briquette for steelmaking raw materials which concerns on this invention is a process which adds a solidification adjuvant to the shot debris containing an iron type metal powder and a shot ball, and compresses the shot waste which added the said solidification adjuvant. The process and the process of drying compression shot short dregs are included.

According to the first method for producing a briquette for steelmaking raw material, by forming the shot residue, the solidification aid added to the shot residue can be infiltrated over almost the entirety of the shot residue. For this reason, even if it contains many shot balls, it can harden shot residue to desired strength by the said compression molding. Therefore, the briquette for steelmaking raw materials can be manufactured easily and inexpensively.

The method for producing the first briquette may further include a step of impregnating the shot residue with a solidifying aid between the step of compressing the shot residue and the step of drying the compressed shot residue. In this case, a briquette with stronger mechanical strength can be obtained.

In the method for producing a briquette for a second steelmaking raw material according to the present invention, a surface aggregate is formed by mixing shot residue with a grinding sludge containing a grinding powder of iron-based metal and a grinding liquid containing oil and water. The process of obtaining, the process of obtaining the brittle molded object of the predetermined shape by which the planar aggregate was compression-molded, the fibrous grinding debris was sheared, and the excess moisture and oil were removed, and the solidified to the said brittle molded object The process of impregnating an adjuvant and the process of drying the said brittle molding which impregnated the solidification adjuvant are included in this order.

According to the second method for producing a briquette for steelmaking raw material, by the compression molding of the planar aggregate, the fiber-like cutting debris, which has been difficult to shear in the past, can be roughly sheared and easily solidified together with the shot dregs. . In addition, the solidification aid impregnated into the brittle molded body can be solidified to a desired strength only by compression molding the brittle molded body, so that it is not necessary to grind it finely to solidify the planar aggregate. Therefore, the briquette for steelmaking raw materials can be manufactured easily and inexpensively.

In the manufacturing method of a said 2nd briquette, it is preferable to mix 10-30 weight% of said shot dregs. If the shot residue in the planar aggregate is less than 10% by weight, it is difficult to obtain a briquette with a high bulk density. Moreover, when the shot dregs in a planar aggregate exceeds 30 weight%, it becomes difficult to solidify this, and when a short dregs is ubiquitous, briquettes become easy to break from the ubiquitous short dregs part.

In the manufacturing method of the said 2nd briquette, it is preferable to use a steel shot ball as shot dregs. In this case, since the content of iron oxide is reduced, a briquette more suitable as a raw material for steelmaking can be obtained.

In the manufacturing method of the said 1st and 2nd briquette, it is preferable to use at least 1 sort (s) chosen from a sodium silicate, colloidal silica, aluminum phosphate, an asphalt emulsion as a solidification adjuvant. This makes it possible to solidify the shot residue more easily and firmly. Especially in the manufacturing method of a 2nd briquette, the brittle molded object containing oil component can be solidified easily and firmly.

BRIEF DESCRIPTION OF THE DRAWINGS It is process drawing which shows the manufacturing method of the briquette for steelmaking raw materials which concerns on 1st Embodiment of this invention.

2 is a process chart showing a method for manufacturing a briquette for steelmaking raw material according to a second embodiment of the present invention.

3 is a partially cutaway perspective view of the briquettes.

4 is a process chart showing a manufacturing method of a briquette for steelmaking raw material according to a third embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail, referring an accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS It is process drawing which shows the manufacturing method of the briquette for steelmaking raw materials which concerns on 1st Embodiment of this invention. In manufacture of this briquette A, while conveying shot debris S (refer FIG. 1 (a)) which arises when shot blasting is performed to an iron type metal by the belt conveyor 1, Then, the liquid solidifying aid (D) is added dropwise to the shot residue (S) (see Fig. 1 (b)).

The shot dregs (S) is composed of a plurality of shot balls (B) which have been thinned to a predetermined diameter or less by a shot, an iron-based metal powder (C), and the like. 60-65 weight% is included. As the solidification aid (D), a solution of 100% sodium silicate is used.

