JP2009127064A - Reduction treatment apparatus and reduction treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction treatment apparatus and a reduction treatment method which can reduce treatment cost. <P>SOLUTION: At least one of sludge, oil spot, tree waste, fiber waste, rubber waste, and animal and plant residues as the waste material, which are effective as the reduction material and act as the heating material, is supplied into a reduction furnace 2, to which zinc-containing iron oxide, or zinc oxide or iron oxide is supplied, so that the reduction treatment is performed by using the waste material as a heat source without uselessly using other reduction materials. Thus, the zinc is reduced and/or the iron oxide is reduced to obtain the metallic iron while reducing the treatment cost by using the above reduction material as the heat source without using the reduction material uselessly. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for reducing zinc-containing iron oxide or zinc oxide or iron oxide, and a method for reducing treatment.

Conventionally, for example, iron mill-generated dust containing zinc-containing iron oxide is treated, and the treated material and zinc oxide and iron oxide in the zinc-containing iron oxide are reduced, for example, carbonaceous materials (reducing material) such as coke. The raw material of the mixture is prepared, and the raw material of the mixture is placed in the furnace of a rotary kiln having an in-furnace atmosphere temperature of 1100 ° C or higher and heated with a heavy oil / oxygen burner (fuel combustion device). There is known a method for dezincing zinc-containing iron oxide using a rotary kiln that reduces the zinc oxide in zinc-containing iron oxide and further evaporates to obtain an iron-containing material that can be charged into a reduction furnace such as a blast furnace. (For example, refer to Patent Document 1).
JP 2002-241850 A

  Here, in the thing of the said patent document 1, reduction of processing cost is desired. Similarly, reduction of the processing cost is desired when the target of reduction treatment is zinc oxide or iron oxide instead of zinc-containing iron oxide.

  The present invention has been made to solve such a problem, and zinc is reduced by heat treatment of zinc-containing iron oxide or zinc oxide or iron oxide and a reducing material and / or iron oxide is reduced. It is an object of the present invention to provide a reduction treatment apparatus and a reduction treatment method capable of reducing the treatment cost when reducing to obtain metallic iron.

  The reduction treatment apparatus according to the present invention is a reduction furnace in which zinc-containing iron oxide or zinc oxide or iron oxide and a reducing material are heat-treated in a reduction furnace to reduce zinc and / or reduce iron oxide to obtain metallic iron. The treatment apparatus, the reduction furnace is a reducing material and a heating material, and at least one of sludge, oil mud, wood waste, fiber waste, rubber waste, and animal and vegetable residues is introduced and used as a heat source. The reduction process is performed without using any other reducing material.

  In the reduction treatment method according to the present invention, zinc-containing iron oxide, zinc oxide or iron oxide, and a reducing material are heat-treated in a reduction furnace, thereby reducing zinc and / or reducing iron oxide and reducing metal iron. A reduction treatment method to be obtained, which is a reducing material and as a heating material, supplying at least one of sludge, oil mud, wood waste, fiber waste, rubber waste, animal and plant residue, and using this as a heat source and the others The reduction treatment is performed without using any reducing material.

  According to such a reduction treatment apparatus and a reduction treatment method, it is a waste that is effective as a reducing material and functions as a heating material in a reduction furnace to which zinc-containing iron oxide or zinc oxide or iron oxide is supplied. Since at least one of sludge, oil mud, wood waste, fiber waste, rubber waste, and animal and vegetable residues is supplied, and this is used as a heat source and no other reducing material is used, the reducing material is wasted. Without being used, the reducing material used is used as a heat source, and while reducing the processing cost, zinc is reduced and / or iron oxide is reduced to obtain metallic iron.

  Here, various types of reduction furnaces may be employed, but it is preferable to employ a rotary kiln that can form a suitable reducing atmosphere in the furnace.

  Further, when a material containing Ca is supplied to the reduction furnace, the basicity in the reduction furnace is increased, and the generation of clinker in the reduction furnace is prevented.

  Further, when zinc-containing iron oxide or zinc oxide or iron oxide is granulated and then introduced into the reduction furnace, the fly ash ratio is reduced and the scattering prevention effect is enhanced.

  Thus, according to the present invention, the processing cost can be reduced.

  Hereinafter, preferred embodiments of a reduction processing apparatus and a reduction processing method according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing equipment equipped with a reduction treatment apparatus according to an embodiment of the present invention. Here, the reduction treatment apparatus is a reduction treatment apparatus for zinc-containing iron oxide.

  As shown in FIG. 1, the facility 100 includes an electric furnace (electric furnace) 1, a rotary kiln (reduction furnace) 2 that heats by introducing electric furnace dust and reducing material of the electric furnace 1, and an outlet 2 f of the rotary kiln 2. A secondary combustion tower 3 that is communicated to complete combustion and an exhaust gas treatment facility 4 that introduces exhaust gas from the secondary combustion tower 3 and performs predetermined exhaust gas treatment are provided.

