JP2008101826A - Recycling method of electric furnace dust - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recycling method of an electric furnace dust, which detoxifies dioxine included in dust generated in filtering an exhaust gas discharged from an electric furnace by a dust collector, and efficiently classifies the dust by a classifier. <P>SOLUTION: The recycling method of the electric furnace dust includes: filtering the exhaust gas discharged from the electric furnace X by the dust collector S; classifying the dust discharged from the dust collector S into the dust of high density including iron oxide and the like, and the dust of low density including zinc and the like by the classifier B; and returning the dust of high density including iron oxide and the like to the electric furnace X. The dust discharged from the dust collector S is heated by a microwave processing device 1, and then distributed to the classifier. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for recycling electric furnace dust, and in particular, exhaust gas discharged from the electric furnace is filtered by a dust collector, and the dust discharged from the dust collector is collected with high-density dust including iron oxide and the like by a classifier. It is related with the improvement of the recycling method of the electric furnace dust which classify | categorizes into the low density dust containing and returns the high density dust containing the said iron oxide etc. to an electric furnace.

Conventionally, as a method for recycling electric furnace dust contained in exhaust gas discharged from an electric furnace, for example, a method based on the flow shown in FIG. 3 has been adopted.
In this conventional electric furnace dust recycling method, exhaust gas containing dust discharged from the electric furnace X is introduced into a dust collector S (for example, a bag type dust collector) by a suction fan F via a gas cooler (not shown), The dust discharged from the dust collector S is transported to the classifier B, and is classified into a high density dust containing iron oxide and the like and a low density dust containing zinc etc. by the classifier B, and a high density containing iron oxide and the like. The dust is pelletized by the granulator P and returned to the electric furnace X by an appropriate means such as a conveyor.

  On the other hand, low density dust containing zinc or the like is sent to silo C, and is granulated by a granulator (not shown) as needed, and then discarded or handed over to a recovery company to collect zinc. (For example, refer to Patent Document 1).

By the way, A press (garbage after secondary dismantling of scrap car) that is an insert into the electric furnace, shredder dust of scrap car, medical waste, etc. include resins containing chlorine such as polyvinyl chloride. In many cases, dioxins generated from these resins are contained in the dust discharged from the dust collector S.
And it is not preferable from the viewpoint of the environment and hygiene that the dust containing such dioxins is discarded as it is or is handed over to a recovery company.
Moreover, the dust discharged | emitted from the dust collector S had the problem that moisture content was high, and it was easy to adhere to a classifier, and classification could not be performed efficiently.
Japanese Patent No. 3317131

  In view of the problems of the conventional electric furnace dust recycling method, the present invention renders the dioxins contained in the dust generated when the exhaust gas discharged from the electric furnace is filtered by a dust collector, and uses a classifier. An object of the present invention is to provide a method of recycling electric furnace dust that enables efficient classification.

  In order to achieve the above object, the method for recycling electric furnace dust according to the present invention is a method of filtering exhaust gas discharged from an electric furnace with a dust collector, and separating the dust discharged from the dust collector with iron oxide or the like with a classifier. An electric furnace dust recycling method for classifying dust into low-density dust containing zinc and the like and returning the high-density dust containing iron oxide and the like to the electric furnace, wherein the dust discharged from the dust collector is micro It heat-processes with a wave processing apparatus, It sends to a classifier after that, It is characterized by the above-mentioned.

  According to the electric furnace dust recycling method of the present invention, the dust discharged from the dust collector is heated by the microwave processing device and then sent to the classifier, so that the dust is sent to the microwave before being sent to the classifier. The dust can be heated to detoxify the dioxins, the dust can be dried, and the dust can be attached to the classifier as much as possible, and the detoxified dust is efficiently classified by the classifier. be able to.

  Embodiments of an electric furnace dust recycling method of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the electric furnace dust recycling method of the present invention.
In this electric furnace dust recycling method, exhaust gas containing dust discharged from the electric furnace X is introduced into the dust collector S (for example, a bag-type dust collector) by the suction fan F, and the dust discharged from the dust collector S is micronized. After being transported to the wave treatment device 1 and heated in the microwave treatment device 1, the dust is transported to the classifier B, and the classifier uses a high density dust containing iron oxide and the like and a low density dust containing zinc etc. The high-density dust containing iron oxide or the like is returned to the electric furnace X by appropriate means, for example, the air transport device A.

