1. Field of the Invention
This invention relates to a process for removing mercury from organic, mineral and/or metallic materials contaminated with mercury, using a thermal treatment in a kiln, wherein the mercury components evaporate, are subsequently washed out of the combustion gases and are separated.
2. Description of Prior Art
Enormous amounts of mercury-contaminated old scrap are known to be all over the world. In part, this scrap comes from electrolysis installations for producing alkaline metals or chlorine, from old waste dumps and from disposal companies which are inappropriately run. Due to a great danger of the spread of mercury, not only are the actual production facilities contaminated, but in most cases so are all the buildings, the surrounding ground, furniture, cables, etc. Added to this is greatly contaminated waste, such as reject production batches, and waste from dentistry. Correspondingly the materials to be decontaminated include mineral and/or metallic materials. Added to this are organic components, such as paper, wood, plastics, which can also be contaminated by mercury.
An important cost item when removing mercury is the determination of the extent of contamination. The analysis to be carried out is time-consuming and correspondingly expensive and, in particular in connection with buildings and installations, must take place in a surface-covering pattern. If the costs of mercury removal can be considerably lowered, it is less expensive to reduce the number of measurements and instead to decontaminate in a surface-covering manner.