苛化淀粉对磁铁矿和金云母浮选分离的影响及机理研究

以磁铁矿和金云母为研究对象，探讨在十二胺浮选体系下苛化淀粉对两种矿物浮选分离的影响及其作用机理。以十二胺为捕收剂，苛化阳离子醚化淀粉（CCES）、苛化羧甲基淀粉钠（CCMS）、苛化糊精（CD）为抑制剂，对磁铁矿和金云母进行浮选分离试验。采用单矿物浮选试验、Zeta电位分析、吸附量测定、红外光谱分析和人工混合矿浮选分离试验等方法分析苛化淀粉与矿物作用方式。结果表明:金云母和磁铁矿表面电性差异较小，十二胺对两种矿物选择性较差；CCES、CD、CCMS均能吸附在磁铁矿和金云母表面，苛化淀粉与磁铁矿的作用方式主要以化学吸附为主，同时存在静电吸附和氢键作用；而与金云母的吸附方式为静电吸附和氢键作用；三种苛化淀粉对磁铁矿的抑制强度为:CCES>CD>CCMS，对金云母的抑制效果较差。 

Effect and Mechanism of Causticized Starch on Flotation Separation of Magnetite and Phlogopite

In this work, the effect and mechanism of causticized starch on flotation separation of magnetite and phlogopite minerals under dodecylamine flotation system were studied. The flotation tests of magnetite and phlogopite were carried out with the collector of dodecylamine, and the depressants of causticized cationic etherified starch (CCES), causticized sodium carboxymethyl starch (CCMS) and causticized dextrin (CD). The interaction way of causticized starch with minerals was analyzed by many methods such as single mineral flotation experiment, Zeta potential analysis, adsorption amount measurements, infrared spectrum analysis (FTIR), and synthetic mixed minerals flotation experiment. The results showed that the difference of surface electrical between phlogopite and magnetite was small, resulting in a poor selectively of dodecylamine for two minerals. All of CCES, CD and CCMS could adsorb on the surfaces of magnetite and phlogopite. The adsorption of the causticized starch on the magnetite surface was dominated by chemisorption, followed by electrostatic adsorption and hydrogen bonding. However, the adsorption of causticized starche on phlogopite surface is electrostatic adsorption and hydrogen bonding. The inhibitory strength of three causticized starches to magnetite followed the order of CCES> CD> CCMS. However, the three causticized starches had poor inhibitory effect on phlogopite.