摘要 |
Molybdenum is selectively extracted from an aqueous solution containing various other metal values, e.g. copper, arsenic, iron, bismuth, antimony, tin, and lead in addition to molybdenum. The molybdenum-bearing solution is adjusted to a pH of about 2.0 or less, and, then, intimately contacted with an organic extracting solution containing an alpha-hydroxy oxime. The loaded organic phase, containing extracted molybdenum values, is separated from the aqueous raffinate, and the molybdenum values contained in the organic phase are stripped therefrom using an aqueous stripping solution containing ammonium hydroxide. The efficiency with which the molybdenum is stripped from the loaded organic solution is poor unless nonylphenol is present in the organic solution as it is being stripped. The nonylphenol can be added to the system anytime prior to the ammonium hydroxide stripping step, e.g. it can be added to the organic solution before the extraction step, or it can be added to the aqueous-organic mixture during the extraction step (in which case it reports to the organic phase), or it can be added to the organic solution just prior to the stripping step. |