Production of a Stable Building Material by Treatment of MSWI Bottom Ash with the Tauw EquiAsh® Process

A process called EquiAsh (R) was developed and tested on a large scale. This process aims at upgrading incinerator bottom ash into a long term environmentally safe and stable product. Driven by the agreement between the incinerator branch and the Dutch government in a 'Green Deal', the leaching behavior of bottom ash needs improvement. The leaching of metals and salts must be lowered. EquiAsh (R), which is a combination of carbonation (accelerated aging), washing and further mineralization, realizes a safe and stable product now and in the future. The bottom ash is in equilibrium with the atmosphere and the pH is stabilized at values around 8.5. Large scale experiments with 1.000-1.300 ton incinerator bottom ash are performed. These experiments give insight into the changes in leaching of metals and salts. In the end, the bottom ash fulfills the Dutch leaching criteria for a freely applicable building material. [GRAPHICS] .