| 摘要 |
<p>In a method for recovering Ta, Nb and Ti values, sources containing less than 10% by weight of Ta and Nb materials and up to 90% of Si, Ca, Fe, Al and Ti compounds are reacted with CaF2 and at least 60% H2SO4, the quantity of fluoride being at least stoichiometrically equivalent to the silicon, and the quantity of H2SO4 being at least sufficient to generate the required amount of HF, so as to remove the Si, and heated at 300-400 DEG C. until the acid content is in the range of 9-15%. The product may be boiled with water and HF to solubilize Nb, Ta and Ti, and the slurry separated into liquid and solids. The residue is boiled with water and reduced, and the oxides of Nb, Ta and Ti precipitated by hydrolysis. The Nb, Ta and Ti are separated by organic extraction. Most of the fluorine, about 80%, used is recovered.</p> |
