不同碱源对合成MgAl-LDHs的结构及除氯性能的影响  

Influence of Different Alkaline Agents on the Structure and Dechlorination Performance of MgAl-LDHs Synthesized

作　　者：易春健 刘淑贤 黄宏[1,2] 聂轶苗 王玲 王龙[1,2] YI Chunjian;LIU Shuxian;HUANG Hong;NIE Yimiao;WANG Ling;WANG Long(School of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China;Key Laboratory of Mining Exploitation and Security Technology of Hebei Province,Tangshan 063210,China)

机构地区：[1]华北理工大学矿业工程学院,河北唐山063210 [2]河北省矿业开发与安全技术重点实验室,河北唐山063210

出　　处：《金属矿山》2023年第11期101-109,共9页Metal Mine

基　　金：国家自然科学基金项目(编号:52004091);中央引导地方科技发展资金项目(编号:236Z3804G);河北省自然科学基金项目(编号:E2022209119)。

摘　　要：为了获得除氯性能较好的镁铝类水滑石,研究了碱源对合成镁铝类水滑石的结构及除氯性能的影响。采用水热合成法,分别以尿素和氢氧化钠为碱源,硝酸根金属盐溶液为前驱体合成了LDHs-A和LDHs-B,采用XRD、SEM、BET、FTIR测试分析了不同碱源对镁铝类水滑石微观形貌的影响,通过氯离子吸附试验比较了2种类水滑石的除氯性能及除氯机理。结果表明,LDHs-A和LDHs-B均具有类水滑石结构的XRD特征峰,呈片层状结构,晶粒尺寸分别为1 000~2 000 nm、200~400 nm,比表面积分别为40.804 m^(2)/g、62.609 m^(2)/g,饱和吸附量分别为45.41 mg/g和78.69 mg/g。LDHs-A为碳酸根插层镁铝类水滑石,LDHs-B为硝酸根插层镁铝类水滑石。LDHs-A符合准一级动力学模型和Langmuir吸附等温模型,除氯机理主要为单层物理吸附;LDHs-B符合准二级动力学模型和Langmuir吸附等温模型,除氯机理主要为单层化学吸附。In order to obtain Mg-Al hydrotalcite with gread dechlorination performance,the effect of alkali source on the structure and dechlorination performance of Mg-Al hydrotalcite was studied.In this paper,LDHs-A and LDHs-B were synthe-sized by hydrothermal synthesis method using urea and sodium hydroxide as base sources and metal nitrate salt solution as pre-cursor,respectively.XRD,SEM,BET and FTIR tests were used to analyze the effects of different base sources on the micro-structure of Mg-Al hydrotalcite.The dechlorination properties and mechanism of two kinds of hydrotalcite were compared by chloride ion adsorption experiment.The results show that LDHs-A and LDHs-B have XRD peaks similar to hydrotalcite struc-ture,with lamellar structure,grain sizes of 1000~2000 nm and 200~400 nm,and specific surface areas of 40.804 m^(2)/g and 62.609 m^(2)/g,respectively.The saturated adsorption capacities were 45.41 mg/g and 78.69 mg/g,respectively.LDHs-A is magnesium and aluminum hydrotalcite by carbonate intercalation and LDHs-B is magnesium and aluminum hydrotalcite by ni-trate intercalation.LDHs-A conforms to the quasi-first-order kinetic model and Langmuir adsorption isothermal model,and the dechlorination mechanism is mainly single-layer physical adsorption;LDHs-B conforms to the quasi-second-order kinetic model and Langmuir adsorption isothermal model,and the dechlorination mechanism is mainly single-layer chemisorption.

关 键 词：类水滑石 水热合成法 氯离子 吸附材料 

分 类 号：TQ426.8[化学工程]