  The microwave processing apparatus used in this electric furnace dust recycling method is used in a solid processing apparatus containing harmful substances such as organic halogen compounds previously proposed by the present applicant in Japanese Patent Application No. 2005-353936. A microwave processing device can be used.

The microwave processing apparatus 1 includes a housing 2 that introduces dust containing harmful substances such as organic halogen compounds, and a microwave irradiation mechanism 3 that irradiates the dust introduced into the housing 2 with microwaves. I am doing so.
The dust discharged from the dust collector is transported into the housing 2 by the transport device (not shown) through the introduction port 2a provided in the upper portion of the housing 2.
And from the microwave irradiation mechanism 3 (in the example shown in the figure, an example where it is disposed at one place on the upper surface is shown), a plurality of places can be disposed on the upper surface and the side surface. Irradiate microwaves to decompose harmful substances such as dioxins contained in dust.
Then, it conveys to the classifier B by the conveying apparatus (illustration omitted) through the discharge port 2b arrange | positioned in the lower part of the housing | casing 2. FIG.

  As long as the classifier B can classify the dust into a high-density dust containing iron oxide or the like and a low-density dust containing zinc or the like, the method and mechanism are not limited. The cyclone type separation device can be suitably used.

  In this electric furnace dust recycling method, the dust discharged from the dust collector S is heated by the microwave processing device 1 in the previous process to be sent to the classifier B. However, since the dust contains moisture, the dust is irradiated by microwave irradiation. Heating effect is high, moisture is evaporated by heating, and dust is detoxified and dried by heating.

  The detoxified and dried dust is sent to the classifier B and efficiently classified into a high density dust containing iron oxide and the like and a low density dust containing zinc and the like.

  Thereafter, the high-density dust containing iron oxide or the like is returned to the electric furnace X by an appropriate means, for example, a conveying device such as an air transport device A or a conveyor (not shown), and is melted.

On the other hand, low-density dust containing zinc or the like is sent to silo C, granulated by a granulator P as necessary, and then discarded or handed over to a recovery company for recovery of zinc.
And since the low density dust containing this zinc etc. does not contain dioxins, even if it is discarded as it is, or it is handed over to a recovery company, there is no problem in terms of the environment and hygiene.

  The dust recycled in the present embodiment is not limited to dust discharged from the dust collector S, but dust discharged from the path from the electric furnace X to the dust collector S, for example, accumulated in the duct and cleaning the duct. The dust generated at the time, the dust accumulated in the gas cooler and discharged through a flap damper or the like disposed below the dust is included, and the same processing as the dust discharged from the dust collector S is performed.

  As mentioned above, although the recycling method of the electric furnace dust of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, In the range which does not deviate from the meaning, that The configuration can be changed.

  The method for recycling electric furnace dust according to the present invention is capable of detoxifying dioxins contained in dust generated when the exhaust gas discharged from the electric furnace is filtered by a dust collector, and can be efficiently classified by a classifier. It can be suitably used for a dust recycling method in general electric furnace equipment.

It is a flowchart which shows the recycling method of the electric furnace dust of this invention. It is a front view of the microwave processing apparatus used for the recycling method of the electric furnace dust of this invention. It is a flowchart which shows the recycling method of the conventional electric furnace dust.

Explanation of symbols

1 Microwave treatment equipment B Classifier P Granulator S Dust collector X Electric furnace

Claims (1)

  The exhaust gas discharged from the electric furnace is filtered by a dust collector, and the dust discharged from the dust collector is classified into a high-density dust containing iron oxide and the like and a low-density dust containing zinc etc. by a classifier, and the oxidation An electric furnace dust recycling method for returning high-density dust containing iron or the like to an electric furnace, wherein the dust discharged from the dust collector is heat-treated by a microwave treatment device, and then sent to a classifier How to recycle electric furnace dust.

Images