刚果金氧化铜矿碳酸铵浸出—负压蒸氨的工艺分析.docx

摘要
本文致力于解决我国铜矿资源日益紧张的难题,研究刚果(金) 铜矿资源开发的湿法冶金工艺。刚果(金)大量含铜约10%的氧化铜矿,由于难以达到火法炼铜和选矿富集的要求,而被长期视为废矿。对此,本文提出了碳酸铵浸出一负压蒸氨的新工艺,创造性地单独采用碳酸铵作浸出剂,不同于需要配加氨水的传统氨浸法,原料成本低、运输方便,而且负压蒸氨运行能耗相对于常压蒸氨有较大幅度降低, 蒸氨渣经煅烧得到高质量的氧化铜产品,氨可实现循环利用,整个过程简单,经济环保,特别适合在基础工业落后的非洲国家运用。
氨浸工序基于刚果(金)氧化铜矿的特点,首次利用碳酸铵在溶液中受热分解产生NH3的性质,实现铜氨配合作用。主要考察了矿石粒度、碳酸铵浓度、液固比、反应温度、反应时间、搅拌速度及洗涤方式等因素对浸出效果的影响。研究表明, mm、 mol·L~、液固LL4:1、温度60℃、时间2 h、搅拌速度350 ~、滤渣采用废氨液洗涤。%,%。
负压蒸氨及氨回收工序同时进行,微负压不但有利于铜氨配合物分解,而且可引导蒸氨产生的NH”C02溶于水中重新生成碳酸铵, 实现氨的回收和循环利用,构成本论文的创新点之一。蒸氨工序主要考察了温度、体系气压及反应液浓度对蒸氨效果的影响,铜沉淀率达到100%,%,蒸氨渣经煅烧即得到氧化铜产品。氨回收工序主要考察了回收用水体积、回收级数、回收瓶结构、回收气压及气体冷凝程度对氨回收效果的影响,%,氨回收液返回用于浸出工序。
在实验室实验基础上,本研究进行了6次工业循环试验,验证了整个工艺流程的可行性和综合效果,得出铜的综合回收率≥92%,氨的综合回收率≥95%,%。文章还对本工艺在刚果(金)建厂运行进行了产业化设计和分析,得出氧化铜单位生产成本28880元,,, 具有非常可观的开发前景。
关键词氧化铜矿,浸出,碳酸铵,负压蒸氨,氨回收
AB STRACT
This work takes up with solving the increasingly austere problem of the depletion of copper ores in China and researching the hydro— metallurgy technology of copper mine of Democratic Republic of Congo. Democratic Republic of Congo has abundant low—grade copper oxide ores,which grade iS about 1 0%.The ores have been chronically discarded, because they can not meet the requirements of copper pyrometallurgy and ore on this,a brand new hydrometallurgical method of Ammonia Carbonate Leaching--Negative—Pressure Ammonia Distillation Technology has been investigated to exploit overseas copper deposits in this technology is differ from the conventional ammonia leaching,as only ammonium carbonate is used as leaching reagent in this carbonate has advantages of lower cost and
convenient ammonia distillation has less energy consuming than atmospheric ammonia copper oxide product is produced after ammonia distillation and calcining is vaporized and then circularly utilized