| Abstract: | ![]()
Experiments with regard to various factors entering into pickling of sheet iron show that: (1) a freshly made sulphuric acid pickling bath pickles faster than a bath in which there is any concentration of ferrous sulphate and that (2) there is no evident advantage in adding a portion of old pickling solution to a new pickling solution “to get it to work right,” although prictical experience indicates otherwise; (3) increased ferrous chloride concentration in a muriatic acid pickling bath increases the rate of pickling; (4) ferric sulphate in a sulphuric acid bath will accelerate the rate of pickling, but will soon change to ferrous sulphate and then retard the rate; (5) decrease in acidity from usual strength decreases rate of pickling; (6) increase of temperature of bath accelerates rate of pickling; (7) iron annealed just previous to pickling loses 250–4000 more in pickling than unannealed iron; (8) use of monel metal basket accelerates the rate of pickling due to electrochemical reactions; and (9) use of muriatic acid or sodium chloride in mixtures with sulphuric acid retards the rate of pickling. |
