... within15 days 4.Fineness of grind:10-100mesh Metaphosphoric acid,hexasodium salt(shmp)We are one of the biggest phosphate Manufacture ... 68.0 2Inactive phosphate,as P 2 O 5 %≤ 7.5 7.5 3 Iron, as Fe, %≤ 0.05 0. ... 05 4 pH of 1% water solution 5.8-7.3 5.8-6.5 5 Solubility Qualified Qualified ... 6 Heavy metal, as Pb, %≤ - 0.001 7 Arsenic, as As, %≤ - 0.0003 8 Fluoride, as F, %≤ ...