| 摘要 |
PURPOSE:To contrive to stabilize the quality of a chromated steel sheet, by analyzing Cr<6+> content in a chromating bath to control the amount of a new treating liquid to be replenished, and analyzing Zn<2+> content in it to control the treatment of regenerating the treating liquid. CONSTITUTION:Cr<6+> content in a chromating bath 5 is analyzed by an automatic analyzer 6, and a pump 4 is driven on the basis of the deviation between an objective concentration and the measured value to replenish a new chromating liquid from a supplementary tank 3. In addition, Zn<2+> content in the treating bath 5 is analyzed, and a pump 7 is driven on the basis of the deviation between an objective concentration and the measured value to introduce the deteriorated treating liquid into filters 8A, 8B for the removal of fine suspended matter from it. Thereafter, the treating liquid is introduced into columns 9A, 9B packed with ion-exchange resin to adsorb and catch cations, e.g. zinc and iron, and Cr<3+> accumulated in the liquid, and the regenerated liquid is returned to the chromating bath 5 again. |
