... flake NaHS:70% Iron(Fe):15-20PPM Useage:mining,leather,dye,water treatment,paper manufacturer Molecular formula: NaHS ... by mill run, pesticide, dye ,leather production and organic compound. compared with other company, high purity, less impurity, not ... dying in the leather production , it can disperse the fibre equably. less iron insure the appearance and good quality of leather.Producing Method: ...