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低品位氧化锌矿浸出萃取工艺基础研究

Leaching-Extraction Process of Low-Grade Zinc Oxide

【作者】 唐双华

【导师】 覃文庆;

【作者基本信息】 中南大学 , 矿物加工工程, 2008, 硕士

【摘要】 随着国民经济的发展,易选硫化锌矿和高品位氧化锌矿的逐年消耗,低品位锌矿资源逐渐成为锌冶炼的重要原料,对其进行经济合理的利用已成为一项重要课题。本文针对广西低品位氧化锌矿矿石,从热力学、动力学方面对锌的分离、富集进行理论分析,提出直接浸出—萃取工艺的原则流程,进行浸出与萃取的工艺试验研究。论文的主要研究内容和结果如下:本文对搅拌浸出和堆浸法进行了对比。搅拌浸出试验研究表明,硫酸用量和液固比是影响锌浸出率的主要因素,随硫酸用量的增加和液固比的提高,锌浸出率提高;加酸方式、搅拌强度、浸出时间、粒度、反应温度等因素对矿石的浸出也有一定影响。在适宜条件下,锌的搅拌浸出率可达99.02%;柱浸9周试验结果表明,锌的浸出率达86.03%。与搅拌浸出相比,虽然堆浸周期较长,但有杂质浸出率低和酸耗少等优点,适宜处理低品位氧化锌矿。浸出过程热力学分析表明,氧化锌的酸浸反应属放热反应,酸浸反应平衡数(25℃)为1.2×1011,具有很大的热力学推动力。动力学研究结果显示,该浸出过程属于未反应收缩核模型,由扩散过程控制。锌萃取条件试验及串级试验表明,以磷酸二(-2-乙基己基)酯(D2EHPA或P204)为萃取剂,260号煤油作稀释剂研究锌溶剂萃取,在萃取剂浓度为20%,相比O/A为3:2,萃取10分钟,萃取强度200r/min,静置分层10分钟时,锌的萃取率可达38.19%;采用三级逆流萃取,锌的萃取率可达98.83%。硫酸可选择性地将有机相中的锌反萃下来,从而实现锌铁分离,富集得到合格的电积液。

【Abstract】 With the depletion of easily processed zinc sulphide ore and high-grade zinc oxide coupled with the rapid development of the economy, low grade zinc has become an important material in the zinc smeltering and the economical utilization of low grade zinc has increasingly become an urgent issue. Low grade zinc ore is studied in this paper from the perspectives of thermodynamics and kinetics in the separation and enrichment of zinc and a direct leaching-extraction process was proposed. The basic contents and results were shown as follows:Agitation leach and heap leach were compared in this paper. It was shown in agitation leach experiments that the dosages of sulfuric acid and liquid-solid ratio are the main factors influencing zinc leaching yield. The yield increases with the increment of sulfuric acid and liquid-solid ratio. The acid addition method, agitation intensity, leaching time, particle size and reaction temperature also has influence on the zinc extraction. Under suitable conditions, the agitation leach yield could reach to 99.02%. The column leach results indicated that the leach yield could reach to 86.03% in nine weeks. Compared with agitation leach, heap leach is favorable in the leaching of low grade zinc ore with the advantages of low impurity yield and low acid consumption. Thermodynamics analysis of leach process suggests that acid leach of zinc oxide was exothermic reaction and equilibrium constant has great thermodynamics boost. Kinetics results show that leach process is controlled by diffusion process and categorized as restricted kernel module.D2EHPA was used as the extractant and 260 kerosene used as diluent in the extraction process. It is shown in zinc extraction condition experiments and cascade experiments that with 20% extractant concentration, phase ratio O/A 3:2, extraction intensity 200r/min, zinc extraction yield could reach to 38.19% in 10 minutes. The extraction yield could reach to 98.83% after five-stage countercurrent extraction under favorable conditions. Sulfuric acid could re-extract zinc from organic phase and render the separation of zinc and iron, thus provide suitable feed for the electro-winning process.

【关键词】 氧化锌矿浸出萃取
【Key words】 zinc oxideextractionleaching
  • 【网络出版投稿人】 中南大学
  • 【网络出版年期】2009年 01期
  • 【分类号】TF813
  • 【被引频次】7
  • 【下载频次】598
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