The manner null which recovers the grain iron powder without leaving the processed strain from the converter

摘要

PURPOSE:To easily recover iron powder of a high grade by drying coase-grained dust separated from the dust collection water of the dust generated by a converter then classifying, separating and magnetically separating extremely small sizes, and treating the same with strong hydrochloric acid, then drying the powder in a nonoxidative atmosphere. CONSTITUTION:The dust generated from the converter is subjected to wet dust collection and the coase-grained dust 2 sized about =40mum grain size is settled by a settling and separating pit from slurry dust 1 in the water. Said dust is preferentially removed and taken out of a removing port 3. After the separated coarse-grained dust 2 is dried, the sizes of =500mum grain size are classified and separated. The dust sized =500m is magnetically separated so that nonmagnetic materials are separated therefrom to some extent; thereafter, the dust is treated with 1-10N aq. hydrochloric acid by which the surface sticking layer of the iron powder is thoroughly removed. After the iron powder is separated by filtration, the iron powder is dried at about 25-100 deg.C in a nonoxidative atmosphere such as N2, Ar, or CO2 and is finally magnetically separated. The high-grade iron powder which is free from work strain and does not contain impurities is thus obtd.