Patent ID: 8003845

Claim:
Process enabling the complete combustion and oxidation of the mineral fraction of combustible waste contained in an apparatus intended to treat waste by direct incineration-vitrification, said process comprising the following steps: a step to add said waste to the apparatus for its depositing on the surface of a molten glass bath contained in the apparatus, an incineration and oxidation step of the waste on the surface of the glass bath, an incorporation step to incorporate combustion products in the glass during which the glass bath, the combustion products and any vitrification additives added to the glass bath are heated until a paste-like, liquid mass is obtained, a step during which said mass is removed from the apparatus and left to cool to obtain finally what is called a confinement matrix, said process being characterized in that the complete combustion and oxidation of the waste is achieved during the waste incineration and oxidation step through the presence of a surface layer, called a temporary protective layer, and at least one other surface layer, called a temporary protective over-layer; wherein the temporary protective layer is present on the surface of the glass bath and enables the waste to be maintained on the surface of the glass bath for a determined time under the oxidizing vapors derived from gases added to the apparatus, said temporary protective layer having a higher surface tension coefficient than the molten glass bath, and having a chemical composition that is different from the composition of the glass bath but that is compatible with the composition of said glass bath; and wherein the at least one temporary protective over-layer has at least one of the following functions: under the effect of the weight of the waste superimposed upon it, to develop interface forces with the temporary protective layer improving the non-penetration into the glass bath of particles derived from said waste; to improve the distribution of mechanical stresses on the entirety of the surface of the temporary protective layer through intermingling of the constituents of said temporary protective over-layer or through chemical bonds which strengthen said temporary protective over-layer; to protect the temporary protective layer against chemical attack by the waste.