Kinetics of carbothermic reduction of marmatite in presence of lime  

石灰存在条件下铁闪锌矿的碳热还原动力学

作　　者：Rafael PADILLA Juan Yamid CARVALLO María Cristina RUIZ Rafael PADILLA;Juan Yamid CARVALLO;María Cristina RUIZ(Metallurgical Engineering Department,University of Concepcion,Concepcion 4070371,Chile)

机构地区：[1]Metallurgical Engineering Department,University of Concepcion,Concepcion 4070371,Chile

出　　处：《Transactions of Nonferrous Metals Society of China》2020年第8期2265-2273,共9页中国有色金属学报（英文版）

基　　金：the financial support of Juan Yamid CARVALLO during his graduate studies。

摘　　要：The direct carbothermic reduction of marmatite in the presence of lime was studied by thermogravimetric method to determine the technical feasibility to produce Zn(g)without polluting with SO2(g).X-ray diffraction analysis of partially reacted samples indicated that the reduction occurred through the formation of ZnCaOS and Ca2Fe2O5 as intermediate products to yield Zn(g),and solid Fe and Ca S as the final products.Temperature had the major effect on the rate of reduction.Complete conversion of marmatite was obtained at 1100℃in about 10 min using 300 mg samples with molar ratio of(Zn,Fe)S:CaO:C equal to 1:1:1.The kinetics of the overall reduction reaction was analyzed by the model ln(1-X)=-kt,which represented the data well up to a fractional conversion of 0.95 in the temperature range of 1000-1150℃.The determined activation energy in this temperature range was 257 k J/mol.The results demonstrated the technical feasibility to produce Zn(g)by this method without producing noxious SO2(g)emissions.采用热重法研究石灰存在条件下铁闪锌矿的直接碳热还原,以确定生产Zn(g)而没有SO2(g)污染的技术可行性。部分反应的样品X射线衍射分析表明,还原反应是通过形成ZnCaOS和Ca2Fe2O5中间产物进行的,最终产物为Zn(g)、固体Fe和CaS。温度对还原速率存在重要影响。在1100℃下,对于300 mg(Zn,Fe)S:CaO:C比为1:1:1的样品,10 min左右可实现铁闪锌矿的完全转化。用ln(1-X)=-kt模型分析总还原反应的动力学,发现在1000~1150℃、转化率不超过0.95时,该模型很好地描述试验数据,在此温度范围内确定的活化能为257 k J/mol。研究结果证实该方法生产Zn(g)而不产生有害的SO2(g)排放的技术可行性。

关 键 词：KINETICS MARMATITE high-iron sphalerite carbothermic reduction direct reduction ZnCaOS 

分 类 号：TF813[冶金工程—有色金属冶金]