Iron dust belongs to the less reactive metal dusts, but an iron dust explosion is still possible. With the advancing development of Direct Reduced Iron (DRI) processes in the steel industry, there is an increasing interest in studying the dust explosion behaviour of the product. Dust explosions are influenced by various parameters, which naturally have a greater impact on less reactive dusts. In this study, dust mixtures were used to experimentally investigate the influence of particle size distribution, iron oxide content, and ignition energy on the explosion overpressure, the rate of pressure rise, and the occurrence of secondary acceleration. These investigations were conducted in a 20-liter apparatus using suitable chemical igniters and a dust concentration of 1250g*m^-3. The evaluation was performed using correlation analysis, analysing the measurement data and the results calculated using a self-developed python script. The following findings were obtained: a strong positive correlation between particle size distribution and explosion overpressure was observed. The influence of iron oxide content (Fe2O3 and Fe3O4) on explosion overpressure, rate of pressure rise, and the occurrence of secondary acceleration varied significantly. Furthermore, it was found that the addition of iron oxides does not necessarily reduce the explosion characteristics due to local concentration fluctuations.