Process & contact
Member of ESPP
Input: sewage sludge incineration ash, from sewage works using biological and/or chemical P-removal
Technical grade phosphoric acid.
Silica filter cake to cement/concrete industries
Heavy metal concentrate.
Fe-III-chloride solution as a coagulant for wastewater treatment
1) Leaching of ash in sulphuric acid to dissolve phosphorus, solid/liquid separation by filtration.
2) Separation of iron, aluminium and heavy metals by solvent extraction
3) Concentration of dilute acid to technical grade phosphoric acid by evaporation
Pilot tests carried out at Tecnicas Reunidas in Madrid, Spain.
Full scale (30,000 t/y ash) implementation planned in Solothurn, Switzerland