Leaching of chromite ore in concentrated KOH by catalytic oxidation using CuO as catalyst  

KOH亚熔盐体系中用CuO催化氧化浸出铬铁矿（英文）

作　　者：Long-jie LIU Hao DU Yang ZHANG Shi-li ZHENG Yi ZHANG 刘龙杰;杜浩;张洋;郑诗礼;张懿(中国科学院过程工程研究所绿色过程与工程重点实验室,北京100190;中国科学院大学,北京100049)

机构地区：[1]Key Laboratory of Green Process and Engineering,Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China [2]University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第4期891-900,共10页中国有色金属学报（英文版）

基　　金：Project(2013CB632601)supported by the National Basic Research of China;Projects(91634111,51404227)supported by the National Natural Science Foundation of China

摘　　要：CuO was used as a catalyst in the concentrated KOH solution to enhance the leaching of chromium from the chromite ore.The impacts of temperature,KOH-to-chromite ore mass ratio,CuO-to-chromite ore mass ratio,and gas flow rate on the chromiumleaching rate were investigated.The results indicated that CuO played an important role in improving the chromium leaching rate.The leaching rate reached98%after leaching for6h when CuO was applied,whereas it was only60.8%without CuO under thesame reaction conditions:temperature230°C,KOH-to-ore mass ratio6:1,stirring speed700r/min,gas flow rate1L/min.Accordingto the kinetics study,the catalytic oxidation was controlled by surface chemical reaction and the activation energy was calculated tobe15.79kJ/mol when the temperature was above230°C.In contrast,without CuO,the rate-determining step was external diffusionand the apparent activation energy was38.01kJ/mol.通过添加CuO催化剂来提高铬铁矿在KOH亚熔盐介质中的浸出率。研究反应体系温度、碱矿质量比,铜矿质量比和气体流速对铬浸出的影响。结果表明:CuO对提高铬铁矿在KOH亚熔盐介子的浸出率起着十分重要的作用。在反应温度为230°C、碱矿质量比为6:1、搅拌转速为700 r/min、气体流速为1 L/min、反应时间为6h的条件下铬的转化率在添加CuO时为98%,而未添加CuO时,铬的转化率仅为60.8%。动力学计算结果表明,添加CuO后在反应温度高于230°C时,反应速度控制步骤为表面化学反应控制,反应活化能为15.79 k J/mol;未添加CuO时,反应速度控制步骤为外扩散控制,反应活化能为38.01 k J/mol。

关 键 词：chromite ore copper oxide LEACHING catalytic oxidation 

分 类 号：TF791[冶金工程—钢铁冶金]