JP5326622B2 - Reduced slag solidification equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently solidify and dry reduced slag in a solidifying apparatus for solidifying and drying the reduced slag discharged from a steel making process. <P>SOLUTION: The solidifying apparatus 10 includes: a vertical cylindrical treating tank 12 having a treating chamber 14 in which a briquette S is filled; a gas introducing part 28 provided in the lower part of the treating tank 12 and for introducing a gas containing carbon dioxide and having at least &ge;100&deg;C into the treating chamber 14; and a gas discharge part 32 provided in the upper part of the treating tank 12 and discharging the gas flowing-in from the gas introducing part 28 and circulating toward the upper side of the treating chamber 14 from the upper part of the treating tank 14. The solidifying apparatus is constructed so that the processed briquette S solidified and dried by the contact with the gas is sequentially discharged from a discharge part 24 of the treating tank 12 and the untreated briquette S is sequentially charged from a carrying-in part 22 of the treating tank 12 to the upper part of a treating chamber 14. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a solidification apparatus for solidifying and drying reduced slag discharged in a steelmaking process.

  Oxidation slag produced by oxidation refining in the steelmaking process using an electric furnace, and after iron refining, a new steelmaking material such as a reducing agent and quick lime is added to remove sulfur in molten steel. By-products such as reduced slag are produced. Because these by-products contain lime (CaO), they can be used in various applications, including civil engineering and building materials for road laying and construction, and submerged materials for algae and fish reefs. Is being used.

Since the by-product discharged in the steelmaking process contains lime as described above, the main product is calcium carbonate (CaCO ₃ ) generated by carbonation by bringing the by-product into contact with carbon dioxide (CO ₂ ). There has been proposed a method of solidifying by-products by solidifying each other as a binder (see, for example, Patent Document 1). Since the method disclosed in Patent Document 1 is insufficient in strength as compared with concrete material when using a by-product solidified as civil engineering / building material or underwater sedimentation material, it is not suitable for fine particles having a particle size of 10 mm or less. By mixing the carbonized Ca-containing raw material with a fine powder raw material having a particle size of 100 μm or less and not particularly limited, and solidifying the mixed raw material by a carbonation reaction, the gap between the uncarbonated Ca-containing raw materials is formed. The bond strength is improved by the existing fine powder material. Further, the solidification device disclosed in Patent Document 1 is composed of a container-shaped main body and a lid that closes the upper portion of the main body, and has a mold that is filled with uncarbonated Ca-containing raw material and fine powder raw material, Carbon dioxide gas is supplied to the gas supply section provided at the bottom of the main body through the gas supply pipe, and carbon dioxide is introduced into the main body from the gas supply section through the gas through hole formed at the bottom of the main body. It has become. Thereby, in the solidification apparatus, the uncarbonated Ca-containing raw material filled in the main body is solidified in order from below, and after solidifying to the upper part, the mold is removed to solidify the solidified carbonate.

JP 2005-154178 A

  In the solidification device disclosed in Patent Document 1, the gap portion may be blocked by the fine powder raw material existing in the gap portion between the fine granular uncarbonated Ca-containing raw materials, and carbon dioxide gas is generated in the main body of the mold. There is a risk that it will not be sufficient. That is, in the solidification device of Patent Document 1, it is difficult to perform the solidification process efficiently. Moreover, when there are too many ratios of a raw material with a small particle size, there exists a problem that the intensity | strength of the carbonic acid solidified body obtained by solidifying becomes insufficient. Furthermore, in the solidification apparatus disclosed in Patent Document 1, when the removal timing of the formwork is set in accordance with the uncarbonated Ca-containing material located at the lower part of the main body, the uncarbonated Ca-containing material located at the upper part of the main body is obtained. It is not solidified enough. On the other hand, in the solidification apparatus, when the removal timing of the mold is set in accordance with the uncarbonated Ca-containing material located in the upper part of the main body, the uncarbonated Ca-containing material located in the lower part of the main body has already solidified. In spite of this, the removal of the mold must be waited until the uncarbonated Ca-containing raw material at the top of the main body is solidified, resulting in poor processing efficiency.

