JP2010202908A - Briquette and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a briquette and a manufacturing method of the same with which effective deoxidizing treatment can be performed. <P>SOLUTION: After removing impurities by heat-treating the used steel can SC and aluminum can AC, these are pelletized to make aluminum pellet AP and steel pellet SP. Successively, after separating the aluminum pellet AP and the steel pellet SP, the aluminum pellet AP and the steel pellet SP, are blended so that the content of the aluminum pellet AP becomes ≥50% wt. ratio. Then, the briquette B is obtained by forming so that the bulky specific gravity of the blended aluminum pellet AP and steel pellet SP, becomes ≥2.9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a briquette used for hot metal and deoxidation of molten steel in a pig iron manufacturing process and a steel manufacturing process, and a manufacturing method thereof.

Conventionally, for example, in a steelmaking process, a deoxidation briquette made of a lump of aluminum has been used to remove oxygen contained in molten steel (see, for example, Patent Document 1). This briquette (aluminum deoxidized briquette lump) is obtained by crushing aluminum scrap and aluminum alloy scrap collected by recycling with a shredder machine, removing impurities by heating with a rotary kiln, and molding with a press machine. It is what Then, the briquette is provided with a specific gravity of 2.6 g / cm ³ from 2.45 g / cm ^3.

  Such a deoxidizing briquette is put into hot metal or molten steel having a high specific gravity at a high temperature, and a slag layer is formed on the surface of the molten iron or molten steel. For this reason, briquettes can be deoxidized by passing through the slag and contacting the hot metal or molten steel after being put on the upper surface of the slag formed on the surface of the hot metal or molten steel Is required. However, the bulk specific gravity of the slag formed on the surface of the hot metal or molten steel is usually 2 to 2.7, and even if the briquette described above is put on the upper surface of such a slag, the briquette quickly slags. It is difficult to pass through and reach hot metal and molten steel. In addition, since the melting temperature of aluminum is lower than that of hot metal or molten steel, there is a problem that conventional briquettes composed only of aluminum tend to burn on slag and become ash. For this reason, efficient deoxidation processing could not be performed with the conventional briquette.

  The present invention has been made to cope with such a problem, and an object thereof is to provide a briquette capable of performing an efficient deoxidation treatment and a method for producing the same.

  In order to achieve the above-mentioned object, the structural feature of the briquette according to the present invention is a briquette formed by molding granular aluminum and granular steel and used for deoxidation of hot metal and molten steel in the pig iron manufacturing process and steelmaking process. Thus, the bulk specific gravity is set to 2.9 or more, and the content ratio of the granular aluminum is set to 50% or more by weight.

  The briquette according to the present invention is configured by adding granular steel for increasing the bulk specific gravity to granular aluminum exhibiting a deoxidizing effect. For this reason, the bulk specific gravity of briquettes can be made larger than the bulk specific gravity of briquettes composed only of aluminum. It passes through and contacts the hot metal and molten steel. Moreover, since the briquette includes granular steel having a high melting point, the briquette can reach the hot metal or molten steel without melting in the slag. For this reason, hot metal and molten steel can be deoxidized efficiently, and the effect as a deoxidation briquette increases.

  In this case, since the bulk specific gravity of the briquette is 2.9 or more and the granular aluminum content is 50% or more by weight, it is possible to obtain a briquette that can quickly pass through the slag while maintaining the deoxidation effect. it can. In addition, if it is a range which can maintain bulk specific gravity at 2.9 or more, it is preferable to increase the content rate of granular aluminum, and it is more preferable to make the content rate of granular aluminum into about 60% or more by weight ratio. preferable. According to this, the deoxidation effect of a briquette can be maintained in a favorable state.

  In order to pass the briquette through the slag more quickly, the granular aluminum content is decreased until it approaches 50% by weight and the granular steel content is increased accordingly, or processing when forming briquettes. Increase pressure to increase density. Thereby, the bulk specific gravity of the briquette can be increased and the briquette can be passed through the slag more quickly. In addition, since the granular steel in a briquette is contained in hot metal or molten steel as a material after melting, there is no adverse effect on the molten metal or molten steel. In this case, the shape of the briquette may be a quadrangular pyramid, a triangular pyramid, a polygonal pyramid having more corners, a conical shape, a quadrangular pyramid shape from which those small diameter portions are removed, or the like. According to this, it can prevent that a briquette rolls carelessly.

