Vitrification, also known as immobilisation is the process whereby metals are recovered and a stabilised product called Synthetic Obsidian is produced.

At a temperature of 1500 degrees Celcius, the ashes from the mineralisation process and other waste materials low in organic content are melted. Chemical reactions take place that separate metals and gaseous compounds from a remaining mineral mix.. The mineral mix is rich in silicates and aluminates and incorporates all other components incl. salts and some heavy metals that remain stable in the surrounding matrix. Liquid synthetic “lava” is produced.