  The facility 100 includes a magnetic separator 8 that sorts iron from the discharge discharged from the outlet 2f of the rotary kiln 2, and a copper sorter 9 that sorts copper from the discharge from which iron has been removed by the magnetic separator 8. I have.

  The electric furnace 1 is for producing steel by melting iron scrap as a raw material at a furnace temperature of 1500 to 1700 ° C., for example, and electric furnace dust is generated from the electric furnace 1 as fly ash. The electric furnace dust has a total iron content (T-Fe) content of about 22%, a metal iron (M-Fe) content of about 0.8%, an iron oxide content of about 30%, and a zinc content. The rate is about 30% and contains a large amount of zinc-containing iron oxide. Therefore, the electric furnace dust is taken up by the non-ferrous smelter in the same state as the waste.

  The rotary kiln 2 has a cylindrical rotating body 2a and is horizontally placed so as to be inclined downwardly from a front part (left side in the figure) on the inlet side to a rear part (right side in the figure) on the outlet side. Arranged. The rotary kiln 2 may be placed horizontally. The rotary kiln 2 has a front end portion of its body portion 2a closed by a front support portion 2b as a fixed portion and is rotatably supported, and a rear end portion of its body portion 2a as a fixed portion as a secondary combustion tower. 3 is supported rotatably.

  The front support portion 2b is provided with an introduction duct 2c for introducing electric furnace dust from the electric furnace 1 into the furnace, and for example, fuel such as heavy oil is burned using combustion air introduced into the furnace. A fuel combustion device 2d is provided. This fuel combustion apparatus 2d is for preheating the interior of the furnace at the time of startup of the furnace so that the reduction temperature in the furnace will be described later. And (in actual operation), the driving is stopped.

  The introduction duct 2c is provided with a reducing material supply device 2e. The reducing material supply device 2e blows the reducing material into the furnace and supplies it to a predetermined position without stopping the operation of the rotary kiln 2.

  Here, the reducing material supplied by the reducing material supply device 2e is at least one of sludge, oil mud, wood waste, fiber waste, rubber waste, animal and plant residues, and these reducing materials can be used as heating materials. Function.

The rotary kiln 2 to which such a reducing material and electric furnace dust are supplied has a furnace in which the O ₂ concentration in the exhaust gas at the outlet 2f is 5% -dry or less and the copper is prevented from melting so that the inside of the furnace is reduced. The actual operation is performed so that the reduction temperature is 800 to 1080 ° C. By operation at this temperature, solid reduction (reduction in a solid state without melting) is performed in the rotary kiln 2.

  In such a rotary kiln 2, first, when the furnace is started up, the fuel combustion device 2d is driven to burn the fuel to generate high-temperature combustion gas and flame, thereby preheating the furnace, The internal temperature is raised to 800 to 1080 ° C. When the furnace temperature is raised to 800 to 1080 ° C., the driving is stopped and the actual operation is started.

  In this actual operation, the body 2a rotates at a predetermined speed, and the electric furnace dust supplied into the furnace through the introduction duct 2c is heated while being conveyed from the inlet side to the outlet 2f. Further, the reducing material supplied into the furnace via the reducing material supply device 2e is given heat to generate heat necessary for the reduction, and effectively functions as the reducing material and the heating material, so that the combustion treatment (heating) Process).

  In this combustion treatment, by the reducing action of the reducing material, zinc is reduced and separated from the zinc-containing iron oxide in the electric furnace dust, and iron oxide is reduced to obtain metallic iron. At this time, since the reduction temperature of the furnace is set to 1080 ° C. or lower, it is possible to prevent copper having a melting point of 1083 ° C. from melting and adhering to iron. Moreover, since the reduction temperature of the furnace is set to 800 ° C. or higher, both the metallization rate (ratio of iron content in iron oxide to become metal iron) and dezincification rate (ratio of zinc removal) are both increased ( Reduction performance is improved).

  And the discharge containing iron and copper flows down from the outlet 2f and is discharged. On the other hand, the zinc separated from the zinc-containing iron oxide is volatilized and scattered as dust having a fine particle diameter, and is accompanied by the exhaust gas and travels to the secondary combustion chamber 3a above the kiln outlet 2f of the secondary combustion tower 3.

  The discharged material discharged from the kiln outlet 2 f is subjected to sorting of iron by the magnetic separator 8, and the iron is supplied as a raw material for the electric furnace 1. As described above, since this iron does not melt copper, it is effectively used as a raw material in which deterioration in quality is prevented. The electric furnace dust generated in the electric furnace 1 is supplied to the rotary kiln 2 as described above, and this is repeated. Further, the discharged material discharged from the kiln outlet 2f and from which iron has been removed by the magnetic separator 8 is subjected to copper sorting by the copper sorter 9, and the copper is used as a raw material for the copper refinery and is effectively used.

