铜阳极泥提银过程取消银转炉工序的试验探索  

Experimental exploration for omitting silver converter process in silver extraction from copper anode slime

作　　者：房孟钊 李伟 FANG Meng-zhao;LI Wei(Daye Nonferrous Metals Co.,Ltd.,Huangshi 435002,China;Key Laboratory of Non-Ferrous Metal Metallurgy and Recycled Utilization in Hubei Province,Huangshi 435002,China)

机构地区：[1]大冶有色金属有限责任公司,湖北黄石435002 [2]有色金属冶金与循环利用湖北省重点实验室,湖北黄石435002

出　　处：《中国有色冶金》2022年第4期68-75,共8页China Nonferrous Metallurgy

摘　　要：某冶炼企业采用回转窑联合湿法工艺回收铜阳极泥中的银,所得粗银粉品位较低,需要增加银转炉工序,致使能耗增加,环境污染严重。为取消银转炉工序,企业尝试采用新的湿法分银工艺取代原有的氨浸分银-水合肼还原分银工艺。试验探索了亚钠分银-甲醛还原-氧化酸浸除杂工艺(亚钠分银-甲醛直接还原工艺)和亚钠分银-分银液破络合-氧化酸浸除杂-甲醛还原工艺(亚钠分银-甲醛间接还原工艺),结果表明亚钠分银-甲醛间接还原工艺稳定性较好,得到的粗银粉品位达到99.93%,其他杂质含量接近0。如果采用亚钠分银-甲醛间接还原工艺代替原有工艺,预计每年为企业增加的效益至少为138.69万元。试验过程中的亚钠液再生与回用是新工艺后续需要攻克的难点,其既可以解决生产过程中液体体积膨胀的问题,又可以降低废水处理量与亚钠用量,对进一步降低生产成本至关重要。The rotary kiln combined with hydrometallurgical process to recover silver from copper anode slime is used by a metallurgical plant. The obtained crude silver powder is of low grade, for which the silver converter process needs to be added, it will result in an increase of energy consumption and severe environmental pollution. In a bid to omit the silver converter process, a new hydrometallurgical process for silver separation is tested by the plant to replace the original silver separation process of ammonia leaching-hydrazine hydrate with the new hydrometallurgical silver separation process. Exploratory tests were conducted on silver separation with sodium sulfite-formaldehyde reduction-oxidative acid leaching process for impurity removal(silver separation with sodium sulfite-formaldehyde direct reduction process) and silver separation with sodium sulfite-decomplexation of silver separation solution-oxidative acid leaching for impurity removal-formaldehyde reduction process(silver separation with sodium sulfite-formaldehyde indirect reduction process). The results showed that the silver separation with sodium sulfite-formaldehyde indirect reduction process featured a sound stability, the grade of obtained crude silver powder reached 99.93% and the content of other impurities approached to zero. If the silver separation with sodium sulfite-formaldehyde indirect reduction process is substituted for the original process, it is estimated that the plant will increase benefits of at least 1 386 900 CNY. The regeneration and recycling of sodium nitrite solution from the test process is the key issue that needs to be tackled for the follow-up new process. It can not only solve the problem of production water volume expansion and but also lower the volume of wastewater treatment and consumption of sodium sulfite, which are of vital importance to further reduction of production cost.

关 键 词：铜阳极泥 银提取 转炉工序 环境污染 生产成本 粗银粉 亚钠分银-甲醛间接还原 

分 类 号：TF832[冶金工程—有色金属冶金]