Polarization behaviour of Eu, Sm, and Gd was investigated in acidic sulfate solutions using Cu and Cu-Hg cathodes and electrolytic reduction-precipitation of europium from sulfate solutions was studied using a mercury-coated copper electrode. The effect of magnetic stirring, N-2 gas sparging, and use of a cation permeable membrane on electrolytic reduction was determined. Europium recovery of 71.9% for magnetic stirring increases to 74.4% for N-2 gas sparging and to 79.5% for N-2 gas sparging + membrane system. The purity of the precipitated EuSO4 is 98.5%, 96.0%, and 94.4%, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.