Residues of the incinerator

A rotary kiln plant produces 2 types of residues.

• Bottom ash from the rotary kiln
• Fly ash from the bag house (Dry flue gas treatment)   or
• Filtercakes (flyash + salts) (Wet flue gas treatment )

Ash from the counter current kiln

The bottom ash from the combustion chamber must contain less than 2% residual carbon.Exceeding 2% of residual carbon,colours the ash to black. Less than 2% residual carbon leaves a coloration varying from dark to light grey. 

The amount of residual carbon shown on this picture is less than 0,5% and is typical ash for counter current kilns.

The bottom ash can be disposed off directly on a landfill or can be immobilized with cement before going to landfill.Choice of any of both methods depends on local regulations. 

Fly ash from the dry scrubber (dust from the bag house)

Because the fly as from the dry scrubber contains heavy metals,it needs to be immobilized with cement before landfilling. This is to prevent dissolution by rain water and possible leakage to drinking water.Once every two years 2 years it will also be necessary to replace the Teflon sleeves in the bag house. The Teflon sleeves can be burned in the incinerator.

Filtercakes from the wet scrubber

Filtercakes from the wet scrubber have always to be immobilized with cement before landfilling.This is to stabilize the heavy metals and the salts,to prevent leakage to drinking water.