Rotary stirring type heat treatment device

Abstract

To provide rotation agitation type heat treatment equipment capable of surely performing heat treatment on, in particular, a massive treatment object, and a heat treatment method using the equipment.SOLUTION: Rotation agitation type heat treatment equipment performing heat treatment on a treatment object is provided, comprising: a heat treatment unit having a cylindrical body which is supplied with the treatment object, from one end of the cylindrical body and performs heat treatment on the treatment object therein, and discharges the treatment object from the other end; heating means heating the inside of the cylindrical body; and treatment zone formation means forming a plurality of treatment zones divided in a circumferential direction of the cylindrical body, and provided inside the cylindrical body and forming a plurality of treatment zones along a longitudinal direction of the cylindrical body. The treatment zone formation means has such structure that it is rotated while oscillated by rotation of the cylindrical body and movement of the treatment object supplied to each treatment zone, to the other treatment zone is suppressed.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a rotary agitation type heat treatment apparatus that performs agitation heat treatment on a workpiece, and a heat treatment method using said apparatus. [Background technology]

[0002] A rotary agitation type heat treatment device is used to perform various heat treatments on objects to be treated. This rotary agitation type heat treatment device introduces the objects to be treated into a rotating cylindrical furnace, and performs heat treatment on the objects to be treated while moving them from the upstream to the downstream of the furnace by the rotation of the cylindrical furnace. On the other hand, the purpose of this heat treatment varies depending on the object to be treated, and examples of such purposes include calcination for lime, mixing for electrode materials, and oxidation for metal powder.

[0003] In this rotary stirring type heat treatment apparatus, various proposals have been made to perform the heat treatment more effectively.

[0004] For example, Patent Document 1 describes a rotary stirring type heat treatment device having a beater member that rolls on the inner circumference of a rotating furnace tube to impart an impact to the workpiece, and it is said that the rolling beater member imparts an impact to the workpiece, preventing the workpiece from adhering to the inner circumference of the furnace tube.

[0005] Furthermore, for example, Patent Document 2 describes a rotary stirring type heat treatment device having a rotor composed of three or four blades inside a rotating furnace tube, in which L / R is 0.1 to 0.6, where L is the length of the rotor blades and R is the inner diameter of the furnace tube, and it is said that this device can oxidize electrolytic copper powder to cupric oxide powder. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2012-163282 A [Patent Document 2] Patent No. 6056709 Summary of the Invention [Problem to be solved by the invention]

[0007] The rotary agitation type heat treatment device described in Patent Document 1 is intended for heat treatment of lime-based objects of 5 mm or less, and the rotary agitation type heat treatment device described in Patent Document 2 is intended for heat treatment of electrolytic copper powder, so that if the object to be treated is a powder or a small object close to powder in size, the heat treatment devices described in Patent Documents 1 and 2 can perform the heat treatment as described. However, Patent Documents 1 and 2 do not describe the heat treatment of lumpy objects, and the inventor's investigation has revealed that although these rotary agitation type heat treatment devices have beater members or rotors, it is difficult to perform sufficient heat treatment when actually performing heat treatment on lumpy objects.

[0008] In particular, an object of the present invention is to provide a rotary stirring type heat treatment apparatus capable of reliably carrying out heat treatment on a lump-shaped object to be treated, and a heat treatment method using said apparatus. [Means for solving the problem]

[0009] The present inventors have conducted extensive research into the structure of a rotary stirring type heat treatment apparatus capable of heat treating even lump-shaped objects, such as lump scrap containing tungsten (W), for which there has been a demand in recent years for inexpensive and reliable recycling, that do not pass through a 5 mm sieve but pass through a 30 mm sieve. Here, sieves with openings of 5 mm and 30 mm refer to sieves having square openings with sides measuring 5 mm and 30 mm, respectively.

[0010] As a result, we have gained the novel discovery that reliable heat treatment can be achieved by dividing a cylinder (furnace tube) in the inner circumferential direction and providing multiple processing zones along the longitudinal direction of the cylinder, rotating these processing zones by the rotation of the cylinder, and preventing the chunks of material supplied to each processing zone from migrating (moving) to other processing zones, so that the material is heat-treated while being stirred, crushed, and sized.

