Abstract The selective separation of titanium-containing minerals is industrially important. Microwave irradiation pre-treatment can be used to modify the surface properties of minerals to promote selective flotation. However, the effects of MW treatment on titanium-containing minerals is not well understood. Therefore, in this study, we investigated the effects of microwave treatment on the flotation behaviour of ilmenite and titanaugite in a mixture of these minerals. The effects of this pre-treatment method were investigated by various techniques, including flotation tests, scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectrometry (ICP-OES), zeta potential measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy. The flotation tests results reveal that, under the optimum microwave conditions (800 W, 450 s), microwave irradiation has a remarkable effect on the flotation of ilmenite but no significant effect on the floatability of titanaugite at pH 6.0. The results of the SEM and ICP-OES analyses indicate that microwave irradiation promotes the dissolution of Ca2+ and Mg2+ ions from the titanaugite surface, whereas the dissolution of these ions from ilmenite is limited. Further, the zeta potential of the microwave-irradiated ilmenite shifted toward negative values, and the isoelectric point shifted from pH 4.9 to pH ~1.9. In addition, the XPS results reveal that microwave irradiation facilitates the conversion of Fe2+ to Fe3+ on the mineral surfaces. The FTIR spectra and zeta potential values indicate that microwave irradiation can enhance the chemical adsorption of oleate ions on the surface of the ilmenite. After microwave irradiation, the effects of both the dissolution of Ca2+ and Mg2+ ions and the oxidation of Fe2+ to Fe3+, the floatability of ilmenite was significantly improved, whereas that of titanaugite was not changed significantly.

中文翻译：

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微波预处理对钛铁矿和钛辉石浮选的影响

摘要 含钛矿物的选择性分离在工业上具有重要意义。微波辐照预处理可用于改变矿物的表面性质以促进选择性浮选。然而，MW处理对含钛矿物的影响尚不清楚。因此，在本研究中，我们研究了微波处理对钛铁矿和钛辉石在这些矿物的混合物中浮选行为的影响。通过各种技术研究了这种预处理方法的效果，包括浮选试验、扫描电子显微镜 (SEM)、电感耦合等离子体发射光谱 (ICP-OES)、zeta 电位测量、X 射线光电子能谱 (XPS)和傅里叶变换红外 (FTIR) 光谱。浮选试验结果表明，在最佳微波条件(800 W, 450 s)下，微波辐照对钛铁矿的浮选效果显着，但对钛辉石在pH 6.0时的可浮性无显着影响。SEM 和 ICP-OES 分析的结果表明，微波辐射促进了钛辉石表面 Ca2+ 和 Mg2+ 离子的溶解，而这些离子从钛铁矿中的溶解是有限的。此外，微波照射钛铁矿的 zeta 电位向负值移动，等电点从 pH 4.9 移动到 pH ~1.9。此外，XPS 结果表明微波辐射促进了矿物表面上 Fe2+ 向 Fe3+ 的转化。FTIR 光谱和 zeta 电位值表明微波辐射可以增强油酸离子在钛铁矿表面的化学吸附。微波辐照后，在Ca2+和Mg2+离子溶解和Fe2+氧化成Fe3+的共同作用下，钛铁矿的可浮性显着提高，而钛辉石的可浮性没有明显变化。