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The effects of arsenic and lead impurities on the current efficiency and deposit composition in alkaline zinc electrowinning
Author(s) -
Hu Mao Pu,
Piron Dominique L.
Publication year - 1992
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450700319
Subject(s) - zinc , arsenic , electrowinning , chemistry , deposition (geology) , inorganic chemistry , tin , metallurgy , electrolyte , materials science , electrode , geology , paleontology , organic chemistry , sediment
The influence of lead and arsenic impurities on zinc deposition, current efficiency and deposit composition was examined in the alkaline zinc electrowinning system. It was observed that lead slightly decreases the current efficiency of zinc deposition, and that the detrimental effect on zinc current efficiency which was observed with arsenic was largely suppressed in the presence of lead. This beneficial effect is related to the fact that the arsenic content of the deposit decreased when lead was present in the electrolyte. It was also found that arsenic promotes the deposition of lead. Tin has no effect on the current efficiency of zinc deposition in alkaline solutions, with or without arsenic. The addition of salicylaldehyde to the solution alleviates the deleterious influence of arsenic on zinc current efficiency, but it somewhat increases the cell voltage.