To provide a treatment method of obtaining a solid content of zinc and lead of little moisture content from heavy metal-containing powder such as fly ash containing calcium, lead, zinc, copper, and a chlorine content.
The method comprises (A) the process of carrying out a solid-liquid separation after a water washing of the heavy metal-containing powder under a liquid of pH9-12 to obtain the solid content, (B) the process of mixing the solid content of the process (A) with a sulfuric acid solution to obtain a slurry of pH2-4, and thereafter, of carrying out the solid-liquid separation to obtain a solid content containing calcium sulfate and lead sulfate, and a liquid containing zinc and copper, (C) the process of mixing the solid content of the process (B) with an alkaline aqueous solution to obtain a slurry of pH13.5 or more, and thereafter, of carrying out the solid-liquid separation to obtain a solid content containing calcium hydroxide, and a liquid containing lead, (D) the process of dipping a zinc metal in the liquid of the process (B) to obtain a metal copper and a liquid containing zinc, and (E) the process of adding the liquid of the process (D) to the liquid of the process (C) by degrees to obtain a mixture of pH9-12, and thereafter, of carrying out the solid-liquid separation to obtain the solid content containing a zinc oxide and lead sulfate.
OGAMI TAKEAKI
SUZUKI TAKAYUKI
IDA MASAYA
MIURA KEIICHI
Shuichi Kitamura