  Another structural feature of the briquette according to the present invention is that granular aluminum and granular steel are heat-treated from used aluminum cans and steel cans to remove impurities, and formed into granules of a predetermined size. It is made up of what you did. According to this, since used aluminum cans and steel cans are used as a material for forming briquettes, resources can be effectively used.

  Still another structural feature of the briquette according to the present invention is that it contains silicon as an additive. In general, various additives are added to give iron and steel predetermined characteristics, and according to the present invention, iron and steel are made difficult to be deformed strongly both in tension and compression. In the case of steel, this makes it possible to obtain high strength steel.

  Still another structural feature of the briquette according to the present invention is that the molten iron is introduced into the hot metal or molten steel by passing through the slag and contacting the molten metal or molten steel after being put on the upper surface of the molten steel or molten steel. In other words, it is intended to deoxidize molten steel and is used for the treatment of hot metal or molten steel in which a slag having a bulk specific gravity of 2.3 to 2.7 is formed on the surface. According to this, the bulk specific gravity of the slag is 2.3 to 2.7, whereas the bulk specific gravity of the briquette is 2.9 or more. Therefore, the briquette is efficiently passed through the slag and the hot metal and molten steel are effectively used. Can be deoxidized.

  A structural feature of the manufacturing method of briquette according to the present invention is a briquetting manufacturing method used for deoxidation of hot metal or molten steel in a pig iron manufacturing process or a steel manufacturing process, in which used aluminum cans and steel cans are heated. Impurity removal process to remove impurities by processing, granulation process to granulate aluminum can and steel can from which impurities have been removed into granular aluminum and granular steel, and separation to separate granular aluminum and granular steel The bulk specific gravity of the step, the blending step of blending the granular aluminum and the granular steel so that the content ratio of the granular aluminum is 50% or more by weight, and the granular aluminum and the granular steel blended by the blending step are 2 And a molding step of molding so as to be 9 or more.

  With the briquette manufacturing method configured as described above, it is possible to obtain a briquette that can efficiently deoxidize hot metal or molten steel using a used aluminum can or steel can, so that resources can be effectively used. . That is, in this briquette manufacturing method, after used aluminum cans and steel cans are granulated, the briquettes are formed by blending granular aluminum and granular steel in a predetermined ratio. For this reason, the bulk specific gravity of the briquette can be made larger than the specific gravity of aluminum, and the temperature at which the briquette melts can be made higher than the melting temperature of aluminum.

  As a result, when the briquette is put into hot metal or molten steel with a slag layer formed on the surface, the briquette passes through the slag without melting in the slag and comes into contact with the molten steel. Hot metal and molten steel can be deoxidized more efficiently than the constructed briquettes. In addition, granular aluminum and granular steel are obtained by granulating the used aluminum can and steel can after removing the impurities by heat treatment, so the impurities may have a negative effect on hot metal and molten steel. Absent. In the granulation step, the aluminum can and the steel can are crushed into a predetermined size into small pieces and each piece is formed into a substantially spherical particle shape. For this reason, it is possible to change the density of the briquettes by adjusting the pressure in the molding step so as to have an arbitrary bulk specific gravity.

  Another structural feature of the briquette manufacturing method according to the present invention is that silicon is contained as an additive in the blending step. According to this, not only oxygen is removed from the hot metal or molten steel processed by briquette, but the obtained iron or steel can be made strong and difficult to deform both in tension and compression.

  Still another structural feature of the briquette manufacturing method according to the present invention is that the briquette is introduced into the upper surface of the slag formed on the surface of the hot metal or molten steel, and then passes through the slag to contact the molten iron or molten steel. Therefore, the hot metal and the molten steel are deoxidized and used for the treatment of the molten iron and the molten steel in which a slag having a bulk specific gravity of 2.3 to 2.7 is formed on the surface. According to this, the briquette which can pass the inside of slag efficiently and can effectively deoxidize hot metal and molten steel can be obtained.

It is the perspective view which showed the briquette which concerns on one Embodiment of this invention. It is the block diagram which showed the outline of the empty can processing system. It is the top view which showed the outline of the briquette molding apparatus.

  Hereinafter, a briquette and a briquette manufacturing method according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a briquette B according to the embodiment. The briquette B is obtained by molding a material made of granular aluminum and granular steel according to the present invention, and is formed in a hexahedron having a trapezoidal shape in which both side surfaces are substantially parallel. In addition, as granular aluminum and granular steel constituting the briquette B, the used aluminum can AC and steel can SC (see FIG. 2) are respectively heat-treated to remove impurities, and then granulated and granulated. Aluminum pellets AP and steel pellets SP (see FIG. 2) are used.

