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

 

Bogdan CZAJKA

Institute of Non-ferrous Metals Branch in Poznań
Forteczna 12, 61-362 Poznań, Poland


Leszek WACHOWSKI


Faculty of Chemistry, A. Mickiewicz University,
6 Grunwaldzka St., 60-780 Poznań, Poland

Andrzej ŁAPIŃSKI


Institute of Molecular Physics, Polish Academy of Science,
17 Smoluchowskiego St., 60-170 Poznań, Poland

Witold RZODKIEWICZ


Institute of Electron Technology,
32/46 Lotników St., 02-668 Warsaw, Poland


Abstract: 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 μm 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
B. Czajka, L. Wachowski, A. Łapiński, W. Rzodkiewicz
the quantity of the released oxygen generated by decomposition of the oxidant,
which did not react with the iron powder.

Keywords: iron powder, Fe-KClO4 mixture, Raman spectroscopy (RS),
ellipsometry, thermo-programmed reduction (TPR), thermogravimetric analysis
(TG/DTA)

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