Next, the shot debris S to which the said solidification aid (D) was added is compression-molded by the press using the shaping | molding die 3 (refer FIG. 1 (c), FIG. 1 (d)). By this compression molding, the solidification aid (D) added to the shot dregs (S) penetrates almost all of the shot dregs (S). Thereby, while solidifying adjuvant (D) can be impregnated throughout the metal powder (C), it can adhere to the surface of the shot ball (B).

Next, by solidifying (drying) the shot dregs (S) impregnated with the solidification aid (D), for example, for about two days (see FIG. 1 (e)), the solidification aid (D) is solidified. The briquette A for steelmaking raw materials is obtained (refer FIG. 1 (f)). On the other hand, at the time of the said curing, normal temperature or cooled air may be blown out and this may be rapidly cooled.

By the above, a dry porous briquette (A) can be obtained. It is preferable that this briquette (A) contains 95-99.5 weight% of shot debris (S) and 0.5-5.0 weight% of solidification adjuvant (D), and by this, shot debris (S) is ensured while ensuring the quality as a steelmaking raw material. ) Can be solidified easily and firmly. That is, if the solidification aid (D) is less than 0.5% by weight, the mechanical strength is weak, and it is easy to be damaged at the time of transportation or other handling. If it exceeds 5% by weight, the content of the iron-based metal is reduced by that amount, and the quality as steelmaking raw material This degrades.

Since the briquette A obtained by the above is a porous thing which solidified the shot debris S, the moisture contained can be removed easily and surely by curing. For this reason, even if it puts into a furnace as it is, there is no possibility that bumping will generate | occur | produce or will fly off and discharge. In addition, since the shot dregs S are solidified using the solidification aid (D), proper mechanical strength can be exhibited, and handling such as transportation and storage is easy. In particular, since the compression-molding aid (D) penetrates almost the entirety of the shot dregs (S), the plurality of shot balls (B) in the shot dregs (S) include the solidification aid (D). It can be bonded to each other through the metal powder (C). For this reason, the shot dregs S can be hardened firmly. Moreover, since it has many shot balls B containing 90 weight% or more of pure iron, the usage-amount of the reducing agent at the time of steelmaking can be reduced. Therefore, the shot dregs S can be reused as a high quality steelmaking raw material.

2 is a process chart showing a method for manufacturing a briquette for steelmaking raw material according to a second embodiment of the present invention. This embodiment differs from the embodiment shown in FIG. 1 between the step of compressing the shot residue S and the step of drying the compressed shot residue S. The solidifying aid is added to the shot residue S. It is the point which added the process of further impregnating (D).

Impregnation of this solidification aid (D) is carried out by immersing, for example, the compacted shot debris (S) in the solidification aid (D) injected into the tank (8) while being conveyed to the belt conveyor (Fig. 2 (d)). As the solidification aid (D) injected into the tank (8), a dilution of sodium silicate with water is used, whereby the permeability of the solidification aid (D) to the compacted shot residue (S) is used. It is secured well. According to this embodiment, the mechanical strength of the briquette A can be further improved.

In addition, also in 1st Embodiment, you may use the thing which diluted sodium silicate with water as a solidification adjuvant (D). In this case, in the compression molding, the solidification aid (D) can be more easily and effectively penetrated into the shot dregs (S).

In any of the above embodiments, at least one selected from sodium silicate, colloidal silica, and aluminum phosphate can be used as the solidification aid (D), and the shot dregs (S) can be easily used. It can solidify solidly.

As the shape of the briquette A, in addition to the cylindrical shape shown in FIG. (pillow) shape may be sufficient (refer FIG. 3). By shaping in such a shape, it is possible to obtain a briquette A that is resistant to compressive loads, which is difficult to collapse, and which is hard to cause partial breakage at corners or the like.

4 is a process chart showing a manufacturing method of a briquette for steelmaking raw material according to a third embodiment of the present invention. In the manufacture of this briquette A, the grinding sludge E is first transported to the belt conveyor 1 while the grinding sludge E (see FIG. 4 (a)) generated when the iron metal is ground. The shot debris S is sprayed on to obtain a planar aggregate M in which the shot debris S is mixed (see Fig. 4 (b)). The grinding sludge (E) is in the shape of a plane containing grinding debris and grinding liquid. In addition, the shot dregs (S) occurs when shot blasting is performed on an iron-based metal, and powder containing 60 to 65% by weight of used shot balls and oxidized iron powder thinned to a predetermined grain boundary or less by shot. It is made of. The mixing amount of this shot residue S is 10 to 30 weight%. If the shot dregs S in the planar aggregate M is less than 10% by weight, it is difficult to obtain the briquette A having a large bulk density. In addition, when the shot dregs S in the planar aggregate M exceeds 30% by weight, it becomes difficult to solidify in a later step, and when the shot dregs S are ubiquitous, the briquettes A are ubiquitous. It becomes easy to break from the short dregs (S) part.

