| 摘要 |
<p>PURPOSE:To separate and recover Sn from leachate and to make the same respectively effectively usable, by leaching Ni and Sn from a waste Ni-Sn catalyst with a mineral acid then adjusting the pH of the leachate and depositing Sn as metastannic acid. CONSTITUTION:A waste Ni-Sn catalyst is pulverized and is then roasted by oxidation to burn and remove the oils, etc. deposited thereon. Such catalyst is put in an aq. soln. of a nonoxidative mineral acid such as hydrochloric acid kept at 60-100 deg.C under stirring to dilute and leach the metallic components such as Ni, Sn or the like contained in the waste catalyst. Solids such as alumina, silica or the like which are insoluble in acids are filtered away, whereafter free acids are removed by an ion exchange membrane or the like, and water is added to the liquid to adjust the pH to 1-2. Since the Sn in the liquid precipitates as metastannic acid, the metastannic acid is separated from the suspension thereof and is roasted whereby said acid is recovered as SnO2. The liquid free from the metastannic acid is neutralized with an alkali to deposit Ni as Ni(ON)2 and the same is reused as Ni or Fe-Ni.</p> |
