Separation of Pd from the Simulated Liquid Wastes by using Hypophosphorous Acid

The separation of palladium from the simulated liquid wastes was experimentally examined in a reduction process with hypophosphorous acid. The obtained main results were as follows: A favorable hypophosphorous acid concentration region was found to be from 0.03 M to 1.0 M, The appropriate nitric acid concentration was confirmed to be about 1.0 M. The suitable stagnant time was found to be within 48 hours. The precipitation fraction of palladium in the simulated liquid wastes was determined to be over 99%. The precipitation fraction of other elements(Rh, Ru, Cs, Ni and Fe) in the simulated liquid wastes was extremely low, and that of Sr was about 25%. The precipitation fraction of palladium was improved with increasing hypophosphorous acid concentration and decreasing nitric acid concentration.