高铟锌精矿非矾渣提锌铟及除铁新工艺试验研究

【作者】 傅永良；

【导师】 何静； 文丕忠；

【作者基本信息】 中南大学 ， 有色金属冶金， 2010， 硕士

【摘要】 目前,广西来宾冶炼厂采用“热酸浸出-黄钾铁矾法”的湿法炼锌流程处理锌(46.47%)、铁(13.56%)、铟(0.07%)含量高的自产闪锌矿。近十年的生产实践表明,该流程存在诸多不足,而北京矿冶研究院所提出的“热酸浸出-还原-赤铁矿法沉铁”工艺也存在流程长、蒸汽耗量大等弊端。为解决生产中的实际困难,本论文研究了“中浸渣热酸还原浸出-中和沉铟-赤铁矿法沉铁”的湿法炼锌提铟新工艺。在理论分析的基础上,对中浸渣热酸还原浸出、中和沉铟、赤铁矿法沉铁等过程进行了详细研究。以中性浸出渣为原料,采用单因素试验法考察了温度、时间、始酸酸度和还原剂用量等因素对热酸还原浸出过程的影响,确定其最佳工艺条件为：浸出温度95℃,时间3h,还原剂锌精矿用量为中浸渣量的40%,始酸酸度165g·L-1。在此优化条件下进行了6个周期的综合扩大试验,三价铁的还原率93.36%,锌、铟的平均浸出率分别为78.18%和89.83%,浸出渣中锌、铟含量分别为Zn 24.63%和In 0.049%-0.054%。以还原浸出液为原料,采用碳酸锌作预中和剂,调节体系pH=l-1.5,再以碳酸锌和氧化锌作沉铟剂,在pH=4.0、温度为90℃、时间30min的条件下进行中和沉铟,铟的沉淀率达到98.5%以上,铟渣含In 0.95%-1.66%。以沉铟后液为原料,在氧分压0.2MPa、温度175℃、时间2.0h、pH值5.0的条件下进行赤铁矿法沉铁,沉铁率高达92%以上,赤铁矿渣含Fe60%。全流程试验结果表明,锌精矿还原效果好,铟富集程度高,原料中的铁以赤铁矿渣产出,铟、铁、锌的总回收率分别达到87%和95%,88%以上,锌、铟的直收率和总回收率得以大大提高。总体而言,该工艺实现了锌冶金过程铟铁高效分离和铁资源的综合利用,实现了无铁渣湿法炼锌,技术创新性强,环境友好,技术指标先进,为来宾冶炼厂湿法炼锌工艺技术改造提供了可行的试验研究。更多还原

【Abstract】 Zinc concentrate ore obtained from zinc hydrometallurgical process system in Guangxi Laibin Smelter of Huaxi Group Company contains a great of sulphur, iron and indium. Currently, thermal acid leaching jarosite method is commonly adopted. After nearly ten years of production practice, it shows that the production process owns some disadvantages such as long flow sheet, low recovery of indium, high production cost, large quantity of alum slag, difficulty in acid making with sulfur dioxide volatilizing from the process of extracting indium in alum slag. To resolve the above shortcomings, different experiments in connection with zinc leaching and indium extraction were carried out by many research institutes, such as thermal acid leaching-goethite reduction method, thermal acid leaching-EZ method, thermocompression acid selective leaching process and thermal acid leaching-hematite reduction method studied by Beijing General Research Institute of Ming and Metallurgy. Compare to the respective experimental methods, the results show that thermal acid leaching-hematite reduction method successfully solves the existing problem of environmental pollution by volatilization of sulfur dioxide from alum slag. Meanwhile, the recovery of zinc and indium is higher than that of thermal acid leaching-jarosite method, especially the enhanced extent of the recovery of indium is improved by more than 15% and iron in the zinc concentrate ore can be transformed into the hematite for use. The thermal acid leaching-hematite reduction method has certain advantages of technology, but the process also exists shortcomings, such as longer flow sheet, high temperature of 95℃in the processes of thermal acid leaching and reduction, and large steam consumption. Based on the technical achievements of the full use of thermal acid leaching-hematite reduction method test research and the maintenance of the advanced technology, and grounded on the similar conditions of the thermal acid leaching and reduction which high temperature of 95℃and normal atmosphere are requested, in order to simplify the process, high acid leaching and the reduction of low acid leachate are merged into one process, namely the thermal acid reduction leaching of neutral leaching residue.The key of thermal acid reduction leaching technology of neutral leaching residue is the separation of Fe and Zn and effective enrichment of indium. This paper took the theoretical analysis and experimental research to validate the feasibility of the technology of thermal acid leaching-zinc concentrate reduction-neutralization and indium precipitation-iron removal with hematite. The results show that the total recovery of indium, zinc and iron in the whole process reaches more than 95%,87% and 88% respectively. It increases the recovery of indium and zinc, and zinc hydrometallurgy without iron residue is achieved. The technology has strong creativity and environmental benign. And the efficient separation of indium and iron in metallurgical process of zinc and efficient comprehensive utilization of the iron resources are realized. Therefore, a feasible experimental research technology for Laibin Smelter is provided to improve the zinc leaching technology.更多还原