Surface features and flotation behaviors of spodumene as influenced by acid and alkali treatments
Surface features and flotation behaviors of spodumene as influenced by acid and alkali treatments
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酸碱处理对锂辉石表面特征和浮选行为的影响
DOI：
10.1016/j.apsusc.2019.145058
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发表时间：
2020-03-30
影响因子：
6.7
通讯作者：
Lu, Dongfang
中科院分区：
文献类型：
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作者：
Zhu, Guangli;Zhao, Yuehao;Lu, Dongfang
表面溶解是锂辉石浮选的基本现象。这项研究提出了一个改进的理解，表面溶解行为和相应的表面状态，涉及考虑地形，化学物种分布，以及油酸酯吸附在锂辉石表面处理氢氧化钠（NaOH）和盐酸（HCl）。微浮选试验结果表明，以油酸钠为捕收剂时，NaOH对锂辉石的浮选起活化作用，而HCl则抑制锂辉石的浮选。AFM成像显示表面形貌的变化，表明不同的溶解行为。水洗处理提高了NaOH处理的锂辉石的浮选响应，但在盐酸处理的情况下没有影响。原位原子力显微镜结果表明，在NaOH溶液中处理后的表面有胶体物质沉淀，不利于油酸的吸附。表面元素的化学状态受处理的影响，和更大的相对含量的Al和不饱和Al在表面与氢氧化钠处理相比，由XPS显示。密度泛函理论计算表明，不饱和铝有利于油酸的吸附。表面不饱和铝的相对含量受酸、碱处理的影响，这似乎决定了油酸的吸附程度。
Surface dissolution was proved as a fundamental phenomenon in the flotation of spodumene. This study presents an improved understanding of surface dissolution behavior and the corresponding surface states involving consideration of topography, chemical species distribution, as well as oleate adsorption at spodumene surface treated by sodium hydroxide (NaOH) and hydrochloric acid (HCl). Micro-flotation results showed that spodumene flotation was activated with NaOH treatment but was depressed with HCl treatment when sodium oleate was used as a collector. AFM imaging revealed variations in surface topography, indicative of different dissolution behaviors. Water rinsing treatment increased flotation response of NaOH-treated spodumene but had no effect in the case of HCl treatment. Colloidal substances precipitated at surface conditioned in NaOH solution as evidenced from in-situ AFM, and appeared to be unfavorable for oleate adsorption. Chemical states of elements at surface were influenced by treatments, and larger relative contents of Al and unsaturated Al at surface with NaOH treatment were revealed by XPS as compared with that treated by HCl. Density functional theory calculations indicated that unsaturated Al was favorable for oleate adsorption. It seems the relative content of unsaturated Al at surface influenced by acid and alkali treatments dominates the extent of oleate adsorption.