| 摘要 |
An aqueous trivalent chromium electrolyte containing a detrimental amount of contaminating metal ions (e.g. ions of Ni, Zn, Fe, Cu or Pb) is purified by adding dimethyldithiocarbamate ions, diethyldithiocarbamate ions, or a mixture thereof in an amount effective to precipitate at least a portion of the contaminating metal ions to reduce their concentration in the electrolyte to a level at which satisfactory performance of the electrolyte is restored and thereafter removing the precipitate from the electrolyte. The purified electrolyte does not produce the commercially unsatisfactory, dark streaky or spongy deposits which are obtained from the contaminated electrolyte. |
