Kinetics of chalcopyrite leaching by sodium nitrate in sulphuric acid
Kinetics of chalcopyrite leaching by sodium nitrate in sulphuric acid
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DOI：
10.1016/j.hydromet.2008.06.012
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发表时间：
2009-02-01
期刊：
影响因子：
4.7
通讯作者：
Zivkovic, Dragana
中科院分区：
文献类型：
--
作者：
Sowic, Miroslav D.;Markovic, Branislav;Zivkovic, Dragana
湿法冶金工艺为处理黄铜矿矿石和精矿提供了巨大的潜力，它可以提高金属回收率并减少空气污染危害。近年来，人们对在硫化物精矿的湿法冶金处理中应用各种试剂的兴趣增加。本工作的目的是研究在硫酸介质中用硝酸钠浸出“Rudnik”浮选厂的黄铜矿精矿。各种化学反应发生的概率是基于文献数据，热力学分析，以及在浸出过程中形成的产物。研究了各种参数的影响，以优化反应条件并确定反应动力学。提高温度、硫酸浓度和硝酸钠浓度、降低搅拌速度和粒度均能提高铜的浸出率。实验数据用混合控制动力学模型拟合得最好。浸出活化能为83 kJ/mol，浸出产物主要是元素硫，对浸出速率有抑制作用。采用XRD和SEM/EDX分析对精矿和浸出渣进行表征，证实了浸出机理。(C)2008 Elsevier B. V.保留所有权利。
Hydrometallurgical processes offer a great potential for treating chalcopyrite ores and concentrates, and it results in increased metal recoveries and reduced air pollution hazards. In recent years interest for application of various reagents in a hydrometallurgical processing of sulphide concentrates has increased. The objective of this work was to examine the leaching of the chalcopyrite concentrate, from "Rudnik" flotation plant, by sodium nitrate in sulphuric acid media. The probabilities of various chemical reactions occurring was based upon literature data, thermodynamic analysis, and the products formed during the leaching process. The influence of various parameters was studied to optimize the conditions and to determine the kinetics of the reaction. An increase in temperature, sulphuric acid and sodium nitrate concentration, and decrease in stirring speed and particle size, enhanced the leaching rate of copper. The experimental data were best fitted by a mixed control kinetic model. An activation energy of 83 kJ/mol was found. Elemental sulphur was formed as the main leaching product and tended to inhibit the leaching rate. The leaching mechanism was confirmed by characterizing the concentrate and the leach residue using XRD and SEM/EDX analysis. (C) 2008 Elsevier B.V. All rights reserved.