碱式还原熔炼法高效回收黑铜泥中的铜

采用碱式还原熔炼法高效分离回收黑铜泥中的铜,并对其中铜、砷物相的迁移转化行为规律进行了探究。结果表明:碱式熔炼过程中碳酸钠不仅可以降低熔渣黏度,提高粗铜相和渣相的分离效率,并使黑铜泥中As2O3与As2O5碱化形成NaAsO2和Na3AsO4,减弱砷氧化物向单质砷的还原,继而减少粗铜的砷含量,增加碳酸钠添加量、提高熔炼温度、延长保温时间可提高黑铜泥中铜的回收率,并有利于降低粗铜的砷含量;焦炭过多时,黑铜泥中的CuSO4易过还原为CuS,夹带进入渣,造成铜损失,在焦炭添加量3.5%、熔炼温度1 400℃、碳酸钠添加量57%、保温时间150 min时,黑铜泥中铜的回收率可达94.15%,熔炼所得粗铜含铜96.51%,含砷2.86%。碱式还原熔炼法可实现黑铜泥中铜的高效分离回收。

Cascade sulfidation and separation of copper and arsenic from acidic wastewater via gas-liquid reaction

Copper and arsenic in acidic wastewater were separated by cascade sulfidation followed by replacement of arsenic in theprecipitates by copper in the solution which was realized by recycling precipitates obtained in the first stage into the initial solution.The effects of reaction time,temperature and H2S dosage on copper and arsenic removal efficiencies as well as the effects of solid-toliquidratio,time and temperature on the replacement of arsenic by copper were investigated.With20mmol/L H2S at50°C within0.5min,more than80%copper and nearly20%arsenic were precipitated.The separation efficiencies of copper and arsenic werehigher than99%by the replacement reaction between arsenic and copper ions when solid-to-liquid ratio was more than10%at20°Cwithin10min.CuS was the main phases in precipitate in which copper content was63.38%in mass fraction.