[0011] The present invention is based on this finding and is as follows. "(1) A rotary stirring type heat treatment device for heat-treating a workpiece, The treated material does not pass through a sieve having square openings with a side length of 5 mm, but passes through a sieve having square openings with a side length of 30 mm. Contains tungsten of a size Lumpy Scrap of and The workpiece is fed into one end, heat-treated inside, and discharged from the other end. 1 piece a heat treatment section having a cylindrical body; A heating means for heating the inside of the cylindrical body; a treatment zone forming means for forming a plurality of treatment zones inside the cylinder, the treatment zones being divided in an inner circumferential direction of the cylinder and arranged along a longitudinal direction of the cylinder; The treatment zone forming means is a radiblade having a cylindrical portion at its center and a plurality of blades provided at equal intervals on the outer periphery of the cylindrical portion, The above Radiblade rotates while oscillating due to the rotation of the cylindrical body, The radiator blade has an M / D ratio of 0.01 to 0.10, where M is the distance between the tip of the blade and the inner circumference of the cylinder when the radiator blade is placed at the center of the cylinder and D is the inner diameter of the cylinder, The material to be treated supplied to each of the treatment zones has a structure that allows movement of 10% by volume or less to other treatment zones, In each of the treatment zones, the material is stirred, crushed, and sized while being oxidized at 850 to 900°C. thing, A rotary stirring type heat treatment device characterized by the above. ( 2 ) The above-mentioned Radiblade The number of the blades is 8 to 16. , in the radial direction of the cylindrical body of The cross-sectional area of ​​the cylindrical portion is 25 to 35% of the cross section. 1) The rotary stirring type heat treatment device according to claim 1 . ( 3 ) mentioned above (1) or (2)A method for heat treating an object to be treated, comprising using the rotary stirring type heat treatment device described in the above. Effect of the Invention

[0012] The rotary stirring type heat treatment device of the present invention is particularly capable of reliably heat-treating bulk materials, and the heat treatment method of the present invention is a method for reliably heat-treating the bulk materials. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view of an example of a rotary stirring type heat treatment apparatus of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of an example of a treatment zone forming means. [Diagram 3] FIG. 11 is a schematic cross-sectional view of another example of the treatment zone forming means. [Figure 4] FIG. 11 is yet another schematic cross-sectional view of the treatment zone forming means. [Diagram 5] FIG. 5 is a schematic perspective view of the treatment zone forming means of FIG. 4. [Figure 6] 5 is a schematic diagram for explaining the distance between the processing zone forming means in FIG. 4 and the inner circumference of a cylinder. FIG. [Figure 7] FIG. 7 is an enlarged view of the circled portion in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention for heat-treating a block of material to be treated will be described with reference to the drawings, but the present invention is not limited to the following embodiment.

[0015] In this specification, the term "lump material" refers to a lump material that does not pass through a 5 mm sieve but passes through a 30 mm sieve (in the case of crushing a lump material that does not pass through the 30 mm sieve, the crushed lump material that passes through the 5 mm sieve is called "lump material"). doExamples of heat treatment of the lump-shaped workpiece include oxidation treatment in the air (in an oxidizing atmosphere) for metals such as titanium, molybdenum, chromium, copper, etc., and calcination treatment for industrial waste such as scrap.

[0016] FIG. 1 shows a rotary stirring type heat treatment according to an embodiment of the present invention. Device 1 has, from upstream to downstream, a supply section 2, a heat treatment section 3, and a discharge section 4. In Fig. 1, the illustration of a processing zone forming means provided in the heat treatment section 3 is omitted.

[0017] The supply section 2 has, for example, a hopper 21 and a screw conveyor 22 (detailed configuration is omitted in the drawing). Agglomerated objects to be heat-treated, for example, agglomerated scrap containing tungsten, are stored in the hopper 21, and a predetermined amount of the stored agglomerated objects is supplied to the heat treatment section 3 by the screw conveyor 22.

[0018] The discharge section 4 has discharge means 41 for discharging the chunks of material that have been heat-treated in the heat treatment section 3 out of the rotary stirring type heat treatment device 1. There are no particular restrictions on the structure of this discharge means 41, so long as it is capable of discharging the chunks of material that have been heat-treated, and any known means may be used as appropriate.

