Abstract
Removal of Pd, Ru and RuO2 from molten glass was studied using liquid Cu as the collecting metal. To increase the collision frequency between Cu and these platinum group metals (PGMs), copper-ruby glass containing Cu nanoparticles was used for the removal. The glass was prepared by the reduction of CuO dissolved in glass using Si as the reductant. Existence of the Cu nanoparticles was conformed by a measurement of the absorption peak of surface plasmon resonance at 595 nm. Another glass containing Cu particles of around 30 μm was prepared as a control specimen. By a heating of the two glasses with PGMs at 1473 K, separable metal buttons formed in both glasses. Metallic Pd and Ru were collected more than 90% in either metal buttons. There was no significant difference between the two glasses for the removal of metals. On the other hand, RuO2, which was reduced to metallic Ru by Cu, was collected 83% for the ruby glass, while not more than 52% for the control glass. The use of copper-ruby glass was effective for the removal of the oxide. The results of a leaching test of the glasses indicated that dispersing smaller Cu particles in glass had an effect to decrease the leaching rate of Cu from the glass into nitric acid.
