WO2007058071A1 - Apparatus for compacting steelmaking dust - Google Patents

Abstract

An apparatus (4) for steelmaking dust compaction with which a compact having satisfactory strength can be produced from a raw dust while minimizing the amount of an additive to be added. When this compact is charged again into a furnace, it can improve the thermal efficiency of the furnace. The apparatus (4) for steelmaking dust compaction is an apparatus in which a raw material for compaction (11p), mainly in a granular form, molded from a powdery mixture of a steelmaking dust and a powder consisting mainly of carbon is pressed to form a compact (41). The apparatus (4) comprises a dampening means (10) and a compaction mechanism part (12). The steelmaking dust is a dust consisting mainly of iron and oxides thereof which generates in the course of steel production. The dampening means (10) infiltrates water into the raw material for compaction (11p) consisting mainly of the granules obtained with a granular (5). The compaction mechanism part (12) presses in a die (30) the raw material for compaction (11p) consisting mainly of the granules and dampened by the dampening means (10) to form the compact (41).

Description

 Specification

 Steelmaking dust solidification equipment

 Technical field

 [0001] The present invention is a method of solidifying a steelmaking dust, which is a solidified product, by putting a dust mainly composed of iron and its oxides generated in a steel production process into a molding die and pressurizing and solidifying. The present invention relates to a steelmaking dust solidifying device for producing shaped products.

 Background art

 [0002] In a steel production process, for example, in a melting furnace, fine particles of iron and iron oxide blown up are collected as dust by a dust collector. Since this dust (hereinafter referred to as “steel-making dust”) is mainly composed of iron and iron oxide, it is desirable to reuse it. Since this steelmaking dust is a fine powder, if it is put into the melting furnace as it is, it will fly up and fly away, and most of it will be collected again by the dust collector, and the reuse efficiency will be extremely low. As a result, landfill disposal has traditionally been the mainstay, but the amount of steelmaking dust generated in Japan has reached several hundred thousand tons per year. From the viewpoint of landfill problems and environmental power, it is not preferable.

 [0003] For this reason, various methods have been tried to reuse steelmaking dust! As an example, Patent Document 1 exemplifies a method of collecting acid pig iron in molten iron by making dust pellets having a diameter of about 2 to 15 mm and inserting them into an electric furnace.

 Patent Document 2 describes a method for adding thermoplastics to form steelmaking dust into a pricket.Patent Document 3 describes a method for adding a grinding aid to form grinding sludge steelmaking dust into a pricket. Each is illustrated!

 Patent Document 1: Japanese Patent Laid-Open No. 11 152511

 Patent Document 2: Japanese Patent Laid-Open No. 09-316512

 Patent Document 3: Japanese Patent Laid-Open No. 2002-194449

[0004] The method of making the pellets of Patent Document 1 is easy to handle, such as the process of charging into the electric furnace from the recovered powder, because it is pelletized. There is a problem with charging efficiency. The method of adding the additives of Patent Document 2 and Patent Document 3 is an effective method for producing a strong pliquet. The process is complicated and has the disadvantage of high costs. Also, the additive is not preferable because it causes environmental impact.

[0005] As a method for producing a steelmaking dust solid material having practically sufficient strength without adding an additive, steelmaking dust and a powder mainly composed of carbon are mixed as a raw material to be put in a mold. It has been proposed to use a mixed granulated body granulated together (Japanese Patent Laid-Open No. 2006-225729). Note that carbon-based powders were added because when the solidified material is reused in an electric furnace, etc., the carbon self-combusts while reducing the steelmaking dust and generates heat, and energy is input from the outside. This is because the thermal efficiency of the furnace is improved.

 According to this method, a higher molding density can be obtained than when dust is placed in a powder mold and pressed. Therefore, a practical molding strength can be obtained without using a reinforcing agent such as a binder. However, there were cases where the molding strength was not satisfactory.

 Disclosure of the invention

 [0006] An object of the present invention is an apparatus for pressurizing a dust mainly composed of iron and its acid product generated in the steel production process to form a solid material, which can be used as a raw material dust as much as possible. Provided is a steelmaking dust solidification device capable of producing a solidified product having good forming strength without adding an additive and improving the thermal efficiency of the furnace when re-inserted into the furnace. It is.

