Study On Flotation Separation And Mechanism Of Fluorite/Dolomite

Fluorite is an important strategic mineral resource,and its value is self-evident.With the development of the national economy,the demand for fluorite is increasing,and the supply of high-quality fluorite concentrate is limited.The reason is that the nature of ore suitable for flotation is decreasing,and it is bound to turn its attention to the accompanying Minerals,especially in the comprehensive utilization of secondary resources to tap potentially.For example,fluorite ore containing more dolomite,it is difficult to achieve the separation by the existing beneficiation technology.Because both fluorite and dolomite are calcium-bearing minerals and contain Ca2+ in the crystal lattice,the ore surface has similar physical and chemical properties,so collectors and inhibitors acting on such minerals behave similarly.In this artical,the fluorite originated from the tailings after magnetic separation of a factory in Inner Mongolia.The fluorite has a low-grade,high-dolomite content,both fine grained and inter-enveloped materials between various minerals.Based on a comprehensive comparison of domestic and foreign beneficiation technologies,it is proposed for this ore to mixed flotation firstly,removing impurities,and then separating fluorite from dolomite.Mixed flotation test showed that: through the open-circuit test of “one-roughing,four-cleaning”,the content of fluorite and dolomite mixed ore was more than 99%,and the recovery rate was 93.48% at a grinding fineness of 94.52%-0.074 mm,dosage of sodium carbonate 700 g/t(p H 9.1),dosage of water glass 600 g/t,aluminum sulfate 150 g/t,caustic starch 1100 g/t,collector FX-6Y 1000 g/t.The test results of the separation fluorite from dolomite showed that: The final fluorite concentrate could be obtained by a process of “one-roughing,two-scaenging and four-cleaning” at a grinding fineness of 86.45%-0.045 mm,dosage of sulfuric acid 7400 g/t(p H 5.0),acidified water glass 3000 g/t,KD 1000 g/t,Y-2 2500 g/t,the Ca F2 content was 97.08%,the recovery rate was 66.56%,the Ca CO3 content was 2.8%,and the Si O2 content was 0.12%.The research on the mechanism showed that the PZC of fluorite is 6.3 and the PZC of dolomite is 3.4.In the acidic conditions,the Y-2 collector,by which the amount of fluorite absorbed was much larger than that of dolomite,was mainly chemistry on the fluorite surface.The KD inhibitor was also mainly chemistry on the dolomite surface,and the amount of dolomite absorbed was much larger than that of fluorite.