葡萄皮选择性吸附黄金的机制研究  

Selective Adsorption Mechanism of Gold by Grape Peel

作　　者：朱佳俊 谢铿 黄凯[1,2] 郭学益 Zhu Jiajun;Xie Keng;Huang Kai;Guo Xueyi(School of Metallurgy and Ecological Engineering,University of Science and Technology Bejing,Beijing 100083,China;Beijing Key Laboratory of Green Recycling and Extraction of Rare and Precious Metals,Beijing 100083,China;Mining and Metallurgy Technology Group Co.,Ltd.,Beijing 100160,China;Metallurgy and Enwironment,Central South University College,Changsha 410083,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]北京稀贵金属绿色循环与提取重点实验室,北京100083 [3]矿冶科技集团有限公司,北京100160 [4]中南大学冶金与环境学院,湖南长沙410083

出　　处：《稀有金属》2024年第10期1436-1445,共10页Chinese Journal of Rare Metals

基　　金：国家重点研发计划项目(2019YFC1907403)资助。

摘　　要：对葡萄皮(GP)吸附剂进行简单处理,即可获得能够在高浓度盐酸(0.1~6 mol·L^(-1))中选择性回收金的吸附剂。吸附实验表明,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。在室温下,金在0.1 mol·L^(-1)HCl介质中的最大吸附容量经评估为34 g·kg^(-1)。在吸附过程中溶液的氧化还原电位(ORP)值会急剧下降,这为葡萄皮吸附剂吸附金离子时发生还原提供了直接证据。温度越高,氧化还原电位ORP值下降越快。动力学模型和等温模型用于分析和解释吸附过程,研究了溶液酸度和吸附时间对金吸附率的影响,优化了吸附工艺参数,等温模型与伪二级动力学模型具有较高的拟合度。在偏光显微镜下观察金颗粒,X射线衍射(XRD)进一步证实了单质金在改性葡萄皮吸附剂上的出现。通过傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、能量色散X射线光谱(EDS)、X射线光电子能谱(XPS)等分析可知,99.9%以上的金离子将被还原为单质金,多酚芳香结构中的大π键被认为是导致金还原的主要原因,表明葡萄皮对金的吸附机制是静电吸引力耦合还原反应。Among the biosorbents for precious metal recovery,polyphenols have always been a research hotspot.Among them,tannins containing phenolic substances on the surface of persimmon skin have always been a research hotspot,but tannins soluble in water are not conducive to solid-liquid separation,so loading persimmon tannins on the surface of resin has always been the focus of research.However,the high cost of loading modification is not conducive to its popularization and application in industrial production.Grape skin waste generated during wine preparation accounts for 25%~35%of the total consumption of grapes and contains a large number of phenolic substances.Currently,there are few studies on the absorption and recovery of gold using grape skins.This paper proposed the selective adsorption of gold using grape skins containing polyphenols.The grape peel was prepared by a hydrothermally treatment of the mixture of raw grape peel particle and water at 120℃for 12 h with the solution with modifier.Then the above-mentioned suspension was filtrated and the peel was washed 3 times with distilled water and then dried at 80℃for 12 h.A series of adsorption experiments were carried out and showed that only 30 min could reach a high adsorption efficiency and adsorption capacity of gold.With the prolonging of adsorption time,the adsorption efficiency of gold would gradually approach to a platform.With the increasing of the temperature,the adsorption efficiency and the adsorption capacity of gold would slightly be increasing.Above experimental data were used for fitting by pseudo-firstorder and pseudo-second-order kinetic equations,and it could be found that they fit the latter model well.By comparing the adsorption capacity of the theoretical calculation and the experimental result,it could be found that the results obtained based on the pseudo-secondorder model were more identical,meaning that this model was more appropriate to describe the adsorption process.The kinetic parameters of adsorption of grape peel from the pseud

关 键 词：黄金 葡萄皮 还原吸附 大π键 多酚 

分 类 号：TF111[冶金工程—冶金物理化学]