 Another object of the present invention is to suppress the generation of cracks after the completion of molding and to ensure productivity.

[0007] A steelmaking dust solid material device according to the present invention is mainly composed of a mixed powder of a dust mainly composed of iron and its oxides generated in a steel production process and a powder mainly composed of carbon. A steelmaking dust solidifying apparatus that pressurizes a forming raw material in a granulated state to obtain a solidified product, a moisture imparting means for impregnating the molding raw material with water, and moisture imparted by the moisture imparting means. And a solidification mechanism portion that pressurizes the molding raw material in a mold to form the solidified product. The rest of the molding raw material excluding the granulated body is in a mixed powder state. Mainly carbon The powder used as a component is not limited to pure carbon powder, and may be graphite.

 [0008] According to this configuration, since dust is granulated and put in a mold and pressed, a higher molding density can be obtained than when dust is put in a mold and pressed in powder form. In this case, since the moisture imparting means impregnates the molding raw material with water immediately before molding by the molding die, the surface of the granulated body in the molding raw material becomes soft, and deformation of the granulated body is not possible when pressing with the molding die. It becomes easy, and a better molding strength can be obtained by increasing the adhesive strength between the granulated bodies. For these reasons, it is possible to secure the necessary strength of the solidified material without adding additives to the raw material dust provided.

 The molding raw material is a mixed granulated material in which steel dust and carbon-based powder are mixed, and the powder containing carbon as the main component is added. When used, the carbon self-combusts while reducing the steelmaking dust and generates heat, reducing the energy input of external power and improving the thermal efficiency of the furnace. Since powder containing carbon as a main component can be easily obtained in or around the steel production process, as with steelmaking dust, even if added, the increase in cost can be suppressed. Force that may reduce the strength of solid materials due to the addition of powder containing carbon as the main component. As described above, the granulated body is impregnated with water just before forming with a mold, so carbon Even if these are added, good molding strength can be obtained.

 [0009] In the present invention, the molding raw material may have a carbon content of 15 to 20% by weight. The higher the carbon content, the greater the effect of improving the thermal efficiency of the furnace when re-charging the furnace. However, as the carbon content increases, the strength of the solid material decreases, and if it exceeds 20% by weight, it is difficult to obtain a practical strength. As a result of the test, it was found that the range of 15 to 20% by weight of the carbon content of the molding raw material is effective for obtaining a good molding strength of the solidified product.

 [0010] In the present invention, the molding raw material may have a moisture content of 8 to 10% by weight.

As a result of the test, it was found that the range in which the water content of the molding raw material was 8 to 10% by weight was effective to obtain a good molding strength of the solidified product. [0011] In the present invention, the moisture imparting means may impart 0.5 to 3% by weight of moisture to the molding raw material immediately before molding. If the amount of additional water is small, the effect of facilitating deformation of the granulated body and the effect of improving the adhesive strength between the granulated bodies are reduced. Conversely, if the amount of additional water is excessive, the granulated body is softened. Molding becomes difficult.

 As a result of the tests, it was found that the range of 0.5 to 3% by weight of the above-mentioned additive content of water in the molding raw material is effective for obtaining good molding strength of the solidified product.

 [0012] In the present invention, the forming raw material may be one in which the ratio of the granulated body is 60% by weight or more. When this proportion is low and the proportion of powder increases, the forming strength decreases.

 As a result of the test, it was found that the range in which the ratio of the granulated material is 60% by weight or more is effective for obtaining good molding strength of the solidified product.

 [0013] In the present invention, the solidification mechanism section is provided with a cylindrical mold, a lid that opens and closes one end of the mold, and is movable in the mold so as to move the molding raw material. A plunger for pressing, a pressurizing mechanism for moving the plunger back and forth, and a pressurizing mechanism control means for controlling the pressurizing mechanism. The plunger presses the solidified product obtained by pressurizing in the mold. The pressurizing mechanism control means may include a control means for making the speed of the plunger at the time of extrusion of the mold force after completion of molding higher than the speed at the time of pressurization. good.