Next, the planar aggregate M is pressurized and compressed to preliminarily adjust the content of water and oil as components of the grinding liquid contained in the grinding sludge E. Pressurization of this planar aggregate M is performed by sandwiching it between a pair of rolls 2 formed near the conveying end of the belt conveyor 1, for example (see Fig. 4 (b)). At this time, the planar aggregate (M) is preferably in a range where the water content does not exceed 50% by weight, and the content of the planar aggregate (M) is not more than 10% by weight. Handling, storage and the like becomes easy.

In addition, the planar aggregate (M) in which the content of water and oil is adjusted is compression-molded by pressing using the mold 3 to obtain a brittle molded body F (see Fig. 4 (c)). By this compression molding, the spiral fiber-like grinding debris contained in the grinding sludge E is roughly sheared. In addition, excess water and oil are removed, and the water content of the brittle molded body (F) is adjusted to 2 to 12% by weight, and the content is adjusted to 1 to 5% by weight. This can effectively prevent the grinding debris from being oxidized by the minimum residual oil. In addition, in the previous step, since the water content of the grinding sludge (E) is previously adjusted in a range of not more than 50% by weight and the content is not more than 10% by weight, the moisture and oil content of the brittle molding (F) is compression molded. Only by adjusting easily and appropriately.

The brittle molded body (F) is formed in a shape that is easy to handle, such as a cylinder, a sphere, a prisms, and the like, and is hardened to such an extent that it does not collapse when conveyed to the next step.

Next, the brittle molded body (F) is impregnated with a liquid solidification aid (D). Impregnation of this solidification aid (D) is performed by immersing in the said solidification aid (D) injected into the tank 8, for example, conveying the brittle molding F to the belt conveyor 7 (FIG. 4 (d)). Reference). As this solidification adjuvant (D), it is preferable to use at least 1 sort (s) chosen from a sodium silicate, colloidal silica, and aluminum phosphate. In this embodiment, sodium silicate is mainly used. It is preferable to impregnate 2-30 weight% of this solidification adjuvant (D). Thereby, the brittle molded body F can be solidified easily and firmly. In addition, as said solidification adjuvant (D), organic binders, such as vinyl acetate, can also be used.

Next, the brittle molding (F) impregnated with the solidification aid (D) (see Fig. 4 (e)) is cured (dried) to remove the water contained therein (see Fig. 4 (f)). Briquette A is obtained (see FIG. 4 (g)). It is preferable to carry out this curing for about two days because the contained moisture can be reliably removed. In the curing, the air may be cooled at room temperature or cooled to rapidly cool it.

As a result, a dry briquette (A) containing shot debris (S), grinding metal (E) of iron-based metal, iron powder and oil can be obtained. The briquette (A) thus obtained contains 5 to 25% by weight of shot debris (S).

Since the said briquette (A) is a porous thing which solidified the brittle molding (F), it can remove easily and reliably moisture contained by curing. For this reason, even if it puts into a furnace as it is, there is no possibility that bumping may generate | occur | produce or fly up and discharge.

Moreover, since content of the shot dregs S in briquette A is 5-25 weight%, it has a moderate bulk density and mechanical strength. That is, for the briquette A for steelmaking raw materials, it is required to fall smoothly without flying at the time of introduction into a blast furnace. For this reason, depending on the kind of furnace, 0.2 or more may be calculated | required as a bulk density, but when the short dregs in briquette A are less than 5 weight%, there exists a possibility that this request cannot be satisfied. In addition, when the shot residue in the briquette A exceeds 25% by weight, when the shot residue is ubiquitous in the briquette A, the briquette A is easily broken from the shot residue portion.

