... ),% ≥21.021.020.5Water content(H2O),% ≤0.20.31.0Free acid(H2SO4)content,% ≤0.030.050.20Fe content, % ≤0.007--As ... the content of Fe,As,heavy metal and water insolubles.2.Package: We usually pack goods with two -layer woven payer ... moisture compared to other fertilizer.2>use in industry ,pharmaceuticals,textiles,welding industry,Dyeing auxilizries of acid dyes,3>Deliming agent of leather ...