Kinetics of carbonated decomposition of hydrogarnet with different silica saturation coefficients  

作　　者：Xiao-feng Zhu Ting-an Zhang Guo-zhi Lü 

机构地区：[1]State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China [2]School of Material Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China [3]Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education,Northeastern University,Shenyang 110819,China [4]Special Metallurgy and Process Engineering Institute,School of Metallurgy,Northeastern University,Shenyang 110819,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2020年第4期472-482,共11页矿物冶金与材料学报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.51874078,U1710257,U1202274,and 51764039);the Open Fund of Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education);Northeastern University,China(No.NEMM2019004).

摘　　要：Carbonated decomposition of hydrogarnet is one of the vital reactions of the calcification–carbonation method,which is designed to dispose of low-grade bauxite and Bayer red mud and is a novel eco-friendly method.In this study,the effect of the silica saturation coefficient(x)on the carbonation of hydrogarnet was investigated from the kinetic perspective.The results indicated that the carbonation of hydrogarnets with different x values(x=0.27,0.36,0.70,and 0.73)underwent two stages with significantly different rates,and the kinetic mechanisms of the two stages can be described by the kinetic functions R3 and D3.The apparent activation energies at Stages 1 and 2 were 41.96–81.64 and 14.80–34.84 kJ/mol,respectively.Moreover,the corresponding limiting steps of the two stages were interfacial chemical reaction and diffusion.

关 键 词：BAYER red mud HYDROGARNET CALCIFICATION carbonation KINETICS SILICA SATURATION coefficient 

分 类 号：TQ133.1[化学工程—无机化工]