  In particular, reduced slag among by-products contains a large amount of lime, so that it is also considered to reuse it as a steelmaking material in the steelmaking process. Here, in the solidification method using carbon dioxide, lime is liberated in the moisture adhering to the surface of the slag, and the liberated lime and carbon dioxide react with each other. Therefore, the slag contains a certain amount of moisture. It is necessary to be out. However, if the solidified slag contains moisture, it cannot be put into the molten steel as it is, and the moisture content must be adjusted in order to put the solidified slag into an electric furnace or the like. In addition, since the reduced slag is in the form of fine powder having a particle size of 1 mm or less, when solidified as it is, it does not maintain sufficient strength, but immediately falls apart, or the size of the solidified body obtained by solidification is small. There are many problems such as being mixed and not being solidified in a size that is easy to handle. At present, there is no particular proposal of an apparatus that considers the reuse of slag as a slagging material. For example, a simple drying apparatus such as the solidifying apparatus disclosed in Patent Document 1 must be provided separately. .

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the reduction slag solidification device according to the prior art, and is a reduction slag capable of efficiently solidifying and drying the reduction slag. An object is to provide a solidification device.

In order to overcome the above-mentioned problems and achieve the intended object, a reducing slag solidifying device according to claim 1 of the present application comprises:
An apparatus for solidifying and drying reduced slag discharged in the steelmaking process,
A processing chamber filled with granular reduced slag , comprising a lower cylindrical portion constituting a lower zone of the reduced slag and an upper cylinder constituting an upper region thereof and a solidified zone of the reduced slag A vertical cylindrical processing tank consisting of parts ,
A carry-in unit that is provided in an upper part of the treatment tank and receives untreated granular reduction slag;
An unloading portion provided at the lower portion of the processing tank, and for discharging the treated reduced slag from the lower portion of the processing chamber;
A gas introduction part that is provided in the lower cylinder part of the treatment tank and introduces a gas containing at least 100 ° C. containing carbon dioxide into the treatment chamber;
A gas exhaust unit that is provided in an upper part of the processing tank, and that exhausts the gas flowing in from the gas introduction unit and flowing upward through the processing chamber from the upper part of the processing chamber;
The treated gas is dried and solidified by contact at a temperature of 100 ° C. or more in the lower cylinder part forming the drying zone and at a temperature of 100 ° C. or less in the upper cylinder part forming the solidification zone . While the slag is sequentially carried out from the carry-out unit, untreated reduced slag is sequentially introduced from the carry-in unit into the upper portion of the processing chamber.
According to the first aspect of the present invention, the reduced slag can be continuously solidified and dried in one processing chamber, and the cycle of discharging the treated reduced slag and charging the untreated reduced slag is also continuous. Can be done automatically. In addition, the solidification apparatus is configured to distribute the gas flowing in from the lower part of the processing chamber to the reducing slag filled in the processing chamber while flowing from the bottom to the top, and the temperature according to the characteristics of the solidification processing and drying processing performed in each region. Gas can be circulated. That is, the solidification apparatus can efficiently perform the solidification process and the drying process of the reduced slag.

The gist of the invention according to claim 2 is that the carry-out section includes a discharge means capable of opening and closing a carry-out path communicating with a lower portion of the processing chamber.
According to the invention which concerns on Claim 2, the quantity of the reduction | restoration slag paid out from a carrying-out part can be easily adjusted by the discharge means.

  According to the solidification device for reduced slag according to the present invention, the reduced slag can be efficiently solidified and dried.

1 is a schematic view showing a solidification device according to a preferred embodiment of the present invention, with a part thereof broken away.

  Next, preferred embodiments of the reduced slag solidifying device according to the present invention will be described below with reference to the accompanying drawings.