  On the other hand, in the secondary combustion chamber 3a, the unburned components in the exhaust gas are completely burned, and the volatilized zinc becomes zinc oxide or the like and goes to the exhaust gas treatment facility 4 at the subsequent stage as high-zinc-concentrated dust. It is collected by a cyclone, a bag filter or the like constituting the exhaust gas treatment facility 4. Since the high zinc concentration dust collected and collected has a zinc concentration of 50 to 80%, it is very effectively used as a raw material for crude zinc ore at a zinc refinery. On the other hand, the gas purified through the exhaust gas treatment facility 4 is released to the atmosphere via the chimney 11 at the subsequent stage.

  Thus, in this embodiment, in the rotary kiln 2 to which zinc-containing iron oxide is supplied, sludge, oil mud, wood waste, fiber waste, which is a waste that is effective as a reducing material and functions as a heating material. Because at least one of rubber scrap and animal and plant residue is supplied and used as a heat source and reduction processing is performed without using any other reducing material, the reducing material is used in vain The reducing material used is used as a heat source, reducing the processing cost (in addition to not using the reducing material unnecessarily, the reducing material functioning as the heat source stops the driving of the fuel combustion device 2d during actual operation) Thus, zinc can be reduced and separated from the zinc-containing iron oxide while reducing the running cost, and metallic iron can be obtained by reducing the iron oxide.

  The present invention has been specifically described above based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, electric furnace dust containing a large amount of zinc-containing iron oxide is used. It is intended to make efficient use of recovered iron and zinc by increasing the recovery rate of iron and zinc as the object to be treated. For example, sludge generated in wastewater treatment equipment that is an electric furnace auxiliary equipment, rolling equipment In other words, it may be a rolling scale generated in the above, and the point is that it contains zinc-containing iron oxide. Further, as being particularly preferable, the object to be reduced is zinc-containing iron oxide, but the present invention can be similarly applied when zinc oxide or iron oxide is used as the object to be reduced instead of zinc-containing iron oxide. In the case of zinc oxide, as in the case of zinc-containing iron oxide, zinc is reduced and can be recovered as dust with a high zinc concentration. In the case of iron oxide, the zinc-containing As in the case of iron oxide, it can be recovered as metallic iron in which the iron oxide has been reduced to prevent degradation.

  Moreover, in the said embodiment, although the rotary kiln 2 is used as a furnace which can form a suitable reducing atmosphere in a furnace, if it is a furnace which functions as a reducing furnace, for example in a shaft furnace, a high-temperature gasification furnace, etc. There may be.

  In addition, when a material containing Ca such as quick lime, slaked lime, limestone or the like is supplied to the reduction furnace, the basicity in the reduction furnace is increased, and generation of clinker in the reduction furnace can be prevented.

  In addition, when the zinc-containing iron oxide or zinc oxide or iron oxide introduced into the reduction furnace is granulated and then introduced into the reduction furnace, the fly ash ratio can be reduced and the scattering prevention effect can be enhanced.

  Further, in the above embodiment, the fuel combustion device 2d is for preheating the interior of the furnace when the furnace is started up. In actual operation, the drive is stopped and no auxiliary fuel is used. The present invention is sometimes applicable to a configuration in which the fuel combustion device 2d is sometimes driven to use auxiliary fuel. In this case, the amount of auxiliary fuel used can be reduced by the reducing material functioning as a heat source, and the processing cost can be reduced.

It is a lineblock diagram showing equipment provided with a reduction processing device concerning an embodiment of the present invention.

Explanation of symbols

  2 ... Rotary kiln (reduction furnace; reduction processing device), 2e ... Reducing material supply device.

Claims (5)

A reduction treatment apparatus for obtaining metal iron by reducing zinc and / or reducing iron oxide by heat-treating zinc-containing iron oxide or zinc oxide or iron oxide and a reducing material in a reduction furnace,
The reduction furnace is
A state in which at least one of sludge, oil mud, wood waste, fiber waste, rubber waste, animal and plant residues is introduced as a heating material and used as a heat source, and no other reducing material is used as a heating material. The reduction processing apparatus characterized by performing reduction processing by.   The reduction processing apparatus according to claim 1, wherein the reduction furnace is a rotary kiln.   The reduction processing apparatus according to claim 1, wherein a material containing Ca is supplied to the reduction furnace.   The reduction treatment apparatus according to any one of claims 1 to 3, wherein the zinc-containing iron oxide or the zinc oxide or the iron oxide is introduced into the reduction furnace after being granulated. A reduction treatment method for reducing zinc and / or reducing iron oxide to obtain metallic iron by heat-treating zinc-containing iron oxide or zinc oxide or iron oxide and a reducing material in a reduction furnace,
Supplying at least one of sludge, oil mud, wood waste, fiber waste, rubber waste, animal and vegetable residues as a heating material as well as the reducing material,
A reduction processing method characterized in that the reduction processing is performed in a state where this is used as a heat source and no other reducing material is used.

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