Yao Wei, Li Maolin, Zhang Ming, Cui Rui, Ning Jiangfeng, Shi Jia
School of Resources and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, People's Republic of China.
Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan 430081, People's Republic of China.
ACS Omega. 2020 Dec 4;5(49):32076-32083. doi: 10.1021/acsomega.0c05104. eCollection 2020 Dec 15.
Grinding, an essential procedure for size reduction and fresh surface exposure of mineral particles, plays an important role in mineral flotation. The grinding media are the key factors for effective grinding and thus for successful flotation. In this study, ceramic ball (CB) and cast iron ball (CIB), two representative grinding media, were chosen to investigate the effects and mechanisms of grinding media on the flotation behavior of scheelite. The results of pure scheelite flotation show that scheelite ground by CB has a better floatability than that ground by CIB. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) analyses indicate that there are Fe species, namely, elemental iron (Fe), ferrous oxide (FeO), and iron oxyhydroxide (FeOOH), coated on the surfaces of scheelite ground by CIB but not in the case of scheelite ground by CB. The dissolved oxygen (DO) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) tests show that Fe ions exist in the CIB grinding slurry but not in the case of CB grinding slurry. Compared with the CB grinding slurry, the CIB grinding slurry has a lower DO content and higher Ca ion concentration. Zeta potential results reveal that the Fe species in the CIB grinding reduce the NaOl adsorption on the scheelite surfaces. Finally, the deleterious effect of CIB grinding on the flotation behavior of scheelite is verified by the actual scheelite ore flotation experiments.
磨矿是矿物颗粒粒度减小和新鲜表面暴露的关键工序，在矿物浮选过程中起着重要作用。磨矿介质是有效磨矿进而成功浮选的关键因素。本研究选取了两种具有代表性的磨矿介质——陶瓷球（CB）和铸铁球（CIB），来研究磨矿介质对白钨矿浮选行为的影响及作用机制。纯白钨矿浮选结果表明，用CB磨矿的白钨矿比用CIB磨矿的白钨矿具有更好的可浮性。扫描电子显微镜-能谱仪（SEM-EDS）和X射线光电子能谱（XPS）分析表明，CIB磨矿的白钨矿表面包覆有铁物种，即单质铁（Fe）、氧化亚铁（FeO）和羟基氧化铁（FeOOH），而CB磨矿的白钨矿表面则没有。溶解氧（DO）和电感耦合等离子体原子发射光谱（ICP-AES）测试表明，CIB磨矿浆中有Fe离子，而CB磨矿浆中没有。与CB磨矿浆相比，CIB磨矿浆的DO含量较低，Ca离子浓度较高。Zeta电位结果表明，CIB磨矿中的Fe物种降低了白钨矿表面NaOl的吸附量。最后，通过实际白钨矿矿石浮选实验验证了CIB磨矿对白钨矿浮选行为的有害影响。
