| 摘要 |
1. Process for the surface treatment of an article made of aluminium or of aluminium alloy for satinizing or chemical machining by means of an alkaline aqueous bath, in which the said article is immersed in a bath devoid of sorbitol, gluconate or other sequestering agents for aluminium and comprising : a) 2 to 60 g/l of a strong base chosen from the group consisting of NaOH and KOH, b) 5 to 50 g/l of a medium chosen from the group consiting of sulphides, thiosulphates, sulphates and mixtures thereof, and c) an Al content of between 4.5 and 15 g/l, the temperature of the bath between 40 and 100 degrees C, and the said bath is continuously filtered to remove the insoluble material formed which it contains and to collect the filtrate, the strong base being regenerated from the said filtrate and recycled, the aluminium present in the said filtrate being collected in the form of alumina. |
