JP5835311B2 - Ferro-coke manufacturing method and manufacturing equipment - Google Patents

Description

  In the present invention, a raw material containing a carbon-containing substance (coal, etc.), an iron-containing substance (iron ore, etc.) and a binder is molded, and the molded product is continuously dry-distilled in a vertical carbonization furnace. The present invention relates to a ferro-coke manufacturing method and a manufacturing facility for manufacturing ferro-coke that has been generated.

  In blast furnace operation, metallurgical coke produced by carbonizing coal in a coke oven is generally used. Metallurgical coke has a role of a spacer for improving ventilation in the blast furnace, a role as a reducing material, and a role as a heat source.

  In recent years, from the viewpoint of improving the reactivity of coke, an iron-containing material (iron ore, etc.) is mixed with a carbon-containing material (coal, etc.) and molded (molding process), and the molded product is dry-distilled (dry distillation process) ), Technology to obtain ferro-coke for metallurgy is being studied.

  Coal and iron ore are mixed and molded, and the ferro-coke is produced by dry distillation in an ordinary chamber-type coke oven. (A) The mixture of coal and fine iron ore is charged into the chamber-type coke oven. And (b) methods of forming coal and iron ore cold (room temperature) and charging the molded product into a chamber-type coke oven have been studied (Non-patent Document 1, etc.).

  However, since ordinary furnace-type coke ovens are composed of silica brick, when iron ore is charged, iron ore reacts with silica, which is the main component of silica brick, and a low melting point firelight is produced. Cause damage to the quartz brick. For this reason, the technique which manufactures ferro-coke with a chamber furnace type coke oven is not implemented industrially.

  In recent years, a continuous molding coke manufacturing method has been developed as a coke manufacturing method replacing the chamber furnace type coke manufacturing method.

  In the continuous molding coke manufacturing method, a vertical shaft furnace composed of chamotte bricks instead of silica brick is used as a carbonization furnace, and coal is molded into a predetermined size in the cold, and then charged into the vertical shaft furnace. By heating using a circulating heat medium gas, the charcoal is carbonized to produce molded coke.

  As a continuous molding coke manufacturing method using a vertical shaft furnace as a dry distillation furnace (vertical dry distillation furnace), the top gas of the dry distillation furnace is used as a cooling gas and introduced into the lower part of the cooling chamber directly connected to the dry distillation chamber of the dry distillation furnace. A method is known in which most of the gas that has passed through the cooling chamber is discharged from the upper portion of the cooling chamber and is supplied as a heating medium gas to the inlet of the middle part of the dry distillation chamber (for example, see Patent Document 1).

  However, in the method of Patent Document 1, the gas that has passed through the red hot coke layer in the cooling chamber is sucked by some means from the cooling chamber of the dry distillation furnace, the flow rate and temperature are adjusted, and the pressure required for blowing the dry distillation chamber tuyere is set. It is necessary to boost the pressure.

  In order to make this pressure increase economically in terms of equipment, an ejector that boosts a part of the furnace top gas with a blower, sucks the cooling chamber outlet gas using this as the driving gas, and supplies the discharge gas to the dry distillation chamber tuyere. A method of use has also been proposed (see, for example, Patent Document 2).

  However, although it can be said that the method of Patent Document 2 is economically effective in terms of facilities and heat intensity, gas balance between the cooling gas discharge outlet and the dry distillation chamber gas supply tuyere located above, the flow rate control, etc. Operationally complicated.

  Therefore, using a vertical distillation furnace with a carbonization zone at the top and a cooling zone at the bottom, cooling gas was blown from the cooling gas blowing tuyere at the bottom of the cooling zone, and the cooling gas heat-exchanged with ferrocoke was raised to the carbonization zone. There has been proposed a method in which high temperature gas is blown from a tuyere at the lower part of the dry distillation zone, and low temperature gas is blown from a tuyere at the middle part of the dry distillation zone (see, for example, Patent Document 3).

  Thus, when manufacturing ferro-coke, the method using a vertical dry distillation furnace is mainly examined from an industrial viewpoint.

