Platinum Metals Rev., 1964, 8, (2), 54
Sintered Platinum Filters
The problems of filtering highly corrosive liquids such as hydrofluoric acid, or of filtration at very high temperatures, have been simplified by the introduction by Johnson Matthey of a range of sintered platinum filter discs of controlled pore size.
Made by hydraulic pressing a carefully graded mixture of platinum powder held in an organic carrier and sintering at high temperature, the filter discs are mechanically strong and present no difficulty in handling. Six standard discs constitute the range available, the mean pore size being from 5 to 100 microns, with an accuracy of ± 15 per cent. The largest disc available at present is 5 inches in diameter and the minimum thickness is 0.065 inch. They can be mounted, as shown in the illustration, into a solid platinum rim to facilitate installation. Cleaning the filters is naturally a simple operation as they are free from corrosive attack by almost all mineral acids and there is no tendency to form oxide films on heating.