Abstract: The present invention relates to a process and an apparatus for separating environmentally hazardous substances, such as heavy metals and oil, from a contaminated mass, such as sewage sludge or soil from industrial sites. According to the process, an aqueous metal hydroxide solution comprising Na, K or Ca is added to the contaminated material in form of high-pressure jets, in order to disintegrate the material and provide a homogeneous mixture. Thereafter, liquid containing the hazardous substances is separated from the washed material and subsequently filtrated. The essentially pure water resulting from the filtration step may be used for producing new metal hydroxide solution to be used in the process.

Abstract: The present invention relates to a method to obtain a suspension and/or a solution of limestone powder in water. The limestone powder is placed on a grating (7) of such a mesh size that only a negligible quantity of the powder by itself passes through the grating (7) of such a mesh size that only a negligible quantity of the powder by itself passes through the grating (7). The grating is sprayed from underneath with water from several nozzles (10) so positioned that the main part of the surface of the grating (7) is sprayed. At least a part of the water passes by this through the grating (7), loosens and/or dissolves the powdered limestone and carries this with it when the water runs back through the grating (7). The water and the suspended and/or dissolved limestone powder in it are collected under the grating (7). The apparatus is also equipped with a vibrating device and has a sedimentation container in the lower portion of the container.