| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems wherein an aqueous solution containing a piperazine dithiocarbamate easily deposits crystals at a low temperature in a high concentration, although being excellent as a heavy metal-treating agent, and especially has trouble with storage stability, when used in cold districts. SOLUTION: This heavy metal-treating agent comprises a piperazine dithiocarbamate having an alkali metal hydroxide concentration of 0.11 to less than 0.3 wt.% and a hydroxide ion concentration of≥0.08 wt.%. The heavy metal-treating agent does not deposit crystals at a low temperature in a high concentrations of 38 to 42 wt.%, does not produce carbon disulfide, and can efficiently and safely be used for heavy metal treatments. COPYRIGHT: (C)2008,JPO&INPIT |
