... Black 50 > 99.9 20 2.3 Spherical SubmicronBlack 800 > 99.0 2 1.5 Spherical Main features;nano-iron, ultra-fine iron powder ... harmful elements , and high antioxidant capacity, low sintering temperature, black powder, average particle size 30-80nm, purity 99.99%. High ... a special electromagnetic wave absorption. Iron, cobalt, zinc oxide powder and carbon-coated metal powder can be used as high-performance ...