| 摘要 |
<p>A method for reclaiming molybdate or tungstate from an aqueous solution, in which molybdate or tungstate from the aqueous solution is bound to a cationized inorganic carrier material which is insoluble in water at a pH value in the range between (2) and (6), the charged carrier material is separated, and the bound molybdate or tungstate is released back into aqueous solution at a pH value between (6) and (14). The cationized inorganic carrier material is, for example, a cationized layered silicate, preferably a bentonite which is ion-exchanged with a quaternary ammonium salt or a similar clay material. The method is suitable for reclaiming molybdate or tungstate during the delignification of cellulose using hydrogen peroxide, which is catalyzed using molybdate or tungstate. The reclaimed molybdate or tungstate can be returned into the delignification.</p> |
