Method and apparatus for recovering metal from electric furnace dust

Abstract

Obtained are a method and an apparatus for recovering a metal from electric furnace dust, which are capable of recovering the metal with high efficiency without causing problems such as occlusion of the apparatus. An apparatus (1) for recovering a metal from electric furnace dust of the present invention, which recovers molten iron and zinc oxide by melting and reducing electric furnace dust, which contains not less than 12% by mass of a chlorine content and a zinc content in total, mainly by electrical energy. The apparatus (1) for recovering a metal from electric furnace dust comprises: a melting / reduction furnace (3); a secondary combustion chamber (5) in which the exhaust gas from the melting / reduction furnace (3) is caused to form an upward flow at an ascending rate of 0.5-2.0 m / s (inclusive); a coarse-grained dust recovery device (7) for recovering coarse-grained dust that settles in the lower part of the secondary combustion chamber (5); and a fine dust recovery device (9) which is disposed on the exhaust gas exit side of the secondary combustion chamber (5) for the purpose of recovering fine dust.

Description

technical field [0001] The present invention relates to a method and apparatus for recovering metal from electric furnace dust generated from electric furnaces (for example, electric arc furnaces for steelmaking) that use scrap, reduced iron, pig iron, etc. as raw materials and melt and smelt them to produce steel (hereinafter referred to as "electric furnace dust") for metal component recovery. Background technique [0002] Electric furnace dust generated in electric furnaces that use iron scrap as the main raw material to manufacture steel contains 20 to 30% iron oxide, 10 to 30% zinc oxide, and 2 to 7% chlorine. [0003] In order to recover zinc components from this electric furnace dust, a rotary kiln is widely used. In the process using this rotary furnace, electric furnace dust and a reducing agent are heated in the furnace to generate metallic zinc vapor, oxidize the zinc vapor in the exhaust gas, and recover zinc as zinc oxide particles. [0004] However, in this m...

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Problems solved by technology

[0004] However, in this method, iron components are not sufficiently reduced, and about 1 to 3% of zinc remains in the partially reduced iron oxide.

In order to completely reduce the iron component and separate the zinc component with high efficiency, the heating temperature of the raw material needs to be raised above the melting temperature of iron oxide, but when the heating temperature is raised, it is difficult to discharge the semi-molten product from the reduction equipment The problem

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