Japanese Examined Patent Publication No. 56-47234 Japanese Patent Publication No. 60-6390 JP 2011-57970 A

Fuel Association "Coke Technology Annual Report" 1958, p. 38

  As described above, ferro-coke is produced by mixing a carbon-containing material (coal, etc.), an iron-containing material (iron ore, etc.), and a raw material containing a binder, and molding and agglomerating the material. There is a dry distillation process in which the formed molding is dry-distilled to obtain ferro-coke.

  In the carbonization process, as described above, from an industrial viewpoint, a vertical carbonization furnace having a carbonization zone in the upper part and a cooling zone in the lower part, similar to the vertical shaft furnace made of chamotte brick, may be used. desirable.

  However, in the case of ferro-coke, if the ferro-coke is not sufficiently cooled, heat may be generated due to oxidation of metallic iron in the ferro-coke. Therefore, it is necessary to cool the ferro-coke after carbonization to a temperature that does not ignite spontaneously in the cooling zone at the bottom of the carbonization furnace (for example, the surface temperature is 100 to 140 ° C. (preferably 100 to 120 ° C.)) before discharging. In order to handle handling such as transporting and storing ferro-coke at 100 ° C. or higher, it is necessary to consider the heat resistance of the equipment, which causes inconvenience in equipment design and management.

  On the other hand, in order to maintain the temperature of the carbonization zone at a high temperature and cool the surface temperature of the ferro-coke discharged from the carbonization furnace to 60 ° C. or less which does not cause inconvenience in handling, a low-temperature cooling gas in the cooling zone is used. There is a problem that the flow rate control considering the flow rate balance with the high-temperature dry distillation gas is required, and the facilities and operations are complicated.

  Energy saving is inevitable in the future steelmaking process, and it is necessary to reduce the energy required for the production of ferrocoke as much as possible, and improvements are being demanded.

  The present invention has been made in view of the above circumstances, and when manufacturing ferro-coke for metallurgy using a vertical carbonization furnace, it is possible to simplify equipment and operations and reduce energy consumption. An object of the present invention is to provide a manufacturing method and manufacturing equipment for ferro-coke.

  In order to solve the above problems, the present invention has the following features.

[1] In a ferro-coke manufacturing method in which a raw material containing a carbon-containing substance, an iron-containing substance, and a binder is molded into a molded product, and the molded product is subjected to dry distillation to produce ferro-coke.
A distillation process in which the molded product is charged from the top of a vertical distillation furnace having a carbonization zone in the upper part and a cooling zone in the lower part, and the ferro-coke discharged from the lower part of the vertical distillation furnace is discharged.
A ferro-coke manufacturing method comprising a cooling step of cooling ferro-coke discharged from a lower part of a carbonization furnace with a cooling device to cool a surface temperature of the ferro-coke to 60 ° C. or less.

  [2] The method for producing ferro-coke according to [1], wherein air is used as a cooling medium in the cooling step.

  [3] The cooling device includes a net conveyor that conveys ferro-coke, a spraying device that cools ferro-coke by blowing air sucked and sucked from outside air, and collection of air after cooling the ferro-coke. The method for producing ferro-coke according to the above [2], comprising a dust collecting device for collecting dust.

  [4] The method for producing ferro-coke as described in [3] above, wherein a flow velocity of air blown to the net conveyor is 0.5 to 2 m / sec.

[5] A production facility for continuously producing ferro-coke,
A molding device for molding a raw material containing a carbon-containing material, an iron-containing material, and a binder into a molded product;
A vertical distillation furnace that has a carbonization zone in the upper part, a cooling zone in the lower part, throws in the molded product from the upper part, and performs carbonization, and discharges ferrocoke that has been carbonized from the lower part,
A ferro-coke manufacturing facility comprising a cooling device that cools the ferro-coke discharged from the vertical distillation furnace and cools the surface temperature of the ferro-coke to 60 ° C. or lower.

  [6] The cooling device includes a net conveyor that conveys ferro-coke, a blowing device that cools ferro-coke by blowing air sucked and sucked from outside air, and collection of air after cooling the ferro-coke. The ferro-coke manufacturing facility according to [5], further including a dust collecting device for collecting dust.

  In the present invention, when manufacturing metallurgical ferro-coke using a vertical carbonization furnace, it is possible to simplify facilities and operations and reduce energy consumption.

