Abstract: In order to determine the suitable beneficiation process flow and reagent system for a high calcium，high silicon and low grade refractory fluorite ore，and obtain satisfactory test indexes，aiming at the characteristics of high CaCO3 mineral content，fine crystal size，coarse crystal size of most fluorite miner‐ als and mutual encapsulation of a small part of fluorite and quartz minerals in the ore，the flotation process exploration，roughing grinding fineness，inhibitor type，regrinding position and grinding fineness conditions are studied. The test results show that the two-stage grinding process of roughing grinding-roughing-two cleaning-concentrate regrinding-five cleaning is adopted. The grinding fineness of roughing is -0.074 mm 60%. The cleaning inhibitor adopts the combination of water glass and DDE. The best regrinding position is after three cleanings，and the regrinding fineness is - 0.038 mm 75%. The fluorite concentrate with CaF2 grade of 97.50% and recovery of 90.08% is obtained in the closed-circuit test.The problem of fluorite and quartz inclusions dissociation and the influence of calcite argillization can be effectively solved by stage grinding and stage separation process. The use of water glass + DDE combined inhibitors can replace tradi‐ tional inhibitors to achieve effective inhibition of calcium carbonate-containing minerals.

Key words: fluorite ore, low grade, high calcium and high silicon, stage grinding