Moreover, in the manufacturing method of the said briquette (A), since the process is carried out in the state which always kept a part of grinding fluid oil, the oxidation of pure iron is effectively prevented. For example, it is confirmed that 60-90 weight% of pure iron is included with respect to the briquette A manufactured using the grinding sludge E containing the grinding waste of bearing steel SUJ-1. Therefore, the dissolution yield is very high, such as 80% or more, and can be provided as a high quality steelmaking raw material to steelmaking makers. In addition, it is easy to carry and handle other things in solid state.

In addition, the production method does not require a step of pulverizing and miniaturizing the planar agglomerate (M) and can solidify the planar agglomerate (M), so that the briquette (A) can be efficiently produced.

The manufacturing method of the above-mentioned briquette (A) is applied especially suitably for reusing the grinding waste containing 0.2 weight% or more of carbon. Such grinding debris is difficult to solidify due to the large springback, but by applying the manufacturing method of the present invention, it is possible to easily obtain a firmly solidified briquette A by removing the influence of the springback. In addition, the grinding waste of bearing steel is mentioned as a typical example of the grinding waste containing 0.2 weight% or more of carbon.

In the said embodiment, although the used shotball and the powder containing the oxidized iron powder were used as shot dregs S, the thing made only by removing the said powder and using only the shotball may be used. In this case, since the content of iron oxide in the briquette (A) decreases, the amount of reducing agent used during steelmaking can be reduced by that amount. For this reason, it becomes more suitable as a raw material for steelmaking raw materials.

Also in the third embodiment, as the shape of the briquette A, the shape of the briquette A has a round shape at the circumferential edge such as an egg shape, an almond shape, a rugby ball shape and the like, in addition to the above-described cylindrical shape, and the like. It may be a substantially pillow shape in which the thickness becomes thicker (see Fig. 3).

In addition, the briquette (A) is a fine dust (dust collecting dust) generated during the steelmaking by an electric furnace or a flat furnace (S), or when refining metals such as copper, lead, tin oxide, and brass. ) May be solidified by the solidification aid (D).

Claims (13)

A dry briquette containing an iron-based metal, wherein briquettes containing iron-based metal powder and a plurality of short balls are solidified with a solidification aid. The briquette for steelmaking raw material according to claim 1, wherein the short balls are bonded to each other through an iron-based metal powder impregnated with the solidification aid. The briquette for steelmaking raw material according to claim 1, wherein the solidification aid contains 0.5 to 5% by weight. The briquette for steelmaking raw materials according to claim 1, further comprising grinding chips and oils of the iron-based metal. 5. The briquette for steelmaking raw material according to claim 4, wherein the shot dreg contains 5 to 25 wt%. The briquette for steelmaking raw material according to claim 4, wherein the shot dregs are steel short balls. The briquette for steelmaking raw materials according to claim 1 or 4, wherein the solidifying aid is at least one selected from sodium silicate, colloidal silica, aluminum phosphate, and an asphalt emulsion. Adding a solidifying aid to a shot dreg containing iron-based metal powder and a shot ball, Compressing molding the shot dregs to which the solidifying aid is added; A method for producing a briquette for steelmaking raw material, comprising the step of drying a compression molded short dreg. The briquette for steelmaking raw material according to claim 8, further comprising a step of impregnating the short dregs with a solidification aid between the step of compressing the short dregs and the step of drying the compressed short dregs. Manufacturing method. A process of mixing shot residue with a grinding sludge containing a grinding powder of iron-based metal and a grinding liquid containing oil and water, and obtaining a surface-like aggregate; A step of compressing the planar aggregate to obtain a brittle molded article having a predetermined shape in which fiber-like grinding debris is sheared and excess water and oil are removed; Impregnating the brittle molded body with a solidification aid; A method for producing a briquette for steelmaking raw material, comprising the step of drying the brittle molded product impregnated with a solidification aid in this order. The method for producing a briquette for steelmaking raw material according to claim 10, wherein 10 to 30% by weight of the shot dregs are mixed. The method of manufacturing a briquette for steelmaking raw material according to claim 10, wherein the shot dregs are steel shot balls. The method for producing a briquette for steelmaking raw material according to claim 8 or 10, wherein at least one selected from sodium silicate, colloidal silica, aluminum phosphate, and an asphalt emulsion is used as the solidification aid.

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