It is a figure which shows the basic composition of Embodiment 1, 2 of this invention. It is a figure which shows an example of the cooling device used in Embodiment 1 of this invention. It is a figure which shows the other example of the cooling device used in Embodiment 1 of this invention. It is a figure which shows an example of the cooling device used in Embodiment 2 of this invention.

  An embodiment of the present invention will be described.

  As described above, when manufacturing ferro-coke, from an industrial point of view, use a vertical carbonization furnace having a carbonization zone at the top and a cooling zone at the bottom, similar to a vertical shaft furnace made of chamotte brick. Is desirable.

  Further, in the vertical distillation furnace, cooling gas is blown from the cooling gas blowing tuyere at the lower part of the cooling zone, and the cooling gas heat-exchanged with ferro-coke is raised to the dry distillation zone. A vertical dry distillation furnace that blows high-temperature gas from the mouth and blows low-temperature gas from the tuyere in the middle of the dry distillation zone has a cooling gas outlet tuyere above the cooling gas blowing tuyere. Compared with the vertical type carbonization furnace in which the gas extracted from the cooling gas extraction tuyere is mixed with the low temperature gas blowing low temperature gas blowing through the tuyere, the equipment is simplified.

  If the surface temperature of the ferro-coke discharged from the vertical distillation furnace is cooled to 60 ° C or less, special handling in facilities must be taken into account when handling the ferro-coke after discharge, handling, etc. However, when the temperature of the ferro-coke after discharging exceeds 60 ° C., a design that takes into account the heat resistance of the member that comes into contact with the ferro-coke and lubricating oil is required.

  In order to cool to 60 ° C. or lower in the cooling zone of the above-mentioned carbonization furnace, means for increasing the amount of cooling gas from the tuyere can be considered, but then excessive cooling gas flows into the carbonization zone at the top of the carbonization furnace. As a result, it will interfere with dry distillation. Furthermore, it is conceivable to extend the cooling zone and lengthen the time required for cooling, but this leads to an increase in the number of facilities and the cost of facilities becomes a problem. As a means of satisfying economical efficiency without using the vertical distillation furnace, the cooling apparatus was separately used.

  Therefore, in this embodiment, after the ferrocoke is discharged from the vertical dry distillation furnace in a high temperature state (for example, the surface temperature is 100 to 140 ° C. (preferably 100 to 120 ° C.)), the ferro coke in the high temperature state is discharged. The surface temperature is cooled to 60 ° C. or lower (preferably 45 ° C. or higher) which does not cause inconvenience in handling.

  Here, as a method for cooling the ferro-coke discharged from the vertical dry distillation furnace, a water sealing method is conceivable, but the ferro-coke after dry distillation contains metallic iron, and the metallic iron is brought into contact with water by contact with water. May be reoxidized, and depending on the temperature difference between the object to be cooled (ferrocoke) and the water temperature, rapid cooling may cause cracks and decrease in strength.

  Therefore, in this embodiment, the ferro-coke discharged from the vertical carbonization furnace is cooled by a cooling device using air as a cooling medium, thereby suppressing the heat generation of the ferro-coke.

  Embodiments (Embodiments 1 and 2) of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a basic configuration of Embodiment 1 of the present invention.

  As shown in FIG. 1, the vertical distillation furnace used in the first embodiment includes a molded product charging device 1, a vertical drying furnace main body 2, and a dry discharge device 3. Then, in a molding process that is a pre-process of the carbonization process, a molded product in which a raw material containing coal, iron ore, and a binder is molded under a predetermined condition is sent to the molded article charging device 1, and a predetermined amount of the molded article is obtained. The low temperature heated gas charged in the vertical carbonization furnace main body 2 and heated by the low temperature gas heating device 10 and blown from the low temperature gas blowing tuyere 4 and the high temperature gas heating device 11 and heated from the high temperature gas blowing tuyere 5 Coal and iron ore in the molded product are coke and metallic iron, respectively, by dry distillation with the high temperature heating gas blown.

  The low-temperature heating gas, high-temperature heating gas, and cooling gas are extracted from the upper part of the furnace, and after the tar is removed and cooled by the circulating gas cooling devices 8 and 9, a part of the gas is circulated for use. Has been. That is, cooling gas is blown from the cooling gas blowing tuyere 7 at the lower part of the cooling zone, the cooling gas heat-exchanged with ferro-coke is raised to the dry distillation zone, and hot gas is blown from the hot gas blowing tuyere 5 at the lower part of the dry distillation zone. The low temperature gas is blown from the tuyere 4 at the middle of the dry distillation zone.

