Speaker
Description
In this work, carbon free pyrometallurgical treatment of non-ferrous iron residue was studied. This approach aimed to recover the valuable metals and convert the material into reusable benign slag using hydrogen as non-fossil reducing agent. Pyrometallurgical treatments involve two stages (oxidation and reduction). The use of hydrogen as a reducing agent after oxidative smelting was studied in this work. Reduction tests were performed within 1200 and 1400℃. Variable compositions of H2 and N2 were used. The reduction time was found to be short, less than 30 minutes. Both oxidation and reduction tests were carried out in a vertical tube furnace.
Preliminary results show that hydrogen is an effective reductant. During reduction stage, speiss phase was observed within the slag. The laboratory scale experiments suggest that slag obtained from pyrometallurgically treated iron residue slag can be further cleaned in fuming process using hydrogen and its mixtures to obtain cleaner slag with respect of volatile metals. The results also show that one can tune the reduction and control the formation of metallic iron phase.
Thermodynamic modelling has also been performed to simulate the fuming stage i.e. reduction of the slag. Speiss formation was studied and elemental distribution between speiss and slag, and results agree well with experimental results.
| Speaker Country | Finland |
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