Reaction mechanism of roasting Zn_2SiO_4 using NaOH  

NaOH焙烧Zn_2SiO_4反应机理（英文）

作　　者：Xiao-yi SHEN Hong-mei SHAO Hui-min GU Bing CHEN Yu-chun ZHAI Pei-hua MA 申晓毅;邵鸿媚;顾惠敏;陈兵;翟玉春;马培华(东北大学冶金学院,沈阳110819;东北大学辽宁省冶金传感器及技术重点实验室,沈阳110819;沈阳理工大学环境与化工学院,沈阳110159;盘锦市环境科学研究院科技研究室,盘锦124401)

机构地区：[1]School of Metallurgy,Northeastern University,Shenyang 110819,China [2]Liaoning Key Laboratory for Metallurgical Sensor and Technology,Northeastern University,Shenyang 110819,China [3]School of Environmental and Chemical Engineering,Shenyang Ligong University,Shenyang 110159,China [4]Science and Technology Laboratory,Academy of Environmental Sciences of Panjin City,Panjin 124401,China

出　　处：《Transactions of Nonferrous Metals Society of China》2018年第9期1878-1886,共9页中国有色金属学报（英文版）

基　　金：Projects(51774070,51204054)supported by the National Natural Science Foundation of China;Project(150204009)supported by the Fundamental Research Funds for the Central Universities of China;Project(2014CB643405)supported by the National Basic Research Program of China

摘　　要：The reaction kinetics of roasting zinc silicate using NaOH was investigated.The orthogonal test was employed to optimize the reaction conditions and the optimized reaction conditions were as follows:molar ratio of NaOH to Zn2SiO4 of 16:1,reaction temperature of 550°C,and reaction time of 2.5 h.In order to ascertain the phases transformation and reaction processes of zinc oxide and silica,the XRD phase analysis was used to analyze the phases of these specimens roasted at different temperatures.The final phases of the specimen roasted at 600°C were Na2ZnO2,Na4SiO4,Na2ZnSiO4 and NaOH.The reaction kinetic equation of roasting was determined by the shrinking unreacted core model.Aiming to investigate the reaction mechanism,two control models of reaction rate were applied:chemical reaction at the particle surface and diffusion through the product layer.The results indicated that the diffusion through the product layer model described the reaction process well.The apparent activation energy of the roasting was 19.77 kJ/mol.研究氢氧化钠焙烧硅酸锌的反应动力学,采用正交试验优化反应条件,优化反应条件为:NaOH和Zn_2SiO_4摩尔配比16:1、反应温度550°C以及反应时间2.5h。为了确定氧化锌和二氧化硅的物相转化和反应过程,采用XRD技术分析不同温度焙烧样品的物相。600°C焙烧样品的最终物相为Na_2ZnO_2、Na_4SiO_4、Na_2ZnSiO_4和NaOH。通过未反应收缩核模型研究焙烧过程的动力学方程,选取2种反应速率控制模型考察反应机理,分别为颗粒表面化学反应控制和通过固体产物层的扩散控制模型。结果表明:NaOH焙烧Zn_2SiO_4的反应过程受通过固体产物层的扩散控制,反应的表观活化能为19.77kJ/mol。

关 键 词：reaction mechanism KINETICS Zn2SiO4 NaOH roasting reaction process phase transformation 

分 类 号：TF813[冶金工程—有色金属冶金]