 In this configuration, the pressurizing speed of the plunger is controlled by the pressurizing mechanism control means so that the speed of the plunger when pushing out the mold force after the molding is completed is higher than the speed at the time of pressurization. Yes. For this reason, the raw material force mainly for the granulated body during the pressurization at a low pressurizing speed of the plunger is secured, and the time for the air to escape is secured, and the occurrence of cracks in the solid material after the molding is suppressed. In addition, the molding force can be shortened by high-speed extrusion by the plunger.

[0014] In the present invention, the solidification mechanism is provided in a standing cylinder-shaped mold, an upper plunger that is a lid for opening and closing the upper end of the mold, and capable of moving forward and backward in the mold. A lower plunger that pressurizes the molding raw material and a pressurizing mechanism that moves the plunger back and forth, and the mold is located above the mold on the side of the mold of the solidification mechanism. A first cylinder that contains the molding raw material to be supplied to The first cylinder is provided with a cut-out mechanism for cutting out and supplying a molding raw material corresponding to one solid cake from the granulator, and the upper end communicates with the lower end of the first cylinder. A second cylindrical body that is slidable between a position and an advanced position where the lower end communicates with the upper end of the molding die, and the molding raw material inside the first cylindrical force is pushed into the second cylindrical body at the retracted position. A granulation body push-in mechanism is provided, a nozzle serving as the moisture applying means is provided in the push-in mechanism, and the lower plunger pushes the molded solid article upwards the molding die force, and the second cylindrical body The solid container to be pushed out may be pushed out from the upper side of the mold when moving from the retracted position to the advanced position.

 According to this configuration, the solidified product can be efficiently formed.

 Brief Description of Drawings

 [0015] The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and description, and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same part number in a plurality of drawings indicates the same part.

 FIG. 1 is a schematic view showing a steelmaking dust solid material device according to an embodiment of the present invention.

 FIG. 2 is a partially broken front view showing a solidification mechanism portion in the steel dust solidifying device.

FIG. 3 is a plan view of a part of a solidification mechanism part in the steel making dust solid material dripping device.

 FIG. 4 is a side view of a granulation body pushing mechanism in the steel dust / dust solidifying device.

 FIG. 5 is a cross-sectional view showing a slide guide mechanism of a second cylindrical body in the steel dusting solid material filing apparatus.

 FIG. 6 is a schematic configuration diagram showing a pressurizing mechanism control means of a lower plunger in the steel making dust solid material haze device.

 FIG. 7 is a process diagram in a solidification mechanism part in the steel dusting solids device.

 BEST MODE FOR CARRYING OUT THE INVENTION

One embodiment of the present invention will be described with reference to FIGS. 1 to 7. In Fig. 1, the steelmaking dust generated in the melting furnace 1 is introduced into the dust collector 3 through the exhaust duct 2 together with the exhaust gas, and is exhausted. The steelmaking dust 11 inside is collected by the dust collector 3 and discharged as powder. This steelmaking dust 11 is mainly composed of iron and its oxides. The steelmaking dust 11 discharged from the dust collector 3 is put into the first hopper 6A of the granulating device 5 in the steelmaking dust solidifying device 4 by a conveying means (not shown), and carbon and water are captured by the granulating device 5. Obtain molding raw material l ip mainly composed of granules. The steelmaking dust solidifying device 4 has a moisture imparting means 10 for impregnating water into a molding raw material l ip mainly composed of the granulated material obtained by the granulating device 5, and moisture is imparted by the moisture imparting means 10. The molding raw material l ip is pressurized in the molding die 30 to form a solidified product 41 and a solidification mechanism 12.

 [0017] The granulating device 5 is a device that mixes the steelmaking dust 11, the powder mainly composed of carbon, and water into a granulated body. The carbon-based powder is not limited to pure carbon powder, and may be graphite.

 [0018] The granulated body has a particle size of, for example, 5 to 15 mm, and the molding raw material l ip mainly composed of this granulated body has a carbon content of 15 to 20% by weight and a water content of 8 to 8%. 10% by weight, the proportion of granulated material is 60% by weight or more, and the proportion of mixed powder is 40% by weight or less.

