| 摘要 |
PROBLEM TO BE SOLVED: To suppress a maintenance cost of an apparatus for chemical conversion treatment.SOLUTION: A tank 12 for chemical conversion treatment is provided with plurality of outlets 51-53 formed at different heights. Also, respective outlets 51-53 are connected to a filter 15 through outlet piping 54-56 and delivery piping 13. When treatment liquid L includes a lot of aluminum sludge Sa, the treatment liquid L including a lot of iron sludge Sf is delivered to the filter 15 from the lower outlet 51. Meanwhile, when the treatment liquid includes a little aluminum sludge Sa, the treatment liquid L including a little iron sludge Sf is delivered to the filter 15 from the upper outlet 53. Thus, without being affected by the generation status of the aluminum sludge Sa and the iron sludge Sf, the iron sludge Sf can be appropriately mixed with the treatment liquid L delivered to the filter 15, so that adhesion of the aluminum sludge Sa to a filter material 23 can be suppressed. |