  As shown in FIG. 1, the solidification apparatus 10 of an Example is comprised considering the processing tank 12 which performs the solidification drying process of reduction | restoration slag as a main body. In the embodiment, a solidification device 10, a gas generation facility 40 for supplying a gas containing carbon dioxide (hereinafter simply referred to as a gas) to the treatment tank 12 of the solidification device 10, and an exhaust facility for recovering the gas from the treatment tank 12. 50, a carrying-in facility 60 for carrying in the processing tank 12 granular reduced slag before solidification drying processing (hereinafter referred to as untreated briquette S) from the previous process, and the solidification drying treatment discharged from the processing tank 12 The reduced slag solidification system is composed of an unloading facility 70 for unloading the granular reduced slag (hereinafter, treated briquette S) to the next process.

  The processing tank 12 is a vertical cylindrical container having upper and lower end surfaces opened, and a processing chamber 14 filled with the briquette S is internally defined. In addition, the processing tank 12 is provided with a carry-in part 22 for feeding the untreated briquette S into the processing chamber 14 at the top, and a carry-out part 24 for dispensing the treated briquette S from the processing chamber 14 at the bottom. Is provided. Furthermore, the processing tank 12 is formed so that the carrying-out part 24 side of the processing chamber 14 is narrower than the carrying-in part 22 side. In the treatment tank 12 of the embodiment, a straight cylindrical lower cylinder portion 16 constituting a lower region of the processing chamber 14 and a hopper shape that is continuously provided at the upper end of the lower cylinder portion 16 and decreases from the top to the bottom. The middle cylinder part 18 and the upper cylinder part 20 that constitutes the upper region of the processing chamber 14 and is connected to the upper end of the middle cylinder part 18 are coaxially connected in a vertical relationship. That is, the processing tank 12 is formed so that the lower cylindrical portion 16 has a smaller plane cross-sectional area than the upper cylindrical portion 20, and the volume of the upper region defined internally in the upper cylindrical portion 20 serving as a solidification band described later is increased. Largely secured. Thereby, in the lower cylinder part 16 used as a drying zone, the drying efficiency of briquette S can be raised, and gas can fully contact the briquette S in the upper cylinder part 20 used as a solidification zone.

  In the processing tank 12 of the embodiment, an opening formed in the upper end surface of the upper tube portion 20 is used as the carry-in portion 22. The processing tank 12 is loaded with untreated briquettes S from the loading section 22 into the processing chamber 14 by a loading facility 60 such as a bucket crane or a conveyor (Example), and the processing chamber 14 is filled with the briquettes S. It is like that. Here, the untreated briquette S is obtained by simply forming the reduced slag obtained in the steelmaking process into a granule of about 20 to 40 mm by compression or the like. The carry-out unit 24 is connected to the bottom of the lower cylinder unit 16 and includes a discharge means 26 such as a rotary valve capable of opening and closing a carry-out path communicating with the bottom of the processing chamber 14. The paying-out means 26 is driven and controlled based on appropriate setting conditions such as every set time so as to pay out the processed briquette S from the processing chamber 14 by a predetermined amount. A carry-out facility 70 such as a conveyor is installed below the carry-out unit 24, and the processed briquette S paid out from the processing tank 12 is delivered to the carry-out facility 70, and is stored by the carry-out facility 70. And transported to the steelmaking process. In the solidification system of the embodiment, the payout unit 26 and the carry-in facility 60 are configured to be interlocked, and an unprocessed amount corresponding to the processed briquette S discharged from the processing chamber 14 by driving the payout unit 26. The briquette S is loaded into the processing chamber 14 by the carry-in facility 60. Here, the unprocessed briquette S to be input by the carry-in facility 60 is set in balance with the payout amount of the processed briquette S in consideration of various conditions such as allowing for a volume change due to the solidification drying process.