[0019] The forming raw material l ip mainly composed of the granulated body of the steelmaking dust 11 granulated by the granulator 5 is accommodated in the first cylindrical body 14 via the cutting mechanism 13 of the solidifying mechanism section 12. The An enlarged front view of the solidifying mechanism 12 is shown in FIG. As shown in the figure, the cutting mechanism 13 includes a hopper 15 into which a molding raw material l ip mainly composed of the granulated body obtained in the granulating mechanism section 7 is placed, and the granulated body accommodated in the hopper 15. A plurality of storage chambers 16a each containing a predetermined amount of molding material lip each containing a fixed amount of a circular divided housing 16 divided in the circumferential direction, and the divided housings 16 around the axis of the housing chamber 16a. And a drive unit 17 that rotates intermittently by one unit. FIG. 3 shows a partial plan view of the cutting mechanism 13. As shown in the figure, each of the storage chambers 16a of the divided storage body 16 is open at the top, and when the opening is located at the discharge port 15a of the hopper 15, the granulated body from the hopper 15 into the storage chamber 16a. It is filled with molding raw material l ip. Further, when the position force dividing container 16 is rotated by one of the accommodating chambers 16a, a predetermined amount of molding raw material ip is cut from the hopper 15 into the accommodating chamber 16a. The bottom plate 16c (FIG. 2) of the divided container 16 is separated from the upper body 16b, and the upper body 16b slides on the bottom plate 16c. One part of the storage chamber 16a is included in a part of the bottom plate 16c. The opening of 16 minutes is provided. It has been. When one of the storage chambers 16a comes to the rotational position aligned with the opening 16ca, the fixed amount of molding raw material l ip stored in the storage chamber 16a passes through the shout 18 provided in the opening 16ca and the first Is inserted into the cylinder 14. The molding raw material 1 lp mainly composed of the granulated material charged into the first cylinder 14 by the cutting mechanism 13 is determined as one solidified material 41 formed by the solidifying mechanism 12. .

 As shown in FIG. 2, a second cylinder 19 is provided below the first cylinder 14. The second cylinder 19 is slidably provided at a retracted position where the upper end communicates with the lower end of the first cylinder 14 and an advanced position where the lower end communicates with the upper end of the molding die 30 described later. Above the first cylinder 14 is provided a granulation body pushing mechanism 20 for pushing the molding raw material l ip inside from the cylinder 14 into the second cylinder 19 in the retracted position.

 As shown in a side view in FIG. 4, the granulated body push-in mechanism 20 includes a plunger 21 that can be moved forward and backward in the first cylindrical body 14, a drive device 22 that drives the plunger 21 forward and backward, and the like. Consists of. The driving device 22 is, for example, a cylinder force and is installed on the frame 25 together with the hopper 15 and the driving device 17 of the cutting mechanism 13. The frame 25 is provided with a pair of guide sleeves 23, 23 at a position sandwiching the driving device 17. The pair of guide rods 24, 24 projecting upward from the plunger 21 is connected to the guide sleeves 23, 2 3. The plunger 21 is guided up and down by being inserted through the.

 [0022] In the plunger 21, there is provided moisture imparting means 10 for impregnating water into the molding raw material lip mainly composed of the granulated body charged in the first cylindrical body 14. The moisture applying means 10 is, for example, a nozzle cutter, and applies moisture so that the additional content ratio of moisture in the molding raw material 1 lp mainly composed of the granulated body is 0.5 to 3% by weight.

As shown in a cross-sectional view in FIG. 5, the second cylinder 19 is moved between the retracted position and the advanced position by the guide member 28 provided on the frame 27 that holds the mold 30. It can be slid freely. The guide member 28 has a guide hole 28a extending in the lateral direction, and a guide convex portion 29a provided on the outer periphery of a ring-shaped holder 29 that holds the second cylindrical body 19 is formed on a side surface of the guide hole 28a. By being guided by the guide groove 28aa, the second cylinder 19 can be slid in the lateral direction. The slide is performed by a driving device such as a cylinder not shown. As shown in FIG. 2, the forming die 30 is in a standing cylinder shape and is disposed below the second cylindrical body 19 in the advanced position. An upper plunger 31 that is a lid that opens and closes the upper end of the mold 30 is provided above the second cylinder 19 in the forward movement position, and can be moved forward and backward in the mold 30 below the mold 30. A lower plunger 32 for pressurizing the molding raw material 1 lp is provided. The upper plunger 31 is a member coupled to the advance / retreat rod of the fluid pressure cylinder 33, and advances into the second cylinder 19 at the forward movement position so that the molding raw material ip in the cylinder 19 is put into the mold 30. At the same time, close the upper end of the mold 30 in the advanced position.

