| 摘要 |
<p>The present invention aims to provide a hydrometallurgical method for nickel oxide ore, wherein, at the time of the startup of a plant after the completion of a periodic inspection, the plant can be smoothly started up without imposing a load onto a filter cloth for a separation treatment of zinc sulfide, and the amount of residual zinc in a mother liquor for nickel recovery (post-dezincification solution) can be reduced to 1 mg/L. In the present invention, in the plant start-up after the completion of a periodic inspection, at the time of starting the start-up, a post-neutralization solution is controlled to be returned to a neutralization reaction tank 31 via circulation piping 38 by adjustment of a switching valve 39 in flow piping 34 without sulfurizing the post-neutralization solution, and, when the flow rate and/or the temperature of the post-neutralization solution circulated reaches a predetermined value or more, a sulfurization treatment is applied to the post-neutralization solution in the dezincification reaction tank thereby to form a zinc-sulfide-containing mother liquor for nickel recovery, and the switching valve 39 is adjusted, whereby the zinc-sulfide-containing mother liquor for nickel recovery is transferred to a filter apparatus 33 via transfer piping 37.</p> |