  The solidification apparatus 10 is provided with a gas introduction portion 28 communicating with the lower portion of the processing chamber 14 and connected to the gas generating facility 40 via a pipe 42 at the lower portion of the processing tank 12. The gas supplied through the gas introduction unit 28 is introduced into the lower part of the processing chamber 14. The gas introduction part 28 has a jacket 28 a that surrounds the outer periphery of the lower cylinder part 16, and a plurality of gas holes 16 a that are supplied between the jacket 28 a and the lower cylinder part 16 are formed in the lower cylinder part 16. It flows into the lower region of the processing chamber 14 via the. The gas introduction unit 28 includes a flow path opening / closing means 30 such as a damper capable of opening and closing the pipe 42, an electric valve, and an electromagnetic valve, and the amount of gas flowing into the processing chamber 14 by adjusting the opening / closing of the flow path opening / closing means 30. Can be adjusted. The amount of gas may be adjusted by controlling the blower B with an inverter. The solidification device 10 monitors the temperature of the gas by a temperature measurement unit (not shown), and controls the flow path opening / closing unit 30 according to the gas temperature to adjust the amount of gas flowing into the processing chamber 14. The temperature is adjusted to 100 ° C. or higher in the drying zone of the processing chamber 14 and to 100 ° C. or lower in the solidification zone of the processing chamber 14. The gas generation facility 40 may be any facility that burns fossil fuel installed in a steel mill such as a boiler, and an exhaust gas containing about 250 ° C. to 400 ° C. carbon dioxide discharged from the facility is used as the solidification device 10. Is effectively utilized as a carbon dioxide source for solidification and a heat source for drying. In particular, the exhaust gas generated when burning city gas, propane gas, heavy oil, natural gas, or kerosene contains a large amount of moisture, and thus is suitable as a gas used in the solidifying device 10. The solidifying device 10 is supplied with a gas of at least 100 ° C. or higher.

  The solidification apparatus 10 is provided with a gas discharge portion 32 communicating with the upper portion of the processing chamber 14 and connected to the exhaust facility 50 via a pipe 52 at the upper portion of the processing tank 12, and gas flowing through the processing chamber 14 is gasified. It is configured to discharge from the discharge unit 32. That is, in the solidification apparatus 10, the gas blown from the gas introduction unit 28 into the lower part of the processing chamber 14 flows from the bottom through the gap between the briquettes S, and from the upper part of the processing chamber 14 through the gas discharge unit 32. Thus, the gas is collected in the exhaust facility 50.

(Effects of Example)
Next, the operation of the reducing slag solidifying device 10 according to the embodiment will be described. In the solidifying device 10, the untreated briquette S conveyed by the carry-in facility 60 is filled into the processing chamber 14 from the carry-in unit 22. The untreated briquette S is soft because it is simply compressed, and is given water for storage and handling or for adjusting the amount of water, and is in a so-called wet state. Gas is supplied to the processing tank 12 by the gas generation facility 40 through the gas introduction unit 28 to the lower part of the processing chamber 14, and this gas is circulated from below through the gap between the briquettes S to be processed. The gas is recovered from the upper part of the chamber 14 into the exhaust facility 50 via the gas discharge part 32. Here, in the lower region of the processing chamber 14, since the briquette S comes into contact with a gas having a relatively high temperature of 100 ° C. or more immediately after being introduced into the processing chamber 14, drying becomes more dominant than the solidification reaction. Functions as a drying zone for drying the briquette S. On the other hand, in the middle and upper regions of the processing chamber 14, heat is removed from the gas in the lower region of the processing chamber 14, and the temperature of the gas decreases to 100 ° C. or lower. In the briquette S in contact with the solidification, the solidification reaction becomes more dominant than the drying, and the intermediate portion and the upper region function as a solidification zone for solidifying the untreated briquette S. Further, in the middle and upper regions of the processing chamber 14, moisture is discharged due to a decrease in the amount of saturated water vapor due to a decrease in temperature.

