Large amounts of drilling sludge containing low levels of natural radioactivity is a resultant by-product of the oil and gas production process. These so-called NORM-sludges (Naturally Occurring Radioactive Material) are often contaminated with both mercury and hydrocarbons. The econ industries VacuDry® technology is recognized in Germany as the first choice for the extraction of the mercury as a secondary raw material. In a typical VacuDry® plant the sludges are heated under vacuum to more than 350°C. The mercury is then extracted through evaporation and condensation. Water and oil are also evaporated during this process. The resultant cleaned solids can be harmlessly disposed in salt mines or similar. The extracted mercury, which is normally of a very high quality, can be used as secondary raw material within the industry, for example the production of energy saving fluorescent lamps. As a result the VacuDry® technology makes a large contribution to satisfying the demand for industrial quality mercury. Each of econ industries’ innovative plants allow for the treatment of mercury contaminated sludges within a closed system, without any danger to man or environment.