Pre-reduction of WO_(3)-Co_(3)O_(4)by H_(2)-C_(2)H_4 in a fluidized bed  

作　　者：Huijun Shang Hengli Li Weijun Li Feng Pan Zhan Du 

机构地区：[1]State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences(CAS),Beijing 100190,China [2]College of Chemical Engineering,Nanjing Technology University,Nanjing 211816,China [3]School of Chemistry and Chemical Engineering,Shihezi University,Shihezi 832003,China [4]College of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [5]Chinalco Environmental Protection and Energy Conservation Group Co.,Ltd.,Xiong’an 071700,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第2期273-284,共12页中国化学工程学报（英文版）

基　　金：the National Natural Science Foundation of China(22078326,21878305,21908227)。

摘　　要：In order to avoid the formation ofηphase(W_(6)Co_(6)C or W_(3)Co_(3)C)that adversely affects the sintering process and its products in the preparation process of ultra-fine WC-Co powder,a technical route of prereduction of WO_(3)-Co_(3)O_(4)to WO_(2)-Co and then deep reduction carbonization to WC-Co powder has been proposed.This study mainly investigates the influence of gas partial pressure on the pre-reduction process of WO_(3)-Co_(3)O_(4)under a mixed atmosphere of H_(2)-C_(2)H_(4)-Ar at 600℃and establishes the kinetic equations of pre-reduction and carbon evolution.The results indicate that increasing the partial pressure of hydrogen is conducive to the rapid and complete conversion of WO_(3) to WO_(2).High carbon content can be generated by the deposition of C_(2)H_(4),and it hinders the diffusion of the reducing gas;WO_(3)still cannot be completely reduced to WO_(2)as the partial pressure of C_(2)H_(4) increases to 60%.For the carbon evolution of C_(2)H_(4),the carbon amount is positively related to the H_(2)partial pressure,but it shows the highest amount and evolution rate when the ethylene partial pressure is 20%.Based on the reduction rate curves of WO_(3) and carbon evolution rate curves of C_(2)H_(4),the rate equations of pre-reduction and carbon evolution of WO_(3)-Co_(3)O_(4)system at 600℃are established.The pre-reduction reaction belongs to the first-order reaction,and its equation is expressed as follows:r=-(dw_(WO_(3)))/dt=(9±0.15)×10^(-2)×P_(H_(2))^(0.44)P_(C_(2)H_(4))&(0.57)The carbon deposition rate equation of C_(2)H_(4) can be expressed as follows:r=-(dc_C)/dt=r_f-r_b≌7.35×10^(-2)×P_(C_(2)H_(4))^(0.31)

关 键 词：FLUIDIZATION WO_(3)-Co_(3)O_(4) Reduction Carbon deposition Rate equation 

分 类 号：TF123[冶金工程—粉末冶金]