氨基三亚甲基膦酸抑制剂在菱镁矿和白云石浮选分离中的作用机理

如何利用高效分离抑制剂实现白云石与菱镁矿的有效分离是含钙型菱镁矿矿石加工利用的研究重点。本文在油酸钠(NaOL)体系下，以氨基三亚甲基膦酸(ATMP)为抑制剂，通过单矿物浮选和人工混合矿浮选试验，考察其对菱镁矿和白云石浮选行为的影响。在此基础上，利用Zeta电位、接触角、红外光谱和X射线光电子能谱等手段揭示了ATMP在两种矿物表面的作用机制。结果表明，针对菱镁矿与白云石质量比4 : 1的人工混合矿，在pH=10、NaOL用量为60 mg/L、ATMP用量为20 mg/L时，可获得MgO品位43.98%、CaO品位3.30%、MgO回收率91.18%的菱镁矿精矿，分选效率达91.18%。ATMP可强烈抑制白云石，而对菱镁矿的浮选几乎没有影响。ATMP通过与白云石表面的Ca位点强烈作用，占据白云石表面活性位点，并通过静电排斥作用阻碍NaOL在白云石表面吸附，进而扩大了菱镁矿和白云石表面疏水性能的差异，实现了对白云石的选择性抑制。 

Effect and Mechanism of Depressant Amino Trimethylene Phosphonic Acid on Flotation Separation of Magnesite and Dolomite

The highly effective depressant of dolomite from magnesite has been the focus in the field of mineral processing. Using sodium oleate (NaOL) as collector and amino trimethylene phosphonic acid (ATMP) as the depressant, the effects of these reagents on the flotation behavior of magnesite and dolomite were investigated through single and artificial mixed ore flotation tests. Furthermore, the mechanism of ATMP on the surfaces of both minerals was revealed using zeta potential, contact angle measurements, FTIR and XPS. Form the artificial mixed ore with magnesite and dolomite in the mass ratio of 4 : 1, the flotation indexes with MgO grade of 43.98%, CaO grade of 3.30%, recovery of 91.18% and separation efficiency of 91.18% could be obtained at approximately pH 10 with a reagent scheme of 20 mg/L ATMP and 60 mg/L NaOL. The results indicated that ATMP displayed an excellent depression effect on the dolomite flotation, whereas it rarely had an influence on magnesite. ATMP occupied a large number of active sites on dolomite surface through strongly interacting with the calcium sites, hindering the adsorption of NaOL on dolomite surface via electrostatic repulsion. In summary, the differential adsorption of the ATMP depressant onto magnesite and dolomite magnified the difference in hydrophobicity between them, which realizing the selective inhibition of dolomite.