J. H. de Boer's iodide process, a method for the preparation and regeneration of metals

The life work of Prof. Dr. J. H. de Boer, who will be seventy this year, lies in the field of adsorption and catalysis. It is sometimes forgotten that he is also the originator of an important metallurgical process— the iodide process. This discovery made possible the preparation of many metals (e.g. Ti, Zr,Hf, V, Nb, Ta) with a lower content of non-metallic impurities than is possible with any other process. It would require a paper of abnormal length to describe all the developments stemming from this 45-year old discovery. For this reason only the basic ideas of the iodide process are discussed here, together with a single recent application—the iodide lamp.