JP2009242934A - Method for charging raw material into top-blowing type sintering machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for charging raw material into a top-blowing type sintering machine, in which the raw material is charged through a hopper to form an ore layer on a fire-grate in a Dwight-Lloyd system top-blowing type sintering machine used in the sintering process for zinc or lead smelting, the blowing-out of the air for sintering from the inner wall of a sidewall being the sidewall of the fire-grate and the gap of the ore-layer. <P>SOLUTION: In the method for charging the raw material through the hopper, at least one method in the following (1) and (2) is adopted. (1) Both end parts at the lower part in an ore-layer damper 10 set at the lower part of the hopper surface in the advancing direction of the fire-grate, are cut at inclining 35-55° angle to 5-10% length to the width of the fire-grate, and the side iron plate 11 of the hopper is cut in the height of the upper end in the cutting portion arranged at both end parts of the lower part of the ore-layer damper 10. (2) The height of a terrace part 9a of the sidewall 9 in the fire-grate, is lowered by 10-50% of the sidewall height from the uppermost part of the sidewall 9. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a raw material charging method to a top blow type sintering machine, and more specifically, on a grate of a Dwightroid type top blow type sintering machine used in a sintering process of zinc / lead smelting, In the method of charging the raw material through the hopper to form the ore layer, the raw material charging to the top blow type sintering machine can be prevented from blowing through the sintering air from the gap between the inner wall of the side wall and the ore layer. About how to enter.

In zinc / lead smelting called the ISP method (Imperial Melting Process method), a sulfide material containing zinc sulfide (ZnS) or lead sulfide (PbS) as a main component (hereinafter sometimes simply referred to as a sulfide material) .) Is used as a raw material, and mainly through two processes, a sintering process and a smelting process, to produce crude zinc and crude lead in a metallic state.
Here, in the sintering process, ZnS and PbS are oxidized mainly in accordance with the reaction formulas represented by the following formulas (1) and (2), and the oxidation reaction heat of sulfur generated at this time is reduced. It is used to produce sintered ingots from charged raw materials. In addition, the sintered ingot produced | generated at the sintering process is thrown into a blast furnace at the next smelting process, and crude zinc and crude lead are produced | generated by the reductive reaction in a blast furnace.

Formula (1): ZnS + 3 / 2O ₂ → ZnO + SO ₂
Formula (2): PbS + 3 / 2O ₂ → PbO + SO ₂

  As described above, the sintered ingot is produced by the fact that the zinc and lead contained in the charging raw material are in a semi-molten state due to the heat generated by the oxidation reaction of sulfur and bonded together. In order to generate a sintered ingot having properties such as sufficient strength suitable as a charging raw material for a blast furnace, it is essential to input a sufficient amount of a sulfide raw material as a heat generation source.

  By the way, in the sintering process of smelting by the ISP method, it is common to use a Dwytroid type top blow sintering machine (hereinafter sometimes simply referred to as a sintering machine). The raw material charged into the sintering machine is prepared in advance by mixing the sulfide raw material and the returned powder with a mixing drum or the like, and mixing the obtained mixed raw material into pellets having a particle diameter of about 4 to 6 mm with a pelletizer or the like. It is processed in the granulation process. Here, by pelletizing the raw material charged into the sintering machine, dust generation during transportation to the sintering machine is prevented, and gas permeability during oxidation roasting in the sintering machine is good. Can be maintained in a stable state.