  The molded product (ferrocoke) obtained by dry distillation is cooled by the cooling gas blown from the cooling gas blowing tuyere 7, transferred to the dry discharging device 3, and discharged from the dry discharging device 3. For example, the dry discharge device 3 is provided with a shut-off valve on the upper and lower sides, and an inert gas such as nitrogen is blown into the inside so that it can be discharged from the upper vertical dry distillation furnace main body with the lower shut-off valve closed. After ferrocoke is discharged to the hopper in an appropriate amount, the inside of the hopper is replaced with nitrogen while the upper and lower shutoff valves are closed, and then the ferrocoke is discharged by opening the lower shutoff valve. By adopting a structure that prevents outside air from entering inside, ferro-coke can be discharged out of the dry distillation furnace in a dry state.

  In addition, in the first embodiment, the ferro-coke discharged from the dry discharge device 3 in a high temperature state is sent to the air-cooled cooling device 12, and the surface temperature is cooled to 60 ° C. or lower.

  FIG. 2 is a diagram showing the cooling device 12 (12A) used in the first embodiment.

  As shown in FIG. 2, the ferro-coke X discharged | emitted from the dry-type discharge apparatus 3 is sent into the entrance a of the cooling device main body c through the conveyance conveyor i and the sieve h. The cooling device main body c is connected to a dust collection pipe e provided with an opening adjustment valve f. A blower (suction device) of the dust collector Z is disposed at the tip of the dust collection pipe e. The ferro-coke after dry distillation sent to the inlet a of the cooling device main body c is sent to the net conveyor d, and the ferro-coke is conveyed on the net conveyor d while being sucked by a suction device (not shown) ( The surface temperature is cooled to 60 ° C. or less by outside air), and is discharged from the discharge port b to the filling step (handling step for filling the storage container) Y.

  The net conveyor d only needs to have a structure in which the belt portion of a normal belt conveyor is formed in a net shape such as a wire net and allows a cooling gas (air here) to pass therethrough. The mesh size may be any size as long as the ferro-coke after dry distillation does not fall, and a mesh size of 5 to 30 mm, which is equal to or less than that of the sieve h, may be selected according to the size of the ferro-coke.

  In addition, the powdery material adhering to the ferro-coke sent to the net conveyor d and the small pieces missing in the conveying process are partly carried by the cooling gas and discharged from the dust collecting pipe e to the dust collecting device Z. Large pieces pass through the opening of the net conveyor d and are discharged out of the system through the opening g.

When cooling by the net conveyor d, the layer thickness (loading density) on the net conveyor d is preferably 15 to 75 mm (20 to 100 kg / m ² ). More preferably, the thickness is 25 to 45 mm (30 to 60 kg / m ² ). By flowing a large amount of cooling gas so as to cross a relatively thin layered ferro-coke, the ferro-coke can be reduced to 60 ° C. or less in a shorter time than by extending the cooling zone of the dry distillation furnace and cooling in the packed bed in the dry distillation furnace. The surface temperature of can be reduced.

  Further, the wind speed of the cooling gas is preferably 0.5 to 2.0 m / s. When the wind speed of the cooling gas is less than 0.5 m / s, a superior cooling rate cannot be obtained as compared with the case of cooling by flowing the cooling gas through the packed bed in the dry distillation furnace. On the other hand, when the wind speed of the cooling gas exceeds 2 m / s, the ferro-coke on the net conveyor that hits directly above the opening g starts to vibrate, and there is a case where it flows backward on the net. Ascending effect is small, and suction power is consumed wastefully.

  In order to adjust the layer thickness (stacking density) on the net conveyor d, a rectifying plate may be provided in the ferro-coke supply unit to the net conveyor d. Cooling efficiency is increased by stacking ferro-coke on the net conveyor d in a relatively thin layer and flowing cooling gas so as to cross the ferro-coke layer.

  In this manner, in the first embodiment, the ferro-coke discharged from the vertical distillation furnace 20 is cooled (forced cooling) by the cooling device 12A, thereby efficiently suppressing the heat generation of the ferro-coke. It became.

