Method for processing and also recycling sludge

A method for processing and/or recycling sludge which has accumulated in a settling tank and comprises solid particles in an aqueous slurry, the sludge being formed by shock-cooling (quenching) from a crude synthesis gas which is produced in a high temperature treatment of waste of all types, wherein

• the sludge is removed from the settling tank, dried at least partially and subsequently mixed with preportioned solid plastic materials,
• a mixing ratio of the dried sludge to the preportioned solid plastic materials of 0.5:1.5 to 1.5:0.5 being maintained, in that this mixture is treated under the effect of temperature and pressure until the plastic materials adopt the binding agent function and form solid conglomerates with the solid particles of the sludge, and in that subsequently these solid conglomerates are returned to the high temperature treatment of the waste.