Here, the production | generation of a sintered compact from the charging raw material using the said sintering machine is demonstrated using figures.
FIG. 1 is a schematic view showing the structure of a dwelloid type top blow sintering machine.
In FIG. 1, first, pellets as a charging raw material are supplied onto a pallet (grate) 1 from a first charging hopper 3 installed in a sintering machine, and usually have a predetermined thickness of about 50 mm. 2 is deposited. Here, while being heated from above by the heavy oil burner 4 for ignition and the like, and sucked downward, combustion starts. Thereafter, the second charging hopper 5 is charged for the second time so that the ore layer made of the charging raw material has a predetermined thickness of usually about 400 mm.
Subsequently, the grate 1 moves in the direction indicated by the dotted arrow on the blower arranged in the longitudinal direction of the entire sintering machine, and is ventilated upward from the blower in the wind box 6. Here, as the drying, preheating, sulfide combustion and cooling progress in order from the lower layer to the upper layer of the ore layer, the charged raw materials oxidize, melt and bond, and the sintered ingot 7 is generated. In addition, about 30-80 mm or less among the sintered ingots 7 is sieved, and is crushed into grains of about 4 mm by the crusher 8, returned to the mixing step as reclaimed powder, and repeatedly used. .

Here, by uniforming the air flow to the ore layer formed on the grate and bringing the raw material and oxygen into efficient contact, the reaction is promoted and the productivity and quality of the sintered ingot can be improved. .
In the above-mentioned sintering machine, the air ventilation is not uniform because the side wall of the grate is the side wall, that is, the air blown from both sides of the grate where the mineral layer made of the charging raw material is formed. Is one of the causes.

  For this reason, in order to prevent air blow-through from both sides of the grate, the shape of the side wall of the grate, the shape of the hopper for charging raw materials, and the like have been made. For example, in order to improve the air permeability between the sidewall and the ore layer portion, a method of depositing coke at both ends of the ore layer (for example, see Patent Document 1) is disclosed. However, since this method is a method related to the bottom blow type sintering machine, and it requires a new installation of a carbonaceous material supply device, the cost is high. Can not.

Japanese Patent Application Laid-Open No. 64-52029 (first page)

  The purpose of the present invention is to form a mineral layer on the grate of a Dwightroid type top blow type sintering machine used in the sintering process of zinc / lead smelting in view of the problems of the above prior art, In the method of charging the raw material through the hopper, the sintering air is prevented from being lost through the gap between the inner wall of the side wall, which is the side wall of the grate, and the ore layer, thereby preventing the loss of sintering air and the sintering speed. In addition to improving the sinterability and productivity by improving, improving the quality of the sintered ingot, saving energy by reducing the amount of air for sintering, and reducing the amount of air for sintering, negative pressure in the sintering machine hood It is an object of the present invention to provide a raw material charging method for an up-blowing type sintering machine, which can prevent leakage gas by increasing the slag.

  In order to achieve the above-mentioned object, the present inventors have used a hopper to form a mineral layer on a grate of a Dwightroid type top blow type sintering machine used in the sintering process of zinc / lead smelting. As a result of earnest research on the method of charging the raw material, means for cutting the lower end portions of the ore deposit damper installed under the hopper surface in the traveling direction of the grate under specific conditions, the terrace portion of the sidewall When at least one of the means for lowering the height of the steel sheet under specific conditions is employed, it has been found that the sintering air can be prevented from being blown from the gap between the inner wall of the side wall and the ore layer. Was completed.

That is, according to the first invention of the present invention, the raw material is passed through the hopper in order to form the ore layer on the grate of the Dwightroid type top blow type sintering machine used in the sintering process of zinc / lead smelting. In the method of charging
There is provided a raw material charging method into an upper blow type sintering machine characterized by employing at least one of the following (1) or (2).
(1) The lower end portions of the ore deposit damper installed at the lower part of the hopper surface in the traveling direction of the grate are cut at an angle of 35 to 55 ° diagonally by a length corresponding to 5 to 10% with respect to the width of the grate. And the side iron plate of a hopper is cut | disconnected by the height of the upper end of the cut part provided in the lower both ends of this mineral deposit damper.
(2) The height of the terrace portion of the side wall of the grate is reduced by 10 to 50% of the height of the side wall from the top of the side wall.

Further, according to the second invention of the present invention, in the first invention, there is further provided a raw material charging method to the top blow type sintering machine, characterized by employing the following means (3): Is done.
(3) The hopper is provided with a pressing jig, and both ends of the ore layer are pressed from 3 to 5% of the height of the sidewall from the top of the sidewall of the grate.

