Ferrous sulphate heptahydrate Ferrous sulfate heptahydrate is the synthesis of acid and iron Shaw, ferrous sulfate content is high, heavy metal content is low. The products are mainly usedas pasture fertilizer, soil amendments. such as industrial catalysts.the mainly specification is as follows, CONTENT98%MIN Fe 20%MIN Pb 9PPM MAX Insoluble matter in water 0.2%MAX Cd 1PPM MAX As1 PPM MAX packing in 25kg pp bag with one pe bag inside