More　efficient　liberation　of　valuable　minerals　from　gangue　would　bring　enormous　benefits　to　the　comminution　process　and　the　downstream　beneficiation　processes.　However,　whether　particle-bed　breakage　can　improve　liberation　compared　with　traditional　grinding　has　been　controversial.　In　this　study,　three　types　of　iron　ores　with　3-0.425　mm　were　comminuted　to　-0.425　mm　via　the　piston-die　compression　unit　or　the　dry　ball　mill　at　essentially　the　same　grinding　degrees.　Liberation　analysis　was　performed　using　Mineral　Liberation　Analyzer　(MLA)　for　each　breakage　method　and　the　size　fraction　product.　Statistical　methods　based　on　bootstrap　resampling　and　standardized　mean　differences　(SMD)　were　used　to　quantitatively　analyze　the　significance　of　differences　in　the　liberation　distribution　of　iron　oxide　minerals　with　different　breakage　methods.　MLA　tests　showed　that　the　particle-bed　breakage　did　not　significantly　improve　the　liberation　degree　compared　to　the　ball　mill　grinding;　the　maximum　difference　of　the　proportion　of　80-100%　liberated　iron　oxide　mineral　in　a　certain　size　fraction　with　the　two　breakage　methods　was　only　5%.　The　SMD　was　less　than　1.2　in　most　size/composition　classes,　which　indicated　that　the　difference　in　the　liberation　distribution　of　iron　oxide　minerals　between　the　two　breakage　methods　was　not　statistically　significant　in　most　size/composition　classes.　The　particle-bed　breakage　slightly　improved　the　liberation　of　iron　oxide　minerals　compared　to　ball　mill　grinding　at　the　particle　size　of　the　products　close　to　the　grain　size　of　the　iron　oxide　minerals　in　the　feeds.