  As a result, in the first embodiment, when manufacturing the metallurgical ferro-coke using the vertical dry distillation furnace 20, it is possible to simplify equipment and operation and reduce the energy used.

  As the cooling device provided with the net conveyor d, a cooling device 12A ′ provided with a net conveyor d having a structure in which an inclined cylindrical mesh rotates as shown in FIG. 3 may be used. In FIG. 3, p is a rotating shaft of a cylindrical mesh, q is an inlet for air (outside air), and r is a conveyor for discharging relatively large pieces dropped from the net conveyor d to the outside of the system.

(Embodiment 2)
The basic configuration of the second embodiment of the present invention is the same as the basic configuration of the first embodiment of the present invention shown in FIG.

  In addition, in the second embodiment, as the cooling device 12, a relatively simple box type cooling device 12B as shown in FIG.

  In the case of this box type cooling device 12B, as shown in FIG. 4A, the ferro-coke X is fed into the cooling box k through the transport conveyor i and the sieve h. As shown in the plan view of FIG. 4B and the side view of FIG. 4C, the cooling box k includes a plurality of air blowing pipes j in the vicinity of the bottom surface. Are provided with a plurality of holes m for ejecting the air blown from the air blowing port n downward.

  As a result, in this cooling device 12B, the ferro-coke X fed into the cooling box k is cooled by the air blown from the air blowing pipe j so that the surface temperature becomes 60 ° C. or lower.

  In this way, in the second embodiment, the ferro-coke discharged from the vertical distillation furnace 20 is cooled (forced cooling) by the cooling device 12B, thereby efficiently suppressing the heat generation of the ferro-coke. It became.

  As a result, in the second embodiment, when manufacturing the metallurgical ferro-coke using the vertical carbonization furnace 20, it is possible to simplify facilities and operations and reduce energy consumption.

  As an example of the present invention, ferro-coke was produced using a vertical distillation furnace.

At that time, as Example 1 of the present invention, ferro-coke was manufactured based on the first embodiment of the present invention. The cooling device 12A provided with the net conveyor d used for cooling (forced cooling) of the ferro-coke discharged from the vertical distillation furnace 20 has a main body c of 10 m in length and a layer thickness on the net conveyor d. Is installed in the dust collecting pipe e, with the ferro-coke being stacked in a state where about 3 pieces are overlapped, that is, with a thickness of 45 mm (45 kg / m ² ), the conveying speed set to 0.33 m / min. The opening degree of the opening degree adjusting valve f was adjusted, and cooling was performed at a wind speed of 0.8 m / s for 30 minutes. Thereafter, the cooled ferro-coke was filled in an approximately cubic container of about 1 m ³ and held for 1 hour.

Moreover, as Example 2 of the present invention, ferro-coke was produced based on the above-described Embodiment 2 of the present invention. The cooling device 12B provided with the cooling box k used for cooling (forced cooling) of the ferro-coke discharged from the vertical carbonization furnace 20 has a length of 1100 mm, a width of 1500 mm, and a height of 1100 mm. 90% of which was charged with ferro-coke and held for 1 hour. Thereafter, the ferro-coke extracted from the cooling box k was filled in an approximately cubic container of about 1 m ³ and held for 1 hour.

On the other hand, as a comparative example, ferro-coke was produced without cooling (forced cooling) the ferro-coke discharged from the vertical distillation furnace 20. That is, the ferro-coke immediately after it was discharged | emitted from the conveyance conveyor i and sieved with the sieve h was filled into the container of about 1 m < ³ > substantially cube, and was hold | maintained for 1 hour.

  In each case (Invention Example 1, Invention Example 2, Comparative Example), the surface temperature of ferrocoke immediately after sieving with sieve h (ferrocoke surface temperature immediately after sieving), immediately after being discharged from cooling device 12 Measure the surface temperature of the ferro-coke (the ferro-coke surface temperature immediately after cooling) and the surface temperature of the center of the ferro-coke filled in the container and held for 1 hour (the surface temperature of the ferro-coke after filling) The results are shown in Table 1.

  The surface temperature of the ferrocoke immediately after sieving with the sieve h is measured using a contact thermometer equipped with a probe having a flat contact surface with the object to be measured. The temperature obtained by inserting the thermocouple up to the center was defined as the surface temperature of the center.