[0019] The heat treatment section 3 has a cylindrical body (furnace tube) 31 that is rotated by a means not shown. The cylindrical body 31 is inclined so that one end side (the side having the supply section 2, upstream) is higher than the other end side (the side having the discharge section 4, downstream) relative to a frame not shown. In other words, the height of the cylinder 31 is lower on the discharge section 4 side than on the supply section 2 side. A processing zone forming means 5 is provided inside the cylinder 31, and as described later, the processing zone forming means 5 rotates while swinging due to the rotation of the cylinder 31, and the lumpy processing material supplied from the supply section 2 is heat-treated while being stirred, crushed, and sized (details will be described in the explanation of the processing zone forming means 5), and moves toward the discharge section 4. Then, when the lumpy processing material arrives at the end of the cylinder 31 on the discharge section 4 side, it falls into the discharge section 4 and is discharged outside the rotary stirring type heat treatment device 1 by the discharge means 41.

[0020] Although not shown in the figure, the heat treatment section 3 is provided with a heater, for example, a resistance heater, as a heating means for heating the lump workpiece, and the heater is caused to generate heat to heat the inside of the cylinder 31 to a predetermined temperature. A predetermined gap is provided between the cylinder 31 and the heater so that the cylinder 31 can rotate.

[0021] A processing zone forming means 5 is provided inside the cylinder 31, which divides the cylinder 31 in the inner circumferential direction and forms a plurality of processing zones 6 along the longitudinal direction of the cylinder. The processing zone forming means 5 has a structure (the specific structure will be described later) that prevents the chunks of material supplied to each of the plurality of processing zones 6 from moving to other processing zones 6 while being heat-treated by the rotary stirring type heat treatment device 1, and has a structure that rotates while swinging due to the rotation of the cylinder 31. Here, preventing the chunks of material from moving does not mean that the chunks of material do not move at all, but means that a maximum of about 10% by volume of the chunks of material in each processing zone 6 is allowed to move.

[0022] The reason for adopting such a structure for the treatment zone forming means 5 will be explained. In the treatment zone forming means 5 such as the beater member described in the above-mentioned Patent Document 1 and the rotor described in the same Patent Document 2, although the treatment zone forming means 5 rotates while oscillating due to the rotation of the cylindrical body of the rotary stirring type heat treatment device, the chunks to be treated in each treatment zone 6 are not prevented from moving to other treatment zones 6 during heat treatment. Therefore, the chunks to be treated that have not been oxidized by the heat treatment are covered by the oxidized chunks to be treated, and when the chunks to be treated are viewed as a whole, unoxidized portions remain, making it difficult to perform uniform heat treatment. This is to prevent this.

[0023] Examples of the treatment zone forming means 5 cut along a radial cross section of the cylinder 31 are shown diagrammatically in FIGS.

[0024] As is clear from the figures, the treatment zone forming means 5 shown in Figures 2 and 3 has a cylindrical portion 7 which is a cylindrical cavity in the center and treatment zones 6 around it, and rotates while oscillating due to the rotation of the cylinder 31, and the outer edges of each treatment zone 6 are isolated from each other, so that the chunks of material supplied to each treatment zone 6 are prevented from moving to other treatment zones 6 while being heat treated by the rotary stirring type heat treatment device 1 (they do not move).

[0025] The treatment zone forming means 5 shown in Fig. 4 uses a ruddy blade, and a schematic perspective view of the means is shown in Fig. 5. As is clear from these figures, the ruddy blade has a cylindrical part 7 at the center, and this cylindrical Part 7 A plurality of blades are provided at equal intervals around the outer periphery of the treatment zone 6.

[0026] Although the number of ruddy blades shown in Figure 4 is eight, the object of the present invention can be achieved with just two ruddy blades, and the object of the present invention can be achieved more reliably with 3 to 16 ruddy blades, and is preferably achieved even more reliably with 4 to 8 ruddy blades.

[0027] As described above, it is more preferable to adjust the distance between the tip of the blade of the ruddy blade and the inner circumference of the cylinder 31 in order to prevent the chunks of material to be treated supplied to each treatment zone 6 from moving to another treatment zone 6 during heat treatment. For chunks of material to be treated, for example, as shown in Figures 6 and 7, when the center of the cylindrical part of the ruddy blade is aligned with the center of the cylinder, the distance between the tip of the blade of the ruddy blade and the inner circumference of the cylinder is M and the inner diameter of the cylinder is D, it is more preferable that M / D is 0.01 to 0.10 (1 to 10%).

