【作者】 张家靓；

【导师】 唐谟堂；

【作者基本信息】 中南大学 ， 有色金属冶金， 2010， 硕士

【摘要】 针对储量巨大的锌品位<10%的高碱性脉石型低品位氧化锌矿尚不能得到有效处理的现状,本论文提出了MACA法循环浸出低品位氧化锌矿制取电锌的新工艺。以兰坪低品位氧化锌矿为原料,利用循环浸出的方法富集浸出液中锌浓度,后经净化、电积制取电锌。通过循环浸出条件试验和综合试验对MACA法循环浸出过程中锌浓度的富集、浸出率的变化规律以及杂质的浸出行为进行了系统而深入地研究。在最优条件下,对含锌6.59%的低品位氧化锌矿进行了10次循环浸出试验,平衡后的浸出液的平均浓度为33.93 g/L,总锌浸出率的和氨可浸锌的平均浸出率分别为69.08%和92.34%。杂质元素进入浸出液的量很少。在优化试验的基础上,对含锌7.72%的低品位氧化锌矿进行了循环浸出扩大-净化-电积试验。循环浸出平衡后的平均锌浓度为37.85g/L,总锌和氨可浸锌的平均浸出率为72.32%和94.15%,杂质进入浸出液的量很小。循环浸出过程中,金属锌、总氨和氯的平衡效果均十分理想,而水洗渣中总氨和氯的含量都很低,其平均值分别仅为1.287%和0.406%。计算得到水洗渣中总氨和氯的损失分别为0.198 t/t锌和0.062 t/t锌。对平衡后的各次浸出液依次进行了净化除砷锑、置换除杂试验,净化后液中绝大部分的杂质含量都很低,As、Mn、Fe、Mg、Si等杂质的含量都低于5 mg/L,而Pb、Cd、Ni、Al、Cu等杂质的含量几乎为0,但是杂质Sb在其净化前后的含量几乎不变。对净化后液进行了电积试验,平均电流效率达到92.94%。电解废液的锌浓度降至17 g/L以下。电积的产品为致密平整的锌板,含锌量大于99.96%,符合国标GB/T 470-20082#电锌标准。MACA法循环浸出低品位氧化锌矿制取电锌的新工艺可有效处理高碱性脉石型低品位氧化锌矿,具有能耗低、工艺流程短、净化负担轻、投资少、环境友好等特点,对解决我国锌资源紧缺,走新型工业化道路及发展循环经济走可持续发展道路具有重大意义。更多还原

【Abstract】 Aimed at the present situation that the large reserves of low grade zinc oxide ores (Zn<10%) bearing high basic gangues can’t be treated effectively, a new process of cycle leaching of low grade zinc oxide ores to produce cathode zinc with MACA method was proposed. Using the low grade zinc oxide ores from Lanping as raw material, a technological process of cycle leaching to enrich the zinc concentration, purification and electrowinning to produce cathode zinc was carried out.Enrichment of zinc concentration, variation of leaching rate and leaching behavior of impurities in the process of cycle leaching was systematically studied during the conditional and integrated experiments of cycle leaching.10 cycle leaching of low grade zinc ores containing zinc 6.59% was carried out under the optimum conditions, the results show that the average zinc concentration of lixivium is 33.93 g/L. The average leaching rate of total zinc and NH3 leachable zinc is 69.08% and 92.34%, respectively. The content of impurities in lixivium is very low."cycle leaching on an enlarged scale-purification-electrowinning" of low grade zinc oxide ores containing zinc 7.72% was carried out based on the optimization experiment. When the cycle leaching is in balance, The average zinc concentration of lixivium is 37.85 g/L. The average leaching rate of total zinc and NH3 leachable zinc is 69.08% and 92.34%, respectively. The content of impurities in lixivium is little. The balance conditions of zinc, total ammonia and chlorine are perfect. The content of total and chlorine is quite low and the loss in washed residue is 0.198 t/t zinc and 0.062 t/t zinc, respectively. The experiment of purification to remove As, Sb and cementation to remove other impurities was carried out. The results show that the content of impurities in purificatory solution is extremely low. The content of As, Mn, Fe, Mg, Si is lower than 5 mg/L and Pb, Cd, Ni, Al, Cu is approximately zero, However, the content of Sb is almost changeless. The electrowinning experiment results show that the average current efficiency is 92.94%. The zinc concentration of spent electrolyte is lower than 17 g/L. The cathode zinc is compact and smooth, containing zinc>99.96% which meets the requirements of second-grade zinc in GB/T 470-2007 standard.The new process of cycle leaching of low grade zinc oxide ores to produce cathode zinc with MACA method can treat low grade zinc oxide ores bearing high basic gangues effectively. This process has lots of advantages, including low energy consumption, a simple flow sheet, easy purification, lower investment, being environment-friendly and so on. Therefore, it is to be significant in solving the shortage of resources and taking a road to new industrialization and sustainable development.更多还原