Process for the making inert (inerting) of combustion residues and also natural and industrial sediments

摘要

According to the invention, a process is provided for converting contaminated, in particular by heavy metals, combustion residues and also natural and industrial sediments into a form which can be landfilled (dumped). In this process, the materials to be treated and, in particular, the reactive pollutants contained therein are made inert by reaction with an alkali metal silicate solution, in particular a sodium or potassium silicate solution, and by subsequent reaction with a calcium hydroxide or magnesium hydroxide slurry or an alkaline earth metal salt solution, in particular a calcium or magnesium chloride solution, and also immobilised by the silica gel precipitating in the process. The material obtained is preferably solidified by addition of a cement to give a fine concrete capable of ultimate storage or use.