Abstract: In order to research effect of HPGR (High Pressure Grinding Roller) crushing on grindability of Luohe iron mine finely products，tests of HPGR open and edge circuit grinding were carried out on on-site finely products，and relative grindablity tests of HPGR product with edge product and on-site finely products recyclest were also investigated，Bond grinding work index tests on samples and HPGR product with edge product was also studied，while influence of HPGR process on increasing capacity of primary balling mill also analytical investigated.Results show that ① HPGR can significantly increase content of fine particle size，and content of edge returned to closed circuit crushing experiment -3 mm product was increased 28.57 percentage points，thus from 56.73% to 85.30%，while content of -5 mm was elevated 24.86 percentage points，thus from 67.79% to 92.65%，after HPGR process with treating capacity of 252 ts/(hm3).② HPGR improved grinding performance of iron ore，and relative grindability of HPGR close circuit test with edge product recycles was 1.294 under the condition of 60% particle size passing 0.075 mm.Bond grinding work index decreased 14.86% from 16.15 kWh/t to 13.75 kWh/t using the HPGR process.③ The capacity of primary balling mill could increased by 35.41% when HPGR close circuit process with edge product recycles was applied to beneficiation plants due to improvement of iron ore grindablity.

Key words: HPGR, Iron ore, Edge product recycles, Closed comminution, Grindability, Bond grinding work index