| 摘要 |
<p>Crushed residue undergoes thermolysis to produce a solid residue rich in pure carbon and thermolysis gases rich in hydrocarbons. The solid residues are treated mechanically to extract the metals and carbon. The waste is then mixed with the treated carbon and subjected to a final heat treatment using the thermolysis gases as fuel gases to produce fumes and decontaminated ashes The ashes from the final heat treatment have a lead content of less than 350 ppm, preferably less than 100 ppm. The ashes are valuable as a by-product for industrial fabrication, preferably in a brickyard, a cement works or for road building. The crushed residues are the granular residues from light crushing, with a grain size of more than 13 mm. The waste mixed with the residues are from a purification station, from dredging or a mixture of the two. The capacity of the process is ca. 50000 tonnes/year of residue and 150000 tonnes/year of waste. The thermolysis is carried out at a temperature such that pure carbon and thermolysis gases are produced in a 1:1 ratio. The PCI of the residues is 3500-4500 kcal/kg. The thermolysis gases are generated with a PCI of 6500-7500 kcal/kg and the pure carbon has a PCI of 1000-2000 kcal/kg. The PCI of the waste used is 650-750 kcal/kg. The final heat treatment includes successive steps in at least one cyclone, at least one combustion chamber, at least one heater with injection of chalk and activated carbon and at least one sleeve filter. The fumes from the heat treatment are controlled for their heavy metal, dioxin and furane concentrations. Co-combustion of the carbon and the thermolysis gases at a mass ratio of 1:1 is at about 1400 degrees C and the temperature reached during the final heat treatment depends on the ratio of waste to pure carbon, staying between 1050 and 1250 degrees C. The temperature is at ca. 1100 degrees C with a ratio of ca. 5. An Independent claim is also included for an apparatus for the above process.</p> |