  According to the third invention of the present invention, in the first or second invention, the raw material is a pellet containing a sulfide raw material and a powdered powder, or a pellet containing a sulfide raw material, an oxide raw material and a powdered powder. There is provided a raw material charging method into an up-blast type sintering machine.

  The raw material charging method to the top blow type sintering machine of the present invention is to form an ore layer on the grate of the Dwightroid type top blow type sintering machine used in the sintering process of zinc / lead smelting. In the method of charging the raw material through the hopper, the sintering air is prevented from being blown out from the gap between the inner wall of the sidewall and the mineral layer, thereby preventing the loss of sintering air and sintering by improving the sintering speed. By increasing the negative pressure in the sintering machine hood by reducing the amount of sintering air, in addition to improving the productivity and productivity, improving the quality of the sintered mass, reducing the amount of air for sintering, etc. Since the leakage gas can be prevented, its industrial value is extremely large.

Hereinafter, the raw material charging method to the top blow type sintering machine of the present invention will be described in detail.
In the method of charging raw materials through a hopper in order to form an ore layer on the grate of a Dwightroid type top blow type sintering machine used in the sintering process of zinc / lead smelting of the present invention, the following (1 ) Or (2) is employed.
(1) The lower end portions of the ore deposit damper installed at the lower part of the hopper surface in the traveling direction of the grate are cut at an angle of 35 to 55 ° diagonally by a length corresponding to 5 to 10% with respect to the width of the grate. And the side iron plate of a hopper is cut | disconnected by the height of the upper end of the cut part provided in the lower both ends of this mineral deposit damper.
(2) The height of the terrace portion of the side wall of the grate is reduced by 10 to 50% of the height of the side wall from the top of the side wall.

Furthermore, the following means (3) can be adopted as necessary.
(3) The hopper is provided with a pressing jig, and both ends of the ore layer are pressed from 3 to 5% of the height of the sidewall from the top of the sidewall of the grate.

  In the method of the present invention, it is important to employ at least one means of (1) or (2) above or further adopt the means of (3) above. As a result, the charging raw material is raised on the side wall terrace, and the ridges of the ore layer formed at both ends of the ore layer are consolidated to increase the pressure loss of the ore layer near the inner wall of the side wall. -Prevent blowing of sintering air from the gap between the inner wall and the ore layer.

Here, the means (1) to (3) and the function and effect thereof will be described with reference to the drawings.
The means of (1) described above is that the lower end portions of the ore deposit dampers installed at the lower part of the hopper surface in the traveling direction of the grate are diagonally 35 to 55 by a length corresponding to 5 to 10% with respect to the width of the grate. And means for cutting the side iron plate of the hopper at the height of the upper end of the cut portions provided at both lower end portions of the ore layer damper.

2, the left figure is a side view of the hopper (viewed from the horizontal direction with respect to the direction of travel of the grate), and the right figure is a front view of the hopper (viewed from the direction of travel of the grate). Represents a conceptual diagram.
In FIG. 2, the mineral layer 2 is deposited on the grate 1 by the pellets supplied from the second hopper 5, and the surface portion of the ore layer 2 is flattened to have a uniform thickness. A mineral damper 10 is attached to the lower part of the iron plate 11. The side wall 9 which hits the side surface with respect to the traveling direction of the grate is provided with a terrace portion 9a thereabove to adjust the thickness of the ore layer 2.

