摘要
In Baotou rare earth tailings ore, the grade of rare earth is close to that of the raw ore nearly. The rare earths are discarded in tailings dam caused by a serious waste of resources. First of all, the decomposition products of bastnaesite-and monazite-mixed rare earth tailings in CaO in reducing atmosphere were studied by means of X-ray diffraction（XRD）. The results show that the normal products are CeO2, Ce2O3, Ca5F（PO4）3, and Ce（0.75）Nd（0.25）O（1.875）, and there are no REPO4 and REFCO3.Secondly, the roasted product was extracted in HCl, and the relationship among roasting time,roasting temperature,CaO addition, and extraction temperature was studied by the quadratic regression-orthogonal analysis. Through analysis, the optimum process conditions of mixed rare earth tailings extracted are obtained as follows： roasting time of 60 min, roasting temperature of 800℃, CaO addition of 30%, extraction temperature of 80℃, and extraction ratio of 99.18%.
In Baotou rare earth tailings ore, the grade of rare earth is close to that of the raw ore nearly. The rare earths are discarded in tailings dam caused by a serious waste of resources. First of all, the decomposition products of bastnaesite-and monazite-mixed rare earth tailings in CaO in reducing atmosphere were studied by means of X-ray diffraction（XRD）. The results show that the normal products are CeO2, Ce2O3, Ca5F（PO4）3, and Ce（0.75）Nd（0.25）O（1.875）, and there are no REPO4 and REFCO3.Secondly, the roasted product was extracted in HCl, and the relationship among roasting time,roasting temperature,CaO addition, and extraction temperature was studied by the quadratic regression-orthogonal analysis. Through analysis, the optimum process conditions of mixed rare earth tailings extracted are obtained as follows： roasting time of 60 min, roasting temperature of 800℃, CaO addition of 30%, extraction temperature of 80℃, and extraction ratio of 99.18%.
基金
financially supported by the Development Program of National Key Basic Research(No.2012CBA01205)
