CODECAL^® in pre-liming before plate filter press

CODECAL® is introduced as a powder before the filter press.  The reaction delay enables to keep lime as CaO during dewatering; the hydration reaction takes mainly place in the dewatered sludge, during storage. Sludge which is dewatered in plate filter presses is usually conditioned with milk of lime and iron chloride. Milk of lime is prepared from hydrated lime in powder or from quicklime.  The hydration of quicklime before the production of milk lime does not bring any temperature increase to the sludge.

CODECAL^® optimises the performance of plate filter presses :

• The lime introduction is done directly in sludge as a powder without milk of lime production; the particle size of about 80 µ and the absence of hydration reaction enable a perfect homogeneous dispersion of lime in the sludge with only slow stirring. 
• The particle size improves filtrability, reduces filtration time, and consequently increases the productivity of the press.
• The D.S. contents after filtration are at least equal to those obtained in traditional process; the hydration of the lime after filtration will give an increase of D.S. contents depending on the lime ratio to the D.S.
• The exothermic hydration reaction enables a temperature increase in the cake, leading to a thermal hygienisation without any additional process.

   

Traditional and CODECAL^® processes