3 and 4 are enlarged views of a cut portion of the mineral damper shown in FIG. Here, the left figure shows a side view of the hopper and the right figure shows a front view, respectively.
FIG. 3 shows an example of a conventional cutting state. In FIG. 3, the cut portion at the lower end portion of the mineral damper 10 indicated by a broken line has a notch angle of 45 °, and is 5 with respect to the width of the grate. It was a notch width of less than 2%, usually about 2%.
FIG. 4 shows an example of the cutting state of the present invention. In FIG. 4, the cutting portion at the lower end of the ore deposit damper 10 has a notch angle of 45 ° and is 5 to 10 with respect to the width of the grate. It was a notch width with a length equivalent to%. A broken line portion is a mineral damper cut portion 13 in which a conventional cut portion is newly provided and a hatched portion is newly provided. Moreover, the lower part of the hopper side iron plate 11 was cut | disconnected by the height of the upper end of the cutting part provided in the lower end part of this mineral deposit damper. Here, the broken line portion represents the hopper side iron plate cutting portion 14.

  FIG. 5 shows the formation state of the ore layer according to the conventional cutting state corresponding to FIG. 3 on the left side, and the formation state of the ore layer according to the cutting state of the present invention corresponding to FIG. 4 on the right side. As a result, conventionally, pellet deposits were not formed on the cut portion of the mineral damper, but in the present invention, pellet deposits are formed, and it is found that air is difficult to escape.

The width of the cut portion provided at both lower end portions of the ore layer damper is 5 to 10% with respect to the width of the grate. That is, when the width of the cut portion is less than 5%, pellet deposition is not formed as described above, and thus air blowout is not sufficiently suppressed. On the other hand, if the width of the cut portion exceeds 10%, the function of leveling the ore layer to a predetermined thickness, which is the original function of the ore layer damper, is impaired, leading to deterioration of the sintered state.
Moreover, the notch angle of the said cut part is 35-55 degrees, and 45 degrees is preferable. That is, when the angle formed by the cut portion and the lowest part of the mineral layer damper is less than 35 °, the function of leveling the mineral layer to a predetermined thickness is impaired. On the other hand, if it exceeds 55 °, the amount of pellets deposited becomes small, and air escape cannot be sufficiently suppressed.

In the above means (2), the height of the terrace portion of the side wall of the grate is from 10 to 50%, preferably from 15 to 40%, more preferably from the top of the side wall. Is a means for reducing 20 to 30%. That is, if the reduction in the height of the terrace portion is less than 10% of the sidewall height, the effect of preventing blow-through from the gap between the sidewall inner wall and the raw material layer is low. On the other hand, as the raw material is stacked on the terrace, the blow-through from the gap between the inner wall of the side wall and the raw material layer decreases. However, if the decrease in the height of the terrace exceeds 50% of the side wall height, conversely the ore layer As a result, a blow-through from the center of the slab occurs, resulting in non-uniform ventilation of the air to the ore layer, which reduces productivity.
In FIG. 6, the left figure shows the state by means of (1) above, and the right figure shows a state in which the height of the side wall terrace portion 9a is lowered from the uppermost part of the side wall by a predetermined ratio of the side wall height. Represents. From FIG. 6, it can be seen that since the ore layer can be stacked higher in the gap between the side wall and the ore layer where air easily escapes, the escape of air is suppressed. In addition, as shown in the left figure, conventionally, the terrace portion 9a of the sidewall is usually installed at the same height as the lower portion of the mineral damper 10, and the position thereof is from the top of the sidewall to the height of the sidewall. This is a position where about 10% of the amount has been reduced.

The means (3) includes a pressing jig on the hopper, and presses both ends of the ore layer from the top of the sidewall of the grate for 3 to 5% of the height of the sidewall. Means.
FIG. 7 shows the attachment position of the pressing jig, the left figure is an enlarged view of the lower side of the hopper, and the right figure is an enlarged view of the lower front part of the hopper. In FIG. 7, the pressing jig 15 is installed in the lower portion of the hopper and presses the pellets deposited in a mountain shape in the vicinity of the terrace portion downward from the uppermost portion of the sidewall.

  The pressing height is 3 to 5% of the total height of the sidewall. Thereby, the space | interval of the pellet of the pellet accumulated in the mountain | separation near the terrace part becomes narrow, and the escape route of air can be prevented.

