Platinum Metals Review - Volume 15, Issue 4, 1971

Platinum as supplied to industry contains less than 200 parts per million of total impurities, and is probably the purest metal refined by chemical means alone. This article reviews the influence of individual impurities upon the properties of platinum, illustrates some of the sophisticated methods of analysis and control employed, and discusses the reasons why particular care is taken to eliminate specific impurities from platinum intended for use in certain applications.

Thermodynamic principles and data are very useful in the solution of industrial problems, particularly in assessing the feasibility and economics of a projected process. This article reviews the application of thermodynamics to the oxidation of platinum and to the life expectancy of platinum coatings on base metal substrates when operating at high temperatures, and describes the derivation of equilibrium diagrams of platinum alloys from the thermochemical properties of the constituent phases.

Palladium dissolves the isotopes of hydrogen in a selective manner and can be used, therefore, to facilitate separation and concentration processes. Although simple absorption techniques permit high separation factors under equilibrium conditions, no satisfactory counter-current process capable of separation by absorption has yet been developed. Better results are obtained by using the electrolytic diffusion technique which allows kinetic separation factors to operate. These effects are discussed in the summary below which is based on a paper presented by Professor E. Wicke of the University of Munster to a Symposium held in the Chemistry Department of Queen’s University, Belfast on “The Formation and Reduction of Surface Oxides, and Processes of Hydrogen Discharge and Exchange at Noble and Quasi-noble Metal Surfaces”.