Flotation technology is an effective way to separate magnesite from dolomite. However, the efficient separation of magnesite from dolomite in sodium oleate (NaOL) system is rather challenging without depressants due to their highly similar physicochemical surface properties. Herein, gellan gum (GG) was employed as a new flotation inhibitor in separating magnesite from dolomite. The depression performance and inhibitory mechanism were systematically studied by flotation experiments, and a number of surface testing technologies. Flotation experiments indicated that GG greatly affected the floatability of dolomite, whereas it had little impact on the magnesite flotation. The artificial mixed mineral experiments confirmed that effective separation of magnesite and dolomite was fulfilled with GG as flotation inhibitor. Zeta potential analyses, surface wettability measurements, and Fourier transform infrared (FTIR) spectroscopy tests indicated that GG strongly prevented the NaOL adhesion on the dolomite, while it scarcely impeded the NaOL adhesion onto magnesite. X-ray photoelectron spectroscopy (XPS) detections demonstrated that GG adhered stronger towards dolomite than magnesite, which was mainly due to its higher affinity towards Ca. AFM images intuitively identified that much stronger interaction and thicker adsorption layer occurred on the dolomite than magnesite. Additionally, higher adsorption concentration, closer adsorption distance and hither adsorption strength of GG on the dolomite was further confirmed by molecular dynamics (MD) simulations. Therefore, GG was a promising flotation depressant to separate magnesite from dolomite and achieve the efficient exploitation of magnesite resources.

中文翻译：

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结冷胶抑制剂浮选菱镁矿与白云石及其抑制机理


浮选技术是从白云石中分离菱镁矿的有效方法。然而，由于菱镁矿和白云石的物理化学表面性质高度相似，在不使用抑制剂的情况下，在油酸钠（NaOL）系统中有效分离菱镁矿和白云石是相当具有挑战性的。本文中，结冷胶（GG）被用作一种新型浮选抑制剂，用于从白云石中分离菱镁矿。通过浮选实验和多项表面测试技术，系统研究了其抑制性能和抑制机理。浮选实验表明，GG对白云石的可浮性影响较大，而对菱镁矿的浮选影响不大。人工混合矿物实验证实，以GG作为浮选抑制剂可实现菱镁矿和白云石的有效分离。 Zeta 电位分析、表面润湿性测量和傅里叶变换红外 (FTIR) 光谱测试表明，GG 强烈阻止 NaOL 在白云石上的粘附，而几乎不阻止 NaOL 在菱镁矿上的粘附。 X射线光电子能谱（XPS）检测表明，GG对白云石的粘附力强于菱镁矿，这主要是由于其对Ca的亲和力更高。 AFM 图像直观地表明，白云石上发生的相互作用比菱镁矿更强，吸附层更厚。此外，分子动力学（MD）模拟进一步证实了GG在白云石上更高的吸附浓度、更近的吸附距离和更高的吸附强度。因此，GG是一种很有前景的浮选抑制剂，可将菱镁矿从白云石中分离出来，实现菱镁矿资源的高效利用。