  The mixing ratio of the aluminum pellets AP and the steel pellets SP constituting the briquette B is set to 50:50 by weight. The aluminum pellets AP and the steel pellets SP are granulated to have a diameter of 3 to 10 mm, and the bulk specific gravity of the briquette B formed from the aluminum pellets AP and the steel pellets SP is 3. It is set to 0. The specific gravity of the aluminum pellet AP is 2.7 (same as the specific gravity of aluminum), and the specific gravity of the steel pellet SP is 7.8 (same as the specific gravity of iron).

  Hereinafter, the manufacturing method of this briquette B is demonstrated. In manufacturing the briquette B, first, the aluminum pellet AP and the steel pellet SP are manufactured from the used aluminum can AC and steel can SC by using the empty can processing system 10 shown in FIG. The empty can processing system 10 includes a roll press 11, a metal heating furnace 12, a granulator 13, and a sorter 14. And between the roll press 11 and the metal heating furnace 12, the conveyance conveyor 15 extended in a substantially horizontal direction is arrange | positioned, Between the metal heating furnace 12 and the granulator 13, the step which extends diagonally upwards is provided. A conveyor 16 is disposed. Further, a pellet conveying conveyor 17 a is disposed between the granulator 13 and the sorting machine 14, and a steel pellet conveying conveyor 17 b is disposed on the downstream side of the sorting machine 14.

  The roll press 11 is configured by arranging two rolls (not shown) whose intervals can be adjusted in parallel inside a hopper-shaped outer portion, and an upper opening inside the outer portion. The volume of the aluminum can AC and the steel can SC, which are charged from the bottom, is reduced by passing between two rolls and crushing. Then, the aluminum can AC and the steel can SC crushed by the roll press 11 fall from the lower opening of the outer shell part to the upstream side of the transport surface of the transport conveyor 15, and the metal heating furnace 12 is transported by the transport conveyor 15. Conveyed in. The metal heating furnace 12 includes a rotating cylinder body in which the aluminum can AC and the steel can SC are conveyed, a rotation driving device (not shown) that rotates the rotating cylinder body in the direction around the axis, and the interior of the rotating cylinder body. It is comprised with the rotary kiln provided with the heating apparatus (not shown) which heats.

  For this reason, when the rotation driving device and the heating device are operated in a state where the aluminum can AC and the steel can SC are put in the rotating cylinder, the inside of the rotating cylinder is heated while rotating. As a result, the aluminum can AC and the steel can SC are heated to about 400 ° C. while rolling inside the rotating cylinder. By this heating and rotation, the paint applied on the surface of the aluminum can AC and the steel can SC and the residue inside the aluminum can AC and the steel can SC are combusted. The can body and the lid portion of the steel can SC are easily separated. At this time, foreign matter adhering to the aluminum can AC and the steel can SC is also burned.

  A dust conveyor (not shown) is provided below the metal heating furnace 12, and a secondary combustion furnace 18 communicating with the inside of the rotating cylinder is provided above the metal heating furnace 12. The dust conveyor discharges carbides and powdered dust generated by combustion generated inside the rotating cylinder to the outside. The secondary combustion furnace 18 heats exhaust gas having a temperature of about 400 ° C. generated inside the rotary cylinder to about 850 ° C. and completely burns it, and then sends it to an air cooling tower (not shown). The exhaust gas sent to the air cooling tower is rapidly cooled, filtered through a cyclone and a bag filter dust collector (both not shown), and then exhausted to the outside.

  The aluminum can AC and the steel can SC from which impurities have been removed by the metal heating furnace 12 are transported above the granulator 13 by the transport conveyor 16. The conveyor 16 extends in the horizontal direction at a position where the metal heating furnace 12 side portion and the granulator 13 side portion are different in height (the metal heating furnace 12 side portion is low and the granulator 13 side portion is high). The central portion is inclined upward from the metal heating furnace 12 side toward the granulator 13 side. For this reason, the conveyance direction of the conveyor 16 is stepped from the metal heating furnace 12 toward the granulator 13 and extends obliquely upward.

