Platinum Metals Review - Volume 2, Issue 3, 1958

Many modern electronic devices call for transducers in the form of precision potentiometers actuated by extremely low operating forces. For the windings of such potentiometers certain of the platinum alloys provide the required combination of properties, and this article discusses both the choice of resistance material and the design and construction of these potentiometers.

The platinum-bearing catalysts now in such substantial use in the petroleum industry retain their high activity during many months of use, but ultimately they require to be replaced by fresh charges. The efficient and economic recovery of the platinum from spent catalyst is therefore of great importance to the commercial success of catalytic reforming. This article describes the methods adopted in the Johnson Matthey refineries, particularly for sampling, to achieve the highest possible recoveries of these residues.

An important factor in the utilisation of the platinum metals at high temperatures is the loss in weight that occurs to some degree due to oxidation and volatilisation. The author critically reviews recent work on this subject and describes some original experimental work.