作者: Xing Liu , Yaoyang Ruan , Chengxiu Li , Renju Cheng
DOI: 10.1016/J.MINPRO.2017.08.006
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摘要: Abstract To elucidate how phosphoric acid (H3PO4) as a depressant achieves selective separation of apatite and dolomite, the flotation response these minerals was investigated using both single mixed mineral flotation. Microflotation results demonstrated that H3PO4 exhibits depressive effect on apatite. Flotation kinetics analyses also revealed presence increases dolomite/apatite selectivity index significantly. The adsorption mechanisms were examined zeta potential tests, X-ray photoelectron spectroscopy, solution chemistry analysis, thermodynamic analysis. H2PO4− found to be pivotal ion for depressing under slightly acidic conditions (pH = 5.0–6.0), where most effective. reacts with free Ca2 + depress acidolysis promote formation aqueous CaHPO4. chemisorbs onto surface by CaHPO4 Ca(H2PO4)2, former being major species Moreover, dissolution Mg2 + from dolomite is thermodynamically more favorable than surface. As Mg(H2PO4)2 soluble, only weak dolomite. Further, collector (sodium oleate) maintains excellent floatability in H3PO4, because chemisorption enhanced reaction abundant Mg2 +. Therefore, selectively depresses apatite/dolomite system.