中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
黄铵铁矾结晶过程与成核机理研究

文献类型:学位论文

作者刘鹏飞
学位类别硕士
答辩日期2016-07
授予单位中国科学院研究生院
授予地点北京
导师张亦飞
关键词黄铵铁矾 黄铁矾渣 诱导期 结晶
学位专业化学工程
中文摘要

黄铁矾法是湿法冶炼过程中应用最广的方法之一,黄铁矾法产生的黄铁矾渣具有渣量大、含铁低、难以回收利用和污染环境等缺点。本文以此为研究背景,首先系统的研究了硫酸和盐酸对黄铁矾渣的浸出影响,验证了工业黄铁矾渣难利用。然后对黄铵铁矾的成核过程和结晶过程进行了系统的研究。系统的考察了反应时间、搅拌速率、酸浓度、温度和液固质量比对黄铁矾渣浸出效果的影响。实验结果表明:在硫酸的最佳浸出工艺条件下,Fe、Zn元素的回收率为80%;在盐酸的最佳浸出工艺条件下,Fe、Zn、Pb三种元素的回收率分别为83%,89%和99%。Fe、Zn元素低的浸出率说明了铁矾渣的难处理。测定了黄铵铁矾(H3O, NH4)Fe3(SO4)2(OH)6在75、85、95℃下的固液相平衡数据,在热力学平衡数据的基础上,在不同温度和酸浓度(9g/L,10.8g/L和12.6g/L)条件下,对(H3O, NH4)Fe3(SO4)2(OH)6的初级成核进行了系统的研究。依据经典成核理论模型进行计算,得到(H3O, NH4)Fe3(SO4)2(OH)6在75、85、95℃下的界面张力分别为2.21、1.85和1.17 mJ/m2,表面熵因子分别为1.51、1.27和1.17。实验结果和固相的物相分析证实了(H3O, NH4)Fe3(SO4)2(OH)6的生长机理属于连续生长机理。利用间歇实验,对(H3O, NH4)Fe3(SO4)2(OH)6的结晶过程进行研究,考察了搅拌速率、反应时间、pH值和过饱和度对(H3O, NH4)Fe3(SO4)2(OH)6结晶过程的影响。随着搅拌速率的增加,晶体的平均粒径减小,晶体由球形向多面体转变,晶体表面的粗糙度下降。反应时间的增加,有利于晶体的生长;随着反应时间增加,晶体平均粒径增大,粒度分布变窄。晶体平均粒径随着pH值的增大而增大。过饱和度的增加会导致晶体平均粒径的减小,粒度分布变窄,晶体越来越趋于球形,表面粗糙度增加。

英文摘要

Despite jarosite is widely application in Hydrometallurgical, the handle of the jarosite residue, which has little potential use. Jarosite residue by sulfuric acid and hydrochloric acid leaching were investigated. Little potential use of jarosite residue was verified. The nucleation process and crystallization process of ammonium jarosite ((H3O, NH4)Fe3(SO4)2(OH)6) were researched.The effects of reaction time, agitation speed, acid concentration, temperature and mass ration of liquid to solid on leaching rate were researched. The results of sulfuric acid leaching show that the recovery rate of Fe and Zn are 80% under the optimum conditions. The results of hydrochloric acid leaching show that the recovery rate of Fe, Zn and Pb are 83%, 89% and 99% under the optimum conditions. Low leaching of Fe and Zn declare that difficulty to deal with jarosite reside.The solid-liquid equilibrium data of (H3O, NH4)Fe3(SO4)2(OH)6 was measured in different temperature (348K, 358K and 368K). Primary nucleation of (H3O, NH4)Fe3(SO4)2(OH)6 is researched in different temperature and concentration of sulfuric acid (9g/L, 10.8g/L and 12.6g/L) based on the equilibrium data. The interfacial tension and surface entropy factor of (H3O, NH4)Fe3(SO4)2(OH)6 are 1.21mJ/m2, 1.85 mJ/m2, 1.71 mJ/m2 and 1.51, 1.27, 1.17 in different temperature. The growth mechanism of (H3O, NH4)Fe3(SO4)2(OH)6 was determined as continuous growth mechanism.The crystallization process of (H3O, NH4)Fe3(SO4)2(OH)6 is investigated by batch experiments. The effects of agitation speed, reaction time, pH and supersaturation on crystallization process were researched. With the increase of agitation speed, the crystal size decreases, the shape of crystal changed from spherical to polyhedron, surface roughness of crystal is reduced. The increase of reaction time favors the crystal growth, but the distribution of crystal gets narrower. When the pH of the solution increases, the crystal size increases. The increase of supersaturation affects the crystallization, it makes the crystal size decreases and the distribution of crystal gets narrower, the shape of crystal tend to be spherical, surface roughness of crystal is increased. 

语种中文
源URL[http://ir.ipe.ac.cn/handle/122111/22947]  
专题过程工程研究所_研究所(批量导入)
推荐引用方式
GB/T 7714
刘鹏飞. 黄铵铁矾结晶过程与成核机理研究[D]. 北京. 中国科学院研究生院. 2016.

入库方式: OAI收割

来源:过程工程研究所

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