  Although it does not specifically limit as the width | variety of the said press jig | tool, It is preferable that it is the length beyond the cutting part of the said mineral damper from the part which contact | connects a sidewall. For example, it may extend over the entire width of the grate. Moreover, the material and the attachment method are not particularly limited as long as the strength can be maintained.

  As a Dwightroid type top blow type sintering machine used in the sintering process of the above zinc / lead smelting, it is a commonly used dwroid type top blow type sintering machine, for example, in FIG. What shows a schematic diagram is used. Here, pellets containing sulfide raw material and powdered powder or pellets containing sulfide raw material, oxide raw material and powdered powder are used as the charging raw material.

  The sulfide raw material used in the above method is not particularly limited, and for example, Zn: 40% by mass, Pb: 16% by mass, S: 27% by mass, and the average particle diameter is about 40 μm. The oxide raw material used in the above method is not particularly limited. For example, Zn: 60% by mass, Pb: 6% by mass, O: 15% by mass, Cd: about 0.1% by mass, The diameter is about 4 mm.

  EXAMPLES The present invention will be described in more detail below with reference to examples of the present invention, but the present invention is not limited to these examples. The metal used in the examples was analyzed by fluorescent X-ray analysis.

Example 1
In the dwelloid type top blow type sintering machine shown in FIG. 1, the operation was performed as follows. [Operation method of sintering machine]
In FIG. 1, first, pellets as a charging raw material are supplied onto a pallet (grate) 1 from a first charging hopper 3 installed in a sintering machine, and usually have a predetermined thickness of about 50 mm. 2 is deposited. Here, while being heated from above by the heavy oil burner 4 for ignition and the like, and sucked downward, combustion starts. Thereafter, the second charging hopper 5 is charged for the second time so that the ore layer made of the charging raw material has a predetermined thickness of usually about 400 mm.
Subsequently, the grate 1 moves in the direction indicated by the dotted arrow on the blower arranged in the longitudinal direction of the entire sintering machine, and is ventilated upward from the blower in the wind box 6.

Here, the following remodeling was performed on the second charging hopper. Here, the thickness of the ore layer on the grate to be formed (width 2.5 m) was about 400 mm.
The lower end portions of the ore deposit damper installed at the lower part of the hopper surface in the traveling direction of the grate are slanted at 150 mm × 150 mm (corresponding to a slant of 45 ° by a length corresponding to 6% of the grate width). The side iron plate of the hopper was cut at the height of the upper end of the cut portions provided at the lower end portions of the mineral damper.
In the above operation, the raw material swells about 30 mm in the height direction from the terrace portion at the upper part of the side wall of the sintering machine, thereby preventing blowing of sintering air from the gap between the inner wall of the side wall and the raw material layer. I was able to.
The quality of the obtained sintered ingot was evaluated by the quality of cadmium which is an impurity. Moreover, various data were compared with the average value for about three months of the daily average value. As a result, compared to normal operation before remodeling, the productivity of the sintered ingot increased by about 8%, the quality of the cadmium could be reduced by 25%, the sinterability and productivity improved by increasing the sintering speed, and the sintered ingot Improved quality. Also, compared to normal operation before remodeling, the amount of sintering air can be reduced by 3%, energy saving by reducing the amount of sintering air, and negative pressure in the sintering machine hood by reducing the air flow for sintering. It was possible to prevent leaking gas by increasing it. The results are shown in Table 1.

(Example 2)
Furthermore, it carried out like Example 1 except having added the following remodeling.
The height of the terrace part of the side wall of the grate was modified so as to be lowered by 90 mm (corresponding to 18% of the side wall height) from the uppermost part of the side wall.
At this time, about 80 mm of the raw material swells in the height direction from the terrace portion, and it is possible to prevent blowing of the sintering air from the gap between the side wall inner wall and the raw material layer, and the productivity of the sintered ingot Was found to increase by about 10%. The results are shown in Table 1.

