This research focused on the inhibition effect and mechanism of a selective depressant PBTCA (2-phosphonobutane-1,2,4-tricarboxylic acid) on flotation separation of magnesite from calcite. The inhibition effect of PBTCA was investigated through micro-flotation tests, and the results showed that PBTCA presented selective inhibition effect on calcite in sodium oleate (NaOL) system. The inhibition mechanism of PBTCA was analyzed by contact angle measurements, zeta potential analysis and X-ray photoelectron spectroscopy (XPS) analysis. The results of contact angle measurements indicated that PBTCA could increase the hydrophilicity of calcite surface while magnesite surface still maintained hydrophobicity with PBTCA and NaOL. Zeta potential measurements results indicated that the adsorption of PBTCA on calcite surface was stronger than magnesite, and NaOL could further adsorb on magnesite surface even PBTCA existed. Furthermore, XPS results confirmed the stronger adsorption between PBTCA and calcite, which could be attributed to the interaction between phosphonyl (–PO₃H₂) structure of PBTCA and calcium ions on calcite surface.

本研究的重点是选择性抑制剂 PBTCA（2-膦酰丁烷-1,2,4-三羧酸）对菱镁矿与方解石浮选分离的抑制作用及机制。通过微浮选试验考察了PBTCA的抑制作用，结果表明PBTCA对油酸钠(NaOL)体系中的方解石具有选择性抑制作用。通过接触角测量、zeta电位分析和X射线光电子能谱(XPS)分析来分析PBTCA的抑制机制。接触角测量结果表明，PBTCA 可以增加方解石表面的亲水性，而菱镁矿表面仍然保持与 PBTCA 和 NaOL 的疏水性。Zeta电位测量结果表明PBTCA在方解石表面的吸附强于菱镁矿，即使存在 PBTCA，NaOL 也能进一步吸附在菱镁矿表面。此外，XPS 结果证实 PBTCA 和方解石之间的吸附更强，这可能归因于膦酰基（-PO₃ H ₂ ) PBTCA 和方解石表面钙离子的结构。