STTP

Raw materials for detergent: STPP  

STPP: Sodium TriPoly Phosphate is a solid inorganic compound used in a large variety of household cleaning products, mainly as a builder, but also in human foodstuffs, animal feeds, industrial cleaning processes and ceramics manufacture. STPP is widely used in regular and compact laundry detergents and automatic dishwashing detergents (in powder, liquid, gel and/or tablet form), toilet cleaners, surface cleaners.

To produce STPP, the raw phosphoric acid must be purified to remove most of the metal impurities and the organics. It is therefore filtered and discolored. Then the H3PO4 is extracted from the aqueous phase, which keeps all remaining impurities. Then the loaded solvent coming from the extraction unit is stripped to remove iron and sulphate, and the phosphoric acid is re-extracted from the organic phase resulting from the stripping by a solution of caustic soda or sodium carbonate. The salted solution from this part is then concentrated, and the concentrated solution is then calcinated to produce marketable STPP.