Production of titanium powder by metallothermic reduction of TiO2 in cold pressed pellets  

TiO2冷压块金属热还原法制备钛粉末

作　　者：ZHENG Hai-yan GUO Yong-chun SHEN Feng-man 郑海燕;郭永春;沈峰满(Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education),Northeastern University,Shenyang 110819,China;School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education),Northeastern University,Shenyang 110819,China [2]School of Metallurgy,Northeastern University,Shenyang 110819,China

出　　处：《Journal of Central South University》2021年第1期48-57,共10页中南大学学报（英文版）

基　　金：Projects(51774071,50804007,51974073)supported by the National Natural Science Foundation of China。

摘　　要：In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO2 to CaCl2(nTiO2/nCaCl2)in the pellets.The results show that metallic Ti was obtained from the reduction of TiO2 in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when TRedu=1273 K,tRedu=6 h,and nTiO2/nCaCl2=4;the reasonable nTiO2/nCaCl2 value is 3−5 for the pellets with enough strength and high RM.为了高效生产低成本金属钛(Ti),开展了基于非接触式二氧化钛(TiO2)冷压块金属热还原法制备Ti粉末的基础研究。本论文重点考察了非接触式金属热还原法的还原机理和还原指数(RM)与还原温度、还原时间及TiO2/CaCl2摩尔比(nTiO2/nCaCl2)的关系。研究结果显示,钙(Ca)蒸气还原TiO2冷压块制备金属Ti粉末方法是可行的;在1273 K时,冷压块可被均匀还原,Ca蒸气在多孔冷压块内的扩散属于Knudsen扩散或分子-Knudsen混合扩散;RM随着温度的升高和时间的延长而增加;在还原温度1273 K、还原时间6 h、nTiO2/nCaCl2=4的实验条件下,RM为96.34%;为了满足冷压块强度和高RM,冷压块内nTiO2/nCaCl2控制在3~5较为合理。

关 键 词：titanium dioxide titanium powder metellothermic reduction cold pressed pellet reduction index 

分 类 号：TF125.22[冶金工程—粉末冶金]