The dissolution behavior of lead plates in aqueous nitrate solutions

The dissolution behavior of metallic Pb plates in aqueous neutral sodium ni trate and ammonium nitrate solutions was investigated. Using a rotating dis k method, the rate of dissolution was measured by weight changes in the dis ks for nitrate concentrations of 0.01-0.2 mol dm(-3), at rotation speeds of 100-800 rpm and 60-90 degrees C. In ammonium nitrate solution, the dissolu tion rate was mainly determined by the chemical reaction at temperatures hi gher than 60 degrees C and by NH4NO3 at concentrations higher than 0.05 mol dm(-3). The dissolution rate in NaNO3 solution was much slower than that i n NH4NO3 solution. X-ray photoelectron spectroscopy analyses showed the for mation and compositional differences of a passive oxide layer containing ni trogen compounds on the lead surface in both nitrate solutions. (C) 1999 El sevier Science Ltd. All rights reserved.