Modification of the Surface of the Iron Powder as an Ingredient of the High Calorific Mixture

Textural properties of iron powders obtained by reduction of iron(II) compounds and by electrolysis were determined. Their specific surfaces were 0.38 and 0.43 m2g-1 respectively, and the prevailing grain sizes amounted to 10 and 43 ?m respectively. Total content of the determined metallic impurities was 0.055 wt.% in the preparation obtained by the electrolysis while in the preparation obtained by reduction it was 0.025 wt.%. It was proved that in initial samples the α-Fe2O3 phase occurred in the outer oxide layer present on the surface of Fe grains, and below this phase a layer of magnetite was found, the thickness of which was considerably greater in iron obtained by electrolysis. Measurements of selected properties showed that modification of the iron powder surface carried out by reduction with dihydrogen led to decreasing the linear rate of burning of the high calorific mixture Fe/KClO4 but it did not affect its calorific value. Moreover, it was found that modification of the iron powder surface resulted in lowering the temperature of ignition of the analysed mixture and decreasing the quantity of the released oxygen generated by decomposition of the oxidant, which did not react with the iron powder.