(Example 3)
Furthermore, it carried out like Example 1 except having added the following remodeling.
The height of the terrace part of the side wall of the grate was modified so as to be lowered by 125 mm (corresponding to 25% of the side wall height) from the uppermost part of the side wall.
At this time, about 110 mm of the raw material swells in the height direction from the terrace portion, and it is possible to prevent blowing of the sintering air from the gap between the side wall inner wall and the raw material layer, and the productivity of the sintered ingot Was found to increase by approximately 15%. The results are shown in Table 1.

Example 4
Furthermore, it carried out like Example 1 except having added the following remodeling.
The height of the terrace portion of the side wall of the grate was modified so as to be reduced by 160 mm (corresponding to 32% of the height of the side wall) from the top of the side wall.
At this time, about 150 mm of the raw material swells in the height direction from the terrace portion, and it is possible to prevent blowing of the sintering air from the gap between the sidewall inner wall and the raw material layer, and the productivity of the sintered ingot is It was found to increase by about 10%. The results are shown in Table 1.

  From Table 1, since Examples 1 to 4 were modified in accordance with the present invention, the raw material swelled in the height direction from the terrace portion, preventing blowing of sintering air from the gap between the sidewall inner wall and the raw material layer. It can be seen that the productivity of the sintered ingot is increased.

  As is clear from the above, the raw material charging method to the top blow type sintering machine of the present invention is the raw material charging of the Dwytroid type top blow type sintering machine used in the sintering process of zinc / lead smelting. It is suitable as a method.

It is the schematic showing the structure of a Dwightroid type top blow sintering machine. The left figure shows the concept of the side view of the hopper, and the right figure shows the concept of the front view of the hopper. It is an enlarged view of the cut part of the mineral damper of FIG. 2 showing an example of the conventional cutting state. It is an enlarged view of the cutting part of the mineral damper of FIG. 2 showing an example of the cutting state of this invention. The left figure shows the formation state of the ore layer according to the conventional cutting state corresponding to FIG. 3, and the right figure shows the formation state of the ore layer according to the cutting state of the present invention corresponding to FIG. The left figure shows the state by means of the above (1), and the right figure shows the state where the height of the terrace portion of the sidewall is lowered. The left figure which shows the attachment position of a pressing jig is a figure showing the enlarged view of the side lower part of a hopper, and the right figure is an enlarged view of the front lower part of a hopper.

Explanation of symbols

1 Pallet (grate)
2 Mineral Formation 3 First Charging Hopper 4 Heavy Oil Burner 5 Second Charging Hopper 6 Wind Box 7 Sintered Mass 8 Crusher 9 Side Wall 9a Terrace 10 Mineral Damper 11 Hopper Side Iron Plate 12 Grate Travel Direction 13 Mineral Damper Cutting part 14 Hopper side iron plate cutting part 15 Pressing jig

Claims (3)

In the method of charging raw materials through a hopper to form a mineral layer on the grate of a Dwightroid type top blow type sintering machine used in the sintering process of zinc / lead smelting,
The raw material charging method to the top blow type sintering machine, wherein at least one of the following (1) or (2) is employed.
(1) The lower end portions of the ore deposit damper installed at the lower part of the hopper surface in the traveling direction of the grate are cut at an angle of 35 to 55 ° diagonally by a length corresponding to 5 to 10% with respect to the width of the grate. And the side iron plate of a hopper is cut | disconnected by the height of the upper end of the cut part provided in the lower both ends of this mineral deposit damper.
(2) The height of the terrace portion of the side wall of the grate is reduced by 10 to 50% of the height of the side wall from the top of the side wall. Furthermore, the method of the following (3) is employ | adopted, The raw material charging method to the top blow type sintering machine of Claim 1 characterized by the above-mentioned.
(3) The hopper is provided with a pressing jig, and both ends of the ore layer are pressed from 3 to 5% of the height of the sidewall from the top of the sidewall of the grate.   3. The top blow type sintering machine according to claim 1, wherein the raw material is a pellet containing a sulfide raw material and powdered powder, or a pellet containing a sulfide raw material, an oxide raw material, and powdered powder. Raw material charging method.

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