[0028] The reason is that within this range, the lumpy materials are heat-treated while being agitated, crushed, and rectified by the oscillating rotation of the ruddy blade caused by the rotation of the cylinder, and the lumpy materials supplied to each treatment zone 6 are more reliably prevented from moving to other treatment zones 6. When the heat treatment is for the purpose of oxidation treatment, an M / D of 0.01 to 0.10 (1 to 10%) further improves the oxidation rate.

[0029] When the treatment zone forming means 5 is a ruddy blade, the treatment zone forming means 5 may be one or a plurality of treatment zones of the same shape, for example, four, may be provided from the upstream to the downstream of the cylinder 31. In this case, each treatment zone forming means 5 rotates almost synchronously. Therefore, in adjacent treatment zone forming means 5, the lumpy material in each treatment zone 6 of the upstream treatment zone forming means 5 moves to each treatment zone 6 of the downstream treatment zone forming means 5 by the rotation of the tilted cylinder 31.

[0030] In addition, when the treatment zone forming means 5 is a ruddy blade, it is preferable to provide a plurality of treatment zone forming means 5 of the same shape rather than providing a single treatment zone forming means 5 from the upstream to downstream (longitudinal direction of the cylinder 31) of the cylinder 31. In other words, each treatment zone forming means 5 is lighter and easier to handle, and in the event of damage, only the corresponding treatment zone forming means 5 needs to be replaced.

[0031] Here, the mechanism by which the processing zone forming means 5 shown in Figs. 2 to 5 rotates while swinging due to the rotation of the cylinder 31 will be described. First, the processing zone forming means 5 rotates slightly in the same direction as the rotating body 31 in association with the rotation of the cylinder 31. That is, due to the rotation of the rotating body 31, the processing zone forming means 5 rotates slightly while the tip of the processing zone forming means 5 is in contact with the inner circumference of the cylinder 31. Then, when this rotational movement is performed by a predetermined amount, the center of gravity of the processing zone forming means 5 is shifted, and the tip of another processing zone forming means 5 that was not in contact with the inner circumference of the cylinder 31 until then comes to contact the inner circumference of the cylinder 31, and the processing zone forming means 5 rotates with swinging. By continuing to change the tip of the processing zone forming means 5 that is in contact with the inner circumference of the cylinder, the processing zone forming means 5 rotates while swinging in the same direction as the cylinder 31 at a rotation speed different from that of the cylinder 31.

[0032] As the treatment zone forming means 5 rotates while oscillating, the chunks of material to be treated supplied to each treatment zone 6 formed by the treatment zone forming means 5 are stirred, crushed and sized within each treatment zone 6, and are efficiently heat-treated.

[0033] It is preferable to supply approximately the same amount of lumpy materials to each treatment zone 6. This is because the lumpy materials in each zone can be uniformly exposed to the atmosphere inside the cylinder 31, and the treatment zone forming means 5 rotates uniformly, so that the lumpy materials are more reliably agitated in the treatment zone 6.

[0034] 2 to 5, the area indicated as the cylindrical portion 7 is not the processing zone 6, and the lump-shaped material is not supplied thereto. ofThe proportion of the cross-sectional area of ​​the cylindrical portion 7 in the cross section is preferably 25 to 35%. The reason for this is that within this range, the movement of the lumpy material to be treated at the center of the cylindrical body 7 is reliably suppressed, ensuring high production efficiency. However, when the treatment zone forming means 5 is a ruddy blade and the number of blades is three or less, the proportion of the cross-sectional area of ​​the cylindrical portion 7 that it occupies is not particularly specified, so long as the ruddy blade can ensure the mechanical strength required for the treatment zone forming means 5.

[0035] Needless to say, the present invention includes any shape other than those shown in these figures, as long as the processing zone forming means 5 is configured to prevent the movement of the chunks of material to other processing zones 6 during heat treatment due to the rotation of the cylinder 31 of the rotary stirring type heat treatment device 1. EXAMPLES

[0036] An embodiment of the rotary stirring type heat treatment apparatus of the present invention will be specifically described below, but the present invention is not limited to this embodiment at all.

[0037] Scrap containing tungsten (WC-Co scrap (mass ratio of WC to Co is 9:1)) was used as the lump treatment material. This scrap was crushed. Then, this scrap was subjected to heat treatment using a rotary stirring type heat treatment device 1 in which the treatment zone forming means 5 was a ruddy blade. The results (Examples 1 to 8) are shown in Table 1.

