During steel production either with EAF or BOF, 15 to 20 kg of dust/t of steel produced are formed, brought out by the gas stream and collected in the filter system. 20 years ago hardly any one knew about the problems related to these residues, but nowadays because of high zinc and lead contents in conjunction with the classification as hazardous waste they generate an additional expense factor. From the metallurgical view the high zinc containing dusts from the steel industry seem to be an interesting secondary raw material for the zinc industry. But because of different unwanted elements it is difficult to manage an economic recycling. As long as the land filing of these residues is still a competitive way of treatment, the different recycling options have to be critically investigated. The remaining room for improvement has to be utilized and research into possible alternative recycling routes has to be done. Referring to the pyrometallurgical treatment routes the influence of different reducing agents on the quality of products and residues form the base for further investigations. This paper describes the results of thermal treatment of an EAF dust in a vertical retort with the use of different reducing agents. Especially the character of the residue formed, that should be reused in the steel mill, is discussed. Beyond this, advantages and disadvantages of carbon and hydrogen as reduction agents are shown and the possibility of a combined use was judged.
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