  The granulator 13 includes a chamber portion 13a and a rotating portion 13b disposed inside the chamber portion 13a and provided with a hammer. A hopper portion 13c is provided on the upper portion of the chamber portion 13a. The hopper 13c receives the aluminum can AC and the steel can SC that are transported by the transport conveyor 16 and fall from the downstream end of the transport conveyor 16, and guides them into the chamber 13a. The aluminum can AC and the steel can SC are sent into the chamber portion 13a through the hopper portion 13c, and the can body and the lid portion are separated in the chamber portion 13a by the rotation of the rotating portion 13b, and are crushed small. And become grainy. Thereby, the aluminum pellet AP and the steel pellet SP are obtained.

  The sorter 14 is a device that sorts the aluminum pellets AP and the steel pellets SP conveyed from the granulator 13 via the pellet conveying conveyor 17a using magnetic force, and the steel on the pellet conveying conveyor 17a. A rotary suction unit 14a is provided that sucks only the pellet SP and sends it to the steel pellet conveyor 17b. That is, of the aluminum pellets AP and the steel pellets SP that are transported by the pellet transporting conveyor 17a, the aluminum pellets AP drop downward at the downstream end of the pellet transporting conveyor 17a and are stored in the aluminum pellet storage box 19a.

  Then, the steel pellet SP is sent to the steel pellet transport conveyor 17b by the sorter 14, falls downward at the downstream end of the steel pellet transport conveyor 17b, and is stored in the steel pellet storage box 19b. At this time, the aluminum pellet AP and the steel pellet SP are respectively sieved, and the powdered aluminum and steel are removed. The aluminum pellets AP and the steel pellets SP obtained by such treatment are blended so that the weight ratio is 50:50, and then the briquette B having a bulk specific gravity of 3.0 is formed by a predetermined briquetting molding device. Molded. In this case, the volume of the aluminum pellet AP is about 2.9 times the volume of the steel pellet SP.

  As the briquette molding apparatus, various molding apparatuses can be used. For example, the briquette molding apparatus 20 shown in FIG. 3 can also be used. The briquette forming apparatus 20 includes a fixed mold 21 and a movable mold 22 that moves forward and backward with respect to the fixed mold 21 (in the direction of arrow a in FIG. 3). Shaped concave portions 21a are formed. In addition, a material filling space 22a having an opening on the mating surface side is formed inside the movable mold 22, and the inside of the material filling space 22a is operated in a direction indicated by an arrow a by operating a drive mechanism (not shown) inside the material filling space 22a. The piston 22b which moves to is arranged. In addition, a material supply port (not shown) communicating with the material filling space 22a is formed in the upper part of the movable mold 22.

  For this reason, the movable die 22 is moved to the fixed die 21 side, and the piston 22b is moved backward (moved to the right in FIG. 3) in a state where the mating surfaces of the fixed die 21 and the movable die 22 are aligned, and the aluminum pellets are moved. After the AP and the steel pellet SP are filled into the material filling space 22a from the material supply port, the piston 22b is moved forward (moved to the left in FIG. 3), so that the space between the molding recess 21a and the piston 22b is reached. Briquette B is formed in the space to be formed. When the briquette B is formed, the movable die 22 is moved backward from the fixed die 21.

  Although not shown, the fixed die 21 is provided with an extrusion pin that can project from the molding surface of the molding recess 21a, and when the movable die 22 moves backward, the extrusion pin projects, The briquette B is pushed out of the molding recess 21a and falls downward. The briquette B formed in this way is used as a deoxidizing agent in a steel mill or the like. The deoxidation treatment is performed in the pig iron manufacturing process and steel making process using a blast furnace, converter, electric furnace, etc., and briquette B is put on the upper surface of the molten iron or molten steel slag layer formed on the surface. Is done.

  In this case, the bulk specific gravity of briquette B is 3.0 and the bulk specific gravity of slag is 2.3 to 2.7 (the bulk specific gravity of molten slag generated in the pig iron manufacturing process is 2.6 to 2.7. Therefore, the briquette B passes through the slag layer and enters the molten metal or molten steel. In this case, the briquette B can pass through the slag layer quickly. Thereby, the aluminum in the briquette B removes oxygen gas in the hot metal or molten steel.

  That is, since aluminum reacts more easily with oxygen than iron or steel and is oxidized, the aluminum in briquette B reacts with the oxygen in hot metal or molten steel by contacting the molten metal or molten steel. By using aluminum dioxide, oxygen is removed from the hot metal and molten steel. In this case, the steel in briquette B melts in hot metal or molten steel and is mixed with the molten iron or molten steel to become a material. Further, the aluminum dioxide generated by deoxidation of the hot metal or molten steel floats on the surface of the molten iron or molten steel and is removed together with the slag. The bulk specific gravity of 2.3 to 2.7 of the slag is obtained by measuring the bulk specific gravity of the cooled and solidified slag, but the bulk specific gravity of the molten slag is almost the same.

