Thermal conversion of tar-containing asphalt integrated into the asphalt production process in combination with energy recovery and re-use of minerals

The Dutch government?s policy is aimed at the final removal of tar-containing material (including tar- containing asphalt) from the environment. Tar, in contrast to bitumen, contains large quantities of hazardous polycyclic aromatic hydrocarbons (PAH?s) and is therefore an acknowledged carcinogenic product. At this moment tar-containing asphalt can still be re-used in a bound form in base courses under conditioned circumstances. This possibility will officially expire and the only option left for this material will be dumping, unless a new processing technology wil1 be developed that will meet the basic principles of the government?s policy. The combination of contractors that includes Heijmans, Rasenberg, Koninklijke Wegenbouw Stevin and NBM- Amstelland has recently developed a new method for the processing of tar-containing asphalt. This rnethod consists of thermal conversion in a totally new way, integrated into the asphalt production prcxess (European patent pending). In this method the binder tar is totally destroyed in a special reactor through a rapid and wel1 controllable incineration process. On top of that, the recovered energy is used efficiently in the asphalt production process and the remaining clean minerals are re-used as supplementary aggregate for new hot asphalt.