  As shown in Table 1, the ferrocoke surface temperature immediately after sieving was 80 to 90 ° C.

  And in the comparative example, the filling center ferro-coke surface temperature after filling holding | maintenance rose to 90-115 degreeC.

  In contrast, in Example 1, the ferrocoke surface temperature immediately after cooling was 48 to 54 ° C., and the filling center ferrocoke surface temperature after filling and holding was 45 to 50 ° C., and no temperature increase was observed.

  In Example 2, the ferrocoke surface temperature immediately after cooling was 50 to 55 ° C., and the filling center ferrocoke surface temperature after filling and holding was 48 to 52 ° C., and no temperature increase was observed.

  Further, as Examples 3, 4, 5, and 6 of the present invention, in order to confirm the influence of the flow velocity (wind speed) of the cooling air in the cooling device 12A provided with the net conveyor d, The opening degree of the opening degree adjusting valve f installed in the dust pipe e was adjusted to carry out even at wind speeds of 0.3 m / s, 0.5 m / s, 1.8 m / s, and 2.0 m / s. The results are shown in Table 2.

  As shown in Tables 1 and 2, the present invention examples 1 and 4 to 6 in which the flow velocity (wind velocity) of the cooling air is 0.5 to 2.0 m / s in the preferred range are the flow velocity of the cooling air ( Better results were obtained than Example 3 of the present invention in which the wind speed was 0.3 m / s, less than 0.5 m / s.

DESCRIPTION OF SYMBOLS 1 Molding charge apparatus 2 Vertical type distillation furnace main body 3 Dry discharge apparatus 4 Low temperature gas blowing tuyere 5 High temperature gas blowing tuyere 7 Cooling gas blowing tuyere 8 Circulating gas cooling apparatus 9 Circulating gas cooling apparatus 10 Low temperature gas heating apparatus 11 High-temperature gas heating device 12 Cooling device 12A Cooling device 12A 'Cooling device 12B Cooling device 20 Vertical carbonization furnace a Cooling device main body inlet b Cooling device main body outlet c Cooling device main body d Net conveyor e Dust collection piping f Opening adjustment valve g Opening h Sieve i Conveyor k Cooling box j Air blowing pipe m Air hole n Air blowing port p Rotating shaft q Outside air inlet r Conveyor X Ferro-coke Y Filling process Z Dust collector

Claims (5)

In a ferro-coke manufacturing method in which a raw material containing a carbon-containing substance, an iron-containing substance, and a binder is formed into a molded product, and the molded product is subjected to dry distillation to produce ferro-coke.
A distillation process in which the molded product is charged from the top of a vertical distillation furnace having a carbonization zone in the upper part and a cooling zone in the lower part, and the ferro-coke discharged from the lower part of the vertical distillation furnace is discharged.
A cooling step of cooling the ferro-coke discharged from the bottom of the carbonization furnace having a surface temperature of 100 to 140 ° C. with a cooling device using air as a cooling medium to cool the ferro-coke surface temperature to 60 ° C. or less. A method for producing ferro-coke, comprising: The cooling device is a net conveyor that transports ferro-coke, a spraying device that cools the ferro-coke by blowing air sucked and sucked from outside air, and collects air after cooling the ferro-coke. The ferro-coke manufacturing method according to claim 1 , further comprising a dust collector. The ferro-coke manufacturing method according to claim 2 , wherein a flow velocity of air blown to the net conveyor is 0.5 to 2 m / sec. A production facility for continuously producing ferro-coke,
A molding device for molding a raw material containing a carbon-containing material, an iron-containing material, and a binder into a molded product;
A vertical distillation furnace that has a carbonization zone in the upper part, a cooling zone in the lower part, throws in the molded product from the upper part, and performs carbonization, and discharges ferrocoke that has been carbonized from the lower part,
A cooling device using air as a cooling medium for cooling the ferro-coke discharged from the vertical distillation furnace and having a surface temperature of 100 to 140 ° C. to cool the surface temperature of the ferro-coke to 60 ° C. or less. Ferro-coke manufacturing facility characterized by The cooling device is a net conveyor that conveys ferro-coke, a blowing device that cools the ferro-coke by blowing air sucked and sucked from outside air, and collects air after cooling the ferro-coke. The ferro-coke manufacturing facility according to claim 4 , further comprising a dust collector.

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