碱式还原熔炼法高效回收黑铜泥中的铜

High Efficiency Recovery of Copper from Copper Electrolytic Sludge byAlkaline Reduction Smelting Method

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。

An alkaline reduction melting method was used to efficiently separate and recover copper resources from copper electrolytic sludge,and the migration and transformation behavior of copper and arsenic phases was investigated.The results show that Na 2CO 3 in the alkali melting process can reduce the viscosity of slag,improve the separation efficiency of crude copper and slag phase,and alkalize As 2O 3 and As 2O 5 in copper electrolytic sludge to form NaAsO 2 and Na 3AsO 4,weaken the reduction conversion of arsenic oxide to singlet arsenic,and then reduce the arsenic content in crude copper.Increasing the addition amount of Na 2CO 3,increase the melting temperature,extend the holding time can improve the recovery of copper,and help to reduce the arsenic content in crude copper,but too much coke,CuSO 4 is easy to over-reduction to CuS,its entrainment into the slag,resulting in copper loss.The recovery rate of copper can reach 94.15%and copper and arsenic contents in crude copper are 96.51%and 2.86%under coke addition amount of 3.5%,smelting temperature of 1400℃,Na 2CO 3 addition amount of 57%and holding time of 150 min.This study could achieve efficient separation and recovery of copper from copper electrolytic sludge.