| 摘要 |
<p>Iron is recovered from spent reduced iron catalyst particles by passivating the spent catalyst by contacting the reduced catalyst particles with an oxidising oxygen-containing gas at a temperature below 100 DEG C, to oxidise the surface layers of the particles without oxidation of the bulk of the particles, reacting the passivated catalyst particles with nitric acid to dissolve the bulk of the un-oxidised iron in said particles, and filtering undissolved material from the reaction mixture, thereby obtaining a nitrate solution. If cobalt is present in the spent catalyst, it will be recovered with the iron. The nitrate solution may be used for the preparation of fresh catalyst by precipitation by addition of a base followed by drying and calcination of the precipitate.</p> |
