| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To simultaneously solve the problem on expensiveness in the conventional technique and the problem on environmental pollution caused by process waste water, when recovering vanadium from vanadium-containing matter such as slag produced, e.g., in a boiler using petroleum based fuel. <P>SOLUTION: The invention includes: a first stage where mixed slurry comprising≤20 pts.wt. oxide type vanadium-containing powder and≥80 pts.wt. ammonia-containing water for leaching with a concentration of≥0.5% is subjected to warming and leaching treatment in an oxidizing atmosphere; a second stage where aqueous ammonia is recovered from the slurry subjected to the leaching treatment; a third stage where leaching residue is removed from the slurry to obtain a clean leach liquor; a fourth stage where the leach liquor is cooled into ammonium metavanadate slurry; and a fifth stage where the residual liquid is separated from the ammonium metavanadate slurry, so as to recover ammonium metavanadate. The aqueous ammonia recovered in the second stage and the residual liquid separated in the fifth stage are circularly used at least as a part of water for leaching in the first stage. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
