Prepartion Of Super-fine Iron Powder By Use Of FeSO₄.7H₂O

Being the byproduct of some industry,it is necessary to research routes for reusing of FeSO₄.7H₂O. In this thesis, using FeSO₄.7H₂O as material to produce FeC₂O₄.2H₂O which will act as the precursor of super-fine Fe powder is studied . Aim to acquire super-fineα－Fe powder(SFP) ,FeC₂O₄.2H₂O will be decomposed and deoxidated in the H₂,and passivated by some materials. In the experiment of precursor preparation, including the influence of reactant system consistence to the precursor appearance, the influence of pH of reactant system to the precursor appearance ,and the influence of system temperature to the precursor appearance etc. are analyzed in detail. As the results of the experiments, we get the better parameters of this process as follows, reactant system consistence should be 1.7M, reactant system pH should be 8.5 and the reactant system temperature should be 25℃.By analyzing the thermal decomposition mechanism of FeC₂O₄.2H₂O precursor, we mainly carried out the experiments of the influence of the deoxidation temperature to the appearance of SFP of α－Fe, the influence of the deoxidation time to the appearance of it. The better deoxidation parameters are also obtained according to these relative experiments, 510℃ is the better temperature and 2.5 hours are the better deoxidation time. About the passivation of theα－Fe , concidering the influence of N2 and its discharge to the oxygen content of α－Fe, 7 l/h is the better discharge of N2 to obtain better product..By contrasting the dimension and appearance of α－Fe of different precursors, verified it is true that the dimension and appearance of precursor affect these facets ofα－Fe.Modern measures , for instance XRD ,TEM, SEM, laser and infrared technique etc. are used to research the technique indexes of SFP of α－Fe , such as crystalline , dimensions and its distribution, shape and appearance, assemble status and its oxygen content. Under better experiment conditions, the finally productionα－Fe has about 100nm diameter ,oxygen content 2.0%, uniform, almost sphere.The results in this paper have shown that super fine powder of α－Fe can be prepared by this route. This make the scientific bases for reusing of FeSO₄.7H₂O andfor the preparation of nanometerα－Fe powder .So, there are huge actual significance and economic advantages.