铬铁矿加压碱浸氧化反应宏观动力学  

Macro-kinetic Investigation on the Oxidative Pressure Leaching of Chromite Ore with Sodium Hydroxide Solution in the Presence of Oxygen

作　　者：张海[1,2] 张小飞[2] 徐红彬[2] 张洋[2] 张懿[2] 

机构地区：[1]中国科学院大学化学与化工学院,北京100049 [2]中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室,绿色过程与工程重点实验室,北京100190

出　　处：《过程工程学报》2013年第3期397-402,共6页The Chinese Journal of Process Engineering

基　　金：国家高技术研究发展计划(863)基金资助项目(编号:2011AA060702);国家重点基础研究发展规划(973)基金资助项目(编号:2013CB632600);国家自然科学基金资助项目(编号:21206178)

摘　　要：研究了铬铁矿加压碱浸氧化反应的动力学过程,考察了铬铁矿粒度、搅拌、碱矿质量比和反应温度等对铬浸出率的影响.结果表明,反应温度250℃、碱浓度60%(ω)、氧分压3.2MPa、铬铁矿粒度小于50m、搅拌转速650r/min、碱矿质量比4.0:1、反应时间240min的条件下,铬铁矿中铬的浸出率达98%以上,且随铬铁矿粒径减小、搅拌转速增加、碱矿质量比增加和反应温度升高而提高.反应产物为MgFe2O4和Mg(OH)2,浸出时呈固态包裹在未反应颗粒外层.宏观动力学研究结果表明,铬铁矿加压碱浸氧化反应过程受反应物在固体产物层中的扩散控制,可用方程1-2/3X-(1-X)2/3=kt描述,该反应的表观活化能E=54.5kJ/mol,指前因子A=328.4min-1.The effects of leaching conditions on chromium extraction rate were investigated in the oxidative pressure leaching process of chromite ore with sodium hydroxide solution, including particle size, stirring speed, NaOH-to-ore ratio and temperature. The results showed that the extraction rate of Cr reached above 98% after 300 min at 250 ℃ with NaOH concentration of 60%（ω）, oxygen partial pressure of 3.2 MPa, particle size below 50 μm, stirring speed of 650 r/min and mass ratio of NaOH to ore 4.0：1. And the chromium extraction rate increased with the decrease of ore particle size and the increase of stirring speed, mass ratio of NaOH to ore and temperature. The macro-kinetic investigation revealed that the leaching process was controlled by reactant diffusion in the solid product layer and described by 1-2/3X-（1-X）2/3=kt with apparent activation energy of 54.5 kJ/mol and pre-exponential factor of 328.4 min-1.

关 键 词：铬铁矿 铬酸钠 加压 碱浸 动力学 氧气 

分 类 号：TQ115[化学工程—无机化工]