Improving platinum precipitation processes

The precipitation of platinum is often enhanced by the addition of wood flo ur; a very fine, non-valuable material as seed. The wood flour acts as surf ace area for precipitate deposition that ensures the formation of reasonabl e sized particles and prevents undesirable mirroring and scaling on the rea ctor walls. However, the downstream removal of wood flour is time consuming and expensive. This work investigated the potential of platinum precipitat ion without wood flour. The ideal product would be grey, dense, have large particle size, large surface area, little evidence of platinum flakes (thes e being undesirable to the customer) and have no mirroring or scale formati on on the reactor wall (causing lost platinum). The method and results are presented in a way that does not disclose priori ty knowledge. (C) 2001 Published by Elsevier Science Ltd. All rights reserv ed.