The heavy metal which is superior in low temperature stability treatment agent and the heavy metal which uses that treatment

摘要

PPROBLEM 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. PSOLUTION: 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. PCOPYRIGHT: (C)2008,JPO&INPIT