99% agri Grade Magnesium Sulfate Heptahydrate main content 99% white crystal very ... , papermaking, metallurgy, electronics, or used as fertilizer, feedstuff additives.99% agri grade Magnesium sulfate heptahydrate quality index: AppearanceWhite small granularMain content99 ... .0002% maxInsoluble0.01% maxSize (mm)0.1-0.3mm 99% AGRI Grade Magnesium Sulfate Heptahydrate