 As shown in FIG. 6, the lower plunger 32 is driven back and forth by a pressurizing mechanism 34 that also has a fluid pressure cylinder force, and the pressurizing mechanism 34 is controlled by a pressurizing mechanism control means 35. The lower plunger 32 can extrude the solid container 41 obtained by pressurizing in the mold 30 to the upper plunger 31 side which is a lid. The pressurizing mechanism 34 includes a hydraulic cylinder 36 that is a drive source of the upper plunger 31, a hydraulic pump 37 that pumps oil from the hydraulic tank 38 to the hydraulic cylinder 36, and the like.

 [0026] The pressurizing mechanism control means 35 controls the advance speed of the lower plunger 32, and a proportional valve 39 arranged in the middle of an oil supply path connecting the hydraulic cylinder 36 and the hydraulic tank 38, or the proportional valve It consists of a controller 40 for controlling the valve 39. The proportional valve 39 may be a force servo valve that also serves as an electromagnetic proportional control valve. By this pressurizing mechanism control means 35, the speed of the lower plunger 32 when the solid container 41 is pushed out from the mold 30 after the molding is completed is made higher than the speed at the time of pressurization.

 In the vicinity of the lower plunger 32, a plurality of position detection sensors 42 are arranged side by side in the advance / retreat direction of the lower plunger 32, and the target 43 of the position detection sensor 42 is provided on the lower plunger 32. Thereby, the advance position of the lower plunger 32 is detected by the position detection sensor 42. The detection signal is input to the controller 40, and the advance speed of the lower plunger 32 is controlled based on the detection signal.

 The solidified product forming process of the solidification mechanism 12 in the steelmaking dust solidifying device 4 having the above-described configuration will be described below with reference to FIG.

When the molding raw material l ip consisting of a mixed powder of steelmaking dust 11 and carbon-based powder is stored in the first cylindrical body 14 from the divided housing 16 of the cutting mechanism 13 by a fixed amount, FIG. ( As shown in (A), from the moisture applying means 10 provided on the plunger 21 of the granule pushing mechanism 20, the granulated material in the first cylinder 14 is mainly used as a molding raw material l ip from 0.5 to 3 Additional moisture by weight is added.

 Next, as shown in FIG. 7 (B), the plunger 21 of the granulation body push-in mechanism 20 advances into the first cylinder 14 in the retracted position, and molding in the first cylinder 14 is performed. The raw material l ip is pushed into the second cylinder 19. When the pushing is completed, the second cylinder 19 is slid to the advanced position as shown in FIG. 7C, and the lower end of the second cylinder 19 communicates with the upper end of the mold 30.

 Next, as shown in FIG. 7 (D), the upper plunger 31 advances into the second cylinder 19 and the molding material l ip in the second cylinder 19 is pushed into the mold 30 and the upper plunger 31 stops at the advanced position as a lid that closes the upper end of the mold 30. Under this condition, as shown in FIG. 7 (E), the lower plunger 32 advances into the molding die 30 and the molding raw material l ip mainly composed of the granulated body in the molding die 30 is pressurized, As a result, the solidified product 41 is formed.

In this case, the molding raw material 1 lp mainly composed of the granulated body in the molding die 30 is additionally given 0.5 to 3% by weight of moisture by the moisture imparting means 10 before this molding step. Therefore, the surface of the granulated body becomes soft and the deformation of the particles becomes easy at the time of pressurization, and the adhesive strength between the particles increases, so that a good molding strength can be obtained. Further, the advancement speed of the lower blanker 32 at the time of pressurization of the molding is made lower than when the molded solid material 41 is extruded from the mold 30 by the pressurization mechanism control means 35 (FIG. 6). This ensures the time for air to escape from the molding raw material l ip mainly composed of the granulated body during molding, so that it is possible to suppress the occurrence of cracks in the solid material 41 after the molding is completed.

