Magnesium sulphateFertilizer used as fertilizer. Magnesium sulphate fertilizer quality index:AppearanceWhite small granularMain content99.5% minMgSO448.59% minMgO16.27% minMg9.81% minPH(5W/V%Sol)5-9Ferron(Fe)0.0015% max Chloride(CL)0.015% maxHeavy metal (Pb)0.0008% maxArsenic(As)0.0002% maxInsoluble0.01% maxSize (mm)0.1-1 0.2-3 1-4