[0038] In contrast, for comparison, a comparative example was used in which the same scrap as in Examples 1 to 8 was used as the lump-shaped treated material, but no treatment zone forming means 5 was provided (Comparative Example 1), and although a ruddy blade was provided as the treatment zone forming means 5, the lump-shaped treated material in each treatment zone was not prevented from moving to another treatment zone. (Comparative Examples 2 to 4) Rotational Agitation Type Heat Treatment Device The results are shown in Table 2.

[0039] In Tables 1 and 2, the supply amount, treatment temperature, and treatment time are the same, and only the presence or absence of a treatment zone forming means, or the presence or absence of suppression of the movement of the lumpy treated material, are different. Here, the supply amount refers to the amount of scrap supplied, the treatment temperature refers to the maximum and minimum temperatures of the cylinder of the rotary stirring type heat treatment device, and the treatment time refers to the residence time of the scrap inside the cylinder. Also, the gap refers to the value of M / D (expressed as a percentage) where M is the distance between the tip of the ruddy blade blade and the inner circumference of the cylinder, as mentioned above, and D is the inner diameter of the cylinder.

[0040] The mass increase rate (%) is: [(mass after heat treatment) / {(mass before heat treatment) x 1.19}] x 100 and corresponds to the oxidation rate. Note that 1.19 is the mass ratio before and after oxidation when WC-Co scrap (the mass ratio of WC and Co is 9:1) is completely oxidized to produce WO3, CoWO4, and CO2.

[0041] [Table 1]

[0042] [Table 2]

[0043] As is clear from Tables 1 and 2, in all of Examples 1 to 8, the migration of the aggregates in each treatment zone to other treatment zones was suppressed, so that the mass increase rate was high and the oxidation treatment was performed efficiently. In contrast, in Comparative Example 1, which does not have a ruddy blade and therefore the agglomerates are not stirred, crushed, or sized sufficiently, and in Comparative Examples 2 to 4, the migration of the aggregates in each treatment zone to other treatment zones is not suppressed, so that the mass increase rate was low and the oxidation treatment was not performed sufficiently. [Industrial Applicability]

[0044] The present invention is particularly capable of efficiently carrying out heat treatment of block materials to be treated, and is capable of providing a fully satisfactory solution for saving energy in heat treatment and reducing costs. [Explanation of symbols]

[0045] 1 Rotary stirring type heat treatment device 2 Supply section 21 Hopper 22 Screw conveyor 3. Heat Treatment Section 31 Cylinder (furnace tube) 4 Discharge section 41 Discharge means 5. Treatment Zone Forming Means 6 Treatment Zone 7 Cylindrical section D: Inner diameter of cylinder M: Distance between the tip of the radiator blade and the inner circumference of the cylinder

Claims

1. A rotary stirring type heat treatment device for heat-treating a workpiece, comprising: the material to be treated is a lump-shaped scrap containing tungsten of a size that does not pass through a sieve having square openings with a side length of 5 mm, but passes through a sieve having square openings with a side length of 30 mm, a heat treatment section having a cylindrical body into which the workpiece is fed from one end, heat-treated therein, and discharged from the other end; A heating means for heating the inside of the cylindrical body; a treatment zone forming means for forming a plurality of treatment zones inside the cylinder, the treatment zones being divided in an inner circumferential direction of the cylinder and arranged along a longitudinal direction of the cylinder; The treatment zone forming means is a radiblade having a cylindrical portion at its center and a plurality of blades provided at equal intervals on the outer periphery of the cylindrical portion, The ruddy blade rotates while swinging due to the rotation of the cylindrical body, The ruddy blade has a structure in which, when the ruddy blade is placed at the center of the cylinder, the distance between the tip of the blade and the inner circumference of the cylinder is M and the inner diameter of the cylinder is D, the M / D ratio is 0.01 to 0.10, and the material supplied to each of the treatment zones is allowed to move to another treatment zone by 10% by volume or less, In each of the treatment zones, the material to be treated is oxidized at 850 to 900° C. while being stirred, crushed, and sized; A rotary stirring type heat treatment device characterized by the above.

2. The rotary stirring type heat treatment device according to claim 1, characterized in that the number of blades of the ruddy blade is 8 to 16, and the proportion of the cross-sectional area of ​​the cylindrical portion in the radial cross section of the cylindrical body is 25 to 35%.

3. 3. A method for heat treating an object to be treated, comprising using the rotary stirring type heat treatment device according to claim 1 or 2.

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