Pressure-Cyanide Dissolution of Palladium by Rotating Disk Method
At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 100°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium was measured in pressure clear cyanide solution using a Palladium rotating disk. The data at different rotation speed, different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressuer, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased.The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution were independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and were well below chemical reaction-limited for cyanide and oxygen.
Weiguo Pan, Jianxing Ren and Yongguang Li
J. S. Zhao et al., "Pressure-Cyanide Dissolution of Palladium by Rotating Disk Method", Advanced Materials Research, Vols. 347-353, pp. 1744-1748, 2012