  Moreover, as other embodiment which concerns on this invention, when mix | blending the aluminum pellet AP and the steel pellet SP, a silicon | silicone can be added as an additive. In this case, since the specific gravity of silicon is 2.3 to 2.4 and smaller than the specific gravity of the aluminum pellet AP, the volume of the void portion of the briquette according to the present embodiment is made smaller than the volume of the void portion of the briquette B described above. . That is, the pressure during briquetting is increased. Thereby, even if silicon is included, the bulk specific gravity of the briquette can be maintained at 2.9 or more. The silicon content is preferably about 10% by weight. According to this, not only oxygen is removed from the hot metal or molten steel processed by briquette, but the obtained iron or steel can be made strong and difficult to deform both in tension and compression.

  Moreover, the briquette and the manufacturing method of a briquette which concern on this invention are not limited to embodiment mentioned above, It can change suitably. For example, the bulk specific gravity of the briquette and the aluminum content in the briquette can be appropriately changed within the technical scope of the present invention, and the briquette can be formed in various shapes. In this case, by maintaining the bulk specific gravity of the briquette at 2.9 and setting the mixing ratio of the aluminum pellets AP and the steel pellets SP to 60:40 by weight, the deoxidation is performed more than the briquettes of the above-described embodiments. A briquette with excellent effects can be obtained.

  In addition, as a briquette forming apparatus, an apparatus in which two rolls having molding concave portions formed on the peripheral surface are arranged with the peripheral surfaces facing each other can be used. According to this, by rotating the two rolls so that the opposing surfaces of the two rolls move from the upper side to the lower side while sequentially supplying the aluminum pellets AP and the steel pellets SP from above the two rolls, The briquette compression-molded in the recess can be dropped downward. In this case, the shape of the briquette can be made symmetrical.

  DESCRIPTION OF SYMBOLS 12 ... Metal heating furnace, 13 ... Granulator, 14 ... Sorter, 20 ... Briquette forming apparatus, AC ... Aluminum can, AP ... Aluminum pellet, B ... Briquette, SC ... Steel can, SP ... Steel pellet

Japanese Patent Laid-Open No. 7-118765

Claims (7)

  A briquette formed by forming granular aluminum and granular steel and used for hot metal and deoxidation of molten steel in a pig iron manufacturing process and a steel manufacturing process, having a bulk specific gravity of 2.9 or more and a content ratio of the granular aluminum Briquette characterized by having a weight ratio of 50% or more.   The briquette according to claim 1, wherein the granular aluminum and the granular steel are formed by heat-treating used aluminum cans and steel cans to remove impurities and to form particles having a predetermined size. .   The briquette according to claim 1 or 2, which contains silicon as an additive.   The molten iron or molten steel is deoxidized by being put on the upper surface of the slag formed on the surface of the molten iron or molten steel, and then passing through the slag and contacting the molten metal or molten steel, and has a bulk specific gravity. The briquette as described in any one of Claim 1 thru | or 3 used for the process of the hot metal and the molten steel in which 2.3-2.7 slag was formed in the surface. A method for producing briquettes used for deoxidation of hot metal and molten steel in a pig iron manufacturing process and a steelmaking process,
Impurity removal process for removing impurities by heat treatment of used aluminum cans and steel cans;
A granulation step of granulating the aluminum can and the steel can from which the impurities have been removed into granular aluminum and granular steel;
A separation step of separating the granular aluminum and the granular steel;
A blending step of blending the granular aluminum and the granular steel such that the content ratio of the granular aluminum is 50% or more by weight,
A briquette manufacturing method comprising: a molding step of molding the granular aluminum and the granular steel blended in the blending step so as to have a bulk specific gravity of 2.9 or more.   The manufacturing method of the briquette of Claim 5 which contains a silicon | silicone as an additive in the said mixing | blending process.   After the briquette is put on the upper surface of the slag formed on the surface of the hot metal or molten steel, it passes through the slag and comes into contact with the hot metal or molten steel to deoxidize the molten iron or molten steel. The manufacturing method of the briquette of Claim 5 or 6 used for the process of the hot metal and molten steel in which the slag whose specific gravity is 2.3-2.7 was formed in the surface.

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