荔枝壳吸附剂对金离子的吸附行为研究  

Study on the Adsorption Behavior of Litchi Shell Adsorbent for Gold Ion

作　　者：黄凯[1,2] 朱庆 朱佳俊 HUANG Kai;ZHU Qing;ZHU Jiajun(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Green Recycling and Extraction of Metals,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]稀贵金属绿色回收与提取北京重点实验室,北京100083

出　　处：《金属矿山》2023年第9期231-239,共9页Metal Mine

基　　金：“十三五”国家重点研发计划项目(编号:2019YFC1907403)。

摘　　要：为回收浸液中的微量金离子,利用荔枝壳制备金离子吸附材料,借助多种仪器对荔枝壳进行了表征分析,详细研究了其吸附金离子的行为及过程机理。在偏光显微镜下观察到吸附后的荔枝壳上出现分散细小的金颗粒,X射线衍射进一步证实该颗粒为金单质。氯金酸离子被吸附是静电吸引与原位还原的耦合过程,而荔枝壳中的多酚被认为是导致金离子被还原的主要电子给予体。XPS分析确认,吸附后的金离子至少94.9%以上被还原为金单质。盐酸浓度和共存贱金属杂质离子对金的吸附效率影响不大,而在1 mol/L的HCl中,几乎50%的Pd和35%的Pt也会被同时吸附。而在0.1 mol/L的HCl介质中,100%的Pd和100%的Pt将被同时吸附。在0.1 mol/L的盐酸浓度下,改性荔枝壳对金的饱和吸附量为33.36 mg/g。在吸附过程中,溶液的ORP(氧化还原电位)值会急剧下降,也证实了荔枝壳吸附金离子过程中发生了还原作用,而且吸附温度越高,ORP值也下降越快。本研究工作利用荔枝壳制备吸附材料,方法简单、成本低、高效绿色,可望成为吸附法回收工业废水中微量金离子的新技术。In order to recover the trace gold ions in the leaching solution,litchi shell was used to prepare gold ion adsorp-tion material.The behavior and mechanism of gold ion adsorption of litchi shell were studied in detail by means of various in-struments.Gold particles were observed under the optical microscope,and the X-ray diffraction further confirmed the appear-ance of gold metal on the modified lychee husk adsorbent,which successfully adsorbed the gold ions in the solution by an elec-trostatic attraction coupled with the in-situ reduction reaction.XPS analysis confirmed that at least 94.9%of the gold ions were reduced to gold.The concentration of hydrochloric acid and co-existing base metal impurity ions have little effect on the adsorp-tion efficiency of gold,and in 1 mol/L of HCl,almost 50%of Pd and 35%of Pt are simultaneously adsorbed.In HCl medium of 0.1 mol/L,100%of Pd and 100%of Pt will be adsorbed simultaneously.Under the concentration of 0.1 mol/L hydrochloric acid,the saturated adsorption capacity of modified litchi shell for gold was 33.36 mg/g.During the adsorption process,the ORP(REDOX potential)value of the solution decreased sharply,which also confirmed that the reduction occurred during the ad-sorption of gold ions by litchi shell.Moreover,the higher the adsorption temperature,the faster the ORP value decreased.The preparation of adsorption materials by litchi shell is simple,low cost,high efficiency and green,and it is expected to be a new technology for recovering trace gold ions from industrial wastewater by adsorption.

关 键 词：生物吸附 金离子 荔枝壳 还原 多酚 

分 类 号：TF111[冶金工程—冶金物理化学]