Technological innovations for copper removal from iron-carbon melts

摘要

There is a problem when steel scrap contains excessive copper.Until now there are no reliable methods to control the copper content in the metal during steelmaking processes except dilution technique.Not any of the investigated methods of copper removal from iron-carbon melts are realized in commercial technologies until now.Their application in industry is restrain either by the low effectiveness of the processes or by the difficulty of coordination with the up to date steelmaking technologies.Technique of sulfidizing treatment was chosen for the development by authors.It was shown,that it is possible to raise effectiveness of the sulfide treatment with the help of special organization of the process:intensive saturation of the iron melt with sulfur in the process of its blowing with powders based on sulfur and sulfur-containing compounds;the creation of favorable conditions for sulfide inclusions formations and following extension of them,as well as further separation of sulfide and iron phases.Tests revealed at least 50% of copper can be removed from the metal during a sulfide treatment.But the considerable technological trouble is concerned with necessity of thorough separation of sulfide and metal phases after treatment.The filtration technique allows considerably increase the total copper removal from metal after sulfidizing treatment up to 70% -80%.In the actual practice the refinement may be done during a special refining heat to make an intermediate product with allowable copper concentration for subsequent charging into electric arc furnaces like a solid material or converting into steel by oxygen blowing.