Physical treatment of zinc
skimmed from galvanized process using fluidized bed up-stream column
The Egyptian General Metallic Company produces a huge amount of zinc skimmed
during galvanization process. It causes problems in handling and storage.
This work aims to study physical treatment of zinc skimmed from galvanized
process of Egyptian general metallic company to attain fractions reach with
zinc suitable for alloying process and preparation of chemical compounds.
The suggested experimental program involves hand sorting to remove iron
pieces, sieving of representative sample of zinc skimmed and dividing it to
four groups according to size from 10mm to 75µm in order to treat each group
separately. The grinding process was carried out for the coarse fractions.
The physical separation such as fluidized bed up-stream column, air
classifier and flotation was carried out on the fine fraction less than
75µm. Results showed that the zinc assay and distribution increase in the
coarse fraction of the skimmed zinc. The grinding process of coarse
fractions larger than 1.161mm leads to increase zinc assay from 70% to 83%
and about 27% by weight of the sample was obtained with zinc assay 83% by
weight. The grinding of size fraction (-1.161+0.075mm) showed that zinc
assay increases from 48% to 76%. The treatment of fines (less than 0.075mm)
using fluidized bed, air classifier and flotation improves the zinc assay
and recovery. The zinc assay increases from 44% to 56%.