The surface chemistry and morphology of minerals produced by alkali pretreatment affects their flotation behaviors. This study systematically investigated the impact on the mineral surface dissolution using NaOH as a modifier, which could modify the surface properties of minerals and improve the floatability difference between spodumene and feldspar. Various characterizations including flotation experiments, flotation kinetics analysis, SEM analysis, microcalorimetry analysis, zeta potential measurements, XPS analysis and ICP-MS analysis were conducted. Single minerals and actual ore flotation experiment results were in good agreement, and the flotation grade and recovery of LiO in spodumene concentrates increased by 1.11 % and 6.99 %, respectively, after NaOH pretreatment. The flotation kinetics results demonstrated the cumulative recoveries of spodumene exhibited the best agreement with the first-order kinetic model and the flotation kinetic constant was improved after alkali pretreatment. Microcalorimetric results indicated the absolute values of the reaction heat for spodumene were higher than that of feldspar reacted with collectors after the alkali pretreatment. XPS and ICP results demonstrated the amounts of Al active sites on the spodumene surface was significantly increased after alkali pretreatment compared to that on the feldspar surface, improving the selective adsorption of NaOL.

中文翻译：

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碱预处理对锂辉石和长石浮选的影响

碱预处理产生的矿物的表面化学和形态影响其浮选行为。本研究系统地研究了NaOH作为改性剂对矿物表面溶解的影响，它可以改变矿物的表面性质，改善锂辉石和长石之间的可浮性差异。进行了各种表征，包括浮选实验、浮选动力学分析、SEM 分析、微量热分析、zeta 电位测量、XPS 分析和 ICP-MS 分析。单矿物与实际矿石浮选实验结果吻合较好，经NaOH预处理后，锂辉石精矿中Li2O的浮选品位和回收率分别提高了1.11%和6.99%。浮选动力学结果表明，锂辉石的累积回收率与一级动力学模型最为吻合，碱预处理后浮选动力学常数有所提高。微量热结果表明，碱预处理后锂辉石的反应热绝对值高于长石与捕收剂反应的反应热绝对值。 XPS和ICP结果表明，碱预处理后锂辉石表面的Al活性位点数量较长石表面显着增加，提高了NaOL的选择性吸附。