Direct heating of sulphuric acid soln. - using electric current passed between electrodes immersed in the soln.

摘要

Direct heating of a soln. of H2SO4 is effected using a current passed between electrodes immersed in the soln. The surfaces of the electrodes are subjected to a passivation pre-treatment, so that the resistance of transition between the electrodes and the H2SO4 soln. is at least as high and pref. 3-5 times the resistance produced by the H2SO4 soln. Used e.g. in the distn. of H2SO to increase its concn. or to eliminate dissolved impurities. Process gives a better thermal transfer and thermal yield than prior indirect processes. Owing to the high resistance between the electrodes and the liq. the process also requires a lower current intensity and therefore simpler electrical appts. than previous direct processes.