  In the solidifying device 10, when the briquette S in the lower region is solidified and the delivery means 26 is driven and controlled at a dry timing, the processed briquette S is delivered from the carry-out unit 24 by a predetermined amount and delivered to the carry-out facility 70. . The payout amount of the briquette S can be easily adjusted by the payout means 26. Thereby, only the solidified and dried processed briquette S on the bottom side of the processing chamber 14 is discharged from the processing tank 12, and the entire briquette S is lowered by its own weight by the discharged briquette S. The briquette S in the middle part of the processing chamber 14 falls to the lower area, and the briquette S in the upper area of the processing chamber 14 falls to the middle part. In addition, an amount of unprocessed briquette S corresponding to the discharged processed briquette S is input to the solidifying apparatus 10 from the upper part of the processing chamber 14 by the carry-in facility 60, and the top of the briquette S input in the previous batch. To deposit. The treated briquette S is chemically solidified and excellent in handleability, and since it is dry, it can be put into molten steel as it is.

  In the next batch, the briquette S in the lower region of the processing chamber 14 has already solidified in the previous batch, and drying proceeds by contact with a high-temperature gas. Similarly, the briquette S in the middle part of the processing chamber 14 and the briquette S in the upper region other than the newly added briquette S has been solidified to some extent in the previous batch, and further solidified by contact with the gas. Is advanced. Further, solidification of the untreated briquette S deposited on the uppermost portion of the processing chamber 14 proceeds by contact with the gas. In the solidifying device 10, the delivery means 26 is driven and controlled at the timing when the briquette S in the lower region is dried, and the processed briquette S is delivered from the carry-out unit 24 by a predetermined amount and delivered to the carry-out facility 70. Accordingly, the entire briquette S is lowered by the amount of the discharged briquette S, the briquette S existing in the middle part of the processing chamber 14 falls to the lower region, and the briquette S present in the upper region of the processing chamber 14 fall into. In addition, an amount of unprocessed briquette S corresponding to the discharged processed briquette S is input to the solidifying apparatus 10 from the upper portion of the processing chamber 14 by the carry-in facility 60. As described above, in the solidification apparatus 10, the processed briquette S solidified and dried by contact with gas is sequentially carried out from the lower portion of the processing chamber 14 through the carry-out unit 24, while the untreated briquette S is carried in the carry-in unit 22. A continuous processing cycle is sequentially introduced to the upper part of the processing chamber 14 and solidification and drying are performed in the process in which the briquette S moves from the loading section 22 toward the unloading section 24 by its own weight.

  Since the gas is first introduced into the lower region of the processing chamber 14 in the solidifying device 10, the briquette S just before the discharge in the lower region of the processing chamber 14 is brought into contact with the hot gas to remove moisture from the briquette S. The drying process can be quickly performed. Here, since the briquette S in the lower region of the processing chamber 14 has already solidified before being lowered to the lower region, the solidification process is not actively performed in the lower region even if moisture is removed in the lower region. There is no effect because there is no. Further, in the solidification apparatus 10, the temperature of the gas is reduced by drying in the lower region of the processing chamber 14, so that the gas having a temperature suitable for solidification is supplied to the middle and upper portions of the processing chamber 14 without particularly adjusting the gas temperature. It can be distributed to the area. As described above, the briquette S is solidified by reacting and solidifying the lime content liberated in the water adhering to the surface of the briquette S with carbon dioxide in the gas. It is said. In the middle part and the upper region of the processing chamber 14, a gas containing water flows in a dry zone whose temperature has decreased, and the moisture of the briquette S is adjusted appropriately, so that the solidification reaction is smoothly performed and solidified. Processing can be performed quickly. As described above, according to the solidifying device 10, the gas flowing from the lower portion of the processing chamber 14 is circulated from the bottom to the upper side while being in contact with the briquette S filled in the processing chamber 14, depending on the temperature of the gas. With a simple operation of adjusting the amount of gas flowing into the gas 14, it is possible to distribute a gas having a temperature that matches the characteristics of the solidification process and the drying process performed in each region. That is, the gas temperature decreases as it moves toward the upper region due to heat exchange with the briquette S, and the saturated water vapor amount decreases. Thereby, since the moisture content of the gas changes, the moisture content of the briquette S is adjusted, and the moisture content of the briquette S is adjusted to an amount suitable for the solidification reaction somewhere in the upper region from the middle region. Therefore, the solidification apparatus 10 can adjust the moisture amount suitable for the solidification reaction in any region of the solidification zone without particularly controlling the moisture amount, and the solidification reaction can be performed in the region where the moisture amount is appropriate. Promoted. Further, in the solidification apparatus 10, the solidification zone can be narrowed by increasing the inflow amount and temperature of the gas to widen the drying zone of the processing chamber 14, and conversely, by reducing the inflow amount and temperature of the gas. The drying zone can be narrowed to widen the solidification zone, and can be easily adjusted according to the processing status of the briquette S.

