TREATMENT METHOD OF WASTE ACID GENERATED IN COPPER SMELTING

摘要

To provide a treatment method of waste acid possible to reduce an amount of water contained in sulfide precipitate and reduce a cost required for drying.SOLUTION: There is provided a treatment method of waste acid including heavy metals, sulfuric acid and arsenic discharged by washing of copper smelting exhaust gas, including: a first sulfurization step 4 for recovering a first sulfide precipitate produced by adding a sulfurizing agent to the waste acid; a second sulfurization step 6 for recovering a second sulfide precipitate produced by removing a gypsum which is produced by adding a neutralizing agent to a clarified liquid obtained by removing the first sulfide precipitate, and thereafter adding the sulfurizing agent to a resulting gypsum final solution. A water content of the second sulfide precipitate is adjusted by an oxidation-reduction potential of a treatment liquid in the first sulfurization step 4.SELECTED DRAWING: Figure 1