| 摘要 |
<p>PURPOSE:To recover every metal component efficiently from a water containing iron, nickel and zinc by bringing a supernatant, which is obtained by precipitating and separating iron component, into contact with an extraction agent at pH 4 or lower to remove zinc and then with an extraction agent at pH 4.5 or higher to remove nickel. CONSTITUTION:A metal-containing water is subjected to a coagulating sedimentation treatment in a thickener A after having its pH adjusted to 4-6 to precipitate and remove iron component alone as Fe(OH)3, etc. Next, a supernatant water, which is free from iron component, is supplied to an ion exchange tower B, wherein nickel and zinc are adsorbed by an ion exchange resin, and the adsorbed nickel and zinc are eluted from the resin by supplying a regenerant to form an eluate containing a high concentration of nickel and zinc afterward. Then, this elute is supplied to 1st extraction apparatus C, wherein zinc is extracted and removed under a condition of pH 4 or lower, and a zinc- containing extract is discharged out of a piping 8. A nickel-containing extraction residue, which is free from zinc, is supplied to 2nd extraction apparatus D, wherein nickel is extracted and removed under a condition of pH 4.5 or higher, and a nickel-containing extract is discharged out of a piping 9.</p> |
