摘要 |
<p>A process for the recovery of aluminium and fluoride values from spent pot lining material comprises: (a) leaching the material in a solution containing a mineral acid and the corresponding aluminium salt in such proportions as to dissolve the aluminium and fluoride values, and (b), subjecting the leached liquid to thermal hydrolysis to cause precipitation of an aluminium fluoride product. Preferably, the spent pot lining material is calcined before leaching to produce an ash having environmentally acceptable levels of cyanide contamination. Preferably, the leaching is carried out in two stages: the acid and the spent pot lining material are mixed first and mixture is aged to prevent the dissolution of silica, and the aluminium salt is added after aging.</p> |