Platinum Metals Rev., 1965, 9, (3), 99
Anodic Protection for Sulphuric Acid Tank Car
The technique of anodic protection as a means of preventing corrosion has been described in this journal (Platinum Metals Rev., 1960, 4, 17 and 86; 1963, 7, 94) and a number of successful applications of the method have been reported in the literature. An unusually interesting example of this simple and inexpensive method has now been reported by the Anotrol Division of Continental Oil Co, who have for some time made available suitable equipment for this purpose.
For over a year one of these units has been in operation on a stainless steel tank truck used to transport 93 and 99 per cent sulphuric acid. The equipment includes a potential controller, a reference electrode, and a platinum cathode, current being derived from the normal battery in the truck. The protective film on the stainless steel is maintained by a pulse of 25 to 30 amp for one or two seconds every ten minutes. The installation reduced iron pick-up in the acid carried from around 10 to 15 p.p.m. down to 2.5 p.p.m. for the 99 per cent and 1.6 p.p.m. for the 93 per cent acid.