 Therefore, it is possible to produce a solidified product 41 that has a good forming strength with as little additive as possible added to the steelmaking dust 11 that is a raw material and has few cracks after forming.

Next, as shown in FIG. 7 (F), the lower plunger 32 is moved with the upper plunger 31 retracted upward from the second cylinder 19 and the second cylinder 19 slid to the retracted position. Then, the solidified material 41 in the mold 30 is pushed out of the mold 30. The advancement speed of the lower plunger 32 at the time of extrusion is made faster than that at the time of molding by the pressurizing mechanism control means 35 (FIG. 6). The speed of the lower plunger 32 is switched by the proportional valve 39 in the pressurizing mechanism control means 35. This speeds up the process of discharging the solidified material 41 from the mold 30 after the molding is completed, thereby shortening the processing cycle time.

 The solid material 41 pushed out from the mold 30 is moved to the chute 4 disposed on the side of the mold 30 by the second cylinder 19 that slides to the advanced position after the retreat position force in the next machining cycle. 4 is pushed out from the chute 44 and then carried out by a conveyor 45 such as a competitor (FIG. 2).

 As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily consider various changes and modifications within the obvious scope by looking at the present specification.

 Accordingly, such changes and modifications are to be construed as within the scope of the invention, which also defines the power of the claims.

Claims

The scope of the claims  [1] Add molding raw materials mainly made into a granulated powder mixture of dust mainly composed of iron and its oxides generated in the steel production process and powder mainly composed of carbon. A steelmaking dust solidifying device that is pressed into a solidified product,  A steelmaking dust solid container comprising: a moisture imparting means for impregnating the molding raw material with water; and a solidification mechanism portion that pressurizes the molding raw material to which moisture has been imparted by the moisture imparting means in a molding die to form the solidified product. apparatus.  [2] The steelmaking dust solidifying device according to claim 1, wherein the forming raw material has a carbon content of 15 to 20% by weight. [3] The steelmaking dust solidifying apparatus according to claim 1, wherein the forming raw material has a moisture content of 8 to 10% by weight.  [4] The steelmaking dust solid soot device according to claim 1, wherein the moisture imparting means imparts 0.5 to 3% by weight of moisture to the molding raw material immediately before molding.  [5] A steel-making dust solid material device according to claim 1, wherein the ratio of the granulated material of the forming raw material is 60% by weight or more and the ratio of the mixed powder is 40% by weight or less.  [6] In Claim 1, the solidification mechanism section includes a cylindrical mold, a lid that opens and closes one end of the mold, and a movable body that can be moved forward and backward in the mold, so that the molding raw material is removed. A plunger for pressing the pressure, a pressurizing mechanism for moving the plunger back and forth, and a pressurizing mechanism control means for controlling the pressurizing mechanism, wherein the plunger is a solidified product obtained by pressurizing in the mold. The pressure mechanism control means has a control function to increase the speed of the plunger at the time of extrusion of the molding die force after the molding is completed than the speed at the time of pressurization. Steelmaking dust solidification equipment.  [7] In Claim 1, the solidifying mechanism section is configured to be a standing cylinder-shaped mold, an upper plunger that is a lid that opens and closes the upper end of the mold, and advancing and retreating in the mold. A lower plunger provided to pressurize the molding raw material, and a pressurizing mechanism for moving the plunger forward and backward. A first cylindrical body that accommodates a molding raw material to be supplied to the molding die is provided above the molding die on a side of the molding die of the solidification mechanism portion, and the first cylindrical body. Is provided with a cutting mechanism for cutting out and supplying the raw material corresponding to one solidified material from the hot tub, and a retracted position where the upper end communicates with the lower end of the first cylinder and the lower end at the upper end of the mold. A second cylindrical body is provided that can be slid at a forward position that communicates therewith, and a granule push-in mechanism is provided that pushes an internal molding raw material from the first cylindrical body into a second cylindrical body at a retracted position, The pushing mechanism is provided with a nozzle serving as the moisture applying means, the lower plunger pushes the molded solid article upwards the molding die force, and the second cylinder is the solid article to be pushed out. Is a steelmaking dust solid material device that is pushed when moving from the retracted position to the advanced position and removed from the upper cover of the mold.