Przemysl Chemiczny, Vol.91, No.5, 860-864, 2012
Control of phase composition of sodium tripolyphosphate at varying parameters of calcination and product recycling
Mixt. of Na2CO3 and extractive or thermal H3PO4 (Na2O/P2O5 ratio 1.57-1.77) were optionally enriched with recycled Na5P3O10 and heated at 250-550 degrees C for 30-60 min to produce Na5P3O10. The product was analyzed for chem. and phase compn. The in-process recycling of Na5P3O10 allowed for decreasing the heating temp. and avoiding the presence of Na4P2O7 in the final product.