Keywords: steel pickling plants, environmental protection, acid spray roasting, acid recycling, regeneration technology, hydrofluoric acid, nitric acid
Acid recycling in steel pickling plants: state-of-the-art and new developments in environmental protection
For acid pickling of heat-treated mild steel and steel products for up to the middle of the last century, sulphuric acid was primarily in use, which has been replaced since the 1960s stepwise by hydrochloric acid. During this time, also the pickling of high alloyed steel with hydrofluoric acid or mixtures of hydrofluoric acid together with nitric acid has been applied on industrial scale. The paper presented here gives a survey on the progress of the state in the art of regeneration technology.