  The solidification apparatus 10 is configured to sequentially discharge the processed briquettes S in the lower region of the processing chamber 14 and sequentially input the unprocessed briquettes S, so that the solidification and drying processing cycles are continuously performed. Since it can do, processing efficiency is good compared with the conventional apparatus which replaces the whole quantity of briquette S thrown into the container. Moreover, the solidifying device 10 can solidify and dry the briquette S in one processing chamber 14, and move the briquette S in the processing chamber 14 and discharge the processed briquette S by its own weight. Since this is done, the apparatus can be simplified and compact.

(Example of change)
The embodiment described above can be modified as follows.
(1) In the embodiment, the gas discharge unit is provided in the upper part of the processing tank separately from the carry-in unit. However, a configuration in which the opening of the carry-in unit is also used as the gas discharge unit may be employed.
(2) The shape of the treatment tank is not limited to the embodiment, and the whole may be a straight tube shape or a hopper shape.

12 treatment tanks, 14 treatment chambers, 22 carry-in parts, 24 carry-out parts, 26 delivery means,
28 Gas introduction part, 32 Gas discharge part, S Reduction slag (briquette)

Claims (2)

An apparatus for solidifying and drying reduced slag (S) discharged in the steelmaking process,
A processing chamber (14) filled with granular reducing slag (S), which constitutes a lower region thereof and constitutes a lower cylindrical portion (16) serving as a drying zone of the reducing slag (S) and an upper region thereof A vertical cylindrical treatment tank (12) comprising an upper cylindrical portion (20) to be a solidification zone of the reduced slag (S), and
A carry-in section (22) that is provided in an upper part of the treatment tank (12) and receives an untreated granular reduction slag (S);
An unloading part (24) provided at the lower part of the processing tank (12), for discharging the treated reducing slag (S) from the lower part of the processing chamber (14);
A gas introduction part (28) provided in the lower cylinder part (16) of the treatment tank (12) for introducing a gas containing carbon dioxide at least 100 ° C. into the treatment chamber (14);
A gas exhaust provided at the upper part of the processing tank (12) and for discharging the gas flowing from the gas introduction part (28) and flowing upward through the processing chamber (14) from the upper part of the processing chamber (14). Part (32),
The gas comes into contact with the lower cylinder portion (16) forming the drying zone at a temperature of 100 ° C. or more, and the gas contacts the upper cylinder portion (20) forming the solidification zone at a temperature of 100 ° C. or less to dry and Solidified treated reducing slag (S) is sequentially carried out from the carry-out section (24), while untreated reduced slag (S) is sequentially put into the upper part of the processing chamber (14) from the carry-in section (22). An apparatus for solidifying reduced slag, wherein   The reducing slag solidifying device according to claim 1, wherein the carry-out section (24) includes a discharge means (26) capable of opening and closing a carry-out path communicating with a lower portion of the processing chamber (14).

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