How stable are Heavy Metal-TMT compounds?
The leachability of heavy metal-TMT compounds from flue gas scrubbing water has been tested according to the German Standard DIN 38 414, part 4 (at pH 4), the Swiss Standard TVA draft 8/88 and US TCLP standard. The results show that heavy metal-TMT compounds, especially TMT-mercury, are transferred into hardly leachable compounds. The complete cracking of Mercury-TMT is only possible with aqua regia under heat and pressure (4 h 180 °C / 356 °F). This is not achievable with concentrated nitric or sulphuric acid. Mercury-TMT precipitates are thermally stable up to 250 °C (480 °F). This allows subsequent drying processes. Due to the high thermal stability of Mercury-TMT TMT 15® is also recommended for the mercury precipitation in flue gas scrubbing water with connected drying processes at the outlet side.
