| 摘要 |
<p>[PROBLEMS] To provide a method of hexavalent-chromium extraction by which hexavalent chromium, which is harmful, remaining on or in a chromium deposit or chromate coating film can be extracted without fail at low cost without the need of a special expensive apparatus to thereby prevent hexavalent chromium from dissolving away from the material treated. Thus, parts having residual hexavalent chromium can be made to be safely used or discarded and can be prevented from causing environmental pollution or influencing the human body. [MEANS FOR SOLVING PROBLEMS] The method, which is for extracting hexavalent chromium remaining in a material (3) to be treated, comprises bringing the material (3) having a coating film containing residual hexavalent chromium into contact with a reducing agent (2) in a liquid or finely particulate form to thereby extract hexavalent chromium from the coating film.</p> |
