【摘要】 对天然黄铁矿进行深加工后获得平均粒径为13μm,w(Fe)、w(S)分别为45.30%、50.95%的超微细黄铁矿粉,并以高级脂肪酸盐对其进行改性,采用TG/DSC、XPS及XRD对粉体进行了表征。XRD和TG/DSC分析表明粉体主要物相为黄铁矿FeS2,表面包覆着有机改性剂;XPS分析结果表明,改性前后黄铁矿表面S分别以SO42-和[S2]2-形式存在,而Fe均以Fe3+形式存在。对粉体试样进行电化学阻抗谱、恒电流放电测试和循环伏安测试,结果表明,改性黄铁矿具有较小的电荷转移电阻和较好的导电性;常温下以0.354A电流放电,截止电压为0.5V,改性黄铁矿的放电电位平台为1.44V,放电比容量达850mAh/g,接近理论容量890mAh/g。更多还原

【Abstract】 Ultrafine pyrite powder was prepared from natural pyrite via deep processing,including gravity sepa-ration,floatation and airflow grind.The content of Fe and S are 45.30wt% and 50.95wt% respectively,and the ave-rage grain size is 13μm.Ultrafine pyrite powder was modified by senior fatty acid salt and investigated by TG/DSC,XRD and XPS.TG/DSC and XRD indicate the phase of mineral powder is mostly pyrite FeS2 coated with organic modi-fier.XPS shows S on the pyrite surface before and after modification exists in the form of SO42-and 2-respectively,and Fe in Fe3+.Meanwhile,electrochemical impedance spectroscopy,cyclic voltammetry measurement and galvanostatic current charge and discharge method were applied to exhibit the electrochemical performance of pyrite.The results show that modified pyrite has lower charge transfer resistance and higher conductivity.The specific discharge capacity of modified pyrite is as high as 850mAh/g under 0.354A current at room temperature and 0.5V cutoff voltage,closing to the theoretical specific capacity of pyrite(890mAh/g),and the voltage plateau is 1.44V.更多还原