... : 1% maxPacking : 50kgs wppbag Steel grade Ammonium sulphate COA Lot No : 20130219 Date : Feb 21, 2013ItemSpecifications Result Nitrogen content : 21%Min ... .73%Free acid (As H2SO4) : 0.5% Max0.13%Sulphate : 24% min24.02%AppearanceWhite color ( no smell ) Usage : used for chemical fertilizers ... chemical agent ,storage battery marking compound fertilizer Ammonium sulphate 20.5%,20.8%,21%