Hydrogen-based mineral phase transformation mechanism investigation of pyrolusite ore  

作　　者：Ruofeng Wang Shuai Yuan Yanjun Li Peng Gao Ru Li 

机构地区：[1]School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China [2]National-local Joint Engineering Research Center of High-efficient exploitation technology for Refractory Iron Ore Resources,Shenyang 110819,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第11期2445-2457,共13页矿物冶金与材料学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2023YFC 2909000);the National Natural Science Foundation of China(No.52174240);the Major Science and Technology Projects of Xinjiang Uygur Autonomous Region(No.2023A03003-2);the XingLiao Talent Program of Liaoning Province(No.XLYC2203167);the Excellent Youth Fund Project of Liaoning Natural Science Foundation(No.2023JH3/10200010);the Fundamental Research Funds for the Central Universities(No.N23011026);the Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2023-15).

摘　　要：Pyrolusite comprises the foremost manganese oxides and is a major source of manganese production.An innovative hydrogenbased mineral phase transformation technology to pyrolusite was proposed,where a 96.44%distribution rate of divalent manganese(Mn^(2+))was observed at an optimal roasting temperature of 650℃,a roasting time of 25 min,and an H2 concentration of 20vol%;under these conditions.The manganese predominantly existed in the form of manganosite.This study investigated the generation mechanism of manganosite based on the reduction kinetics,phase transformation,and structural evolution of pyrolusite and revealed that high temperature improved the distribution rate,and the optimal kinetic model for the reaction was the random nucleation and growth model(reaction order,n=3/2)with an activation energy(E_(a))of 24.119 kJ·mol^(−1).Throughout the mineral phase transformation,manganese oxide from the outer layer of particles moves inward to the core.In addition,pyrolusite follows the reduction sequence of MnO_(2)→Mn_(2)O_(3)→Mn_(3)O_(4)→MnO,and the reduction of manganese oxides in each valence state simultaneously proceeds.These findings provide significant insight into the efficient and clean utilization of pyrolusite.

关 键 词：REDUCTION PYROLUSITE phase transformation microstructural evolution 

分 类 号：P618.32[天文地球—矿床学]