摘要
目前银还原常用甲醛作为还原剂,但是甲醛储存要求高,易结晶,还原后液的化学需氧量高,对于废水处理有较高的要求。以铜阳极泥处理过程的中间物料氯化银为研究对象,采用水合肼还原:初始碱度100 g/L;液固比4∶1;水合肼用量为理论的1.2倍,制备的粗银粉浇铸成阳极板银的主品位为99.8%,满足银电解阳极板品位的要求;银还原后液COD均值为4510 mg/L,远小于现有的甲醛还原后液。水合肼还原替代甲醛,可以有效降低废水COD值,对于推进工厂的生态环保工作具有重大意义。
At present,formaldehyde is commonly used as a reducing agent for silver reduction,but formaldehyde has high storage requirements,is easy to crystallize,and the COD value of the reduced solution is high,which has high requirements for wastewater treatment.Taking silver chloride as the intermediate material in the treatment process of copper anode slime as the research object,hydrazine hydrate reduction was used with an initial alkalinity of 100 g/L;Liquid solid ratio 4∶1;the amount of hydrazine hydrate is 1.2 times the theoretical amount,and the main grade of silver in the prepared coarse silver powder cast into the anode plate is 99.8%,which meets the requirements for the grade of the silver electrolysis anode plate.The average COD of the silver reduction solution is 4510 mg/L,which was much smaller than the existing formaldehyde reduction solution.Hydrazine hydrate reduction replacing formaldehyde can effectively reduce the COD value of wastewater,which is of great significance for promoting the ecological and environmental protection work of factories.
作者
黄晶明
雷刚
夏志薇
HUANG Jingming;LEI Gang;XIA Zhiwei(Guixi Smelter,Jiangxi Copper Co.,Ltd.,Guixi 335424,China)
出处
《湖南有色金属》
CAS
2024年第4期53-56,共4页
Hunan Nonferrous Metals
关键词
银还原
甲醛
水合肼
COD
环保
silver reduction
formaldehyde
hydrazine hydrate
COD
environment protection
