FORMATION OF PYROPHORIC IRON PARTICLES BY H-2 REDUCTION OF OXALATE AND OXIDES

The thermal decomposition and reduction of Fe-oxalate to form pyrophoric iron particles were investigated. Decomposition and reduction experiments were performed in a tubular quartz reactor at 450-520 degrees C under reducing environment of 5-50 vol% H-2 and 95-50 vol% N-2. Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) revealed that the decomposition of Fe-oxalate in an inert atmosphere is a two-step process involving the removal of water and decomposition of oxalate to iron oxides. In the presence of H-2, the products of decomposition are reduced into alpha-Fe particles. The results have shown that Fe-particles generated from oxalate are pyrophoric in air and burn within 15-30 seconds with maximum temperatures generated in the range of 620-820 degrees C. The effect of reduction temperature, H2 concentration, and sample geometry on pyrophoric behavior was also investigated. In other efforts, Feoxalate was synthesized from FeCl2 center dot 2H(2)O and its pyrophoric performance was compared with the commercial material.