Experiments on solidification of elemental mercury waste were conducted by amalgamation with several metalpowders such as copper, zinc, tin, brass and bronze. Unlike the previous studies which showed a dispersible natureafter solidification, the waste forms were found to possess quite large compressive strengths in both copper andbronze amalgam forms. The durability was also confirmed by showing very minor changes of strength after 90 daysof water immersion. Leachability from the amalgam forms is also shown to be low: measured mercury concentrationin the leachate by the Toxicity Characteristic Leaching Procedure (TCLP) was well below the EnvironmentalProtection Agency (EPA) limit. Long term leaching behavior by Accelerated Leach Test (ALT) has shown that theleaching process was dominated by diffusion and the effective diffusion coefficient was quite low (around 10-19cm 2 /sec). The mercury vapor concentration from the amalgam forms were reduced to a 20% level of that forelemental mercury and to one-hundredth after 3 months.
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