| 摘要 |
<p>The present invention makes it possible that, at the time of start-up of a dezincification plant used in a dezincification step in a hydrometallurgical method for nickel, a decrease in the throughput in the dezincification plant is controlled to prevent a decrease in production volume, and moreover, an excellent cake layer is formed on a filter cloth provided to a filter device inside the dezincification plant, whereby efficient filtration is performed. When, upon start-up of the dezincification plant, a slurry containing a formed zinc sulfide is supplied to a filter for filtration and separation, an adjustment is performed in such a manner that the flow rate of the slurry is increased in stages to reach a target flow rate in a time T2 which satisfies the following relational expression (i), where T1 represents the time between starting a slurry supply and attaining the target flow rate in the case of transferring the slurry at the maximum liquid transfer capacity of a pump configured to transfer the slurry. 3 × T �¢ 1 ‰¤ T �¢ 2 ‰¤ 5 × T �¢ 1</p> |
