Predicting　the　liberation　distribution　of　minerals　in　comminuted　ore　particles　is　one　of　the　fundamental　problems　in　mineral　processing.　However,　there　is　still　no　widely　accepted　liberation　model　due　to　the　complexity　of　the　mineral　fracture　mechanism.　In　this　study,　the　shape　constants　of　the　cumulative　beta　distribution　were　further　optimized　based　on　the　investigation　of　the　liberation　distribution　and　fracture　mechanism　of　iron　oxide　minerals　in　three　types　of　iron　ores　with　different　grain　sizes　by　locked-cycle　grinding　and　batch　grinding　to　model　the　liberation　distribution　of　iron　oxide　minerals　with　different　grinding　methods.　The　results　showed　that　the　liberation　distribution　of　iron　oxide　minerals　in　the　three　types　of　iron　ores　with　locked-cycle　grinding　and　batch　grinding　was　related　to　intergranular　fracture　proportion　and　the　closeness　of　ore　particle　size　and　mineral　grain　size.　By　relating　the　shape　constants　of　cumulative　beta　distribution　to　ore　particle　size,　mineral　grain　size,　and　the　proportion　of　intergranular　fracture,　the　developed　liberation　model　well　predicted　the　liberation　distribution　of　iron　oxide　minerals　with　different　grinding　methods　and　its　coefficient　of　determination　(R2)　was　between　0.85–0.93.　©　2023　Taylor　&　Francis　Group,　LLC.