Kinetics and mechanism of natural wolframite interactions with sodium carbonate

作     者：Evgeniy Nikolaevich Selivanov Kirill Vladimirovich Pikulin Lyudmila Ivanovna Galkova Roza Iosifovna Gulyaeva Sofia Aleksandrovna Petrova 

作者机构：Institute of Metallurgy of the Ural Branch of the Russian Academy of Sciences 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2019年第26卷第11期

页      面：1364-1371页

核心收录：

学科分类：080602[工学-钢铁冶金] 0709[理学-地质学] 0819[工学-矿业工程] 0806[工学-冶金工程] 08[工学] 0708[理学-地球物理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0802[工学-机械工程] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Basic Research of the Ural Branch of the Russian Academy of Sciences (No. AAAA-A18-118012590113-6) using equipment of Collaborative usage centre “Ural-M” 

主　　题：wolframite structure sodium carbonate sintering thermal analysis kinetics 

摘      要：The kinetics and mechanism of natural wolframite interactions with sodium carbonate during air heating were studied.X-ray phase and X-ray microanalysis were used to establish that the initial monocrystalline wolframite consists of Fe0.5 Mn0.5 WO4 and Fe0.3 Mn0.7 *** thermal analysis showed that the interaction of wolframite with sodium carbonate begins above 450°C with the formation of tungstate,sodium ferrite,iron oxides,and *** experiments on sintering with the subsequent removal of water-soluble compounds(leaching)tracked the change in the structure of *** atomic ratio of Fe/Mn in wolframite does not change up to 600°C,and subsequently decreases to 0.2 during heating,which allows the mechanism of the process to be identified and indicates the greater reactivity of wolframites with an increased proportion of *** analysis with data processing using non-isothermal kinetics established that the interaction of wolframite with sodium carbonate in an air stream proceeds via a two-stage mechanism,wherein the first stage is limited by diffusion(activation energy,E=243 kJ/mol)and the second stage is limited by autocatalysis(activation energy,E=212 k J/mol)due to the formation of a Na2 WO4–Na2 CO3 eutectic.