| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a non-hydrofluoric acid-based aqueous solution of refractory metal and production method therefor.SOLUTION: Provided is a non-hydrofluoric acid-based aqueous solution of refractory metal characterized in that it is an alkaline aqueous solution comprising refractory metal, chelator and hydrogen peroxide and that it does not contain hydrofluoric acid; preferably a non-hydrofluoric acid-based aqueous solution of refractory metal characterized in that the refractory metal is niobium, tantalum or tungsten, the chelator is ethylene-diamine-tetra-acetic acid, ethylene-diamine-N,N'-disuccinic acid or diethylene-triamine penta-acetic acid, and the alkaline aqueous solution is ammonia aqueous solution.</p> |
