Estimation of the Concentration of Acid in Pickling Steel and Determination of the Suitable Concentration of Acid

Abstract

Regretting that there is no suitable method of estimating the concentration of acid, the author devised the simplest apparatus, to which he applied the principle that concentration is determined by titration with standard sodium bicarbonate solution, using potassium ferrocyanide as indicator in presence of ferric salts.
The author next determined the suitable concentration of acid in which pickling can be completed in 1517 hours.