剪切强化针铁矿沉铁过程晶体生长规律研究  

Crystal growth mechanism in the process of iron removal by shear-enhanced goethite method

作　　者：朱强 杨建广 周远林[2] 汪文超 南天翔 唐朝波 曾伟志 Qiang ZHU;Jianguang YANG;Yuanlin ZHOU;Wenchao WANG;Tianxiang NAN;Chaobo TANG;Weizhi ZENG(School of Metallurgy and Environment,Central South University,Changsha,Hunan 410083,China;Jiangxi Environmental Engineering Vocational College,Ganzhou,Jiangxi 341000,China)

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083 [2]江西环境工程职业学院,江西赣州341000

出　　处：《过程工程学报》2022年第2期186-194,共9页The Chinese Journal of Process Engineering

基　　金：国家重点研发专项课题(编号:2018YFC1900403)。

摘　　要：采用X射线衍射光谱(XRD)、扫描电子显微镜(SEM)、电感耦合等离子发射光谱法(ICP)等分析方法,考察了ZnSO_(4)-FeSO_(4)体系下剪切强化针铁矿法除铁,在均相成核、异相成核过程中针铁矿渣的晶型结构、微观形貌、元素赋存的变化规律,并于真实溶液中验证剪切强化针铁矿法除铁的规律性。结果表明,剪切强化均相成核,沉铁渣初期无明显的针铁矿晶体特征,均为类圆球状的无定形晶核,渣中铁品位、锌含量波动大,分别由前期43.13wt%和4.57wt%增至57.76wt%和6.12wt%。模拟溶液中,异相成核初期以晶种的二次长大的方式为主,有效避免大量无定形相产生,相比均相成核晶体尺寸更大、结晶度更高,且最终沉铁渣铁品位为58.65wt%,锌含量为5.60wt%。相比模拟溶液,性质复杂的真实溶液针铁矿晶体生长发育更难控制,但能确保以针铁矿晶体析出,且沉铁渣中铁、锌含量分别控制在57.63wt%和5.90wt%。采用工业氧化锌烟尘作为中和剂,得到最终的沉铁渣含铁52.59wt%、含锌6.93wt%。本研究为针铁矿法在工业中的应用与成核方式的选择进一步提供了理论依据。Removing iron from the solution is an indispensable procedure to ensure the quality of zinc products in zinc hydrometallurgy.Regarding the requirements of economic cost and environmental protection,the goethite method has a significant advantage in iron removal.However,due to the existing regulation technology of iron removal by the goethite process,the crystal shape of goethite residue is difficult to be controlled stably,which leads to the problems of poor filtration performance.At the same time,the iron grade is low and the zinc content is high in the produced goethite residue.The mechanism of crystal structure,microscopic morphology and element occurrence in the homogeneous and heterogeneous nucleation crystal growth process was investigated by X-ray diffraction spectroscopy,scanning electron microscope,and inductively coupled plasma emission spectroscopy in the ZnSO_(4)-FeSO_(4) system.Moreover,the regularity of iron removal by shear-enhanced goethite was verified in a real solution.The results showed that there were no obvious goethite crystal characteristics at the initial stage of iron settling slag in the process of homogeneous nucleation,and the amorphous nuclei were spherical.The iron grade and zinc contented fluctuate greatly,increased from 43.13wt%and 4.57wt%in the early stage to 57.76wt%and 6.12wt%,respectively.In the early stage of heterogeneous nucleation,the secondary growth of the seed was the main method,which effectively avoided the generation of a large number of amorphous iron residues.Compared with homogeneous nucleation,the size of the crystal was larger and the crystallinity was higher,and the zinc was finally controlled at 5.60wt%.Compared with the simulated solution,the growth and development of goethite crystal in the real solution with complex properties were more difficult to control,but it can ensure the goethite crystal precipitation,and the content of iron and zinc in the iron-settling slag was controlled at 57.63wt%and 5.90wt%,respectively.The industrial zinc oxide fume was used

关 键 词：剪切强化 针铁矿 晶体生长 均相成核 异相成核 

分 类 号：TF813[冶金工程—有色金属冶金] O78[理学—晶体学]