Development of an automated single particle impact tester for iron ore sinter

Due to mechanical stress during transport, iron ore sinter partly degrades and fines are produced, which have to be re-sintered causing high costs and emissions. Standardized tests for sinter strength are carried out with bulk samples, but for a detailed determination of breakage behavior and discrete element simulations single particle tests are necessary. The great heterogeneity and undefined shape demand a high sample number. In this work a highly automated test rig for rapid single particle impact testing with integrated fragment analysis was developed. The fragment size distributions, return fines production and breakage probability for different size fractions of sinter were investigated and clear trends could be determined. A general return fines production curve could be calculated by introducing a size factor. Contrary to other investigations, it was found that relative return fines generation is not linearly related to specific impact energy input but follows a limited growth trend. Furthermore, a size-independent description of sinter breakage behavior by the well-established tn-modeling concept was performed.