湿法炼锌过程铜回收率提升工艺研究  

Process of improving copper recovery rate in zinc hydrometallurgy

作　　者：保雪凡 张程 邓志敢[1] 周正华 林文军 刘自虎 邱伟佳 魏昶[1] BAO Xuefan;ZHANG Cheng;DENG Zhigan;ZHOU Zhenghua;LIN Wenjun;LIU Zihu;QIU Weijia;WEI Chang(Faculty of Metallurgy and Energy Engineering,Kunming University of Technology,Kunming 650093,China;Zhuzhou Smelter Group Co.Ltd.,Zhuzhou 412000,China;Yunnan Yuntong Zinc Co.Ltd.,Kunming 650000,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093 [2]株洲冶炼集团股份有限公司,湖南株洲412000 [3]云南云铜锌业股份有限公司,云南昆明650000

出　　处：《中南大学学报（自然科学版）》2023年第12期4652-4661,共10页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51964029,51804146);国家重点研发计划项目(2018YFC1900402);云南省应用基础研究计划项目(202001AT070079)。

摘　　要：针对常规炼锌工艺中存在铜回收率低、杂质累积等问题,本文提出了弱酸浸铜沉铁-低酸强化浸铜两段逆流酸浸、弱酸浸出液回收铜-中和除杂的湿法浸出工艺。首先,对锌焙砂进行弱酸浸出,避免中性浸出存在的铜沉淀问题,同时将部分铁沉淀入渣;然后,通过低酸浸出破坏原料中的氧化物、铁酸盐和硅酸盐等多种含铜化合物的矿物结构,最大限度地实现铜的高效浸出;第三,通过铁粉置换的方法从弱酸浸出液中回收铜,再进行中和除杂;最后,考察体系酸度、反应温度和时间等参数对浸出过程锌、铁、铜元素浸出及沉淀的影响。研究结果表明:浸出过程中元素行为以及焙砂中复杂锌、铜物相的破坏溶出主要受体系酸度影响。反应温度以及反应时间对于复杂物相的溶出影响较小。在温度为80℃、反应时间为2.5 h、搅拌转速为400 r/min的条件下,弱酸浸出铁的沉淀率为72.17%,铜的浸出率为67.24%;低酸浸出锌和铜浸出率分别为91.86%和71.83%。在温度为70℃、反应时间为20 min、搅拌转速为400 r/min的条件下,弱酸液沉铜铁粉添加系数为3,铜沉淀率为93.2%。由于锌、铜在原料中的赋存状态复杂,难溶和易溶物相种类多样,增大了锌、铜金属高效综合回收的难度。氧化物、硅酸盐等多种矿物结构均被较彻底地破坏,而硫化物、铁酸盐溶出效果欠佳,铜的回收率提高至70%。Aiming at the problems of low copper recovery and impurity accumulation in conventional zinc refining process,a two stage countercurrent acid leaching process was proposed,which includes weak acid leaching of copper while precipitating iron,strong acid enhanced copper leaching,recovery of copper from weak leaching solution,neutralization and impurity removal.Firstly,zinc calcine was leached with weak acid to avoid the problem of copper precipitation in neutral leaching,and some iron was precipitated into residue.Secondly,strong acid leaching destructed mineral structures such as oxides,ferrites,silicates,and the maximum leaching of valuable copper components was realized.Thirdly,copper was recovered from weak acid leaching solution by iron powder replacement method and then neutralized to remove impurities.Finally,the effects of parameters such as system acidity,reaction temperature and time on the leaching and precipitation of Zn,Fe and Cu elements in leaching were investigated.The results show that the elemental behavior of the leaching process and the destructive dissolution of complex Zn and Cu phases in the roasted ore are mainly influenced by the acidity of the system.The reaction temperature and reaction time have less influence on the dissolution of complex phases.Under the conditions of 80 ℃,2.5 h,and 400 r/min stirring speed,the precipitation rate of iron is 72.17% and the copper extraction is 67.24% for weak acid leaching,and the leaching rates of zinc and copper are 91.86% and 71.83% for low acid leaching,respectively.The copper precipitation rate in the copper precipitation stage of weak acid leaching solution is 93.2% under the condition of 70 ℃,20 min,400 r/min stirring speed and iron powder addition coefficient of 3.Due to the complexity of zinc and copper in the raw material,insoluble and soluble phases are diverse,increasing the difficulty of efficient comprehensive recovery of zinc and copper metals.Oxides,silicates and other mineral structures are more thoroughly destroyed,while sulfides,f

关 键 词：铜回收率 湿法炼锌 水解沉铁 铁粉沉铜 

分 类 号：TF811[冶金工程—有色金属冶金] TF813