Improvement of the electrolytic metal pickling process by inter-electrode insulation

Abstract

The existing industrial electrolytic steel pickling process is only 30% current efficient. Use of approximate modelling of the process and solution of the model predicts that inter-electrode insulation improves the current and energy efficiency, and this paper describes the experimental work that has validated this prediction. Some of the main results are: (a) the current efficiency varied from 20% without insulation to 100% with complete insulation, (b) the use of just partial insulations yielded a significant improvement in the process efficiency and at the same time maintained good electrolyte mixing and homogeneity which can not be attained with complete insulation. The theoretical foundations of this method and its various consequences are discussed. The method is relatively easy to apply to existing industrial electrolytic pickling tanks, and also provides system control flexibility for optimal pickling of different steel grades. The method's application cost is relatively low and saves investment in new equipment if a retrofit of an existing system is desired.