| 摘要 |
PURPOSE:To reduce the amount of sludge produced, to make the particles of the sludge fine and to prevent the solidification of the sludge by adding an amine compound to a phosphating soln. to regulate the ratio of phosphoric acid in the soln. CONSTITUTION:An amine compound such as triethanolamine is added to an aqueous soln. contg. phosphoric acid and a primary phosphate to regulate the ratio of the acid in the soln. A metallic product is then immersed in the soln. to form a phosphate film on the surface. Thus, the amount of sludge produced is reduced, the particles of the sludge are made fine, and the sludge is prevented from settling and solidifying even after the lapse of a long time. |
