Zinc production method using electric furnace dust as raw material

Abstract

A zinc production method including a chlorination step 101 at which crude zinc chloride vapor 3 and an oxygen gas 2 are obtained by bringing electric furnace dust 1 containing zinc oxide or secondary dust 1 generated at the time of reducing the electric furnace dust in a reduction furnace into contact with a mixed gas containing a chlorine gas 8 and an oxygen-containing gas 10, converting a zinc oxide component in the electric furnace dust 1 or the secondary dust 1 into zinc chloride, and vaporizing the zinc chloride. The zinc production method further includes purification steps 102, 104, and 105 at which a zinc chloride component contained in the crude zinc chloride vapor 3 is separated from components 5 and 7 other than zinc chloride contained in the crude zinc chloride vapor 3 to obtain a purified zinc chloride melt 6, and an electrolysis step 103 at which the purified zinc chloride melt 6 is electrolyzed to obtain a zinc melt 9 and the chlorine gas 8.

Description

TECHNICAL FIELD[0001]The present invention relates to a zinc production method, and more particularly relates to a zinc production method using, as a raw material, electric furnace dust generated at the time of melting and refining of scraps in an electric furnace method, being one of iron-making processes, or dust generated in a reduction furnace at the time of recycling electric furnace dust as an iron-making raw material, a non-ferrous material, or a cement extender (hereinafter, “secondary dust”).BACKGROUND ART[0002]Generally, in the electric furnace method, being one of the iron-making processes, electric furnace dust is generated as industrial waste containing zinc oxide components in an amount of about 1.5% to 2.0% of steel production at the time of melting and refining of scraps. It is reported that 7 million tons of electric furnace dust are generated globally, and 0.5 million tons of electric furnace dust are generated in Japan.[0003]Most of iron scraps are from discarded ...

AI Technical Summary

Benefits of technology

The present invention provides a method for producing zinc with a high purity of 4N or more using a closed-cycle system that reduces waste. The method allows for the selective chlorination of zinc oxide and separation from iron oxide and free iron oxide in zinc ferrite. The purification steps involve distillation and electrolysis to obtain a purified zinc chloride melt for use in reducing purification and zinc production. Additionally, the method can use air as the oxygen-containing gas without the need for a separate supply source.

Problems solved by technology

Therefore, the electric furnace dust contains hazardous organic matter such as chloride and dioxin, in addition to heavy metals such as zinc and lead.

However, it is difficult to directly use the electric furnace dust as a raw material for aqueous electrolysis, which is a mainstream of the current zinc production method.

In addition, the electric furnace dust also contains halogen such as chlorine, which is harmful for aqueous electrolysis.

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