Na型蛭石中2Na^+=Pb^(2+)离子交换过程的动力学研究  

Study on kinetics of 2Na^+=Pb^(2+) cations exchange process in Na-vermiculites

作　　者：张宝述[1] 宋海明[1] 王励生[2] 彭同江[3] 

机构地区：[1]西南科技大学先进建筑材料四川省重点实验室,四川绵阳621010 [2]四川大学化工学院,四川成都610065 [3]西南科技大学矿物材料及应用研究所,四川绵阳621010

出　　处：《功能材料》2007年第5期790-794,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(40502008);四川省应用基础研究资助项目(05JY029-008)

摘　　要：通过实验探讨了Na型蛭石在不同的Pb2+溶液浓度和不同的温度下的2Na+=Pb2+离子交换动力学关系,实验结果表明:蛭石中2Na+=Pb2+离子交换很快,0.5min以内交换吸附率已达70%~80%以上,达到交换平衡的时间与溶液的起始浓度和交换时的温度有关,原液浓度越大达到平衡所需要的时间越长,温度越高交换越快;蛭石中2Na+=Pb2+离子交换过程受粒内扩散控制;动力学方程符合克-金-布扩散(粒内扩散)方程;计算出了蛭石中2Na+=Pb2+离子交换过程的表观活化能E′a的平均值为25.21kJ/mol;推导出了蛭石中2Na+=Pb2+离子交换过程的动力学方程为:1-2/3α-(1-α)2/3=k0r-02exp-25 R.21.The kinetics of 2Na^＋ = Pb^2＋ cations exchange in Na-vermiculites in different Pb^2＋ concentrations and temperatures were discussed. Through a serious of experiments, it is showed that it is very fast 2Na^＋ =Pb^2＋ cations exchange in vermiculites and depends on the initial concentrations and reaction temperature, more higher more faster; The 2Na^＋ = Pb^2＋ cations exchange process of Na-vermiculite is controlled by intraparticle diffusion; The kinetics equation of this process can be described as intraparticle diffusion eouation. 1-2/3α-（1-α）^2/3=k＇t;With the dates and the equations the apparent activated energy E＇a, was calculated, which average value is 25.21kJ/mol; According to the apparent activated energy, the 2Na^＋ =Pb^2＋ cations exchange kinetics equation：1-2/3α-（1-α）^2/3=k0r0^-2exp（-25 .21/R·1/T ）^t in Na-vermiculite was deduced.

关 键 词：蛭石 离子交换 NA^+ PB^2+ 动力学 

分 类 号：P579[天文地球—矿物学]